基于边界层理论旋风分离器分离效率的改进模型

An Extended Model for Determining the Separation Efficiency of a Cyclone With Boundary Layer Theory

针对工业上广泛应用的旋风分离器结构(除了筒体和锥体外,还应包括料腿和灰斗),利用最新的旋风分离器自然旋风长预测模型修正了Leith&Licht模型中有关气流的停留时间;分析了边界层中颗粒的受力情况,认为由于边界层中较高的速度梯度会导致颗粒受力的改变,即除了受到离心力和阻力外,还会受到这种速度差所导致的升力作用。在此基础上基于边界层理论,文中改进了旋风分离器分离效率模型,并将所得模型的计算结果和有关试验数据进行比较。结果表明:改进的分离模型和试验数据吻合较好。和其它经典的分离模型相比,改进模型在预测旋风分离器分离效率方面更具优势。

The gas residence time in Leith ＆ Licht model was modified by means of the new predicted model of the natural vortex length aiming at most cyclones used in the practice operations（besides cylinders and cones, the dipleg and dustbin should be included in their geometries）. On the other hand, the lift force on a particle in the boundary layer was considered because of larger velocity gradient here. Based on this, the extended model was obtained by the boundary layer theory. The availability of the extended model was verified by comparisons of the calculated grade efficiency with experimental data and theoretical models in the literature. The result shows that the grade efficiencies calculated by the extended model and experimental data correspond reasonably well. Comparing the extended model with the experimental data and some classical models, the extended model has more advantage in predicting the grade efficiency of the cyclone than other classical models.