Filtration is a physical process which is aimed to separate a distinct phase from a continuous phase. Based on the phases, filters are classified into dry gas filter, gas-liquid coalescer, liquid-solid filter, liquid-liquid coalescer and gas filter separator. From a different perspective, filters are categorized into disposable and regenerable. Disposable filters need replacing after exceeding the allowable pressure drop while regenerable filters are frequently cleaned by backwash and blowback system.

Filtration is an essential section in almost all industrial plants including food and beverage, oil and gas, petrochemical, polymer, pulp and paper, water treatment and so on. The filtration system may comprise prefiltration, knockout, filtration, coalescence, and final separation depending on the particular application.

To meet the required specifications of each industry, design of filtration system is critical. Configuration of filters in the housing, available surface area, media material and other factors exert a significant effect on filtration efficiency.