Development status of various dust collectors in iron and steel, thermal power, cement, and garbage incineration industries

There are many ways of dust removal. According to different principles, it can be roughly divided into electrostatic dust collector, liquid dust collector and baghouse. At present, the most widely used are baghouse and electrostatic dust collector.

At present, the research and development focus of ESP technology in China is mainly in the following aspects: universal resistance ESP technology, mobile electrode ESP technology, membrane ESP technology, laminar electrocoagulation technology. Bag filter can be divided into positive pressure and negative pressure according to different pressure, but at present, negative pressure is widely used in our country. Bag type dust collector has many kinds of structure forms, such as pulse injection type, long bag low pressure pulse type, chamber injection pulse type, filter simple pulse injection type, flat bag pulse injection type, rotary reverse blowing type, gas box pulse type, etc.

Iron and Steel Industry: Wide Market Space for Dust Removal Equipment

In China, the pollution problem of the iron and steel industry has always been very serious. The main sources of pollutants are sulfur dioxide, dust, wastewater and solid waste. Following the success of bag-type dust removal technology in large blast furnace dust removal, a large number of dry blast furnace gas dust removal systems have been built and put into operation. Through new construction or renovation, Shougang, WISCO, TISCO, Baosteel, Laigang, Baotou Steel, Tonggang, Chenggang, and other enterprises have realized the filtering and dust removal of blast furnace gasbags. According to incomplete statistics of Bag Committee, more than 100 blast furnaces in China have adopted dry bag filter technology, including 2500 m3, 3200 m3, 5500 m3 and other large-scale blast furnaces, the largest of which is 5800 m3. With the application of bag filter in the iron and steel industry becoming more and more mature, it will develop steadily with the expansion of industrial capacity in the future.

Thermal power industry: bag type and static electricity have their own advantages.

China's primary energy structure dominated by coal determines that thermal power generation will be the main mode of China's electric power production for a considerable period of time in the future. In recent years, China's thermal power installed capacity has maintained steady growth.

The demand of thermal power industry can be divided into two kinds: (1) the demand of retrofitting existing power plant dust collector and the demand of new power plant: (1) the demand of retrofitting. According to our investigation and understanding, at present, in the thermal power enterprises which have implemented dust removal transformation, the main transformation path is to change the electrostatic precipitator to the electric bag composite precipitator or or the bag type precipitator. (2) New demand. According to our investigation and understanding, there are few ESPs used in newly built thermal power plants, most of which are bagged or combined ESPs. The main reason is that it is difficult for ESP to meet the new discharge standard. Because the time of retrofitting dust collectors in power plants is generally not long, there is no unified view on which technology is better, and it takes longer to observe.

Generally speaking, the improvement of emission standards of coal-fired power plants will bring good opportunities to the rapid development of dust collector industry. In terms of selection, by comparing the three types of dust collectors, the application of dust collectors in thermal power industry will continue to shift to bag type dust collectors and electrostatic bag composite dust collectors in the future, and the share of electrostatic precipitators will gradually decrease.

Cement Industry: Bag Dust Removal is the Absolute Advantage

In cement industry, because of the difference between kiln head and kiln tail, and the temperature difference between them is very far, so the selection of dust collector can not be generalized. Generally speaking, kiln head tends to use electrostatic precipitator, kiln tail and other parts of low temperature tend to use bag precipitator. This is because the dust collected by the bag filter is actually cement concentrate, which can bring revenue to the company. However, there is also a trend in recent years, that is, most of the new 4,000 tons/day, 5,000 tons/day, 10,000 tons/day and 12,000 tons/day scale production lines in the cement industry adopt bag dust collectors at the kiln head and kiln tail. Bag dust collectors are used all over the line. The air handling capacity of a single machine ranges from hundreds of thousands of m3/h to millions of m3/h. Many cement enterprises will transform the existing electrostatic precipitators into bag dust collectors.

Because bag filter has been used in the cement industry, its main growth will come from the increase of cement production capacity in the country. With the steady growth of demand for cement in domestic market, the application of bag filter in cement industry will also grow steadily.

Waste incineration industry: bag dust removal is the only choice

Compared with other waste disposal methods, waste incineration power generation has the advantages of good capacity reduction effect, complete disinfection, reducing (or eliminating) the environmental impact of subsequent disposal process, turning waste into treasure, and small incinerator area. The flue gas generated during the incineration process of refuse has the characteristics of great harm, high moisture content, high and low temperature alternation, fine dust particles and strong corrosiveness, which put forward high requirements for the performance of dust removal equipment. In recent years, bag filter technology has been well adapted to the conditions of waste incineration smoke and dust, and successfully overcome the above difficulties.

In the future, the field of tail gas purification in waste incineration and waste incineration power generation industry will develop into a mature industry. From scheme design, equipment manufacturing to construction and operation, it will gradually move towards professional operation. Therefore, the host and filter materials of bag filter matched with waste incineration tail gas purification will have a great development prospect, or will become a new growth point of the demand of bag filter.