I. Excessive dust emission
Causes of excessive dust emissions
(1)The initial layer of the filter bag surface is not enough;
(2) filter bag damage;
(3)poor filter bag assembly;
The dust collector maintenance is described as follows:
1, the initial layer of the filter bag surface is not enough
In the operation of the dust collector, if the discharge exceeds the standard and the operating pressure of the dust collector is lower than designed, it is most likely that the initial powder layer on the surface of the filter bag is insufficient, which may be due to the high filter speed of the filter bag and the filter bag. The cleaning cycle is too short, the pressure of the compressed air is too high, and the load of the dust is reduced.
Excessive filtration rate will increase the discharge rate of dust. If the filtration rate is too high, the initial dust layer will be broken and the dust will hit the filter bag and cause excessive wear. If the number of filter bags is too high at this time, it will easily lead to filtration. Loose fabric bags, these will make the dust collector discharge exceeded.
When setting the period of pulse cleaning of the dust remover, it is possible to ensure that the dust remover works under a stable pressure, the longest time of the set pulse cleaning cycle is good, and the pulse cleaning time can ensure that the initial dust does not fall off, and the set time The shortest cleaning time is good. Therefore, if the initial dust layer is insufficient, an extended cleaning cycle can be used to compensate. If pressure differential control is used, the stability of the dust collector inlet and outlet pressure settings can be improved.
If the dust collector exceeds the standard discharge only after the filter bag is cleaned, it is only necessary to check whether the pressure of the pulsed compressed air is too large.
The dust load reduction may come from a decrease in productivity, or due to the overhaul and adjustment of the dust collector control system. The dust collector repair method can be solved by using a light load and slowly lifting or using pre-dust. .
2, dust filter repair bag damage
The use of filter bags accounts for the largest amount of dust collector maintenance costs, up to more than 70% of maintenance costs. The basic conditions of dust collector maintenance are wear, burn, corrosion, etc. The solution can be used in the following ways:
1 wear
Excessively high filtration rate results in dust impact and abrasion of the filter bag. As a result, the fiber tension of the filter bag is also impaired. The solution is to adjust the exhaust gas flow rate of the filter to increase the flow rate when the expected flow rate changes greatly. The automatic control system ensures that the dust collector operates in a stable volume.
Dust collector is not uniform in the distribution of air, it is easy to make high-content dust directly impact the local filter bag, easy to make some filter bag perforation at the inlet of the waste gas, the use of a short period, the solution: in the dust inlet duct inlet Install air distribution guides, or replace them with filter bags that are frequently worn.
The distance between the filter bags is too small, the keel bends, etc., can easily cause wear between the filter bags. The firm filter bags should be adjusted and installed, and the bent keel should be replaced.
The difference between the diameter of the filter bag and the keel is too small. The cleaning effect is poor. The cleaning cycle should be increased and the pressure of the blowing air should be increased. When the filter bag is too large, the friction between the filter bag and the keel will accelerate the wear. The better fit is the filter bag ratio. The keel’s circumference is 10~20mm long and its length should be the same. Special attention should be paid to certain filter cloths with large temperature changes and elongation characteristics.
When the keel weld has a hole or burr, or a rough surface due to corrosion, it will also accelerate the wear of the filter bag. Precipitator maintenance filter bag and porous plate sealing is not strict, it will cause the filter bag at the top of the anti-folding wear, the use of elastic ring is better. Therefore, the Venturi tube or the pulse tube is not properly aligned with the filter bag, and it is easy to cause mechanical friction in the upper part of the filter bag and should be adjusted. Cleaning the filter bag too often will accelerate the wear of the filter bag and should be adjusted. Dust in the exhaust gas exceeds the design criteria and will also cause accelerated wear of the filter bag. Excessive dust accumulation in dust collector dust collection will also accelerate filter bag wear.
The above reasons will cause the dust collector to discharge excessively, and it will also reduce the service life of dust collector components.
2 Precipitator Maintenance Corrosion
Condensation in the air stream can also cause the filter bag to clog. When the initial dust layer on the surface of the filter bag is dried due to moisture, the dust will condense and become compacted. This will cause the filter bag type to be elastic, if under this condition. Pulse cleaning the filter bag will accelerate the damage of the filter bag.
After using the dust filter to stop and then pulse cleaning the filter bag several times, it is beneficial to protect the filter bag.
Second, the resistance is too high
The resistance of the dust collector has been determined in the design of the dust collector. However, if during the operation of the dust collector, the resistance of the dust collector increases rapidly in a short period of time, it indicates that the dust collector has a problem and should be repaired and adjusted.
1 poor cleaning device adjustment
Check the quality of compressed air, whether it contains oil or water, check whether the air supply pipeline is unblocked, check whether the pulse solenoid valve is working properly, whether the fastening bolt is loose, whether the diaphragm is damaged, whether the electromagnetic coil is loose, and whether the valve core is stuck; Whether the setting of the controller complies with the requirements and whether it has been changed; whether the jet manifold or the venturi is installed accurately;
2 filter bag blocking dust collector repair
Blockage of the filter bag is mainly due to excessive filtering speed, fine dust, sticky dust, poor cleaning of the filter bag, and dampness of the filter bag.
If the design of filter gas speed filter bag that the dust collector operates is very easy to cause fine dust in the airflow to get stuck inside the filter bag fiber. As a result, plugging of the filter bag occurs. It is better to use coated media or to pre-coat protective powder on the surface of the filter bag.
Turns on when the dew point is below;
When the dust collector is shut down, the filter bag is restarted when there is condensed water on the surface. In this case, a large amount of dust-laden air enters, and the dust collector maintenance and high humidity will cause muddy surface of the filter bag.
In order to prevent this, the precipitator inlet dust air or pre-dust layer should be warmed up.
3 Precipitator maintenance improper gas distribution
If the gas distribution of the dust remover is not uniform, resistance will occur when the dust remover is turned on. Therefore, maintenance of the dust remover should ensure uniform distribution of the intake air of the dust remover.
Third, the filter bag’s life is too short
The factors affecting the service life of the filter bag are as follows:
Improper use of filter bag type; quality of filter bag; dust filter maintenance and filtration rate; dust load; dust composition; dust characteristics; cleaning method; therefore, cleaning frequency; system startup, shutdown times; and related maintenance work.