Compared with other gas-solid separation equipment, bag filters have the advantage of high filtration efficiency, generally maintaining a filtration efficiency of over 99%, resulting in less dust content in the discharged gas after filtration; When the filtration speed is selected appropriately, the change in inlet particle concentration has little effect on filtration efficiency and pressure loss, and has high operational stability and strong adaptability; Easy to recycle powder and achieve comprehensive utilization. The disadvantages are: heavy labor and poor working conditions for inspecting and replacing filter bags; The temperature of the filtered gas is limited by the temperature resistance of the filter material.
1. Filtering efficiency. The filtration efficiency of short fiber blanket filter material is higher than that of long fiber fabric filter material. When cleaning dust, thin filter materials are more likely to damage the initial dust layer than thick filter materials, resulting in a decrease in filtration efficiency.
2. Pressure drop. The pressure loss of the filter material should be minimized as much as possible. In general, the pressure drop of filter media is one order of magnitude smaller than that when there is a dust layer, and can even be ignored.
3. Dust tolerance. The dust capacity is related to the porosity and permeability of the filter material, which determines the cleaning time and thus affects the service life of the filter material. Generally, it is advisable to consider using filter media with high dust capacity, such as felt filter media.
4. Breathability. It is defined as the ratio of the actual volume flow rate of flue gas to the area of the filter cloth, also known as the gas cloth ratio. The pressure difference for calibrating the air permeability in our country is 127Pa. Air permeability generally refers to the air permeability of clean filter materials. Whenever possible, filter media with high permeability should be selected to avoid an increase in pressure drop.
5. Temperature resistance. It is the main factor in selecting filter media - high-temperature resistant filter media can recover heat energy and save energy. And it can simplify the cooling equipment.
6. Mechanical performance. The filter material should have advantages such as resistance to obstruction, bending, and wear, especially wear resistance, which determines the service life of the filter material.