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Using a ring (regenerative) blower
ACEMBL
Top  #21 Print Post
Posted on 01/18/2023 11:59 AM
Sorry to be so late to the party on this conversation. I’m playing with a forced air roaster that uses a side channel blower (that’s what they call it in UK), a fairly big 3.3kW air gun element and a my sort of Sivitz inspired chamber.

I have been looking into recirculating some of the heat into the blower and with some advice from a pro and Renatoa’s 80C guidance (made some time ago) have been channeling some back from the cyclone. I’m currently working on a motorised valve idea to manage the exhaust recirculation.

I’d roughly estimate that it’s about 25% more efficient just by ending the exhaust 3 inches from the inlet. With proper control I’m sure it will be even more so.

I
 
fpcf
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Posted on 01/19/2023 9:54 AM
Thank you ACEMBL that's a great idea to protect the motor of the blower with heat controlling.
Mixing the inlet air from the heat exchanger ( automobile intercooler) with fresh air with a motorized valve to cool it down is really the goal. I already use two motorized valves from an automobile exhaust pipe for bean charge and bean drop.

My main problem is that I don't know the exhaust temperature behind the cyclone chaff collector and how efficient will be an air heat exchanger?
 
ACEMBL
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Posted on 01/21/2023 3:38 AM
Ooh I like the sound of those motorised exhaust valves. I’ve been thinking about solutions that will handle the hot air out of the cyclone.

I’m going to have a go at making a diverter/valve that will proportion the cold and recirculation air.

Just out of interest would it be worth testing matched roasts with and without recirculation to see if there’s any notable undesirable flavours? If your cyclone is efficient enough at getting rid of small particulates you might not need the inter cooler.
 
fpcf
Top  #24 Print Post
Posted on 01/24/2023 4:50 AM
Hi ACEMBL , the reason for using the intercooler is not to have fumes from the beans in the circulation. I only want to have preheated fresh air passing the beans. So I have to use the intercooler as heat exchanger to separate exhausts from fresh air. Having a motorized valve to control air temperature is pretty cool idea.
 
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