5.36 A 3 1 type M copper tube double-pipe counterflow heat exchanger is used to cool...

5.36 A 3 × 1¼ type M copper tube double-pipe counterflow heat exchanger is used to cool a flow of liquid toluene. The heat exchanger consists of three 10-ft-long DPHX hairpinned together. The toluene enters the annulus of the heat exchanger at a flow rate of 25,000 lbm/h and a temperature of 200°F.

The toluene is being cooled using a 20% solution of ethylene glycol. The ethylene glycol enters the inner tube at 20°F with a mass flow rate of 15,000 lbm/h.
Determine the following information for this heat exchanger:

a. UA product for the heat exchanger for both clean and fouled conditions (Btu/h·°F)

b. Outlet temperatures of each fluid (°F)

c. Pressure drop of each fluid through the heat exchanger (psi)

d. Heat transfer rate between the fluids (Btu/h)