Hot demineralized water flowing at 80 gpm, 185F, needs to be cooled to 130F using a 1/1-U counterflow PFHX with chevron patterns of = 30. Cold city water (hard water), flowing at 65 gpm, 50F, is used to do the required cooling. The plates are made of AISI 316 stainless steel. Each plate has a heat transfer area of 4.5 ft2 . The plates are 0.04 in. thick, have a spacing of 0.18 in.,and have a width of 18 in. Determine the minimum number of active plates required and the corresponding pressure drop of each fluid