Dual-circulation absorption tower

Abstract

The invention discloses a dual-circulation absorption tower. The tower comprises a front absorption tower and a main absorption tower. A flue gas channel between the towers is arranged between a second flue gas outlet of the front absorption tower and a first flue gas inlet of the main absorption tower. A circulating pump for pumping out the slurry in a slurry pond is respectively arranged on the main absorption tower and the front absorption tower. An outlet tube of the circulating pump is connected to a spray layer. A forced oxidation device for forced oxidation of the slurry in a first slurry pond is not arranged on the main absorption tower, while the forced oxidation device for forced oxidation of the slurry in a second slurry pond is arranged on the front absorption. The dual-circulation absorption tower also comprises a slurry pump for discharging the product generated by the main absorption tower into the slurry pond of the front absorption tower. The inventive dual-circulation absorption tower has simple structure and low cost, can realize a SO2 removal efficiency more than 95% only through a two-step method without increasing the circulating pump number or the chemical additive used amount.

Description

technical field [0001] The invention belongs to the technical field of environmental protection equipment, in particular to an absorption tower equipment capable of efficiently removing pollutants in coal-fired flue gas. Background technique [0002] The wet absorption tower is the SO in the coal-fired flue gas 2 Common equipment for the removal process. The wet absorption tower technology is mature and effective. At present, the single-loop wet absorption tower is mostly used in the technology. When removing SO 2 When the efficiency requirement is about 95%, the single-loop wet absorption tower has good economy and operation stability. [0003] Due to the sharp increase in fuel demand in China, many power plants are not allowed to burn high-sulfur coals. However, due to the increasing environmental protection requirements, power plants have to require higher desulfurization efficiency. When the desulfurization efficiency of the single-loop wet absorption tower exceeds 97...

AI Technical Summary

Problems solved by technology

[0006] Generally speaking, when the desulfurization efficiency increases from 95% to 99%, the number of circulating pumps will at least double, and the power consumption of a single circulating pump in the desulfurization system is about 600-1200KW, and the power consumption of all circulating pumps accounts for about 100KW. 40%-70% of the power consumption of the desulfurization system, therefore, increasing the number of circulating pumps will greatly increase the operating cost

When chemical additives are used, since the forced oxidation device is installed in the slurry tank, the chemical degradation rate of the chemical additives will be very fast, and the amount of chemical additives used is often large.

[0007] In addition, many countries have begun to restrict the emission of NOx in flue gas. Adding zinc, iron, and copper series metal chelates to the desulfurization absorption tower can reduce NOx emissions. x However, since the single-loop wet absorption tower absorbs SO2, it will also suck the easily absorbed HCL, HF and a large amount of dust into the slurry tank, causing more side reactions of metal chelates and high cost of use. Therefore, the current desulfurization tower removes NO x technology is not practical

Images