Faults and Avoidance Methods of Dust Filter Bags

1. Burning: The main reason for the burning of the dust collector bag is that the initial layer thickness on the surface of the dust collector bag is not enough, and the temperature of the flue gas is too high. If the temperature of the flue gas treated by the dust collector for a long time exceeds the working conditions of the bag, it is easy to harden and shrink the dust bag, or melt and cause holes. If the thickness of the initial layer is not enough, sparks in the flue gas will flow in, or the dust will heat up, which may also cause the dust bag to burn out the holes. The burning of the dust bag is mainly reflected in the newly replaced dust bag online. Since there is no pre-painting after online replacement, the high temperature flue gas carries sparks and directly touches the bag, which is easy to burn the dust bag. Measures to prevent burnout: initial layer thickness on the surface of the dust bag. The exhaust gas temperature is not over-temperature (the control standard of #3 and #4 furnaces is not higher than 180℃).

2. Wear: The wear of the dust removal bag mainly occurs in the middle part of the dust collector, and on a single dust removal bag, it mainly occurs within 1 meter of the bag from the outlet. The main reason is the uneven distribution of flue gas, the high flow velocity in the middle of the single chamber, and the excessively high filtration gas velocity at the outlet of a single dust bag, which causes dust to impact and wear the bag, and also causes the fabric fiber tension of the dust bag to be affected. damage, it is easy to perforate local bags, and the service cycle is too short. The dust bag for the frequently worn parts is replaced by a bag.

Third, the distance between the dust removal bags is too small, the keel is bent, etc., it is easy to cause wear between the bags. The difference between the diameter of the cloth bag and the keel is related to the difference between the diameter of the cloth bag and the keel. If it is too small, the cleaning effect will not be good, which will shorten the cleaning cycle and increase the pressure of the blowing air. When it is too large, the friction between the cloth bag and the keel will accelerate the wear. Special attention should be paid to the characteristics of some filter cloths that change greatly with temperature and have elongation characteristics.

Fourth, when there are holes or burrs in the keel welding, or the rough surface caused by corrosion, it will also accelerate the wear of the bag. The bag is not tightly sealed with the perforated plate, which will cause the wear of the bag's anti-fold.

5. The misalignment of the venturi or pulse tube relative to the cloth bag will easily cause the air flow from the blowing pipe to directly wash the upper section of the cloth bag and cause wear. Washing the bag too frequently will accelerate the wear of the bag.

6. Excessive filtering air velocity will break the initial dust layer, and the dust will impact the cloth bag and cause excessive wear. If the cleaning frequency of the cloth bag is too high at this time, the fabric of the cloth bag will be loosened and the wear of the cloth bag will be accelerated. The dust contained in the flue gas exceeds the design standard, which will also accelerate the wear of the cloth bag. Too much dust in the small ash hopper will cause the dust in the flue gas to be too large, which will accelerate the wear of the cloth bag.

7. Measures to reduce wear and tear: during the production process of the dust removal bag, thicken the weak parts of the dust removal bag; during the installation process of the bag, adjust and replace the bag whose distance is too small and the keel is bent; the dust removal bag and the keel should be properly matched (+10～20㎜), and the length should be the same; the keel should be strictly inspected in use, and the damaged keel should not be used; the dust bag and the orifice plate should be sealed tightly without leakage; the venturi and the pulse tube should be correctly aligned. In the process of operation, it is necessary to prevent the factors that the filtration speed is too high, the cleaning cycle of the bag is too short, and the pressure of blowing compressed air is too high. When setting the pulse cleaning cycle of the dust collector, it is better to make the dust collector work under a stable pressure and the set pulse cleaning cycle time is long. The pulse cleaning time is so that the initial dust does not fall off. Well, if the initial dust layer is not enough, you can extend the cleaning cycle to make up for it. If you use differential pressure control, you can improve the stability of the inlet and outlet pressure settings.