Pressure Drop in Plate Heat Exchangers During Crystallization Fouling

Pressure drop and heat transfer coefficient are measured during calcium sulphate deposit formation in a plate and frame heat exchanger. The performance of the plate heat exchanger is compared with that of a double pipe heat exchanger. Although the plate heat exchanger, due to its superior design, fouls less than the double pipe heat exchanger, it still suffers from a severe reduction in performance. Deposits on the plates restrict the flow through the narrow flow channels increasing the pressure drop across the plate heat exchanger several times above the starting value when there is no fouling. This may overcome the advantages of higher heat transfer coefficient and reduced fouling, and make the installation of plate heat exchangers economically unattractive. Depending on the design of the plates, the pressure drop may increase significantly even though the heat transfer surface remains almost clean. Keywords: Plate heat exchanger, double pipe heat exchanger, pressure drop, heat transfer, fouling resistance, crystallization, calcium sulphate.