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Topic: PID controlled fluid bed temp and profile (10 msgs / 321 lines)
1) From: Dave Bush
Well, I tried posting yesterday, but apparently something went wrong.  
Getting messages in digest form and trying to reply to them doesn't  
work too well. Anyway...
I've been roasting with a popcorn popper for a couple of years and  
decided to try to build a bigger version, basically a Sivetz-like  
fluid bed roaster. I'm using a 4750W 240V heater with a PID  
controller. The air flow will be adjustable with a motor speed  
control. What I'm wondering is what air temperature I should target  
for the air entering the roasting chamber. My research has resulted in  
everything from 500 to 750 F. I've seen someone report that their  
Sivetz roaster runs at 550 F which sounds like a good temp, but I was  
wondering if any of you have experience with this. Also, since this  
thing will be PID controlled I'm looking for recommended roast  
profiles that I can program it for. Again, I can find all kinds of  
suggestions, but am looking for expert opinions.
Thanks!
Dave
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2) From: Bill
Dave, digest mode is pretty tough to navigate.  Did you see the posts from
others in other threads about your question?  I have nothing to add, just
wanting to make sure that you're seeing it...
Most of us either set up other email accounts or folders in our current
email accounts to handle homeroast mail... a lot better than reading the
digest!
my 2 cents
bill
and welcome!
On Mon, Apr 14, 2008 at 8:23 PM, Dave Bush  wrote:
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3) From: Michael Dhabolt
Dave,
I usually recommend a unique Gmail account for this list to people
(not using digest mode) it threads well and most folks seem to be
happy with it YMMV.
A profile that has been a good 'Starting Place' for me is as follows:
Ramp 1   220 F	2:30 Minutes
Ramp 2   300 F	3:00 Minutes
Ramp 3   380 F	3:00 Minutes
Ramp 4   400 F	2:00 Minutes
Ramp 5   445 F	5:00 Minutes
Ramp 6   475 F	2:00 Minutes
Ramp 7   32  F	1:00 Minutes
Ramp 1 is target from ambient. The short ramp 4 is slow things down so
I don't overshoot and go into first crack with a lot of momentum.  I
very seldom end the roast anyplace other than during  ramp 5, ramp 6
is only there because I do a little French roast for a guy when I
can't talk him out of it, and ramp 7 is there to ensure that the
machine shuts itself down prior to fireworks.  Most of this is machine
specific and an artifact predicated on the limitations of my
particular setup.  All the temperatures are thermocouple sensed
temperatures in the middle of the circulating bean mass (in my case it
is 2.1 inches or so from the air inlet due to the geometry of a
Poppery 1 roast chamber).
In my limited experience - different model Sivetz machines monitor
temps at several different physical locations.  The one universal is
bean temperature with the probe in the circulating bean mass which
seems to be the temperature that is used to control the roaster.  I'll
check to see if I can come up with an air inlet temperature for one of
the machines and post it.
Mike (just plain)
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4) From: Michael Mccandless
I have a profile of the Sonofresco chamber temp @:
Sonofresco graph 
McSparky
On Mon, Apr 14, 2008 at 7:23 PM, Dave Bush  wrote:
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5) From: Dave Bush
Mike, et.al.,
Thanks for all the inputs on profiles, email handling etc. I finally  
finished my taxes and had time to turn off the digest mode and set up  
my mail client to filter these messages. I'll see how this works and  
may still go to gmail if necessary.
Mike, I'll give your profile a try when I finish the roaster. It's  
longer than I get now with the popper, but that's to be expected. It  
probably makes it possible to roast a larger batch since there's more  
time to transfer the heat. If you have a chance to post the Sivetz  
inlet air temp, I'm still interested.
I'm also building a Turbo Crazy that I intend to PID. I think I have  
an idea to get a decent bean mass for measuring. We'll see...
Just received another 18 pounds of green from SM yesterday so I have  
some work to do this weekend.
Thanks again for the assistance. I'm sure I'll have more questions as  
I get these roasters put together.
Dave
-----------------------------------------------------
Date: Tue, 15 Apr 2008 14:30:10 -0700
From: "Michael Dhabolt" 
Subject: Re: [Homeroast] PID controlled fluid bed temp and profile
	recommendations?
To: homeroast
Message-ID:
	
Content-Type: text/plain; charsetO-8859-1
Dave,
I usually recommend a unique Gmail account for this list to people
(not using digest mode) it threads well and most folks seem to be
happy with it YMMV.
A profile that has been a good 'Starting Place' for me is as follows:
Ramp 1   220 ?F	2:30 Minutes
Ramp 2   300 ?F	3:00 Minutes
Ramp 3   380 ?F	3:00 Minutes
Ramp 4   400 ?F	2:00 Minutes
Ramp 5   445 ?F	5:00 Minutes
Ramp 6   475 ?F	2:00 Minutes
Ramp 7   32  ?F	1:00 Minutes
Ramp 1 is target from ambient. The short ramp 4 is slow things down so
I don't overshoot and go into first crack with a lot of momentum.  I
very seldom end the roast anyplace other than during  ramp 5, ramp 6
is only there because I do a little French roast for a guy when I
can't talk him out of it, and ramp 7 is there to ensure that the
machine shuts itself down prior to fireworks.  Most of this is machine
specific and an artifact predicated on the limitations of my
particular setup.  All the temperatures are thermocouple sensed
temperatures in the middle of the circulating bean mass (in my case it
is 2.1 inches or so from the air inlet due to the geometry of a
Poppery 1 roast chamber).
In my limited experience - different model Sivetz machines monitor
temps at several different physical locations.  The one universal is
bean temperature with the probe in the circulating bean mass which
seems to be the temperature that is used to control the roaster.  I'll
check to see if I can come up with an air inlet temperature for one of
the machines and post it.
Mike (just plain)
Homeroast mailing list
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6) From: Michael Mccandless
I believe it ramps a little quickly to FC.
Good starting place.
McSparky
On Fri, Apr 18, 2008 at 5:16 PM, Dave Bush  wrote:
<Snip>
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7) From: Michael Dhabolt
Dave,
I checked out a small (It is 1/4 bag or 17 Kilo) Sivetz during a
couple of roasts.  Air inlet plenum temp never reached any higher than
550ish.  I have no idea of the accuracy of the temp. monitoring
equipment.  The location that is monitored is past the burners a
couple of feet, after a substantial amount of air mixing.
I just re-read my earlier post (with basic profile) and realized I had
not explained my logic (or lack thereof) for the rapid Ramp 6 from 445
F to  475 F in 2:00 Minutes.  As I mentioned, I don't like to go
that far with my personal roasts and the darker roasts seem to me to
keep a little bit more of the varietal flavor (Vs. charcoal) if I
really push that ending ramp.  The Ramp 6 heat-up rate is beyond what
my roaster will accomplish without cutting air flow too far, so it
just forces the heater to 'on' 100% of the time and the roaster chases
the ramp until I stop things manually.
Mike (just plain)
On Fri, Apr 18, 2008 at 5:16 PM, Dave Bush  wrote:
<Snip>
ee.com
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m/gallery/main.php?g2_itemId=7820
<Snip>
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8) From: Dave Bush
Mike,
Thanks for the Sivetz data. 550 sounds like a reasonable peak temp.  =
Common sense tells me it should be as cool as possible while still  =
being able to achieve the target profile as long as you're not  =
overloading the roaster with too many beans. That reduces the chance  =
of scorching the beans. Hopefully I have enough time to get the fluid  =
bed roaster finished soon. Always more projects than time...
I seldom roast beyond 445 except for some espresso blends. I'll have  =
to see what my roaster can achieve and adjust accordingly.
I appreciate the advice. I'll share some results if I ever get this  =
thing finished. I may go ahead and finish the Turbo Crazy first so I  =
have a bigger roaster to use in the meantime.
Dave
BTW, is it just me or does everyone's emails to this address take a  =
day or two to get delivered?
On Apr 20, 2008, at 6:05 PM, Michael Dhabolt wrote:
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fee.com
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om/gallery/main.php?g2_itemId=7820
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ee.com
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m/gallery/main.php?g2_itemId=7820
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9) From: raymanowen
"...I can find all kinds of suggestions, but am looking for expert
opinions."
Expert opinions are just suggestions that always work. -ro
On Mon, Apr 14, 2008 at 8:23 PM, Dave Bush  wrote:
<Snip>
-- 
"When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Mighty
Wichita (ex- NYC Paramount) WurliTzer- 1976
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10) From: Bill
Dave,
no, it is just you.  I've noticed that your emails come after huge delays.
 I wonder why?  The list was switched to a different server in Feb, and
there've been some problems with it, sometimes taking a while to move
emails... but your emails seem to take a long long time to show up.
The HG users on this list are probably obnoxious with always saying this,
but here goes... if you want a fast and easy way to roast beans until your
roaster is up, look into heat gun roasting.  I went with a more pricey gun,
about 90 bucks, a 5 dollar bowl, and I was ready to rock... people here are
using 30 dollar guns with great effect.  Nice and easy and easier than
getting a TO up to snuff...  let us know if you want to know more, I don't
want to ram it down your throat...:)
good luck with that roaster.  i want to hear how it goes
happy roasting
bill
On Sun, Apr 20, 2008 at 8:48 PM, Dave Bush  wrote:
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ee.com
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