过热蒸汽气流磨粉碎实验研究

Experimental Studies on the Jet Mill with Superheated Steam

对过热蒸汽气流磨和空气气流磨的粉碎性能进行了比较,并以过热蒸汽气流磨作了分级试验,考察了工艺参数对分级性能和效果的影响。结果表明:在相同的气流流量条件下,过热蒸汽气流磨粉碎产量是空气气流磨的5倍以上。通过选取合理的分级机转速、入口压力、二次风量、加料量等操作参数可控制成品料粒度和产量:分级机转速与加工出的微粉粒度成反比;蒸汽喷嘴入口压力越大,产品粒度越细,粒度分布越窄,最佳的喷嘴入口压力与物料的可粉碎性及粒度要求有关;加料量增大,成品料粒度有所减小,应注意加料速度及加料的连续均匀性;二次风量增大使分级效果明显好转。

The jet mill with superheated steam is provided with lower-energy consumption and higher comminution force than that of the air medium. Its classification effects were analyzed and tested. The experimental results show that the classification effects of the jet mill, including the particle size and its outputs, can be controlled by adjusting the parameters of the classifier rotate speed, entrance pressure, steam flux, secondary wind flux and input the raw material capacity, etc. The classifier rotate speed has a reciprocal proportion to the particle size, The higher the entrance pressure of the steam nozzle is, the finer the particle size is and the narrower the particle size distribution is. The best entrance pressure of the steam nozzle is related to the pulverizability and particle size of the additives. As the additives increase, the particle size of additive products decrease and attention should be paid to the feeding speed and continuous uniformity. The incease of secondary wind flux gives a upturn to the classification effects.