System for direct-injection removing NOX and SO3 in bypass flues of boiler

Abstract

The invention discloses a system for direct-injection removing NOX and SO3 in bypass flues of a boiler. The system for direct-injection removing NOX and SO3 in bypass flues of athe boiler comprises adirect injection device of the bypass flues of the boiler and an SCR (SelectiveCatalytic Reduction)denitration device which are in communication with each other. The direct-injection device of the bypass flues of the boiler comprises sequentially connected boiler bypass flues, a pyrolysis chamber, a conical collection box and an injection device. An injection gun is further comprised. The SCR denitration device comprises an economizer outlet horizontal flue, an SCR inlet ascending flue, an SCR reactor and an SCR reactor outlet flue. According to the system for direct-injection removing NOX andSO3 in bypass flues of the boiler provided by the invention, an ammonia-contained gas injection device at the bypass flue outlet and a large-scale gas mixing device at the denitration inlet are designed for a process of direct-injection carbamide pyrolysis and denitration at bypass flues of the boiler, and a high efficient and low-cost removal of NOX and SO3 can be realized, so as to fundamentally solve the ABS (Ammonium Bisulfate)problem. According to the invention, the ammonia-nitrogen molar ratio distribution uniformity of the catalyst inlet reaches a level of the existing SCR denitrationdevice, and the key technical problem for the practical application of the process of direct-injection carbamide pyrolysis and denitration at bypass flues of the boiler is solved.

Description

technical field [0001] The invention belongs to the technical field of flue gas pollutant treatment, in particular, the invention relates to the direct injection of boiler bypass flue to remove NO X and SO 3 system. Background technique [0002] With NO X With the increasingly stringent emission standards, coal-fired power plants in my country generally install NH 3 French SCR flue gas denitrification device. SCR (Selective Catalytic Reduction) denitrification technology means that in the range of 280-420 ° C, reducing agents (such as liquid ammonia, urea, and ammonia water, etc.) "selectively" react with NO in the flue gas under the action of a catalyst. X reaction to produce non-polluting N 2 and H 2 O's NO X emission reduction technologies. The preparation of SCR denitrification reducing agent usually adopts liquid ammonia evaporation method, urea pyrolysis / hydrolysis method, and ammonia water evaporation method. The liquid ammonia evaporation method is the most ...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is: aiming at the boiler bypass flue direct injection urea pyrolysis denitrification process, research and development of a boiler bypass flue direct injection NO removal X and SO 3 The system and the flue gas large-scale mixing device at the denitrification inlet make the molar ratio distribution uniformity of ammonia nitrogen at the catalyst inlet reach the level of the existing SCR denitrification device, control the amount of ammonia escape and remove SO in the flue gas 3 , to achieve NO X and SO 3 High-efficiency and low-cost removal, solve the problem of ABS clogging from the source

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