Back of the Evaporator
This is the back of the evaporator. Right under where you see the steam rising, is the big tank that is used to store the sap when it comes in from the holding tank outside. In the middle of the tank there is a bunch of square rods that run along the bottom from front to back of this part of the tank. The fire heats these rods, and makes the sap boil, and the steam is the water that is evaporating off the sap.