Question: A composite furnace wall consists of 9 in. of firebrick [k = 0.96 Btu/(h ft OF)], 4 1/2 in. of insulating brick [k = 0. 183 Btu/(h ft OF)], and 4 1/2 in. of building brick [k = 0.40 Btu/(h ft OF)]
(a) Calculate the heat flux in Btu/(h ft2) when the inside surface temperature is 2400°F and the outside is 100°F.
(b) What are the temperatures at the interfaces of each layer of brick? Is the temperature of the insulating brick below the maximum allowable value of 2WF?