背压和热压缩空气对流化床气流粉碎的影响

Effect of Back Pressure and Hot Compressed Air on Jet Grinding of Fluidized-bed

为了提高气流粉碎机的粉碎效率并降低能耗,本实验通过粉碎区背压对粉碎的影响和热压缩空气对喷嘴气流速度的影响进行了研究。结果表明:对超音速喷嘴,与喷嘴背压相匹配的值才能产生最好的粉碎效率;通过相同马赫数的喷嘴,在入口温度为80oС、150oС、300oС时,出口气流速度分别比30oС时的喷嘴出口速度高8%、18%、38%;将压缩空气加热到150oС用于粉碎气源,比常温压缩空气要节约26%～31%的粉碎能耗,同时热空气粉碎具有较好的剥片性,能有效保护云母等矿物的片状结构特性。

Nowadays the higher Mach number is adopted to deign nozzle, however, the fluidity parameters of nozzle and systematic airflow status are not considered in jet grinding. So it is difficult to ensure the efficiency of jet grinding and lower the systematic energy. To improve the efficiency of jet grinding and lower the systematic energy, the study was focused on the effect of back pressure on efficiency in jet grinding and the impact of hot compressed air on airflow velocity. The results show： the values matching with back pressure Of nozzle can produce best efficiency of jet grinding for supersonic nozzles. The hot compressed air can improve the yields of jet grinding and lower systematic energy.