Compressor Knock-Out Drum
Compressor knockout drums are used to remove liquid droplet carryover in gases and to thus protect the downstream equipment, usually a reciprocating or centrifugal compressor. Most compressor suction knockout drums are arranged vertically. Gravity causes the liquid to settle to the bottom of the vessel, where it is withdrawn. The vapor travels upward at a design velocity which minimizes the entrainment of any liquid droplets in the vapor as it exits the top of the vessel.