Baghouse are highly effective in removing harmful gases. For example, the purification of electrolytic aluminum fluoride flue gas is realized by a bag type dust removal system. The most effective purification method for asphalt flue gas is to suck dust and separate it with a bag filter. The test results show that in the semi-dry desulfurization, the bag filter can improve the desulfurization efficiency by about 10% compared with the electrostatic precipitator. The dust layer on the surface of the filter bag contains an unreacted desulfurizing agent, which acts as a "fixed bed" and can significantly prolong the desulfurization reaction time. In the waste incineration flue gas purification, the "fixed bed" characteristics of the bag filter are of great value for the purification of waste incineration flue gas. One of the purification methods of dioxins in waste incineration flue gas is to remove by using activated carbon adsorption and then using a bag filter. At present, a new technology for removing dioxin in foreign countries is to add a catalyst to the filter material of the bag filter to promote the decomposition of dioxins.
The bag filter has a good collection effect on various soot and dust, and is not affected by characteristics such as dust composition and specific resistance. Bag-type dust collectors are not sensitive to the dust concentration of the inlet, and can achieve very low dust emissions under conditions of high or low dust concentration. In the past, the application of bag filter was restricted by many unfavorable factors. In recent years, the development of bag dust removal technology has greatly improved this situation. The oriental environmental bag filter can be successfully applied and stable under various adverse conditions.
1. The smoke is hot. It has been generally used at ≤280 °C; it can also be used in the range of 300 °C to 500 °C, and there are examples for higher temperatures in foreign countries.
2. The smoke is high in humidity. For example, exhaust gas purification of a dryer, a spray dryer, and the like.
3. High dust concentration. The gas with a dust concentration of 1400g/Nm3 can be directly treated and discharged to the standard; the gas with a dust concentration of 30,000g/Nm3 (for example, a warehouse pump) can be directly treated and discharged.
4. Highly corrosive. For example, the flue gas purification of a waste incineration power plant, the flue gas contains corrosive gases such as HCl and HF.
5. The flue gas contains flammable, explosive dust or gas. For example, blast furnace gas, carbon black production flue gas, coal powder mill exhaust gas, coal conditioning wet exhaust gas, and the like.
6. The dust removal system has a high negative pressure or a high positive pressure. Some large coal mill dust collection systems have a negative pressure of 14,000 to 16,000 Pa; large blast furnace gas bag filtration purification systems have a positive pressure of 0.3 MPa; and some water gas bag filtration and purification systems have a positive pressure of 0.6 to 4.0 MPa.