基于离散元仿真模拟的螺杆加料机加料性能研究

Study on feeding performance of screw feeder based on discrete element simulation

利用建模软件建立不同螺杆导程、外径以及头数的螺杆结构;在离散元数值模拟仿真软件中建立颗粒模型、设置接触参数后,对不同结构下螺杆的输送过程进行模拟仿真;利用后处理模块对颗粒在输送过程中的受力以及加料机的出口质量流率进行分析,探讨螺杆结构对加料质量的影响规律。结果表明,螺杆导程是螺杆加料机输送效率的主要影响因素,20 mm导程的螺杆输送效率是14 mm导程的15倍左右,但是出料精度有所下降;螺杆间隙是颗粒受力的主要影响因素,间隙的减小会导致颗粒受力的增大,1 mm间隙下的平均受力在1.2×10-2 N左右;双头螺杆导致颗粒输送过程中受力的激增,峰值达到15 N左右,出料效率降低,但是出料稳定性提高。

A series of screw structures with different screw leads,outer diameters,and head numbers were established by using a modeling software.After the particle model was established and the contact parameters were set in the discrete el-ement numerical simulation software,the conveying process of screw under different structures was simulated.The post-treatment module was used to analyze the force of particles in the conveying process and the mass flow rate at the outlet of the feeder,and the effect of screw structure on the feeding quality was discussed.The results indicated that the screw lead was the main factor affecting the conveying efficiency of the screw feeder.The conveying efficiency of the screw with the 20 mm lead was about 15 times as high as that with the 14mm lead;however,the discharging accuracy was re-duced.The screw clearance is the main factor affecting the force of particles.The decrease of the clearance can lead to an increase in the force of particles.The average force of the screw clearance is about 1.2×10-2 N.The double-headed screw caused the surge of force in the particle conveying process,resulting in a peak value of about 15 N.Meanwhile,the discharge efficiency was reduced,but the discharge stability was improved.