Four key considerations when selecting dust collector filter media

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This post was last edited by li*ch1968 on 2012-5-29 at 18:15. The four key considerations when selecting dust collector filter media: Dust collection filter media are one of the important components of bag dust collectors, and the performance of these collectors depends on the quality of the filter media. The performance of filter media mainly includes filtration efficiency, air permeability, and strength, all of which are related to the material and structure of the filter media. Based on the dust removal mechanism of bag filters and the characteristics of dust density, the following requirements are placed on the dust removal filter media. (1) It has a large dust holding capacity; after dust cleaning, it retains a certain amount of dust that can be used to maintain high filtration efficiency ； (2) Good air permeability and low pressure loss under uniform dust loading conditions ； (3) Good resistance to wrinkles, wear, temperature, and corrosion, with high mechanical strength ； (4) Low hygroscopicity, easy to clean dust ； (5) Long service life and low cost. These requirements depend on the physicochemical properties of the fibers and the structure of the filter media. Some filter media find it difficult to meet all operating conditions simultaneously; it is necessary to select the appropriate filter media based on the specific usage conditions. The raw materials for filter media are as follows: 1. Natural fiber filter media: (1) Cotton cloth is the cheapest option; it can generally only be used at temperatures below 80°C, as its strength drops sharply at higher temperatures. It has poor acid resistance and a low filtering efficiency for dust particles smaller than 10μm, which is why it is rarely used. (2) Woven filter cloths (woolen fabrics) are usually made of wool into a flocked fabric; they are thicker than cotton cloth, and their fibers are finer than cotton fibers. It has good air permeability, low resistance, a large dust holding capacity, high filtration efficiency, and is easy to clean. It also has good resistance to acids and alkalis, but can only be used at temperatures below 90°C. Its price is much higher than that of cotton or synthetic fiber filter fabrics. (3) Tussah silk fabric (plain cloth): It has a smooth surface, is easy to clean of dust, and offers good air permeability; however, it can hold little dust, and its efficiency is low at high filtration rates. 2. Inorganic fiber filter media have advantages such as good filtering performance, low resistance, good chemical stability, high temperature resistance, non-hygroscopicity, and low cost. Cylindrical filter cloths made of medium-alkali glass fiber are widely used in gas purification in industries such as cement, smelting, carbon black, and pesticides. The filtration efficiency of glass fiber filter cloths is lower than that of natural and synthetic fiber filter media. Glass fiber is not wear-resistant, not resistant to bending, and prone to breaking. To improve its performance, it can be treated with aromatic organosilicon, polytetrafluoroethylene, graphite, and other methods. After treatment, it improves wear resistance, hydrophobicity, acid resistance, and softness; its smooth surface makes dust removal easy, thereby extending its service life. 3. Synthetic fiber filter media: Synthetic fiber filter media are developing rapidly and have the potential to replace natural fiber filter media. Commonly used materials include polyamides (nylon, acrylic), polyesters (polyester), polyacrylonitrile (acrylic fiber, orlon), polyvinyl chloride (vinylon), and polytetrafluoroethylene, among others. The \"208\" industrial polyester fleece fabric produced in our country boasts advantages such as high filtering capacity, high efficiency, low resistance, and strong strength. It can withstand temperatures up to 130°C and is widely used in various bag filters. Synthetic fibers can also be mixed with cotton and wool fibers to weave fabric; vinylon yarn is used for the warp threads due to its good wear resistance, while wool or cotton yarn is used for the weft threads, allowing for the creation of seamless cylindrical twill fabric with excellent filtering and breathability properties. 4. Felt filter media: Felt filter media have a high dust removal efficiency and can be used for high-speed filtration. Under the same porosity conditions, its average filtration rate is 2 to 3 times higher than that of other fabrics. Rolled felt, as well as fine filtering felts and needle-punched felts made by mixing in synthetic fibers. But it is wear-resistant and has poor bendability. The surface structure of felt is loose, allowing dust to penetrate deep into it; as a result, it is difficult to clean, and it is only suitable for dust collectors that use powerful cleaning methods. To this end, various surface treatments can be applied to the felt, such as fusion, resinification, or controlled heat treatment (heated compression), in order to improve its dust capture and cleaning performance. Felt is more expensive than fabric, making it suitable for large-scale installations, while fabric is suitable for small-scale ones.