An observation cabin is located in a hot-strip mill

Chapter , Problem 13.92

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An observation cabin is located in a hot-strip mill directly over the line, as shown in the schematic. The cabin floor is exposed to a portion of the hot strip that is at a temperature of Tss 920C and has an emissivity of ss 0.85, as well as to surroundings within the mill (not shown) at a temperature of Tsur 80C. To protect the operating personnel in the cabin, the floor must be maintained at Tf 50C. Determine the coolant system heat removal rate required to maintain the cabin floor at 50C for the following conditions: (a) when the floor, with an emissivity of f 0.6, is directly exposed to the strip; and (b) when a radiation shield of emissivity s 0.1 is installed between the floor and the strip. 13.9