Liquid/gas coalescer cartridges are similar to cartridge filters in appearance and size. The media is designed for the gas flow inside to out, thus allowing the coalesced liquids to “wick” down the special outer media wrap into a basin for removal. This design is extremely effective due to the media pore structure of 0.3 micron absolute. Basically, this rating means that particles greater than 0.3 micron in size cannot flow through the media.
The extremely small pore structure is due to the unique flow characteristics of submicron particles. Liquid and gas particles 0.1 to 0.6 micron in size tend to flow along the path taken by the gas, as opposed to impinging on pipe walls and dropping out. The particles are not large enough to be removed by inertial impingement and not small enough to be removed by Brownian motion. The 0.3 micron pore media is designed to trap this unscrubbed portion of gas.
This design has proven to be highly successful in numerous refinery and producing field applications. In most instances, installing a high efficiency coalescer is less costly and more effective than making machinery modifications or adding additional knockout capability. It is recommended for use in such applications as produced gas streams, refinery hydrogen recycle streams, gas recovery compression and gas turbine fuel gas supply. Figure P-13 illustrates a high efficiency liquid/gas coalescer.