Dust usually refers to the industrial waste gas containing dust in the mechanical processes such as crushing, screening, conveying and blasting in the processing of solid materials, or in the processes of combustion, high-temperature melting and chemical reaction. Based on many years' experience in dust control engineering, the Research Center for Environmental Monitoring and Control Optimization of China Academy of Building Research draws the conclusion that the former contains dust with larger particle size and the same chemical composition as the original solid substance, while the latter contains dust with smaller particle size and different chemical properties from the substance that produces it. The production of particulate matter can be reduced by improving production technology and combustion technology.
The comprehensive dust suppression technology mainly includes the key technologies such as Baimeidikang bio-nano membrane dust suppression technology, cloud dust suppression technology and wet dust removal technology. Biological nano-film dust suppression technology, biological nano-film is a double-layer ionospheric film with nano-layer spacing, which can maximize the ductility of water molecules and has strong charge adsorption; Spraying biological nano-film on the surface of the material can attract and condense small particle dust, which will be polymerized into large particle dust, which will increase its own weight and settle; The highest dust removal rate of this technology can reach above 99%, and the average operating cost is 0.05~0.5 yuan/ton.
Mechanical dust collector relies on mechanical force to remove dust particles in airflow, which has simple structure, low equipment cost and operating cost, but low dust removal efficiency; Electrostatic precipitator uses electrostatic force to separate dust particles from airflow. There are basically two kinds of electrostatic precipitators: plate electrostatic precipitator and tube electrostatic precipitator. The airflow resistance of electrostatic precipitator is small, and the dust removal efficiency can reach over 99%. The initial investment of electrostatic precipitator is relatively high, and it covers a large area. Bag filter separates dusty airflow and collects dust particles through bag filter material, and the dust removal efficiency is generally 90% ~ 99%. However, due to the temperature resistance of bag filter material, it is sometimes not suitable for dusty high-temperature industrial waste gas. Washing dust remover washes dusty industrial gas with liquid (usually water and organic solvent), so that dust particles collide with liquid droplets or liquid films and are captured and separated from gas flow. The dust removal efficiency is 80% ~ 95%, and the operation cost is high. The absorbed waste liquid needs to be considered for recycling or secondary treatment.
Personal suggestion: On September 8, 20 15, a "dust removal giant" appeared at the site of SINOMACH International Demolition in Laodong Road, Changsha: a pneumatic spray dust collector. The person in charge of the construction site said that the construction site was the first in Changsha to use the air-delivered spray dust collector to control dust. As far as the current dust suppression effect is concerned, the construction site not only improves the work efficiency, shortens the demolition time, but also basically eliminates dust pollution.