Knock Out Drum

A knockout drum with a mist eliminator is common whenever a process requires entrained droplets to be separated from vapour stream.

A simple knockout drum (without a mist eliminator) will remove droplets larger than about 380 microns by gravity settling. Generally, gravity settling removes 90% of the liquid entering the vessel. However, the remaining droplets smaller than 380 microns can be significant problem for a downstream unit. A mist eliminator at the top of the knockout drum will remove the remaining droplets down to a diameter of 6 microns or less, depending on the type of mist eliminator.

A knockout drum with mist eliminator can achieve an overall efficiency of 99% liquid remova.