Closed dust removal belongs to passive dust removal, and its principle is: keep the mine dust generated by local dust sources in a closed space as small as possible, require absolute sealing, and minimize the scope and space affected by dust. However, due to cost and technical reasons, it is difficult to achieve absolute sealing in reality. For example, in some mine sites in China, the equipment is only separated by simple partitions, and the workers or equipment in the space are still threatened by dust.
2. Filter dust removal (bag dust removal)
The filter material is used to filter the gas containing dust, so that the dust stays on the filter material to achieve the purpose of dust removal.
Filtration is divided into two stages: first, dusty gas passes through clean filter material, and fiber is the main filter body at this time; Then, when the amount of retained dust increases, part of the dust is embedded in the filter material, and the other part is covered on the surface to form a dust layer. The later filtration mainly depends on the dust layer, and the role of the dust layer is more important than the filter material.
Characteristics of bag dust removal: Because of the different efficiency and resistance of two different filtration stages, the stability of dust removal effect is poor.
3. Electrostatic dust removal technology
It is a technology that uses the strong field strength generated by high voltage electricity to ionize the gas, that is, to generate corona discharge, to charge the dust and separate the suspended particles in the gas under the action of electric field force. Electrostatic precipitation technology is widely used in flue gas purification in electric power, building materials, metallurgy, chemical industry, light industry, electronics and other industries.
Advantages: high dust removal efficiency, small resistance loss, and graded enrichment of soot with different particle sizes.
Disadvantages: it is not easy to adapt to the change of working conditions, the application scope is limited by dust specific resistance, and the requirements for manufacturing, installation and operation are high; High energy consumption, large steel consumption, large floor space and high input cost.
4, water spray or spray dust removal (wet dust removal)
Water is used as a medium for dust removal. Generally speaking, although water spraying or spraying has a certain dust removal effect, it will wet the materials and affect the quality of finished products, and the wet materials will cause great wear and tear to the equipment, and in addition, it will produce water pollution and need sewage treatment. On the surface, water spraying dust removal is quick and low cost, but considering the use cost, management cost and environmental damage, the cost of this dust removal method is very high.
5, biological nano-film dust suppression
Belonging to the source dust suppression technology. Starting from the source of dust generation, rapid dust reduction can be realized. BME's original biological nano-film dust suppression technology has been typically used in domestic mines, metallurgy, garbage disposal and other places. This dust removal technology belongs to dust suppression before dust discharge. Compared with other dust removal after dust discharge, it has great advantages and can effectively control the dust discharge in the whole process of material production. The comprehensive dust suppression system using biological nano-membrane technology can achieve 98% or even higher dust suppression rate. The dust generated in the crushing process is aggregated into fine materials, and finally becomes a finished product, which can increase the output by 0.5%-3%.
Advantages: no water pollution, no side effects on the environment, no influence on the quality of finished products, low input cost, obvious effect of preventing and controlling PM2.5 and other fine particulate pollution, and suitable for various industrial and mining enterprises. Dust can be directly converted into finished products, increasing economic benefits.
Disadvantages: it requires the investment of precision professional equipment and requires high operation requirements.