剪切力作用下颗粒的絮凝与破碎

Aggregation and breakup under shear flow

根据实验数据探讨了剪切力作用下胶体颗粒凝聚过程的机理:颗粒聚集体在絮凝过程中经历生长和破碎两个阶段,在生长阶段主要影响因素为絮凝剂、G值和溶液的pH值。提出了表征剪切力大小的能量概念G值,并给出不同流动条件下的估算方法及物理意义。最后讨论了在快混初期出现的三个特殊现象:突变、衰减和震荡。

An analysis of aggregation and breakup mechanics of particles under a shear flow was carried out based on the experimental data. The particle-aggregation experience growing and breakup phases during the aggregation process and the main inflection factors in the growing process are coagulant, G value and pH value of the solution. G value, an energy concept was put forward to represent the magnitude of the shear flow. Also, estimate methods and physical significance of G value in different flow conditions were given in the paper. Finally, three special phenomena appeared in the initial stage of fast mixing were discussed, which were mutation, attenuation and concussion.