A proposed alternate form for the heat exchanger described in Problem 10.37 is shown in Fig. 10.33. The entire flow conduit is a 3/4-in steel tube with a wall thickness of 0.065 in. the ID for this tube is 0.620 in, slightly smaller than that of the 1/2-in Schedule 40 pipe (D = 0.622 in). The return bend formed by two 90° bends with a short length of straight tube between them. Compute the pressure difference between the inlet and the outlet of this design and compare it with system from Problem 10.37

Problem 10.37

A simple heat exchanger is mode by installing a close return bend on two 1/2-in Schedule 40 steel pipes as shown in Fig. 10.32. Compute the pressure difference between the inlet and the outlet for a flow rate of 12.5 gal/min of ethylene glycol at 77°F.

Figure 10.32

Figure 10.33

Transcribed Image Text:

-in Schedule 40 pipe Flow Inlet Outlet Close return bend 4.00 ft -in steel tube, 0.065-in wall Inlet Flow 6 in Outlet 4.00 ft R- - 3.50 in