Research On The Structure And Filter Performance Of Knitted Cylindrical Air Filter Material

With the advancement of industrialization of human society,the serious air pollution caused by industrial exhaust has become the price of social progress,and has always threatened human health.The country's continuous promotion of revised pollutant discharge standards and the increase in people's awareness of environmental safety make the efficient filtration of fine particles in the air particularly important.This paper takes the filter material used in the bag dust filter that filters industrial waste gas as the main object.In view of the two major problems of dust leakage and short life cycle of the filter bag suture,a new circular weft knitted cylindrical biaxial lining is proposed Warp-inserted knitted filter material.It aims to develop seamless knitted filter materials with high production efficiency,good filtration efficiency and long service life.Therefore,analysis of its structure and filter performance can provide a theoretical basis for the optimization of filter bag filter materials.In this paper,a three-dimensional geometric model of the knitted cylindrical air filter material is constructed,and the flow calculation domain is constructed.According to the principle of air filter particle testing,the pressure drop of the filter material and the particle collection efficiency are simulated and calculated.Using ANSYS finite element analysis software,based on Fluent's fluid Lagrangian discrete model,the geometric model was meshed and the particle materials and boundary conditions were set.The air at 0.27 m/s was used as the continuous phase and the sprayed particles were used as the continuous phase.Discrete phase,real-time tracking of particle trajectory,simulating the trapping efficiency of knitted cylindrical air filter material for dust particles of different sizes,to achieve the purpose of predicting and evaluating the filtering efficiency of knitted cylindrical air filter material,aiming to simulate the flow of knitted filter material Provide theoretical reference.Aiming at the two major problems faced by traditional filter bags,this paper uses circular weft knitting technology and warp and weft inserting technology to propose a new type of knitted tubular air material.First,the structure and fabric characteristics of the warp and weft inserting knitted fabric are analyzed.After selecting raw materials,yarn configuration,and weaving on the machine,the base fabric of the warp-inserted and weft-inserted knitted fabric is obtained,and then the warp-inserted and weft-inserted structure technology,weaving principle and problems encountered on the machine are discussed in detail.And through the cylindrical needle punching process,while retaining the seamless characteristics,the inner and outer layers of the cylindrical warp-lined weft-inserted fabric are penetrated into the dense nonwoven fiber layer to successfully prepare three kinds of knitted cylindrical air with different yarn specifications filter material.Finally,the text characterizes and analyzes the basic morphology of the thickness and grammage of the knitted cylindrical air filter material,and conducts experimental testing and characterization of its filtration performance,porosity,pore size and other filtration indicators.According to the test results,the structure and filtration mechanism of the knitted cylindrical air filter material are analyzed.Compared with the performance of all aspects of the industrial filter bags on the market,the structural performance of the optimized warp and weft lining filter material is analyzed.And the experimental data shows that,in the case of the same raw materials,the stiffness,dimensional stability,and fiber filling rate of the knitted tubular air filter material are better than those of the actual filter bag filter material of the factory,and the porosity of the knitted tubular air filter material reaches 85.2%.The average pore size is 11.92 ?m,and the filtration efficiency under the particle size ?5.0 ?m is as high as 92.58%,which has exceeded the filtration efficiency of the filter material of the factory filter bag under the same test conditions.The filtration efficiency test results are compared with the discrete phase simulation capture rate results,and the results are basically consistent in the case of different particle sizes,further verifying the reliability of the experimental data,the accuracy of the knitting model simulation calculation,and the knitted cylindrical air filter material application potential on filter bags.The knitted cylindrical air filter materials adopts a non-woven structure with warp and weft lining,which limits the elasticity of the knitted fabric.The tortuous pores of the knitted fabric greatly increase the porosity of the fabric and have good filtration efficiency.The knitted cylindrical air filter material It is an ideal filter material,which provides ideas for the development of filter materials for filter bags and provides ideas for the development of knitted filter materials.