Bag air filter is a multi-purpose air purification equipment with novel structure, small volume, simple and flexible operation, energy saving, high efficiency, closed operation and strong applicability. Bag filter is a new type of filtration system. The filter bag is supported by a metal mesh basket in the filter bag, and air enters through the inlet. After being filtered through a filter bag, it flows out of the outlet. Impurities are trapped in the filter bag.
The main reasons for the blockage of filter bags in bag air filters are fast filtering speed, fine dust, sticky dust, poor dust cleaning, bag pasting, coagulation and hardening. When the filter air speed of the filter exceeds the design standard of the filter bag, the fine dust in the flue gas can easily enter the fiber of the filter bag and increase the blocking resistance of the filter bag. It is a better method to coat the filter material, the filter material or the pre-coated film on the surface of the filter bag. For high viscous dust, it is necessary to reduce the filtering speed, or increase the pulse spraying pressure, or use off-line pulse ash cleaning filter bag. However, the better way is to increase the filtering area, reduce the filtering speed and prolong the service life of the filter bag.
The main manifestations of bad cleaning of filter bags are more cleaning times and longer cleaning time. Too many times of cleaning and too much pressure of cleaning can easily loosen the fibrous tissue of the filter bag, increase the fine dust in the flue gas and block the filter bag. If the cleaning time is too long, the initial powder layer on the surface of the filter bag will be washed out, which will result in the decrease of the filtering accuracy of the filter bag. If the cleaning time is too short and the dust on the surface of the filter bag is not completely cleaned, then start the filter. Dust gradually accumulated on the surface of the filter bag, resulting in blockage of the filter bag. In order to solve this problem, the spray controller can be adjusted after several trial runs.
Water is a major cause of filter bag clogging, water is usually caused by low temperature condensation, especially in the treatment of high-temperature flue gas, to prevent this situation: to avoid inappropriate start-up; high resistance, to avoid starting the dust collector; open below dew point. If the dust collector operates below dew point, it is easy to cause problems. If the intake air distribution is not uniform, it is easy to cause local corrosion of the dust collector shell. Therefore, it should be avoided that the dust collector works below dew point. If it is inevitable to start at low temperature, please use insulation devices, such as steam insulation or electric heating insulation.
Air leakage. Air infiltration usually occurs in the flange of the dust collector, the overhaul door or the mobile device of the dust collector. If the seal is not strict, the external air enters the dust collector. When dealing with the high-temperature flue gas, it will produce a low-temperature zone inside the dust collector, resulting in low-temperature condensation, corrosion of the dust collector, resulting in sticking bag filter bags or board of directors.