Demister pads are effective in separating liquid phase from vapor phase. Typically demisters are mesh type coalescers, but can be constructed of vane pack as well. The function of Demister Pad is to coalesce fine droplets so that the combined drop is heavy and pulled down due to gravity. Usage of Demisters can help in reduction of size of Separator Vessels. The gas/vapor exiting the Separator Vessel is devoid of liquid droplets.
In the working principle, the vane demister pads are different from the wire mesh demister pads. Liquid drainage in the vane demister pad occurs outside the gas flow.
Vane mist eliminator is widely used to separate entrained liquid droplets from gas stream, which the liquid droplets are 8 μm or larger. When the gas stream passes through the vane demister pad and change direction, the liquid droplets are unable to change direction as quick as the gas due to their momentum. So the liquid droplets impact on the chevron blade and then coalesce and form large droplets until drain away.
Feature of Demister & Vane Packs: