斜板沉降池油水分离特性研究

STUDY ON OIL-WATER SEPARATION PROPERTIES OF INCLINED PLATE SETTLING POOL

斜板沉降池因较传统沉降方式具有分离精度高,速度快等优点被广泛应用,其内部流场特性直接影响着分离性能,掌握流场分布规律对指导新结构设计具有一定指导意义。文章基于计算流体动力学(Computation Fluid Dynamic,以下简称CFD)方法,采用多相流混合模型,对油水分离用的斜板式沉降池内部流场特性及分离性能进行数值模拟分析,完成了沉降池内的油水分离过程描述。得出在固定斜板间距及斜板倾角下沉降池内部流体迹线及速度场、浓度场及分离性能随时间的变化规律。结果显示,围绕斜板周围存在较多涡流,致使流场扰乱影响分离性能。同时斜板周围及间隙内的流体流动速度呈现出先增加后降低的趋势。一定范围内,随着沉降时间的增加分离效率逐渐升高,直至4 h以后分离效率趋于稳定。

The inclined plate settling tank is widely used because of its high separation precision and high speed compared with the traditional settlement method.Its internal flow field characteristics directly affect the separation performance.Knowing the flow field distribution law has a certain significance to guide the new structure design.Based on computational fluid dynamics(CFD)method and multiphase flow mixing model,the flow field characteristics and separation performance of inclined plate settling tank for oil-water separation are numerically simulated and analyzed in this paper,and the oil-water separation process in the settling tank is described.The variation laws of fluid trace and velocity field,concentration field and separation performance with time are obtained under the condition of fixed inclined plate spacing and inclined plate inclination angle.The results show that there are many eddy currents around the inclined plate,which results in the disturbance of the flow field and affects the separation performance.At the same time,the flow velocity around the inclined plate and in the gap shows a trend of increasing at first and then decreasing.In a certain range,the separation efficiency increases gradually with the increase of sedimentation time,and tends to be stable after4hours.