Assertion: furnace | /r/AtLocation | operation
Facets:
Source sentences:
text: It is equipped with a lined cast iron door which clamps down tight on the steel collar when the furnace is in operation, and is easily manipulated by means of a lever located at the rear of the furnace.
text: Because of the thickness of the wall section (commonly over 12 inches) and the insulating capacity of its inner layer 2, there will be a substantial temperature difference between the inner firebrick wall and the outer steel wall when the furnace is in operation.