Treatment system for poisoning of wet desulphurization slurry

Abstract

The invention relates to a treatment system for poisoning of wet desulphurization slurry. The treatment system comprises a desulfurization absorption tower, wherein a gas inlet pipeline is arranged onthe side wall of the desulfurizing absorption tower; a spray header is arranged in the desulfurization absorption tower; a first circulating pipeline is arranged on the side wall of the desulfurization absorption tower; one end of the first circulating pipeline is connected with the lower part of the desulfurization absorption tower; the other end of the first circulating pipeline is connected with the spray header; an absorption liquid adding pipeline is arranged on the side wall of the desulfurization absorption tower; the desulfurization absorption tower is connected with a sulfur slurry poisoning treatment system; the sulfur slurry poisoning treatment system comprises a chemical storage tank; a stirrer is arranged in the chemical storage tank; a chemical feeding pipeline is arranged at the upper end of the chemical storage tank; a second circulating pipeline is arranged on the side wall of the chemical storage tank; a branch is led out of the second circulating pipeline; and the branch is connected with the absorption liquid adding pipeline. According to the invention, up-to-standard emission of sulfur dioxide in flue gas is ensured, and secondary pollution caused by storage and outward transportation of muddy gypsum is avoided.

Description

technical field [0001] The invention belongs to the technical field of flue gas treatment devices, and in particular relates to a wet desulfurization slurry poisoning treatment system. Background technique [0002] Most of the generator sets of large coal-fired power plants in my country adopt wet desulfurization. The flue gas after boiler combustion is denitrified and dedusted and then enters the desulfurization absorption tower. Reaction, that is, the chemical reaction between calcium carbonate and sulfur dioxide to generate calcium sulfite or calcium sulfate, in order to remove sulfur dioxide in the flue gas. The indicators monitored during its operation include: desulfurization efficiency, net flue gas sulfur dioxide concentration, slurry pH value and slurry density, etc. [0003] Serum poisoning often occurs in the operation of wet desulfurization. After the serous poisoning, the performance is (1) the reaction of the absorption tower is blocked, and the pH value of the...

AI Technical Summary

Problems solved by technology

[0003] Serum poisoning often occurs in the operation of wet desulfurization. After the serous poisoning, the performance is (1) the reaction of the absorption tower is blocked, and the pH value of the slurry cannot be controlled, showing a slow downward trend; (2) increasing the limestone slurry supply has no obvious effect and increases Large flue gas volume, PH value drops very quickly; (3) The concentration of sulfur dioxide in the net flue gas increases, the desulfurization efficiency decreases, and the emission of sulfur dioxide in the flue gas exceeds the standard; (4) The gypsum is muddy, the quality deteriorates, and it cannot be dehydrated

[0004] Reasons for slurry poisoning: (1) Unburned oil and coal powder enter the desulfurization system when the unit is started; (2) The quality of the incoming coal is poor, the boiler frequently injects a large amount of oil to support combustion, the dust removal efficiency of the electrostatic precipitator is reduced, and a large amount of oil and ash (3) The high-density slurry in the absorption tower is not discharged in time, and the saturated calcium sulfate dihydrate in the slurry inhibits the dissolution reaction of calcium carbonate; (4) Insufficient oxidation causes sulfite blinding; (5) Poor quality of process water and poor quality of limestone cause limestone dead zone in absorption tower slurry

In the case of sufficient oxidation, process water quality and limestone quality guaranteed, the main cause of slurry poisoning is: unburned oil, coal powder and ash powder enter the absorption tower, on the one hand, the formed fluoroaluminum complex will inhibit the limestone On the other hand, the fluorine-aluminum complex covers the surface of the limestone, which makes the pH value of the slurry drop rapidly, the desulfurization efficiency drops sharply, and the sulfur dioxide in the flue gas exceeds the standard.

Images