CN210021739U

CN210021739U - SCR denitration system for industrial kiln tail gas NOx

Info

Publication number: CN210021739U
Application number: CN201920709135.3U
Authority: CN
Inventors: 贾章椿; 乔勇; 崔伟; 刘彬; 曾建武; 陈茂波; 段小乐; 邱田迎; 李新存; 巩天敏; 叩立刚; 李玲
Original assignee: China Aluminum Shandong Engineering Technology Co Ltd
Current assignee: China Aluminum Shandong Engineering Technology Co Ltd
Priority date: 2019-05-17
Filing date: 2019-05-17
Publication date: 2020-02-07
Anticipated expiration: 2029-05-17

Abstract

An SCR denitration system of industrial kiln tail gas NOx belongs to the technical field of pollutant treatment. The method is characterized in that: the device comprises a first ammonia spraying module (1), a mixer (2), a front SCR reactor (3), a second ammonia spraying module (4), a rear SCR reactor (5) and an exhaust fan (6) which are sequentially connected through pipelines, wherein a tail gas inlet of the first ammonia spraying module (1) is connected with a tail gas outlet of a kiln (13) through a pipeline; the first ammonia spraying module (1) and the second ammonia spraying module (4) are connected with an ammonia water supply assembly; and a tail gas outlet of the exhaust fan (6) is connected with a circulating pipeline (10) and a chimney (16), and the circulating pipeline (10) is connected to a tail gas inlet of the first ammonia spraying module (1). The utility model discloses can be applicable to various industry tail gas denitration occasions, it is little to be particularly useful for the tail gas flow, the occasion of NOx high concentration.

Description

SCR denitration system for industrial kiln tail gas NOx

Technical Field

An SCR denitration system of industrial kiln tail gas NOx belongs to the technical field of pollutant treatment.

Background

The tail gas denitration technology has various types, and the denitration technology which is applied more at home and abroad and is widely applied in recent years mainly comprises a low NOx combustion technology, a selective non-catalytic reduction denitration technology (SNCR) and a selective catalytic reduction denitration technology (SCR). The mainstream denitration technology is widely applied to the power industry, the cement industry and the glass industry, the technology is mature, and industrial tail gas treatment of industrial enterprises is in the need of reaching the emission standard along with the continuous upgrading of the national environmental protection policy in recent years.

The concentration of NOx in the boiler flue gas in the power industry is about 200mg/Nm³～800mg/Nm³In between, the concentration of NOx in the tail gas of the industrial kiln in the non-electric industry is about 200mg/Nm³～400mg/Nm³While for NOx concentration 30000mg/Nm³Above, even up to 60000mg/Nm³The industrial kiln tail gas adopts the SCR denitration technology,at present, NO related project verification exists, if a traditional SCR denitration system is adopted, the inlet temperature of an SCR reactor after ammonia spraying cannot meet the requirement, the outlet temperature possibly exceeds the temperature-resistant limit of a catalyst, and the catalyst is burnt out_XThe SCR denitration system solves the problems.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is: overcomes the defects of the prior art and provides a catalyst suitable for high-concentration NO_XSCR deNOx systems of industrial kiln tail gas NOx of tail gas.

The utility model provides a technical scheme that its technical problem adopted is: this SCR deNOx systems of industrial kiln tail gas NOx, its characterized in that: the system comprises a first ammonia spraying module, a mixer, a front SCR reactor, a second ammonia spraying module, a rear SCR reactor and an exhaust fan which are sequentially connected through pipelines, wherein a tail gas inlet of the first ammonia spraying module is connected with a tail gas outlet of a kiln through a pipeline; the first ammonia spraying module and the second ammonia spraying module are connected with an ammonia water supply assembly; and a tail gas outlet of the exhaust fan is connected with a circulating pipeline and a chimney, and the circulating pipeline is connected to a tail gas inlet of the first ammonia spraying module.

The utility model discloses an industrial kiln tail gas contains high concentration NOx's SCR deNOx systems, before tail gas gets into the SCR reactor, mix with the circulation tail gas of exhaust fan export earlier, then through spouting ammonia module and mixing section, get into the SCR reactor, the tail gas of reactor export is discharged through the exhaust fan, and SCR reactor entry is got back to through circulating line to most tail gas, and the small part tail gas passes through chimney discharge to reach standard.

Preferably, a dust collector and an induced draft fan are arranged on a pipeline of the tail gas inlet of the first ammonia spraying module, which is connected with the kiln.

Preferably, a mixer is further arranged on a connecting pipeline between the second ammonia injection module and the rear SCR reactor. The supplemented ammonia water and the tail gas are further mixed, so that the denitration effect can be better improved.

Preferably, the circulating pipeline is provided with an air supplementing pipeline through a tee joint, the air supplementing pipeline is provided with an air supplementing electric regulating valve, and the circulating pipeline is provided with a circulating pipeline electric regulating valve in front of the tee joint; and the tail gas outlet of the exhaust fan is connected with the pipeline of the chimney, and an electric adjusting valve of an exhaust pipeline is arranged on the pipeline. The automatic control of various operations of tail gas emission, tail gas circulation treatment and gas supply is realized, and thorough denitration is ensured.

Preferably, the ammonia water supply assembly is respectively connected with the first ammonia spraying module and the second ammonia spraying module through parallel pipelines, and the two parallel pipelines are respectively provided with an electric regulating valve. And the independent control of the supply and the supply amount of ammonia water of the first ammonia injection module and the second ammonia injection module is realized.

Preferably, the ammonia water supply assembly comprises an ammonia water tank and an ammonia water pump, and the ammonia water pump is arranged on a pipeline which is connected with the first ammonia spraying module and the second ammonia spraying module through the ammonia water tank.

Compared with the prior art, the utility model discloses an industrial kiln tail gas NOx's SCR deNOx systems beneficial effect who has is: the utility model aims at providing an industrial kiln tail gas contains high concentration NOx's SCR deNOx systems, before this deNOx systems tail gas gets into the SCR reactor, mix with the circulation tail gas of exhaust fan export earlier, then through spouting ammonia module and mixing section, get into the SCR reactor, the tail gas of reactor export is discharged through the exhaust fan, and SCR reactor entry is got back to through circulating line to most tail gas, and the small part tail gas passes through the discharge to reach standard of chimney. The method is suitable for various industrial tail gas denitration occasions, and is particularly suitable for occasions with small tail gas flow and high NOx concentration. Solves the problem that the concentration of NOx in the tail gas of the industrial kiln exceeds 10000mg/Nm³The SCR denitration system is adopted to realize that the NOx emission concentration is lower than 100 mg/Nm³The problem of (2). The SCR denitration system is adopted to realize the standard emission of high-concentration NOx, reduce the emission of NOx and efficiently and thoroughly treat the atmospheric pollutants in the kiln.

Drawings

Fig. 1 is the utility model discloses a process flow of SCR deNOx systems of industrial kiln tail gas NOx.

The system comprises a first ammonia spraying module 1, a first ammonia spraying module 2, a mixer 3, a front SCR reactor 4, a second ammonia spraying module 5, a rear SCR reactor 6, an exhaust fan 7, an exhaust pipeline electric regulating valve 8, a circulating pipeline electric regulating valve 9, an air supplementing electric regulating valve 10, a circulating pipeline 11, an ammonia water tank 12, an ammonia water pump 13, a kiln 14, a dust collector 15, an induced draft fan 16 and a chimney.

Detailed Description

Fig. 1 is a preferred embodiment of the present invention, and the present invention will be further explained with reference to fig. 1.

Referring to figure 1: an SCR denitration system of industrial kiln tail gas NOx comprises a first ammonia spraying module 1, a mixer 2, a front SCR reactor 3, a second ammonia spraying module 4, a mixer 2, a rear SCR reactor 5 and an exhaust fan 6 which are sequentially connected through pipelines, wherein a tail gas inlet of the first ammonia spraying module 1 is connected with a tail gas outlet of a kiln 13 through a pipeline, and a dust collector 14 and an induced draft fan 15 are arranged on the front and the rear of the pipeline, which is connected with the tail gas inlet of the first ammonia spraying module 1, of the kiln 13; the ammonia water supply assembly is respectively connected with the first ammonia spraying module 1 and the second ammonia spraying module 4 through parallel pipelines, electric regulating valves are arranged on the two parallel pipelines, the ammonia water supply assembly comprises an ammonia water tank 11 and an ammonia water pump 12, and the ammonia water pump 12 is arranged on a pipeline on which the ammonia water tank 11 is connected with the first ammonia spraying module 1 and the second ammonia spraying module 4; a tail gas outlet of the exhaust fan 6 is connected with a circulating pipeline 10 and a chimney 16, and the circulating pipeline 10 is connected with a tail gas inlet of the first ammonia spraying module 1; an air supplementing pipeline is arranged on the circulating pipeline 10 through a tee joint, an air supplementing electric regulating valve 9 is arranged on the air supplementing pipeline, and a circulating pipeline electric regulating valve 8 is arranged in front of the tee joint on the circulating pipeline 10; and an electric exhaust pipeline regulating valve 7 is arranged on a pipeline of a tail gas outlet of the exhaust fan 6 connected with the chimney 16.

An ammonia spraying module: when large-scale industrial kiln tail gas pipeline cross-section is great, generally adopt and spout ammonia grid or spray gun + baffler form and realize aqueous ammonia and tail gas homogeneous mixing, when small-size industrial kiln tail gas pipeline cross-section is less, adopt the spray gun directly to spout aqueous ammonia in the pipeline, in order to make tail gas and aqueous ammonia homogeneous mixing, set up the curved U type of mixing section, the tail gas temperature is higher, and this U type also can play the effect of thermal compensation.

The SCR reactor is internally provided with a catalyst module, the airspeed can be reduced for high-concentration NOx, when the concentration of the NOx is higher, a large amount of reaction heat can be released in the denitration reaction, a catalyst with a proper temperature window is selected at the moment, and if the tail gas temperature exceeds the upper limit of the temperature window of the catalyst due to the reaction heat, the problems can be solved by adopting the system provided by the invention, which is detailed in the following.

When the concentration of NOx is high, the temperature of tail gas after denitration reaction can rise, a high-temperature fan needs to be selected for the exhaust fan, the use temperature exceeds 350 ℃, and the exhaust fan is controlled in a variable frequency mode so as to adjust the circulating air quantity. The exhaust pipeline electric regulating valve and the circulating pipeline electric regulating valve adopt valves with high temperature resistance, corrosion resistance and good regulating performance; the air supply electric regulating valve can quickly supply cold air by adopting the electric regulating valve, and the temperature of the mixed tail gas is prevented from exceeding a set value.

And the ammonia water tank 11 is used for storing ammonia water required by the denitration reaction.

The ammonia pump 12 can adopt a system form of a centrifugal pump and a return pipe when the ammonia water consumption is large, and the ammonia water consumption is small and can adopt metering.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical substance of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. The utility model provides a SCR deNOx systems of industrial kiln tail gas NOx which characterized in that: the device comprises a first ammonia spraying module (1), a mixer (2), a front SCR reactor (3), a second ammonia spraying module (4), a rear SCR reactor (5) and an exhaust fan (6) which are sequentially connected through pipelines, wherein a tail gas inlet of the first ammonia spraying module (1) is connected with a tail gas outlet of a kiln (13) through a pipeline; the first ammonia spraying module (1) and the second ammonia spraying module (4) are connected with an ammonia water supply assembly; and a tail gas outlet of the exhaust fan (6) is connected with a circulating pipeline (10) and a chimney (16), and the circulating pipeline (10) is connected to a tail gas inlet of the first ammonia spraying module (1).

2. The SCR denitration system of the industrial kiln tail gas NOx of claim 1, is characterized in that: a dust collector (14) and an induced draft fan (15) are arranged on a pipeline of the tail gas inlet of the first ammonia spraying module (1) connected with the kiln (13).

3. The SCR denitration system of the industrial kiln tail gas NOx of claim 1, is characterized in that: and a mixer (2) is also arranged on a connecting pipeline between the second ammonia injection module (4) and the rear SCR reactor (5).

4. The SCR denitration system of the industrial kiln tail gas NOx of claim 1, is characterized in that: an air supplementing pipeline is arranged on the circulating pipeline (10) through a tee joint, an air supplementing electric regulating valve (9) is arranged on the air supplementing pipeline, and a circulating pipeline electric regulating valve (8) is arranged in front of the tee joint on the circulating pipeline (10); and a tail gas outlet of the exhaust fan (6) is connected with a pipeline of the chimney (16) and is provided with an electric exhaust pipeline regulating valve (7).

5. The SCR denitration system of the industrial kiln tail gas NOx of claim 1, is characterized in that: the ammonia water supply assembly is respectively connected with the first ammonia spraying module (1) and the second ammonia spraying module (4) through parallel pipelines, and the two parallel pipelines are respectively provided with an electric regulating valve.

6. The SCR denitration system of the industrial kiln tail gas NOx of claim 1 or 5, is characterized in that: the ammonia water supply assembly comprises an ammonia water tank (11) and an ammonia water pump (12), wherein the ammonia water pump (12) is arranged on a pipeline which is connected with the first ammonia spraying module (1) and the second ammonia spraying module (4) through the ammonia water tank (11).