Synergistic spray charging and electrostatic dust collecting method and device

Abstract

The invention relates to a synergistic spray charging and electrostatic dust collecting method by which a water spray charging device is combined with an electrostatic dust collector, flue gas is conditioned by using water spray, agglomeration of dust particles is promoted and the charging characteristic of the dust particles is improved through charging drops containing an agglomerating agent, thus the dust collection efficiency of the electrostatic dust collector is increased, the fine dust collecting efficiency is higher than 90 percent, and the concentration of smoke dust at an outlet is lower than 50 milligrams per cubic meter. The invention also discloses a synergistic spray charging and electrostatic dust collecting device which comprises the electrostatic dust collector and the water spray charging device, wherein the electrostatic dust collector is arranged on a flue; and the water spray charging device is arranged on a flue in front of an inlet of the electrostatic dust collector, or on a gradually expanded section of the inlet or on a position of a bottom second-stage or third-stage electric field in the electrostatic dust collector. The water spray charging device comprises a dual-fluid atomizing nozzle and a corona ring, wherein the dual-fluid atomizing nozzle is arranged at the front part of the corona ring, an insulator is arranged outside the upper end of the corona ring, and the corona ring is connected with a high-voltage power supply through a wire. The synergistic spray charging and electrostatic dust collecting device has a simple structure, low cost and high dust collecting efficiency.

Description

technical field [0001] The invention belongs to the field of flue gas pollution control, and in particular relates to a water mist charging and efficiency electrostatic dust removal method and device. Background technique [0002] my country is the country that uses the largest number of coal-fired boilers in the world. According to statistics, between 2000 and 2007, my country's annual industrial smoke emissions exceeded 8 million tons, of which fine particles (PM10, PM2.5) were about 4 million tons. Coal-fired power plants are an important emission source of particulate matter in the atmosphere. The annual soot emission of coal-fired power plants in my country is about 4 million tons, of which the emission of fine particles exceeds 3 million tons. The emission of a large amount of soot from coal combustion has caused serious environmental pollution. [0003] In order to control the emission of coal-fired smoke and dust, coal-fired power plants are equipped with dust remov...

AI Technical Summary

Problems solved by technology

ESP dust removal efficiency is high, and the removal efficiency of dust particles with a particle size above 10 μm is as high as 99%. However, for fine particles below 10 μm (especially 2.5 μm), it is difficult to charge the fine particles, and the secondary dust generated by electrode rapping is easy to cause The trapped fine particles escape, resulting in a sharp drop in removal efficiency. Among the 1% of the escaped dust particles, the fine particles with a particle size of less than 2.5 μm can reach more than 90% of the total escaped dust particles

The escape of a large number of fine dust particles leads to excessive emission of dust concentration, which is not only difficult to meet the dust emission concentration (50mg / Nm 3 ), and because the main pollutants that are toxic and harmful to the human body are mostly concentrated in fine dust particles below 10 μm, the escape of a large number of fine dust particles also seriously affects people's health and causes huge economic losses

[0004] A common way to improve the efficiency of electrostatic precipitators is to increase the number of electric fields of the electrostatic precipitator, but limited by the dust removal principle of the electrostatic precipitator itself, the dust that cannot be collected in the first few electric fields is still difficult to collect in the newly added electric field , especially for fine dust particles, it is very difficult to improve the dust removal efficiency and meet the new emission standards simply by increasing the number of electric fields, and it also increases the floor area, construction investment and operating costs

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