Gas/liquid flow in plate-and-frame heat exchangers -: Part I:: Pressure drop measurements

Pressure drop is measured during steady-state adiabatic gas/liquid flow in a single channel of a plate-and-frame heat exchanger: Channels with chevron angle configurations of 30 degrees /30 degrees, 30 degrees /60 degrees, and 60 degrees /60 degrees and channel gaps of 2 and 3 mm are investigated. The two-phase mixture consists of air and either tap,vater or an aqueous solution of carboxymethylcellulose. Flow qualities range from 0 to 1 at a mass flux of 50 kg/m(2)s and from 0 to 0.05 at the highest mass flux of 600 kg/m(2)s. In addition to the measurement of the pressure difference between inlet and outlet (port to port), pressure taps located inside the channel enable the measurement of the pressure drop across the corrugated section only, allowing for a clear description of the influence of corrugation geometry on pressure drop. Pressure drop is shown to be greatly influenced by channel geometry. For flow of constant mass flux, frictional pressure drop is observed to increase linearly with flow quality. It is independent of flow direction at mass fluxes below 400 kg/m(2)s. Increasing the liquid viscosity appears to influence the measured pressure drop only at low flow qualities.