Example 4-5 Wire Mesh Entrainment Separator

Design a flash drum to separate liquid ethylene entrainment for the following conditions  

Volume of vapor = 465 CFM —110°F and 35 psig Density of vapor = 0.30 Ib/cu ft Density of liquid ethylene = 33 lb/cu ft Allowable velocity for wire mesh  

When placing mesh in small diameter vessels it is important to discount the area taken up by the support ring before determining the operating velocity of the unit. For small 6-, 8-, and 12-inch vessels (such as in-line, pipe-with-mesh units) it is usual practice to use 6- or 8-inch thickness of mesh for peak performance. 

Deduct 4 inches from effective diameter for 2-inch support ring inside. 

This is 97% of maximum allowable design, too high. Second Try  

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