KR20160002995U - Urea Injection Structure in Selective Catalytic Reduction System - Google Patents

Urea Injection Structure in Selective Catalytic Reduction System Download PDF

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Publication number
KR20160002995U
KR20160002995U KR2020150001171U KR20150001171U KR20160002995U KR 20160002995 U KR20160002995 U KR 20160002995U KR 2020150001171 U KR2020150001171 U KR 2020150001171U KR 20150001171 U KR20150001171 U KR 20150001171U KR 20160002995 U KR20160002995 U KR 20160002995U
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KR
South Korea
Prior art keywords
exhaust gas
urea injection
urea
injection nozzle
gas pipe
Prior art date
Application number
KR2020150001171U
Other languages
Korean (ko)
Inventor
김형주
한주석
박남기
Original Assignee
현대중공업 주식회사
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Priority to KR2020150001171U priority Critical patent/KR20160002995U/en
Publication of KR20160002995U publication Critical patent/KR20160002995U/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9404—Removing only nitrogen compounds
    • B01D53/9409—Nitrogen oxides
    • B01D53/9413—Processes characterised by a specific catalyst
    • B01D53/9418—Processes characterised by a specific catalyst for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • F01N3/2066—Selective catalytic reduction [SCR]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
    • F01N3/28—Construction of catalytic reactors
    • F01N3/2896—Liquid catalyst carrier
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2590/00—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines
    • F01N2590/02—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines for marine vessels or naval applications
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00—Adding substances to exhaust gases
    • F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00—Adding substances to exhaust gases
    • F01N2610/14—Arrangements for the supply of substances, e.g. conduits
    • F01N2610/1453—Sprayers or atomisers; Arrangement thereof in the exhaust apparatus

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Combustion & Propulsion (AREA)
  • Health & Medical Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Toxicology (AREA)
  • General Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

The present invention relates to a urea injection structure in an SCR system (Selective Catalytic Reduction System).
The present invention relates to a urea injection structure of an SCR system for injecting urea into an exhaust gas flowing into a reactor, the urea injection structure being integrally provided on a wall surface of an exhaust gas pipe at an inclination at a predetermined angle, A coupling end having an insertion hole; And a urea injection nozzle which is inserted in the insertion hole of the coupling end and is provided so as not to protrude into the exhaust gas passage in the exhaust gas pipe at an inclined angle and which is not directly exposed to the exhaust gas but injects urea into the exhaust gas, And an urea injection structure in the SCR system.
According to the present invention, in the case where the process of injecting urea into the exhaust gas flowing into the reactor from the SCR system and injecting the exhaust gas and removing the nitrogen oxide of the exhaust gas by the reactor is performed, the urea injection nozzle is not directly exposed to the exhaust gas So that the urea injection nozzle is prevented from being contaminated and damaged.

Description

Urea Injection Structure in Selective Catalytic Reduction System (SCR)

The present invention relates to a selective catalytic reduction (SCR) system for treating nitrogen oxides contained in exhaust gas discharged from a diesel engine installed on a ship, and more particularly, to a selective catalytic reduction system for injecting urea into an exhaust gas flowing into a reactor in an SCR system The urea injection nozzle is not directly exposed to the exhaust gas, and the urea is atomized in the exhaust gas to inject the urea injection nozzle so that the contamination and damage of the urea injection nozzle can be prevented To the urea injection structure in the SCR system.

Nitrogen oxides and sulfur oxides among exhaust gases emitted from diesel engines commonly used in ships are representative air pollutants subject to emission regulation from the International Maritime Organization (IMO), which is a member of the United Nations (UN).

Nitrogen oxides refer to NO, NO2, NO3, N2O, N2O3, N2O4 and N2O5, but most nitrogen oxides are NO and NO2. Sulfur oxides are mainly SO2 in which sulfur components contained in fuels such as coal and petroleum are oxidized in the combustion process.

Nitrogen oxides are generated by the reaction of Nitrogen in the combustion process with thermal NOx generated by the reaction of nitrogen and oxygen in the air in the high temperature region, Prompt NOx generated by the reaction of hydrocarbons generated from the fuel with nitrogen in the air, Fueled NOx.

SCR systems have been used to remove nitrogen oxides generated by the combustion reaction of fossil fuels. The SCR system uses ammonia (NH3), urea (UREA, CO (NH2) 2) and the like as a reducing agent by passing the exhaust gas mixed with the reducing agent through the catalyst layer to reduce nitrogen oxide into nitrogen (N2) , Urea (UREA, CO (NH2) 2) is mainly used as a reducing agent in recent years because of convenience of storage and use of a reducing agent.

In the SCR system, as shown in Equations (1) and (2), the nitrogen oxide of the exhaust gas is converted into nitrogen and water by a catalyst provided in the reactor and removed by injecting urea into the exhaust gas flowing into the reactor .

4NO + 4NH3 + O2 - > 4N2 + 6H2O (Formula 1)

6NO2 + 8NH3 - > 7N2 + 12H2O (Formula 2)

In the conventional SCR system, when urea is injected into the exhaust gas flowing into the reactor, urea in the form of an aqueous solution stored in the tank is injected and injected through the urea injection nozzle. As shown in FIG. 1, the exhaust gas pipe 15 The urea injection nozzle 20 is injected into the exhaust gas by injecting urea in the form of an aqueous solution and compressed air into the urea injection nozzle 20 to atomize the urea.

As described above, in the conventional SCR system, the urea injection nozzle 20 injects urea into the exhaust gas while the urea injection nozzle 20 is inserted into the exhaust gas passage inside the exhaust gas pipe 15 Thereby causing a problem of damaging or contaminating the urea injection nozzle 20.

That is, there is a problem that the urea injection nozzle 20 is directly exposed to the high temperature exhaust gas and is damaged by the high temperature. The urea injection nozzle 20 is in direct contact with the high temperature exhaust gas, There is a problem that the urea injection nozzle 20 is solidified in the urea injection nozzle 20 due to the evaporation of the urea aqueous solution, thereby contaminating the urea injection nozzle 20 and hindering the urea supply. There is a problem that the urea injection nozzle 20 is contaminated by the falling soot coming into contact with the urea injection nozzle 20.

The present invention has been proposed in order to solve the problems of the prior art as described above. In the SCR system, the urea is injected into the exhaust gas flowing into the reactor, and the nitrogen oxide of the exhaust gas is removed by the reactor It is an object of the present invention to provide a urea injection structure in an SCR system which prevents contamination and damage of a urea injection nozzle by atomizing urea into an exhaust gas without injecting the urea injection nozzle directly into the exhaust gas.

In order to achieve the above object, the present invention provides a urea injection structure in an SCR system for injecting urea into an exhaust gas flowing into a reactor, the urea injection structure being integrally provided on a wall surface of an exhaust gas pipe, A coupling end having an insertion hole for inserting and installing a urea injection nozzle therein; And a urea injection nozzle which is inserted in the insertion hole of the coupling end and is provided so as not to protrude into the exhaust gas passage in the exhaust gas pipe at an inclined angle and which is not directly exposed to the exhaust gas but injects urea into the exhaust gas, And an urea injection structure in the SCR system.

According to the urea injection structure in the SCR system according to the present invention, the urea injection nozzle is installed by being retracted from the wall surface of the exhaust gas pipe by a predetermined distance.

According to the urea injection structure in the SCR system according to the present invention, when the urea injection nozzle is inserted into the insertion hole of the coupling end, the space between the inner wall of the insertion hole of the coupling end and the body surface of the urea injection nozzle Sealant is inserted and sealed.

According to the urea injection structure in the SCR system according to the present invention, the coupling end is installed at a predetermined interval around the wall surface of the exhaust gas pipe, and the position is set symmetrically with respect to the center axis of the exhaust gas pipe do.

According to the present invention, in the case where the process of injecting urea into the exhaust gas flowing into the reactor from the SCR system and injecting the exhaust gas and removing the nitrogen oxide of the exhaust gas by the reactor is performed, the urea injection nozzle is not directly exposed to the exhaust gas So that the urea injection nozzle is prevented from being contaminated and damaged.

1 is a view showing a urea injection structure in a conventional SCR system.
2 is a diagram illustrating a urea injection structure in an SCR system according to the present invention.
3 is a view illustrating a coupling end for installing a urea injection nozzle in the present invention.
FIG. 4 is a view illustrating an installation position of the urea injection nozzle in the present invention. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Although the present invention has been described with reference to the embodiments shown in the drawings, it is to be understood that the present invention is not limited thereto.

In the SCR system, when the urea is injected into the exhaust gas flowing into the reactor and the process is performed to remove the nitrogen oxide of the exhaust gas by the reactor, the urea injection nozzle is not directly exposed to the exhaust gas, And spraying the urea atomized in the gas to prevent contamination and damage of the urea injection nozzle.

The urea injection structure in the SCR system according to the present invention for achieving the above-described structure is as illustrated in FIG.

The urea injection structure of the present invention has a structure in which a plurality of urea injection nozzles 120 are provided on the wall surface of the exhaust gas pipe 115 at an angle to a predetermined angle, and the urea injection nozzles 120 are provided so as not to protrude into the exhaust gas passage inside the exhaust gas pipe 115. The urea injection nozzle 120 is injected into the exhaust gas in a state in which the urea injection nozzle 120 is not directly exposed to the exhaust gas.

The urea injection nozzle 120 is installed on the wall surface of the exhaust gas pipe 115 so as to be inclined at a predetermined angle and is disposed at a position retreated from the wall surface of the exhaust gas pipe 115 by a predetermined distance, And is not directly exposed to the exhaust gas passing therethrough.

The urea injection nozzle 120 is supplied with the urea in the form of an aqueous solution and supplied with the compressed air in a state where the urea injection nozzle 120 is installed at a predetermined angle on the wall surface of the exhaust gas pipe 115, And injects urea into the exhaust gas flowing into the reactor 110 by injecting urea at an angle upward (upward) with a set angle.

When the urea injection nozzle 120 is installed on the wall surface of the exhaust gas pipe 115 at a predetermined angle, the urea injection nozzle 120 is inserted into the coupling end 116 integrally formed on the wall of the exhaust gas pipe 115.

3, the exhaust gas pipe 115 for introducing exhaust gas into the reactor 110 is provided with a coupling end 116 provided at an inclined angle with respect to the wall surface of the exhaust gas pipe 115, And the urea injection nozzle 120 is inserted into the insertion hole H of the coupling end 116 to install it. When the urea injection nozzle 120 is inserted into the insertion hole H of the coupling end 116, a gap is formed between the inner wall of the insertion hole H of the coupling end 116 and the body surface of the urea injection nozzle 120 The sealed state is maintained by inserting the sealant.

For example, a screw thread is provided on the inner wall of the insertion hole H of the coupling end 116, a screw thread is provided on the body surface of the urea injection nozzle 120, When the nozzle 120 is installed, the screw thread of the urea injection nozzle 120 may be fastened to the corresponding screw groove of the coupling end 116. When the urea injection nozzle 120 is attached to the coupling end 116 by tightening the screw thread and the screw groove, the sealant may be inserted between the screw thread and the screw groove to maintain the sealed state.

2 and 3 show that two urea injection nozzles 120 are provided in the exhaust gas pipe 115. However, the present invention is not limited to this, and the number of the urea injection nozzles 120 The number of required urea injection quantities can be satisfied.

In this way, two or more urea injection nozzles 120 are provided on the wall surface of the exhaust gas pipe 115 so as to be inclined at a predetermined angle, and the urea injection nozzles 120 are provided so as not to protrude into the exhaust gas passages inside the exhaust gas pipe 115 4, it can be installed symmetrically to a plurality of positions P1 to P4 set at predetermined intervals around the wall surface of the exhaust gas pipe 115. [

4 shows a case in which four urea injection nozzles 120 are inclined at a set angle on the wall surface of the exhaust gas pipe 115. The exhaust gas pipe 115 is disposed at a position P1 To P4, and the positions P1 to P4 are set symmetrically with respect to the center axis of the exhaust gas pipe 115.

When the urea injection nozzles 120 are installed in the plurality of positions P1 to P4 as described above, insertion of the respective engagement ends 116 provided at the predetermined positions inclined at the positions P1 to P4, A plurality of urea injection nozzles 120 are provided so as not to be directly exposed to the exhaust gas passing through the inside of the exhaust gas pipe 115 by inserting the urea injection nozzle 120 into the hole H.

As described above, the present invention is characterized in that a plurality of urea injection nozzles 120 are provided on a wall surface of an exhaust gas pipe 115 for introducing exhaust gas into a reactor 110 so as to be inclined at a predetermined angle, The urea injection nozzle 120 is provided so as not to protrude from the exhaust gas passage of the urea injection nozzle 120. Thus, the urea injection nozzle 120 injects urea into the exhaust gas without being directly exposed to the exhaust gas.

Thus, the exhaust gas containing urea injected by the urea injection nozzle 120 flows into the reactor 110, and the reactor 110 proceeds to the process of removing the nitrogen oxide of the exhaust gas.

In this case, since the urea injection nozzle 120 injects urea into the exhaust gas flowing into the reactor 110 without directly exposing the urea injection nozzle 120 to the exhaust gas, the urea injection nozzle 120 is directly exposed to the high- It is possible to prevent the urea injection nozzle 120 from being damaged by the high temperature contact.

Since the present invention does not directly expose the urea injection nozzle 120 to the high temperature exhaust gas, evaporation of the urea aqueous solution due to high temperature can be prevented, and the urea is solidified in the urea injection nozzle 120, So that the urea injection nozzle 120 can be prevented from being contaminated and the urea supply to the urea injection nozzle 120 can be smoothly performed.

In the present invention, since the urea injection nozzle 120 is provided so as not to protrude into the exhaust gas passage in the exhaust gas pipe 115, when the operation of the SCR system is stopped, It is possible to prevent contamination of the urea injection nozzle 120 by turning off the nozzle.

It is to be understood that the present invention is not limited to the above description and that various changes and modifications may be made without departing from the spirit of the present invention as long as those skilled in the art are familiar with the present invention And that the implementation of such changes falls within the technical scope of the present invention.

The present invention can be applied to an SCR system for removing nitrogen oxides of engine exhaust gas. According to the present invention, in the case where the process of injecting urea into the exhaust gas flowing into the reactor from the SCR system and injecting the exhaust gas and removing the nitrogen oxide of the exhaust gas by the reactor is performed, the urea injection nozzle is not directly exposed to the exhaust gas So that the urea injection nozzle is prevented from being contaminated and damaged.

10, 110; Reactors 15 and 115; Exhaust gas piping
20, 120; A urea injection nozzle 116; Coupling stage
P1 to P4; Urea Nozzle Installation Location

Claims (4)

As a urea injection structure in an SCR system (Selective Catalytic Reduction System) for injecting urea into an exhaust gas flowing into a reactor,
A coupling step provided integrally with the wall surface of the exhaust gas pipe so as to incline at a predetermined angle, and having an insertion hole for inserting a urea injection nozzle into itself;
And a urea injection nozzle which is inserted in the insertion hole of the coupling end and is provided so as not to protrude into the exhaust gas passage in the exhaust gas pipe at an inclined angle and which is not directly exposed to the exhaust gas but injects urea into the exhaust gas, The urea injection structure in the SCR system.
The method according to claim 1,
Wherein the urea injection nozzle is retracted by a predetermined distance from the wall surface of the exhaust gas pipe.
The method according to claim 1,
And a sealing agent is inserted between the inner wall of the insertion hole of the coupling end and the body surface of the urea spray nozzle when the urea injection nozzle is inserted into the insertion hole of the coupling end to seal the Urea injection nozzle. Injection structure.
The method according to claim 1 or 3,
Wherein the coupling end is set at a predetermined interval around the wall surface of the exhaust gas pipe, and the position is symmetrically set with respect to the center axis of the exhaust gas pipe.
KR2020150001171U 2015-02-23 2015-02-23 Urea Injection Structure in Selective Catalytic Reduction System KR20160002995U (en)

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KR2020150001171U KR20160002995U (en) 2015-02-23 2015-02-23 Urea Injection Structure in Selective Catalytic Reduction System

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