I wonder if they too have this same "Welcome" sign at the gate?
It’s much more efficient than the 1940’s. They likely use something called a rotary kiln/furnace which can run at a steady state volumetric rate. You can feed most anything in regardless of the moisture/fluid content as the heat will evaporate the fluids. Ash falls out the other end of the process. Material can be brought in on a conveyor belt and ash falls out carried away on another belt.