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Bubbling Fluidized Bed Roaster Build
jkoll42
Top  #176 Print Post
Posted on 10/28/2011 12:44 PM
I am fine with a standard profile - I am going to start off with the high initial heat profile as others have used

1 - 215 F
2 - 270
3 - 285
4 - 300
5 - 330
6 - 360
7 - 390
8 - 406
9 - 415
10 - 424
11 - 433
12 - Finish

What I am interested in is input on a abbreviated time roast as described by the zoellner patents / Nepro roasters which this plate is based off.

The airflow will be adjusted throught the roast to keep the fluid bed calm and I have overhead on the heat which should allow for the necessary temperatures. The question is will it scorch, taste nasty, etc., and I indend to find out :)
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
seedlings
Top  #177 Print Post
Posted on 10/28/2011 1:48 PM
That is pretty much my standard profile. I can shorten the 0-300F range by about a minute, but can't shorten any segment past that. Of course the roaster can lengthen any of them.

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
jkoll42
Top  #178 Print Post
Posted on 10/28/2011 7:13 PM
Have you noticed any difference in taste in reducing 0-300 by a minute v. the 4 min time?

Any thoughts on the short roast profile? Just go balls out and see what happens?
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
allenb
Top  #179 Print Post
Posted on 10/28/2011 7:57 PM

Quote

jkoll42 wrote:
I added a port between the blower and heat to dump air. It can be adjusted from 1" down to 1/2" to tune it. Hope to try it out this weekend, but now we are forecast to get 2-4" of snow in the philly area. Snow? Before Halloween? Ugh.

Once I have this tweaked and dialed in to my standard roasting profile I want to do a comparison roast between a 'standard' air profile and something more along the lines of the Nepro roasters to see how the output compares. I am hoping that the forum can come to a concensus on a profile to shoot for.

Promo info suggests for the smaller batch roasters they are roasting in around 3 min @ 520F. The overall time/temp range is 1-5 min @ 430-520F. I am thinking that 3-5 min would be ideal. Once I get the airflow figured out I will be able to see what max temp I am actually able to maintain.


Unfortunately you are blazing a trail that few have dared. The only info I've read is probably what you've already seen.

The 3 to 5 is what I've seen as well but I also read somewhere that to accomplish this feat it's pretty much giving it all you've got with no real profile to speak of.

Zoellner seemed to be saying that part of the reason they were able to pull off a decent roast moving that fast was the reduced oxygen environment by recirculating. Either way it will be very interesting to cup a flash roast compared to a standard 4-4-4. One thing you'll need even with your ample heating power is to do some preheating just before the roast. As for what temperature to roast at will only be found by experimentation.

Looking forward to seeing progress reports!;)
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
jkoll42
Top  #180 Print Post
Posted on 11/06/2011 3:39 PM
Had a small roasting session today to try and nail the control down. Gotta get my act in gear since the swap is coming up!

Dumping air has worked well. I added a 3/4" port (adjustable from 1/2 - 1" ) and now the beans are under control. My first roast overshot the profile.... really overshot the profile. This thing has a ton of overhead as far as power goes. Thankfully the sievert burner stays lit even down to basically an idle. I forgot to screencapture the roast but basically...
1 min - 260F
2 min - 310F

The good news is that the beans didn't look too bad and I now know I can at least give the flash profile a shot at some point. I only had the burner at 25 psi for the first minute at it is rated for 30.

Next I thought I would give 1# a shot in the roaster for fun. Poor planning - the thermocouple didnt touch the beans! I ended up trying to roast a profile based on exhaust gas Shock

The last roast I did turned out great (we will see about taste) Pretty much right on target running between 12-18 psi during the roast. Beans look extremely even and only a few beans out of 2# show the very start of tipping - I wouldn't even consider them tipped. This was my main concern with the lack of crazy bean movement but it seems that the fluid bed did a good job transferring the heat.

farm7.static.flickr.com/6234/6319984804_b3b14a1d7f_b.jpg
roast201111061541-4609
Edited by jkoll42 on 11/06/2011 3:39 PM
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
JETROASTER
Top  #181 Print Post
Posted on 11/06/2011 5:22 PM
Exhaust gas temp can be surprisingly accurate. I still don't know why.....but it is what it is. Nice work. Scott
 
endlesscycles
Top  #182 Print Post
Posted on 11/07/2011 10:07 AM

Quote

freshbeans wrote:
Exhaust gas temp can be surprisingly accurate. I still don't know why.....but it is what it is. Nice work. Scott


I have seen that too, but I think it is conditional of good heat exchange. I imagine a short bed high airflow system would read higher.
-Marshall Hance
Asheville, NC
 
jkoll42
Top  #183 Print Post
Posted on 11/07/2011 10:25 AM
Yeah, I have to look at the chart again, but it wasn't too far off what I expected BT to be. I want to say that 1C hit about 20F lower than expected BT would have been. It was a batch of Rwanda and trying it this morning it is drinkable. I took it just to 2C since I had no idea what the real temp was but considering they got there pretty quick it actually tastes ok.
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
jkoll42
Top  #184 Print Post
Posted on 11/10/2011 3:12 PM
Does air roasted coffee generally take longer to offgas? I roasted some espresso blend on Sunday (the batch I finally nailed the profile on) and pulled a shot today after work. First I will say that it was great. Best espresso roast I have ever done - the bittersweet chocolate finish was very developed. The reason I ask is that I had some bubbles in the crema and the extraction cone had some volume to it - usually I only see this if I am forced to pull shots on day or two old beans. This is 4 days out so it is unusual.
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
JETROASTER
Top  #185 Print Post
Posted on 11/10/2011 4:29 PM
I've never drummed...so I can't make that comparison.

My Air-roast observations...very un-scientific.

1) Darks offgas more readily than lights.

2) Any roast profile that swells the beans more, typically results in a more aggressive offgas.
Pushing hard,early in the roast produces this result for me.

Were you drumming before this new machine? -Scott
 
jkoll42
Top  #186 Print Post
Posted on 11/10/2011 6:04 PM
I was HG/BM (and poppery a long time ago)
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
seedlings
Top  #187 Print Post
Posted on 11/11/2011 8:26 AM
I heard somewhere sometime that air roasted degasses (and spoils) faster than drum roasted, but have no idea what the source was.

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
Coffee makes the world goround
Top  #188 Print Post
Posted on 11/11/2011 2:04 PM

Quote

seedlings wrote:
I heard somewhere sometime that air roasted degasses (and spoils) faster than drum roasted, but have no idea what the source was.

CHAD


I read that too

AND i think its true (taste in the cup)

I have roasted in the (modded)popper and my minni Turbo raster

AND the beans from a hot air expands MORE ,,this could mean =more tiny cracks = faster degassing
 
jkoll42
Top  #189 Print Post
Posted on 11/11/2011 6:50 PM
I will see how it goes tomorrow morning, but it seems like the opposite w/ this batch. Either they are outgassing slower, or for some reason the beans are retaining more co2 in the structure. Weird. At least they taste awesomeThumbsUp
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
allenb
Top  #190 Print Post
Posted on 11/11/2011 9:09 PM
I'm glad to hear the bubblebed can produce great tasting coffee. You are the first I know of who has gotten to the point of being able to roast in one and provide feedback on roast quality.

What was your max environment temp during the roast?

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
jkoll42
Top  #191 Print Post
Posted on 11/12/2011 9:52 AM
I should have some better data tomorrow - friend is coming over for a roasting session. Right now I have a 2 TC's.. One BT that is about halfway deep in the bed and a second in the furnace about 3" below the plate. I hope soon to get a third hooked up for exhaust gas. In the one roast that I tried 1# the BT probe was never in the beans and after review was showing exhaust gas to be about 25-30F below the guesstimate on BT.

Gas temps preplate maxed out at just over 600 but spent most of their time 575F or below. I did a 15 sec moving average on the graph to make the data a bit more usable. I have to play with the averaging on the TC$ output - you can see the swings up and down in gas temp since there is a lag in the ROR calcs. Should have some more good data after this weekend.

farm7.static.flickr.com/6059/6337643784_a30abde634_b.jpg
Edited by jkoll42 on 11/12/2011 9:52 AM
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
dja
Top  #192 Print Post
Posted on 11/12/2011 10:46 PM
looking at the red average line looks like it was trying to level out and fly right there at the end.

if I could ever find a piece of 5 inch od tubing I would try gas heat in mine. but I'm pretty happy with the way it roast but do wish I could get it on 110 so I could be a traveling roaster. 220 sort of limits you to where you can roast at.
I pour Iron and roast Coffee BeansThumbsUp
If life seems normal your not going fast enough Mario Andrette
 
Bhante
Top  #193 Print Post
Posted on 11/26/2011 3:31 PM

Quote

Coffee makes the world goround wrote: the beans from a hot air expands MORE

Expansion depends on the RoR during the phase before first crack, not on roaster type.

According to my friend the Vortex was not the first bubblebed. Here is a photo he sent me of a bubblebed in New York:

up.picr.de/8857277scj.jpg

The largest roaster on the Vortex website is located at Fine Foods International in Berlin, where it roasts instant coffee. One of the smaller models was built for Poland. The smallest was construed as a shop-roaster, but apparently does not seem to have been a success/in use.

The ultra fast roast times are for industrial use, and do not have a good reputation as far as quality is concerned. That's the sort of coffee you buy in rectangular blocks in the supermarket! I gather such short high temperature roasts are the norm for low quality industrial coffee.

Bhante
Edited by Bhante on 11/26/2011 3:33 PM
 
Bhante
Top  #194 Print Post
Posted on 12/03/2011 3:39 PM
I had a very interesting chat with my friend yesterday about the Zoellner/Nepro roasters, which he knows well and has seen several times.

He was one of the first 10 people ever to see a demonstration of the roasting plate shown in the Zoellner patent. The plate itself was rectangular exactly as shown in the patent, about 120 cm by 40 cm, with the same repeated circular areas of higher density holes. In this demonstration only unheated air was used on pre-roasted beans. 5 green-painted beans were dropped into the centre region, and they were very quickly distributed throughout the mass of coffee beans. The movement of the beans was very gentle - the entire mass of beans was gently levitated, with quite a gentle movement, but nevertheless very effective mixing. I.e. not the vigorous motion shown in the photo I posted above, nor in the videos earlier in this thread. He described a gentle "plop, plop" movement, which implies it was not a constant and continuous movement but a periodic movement at each high-density region (not sure if they were synchronised - I suspect not). As I understand it, the movement is a bit like a bubble of air coming up periodically through a layer of mud and then bursting as it reaches the surface, but in this case it is a bubble of beans - hence the name, bubble bed. According to this understanding the photo I posted above would not qualify as a bubble bed because the movement is too strong. This is the type of plate used in the very large roaster at Fine Foods in Berlin.

The middle scale of roaster uses an annular plate about 40-50 cm in diameter. The air is blown in from above over heating elements located in the centre of the annulus, and this air then comes back up through the holes in the plate. The plate (which my friend was able to examine closely and even hold up to the light) was designed in exactly the same way as the large rectangular plate with multiple circular areas of high density holes, but it had very special qualities (hinted at on the Nepro site but not adequately described there) which the rectangular plate does not show - these properties are evidently dependent only on the circular form (maybe necessarily annular) of the roasting chamber and nothing else. Zoellner himself declared that he could not understand or explain how the rotation effect worked.

What happened is that a gentle circular wave motion arose sponaneously, INSTEAD OF the gentle (and as I understand, intermittent) bulges over the high density regions that were observed with the rectangular plate. As the wave passed over a certain region the beans from underneath would be deposited on the topsurface of the trailing edge of the wave, while the rest of the bean mass appeared virtually motionless apart from the levitation. The wave would move around the roasting chamber, according to my friend about once every thirty seconds which is somewhat slower than the rate given on the Nepro site, but the difference is probably just due to the fact that this demo was seen some years ago. I asked which direction the wave moved - he reckoned probably clockwise.

This is all consistent with the Coriolis Effect, which causes for example winds in atmospheric high pressure zones in the northern hemisphere to rotate clockwise around the high and in low pressure anticlockwise (and conversely for Brad and Lee in Australia). Also the water going down the drain of the bathtub or toilet tends to go down with an anti-clockwise vortex (clockwise in the southern hemisphere). For a description of the Coriolis Effect which is caused by the rotation of the earth see here:

http://en.wikiped...lis_effect

Because the Coriolis force is very small, the roasting chamber probably has to be an annulus, otherwise the wave motion will not be stable in the centre and so you will just get the same effect as the rectangular plate with periodic bubbles instead of the continuous wave.

Just as the vortex in a bathtub can be made to go in the opposite direction from that normally predicted from the earth's rotation as a result of very small local disturbances in the water movement, it follows that in the same way the wave motion could be triggered by a very slight vortex in the air circulation as a result of the fan mechanics - this does not "push" the wave around, it simply causes a slight local discontinuity in the forces which is then amplified by the coriolis effect. According to my understanding no initial vortex in the air movement is required however. If the rotation of the earth were to come to a halt, the wave would also stop, and will then be replaced by periodic bubbles above each high density region (however since the earth coming to a halt would have more drastic effects on life on earth, we might rapidly lose interest in what happens to the wave, or even not be around to watch it!).

As regards the video on the Nepro site, I believe it is a fake, made up of still photos of beans in various stages of roast poured into a cylinder, which probably has a fluidised bed but without the wave peculiar to the annular roast chamber. I believe the swirl as the beans are poured in is a fanciful fake induced by trick imagery, because the originators of the video did not understand the causes of the wave. Some of the still images are repeated to reduce the number of images required (or more probably to adjust the average apparent speed of movement), which is why the video appears so uneven. I think the general low quality of the video is simply a disguise to cover the fact that it is faked.

The Zoellner roasters were apparently not very successful as a business, and Zoellner himself was eventually eased out of the company; since then he has passed away. Not many of the roasters were built, and I think only one of the very large ones.

Anyone interested in trying a 40 cm diameter annular roaster? It might also work on a smaller scale. If you want to bring in the hot air from below (which is mechanically easier), you just need a vertical tube in the middle of the roast chamber to form the annulus, so that the wave will be able to form. I suspect you could successfully scale down the high density areas for a 15 cm diameter rosting chamber, with maybe 5 cm inner tube.

Bhante
 
Bhante
Top  #195 Print Post
Posted on 12/03/2011 3:50 PM

Quote

Bhante wrote: I asked which direction the wave moved - he reckoned probably clockwise.

The water in the bathtub is moving DOWN, while the air causing the wave in the roaster is moving UP - this is why the wave moves clockwise. If Brad would like to experiment, he will probably find it moves anti-clockwise, since he is in the southern hemisphere (unless it is caused more by turbulence or slight rotation in the incoming air, in which case it could go in either direction).
 
allenb
Top  #196 Print Post
Posted on 12/04/2011 10:22 AM
The Nepro's seem to get more mysterious each time more is learned about them.

The Rototerm with it's annular RC is a different animal compared to the smaller true bubblebed in the Nepro video. I've seen a video of it in operation a while back and not sure if it's still on their site. It showed the revolving wave movement you're describing. Sounds like the wave movement was accidental.

I'm fairly confident the video of the smaller "shop roaster" bubblebed is not doctored but looks weird due to the time lapse shooting. If you look carefully at the video toward the end you'll see smoke moving away from the beans just prior to dumping. As far as whats causing the rotational movement of the bean mass in this roaster, I still believe there is some type of rotating convection currents from above which caused the incoming greens to spiral while falling. It's too bad the video is so poor.

http://www.nepro....ite8x2.htm

Allen
Edited by allenb on 12/05/2011 2:02 PM
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
Unta
Top  #197 Print Post
Posted on 12/04/2011 10:48 AM

Quote

Bhante wrote:

Quote

Coffee makes the world goround wrote: the beans from a hot air expands MORE

Expansion depends on the RoR during the phase before first crack, not on roaster type.

According to my friend the Vortex was not the first bubblebed. Here is a photo he sent me of a bubblebed in New York:

up.picr.de/8857277scj.jpg

The largest roaster on the Vortex website is located at Fine Foods International in Berlin, where it roasts instant coffee. One of the smaller models was built for Poland. The smallest was construed as a shop-roaster, but apparently does not seem to have been a success/in use.

The ultra fast roast times are for industrial use, and do not have a good reputation as far as quality is concerned. That's the sort of coffee you buy in rectangular blocks in the supermarket! I gather such short high temperature roasts are the norm for low quality industrial coffee.

Bhante


I had my doubts that the image was a Bubble bed, i thought it was a spouting cone, due to the similarities to the Sivetz Glass display model of which the RC and dump are nearly identical.
As I suspected it is a spouting cone, called the Javabot. Here is another pic from the Roasting Plant Website.
Sean
Unta attached the following image:
javabot.jpg
Edited by Unta on 12/04/2011 10:52 AM
Sean Harrington
educate.
 
Web
Unta
Top  #198 Print Post
Posted on 12/04/2011 10:53 AM
The Sivetz Glass machine.
Unta attached the following image:
glasstuberoaster.jpg
Edited by Unta on 12/04/2011 10:54 AM
Sean Harrington
educate.
 
Web
dja
Top  #199 Print Post
Posted on 12/04/2011 5:22 PM

Quote

Unta wrote:


up.picr.de/8857277scj.jpg



I had my doubts that the image was a Bubble bed, i thought it was a spouting cone, due to the similarities to the Sivetz Glass display model of which the RC and dump are nearly identical.
As I suspected it is a spouting cone, called the Javabot. Here is another pic from the Roasting Plant Website.
Sean[/quote]

Heck them guys stole my idea and fancied it up a bunch is all they did.
but my beans don't spin in circles
I pour Iron and roast Coffee BeansThumbsUp
If life seems normal your not going fast enough Mario Andrette
 
jkoll42
Top  #200 Print Post
Posted on 12/04/2011 5:39 PM
Here are two new vids with the bean action after fixing the excess air issue. My current issue is that it seems that as the beans pass 1C the temp reading of the bean TC becomes understated. I assume that there are more gaps between the larger lighter beans so it is more an aggregate between air temp and bean temp. According to the TC4 My ROR is 9 deg like I want, but I am running the end of 1C into the start of 2C. Gotta fix that and not sure how. I guess I could just change the position of the TC and see if that helps. Will also have some more time tomorrow to comment on the previous interesting posts

[video]http://www.youtube.com/watch?v=ICrLlEPZXSg[/video]

[video]http://www.youtube.com/watch?v=EO526CIrEfw[/video]
Edited by jkoll42 on 12/04/2011 5:39 PM
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
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