| 摘要 |
<p>1,145,921. Drying granular material. F. L. SMIDTH & CO. A/S. 10 Jan., 1967 [10 Jan., 1966], No. 1112/66. Heading F4G. In apparatus for drying moist granular material, e.g. cement, the material is introduced into the lower end of a riser pipe 4 from a conveyer 11 which is supplied with hot waste gas from a furnace (not shown) via a fan 1 and the smaller particles of which material are upwardly conveyed by the gas stream, the supply of water to a spray nozzle 26 continuously or intermittently introduced into the gas being controlled in accordance with at least one physical condition in the pipe. As shown, the amount of material fed to the pipe is sensed by a feeler 14 above the conveyer 11 to control a valve 28 leading to the nozzle and in a further embodiment several spray nozzles each controlled by a physical condition in the pipe are described, e.g. temperature and moisture of the moist gas stream. The dried material passes to a cyclone separator 5 and an electrostatic precipitator 8, and the larger, undried material passes from the base of the pipe via crusher rollers 20 to an elevator 22 either to discharge and a grinding mill or for recirculation. The or each nozzle may be retractible out of the gas stream in response to physical conditions in the pipe. The water is introduced into the gas in order to control its temperature and water content so that clogging tendencies in the mill or unsatisfactory operation of the precipitator 8 are reduced or prevented.</p> |
