Reasons for the low efficiency of air dust filter bags

Several factors influencing dust removal efficiency in the design of dust collector.

　　The main influencing factors are:

　　 1. The characteristics of dust

　　 The dust removal efficiency of the dust filter bag is directly related to the size, gravity, shape, electrostatic effect and dust concentration of the dust particles. For dust with large particles, heavy weight, irregular shapes, and significant electrostatic effects, the dust removal efficiency is higher.

　　 2. Dust bag performance

   The performance of filter cloth has a great influence on dust removal efficiency and resistance.

　　 1. It can block the passage of fine dust. The interweaving holes of the warp and weft threads of the fabric should be small, and the warp and weft threads themselves should be thin, which can increase the filtering area and reduce the resistance;

　　 2. The material fiber must be long and elastic, so as to cover the pores and have a certain strength;

　　3. In order to facilitate cleaning with reverse airflow, the dust-facing surface is located on the side that is in contact with dusty air.

　　 3. The influence of filtration speed

　　The lower the filtration rate, the easier it is to form a layer of primary dust particles with a small particle size and a large porosity, and the more fine dust particles can be collected. When the filtration speed is too high, the penetration of dust particles into the filter material will increase, and the filtration efficiency will decrease. Of course, the penetration phenomenon can also be overcome by selecting a suitable filter material. In addition, when the filter wind speed changes within a certain range, the dust removal efficiency of some filter materials is hardly affected.

　　 Fourth, the influence of the dust layer on the filter medium In the initial stage of the operation of the dust bag, there is no dust layer on the new filter medium. At this time, the dust collection capacity is low. With the process of filtering the powder, the dust layer is gradually formed, and the dust removal efficiency is correspondingly improved. When the dust layer is formed, the filtration efficiency can reach more than 99%, and it also has a good collection effect on fine dust particles less than 1μm.

　5. Leakage and resistance:

　　Theoretically, the dust removal efficiency of the dust filter bag can reach to 99%, but it cannot be achieved in actual measurement, mainly due to the influence of air leakage and resistance. The lower the air leakage rate, the better the dust removal efficiency; resistance has a certain influence on the dust removal efficiency. The dust filter bag can be emptied frequently to reduce resistance and improve dust removal efficiency. The dust collecting hood should be as close as possible to the furnace head, so that dust can easily enter the hood, increasing the amount of dust collection, and reducing fugitive emission pollution.