介质黏度对旋流泵内流结构的影响

以150WX-200-20型旋流泵为研究对象,分析了输送化工废液时旋流泵内循环流与贯通流的压力梯度与速度梯度变化.研究结果表明随着黏度增大,旋流泵扬程降低,轴功率升高,效率下降.同时内流结构也随之改变,循环流在轴向方向被压缩,大量流体堆积在后缩腔内,降低了旋流泵的效率.对旋流泵内循环流与贯通流进行量化分析,在压力梯度与速度梯度2个方面分析最佳效率点.黏度的改变使贯通流速度梯度走向改变,从先增大后减小变为先减小后增大,对循环流而言,最大速度梯度与最小速度梯度之差在黏度不高于0.10 Pa·s时越大,效率越高,高于0.10 Pa·s时越小,效率越高.研究结论对旋流泵在化工领域应用具有重要的参考价值和指导意义.

Influence of liquid viscosity on internal flow structure in vortex pumps

Taking 150WX-200-20 vortex pump as the research object, the change of pressure gradient and velocity gradient of the circulating and through flow in the vortex pump when transporting chemical waste liquid was analyzed, and the influence of viscosity on its internal flow structure was explored. The research results show that as the viscosity increases, the head of the vortex pump decreases, the shaft power increases, and the efficiency decreases. At the same time, the internal flow structure also changes. The circulating flow is compressed in the axial direction. A large amount of fluid accumulates in the retracting cavity, which reduces the efficiency of the swirl pump. The circulation flow and through flow in the vortex pump are quantified, and the best efficiency point in terms of pressure gradient and velocity gradient is analyzed. The change of viscosity changes the direction of the through flow velocity gradient, from first increase and then decrease to first decrease and then increase. For the circulating flow, the greater the difference between the maximum velocity gradient and the minimum velocity gradient when the viscosity is not higher than 0.10 Pa·s, the higher the efficiency, and when the viscosity is higher than 0.10 Pa·s, the smaller the difference, the higher the efficiency. This conclusion has important reference value and guiding significance for the application of rotary pump in the chemical field.