The Firing Instrument is located at the center on the crown in the oil furnace and at the center on the floor (bottom) in the gas furnace. The oil and gas in advance mixed with high-pressure air of 3 to 5 % at theoretical firing rate. It emits a jet of the old and the gas downwards and upwards respectively.
Also, an appropriate amount of air to generate the firing, measuring and being supplied by a turbo floor, is pre-heated at 800 centi-grade in a boiler under the furnace. The air spreads out from the nozzle from the back of furnace and whirls in the furnace.
At this moment, the frame of furnace reaches it's heighest temperature, so that every crucible can be uniformly and completely heated, especially even at the bottom, higher in comparison to the usual type of furnace.