Blue Sky Thinking indeed, I think it's safe to say that this one really is an "out of the box" idea.
OK, principle of microwave ovens. A magnetron tube creates electromagnetic waves which food readily absorbs causing the particles to align with the waves. The waves constantly change (at a high frequency) hence the food particles gets moved about and this causes heat via friction. Science lesson over, back to practical work now......
It's almost the perfect way to warm up your veg oil (or Lard since you're a Northerner).
The downside to this is that metalic objects reflect the electromagnetic waves and your feed to the injector is a copper pipe so your first challenge is to find a non metalic pipe that will withstand the pressure of the diesel pump. Having solved that challenge (the easy way being to put the "heater" before the pump), you now have to build a metalic box around the pipe into which you aim the magnetron.
Sealing it isn't too bad since the microwaves actually have a wavelenth such that the perforated holes in the foil of the conventional microwave oven door allow light through but are small enough that they are seen as a solid wall and reflect the waves back so it doesn't need to ne "air tight", just make sure there are no holes bigger than a few mm's.
Heating your bigger storage tank is much easier since this will most likely be a metal tank anyway so you just need a metal lid for it (with a few holes to let out any steam in case you get the lard too hot) and your magnetron will happily melt your lard for you. You'll have to experiment with how much energy you need to put into your lard depending on how much there is in the tank and the ambient temperature.......
Can't wait to see it all happening, from a safe distance of course
