Asphalt waste gas treatment solutions

Asphalt waste gas treatment solutions
Asphalt flue gas contains tar particles, hydrocarbons, H2O, S2O, CO2, benzopyrene and other complex components. Polycyclic aromatic hydrocarbons and a small amount of O2, N2, SO4 heterocyclic compounds, including naphthalene, phenanthrene, carbazole, phenol and so on more than 100 kinds of substances, among which dozens of substances can cause cancer, especially benzene compounds to human body, plants and animals will cause serious harm. At present, there are several methods, such as incineration, wet method, dry method, etc., because the purification effect and cost factors are used less. The conventional precipitator can not meet the environmental requirements of purification. It is relatively mature and can be purified by electric trapping method. The effect is obvious after many years of use. In the process of asphalt waste gas treatment and purification, the specific resistance of the medium is low when the flue gas temperature is reduced, which is conducive to improving the absorption effect. Electric tar (dust) catcher in a long time of use summary, suitable for specific resistance 104Ω·cm -- 5×104Ω·cm range of materials. When the material is lower than 104Ω·cm, the material deposited in the anode plate is easy to cause backflow; When the material specific resistance is higher than 5×104Ω·cm, it is easy to produce reverse corona. Therefore, it is necessary to purify the flue gas by pretreatment plus electric trapping. According to the relevant design specifications, data, and actual use effect of electric capture, the better suction temperature of electric capture is 20-40℃, the gas temperature is reduced or increased by 10℃, the purification effect can be increased or reduced by about 7%. In carbon production, it is necessary to take full account of asphalt tar coking when the temperature is too low, and also consider the use effect, so as to make the normal operation of electric capture. In the production process, choose to adjust the flue gas temperature of about 90℃ is more appropriate, the lowest temperature is greater than 75℃, winter due to the low external temperature can be properly adjusted higher, in this temperature range of the specific resistance of the purification material is also in the corona suction better range, asphalt tar is also softening flow state, not easy to coking, easy to exclude. Therefore, in the design of carbon electrocapture, it is necessary to fully consider the absorption efficiency of carbon electrocapture at higher temperatures, increase the retention time of gas in electrocapture and reduce the flow rate. In addition, it is also necessary to consider the long-term work of the kiln, resulting in gas leakage phenomenon to increase the surplus of electric capture, so as to meet the needs of the purification of carbon flue gas. The flue gas is first washed and cooled by the pretreatment tower. The gas temperature before the flue gas enters the pretreatment tower is relatively high, its specific resistance is high, and the electric capture is difficult. The temperature of the flue gas is reduced to about 90℃ through the pretreatment (washing cooling). First, reduce the temperature of the flue gas, to avoid the high temperature of the flue gas caused by internal fire, unnecessary loss. Second, reduce the flue gas temperature, close to the appropriate capture temperature, solve the specific resistance value into the electric capture gas, but also inhibit the asphalt tar assembly; After the pretreatment of the gas under the action of spray water. Particles larger than 100μm are basically removed, thus reducing the working pressure of electrocapture. Particles less than 100μm are difficult to wash off with water, the reason is the effect of water surface tension, after the pretreatment washing treatment of gas, into the range of electrotrapping particles is generally between 0.01- 100μm. The effect of electrotrapping on particles larger than 5μm is obvious. The effect of electrotrapping on particles between 3 and 5μm is not obvious. It has no effect on particulate matter less than 3μm. Particulate matter below 5μm can be cleared after chemical reaction.