Help: Need LPG Gas Valve Help!

[Thomasvillepavers]

First off I am sorry this is not brew related but I have been searching for months trying to find help and answers for a project I am working on and I keep finding more and more useful info on your forums and the knowledge you have for LPG is exactly what I need!!

I own a small paving company and we have just recently started to recycle asphalt, this process requires heating the old, hardened chunks of asphalt for hours to make it pliable and useful again, we have been doing this on small scale and want to step it up. I need to heat over 2 tons of product to 300 degrees and LPG seems the only way to go so I can stay mobile and cost efficient, I have the burners I need and high pressure regulators and the basics in place on the rig, we have tested the setup and now I want to make it user friendly and SAFE... I want to incorporate a flame failure device but cannot find something that will flow at the rate I need... Or so I think as I know 1/2 psi is insufficient...

My current setup:
2x 500,000 BTU burners
2x 0-60 adjustable pressure regulator
3/8" pipe for all items

It is very basic which I like but my obvious concern is that it takes hours to get the product to the temperature it requires so I do not wish to baby sit and I am very concerned of a flame going out and that much LPG flowing!!

I appreciate any guidance or help you have to offer!
P.S. I can add 12volt supply if needed

 

[stlbeer]

I think this is something you could check with an HVAC person about. Something like how a gas furnace operates so if the flame goes out the gas is turned off.

 

[broadbill]

Isn't there any other paving operations that are doing this that you could call and pick their brains about this?

Seems like this is a problem that somebody should have already solved, and asking them would be a more efficient way to figure it out than relying on a bunch of homebrewers to reinvent the wheel for you.

 

[Gunfighter04]

Oil furnaces have a photo-sensor that is located just above the ignition rods. It runs as a timer so that the photo sensor is disabled for about 15 seconds while the burner attempts to ignite. If it fails to ignite it shuts down the pump

In a propane system, I would imagine you would have to change that to a electro-mechanical valve to shut off the propane, but I think the theory would still be sound.

 

[billfloyd806]

Look at a Honeywell 7800 flame safety relay. You might have to use a generator as well to supply 110vac for the control system, but you could use a ultra-violet peeper for LP. I have built a lot of control systems using to monitor the flame on a tube burner up to 4,000,000 btu. You can change purge times, pilot times etc, plus monitor safety interlocks.