Pipeline After cooler with moisture separator: A water-cooled pipeline after cooler comes in different styles. The most common style for compressed air service is a Shell and Tube Heat Exchanger/After cooler. The pipeline after cooler consists of a shell with a bundle of tubes fitted inside. Typically, the compressed air flows through the tubes in one direction as water flows on the shell side in the opposite direction. Heat from the compressed air is transferred to the water. Water vapor forms as the compressed air cools. The moisture is removed by the moisture separator and drain valve. A modulating valve is recommended to maintain a consistent temperature and reduce water consumption. The tube bundles can be fixed or removable. Fixed tube bundles cost less but are more difficult to maintain than bundles that can be removed for cleaning or service.
A moisture separator installed at the discharge of the after cooler removes most of the liquid moisture from the compressed air. Utilizing centrifugal force, moisture collect at the bottom of the moisture separator. An automatic drain should be used to remove the moisture and solids. Moisture Separator with Demister Pad are the Chevron type which consist of a set of specially designed vanes with a well-defined geometry.

VFH (Vertical Flow – Horizontally Placed)
HFV (Horizontal Flow – Vertically Placed)

Gas with entrained liquid droplets flows between the vanes of the Demister Pad. The gas can easily take the turns while the liquid droplets cannot follow the gas streamlines and impinge upon the walls of the vanes and coalesce to a size where they drop down and are collected and removed.