Flue gas baffling double-slurry pool absorbing tower

Abstract

The invention relates to a flue gas baffling double-slurry pool absorbing tower, characterized in that: the interior of the absorbing tower is separated into an independent prescrubbing section slurry pool and an independent absorption section slurry pool by baffle plates, a corresponding upper gas-liquid contact area is separated into a prescrubbing section and an absorption section, the baffle plates have a distance from the tower top, the tower top is provided with guide vanes; a demister is arranged in an export of flue gas; the pH value of the slurry in the prescrubbing section slurry pool is lower than the pH value of the slurry in the absorption section slurry pool, and an unidirectional conveying pipeline is arranged between the two slurry pools and communicated with the two slurry pools. According to the invention, by slurry pools with different pH values and the baffling flue gas path, the desulphurization system has strong SO2 buffering ability, the desulphurization efficiency does not fluctuate with the flue gas flux and the load change of SO2 in the flue gas, the utilization rate of limestone is greatly increased, and the gypsum rain is effectively prevented.

Description

technical field [0001] The invention relates to a kind of equipment applicable to the absorption tower of flue gas limestone-gypsum wet desulfurization (WFGD) in thermal power plants for segmental control reaction, in particular to a flue gas deflection type double slurry pool absorption tower, which belongs to The technical field of environmental protection equipment. Background technique [0002] In the next few years, China will maintain a power energy structure dominated by coal-fired generating units, which will lead to serious air pollution. One of the main pollutants is SO 2 . In the field of flue gas desulfurization in thermal power plants, the most widely used technology is limestone-gypsum wet flue gas desulfurization technology, and the desulfurization efficiency can reach more than 95%. [0003] In the limestone-gypsum wet flue gas desulfurization process, the desulfurization tower used is a traditional countercurrent spray tower. The spray tower is divide...

AI Technical Summary

Problems solved by technology

For example, the high pH environment of the slurry is conducive to SO 2 absorption, when the pH value reaches 6, the slurry for SO 2 The absorption effect is the best; but the low pH environment of the slurry is conducive to the dissolution of limestone and CaSO 3 Oxidation of the slurry, when the pH value of the slurry is lower than 3.5, the oxidation rate and dissolution rate are extremely high, but at this time the slurry has a 2 It is very difficult to absorb

[0004] The traditional countercurrent spray tower has the following defects: 1. The setting of a single slurry pool will inevitably lead to a compromise in the pH value of the slurry, and the suppression of the slurry to SO 2 The absorption capacity, that is, the selection of pH value is to improve the dissolution of limestone and CaSO in the slurry 3 Oxidation starting, to a certain extent, the slurry to SO 2 The maximum absorption capacity of the system is limited; 2. In the case of limited flue gas flow rate in the tower, the pure countercurrent contact mode of gas and liquid leads to a large amount of slurry carried by the flue gas, and it is easy to cause a large amount of slurry to be entrained by the flue gas and discharged out of the chimney Causes "gypsum rain" phenomenon

[0005] In order to ensure the high desulfurization efficiency of the desulfurization system, measures such as increasing the liquid-gas ratio and increasing the number of spray layers are generally adopted, but a series of problems are also derived: the increase of the liquid-gas ratio makes the gas in the flue gas after the gas-liquid contact The entrained slurry volume increases, and the phenomenon of "gypsum rain" is more likely to occur. At the same time, the volume of the slurry tank and the circulation volume of the slurry increase accordingly, resulting in an increase in the power consumption of the circulation pump and the oxidation fan. The increase in the number of spray layers will lead to an increase in the height of the absorption tower. Ultimately, the cost of the desulfurization device and desulfurization power consumption will increase, and the operating cost will increase, which will bring a heavy operational and economic burden to the power plant.

In addition, with the problem of energy supply in my country in recent years, many power plants cannot control the source of coal, the quality of coal combustion is poor, and the coal sulfur content is high, resulting in great changes in the composition of coal burned by power plant boilers, SO in flue gas 2 There will be great fluctuations, and the desulfurization device even needs to be overloaded to deal with flue gas with high sulfur content, and its desulfurization capacity will be greatly reduced

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