Cyclones are force-of-gravity separators. The separation principle is based on centrifugal force, which is produced by the tangential injection of the raw air. Cyclones are used as pre-filters or for the separation of large quantities of dust and swarf. The degree of separation of a cyclone is not normally sufficient to meet the usual environmental protection requirements. The cyclone exhaust air must be post-filtered in most cases.
A cyclone essentially consists of three parts: the intake cylinder, the cone and the immersion tube. In the intake cylinder, the raw air is brought into a circular path by means of tangential injection. Due to the taper of the subsequent cone, the speed of rotation increases sharply, so that the particles are pressed by centrifugal force against the outer wall and decelerated by friction, causing them to drop out of the air stream and fall down. The cleaned air leaves the cone in an upward direction via the central immersion tube. Cyclones are usually welded sheet steel structures. Cellular wheel sluices or, in individual cases, double-gate sluices are used for the pressureless discharge of the material. In order to increase the cyclone effect, or the degree of separation, counter-spirals with a pipe connection can be placed on top of the immersion tube.
Further options are, for example, wearing devices, explosion pressure relief devices, control flaps, level monitoring devices and manufacturing in stainless steel or galvanised sheet steel.