Cyclones are very common particulate control devices used in many applications, especially those where relatively large particles need to be collected. They are not very efﬁcient for collecting small particles because small particles have little mass that can generate a centrifugal force. Cyclones are very simple devices that use centrifugal force to separate particles from a gas stream. They commonly are constructed of sheet metal, although other materials can be used. They have a low capital cost, small space requirement, and no moving parts. Cyclones are able to handle very heavy dust loading, and they can be used in high-temperature gas streams.
A typical cyclone has a tangential inlet to cylindrical body, causing the gas stream to be swirled around. Particles are thrown toward the wall of the cyclone body. As the particles reach the stagnant boundary layer at the wall, they leave the ﬂowing gas stream and presumably slide down the wall, although some particles may be re-entrained as they bounce off of the wall back into the gas stream. As the gas loses energy in the swirling vortex, it starts spinning inside the vortex and exits at the top. The vortex ﬁnder tube does not create the vortex or the swirling ﬂow. Its function is to prevent short-circuiting from the inlet directly to the outlet. Cyclones will work without a vortex ﬁnder, although the efﬁciency will be reduced.
Iron and Steel
Mining and Industrial Steel