High-temperature baghouse dust removal technology helps the battle for blue skies
In mid-October, smog shrouded the capital again and again, in an endless cycle. In a WeChat group for parents at a certain kindergarten, Ms. Lin, the mother of a 5-year-old child, kept asking anxiously: "The smog is so severe, are the air purifiers in the classroom turned on?"
In the end, she received an affirmative answer and a bit of comfort. Though as an adult, she clearly understood the truth that when the nest is overturned, no egg remains unbroken.
At present, the regions with the most severe fine particulate matter pollution in the world are North Africa and China's North China, East China and Central China regions. The annual average concentration of fine particulate matter in most parts of China is close to 80 micrograms per cubic meter, about 8 times the safety value set by the World Health Organization (annual average of 10 micrograms per cubic meter), and the air pollution situation is grim. Data shows that industrial pollution is currently the largest source of PM2.5 in China, among which cement manufacturing, coal-fired power stations and iron and steel metallurgy are the three major killers among industrial pollution sources.
To tackle PM2.5, industrial dust removal is a key link that cannot be ignored. So how to upgrade industrial dust removal technology so that, through technical means, production is ensured while dust emissions are reduced, has become a key issue in air pollution prevention and control.
"Baghouse dust removal technology is an effective path for preventing and controlling air pollution and reducing industrial soot emissions, and high-temperature filter materials using high-tech fibers as substrates are the key to the application of baghouse dust removal technology," said Cao Xuejun, deputy director of the Consumer Goods Industry Department of the Ministry of Industry and Information Technology, at the "China Textile International Science and Technology Forum - Development and Application of High-temperature Baghouse Dust Removal Technology" held in mid-October.
So-called baghouse dust removal means relying on filter bags made of fiber filter material to purify gas. Among various dust removal devices, the baghouse dust collector is one with very high dust filtration efficiency; for almost all dust in general industry, its dust removal efficiency can reach more than 99%.
"China is the world's largest user of fossil energy. Along with the development of the power and cement industries, Chinese enterprises have also begun to implement the European standards of the international market. Corporate emission standards have become stricter and accountability is strong." Xia Qianjun, general manager of Nanjing Jihua 3521 Special Equipment Co., Ltd., believes that "the driving force for progress in high-temperature baghouse dust removal technology comes from huge demand."
Liu Jingxian, director of the Filter Material Testing Center of Northeastern University, told reporters that the performance of filter materials produced by domestic enterprises can now rival that of foreign brands, but product stability is relatively poor, and there are also phenomena such as lack of industry self-discipline and low-price competition.
It is introduced that as the organizer of the China Textile Science and Technology Forum, the China Textile Academy undertook the relevant construction work of the public service platform for the development and application of high-temperature baghouse dust removal filter materials supported by the Ministry of Industry and Information Technology, aiming to provide filter bag production and application enterprises with industry-wide common services such as filter bag quality and performance evaluation, new filter material technology development, and waste filter bag recycling. As the platform's work advances, it will play an important role in achieving healthy and sustainable development of the high-temperature filter material industry.
In the industry, everyone recognizes that filter material is the "heart" of baghouse dust removal technology. The popularization of baghouse dust removal technology has also continuously raised requirements for the material of the filter bags - textile filter materials. The original textile filter materials could not meet the growing technical demands.
"In the past 5 years, the annual average growth rate of the filtration and separation textiles industry reached 14.7%. Major breakthroughs have been achieved in key products and technologies such as gradient filter materials, ultrafine fiber filter materials, polytetrafluoroethylene, and foam coatings, enabling baghouse dust removal technology to achieve fine particulate matter dust emission concentrations of less than 10 milligrams per cubic meter, and even reach ultra-clean emission levels. The service life of filter bags has reached more than 4 years, and the proportion of baghouse dust removal applications in coal-fired power plants has increased from 10% to more than 20%," summarized Li Lingshen, vice president of the China National Textile and Apparel Council and president of the China Nonwovens and Industrial Textiles Association. (Reporter Guan Jingjing)