| 摘要 |
1,265,085. Endothermic processes. METALLGESELLSCHAFT A.G. 30 May, 1969 [30 May, 1968], No. 27593/69. Heading B1X. [Also in Divisions Cl and F4] In an endothermic process, a solid material to be treated, other than aluminium hydroxide, is heated and dewatered in a system of Venturi driers 3, 6 and cyclones 4, 5, 7 operated by exhaust gases from a fluidized bed furnace 9 before being fed to the latter. The solids are circulated in the furnace 9 by means of a cyclone 8 and are subsequently removed by a metering unit 15 and charged into a fluidized bed cooler 16 in which they are cooled directly by fluidizing air, the dust from which is removed by a cyclone 23, and indirectly by air passing through a system of tubes 21. Part of the air from the tubes 21 is supplied as fluidizing air through a grate 11 to the furnace 9, part is supplied at 12 as secondary air into the furnace, and part is combined with the air from cyclone 23 and passed to the system of Venturi driers 3, 6 and cyclones 4, 5, 7 by a conduit 26. Alternatively Fig. 2 (not shown), the whole of the air from the tubes 21 is passed through the grate to the furnace 9, the air from the cyclone 23 is blown as secondary air into the furnace 9 at 12 and solids are discharged for cooling from the cyclone 8. Solids leaving the cooler 16 are discharged through a star lock feeder 24 and by a bucket elevator 25. Fuel, e.g. oil or coal, is supplied to the furnace 9 at 10. The process may be applied to the treatment of phosphate rock, reducing reactions such as the formation of calcium sulphide from gypsum, the dewatering of inorganic compounds such as magnesium hydroxide and iron hydroxide, calcining and cracking processes involving lime, dolomite, raw cement powder or iron sulphate, or high temperature reactions such as the oxidation of ilmenite. |
