离散相入射位置对旋流器分离性能的影响研究

摘要

A discrete phase model (DPM) was applied to simulate oil droplet trajectory when entering a liquid-liquid separation hydrocyclone at various inlet cross-section positions. Moving rules for oil droplets entering hydrocyclone through different positions were studied. Results show that oil droplets that entering hydrocyclone at 2~2.5 mm from upper cover plate can easily form short-out flow, lower cover flow and cyclic flow. When droplets enter hydrocyclone at 0~0.5 mm radially and 0~7.6 mm axially of lower right area, they generally escape via underflow, and others are trapped by overflow. It is possible to improve the performance of the hydrocyclone by reducing underflow escaping rates through controlling of the initial position of dispersed phase droplets. This method is verified by experimental results of hydrocyclone separation efficiency.%采用欧拉-拉格朗日方法(DPM)对液-液分离水力旋流器内部油滴运移轨迹及其分布规律进行了数值模拟分析,对油滴由旋流器入口截面不同位置进入旋流器的运移情况进行研究.得出在离散相油滴入口不同位置进入旋流器时其运移轨迹有所不同,且呈现出一定的规律性,结果表明:(1)油滴由入口处轴向上距上盖板2~2.5 mm区域进入时,易形成影响旋流器分离性能的短路流、盖下流、循环流等;(2)油滴由入口截面右下方区域径向0~0.5 mm轴向上0~7.6 mm区域内进入旋流器内时,其运移轨迹均由底流口逃逸.由此外的其它区域进入旋流器内的油滴粒子,较易被溢流口捕获;(3)可通过控制离散相油滴在旋流器入口处的入射区域,减少底流逃逸率从而提高旋流分离性能.