Need Help Revamping Our 20yr Old Diedrich Roaster

The actual questions are on the second post...

So we bought earlier this year a 20yr Old Diedrich Roaster along with the rest of a coffee shops eq. We have a farm in Honduras and we are planning to move from TX to HND next year and setup a Cafe near the farm in town. Our farm thread is here: http://www.coffeeforums.com/forum/c...coffee-farm-future-cafe-copan-ruinas-hnd.html.

So I have done some roasting on a sample roaster and I've looked over many other people's and for our plans we chose the one we bought. I personally love the fact that it's manual and simple. My only concern is it doesn't have many of the temp range sensors, gas gauge and various upgrades I feel that could benefit us.

Before its stated I have looked over many threads and I'm taking an online course for roasting that has pointed out the things we may need. However I much prefer to interact with others and get your advice before I mess something up.

Oh and officially this isn't an actual Diedrich Roaster. It was designed after one and built 20yrs ago by their master roaster of 20+yrs at the time. He built it along with his friend who was a Harley builder so it has many Harley Davidson parts intergraded. It's almost artistic. Almost forgot it's a 5lb roaster, propane and all self contained chaff collector.

Onto the pics...

Pic with me for size reference. I'm 6' tall.








Start there I guess. Thank you!! -Daniel Kent

I realize my questions may not be specific enough, so here goes...
1. Currently all I have is the inside drum temp. So I believe I need the outside air temp, exiting and entering air temp as well.
First: is that correct?
Second: suggestions on proven brands of sensors?
Third: digital or analog?
Forth: best locations for said sensors based on the pics I provided?
Fifth: specifics to sealing off sensors from outside temps where I place them?

2. I understand a gas gauge is good to have after the burner adjustment valve.
First: where should I put it after the valve for best view?
Second: best brand to use?

3. There is a spot between the burner and the drum where the chaff falls and it needs vacuumed even while roasting. Is there any ideas to stop that or just deal with it? Maybe build a shield to at least reduce contact with the flame?

Any other suggestions?? THANK YOU!!!!!!! -Daniel Kent

1. Currently all I have is the inside drum temp. So I believe I need the outside air temp, exiting and entering air temp as well.
First: is that correct?
A: Most people measure bean mass temperature and exhaust air temperature.
Second: suggestions on proven brands of sensors?
A: Omega Engineering is the 'big' brand... its the only company I have used.
Third: digital or analog?
A: I'm not sure I understand the question.. a thermocouple is taking a analog temp reading and converting it to a digital format.
Forth: best locations for said sensors based on the pics I provided?
A: Mine was installed by USRC... my bean mass is located in a similar location as yours. Exhast is installed where the bean shoot meets the drum.
Fifth: specifics to sealing off sensors from outside temps where I place them?
A: You don't really need to seal them off... when I installed on my Quest they suggest using clear nail polish to hold them in place.

2. I understand a gas gauge is good to have after the burner adjustment valve. - SORRY no help here...
First: where should I put it after the valve for best view?
Second: best brand to use?

3. There is a spot between the burner and the drum where the chaff falls and it needs vacuumed even while roasting. Is there any ideas to stop that or just deal with it? Maybe build a shield to at least reduce contact with the flame?

A: Is the chaff falling off in the spacing between the drum and exterior? If so - most drums can be adjusted so the gap is reduced eliminating most chaff droppings. Some is going to happen ...

First off thank you! As for the analog gauge, this is what I meant:
I'll check out that company on their gauges. Very interesting on the nail polish. Lol
Maybe that company has an idea on the gas gauge.
Thanks again. -Daniel Kent

Ok I talked in chat with Omega Engineering and they say analog is pretty slow to read do guess I'll go with digital. I need to actually call them to clarify options.

You have choices on thermocouple placements; the original one actually is good enough without anything else. A split wire thermocouple for the bean temp. could feed the PID and a datalogging program; the best option. Of course ET is nice as well, especially if your datalogging.

Retrofitting the gas with a gauge and valve goes like the photo; I'd let a gas company/appliance repair tech install it. Amazon has nice Dwyer gauges, you would need to figure out which range to buy.

Yeah I'd like to eventually data log. I'll look at those gauges on Amazon. I def appreciate the visual on the gauge.
Thank you!!

Ok so I'm checking on gauges and I'm not sure where to find out what gauge range I need. Is it based on my roaster BTU's?

Daniel - for a reasonably inexpensive data interface take a Amprobe TMD-56... its a 2 channel non-wireless interface. I think I paid around $125 and use Artisian logging software which is free.

Thank you! I'll check those out!

Dwyer® 2.5" Low Pressure Gage, LPG5-D8222N, Bottom Connection, 0-35" w.c. (0-8.75 kPa): Industrial Pressure Gauges: Amazon.com: Industrial & Scientific

Think this gauge is going to work paired with a high pressure LPG regulator. As for the gas valve, I would use something that fit inline with the incoming gas train with the gauge tee'd off nearby. Some valves are easier to adjust than others; something to look for.

Cool that's the gauge I was looking at. Here's some pics of the gas valve and regulator. Just above the valve is where I'll put the gauge. I just want to try and maintain the clean, artistic look of the roaster no matter where I place it.

Hello Daniel,
how are you? Currently I am contacting my customers to invite them for next harvest in Guatemala. and I ran across this company who mainly buys their coffee from Honduras where your farm is at.

In case that you want to sell to USA customers, he might be a good candidate for you.
good luck.

William Dunaway
Copan Trade
[email protected]
C. 281.253.6274
O. 832.515.7100
Skype: william_dunaway
www.facebook.com/CopanTrade

Hey thanks bud! I'll reach out to him as that's been one of our hurtles. Exporting your coffee, especially if your farm is smaller isn't easy.

So you already have an gas adjustment valve; just need a gauge? The pressure gauge needs to fit in after the gas valve, and that would require re-locating the knob. What about tee in the gauge between the regulator and burners; then mount it outside the roaster?