Vapor Liquid Horizontal Separator Sizing

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Solved Examples

Design a horizontal separator to separate a vapor liquid mixture. Vapor mass flowrate is 10000 Kg/h and density 20.18 Kg/m3. Liquid mass flowrate is 5000 Kg/h and density 736.1 Kg/m3. Take holdup and surge time to be 5 minutes each. Estimate K Value for operating pressure of 10 Barg. Use Momentum criteria for nozzle sizing as 744.08 Kg/m.s2 for feed inlet and vapor outlet nozzle. Use 2 m/s max velocity for liquid line sizing. L/D to be considered 3. Separtor to be designed for 75% of the terminal velocity.

Result
Diameter 1200 mm
Length 3600 mm

Design a Knock out drum without a demister for separating 20,000 lb/h of vapor from 50,000 lb/h of liquid. Vapor density is 1.3 lb/ft3 and Liquid density is 54.0 lb/ft3. Use residence time as 5 min for holdup and surge. Liquid droplet size is 250 micron and vapor viscosity is 0.013 cP. Design velocity to be taken as 75% of terminal velocity. Momentum criteria for Feed Inlet and Vapor outlet line sizing to be used as 500. Liquid outlet line to be sized for 5 ft/s. Low Liquid Level to be taken 6 inch above bottom.

Result
Diameter 4.5 ft
Length 13.5 ft