This is a very efficient and cheap kiln, which took my fancy.  A couple of diesel fuel pumps are driven by an electric motor, paralleled in 3’s to give 4 outlets of high flow diesel through 4 injectors to fire a kiln for bricks.

The fuel is filtered sump oil, and the secret of getting it to burn is to mix water with it – the water evaporates and disperses the oil, allowing it to combust completely.