The knitted wire mesh entrainment separator, commonly referred to as a demister*, is in common use to separate entrained liquid from vapor streams. However, little quantitative information is available concerning the effect of physical properties of the entrained liquid on allowable gas velocities.
Studies were made on two demister styles to determine the effect of liquid viscosity on demister performance, Liquid viscosities from 0.9 to 12 centipoise were investigated using water, glycerine-water mixtures and heavy no. 2 fuel oil as the test liquids. Air was used as the gas medium in all cases.
Regression analysis of the test data indicates that by increasing viscosity from 3.9 to 12 centipoise the allowable vapor velocity is decreased by only 10%. The effects of other liquid and demister properties on flooding velocity can be approximated by the following proposed equation:
VFLOOD = 5.45 (ρl)0.47 (γ)0.20/((α/ε3)0.30 μl)0.036 (GL)0.11)
* Registered trademark of Otto York Company.
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