Air at 4 °C is being carried within a metal cylindrical pipe to a storage room at a bioprocessing facility, where a heat-sensitive protein product must be stored until it is transferred to another facility. The outer diameter of the pipe is 400 mm, and the thickness of the pipe is 2 mm. The pipe is installed within a larger room where the room temperature is kept at 20°C. There is a layer of insulating material around the metal pipe. Thermal conductivity of the metal pipe is 60 W/m*K, whereas the thermal conductivity of the insulating material is 0.04 W/m*K. Heat gain by the air being transported occurs at a steady rate of 40 W. A while later, it becomes necessary to reduce the temperature of the flowing air down to 0 °C for another protein product. By how much (in percentages) should the insulation material thickness should increase in order to maintain this air temperature within the pipe? Assume the inner surface temperature of the metal pipe is equal to the air temperature in the pipe, and the outer surface temperature of the metal pipe is equal to the surrounding air temperature
Air at 4 °C is being carried within a metal cylindrical pipe to a
storage room at a bioprocessing facility, where a heat-sensitive protein product must be stored until it is transferred to another facility. The outer diameter of the pipe is 400 mm, and the thickness of the pipe is 2 mm. The pipe is installed within a larger room where the room temperature is kept at 20°C. There is a layer of insulating material around the metal pipe. Thermal conductivity of the metal pipe is 60 W/m*K, whereas the thermal conductivity of the insulating material is 0.04 W/m*K. Heat gain by the air being transported occurs at a steady rate of 40 W. A while later, it becomes necessary to reduce the temperature of the flowing air down to 0 °C for another protein product. By how much (in percentages) should the insulation material thickness should increase in order to maintain this air temperature within the pipe? Assume the inner surface temperature of the metal pipe is equal to the air temperature in the pipe, and the outer surface temperature of the metal pipe is equal to the surrounding air temperature
Step by step
Solved in 4 steps with 9 images
