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Electronics Continuity for Planned FB Roaster
10centNickle
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Posted on 11/14/2023 3:23 AM
I want to build a FB roaster capable of roasting half a pound, but I'm completely new to circuits and the like, can someone verify with me that the electronics that I have in my cart right now will all work together + be enough to do half a roast + I don't have any severely unnecessary parts? Currently I have a 1 and 1/4 qt bain marie as my RC, with a diameter of 4.88in. Air comes from a 110v 400w leaf blower, AC. Heat comes from a 110v 1500w ceramic heating element that is AC/DC universal, and for power, I have 2 40A DC 3-32V to AC 24-380V SSR. The brains will be an Arduino Mega.
 
renatoa
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Posted on 11/14/2023 8:05 AM
And the roaster type is ?
The closer to the parts list seems to be a kind of perforated drum, but in this case the blower is too powerful, imo.
400W leaf blower is capable to levitate a pound of greens, so for a drum will be a storm inside.

Type of ceramic element is also important, is it a cartdrige type, to be mounted in a heatgun style and heat airflow?
Or a radiant element, intended to heat the drum ?

The more details, the better...
 
allenb
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Posted on 11/14/2023 8:17 AM

Quote

renatoa wrote:

And the roaster type is ?
The closer to the parts list seems to be a kind of perforated drum, but in this case the blower is too powerful, imo.
400W leaf blower is capable to levitate a pound of greens, so for a drum will be a storm inside.

Type of ceramic element is also important, is it a cartdrige type, to be mounted in a heatgun style and heat airflow?
Or a radiant element, intended to heat the drum ?

The more details, the better...


Hey renatoa, he stated it would be a fluidbed (FB). But yes, more detail needed.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
renatoa
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Posted on 11/14/2023 9:39 AM
Ah, didn't noticed the FB letters... sorry

For half pound the 400w leaf blower is a lot too much, will work severely braked, very possible in the area under 50%, where the speed vary a lot with the load and voltage... thus unstable airflow and temperature.
For this load (2-300 grams) me and fellows in local roasting community have good results with inflatable pumps having 75-120W power, like Bestway SIDEWINDER or similar.

The 1500W power also will limit the load, a rough estimate for FB machines is 1000W per each 100 grams intended load.
 
10centNickle
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Posted on 11/14/2023 11:50 AM
I'd rather upgrade components than downgrade them, the heating element is this one:

https://www.amazo...Q&th=1

If I stack 3 of these, would that provide adequate power for a 1lb roast? Would an Arduino be able to handle that much?
Edited by renatoa on 11/14/2023 1:39 PM
 
allenb
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Posted on 11/14/2023 12:25 PM
You won't be able to use this type of heater for a coffee roaster unfortunately. High temp limit of these are too low.

The temperature operating range of the positive temperature coefficient PTC heaters is 40 degrees C to 220 degrees or 104 degrees F - 428 degrees F. Keep in mind that is the temperature of the actual ceramic heating element.

The air leaving one of these would be well below the max stated above and you need to be able to reach at least 500F (260C) air discharge.

Look for anything with resistive wire (nichrome for an example) which can handle the needed temperatures.
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
10centNickle
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Posted on 11/14/2023 11:10 PM
Hmm, guess I totally missed that part when I was checking it out. Thanks! Would it be advisable to what I've seen a lot here, which is take the heating element out of a ceramic heat gun? Would two of these work?

https://www.amazo...09GYD31FR/
Edited by renatoa on 11/15/2023 2:20 AM
 
allenb
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Posted on 11/16/2023 12:10 PM
You didn't miss it. I posted something from a different site showing the limitations of PTC heaters.

On the heat gun elements question, it depends on what particular style of element those guns are using. Some, like the ones in harbor freight low cost ones, the nichrome wire is wound around some kind of odd mica rod shaped formers which works fine for a heat gun but not so fine for heating higher air flow. Some other heat guns use enclosed ceramic formers which would work if using more than one as they have small air passages limiting how many cfm will easily flow through them. Others use open frame traditional coiled nichrome elements which are the easiest to work into our designs but these are not used on many of the current heat guns. I would recommend just buying the open frame nichrome replacement elements which would allow you to know what you will end up with.

https://www.zoro....lsrc=aw.ds
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
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