Bag filter is a high-dust air pollution control equipment.

     Bag filter dust is the greatest advantage of high efficiency up to 99.9999% in the laboratory, in practical applications has reached 99.99%, the concentration of dust emissions can be achieved 10mg/Nm3 the following, even to 2mg/Nm3, this is the bag filter determined by the filter mechanism. This mechanism is to make the dust attached to the bag, and with the dust to filter dust. Therefore, the most efficient bag filter dust. Strategy of sustainable development in our country, vigorously strengthen environmental protection, the implementation of total pollutant control, tightening up the case, the bag filter in the control of dust, soot, sulfur dioxide, dioxins and other pollution, will accomplish much. The biggest drawback is the bag filter bag needs to be replaced, due to fewer filter variety, poor quality, sewing kit technology not pass, and the dust removal system for other reasons, for relatively short cycle bags, increased operating costs and maintenance, and inconvenience to users. Now, our filter varieties increased, quality improvement, sewing kit technology has greatly improved bag life expectancy has increased to more than 2 years, or even longer, to meet the user requirements. Therefore, the bag filter will be the rapid development of the next decade.

    I. Overview of bag filter

    Bag Filter China 50 years in the twentieth century the main types of products with the former Soviet Union, six, 70 years a small number of design, research units in counterfeit United States, Japan and other countries of the pulse-type, mechanical rotary cleaning flat bag Based on the dust began producing their own products. In 1973, domestic production began to appear a number of bag filter business, since most of the dust bag has become the backbone of our production company. Into the eighties, China's bag filter to achieve a certain scale of production. The research and design institutes and tertiary institutions of learning, introducing, digesting, and transplantation, based on combining the needs of domestic industry applications and manufacturing plant to develop a suitable carbon black industry, pulse jet bag filter, not only as a dust removal device also as an indispensable process equipment; iron and steel industry, nonferrous metallurgy equipment to meet the processing needs of wind capacity, the development of the sub-chamber bag filter and anti-hair long bag and low or high pressure pulse bag filter, dust removal equipment to large, per hour, can handle 1 million m3 ~ 291 万 m3 air volume; to adapt to China's large shaft kiln cement industry wide characteristics, development of high temperature kilns, dryers, and glass fiber bag filter bag of coal mill explosion-proof type Filter. The same time, companies from the U.S. introduction of the gas-rich music box pulse bag filter and stand-alone dust collector; construction of highway (asphalt, gravel mix) flue gas purification, the introduction and development of the pulse jet bag filter; urban construction waste incineration furnace dust tail, with the exception of dioxin and other harmful gases, the development and introduction of a bag filter, bag filter so that the domestic product variety becomes more advanced, complete, complete, effective application and use of foreign terms and close to that The already reached the international advanced level.

   Our filter media, filter bags and bag filter technology is the simultaneous development, currently capable of producing chemical fiber woven fabric, room temperature needle felt, anti-static needle felt, waterproof waterproof felt, high temperature resistant needle continuous glass fiber mat and fabric, glass yarn, glass fiber filter needle felt, etc., as well as PTFE membrane filter media and other working conditions for the performance of a variety of fine filter material. Sewing bags have made great progress in technology, some bag factory has reached the level of foreign sewing bag.

   The current emission levels of environmental protection standards must be tens of milligrams per standard cubic meters less. Of the dust properties, the general only the bag filter and electrostatic precipitator capable, ESP low pressure loss in the operation, in power, steel, cement, and pulp industries using large air volume of dust was more But in other aspects of the use of wind capacity, has now been replaced by bag filter. Simple bag filter, dust collection efficiency is high, accounting for more than 85% of Dust Collector in more than 50 kinds of industries widely used.

    Second, the application of bag filters in China

China's steel industry has more than 1,600 companies, is the largest user of bag filter. Bag filter used in a wide range of iron and steel industry, from ore crushing, screening, conveyor, sintering, iron making, steel making, steel rolling, ferroalloy smelting, coke, lime, refractories, etc., essentially in the production process each process, bag filter can be used, with favorable results. Baosteel, Shougang Group, Wuhan Iron and Steel, Panzhihua Iron and Steel and other large companies have more than 200 bag filter.

Case of Shanghai Baosteel, Baoshan Steel an annual output of more than 10 million tons, more than dust source, flue gas temperatures are high, emissions of soot, dust is significant. To control dust, smoke on the plant and the pollution of atmospheric environment, the first phase of the project by bag filter 109, Taiwan, accounting for plant removal equipment for more than 70% of the total deal volume of flue gas 18  8 × 104m3/min, the total installed capacity 2  8 million kilowatts, the overall effect is good. Annual quantity of dust recovered 47  5 million tons, of which the direct return to the production line 24  2 million tons, making the ball get fired back with a 19  5 million tons, 92% recovery efficiency, and achieved good economic and environmental benefits . Baosteel first, second and third phase of investment in environmental protection reached 43  4 billion, with 316 sets of environmental protection facilities, environmental protection investment accounts for 5% of the total investment. One bag filter 205 units (not including small single and small unit), installed capacity of filter media to reach 800,000 m2 (accounting for 10% of the country around filter output), total air volume 55  22 × 104m3/min. Baosteel bag filter emission control standard concentrations of 35mg/Nm3, the lowest reach 4  8mg/Nm3, has reached the advanced level in developed countries. Baosteel Shanghai Urban Air Quality better than that, Baosteel has also adopted the ISO14000 international environmental standard.

    China's total cement production enterprises 8435, annual production capacity of 5  9 million tons, ranking first in the world, but also caused serious pollution to the environment. Per 1 ton of cement production to processing 3 tons of materials, China's cement industry dust, soot emissions by as much as 1200 tons. 2000 China has eliminated 4  4 tons / years of small cement 4400, production is about 200 million tons. Structural adjustment of cement industry, "the big Gaixiao", pay attention to environmental protection has become the consensus of the industry. In particular the introduction of the United States Fuller Bag filter technique, the new Nissan on the 700 tons 1,000 tons, 2,000 tons, 4,000 tons of dozens of widely used line filter technique the United States Fuller bags, just the air box pulse bag dust device usage has reached 1,500 sets.

Daily output of 2,000 tons of Beijing Cement Plant Cement, the whole plant were equipped with dust removal equipment 79 sets, in addition to using an electric Kiln dust, the other are basically dust collector, total investment in 1622  3 万元. Filter bag to large-scale kiln, for example, kiln flue gas volume of 370,000 m3 / h, 16300m2 fiberglass bulk yarn used to make high-temperature sub-chamber filter bag filter cleaning. 1996 emission levels 24mg/Nm3, 1997 year 19  4mg/Nm3, 1998 only 3  17mg/Nm3, SO2 removal rate of 88%, filter bag life of more than three years, 8 tons of dust per hour recyclable about. The factory produces an annual economic benefits of dust collection, net of operating costs 2.13 million, up 583  26 million, two and a half can recover the investment of all dust. If China's large and medium size cement plant cement plant can be done as Beijing, then cement industry of dust, smoke and dust emissions will be reduced by several million tons of dust collection cost per year will be millions of dollars.

    In recent decades, China's aluminum smelting industry have seen significant developments, mainly the Preparation of aluminum by electrolysis, the main device is a cell, the production process produce large amounts of fluoride and dust and other harmful substances, is a more polluting production process. Such as Guizhou and Guangxi Pingguo aluminum smelter, electrolytic cell system air volume was 2.78 million m3 / h and 2.91 million m3 / h, the entrance of dust concentrations were 30g/Nm3 ~ 50g/Nm3, respectively 1  68 万 m2 and 2  17 万 m2 filtration area, pulse jet bag filter, export concentration dropped to 9  11mg/Nm3 and 9  34mg/Nm3, export fluoride concentrations were 0  22mg/Nm3 and 0  84mg/Nm3. Bag filter used to clean aluminum gas tank system, technology is mature, reliable, effective control of smoke pollution, more completely solved the electrolyzer gas pollution. In addition to aluminum smelting, heavy non-ferrous metal smelting bag filter is also widely used to good effect.

    In addition to the iron and steel, cement, nonferrous metallurgy, the machinery, batteries, carbon black, power, coal, ceramics, chemicals, fertilizers, pharmaceuticals, agricultural chemicals, light industry, tobacco, flour, feed, oil processing, grain storage, port forwarding, transport and roads, garbage incineration is used by more than 20 trades a bag filter. Zai various industries in particular are small and medium scale in the source She Shi Shang, using a wide range of bag filter Geng Wei, good results, Wei protection of atmospheric environment in China, Zhi Li dust, soot and SO2, dioxins Deng made of harmful gas pollution great contributions.
    
Third, the development trend of bag filter

      China's economic size of a large, heavy chemical industry, raw materials, energy industry, many are still extensive production, backward production technology and equipment, resources, large energy consumption and serious pollution. Bag filter market in China is not too realistic. According to 2000 statistics, the bag filter output was 17  7 billion, and our dust, smoke and dust pollution situation in need of treatment not match.

      China's major coal-fired power plant boiler dust is a huge market for high efficiency dust removal equipment. For various reasons, our bag filters in the market situation has not yet opened. The coal-fired thermal power plants in developed countries boiler dust removal, desulfurization, take up a considerable share of the bag filter. The highest efficiency of bag filter dust, and dust from the impact of changes than the resistance, as well as some desulfurization function.

Along with the increasingly stringent environmental regulations, bag filter in the domestic coal-fired power plant boiler dust removal, desulfurization market share will be entitled to share. Incinerator dust, in addition to the work of dioxins harmful gas in our country has just started, non-bag filter must go. Others include industrial boilers, heating boilers, furnaces, gas purification, construction of highways, asphalt, stone dust mixing of high temperature, in addition to harmful gases, and various high temperature industrial furnace dust, bag dust removal technology are the focus of future development and direction. Dust bag industry in China will further develop new technologies, new materials, new processes, new products to meet China's growing environmental protection.