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The Basics - tools, capabilities and concepts
David
Top  #41 Print Post
Posted on 10/06/2007 6:04 PM
You suggested in another thread that we might build this in "tandem."

While I like the idea of working from your plans, I can see that following your lead in the actual building could be even better.

If you are willing to build a piece, take pictures and then post them; that could be a lot easier for me as I would be better able to visualize what is going on. I might need several camera angles to really understand.

:(

That said, if you are willing then I certainly am. B) Grin
 
Alchemist
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Posted on 10/06/2007 9:29 PM
I am good for the start at least. I don't think I can commit the time to build the whole roaster right now, but I do think I can do the cooler. My hope in that case would be that you get to see how my drawings and language turn into a 3-D manufactured item.

Does that work? If so, I will review things, see what other parts we need and get some things posted.
 
David
Top  #43 Print Post
Posted on 10/07/2007 12:41 PM
OK. I understand about the time and I have similar constraints.
Onward with the cooler! Grin
 
Alchemist
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Posted on 11/03/2007 12:49 PM
I have modified my Zen II to use two 500W halogen bulbs in lieu of one of the 10 amp tubular heaters.

Yesterday one of the bulbs blew. Being left is only 15 amps of roasting power, I decided to try a 1 kilo test. Basically a proof of concept for the Zen 4.2 here.

I preheated to 450 F and loaded the beans. Since I have to complete open the roasting chamber to load, th temperature dropped to 275 F. It quickly recovered to a reasonable 350+ in about 2 minutes, and steadily climbed. I had the first outliers of 1st at 11:30 and a solid 1st crack at 12:30. I started pulling the power back at the 11:45 mark so I didn't roll directly into 2nd. A kilo of beans produces quite the amount of smoke and 1st goes on and on. 1st finally finished up (as I kept pulling the power back) around 14:00. I stretched the start of 2nd out to 15:30. At the first snaps of 2nd I pulled the roast.

So there we go. I have solid data we can do 1 kilo on 15 amps in what I consider reasonable time, in a moderately insulated roaster, with power to spare at the end.

I am having 2nd thoughts about the afterburner. I am not sure if we can indeed burn off that level of smoke on the power we have. My plan will be to use that same burner as a heat source for the beans, but even so. Worst case we design it in and if it doesn't work, then we really have nothing lost.

Finally, I had a 11.5" x 3" cake pan I dumped the beans in. About 2" deep. A kilo is a LOT of beans and took quite the air flow to cool. You may be right about your concern about the little tangential blower not being up to the task. I have never cooled that many beans before. But again, it isn't wasted money. If it doesn't work I will want to use it for our motor and wiring space cooler.
 
David
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Posted on 11/03/2007 11:13 PM
Nice proof of concept, sir. A kilo with a single 500 watt halogen plus one of the 10 amp tubular heaters, right?

It would be nice if we could all that smoke. I'm not at all certain that we can reduce it enough for this baby to be an "indoor" roaster. Agreed: no harm in playing with the afterburner design.

Thanks for the details of the trial roast.
 
Alchemist
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Posted on 11/05/2007 1:52 PM
Yes, that is correct. Total of around 1600 watts for 1 kg.

I agree - we play with the design, and if it works, great, if not, I brave the smoke every day. Another thing I have noticed is that with an oxygen deficient roasting chamber, smoke production is way down. That may (or may not) go a long way to keeping smoke under control.
 
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