2020-3-14 · Furnace Cooling. The base of the furnace is cooled by air flowing at approximately 1,300 cfm through a plenum formed by six 4-in-high I-beams upon which the furnace rests. The furnace shell, roof, cinder monkey, slag launder, metal taphole collar, and power supply transformer, as well as the electrode arms, cables, and clamps, are water cooled.