不同结构和颗粒黏性对双螺旋输送机性能影响

The Effect of Different Structures and Particles with Different Viscosity on the Performance of Double Screw Conveyors

对双螺旋输送机进行了离散元仿真,研究其在运输不同黏度物料时,不同参数和结构对其性能的影响并对现象产生的原因进行分析。分析结果表明:适当的增大双螺旋输送机的螺旋转速和填充率可提高其输送能力;当输送机运输黏性物料时,两螺旋叶片间应采用大交叠量,错位量为半螺距的结构设计;当输送机运输无黏性物料时,两螺旋叶片间应采用无交叠量,错位量为半螺距的结构设计;双螺旋输送机更适合运输黏性物料;由于颗粒间的团聚作用,使得颗粒间碰撞以及颗粒和外壳间摩擦作用减小,颗粒的轴向平均速度增大,使得输送机整体功率消耗下降,输送量上升;颗粒间的团聚作用会在输送机底部形成空穴,所以其填充率不宜过大。以上结果可为双螺旋输送机工况选择和结构设计提供参考。

The discrete element simulation of double screw conveyors is carried out to study the influence of different parameters and structures on their performance when transporting particles with different viscosity,and analyze the causes of the phenomenon. The analysis results show that the increase of screw speed or filling ratio of double screw conveyors properly can improve the conveying capacity;When the double screw conveyor is used to transport cohesive particles,the structure with half pitch’s offset and large overlap between two screw blades should be adopted;When the conveyor is used to transport non-cohesive particles,the structure with half pitch’s offset and no overlap between two screw blades should be adopted;Double screw conveyors are more suitable to be used to transport cohesive particles;Due to the agglomeration of cohesive particles,the collision of particle-particle and friction between particles and the shell are reduced,the average axial velocity increases,which lead to the decrease of power consumption and the increase of conveying capacity;The agglomeration of cohesive particles will also form a hole at the bottom of the conveyor,so the filling ratio should not be too large. The results above can provide references for the selection of the working conditions and structural design of double screw conveyors.