Process for reducing ultra-low emission treatment system faults of low-temperature flue gas after wet desulfurization and SCR denitration

Abstract

The invention discloses a process for reducing faults of an ultra-low emission treatment system with low-temperature flue gas firstly subjected to wet desulfurization and then subjected to SCR denitration, and belongs to the technical field of flue gas treatment. In order to reduce faults of an ultra-low emission treatment system in which low-temperature flue gas is firstly subjected to wet desulphurization and then subjected to SCR denitration, the invention provides a connection process. The process comprises the following steps: after being subjected to dust removal, enabling the low-temperature flue gas to be in countercurrent contact with a desulfurizing agent for desulfurization reaction and to be subjected to deep dust removal and demisting treatment, and to be subjected to first-stage heat compensation, heat exchange and second-stage heat compensation for heating; after heating, carrying out denitration reaction; finally, exchanging heat with to-be-denitrated unsaturated flue gas, and discharging the flue gas. According to the method, the water content, the SOx concentration, the particulate matter concentration and the unsaturation degree of the flue gas before entering the GGH in the flue gas after desulfurization are reduced, so that the GGH is prevented from being corroded and blocked, faults are reduced, and the problem that the fault rate is high when the combined process is used for the low-temperature flue gas is solved.

Description

technical field [0001] The invention belongs to the technical field of flue gas treatment, and in particular relates to a process for reducing failures of an ultra-low emission treatment system in which low-temperature flue gas is desulfurized by wet method first and then denitrated by SCR method. Background technique [0002] There are few engineering application technologies for low-temperature flue gas (such as sintering flue gas) to achieve ultra-low emissions, the application time is short, and the process technology is not mature enough. For example, a steel plant uses a limestone-gypsum wet desulfurization + SCR denitrification combined process to treat sintering fume Gas, which was put into operation at the end of 2018. After half a year of operation, the wet electrostatic precipitator and GGH heat exchanger connecting the desulfurization and denitrification processes both failed; due to the unreasonable design of the connecting process, production and operation were ...

AI Technical Summary

Problems solved by technology

[0009] The problem to be solved by the present invention is that when the combined process of limestone-gypsum desulfurization and SCR denitrification is selected for the control of low-temperature flue gas to achieve ultra-low emissions, wet electrostatic precipitator is used to connect the two processes, and the cathode and anode of the wet electrostatic precipitator are easy to corrode. , The problem of GGH corrosion and blockage leads to a high failure rate of the system, which cannot meet the standard stably, and the production operation is not smooth

Images