惰性粒子对气液固三相流化结晶粒度分布的影响

引　言换热壁面垢层的形成增加了热阻和流动阻力 ,降低了换热效率 ,严重时可产生局部过热损坏整个换热设备 ,使得设备的维护、检修费用增加 .李修伦、张利斌等[1,2 ] 80年代以来开发出的三相流化床蒸发沸腾换热技术较好地解决了这一问题 ,然而将该技术应用于带有结晶过程的体系 (如卤水蒸发器 )时 ,由于引入的惰性粒子对结晶过程来说为一外来杂质 ,会对晶体的生长产生影响[3] ,而早期的试验也出现过晶粒变小的问题[4 ] .因此有必要对此进行研究 ,为进一步完善和改进三相流化床技术的工业应用提供必要的基础 .1　实验研究1.1　实验装置及流程…

EFFECTS OF INERT PARTICLES ON CRYSTAL SIZE DISTRIBUTION OF GAS-LIQUID-SOLID THREE-PHASE FLUIDIZED CRYSTALLIZATION

The influence of inert particles on crystal sized distribution (CSD) in gas-liquid-solid three-phase fluidized crystallization process is studied with potassium chloride solution in a conical fluidized bed. The results show that nature of inert particles,volume concentration, size and shape affect crystal size distribution effectively, with the increase density, size and concentration of inert particles, CSD becomes worse. CSD also becomes worse with the increase of gas flow rate, however, when gas flow rate further increases, CSD will become better and then worse again. Increasing density, size,concentration of inert particles will make the effects of enhancing gas flow rate on CSD less effective, meanwhile the gas flow rate corresponding with the turning point of CSD from worse to better will increase. To inhibit the adverse effects of inert particles on CSD, light, small and low concentration particles should be used.