竖冷设备结构的离散元法模拟优化

Structure optimization of the vertically arranged cooler based on the simulation with discrete element method

针对国内某钢厂竖冷设备,建立了基于离散元方法的模型,研究了竖冷设备中烧结矿石的装料过程。结果表明,由于原装料结构烧结矿石下落高度大,不同粒径烧结矿石下落速度相差明显,因此,在载料车倾料过程中出现小颗粒在下、大颗粒在上的偏析形态,同时缓冲仓内缺少限制颗粒运动的结构,导致排料过程中烧结矿石的偏析不断加剧。针对原设备的问题,首先将单一缓冲仓改为上下两层缓冲仓,上层缓冲仓用于降低颗粒下落高度,减小不同粒径颗粒的速度差;其次在缓冲仓底部引入斜栅栏结构,从而阻碍大颗粒运动,减小其运动距离,且限制了角落处的大颗粒再次进入缓冲仓出料口,避免加剧缓冲仓内的颗粒偏析。模拟结果表明新结构能有效改善竖冷设备内颗粒偏析。

The particle diameter distribution of sinters ore in vertically arranged cooler leads to serious segregation,which will greatly reduce the heat recovery efficiency of vertically arranged cooler.In order to solve the segregation problem of sinters ore,the simulation of the original vertically arranged cooler form domestic steel plant was conducted,which was based on discrete element method with graphics processing unit parallel computing.In the feeding process,the behaviors of sinter ore and their distribution of diameters were studied.The simulation results showed that the difference of movements of particles,which was caused by diameters of different sinters ore,increased with the height of sinters ore dropping from the bunker.Furthermore,larger sinters ore would aggregate in the corners and small sinters ore would aggregate around the point of falling sinters ore,which was due to the lack of internal structures restricting their movements,leading to more serious of segregation happen.Thus,a hopper and the inclined fences were introduced in the top and around the bottom of the storage bin,respectively.The hopper,which turned original design to two-layer storage bin,aimed to reduce the height and tailor the direction of the sinter ore dropping from the bunker,and thus the difference of the velocities and moving behaviors for the sinters ore of different diameters would be reduced greatly.The inclined fence aimed to restrict the movements of the largest sinters ore,so that their aggregation would be reduced.The simulation results of the new structure,including the distribution of the average diameter,the evolution of the segregation and the standard deviation of the average diameter of sinters ore,indicated that the new structure was advantageous in solving the segregation problem of sinters ore in the vertically arranged cooler.