There is a long discussion of these heaters in Biodiesel for Heating.
These are large vaporizing pot burners supplied since ww2 to the US army. They are of very heavy construction, typical of military hardware and are designed to burn a wide variety of fuels from gasoline to heavy diesel oil.
With the supplied float valve ( sometimes called a carb) it is not possible to burn WVO unless thinned with diesel or kerosene. However once the burner is lit and running WVO can be fed into the pot from above. With a suitable dosing pump the burner will burn WVO cleanly and reliably.
I have installed one of these burners into a stove in my workshop ( pictured below) and use it for 8 - 10 hours per day throughout the winter. The output of the stove is around. 7 kilowatt.
I use yellow grease as the fuel. This the semisolid mixture of veg oil and animal fats that is too thick to make biodiesel with. The yellow grease is warmed by the heat of the stove to keep it liquid.
I have just completed a boiler powered by one of these burners which I am installing in my house.
If you click on the image below it will take you to My Imageshack where you can view the construction of the workshop stove.

Posted 21 January 2009 09:58 AM Hide Post
Well its done, my heating system is up and running after a few problems with getting the flue up through the roof it was all fairly straightforward.
The boiler is one I have built myself using a steel oildrum as the outer body and a smaller stainless steel drum for the heat exchanger. A full diagram and explanation of the design is posted on the topic of the same name as this one in "Biodiesel for heating"
After the first hour the burner runs on plain waste veg oil with no addition of other more flammable fuels.
Just to describe the system the fuel tank is a small 60 litre steel drum fitted with a 300W electric heating element salvaged from a heated towel towel rail. A thermostat maintains the veg oil at 50 degrees C. This is important for my system because I only use the thick semi solid mixture of veg oil and animal fat that is known as yellow grease. All the clean liquid veg oil that I collect gets converted into biodiesel for my car.
A Williamson peristaltic pump is used to deliver the warm oil into the preheat coil of the burner.
The boiler and fuel tank are installed in a utility room and the hot water is piped through to the house. I have connected up four large radiators each about 6 feet long and rated at 1500w at 50 degrees. I didnt want to connect it to my existing heating system in the middle of winter in case it didnt work.
I started the boiler for the first time this morning. At 11.00 I lit the burner with a shot of methanol, dropped in a match and turned on the oil control/ carb. For the first hour the burner runs on biodiesel with 10 per cent kerosene. You could use diesel or kerosene instead. Then at 12 noon I turned off the oil control/ carb and turned on the peristaltic pump. The warm oil flowed in and the burner continued to run with a slightly cleaner flame.
At 12.15 the thermostat on the outlet pipe of the boiler sensed a temperature of 45 Degrees and switched on the circulation pump.
By one oclock the radiators were at 60 degrees and I had to turn down the burner. Its now 3.00 pm and the burner is running at its lowest setting and the radiators are at a steady 55 degrees. The rooms are warm and Im a very happy camper. Its difficult to be exact but I would estimate that this boiler could heat 6- 8 radiators and a hot tank. Got to run, school pick up time. I will report progress tomorrow.

I love it when a plan comes together ? Who said that
Déise great that you have the boiler up and running’ you should definitely think about connecting it to your hot water; for winter and summer
Large rads that can give off heat at low temperatures is a good idea; something that I will be doing’ as mine get older’ it will make my system more efficient
I presume it is an open system; so should not be to difficult to tie it into your existing system
Crazy horse should have a few ideas on how to do this; of coerce we would have to inspect your work provided you throw in a few cups of Coffey and biscuits; complements to the chef by the way’ last batch were exceptional
Tying it into your exiting heating system; will give you more scope, like when you are not there;
the hho will kick in; when you light the wvo it will cut out
Nice bit of work glad it worked out

Ill be around on Saturday morning if you want to call in. As you know our house is for sale so I dont want to install this boiler permanently in case we move. Mind you, that could be years the way the property market has gone.
I reluctantly turned off the boiler at 11.00 pm last night.( I dont want to run it overnight until I fit certain safety cutouts that I am testing) The boiler ran for a total of 12 hours without needing any adjustment.
I already can see some ways to improve its performance. I had drilled 3 one inch viewing holes so that I could check on the flame now and then. I had thought they would not affect the airflow through the burner too much but I was wrong. By closing up 2 of them the flame was noticably cleaner and by fitting a hinged flap over the third one the flame is now a perfect deep blue. Within 30 seconds of opening the flap the crown of the flame turns an orange colour.
If I turn up the burner above the lowest setting I get a tinking noise coming from the boiler. This seems to be small bubbles of steam rising off the bottom and then striking the top of the boiler. The system is an open, vented one and has a pressure release valve for good measure so its not dangerous but its undesirable. More radiators would probably solve the problem. If not a sheet metal sheild on the bottom of the boiler to deflect the flame.
Ill take some pictures and post them tomorrow.

Here is a picture of the boiler. After three days running the original paint on the oildrum is intact thanks to the insulated lining. The pieces of silver coloured metal screwed onto the lower part of the boiler are covering the view holes which I no longer use. The left hand one swings out of the way if I want to view the flame.
the white vessel to the right behind the boiler is the heated fuel tank.