沉降室升降阀板的气固两相流场数值分析

Numerical simulation and analysis on lifting value plate of settlement chamber

为了调整机制砂石骨料级配,在制砂线中引入风选沉降系统。本文采用Realizable k-ε湍流模型和Euler-Lagrange离散相模型,分别对沉降室的气相流场和气固两相流场进行数值计算,并且研究了气流对沉降室的影响。对比分析了在不同升降阀板长度下沉降室速度压力云图、颗粒运动轨迹、沉降效率与系统阻力。结果表明:随着升降阀板长度的增加,沉降室内气流速度大小发生分级,气流方向在升降阀板位置发生改变,砂石颗粒从气流中分离出来产生沉降;同时在升降阀板左右两侧产生明显的压力分界线;在升降阀板长度为600 mm时,粒径75~150μm颗粒沉降效率为68.23%,选粉率低,最符合砂石级配和实际工况要求;工作时升降阀板和沉降室的最大应力为19.13 MPa,最大应变为0.73 mm,满足实用强度和刚度要求。

In order to adjust the gradation of the mechanism sand,a wind-selection settlement system is introduced in the sand making system.In this paper,Realizable k-εturbulence model and Euler-Lagrange discrete phase model are applied to numerically calculate the air phase flow field and air-solid two-phase field in the sedimentation chamber,and the influence of air flow on the sedimentation chamber is studied.The speed and pressure cloud map,particle motion trajectory,sedimentation efficiency and system resistance of the sedimentation chamber are compared and analyzed under different lifting valve plate lengths.The results shows that with the increase in the length of the lifting valve plate,the airflow velocity in the settling chamber is graded,the airflow direction changes in the position of the lifting valve plate,and the sand particles are separated from the airflow to generate settlement;at the same time,the left and right sides of the lifting valve plate are obviously the pressure dividing line;when the length of the lifting valve plate is 600 mm,the sedimentation efficiency of the particle size 75~150μm is 68.23%,the powder selection rate is low,and the settling chamber resistance is 560 Pa,which is most in line with the sand grading and actual working conditions;the maximum stress of the plate sand settling chamber is 19.13 MPa and the maximum strain is 0.73 mm,meeting the requirements of practical strength and stiffness.