JP3292887B2 - Ammonia injection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support mechanism for an ammonia injection nozzle installed in a duct of an exhaust gas denitration apparatus.

[0002]

2. Description of the Related Art Exhaust gas from a boiler is processed in the following procedure as shown in FIG. Exhaust gas discharged from the boiler 12 passes through a duct and passes through the ammonia injection device 1
Ammonia gas is supplied by 3, nitrogen oxides are removed by a denitration reactor 14, and after being cooled by an air preheater 15, dust is removed by an electric precipitator 16, sulfur compounds are removed by a desulfurizer 17, and a Released. The present invention includes the ammonia injection device 13
And the ammonia injection device 13 of the denitration device including the denitration reactor 14.

A conventional ammonia injection apparatus, particularly a support mechanism for an ammonia injection nozzle, is as shown in FIGS. 10 to 12, for example. 10 is a schematic view thereof, FIG. 11 is a partial detailed view of FIG. 10, and FIG. 12 is a side sectional view thereof. In FIGS. 10 to 12, ammonia gas is injected from an ammonia injection header 1 provided in a duct casing 7 as shown by an arrow, and via an ammonia injection mother pipe 4 connected to the ammonia injection header 1. The ammonia is supplied from the ammonia injection nozzle 3 provided in the ammonia injection mother pipe 4 into the duct. In this case, the ammonia injection mother pipe 4 is supported by a large number of support members 9 arranged in the duct casing 7 in order to prevent bending and vibration due to its own weight. In this example, as shown in FIG. 10, the ammonia injection headers 1 are provided on the left and right sides of the duct casing 7, and the ammonia injection header 4 connected to these ammonia injection headers 1 is shown in FIGS. 11 and 12. As described above, the support member 9 extends to the center, and is supported and fixed to the support member 9, and the intermediate portion thereof is fixed to the support member 9 with a U bolt or the like.

[0004]

However, FIG.
In the conventional ammonia injection nozzle support mechanism as shown in FIG. 12 to FIG. 12, the flow of exhaust gas in the duct casing 7 is disturbed by a large number of support members 9 arranged in the duct casing 7. In order to install the support member 9, it is necessary to widen the mounting interval of the ammonia injection nozzle 3, so that there is a problem that uniform ammonia injection cannot be performed.

Accordingly, it is an object of the present invention to eliminate or reduce the number of the support members 9 in order to solve these disadvantages, to improve the strength of the support mechanism of the ammonia injection nozzle, and to achieve a uniform ammonia gas. To provide an ammonia injection device capable of supplying water.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
This is achieved by the following configuration of the ammonia injection device. That is, an ammonia injection header is provided in the upstream duct of the catalyst layer of the exhaust gas denitration device, and an ammonia injection mother pipe is provided in connection with the ammonia injection header, and an ammonia injection nozzle is provided in the ammonia injection mother pipe. In an ammonia injection device having an ammonia injection nozzle group formed in a duct in a horizontal direction or a vertical direction, the ammonia injection header having one end closed by the ammonia injection header is arranged in a comb shape, and The side not connected to the injection header is supported and fixed to another ammonia injection header.

This ammonia injection apparatus is characterized in that a plurality of ammonia injection mother pipes are grouped as a group, and the support for fixing them to the ammonia injection header is formed in a cross-girder shape. Further, in this ammonia injection apparatus, a plurality of ammonia injection headers are provided in the vertical direction of the duct casing, and the side of the ammonia injection mother pipe that is not connected to the ammonia injection header is supported and fixed to the ammonia injection header thereunder. It is characterized by doing so.

[0008]

The ammonia injection header is provided in the duct casing, the ammonia injection header having one end closed is connected to the ammonia injection header in a comb shape, and the ammonia injection header is connected to the ammonia injection header of the ammonia injection header. The ammonia injection nozzle group was formed in the ammonia injection mother tube by supporting and fixing the non-equipped side to another ammonia injection header, so that the support member 9 in the conventional ammonia injection nozzle support mechanism was eliminated, or
The number can be reduced. As a result, uniform injection of ammonia can be performed.

In such an ammonia injection device,
A plurality of ammonia injection pipes are grouped into one group, and these are fixed to the header for ammonia injection in a cross-girder shape, so that uniform ammonia injection is possible and the strength of the support mechanism of the ammonia injection nozzle is improved. .

In such an ammonia injection apparatus, a plurality of ammonia injection headers are provided in the vertical direction of the duct casing, and the side of the ammonia injection mother pipe that is not connected to the ammonia injection header is located below the ammonia injection header. Because I fixed it to the header,
Similarly, uniform ammonia injection can be performed, and the strength of the support mechanism of the ammonia injection nozzle can be improved.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of one embodiment of the present invention,
FIG. 2 is a partially detailed view of FIG. 1, and FIG. 3 is a side sectional view thereof. 1 to 3, an ammonia injection header 1 and a similar ammonia injection header 2 are provided in a duct casing 7, and ammonia gas is injected from these ammonia injection headers 1 and 2 as shown by an arrow A. . One end of each of the ammonia injection headers 1 and 2 is closed, and an ammonia injection mother pipe 4 provided with a plurality of ammonia injection nozzles 3 is connected thereto. As shown in FIG. 2, the ammonia injection mother pipe 4 is connected to the ammonia injection header 1 up to the fourth from the left, and the ammonia gas moves as shown by the arrow B. On the other hand, one end of the ammonia injection mother pipe 4 on the side not connected to the ammonia injection header 1 is closed, and the end is supported and fixed to the ammonia injection header 2. And the next four headers 2 for ammonia injection
One end of the side not connected to the ammonia injection header 2 is closed, and the end is supported and fixed to the ammonia injection header 1. Similarly, the ammonia injection mother tube 4 is connected to the ammonia injection header 2 up to the fourth tube from the right, and the ammonia gas moves as shown by the arrow C. On the other hand, one end of the ammonia injection mother pipe 4 which is not connected to the ammonia injection header 2 is closed, and the end is supported and fixed to the ammonia injection header 1. The next four are connected to the ammonia injection header 1, one end of the side not connected to the ammonia injection header 1 is closed, and the other end is supported and fixed to the ammonia injection header 2. ing. The supporting and fixing method may be U bolts or welding. Thus, the ammonia injection headers 1 and 2 and the ammonia injection mother pipe 4 are grouped into four ammonia injection mother pipes 4 as one group,
The support structure of the ammonia injection nozzle 3 can be improved in strength by supporting and fixing it in a so-called cross-girder shape.

The ends of the ammonia injection headers 1 and 2 are fixed to the duct casing 7, but the ammonia injection headers 1 and 2 between the fixing points 5 and 6 have a temperature difference from the duct casing 7. Causes a difference in thermal expansion. In order to absorb this thermal expansion, in the example shown in FIG.
The central portion 8 is a double tube so as to slidably absorb the respective thermal expansion. In this example, a slightly left side of the center portion 8 of the ammonia injection header 1 is a double tube, and a slightly right side of the center portion 8 of the ammonia injection header 2 is a double tube.

FIG. 4 is a schematic view of another embodiment of the present invention, FIG. 5 is a partially detailed view of FIG. 4, and FIG. 6 is a side sectional view thereof. The ammonia injection headers 1 and 2 are fixed to a duct casing 7, the ammonia injection headers 1 and 2 are connected to an ammonia injection mother pipe 4, and these are formed in a cross-girder shape and supported and fixed. This is similar to the embodiment shown in FIG. In this embodiment, as a method for absorbing thermal expansion due to the temperature difference,
A central portion 8 of each of the ammonia injection headers 1 and 2 is divided, and each divided portion is supported by a support member 9 with a U-bolt or the like so as to be slidably absorbed.

In the embodiment shown in FIGS. 1 to 6, the ammonia injection mother pipe 4 is connected to the ammonia injection headers 1 and 2 and these are formed in a grid shape and supported and fixed. Are grouped as one group, but the number is not limited to this and the number can be determined as appropriate. Further, in an extreme case, the support may be formed by alternately forming a cross in a one-by-one manner.

In the embodiment shown in FIGS. 1 to 6, the support mechanism of the ammonia injection nozzle 3 described in detail in FIGS. 2 and 3 and FIGS. Although only partially shown in FIG. 4, it is provided on the entire surface inside the duct casing 7 to constitute an ammonia injection device.

7 to 9 show still another embodiment of the present invention. FIG. 7 is a schematic diagram thereof, and FIG.
9 is a side sectional view of FIG. FIG.
In FIG. 9 to FIG. 9, an ammonia injection header 10 is provided in the vertical direction of the duct casing 7 so as to be sequentially fixed at fixing points 5 and 6, and the ammonia injection header 10 is provided with a plurality of ammonia injection nozzles 3. The provided ammonia injection mother pipe 4 is connected. And
One end opposite to the side to which the ammonia injection mother pipe 4 is connected is closed, and is supported and fixed to the ammonia injection header 10 immediately below the ammonia injection header 10 to which the ammonia injection mother pipe 4 is connected. ing. Such a support mechanism is sequentially and repeatedly performed, and the duct casing 7
It covers the whole inside. In this case, a support pipe is provided at the lower end of the last ammonia injection mother pipe 4 instead of the ammonia injection header 10, and the lower end is supported and fixed. Further, in this embodiment, as in the case of FIGS.
In order to absorb the thermal expansion due to the temperature difference between the inside and outside, the central portion 8 of the ammonia injection header 10 is divided, and the divided portion is supported by the support member 9. In this case, in order to improve the strength of the ammonia injection header 10, another one pipe is provided inside and the pipe is made a double pipe. A spacer 11 is provided on the inner pipe between the ammonia injection header 10 (outer pipe). By making the ammonia injection header 10 a double tube in this way, a stronger support mechanism for the ammonia injection nozzle 3 is possible. In this case, the ammonia gas is injected into both the inner pipe and the outer pipe in consideration of the uniform distribution of the ammonia gas. That is, as shown in FIG.
Arrow A on the inner tube and arrow D on the outer tube 10
Inject from the direction.

In this embodiment, the header 10 for injecting ammonia is sequentially fixed in the vertical direction. However, the present invention is not limited to this, and a configuration in which the header 10 is mounted in a horizontal direction in some cases is also possible.

[0018]

As described above, according to the present invention, the support mechanism of the ammonia injection nozzle 3, that is, the relationship between the ammonia injection header 1 and the ammonia injection mother pipe 4, is described. The ammonia injection mother pipe 4 is connected in a comb shape, and the side of the ammonia injection mother pipe 4 which is not connected to the ammonia injection header 1 is supported and fixed to another ammonia injection header 1. Can be improved, and the number of support members 9 can be eliminated or the number of support members 9 can be reduced. Therefore, disturbance of the flow of exhaust gas can be eliminated, and uniform supply of ammonia gas can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of one embodiment of the present invention.

FIG. 2 is a partially detailed view of FIG. 1;

FIG. 3 is a side sectional view of FIG. 2;

FIG. 4 is a schematic explanatory view of another embodiment of the present invention.

FIG. 5 is a partially detailed view of FIG. 4;

FIG. 6 is a side sectional view of FIG. 5;

FIG. 7 is a schematic explanatory view of still another embodiment of the present invention.

FIG. 8 is a partially detailed view of FIG. 7;

FIG. 9 is a side sectional view of FIG. 8;

FIG. 10 is a schematic explanatory view of a conventional ammonia injection device.

FIG. 11 is a partial detailed view of FIG. 10;

FIG. 12 is a side sectional view of FIG. 11;

FIG. 13 is a basic system diagram of an exhaust gas treatment of a boiler with a denitration device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ammonia injection header 2 Ammonia injection header 3 Ammonia injection nozzle 4 Ammonia injection mother pipe 5 Fixed point 6 Fixed point 7 Duct casing 8 Ammonia injection header central part 9 Support member 10 Ammonia injection header 11 Spacer 12 Boiler 13 Ammonia injection Apparatus 14 Denitration reactor 15 Air preheater 16 Electric precipitator 17 Desulfurizer 18 Chimney

──────────────────────────────────────────────────の Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B01D 53/34 B01D 53/86 B01D 53/94 B01J 21/00-38/74 B05B 15/00-15 / 12

Claims (3)

(57) [Claims] 1. An ammonia injection header is provided at an upstream duct of a catalyst layer of an exhaust gas denitration apparatus, an ammonia injection mother pipe is connected to the ammonia injection header, and an ammonia injection nozzle is arranged at the ammonia injection mother pipe. In the ammonia injection apparatus, a group of ammonia injection nozzles is formed in a duct in a horizontal direction or a vertical direction in the duct, and the ammonia injection header, one end of which is closed in the ammonia injection header, is arranged in a comb shape. An ammonia injection apparatus characterized in that a side of the tube not connected to the ammonia injection header is supported and fixed to another ammonia injection header. 2. The ammonia injection apparatus according to claim 1, wherein a plurality of the ammonia injection mother pipes are grouped into a group, and the support and the ammonia injection header are fixed in a grid shape. 3. The ammonia injection header according to claim 1, wherein a plurality of ammonia injection headers are provided in a vertical direction of the duct casing, and a side of the ammonia injection mother pipe that is not connected to the ammonia injection header is supported by the next ammonia injection header. An ammonia injection device characterized by being fixed.