1、 Tips for selecting dust collector bags: 1. Choose dust collector bags according to the cleaning method of the dust collector. (1) Mechanical vibration type bag filter. The requirement is to choose a dust collector bag with thin and smooth filter material, soft texture, and conducive to transmitting vibration waves;. (2) Pulse bag filter. Usually, outer filter bags with frames are used. Require the use of thick and strong tensile materials. (3) Backblowing bag filter. You should choose cloth bags with soft texture, stable structure, and good quality. 2. Select the appropriate dust collector bag (1) based on the requirements of the working conditions and gas temperature. Choose a normal temperature dust collector bag when the gas temperature is below 130 ℃, and a high temperature dust collector bag when the temperature is between 130 ℃ and 260 ℃. (2) The chemical properties of gases. In various furnace flue gases and chemical waste gases, there are often chemical components such as acids, alkalis, oxidants, solvents, etc. When choosing a bag, acid resistant, alkali resistant, and dust collector bags should be reasonably selected based on the chemical composition contained in the flue gas. (3) Gas humidity. Dust containing gases are classified into three states based on relative humidity: dry gas (relative humidity below 30%), general state (relative humidity between 30% -80%), and high humidity gas (relative humidity above 80%). When the humidity of the gas is high, a laminated cloth bag should be chosen. 3. Select a dust collector bag (1) based on the nature of the dust, taking into account its moisture and adhesion properties. If the dust is hygroscopic and has strong adhesion, choose a dust collector bag with membrane filter material. (2) The combustibility and electrical charge of dust. When certain dust is flammable, flame-retardant dust collector bags should be selected. Dust collector bags are specifically designed for electrically charged dust. 2、 The testing and calibration of dust collector bags are particularly important for the processing of dust collector bags. In recent years, some small manufacturers have adopted small sewing machines as processing equipment, and used inferior thread as raw materials during processing, resulting in fake and fake products, and their processing level is far behind. Causing the cloth bag to develop issues such as loose threads, cracks, and bottom drops shortly after use. Although a slightly smaller bag size can still be used, after adsorbing dust with a higher specific gravity, the bag will fall off after a period of use. The surface filtration method of the dust collector bag is to use a thin layer of filter medium with a pore size smaller than the required particle size to capture particles. The surface filter medium of the dust collector bag belongs to a woven single-layer structure. Therefore, although the pore size of the filter medium is smaller than the particle size of the dust to be captured, when the dust carried by the air passes through the filter medium, the dust particles are easily bridged on the small holes of the filter medium, resulting in a decrease in the pore size of the filter medium. Gradually, with the increase of the amount of dust collected by the bag of the dust remover, the powder formed on the surface of the filter medium acts as the filter medium, and the filter medium itself only serves as the support of the powder. The average pore diameter of powder is smaller than the particle size of the dust to be collected, so the dust in the mixed airflow can be collected. "Surface filtering" is named for the collection of dust particles on the outer surface of the gradually thickened powder. 3、 The main reason for dust collector bag blockage is the presence of moisture inside the dust collector, which is usually caused by condensation at low temperatures, especially when dealing with combustion or high-temperature flue gas. Below we will introduce measures to prevent this problem: 1. Avoid improper startup. 2. When the dust collector is operated below the dew point, problems are prone to occur. If the intake distribution is uneven, it can easily cause local corrosion of the dust collector housing. Therefore, it is necessary to avoid the dust collector working below the dew point, and insulated devices should be used. 3. Avoid starting the dust collector when there is high resistance; Turn on when the dew point is below; When there is condensation on the surface of the filter bag after the dust collector is shut down and restarted, a large amount of dusty air will enter, and high humidity will cause the surface of the filter bag to become muddy. To prevent this situation, it is necessary to preheat the dust laden air in the dust collector or pre cover it with a dust layer. 4. Air infiltration often occurs in the flanges, maintenance doors, or movable devices of bag filters. If the sealing is not tight, external air can enter the dust collector. When dealing with high-temperature exhaust gas, a low-temperature zone will be generated inside the dust collector, leading to condensation at the low-temperature area, corrosion of the dust collector, and moisture absorption of the filter bag. 4、 The filtration process of the dust collector bag filter material can be divided into two stages according to time series, namely stable filtration and non stable filtration stages. In the stable filtration stage, assuming that the deposition of irregular particles causes a change in the structure of the filter cloth, the particles are trapped in contact with the fibers without considering the correction of the filtration mechanism. Therefore, the trapping efficiency is not affected by the filtration time. As the filtration time increases, the particles gradually formed on the surface of the fibers lead to the unstable filtration stage. The change in the porosity of the bag is beneficial for the improvement of the fiber trapping ability, resulting in an increase in the trapping efficiency with the increase of filtration time and particle deposition amount. The single fiber capture efficiency of a dust collector bag in a clean state is defined as the ratio of the height at the entrance of the particle trajectory to the fiber diameter. In the actual filtration process, the formation and size of fibers change significantly with time. Relevant studies have shown that in general, the single fiber capture efficiency increases linearly with the amount of particle deposition. The capture efficiency of unstable filtration process is a function of fiber packing density, fiber diameter, single fiber capture efficiency, filtration speed, initial concentration of dust particles, total deposition mass of dust particles, and filtration time.
