Problem 1 (40 points) A petroleum oil at a total flow rate of 200 gal/min is to be heated from 100F to 180F in a horizontal multipass heater with steam at 60 lb/in2 gauge. The oil enters the tubes at about 4 ft/s. The tubes are steel 3/4-in OD by BWG 16, and their maximum length is 15 ft. Table 1 on the next slides for the oil properties. a) Calculate the heat transfer coefficient of the oil (h) in Btu/h.ft2, F . Assume the wall inside temperature is 300F and hence the correction factor is 1.323. Remember to calculate Re at the entrance to find the type of flow. b) Calculate the overall heat transfer coefficient based on the inside area of the pipes (U). Assume the steam-film coefficient to be 1,200 Btu/h.ft.F. total # of tubes c) Calculate the heat load (q) in Btu/h. d) Assuming complete mixing of the oil after each pass, how many passes are required. Atotal e) Check the validity of assuming the wall inside temperature to be 300F. = 4 of passes A of tuke . #of number of tube Passes one Table 1. Oil Properties for Problem 1 Temperature, F 100 120 140 160 180 200 220 240 260 Thermal conductivity, Btu/ft.h. F 0.0739 0.0737 0.0733 0.0728 0.0724 0.0719 0.0711 0.0706 0.0702 Kinematic viscosity, 10 ft/s 36.6 21.8 14.4 10.2 7.52 5.70 4.52 3.67 3.07 Density, ib/ft? 55.25 54.81 54.37 53.92 53.48 53.03 52.58 52.13 Specific heat, Btu/lb. F 0.455 0.466 0.477 0.487 0.498 0.508 0.519 0.530 0.540