FI750617

1500117 Cyclone separators BAYER AG 6 March 1975 [6 March 1974] 9340/75 Heading B2P Solids are separated from a gas stream by passing the solids-laden gas stream through a cyclonic separation zone founded by the inner surface of an at least partly porous wall, causing a flushing gas to flow into the separation zone through the wall so that a film of flushing gas is formed over the inner surface of the wall, and withdrawing the solids and the gas stream independently from the separation zone. As shown in Fig. 2, the solids-laden gas stream is introduced through an inlet pipe 1 tangentially into a double-conical cyclone having inner porous walls 6 and outer gasimpervious walls 4 defining with the walls 6 intermediate zones 8 to which flushing gas is supplied via conduits 10. The gas stream outlet pipe is also provided with an inner porous wall 7 surrounded by a gas-impervious outer wall 5, the intermediate zone 9 being supplied with flushing gas through a conduit 10. In another embodiment, the cyclone is of the single-cone type. Water, e.g. in vapour form, may be added to the gas strain before or after it is introduced into the cyclone. The outer walls of the cyclone may be cooled with water. The inner walls 6, 7 may be made of metallic or non-metallic materials, e.g. ceramics, carbon or graphite; the porosity may be produced by sintering, punching, drilling or electrolytically; or the walls may be made from screens or cloths. The flushing gas may consist of one, e.g. nitrogen, chlorine or carbon dioxide, which is inert to the solidsladen gas stream, to the solids and to the constructional materials of the cyclone. Alternatively, part of the separated gas which has been cooled may be recycled as flushing gas. Examples of solids which may be separated out of gases are given.