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Main
Date: 03 Oct 2006 08:58:28
From: Wes
Subject: stainless steel pipe style coffee roaster
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Hi all, I'd like to build a version of the stainless steel pipe style
coffee roaster I found on the internet. Has anyone here ever built
their own coffee roaster? I'd like to be able to roast 5 pounds of
coffee at one time. thanks.
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Date: 13 Oct 2006 08:24:10
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
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Yeah me too. I'd like to be in the loop for that info! hey Dan, email
me at inabcentia at gmail if you have time. -Wes
Dan Bollinger wrote:
> > Be very interested to see the figures
>
> Me, too. It should tell us everything we need to know about blower and orifice
> selection given a certain depth of beans.
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Date: 13 Oct 2006 05:47:48
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
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RobvL wrote:
> Sivetz patented this in the 70s (IINM), the patent ran out a few years ago.
>
> Rob
The patent wasn't for the spouting bed design though. It was for the
asymetrical chamber. The one he licensed to Neuhaus Neotec. The
spouting bed has been around long before Sivetz came on the scene.
Erik
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Date: 13 Oct 2006 05:44:21
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
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Andy Schecter wrote:
> I was told, but haven't confirmed, that this roaster uses IR temperature sensing:
> http://www.freshroastsystems.com/machine.htm
> --
Hey, thanks for sharing that link. I had heard of this machine but
could never find it. Didn't know the name.
Erik
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Date: 12 Oct 2006 21:15:15
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
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Andy Schecter wrote:
> I tested a pretty decent quality ($400) industrial non-contact IR thermometer
> in a hot air roaster a few years ago. It was easily fooled by roasting smoke
> and the soot that accumulated on its special ($40) IR-transmitting window, In
> addition, it had to be calibrated for infrared emissivity via the "wild-ass
> guess" method.
I am using a Raytek at the moment but smoke is not an issue with my
roaster unless I am roasting 8lbs deep into second crack. Full City
doesn't bother it a bit. I also have an Exergen that came off of a
gazillion dollar piece of semiconductor fab equipement that was never
put into production. It has air purge collar to keep the lens clean and
is the one that claims repeatability of 0.1F. I can't really confirm
that of course. I do know that even the cheaper does pretty well even
though the factory specs say it is accurate to only 0.5% I think it
was. I wanted something better and also phoned raytek. I came away
thinking that they weren't going to do it for me. So, I found Exergen.
I really think that they are much better than Raytek. Emissivity I
haven't nailed down yet.
> After reporting the results of a few dismal roasts, the factory (Raytek)
> engineer suggested that their $1500 model might do a better job. I decided
> that a $25 conventional thermocouple, properly placed, would do just fine.
I don't disagree, just that with some of my hairbrained ideas that I
want to test, IR is much better for the app. Also, >$600 sensor for $45
on eBay. Who can argue with that?
> The guy who told you 0.1F repeatability must not have seen the application
> with his own eyes, or he never would have made such an astounding claim.
>
> Just my opinion, for what it's worth....
I am most certainly not a controls man. I just stumble about. But I may
stumble upon a few things that work. My coffee certainly tastes good!
Even my wife occasionally says so.
Thanks Andy,
Erik
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Date: 13 Oct 2006 06:37:35
From: Andy Schecter
Subject: Re: stainless steel pipe style coffee roaster
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Erik Groomer wrote:
> I don't disagree, just that with some of my hairbrained ideas that I
> want to test, IR is much better for the app.
I hear you. The IR sensor has advantages, if it can be made to work reliably.
I was told, but haven't confirmed, that this roaster uses IR temperature sensing:
http://www.freshroastsystems.com/machine.htm
--
-Andy S.
http://www.flickr.com/photos/andy_s/sets/
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Date: 12 Oct 2006 17:40:37
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
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Hey Erik, thanks for all that. great info! just so I am clear, you
located the TC underneath the perf plate? I was thinking of the roast
chamber as the area above the perf plate (necking up funnel fashion at
first then progressing to the RC walls going straight up). Does the
perf plate get in the way of the infrared beam as it is making it to
the beans? -Wes
Erik Groomer wrote:
> Wes wrote:
> > Hey Erik,
> > How do you have your TC connected to your heater elements? Does it
> > control the heat output? -Wes
>
> Wes,
> TC(fancy thermometer) is installed just downstream from the heated air
> stream before it enters the roast chamber.
>
> The PID controller accepts the TC input and outputs a control signal to
> either a SSR(solid state relay) or in my case a phase angle fired
> SCR(silicon controlled rectifier). The SSR is the simplest option. Then
> the heater elements are connected to the SSR. The PID can then sense
> the air temp and turn the heater elements on and off to control the
> roast air temp based on internal control algorithms. Most cheap PID's
> are able to sample at 4x's per second or faster. Many also have a nice
> autotune feature.
>
> I use the Infrared TC to measure actual bean temp and manually stop the
> roast.
>
> Erik
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Date: 12 Oct 2006 15:19:20
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
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Wes wrote:
> Hey Erik,
> How do you have your TC connected to your heater elements? Does it
> control the heat output? -Wes
Wes,
TC(fancy thermometer) is installed just downstream from the heated air
stream before it enters the roast chamber.
The PID controller accepts the TC input and outputs a control signal to
either a SSR(solid state relay) or in my case a phase angle fired
SCR(silicon controlled rectifier). The SSR is the simplest option. Then
the heater elements are connected to the SSR. The PID can then sense
the air temp and turn the heater elements on and off to control the
roast air temp based on internal control algorithms. Most cheap PID's
are able to sample at 4x's per second or faster. Many also have a nice
autotune feature.
I use the Infrared TC to measure actual bean temp and manually stop the
roast.
Erik
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Date: 12 Oct 2006 14:56:24
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
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Going faster can also carry the heat past the beans. Not enough contact
time to transfer the energy. Waste.
Dan Bollinger wrote:
> > either way the speedy heat gain is the trick it
> > seems. -Wes
>
> Drum roasters have learned that roasting happens faster and more evenly when
> drum speeds are increased. I think it has to do with the airspeed wisking away
> the bean's boundary layer, permitting hot air to contact the bean and transfer
> heat. You can move the bean through the air (drum roaster) or move the air past
> the bean (hot air roaster). What we know doesn't work is when both are
> stagnant; beans baked on a tray in a standard oven only makes drek. What we
> also know is that this effect has diminishing returns. You only have to go fast
> enough. Going faster only makes noise.
>
> Dan
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Date: 12 Oct 2006 07:16:57
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
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Hey Erik,
How do you have your TC connected to your heater elements? Does it
control the heat output? -Wes
Erik Groomer wrote:
> Andy, I agree that those are good points. The one about spouting bed
> being better for TC placement is moot for me. I am using a noncontact
> TC for measuring bean temp. I spoke with one of the engineers who
> designed it and he said 0.1F repeatability. Suits me fine. And not
> fooled by air temp.
>
> Erik
>
> Andy Schecter wrote:
>
> >
> > 2) OTOH, one of the benefits of the spouting bed is that the non-spouting
> > locations in the roast chamber provide ideal locations for a bean temp sensing
> > thermocouple. Because these areas are out of the main heated airflow, the
> > thermocouple reading will be much less influenced by the heated air and will
> > more accurately reflect the true external bean temp. This always seemed to me
> > to be a plus in favor of Sivetz' original asymmetrical roast chamber
> >
> > If one roasts strictly by sound, smell and color, then accurately measuring
> > bean temp is not an issue. But those of us who wish to move in the direction
> > of digital control of the roast process require accurate bean temp measurement.
> >
> > --
> >
> >
> > -Andy S.
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Date: 12 Oct 2006 06:32:55
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
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Andy, I agree that those are good points. The one about spouting bed
being better for TC placement is moot for me. I am using a noncontact
TC for measuring bean temp. I spoke with one of the engineers who
designed it and he said 0.1F repeatability. Suits me fine. And not
fooled by air temp.
Erik
Andy Schecter wrote:
>
> 2) OTOH, one of the benefits of the spouting bed is that the non-spouting
> locations in the roast chamber provide ideal locations for a bean temp sensing
> thermocouple. Because these areas are out of the main heated airflow, the
> thermocouple reading will be much less influenced by the heated air and will
> more accurately reflect the true external bean temp. This always seemed to me
> to be a plus in favor of Sivetz' original asymmetrical roast chamber
>
> If one roasts strictly by sound, smell and color, then accurately measuring
> bean temp is not an issue. But those of us who wish to move in the direction
> of digital control of the roast process require accurate bean temp measurement.
>
> --
>
>
> -Andy S.
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Date: 13 Oct 2006 00:58:01
From: Andy Schecter
Subject: Re: stainless steel pipe style coffee roaster
|
Erik Groomer wrote:
> I am using a noncontact
> TC for measuring bean temp. I spoke with one of the engineers who
> designed it and he said 0.1F repeatability. Suits me fine. And not
> fooled by air temp.
I tested a pretty decent quality ($400) industrial non-contact IR thermometer
in a hot air roaster a few years ago. It was easily fooled by roasting smoke
and the soot that accumulated on its special ($40) IR-transmitting window, In
addition, it had to be calibrated for infrared emissivity via the "wild-ass
guess" method.
After reporting the results of a few dismal roasts, the factory (Raytek)
engineer suggested that their $1500 model might do a better job. I decided
that a $25 conventional thermocouple, properly placed, would do just fine.
The guy who told you 0.1F repeatability must not have seen the application
with his own eyes, or he never would have made such an astounding claim.
Just my opinion, for what it's worth....
--
-Andy S.
http://www.flickr.com/photos/andy_s/sets/
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Date: 12 Oct 2006 06:16:53
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
I should have said to have the beans circulate more quickly (as with
the raindrops analogy) or circulate more often through a larger (25% or
greater?) heat spout. either way the speedy heat gain is the trick it
seems. -Wes
Wes wrote:
> Hi Dan,
> Discovery's Mythbusters showed that running should not be preferred
> over walking in rain as the former was observed to collect more
> moisture than the later.
>
> The principle working here is that when you are running, you are not
> only collecting raindrops falling upon you, but also the raindrops that
> were meant to fall before you.
>
> While in walking, you just collect your share of drops and keep on
> moving.
>
> So, if that analagy holds for our discussion, it would be better for
> the beans to cycle more quickly since we are trying to collect more
> heat (raindrops).
>
> Although I was wondering about what Ed alluded to earlier which is that
> the entire bean mass is gaining heat all the way along. the bigger the
> bean mass the more heat is held. So using the red bean as a ker, it
> goes through the spout collecting some heat, circulates with other
> beans heating up and by the time it hits the spout again it gains more
> heat, never having lost all of its initial heat gain. so if you could
> graph the results it would start off slowly (close to say the x axis of
> the graph; if X is time and Y is temp) and then as more and more heat
> failed to be lost it would arc up away from the x axis. So, it seems it
> you have a strong enough heat source and move the beans quickly it'll
> do the trick. I'm thinking now the FB is the superior way to roast but
> the devil is in the details ain't it. :) -Wes
>
> Dan Bollinger wrote:
> > > I placed a red painted bean in the mass and tested it cold a couple of years
> > > ago i counted how often the bean blew up thru the column can't remember what
> > > the numbers were.
> >
> > I've used the same trick to measure 'mixing', too. Simple, but effective!
> > Makes you wonder what the optimal mixing ratio is.
> >
> > > But simply if the spouting area or weight of beans above
> > > the perf plate is 25% then they are going to be in the heated column 25% of
> > > the time.
> >
> > This is sorta like the deal of running or walking through the rain, which is
> > wetter? Since the spouting portion is traveling many times faster than the
> > remaining 25% (which is moving at a snail's crawl), the time a bean is in the
> > spouting column is going to be closer to 2.5% than 25% of the time.
> >
> > > Possibly but IIRC Sivetz claims lower MET temps (or inflow temps) than for
> > > many drum roasters.
> >
> > I've heard this too, and considering the increased air speed believe it to be
> > true. Just as a convection oven, because the air is moving much faster it is
> > heating better, you can reduce the temperature setting on the thermostat.
> >
> > > Yup i like this feature heaps. Real easy to profile roasts and get
> > > consistency.
> >
> > I thought it was Gardfoods 'Roller Roaster' that uses this. Is this a Sivetz
> > invention or theirs? http://www.gardfoods.com/coffee/coffee.roaster.htm
> >
> > I now have a manometer and am half way through building a spouting bed test bed.
> >
> > Dan
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Date: 12 Oct 2006 09:30:14
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> either way the speedy heat gain is the trick it
> seems. -Wes
Drum roasters have learned that roasting happens faster and more evenly when
drum speeds are increased. I think it has to do with the airspeed wisking away
the bean's boundary layer, permitting hot air to contact the bean and transfer
heat. You can move the bean through the air (drum roaster) or move the air past
the bean (hot air roaster). What we know doesn't work is when both are
stagnant; beans baked on a tray in a standard oven only makes drek. What we
also know is that this effect has diminishing returns. You only have to go fast
enough. Going faster only makes noise.
Dan
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Date: 12 Oct 2006 06:06:49
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
Hi Dan,
Discovery's Mythbusters showed that running should not be preferred
over walking in rain as the former was observed to collect more
moisture than the later.
The principle working here is that when you are running, you are not
only collecting raindrops falling upon you, but also the raindrops that
were meant to fall before you.
While in walking, you just collect your share of drops and keep on
moving.
So, if that analagy holds for our discussion, it would be better for
the beans to cycle more quickly since we are trying to collect more
heat (raindrops).
Although I was wondering about what Ed alluded to earlier which is that
the entire bean mass is gaining heat all the way along. the bigger the
bean mass the more heat is held. So using the red bean as a ker, it
goes through the spout collecting some heat, circulates with other
beans heating up and by the time it hits the spout again it gains more
heat, never having lost all of its initial heat gain. so if you could
graph the results it would start off slowly (close to say the x axis of
the graph; if X is time and Y is temp) and then as more and more heat
failed to be lost it would arc up away from the x axis. So, it seems it
you have a strong enough heat source and move the beans quickly it'll
do the trick. I'm thinking now the FB is the superior way to roast but
the devil is in the details ain't it. :) -Wes
Dan Bollinger wrote:
> > I placed a red painted bean in the mass and tested it cold a couple of years
> > ago i counted how often the bean blew up thru the column can't remember what
> > the numbers were.
>
> I've used the same trick to measure 'mixing', too. Simple, but effective!
> Makes you wonder what the optimal mixing ratio is.
>
> > But simply if the spouting area or weight of beans above
> > the perf plate is 25% then they are going to be in the heated column 25% of
> > the time.
>
> This is sorta like the deal of running or walking through the rain, which is
> wetter? Since the spouting portion is traveling many times faster than the
> remaining 25% (which is moving at a snail's crawl), the time a bean is in the
> spouting column is going to be closer to 2.5% than 25% of the time.
>
> > Possibly but IIRC Sivetz claims lower MET temps (or inflow temps) than for
> > many drum roasters.
>
> I've heard this too, and considering the increased air speed believe it to be
> true. Just as a convection oven, because the air is moving much faster it is
> heating better, you can reduce the temperature setting on the thermostat.
>
> > Yup i like this feature heaps. Real easy to profile roasts and get
> > consistency.
>
> I thought it was Gardfoods 'Roller Roaster' that uses this. Is this a Sivetz
> invention or theirs? http://www.gardfoods.com/coffee/coffee.roaster.htm
>
> I now have a manometer and am half way through building a spouting bed test bed.
>
> Dan
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Date: 13 Oct 2006 23:32:29
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Wes" <inabcentia@gmail.com > wrote in message
news:1160658409.837407.246770@m73g2000cwd.googlegroups.com...
> Hi Dan,
> Discovery's Mythbusters showed that running should not be preferred
> over walking in rain as the former was observed to collect more
> moisture than the later.
>
> The principle working here is that when you are running, you are not
> only collecting raindrops falling upon you, but also the raindrops that
> were meant to fall before you.
>
> While in walking, you just collect your share of drops and keep on
> moving.
>
> So, if that analagy holds for our discussion, it would be better for
> the beans to cycle more quickly since we are trying to collect more
> heat (raindrops).
>
> Although I was wondering about what Ed alluded to earlier which is that
> the entire bean mass is gaining heat all the way along. the bigger the
> bean mass the more heat is held. So using the red bean as a ker, it
> goes through the spout collecting some heat, circulates with other
> beans heating up and by the time it hits the spout again it gains more
> heat, never having lost all of its initial heat gain. so if you could
> graph the results it would start off slowly (close to say the x axis of
> the graph; if X is time and Y is temp) and then as more and more heat
> failed to be lost it would arc up away from the x axis. So, it seems it
> you have a strong enough heat source and move the beans quickly it'll
> do the trick. I'm thinking now the FB is the superior way to roast but
> the devil is in the details ain't it. :) -Wes
>
My ideal roaster would be a drum with moderately high air flow. Not sure if
it would actually improve anything but it would mean the air flow can be
adjusted without affecting the bean agitation.
Rob
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Date: 11 Oct 2006 17:39:54
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
Hi Dan, I just checked out your roaster on homeroaster.org. Is that a
FB roaster? I didn't know you are in WL. I down here in Bloomington.
-Wes
Dan Bollinger wrote:
> > As a comparison the 1100 watt vacuum cleaner motor i use has a 5" (approx)
> > impellor and can fluidize 3kg, least ways create an adequate spout of beans
> > to evenly roast 3kg (6.7lbs).
>
> Rob, there is a unit of measure in vacuum motors that may help us. It is called
> air watts.
>
> Air Watts = Airflow (cfm) * Static Pressure (inches of water)
> ___________________________________
> 8.5
>
>
>
> Dan
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Date: 11 Oct 2006 17:38:03
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
Hi Dan, I just checked out your roaster on homeroaster.org. Is that a
FB roaster? I didn't know you are in WL. I down here in Bloomington.
-Wes
Dan Bollinger wrote:
> > As a comparison the 1100 watt vacuum cleaner motor i use has a 5" (approx)
> > impellor and can fluidize 3kg, least ways create an adequate spout of beans
> > to evenly roast 3kg (6.7lbs).
>
> Rob, there is a unit of measure in vacuum motors that may help us. It is called
> air watts.
>
> Air Watts = Airflow (cfm) * Static Pressure (inches of water)
> ___________________________________
> 8.5
>
>
>
> Dan
|
| |
Date: 11 Oct 2006 17:28:24
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
Hi Dan, I just checked out your roaster on homeroaster.org. Is that a
FB roaster? I didn't know you are in WL. I down here in Bloomington.
-Wes
Dan Bollinger wrote:
> > As a comparison the 1100 watt vacuum cleaner motor i use has a 5" (approx)
> > impellor and can fluidize 3kg, least ways create an adequate spout of beans
> > to evenly roast 3kg (6.7lbs).
>
> Rob, there is a unit of measure in vacuum motors that may help us. It is called
> air watts.
>
> Air Watts = Airflow (cfm) * Static Pressure (inches of water)
> ___________________________________
> 8.5
>
>
>
> Dan
|
| | |
Date: 11 Oct 2006 22:06:09
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Hi Dan, I just checked out your roaster on homeroaster.org. Is that a
> FB roaster? I didn't know you are in WL. I down here in Bloomington.
> -Wes
Wes, That's my homebuilt, one-pound sample roaster. Works well. There are
about five other Hoosiers on this list and the Sweetias list. We've been
wanting to do a get together for two years, but haven't worked out the details.
Dan
>
> Dan Bollinger wrote:
>> > As a comparison the 1100 watt vacuum cleaner motor i use has a 5" (approx)
>> > impellor and can fluidize 3kg, least ways create an adequate spout of beans
>> > to evenly roast 3kg (6.7lbs).
>>
>> Rob, there is a unit of measure in vacuum motors that may help us. It is
>> called
>> air watts.
>>
>> Air Watts = Airflow (cfm) * Static Pressure (inches of water)
>> ___________________________________
>> 8.5
>>
>>
>>
>> Dan
>
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Date: 11 Oct 2006 16:15:15
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
Hey Johnny, are there pics of your heat exchanger posted anywhere?
Somewhere on the Sivitz site it mentions a baffle he places above the
roast chamber that directs the heat back down. and since I am on the
subject with Erik, what kind of insulation did you use around your heat
exchanger? -wes
Johnny wrote:
> "RobvL" <wontwork@dontbother.net> wrote in message
> news:452cc22c@clear.net.nz...
> > Hi Wes
> >
> > I didn't realize that tell i looked back at Ed's site and saw the title of
> > the page with my roaster. Send me your email i'll email a pic of the SS
> > roaster. In the past threads about this sort of roaster project haven't
> > lasted long, just not that many people here at a.c interested. Even Ted
> > doesn't mention much about his roaster now days. Actually Ted doesn't post
> > much at all now days.
> >
> Just 'cos we don't post much on the subject does not mean we aren't
> interested. I for one have really enjoyed this thread and it has almost got
> me reviving shelved air roaster projects. I've learned a lot from the
> interchange.
>
> Several years ago I brazed up a heat exchanger out of thin-walled copper
> tubing.
> The heat exchanger sat in a regular bbq with the inlets and outlets going
> through the rotisserie spit holes. I used a $25 shop vac to blow air through
> the heat exchanger and a stainless steel milkshake cup acted as the roast
> chamber with a lamp glass above for sighting the roast leading into 4 inch
> aluminum ducting to transport the chaff to a bin.
> Initially I couldn't get enough heat out of the bbq to roast with but once I
> added insulation around the heat exchanger and inside the bbq lid there was
> heat to spare.
> The shop vac was so noisy that I had to build an insulated box around it so
> I could hear the cracks. I also made a makeshift water column out of a fence
> paling and some translucent tubing so I could test the pressure generated by
> various vacuum cleaners.
>
> It was for me a great advance on corn popper roasting as I was now able to
> easily roast around 400g and the shop vac had enough power to loft way more
> but the roast chamber was too small to hold any more once the beans had
> expanded during the roast. Because 400g wasn't enough I took it apart to
> make the roast chamber larger and never finished doing that so it's
> gathering dust now.
>
> Next, inspired by Ted's rig I purchased a 1 hp blower from harbor freight
> and tried to make a larger air roaster. Made a great bean cannon when I
> accidentally opened the inlet flue all the way during testing, what a mess
> :-) but I was confused by finding that although I could easily loft a kilo
> of beans when the heat wasn't on, the loft failed once I applied heat to the
> air stream. I figure it must have been something to do with the air
> expanding and so being less dense when hot and that my blower just didn't
> have enough oopmh to cope with that. So that's shelved for now also till I
> get a better blower.
>
> So keep this discussion going, tell us more. Maybe we can get Ed to turn
> homeroaster into a roasting equivalent of home-barista ;-)
>
> Johnny
|
| | |
Date: 11 Oct 2006 20:36:27
From: Johnny
Subject: Re: stainless steel pipe style coffee roaster
|
"Wes" <inabcentia@gmail.com > wrote in message
news:1160608515.680810.45470@c28g2000cwb.googlegroups.com...
> Hey Johnny, are there pics of your heat exchanger posted anywhere?
no prizes for well-designed pages (plumbers taps...)
http://johnnykent.com/coffee/heatexchanger.jpg
and http://johnnykent.com/coffee/Mk2.1/k2_1.html
|
| |
Date: 11 Oct 2006 15:17:52
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Dan Bollinger wrote:
> btw: In the Grainger catalog, all the Amtek vacuum motors list the airwatts.
>
> Dan
I never noticed. Hmm. Ironic then that the Dayton engineer didn't seem
too excited about them.
Erik
|
| |
Date: 11 Oct 2006 15:15:47
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Wes wrote:
> Hey Erik,
> I think I must have missed the reference to the heat exchanger. Is that
> a device that fits onto the blower?
Check Johnny's post. he talks about it there. I would love to see pics
of it. With my luck, after saying that I will be told that pics of it
have been posted on Homeroasters.org for the past 4 years. I better go
check first before I ask.
> What is a "free air condition" and what is meant by deadheaded?
Free air just means that nothing is hooked to the blower. It sits there
and spins and moves lots of air because there is no resistance to flow,
the most cfm the blower can develop. Deadheaded would be like putting
your hand over the outlet and not allowing any air to escape. That is
also the maximum pressure the blower is able to develop.
> I'll bite, how
> much for the Sivitz 1.25lb roaster?
$1600.00 That is a lot of green. But it sure is cool.
>Last question, what kind/type
> material would be suitable for wrapping around the roast tube ( the
> metal tube surrounding the heater elements) for insulation?
Rock wool (rockwell?) insulation is what I am using right now. I want
to use ceramic paper though. Or a ceramic insulation coating almost
like powdercoating that hotrodders use on exhaust headers. Amazing
stuff and has a lustre like polished nickel. Very $$$ but cool to the
touch at our temps. I think that I am almost the only guy using big
amounts of electric heat on this thread. I do believe that insulating
the roast chamber is a good idea and will allow you to lower your MET
(mean environment temp) which is a good thing for drip coffee.
Good luck Wes.
Erik
|
| |
Date: 11 Oct 2006 15:04:43
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
I must live in a cave. I haven't checked out www.homeroasters.org
Thanks for the heads up.
If you are at all like me then there is no way you have the time for
setting up a forum. I wish I could help with it. I don't think that the
actual setup is too complex from friends that do it.
Ed Needham wrote:
> I'm still listening...
> If I had the HTML skills, and time, something more exciting than what I have
> on my website would be wonderful. I'm also involved in the
> www.homeroasters.org web site. It's a great forum for homeroasters to show
> pics and get commentary on beans, roasters, plans, etc...
>
|
| |
Date: 11 Oct 2006 11:34:01
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
Hey Erik,
I think I must have missed the reference to the heat exchanger. Is that
a device that fits onto the blower? I also need some help with terms.
What is a "free air condition" and what is meant by deadheaded? Are you
saying the blower needs to sit higher up off the floor? I'll bite, how
much for the Sivitz 1.25lb roaster? Last question, what kind/type
material would be suitable for wrapping around the roast tube ( the
metal tube surrounding the heater elements) for insulation? I'd be
interested in hearing everyone's input on any of the above. -Wes
Erik Groomer wrote:
> Johnny wrote:
>
> > So keep this discussion going, tell us more. Maybe we can get Ed to turn
> > homeroaster into a roasting equivalent of home-barista ;-)
> >
> > Johnny
>
> I think that is a great idea. I haven't frequented SM's forum. Perhaps
> there...
>
> I love the idea of the heat exchanger. I've thought of trying to recoup
> some of the heat from the exhaust that way. Probably no go. Where do
> you get something like that?
>
> I spoke with Chuck from Coffee Wisdom for about an hour last night. He
> has big plans for a 20lb fluid bed hybrid thingy. He seems to have
> really learned a lot from experimenting around. Little pieces of wisdom
> he threw out there.
>
> EG: When a blower is in a free air condition it uses more horsepower
> than when it is deadheaded.(He said 5x's as much. I don't quite see
> that.) Why? Because work for a blower is moving air. No air movement,
> no work. There is no more air movement for a blower than when it is
> sitting on the floor.
>
> I didn't realize that was what I was seeing when I put an amp clamp on
> a new blower I got about a year ago and the current flow was about
> double that of the nameplate rating. Interesting, eh?
>
> By the way Rob. He told me how much the little Sivetz cost in those
> pictures you linked to. Any guesses? And it wasn't even assembled when
> he picked it up.
>
> Asta,
> Erik
|
| |
Date: 11 Oct 2006 06:27:56
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Ah, yes. My brother-in-law was a vacuum cleaner salesman and he went on
and on about those. At the time I had nothing to relate it to. Most
manufacturers don't use those though, do they? I asked the Dayton
engineer about that and he literally scoffed. Doesn't mean it isn't
useful though.
> Rob, there is a unit of measure in vacuum motors that may help us. It is called
> air watts.
>
> Air Watts = Airflow (cfm) * Static Pressure (inches of water)
> ___________________________________
> 8.5
>
>
>
> Dan
|
| | |
Date: 11 Oct 2006 10:13:46
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Ah, yes. My brother-in-law was a vacuum cleaner salesman and he went on
> and on about those. At the time I had nothing to relate it to. Most
> manufacturers don't use those though, do they? I asked the Dayton
> engineer about that and he literally scoffed. Doesn't mean it isn't
> useful though.
I've not used them, but it is an interesting concept. For one, it implies a
linear, inverse relationship between airflow and pressure.
btw: In the Grainger catalog, all the Amtek vacuum motors list the airwatts.
Dan
|
| |
Date: 11 Oct 2006 06:25:15
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Johnny wrote:
> So keep this discussion going, tell us more. Maybe we can get Ed to turn
> homeroaster into a roasting equivalent of home-barista ;-)
>
> Johnny
I think that is a great idea. I haven't frequented SM's forum. Perhaps
there...
I love the idea of the heat exchanger. I've thought of trying to recoup
some of the heat from the exhaust that way. Probably no go. Where do
you get something like that?
I spoke with Chuck from Coffee Wisdom for about an hour last night. He
has big plans for a 20lb fluid bed hybrid thingy. He seems to have
really learned a lot from experimenting around. Little pieces of wisdom
he threw out there.
EG: When a blower is in a free air condition it uses more horsepower
than when it is deadheaded.(He said 5x's as much. I don't quite see
that.) Why? Because work for a blower is moving air. No air movement,
no work. There is no more air movement for a blower than when it is
sitting on the floor.
I didn't realize that was what I was seeing when I put an amp clamp on
a new blower I got about a year ago and the current flow was about
double that of the nameplate rating. Interesting, eh?
By the way Rob. He told me how much the little Sivetz cost in those
pictures you linked to. Any guesses? And it wasn't even assembled when
he picked it up.
Asta,
Erik
|
| | |
Date: 11 Oct 2006 10:12:02
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
>> So keep this discussion going, tell us more. Maybe we can get Ed to turn
>> homeroaster into a roasting equivalent of home-barista ;-)
Ed, and others, already have! It is at www.homeroasters.org
> EG: When a blower is in a free air condition it uses more horsepower
> than when it is deadheaded.(He said 5x's as much. I don't quite see
> that.) Why? Because work for a blower is moving air. No air movement,
> no work.
Quite right. The other term used is 'shutoff'. On many occasions, I see
centrifugal chemical process pumps use a constriction in the outlet plumbing to
artificially create a situation whereby the pump is never able to 'run free'.
This not only draws more amps, but can lead to cavitation, too.
>There is no more air movement for a blower than when it is
> sitting on the floor.
True, but the air within the casing is moving, rubbing against the walls and
becoming heated. This results in a small energy requirement.
> I didn't realize that was what I was seeing when I put an amp clamp on
> a new blower I got about a year ago and the current flow was about
> double that of the nameplate rating. Interesting, eh?
|
| |
Date: 11 Oct 2006 05:53:04
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
Hey Rob,
send it to inabcentia at gmail
-Wes
RobvL wrote:
> Hi Wes
>
> I didn't realize that tell i looked back at Ed's site and saw the title of
> the page with my roaster. Send me your email i'll email a pic of the SS
> roaster. In the past threads about this sort of roaster project haven't
> lasted long, just not that many people here at a.c interested. Even Ted
> doesn't mention much about his roaster now days. Actually Ted doesn't post
> much at all now days.
>
> Rob
>
>
>
> "Wes" <inabcentia@gmail.com> wrote in message
> news:1160417164.595241.306800@h48g2000cwc.googlegroups.com...
> > Hi Rob,
> > You know you are the cause of this thread because after I saw your
> > first stainless steel roaster on Ed's site I couldn't stop thinking
> > about it for weeks. I had so many questions I needed to bounce them off
> > someone but as I told Erik in another email this is a particular set of
> > problems not easily discussed except among those interested in home
> > roasting. I have had many 1000-yard stares from friends I tried
> > engaging in conversations about design particulars of coffee roasters.
> > I agree with Erik this thread is awesome! Too bad the discussion can't
> > take place in someone's shop over a fresh roasted, brewed pot of
> > coffee. Anyway, something here is not making sense to me. If you double
> > the size of perforated area from 2" to 4" and leave the bed height 12",
> > aren't you doubling the weight of the coffee bean column above the
> > perforated area and so need double the pressure to initially raise
> > them? The part about doubling the air flow makes sense though. what am
> > I missing? -Wes
> >
> >
> > RobvL wrote:
> > > "Andy Schecter" <schecter@remove.me.rochester.rr.com> wrote in message
> > > news:V%iWg.7123$484.6432@twister.nyroc.rr.com...
> > > > RobvL wrote:
> > > > > Question is how much pressure is required to move X weight of beans?
> How
> > > > > much flow?
> > > >
> > > > The pressure required equals the weight of the beans divided by the
> > > > cross-sectional area of the chamber. Typical pressure required in a
> popper
> > > is
> > > > only 2" water column. Your blower may have to develop considerably
> more
> > > > depending on the bean load, diameter of chamber, and pressure losses
> in
> > > the
> > > > air delivery piping.
> > > > --
> > > >
> > > >
> > > > -Andy S.
> > > >
> > > > http://www.flickr.com/photos/andy_s/sets/
> > >
> > >
> > > Far too simple Andy couldn't possibly be true! Well colour me stupid,
> makes
> > > perfect sense. That being the case the pressure would relate to height
> of
> > > the column of beans regardless of diameter. That is if the area that is
> > > perforated is 2 sqr inches and the bean column 12" high then if the you
> > > change the perforated area to 4 sqr inches and the column remains at 12"
> the
> > > pressure required should be the same only the required air flow would
> need
> > > to be doubled. This would be regardless of the diameter of the roast
> chamber
> > > as only the beans above the perforated sectioned come into the equation.
> > > Thanx Andy.
> > >
> > > RobvL
> > > NZ
> >
|
| |
Date: 10 Oct 2006 12:16:30
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
I'll pick up a Mach Handbook. Thanks for the info.
Dan Bollinger wrote:
> > Thanks Dan. The real question for me is: where can I turn to learn this
> > stuff about airflows, etc? I am not an engineer nor am I particularly
> > gifted at the math. Where did you pick all this up?
>
> Bits and pieces, here and there. Mfgr brochures are filled with common sense
> information. The Machinery's Handbook is a must, too. By the way, I ordered a
> digital manometer yesterday. It will measure low pressures in the 0-45 inches of
> water range. I decided we HAD to have one at work. :)
|
| |
Date: 10 Oct 2006 12:07:01
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Which manometer did you get? A Dwyer?
Dan Bollinger wrote:
> > Thanks Dan. The real question for me is: where can I turn to learn this
> > stuff about airflows, etc? I am not an engineer nor am I particularly
> > gifted at the math. Where did you pick all this up?
>
> Bits and pieces, here and there. Mfgr brochures are filled with common sense
> information. The Machinery's Handbook is a must, too. By the way, I ordered a
> digital manometer yesterday. It will measure low pressures in the 0-45 inches of
> water range. I decided we HAD to have one at work. :)
|
| | |
Date: 10 Oct 2006 16:27:07
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Which manometer did you get? A Dwyer?
Yes, the little 467-0. It arrived today. :)
>
> Dan Bollinger wrote:
>> > Thanks Dan. The real question for me is: where can I turn to learn this
>> > stuff about airflows, etc? I am not an engineer nor am I particularly
>> > gifted at the math. Where did you pick all this up?
>>
>> Bits and pieces, here and there. Mfgr brochures are filled with common sense
>> information. The Machinery's Handbook is a must, too. By the way, I ordered
>> a
>> digital manometer yesterday. It will measure low pressures in the 0-45 inches
>> of
>> water range. I decided we HAD to have one at work. :)
>
|
| |
Date: 10 Oct 2006 07:53:08
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Rob,
My column size is about 15% of total area. Do you find that with your
perf offset to the side of the roast tube that your beans spout well
enough to ensure good circulation of the beans?
Erik
RobvL wrote:
> "Erik Groomer" <ViridianCoffee@gmail.com> wrote in message
> news:1160432623.002497.19530@m7g2000cwm.googlegroups.com...
> > I agree that one of these blowers would not fluidize 20 Pounds. Two of
> > them would be close to doing it. I use two blowers from Grainger that
> > produce about 91 inches, 95 cfm each and i can fluidize 15 lbs. Also,
> > combined cost is about the price of the one blower you mentioned. The
> > blowers I use are Grainger 2M192. $126.60 for two of them. I put them
> > in series, run them off 240V and use a $60 fan control from Grainger.
> > Works great.
> >
> > As a result of this thread I think I must be using perf that is too
> > much open. I have an 11" diameter tube with cone necking down to 4
> > 1/4" diameter with 60% open 9/32" perf plate at the bottom.
>
> Yeah My 4" roaster has a flat section that is perfed and is about 23% of the
> RC area, the sum of the area of the 33 1/8" holes is equal to about 14.7% of
> this but 3.4 % of the hole roast chamer. The other 77 % is the elipse plate
> at 45 deg that the beans flow back to the perf plate. The 6" flat perf plate
> is about 17% of the RC area. I do notice slight variations in the way the
> beans heat up The 6" can seem to be slower at the start, Maybe because the
> column is beans is smaller relative to the RC and requires a few more cycles
> for the beans to get the same amount of heating..
>
> >
> > Coming back to the 4% open area number that some of you guys came up
> > with: at this point wouldn't it make more sense to come up with a
> > number that was relative to the diameter of the column of beans you are
> > trying to loft instead of in relation to the total roast chamber tube
> > diameter?
>
>
> MY ballpark figure for the size of the column would be between 20 & 25 % of
> the RC area.
>
> Rob
>
>
> >
> > Wouldn't a set open area percentage perf plate work for any size roast
> > tube?
> >
> > What number does that happen to be for you guys?
> >
> > Erik
> >
> > > Check at www.grainger.com The largest I saw was an Ametek, (Grainger
> 4M922)
> > > 3-stage, 120VAC, 13.5A, 137 inches water, 101 cfm (with 2" orifice),
> $140
> > >
> > > We don't yet know what pressure these units develop, and we are just now
> > > figuring out the phsycial requirements of a spouting bed in this thread,
> so
> > > can't answer any more of your questions.
> > >
> > > I can say I doubt that the above vacuum motor could fluidize 20 pounds.
> Dan
> >
|
| | |
Date: 11 Oct 2006 22:51:49
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1160491988.318329.157340@i3g2000cwc.googlegroups.com...
> Rob,
> My column size is about 15% of total area. Do you find that with your
> perf offset to the side of the roast tube that your beans spout well
> enough to ensure good circulation of the beans?
The offset roast chambers work real well, the beans literally flow across
the top. The correct amount and size of holes in the perf plate make all the
difference. By my guestamates you wouldn't want to go less than 15%, as Dan
mentioned this affects how often the beans end up in the heat stream.
Rob
> Erik
>
> RobvL wrote:
> > "Erik Groomer" <ViridianCoffee@gmail.com> wrote in message
> > news:1160432623.002497.19530@m7g2000cwm.googlegroups.com...
> > > I agree that one of these blowers would not fluidize 20 Pounds. Two of
> > > them would be close to doing it. I use two blowers from Grainger that
> > > produce about 91 inches, 95 cfm each and i can fluidize 15 lbs. Also,
> > > combined cost is about the price of the one blower you mentioned. The
> > > blowers I use are Grainger 2M192. $126.60 for two of them. I put them
> > > in series, run them off 240V and use a $60 fan control from Grainger.
> > > Works great.
> > >
> > > As a result of this thread I think I must be using perf that is too
> > > much open. I have an 11" diameter tube with cone necking down to 4
> > > 1/4" diameter with 60% open 9/32" perf plate at the bottom.
> >
> > Yeah My 4" roaster has a flat section that is perfed and is about 23% of
the
> > RC area, the sum of the area of the 33 1/8" holes is equal to about
14.7% of
> > this but 3.4 % of the hole roast chamer. The other 77 % is the elipse
plate
> > at 45 deg that the beans flow back to the perf plate. The 6" flat perf
plate
> > is about 17% of the RC area. I do notice slight variations in the way
the
> > beans heat up The 6" can seem to be slower at the start, Maybe because
the
> > column is beans is smaller relative to the RC and requires a few more
cycles
> > for the beans to get the same amount of heating..
> >
> > >
> > > Coming back to the 4% open area number that some of you guys came up
> > > with: at this point wouldn't it make more sense to come up with a
> > > number that was relative to the diameter of the column of beans you
are
> > > trying to loft instead of in relation to the total roast chamber tube
> > > diameter?
> >
> >
> > MY ballpark figure for the size of the column would be between 20 & 25 %
of
> > the RC area.
> >
> > Rob
> >
> >
> > >
> > > Wouldn't a set open area percentage perf plate work for any size roast
> > > tube?
> > >
> > > What number does that happen to be for you guys?
> > >
> > > Erik
> > >
> > > > Check at www.grainger.com The largest I saw was an Ametek,
(Grainger
> > 4M922)
> > > > 3-stage, 120VAC, 13.5A, 137 inches water, 101 cfm (with 2" orifice),
> > $140
> > > >
> > > > We don't yet know what pressure these units develop, and we are just
now
> > > > figuring out the phsycial requirements of a spouting bed in this
thread,
> > so
> > > > can't answer any more of your questions.
> > > >
> > > > I can say I doubt that the above vacuum motor could fluidize 20
pounds.
> > Dan
> > >
>
|
| |
Date: 09 Oct 2006 20:19:34
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Thanks Dan. The real question for me is: where can I turn to learn this
stuff about airflows, etc? I am not an engineer nor am I particularly
gifted at the math. Where did you pick all this up?
Dan Bollinger wrote:
> > I talked with an engineer at Grainger/Dayton and he said 91" of both
> > vacuum and pressure. I said "what?" He said same-same. I was surprised,
> > but then he should know.
>
> Erik, that's good to know, it will make selection of those motors easier. I
> just wish they weren't so danged noisy.
>
> > I just worked the math before I saw your post Dan. Yes, almost 9% open.
> > I meant 9/64" not 9/32" hole size.
>
> As a side note, although technically, it is about 9% open, it acts as less than
> that since a series of holes has more friction than lots of smaller ones of the
> same total area. I have no idea how much less.
>
> Dan
|
| | |
Date: 10 Oct 2006 12:26:15
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Thanks Dan. The real question for me is: where can I turn to learn this
> stuff about airflows, etc? I am not an engineer nor am I particularly
> gifted at the math. Where did you pick all this up?
Bits and pieces, here and there. Mfgr brochures are filled with common sense
information. The Machinery's Handbook is a must, too. By the way, I ordered a
digital manometer yesterday. It will measure low pressures in the 0-45 inches of
water range. I decided we HAD to have one at work. :)
|
| |
Date: 09 Oct 2006 19:35:02
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Ok, I should have been more careful. I was trying to read and post
between feeding the kids supper and putting them to bed.
I talked with an engineer at Grainger/Dayton and he said 91" of both
vacuum and pressure. I said "what?" He said same-same. I was surprised,
but then he should know.
I just worked the math before I saw your post Dan. Yes, almost 9% open.
I meant 9/64" not 9/32" hole size.
I had previously used a much smaller open area perf when I tried the
15lbs. I haven't tested the max loft since installing the 9/64" 60%
open perf. I just "assumed" it would be better. I also just assumed
that my open area would be a greater % without running the numbers
compared with what Rob claimed his open area was.
Dan, you make some really good points. I guess I'll mull all this over.
Next time I will try to think twice and type once.
Thanks,
Erik
Dan Bollinger wrote:
> >I agree that one of these blowers would not fluidize 20 Pounds. Two of
> > them would be close to doing it. I use two blowers from Grainger that
> > produce about 91 inches, 95 cfm each and i can fluidize 15 lbs. Also,
> > combined cost is about the price of the one blower you mentioned. The
> > blowers I use are Grainger 2M192. $126.60 for two of them. I put them
> > in series, run them off 240V and use a $60 fan control from Grainger.
> > Works great.
>
> I checked those specs, the 91" is vacuum, not pressure.
>
> > As a result of this thread I think I must be using perf that is too
> > much open. I have an 11" diameter tube with cone necking down to 4
> > 1/4" diameter with 60% open 9/32" perf plate at the bottom.
>
> What you have is the equivalent (area-wise) of a 9% orifice.
>
> > Coming back to the 4% open area number that some of you guys came up
> > with: at this point wouldn't it make more sense to come up with a
> > number that was relative to the diameter of the column of beans you are
> > trying to loft instead of in relation to the total roast chamber tube
> > diameter?
> > Wouldn't a set open area percentage perf plate work for any size roast
> > tube?
>
> Yes and no. A lot will depend on whether or not your chamber has a conical
> bottom or not, to aid mixing. If the bottom is flat, and the diameter is large,
> there will be some beans left in the corner unroasted.
>
> A given orifice might, with a conical bottom, move beans in a large range of
> roasting chamber sizes. The difference being that the beans will travel from top
> to bottom, and spouted back up to the top more often in a smaller chamber than
> larger. Think of it as mixing speed. This is similar to changing the drum speed
> on drum roasters.
>
> At some point, when the chamber increases in diameter, you'll be forced to
> increase the orifice, too.
>
> Dan
|
| | |
Date: 09 Oct 2006 23:06:08
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> I talked with an engineer at Grainger/Dayton and he said 91" of both
> vacuum and pressure. I said "what?" He said same-same. I was surprised,
> but then he should know.
Erik, that's good to know, it will make selection of those motors easier. I
just wish they weren't so danged noisy.
> I just worked the math before I saw your post Dan. Yes, almost 9% open.
> I meant 9/64" not 9/32" hole size.
As a side note, although technically, it is about 9% open, it acts as less than
that since a series of holes has more friction than lots of smaller ones of the
same total area. I have no idea how much less.
Dan
|
| | | |
Date: 10 Oct 2006 22:54:25
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Dan Bollinger" <danNObollinger@insightSPAMbb.com > wrote in message
news:kMidnXPZQpO_k7bYnZ2dnUVZ_smdnZ2d@insightbb.com...
> > I talked with an engineer at Grainger/Dayton and he said 91" of both
> > vacuum and pressure. I said "what?" He said same-same. I was surprised,
> > but then he should know.
>
> Erik, that's good to know, it will make selection of those motors easier.
I
> just wish they weren't so danged noisy.
>
> > I just worked the math before I saw your post Dan. Yes, almost 9% open.
> > I meant 9/64" not 9/32" hole size.
>
> As a side note, although technically, it is about 9% open, it acts as less
than
> that since a series of holes has more friction than lots of smaller ones
of the
> same total area. I have no idea how much less.
>
> Dan
>
True but you are comparing apples with apples, IE any FB roaster would have
the holes and so it is a variable in common to all. Holes size matter i did
a roaster with 2.9mm holes that would work properly redrill them to 3.2 1/8"
and it worked fine.
Rob
|
| | | | |
Date: 11 Oct 2006 22:41:45
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"RobvL" <wontwork@dontbother.net > wrote in message
news:452b6dd4$1@clear.net.nz...
>
> "Dan Bollinger" <danNObollinger@insightSPAMbb.com> wrote in message
> news:kMidnXPZQpO_k7bYnZ2dnUVZ_smdnZ2d@insightbb.com...
> > > I talked with an engineer at Grainger/Dayton and he said 91" of both
> > > vacuum and pressure. I said "what?" He said same-same. I was
surprised,
> > > but then he should know.
> >
> > Erik, that's good to know, it will make selection of those motors
easier.
> I
> > just wish they weren't so danged noisy.
> >
> > > I just worked the math before I saw your post Dan. Yes, almost 9%
open.
> > > I meant 9/64" not 9/32" hole size.
> >
> > As a side note, although technically, it is about 9% open, it acts as
less
> than
> > that since a series of holes has more friction than lots of smaller ones
> of the
> > same total area. I have no idea how much less.
> >
> > Dan
> >
>
> True but you are comparing apples with apples, IE any FB roaster would
have
> the holes and so it is a variable in common to all. Holes size matterS, i
did
> a roaster with 2.9mm holes that would NOT work properly, redrill them to
3.2 1/8"
> and it worked fine.
>
> Rob
>
Sheesh half asleep when i wrote that see corrections.
|
| | | | |
Date: 10 Oct 2006 12:28:04
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> True but you are comparing apples with apples, IE any FB roaster would have
> the holes and so it is a variable in common to all. Holes size matter i did
> a roaster with 2.9mm holes that would work properly redrill them to 3.2 1/8"
> and it worked fine.
I'm just saying that there is a net pressure loss as the orifice size is reduced
while the total free area remains the same. Dan
|
| |
Date: 09 Oct 2006 15:23:43
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
I agree that one of these blowers would not fluidize 20 Pounds. Two of
them would be close to doing it. I use two blowers from Grainger that
produce about 91 inches, 95 cfm each and i can fluidize 15 lbs. Also,
combined cost is about the price of the one blower you mentioned. The
blowers I use are Grainger 2M192. $126.60 for two of them. I put them
in series, run them off 240V and use a $60 fan control from Grainger.
Works great.
As a result of this thread I think I must be using perf that is too
much open. I have an 11" diameter tube with cone necking down to 4
1/4" diameter with 60% open 9/32" perf plate at the bottom.
Coming back to the 4% open area number that some of you guys came up
with: at this point wouldn't it make more sense to come up with a
number that was relative to the diameter of the column of beans you are
trying to loft instead of in relation to the total roast chamber tube
diameter?
Wouldn't a set open area percentage perf plate work for any size roast
tube?
What number does that happen to be for you guys?
Erik
> Check at www.grainger.com The largest I saw was an Ametek, (Grainger 4M922)
> 3-stage, 120VAC, 13.5A, 137 inches water, 101 cfm (with 2" orifice), $140
>
> We don't yet know what pressure these units develop, and we are just now
> figuring out the phsycial requirements of a spouting bed in this thread, so
> can't answer any more of your questions.
>
> I can say I doubt that the above vacuum motor could fluidize 20 pounds. Dan
|
| | |
Date: 10 Oct 2006 23:05:27
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1160432623.002497.19530@m7g2000cwm.googlegroups.com...
> I agree that one of these blowers would not fluidize 20 Pounds. Two of
> them would be close to doing it. I use two blowers from Grainger that
> produce about 91 inches, 95 cfm each and i can fluidize 15 lbs. Also,
> combined cost is about the price of the one blower you mentioned. The
> blowers I use are Grainger 2M192. $126.60 for two of them. I put them
> in series, run them off 240V and use a $60 fan control from Grainger.
> Works great.
>
> As a result of this thread I think I must be using perf that is too
> much open. I have an 11" diameter tube with cone necking down to 4
> 1/4" diameter with 60% open 9/32" perf plate at the bottom.
Yeah My 4" roaster has a flat section that is perfed and is about 23% of the
RC area, the sum of the area of the 33 1/8" holes is equal to about 14.7% of
this but 3.4 % of the hole roast chamer. The other 77 % is the elipse plate
at 45 deg that the beans flow back to the perf plate. The 6" flat perf plate
is about 17% of the RC area. I do notice slight variations in the way the
beans heat up The 6" can seem to be slower at the start, Maybe because the
column is beans is smaller relative to the RC and requires a few more cycles
for the beans to get the same amount of heating..
>
> Coming back to the 4% open area number that some of you guys came up
> with: at this point wouldn't it make more sense to come up with a
> number that was relative to the diameter of the column of beans you are
> trying to loft instead of in relation to the total roast chamber tube
> diameter?
MY ballpark figure for the size of the column would be between 20 & 25 % of
the RC area.
Rob
>
> Wouldn't a set open area percentage perf plate work for any size roast
> tube?
>
> What number does that happen to be for you guys?
>
> Erik
>
> > Check at www.grainger.com The largest I saw was an Ametek, (Grainger
4M922)
> > 3-stage, 120VAC, 13.5A, 137 inches water, 101 cfm (with 2" orifice),
$140
> >
> > We don't yet know what pressure these units develop, and we are just now
> > figuring out the phsycial requirements of a spouting bed in this thread,
so
> > can't answer any more of your questions.
> >
> > I can say I doubt that the above vacuum motor could fluidize 20 pounds.
Dan
>
|
| | |
Date: 09 Oct 2006 18:52:16
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
>I agree that one of these blowers would not fluidize 20 Pounds. Two of
> them would be close to doing it. I use two blowers from Grainger that
> produce about 91 inches, 95 cfm each and i can fluidize 15 lbs. Also,
> combined cost is about the price of the one blower you mentioned. The
> blowers I use are Grainger 2M192. $126.60 for two of them. I put them
> in series, run them off 240V and use a $60 fan control from Grainger.
> Works great.
I checked those specs, the 91" is vacuum, not pressure.
> As a result of this thread I think I must be using perf that is too
> much open. I have an 11" diameter tube with cone necking down to 4
> 1/4" diameter with 60% open 9/32" perf plate at the bottom.
What you have is the equivalent (area-wise) of a 9% orifice.
> Coming back to the 4% open area number that some of you guys came up
> with: at this point wouldn't it make more sense to come up with a
> number that was relative to the diameter of the column of beans you are
> trying to loft instead of in relation to the total roast chamber tube
> diameter?
> Wouldn't a set open area percentage perf plate work for any size roast
> tube?
Yes and no. A lot will depend on whether or not your chamber has a conical
bottom or not, to aid mixing. If the bottom is flat, and the diameter is large,
there will be some beans left in the corner unroasted.
A given orifice might, with a conical bottom, move beans in a large range of
roasting chamber sizes. The difference being that the beans will travel from top
to bottom, and spouted back up to the top more often in a smaller chamber than
larger. Think of it as mixing speed. This is similar to changing the drum speed
on drum roasters.
At some point, when the chamber increases in diameter, you'll be forced to
increase the orifice, too.
Dan
|
| |
Date: 09 Oct 2006 11:12:22
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
Hey Dan,
thanks for all the input. I've learned more from you and the others
here in a couple of days than weeks on the web. I have been mostly
trying to follow along and absorb the info. One point of clarification,
in your earlier post did you mean 10kg (22 lbs.) or 6 lbs? -Wes
> All blowers have an airflow/pressure curve. If you operated the regen at lower
> pressure you gain a little airflow. Enough to make it work? I checked the stats
> on a Fuji 1/2Hp regen, model VFC300P-5T. At 20" water, it could loft 10kg of
> beans (about 6 pounds) using 46cfm. I'm guessing that that airflow would work
> in an 8-9" roasting chamber. The output/input of the regen is 1.25 pipe, which
|
| | |
Date: 09 Oct 2006 14:43:55
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
Oops! I meant 10kg (22 lbs.)
|
| |
Date: 09 Oct 2006 11:06:04
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
Hi Rob,
You know you are the cause of this thread because after I saw your
first stainless steel roaster on Ed's site I couldn't stop thinking
about it for weeks. I had so many questions I needed to bounce them off
someone but as I told Erik in another email this is a particular set of
problems not easily discussed except among those interested in home
roasting. I have had many 1000-yard stares from friends I tried
engaging in conversations about design particulars of coffee roasters.
I agree with Erik this thread is awesome! Too bad the discussion can't
take place in someone's shop over a fresh roasted, brewed pot of
coffee. Anyway, something here is not making sense to me. If you double
the size of perforated area from 2" to 4" and leave the bed height 12",
aren't you doubling the weight of the coffee bean column above the
perforated area and so need double the pressure to initially raise
them? The part about doubling the air flow makes sense though. what am
I missing? -Wes
RobvL wrote:
> "Andy Schecter" <schecter@remove.me.rochester.rr.com> wrote in message
> news:V%iWg.7123$484.6432@twister.nyroc.rr.com...
> > RobvL wrote:
> > > Question is how much pressure is required to move X weight of beans? How
> > > much flow?
> >
> > The pressure required equals the weight of the beans divided by the
> > cross-sectional area of the chamber. Typical pressure required in a popper
> is
> > only 2" water column. Your blower may have to develop considerably more
> > depending on the bean load, diameter of chamber, and pressure losses in
> the
> > air delivery piping.
> > --
> >
> >
> > -Andy S.
> >
> > http://www.flickr.com/photos/andy_s/sets/
>
>
> Far too simple Andy couldn't possibly be true! Well colour me stupid, makes
> perfect sense. That being the case the pressure would relate to height of
> the column of beans regardless of diameter. That is if the area that is
> perforated is 2 sqr inches and the bean column 12" high then if the you
> change the perforated area to 4 sqr inches and the column remains at 12" the
> pressure required should be the same only the required air flow would need
> to be doubled. This would be regardless of the diameter of the roast chamber
> as only the beans above the perforated sectioned come into the equation.
> Thanx Andy.
>
> RobvL
> NZ
|
| | |
Date: 11 Oct 2006 23:06:31
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
Hi Wes
I didn't realize that tell i looked back at Ed's site and saw the title of
the page with my roaster. Send me your email i'll email a pic of the SS
roaster. In the past threads about this sort of roaster project haven't
lasted long, just not that many people here at a.c interested. Even Ted
doesn't mention much about his roaster now days. Actually Ted doesn't post
much at all now days.
Rob
"Wes" <inabcentia@gmail.com > wrote in message
news:1160417164.595241.306800@h48g2000cwc.googlegroups.com...
> Hi Rob,
> You know you are the cause of this thread because after I saw your
> first stainless steel roaster on Ed's site I couldn't stop thinking
> about it for weeks. I had so many questions I needed to bounce them off
> someone but as I told Erik in another email this is a particular set of
> problems not easily discussed except among those interested in home
> roasting. I have had many 1000-yard stares from friends I tried
> engaging in conversations about design particulars of coffee roasters.
> I agree with Erik this thread is awesome! Too bad the discussion can't
> take place in someone's shop over a fresh roasted, brewed pot of
> coffee. Anyway, something here is not making sense to me. If you double
> the size of perforated area from 2" to 4" and leave the bed height 12",
> aren't you doubling the weight of the coffee bean column above the
> perforated area and so need double the pressure to initially raise
> them? The part about doubling the air flow makes sense though. what am
> I missing? -Wes
>
>
> RobvL wrote:
> > "Andy Schecter" <schecter@remove.me.rochester.rr.com> wrote in message
> > news:V%iWg.7123$484.6432@twister.nyroc.rr.com...
> > > RobvL wrote:
> > > > Question is how much pressure is required to move X weight of beans?
How
> > > > much flow?
> > >
> > > The pressure required equals the weight of the beans divided by the
> > > cross-sectional area of the chamber. Typical pressure required in a
popper
> > is
> > > only 2" water column. Your blower may have to develop considerably
more
> > > depending on the bean load, diameter of chamber, and pressure losses
in
> > the
> > > air delivery piping.
> > > --
> > >
> > >
> > > -Andy S.
> > >
> > > http://www.flickr.com/photos/andy_s/sets/
> >
> >
> > Far too simple Andy couldn't possibly be true! Well colour me stupid,
makes
> > perfect sense. That being the case the pressure would relate to height
of
> > the column of beans regardless of diameter. That is if the area that is
> > perforated is 2 sqr inches and the bean column 12" high then if the you
> > change the perforated area to 4 sqr inches and the column remains at 12"
the
> > pressure required should be the same only the required air flow would
need
> > to be doubled. This would be regardless of the diameter of the roast
chamber
> > as only the beans above the perforated sectioned come into the equation.
> > Thanx Andy.
> >
> > RobvL
> > NZ
>
|
| | | |
Date: 11 Oct 2006 05:32:13
From: Johnny
Subject: Re: stainless steel pipe style coffee roaster
|
"RobvL" <wontwork@dontbother.net > wrote in message
news:452cc22c@clear.net.nz...
> Hi Wes
>
> I didn't realize that tell i looked back at Ed's site and saw the title of
> the page with my roaster. Send me your email i'll email a pic of the SS
> roaster. In the past threads about this sort of roaster project haven't
> lasted long, just not that many people here at a.c interested. Even Ted
> doesn't mention much about his roaster now days. Actually Ted doesn't post
> much at all now days.
>
Just 'cos we don't post much on the subject does not mean we aren't
interested. I for one have really enjoyed this thread and it has almost got
me reviving shelved air roaster projects. I've learned a lot from the
interchange.
Several years ago I brazed up a heat exchanger out of thin-walled copper
tubing.
The heat exchanger sat in a regular bbq with the inlets and outlets going
through the rotisserie spit holes. I used a $25 shop vac to blow air through
the heat exchanger and a stainless steel milkshake cup acted as the roast
chamber with a lamp glass above for sighting the roast leading into 4 inch
aluminum ducting to transport the chaff to a bin.
Initially I couldn't get enough heat out of the bbq to roast with but once I
added insulation around the heat exchanger and inside the bbq lid there was
heat to spare.
The shop vac was so noisy that I had to build an insulated box around it so
I could hear the cracks. I also made a makeshift water column out of a fence
paling and some translucent tubing so I could test the pressure generated by
various vacuum cleaners.
It was for me a great advance on corn popper roasting as I was now able to
easily roast around 400g and the shop vac had enough power to loft way more
but the roast chamber was too small to hold any more once the beans had
expanded during the roast. Because 400g wasn't enough I took it apart to
make the roast chamber larger and never finished doing that so it's
gathering dust now.
Next, inspired by Ted's rig I purchased a 1 hp blower from harbor freight
and tried to make a larger air roaster. Made a great bean cannon when I
accidentally opened the inlet flue all the way during testing, what a mess
:-) but I was confused by finding that although I could easily loft a kilo
of beans when the heat wasn't on, the loft failed once I applied heat to the
air stream. I figure it must have been something to do with the air
expanding and so being less dense when hot and that my blower just didn't
have enough oopmh to cope with that. So that's shelved for now also till I
get a better blower.
So keep this discussion going, tell us more. Maybe we can get Ed to turn
homeroaster into a roasting equivalent of home-barista ;-)
Johnny
|
| | | | |
Date: 11 Oct 2006 10:26:54
From: Ed Needham
Subject: Re: stainless steel pipe style coffee roaster
|
I'm still listening...
If I had the HTML skills, and time, something more exciting than what I have
on my website would be wonderful. I'm also involved in the
www.homeroasters.org web site. It's a great forum for homeroasters to show
pics and get commentary on beans, roasters, plans, etc...
--
*********************
Ed Needham®
"to absurdity and beyond!"
http://www.homeroaster.com
(include [FRIEND] in subject line to get through my SPAM filters)
*********************
"Johnny" <removethis.huuanito@hotmail.com > wrote in message
news:Ku5Xg.1159$UJ2.1138@fed1read07...
>
> "RobvL" <wontwork@dontbother.net> wrote in message
> news:452cc22c@clear.net.nz...
>> Hi Wes
>>
>> I didn't realize that tell i looked back at Ed's site and saw the title
>> of
>> the page with my roaster. Send me your email i'll email a pic of the SS
>> roaster. In the past threads about this sort of roaster project haven't
>> lasted long, just not that many people here at a.c interested. Even Ted
>> doesn't mention much about his roaster now days. Actually Ted doesn't
>> post
>> much at all now days.
>>
> Just 'cos we don't post much on the subject does not mean we aren't
> interested. I for one have really enjoyed this thread and it has almost
> got
> me reviving shelved air roaster projects. I've learned a lot from the
> interchange.
>
> Several years ago I brazed up a heat exchanger out of thin-walled copper
> tubing.
> The heat exchanger sat in a regular bbq with the inlets and outlets going
> through the rotisserie spit holes. I used a $25 shop vac to blow air
> through
> the heat exchanger and a stainless steel milkshake cup acted as the roast
> chamber with a lamp glass above for sighting the roast leading into 4 inch
> aluminum ducting to transport the chaff to a bin.
> Initially I couldn't get enough heat out of the bbq to roast with but once
> I
> added insulation around the heat exchanger and inside the bbq lid there
> was
> heat to spare.
> The shop vac was so noisy that I had to build an insulated box around it
> so
> I could hear the cracks. I also made a makeshift water column out of a
> fence
> paling and some translucent tubing so I could test the pressure generated
> by
> various vacuum cleaners.
>
> It was for me a great advance on corn popper roasting as I was now able to
> easily roast around 400g and the shop vac had enough power to loft way
> more
> but the roast chamber was too small to hold any more once the beans had
> expanded during the roast. Because 400g wasn't enough I took it apart to
> make the roast chamber larger and never finished doing that so it's
> gathering dust now.
>
> Next, inspired by Ted's rig I purchased a 1 hp blower from harbor freight
> and tried to make a larger air roaster. Made a great bean cannon when I
> accidentally opened the inlet flue all the way during testing, what a mess
> :-) but I was confused by finding that although I could easily loft a kilo
> of beans when the heat wasn't on, the loft failed once I applied heat to
> the
> air stream. I figure it must have been something to do with the air
> expanding and so being less dense when hot and that my blower just didn't
> have enough oopmh to cope with that. So that's shelved for now also till I
> get a better blower.
>
> So keep this discussion going, tell us more. Maybe we can get Ed to turn
> homeroaster into a roasting equivalent of home-barista ;-)
>
> Johnny
>
>
|
| | |
Date: 09 Oct 2006 14:46:54
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> If you double
> the size of perforated area from 2" to 4" and leave the bed height 12",
> aren't you doubling the weight of the coffee bean column
Nope. Area of a circle is the square of the diameter. Double the diameter and
the area increases 4 times.
above the
> perforated area and so need double the pressure to initially raise
> them?
No. Instead of thinking weight, think weight per unit area. That is, pounds per
square inch. The PSI of a 12" column of beans is the same regardless of its
size.
However, the airflow (cfm) needed to sustain that pressure is now much greater.
Dan
|
| |
Date: 09 Oct 2006 06:35:40
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
Hi Rob
I'd be interested in see pics of you tilting plate beans dumper also.
thanks -Wes
RobvL wrote:
> "Erik Groomer" <ViridianCoffee@gmail.com> wrote in message
> news:1159965015.800751.192550@m73g2000cwd.googlegroups.com...
> > Wow Rob, looks like you are pretty serious there. And you have really
> > thought it out. Very cool. I have elected to stay with electric heat
> > wich limits my intake heat level and makes recirculating complicated. I
> > like that you pull from the cooler for supply air. How heavy is that
> > pipe for the roast tube?
> >
> > Erik
>
> As I use a vacuum cleaner motor for the blower it is ok for cooling the
> beans with the 650gm roast chamber, but for the 2kg RC I dump in a cooling
> bin that sits on a 1hp dust extractor fan setup. Pulls 1.7kg of roasted to
> cold in under 3 minutes. The 650 RC is 3.5kg and the 2kg is 7.5kg (i didn't
> know that till tonite). Since those pics i have built a completely stainless
> unit that has a fixed roast chamber and dumps the beans thru a tilting
> plate. I also did a roast chamber that will do 3kg of green, Eddie (Nth Isld
> some time altie) has that one.
> I just need more time to work on the roaster projects.
>
> Rob vL
> NZ
|
| |
Date: 09 Oct 2006 06:25:24
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
Hey Dan,
I am new to this so bear with me. When you say "Small triple-stage
blowers (aka ShopVacs) have good pressure and flow," how small are we
talking? Or rather, what is the largest triple stage blower that is
easily obtained and what (aprox.) size batch of coffee beans would it
keep aloft. My follow on to that is, what size triple stage blower
(specs) would be required for 20-25lbs of beans? How many "inches of
water" pressure and how much flow should I be looking for to roast that
quantity of beans? -Wes
Dan Bollinger wrote:
> >> What is a "regenerative" blower?
> >>
> > They build more pressure.
>
> A 1/2 Hp regen develops about 40-50 inches of water and 20-25 cfm.
>
> The 1/2Hp single-stage centrifugal blowers (7-9" wheels) I have develop about
> 3-5 inches of water and 150-175 cfm.
>
> It takes pressure to lift that bean mass, and it takes airflow (cfm) to keep it
> lofted once the beans separate and air leaks by. It is this balance of pressure
> and flow that is required.
>
> For instance, a plain 20" breeze box fan laid flat develops plenty of airflow,
> but does not develop enough pressure to loft the beans.
>
> I suspect you will find that the regen has more than enough pressure to lift a
> column of beans, but won't be able to keep them lofted because it does not
> develop enough airflow. The inlet on a lot of regens are pipe thread, pretty
> small hole for all your air to go through.
>
> Small triple-stage blowers (aka ShopVacs) have good pressure and flow for this
> application, but you can't buy large units, which is what we need for roasting
> larger batches.
>
> So, in my opinion, we are left with using larger diameter single-stage blowers
> like the one I mentioned from Graingers seem to be better suited, but as yet
> untested.
>
> Ed may be on the right track using a multi-stage blower from a whole-house
> vacuum system.
>
> When in doubt, get a blower with more flow, since you can always throttle that
> down.
>
> Dan
>
>
> > I'll look forward to seeing whatever pics you can find. I've started
> > working on a larger scale poppery II type chamber to allow me to get
> > the beans out without vacuuming. It's going to be tricky to be able to
> > move any amount of beans though. I might try a modified sivetz design
> > instead.
> >
> > Are you actually in New Zealand?
> >
> > Erik
> >
|
| | |
Date: 13 Oct 2006 06:35:40
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Dan Bollinger wrote:
> > You would question THE MAN???!!! (shocked look)
> >
> > If you ever talked with him you would know what I mean.
>
> One look at the picture of himself he chose to put on his website tells the
> whole story. ;)
Too true. Although, the woman who works in his shop says that he is
great to work for. Go figure. I know of at least 3 roasters who walked
out of his shop swearing that they would never buy even a plastic spoon
from him. He's hung up on me when I was asking about pricing on his
machines. I had been warned and was on my best behaviour too.
Erik
|
| | | |
Date: 13 Oct 2006 09:52:20
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Too true. Although, the woman who works in his shop says that he is
> great to work for. Go figure. I know of at least 3 roasters who walked
> out of his shop swearing that they would never buy even a plastic spoon
> from him. He's hung up on me when I was asking about pricing on his
> machines. I had been warned and was on my best behaviour too.
A friend of mine is an I/O psychologist and her research shows that management
style has nothing to do with management effectiveness, so I'm not surprised.
Dan
|
| | |
Date: 09 Oct 2006 09:55:38
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> I am new to this so bear with me. When you say "Small triple-stage
> blowers (aka ShopVacs) have good pressure and flow," how small are we
> talking? Or rather, what is the largest triple stage blower that is
> easily obtained and what (aprox.) size batch of coffee beans would it
> keep aloft. My follow on to that is, what size triple stage blower
> (specs) would be required for 20-25lbs of beans? How many "inches of
> water" pressure and how much flow should I be looking for to roast that
> quantity of beans? -Wes
Wes, These are commonly called vacuum motors. I have used a large 3-stage unit
to power a modelmaker's vacuum former. Each stage adds about 45 inches of water
vacuum.
Check at www.grainger.com The largest I saw was an Ametek, (Grainger 4M922)
3-stage, 120VAC, 13.5A, 137 inches water, 101 cfm (with 2" orifice), $140
We don't yet know what pressure these units develop, and we are just now
figuring out the phsycial requirements of a spouting bed in this thread, so
can't answer any more of your questions.
I can say I doubt that the above vacuum motor could fluidize 20 pounds. Dan
|
| |
Date: 09 Oct 2006 05:44:05
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
That is pretty much what was niggling at me. I couldn't put into words
as succinctly though. I like it.
Thanks guys!
RobvL wrote:
> "Andy Schecter" <schecter@remove.me.rochester.rr.com> wrote in message
> news:V%iWg.7123$484.6432@twister.nyroc.rr.com...
> > RobvL wrote:
> > > Question is how much pressure is required to move X weight of beans? How
> > > much flow?
> >
> > The pressure required equals the weight of the beans divided by the
> > cross-sectional area of the chamber. Typical pressure required in a popper
> is
> > only 2" water column. Your blower may have to develop considerably more
> > depending on the bean load, diameter of chamber, and pressure losses in
> the
> > air delivery piping.
> > --
> >
> >
> > -Andy S.
> >
> > http://www.flickr.com/photos/andy_s/sets/
>
>
> Far too simple Andy couldn't possibly be true! Well colour me stupid, makes
> perfect sense. That being the case the pressure would relate to height of
> the column of beans regardless of diameter. That is if the area that is
> perforated is 2 sqr inches and the bean column 12" high then if the you
> change the perforated area to 4 sqr inches and the column remains at 12" the
> pressure required should be the same only the required air flow would need
> to be doubled. This would be regardless of the diameter of the roast chamber
> as only the beans above the perforated sectioned come into the equation.
> Thanx Andy.
>
> RobvL
> NZ
|
| |
Date: 08 Oct 2006 09:17:07
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Wow, he lives an hour away from me and the ironic part is that my wife
and I have been planning to go see him re chocolate for about a year
now. Do you think I am motivated now?
Thanks Johnny!
Johnny wrote:
> "Erik Groomer" <ViridianCoffee@gmail.com> wrote in message
> news:1160281854.314263.146330@c28g2000cwb.googlegroups.com...
> <snip/>
>
> > Johnny, are you "alchemist John"?
>
> not me.
>
> that'd be John Nanci who hangs on the SM mailing list:
> AlChemist at large
> Zen Roasting , Blending & Espresso pulling by Gestalt
> http://www.chocolatealchemy.com/
|
| | |
Date: 08 Oct 2006 13:12:36
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
John wrote back. He said that spreadsheet is based on a real, fluid bed
engineering. However, it is for a 'true' fluid bed where the entire bottom is
open, and not the 'spouting' or 'fountain' effect we are looking at. He didn't
think it would be easy to modify that spreadsheet to accomplish our goal and
said empirical methods would be the best route. So, back to the shop!
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1160324227.158236.122120@b28g2000cwb.googlegroups.com...
> Wow, he lives an hour away from me and the ironic part is that my wife
> and I have been planning to go see him re chocolate for about a year
> now. Do you think I am motivated now?
> Thanks Johnny!
>
> Johnny wrote:
>> "Erik Groomer" <ViridianCoffee@gmail.com> wrote in message
>> news:1160281854.314263.146330@c28g2000cwb.googlegroups.com...
>> <snip/>
>>
>> > Johnny, are you "alchemist John"?
>>
>> not me.
>>
>> that'd be John Nanci who hangs on the SM mailing list:
>> AlChemist at large
>> Zen Roasting , Blending & Espresso pulling by Gestalt
>> http://www.chocolatealchemy.com/
>
|
| |
Date: 07 Oct 2006 21:30:54
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
That's the one! I guess I should have been able to find that. Thanks.
Also, thanks to Dan for already sending it to me. I have to ask, is
this assuming a 4% open area at the bottom of the roast tube(with
reducing cone?)? I have played with some of the variables(weight and
tube diameter) and found interesting results. When tube diameter is
increased required cfm increases but static pressure decreases. Very
interesting. I guess you want to find a balance.
Johnny, are you "alchemist John"?
Johnny wrote:
> "Erik Groomer" <ViridianCoffee@gmail.com> wrote in message
> news:1160233436.935198.57650@m73g2000cwd.googlegroups.com...
> > This is all VERY interesting. Dan, could you send me the spreadsheet?
>
> perhaps it's the one on Ed' site
> http://www.homeroaster.com/intro1.html
> where it says
> Alchemist John's Fluidization Spreadsheet (Right click link to download)
|
| | |
Date: 08 Oct 2006 09:37:16
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Also, thanks to Dan for already sending it to me. I have to ask, is
> this assuming a 4% open area at the bottom of the roast tube(with
> reducing cone?)?
I have no idea. You'd have to ask Alchemist John. I think we are entering
unknown territory. At least, unpublished. It seems each of us experimenters know
bits and pieces, but not the whole deal. We should get together in my shop and
figure this out! Dan
|
| | | |
Date: 08 Oct 2006 09:45:13
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> I have no idea. You'd have to ask Alchemist John.
PS: I asked John, will copy reply here. Dan
|
| | |
Date: 07 Oct 2006 22:33:14
From: Johnny
Subject: Re: stainless steel pipe style coffee roaster
|
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1160281854.314263.146330@c28g2000cwb.googlegroups.com...
<snip/ >
> Johnny, are you "alchemist John"?
not me.
that'd be John Nanci who hangs on the SM mailing list:
AlChemist at large
Zen Roasting , Blending & Espresso pulling by Gestalt
http://www.chocolatealchemy.com/
|
| |
Date: 07 Oct 2006 18:22:38
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Where did the magic 2-4% open area number come from? I tried SS mesh as
well but found that the beans did not flow well across it into the air
stream. Or at least that is what I attributed the poor movement to.
Rob, I totally agree that blowing the beans out is much better than
sucking them out.
Dang, this thread rocks!
|
| |
Date: 07 Oct 2006 08:03:56
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
This is all VERY interesting. Dan, could you send me the spreadsheet?
I've been doing the guess and golly method. I should have my regen
hooked up in the next couple of weeks. Someone bought the one I am
using now. I have a 1hp regen and a High Pressure Fuji 2.6hp which I
hope will do the job. Also, I am not too concerned about heat. I just
don't want to melt the insulation on my hi-temp wire going to the
heating elements.
Erik
Dan Bollinger wrote:
> > Question is how much pressure is required to move X weight of beans? How
> > much flow?
>
> I looked at the spreadsheet, it said, for a 6" diameter chamber holding 500g
> beans, you'd need 28 cfm at 1.0" water.
>
> It shows that the airflow (cfm) remains the same for a given diameter of
> chamber regardless of the mass, but that the pressure rises with the mass.
>
> My blower develops 2" water, so it seems it will loft 1kg, but have a lot of
> excess airflow. If true, then a higher pressure blower is needed for larger
> roasts, making Erik's regen blower now look attractive.
>
> However, although his regen could theoretically loft 20kg of beans, because of
> its low flow, you would be stuck using a 5-6" diameter chamber. Loaded with 20kg
> of beans would make it VERY tall.
>
> So, we are back to the same problem. One blower having insufficient pressure,
> and the other insufficient flow.
>
> All blowers have an airflow/pressure curve. If you operated the regen at lower
> pressure you gain a little airflow. Enough to make it work? I checked the stats
> on a Fuji 1/2Hp regen, model VFC300P-5T. At 20" water, it could loft 10kg of
> beans (about 6 pounds) using 46cfm. I'm guessing that that airflow would work
> in an 8-9" roasting chamber. The output/input of the regen is 1.25 pipe, which
> is about right for your 2-4% bottom opening specification.
>
> Of course, a regen larger than 1/2Hp could be used, too. When do you think
> you'll get around to testing your regen?
>
> Dan
>
> PS: I got all this information from a Grainger catalog.
|
| | |
Date: 07 Oct 2006 20:14:45
From: Johnny
Subject: Re: stainless steel pipe style coffee roaster
|
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1160233436.935198.57650@m73g2000cwd.googlegroups.com...
> This is all VERY interesting. Dan, could you send me the spreadsheet?
perhaps it's the one on Ed' site
http://www.homeroaster.com/intro1.html
where it says
Alchemist John's Fluidization Spreadsheet (Right click link to download)
|
| | | |
Date: 08 Oct 2006 09:25:36
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
Yes, that's it! Good to know who the author was, now I can credit him.
"Johnny" <removethis.huuanito@hotmail.com > wrote in message
news:H2_Vg.989$UJ2.844@fed1read07...
>
> "Erik Groomer" <ViridianCoffee@gmail.com> wrote in message
> news:1160233436.935198.57650@m73g2000cwd.googlegroups.com...
>> This is all VERY interesting. Dan, could you send me the spreadsheet?
>
> perhaps it's the one on Ed' site
> http://www.homeroaster.com/intro1.html
> where it says
> Alchemist John's Fluidization Spreadsheet (Right click link to download)
>
>
>
>
|
| |
Date: 06 Oct 2006 05:39:26
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
RobvL wrote:
> What is a "regenerative" blower?
>
Also known as a ring compressor.
http://www.fujielectric.com/ringc/rcblower.htm
They build more pressure.
I'll look forward to seeing whatever pics you can find. I've started
working on a larger scale poppery II type chamber to allow me to get
the beans out without vacuuming. It's going to be tricky to be able to
move any amount of beans though. I might try a modified sivetz design
instead.
Are you actually in New Zealand?
Erik
|
| | |
Date: 13 Oct 2006 05:42:48
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
RobvL wrote:
Who is to say that the
> S*vetz roaster setup is optimum.
You would question THE MAN???!!! (shocked look)
If you ever talked with him you would know what I mean.
|
| | | |
Date: 13 Oct 2006 09:16:42
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> You would question THE MAN???!!! (shocked look)
>
> If you ever talked with him you would know what I mean.
One look at the picture of himself he chose to put on his website tells the
whole story. ;)
|
| | |
Date: 07 Oct 2006 16:57:22
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1160138366.244267.289530@k70g2000cwa.googlegroups.com...
>
> RobvL wrote:
> > What is a "regenerative" blower?
> >
>
> Also known as a ring compressor.
> http://www.fujielectric.com/ringc/rcblower.htm
>
> They build more pressure.
>
> I'll look forward to seeing whatever pics you can find. I've started
> working on a larger scale poppery II type chamber to allow me to get
> the beans out without vacuuming. It's going to be tricky to be able to
> move any amount of beans though. I might try a modified sivetz design
> instead.
>
> Are you actually in New Zealand?
>
> Erik
Ah a compressor lots of pressure but enough flow?
I will probably email you the pics. With my roaster if i want i can blow the
beans out which is easier than vacuuming them out IMO.
Yup in New Zealand.
Rob vL
NZ
|
| | | |
Date: 08 Oct 2006 20:25:39
From: Brent
Subject: Re: stainless steel pipe style coffee roaster
|
well actually in Christchurch, which is more an honourary part of NZ - NZ
officially stops at the Bombay Hills, everything south of there is like a
soveriegn territory...
:)
Brent
(lives near the Bombay Hills, so is considered a southerner)
>> Are you actually in New Zealand?
>>
>> Erik
>
> Yup in New Zealand.
>
> Rob vL
> NZ
>
>
|
| | | | |
Date: 09 Oct 2006 22:37:33
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
You've lived and worked in Auckland too long Brent, time to move somewhere
real. ;-)
Rob
"Brent" <me@privacy.net > wrote in message
news:4ornfpFft4bhU1@individual.net...
> well actually in Christchurch, which is more an honourary part of NZ - NZ
> officially stops at the Bombay Hills, everything south of there is like a
> soveriegn territory...
>
> :)
>
> Brent
> (lives near the Bombay Hills, so is considered a southerner)
>
>
> >> Are you actually in New Zealand?
> >>
> >> Erik
> >
> > Yup in New Zealand.
> >
> > Rob vL
> > NZ
> >
> >
>
>
|
| | | | | |
Date: 10 Oct 2006 10:01:13
From: Brent
Subject: Re: stainless steel pipe style coffee roaster
|
Like (d)Auckland central you mean?
It would be closer to the office...
The view wouldn't be as good.
:)
Brent
> You've lived and worked in Auckland too long Brent, time to move somewhere
> real. ;-)
>
> Rob
>
>
>> well actually in Christchurch, which is more an honourary part of NZ - NZ
>> officially stops at the Bombay Hills, everything south of there is like a
>> soveriegn territory...
>>
>> :)
>>
>> Brent
>> (lives near the Bombay Hills, so is considered a southerner)
>>
>>
>> >> Are you actually in New Zealand?
>> >>
>> >> Erik
>> >
>> > Yup in New Zealand.
>> >
>> > Rob vL
>> > NZ
>> >
>> >
>>
>>
>
>
|
| | |
Date: 06 Oct 2006 10:00:32
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
>> What is a "regenerative" blower?
>>
> They build more pressure.
A 1/2 Hp regen develops about 40-50 inches of water and 20-25 cfm.
The 1/2Hp single-stage centrifugal blowers (7-9" wheels) I have develop about
3-5 inches of water and 150-175 cfm.
It takes pressure to lift that bean mass, and it takes airflow (cfm) to keep it
lofted once the beans separate and air leaks by. It is this balance of pressure
and flow that is required.
For instance, a plain 20" breeze box fan laid flat develops plenty of airflow,
but does not develop enough pressure to loft the beans.
I suspect you will find that the regen has more than enough pressure to lift a
column of beans, but won't be able to keep them lofted because it does not
develop enough airflow. The inlet on a lot of regens are pipe thread, pretty
small hole for all your air to go through.
Small triple-stage blowers (aka ShopVacs) have good pressure and flow for this
application, but you can't buy large units, which is what we need for roasting
larger batches.
So, in my opinion, we are left with using larger diameter single-stage blowers
like the one I mentioned from Graingers seem to be better suited, but as yet
untested.
Ed may be on the right track using a multi-stage blower from a whole-house
vacuum system.
When in doubt, get a blower with more flow, since you can always throttle that
down.
Dan
> I'll look forward to seeing whatever pics you can find. I've started
> working on a larger scale poppery II type chamber to allow me to get
> the beans out without vacuuming. It's going to be tricky to be able to
> move any amount of beans though. I might try a modified sivetz design
> instead.
>
> Are you actually in New Zealand?
>
> Erik
>
|
| | | |
Date: 07 Oct 2006 22:01:29
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Dan Bollinger" <danNObollinger@insightSPAMbb.com > wrote in message
news:sfednciXjPcS_LvYnZ2dnUVZ_sidnZ2d@insightbb.com...
> >> What is a "regenerative" blower?
> >>
> > They build more pressure.
>
> A 1/2 Hp regen develops about 40-50 inches of water and 20-25 cfm.
>
> The 1/2Hp single-stage centrifugal blowers (7-9" wheels) I have develop
about
> 3-5 inches of water and 150-175 cfm.
>
> It takes pressure to lift that bean mass, and it takes airflow (cfm) to
keep it
> lofted once the beans separate and air leaks by. It is this balance of
pressure
> and flow that is required.
>
> For instance, a plain 20" breeze box fan laid flat develops plenty of
airflow,
> but does not develop enough pressure to loft the beans.
>
> I suspect you will find that the regen has more than enough pressure to
lift a
> column of beans, but won't be able to keep them lofted because it does not
> develop enough airflow. The inlet on a lot of regens are pipe thread,
pretty
> small hole for all your air to go through.
>
> Small triple-stage blowers (aka ShopVacs) have good pressure and flow for
this
> application, but you can't buy large units, which is what we need for
roasting
> larger batches.
>
> So, in my opinion, we are left with using larger diameter single-stage
blowers
> like the one I mentioned from Graingers seem to be better suited, but as
yet
> untested.
>
> Ed may be on the right track using a multi-stage blower from a whole-house
> vacuum system.
>
> When in doubt, get a blower with more flow, since you can always throttle
that
> down.
>
> Dan
>
Thanx for the explanation Dan.
Question is how much pressure is required to move X weight of beans? How
much flow? To date my way of working it out is to suck it and see. Which
means guesstimating. I do seem to recall someone posting data here once, did
a search for it but couldn't find it.
If i was to guesstimate the right size blower for a 7kg roaster it would be
a 1500 watt motor (speed approx 3000rpm) driving a blower with a 9 or 10"
impellor with backward curved blades. Assuming it developed suitable
pressure, the minimum of which i'm not sure.
Once i have mocked up the 7kg roast chamber i will test it with a couple or
3 "vacuum" blowers, then take it to a fan supplier who will work out the
required blower to do the job. I'm probably gonna go for a 3 phase motor and
use a micro controller or similar to control the speed. Yeah that was my
thought too, get a blower with some in reserve and throttle it back. Then it
might even be good if i decide to build 12 kg roaster. ;-)
Rob
|
| | | | |
Date: 09 Oct 2006 03:05:25
From: Andy Schecter
Subject: Re: stainless steel pipe style coffee roaster
|
RobvL wrote:
> Question is how much pressure is required to move X weight of beans? How
> much flow?
The pressure required equals the weight of the beans divided by the
cross-sectional area of the chamber. Typical pressure required in a popper is
only 2" water column. Your blower may have to develop considerably more
depending on the bean load, diameter of chamber, and pressure losses in the
air delivery piping.
--
-Andy S.
http://www.flickr.com/photos/andy_s/sets/
|
| | | | | |
Date: 09 Oct 2006 19:37:47
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Andy Schecter" <schecter@remove.me.rochester.rr.com > wrote in message
news:V%iWg.7123$484.6432@twister.nyroc.rr.com...
> RobvL wrote:
> > Question is how much pressure is required to move X weight of beans? How
> > much flow?
>
> The pressure required equals the weight of the beans divided by the
> cross-sectional area of the chamber. Typical pressure required in a popper
is
> only 2" water column. Your blower may have to develop considerably more
> depending on the bean load, diameter of chamber, and pressure losses in
the
> air delivery piping.
> --
>
>
> -Andy S.
>
> http://www.flickr.com/photos/andy_s/sets/
Far too simple Andy couldn't possibly be true! Well colour me stupid, makes
perfect sense. That being the case the pressure would relate to height of
the column of beans regardless of diameter. That is if the area that is
perforated is 2 sqr inches and the bean column 12" high then if the you
change the perforated area to 4 sqr inches and the column remains at 12" the
pressure required should be the same only the required air flow would need
to be doubled. This would be regardless of the diameter of the roast chamber
as only the beans above the perforated sectioned come into the equation.
Thanx Andy.
RobvL
NZ
|
| | | | | | |
Date: 09 Oct 2006 09:21:39
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
>> The pressure required equals the weight of the beans divided by the
>> cross-sectional area of the chamber. Typical pressure required in a popper
> is
>> only 2" water column. Your blower may have to develop considerably more
>> depending on the bean load, diameter of chamber, and pressure losses in
> the
>> air delivery piping.
>> --
>>
>>
>> -Andy S.
>>
>> http://www.flickr.com/photos/andy_s/sets/
>
>
> Far too simple Andy couldn't possibly be true! Well colour me stupid, makes
> perfect sense. That being the case the pressure would relate to height of
> the column of beans regardless of diameter. That is if the area that is
> perforated is 2 sqr inches and the bean column 12" high then if the you
> change the perforated area to 4 sqr inches and the column remains at 12" the
> pressure required should be the same only the required air flow would need
> to be doubled. This would be regardless of the diameter of the roast chamber
> as only the beans above the perforated sectioned come into the equation.
> Thanx Andy.
Think of the bed as a leaky piston in a cylinder and the factors fall into place
quickly.
That is essentially what Alchemist John's spreadsheet says if you look at it.
He goes a little further and deals with the fact that the beans are not
spherical and that effects the outcome, too. It even allows for temperature of
the air, but this is a minor factor. He said that the spreadsheet is what
engineers use for large fluid beds. On large beds, friction with the sidewall is
next to nil, but not so in our itty-bitty 6" chambers.
As a reminder, what the spreadsheet, Andy, Rob, and Erik are talking about here
is a 'true' fluid bed, where the entire chamber floor is one, large orifice.
What is used on coffee roasters is what I call a 'spouting bed'. This is used
because it keeps the bed moving and mixing, while using less airflow. Less
airflow, less heat required.
So, take those calculations and redo them a bit. I figure, since the spouting
column is rubbing against non-moving beans, there is a lot of additional
friction, so you need to increase your pressure for any given bed height, say
30-50%. However, you can reduce your airflow by a factor of 10 or so, I'd
guess.
Dan
|
| | | | | | | |
Date: 12 Oct 2006 02:16:28
From: Andy Schecter
Subject: Re: stainless steel pipe style coffee roaster
|
Dan Bollinger wrote:
> As a reminder, what the spreadsheet, Andy, Rob, and Erik are talking
> about here is a 'true' fluid bed, where the entire chamber floor is one,
> large orifice. What is used on coffee roasters is what I call a
> 'spouting bed'. This is used because it keeps the bed moving and mixing,
> while using less airflow. Less airflow, less heat required.
An important distinction.
I believe there may be some other subtleties at work here, and this seems like
a good time to add them to this interesting thread.
1) As home roasting fanatics, we are not only looking to build an efficient
roaster as cleverly as possible, but we're also (of course) desiring the best
possible roast quality.
In a spouting bed, each individual bean rapidly moves in and out of the heated
air "spout." So you would surmise that each bean receives a rapid _succession_
of heat _pulses_ rather than a steadier, smoother heat buildup. That is
undoubtedly an oversimplification, but there is probably be some truth to it.
Is this a negative factor in terms of roast quality? If it is a negative, then
a true fluid bed would presumably give a smoother heat buildup and a better
roast. And a spouting bed with a higher "spout percentage" of the whole might
have a quality advantage.
It would also seem that a true fluid bed would allow any predetermined bean
temperature profile to proceed at a lower environmental (hot air) temperature,
and that's supposed to be good for roast quality.
2) OTOH, one of the benefits of the spouting bed is that the non-spouting
locations in the roast chamber provide ideal locations for a bean temp sensing
thermocouple. Because these areas are out of the main heated airflow, the
thermocouple reading will be much less influenced by the heated air and will
more accurately reflect the true external bean temp. This always seemed to me
to be a plus in favor of Sivetz' original asymmetrical roast chamber
If one roasts strictly by sound, smell and color, then accurately measuring
bean temp is not an issue. But those of us who wish to move in the direction
of digital control of the roast process require accurate bean temp measurement.
--
-Andy S.
http://www.flickr.com/photos/andy_s/sets/
|
| | | | | | | | |
Date: 12 Oct 2006 23:36:32
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Andy Schecter" <schecter@remove.me.rochester.rr.com > wrote in message
news:0AhXg.6320$0L1.3579@twister.nyroc.rr.com...
> Dan Bollinger wrote:
> > As a reminder, what the spreadsheet, Andy, Rob, and Erik are talking
> > about here is a 'true' fluid bed, where the entire chamber floor is one,
> > large orifice. What is used on coffee roasters is what I call a
> > 'spouting bed'. This is used because it keeps the bed moving and mixing,
> > while using less airflow. Less airflow, less heat required.
>
>
> An important distinction.
>
> I believe there may be some other subtleties at work here, and this seems
like
> a good time to add them to this interesting thread.
>
> 1) As home roasting fanatics, we are not only looking to build an
efficient
> roaster as cleverly as possible, but we're also (of course) desiring the
best
> possible roast quality.
>
> In a spouting bed, each individual bean rapidly moves in and out of the
heated
> air "spout." So you would surmise that each bean receives a rapid
_succession_
> of heat _pulses_ rather than a steadier, smoother heat buildup. That is
> undoubtedly an oversimplification, but there is probably be some truth to
it.
>
> Is this a negative factor in terms of roast quality? If it is a negative,
then
> a true fluid bed would presumably give a smoother heat buildup and a
better
> roast. And a spouting bed with a higher "spout percentage" of the whole
might
> have a quality advantage.
I have thought the same thing Andy, aiming for a minimum of 25% for the
spouting area for future roast chambers. Having roasted alot of coffee with
this type of roaster i don't think the pulsed heat thing is an issue. Hard
to test let alone prove one way or the other.
I placed a red painted bean in the mass and tested it cold a couple of years
ago i counted how often the bean blew up thru the column can't remember what
the numbers were. But simply if the spouting area or weight of beans above
the perf plate is 25% then they are going to be in the heated column 25% of
the time.
> It would also seem that a true fluid bed would allow any predetermined
bean
> temperature profile to proceed at a lower environmental (hot air)
temperature,
> and that's supposed to be good for roast quality.
Possibly but IIRC Sivetz claims lower MET temps (or inflow temps) than for
many drum roasters.
>
> 2) OTOH, one of the benefits of the spouting bed is that the non-spouting
> locations in the roast chamber provide ideal locations for a bean temp
sensing
> thermocouple. Because these areas are out of the main heated airflow, the
> thermocouple reading will be much less influenced by the heated air and
will
> more accurately reflect the true external bean temp. This always seemed to
me
> to be a plus in favor of Sivetz' original asymmetrical roast chamber
Yup i like this feature heaps. Real easy to profile roasts and get
consistency.
> If one roasts strictly by sound, smell and color, then accurately
measuring
> bean temp is not an issue. But those of us who wish to move in the
direction
> of digital control of the roast process require accurate bean temp
measurement.
Yup thats the way i'm heading - better digital control, i don't even look at
the beans any more while they are roasting, the temp and the cracks are all
i need. I base my profiling on the rate of change not the actual temp.
Rob
|
| | | | | | | | | |
Date: 12 Oct 2006 08:00:27
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> I placed a red painted bean in the mass and tested it cold a couple of years
> ago i counted how often the bean blew up thru the column can't remember what
> the numbers were.
I've used the same trick to measure 'mixing', too. Simple, but effective!
Makes you wonder what the optimal mixing ratio is.
> But simply if the spouting area or weight of beans above
> the perf plate is 25% then they are going to be in the heated column 25% of
> the time.
This is sorta like the deal of running or walking through the rain, which is
wetter? Since the spouting portion is traveling many times faster than the
remaining 25% (which is moving at a snail's crawl), the time a bean is in the
spouting column is going to be closer to 2.5% than 25% of the time.
> Possibly but IIRC Sivetz claims lower MET temps (or inflow temps) than for
> many drum roasters.
I've heard this too, and considering the increased air speed believe it to be
true. Just as a convection oven, because the air is moving much faster it is
heating better, you can reduce the temperature setting on the thermostat.
> Yup i like this feature heaps. Real easy to profile roasts and get
> consistency.
I thought it was Gardfoods 'Roller Roaster' that uses this. Is this a Sivetz
invention or theirs? http://www.gardfoods.com/coffee/coffee.roaster.htm
I now have a manometer and am half way through building a spouting bed test bed.
Dan
|
| | | | | | | | | | |
Date: 13 Oct 2006 23:29:13
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Dan Bollinger" <danNObollinger@insightSPAMbb.com > wrote in message
news:g66dnW9-F5cBs7PYnZ2dnUVZ_qSdnZ2d@insightbb.com...
> This is sorta like the deal of running or walking through the rain, which
is
> wetter? Since the spouting portion is traveling many times faster than
the
> remaining 25% (which is moving at a snail's crawl), the time a bean is in
the
> spouting column is going to be closer to 2.5% than 25% of the time.
If it takes 1.5 seconds for 25% of the beans to pass thru the spouting
portion then the remaining 75% should take 4.5 seconds, least ways thats the
way i see it, thus 25% of the time?
> > Possibly but IIRC Sivetz claims lower MET temps (or inflow temps) than
for
> > many drum roasters.
>
> I've heard this too, and considering the increased air speed believe it to
be
> true. Just as a convection oven, because the air is moving much faster it
is
> heating better, you can reduce the temperature setting on the thermostat.
>
> > Yup i like this feature heaps. Real easy to profile roasts and get
> > consistency.
>
> I thought it was Gardfoods 'Roller Roaster' that uses this. Is this a
Sivetz
> invention or theirs? http://www.gardfoods.com/coffee/coffee.roaster.htm
Sivetz patented this in the 70s (IINM), the patent ran out a few years ago.
Rob
>
> I now have a manometer and am half way through building a spouting bed
test bed.
Be very interested to see the figures
Rob
|
| | | | | | | | | | | |
Date: 13 Oct 2006 08:43:58
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Be very interested to see the figures
Me, too. It should tell us everything we need to know about blower and orifice
selection given a certain depth of beans.
|
| | | | | | | | |
Date: 11 Oct 2006 22:38:01
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> I believe there may be some other subtleties at work here, and this seems like
> a good time to add them to this interesting thread.
Excellent points, Andy. Certainly, different machine types, drum, fluid bed,
spouting bed, etc. each influence the roast profile differently. I don't presume
to say that one is better than the other. The main advantage of a spouting bed
over a fluid bed is its lower blower and energy costs.
Dan
|
| | | | | | | | | |
Date: 12 Oct 2006 00:01:00
From: Ed Needham
Subject: Re: stainless steel pipe style coffee roaster
|
On my Hearthware Precision roaster, which is a spouting bed roaster, I would
guess that the ambient temp inside the roast chamber is not much less than
the temp of the air column. I have not measured the temp of the roast
chamber itself, but the air column, according to Hearthware, is set for
500F. So that means that if the roast chamber is 50F less (a guess), then
it's still hot enough to adequately roast beans. The variable heat might be
a plus or minus, but the Precision does a decent job of roasting.
--
*********************
Ed Needham®
"to absurdity and beyond!"
http://www.homeroaster.com
(include [FRIEND] in subject line to get through my SPAM filters)
*********************
"Dan Bollinger" <danNObollinger@insightSPAMbb.com > wrote in message
news:jeednaG4h8oXN7DYnZ2dnUVZ_rqdnZ2d@insightbb.com...
>> I believe there may be some other subtleties at work here, and this seems
>> like a good time to add them to this interesting thread.
>
>
> Excellent points, Andy. Certainly, different machine types, drum, fluid
> bed, spouting bed, etc. each influence the roast profile differently. I
> don't presume to say that one is better than the other. The main
> advantage of a spouting bed over a fluid bed is its lower blower and
> energy costs.
>
> Dan
|
| | | | | | | | | | |
Date: 12 Oct 2006 01:03:47
From: Craig Andrews
Subject: Re: stainless steel pipe style coffee roaster
|
"Ed Needham" <ed@NOSPAMhomeroaster.com > wrote in message
news:_cOdnaxoxPNlILDYnZ2dnUVZ_r6dnZ2d@insightbb.com...
> On my Hearthware Precision roaster, which is a spouting bed roaster, I
> would guess that the ambient temp inside the roast chamber is not much
> less than the temp of the air column. I have not measured the temp of
> the roast chamber itself, but the air column, according to Hearthware,
> is set for 500F. So that means that if the roast chamber is 50F less
> (a guess), then it's still hot enough to adequately roast beans. The
> variable heat might be a plus or minus, but the Precision does a
> decent job of roasting.
> --
> *********************
> Ed Needham®
> "to absurdity and beyond!"
> http://www.homeroaster.com
> (include [FRIEND] in subject line to get through my SPAM filters)
> *********************
Ed, I started out Homeroasting with a Hearthware Precision & I
absolutely love mine. It's still workin' like a champ since 1/01, 5
years 7 months plus! with 634 roasts on it!!
Cheers!
Craig.
|
| | | | | | | | | | | |
Date: 12 Oct 2006 07:48:49
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Ed, I started out Homeroasting with a Hearthware Precision & I
> absolutely love mine. It's still workin' like a champ since 1/01, 5
> years 7 months plus! with 634 roasts on it!!
> Cheers!
Man, that's gotta be some kinda record!
|
| | | | | | | | | | | | |
Date: 12 Oct 2006 12:41:43
From: Craig Andrews
Subject: Re: stainless steel pipe style coffee roaster
|
"Dan Bollinger" <danNObollinger@insightSPAMbb.com > wrote in message
news:O9ednQEJ4uc_trPYnZ2dnUVZ_vGdnZ2d@insightbb.com...
>> Ed, I started out Homeroasting with a Hearthware Precision & I
>> absolutely love mine. It's still workin' like a champ since 1/01,
>> 5 years 7 months plus! with 634 roasts on it!!
>> Cheers!
>
> Man, that's gotta be some kinda record!
lol, thanks Dan! {;-) There'd be a LOT more roasts on it too, if it
weren't for my Alp, Bravi, SC/GG (Stir Crazy Galloping Gourmet), BBQ
roaster! {;-D
Craig.
|
| | | | | | | |
Date: 11 Oct 2006 21:23:21
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Dan Bollinger" <danNObollinger@insightSPAMbb.com > wrote in message
news:3PCdnTkavat40bfYnZ2dnUVZ_vKdnZ2d@insightbb.com...
> >> The pressure required equals the weight of the beans divided by the
> >> cross-sectional area of the chamber. Typical pressure required in a
popper
> > is
> >> only 2" water column. Your blower may have to develop considerably more
> >> depending on the bean load, diameter of chamber, and pressure losses in
> > the
> >> air delivery piping.
> >> --
> >>
> >>
> >> -Andy S.
> >>
> >> http://www.flickr.com/photos/andy_s/sets/
> >
> >
> > Far too simple Andy couldn't possibly be true! Well colour me stupid,
makes
> > perfect sense. That being the case the pressure would relate to height
of
> > the column of beans regardless of diameter. That is if the area that is
> > perforated is 2 sqr inches and the bean column 12" high then if the you
> > change the perforated area to 4 sqr inches and the column remains at 12"
the
> > pressure required should be the same only the required air flow would
need
> > to be doubled. This would be regardless of the diameter of the roast
chamber
> > as only the beans above the perforated sectioned come into the equation.
> > Thanx Andy.
>
> Think of the bed as a leaky piston in a cylinder and the factors fall into
place
> quickly.
>
> That is essentially what Alchemist John's spreadsheet says if you look at
it.
> He goes a little further and deals with the fact that the beans are not
> spherical and that effects the outcome, too. It even allows for
temperature of
> the air, but this is a minor factor. He said that the spreadsheet is what
> engineers use for large fluid beds. On large beds, friction with the
sidewall is
> next to nil, but not so in our itty-bitty 6" chambers.
>
> As a reminder, what the spreadsheet, Andy, Rob, and Erik are talking about
here
> is a 'true' fluid bed, where the entire chamber floor is one, large
orifice.
> What is used on coffee roasters is what I call a 'spouting bed'. This is
used
> because it keeps the bed moving and mixing, while using less airflow. Less
> airflow, less heat required.
>
> So, take those calculations and redo them a bit. I figure, since the
spouting
> column is rubbing against non-moving beans, there is a lot of additional
> friction, so you need to increase your pressure for any given bed height,
say
> 30-50%. However, you can reduce your airflow by a factor of 10 or so, I'd
> guess.
>
> Dan
>
This is what i figured too Dan, add 50% to give it some in reserve. Plus it
takes a little extra to get the beans moving once moving the control can be
turned down a little. Actually i do recall saving that spread sheet at some
stage. It wasn't that i could find, it was just that i couldn't make it work
for my application, thinking different now.
Rob
|
| | | | |
Date: 07 Oct 2006 09:52:36
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Question is how much pressure is required to move X weight of beans? How
> much flow?
I looked at the spreadsheet, it said, for a 6" diameter chamber holding 500g
beans, you'd need 28 cfm at 1.0" water.
It shows that the airflow (cfm) remains the same for a given diameter of
chamber regardless of the mass, but that the pressure rises with the mass.
My blower develops 2" water, so it seems it will loft 1kg, but have a lot of
excess airflow. If true, then a higher pressure blower is needed for larger
roasts, making Erik's regen blower now look attractive.
However, although his regen could theoretically loft 20kg of beans, because of
its low flow, you would be stuck using a 5-6" diameter chamber. Loaded with 20kg
of beans would make it VERY tall.
So, we are back to the same problem. One blower having insufficient pressure,
and the other insufficient flow.
All blowers have an airflow/pressure curve. If you operated the regen at lower
pressure you gain a little airflow. Enough to make it work? I checked the stats
on a Fuji 1/2Hp regen, model VFC300P-5T. At 20" water, it could loft 10kg of
beans (about 6 pounds) using 46cfm. I'm guessing that that airflow would work
in an 8-9" roasting chamber. The output/input of the regen is 1.25 pipe, which
is about right for your 2-4% bottom opening specification.
Of course, a regen larger than 1/2Hp could be used, too. When do you think
you'll get around to testing your regen?
Dan
PS: I got all this information from a Grainger catalog.
|
| | | | |
Date: 07 Oct 2006 06:30:40
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Thanx for the explanation Dan.
>
> Question is how much pressure is required to move X weight of beans? How
> much flow? To date my way of working it out is to suck it and see. Which
> means guesstimating. I do seem to recall someone posting data here once, did
> a search for it but couldn't find it.
> If i was to guesstimate the right size blower for a 7kg roaster it would be
> a 1500 watt motor (speed approx 3000rpm) driving a blower with a 9 or 10"
> impellor with backward curved blades. Assuming it developed suitable
> pressure, the minimum of which i'm not sure.
> Once i have mocked up the 7kg roast chamber i will test it with a couple or
> 3 "vacuum" blowers, then take it to a fan supplier who will work out the
> required blower to do the job. I'm probably gonna go for a 3 phase motor and
> use a micro controller or similar to control the speed. Yeah that was my
> thought too, get a blower with some in reserve and throttle it back. Then it
> might even be good if i decide to build 12 kg roaster. ;-)
>
> Rob
Someone made a spreadsheet for calculating the flow requirements. I have a copy
if you want. Unfortunately, it stops at 500g, but you could probably extend
that. Dan
|
| |
Date: 05 Oct 2006 15:01:30
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Dan, I didn't know that regens run hot. I haven't tested mine yet.
Erik
On Oct 5, 6:20 am, "Dan Bollinger" <danNObollin...@insightSPAMbb.com >
wrote:
> I've been looking at those. How much weight of beans do you think that
> fan will move?
> Erik
>
> Erik, I don't know. I've been wanting to jury-rig a test. I wouldn't be
> surprised to see 5 pounds lofted. I have the smallest model, the 7.5" wh=
eel.
> One could always go larger, if needed. Connect one of these up with one o=
f those
> million BTU weedburner/turkeyfryer burners and you'd have something large=
and
> quick.
>
> These are much cheaper than a regen, and regens run hot.
>
> Dan
>
> Dan Bollinger wrote:
> > > You guys are making me want to go out and finish my 2 pound air roast=
er that
> > > has been about 90% complete for several years. Drum roasting just st=
ole my
> > > heart. It's hard to beat effortless five pound batches...and near si=
lence
> > > except for the churning of the beans.
>
> > You and me, both, Ed! I am now the proud owner of a used high pressure=
blower
> > that should loft a fair amount of beans. It is a Dayton, 1/2Hp, develo=
ps 157
> > cfm at 2". Blower can be reversed and oriented every 45=B0
>=20
> > Searchhttp://www.grainger.com/ for item number 2C940
>=20
> > Dan
|
| | |
Date: 06 Oct 2006 09:55:09
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
Some people use them as hot air dryers! Internally, the air is bounced back and
forth between impeller vanes and stator vanes creating turbulence, hence
friction, hence heat. I hope you test yours so we have some idea what size
chamber and load it will loft. Dan
Dan, I didn't know that regens run hot. I haven't tested mine yet.
Erik
On Oct 5, 6:20 am, "Dan Bollinger" <danNObollin...@insightSPAMbb.com >
wrote:
> I've been looking at those. How much weight of beans do you think that
> fan will move?
> Erik
>
> Erik, I don't know. I've been wanting to jury-rig a test. I wouldn't be
> surprised to see 5 pounds lofted. I have the smallest model, the 7.5" wheel.
> One could always go larger, if needed. Connect one of these up with one of
> those
> million BTU weedburner/turkeyfryer burners and you'd have something large and
> quick.
>
> These are much cheaper than a regen, and regens run hot.
>
> Dan
>
> Dan Bollinger wrote:
> > > You guys are making me want to go out and finish my 2 pound air roaster
> > > that
> > > has been about 90% complete for several years. Drum roasting just stole
> > > my
> > > heart. It's hard to beat effortless five pound batches...and near silence
> > > except for the churning of the beans.
>
> > You and me, both, Ed! I am now the proud owner of a used high pressure
> > blower
> > that should loft a fair amount of beans. It is a Dayton, 1/2Hp, develops
> > 157
> > cfm at 2". Blower can be reversed and oriented every 45°
>
> > Searchhttp://www.grainger.com/ for item number 2C940
>
> > Dan
|
| |
Date: 05 Oct 2006 05:35:02
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
I've been looking at those. How much weight of beans do you think that
fan will move?
Erik
Dan Bollinger wrote:
> > You guys are making me want to go out and finish my 2 pound air roaster=
that
> > has been about 90% complete for several years. Drum roasting just stol=
e my
> > heart. It's hard to beat effortless five pound batches...and near sile=
nce
> > except for the churning of the beans.
>
> You and me, both, Ed! I am now the proud owner of a used high pressure b=
lower
> that should loft a fair amount of beans. It is a Dayton, 1/2Hp, develops=
157
> cfm at 2". Blower can be reversed and oriented every 45=B0
>=20
> Search http://www.grainger.com/ for item number 2C940
>=20
> Dan
|
| | |
Date: 05 Oct 2006 09:20:42
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
I've been looking at those. How much weight of beans do you think that
fan will move?
Erik
Erik, I don't know. I've been wanting to jury-rig a test. I wouldn't be
surprised to see 5 pounds lofted. I have the smallest model, the 7.5" wheel.
One could always go larger, if needed. Connect one of these up with one of those
million BTU weedburner/turkeyfryer burners and you'd have something large and
quick.
These are much cheaper than a regen, and regens run hot.
Dan
Dan Bollinger wrote:
> > You guys are making me want to go out and finish my 2 pound air roaster that
> > has been about 90% complete for several years. Drum roasting just stole my
> > heart. It's hard to beat effortless five pound batches...and near silence
> > except for the churning of the beans.
>
> You and me, both, Ed! I am now the proud owner of a used high pressure blower
> that should loft a fair amount of beans. It is a Dayton, 1/2Hp, develops 157
> cfm at 2". Blower can be reversed and oriented every 45°
>
> Search http://www.grainger.com/ for item number 2C940
>
> Dan
|
| | | |
Date: 06 Oct 2006 23:58:50
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
Yup keen to see how much your unit will loft too. I see from the Grainger
site that blower doesn't have a motor, did you have to buy that separately?
I have mocked up roast chambers in wood and plastic to test how well the
beans loft and rotate. Gotta do that with my 7kg roast chamber. Need to work
out the right size blower for 7kg.
Rob
"Dan Bollinger" <danNObollinger@insightSPAMbb.com > wrote in message
news:I5mdne9DErY2m7jYnZ2dnUVZ_tKdnZ2d@insightbb.com...
> I've been looking at those. How much weight of beans do you think that
> fan will move?
> Erik
>
> Erik, I don't know. I've been wanting to jury-rig a test. I wouldn't be
> surprised to see 5 pounds lofted. I have the smallest model, the 7.5"
wheel.
> One could always go larger, if needed. Connect one of these up with one of
those
> million BTU weedburner/turkeyfryer burners and you'd have something large
and
> quick.
>
> These are much cheaper than a regen, and regens run hot.
>
> Dan
>
>
>
>
>
> Dan Bollinger wrote:
> > > You guys are making me want to go out and finish my 2 pound air
roaster that
> > > has been about 90% complete for several years. Drum roasting just
stole my
> > > heart. It's hard to beat effortless five pound batches...and near
silence
> > > except for the churning of the beans.
> >
> > You and me, both, Ed! I am now the proud owner of a used high pressure
blower
> > that should loft a fair amount of beans. It is a Dayton, 1/2Hp,
develops 157
> > cfm at 2". Blower can be reversed and oriented every 45°
> >
> > Search http://www.grainger.com/ for item number 2C940
> >
> > Dan
>
|
| | | | |
Date: 06 Oct 2006 09:25:42
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Yup keen to see how much your unit will loft too. I see from the Grainger
> site that blower doesn't have a motor, did you have to buy that separately?
There is a w/motor option that I used the first time I bought one at work, but
not the second time. The motor had sleeved bearings. So, I just bought a
separate motor with ball bearings the second time. The blower is adjustable and
will fit many motor frame sizes. You may already have a 3450 rpm motor.
> I have mocked up roast chambers in wood and plastic to test how well the
> beans loft and rotate. Gotta do that with my 7kg roast chamber. Need to work
> out the right size blower for 7kg.
I'm thinking of trying heater ductwork to test mine. Begin with 4" at the
blower, use a conical transition to 6", and then 24" of 6" pipe as the
'chamber'. 1/4" hardware cloth at the bottom of the chamber.
Dan
|
| | | | | |
Date: 07 Oct 2006 16:49:40
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Dan Bollinger" <danNObollinger@insightSPAMbb.com > wrote in message
news:ZM2dnQGslNjKxLvYnZ2dnUVZ_o2dnZ2d@insightbb.com...
> > Yup keen to see how much your unit will loft too. I see from the
Grainger
> > site that blower doesn't have a motor, did you have to buy that
separately?
>
> There is a w/motor option that I used the first time I bought one at work,
but
> not the second time. The motor had sleeved bearings. So, I just bought a
> separate motor with ball bearings the second time. The blower is
adjustable and
> will fit many motor frame sizes. You may already have a 3450 rpm motor.
>
> > I have mocked up roast chambers in wood and plastic to test how well the
> > beans loft and rotate. Gotta do that with my 7kg roast chamber. Need to
work
> > out the right size blower for 7kg.
>
> I'm thinking of trying heater ductwork to test mine. Begin with 4" at the
> blower, use a conical transition to 6", and then 24" of 6" pipe as the
> 'chamber'. 1/4" hardware cloth at the bottom of the chamber.
>
> Dan
Don't go for the mesh, too much airflow required. For both my roaster
chambers it works out that the total area of the holes is 3.4% of the area
of the roast chamber. For the 4" (98mm ID) Roast chamber cross section area
is 7540 sqr mm, 1755 sqr mm is flat the rest is sloped. 33 holes @ 1/8"
(3.175mm) in the flat section =261 sqr mm. which is 3.46% of 7543. The 6"
RC has 78 holes of 1/8", works out at about 3.4% as well. When i tried a
roast chamber with a fully perforated plate* it was a disastor the beans had
a very erratic movement with more than the odd bean firing out of the top.
The airflow to get them moving was more than twice that with the 3.4 %
setup.
* When i say fully perforated plate it worked out to about 8% of the bottom
of the a 4" pipe.
If you use hardware cloth across a 4" pipe with a 6" to 4" reducer above and
a 6 inch pipe above that then if wire from the hardware cloth drops the 4"
opening to say 70% (guesstamate) it is still 5280 sqr mm, which is 29% of
the area of the 6" pipe. (I prefer to calculate in millimetres). You will
require heaps of air flow to get enough velocity to get the beans moving and
you are blowing most of your heat away. Not to mention an erratic bean flow.
The Sivetz 1.25lb roaster works out to about 2% of the area of the 6" pipe
being perforated (assuming the holes are 4 mm) check out
http://www.coffeewisdom.com/sivitz1lb.htm.
Rob vL
NZ
7
and 3 half built.
|
| | | | | | |
Date: 09 Oct 2006 09:36:20
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Don't go for the mesh, too much airflow required.
Rob, I tried my blower to fluidize some beans. Mine is a 1/2Hp high-pressure
blower from Graingers. Develops up to 2" water column. The chamber was 7",
necked down at the bottom to 4", with a flat-bottomed 4" diameter floor. In the
center was a 1" orifice. I selected the 1" orifice because any smaller the and
blower shutoff.
With this unit I could keep 2 pounds of beans spouting. Any more and it
stalled.
For comparison, I used my shopvac to power the chamber. I believe it is a
1-stage vacuum motor. It can spout 3 pounds of beans.
This does not look good for using the Grainger blower series. With some
modification to the wheel and casing, I'm sure it could be made to spout 3
pounds of beans. If you were to use a 3-phase motor on the modified blower and
power it by a VFD, you could increase the motor speed and spout, say, five
pounds.
By the time you did all of that a used regen might be just as effective.
Dan
|
| | | | | | | |
Date: 11 Oct 2006 22:38:39
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Dan Bollinger" <danNObollinger@insightSPAMbb.com > wrote in message
news:5L2dnYgZwKXLzbfYnZ2dnUVZ_uWdnZ2d@insightbb.com...
> > Don't go for the mesh, too much airflow required.
>
> Rob, I tried my blower to fluidize some beans. Mine is a 1/2Hp
high-pressure
> blower from Graingers. Develops up to 2" water column. The chamber was
7",
> necked down at the bottom to 4", with a flat-bottomed 4" diameter floor.
In the
> center was a 1" orifice. I selected the 1" orifice because any smaller the
and
> blower shutoff.
>
> With this unit I could keep 2 pounds of beans spouting. Any more and it
> stalled.
>
> For comparison, I used my shopvac to power the chamber. I believe it is a
> 1-stage vacuum motor. It can spout 3 pounds of beans.
>
> This does not look good for using the Grainger blower series. With some
> modification to the wheel and casing, I'm sure it could be made to spout 3
> pounds of beans. If you were to use a 3-phase motor on the modified blower
and
> power it by a VFD, you could increase the motor speed and spout, say, five
> pounds.
>
> By the time you did all of that a used regen might be just as effective.
>
> Dan
>
As a comparison the 1100 watt vacuum cleaner motor i use has a 5" (approx)
impellor and can fluidize 3kg, least ways create an adequate spout of beans
to evenly roast 3kg (6.7lbs).
Rob
|
| | | | | | | | |
Date: 11 Oct 2006 09:11:22
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> As a comparison the 1100 watt vacuum cleaner motor i use has a 5" (approx)
> impellor and can fluidize 3kg, least ways create an adequate spout of beans
> to evenly roast 3kg (6.7lbs).
Rob, there is a unit of measure in vacuum motors that may help us. It is called
air watts.
Air Watts = Airflow (cfm) * Static Pressure (inches of water)
___________________________________
8.5
Dan
|
| | | | | | |
Date: 08 Oct 2006 20:23:50
From: Brent
Subject: Re: stainless steel pipe style coffee roaster
|
your learning to count?
:)
> Rob vL
> NZ
> 7
> and 3 half built.
>
>
>
|
| | | | | | | |
Date: 08 Oct 2006 22:56:47
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
It's a Davism. ;-)
"Brent" <me@privacy.net > wrote in message
news:4ornccFfuc14U1@individual.net...
> your learning to count?
>
> :)
>
>
> > Rob vL
> > NZ
> > 7
> > and 3 half built.
> >
> >
> >
>
>
|
| | | | | | | | |
Date: 08 Oct 2006 05:32:05
From: Johnny
Subject: Re: stainless steel pipe style coffee roaster
|
"RobvL" <wontwork@dontbother.net > wrote in message
news:4528cb6a$1@clear.net.nz...
> It's a Davism. ;-)
>
LOL ! :-)
|
| | | | | | |
Date: 07 Oct 2006 06:27:49
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> Don't go for the mesh, too much airflow required.
I hear what you are saying. I'll keep that in mind. By the way, the blower I'm
talking about is in those pictures! It is the gray one being used to remove
smoke and heat.
> http://www.coffeewisdom.com/sivitz1lb.htm.
>
> Rob vL
Rob
|
| |
Date: 05 Oct 2006 05:31:51
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
> Cool roaster by the way Erik. What did you use for a blower? I am still
> looking to source a suitable blower for a 7kg roaster.
>
> Rob vL
> NZ
Rob, I would like to see a few pics of your newer SS roaster with the
tilt-plate dump. Sounds interesting.
I am using two vacuum motors in parallel driven by a light dimmer. I
can move 15lbs of beans with that set up. But I have bought a couple of
regenerative blowers for my next one. Much quieter. Much more
expensive. Ouch.
I know what you mean about time. I have two kids under four.
|
| | |
Date: 12 Oct 2006 15:04:01
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
RobvL wrote:
> The perf plate looks to be about 40mm dia I am guessing at the holes based
> on the photo. Just my opinion but 1/8 (3.2mm) would be minimum size and i
> don't see the point in going bigger than 4mm. With 4mm you might go for a
> few less holes, at the end of the day it is whatever works, i know what has
> worked for me.
>
> Rob
Would it be helpful for me to go take a picture of it with a tape
measure for reference?
I do have a really bad pic of a Sivetz 12lb FB roast tube and you can
make out the perf at the bottom of the cone. It looks to me to be the
same hole size and spacing as on the 1.25lb machine.
Erik
|
| | | |
Date: 13 Oct 2006 23:38:38
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1160690641.154689.163200@m7g2000cwm.googlegroups.com...
>
> RobvL wrote:
> > The perf plate looks to be about 40mm dia I am guessing at the holes
based
> > on the photo. Just my opinion but 1/8 (3.2mm) would be minimum size and
i
> > don't see the point in going bigger than 4mm. With 4mm you might go for
a
> > few less holes, at the end of the day it is whatever works, i know what
has
> > worked for me.
> >
> > Rob
>
> Would it be helpful for me to go take a picture of it with a tape
> measure for reference?
>
> I do have a really bad pic of a Sivetz 12lb FB roast tube and you can
> make out the perf at the bottom of the cone. It looks to me to be the
> same hole size and spacing as on the 1.25lb machine.
>
> Erik
Actually the photo is good enough to work out that the pref plate is approx
40mm, too pixelated to work out the holes.
But it's a non issue to me, my setup works for me. Who is to say that the
S*vetz roaster setup is optimum.
|
| | |
Date: 06 Oct 2006 23:39:54
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1160051511.057271.248390@c28g2000cwb.googlegroups.com...
>
> > Cool roaster by the way Erik. What did you use for a blower? I am still
> > looking to source a suitable blower for a 7kg roaster.
> >
> > Rob vL
> > NZ
>
> Rob, I would like to see a few pics of your newer SS roaster with the
> tilt-plate dump. Sounds interesting.
I actually sold that one, only took a coupleof photos of it before it went.
I will dig them out and put on my site or email them to you.
> I am using two vacuum motors in parallel driven by a light dimmer. I
> can move 15lbs of beans with that set up. But I have bought a couple of
> regenerative blowers for my next one. Much quieter. Much more
> expensive. Ouch.
I figured it would take 2 or 3 vacuum motors to loft 7kg, that was how i was
going to test my mock up before i build it in stainless steel.
But a quieter blower was how i wanted to do it for the actual roaster.
What is a "regenerative" blower?
>
> I know what you mean about time. I have two kids under four.
My 2 are 10 & 14 it don't get easier, now we are a taxi service.
Rob
|
| |
Date: 04 Oct 2006 21:08:20
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Actually my air roaster is very quiet. First and second cracks are
loud. Yes, lots of power, but power is pretty cheap. About 25cents per
batch. Big deal.
Brent wrote:
> electric will use a lot of power I owuld suspect :(
>
> Brent
>
>
> > Very cool. I have elected to stay with electric heat
> > wich limits my intake heat level and makes recirculating complicated.
> >
> > Erik
|
| | |
Date: 11 Oct 2006 17:22:01
From: Wes
Subject: Re: stainless steel pipe style coffee roaster
|
Hi Rob,
what was the diameter of the perf plate on the sivetz you mention
there. and are you saying that 4 mm holes are more optimal than 3 mm
holes? -Wes
RobvL wrote:
> I figured the holes to be approx 4mm and there are 27 of them on the sivetz
> roaster. For my roaster I just drilled them myself, Even in 4mm ss plate
> with sharp bits and cutting fluid it doesn't take long , and that was 78 on
> my 6" RC.
>
> Rob
>
> "Erik Groomer" <ViridianCoffee@gmail.com> wrote in message
> news:1160518397.881148.118320@e3g2000cwe.googlegroups.com...
> > I just picked up some new perf plate to experiment with. I went by cafe
> > bonito to see the little sivetz roaster that Rob posted the link to and
> > then tried to match it by eye at the steel recyclers. Not a very
> > exacting way to do it, but I was pressed for time and didn't have a
> > tape with me at Chuck's when I looked at the little roaster. $30 for 3
> > square feet of 18 guage SS. I think 1/8" ~40% open area. Not sure of
> > the spacing yet. I'll post when I am able to compare the flow to my 60%
> > open area.
> >
> > Dan Bollinger wrote:
> > > > Which manometer did you get? A Dwyer?
> > >
> > > Yes, the little 467-0. It arrived today. :)
> > >
> > >
> > > >
> > > > Dan Bollinger wrote:
> > > >> > Thanks Dan. The real question for me is: where can I turn to learn
> this
> > > >> > stuff about airflows, etc? I am not an engineer nor am I
> particularly
> > > >> > gifted at the math. Where did you pick all this up?
> > > >>
> > > >> Bits and pieces, here and there. Mfgr brochures are filled with
> common sense
> > > >> information. The Machinery's Handbook is a must, too. By the way, I
> ordered
> > > >> a
> > > >> digital manometer yesterday. It will measure low pressures in the
> 0-45 inches
> > > >> of
> > > >> water range. I decided we HAD to have one at work. :)
> > > >
> >
|
| | | |
Date: 12 Oct 2006 23:16:51
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
The perf plate looks to be about 40mm dia I am guessing at the holes based
on the photo. Just my opinion but 1/8 (3.2mm) would be minimum size and i
don't see the point in going bigger than 4mm. With 4mm you might go for a
few less holes, at the end of the day it is whatever works, i know what has
worked for me.
Rob
"Wes" <inabcentia@gmail.com > wrote in message
news:1160612520.996248.101490@i42g2000cwa.googlegroups.com...
> Hi Rob,
> what was the diameter of the perf plate on the sivetz you mention
> there. and are you saying that 4 mm holes are more optimal than 3 mm
> holes? -Wes
>
> RobvL wrote:
> > I figured the holes to be approx 4mm and there are 27 of them on the
sivetz
> > roaster. For my roaster I just drilled them myself, Even in 4mm ss plate
> > with sharp bits and cutting fluid it doesn't take long , and that was 78
on
> > my 6" RC.
> >
> > Rob
> >
> > "Erik Groomer" <ViridianCoffee@gmail.com> wrote in message
> > news:1160518397.881148.118320@e3g2000cwe.googlegroups.com...
> > > I just picked up some new perf plate to experiment with. I went by
cafe
> > > bonito to see the little sivetz roaster that Rob posted the link to
and
> > > then tried to match it by eye at the steel recyclers. Not a very
> > > exacting way to do it, but I was pressed for time and didn't have a
> > > tape with me at Chuck's when I looked at the little roaster. $30 for 3
> > > square feet of 18 guage SS. I think 1/8" ~40% open area. Not sure of
> > > the spacing yet. I'll post when I am able to compare the flow to my
60%
> > > open area.
> > >
> > > Dan Bollinger wrote:
> > > > > Which manometer did you get? A Dwyer?
> > > >
> > > > Yes, the little 467-0. It arrived today. :)
> > > >
> > > >
> > > > >
> > > > > Dan Bollinger wrote:
> > > > >> > Thanks Dan. The real question for me is: where can I turn to
learn
> > this
> > > > >> > stuff about airflows, etc? I am not an engineer nor am I
> > particularly
> > > > >> > gifted at the math. Where did you pick all this up?
> > > > >>
> > > > >> Bits and pieces, here and there. Mfgr brochures are filled with
> > common sense
> > > > >> information. The Machinery's Handbook is a must, too. By the
way, I
> > ordered
> > > > >> a
> > > > >> digital manometer yesterday. It will measure low pressures in the
> > 0-45 inches
> > > > >> of
> > > > >> water range. I decided we HAD to have one at work. :)
> > > > >
> > >
>
|
| | |
Date: 05 Oct 2006 22:36:07
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
Mine is a little loud but I here the cracks ok. I think Brents point was
more to do with the wiring you would have to run to supply the power. There
is nothing in the cost difference from what i can see. Here (NZ) the cost of
LPG is pegged to the electricity price, if power goes up so does the gas. To
me LPG is just an easier way of doing it. If i want more heat I can unscrew
the 2941 nozzle and screw on a 2942 and the max rating goes from 7KW to
26KW. Course then there are a few other issue to deal with.
Cool roaster by the way Erik. What did you use for a blower? I am still
looking to source a suitable blower for a 7kg roaster.
Rob vL
NZ
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1160021300.545930.83540@b28g2000cwb.googlegroups.com...
> Actually my air roaster is very quiet. First and second cracks are
> loud. Yes, lots of power, but power is pretty cheap. About 25cents per
> batch. Big deal.
>
> Brent wrote:
> > electric will use a lot of power I owuld suspect :(
> >
> > Brent
> >
> >
> > > Very cool. I have elected to stay with electric heat
> > > wich limits my intake heat level and makes recirculating complicated.
> > >
> > > Erik
>
|
| |
Date: 04 Oct 2006 05:30:15
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
Wow Rob, looks like you are pretty serious there. And you have really
thought it out. Very cool. I have elected to stay with electric heat
wich limits my intake heat level and makes recirculating complicated. I
like that you pull from the cooler for supply air. How heavy is that
pipe for the roast tube?
Erik
RobvL wrote:
> Hi Wes
>
> The current version of my homebuilt roaster does 2.1 kg about 4.68 lbs
> (sorry not quite the 5 lbs your after).
>
> Some pictures here
>
> http://homepages.paradise.net.nz/loenhout/Roaster.html
>
> http://homepages.paradise.net.nz/loenhout/tcdisplay.html
>
> pics not updated for a long time.
>
> Rob vL
> NZ
>
> "Wes" <inabcentia@gmail.com> wrote in message
> news:1159891107.836538.40710@m7g2000cwm.googlegroups.com...
> > Hi all, I'd like to build a version of the stainless steel pipe style
> > coffee roaster I found on the internet. Has anyone here ever built
> > their own coffee roaster? I'd like to be able to roast 5 pounds of
> > coffee at one time. thanks.
> >
|
| | |
Date: 10 Oct 2006 15:13:17
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
I just picked up some new perf plate to experiment with. I went by cafe
bonito to see the little sivetz roaster that Rob posted the link to and
then tried to match it by eye at the steel recyclers. Not a very
exacting way to do it, but I was pressed for time and didn't have a
tape with me at Chuck's when I looked at the little roaster. $30 for 3
square feet of 18 guage SS. I think 1/8" ~40% open area. Not sure of
the spacing yet. I'll post when I am able to compare the flow to my 60%
open area.
Dan Bollinger wrote:
> > Which manometer did you get? A Dwyer?
>
> Yes, the little 467-0. It arrived today. :)
>
>
> >
> > Dan Bollinger wrote:
> >> > Thanks Dan. The real question for me is: where can I turn to learn this
> >> > stuff about airflows, etc? I am not an engineer nor am I particularly
> >> > gifted at the math. Where did you pick all this up?
> >>
> >> Bits and pieces, here and there. Mfgr brochures are filled with common sense
> >> information. The Machinery's Handbook is a must, too. By the way, I ordered
> >> a
> >> digital manometer yesterday. It will measure low pressures in the 0-45 inches
> >> of
> >> water range. I decided we HAD to have one at work. :)
> >
|
| | | |
Date: 11 Oct 2006 23:02:46
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
I figured the holes to be approx 4mm and there are 27 of them on the sivetz
roaster. For my roaster I just drilled them myself, Even in 4mm ss plate
with sharp bits and cutting fluid it doesn't take long , and that was 78 on
my 6" RC.
Rob
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1160518397.881148.118320@e3g2000cwe.googlegroups.com...
> I just picked up some new perf plate to experiment with. I went by cafe
> bonito to see the little sivetz roaster that Rob posted the link to and
> then tried to match it by eye at the steel recyclers. Not a very
> exacting way to do it, but I was pressed for time and didn't have a
> tape with me at Chuck's when I looked at the little roaster. $30 for 3
> square feet of 18 guage SS. I think 1/8" ~40% open area. Not sure of
> the spacing yet. I'll post when I am able to compare the flow to my 60%
> open area.
>
> Dan Bollinger wrote:
> > > Which manometer did you get? A Dwyer?
> >
> > Yes, the little 467-0. It arrived today. :)
> >
> >
> > >
> > > Dan Bollinger wrote:
> > >> > Thanks Dan. The real question for me is: where can I turn to learn
this
> > >> > stuff about airflows, etc? I am not an engineer nor am I
particularly
> > >> > gifted at the math. Where did you pick all this up?
> > >>
> > >> Bits and pieces, here and there. Mfgr brochures are filled with
common sense
> > >> information. The Machinery's Handbook is a must, too. By the way, I
ordered
> > >> a
> > >> digital manometer yesterday. It will measure low pressures in the
0-45 inches
> > >> of
> > >> water range. I decided we HAD to have one at work. :)
> > >
>
|
| | |
Date: 05 Oct 2006 22:56:15
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1159965015.800751.192550@m73g2000cwd.googlegroups.com...
> Wow Rob, looks like you are pretty serious there. And you have really
> thought it out. Very cool. I have elected to stay with electric heat
> wich limits my intake heat level and makes recirculating complicated. I
> like that you pull from the cooler for supply air. How heavy is that
> pipe for the roast tube?
>
> Erik
As I use a vacuum cleaner motor for the blower it is ok for cooling the
beans with the 650gm roast chamber, but for the 2kg RC I dump in a cooling
bin that sits on a 1hp dust extractor fan setup. Pulls 1.7kg of roasted to
cold in under 3 minutes. The 650 RC is 3.5kg and the 2kg is 7.5kg (i didn't
know that till tonite). Since those pics i have built a completely stainless
unit that has a fixed roast chamber and dumps the beans thru a tilting
plate. I also did a roast chamber that will do 3kg of green, Eddie (Nth Isld
some time altie) has that one.
I just need more time to work on the roaster projects.
Rob vL
NZ
|
| | |
Date: 05 Oct 2006 09:25:09
From: Brent
Subject: Re: stainless steel pipe style coffee roaster
|
electric will use a lot of power I owuld suspect :(
Brent
> Very cool. I have elected to stay with electric heat
> wich limits my intake heat level and makes recirculating complicated.
>
> Erik
|
| | |
Date: 04 Oct 2006 10:10:33
From: Ed Needham
Subject: Re: stainless steel pipe style coffee roaster
|
You guys are making me want to go out and finish my 2 pound air roaster that
has been about 90% complete for several years. Drum roasting just stole my
heart. It's hard to beat effortless five pound batches...and near silence
except for the churning of the beans.
--
*********************
Ed Needham®
"to absurdity and beyond!"
http://www.homeroaster.com
(include [FRIEND] in subject line to get through my SPAM filters)
*********************
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1159965015.800751.192550@m73g2000cwd.googlegroups.com...
> Wow Rob, looks like you are pretty serious there. And you have really
> thought it out. Very cool. I have elected to stay with electric heat
> wich limits my intake heat level and makes recirculating complicated. I
> like that you pull from the cooler for supply air. How heavy is that
> pipe for the roast tube?
>
> Erik
>
> RobvL wrote:
>> Hi Wes
>>
>> The current version of my homebuilt roaster does 2.1 kg about 4.68 lbs
>> (sorry not quite the 5 lbs your after).
>>
>> Some pictures here
>>
>> http://homepages.paradise.net.nz/loenhout/Roaster.html
>>
>> http://homepages.paradise.net.nz/loenhout/tcdisplay.html
>>
>> pics not updated for a long time.
>>
>> Rob vL
>> NZ
>>
>> "Wes" <inabcentia@gmail.com> wrote in message
>> news:1159891107.836538.40710@m7g2000cwm.googlegroups.com...
>> > Hi all, I'd like to build a version of the stainless steel pipe style
>> > coffee roaster I found on the internet. Has anyone here ever built
>> > their own coffee roaster? I'd like to be able to roast 5 pounds of
>> > coffee at one time. thanks.
>> >
>
|
| | | |
Date: 05 Oct 2006 07:59:06
From: Dan Bollinger
Subject: Re: stainless steel pipe style coffee roaster
|
> You guys are making me want to go out and finish my 2 pound air roaster that
> has been about 90% complete for several years. Drum roasting just stole my
> heart. It's hard to beat effortless five pound batches...and near silence
> except for the churning of the beans.
You and me, both, Ed! I am now the proud owner of a used high pressure blower
that should loft a fair amount of beans. It is a Dayton, 1/2Hp, develops 157
cfm at 2". Blower can be reversed and oriented every 45°
Search http://www.grainger.com/ for item number 2C940
Dan
|
| | | |
Date: 05 Oct 2006 22:39:39
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
"Ed Needham" <ed@NOSPAMhomeroaster.com > wrote in message
news:aOOdnbJ8FofWXL7YnZ2dnUVZ_q6dnZ2d@insightbb.com...
> You guys are making me want to go out and finish my 2 pound air roaster
that
> has been about 90% complete for several years. Drum roasting just stole
my
> heart. It's hard to beat effortless five pound batches...and near silence
> except for the churning of the beans.
> --
Yeah go on Ed you know you want to.
My stories the reverse, started to build the drum roaster then went the air
way (or the dark side as Brent puts it). The drum roaster is still no
further along some 2 or 3 years later. Sigh.....
Rob
> *********************
> Ed Needham®
> "to absurdity and beyond!"
> http://www.homeroaster.com
> (include [FRIEND] in subject line to get through my SPAM filters)
> *********************
>
> "Erik Groomer" <ViridianCoffee@gmail.com> wrote in message
> news:1159965015.800751.192550@m73g2000cwd.googlegroups.com...
> > Wow Rob, looks like you are pretty serious there. And you have really
> > thought it out. Very cool. I have elected to stay with electric heat
> > wich limits my intake heat level and makes recirculating complicated. I
> > like that you pull from the cooler for supply air. How heavy is that
> > pipe for the roast tube?
> >
> > Erik
> >
> > RobvL wrote:
> >> Hi Wes
> >>
> >> The current version of my homebuilt roaster does 2.1 kg about 4.68 lbs
> >> (sorry not quite the 5 lbs your after).
> >>
> >> Some pictures here
> >>
> >> http://homepages.paradise.net.nz/loenhout/Roaster.html
> >>
> >> http://homepages.paradise.net.nz/loenhout/tcdisplay.html
> >>
> >> pics not updated for a long time.
> >>
> >> Rob vL
> >> NZ
> >>
> >> "Wes" <inabcentia@gmail.com> wrote in message
> >> news:1159891107.836538.40710@m7g2000cwm.googlegroups.com...
> >> > Hi all, I'd like to build a version of the stainless steel pipe style
> >> > coffee roaster I found on the internet. Has anyone here ever built
> >> > their own coffee roaster? I'd like to be able to roast 5 pounds of
> >> > coffee at one time. thanks.
> >> >
> >
>
>
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Date: 04 Oct 2006 21:27:30
From: RobvL
Subject: Re: stainless steel pipe style coffee roaster
|
Hi Wes
The current version of my homebuilt roaster does 2.1 kg about 4.68 lbs
(sorry not quite the 5 lbs your after).
Some pictures here
http://homepages.paradise.net.nz/loenhout/Roaster.html
http://homepages.paradise.net.nz/loenhout/tcdisplay.html
pics not updated for a long time.
Rob vL
NZ
"Wes" <inabcentia@gmail.com > wrote in message
news:1159891107.836538.40710@m7g2000cwm.googlegroups.com...
> Hi all, I'd like to build a version of the stainless steel pipe style
> coffee roaster I found on the internet. Has anyone here ever built
> their own coffee roaster? I'd like to be able to roast 5 pounds of
> coffee at one time. thanks.
>
|
| |
Date: 03 Oct 2006 22:37:37
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
I feel pretty silly putting this link up, but since you asked...
http://virtualviridian.blogspot.com/
The pic of the actual roast chamber seems to be broken. I'll try to
fix it. I have a demanding job and a young family. This is my hobby,
whatever time I can throw at it; Life is pretty dishevelled for me. I
would be happy to answer any specific questions you have about what I
have done, or what I am doing on the next roaster.
Sincerely,
Erik Groomer
Ed Needham wrote:
> OK...You have my interest. Care to explain and share a few more pics?
> --
> *********************
> Ed Needham=AE
> "to absurdity and beyond!"
> http://www.homeroaster.com
> (include [FRIEND] in subject line to get through my SPAM filters)
> *********************
|
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Date: 03 Oct 2006 18:05:02
From: Erik Groomer
Subject: Re: stainless steel pipe style coffee roaster
|
This is my 7lb fluid bed roaster. It is set up to roast 15lbs but I
don't have enough power in my shop. I'm currently working on k II of
the roaster. Much better design. 5lbs of beans cool in about 2 minutes.
http://static.flickr.com/47/179821276_e8627b2a83.jpg?v=0
Wes wrote:
> Hi all, I'd like to build a version of the stainless steel pipe style
> coffee roaster I found on the internet. Has anyone here ever built
> their own coffee roaster? I'd like to be able to roast 5 pounds of
> coffee at one time. thanks.
|
| | |
Date: 03 Oct 2006 23:48:10
From: Ed Needham
Subject: Re: stainless steel pipe style coffee roaster
|
OK...You have my interest. Care to explain and share a few more pics?
--
*********************
Ed Needham®
"to absurdity and beyond!"
http://www.homeroaster.com
(include [FRIEND] in subject line to get through my SPAM filters)
*********************
"Erik Groomer" <ViridianCoffee@gmail.com > wrote in message
news:1159923902.891182.203680@i3g2000cwc.googlegroups.com...
> This is my 7lb fluid bed roaster. It is set up to roast 15lbs but I
> don't have enough power in my shop. I'm currently working on k II of
> the roaster. Much better design. 5lbs of beans cool in about 2 minutes.
> http://static.flickr.com/47/179821276_e8627b2a83.jpg?v=0
|
| |
Date: 04 Oct 2006 09:18:56
From: Brent
Subject: Re: stainless steel pipe style coffee roaster
|
Have a look at www.homeroaster.com and look at Rob vL's contraption,sounds
like what you want, and he might be able to tell you how to do it...
> Hi all, I'd like to build a version of the stainless steel pipe style
> coffee roaster I found on the internet. Has anyone here ever built
> their own coffee roaster? I'd like to be able to roast 5 pounds of
> coffee at one time. thanks.
>
|
|
