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renatoa
03/25/2024 12:38 PM
coffee drink, Ramper?

allenb
03/24/2024 12:10 PM
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Building a drum roaster
allenb
Most of my "breakthrough" improvements in roasting were found by screw ups. Most of the time I'm too worried about messing up a good bean to experiment much.

I think we need to designate someone to run a "test kitchen" for the forum who has a good fluid bed and drum roaster. We can all contribute high-end greens to the person for an endless supply of experimental roasting stash. All we'll require is a monthy report on "best profiles" for a given bean. For compensation they would have use of the roasts for all personal use. We would obviously have to put together a TV spot on the cooking channel to show off gear and roasting tips.

Alright, who's up for this position?
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
Vidget
Thank you Ringo for agreeing to advise:)
Your drum has a diameter of 8 inches and a length of 1 foot. What is the minimum he can roast with a stable quality of roasting and what the optimal batch for this size?

I design roster, from 1 to 3 pounds. It turns out I need a drum of smaller size than yours.
 
JETROASTER

Quote

allenb wrote:

I think we need to designate someone to run a "test kitchen" for the forum who has a good fluid bed and drum roaster.

Alright, who's up for this position?


.....Under the bus you go....

I nominate AllenGrin !!! -Scott
 
allenb

Quote

freshbeans wrote:

Quote

allenb wrote:

I think we need to designate someone to run a "test kitchen" for the forum who has a good fluid bed and drum roaster.

Alright, who's up for this position?


.....Under the bus you go....

I nominate AllenGrin !!! -Scott


I guess I had that coming.

Nah, I wouldn't be a good host. I'm not photogenic.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
Ringo
Vidget
I can roast 1 pound reliably, that is the size roast I seem to do most often. I have roasted 1/2 pound but I really have to be carefull. I do a lot of 2.5 pound roast becouse its a even brakedown on the 5, 10 and 15 sizes we buy. One thing to think is the larger the dia of the drum makes the build easyer. With a small drum it would be hard to weld the stirring veins in the drum. The biggest problem is the front plate. There is a lot of stuff to fit in, The bearing uses a lot of the aria. If I did another build I would find a smaller bearing, most commercial drum just use a bearing in a sleave. You have to have a big hole for the Bean drop/ fume exhaust. A bean temp probe, environmental probe, view port for seeing the beans roast. A dump door. So as I was planning a roaster most of my planning would be on this frony plate. The three that really compete for the same spot are the bearing, the view hole and the bean temp probe. There is a sweet spot that is very important its at between 7 and 9 o'clock on the left side of the drum, the bean probe and the view port have to be there but the bearing uses up a lot of room. If you look at a picture of my drum my first view window was in my dump door, this was unusable. The beans just flew by the window too fast to see. I had to add a second window were the beans slow down as the roll off the stirring veins. This is also were the bean temp probe has to be becouse that is the biggest pile of beans. If I was going to build a new roaster I would use 1/8 inch steel on the drum if I wanted to do small roast. After a roast my drum is heated to around 430 deg, I drop my beans in for a small roast at 230 deg. I have a 10 min delay for cooldown. I use this time for packing the last roast, filling out the roast logs, getting the next roast ready but it a pain. I feel like all the steel help on large roast, for me on a propain roaster profile changes can be too fast so the steel helps smooth out the profile. If I was building a commercial roaster I would use less steel, that cooldown delay would kill you production. One more important part to plan is a big motor to turn the drum. Beans get stuck between the drum and the front plate the motor has to be able to overcome this. I would look for a min 1/4 horse that bolts directly to a gear box. The best would be a motor gearbox that slipped over the drum shaft. This would let you not have a bearing on the back of the drum. This motor gearbox will be very expensive. My gearbox was salvaged so the price was right but it only got the RPM down to around 145 rpm, so I had to do the final reduction with sprokets. Put a smaller sproket on the motor and a larger on on the drum and you can get your drum to 60 RPM. Sorry for the long run on explination just wanted help
with what I think are the important design points. I have said this before but I am not an engineer just a hacker so anything I say in just a guess not an educated guess.
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
Vidget
Thank you Ringo for the very helpful advice and surround the text. Your information helped me a lot in understanding the construction of a roster.
How do you solve the problem of chaff and chaff collector?
 
Ringo
Build a cyclone for your roaster, send the exhaust into a drum at a tanget so the air will spin around the drum, this spining will sling the chaff to the outside and it will fall to the bottom. In the top add a pipe that goes down into the drum a foot or so at the center. Put your exhaust fan on this pipe. The exhaust fan will pull the chaff out of the roaster with the exhaust it will pull it to the cyclone, spin out the chaff and exhaust the gasses outside. Chaff is big and heavy so it spins out easy. Do a google image search for "Sawdust Cyclone" and "Coffee Roaster" and it should help you understand.
Edited by Ringo on 10/16/2010 7:50 PM
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
Vidget
I know about the cyclone, I was interested to learn about the designs of chaff tray.
 
Ringo
I do not know how chaff trays work, I do not have one. All my chaff goes to the cyclone, I know some commercial roasters used them but have never seen one. I do not think you would need both. I would guess a screen that the exhaust filters through would work well.
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
Vidget
The question has arisen. The roster needs to be heat insulation? and how to implement it in design?
 
Ringo
I used 1" fibeglass duct board, used to build heating ducts. You could see if you can find cut offs from the local heating contracter. You could get Kaowool off ebay.
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
John Despres
Kao Wool is very easy to use. E-Bay or your local fireplace supplier will have it. It comes in variable thicknesses as well.

John
Respect the bean.
John Despres
Fresh Roast 8, Gene Cafe, JYTT 1k, Quest M3, Mazzer Mini, Technivorm, various size presses and many more brewers.
 
Vidget
I have to use other materials, because I'm from Russia.
Next question:) Do I need a motor for circulating air in the drum and remove the chaff to be heat resistant? How did you decide this question? High temperature 200 degrees Celsius would be bad for the bearings and motor, in theory.
 
Ringo
I used a big cyclone with a leaky door, this dilutes the heat before it gets to the blower. I did not use a high temp blower but it could go out I guess. I wanted the cyclone to run cool so there is less of a chance of a chaff fire.
Edited by Ringo on 10/18/2010 5:02 PM
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
Vidget
Can you share more photo of roaster and cyclone?
 
Dan
Small roasters don't need a blower to circulate heat. Making the drum perforated helps with heat transfer and getting rid of chaff, too.

I have a one-pound sample roaster. It's open 'snout' is all the ventilation it needs.
 
Ringo
Look at post 79, thats a picture of the cyclone in the back ground. Its just a pipe that I welded the ends shut, add a clean out door, you can see the 3 inch exhaust pipe going to the cyclone and the small exhaust motor on top. Stick a pipe in a 55 gal drum, bolt a motor to the top-you got a great cyclone. Like Dan said when you are roasting very little air goes through the roaster, If I run too much air the coffee out of my drum is flat, but I love air roasted coffee, I dot not have a clue why air in my drum hurts the flavor. I do run a lot of air between roast too cool off the drum. If you build a drum you will not be able to design everthing before you start, it will be a process. Things will not work and have to be changed, just realize that going in and have fun. I built my drum for around $1000, thats a lot of cash. Have to be willing to see that lost if you can not get it to work. If you read my thread you will see I had a very hard time getting the drum to turn reliably and the burner to work, you will have problems also but you have too keep pushing. The biggest design advice I can give is put in too much of everthing! Have a ventilation system thats too big but can be adjusted down, add way too much heat but be able to control it, use motors that are too big. The reason I say this is if you underestimate any one of the three you will not be able to roast well. If I ever built a second or third roaster I would be able to dial things back a little. You also need to look for used parts if all my motors gearboxes and electronics were new I would have spent triple.
Edited by Ringo on 10/19/2010 7:33 AM
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
Vidget
Hello Ringo, in the process of construction arose another question. Air from the drum which is taken and passes through the cyclone is returned to the drum? And if you returned, then where?

Unfortunately in my town is hard to find used equipment and even find a new fan was for me a big headache. As always offered great industrial options.

Thanks again for your help:)
Edited by Vidget on 10/22/2010 8:51 AM
 
Ringo
Vidget
The air out off the roaster cyclone is exhasted to the outside, some air roasters recycle but drums do not. As you build post pictures, others will be interested. Good luck

Ringo
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
Vidget
Hi Ringo, the whole process of construction I will photograph and lay out here when it comes to metal. I now develop detailed drawings and models in SolidWorks, to minimize the possibility of error and the need to alter anything, as a direct manufacturer will be made at factories in our city and I will be to assemble a roster. Since I live in a city apartment and I'm difficult to deal with it by welding and mechanical works:) Although I can do it all myself:)
 
broeker

Quote

Ringo wrote:

The biggest design advice I can give is put in too much of everthing! Have a ventilation system thats too big but can be adjusted down, add way too much heat but be able to control it, use motors that are too big. The reason I say this is if you underestimate any one of the three you will not be able to roast well.


This is really good advice, I design & fabricate machines for a variety of very different industries.... When doing a new design or machine were I'm not sure exactly how it will perform I always over engineer or over specify the critical elements to ensure enough adjustment for the process to work............... It's a lot easier the down spec in version 2.0
 
Ringo
I built this roaster 7 years ago and it still works great. I did have a problem on the last roast and thought it would be a good idea to warn people. I left the bottom of the roaster open when I built it. I was doing a roast 5 pounds of a really nice Ethiopian, after the roast I dumped in the cooling tray and little bits of cloth came out in the tray with the coffee, I suspected bad beans. I had 5 more pounds of a nice guat in the funnel I dropped it into the roaster. When it was done more scraps. Long story short I had a mouse build a nest on top of my burners and the fan sucked the pieces all through the roaster. I sent two days taking the roaster apart and cleaning everything and adding a screen under the burners. Bought 10 pounds of cheap throwaway beans roasted them to season the drum. It was an expensive lesson.
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
Ringo
So I have a new warning for roasters. When I built my roaster many years ago I put a big Chaff cyclone on it, mainly because I had a big piece of pipe laying around. When I roast I normally do 4 5 lb batches. I freeze it all and then just take it out as i need. I was on my 4 th roast for the night doing a darker roast than normal and i had a fire in my cyclone. I roast in my detached garage with double walled pipe going outside and that goes through a thimble in the wall. So it fire resistant and i finished the roast then put the fire out. My warning is if you roast inside make sure you have a good vent pipe. I attended a roasting class years ago and they said if you are vented well and you have a fire keep the roaster running till it gets cool. if you shut the air off you run a risk of the beans catching fire. Have not been able to make myself go back and clean the roaster yet but i did drill holes in the side of the cyclone so i could spray water in it if it happens again. Have a plan if this happens to you.
All you need in life is ignorance and confidence, and then success is sure. Mark Twain
 
JackH
Thanks for posting this information. I am glad everything is OK Ringo
---Jack

KKTO Roaster.
 
goat4hooves
Thank you for the sage advice! I'm thankful for knowledge you have shared here. It is good to be prepared and have a plan that you can execute at a moments notice.
 
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