Industrial waste gas pollution control is mainly caused by the burning of fossil fuels (coal and petroleum) during production and living activities, rock drilling, blasting, crushing, and screening of building materials, smelting, and casting during mining. Air pollutants mainly include dust particles, carbon dioxide, sulfur dioxide, or nitrogen oxides.
The technology of industrial waste gas treatment pollutants is different for different pollutants.
1. Industrial waste gas treatment technology for particulate pollutants
According to the size of particle pollutants, industrial waste gas treatment methods mainly include a dry method, wet method, filtration, and static electricity. The most commonly used are bag dust collector (filter), cyclone dust collector (dry method), and foam dust collector. (Wet method) and so on. As the requirements for dust removal efficiency increase, electrostatic dust removal has gradually begun to be used.
The electrostatic precipitator consists of two electrodes. After a current and voltage are applied between the electrodes, an electric field is generated between the electrodes. Particulate pollutants travel through the electric field with the exhaust gas, and the particles are collided with ions and make them charged. The charged dust moves to the dust collecting pole and reaches the pole plate. In this way, the pollutants in the air are adsorbed on the electrode plate, so that the air is purified, and the dust particles fall into the ash hopper due to their own gravity.
The electrostatic precipitator can capture all fine particles or liquid droplets, processes a large amount of waste gas, and has a wide operating temperature range, so it is widely favored by industrial enterprises. However, due to the large area and large investment, some small and medium-sized enterprises cannot choose.
2. Nitrogen and sulfur oxide treatment technology
Because there are a lot of nitrogen oxides and sulfur oxides in the atmosphere, air pollution occurs, and pollution incidents occur one after another. In view of the nature of these oxides, scientists have proposed technologies to solve pollution, including the absorption method, an adsorption method, condensation method, catalytic conversion method, combustion method, biological purification method, membrane separation method, and dilution method. The most commonly used method is the horizontal wet scrubber. The exhaust gas passes through the absorption tower and communicates with the absorption liquid flowing down the top of the tower, so that the components in the absorption liquid and the harmful components in the exhaust gas chemically react, reducing the harmfulness of the exhaust gas. Element. Finally, when the exhaust gas comes out of the top of the tower, it has become a clean gas. This kind of pollution control method is simple, less investment, and convenient to operate. Malaysia and Singapore mostly use this method.
There is also a commonly used method of high chimney dilution for pollution control. From the 1950s to the 1960s, European industry developed rapidly. For a while, no suitable treatment technology could be found, and no suitable treatment technology could be used to pollute the city. Chimneys as high as several hundred meters were created. The characteristics of rapid diffusion of high airflow were used to dilute gaseous pollutants. This method is still widely used. For example, the Ruhr Industrial Zone in Germany takes advantage of the characteristics of European southerly winds and can diffuse exhaust gas to 2000 kilometers away through chimneys with a height of 200 meters to 300 meters. Some large companies in the United States and Japan also often use this method to evade responsibility for environmental protection. In developing countries such as Singapore, Singapore, Malaysia, Pakistan, and other countries, the most widely used wet scrubber adsorption method is the quality of waste gas pollution.
With the development of science and technology, there are mainly four types of treatment methods for air pollution industrial waste gas: dry, wet, filtration, and static electricity. The most commonly used are bag filter (filter), cyclone dust collector (dry method), and foam. Dust collector (wet method), etc. As the requirements for dust removal efficiency increase, electrostatic dust removal has gradually begun to be used.
