At present, as far as China’s flue gas emission standards are concerned, electrostatic precipitators are still the preferred method for controlling the dust from coal-fired power station boilers. However, due to the dust collection efficiency of electrostatic precipitators is greatly affected by the nature of dust, and China’s coal composition is ever-changing, the nature of dust is different, so many power plants are difficult to achieve long-term, efficient and stable in coal-fired power station boilers. Electrostatic precipitators are used. With the improvement of the dust emission indicators of the country, the advantages of strong adaptability to dust bags, high dust removal efficiency, and reliable operation have gradually emerged.
Dust bag is one of the main equipments that can effectively control smoke pollution. It has high dust removal efficiency. The dust concentration of the flue gas filtered by the dust filter bag is generally lower than 50 mg/m3, and at the same time, the fine dust in the flue gas can be effectively removed. The type of dust bag is divided into four types according to the cleaning method: mechanical vibration cleaning dust bag, pulse jet dust bag, rotary counter-flat bag filter, and air ring counter-current dust bag.
Dust bag as a dust removal device has a history of a century. In foreign countries, dust bag has been used in coal-fired power station boilers for 20 to 30 years and has achieved good results. Currently. Dust bag has been widely used in power station boilers. For example, in the power station boilers in New South Wales, Australia, 80% have adopted dust bags. In addition, some countries have also reformed the original electrostatic precipitators. In China, dust bag is widely used in metallurgy, building materials, chemical industry, road construction and other industries. China also tried to use dust bags on coal-fired power station boilers in the early 1980s, but due to the lack of mastery of the technology at the time and the constraints of objective conditions at the time, there were short filter bag life, ash plugging, burning bags, and failure rates. Problems such as being high and affecting the safe operation of the unit have not been successful, but they have provided valuable experience for the application and development of dust bag on coal-fired boilers. In 2001, the successful operation of a full set of imported bag-type dust-removal equipment from a power plant in Inner Mongolia laid a good foundation for the use of dust bags in coal-fired power station boilers in China.