Stiffening Of Needle Felt Filter Material And Processing Technology Of Filter Cartridge

With the increasingly stringent national emission standards for particulate matter in heavy pollution areas such as thermal power,steel and cement,and the rapid increase of smoke and dust air volume caused by the improvement of industrial capacity,the original bag filter can not meet the national emission requirements due to site restrictions.Because the area of filter cartridge is much larger than that of filter bag,when the shell and structure of dust collector remain unchanged,the filtering area increases several times,which can reduce the filtering wind speed and resistance,and improve the filtering efficiency.It is widely used in industry.At present,the filter cartridge is widely used at home and abroad.It is mainly based on spunbond filter paper and used in clean air supply system filtration.Its fragile filter paper can not cope with the harsh environment of industrial waste gas,such as extremely high temperature,large particle concentration,dust erosion,etc,It is very meaningful to upgrade the old bag filter.The formulation and parameters of filter material stiffening agent were studied.The hardened polyester needle felt filter material can meet the requirements of making filter cartridge.For the special low gram weight polyester needle punched felt filter material,the water-based stiffening agent with polyacrylate as monomer was used for 50%concentration dilution,three dipping and three rolling,and curing at 175℃ for 30 min.after that,the polymer film was formed on the fiber surface of the filter material and the effective cross-linking was formed between the fibers.The stiffening effect was good.The stiffness increased from 2.5 Mn*m to 23 Mn*m,and the air permeability was 47.33 M 3/M2*min,which has met the very low minimum requirement for making filter cartridge.At the same time,the filtration efficiency and mechanical strength of the filter material were improved by 38.1%and 30.7%respectively,and the air permeability and folding resistance of the filter material were also reduced by 74.44%and 85.2%respectively.A filter tube based on the rigid polyester needle felt was developed.The pleating technology,the shape of the filter tube and the processing technology of the filter tube were optimized.The filter material is hardened and pleated by a special mold developed.The pleated filter material with uniform angle,stable pleat,structure and non destruction of filter fiber structure is obtained.The structure of the internal and external bimetal framework of the original filter cartridge was reformed and upgraded.The tooth belt was used instead of the outer metal skeleton,which reduced the weight and manufacturing cost of the filter cartridge.Based on the thickness of needle felt filter material and relevant standards,the size and specification parameters of the filter cartridge are determined as follows Φ 350/300 ×800mm(OD/ID × length),36 pleats and 50mm deep pleats.The technological process of equipment manufacturing of filter tube of polyester needle felt filter material is designed.The filter tube was tested.The results show that the weight and counting filtration efficiency of the filter tube are 75.3%and 72.8%,respectively,the dust capacity is 496.9g when the resistance is 132pa,the best blowing time is 0.5s when the pressure of compressed gas is 0.5MPa,5 times of spraying and 30 seconds apart.To sum up,the filter cartridge developed based on stiff needle felt filter material has the advantages of large air volume,high efficiency and low resistance,low cost,low.weight and large dust capacity.It can be used to upgrade the old bag filter in the industrial field,so as to meet the improvement of industrial capacity and the increasingly stringentemission standards of atmospheric particles.