Demister Pads Operation Principle

Operation Principle

Demister pad is a device used for removing entrained liquid droplets from a gas stream. As the name indicates the demister is used for removal of the mist from gaseous phase.

Demister pad is often fitted just below the top vapor outlet of a vapor liquid separator. The demister pads work by coalescing smaller liquid droplets by obstructing their path.

 Obstruction of path causes increased collisions among the liquid droplets.Most of these droplets stick together and form bigger droplets which are too heavy to rise with the gas stream. Thus the bigger liquid drops drop down in the pool of liquid below. 

Gas stream is not affected by the obstruction in the path and escapes through top vapor outlet. The obstruction in the path of liquid droplets can be achieved by a variety of geometries. Demister pad may be a mesh type coalescer to aggregate the mist into droplets that are heavy enough to separate from the vapor stream.

Tower Equipment Types