Reasons for the damage of the air dust filter bag

Either improper installation or improper operation will cause damage to the filter bag. There are several reasons for damage:

1 Filter wind speed

In the design of the dust collector, if the filter wind speed is too high, it is easy to increase the running resistance and frequent dust removal, which will greatly shorten the service life of the filter bag. When the project dust collector does not clean the dust, the filter wind speed is selected to be 0.66 m/min, and the wind speed is within a reasonable range to eliminate the influence of excessively high filter wind speed on the filter bag.

2 Temperature effect

The service life of different filter bags is different. The material of the filter bag is treated with PTFE+PTFE film, and the overall service life is not less than 3 years. The planned temperature resistance requirements: the normal allowable flue gas operating temperature is 100-130°C, and the instantaneous temperature can reach 180°C. The operating temperature is too high, and the actual exhaust gas temperature is controlled at about 160°C, which does not exceed the instantaneous temperature peak and continuous operating temperature of PTFE, which eliminates the possibility of burning the filter bag due to excessively high smoke temperature in a short time. At the same time, the exhaust gas temperature is too low, and the water vapor condenses in the flue gas. After passing through the filter bag, it adheres to the filter bag, which will also form the filter bag compaction. Therefore, it is necessary to strictly control the exhaust gas temperature, and the automatic control part needs to set the alarm value of the exhaust gas temperature of the bag filter and the emergency parking value to prevent abnormal rise of the exhaust gas temperature or damage to the filter bag.

3 Blowing wear

Check the following three conditions: the blowing pressure is too high, which increases the impact of the cleaning air flow on the filter bag, resulting in scouring and abrasion; the setting of the blowing time distance is unreasonable and frequent blowing; the quality of the compressed air is unqualified, With water and oil, compaction of the filter bag is formed for a long time. The damage position of the filter bag of the project is inconsistent, generally in the position of the bag body, to remove the damage caused by the spray to the filter bag.

4 Grease adhesion

Due to frequent boiler incineration start-ups and low-load operation, it takes a long time to throw oil, and unburned oil is attached to the filter bag, which gradually loses activity and causes serious damage. The bag filter has been pre-sprayed in this project, which can effectively avoid the adhesion of oil stains.

5 Mechanical damage

After removing the above 4 damage factors, the author basically confirms that the damage of the filter bag is caused by mechanical damage. The mechanical damage includes the following three conditions: the bag cage is damaged during production and transportation, showing burrs or sharp edges, which damages the filter bag; ash bucket and The ash level is improperly controlled, and when the filter bag is abnormally raised, the bag cage is displaced and deformed, resulting in squeeze damage of the filter bag; the size of the filter bag and the bag cage does not match.