Removal of Entrained Liquid Droplets by Wire-Mesh Demisters

Abstract

This paper is concerned with the factors governing the performance of wire-mesh demisters, and in particular with their application to entrainment removal in pool boiling systems. The efficiency of a demister pad is derived from the collection efficiency of a single wire, and from this a minimum vapour velocity for efficient droplet removal is determined as a function of droplet size. Correlations for both single-phase and two-phase pressure drop through the demister are given together with a correlation between vapour and liquid velocities when flooding of the demister occurs. These correlations are discussed in relation to experimental results on demisters obtained in the present programme together with published data for packed beds. The effect of the height of the demister above the interface in pool boiling systems is discussed, including the allowable velocities in the vapour space and through the demister.