Method for multistage wet method removal of PM2.5 in industrial tail gas

Abstract

The invention discloses a method for multistage wet method removal of PM2.5 in industrial tail gas. The method is characterized in that industrial tail gas is orderly treated by multistage gas washing units, in each grade of the gas washing unit, the industrial tail gas goes through a heating humidifying chamber and then enters into a condensation chamber, each grade of the heating humidifying chamber is used for heating the industrial tail gas at a temperature of less than 100 DEG C before entrance to a temperature of 100 DEG C or more, through humidifying, the industrial tail gas has a water vapor mass rate of 20-50%, a falling film flowing cold absorption liquid is fed into the condensation chamber in each grade of the gas washing unit so that across flowing of the cold absorption liquid and the industrial tail gas is formed, and under action of temperature and humidity gradient, PM2.5 in the industrial tail gas directionally moves to the surface of the cold absorption liquid and then is captured by the cold absorption liquid so that PM2.5 removal is realized. Through multistage heating, humidification and condensation means, the problem that the single stage gas washing process has poor driving force at the rear section because of temperature and humidity difference of the industrial tail gas and the cold absorption liquid is solved so that a PM2.5 removal rate is improved.

Description

technical field [0001] The invention relates to gas PM2.5 treatment, specifically a multi-stage wet method for removing PM2.5 from industrial tail gas, and belongs to the technical field of gas purification. Background technique [0002] Inhalable particulate matter (PM2.5) with a kinetic diameter of less than 2.5 μm has become the main pollutant in the current urban atmospheric environment, and it is also one of the main factors for the generation of smog. Therefore, when the new "Ambient Air Quality Standards" was released in 2012, PM2.5 was included for the first time, and the PM2.5 index was added. Due to the small particle size of PM2.5, it cannot be removed by traditional gas-solid separation technology. [0003] The existing PM2.5 removal technologies mainly include dry PM2.5 removal technology and wet PM2.5 removal technology. Although the fiber process in the dry process has a high removal rate, it has the disadvantages of large filtration resistance loss and po...

AI Technical Summary

Problems solved by technology

Bubble tower washing mainly has the disadvantages of large flow resistance loss and large mist entrainment. Although spray tower washing has a large gas-liquid contact area, there is also a large mist entrainment after the absorption liquid is dispersed into several droplets. Disadvantages: Although the gas-liquid cross-flow washing has a large gas-liquid contact area and can reduce mist entrainment, the temperature and humidity of the gas decrease after the high-temperature gas contacts the cold absorption liquid, so that the gas-liquid phase in the latter part Insufficient driving force between temperature and humidity differences, resulting in reduced PM2.5 removal rate

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