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Brewer to Roaster..blower question...
oldgearhead
Top  #151 Print Post
Posted on 09/17/2011 7:29 PM

Quote

dja wrote:
OGH I see the roaster is alive and well, or anyway it sounds like it is.

I wonder if I could get a sketch of how your latest chaff collection system is put together, I don't mind the smoke as I can blow that outside when its terrible cold in the winter, but that chaff just gets into everything if I do and uncontained roast in the house.

DJA


_Exploded view,left-to-right:
1 - 200mm 'K' TC
2 - 5/16" nuts
1 - 5/16" washer
1 - 5/16" silicone 'O' ring
1 - 5/16" threaded rod
1 - 3.5" diameter cocktail shaker (body)
1 - Angel Cake center post
1 - 5/16" toggle nut
1 - strainer

David - Of course you could just use the srainer and vacuum the chaff off the top after you end the roast. That works well also..
oldgearhead attached the following image:
chaffcollecter.jpg
Edited by oldgearhead on 09/19/2011 4:05 PM
No oil on my beans...
 
oldgearhead
Top  #152 Print Post
Posted on 09/27/2011 11:10 AM
>snip<

If possible, shoot us a time/BT profile of the roast.

Allen[/quote]

Profile - Here is a list of what I know at this point:
1)The roaster can take one pound of beans to 300F in 4 minutes using 100% heat and 40% recycled air from the RC. However, I choose to roast 410 grams loads and go slower to 300F. So I start at 70% heat and 28% recycled air. This gets me to 300F in 5 minutes, and a drying time of 2 minutes (230-300F).
2 - BMT (K-TC) probe performance - It reads 400F at start of first crack, which is perfecct for me. However, it cannot pin-point the exothermic phase, kineticaly. as the probe in my Z&D can, because there is just too much air in the beans at that point in the roast. However, 440F sure does look like full city. I might try an RTD later on.

Sumatra Gayo Lintang (9-26-2011):
1) Heat 70%, Recycle 28%, - 60F - 300F = T0 + 5 min
2) Heat 90%, Recycle 40%, - 300F - 400F = T0 + 14 min
3) Heat 80%, Recycle, 28% - 400F - 440F = T0 + 19min

Next time I'll ride the air speed control a bit lower in phase 2.
oldgearhead attached the following image:
dsc_0268.jpg
No oil on my beans...
 
dja
Top  #153 Print Post
Posted on 09/27/2011 11:24 AM
sorry about not answering sooner, I roast outside so I don't really have a chaff problem I let the nebighors keep all they want. I have to 5/8 inch vent holes in the top plate that are suppose to have sliding damper on them I said suppose too. the chaff is blown out thru them and the fill/dump door as it has a small crack under it. now if I am roasting say 1.75 lbs them the chaff may start sticking and build up around the holes and block them off so that there is chaff in the tube when done roasting and cooling down.

David
I pour Iron and roast Coffee BeansThumbsUp
If life seems normal your not going fast enough Mario Andrette
 
oldgearhead
Top  #154 Print Post
Posted on 11/30/2011 11:55 AM
A geek on another coffee forum asked about the cost of my roaster,
so I added it up:
$510. for the parts (note: I over-paid for the brewer)
$66.00 for drill bits and Bandaids.

I should say I called in a favor from a machinist friend for some of the more difficult cuts. Furthermore, David (dja) made a couple of great parts for a very reasonable fee...

I'll try to post some photos of the baffle I'm using to keep the inlet air temperatures in the 150-160F range during the current cool spell..

Happy Holidays!
Edited by oldgearhead on 11/30/2011 11:56 AM
No oil on my beans...
 
oldgearhead
Top  #155 Print Post
Posted on 12/21/2011 2:42 PM
Merry Christmas/Happy New Year!
We traded the traditional Indiana turkey Thanksgiving for tacos on
Myrtle Beach and dinner in Charlestown. The 70F weather was refreshing.

Update to the roaster:
1) Reliability -Its still working fine, nothing has failed.

2) Chaff - I am now able to track my roasts using the manifold TC. So,
I am using only the 20 mesh screen, with no chaff collector or BMT. I simply vacuum off the chaff after the roast cools. The collector was only 50-60% efficient and I had to vacuum some anyway, so this saves a step.

3) RC expelled air/intake air mixer - I have finished the engineering of the ambient air sliding door. I now have a setting for 30F, 40F, 50F, and 60+. This allows me to maintain the inlet air at 150F (+-8F) from the end of drying to finish. I still need to fab the pieces and install it. In the meantime I'm using gaffer's tape.

4) Summary:
Roast loads - 400-500 grams
Drying phase = 3 -5 minutes
Ramp to 1C = 3-4 minutes
Finish = 3-5 minutes
Cooling = 4 minutes

5) Current draw = 2250VA
oldgearhead attached the following image:
dsc_0095.jpg
Edited by oldgearhead on 12/21/2011 2:43 PM
No oil on my beans...
 
seedlings
Top  #156 Print Post
Posted on 12/21/2011 3:26 PM
Chaff collection is for the birds.

CHAD
Roaster: CoffeeAir II 2# DIY air roaster
Grinder: Vintage Grindmaster 500
Brewers: Vintage Cory DCU DCL, Aeropress, Press, Osaka Titanium pourover
 
oldgearhead
Top  #157 Print Post
Posted on 01/07/2012 9:13 AM
Last Monday the roaster preformed very well throughout its big test. What was the test? The ambient temperature was 36F. I knew when I completed the design it might be marginal in below 40F ambient temperature. After all, I'm roasting one pound of green coffee with a 1500 watt heat source.

I left the mixing door at the 40F setting and roasted one pound of Sumatra Gayo Lintang and one pound of the excellent A-1 Harrar. The
roast times were 12 and 14 minutes respectively. However, the best news is the intake air screen was 158F at the 4 minute point for both roasts.
(Note: all my roasts are full-city, no oil allowed)

The mixing door works! If I position the door based on the ambient temperature, then the intake air will be between 150F and 160F.

The roaster in now over 6 months old and still roasting 2-4 pounds a week.

This spring (March), I'll remove the blower from its rubber case and see how much tar build-up I'm getting on the inside. However, If the inlet air PVC pipe is any indication, it won't be too bad..
No oil on my beans...
 
allenb
Top  #158 Print Post
Posted on 01/07/2012 1:07 PM
It's great to hear that recirc is possible without having to use an industrial high temp blower.

I think you are providing valuable research for all of us who want to be able to roast more than a 1/4 lb batch (in a fluidbed) with household 120 volts. I'm hoping many more at HRO will be trying their hand with a recirculating fluidbed build and who knows, with enough folks in the mix there might be further breakthroughs allowing simplified designs.

Keep the posts coming

Allen
Edited by allenb on 01/07/2012 1:32 PM
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
oldgearhead
Top  #159 Print Post
Posted on 01/08/2012 10:04 AM

Quote

allenb wrote:
>snip<

I think you are providing valuable research for all of us who want to be able to roast more than a 1/4 lb batch (in a fluidbed) with household 120 volts. I'm hoping many more at HRO will be trying their hand with a recirculating fluidbed build and who knows, with enough folks in the mix there might be further breakthroughs allowing simplified designs.

Keep the posts coming

Allen


Allen,
I cannot quite use a standard 20A circuit, unless I run the blower with a varible-autotransformer (16.5A total). The blower pulls 2 amps on the Variac and 5+ amps on the DC drive. I prefer the torque control of the DC drive, therefore I'm running the unit on a 30A 120V circuit pulling 19.5A..
I have roasted a few one-pound batches of decafe with the heat energy fixed at 1200 watts. So 120V/20A is possible, but not important to me at this time....
No oil on my beans...
 
allenb
Top  #160 Print Post
Posted on 01/08/2012 11:15 AM
To be honest, to be able to do 1/2 or 3/4 lb with household 120-20 amp circuit breakers in a fluidbed would be a huge improvement and well worth the extra work of building in a recirc feature.

Many folks abandon fluidbeds for this reason alone. Two pots of coffee per roast after a while can be a little much.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
prs16001
Top  #161 Print Post
Posted on 02/29/2012 5:06 PM

Quote

oldgearhead wrote:
Things are moving right along on this project. I only need to receive three parts and drill 3 holes before I start testing. Here is a copy of my final (120 VAC version) bill of material:
Brewer_Roaster_BOM

+ 1 - Bloomfield 8773 (Junk) Coffee Brewer
+ 1 - Wooden box 30?x18?x13?
+ 4 - 2.5? Castors
+ 4 feet of 2? Schedule 40 PVC pipe
+ 1 - 3 inch Schedule 40 PVC flange
+ 1 - 3 inch-to-two inch Schedule 40 PVC adapter
+ 8 feet of 2.5? flex hose
+ 1 - 2? Schedule 40 PVC ?T?, for bean-evac-to quart jar
+ 2 - Two inch Schedule 40 PVC couplers
+ 1 - 1-1/2 HP spa blower (booted)
+ 6 - ?T? nuts (10-24)
+ 2 - 1? x 3? piano hinges
+ 1 lot machine screws, washers, and nuts
+ 1 - 12?x 1.5? Chrome sink drain extension
+ 1 - 3.5? Stainless steel cocktail shaker
+ 1 - Master HAS-043K heat gun element
+ 1 lot Permatex Red silicone
+ 1 lot hookup wire
+ 1 - 14/3 Power cord
+ 1 - 7.75? piece of 35 mm DIN rail
+ 10 - 8 mm DIN terminals
+ 1 - Ice cube relay & socket
+ 1- Nema 4x Enclosure 9?x 7? x 4?
+ 1 - Extech VFL PID Controller
+ 1 - Tyco 50A SSR
+ 1 - Brew switch (momentary rocker)
+ 1 - Heater stop switch (momentary N.C. push button)
+ 1 - Corning bread tube (3.75? x 14?)
+ 1 - 3? x 3? Aluminum turbo hose coupler
+ 1 - Zach & Dani chaff screen and baffle-type separator
+ 3 - Very nice RC parts, custom built by DJA
+ 1 - Lot of silicone o-rings
+ 1 - Box of Band-Aids
___ 1 - Tyco 30A circuit breaker
___ 3 - DIN Ground terminals
___ 1 - Green Pilot light
___ 1 - Main switch (maintained rocker)
___ 1 - Dayton 4X796B motor speed controller
___ 1 - Shop vac hose and wand assembly (1.25 inch) for bean-evac-to-quart jar

Cheers,
OGH


Hello,

I'm replicating your build,specifically the heater manifold. I'm trying to locate the cocktail shaker, do you have the make and model of the shaker you used?

Thanks
Pete
 
oldgearhead
Top  #162 Print Post
Posted on 02/29/2012 9:04 PM
No model number available its a 3.5" diameter stainless from Target
No oil on my beans...
 
lmclaren
Top  #163 Print Post
Posted on 03/01/2012 1:47 AM

Quote

allenb wrote:
It's great to hear that recirc is possible without having to use an industrial high temp blower.

Allen


Oldgearhead, if the temps for the blower are getting a bit high or you want more, you may also be able to create a basic venturi by injecting you hot air from the blower / heater into a T piece with the return from the top of the roast chamber, similar to the way I inject cold air to cool my exhaust.

Similar to this but instead the LHS would be hot air from the blower / heater and the top would be from the RC.

lh4.googleusercontent.com/-EfXafhkL6sU/TpK2c52isEI/AAAAAAAAA8c/FkzvwyTltlU/s800/DSC03157.JPG
 
oldgearhead
Top  #164 Print Post
Posted on 03/01/2012 8:25 AM
Imclaren - The unit has been in use for 8 months now, and
the four 1/4" bleed holes located between the blower outlet and the heater inlet have done the job, so far. I don't know how much the motor will take but its been getting along fine with 150F inlet temperatures. (I know the PVC doesn't like 165F)

When the motor fails I'll just 'pop' in a new one, because this one had seen several hours of hot tub abuse before I
rescued it. I mainly bought it for the rubber boot motor housing.
B)

No oil on my beans...
 
lmclaren
Top  #165 Print Post
Posted on 03/02/2012 1:43 AM
no problem, glad it is working for you.

best regards

Lee
 
oldgearhead
Top  #166 Print Post
Posted on 05/18/2012 11:44 AM
We had a few days of unseasonably warm ambient temperatures in March. My roaster has a sliding door that has four, ambient temperature, positions: 40F, 50F, 60F, & 70F.
I was half-way through a roast when I realized it was 80F and I had the door set for 40F. A quick check of inlet air temperature indicated it was at 185F! After the roast completed, I took the pipe apart and inspected it. I found no signs of any problems. However, I though it might be a good idea to do a bit of research. I read 11 MSDS about PVC pipe and here is what I found:
1) Lowest combustion temperature I found was 730F (388C). Some of the sheets stated 849F (454C) for combustion, but I think this referred to ?flash over?. (When PVC is burning it emits toxic gas)

2) Melting point - 284F (140C)

3) Deflection - 167F (75C)

Therefore, keeping it in the 150F - 165F range is a good idea?.


Cheers,
OGH
oldgearhead attached the following image:
dsc_8390.jpg
No oil on my beans...
 
Dan
Top  #167 Print Post
Posted on 05/19/2012 6:42 AM
More info: When PVC burns it releases chlorine, which instantly combines with the hydrogen and moisture in the air to form hydrochloric acid fumes.
 
Web
oldgearhead
Top  #168 Print Post
Posted on 07/27/2012 9:25 AM
I guess if it works don?t fix it... This month, July, marks the first anniversary for this coffee roaster. It has successfully completed 150 pounds of green beans without any problems. I was planning to tear down the vacuum motor, inlet and outlet tubing, and check motor brushes and etc. However, after checking a couple of sections of inlet tubing (PVC pipe), I?ve decided to just keep roasting. The first year design changes and maintenance were:

Because the ?baffle separator? was only 50% effective I had to vacuum one-half of the chaff from the top of the roasted beans. So I removed the chaff collector and simply vacuum all of the chaff from the top of the beans. You see, all of the chaff ?sticks? to the 30 mesh screen and stays inside the roasting chamber, so a couple of ?taps? to the screen and it all drops and is easily removed after cooling and before evacuating the roasted beans.

Sound - I added pyramid waffle sound insulation to several areas of the roaster and ?cracks? are now very easy to hear. Actually that was a major accomplishment because my 71 year-old ears were ?pounded? from years of completive clay target shooting. My first attempt caused my temperature controller to overheat and ?blink? a few protests, but I rearranged the insulation and it?s happy now.

Maintenance has been very easy. I vacuum both screens after each roast and wash the roasting chamber and the screens with soap and water every six months. When I roast ?dry/natural process? beans I also need to vacuum the air-mixing chamber area of the roaster. But with ?wet process? all is very clean.

I?m pretty sure the vacuum motor will need to be replaced some day because it had seen several hours of hot tub use before I purchased it, but it should be an easy swap. The heater element is still working perfectly and I have a spare, but it won?t be as easy as the motor.

Summary - If you are like me and never go very far into second crack, recycling 50% of the RC air is simple and rewarding.
oldgearhead attached the following image:
dsc_5399_4.jpg
No oil on my beans...
 
oldgearhead
Top  #169 Print Post
Posted on 08/29/2012 12:52 PM
Can you hear the ?cracks??

I?ve spent the last few days thinking about ways to decrease the ?noise? level of the vacuum motor?s air inlet. My hearing has been dulled by both age and thousands of rounds of 12 gauge shots fired after fleeing clay pigeons. Therefore, it?s a bit difficult, but not impossible, to hear the ?cracks?.

So how loud is my roaster? I dumped in 450 grams of greens and starting measuring, (?C? weight/slow):
T= 0min. _ 81 db
T= 3min. _ 71 db
T= 6min. _ 73 db
T= 9min. _ 73 db

Next, I got to wondering if a 40 micron, sintered bronze, pneumatic silencer would decrease the sound level. So I got one and ran a couple of more tests:
1) 450 grams of spouting, green, coffee beans, with my usual 120 mesh screen in place = 81 db/ 80 volts/ 4.3 amps.
2) 450 grams of spouting, green, coffee, beans, with a bronze silencer in place of the 120 mesh screen = 74 db/ 110 volts/ 7.2 amps.
Conclusion - A reduction of 7 db is pretty significant, but I would have to replace my DC drive (its max is only 90 volts) and the vacuum motor is working much harder at over 7 amps.

But, how much difference is there at the T=8min point in a roast when the cracks can be heard and the blower is turned down? I checked, and its 69 db with the bronze silencer and 73 db with the 120 mesh screen.

The 4 db is not a bad improvement especially because ?bean noise? seems to overcome the vacuum intake noise with the silencer. I?ll probably try a roast or two with my variable-autotransformer before jumping to a 130 volt drive. Do you think the vacuum motor?s life will be decreased?
oldgearhead attached the following image:
dsc_7431.jpg
No oil on my beans...
 
lmclaren
Top  #170 Print Post
Posted on 08/30/2012 5:39 AM
If you are working on the cold inlet, you could make a higher flow 'muffler' with some egg carton like foam, couple of 90deg changes I suspect would soak up a lot of the noise.


I know just putting some cardboard around help mine a lot, by the time i put the panels on the outside with some foam to soak up a bit of noise, it should be a lot quieter.

regards

Lee
 
JETROASTER
Top  #171 Print Post
Posted on 08/30/2012 8:08 AM

Quote

oldgearhead wrote:

Do you think the vacuum motor?s life will be decreased?


I thought I saw your ametek part# somewhere....but I can't find it.

Anyway, can you capture a vacuum pressure reading infront of the fan?
At least for me, that would offer some indication of how hard it is working, and how much cooling air it is getting.
-Scott
 
oldgearhead
Top  #172 Print Post
Posted on 08/30/2012 9:45 AM
Scott -It's a two-stage, flow through, #116671-50. What's an air-watt (321)? I don't have a vacuum gage, but maybe I can find one. I think the motor is rated near 100/100 (cu.in./in.H2o)..
oldgearhead attached the following image:
dsc_7333_1.jpg
No oil on my beans...
 
JETROASTER
Top  #173 Print Post
Posted on 08/30/2012 10:04 AM
Airwatts are kinda the 'smoke and mirrors' of the central vac sales world. It does offer some insight into performance, but it's not exact by any stretch.
http://builtinvac...tions.html

I'll see if that part # comes up on the ametek site. The site was inop yesterday.

Does it sound like the RPM has ramped up alot?
(in relation to the power you're giving it)
-Scott
 
oldgearhead
Top  #174 Print Post
Posted on 08/30/2012 11:09 AM
No, rpm seems to increase only slightly.
I think I'm going to do a heat-rise check next.

I keep hearing my departed father saying: "If it works, don't fix it"....lol
No oil on my beans...
 
JETROASTER
Top  #175 Print Post
Posted on 08/30/2012 11:16 AM
I tend to agree. It sounds like that filter doesn't offer too much restriction. ....let 'er rip! -Scott
 
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