关键词: 立磨选粉机, 叶片结构, 分级区, 速度场, 速度梯度

Abstract: Velocity field in the grading zone of vertical mill classifier is the main factor affecting the classification performance. Gas-solid two-phase flow in vertical mill classifier is non-ideal fluid. By applying the theory of viscosity and velocity gradient in fluid mechanics，the reason why a big velocity gradient would make a decline on the classification precision and the classification efficiency of a classifier is analyzed. The model of vertical mill classifier with individual rotor blade structure was built，and in which variations in velocity field，including velocity direction，velocity size and velocity gradient in grading zone，are simulated numerically and analyzed through the Fluent software. A test of structural transformation on rotor blade of vertical mill classifier was made. And the test showed that the production of the vertical mill classifier with the Z-blade rotor structure was improved by 15 t/h，and the residue on sieve of 0.08mm particles reduced by 10%，compared to the one with straight blade.

Key words: vertical mill classifier, blade structure, grading zone, velocity field, velocity gradient