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10/17/2021 12:40 PM
Welcome, Ploni

10/15/2021 2:19 AM
merlot85, maycondelpiero and hoeltz, Welcome !

10/14/2021 10:06 AM
Thanks for the addition to the group. Seriously considering building a drum roaster along the lines of oldgrumpus's. Love the design and craftsmanship.

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Evan Slack and CupOfJoe, Welcome !

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First Fluid Bed Attempt
wbbh
Credit to Omega for inspiring me to attempt this build. I chose to use Sanitary flange stainless steel to build the body.

Testing air flow:


Edited by wbbh on 05/13/2021 9:09 AM
Koffee Kosmo
Excellent job
What is the green bean capacity ?

KK
I home roast and I like it. Designer of the KKTO
Roaster Build information
https://forum.hom...ad_id=1142

https://docs.goog...lide=id.i0
Blog - http://koffeekosm...gspot.com/

Bezzera Strega, Mazzer Robur Grinder, Pullman Tamper Convex,
(KKTO) Turbo Oven Home Roaster.
wbbh

Quote

Koffee Kosmo wrote:

Excellent job
What is the green bean capacity ?

KK


Undetermined, but I'm pretty sure it will do at least two pounds.
allenb
Hey wbbh, super looking build! Keep us up to date with how everything turns out.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
wbbh
I got the propane burner installed, did a test, increased the pressure, but I'm not really getting enough heat. I'm baking the beans, not really roasting them. My next step is to drill out the propane burner to get more volume.

live.staticflickr.com/65535/51180646100_62a6c85650_c.jpgburner by , on Flickr

live.staticflickr.com/65535/51180646115_339df7e7d2_c.jpgbakedbeans by , on Flickr
Edited by wbbh on 05/14/2021 10:39 PM
Koffee Kosmo
You need a flame like jet exhaust

KK
I home roast and I like it. Designer of the KKTO
Roaster Build information
https://forum.hom...ad_id=1142

https://docs.goog...lide=id.i0
Blog - http://koffeekosm...gspot.com/

Bezzera Strega, Mazzer Robur Grinder, Pullman Tamper Convex,
(KKTO) Turbo Oven Home Roaster.
allenb
The mushroom burner will work fine but as with any burner, the BTU rating must be matched to the BTUs needed for the batch size.
I would reduce your air flow down to the point where you are getting just enough bean movement to adequately move the beans but not so much where they are in a fast flow. The mushroom burner I used in a fluidbed design was just enough to roast a 1 lb batch with some headroom but not sure if it would have been enough heat for a 2 lb batch.

Shoot us some details so we can help troubleshoot:

Burner BTU rating
Propane pressure to burner at max
Burner orifice size
Temperature of heated air (max)
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
wbbh

Quote

allenb wrote:

The mushroom burner will work fine but as with any burner, the BTU rating must be matched to the BTUs needed for the batch size.
I would reduce your air flow down to the point where you are getting just enough bean movement to adequately move the beans but not so much where they are in a fast flow. The mushroom burner I used in a fluidbed design was just enough to roast a 1 lb batch with some headroom but not sure if it would have been enough heat for a 2 lb batch.

Shoot us some details so we can help troubleshoot:

Burner BTU rating
Propane pressure to burner at max
Burner orifice size
Temperature of heated air (max)


It's a 3500 watt rated camp stove so about 11,000 BTUs
10 PSI

The jet is marked with the number: "35" I have some number 77 drills coming to open the orrifce.

While playing with air flows I could get between 690 and 1,100 F on the temperature probe just below the RC. I did adjust the airflow to just enough to keep the beans moving.

I think I need to put more restriction on the airflow into the RC. I have some sheet steel stock on order but I was in a hurry to try out the roaster. When I tested out the air flow I coverd half the holes with some alumium flashing sheet, but though it was too thin and being alumimun not suitable for roasting. I used the screws/nuts/washers pictured as temporary restrictors. I intended the temp probe to be on the opposite side, but after installing the screws felt the rounded screw heads would not slow bean movement like the nuts.

Since I have plenty of RC space and blower power but a minimal burner, should I consider say a propane tourch burner?

live.staticflickr.com/65535/51180535326_2b47d561ce_c.jpg

I really appreceiate the help.
allenb
The burner you have should be sufficient for 2 lbs charge. Unfortunately, getting a temperature read on RC entering air, with the tendency for stratification, is sketchy at best without some kind of turbulator or swirl plate to blend the burner heat with incoming blower air. One will usually find that moving the temp probe even as little as 1/2" will see a temp swing as much as 100-300 F so you are most likely not measuring a real average temp at all. But, you can probably play around with various perf plates configuration and air flows and get it to work fine without trying to get a fully homogenous ET mix.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
wbbh

Quote

allenb wrote:

The burner you have should be sufficient for 2 lbs charge. Unfortunately, getting a temperature read on RC entering air, with the tendency for stratification, is sketchy at best without some kind of turbulator or swirl plate to blend the burner heat with incoming blower air. One will usually find that moving the temp probe even as little as 1/2" will see a temp swing as much as 100-300 F so you are most likely not measuring a real average temp at all. But, you can probably play around with various perf plates configuration and air flows and get it to work fine without trying to get a fully homogenous ET mix.


Thank you, I will try playing with the perf plate.

Would moving the burner down/away from the perf plate help with mixing?

I might end up inserting the probe in the bottom flange of the RC if I cannot move it to a satisfactory placement.
allenb

Quote

Would moving the burner down/away from the perf plate help with mixing?


How many inches between top of burner up to perf plate? You want to make sure that there is at least some gap between the tip of the flame and the perf plate otherwise you will have a mix of extreme high temp and lower temp air and scorching is bound to happen.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
wbbh

Quote

allenb wrote:

Quote

Would moving the burner down/away from the perf plate help with mixing?


How many inches between top of burner up to perf plate? You want to make sure that there is at least some gap between the tip of the flame and the perf plate otherwise you will have a mix of extreme high temp and lower temp air and scorching is bound to happen.


2.75 inches
allenb
Do you have a viewing port to determine if there is a sizeable gap between flame tip and perf plate?
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
wbbh

Quote

allenb wrote:

Do you have a viewing port to determine if there is a sizeable gap between flame tip and perf plate?


No, I've got the fitting, but I'm waiting on the delivery of a carbide hole saw to do the installation. These SS pipe spools are a little tough to drill.

Would there be any downside to lowering the burner?
Edited by wbbh on 05/16/2021 10:27 PM
allenb

Quote

wbbh wrote:

Quote

allenb wrote:

Do you have a viewing port to determine if there is a sizeable gap between flame tip and perf plate?


No, I've got the fitting, but I'm waiting ion the delivery of a carbide hole saw to do the installation. These SS pipe spools are a little tough to drill.

Would there be any downside to lowering the burner?


No downside at all, would be an advantage if you can swing it. I know what you mean on cutting stainless. tough stuff!
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
wbbh

Quote

No downside at all, would be an advantage if you can swing it. I know what you mean on cutting stainless. tough stuff!


I moved the burner down about 3 inches and added a solid baffle over about 2/3's of the perf plate.

Gave it another try, much better, but I still think I need a llittle more heat by drilling out the burner jet by a tiny amount and covering more perf plate holes. I had some beans that didn't roast because I made the baffle plate flat and they hung up around the temperature probe. I'll make a new baffle that slopes downward towards the open perforations and move the temperature probe.
wbbh attached the following image:
9nxy7r04sb2sh0yimz2nxw_thumb_675.jpg
wbbh
I added a perforated baffle above the burner and modified the sloping baffle on the bottom of the RC. I tried another roast and it was successful.

I still had some beans getting scorched/burning. I believe they are getting stuck under the temperature probe and when I was adjusting the fan control. I removed the probe and I'm getting used to riding the fan speed control. I will probably drill a hole above the lower flange in the site glass RC assembly.

I had to add a second plate on the bottom to prevent the air pressure from bending up the sloped plate and making it too hot. There is scorching evident on the sloping plate from my first test and the reason I added a baffle below the perf plate.

The baffle plate:
live.staticflickr.com/65535/51193837107_6485a5a8e4_c.jpg

The bottom of the perf plate:
live.staticflickr.com/65535/51193837087_375fc8d9ac_c.jpg

The top of the perf plate:
live.staticflickr.com/65535/51195608075_4ce7cbe3a0_c.jpg
Edited by wbbh on 05/21/2021 11:15 PM
wbbh


I dropped one temperature probe into the top of the RC and drilled a hole for one in the bottom flange of the RC.
allenb
Please shoot us the temp readings for both sensors at start of roast, mid point and during 1st crack. Looking real good! I think you've got this roaster working for you now.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
wbbh

Quote

allenb wrote:

Please shoot us the temp readings for both sensors at start of roast, mid point and during 1st crack. Looking real good! I think you've got this roaster working for you now.


I'll give it a try. I'm tempted to drop a microphone into the top of the RC, I've got tinnitus and it's difficult to hear over the roar of the blower. I may try adding a filter housing of some sort to reduce the noise level. If I build a second version, the blower will be mounted below the roaster.
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