Ultra-low-temperature denitration device by combining lime-gypsum desulfurization process

Abstract

The invention discloses an ultra-low-temperature denitration device by combining a lime-gypsum desulfurization process. The device comprises a desulfurization tower, a denitration tower, a denitrationagent storage tank and an oxidation air blower, wherein one side of the desulfurization tower is connected to a smoke inlet pipe and a circulating tank is arranged in the tower bottom; the denitration tower is connected to a denitration circulating pump and is connected to the top of the desulfurization tower through a pipeline; the denitration agent storage tank is connected to the denitration agent pump; and the oxidation air blower is connected to an oxidation air hose connected to the bottom of the circulating tank. A calcium-based desulfurizer liquid is arranged in the circulating tank;a reducing circulating pump and a desulfurization circulating pump connected to a desulfurization sprayer located in the desulfurization tower are separately connected to two sides of the circulatingtank, separately; a demister, a chimney connected to the top of the denitration tower, a denitration sprayer connected to the denitration circulating pump and a reducing sprayer connected to the reducing circulating pump are arranged in the direction from the bottom to the top of the denitration tower; and one side of the bottom of the denitration tower is connected to the denitration agent pump.By combining the lime-gypsum desulfurization process with a low temperature denitration technology, the device is simple in structure. The desulfurization product is reasonably utilized to denitrify,so that the cost is lowered. Meanwhile, the synchronous desulfurization rate and denitration rate are improved.

Description

technical field [0001] The invention relates to the technical field of flue gas purification, more specifically, it relates to an ultra-low temperature denitrification device combined with a lime-gypsum desulfurization process. Background technique [0002] The flue gas denitrification of industrial furnaces is an environmental protection policy proposed and promoted by the state in recent years. It is in the stage of development and exploration; at present, SNCR and SCR methods are usually used for denitrification of industrial furnace flue gas; SNCR denitrification is to spray ammonia, urea and other reducing agents into the boiler furnace to select NOx under the condition of no catalyst However, reducing agent must be added in the high temperature area. This technology is greatly affected by the size of the boiler structure, and the denitrification rate is low; SCR denitrification refers to the reduction agent (liquid ammonia) and The nitrogen oxides in the flue gas reac...

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Problems solved by technology

[0002] The flue gas denitrification of industrial furnaces is an environmental protection policy proposed and promoted by the state in recent years. It is in the stage of development and exploration; at present, SNCR and SCR methods are usually used for denitrification of industrial furnace flue gas; SNCR denitrification is to spray ammonia, urea and other reducing agents into the boiler furnace to select NOx under the condition of no catalyst However, reducing agent must be added in the high temperature area. This technology is greatly affected by the size of the boiler structure, and the denitrification rate is low; SCR denitrification refers to the reduction agent (liquid ammonia) and The nitrogen oxides in the flue gas react to generate harmless nitrogen and water, thereby removing NOx in the flue gas. The denitrification efficiency of the SCR method can reach 70-90%. , The flue gas temperature of the blowing furnace and coke oven is below 200°C. If the temperature after wet desulfurization is lower than 60°C, if the SNCR and SCR denitrification methods are used, the flue gas needs to be heated. Significantly increased operating costs

[0003] The limestone / lime-gypsum flue gas desulfurization process uses calcium-based desulfurizers to absorb sulfur dioxide to produce two desulfurization products, calcium sulfite and calcium sulfate. However, the utilization rate of these two desulfurization products is not high and their solubility is small , it is easy to form fouling in the desulfurization absorption tower, resulting in blockage, easy to cause waste of desulfurization products and affect the normal operation of the desulfurization system

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