A shell and tube heat exchanger is used to heat a non-viscous process fluid from 30C to 55C. The heating is to be accomplished by passing 10000 kg/h hot water through the shell that has 290 mm inside diameter. The water makes a single shell pass entering at 90C and leaving at 68C. The process fluid flows through 20 steel tubes of 23 mm inside diameter and 26 mm outside diameter, with each tube making two passes through the shell. The tubes are arranged as triangular by using 32 mm tube pitch. The thermal conductivity of the steel is 60 W/mK. It is known that the heat transfer coefficient of the process fluid is 9000 W/m2K. Thermophysical properties of the water can be assumed constant as: = 995 kg/m3 , Cp= 4180 J/kgK, k= 0.632 W/mK, = 649x10-6 N.s/m2 .

Calculate the overall heat transfer coefficient, the required heat transfer area and tube length per pass. Assume negligible fouling effects. Choose 60 mm baffle spacing and 35% baffle cut. (Please answer crystal clear)