Mechanical damage includes the wear of the filter bag by the cage bone, the abrasion of the filter bag by the blast air flow, the wear of the filter bag against the dust surface, and the plugging of the filter bag.
The wear of filter bags by cage bones is mainly due to structural changes of cage bones, bending of cage bones, increased wear of filter bags and possible wear between filter bags; sharp edges or improper handling of interfaces, causing wear and destruction of filter bags; The size does not match the filter bag. If it is too small, the filter bag cannot be supported. If the filter bag is too large, the filter bag is worn. The anti-corrosion treatment is poor, and the surface that becomes rough due to corrosion will cause serious abrasion of the filter bag. In summary, it is possible to thicken the wearable parts during the production process of the bag. In the production of the cage bones, the edge and the interface are trimmed and smoothed. The size of the cage bones must be matched with the filter bag, and the structure change, damage and corrosion must be timely during use. Cages are adjusted or replaced.
The main reason for the wear of the filter bag by the jet air flow is that the injection pressure is too high and the number of times is too high, which increases the impact of the cleaning gas flow on the filter bag. If the initial dust layer is dropped, the cleaning efficiency is reduced, and the cleaning dust is reduced at this time. It is easy to cause the fabric structure of the filter bag to loosen and accelerate the wear; the compressed air used for cleaning is not separated by oil and water, so the phenomenon of sticking and knoting is easy to occur, and the filter bag is blocked, so that the resistance to filtration and cleaning is increased, and when it is serious, it can be caused. The filter bag is broken; the injection pipe is skewed and the flower plate is deformed so that the injection position is not proper, and the filter bags are not easy to be cleaned. Therefore, it is necessary to timely maintain the deformation plate, check the position of the injection pipe, ensure that the injection port is aligned with the center of the bag, and adjust the injection pressure. Strict oil-water separation using compressed air for cleaning. It is better to set the cleaning cycle to ensure that the dust collector works under a stable pressure and the cleaning cycle is longest. It is better to ensure that the initial dust layer does not fall off. The cleaning time is the shortest, if the initial dust layer is insufficient, Extend the cleaning cycle to compensate.
The main reason for the wear of the filter bag against the dust surface is that the spacing between the orifices is too dense and the distance between the filter bags is too small, and it is prone to collision wear; the deformation of the plate or the cage bone is not installed vertically, causing the bottom of the filter bag to collide, rub or rub against the box. Damaged; ash bucket is not timely unloaded, dust accumulation is too high, dust formation vortex cyclone wear filter bag; high abrasive dust content in the flue gas, exacerbated by dust on the filter bag wear; uneven distribution of air flow, in addition to lead to Some filter bags are also known to cause erosion and wear of the cyclone and secondary dust, causing impact on the filter bag and increasing wear. Therefore, the spacing between flower board holes should be appropriate during design, and sharp tools should be avoided during the installation to ensure that the cage bone and the filter bag are installed vertically to avoid collision. If the board is deformed, it needs to be repaired or replaced in time, and the hopper should be unloaded in time. For the flue gas with high content of strong abrasive dust, the wind speed and air intake method should be designed reasonably, and the airflow distribution in the equipment should be reasonably designed to make it as uniform as possible.
The main reason for the filter bag clogging is that the filtering speed is too large, the filter bag processing smoke volume is too large, and the cleaning cycle and time are still set when the filtering speed is normal, causing the cleaning time to not be timely, the filter bag is gradually blocked, and the dust is too fine. Infiltrated into the fiber inside the filter bag, causing plugging; more viscous components in the dust, so that the dust in the filter bag surface adhesion and clogging; equipment sealing is not strict, broken air inlet pipe, poor insulation effect and other factors caused by air into the dust collector , Or dust collector operating temperature is lower than the acid dew point, resulting in paste bags, knots, plug the filter bag. Therefore, it is necessary to ensure the tightness of the dust collector and check and eliminate the air leakage. Ensure that the exhaust chamber and the clean room are sealed. Do a good job of dust collector insulation.
Chemical corrosion includes oxidative corrosion, acid condensation and corrosion.
The oxidizing components such as NO2, SO2, and O2 in the flue gas will cause oxidation corrosion to the polymer fiber filter at high temperature. If the content of oxygen in the flue gas is high, the conversion rate of SO2 generated by SO2 will increase, the temperature of acid dew point will rise, and in addition, when the content of NO2 is large, condensation will occur easily to form concentrated nitric acid and cause corrosion to the filter bag. In this case, the oxygen content of the flue gas should be controlled below 8%, and pre-treatment, pre-coating and other techniques should be used to minimize the acid gas in the equipment.
The high temperature damage of the high temperature damage filter bag is mainly due to the fact that the filter material is not processed with superheat shrinkage before leaving the factory, or the temperature of the flue gas exceeds the temperature of the filter bag, so that the filter bag is thermally shrunk and cannot be extracted or broken by the cage; the flue gas contains High-temperature particles cause the filter bag to burn; the filter bypass is not turned on when fuel injection assists combustion, Mars enters the filter with the flue gas to burn and damage, or the flammable lubricating oil remains on the surface of the filter bag and is ignited by high-temperature gas. bag. Therefore, the temperature of the flue gas should be strictly controlled and the operating equipment should be standardized to prevent the high-temperature particles and combustible oil star from entering the filter box.