Hand written explanation required

1. A pipe is covered with three insulation layers where the corresponding thicknesses are 50 mm, 80mm and 100mm and the respective thermal conductivitye 1.15 W/m.C, 1.45 W/m-C and 2.8 W/m-C. The inner side of the pipe which has a diameter of 30 cm is exposed to a hot gas at 1200 "C with convection coefficient of 50 W/m C and the temperature of the inner side of the pipe surface is 900 "C. The air outside the pipe is at 25"C with a convection coefficient of 20 W/m-C. a. Draw a schematic diagram which represents the heat transfer process [1 mark] b. Calculate the Heat transfer rate [3 mark] c. The overall heat transfer coefficient "U" of the system based on the inner pipe (3 mark] d. Temperature at each of the layers and at the outermost surface of the pipe. [3 mark]