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Thread: Propane regulator iceing up
09-17-2009, 10:26 AM #1
Propane regulator iceing up
At work we have an old Kohler generator with a Wisconsin 40hp engine that ran on natural gas. We decided to run the gen on propane so we could move it from building to building. I hooked up a propane bottle from our forklift as we always have about 10 bottles in reserve. I used a regulator I had on the shelf for one of our forklifts and the engine runs great. The only issue is the regulator freezes up after 20 minutes. I figure we'll be using this in the winter sometimes and the cold won't help the situation. Any ideas how to fix this. The regulator has the ports for coolant, but won't help me on the air cooled wisconsin.
09-17-2009, 10:38 AM #2
Get a larger tank, say 500 gallons, and use the vapor withdraw line rather than a liquid line. Even at that, if outside, you may have freezing problems in the winter. Another solution may be to heat the regulator with the exhaust. Could be a new product: Water jacketed exhaust with thermosiphon fluid movement to warm vaporizor.
This is a real problem with propane and cold weather, even on liquid cooled engines.
09-17-2009, 10:55 AM #3
The regulator you are using is the issue, get a demand type regulator which has a vaporizer built in. Some regulators will also have a provision for piping the engine radiator water through the regulator for to prevent freezing. Look in the Onan section on Antique Engines: http://www.smokstak.com/forum/forumdisplay.php?f=1 Search for propane conversions.
09-17-2009, 11:16 AM #4
Lift truck tanks have a suction tube going to the bottom of the tank so liquid is drawn. If you turn the tank upside down so the suction is from the top, you will get gas. This should solve you iceing problem.
09-17-2009, 11:19 AM #5
Depending on what vaporizer you are using, some can use oil for heat transfer. Years ago we use to have problems with engines that didn't have water pumps thus not enough water flow. So we used the bypass oil from the engine lube system (came from the oil filter line), also doubled as a quasi oil cooler. Also you could use an air warmed vaporizer by Century which uses the cooling air from the engine so using the 33 LB forklift tanks would be possible. Bill
09-17-2009, 11:19 AM #6
Camping stores sell 12 volt clip-on heating elements for this. Alternatively you could try what we call tracing wire. This looks like a mains electrical wire but acts as a heating element. It is wrapped around water pipes to keep them frost-free. They connect to mains power, sometimes through a transformer.
09-17-2009, 02:42 PM #7
The Wisconsin is it the V-4 aircooled engine? Horrible devices! We had a roadsaw that kept freezing the regulator, either add some fins to it to increase surface area or do what I did and duck some of the warm air off the cylinders towards the reg.
09-17-2009, 05:25 PM #8
The propane tank i'm using is standing up vertical with the valve on top. I did mount the regulator where the warm air off the motor blows on it. It helps, but still freezes up. I'll let it run through a tank full and see if stays running with the ice.
09-17-2009, 07:39 PM #9
too much propane vaporizing too quickly...get a larger tank and some of this will stop.also that regulator is probably not disigned to operate without coolant to help the process.go to your local propane dealer and they should be able to get you set up with a properly sized regulator for a reasonable cost.
09-17-2009, 07:46 PM #10
If you can see frost now, I am quite certain it will not work this winter when everything is cold.
As an example, I have a 500 gallon propane tank works just fine as a 50 hp vaporizor in the summer. That 50 hp draw would freeze the tank to the point there is no tank pressure when the air temperature dropped below 35 degrees F.
In that case I had to go to a liquid withdraw line and plumb in a water heated vaporizor. I also had to rework the intake so the vaporizor could be plumbed as a thermostat bypass or the vaporizor would freeze up before the thermostat opened.
09-17-2009, 10:58 PM #11
09-18-2009, 05:05 AM #12
Most air cooled system that I have seen dont use liquid propane. They use vapor from the tank. They have a regulator, but not a converter. The tanks have a different valve set up in them, and regular tanks cannot be used. They seem to work ok until it gets cold out and the propane does not gas off so well.
I think trying to use a liquid system they way you are is going to lead to aggravation because it does not have the relative constant of the engine coolant.
09-21-2009, 08:48 AM #13
I have had some people tell me that it's bad to run this engine off propane in liquid form . What's the difference between this 4 cylinder engine and every 4 cylinder forklift I've run? I notice the tank has a fitting saying vapor line, but nobody has a fitting for it( I have called several local places). I think I'm more confused now than when I started.
09-21-2009, 09:01 AM #14
If it has a vapouriser it won't (shouldn't) see any liquid in the intake.
09-21-2009, 11:11 AM #15
Not sure if this applies to your engine, but I have some experience with a Waukesha engine that was able to run on either natural gas or propane. When the engine was switched between the different fuels it required changing the timing and running with different fuel mixture settings. This is due to the vast difference in BTU values of propane and natural gas. Just a thought.
09-22-2009, 03:05 AM #16
I called Impco, who got me in touch with a company that deals with propane carbs. The guy there really know his stuff. He recommended a vaporizer that is made for air cooled engines and has large fins to keep from freezing up. I learned a lot from him. The number is 1-952-445-3910. Ask for Dave if anyone has any questions.
09-22-2009, 05:41 AM #17
I don't think that tank size is your issue. That will keep the tank from freezing, but won't do much for the regulator. Several good suggestions already made above, but stepping the pressure down in stages will help, basically distributing the thermal load (or unload in this case) between them.
You do want to be dern sure that the bottle you are using is drawing (liquid or vapor) what the regulator and engine are designed for.
09-22-2009, 08:57 AM #18
Reg freezing up
Sounds like you have the problem whipped. I would see if you have extra output from the generator then I would make a little coolant system with a tank heater(the kind you use on a car or whatever liquid cooled engine) running antifreeze to the ports on the regulator. Just let it thermal siphon.
But then that is what a farmer would do.
09-22-2009, 09:25 AM #19
Richp: That's what I figured you had already. The one we had fitted on our roadsaw was finned also. I couldn't figure how it was still freezing if it was in the warm airflow. Our engine was a 60hp V-4 Wisconsin.
10-19-2009, 04:17 AM #20
On some air cooled VW applications for propane conversions they drill a small hole in the exhaust and route that through the water ports on the regulator, you can try that