The Permeability of Screen Wicks

Abstract

An experimental study was performed on the permeability of screen wicks using water. An equation for the wick porosity influencing the permeability was also proposed based on a model of the screen geometry. In the present experiment, the screen mesh size, number of screen layers, packing condition of the screen and flow rate were varied. For the friction factor, a correlation C_f=A/Re was obtained ; here the coefficient A was related to the packing number ω defined by the ratio of n-layer thickness to n-times the single-layer thickness of the screen. Consequently, it was found that the permeability of the screen wicks could be predicted considerably well from the expression presented in this study and increased steeply with the increase in the packing number ω, which showed the degree of hold-down pressure for the screen wicks.