Cyclonic Separation

Cyclonic separation removes particulates from a stream of air, gas or liquid through vortex motion alone, without any filter; the liquid version of the device is called a hydrocyclone and the gas version a gas cyclone or cyclone separator. Incoming air spirals downward inside a cylindrical or cone shaped container, and because denser particles cannot follow the tight curve of the spiral, inertia throws them against the outer wall, where they fall to the bottom for collection; in a conical cyclone the spiral radius shrinks as it descends, letting progressively smaller particles be separated out, with the device shape and flow rate together setting its cut point, the particle size it removes with 50 percent efficiency. Cyclone separators are widely used across pulp and paper plants, cement plants, steel mills, petroleum coke plants, metallurgical plants and saw mills, where they strip sawdust from mill exhaust, separate oil and gas in refineries, serve as preheater components in cement kilns, and appear in bagless household vacuum cleaners and kitchen range hoods as well.