In centrifuges, a centrifugal force, generated by high speed rotations, is used to separate solids from liquids. Centrifugation can be used to recover solids from slurries, to clarify liquids, or to clarify solids.
Cyclones are used mainly to separate solids from liquid or gas streams. The hydrocyclone shown below is used to clean coal.
Electrostatic precipitators are used to separate small particles, 1 micron or smaller, from gas streams. This process is also used in desalters to separate salts and sediment from crude oil feeds.
Filters are used to separate a liquid-solid or gas-solid mixture. They are used in a wide range of applications, and in many fields, as described below.
Gravity separators classify dry, granular, free-flowing particles based on their specific gravity.
Mist eliminators separate mist from a gas stream to recover valuable products, improve emissions, protect downstream equipment, and improve product purity.
Screening or sieving is a method of separating granular solids according to size. Screens are widely used in nearly every process that handles particulate materials.
By not letting steam escape, heated systems can more efficiently maintain correct process temperatures. Steam traps are automatic valves that sense the difference between steam, air, condensate, and noncondensable gases such as CO2.
Thickeners and clarifiers are both used to separate liquids and solids by settling. Thickeners are used to concentrate solids, while clarifiers are used to purify liquids.