Medium and low temperature denitration system for kiln tail flue gas produced by using carbide slag to produce cement clinker

Abstract

The invention discloses a medium-low temperature denitration system for kiln tail flue gas produced by using carbide slag to produce cement clinker, and mainly solves the problems that the temperature of an air outlet of a preheater C1 is high, and a catalyst at a high-temperature section is easy to sinter; the temperature of flue gas after drying is low, the low-temperature section cannot meet the requirement of an SCR reaction temperature window, and the requirement for ultralow emission of NOX needs to be met under the working condition. Secondly, the problem of low SNCR denitration efficiency is solved. The system comprises a decomposing furnace, an electric dust remover, a heat exchanger and an SCR reactor; an SNCR ammonia spraying system is arranged in the decomposing furnace; an inlet of the electric dust remover communicates with an air outlet of the decomposing furnace, and the electric dust remover is used for carrying out dust falling treatment on the high-temperature dust-containing flue gas from the decomposing furnace; an inlet of the heat exchanger communicates with an air outlet of the electric dust remover and an air outlet of a grate cooler, and the heat exchanger is used for conducting heat exchange on the high-temperature dust-containing flue gas from the grate cooler and the low-temperature flue gas from the electric dust remover; and an inlet of the SCR reactor communicates with the air outlet of the heat exchanger, and the SCR reactor is used for carrying out reduction reaction on the to-be-treated flue gas from the heat exchanger and discharging the flue gas reaching the standard.

Description

technical field [0001] The invention relates to the technical field of flue gas denitrification, in particular to a medium-low temperature denitrification system for flue gas at the tail of a cement clinker kiln produced by carbide slag. Background technique [0002] The current denitrification of calcium carbide slag cement kiln tail gas mostly adopts Selective Non-Catalytic Reduction (SNCR, Selective Non-Catalytic Reduction) process. The method is to put the meaning NH X After the base reducing agent is sprayed into the area where the temperature of the furnace is 850°C to 1100°C, it will be rapidly thermally decomposed into NH 3 and other by-products, followed by NH 3 and NO in flue gas X SNCR reaction to generate N 2 . [0003] The reaction of SNCR to reduce NO is very sensitive to temperature conditions. The selection of the injection point on the furnace, that is, the selection of the so-called temperature window, is the key to the efficiency of SNCR to reduce NO....

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Problems solved by technology

[0005] The embodiment of the present invention provides a low-temperature denitrification system for cement clinker kiln tail flue gas produced by carbide slag, which is used to solve the problem that the temperature of the air outlet of preheater C1 is high and the catalyst in the high-temperature section is easy to sinter; The problem that the section does not meet the requirements of the SCR reaction temperature window;

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