| 摘要 |
1,270,020. Evaporators for spray drying. NIRO ATOMIZER A.S. 7 July, 1969 [9 July, 1968], No. 34229/69. Heading B1B. A solution or suspension of a solid material, e.g. ceramic clay, in a liquid is dried in chamber 1 where the atomized material is contacted with drying air supplied via filter 18, heater 19 and annular chamber 4, some of the liquid being atomized by rotating wheel 2, and another supply of the liquid being atomized by nozzle 10 which discharges in the direction of wheel 2, whereby a powder product having a desired range of particle sizes can be produced. The powder product is withdrawn from chamber 1 through valve 8. The drying air flows out through duct 6 which leads to cyclone 21 for the separation of fine particles. The distance of nozzle 10 from wheel 2 is greater than half the distance between wheel 2 and outlet valve 8. Wheel 2 is preferably driven at a speed which is higher than the speed corresponding to the obtention of the desired particle size; and the liquid is distributed approximately evenly between wheel 2 and nozzle 10. The mean particle size and moisture content of the product powder may be controlled by adjusting liquid supply pumps 12 and 16, the rate of rotation of wheel 2 by gearing 14, and the supply of heat to heater 19. Several nozzles 10 may be disposed symmetrically around the axis of chamber 1. |
