The working mechanism of the dust filter bag is that the dust-containing flue gas passes through the filter material, and the dust particles are filtered. The filtering material collects the coarse-grain dust mainly by inertial collision. The collection of the fine-grain dust mainly depends on diffusion and screening. The dust layer of the filter also has a certain filtering effect.
The advantages and disadvantages of dust filter bag dust removal are related to many factors, but mainly depend on the filter material. The filter material of the dust filter bag is synthetic fabric, natural fiber or glass fiber woven cloth or felt. If necessary, sewn cloth or felt into a cylinder or a flat filter bag. Depending on the nature of the flue gas, filter media suitable for the application conditions are selected. Generally, when the flue gas temperature is lower than 120°C, and the filter material is required to have acid resistance and durability, polyester fleece and polyester needle felt are often used; when high-temperature flue gas (<250°C) is processed, graphitization is mainly used. Glass cloth; in some special circumstances, the use of carbon fiber filters.
It is important to control the speed at which the flue gas passes through the filter material (called the filtration rate) during operation of the filter bag. Generally, the filtration rate is 0.5-2 m/min, and the particle efficiency greater than 0.1 μm can be more than 99%, and the device resistance loss is about 980-I470 Pa.