Bag filter is used widely in modern industry, a highly efficient and effective dust removal equipment, its history has been over a hundred years, especially in the fifties after the more rapid development. Bag filter bag material development mainly in the improvement and reform of both cleaning methods. Currently, the bag filter has been available for high density, high temperature, high humidity, corrosion, adhesion, explosive and moisture, dust and other deliquescent gas purification, and widely used in metallurgy, mining, building materials, foundry, chemicals, carbon , food and other departments, its use will be expanded with the development.
Bag filter dust removal mechanism, mainly depend on the dust generated when airflow through the sieve bag fibers, collision, hook, diffusion, gravity and electrostatic effects such as six areas, dust adhesion to the surface and can be purified in the bag , the removal efficiency up to 99.5%.
Bag filter of the filtering effect is mainly through sieve. Dust filter bag is formed by the fabric, fabric surface of a large number of pores, including single fiber porosity and pore between two latitude and longitude lines, generally single fiber pore is 100 ~ 200u, accounting for fabric porosity 30 ~ 50% porosity was between longitude and latitude, 300 ~ 700u. Therefore, the use of the porosity with the fabric to filter submicron dust is not possible, that rely on fiber fabric bag filter dust-laden air carried on the sieve purification, this claim is not accurate. In essence, bag filter dust in the air filter, the first is to rely on hook, diffusion, electrostatic, screen filter and other effects, so that the surface of the porous fabric layer are Nianman "dust film" called "once the dust "Using this" one-dust "in order to be effective against dust air filter, so that" once the dust "from the floor above and then attach the new product" dust film "called" secondary dust ", bag filter is to periodically clear the "secondary dust" running under the circumstances, in the clear "secondary dust" of the operation asked not to undermine the fabric surface, "a dust", otherwise it will affect the dust of the purifying effect. So, in fact, is the use of fabric bag filter as a "skeleton", so that the establishment of "a dust", relying on this "once the dust" as filters to purify air in the dust dust, that is used to filter the dust layer A dust filter.
More bag filter type, with mechanical shaking, anti-hair, pulse, and other means, we mainly on the wide use of the current pulse, rotary cleaning bags and anti-hair flat three kinds of bag filter According to reflect actual use in a number of specific issues, give a brief exposition.
A pulse bag filter Pulse bag filter in 1957 by Leinahaer (TVRenauer) invented it in 1950 Hessian (HJHersey) invented the gas ring with cleaning bag filter bag filter is considered a revolution in the bag filter performance area is famous for the first time, to achieve continuous operation. It is simple, continuous cleaning, resistance stability, high filtration rate, no internal moving parts, simple design and so on, is a highly efficient bag filter.
Home, since l966 a pesticide factory in Beijing mark the introduction of the British Empire after the pulse bag filter, 1988, the copper smelter in the Fuchun River gas processing system, the first time, China's first successful trial pulse bag filter, after the relevant units in the factories, mines and collaborative efforts, through the pulse control apparatus and filter bag materials continue to improve, since 1971, developed a gas-controlled, non-contact three types of electrical control and machine control shaped products. To pulse bag filter air filter at room temperature, the field has been rapidly expanded, now spread to the metallurgical, mining, building materials, foundry, chemicals, carbon, food and other departments.
Pulse bag filter is an inverse under the inlet jet bag filter. Dust bag periodically use compressed air injection, injection period of 30 to 60 seconds, injection time of 0.1 to 0.2 seconds.
Pulse bag filter has the following characteristics:
(1) filtering of wind velocity. Devices are small, covering an area of less?? Pulse bag filter as the pulse period is short (30 ~ 60 seconds), cleaning efficiency, and therefore its filtration velocity of up to 2 to 4 m / min, compared with the same type of bag filter devices to high-2?? 4 times, resulting in less of its filtration area, equipment, light volume, small footprint. 10,000 m 3 per treatment General / when gas flow, pulse bag filter device weighs 2 to 5 tons, flat bag rotation cylinder 0.7 to 7 tons, anti-hair bag filter 5 to 8 tons.
(2) fluctuations of small dust processing gas, the pressure stability?? Pulse bag filter bag room, regardless of grid points as room and realized by a continuous row of non-stop wind blowing, so the processing gas flow is not due to injection caused by cyclical fluctuations, resulting in filter pressure loss is relatively stable.