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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
tb

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PID'ed Gas-fired fluid bed roaster
tamarian
That's perfectly fine, we don't have code inspectors here in Riyadh. This whole basement wasn't even in the blueprint. Grin
Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
http://english.varietalcafe.com
Dan
It always surprises me that the capital of Saudi Arabia isn't on the coast, but in the middle of the desert. You should probably have a good source for Yemeni coffee, right?
1 pound electric sample roaster, 3 pound direct-flame roaster, both handmade; modified Mazzer Mini grinder, LaSpaziale Vivaldi II automatic espresso machine. When the electricity goes out I make vacpot coffee from beans ground on my Zassenhaus hand grinder, and heat the water with a teakettle on the gas range.
 
http://www.intactamerica.org
jkoll42
It still blows my mind the diversity of homeroasters we have here.
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
tamarian
Dan wrote:

It always surprises me that the capital of Saudi Arabia isn't on the coast, but in the middle of the desert. You should probably have a good source for Yemeni coffee, right?


I should, but unfortunately, coffee merchants here don't understand or care about green coffee storage, and with the dry weather and heat we get here, it won't last a month in storage before paling to past crop.
Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
http://english.varietalcafe.com
BryanG
as my build moves forward, this is very interesting. It would be great to be able to create profile programs and then let the machine adjust heat and air flow as parameters are met.

Doing a quick search it seems like the boys that are doing home brewing may be doing some of this already, although, it seems their situation is easier with on and off of heat to maintain fluid temps. Our scenario is more complex as we want to alter the flow of gas to change gas temps ... interesting.
 
tamarian
Progress so far: I've sourced a black iron pipe, just to be on the safe side. Will drill holes in it for torch, glass window and ignitor.

Then got sidetracked with gas safety concerns, in case the flame goes off. Since this is an air tight fluid bed, and any source of access to the torch requires disassembly, I thought I should work on a flame monitoring and re-igniting solution. And found that arduino would fit the bill: http://forum.home...ad_id=3485

The Arduino module is ready and it was a pleasant learning curve. It uses:

1. Arduino Uno board
2. Flame sensor module
3. 1 channel 10A relay module
4. Buzzer module
5 LED + resistor
6 Breadboard

These tiny modules range from $2-$4 on Amazon and eBay. A simple sketch modified from basic tutorials taking analog value from sensor and if there's a flame, do nothing. Else, send relay signal to turn on the silicon nitride ignitor, buzzer and LED's for 2 seconds.

Will need to modify the values based on actual testing and positioning on the ignitor, glass window and flame sensor.

Here's a video of the initial test (note the silicon nitride ignitor held in the vice going on and off):



Remaining work:

1. Integrating this flame sensor module and ignitor to the roaster's control panel.
2. Then work (mostly drilling) on the black pipe.
3. Need to position the flame sensor close to the pipe's glass window and tune the module to be sensitive to detect the gas flame, without interface from other light sources.
4. Secure the gas tubing, gauges, regulator and valve to the roaster.
5. Integrate the valve driver to the control panel
6. Assemble the whole thing, mostly screwing it on together and clean up the wiring.
7. Run with old beans for tuning. There's PID tuning, which will differ alot since my heating chamber is no longer insulated. Proportional valve tuning for min and max flow, and flame sensor tuning.

If the universe cooperates, I'm hoping for less interruptions so I can get this done within a week, as I'm running low on roasted beans.
Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
http://english.varietalcafe.com
tamarian
BryanG wrote:
Doing a quick search it seems like the boys that are doing home brewing may be doing some of this already, although, it seems their situation is easier with on and off of heat to maintain fluid temps. Our scenario is more complex as we want to alter the flow of gas to change gas temps ... interesting.


Yes! I often run into home brewing blogs and threads when I run a search on various aspects of PID's, SSR's and arduino.
Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
http://english.varietalcafe.com
tamarian
Done with the wiring, Arduino and control box reconfiguration. That was the hard part, since I had to practice soldering a lot and watch tutorials before risking damage to Arduino sensors. Drilling the pipes, I hope, is the easy part, since I've done quite a bit of that on my roasting chamber.

Here's how the newly reconfigured control box looks like:

forum.homeroasters.org/forum/attachments/img-20130910-wa0000.jpg

From top left: Fuji PID for electric element; Fuji PID for gas; Proportional valve driver; blower control.
Bottom, from the left: separate box for flame sensor (to be directed at flame window); Arduino board; Switches (PID1, PID2, Cooler, light, electric element, Arduini and valve driver); breaker.
Bottom most: 16A fuse and 36A fuse (for electric element).
Top most: thermocouple sockets, one for each PID.

Below the control box is the proportional valve and gauges.

It started to get cluttered, since it is meant to control either electric or gas heating chambers.

Now that I discovered Arduino, next project is to convert this control box into a much simpler Arduino control box, and reducing a lot of the clutter. But, let me get this thing done first, I'm anxious to get back to actual roasting.
tamarian attached the following image:
img-20130910-wa0000.jpg

Edited by tamarian on 09/10/2013 6:31 AM
Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
http://english.varietalcafe.com
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tamarian
Got the heating chamber drilled for torch, silicon nitride igniter and glass window. The glass window is a small cup, the sides to be covered in tape, to block outside sources of light, and place the flame sensor inside it.
tamarian attached the following images:
img-20130912-wa0001.jpg img-20130912-wa0000.jpg

Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
http://english.varietalcafe.com
tamarian
Finally installed the heating chamber to test, but having difficulty igniting the torch with the blower running. Without the blower, it can ignite with a delay, not instantly like the test I ran in the first post, and the delay would cause a scary bang when it ignites.

Here's a top view:
forum.homeroasters.org/forum/attachments/img-20130912-wa0002.jpg

The silicon nitride igniter is one inch above the torch. Any tips on igniting to make it more reliable?
tamarian attached the following image:
img-20130912-wa0002.jpg

Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
http://english.varietalcafe.com
allenb
I love your control package on the cart! Very professional and very high tech looking to boot!

On your burner ignition issue. Scary bang bad! Have you tried igniting with the blower barely on instead of full on or totally off?

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
BryanG
can you put a little deflector shield under the torch to route that high speed air out away from the ignition point a bit?
 
Dan
It seems the the ignition on my water heater and 2 HVAC units are the same. The blower and ignitor come on, and then when the ignitor is hot, the gas valve opens.

hope this helps, Dan
1 pound electric sample roaster, 3 pound direct-flame roaster, both handmade; modified Mazzer Mini grinder, LaSpaziale Vivaldi II automatic espresso machine. When the electricity goes out I make vacpot coffee from beans ground on my Zassenhaus hand grinder, and heat the water with a teakettle on the gas range.
 
http://www.intactamerica.org
tamarian
Thanks for the input everyone.

It turned out I had the hose restricted/twisted when I screwed on the heating chamber into the blower, possibly giving a restricted, unpredictable flow.

But Dan's observation on HVAC ignition seem to be the case here. The ignitor turns bright orange in 2 seconds after being turned on. I need to modify my ignition setup. In addition to the flame sensor turning on igniter, I need a switch to turn on ignition initially before turning on the valve, then turn it off and let the Arduino flame sensor take care of monitoring the flame.

Need further tests to see if the Arduino setup can re-ignite the flame if it goes off, maybe by adding a couple more seconds delay. But if it doesn't, it's still good to have the loud alarm in place to do something manually...

Next issue is that the roaster may turn out to be a direct flame roaster! I have 15 inches of pipe above the torch, and still see the blue flame coming out of the pipe (I have not yet screwed on the roasting chamber).

All in all, it's getting close, and I may start PID tuning with beans by tomorrow, after I add a manual ignition switch
Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
http://english.varietalcafe.com
tamarian
I couldn't wait till tomorrow! Did a quick test with dry beans and got into a few problems:

1. The valve is too powerful, I may need to cut the max flow in half or more. The thermal tape I had on the de-chaffer started smoking, which it never did in 100+ roast on the electric element. I have pre-set my PID to 10% min, and 80% max, but my need 20% min and 50% max. Lots of tuning to do on the valve and PID.

2. Ignition is troublesome mid-roast when the PID reached set value, the flame goes off, and can't come back on until I slow down the blower. I need another way of insuring flame remains on.

I need to stop for a few days to work on the electric element so I can roast a few batches (running out of coffee), then get back to the gas which needs more work and research.
Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
http://english.varietalcafe.com
Erichimedes
This build looks really cool! I'm sorry I've missed it until now.

I'm trying to learn how to use Arduino at the moment. I don't have a ton of time to invest in it, so I'm learning slowly. I think it's a fantastic platform for stuff like this, and there's so much (free!) support for it online.

As for getting the ignitor to work, I built a blaster style stove for my home distilling setup. It was just a pipe with a high pressure propane jet in the bottom that pulled air up into the chamber and combusted. I found that I couldn't light it near the jet, because the propane had to mix with air before it would combust. It lit best right up at the top. So I'm wondering if moving your ignitor further up the chamber would help.

Also, regarding having Arduino re-ignite the flame; I'm not sure if this is a concern, but consider programming it to turn the gas off completely, turn ignitor on, wait 2 seconds, then turn gas back on. I'm just envisioning filling your combustion chamber, roast chamber, and exhaust with a perfect mix of propane and air and then igniting it. Yikes!

Awesome build! I'm liking everything you've got going here.
 
tamarian
Thanks Erichimedes. I thought my problem was that I needed to bring the igniter even closer. But what you are saying makes sense, I'll try that.

Having Arduino turn off the gas valve is doable, by running the valve driver via a relay switch on Arduino. But I'm hoping to avoid that by setting a minimum value where the flame would still be on.

I managed to revive an old roaster (made a thread about it, Heat gun + egg beater), so I now have a spare roaster and decent coffee, and don't need to rush this thing.

One idea I had is once I find the right location for the ignitor is to keep it on for the entire duration of the roast. If it can last through 20+ roasts (it survived one already), then it will cost less than a $1 per roast. I have a spare, and will see how it goes. I like the peace of mind, despite all the safety measures in place.
Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
http://english.varietalcafe.com
allenb
In my previous home we had a hot water heater that kept the hot surface ignitor on during the entire heating cycle instead of just at ignition. We were there for 10 years and no ignitor failures. Severe bumps and jolts are more likely to cause these to fail than run time.

Allen
1/2 lb and 1 lb drum, Siemens Sirocco fluidbed, presspot, chemex, cajun biggin brewer from the backwoods of Louisiana
 
Dan
Ignitor failures are often a result of some combustible substance on the ignitor's surface. Even the oil from fingerprints can cause the ignitor to fail. Ditto with chaff being sucked into the blower inlet or entering the airflow from a recirculation. New water heaters and furnaces using ignitors have airfilters to prevent premature failure.

hope this helps, Dan
1 pound electric sample roaster, 3 pound direct-flame roaster, both handmade; modified Mazzer Mini grinder, LaSpaziale Vivaldi II automatic espresso machine. When the electricity goes out I make vacpot coffee from beans ground on my Zassenhaus hand grinder, and heat the water with a teakettle on the gas range.
 
http://www.intactamerica.org
tamarian
allenb wrote:

In my previous home we had a hot water heater that kept the hot surface ignitor on during the entire heating cycle instead of just at ignition. We were there for 10 years and no ignitor failures. Severe bumps and jolts are more likely to cause these to fail than run time.


That is good to hear. As an unintended side-effect, the brightness of the ignitor is enough to silence the flame sensor alarm. If it's off, and there's no flame, the alarm will sound.
Wa'il. 1 Kg PID'ed gas-fired fluid bed roaster, GS/3MPS, K10F
 
http://english.varietalcafe.com
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