Five factors that affect the performance of the bag filter

Bag filter is one of the major equipment able to effectively control dust pollution, with high dust removal efficiency. With the improvement of dust emission index, the advantages of bag filter, such as high adaptability, high dust removal efficiency and reliable operation are gradually appearing and favored by the enterprises in the industry. Is also the main equipment used by enterprises to meet the increasingly stringent environmental requirements. The performance of bag filter is mainly affected by five aspects: 1. Quality of dust filter bag. The quality of the filter bag is the key to the efficiency of bag filter dust removal. The dust filter bag material requirements, in addition to good performance of the filter cloth and the specific density and breathability, but also should have good corrosion resistance, heat resistance and high mechanical strength. Power plant flue gas discharge temperature is generally controlled at 120 ~ 160 ?, usually using polyphenylene sulfide PPS filter bag. However, in actual use, the polyphenylene sulfide PPS is greatly affected by the oxygen content in the boiler operation, and the oxygen content and temperature of the flue gas have a direct impact on the service life of the PPS filter media. Therefore, the flue gas oxygen content is one of the main factors that determine the working life of filter bag. 2. Selection of filter speed. Bag filter dust speed is actually refers to the average speed of gas through the filter cloth, on behalf of the bag filter gas handling capacity, is an important technical and economic bag filter. If the filter speed is too high, the filter bag life will be shortened; if the filter speed is too low, the investment costs will increase, so the need to choose a reasonable filter speed. According to the actual operation experience of various countries, the filtration speed should be controlled at about 1.0m / min, the use of polyphenylene sulfide PPS material, you can guarantee the filter bag life of up to 30000h. For high dust concentration bag filter, the filtration speed is generally below 0.8m / min. This distribution of air flow and extend the life of the filter bag is more favorable. 3. Running resistance of bag filter. According to theoretical calculations, baghouse dust removal efficiency up to 99%.However, in actual operation, it will be affected by air leakage and resistance of the precipitator. The lower the air leakage rate, the better the dust removal effect; the lower the resistance and the better the dust removal effect. Bag filter resistance and injection pressure are related, the larger the injection pressure, the more air is injected into the filter bag and the air is induced, the greater the blowback velocity is, the better the cleaning effect is and the more the resistance of the precipitator drops. As the injection pressure increases, the resistance of the precipitator increases with the increase of filtration velocity, but the increasing rate becomes slower and slower. Therefore, within a certain range, increasing the injection pressure can reduce the operational resistance of the precipitator. 4. Temperature of the medium. When the medium temperature increases beyond the working range of the filter bag, the dust removal performance of the filter bag will gradually change, such as embrittlement, surface shrinkage, deformation, ventilation, etc., serious when there will be "burning bag" so that the filter bag is damaged, the performance of a sharp decline in dust. 5. Condensation of filter bag. Condensation is the most common problem in bag filter operation. The moisture in the medium is the most important factor that affects the dew condensation of the filter bag, especially when dealing with the high temperature medium. When the filter bag condensation occurs, the initial dust layer on the surface of the filter bag will contain moisture and moisture to bond the surface of the filter bag and form a knot, thus accelerating the corrosion and damage of the filter bag, resulting in the filter bag losing elasticity and failure to work normally. The quality of dust filter bag, the selection of filter speed, and bag filter operation resistance, medium temperature, filter bag condensation will not only affect the dust removal efficiency, but also affect the dust removal performance, prevent the normal operation of the bag filter.