The wall of a drying oven is constructed by sandwiching an insulation material of thermal conductivity...

Transcribed Image Text:

The wall of a drying oven is constructed by sandwiching an insulation material of thermal conductivity k = 0.075 W/m-K between thin metal sheets. The oven air is at T; = 400°C, and the corresponding convection coefficient is h; = 25 W/m2K. The inner wall surface absorbs a radiant flux of qrad = 120 W/m? from hotter objects within the oven. The room air is at To = 22°C, and the overall coefficient for convection and radiation from the outer surface is ho = 12 W/m?K. What insulation thickness L is required to maintain the outer wall surface temperature at Twall = 70°C? [20] The wall of a drying oven is constructed by sandwiching an insulation material of thermal conductivity k = 0.075 W/m-K between thin metal sheets. The oven air is at T; = 400°C, and the corresponding convection coefficient is h; = 25 W/m2K. The inner wall surface absorbs a radiant flux of qrad = 120 W/m? from hotter objects within the oven. The room air is at To = 22°C, and the overall coefficient for convection and radiation from the outer surface is ho = 12 W/m?K. What insulation thickness L is required to maintain the outer wall surface temperature at Twall = 70°C? [20]