5.48 A 1-1/U counterflow PFHX has 37 active plates. The plates are made from titanium and stamped with a 30° chevron pattern. Each plate has a length of 32 in. and a width of 17 in. The plate thickness is 0.09 in. and the separation distance is 0.2 in. The hot fluid, hard water, flows at 120,000 lbm/h with an average temperature of 145°F. The cold fluid is hard water flowing at 180,000 lbm/h and an average temperature of 50°F. Determine the following:

a. Conduction resistance between the two fluids due to the plate (h·ft2·°F/Btu).

How does this compare with the fouling factor on each side of the plate?

b. Pressure drop of the hot and cold water flows due to friction effects of the plates (psi).