Solutions for air dust filter bag wear, burnout and corrosion

Damaged filter bag

(Wear, Burn, Corrosion) The use of filter bags accounts for the largest maintenance cost of the dust collector, up to more than 70% of the maintenance cost. The basic conditions are wear, burn, corrosion, etc. The solution can be in the following ways:

(1) Wear

Excessive filtering air velocity will cause dust impact, wear filter bag, and damage the fabric fiber tension of filter bag.

Solution: Adjust the exhaust gas flow of the dust collector. When the expected flow rate changes greatly, the automatic flow control system can be added to ensure that the dust collector works at a stable gas volume.

The air intake of the dust collector is unevenly distributed, and it is easy for the high content of dusty exhaust gas to directly impact the local filter bags, and it is easy to perforate some of the filter bags at the exhaust gas inlet, and the service cycle is too short.

Solution: install an air intake distribution guide plate at the air inlet duct of the dust collector, or replace the filter bag in the frequently worn part with a wear-resistant filter bag. If the distance between the filter bags is too small and the keel is bent, it is easy to cause the wear between the filter bags. For example, the glass fibers are very sensitive to wear between each other. The filter bags should be adjusted and installed firmly and the bent keel should be replaced.

The difference between the diameter of the filter bag and the keel is related to the difference between the diameter of the filter bag and the keel. If it is too small, the cleaning effect will not be good. The cleaning cycle should be increased and the pressure of the blowing air should be increased. When it is too large, the friction between the filter bag and the keel will accelerate the wear. The circumference of the keel is 10~20mm, and the length should be the same. Special attention should be paid to some filter cloths that change greatly with temperature and have the characteristics of elongation. When there are holes or burrs in the keel welding, or the rough surface caused by corrosion, the wear of the filter bag will also be accelerated. The filter bag and the porous plate are not tightly sealed, which will cause the wear of the anti-fold at the top of the filter bag. It is better to use an elastic ring instead.

The misalignment of the venturi or pulse tube relative to the filter bag will easily cause mechanical friction on the upper section of the filter bag and should be adjusted. If the filter bag is cleaned too frequently, it will accelerate the wear of the filter bag and should be adjusted. The dust content in the exhaust gas exceeds the design standard, which will also accelerate the wear of the filter bag. Too much dust stored in the dust collector hopper will also accelerate the wear of the filter bag.

The above reasons will make the dust collector discharge exceeding the standard, and will also reduce the service life of the dust collector components, which should be paid attention to.

(2) Burned

The main reason for the burning of the filter bag of the dust collector is that the temperature of the exhaust gas is too high. If the temperature of the exhaust gas treated by the dust collector for a long time exceeds the working conditions of the filter bag, it is easy to harden and shrink the filter bag, or melt to produce holes, and the exhaust gas will be damaged. The inflow of sparks, or the heat of dust, may also cause the filter bag to burn into holes, which is particularly important when choosing a filter bag. If it is necessary to cool the exhaust gas, when using the cooling method, pay attention to the humidity of the cold air and whether it contains acid and alkali components. At the same time, try to ensure that the airflow temperature of the exhaust gas treated by the dust collector is higher than the dew point, and avoid water droplets directly entering the filter bag.

In order to prevent sparks from entering the dust collector and causing the filter bag to be burnt, pretreatment methods can be used, such as: pre-coating a protective layer on the surface of the filter bag, kaolin, limestone powder, etc. can be used. At the same time, it is necessary to prevent the secondary combustion of unburned carbon materials in the dust collector.

(3) Corrosion

The main reason for corrosion is that the exhaust gas contains acid and alkaline components, and the dew point changes with the concentration of these chemical substances. If the dust collector is started or stopped below the dew point, the SO2 in the exhaust gas will meet water to form H2SO2, which will cause filter bag fibers. Deformation and loss of strength can be prevented by using acid and alkali-resistant filter bags, insulating the air intake pipe and shell of the dust collector, and heating the dust collector if conditions permit.

The condensation water in the exhaust gas will also cause the blockage of the filter bag. When the initial dust layer on the surface of the filter bag is due to moisture, the dust will condense and harden after drying, which will cause the filter bag to lose its elasticity. Pulse cleaning the filter bag will accelerate the damage of the filter bag. It is beneficial to protect the filter bag by using pulse backflushing to clean the filter bag several times after the dust collector is stopped.