Homeroasters - Home Roasting Coffee Community » BUILDING A ROASTER » Drum Roasters
Who is here? 1 guest(s)
Page 2 of 11: 12345...11
 Print Thread
Dan's Direct-Flame Roaster
allenb
Top  #26 Print Post
Posted on 03/16/2011 11:47 AM
It would be interesting to know if the Whitmee has a burner running the full length of the inside of the drum or just covers a small area at the front.

A few more observations and curiosities from looking at pics and the video,

Is it possible to dump all beans from a standard drum shape out through a hole smaller than the drums' OD using standard tumbling vanes without incorporating a spiral screw vane as used in a cement mixer design? This is regarding the Whitmee and not the current build project.

I'm not sure where I've read this but remember a while back reading that the Whitmee incorporated a hefty air flow entering the drum (not sure if it was at the mouth end or somewhere else inside the drum) to help offset the affects of the higher temperatures of a direct flame.

It is reported that the Whitmee used a perforated drum in all of their roasters. This would probably help keep overly high internal ET's from occurring and allow an exhaust path from the whole drum into the inner roaster shell space and into the exhaust port at the top.

Another observation is what looks to be a rather shallow drum depth in photos of the Whitmee. It looks like the drum might be a bit less in length than it's diameter.

Not much out there covering the Whitmee.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
Dan
Top  #27 Print Post
Posted on 03/16/2011 11:58 AM
Allen, I found very little, too. I even used different search engines, but that didn't help much. There is a little information about them in the Ukers book.

I did learn that the Whitmees used two burner types. A blowtorch burner, like mine. And a pipe burner (long pipe with many orifices) that produces a knife-like flame. The pipe burners needed a bean deflector above them, but not so with the blowtorch. I suspect that the larger roasters needed the pipe burners.

I think getting ride of excess heat will be an issue. For a small batch roaster like mine, the large front opening might be enough. I plan on monitoring the roasting environment temperature as well as the bean mass temperature using TC probes.

One thing that will help reduce heat buildup is that my drum isn't insulated with a cabinet. If too much heat builds up, I can add vent holes on the back, or even install an exhaust vent blower. What I don't want to do is drill hundreds of little holes, all of which will need deburring. :(

I hope to make some progress over the weekend. I need to do some welding tests before subjecting those bowls to my welding talents. ;)
 
Web
seedlings
Top  #28 Print Post
Posted on 03/16/2011 12:38 PM
Great work Dan! I never knew such a monster existed, the direct flame roaster. Do you have any of the parts starting to come together? I've been away for a few days.

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
Dan
Top  #29 Print Post
Posted on 03/16/2011 1:05 PM
Chad, I have the bowls, shims, and chain ready to weld together to make the drum. Everything else is just a box of parts, but it should come together quickly once I get past the drum assembly.
 
Web
Coffee makes the world goround
Top  #30 Print Post
Posted on 03/16/2011 2:12 PM
I am pretty sure the drum is perforated
take a look at the photo i posted

you can see the bearings outside the housing that the drum is surported by

and the top cover
its vented , and it looks like it gets hot

i i am very sure i know why we dont see them anymore

they must be very fuel wasting ,
like a popper , they waste the hot air after it has touched the beans once
no recycling

but for a home roster that isnt such a big deal

there has been shown a very old direct home roaster somewhere on the net
its hand driven perforated drum ,like the ones used in a BBQ
with a long tube inside with small hole for the gas
 
Coffee makes the world goround
Top  #31 Print Post
Posted on 03/16/2011 3:37 PM
Here it is
www.toomuchcoffee.com/modules/PNphpBB2/files/sta_0172.jpg

from here

http://www.toomuc...amp;t=2326

also found this

lh4.ggpht.com/_kiish7RHl2E/S9XCnQZ1o3I/AAAAAAAACAw/wEa3nakzSVk/s800/IMG_0278.JPG
 
Dan
Top  #32 Print Post
Posted on 03/16/2011 3:58 PM
CMtWGR, Way cool! So the concept isn't dead. Note the rotating union for the gas supply on the left side of the frame in the second picture. Those aren't cheap. I wonder what size the batch is.
 
Web
coffeeroastersclub
Top  #33 Print Post
Posted on 03/16/2011 6:38 PM

Quote

Coffee makes the world goround wrote:
Here it is
www.toomuchcoffee.com/modules/PNphpBB2/files/sta_0172.jpg

from here

http://www.toomuc...amp;t=2326

also found this

lh4.ggpht.com/_kiish7RHl2E/S9XCnQZ1o3I/AAAAAAAACAw/wEa3nakzSVk/s800/IMG_0278.JPG


I checked out the link regarding the 1st pictured roaster, and the beans that came from that roast look a bit unevenly roasted (probably due to vane configuration and unevenness of flame dispersion).

Len
"If this is coffee, please bring me some tea but if this is tea, please bring me some coffee." ~Abraham Lincoln
 
Web
Coffee makes the world goround
Top  #34 Print Post
Posted on 03/16/2011 6:58 PM
i dont think the gas pipe is rotating
, the shaft is hollow

about uneven
the roaster in the picture isnt inside something , like the one from the first link

that had me thinking

what if you made a inner perforated drum , and some space between this and the outer drum

that way the beans would not at one time touch the hot flame , and next the much colder drum

you could still use the drum you have

just ad some holes so that some heat can escape , or at first no holes , and as time will show , maybe ad some

you want to roast the beans, not cremate them smile
 
Beaner
Top  #35 Print Post
Posted on 03/16/2011 7:08 PM
Here's a concept for ya Dan:


Image is taken from a interesting article titled "THE EVOLUTION OF COFFEE APPARATUS"

http://www.web-bo...MB701.html
Beaner attached the following image:
roaster_4.jpg
Edited by Beaner on 03/16/2011 7:08 PM
 
Dan
Top  #36 Print Post
Posted on 03/17/2011 6:32 AM
I made a little progress last night and took these crude pictures. If I bothered to setup lights and a backdrop I'd never get them taken.

claycritters.com/coffee/bollinger_flame_roaster/bfr1.jpg
SS 13 quart bowl with bottom removed. Hole is 7" in diameter.

claycritters.com/coffee/bollinger_flame_roaster/bfr2.jpg
Adding .050" shims (note one arc-shaped shim on bench) to rim joint. The shims do two functions. First, they provide a heat sink and parent material for welding the very thin bowls together. Second, they make the rim joint wide enough to engage with the spaces between the inner links of the chain.

claycritters.com/coffee/bollinger_flame_roaster/bfr3.jpg
Close up of shim.

claycritters.com/coffee/bollinger_flame_roaster/bfr4.jpg
Drive components I've collected from my bins. Note sketch on the board. Chain goes around the bowl rim, supported by the idler sprocket (right), and driven by the sprocket (left). Sprocket is driven by the step-down cogged belt pulleys and a small 1725 rpm motor. Drum speed should be about 75 rpm.
 
Web
Dan
Top  #37 Print Post
Posted on 03/17/2011 7:06 AM
CMtWGR, You are right, the pipe burner would be stationary, no need for a rotating union. That must be the venturi.

I think there is a need for removing excess heat from a direct-flame roaster, that's why those two don't have enclosures. Neither will mine, but time will tell if I need one. but like I said, I don't want to drill and deburr hundreds of little holes in those bowls. Shock

Beaner, That's an indirect-heated drum. Bean-there-roasted-that. smile
Edited by Dan on 03/17/2011 9:03 AM
 
Web
Dan
Top  #38 Print Post
Posted on 03/17/2011 8:04 PM
claycritters.com/coffee/bollinger_flame_roaster/bfr5.jpg
The drum spot welded together, ready for the chain.
 
Web
JETROASTER
Top  #39 Print Post
Posted on 03/18/2011 6:41 AM
Cool!!! Nice, clean work. What tools were involved in making the cuts? - Scott
 
Dan
Top  #40 Print Post
Posted on 03/18/2011 7:27 AM
Thanks, The bowl was too large to mount on my lathe, so I couldn't use it to cut the hole and roll a bead. Instead, I used one of those step bits to drill a large pilot hole and my favorite snip the Wiss M6 offset (bypass). Heavier duty than the LeverSnips brand. Then, lots of filing and sanding to smooth the edge.
www.cooperhandtools.com/_cache/0caaa2fe4d7de4e556d43e4627e6181a.jpg

I did a test using MIG, torch, and brazing to join the bowls. The MIG worked best once I learn the trick of using a one second shot with the torch held at about 30?. The worst one (on the left side of the picture) burnt through one rim a little. I think I can repair it.
 
Web
coffeeroastersclub
Top  #41 Print Post
Posted on 03/18/2011 1:48 PM

Quote

Dan wrote:
Thanks, The bowl was too large to mount on my lathe, so I couldn't use it to cut the hole and roll a bead. Instead, I used one of those step bits to drill a large pilot hole and my favorite snip the Wiss M6 offset (bypass). Heavier duty than the LeverSnips brand. Then, lots of filing and sanding to smooth the edge.
www.cooperhandtools.com/_cache/0caaa2fe4d7de4e556d43e4627e6181a.jpg

I did a test using MIG, torch, and brazing to join the bowls. The MIG worked best once I learn the trick of using a one second shot with the torch held at about 30?. The worst one (on the left side of the picture) burnt through one rim a little. I think I can repair it.


Dan, I do alot of welding and must say that looks like a fine job. I know how difficult welding thin stainless is. Personally I would have welded just the rims together with my spot welder, but I can see where you are getting an additional benefit with the thicker shimmed joint.

Looks great. ThumbsUp

Len
"If this is coffee, please bring me some tea but if this is tea, please bring me some coffee." ~Abraham Lincoln
 
Web
Dan
Top  #42 Print Post
Posted on 03/18/2011 2:23 PM
Len, Thanks. I almost took the thing to the university to borrow their spot welder! This will work, and the chain will hide that mess. I thought the torch would have worked well on those standing joints. I've done that many times and you don't need filler rod. I don't think the SS liked mixing with the CRS.
Edited by Dan on 03/18/2011 3:58 PM
 
Web
Dan
Top  #43 Print Post
Posted on 03/20/2011 8:48 AM
claycritters.com/coffee/bollinger_flame_roaster/bfr6.jpg
Drive components laid out. I made two new pillow blocks for the jackshaft to match the height of the idler sprocket shaft I already had. All the bearings are sintererd bronze. I reduced the diameter on the sprockets about .080 so that the teeth wouldn't pass through the chain and strike the drum. I also tapered the teeth more than usual so that the drum would be less likely to "jump the track."

claycritters.com/coffee/bollinger_flame_roaster/bfr7.jpg
It took about an hour of die grinding to get the welded rim width just right to engage the chain, and to get the drum diameter just right so that the chain would come together with equispaced ends. Since the chain will be welded on, there was no need to join the chain like you would do normally. What was important was to keep the spacing on the end pieces the same as the chain's pitch.
Edited by Dan on 03/20/2011 9:19 AM
 
Web
allenb
Top  #44 Print Post
Posted on 03/20/2011 9:57 AM
Great progress! Did you already cover what else supports the drum besides the sprockets?

Here's another vid showing a Whitmee in action. You have to fast forward a bit.

http://www.youtub...4lPpiKeSWE
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
Dan
Top  #45 Print Post
Posted on 03/20/2011 10:18 AM
Allen, There is a third point for support, a bearing on the rear handle. It will have to be a quick disconnect mechanism in order to dump the beans. I haven't figured that out yet.

Cool video. I like the way the flapper works three ways, to view and load the beans, to close the roaster opening, and finally to dump the beans. Someone was thinking!
 
Web
allenb
Top  #46 Print Post
Posted on 03/20/2011 11:25 AM

Quote

Dan wrote:
Allen, There is a third point for support, a bearing on the rear handle. It will have to be a quick disconnect mechanism in order to dump the beans. I haven't figured that out yet.

Cool video. I like the way the flapper works three ways, to view and load the beans, to close the roaster opening, and finally to dump the beans. Someone was thinking!


One interesting thing this video shows is the burner flame is orange as in the Pumphreys Whitmee. I guess they intentionally keep a rich gas to air mixture for keeping the flame temp as low as possible.

Seeing that the door can close off the drum mouth means the exhaust path must be from under the drum, up and through the top. You're right about the flapper. This took some real engineering to pull off such a multi purpose device.

I wish we had an HRO member in England who could do some photo shoots of the internals of a Whitmee.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
dja
Top  #47 Print Post
Posted on 03/20/2011 1:55 PM
the dust thats in the coffee and the chaff and a lot of other things will make the flame orange, but you may be right on it being fuel rich, although I see no reason for them to run the burner in such an ineffecient manner, The hottest part of the flame is the white cone coming off the burner an a roaster that size is going to take some btu's to heat it up.
I pour Iron and roast Coffee BeansThumbsUp
If life seems normal your not going fast enough Mario Andrette
 
allenb
Top  #48 Print Post
Posted on 03/20/2011 4:19 PM

Quote

dja wrote:
the dust thats in the coffee and the chaff and a lot of other things will make the flame orange, but you may be right on it being fuel rich, although I see no reason for them to run the burner in such an ineffecient manner, The hottest part of the flame is the white cone coming off the burner an a roaster that size is going to take some btu's to heat it up.


You're right about coffee particulates causing orange/yellow flame color but the orange color seen in the video posted today is before any coffee is charged into the roaster.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
Beaner
Top  #49 Print Post
Posted on 03/20/2011 8:43 PM
I wonder if something like this toggle clamp could work for a quick disconnect device. Maybe if the bearing was mounted on either end of the threaded bolt and the clamp mounted in such a way that when locked in place the bearing would just make contact with the bowl.
Beaner attached the following image:
toggle-clamp.jpg
Edited by Beaner on 03/20/2011 8:50 PM
 
Dan
Top  #50 Print Post
Posted on 03/20/2011 9:12 PM
Beaner, Good thinking. That might work. I think I have a miniature version of that somewhere in my bins. smile I finished welding the chain on the bowls today. I would have gotten more done, but had to make some patterns, RTV molds, and urethane parts for work instead.
 
Web
Page 2 of 11: 12345...11
Jump to Forum: