1. Improper filter cloth installation: A. During installation, irregular storage and handling of the filter bags and bag cages can cause the cloth or bag cages to become distorted and tangled due to compression; B. Misalignment between the cloth and the filter panel can lead to prolonged friction between the cloth and the panel, resulting in damage to the filter cloth; C. If the injection tubes are skewed, or if the blowing or injection pressure is too high and the frequency is excessively high, it can easily cause ring-shaped bags, packed bags, or even the separation of the bag’s head from its body, leading to bag damage.
2. Washed-sand filter cloths are primarily used for air filtration and dust removal, capturing particulate matter and powders to purify the air and protect the environment in industries such as smelting plants, chemical plants, sugar refineries, dye factories, pharmaceuticals, and food processing. By extending the service life of sludge filter bags and reducing the frequency of cleaning, these filter cloths help lower equipment maintenance costs. When selecting filter cloths tailored to specific sludge characteristics and particle sizes, it’s crucial to consider factors such as the pore size and water permeability (air permeability) of the cloth. Poor equipment manufacturing can lead to several issues: A. Rough machining of bag cages—such as rust, weld scars, burrs, or open welds—can accelerate mechanical wear on the filter cloth; B. Deformation of the plenum plate, failing to meet the required flatness tolerance of 2/1000, or even exhibiting uneven deformation, can compromise the verticality of the bag cage. This may cause collisions between the bottom of the filter cloth and the elastic steel ring at the cloth opening, easily leading to damage, compromising the installation and sealing of the filter cloth, and resulting in air leaks and damage to the filter cloth itself; C. Deviation in the holes of the plenum plate—when the deviation reaches just 2-3 mm—can prevent the filter cloth from being properly installed, causing dust to escape or the filter cloth to detach from the plenum plate holes, ultimately rendering the baghouse dust collector inoperable.
3. Unstable temperature of dust removal equipment: a. The higher the flue gas temperature, the faster the chemical reactions proceed, and the more sensitive the filter materials become to chemical reactions such as oxidation. Under such operating conditions, the filter materials are prone to damage, significantly shortening their service life. During operation, the dust removal equipment must always maintain the temperature above the dew point. If the temperature falls below this threshold, water vapor in the flue gas will condense. The concentrated water vapor will mix with dirty smoke and dust, forming corrosive acid droplets. This corrosion of filter cloths or bag filters can shorten their service life or reduce their resistance to dust removal equipment, and in severe cases, may even render the dust collector inoperable. c. The temperature of the dust also affects the flue gas; sparks frequently ignite the filter cloth.
4. Improper selection of filter media: a) Commonly used polyester and aramid filter media are highly susceptible to hydrolysis. The higher the moisture content and temperature of the gas, the faster the damage caused by hydrolysis. Therefore, these filter media are not suitable for use in working conditions involving water or high humidity. b) Commonly used polypropylene and polyphenylene sulfide filter media are prone to oxidation; when the oxygen content exceeds 15%, these media should not be used. c) Glass fiber filter media, when used in dust removal and purification environments containing fluorine-containing flue gases, degrade even more rapidly.
Some suggestions and measures to prevent damage to filter cloths.
A. The number of skeleton reinforcing ribs should be appropriately matched to the material of the filter media. They should be smooth, flat, free of hair-like defects, sufficiently strong, meet industry standards for verticality, and have good compatibility with the filter cloth.
B. The plates are flat, with smooth inner surfaces of the plate holes. Moreover, there is a sufficient safety distance between the plate holes and both the box walls and the plate holes themselves, thereby preventing plate inaccuracies and frame tilting that could cause the filter cloths to collide and wear out.
The pulse nozzle should be concentric and perpendicular to the plate hole, with an error of less than 2 mm.