Cement industry due to the production process to produce a lot of dust, and is included in the high polluting industries. With the new "cement industrial air pollutant emission standards" promulgated by the state, the cement industry facing severe test, gradually move towards the road of anti dust haze. For dust control, the main use of electric dust and bag filter. Bag filter is widely used because of its high efficiency and good dust removal effect.
China's cement industry SO2, NOx, PM2.5 emissions accounted for the proportion of the total national emissions are as high as 20% - 3%, 4% - 8%, 15% - 10%, belonging to the focus of pollution control industry. At present our country every year because of cement production to air emissions of dust and gas emissions of about 12000000 tons or more. Cement enterprises in the process of production, produce a lot of dust and dust, the pollution of the environment is very serious.
With the aggravation of pollution, the protection of the environment is becoming more and more important. Promulgated the relevant policies, in December 2013, the Ministry of environmental protection in conjunction with the State Administration of quality supervision and re revised and released the cement industry air pollutant emission standards (GB4915 - 2013), the cement kiln co disposal of solid waste pollution control standards (GB30485 - 2013) and its supporting the cement kiln disposal of solid waste environmental protection technology standards (HJ662 - 2013) and other 3 standards, the new standards focus on improving the particulate matter, NOx emission control requirements.
According to the latest "cement industry air pollutant emission standards", cement kiln dust emission standards will be from the original 50mg/Nm3 (cement kiln and other thermal equipment) and 30mg/Nm3 (cement grinding and other ventilation equipment) fell to 30mg/Nm3 and 20mg/Nm3.
With the implementation of the new standard, the cement industry to an anti dust haze road. For dust produced in the process of cement production, there are two kinds of dust removal method in the industry.
Based on different technological features, compared with the bag filter, the operation and maintenance of electric dust is lower, but the effect of dust removal under the same scale is slightly worse. Due to the large amount of dust in cement industry, the efficiency of dust removal and dust removal efficiency is greatly influenced by the equipment performance, enterprise management level, production line operating conditions and other factors. Because of this, the constraints are relatively small, the dust removal efficiency is more high, the bag filter becomes the first choice for more cement companies to reduce dust emissions.
Bag filter as the cement industry wide application of energy saving equipment, with large amount of treatment, high efficiency, good stability, and effectively improve the recovery rate and other characteristics, in line with the national energy saving and emission reduction of industrial policy, the national development and Reform Commission to focus on encouraging the development of environmental protection equipment. According to the "cement industry access conditions", the Ministry of industry in November 2010 issued a "guidance on the cement industry energy saving and emission reduction" will be electrostatic precipitator for the bag filter column for cement industry energy saving key construction projects.
China Environmental Protection Industry Association bag filter committee secretary general Wu Shangan also said that the electric dust precipitator is the only way to change the bag filter is the cement industry. Bag type dust collector is the most effective device to control the particles, especially PM2.5 ultrafine particles. Compared with the electric dust collector, the bag type dust removal technology has a high efficiency of trapping, and the test of the fine surface layer and the film filter material shows that the removal efficiency of 0.01 m~1.0 M can reach 97%~99%, or even higher.
In recent years, the bag type dust has become the development direction of the particle capture technology, the key is to develop high efficiency, low resistance, long life, functional filter material, especially for PM2.5 fine particles of the special filter will be the main research and development direction. Bag filter in cement, steel, nonferrous metals, electric power, chemical industry, and other industries have been gradually replaced by the application of electric dust collector. Future bag filter will have a wider development space.
