Numerical Simulation And Study Of Airflow Uniformity And Optimization In Bag Filter

Bag filter dust has the characteristics of high efficiency, strong adaptability, large elasticity of operation, the use of flexible, simple structure, stable work, etc,which is widely applied in metallurgy, casting, building materials, food, machinery, light industry and other industrial and mining enterprises of ventilation and dust collection system.But unreasonable air distribution is one of the main problems of bag filter, filter bag wind speed is too large,will scour filter bag surface for a long time constantly,and the filter bag dust load is too high, frequent ash removal leads to filter bag fabric loose, contact position of filter bag and the bag cage fold and fracture damage,will accelerate the damage of filter bag, the dust will scour diagonal esions, increasing damage over time, eventually damage to mouth ring and even bag body and head separation. Filter bag perforation can make the dust gas directly into the atmosphere, reduce the dust removal efficiency, pollute atmospheric environment, increase the concentration of inhalable particles in air and make the residents health and urban atmospheric environment quality threatened.Therefore,the problem of unreasonable air distribution in operation is to be solved as soon as possible.This paper adopts the method of numerical simulation and supported by University Industrialization Cultivation Project of Hunan Province(12CY001),carried out the following researches:(1)With physical model of the three-dimensional models of the flow inside the bag filter, combined the dust removal equipment basic principle of the gas-solid separation and numerical method to determine the boundary conditions of the import, the filter bag and export, establish filter bag for the Boundary of gas flow mathematical model,to analyze the internal folw field and air flow distribution of sideward and downward inlet bag filter under different velocities,and determine the location of local filter bag which the speed is too high,each filter bag flow distribution,etc.(2)Based on coupled Lagrange model, the particle size distribution function of rosin- rammler is used, study the diffusion motion law of gas-solid two-phase flow in the bag filter,simulate the particle trajectory in the bag house, each filter bag processing dust load and the concentration distribution.(3)In view of the uneven distribution of flow distribution and the concentration field, optimization measures are put forward, to simulate to set baffle and blunt body at the entrance, the air distribution in bag filter, the degree of wear and tear, the movement of particles in bag house, provide a reference for direction of structural optimization of the dust collector.(4)Compared the sideward inlet,downward inlet with the optimized downward inlet,the air flow distribution, the position of the filter bag easily torn,concentration distribution and equipment resistance are analyzed, and compare the advantages and disadvantages of various modes and point out that the air distribution of improved downward type bag filter is the most reasonable, the filter bag of minimum wear and tear, and the comprehensive effect is best.