Wet type electrostatic dust collector for semidry method (CFB) waste water zero discharging

Abstract

The invention discloses a wet type electrostatic dust collector for semidry method (CFB) waste water zero discharging. The wet type electrostatic dust collector comprises a smoke humidification device, a wet type electrostatic smoke purifying system and a waste water circulating utilizing system. The wet type smoke purifying system mainly comprises a spraying device, an anode plate and a cathode wire. The waste water circulating utilizing system comprises a waste water tank, a circulation water tank, a waste water pump, a circulation water pump, an alkali liquor tank, an alkaline pump, an automatic filter, a technology water tank and a technology water pump. By means of the wet type electrostatic dust collector, tiny dust, SO3, heavy metal and the like in smoke can be efficiently removed, meanwhile, waste water zero discharging is achieved, environmental friendliness is achieved, and good economic benefits and social benefits are achieved.

Description

technical field [0001] The invention belongs to the technical field of flue gas purification in coal-fired power plants, and in particular relates to a wet electrostatic precipitator for zero discharge of semi-dry process (CFB) wastewater. Background technique [0002] Pollutants produced by coal-fired power plants and industrial boilers are the main source of air pollution. The latest ultra-clean emission standard stipulates that the dust emission limit reaches 5mg / Nm 3 , the traditional dry electrostatic precipitator has not reached the emission standard. The wet electrostatic precipitator uses water spray to clean the anode plate, the removal efficiency of acid mist, toxic heavy metals, especially PM2.5 is higher than 95%, and the dust emission concentration is lower than 5mg / Nm 3 . [0003] The desulfurization absorption and product treatment of the semi-dry method (CFB) are carried out in a dry state. This method has the advantages of no sewage waste acid discharge, l...

AI Technical Summary

Problems solved by technology

The outlet flue gas temperature of the semi-dry method (CFB) is 70-90°C, which is higher than that of the wet desulfurization system (<70°C), and it is dry flue gas, which does not meet the inlet requirements of the existing wet electrostatic precipitator. Therefore, the existing wet electrostatic precipitator Dust collectors cannot be applied to power plants with semi-dry flue gas desulfurization (CFB) systems

In addition, the application of wet electrostatic precipitators is also affected by the secondary pollution of water and water consumption. If the problem of recycling waste water is not solved, it will be difficult for wet electrostatic precipitators to be popularized and applied in coal-fired power plants.

The water discharged after being sprayed and washed by the wet electrostatic precipitator contains a large amount of acidic substances and fine particles. Direct discharge will cause secondary pollution, and the water consumption is large and the operating cost is high. The water must be recycled.

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