Flue gas desulfurization method, flue gas desulfurization equipment and flue gas desulfurization system

Abstract

The invention discloses a flue gas desulfurization method, flue gas desulfurization equipment and a flue gas desulfurization system. The method comprises the steps that flue gas generated by a flue gas source is divided into at least two gas paths, wherein one gas path is a fluidifying gas path and other gas paths are regulating gas paths; the fluidifying gas path is introduced into an absorptiontower after being accelerated and participates in fluidifying of a powdery desulfurization agent, and the regulating gas paths are directly introduced into an absorption area of the absorption tower to participate in desulfurization; by regulating the flue gas amount of the regulating gas paths, the flue gas amount of the fluidifying gas path is larger than or equal to the minimum fluidifying airamount; under the minimum fluidifying air amount, the flow velocity of the flue gas accelerated by the fluidifying gas path reaches a flow velocity set value for fluidifying the powdery desulfurization agent. According to the flue gas desulfurization method, the flue gas desulfurization equipment and the flue gas desulfurization system, whether under low loads or high loads of the flue gas source,it can be guaranteed that flue gas desulfurization does not collapse, the phenomenon in the prior art can be avoided that the flue gas at an outlet of the absorption tower is introduced back to an inlet of a Venturi throat for recycling the flue gas, and the running cost is lowered.

Description

technical field [0001] The invention relates to the technical field of flue gas desulfurization, in particular to a method for flue gas desulfurization. The invention also relates to a flue gas desulfurization device and a flue gas desulfurization system based on the flue gas desulfurization method. Background technique [0002] In the chemical industry, metallurgy and other fields, the flue gas produced by some equipment contains a large amount of sulfur dioxide and other acidic gases, such as boiler coal-fired flue gas, which cannot be directly discharged into the atmosphere, and the flue gas needs to be desulfurized by a flue gas desulfurization device first. . [0003] Existing flue gas desulfurization methods mainly include wet desulfurization, dry desulfurization and semi-dry desulfurization. Among them, wet desulfurization refers to passing flue gas into a desulfurization device, and desulfurizing by spraying desulfurization slurry in contact with flue gas. Wet desu...

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Problems solved by technology

[0003] Existing flue gas desulfurization methods mainly include wet desulfurization, dry desulfurization and semi-dry desulfurization. Among them, wet desulfurization refers to passing flue gas into a desulfurization device, and desulfurizing by spraying desulfurization slurry in contact with flue gas. Wet desulfurization has the advantage of high desulfurization efficiency, but the desulfurization slurry is highly corrosive to desulfurization equipment; dry desulfurization refers to passing the flue gas into the desulfurization device, and the flue gas is blown by the dry powder desulfurization agent passed into the equipment. Although the dry desulfurization has little corrosion on the equipment, the desulfurization efficiency is low; the semi-dry desulfurization means that the flue gas is passed into the desulfurization device, and the flue gas will pass into the dry powder desulfurization agent in the equipment Blow up and spray a small amount of liquid, so that the flue gas is desulfurized by contact with the semi-dry powder desulfurizer mixed with a small amount of water. This method takes into account the advantages of both wet desulfurization and dry desulfurization. At present, it is widely used

[0004] For dry desulfurization and semi-dry desulfurization, the existing problems are: the flue gas passes through the Venturi throat in the flue gas pipeline into the absorption tower, and the dry powder desulfurizer and semi-dry powder desulfurizer pass through the desulfurizer pipeline. The high flow rate of the flue gas passing through the venturi throat in the absorption tower is an important factor to ensure that the absorption tower does not collapse. Usually, when the flow rate of the flue gas is greater than 35m / s, it can ensure that the flue gas blows up the desulfurizer. Don't collapse the bed

However, in order to ensure the smooth discharge of boiler flue gas, the size of the Venturi throat is designed according to the flue gas discharge volume under the maximum load of the boiler, so when the boiler is operating at a small load, the venturi throat will be lowered to a certain extent. The flue gas flow rate at the outlet is too low, resulting in the desulfurization agent in the tower cannot be fluidized, and the bed collapses

In order to solve this problem, there was a technology to solve the problem of low-load operation stability by introducing the flue gas from the outlet of the absorption tower back to the inlet of the Venturi throat for flue gas recirculation, which caused the induced draft fan to be Running at full load, resulting in increased power consumption and high operating costs

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