KR101812630B1 - Backflow prevention apparatus of reducing agent spray nozzle - Google Patents

Abstract

The present invention relates to a backflow preventing device for a non-catalytic reaction facility, which comprises: a nozzle supporting body which is supported by a boiler; a movable body which moves through a moving means placed in a lower part of the nozzle supporting body; a mixer body which is able to move by being fixed to the movable body, and where a reductant supplied through a reductant supply pipe is mixed with air supplied through an air supply pipe; a spray tube which is placed in the mixer body in order to spray a spray liquid, where the reductant and the air are mixed, through a spray tip; and an opening and closing unit which is combined with the spray tube, and opens or closes an inside flow path of the spray tube according to the movement of the mixer body. In addition, the backflow preventing device further comprises: a first valve body which is placed between the reductant supply pipe and the air supply pipe within the mixer body, is placed at the air supply pipe side, and has a first air flow path therein; a second valve body which is placed between the reductant supply pipe and the air supply pipe within the mixer body, is placed at the reductant supply pipe side, and has a second air flow path therein; a valve body which is formed in a weight shape, is placed along the first air flow path and the second air flow path, and opens or closes the second air flow path; a valve cap which is combined with the valve body in order to open or close the first air flow path; and an elastic body which provides elastic force so that the valve body and the valve cap can be restored to the original position respectively. Therefore, the backflow preventing device for a reductant spray nozzle can prevent an air supply pipe from being clogged by backflow or hardening of a urea solution into the air supply pipe which supplies air to a reductant spray nozzle of a selective non-catalytic reduction (SNCR).

Description

BACKFLOW PREVENTION APPARATUS OF REDUCING AGENT SPRAY NOZZLE BACKGROUND OF THE INVENTION [0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air supply pipe for supplying air to a reducing agent injection nozzle of a selective non-catalytic reduction (SNCR) facility, and a backflow of a reducing agent injection nozzle capable of preventing the air supply pipe from clogging, Prevention device.

As is well known, the non-catalytic denitrification system provided for treating the exhaust gas of a boiler is provided with a reducing agent injection nozzle for injecting a reducing agent into the boiler, and a reducing agent such as urea water (UREA) (NO _x ) generated during combustion can be removed by mixing the mixture in the form of an atomized liquid and injecting the mixture into the nitrogen oxide generating region.

The reducing agent injected from the reducing agent injection nozzle into the atomized liquid state has a phenomenon in which ammonia (NH ₃ ) slips into an unreacted state at a low temperature and oxidizes to generate another nitrogen oxide at a high temperature, The nitrogen oxides can be stably removed only by maintaining an appropriate temperature (for example, 870-1050 占 폚) for the reaction.

On the other hand, when the operation of the reducing agent injection nozzle is stopped in the conventional non-catalytic denitration facility as described above, the urea water remaining in the body of the reducing agent injection nozzle flows back to the air supply pipe side, There is a problem that the air supply pipe is clogged.

If the air supply pipe is clogged, malfunction of the detection sensor installed on the air supply pipe side is caused, so that the urea water is introduced into the reaction chamber, thereby corrosion of the inside of the reaction chamber.

1. Registration No. 10-0549239 (Registered on Jan. 26, 2006): Reducing agent injection nozzle of non-catalytic reaction system 2. Registration No. 10-0475332 (registered on February 25, 2005): Reducing agent injection device of non-catalytic reaction facility

An object of the present invention is to provide an apparatus for preventing the backflow of a reducing agent spraying nozzle which can prevent the air supply pipe from being clogged due to the reverse flow and curing of urea water by an air supply pipe for supplying air to the reducing agent spraying nozzle of the non- .

In addition, the present invention provides a shut-off valve in the mixer body of the reducing agent injection nozzle to prevent backward flow of urea water, thereby preventing the urea water from entering into the reaction chamber and corroding it, The present invention also provides an apparatus for preventing backflow of a reducing agent spray nozzle which can reduce the cost by extending the period of replacing the supply pipe as well as improving the efficiency of the non-catalytic denitration facility.

The objects of the embodiments of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description .

According to an embodiment of the present invention, there is provided a nozzle support apparatus comprising: a nozzle support supported by a boiler; a moving body moving through a moving means provided below the nozzle support; a reducing agent movable fixedly with the moving body, A mixing tube body for mixing the air supplied through the air supply tube, a spray tube provided in the mixer body for spraying the spray liquid mixed with the reducing agent and air through the spray tip, And a first air flow passage provided inside the mixer body and located between the reducing agent supply pipe and the air supply pipe, the first air flow passage being located on the air supply pipe side, And a second valve body provided between the reducing agent supply pipe and the air supply pipe among the inside of the mixer body A second valve body disposed on the reductant supply pipe side and having a second air flow path therein, a second valve body formed in a spiral shape and provided along the first air flow path and the second air flow path, A valve cap connected to the valve body for opening and closing the first air flow path and an elastic body for providing an elastic force so that the valve body and the valve cap can be restored to their original positions, A backflow prevention device may be provided.

An object of the present invention is to provide an air supply pipe for supplying air to a reducing agent spray nozzle provided in a non-catalytic denitrification facility (SNCR), and prevent the air supply pipe from being clogged by the reverse flow and cure of urea water, The valve is provided to prevent the back flow of the urea water, thereby preventing the urea water from flowing into the reaction chamber and corroding it.

Further, according to the present invention, since the urea water does not flow back to the air supply pipe side through the backflow prevention device, the nozzle of the non-catalytic denitration facility can be stably operated by preventing the clogging of the air supply pipe, It is possible to prevent corrosion inside the boiler, to improve the efficiency of the denitration facility, and to extend the cycle of replacing the supply pipe, thereby reducing costs.

1 is a view illustrating an apparatus for non-catalytic reaction equipped with a reducing agent injection nozzle according to an embodiment of the present invention,
FIG. 2 is a view illustrating a reducing agent spraying nozzle provided with a backflow preventing device according to an embodiment of the present invention,
3 and 4 are views illustrating an apparatus for preventing the backflow of a reducing agent spraying nozzle according to an embodiment of the present invention.

Advantages and features of embodiments of the present invention and methods of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions in the embodiments of the present invention, which may vary depending on the intention of the user, the intention or the custom of the operator. Therefore, the definition should be based on the contents throughout this specification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view illustrating an apparatus for non-catalytic reaction equipped with a reducing agent spraying nozzle according to an embodiment of the present invention. FIG. 2 is a view illustrating a reducing agent spraying nozzle provided with a backflow preventing apparatus according to an embodiment of the present invention. 3 and 4 are views illustrating an apparatus for preventing a reducing agent spray nozzle from flowing backward according to an embodiment of the present invention.

1 to 4, in the non-catalytic denitrification system according to the embodiment of the present invention, combustion energy is supplied to the inside of the boiler and the combustion gas is injected into the boiler. The nitrogen oxide (NO _x ) (NO _x ) contained in the incompletely burned exhaust gas can be reduced and removed using a reducing agent (for example, urea water) injected through the reducing agent injection nozzle 100, and then discharged.

The reducing agent spraying nozzle 100 includes a nozzle support 110, a moving unit 120, a moving unit 130, a mixer body 140, a fixing unit 150, a reducing agent supplying unit 160, an air supplying unit 170, (180), a door (190), and the like.

Here, the nozzle support 110 supports the reducing agent injection nozzle 100 firmly to the boiler. The nozzle support 110 includes a nozzle support 112 protruded upward, a support (not shown) coupled to the nozzle support 112, The nozzle 100 can be stably engaged and fixed.

The moving means 120 moves the moving body 130 movably coupled to the lower portion of the nozzle support 110. The moving means 120 moves the moving body 130 through the moving guide 122 coupled to the moving body 130, (For example, forward movement, rearward movement, etc.).

The mixer body 140 is fixed to the moving body 130 through a fixture 150 provided at a lower portion of the moving body 130 by mixing a reducing agent such as urea water and air and is connected to a reducing agent supply pipe 160 And the air supplied through the air supply pipe 170 may be mixed with each other. That is, when the moving body 130 moves through the moving means 120, the mixer body 140 fixed with the moving body 130 can be moved in the same direction as the moving direction of the moving body 130.

The spray tube 180 is provided in the mixer body 140 and moves the spray liquid mixed with the reducing agent and the air into the boiler. The spray tube 180 is coupled to the mixer body 140 at one end and extends to the inside .

A spray tip 182 may be mounted on the other end of the spray tube 180. The spray tip 182 may be made of a material such as tungsten carbide to improve heat resistance and corrosion resistance, And a plurality of spray holes are formed while curving the other end in a round shape, so that the spray liquid can be sprayed.

The opening and closing port 190 includes a check valve or the like inside so as to be closed when the internal flow path is restored to its original position when it moves in the rear end direction and is connected to the spraying tube 180 to move the mixer body 140 A mixer body 140 which is coupled to a specific position of the spray tube 180 and is fixed through the moving body 130 and the fixture 150 in a state where the internal flow path is closed, Closing port 190 coupled to the spray tube 180 is supported by the opening and closing port support protrusion 114 protruding from the lower portion of the nozzle support 110 and is moved in the rear end direction when the spray tip 182 moves in the forward direction, Accordingly, the inner flow path of the spray tube 180 is opened and communicated, so that the spray liquid can move in the front end direction in which the spray tip 182 is installed.

In order to prevent the reducing agent remaining in the inside of the mixer body 110 from flowing back to the air supply pipe 170 after the reducing agent such as urea water is supplied to the reducing agent spray nozzle 100, (200) can be installed.

The backflow prevention device 200 may include a first valve body 210, a second valve body 220, a valve body 230, a valve cap 240, an elastic body 250, and the like.

The first valve body 210 is disposed between the reducing agent supply pipe 160 and the air supply pipe 170 in the interior of the mixer body 140 and is located on the air supply pipe 170 side. 212 may be provided.

The first air passage 212 is formed such that the air supply pipe 170 side is formed with a relatively large diameter (the 1-1 air passage area), and is formed so as to be inclined toward the center (the 1-2 air passage area) (The first to third air flow passage regions) and to be widened outwardly (the first to fourth air flow passage regions).

The second valve body 220 is disposed between the reducing agent supply pipe 160 and the air supply pipe 170 in the interior of the mixer body 140 and is located on the side of the reducing agent supply pipe 160, 222 may be provided.

The second air passage 222 is formed such that the first valve body 210 is formed with a relatively large diameter (the second-1 air passage area) and is inclined toward the center (the second-2 air passage area) (The second to fourth air passage area) formed to have a relatively narrow diameter by a predetermined distance (the second to third air passage area) and formed so as to be inclined outwardly (the second to fourth air passage area).

The valve body 230 is formed in a spiral shape and is provided along the first air passage 212 and the second air passage 222 to open and close the second air passage 222. The valve body 230 has a relatively small diameter circular rod And an opening and closing weight 234 having a relatively large diameter may be provided in the shape of a circle in the end of the circular rod 232 (that is, in the direction of the reducing agent supply pipe 160). The opening and closing weight 234 may be formed to have a size corresponding to the inclined surface of the second-4 air passage area in the second air passage 222.

The valve cap 240 is coupled to the valve body 230 to open and close the first air flow passage 212 and is coupled to the circular rod 232 of the valve body 230, And may be inclined in a shape corresponding to the inclined surface of the first-fourth air flow passage area. The valve cap 240 is provided with a sealing member having elasticity such as an O-ring on the inclined surface so as to be in close contact with the first to fourth air passage area of the first air passage 212, The flow path 212 can be completely closed.

The elastic body 250 provides an elastic force so that the valve body 230 and the valve cap 240 can be restored to their original positions. The elastic body 250 is coupled to the outer periphery of the circular rod 232 of the valve body 230, The valve cap 230 and the valve cap 240 are supported by the support end 224 formed on the second valve body 220 and the other end supported on the valve cap 240, So as to open the first air passage 212 and the second air passage 222 or to return to the original position to close the first air passage 212 and the second air passage 222 It is possible to provide an elastic force (restoring force).

When the reducing agent injection nozzle 100 is operated, the front end where the spray tube 180 is positioned according to the negative pressure of air supplied through the air supply pipe 170, The first air passage 212 and the second air passage 222 can be opened by moving the valve body 230 and the valve cap 240 in the direction Can be introduced into the reducing agent and mixed with the spray liquid.

As the mixer body 140 fixed to the moving body 130 moves in the front end direction, the opening and closing port 190 is supported by the opening and closing port support 114 to open the internal flow path of the spraying tube 180, May be injected through the spray tip 182 into the region where the nitrogen oxide is generated in the boiler.

When the operation of the reducing agent injection nozzle 100 is stopped, the valve body 230 and the valve cap 240 are moved to the rear end direction (original position) where the air supply pipe 170 is positioned according to the restoring force of the elastic body 250 The first air passage 212 and the second air passage 222 can be closed. Here, the mixer body 140 can close the spray tube 180 through the opening / closing port 190 as the moving body 130 moves in the rearward direction.

Accordingly, it is an object of the present invention to provide an air supply pipe for supplying air to a reducing agent spray nozzle provided in a non-catalytic denitrification facility (SNCR), and prevent urea from clogging the air supply pipe, It is possible to prevent the urea water from flowing into the reaction chamber and corroding it.

Further, according to the present invention, since the urea water does not flow back to the air supply pipe side through the backflow prevention device, the clogging of the air supply pipe is prevented in advance, so that the nozzle of the non-catalytic denitration facility can stably operate and the air supply pipe clogging It is possible to prevent corrosion inside the boiler, to improve the efficiency of the denitration facility, and to extend the cycle of replacing the supply pipe, thereby reducing costs.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be readily apparent that such substitutions, modifications, and alterations are possible.

100: Reducing agent injection nozzle 110: Nozzle support
120: moving means 130: moving object
140: mixer body 150: fastener
160: Reducing agent supply pipe 170: Air supply pipe
180: Spray tube 190:
200: backflow prevention device 210: first valve body
220: second valve body 230: valve body
240: valve cap 250: elastomer

Claims (4)

A nozzle body supported by the boiler; a moving body which moves through a moving means provided below the nozzle body; a reducing agent supplied through a reducing agent supply tube and movable through a fixed movement with the moving body; A spray tube for spraying the spray liquid mixed with the reducing agent and the air through the spray tip, the spray tube being provided in the mixer body and being connected to the inside of the spray tube in accordance with the movement of the mixer body; And an opening / closing port for opening and closing the flow path,
A first valve body disposed between the reducing agent supply pipe and the air supply pipe among the inside of the mixer body, the first valve body being located on the air supply pipe side and having a first air flow path therein;
A second valve body disposed between the reducing agent supply pipe and the air supply pipe among the inside of the mixer body, the second valve body being located on the reducing agent supply pipe side and having a second air flow path therein;
A valve body formed in a spiral shape and provided along the first air passage and the second air passage to open and close the second air passage;
A valve cap coupled to the valve body to open and close the first air passage,
The valve body and the valve cap are elastically deformed to provide an elastic force so that the valve body and the valve cap can be restored to their original positions.
Wherein the reducing agent injecting nozzle is provided with a return flow preventing device.
The method according to claim 1,
Wherein the first air passage and the second air passage are formed in bottleneck shapes, respectively.
The method according to claim 1,
Wherein the valve body is provided with a relatively small diameter circular rod, and a relatively large diameter opening / closing is additionally provided at an end of the circular rod.
4. The method according to any one of claims 1 to 3,
When the reducing agent spraying nozzle is operated, the valve body and the valve cap move in the forward direction to open the first air passage and the second air passage. When the operation of the reducing agent spraying nozzle is stopped Wherein the valve body and the valve cap move in the rearward direction to close the first air passage and the second air passage.

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