The working principle of pulse bag filter:
Pulse bag filter; Although there are many types of filters, there are currently only two types: one is the local filter type, where the dusty gas flows from the outside to the inside of the filter bag, and the dust is trapped on the outer surface; Another type is the internal filter type, in which the direction of the dusty gas flow is opposite to the former, and the dust is trapped on the inner surface of the filter bag. Bag filters can be divided into two types based on the shape of their filter bags: cylindrical and flat (also known as flat plate). Regardless of the form, its working principle is the same, which is to capture the dust in the dusty gas through various effects of the filter bag. There are many methods to clean the dust accumulated on the surface of the filter bag, some of which use manual or mechanical methods to cause mechanical deformation of the dust removal bag; Some methods use reverse airflow and simultaneous deformation and reverse blowing of the filter bag; Some use vibration and other methods to adsorb dust through filter bags.
As the usage time increases, the dust adsorbed on the surface of the dust removal filter bag increases, the permeability of the filter bag decreases, the pressure loss of the filter bag increases, and the amount of gas passing through the filter bag decreases. If the dust can be adsorbed on the filter bag in a timely manner to restore its breathability and reduce pressure loss, the amount of gas passing through can be stabilized within the required range. Dust removal without a dust cleaning device relies on the self weight of the dust adsorbed on the filter bag to naturally fall off, resulting in a lower ability to remove particles. The filtration wind speed is generally 0.15-0.25 meters per minute. The dust collector using mechanical deformation and anti blowing methods can increase the filtration air speed to 2-2.5 meters per minute. A dust collector that uses high-pressure air reverse airflow to clean dust, with a filtration speed of up to 5 meters per minute. From this, it can be seen that a filter bag with the same filter material has a better cleaning effect and a larger volume per unit area. On the contrary, the cleaning effect is poor, and the volume per unit area is small. Therefore, the effectiveness of dust removal is an important factor in measuring whether a dust collector is effective or not. Pulse bag filter is a type of reverse airflow external filter bag filter. It uses compressed air to periodically spray into each row of filter bags, causing reverse airflow and vibration opposite to the filtered airflow, and adsorbing dust on the filter bags. It has a greater dust cleaning capacity than a typical bag filter. Using dense filter media as filter bags can maintain a high filtration air velocity.
Advantages of pulse bag filter:
The advantages of pulse bag filter are compared to mechanical vibration, chamber back blowing, and pulse blowing; The dust cleaning ability of the first two is weaker than that of pulse blowing, making it more difficult to clean dust. The latter is more suitable; Under the same usage conditions, the pressure drop of the first two is often higher than that of pulse injection; Both of the first two methods require the filter bag to stop filtering before cleaning (i.e. offline cleaning), and can only be used for dust collectors that work intermittently, or for adding a portion of reserve dust filter bags. Clean the dust alternately in different rooms. Pulse blowing should not clean the dust when filtering stops (i.e. online cleaning can be used). Dust collectors that use pulse blowing for cleaning can handle gases with high dust concentration, while the first two methods require the addition of a pre dust collector when the dust concentration is high; The operation and maintenance cost of mechanical vibration dust cleaning is relatively high. The pulse jet dust cleaning system requires a good high-pressure air source, and valves and other components need to be repaired carefully. The structure of the chamber back blowing dust cleaning system is relatively simple, with few moving parts and less maintenance workload; Under the same usage conditions of the machine, the lifespan of the filter bag blown back by the pulse jet is longer; The major advantage of pulse jet bag filter is that, with the same volume, it requires much less filter material area than the first two types, resulting in much smaller equipment volume, weight, and footprint, and much lower initial investment. Due to the many advantages of pulse jet bag filter, its application is expanding day by day.
The importance of maintaining pulse bag filter:
Pulse bag filter is generally used in environments with severe dust pollution such as steel, smelting, chemical, power generation, cement, etc. Due to the harsh working environment of pulse bag filter, inadequate maintenance and management of the filter can shorten its service life. Therefore, maintenance and repair of pulse bag filter are important for its normal operation, full play of its role, extension of its service life, and effective dust removal work. In order to maintain and repair the pulse bag filter, it is necessary to be able to use and inspect it, identify problems, and handle them in a timely manner to ensure the normal operation of the dust removal system.
During the operation of the pulse bag filter, it is necessary to regularly check the working condition of the main unit and dust removal accessories, and do a good job in maintenance and upkeep.
The dust collector box is the "outer shell" of the dust collector, and its maintenance and repair cannot be ignored. Always pay attention to tightening loose screws and sealing areas with dust leakage, especially for movable doors such as inspection doors, observation holes, and cover plates. The filling and sealing rings of the covers should be kept tight. If aging or damaged packing is found to lose its sealing function, it should be replaced in a timely manner. For the parts of the pulse bag filter that have been used for a long time or have paint peeling off, the oil should be promptly brushed to prevent rusting of the filter box.
