EBay Burkert Digital Control Valve - Page 2

December 26th, 2018, 12:51 pm

baldheadracing wrote:First of all, I just started using Artisan this month - I was using Roastlogger with the Hottop. Second, I've only used a Phidget to read the thermocouple on a Scace device. In other words, I have no idea what I am doing ... but this is how I think it should work. I definitely do stand to be corrected.

The Burkert assembly is an electronically-controlled valve. The valve takes a bunch of different control inputs, but consider the 5 volt input:
- I send 0 volts to the valve - it is closed.
- I send 5 volts to the valve - it is fully open (100%)
- I send 2.5 volts to the valve - it is half-open (50%)
- I send 1v, the valve is open 20%, etc.

I see three phases to using the Burkert:

Phase 1. Use a 5v power supply (or batteries, or the 5v line in USB) and a potentiometer and send a variable voltage to the Burkert. This results in a fancy electronic equivalent to a needle valve.

Phase 2. Read the voltages from Step 1 with a Phidget VINT hub port. A VINT hub port can be configured to read a 0-5v input. For example, if I rotate the potentiometer half-way, then 2.5 v will go to Burkert and Artisan will also be told via Phidget VINT port that 2.5v has been sent to the Burkert. Now Artisan will be able to log all the manual changes made to the gas during a roast.

Phase 3. Replace Phase 1 and instead use Artisan to send a voltage between 0-5v to the Burkert. To do this Artisan has to be connected to a Voltage output Phidget. (I ordered the 12-bit one.) Then a slider/potentiometer (software or hardware) inside Artisan/Phidgets could adjust the gas flow. (Step 2 still does the same thing, but now within Artisan/Phidgets.)

With Phase 3 in place, in a producion scenario:
Step 0. Follow a standard morning startup procedure for your roaster
Step 1. Follow a standard warm-up/charge procedure for consistent starting conditions for each and every roast.
Step 2. Dial in your production roast for a particular coffee using manual gas adjustments (and fix your drum rpm and airflow to be Rao-esque ) Now you have the gas adjustments for your dialed-in production roast recorded in Artisan.
Step 3. go back to Step 1, but now instead of step 2, have Artisan replicate your production roast gas adjustments. You can still over-ride what is happening.
Result: Most consistent coffee. It won't be perfect as environmental conditions change, etc., but when you want to "follow the recipe ..."

More can be done - my roaster is relatively old and I can also use the Burkert to turn off the gas if a probe in the cyclone reads too high, etc.

Thank you so much for posting this! I ordered one and will be using it for the fluid bed roaster I'm building. This info is extremely helpful!

#12: Post by **popeye** » December 26th, 2018, 1:55 pm

What are neutral gases? The Burkert website says the valve is rated for neutral gases (and liquids on request). Does that mean non-corrosive gases? Someone versed in chemistry want to chime in on long-term use of this valve with propane or natural gas?

December 26th, 2018, 2:04 pm

I took three things from the Clippard thread:

1. Is the eBay Burkert valve the right size for a particular roaster model, propane/natural gas, etc.?
- I don't know. The eBay valve has an 8mm orifice, which is probably large enough for my 1kg roaster. However, the valve may be way too large for my roaster.

2. Will the Burkert work fast enough?
- Again, I don't know, but this is related to size. If the valve is - eta: opened - too small or too large, then it will be too slow, or it may not react at all.

3. Can the valve be a PID control output?
- With my roaster, I would guess not, and wasn't planning to try. TBH, it has been decades and three careers ago since I worked on process control systems design, but that's my gut reaction.

December 26th, 2018, 3:19 pm

freeadvice wrote:Thank you so much for posting this! I ordered one and will be using it for the fluid bed roaster I'm building. This info is extremely helpful!

Please keep in mind my disclaimer. Until I have it working, I have only ideas.

In other news, I just got shipping notification on the Burkert; I'll have it in about a month.

#15: Post by **ira** » December 29th, 2018, 3:45 pm

What are people doing for the little 4 pin connector. Burket want's $38 for the connector with 5 meters of cable. So far, I've found them with no wires for around 9 but I need to buy more than one.

Ira

#16: Post by **freeadvice** » December 29th, 2018, 3:54 pm

It has an m12 connection which has 4 pins (you can google that); typically only two pins are used, open and closed, and it does so via 24V power + and -.

The manual also shows how you can bypass those pins and wire directly the + and - . It's detailed on the eBay listing.

#17: Post by **ira** » December 29th, 2018, 4:35 pm

Yes, but using the proper connector means it's waterproof and as I will be using it outside I'd like to keep it that way. And FWIW, I think it's a 13mm Switchcraft Micro-Con-X connector. http://www.switchcraft.com/Stock_Check_ ... 82-4SG-518

Ira

January 1st, 2019, 1:43 pm

Valve in hand. Just waiting for a 4-20mA current control box to arrive and I can test as a manually controlled valve described in phase 1.

January 3rd, 2019, 11:43 pm

Update: Phase 1 test install works

.

Notes for the video (two minutes long):
- pressure gauge is showing mmAq.
- Burkert is displaying percent of valve opening, including tenths of a %.
- my control input is set to 0 to 10 volts but I used a 9v power supply to test so the valve never fully opens in the video (but max. gas is reached with the valve partially-open.)
- Burkert is mounted sideways because of the simple support I will be adding. The unit is heavier than it looks.
- I couldn't find the right M12 connector (for a decent price) so I ran the wires to the inside of the control unit.
- the unit makes noise. You can't tell in the video, but there is a whine that varies in frequency as the valve is opened
- the shut-off feature that I mention at the end is configurable and can be turned off. The default is any value under 2% results in shut-off.
ETA: To clarify, the rheostat was wired as a potentiometer, not a rheostat.

#20: Post by **ballpencil** » January 4th, 2019, 9:28 am

Reading this brings me back to when i was installing a standalone engine computer for my car. It would be very easy to log my roast if i have a spare ECU to put in my roaster.

This Burkert valve can be read using Throttle Position input. Exhaust Gas Temp input can easily be used for BT and ET. Tach input can of course be used to log drum RPM.. or if deemed unnecessary, log airflow fan speed. We might even be able to detect first and second crack using engine knock sensor.