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snwcmpr
03/20/2019 4:17 AM
Eth Yirg Nat Idido Gr1 today.

snwcmpr
03/18/2019 8:15 AM
1 lb roasted lasts a week. I can taste the flavor increase to peak, then drop after. Still very good, but interesting to follow the wave of flavor rise and fall.

snwcmpr
03/11/2019 4:10 PM
Roasted Panama Gesha Esmeralda yesterday. Yummy.

Beebee74
03/11/2019 3:10 PM
I seem to have lost any roasting touch I thought I had. Very frustrated to be wasting time and money. I’m hoping someone can provide some insight on roasting at high altitude. I’m at 4400ft. Thank

aicardo
03/07/2019 8:50 AM
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5400 Watt Air Roaster capacity?
greencardigan
Hi All,

I'm attempting to build another large electric air roaster and have been gathering parts for the build. Shock

At this stage I'm going to use 3 x 1800 Watt heatgun elements for a total of 5400 Watts. Will this be enough for a 2.75 pound (1.25kg) green bean load? The goal is to do 2.2 pounds (1kg) roasted. Any thoughts?

I'm expecting to have a 5.5inch diameter cylindrical roast chamber with a central spouting fluid bed design.
Edited by greencardigan on 01/24/2018 6:02 PM
 
btreichel
I would think so, but depends on how you are able to handle the airflow. Too little, not enough motion, to much, too high of heat loss.
 
renatoa
Why the whole heat should be provided by hot air ?
Why not heat the walls also, if metal, or place some IR elements outside, if glass.
 
greencardigan
I could do that but I'd like to keep cheap and simple. I want a removable roast chamber so I can switch between different sizes.
 
renatoa
What about the RC? a big glass tube a la Sonofresco ?

1.25kg FB, cheap and simple... Good luck! :)
For me 500 grams was end of the road with FB :(
 
Will2
What powerful motor do you intend to use?
On my biggest roaster 150/144mm I did not succeed with the 700w engine to pick up the beans.
Also, I think the power of 5400W heaters is low, I count with a minimum of twice the value.
Maybe 3x3000 to 3x 4000W, I'm not done yet.
It is supposed to be the same philosophy and the same roasting profile for all roasters.

up.picr.de/31455273ee.jpg
Viliam
 
BenKeith
I've not gotten into the fancy math, formulas and calculations. About 15 years ago I started with a Poppery II, and just kept modifying things to get what I needed. I've since gone through every Hearthware roaster they made and still using the iRoast-2 body, roast chamber and blower but running 2,400 watt heating element I made for it, and it's too small when running the fan at 100% once it gets above about 320F. Especially during the winter when it's cold in the garage. With this setup, 200 grams is the max I can run, and 150 grams in some beans. The blower is not strong enough to move the beans and I get scorched spots and scorched beans on heavy, dense beans.
With 2,400 watts and 150 grams of beans sometimes I have to use a heat gun aimed at the air intake for raise the incoming about 50 degrees to keep the heating element in the roaster from staying on 100% I try to keep the heat so it never stays on 100% for more than a couple of seconds, to keep from throwing the PID timing off.
500 grams is about the max I care to roast at one time and getting the stuff together to make one. I've just gotten the flexible mica I ordered to line the inside of the heat chamber and hard mica to hold the heating element. I Plan to use a piece of 4" exhaust pipe to make the housing.
My flow bench has 12, 105 CFM Vacuum motors and since I no longer do supercharged engines, I don't need that much air flow so I'm pulling two motors out of it. Since they in series/parallel I have to pull two, even if it only takes one.
For this 500 gram roaster, with the airflow I'm thinking it's going to take for good bean movement, I plan to make a 5,000 watt heating element for it
Now, if some reclaimed/recirculated air was used, the power requirement could be significantly reduced. Years back I tried that when trying to push that old Poppry II to it's limits and never like the taste of the beans I got.
So, with all that said, I personally don't think 5,000 watts is going to be enough for your project, but until I've tried it in my 500 gram one, I can't say one way of the other for sure.
With all my other projects I have going, maybe before too long, I can get this thing going.
If you are not doing this in the next few weeks, I might be able to make you a 5,000 watt heater like I'm going to make. It's not going to be real pretty because formed shaped reducers on each end are fairly expensive so, I'm going to do a little redneck engineering to form reduced ends.
Edited by BenKeith on 01/25/2018 7:50 AM
 
greencardigan
I’m planning to try a 600 Watt vacuum blower. It’s the same type as I use on my 350g roaster but I only use between 10% and 20% power on it. So I’m hopeful it can do up to 1kg.

Is anyone familiar with the Artisan 2.5 air roaster? It apparently uses 5200 Watts to do up to 3lb (1.36kg) batches. Maybe it recycles exhaust air? Specs PDF here - https://coffeecra...-Sheet.pdf
 
allenb
Looking at the table I put together a while back, it looks like 5200 watts would be in the ballpark without reclaiming. The table isn't based on calculations but is from pulling advertised specs from various makes/models.

Fluidbed--------------------Drum

lbs---BTU's---KW---------lbs---BTU's---KW
1-----10200--3kw---------1----6800----2kw
2-----17000--5kw---------2----10200---3 kw
5-----25500--7.5kw-------5----17000---5kw
8-----34000--10kw--------8
10----40800--12kw-------10---35700---10.5kw
12----47600--14kw
Edited by allenb on 01/27/2018 8:07 AM
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
renatoa
900 grams = 2 lbs --- 1.5 kW - IR + convection
 
greencardigan
Thanks Allen for the table. I was looking for that but hadn't found it.
 
greencardigan
BenKeith wrote:
If you are not doing this in the next few weeks, I might be able to make you a 5,000 watt heater like I'm going to make.

I can't use a single 5000W element. I probably will only have access to a 3600W and a 2400W power circuit. I'll be splitting the heating elements over both circuits.
 
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