A hydrocarbon oil with the properties given in Problem 15.15 is to be cooled from 120 to 60°C in a plate-type exchanger. Cooling water at 30°C enters the exchanger at twice the mass flow rate of the oil. If the oil velocity is 1.0 ft/s. estimate the overall coefficient for the exchanger.

Prob. 15.15

A shell-and-tube exchanger with 1-in. BWG 14 tubes will be used to cool a heavy oil from 120 to 50C, using cooling water at 25C. The oil properties are:

(a) To help decide which fluid to put in the tubes, compare the oil-film coefficient for flow in the tubes at 30 cm/s with the coefficient outside the tubes at the same velocity. Assume G_b = G_c for flow on the shell side.

(b) How is the comparison in part,

(a) affected by the velocity chosen?