A coupling of turbulence and chemical agglomeration promotes PM 2.5 Apparatus and method for growing up

Abstract

The invention discloses a device and a method for increasing grain size of PM2.5 through turbulent flow and chemical agglomeration coupling. Dust-containing flue gas sequentially flows through a chemical agglomeration area and a turbulent flow generation area in a flue and finally enters an electrostatic dust collector; when the dust-containing flue gas flows through the chemical agglomeration area, the PM2.5 particles in the flue gas are primarily contacted with agglomeration solution fogdrops sprayed in through a dual-fluid atomizing nozzle, agglomeration solution liquid drops are evaporated, in the evaporation process, the PM2.5 particles are connected through macromolecule chains with polar groups, and the grain size of the PM2.5 is increased; the flue gas flows through the turbulent flow area, the agglomeration solution fogdrops are promoted to collide and contact the PM2.5, the PM2.5 are promoted to collide and contact the crude dust under the turbulent flow disturbance generated by a turbulence bar, the PM2.5 are further aggregated and increased in size, meanwhile, the residence time of the agglomeration solution liquid drops in the flue is prolonged, before entering the electrostatic dust collector, the agglomeration solution liquid drops are completely evaporated, and the particles of which the size is increased through agglomeration are finally moved by the electrostatic dust collector. The agglomeration increasing effect of the PM2.5 is obviously enhanced, and the using amount of an agglomeration solution is reduced.

Description

technical field [0001] The invention belongs to coal-fired flue gas fine particulate matter (PM 2.5 ) technical field of emission control, especially related to a method of coupling turbulent flow and chemical agglomeration to promote PM 2.5 Method and device for growing up. Background technique [0002] PM with an aerodynamic diameter less than 2.5 μm 2.5 Pollution has become a prominent atmospheric environmental problem in my country, which leads to reduced atmospheric visibility and acid rain; the main reason is PM 2.5 The specific surface area is large, and it is easy to enrich various heavy metals and chemical carcinogens, but it is difficult to effectively capture them by conventional dust removal technology, resulting in a large amount of PM 2.5 into the atmosphere. Coal burning is the cause of PM in my country's atmospheric environment 2.5 The main reason for the increase in content. Therefore, control of coal-fired PM 2.5 Emissions are a key issue that urgent...

AI Technical Summary

Problems solved by technology

Although the dust removal efficiency of the electrostatic precipitator can be as high as 99%, but due to PM 2.5 Insufficient charge, PM still exists 2.5 Technical bottlenecks that are difficult to effectively remove

PM 2.5 The technical development direction of effective control is mainly to set pretreatment measures in front of conventional dust removal equipment, so that they can be removed after growing into larger particles through physical or chemical action, including acoustic agglomeration, electrocoagulation, turbulent agglomeration, chemical agglomeration, and steam phase change etc.; among these measures, steam phase change is not suitable for combining with electrostatic precipitator, although electrocoagulation basically has the conditions for industrial application, but the investment and operation cost is too high

Chemical agglomeration technology and turbulent flow can effectively improve the removal efficiency of electrostatic precipitator for fine particles under the condition of neither changing the normal production conditions nor changing the existing electrostatic precipitator equipment and operating parameters. The main problems of single use of chemical agglomeration Yes: the collision between sprayed agglomerating agent droplets and particles is insufficient, and the liquid droplets stay in the flue for a short time, so it is difficult to fully ensure that the agglomerating agent droplets are completely evaporated before entering the electrostatic precipitator, which will affect the normal operation performance of the electrostatic precipitator

However, if the turbulent flow agglomeration technology is used alone, the effect of agglomeration and growth of fine particles is limited.

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