Smoke desulfurization method for coal-fired boiler

Abstract

The invention discloses a smoke desulfurization method for a coal-fired boiler. The smoke desulfurization method comprises the following steps that: firstly, non-desulfurized smoke generated in the coal-fired boiler is introduced into a flue by a high-voltage electrostatic precipitator; secondly, smoke generated in a soda recovery furnace is introduced into the flue in the first step by virtue of another high-voltage electrostatic precipitator; and thirdly, after the smoke generated in the coal-fired boiler and the soda recovery furnace in the first and second steps simultaneously enter the common flue and then are fully mixed and reacted, the reacted smoke is discharged from the flue by a draught fan. The smoke desulfurization method has the beneficial effects that the input is small, the desulfurization cost is low, secondary pollution is avoided, the aim of treating wastes with wastes is achieved by utilizing waste gas discharged from the soda recovery furnace to perform the desulfurization, the effect is optimal, the economic benefits are remarkable, and thus the method is the optimal method which can not be replaced by other desulfurization methods.

Description

technical field [0001] The invention relates to a desulfurization method, in particular to a desulfurization method for flue gas of a coal-fired boiler. Background technique [0002] At present, the mature coal-fired desulfurization methods can be divided into four categories: desulfurization before coal combustion, desulfurization during combustion, desulfurization after combustion and desulfurization of coal conversion forms. Desulfurization after combustion is common, and desulfurization after combustion is specifically divided into: lime / limestone method, sodium-alkali method, double-alkali method, magnesium oxide method, ammonia absorption method, etc. Among them, the most reliable and mature desulfurization technology is lime / lime method and sodium-alkali method. Common desulfurizers are: limestone, lime, slaked lime, soda ash (Na 2 CO 3 ), magnesium, liquid ammonia and alkaline compounds, etc. [0003] However, using the above-mentioned methods for coal-fired desu...

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Problems solved by technology

[0005] The main purpose of the present invention is to solve the problems of large investment, high cost and easy occurrence of secondary pollution in the existing coal-fired desulfurization method;

[0006] Another object of the present invention is to solve the problem that some alkali is discharged along with the flue gas during the alkali recovery process in the caustic soda pulping and papermaking industry, which cannot be used and causes loss and waste.