Air pollution is one of the world's most prominent environmental problems, the main source of pollutants is industrial exhaust, industrial exhaust due to the production of different processes, the types of pollutants produced by different pollutants should be used for different types of treatment processes.
1, organic waste gas
(1) the main source: industrial production will produce a variety of organic waste gas, including a variety of hydrocarbons, alcohols, aldehydes, acids, ketones and amines. The source of these gases is very wide, some of which are chemical industry petrochemical, organic synthesis reaction equipment exhaust, printing industry printing ink in organic solvents, machinery industry machinery spray paint, metal products produced by the odor, the automotive industry automobile paint, drying furnace casting production equipment exhaust, hardware, home furnishings factory spraying equipment exhaust, etc..
(2) the hazards of organic waste gas: in production, organic emissions has been a very prominent issue, the vast majority of organic waste gas is harmful to human health. Organic waste gas can also cause serious air pollution.
(3) exhaust treatment methods:
a. Water film dust removal + activated carbon adsorption method;
b. Dry filtration dust removal + activated carbon adsorption method;
c. Activated carbon adsorption + catalytic combustion method;
2. Acid mist exhaust gas
(1) the main source: chemical, electronics, metallurgy, electroplating, textile (chemical fiber), Food, machinery manufacturing and other industries in the process of emission of acid, alkaline exhaust, such as flavored food, acid, pickling, electroplating, electrolysis, storage batteries and so on.
(2) the hazards of acid mist exhaust: acid mist gas caused by air pollution on the human body caused by the greater harm, especially on the site of the operation of the workers, the factory near the crops, soil and the direct damage caused by the indirect impact of the often can not be measured in monetary terms.
(3) Exhaust gas treatment method: water film packing tower + alkali (acid) liquid absorption.
3, furnace exhaust, black smoke power generation
(1) the main source: hardware industry, die-casting industry, foundry furnace equipment in the metal melting process of metal dust particles and combustion of diesel fuel (heavy oil) produced in the process of SO2, NOX harmful gases, generators work in the process of combustion of diesel fuel (heavy oil) generated during the exhaust gas, etc..
(2) the harm of the furnace exhaust, generator black smoke: furnace exhaust, generator black smoke is the main cause of the formation of acid rain, caused by air pollution, especially on the site of the operation of the workers, the plant near the crops, the soil caused by the direct damage and indirect impact.
(3) treatment method: cyclone washing and spraying method + alkali absorption
The furnace exhaust, generator sets discharged exhaust black smoke, according to the current conventional practice is the use of cyclone washing and spraying method, the use of cyclone spray tower, the gas in the tower from the bottom upward high-speed movement, and the top-down spraying of the washing liquid contact, due to the tower is set up with a multi-layer cyclone, it can increase the gas and liquid Due to the multi-layer cyclone plate set up in the tower, it can increase the gas-liquid contact area and contact time, so that the exhaust gas and water in the tower and on the surface of the plate to fully contact. The pollutant carbon black in the tail gas is fully adsorbed by the water in the process of contacting with the spray water and purified; NOx, SO2 and other gaseous pollutants in the tail gas are neutralized by adding a certain proportion of NaOH into the spray water to make the spray water alkaline, and when the water comes into contact with the tail gas in the process of spraying, a chemical reaction occurs, which neutralizes the NOx, SO2 and other gaseous pollutants and achieves a good treatment effect.
4, kitchen fumes, fire smoke
(1) the main source: fumes are fumes gas molecules produced by various types of manufacturers kitchen frying. Fire smoke is the stove completely or incompletely combustion of harmful gases emitted, is mainly free carbon black soot, flocculent, easy to adhere to solid material, the rest is COX, SO2, NOX, is a high concentration of soot gas
(2) kitchen oil smoke, fire smoke hazards: kitchen oil smoke contains many substances that are seriously harmful to the human body, it will increase the chances of people suffering from lung cancer. Kitchen fire smoke is also one of the main air pollution, the gas is acidic, easy to form acid in contact with water, will pollute the water and soil and corrosion of buildings.
(3) governance methods:
A. Oil smoke
a. Filter adsorption oil smoke purification: filter adsorption oil smoke gas purification equipment can be used with high oil absorption performance of organic polymer composite fabrics or felts, inorganic filtration materials (water-repellent perlite, ceramics, coke, etc., used alone or in combination), the filtering material can be used perpendicular or parallel direction of the flow direction of flue gas. The filtering material can be placed perpendicular or parallel to the direction of flue gas flow, and the purification efficiency should be more than 80%.
b. Electrostatic fume purification: electrostatic deposition method is to introduce the fume gas into the high-voltage electric field, so that the fume, fire smoke particles in the charge, under the action of the electric field force to the dust collection pole movement and deposition. The purification efficiency is usually up to 85% or more, and the pressure drop is small.
c. Low-temperature plasma method: its principle is the use of high-voltage electrostatic method at the same time, in the electrostatic field set up at the front end of the plasma field, the use of its high-energy excited by a large number of sexual radicals on the soot particles degradation, so that the viscosity decreases; plasma in the process of generating a high-frequency discharge of transient high-energy, which can open up some of the harmful gases of the chemical bonding, so that the decomposition of the monomolecular atoms or harmless molecules. The technology is the most advanced on the market. This technology is the most advanced oil smoke and fire smoke treatment technology in the market at present, with high removal rate (below 90%), no odor after treatment, convenient maintenance, but high investment in equipment.
B. Fire Smoke
The high concentration of kitchen fire smoke gas using cyclone wash spray method, using cyclone spray tower, the gas in the tower from the bottom upward high-speed movement, and from the top down sprayed with the washing liquid contact, due to the tower is set up with a multi-layer cyclone, it can increase the gas-liquid contact area and contact time, so that the exhaust gas and the water in the tower and the plate surface is in full contact. Pollutants in the tail gas carbon black in the contact process with the spray water, the water is fully adsorbed, to be purified; NOx, SO2 and other gaseous pollutants in the tail gas by adding a certain proportion of NaOH in the spray water to make the spray water alkaline, in the process of spraying, the water and the tail gas in contact with the chemical reaction occurs, so that NOx, SO2 and other gaseous pollutants can be neutralized to achieve good treatment results.