Figure 3 shows the temperature distribution through a furnace wall consisting of fire brick and high temperature block insulation and steel plate. The thermal conductivity of the fire brick is 1.13 W/m.C, Determine; a. Rate of heat per unit area of furnace wall; b. Thermal conductivities of block insulation and steel; c. Combined convective and radiative heat transfer coefficient for the outside surface of the furnace wall; d. Heat exchange by radiation between the hot gases and inside surface of the furnace wall. The absorptivity and emissivity of the fire brick wall surface is 0.82. e. Convective heat transfer coefficient for the inside of the furnace wall. Fire brick 810C Hot gases A KL, -6.5 cm -Block insulation -Steel casting L = 12 cm = 0.65 cm Outside air -26C 4-808C 42-777C 1,-78.5C -78.4C