糖用微涡流重力沉降器中的流体特征流动与颗粒絮凝沉降

介绍了一种在糖厂用于澄清无滤布吸滤机滤汁的波纹斜槽板微涡流重力沉降器.探讨了该沉降器的工作原理,分析了流体在波纹斜槽中的流动情况.在一定的简化条件下,推导了斜槽区水力学特征流动的速度分布表达式.指出对沉降固液分离产生强化作用的特征流动是直立斜槽板上的涡旋流和沿波纹斜槽轴向的二次流,涡旋流与二次流的流速都随主体流速的增大而增大,随斜槽直径的减小而增大.文中还推导出了产生涡旋流?二次流的斜槽结构条件下颗粒的沉降速度.结果表明,颗粒的沉降速度随涡旋流和二次流的加剧而提高,从而证明在新型沉降器中,形成的特征流动对颗粒沉降具有强化作用,这也为该新型沉降器的进一步改进提供了理论依据.

Characteristic Flows of Fluid and Flocculation Settling of Particles in Micro-Vortex Settler for Sugar Mills

A micro-vortex settler with corrugated inclined troughs,which has been used for the clarification of filtrate from non-cloth vacuum rotary filter in several Chinese sugar mills,is introduced in this paper.The working principle of the settler is then discussed and the flows of the fluid in the corrugated inclined troughs are analyzed.Moreover,the corresponding velocity equations of hydraulic characteristic flows are deduced with certain simplification.It is pointed out that,in the settler,the characteristic flows of the fluid that enhance the separation of floccule from the filtrate are the vortex flow on the upstanding corrugated plates and the secondary flow in the axial direction of corrugated inclined troughs,and that the velocities of both the vortex and the secondary flows increase with the increasing of main body flow velocity and with the decreasing of trough diameter.Simplified equations for the particle settling rates under such characteristic flows are deduced too.The results show that the settling rate of particles increases with the intensification of the vortex flow and the secondary flow.It can thus be concluded that the settling rate is enhanced by the characteristic flows in the settler.This may provide theoretical references for the modification of the novel settler.