Semi-dry desulfurization system suitable for low-sulfur flue gas

Abstract

The invention discloses a semi-dry desulfurization system suitable for low-sulfur flue gas. The system comprises a desulfurization absorption tower, a pulse-jet bag-type dust collector, a process water storage and conveying device, a desulfurizer storage and conveying device, a desulfurization circulating ash conveying device and a compressed air device. The desulfurization absorption tower is not internally provided with a circulating fluidized bed, but is provided with a Venturi structure, and the Venturi structure is also provided with a desulfurization circulating ash multi-point distribution device. The process water storage and conveying device, the desulfurizer storage and conveying device and the desulfurization circulating ash conveying device are respectively connected with the Venturi structure of the desulfurizing absorption tower, and the compressed air device is connected with the process water storage and conveying device. The system further comprises a desulfurization tail ash conveying and storing device and a flue gas pipeline. By adopting the system, the purification requirement of ultralow emission of low-sulfur flue gas can be met, meanwhile, the system configuration is simplified, the operation energy consumption of the desulfurization system is reduced, and the stability and the reliability of the desulfurization system are improved.

Description

technical field [0001] The invention belongs to the field of environmental protection and relates to industrial waste gas treatment technology, in particular to a semi-dry desulfurization system suitable for low-sulfur flue gas. Background technique [0002] At present, my country's environmental protection efforts are gradually increasing, and based on the successful experience in the treatment of flue gas pollutants in the power industry, the control and control of flue gas pollutants in various industrial kilns has been further strengthened, and the flue gas pollutants in industrial kilns have been reduced again. emission concentration limit. Therefore, the flue gas from industrial kilns that did not need to be desulfurized due to the low concentration of sulfur dioxide needs to be treated to reduce it below the limit before it can be discharged. For example, in the electrolytic aluminum industry, the concentration of sulfur dioxide in the flue gas generally does not exce...

AI Technical Summary

Problems solved by technology

Therefore, the application of circulating fluidized semi-dry flue gas desulfurization (CFB-FGD) process in the purification of electrolytic aluminum flue gas is gradually increasing, but the existing CFB-FGD equipment for low-sulfur flue gas purification mainly has the following problems: ( 1) In order to ensure the removal efficiency of sulfur dioxide, the desulfurization material in the CFB-FGD absorption tower needs to be circulated and fluidized. Accordingly, it is necessary to build a circulating fluidized bed in the absorption tower. There is a risk of material collapse when the flue gas working conditions change , resulting in unstable operation of the desulfurization system; (2) The desulfurization material inlet of the existing CFB-FGD equipment is single, because the concentration of sulfur dioxide to be removed in the flue gas is reduced, the amount of desulfurization agent (recycling ash) required is reduced, and the single The injection point of desulfurization ash can easily lead to insufficient contact between materials and flue gas, and sulfur dioxide in part of flue gas cannot be effectively removed; There is a big difference in flue gas working conditions, and taking the electrolytic aluminum flue gas as an example, the front-end flue of the desulfurization system is generally not insulated, resulting in the flue gas temperature being greatly affected by the environment. Higher requirements, the existing CFB-FGD equipment is equipped with a single dual-fluid spray gun to add process water, it is difficult to meet the adjustment range of process water and the process water atomization requirements required for operation at the same time; (4) the existing CFB-FGD equipment The flue gas enters the flue from the side at the bottom of the absorption tower, causing the flue gas to be in a biased flow state in the absorption tower. After the flue gas is accelerated by the Venturi structure, eddy currents occur in the cylindrical structure area above the Venturi, which is prone to serious knots. Dirt, causing hidden dangers in equipment operation

In addition, the existing CFB-FGD equipment requires high construction investment and operating costs, and the operation is unstable

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