| 摘要 |
1,142,046. Pelletizing powders. UBE KOSAN K.K. 20 June, 1966 [27 Aug., 1965], No. 27556/66. Heading B5A. Pellets of less than 5mm. diameter are produced from powders e.g. of fertilizers, cement, minerals, abrasives, refractory materials, uranium, metal, resins, agricultural chemicals, foodstuffs, or carbon, by forming a fluidized bed of the powder by means of a fluidizing gas and introducing a liquid into the bed to cause agglomeration of the powder which is forced to circulate by introducing a jet of further gas through a pellet discharge outlet in a fluidizing gas distributer. The powder may be introduced moist or powder and liquid may be introduced simultaneously in admixture e.g. as a slurry. Seed pellets may also be introduced into the bed with the powder. The fluidized bed is formed by a porous gas distributing member 16 through which fluidizing gas from a blower 17 passes and is supplied, at inlet 33, with powder from hopper 14 by a gas stream from blower 12 or, alternatively, by a screw conveyer. Larger pellets are selectively discharged at outlet 32 by the jet of further gas, introduced through the outlet 32 from blower 21. An atomizing device 6, comprising concentric openings (34, 35) (Fig. 2, not shown) for respective gas and liquid feeds from a compressor 9 and pump 10, injects liquid or slurry directly into the bed and which gas may also comprise a further jet of circulating gas. The pellets are discharged to a hopper 20 through one or more pipes 19 and are fed to a container 23 and dried by the passage therethrough of a heated gas stream. Minute particles containing seeds which escape via exhaust port 36 above the fluidized bed are separated from the gas by a cyclone 2 and recycled via a pipe 5. |
