Been playing with waste vegetable oil [ WVO ] with the intent to use it as free fuel in my central heating boiler. I have a good supply of used french-fry [ chips, frites ] oil lined up from a couple of restaurants. I’m reluctant to go the whole hog and convert it to esters, because of the toxic chemicals, messing with waste-products, titrating, washing, etc., plus my pump has butyl-rubber seals that the esters will attack, meaning changing out the pump to Viton.

I’m going try to use the oil straight, [ that is without diluting it with #1 or #2 oil ] after filtering out the chicken legs and drying it, but I need to heat it to reduce its viscosity to near #2 agricultural mazout. Viscosity before the burner is not a problem, as I already have a pre-heater capable of feeding the pump warm oil, but can only take that up to 150ºF [65ºC]- it's those darned pump seals again.

I have a good spare Italian top-spec. 35Kw oil-burner rigged for trials; c/w oil-pump, flame out, HT spark ignition & air turbine. My plan is to make an induction heater and put a coil round the injector bar just prior to the nozzle tip; [ 7/8” diameter x 6” long drilled-steel injector bar, copper tube rear oil feed-in, pressure set at 180 psi ]. I calculate I need 300ºF [150ºC] and about 200W at first call, reducing as the flame heats up the injector. From the oxide-color of the existing steel bar, flame-heat never exceeds about 350ºF. The thermostat part is easy, 2 range oven-thermocouples on the injector bar [ control + safety overheat ].

Can any of you clever folks point me to how to build the high-frequency part. I promise not to electrocute myself! [Linked Image]

And of course, I’ll publish all the pics here as another project.

Alan

Wood work but can't!