Demister

A demister, also known as a mist eliminator or entrainment separator, is a critical component within an absorption column system. It is typically installed at the top of the column or in the vapor outlet line. Its primary function is to capture and coalesce fine liquid droplets (mist) that are carried upward by the gas/vapor stream, preventing liquid carryover into downstream equipment. This ensures product purity, protects compressors or other units, improves separation efficiency, and reduces solvent loss.

The demister operates based on inertial impaction, interception, and diffusion. As the gas/vapor stream laden with liquid droplets passes through the demister pad (usually made of knitted wire mesh, vane packs, or fiber beds), the droplets collide with the surfaces of the demister elements. These collisions cause the droplets to coalesce into larger droplets. Once the droplets become sufficiently large, gravity overcomes the drag force of the gas stream, causing the liquid to drain down the demister elements and back into the column or a collection sump, while the cleaned gas/vapor exits.