CN212262908U

CN212262908U - Built-in blowing device of flue

Info

Publication number: CN212262908U
Application number: CN202022124585.1U
Authority: CN
Inventors: 井小海; 杨明华; 杨源满
Original assignee: Capital Engineering & Research Inc Ltd; Ceri Environmental Protection Techonology Co Ltd
Current assignee: Capital Engineering & Research Inc Ltd; Ceri Environmental Protection Techonology Co Ltd
Priority date: 2020-09-24
Filing date: 2020-09-24
Publication date: 2021-01-01
Anticipated expiration: 2030-09-24

Abstract

The utility model relates to a built-in jetting device of flue, this built-in jetting device of flue is including being used for carrying the distribution valve and many defeated powder branch pipes in the flue shell with catalyst powder, the distribution valve is used for setting up on the flue shell, the entry of dusting of distribution valve is used for being linked together with the outside of flue shell, the export of dusting of distribution valve is used for with each defeated powder branch union coupling that is located the flue shell, all be provided with a plurality of nozzles on each defeated powder branch pipe, each nozzle all is used for the flow direction the same with flue shell interior flue gas to catalyst powder's injection direction. The utility model provides a catalyst powder who spouts into the flue mix inhomogeneous, the lower technical problem of desulfurization efficiency with the flue gas.

Description

Built-in blowing device of flue

Technical Field

The utility model relates to a flue gas purification technical field, it is further, relate to a flue gas desulfurization device, especially relate to a built-in jetting device of flue.

Background

The excessive emission of the flue gas is the main reason for causing the atmospheric environmental pollution, the environmental protection department strictly controls the emission of the flue gas, and the emission of the flue gas of the metallurgical enterprises must reach the standard. The main components of the flue gas are NOx and SO₂COx and moisture, etc., wherein SO₂Accounting for 38% of the mass of the flue gas, is a main factor causing air pollution and acid rain, and the flue gas must be subjected to desulfurization treatment to meet the emission requirement.

At present, the main methods for desulfurizing flue gas at home and abroad can be roughly divided into a dry method, a semi-dry method and a wet method.

Among them, dry flue gas desulfurization is popular because it has the characteristics of simple equipment, small floor space, low investment and operation cost, convenient operation, low energy consumption, convenient disposal of products, no sewage treatment system, etc. compared with wet systems. The dry desulfurizing process includes spraying the fine catalyst powder into flue with compressed air to mix with flue gas and to contact with SO in flue gas₂The reaction produces sulfate particles, the sulfate particles and fly ash are collected by a dust remover or discharged by a chimney, thereby achieving the purpose of flue gas desulfurization, and the by-products recovered by the dust remover can be reused as chemical products. The dry desulfurization method has the advantages that no waste water and waste acid are discharged during treatment, and secondary pollution is reduced; the disadvantages are low desulfurization efficiency and large equipment.

The devices for dry flue gas desulfurization have various structures, for example: a plurality of spray heads are arranged in the vertical direction of the flue in a telescopic way, and each spray head is provided withWhen catalyst is needed to be sprayed into the flue, the spray nozzle is controlled to extend into the flue, the external powder bin is connected with the spray nozzle through a spray pipe, the spray nozzle can rotate in the axial direction of the spray nozzle in the flue, and therefore powder can be sprayed through the spray holes (the powder can be sprayed with SO)₂Catalyst powder for producing sulfate by reaction) is blown into the flue; when the catalyst is not required to be sprayed into the flue, the spray nozzle is controlled to withdraw from the flue, but the powder spraying is sprayed into the flue from one point of the inner wall of the flue in a divergent manner, so that the powder spraying is easy to hit the inner wall of the flue, and the accumulation of the powder spraying is easy to cause; in addition, if the device is in a large amount of dust in the environment, the situation that the dust blocks the action of the spray head easily occurs, and the normal operation of the work cannot be guaranteed. Another example is: the powder spraying connecting pipe is directly inserted into the flue, and the compressed air doped with the powder spraying is pumped into the flue, so that the mixing of the flue gas and the powder spraying is realized, but the device cannot mix the flue gas and the powder spraying very unevenly, has low desulfurization efficiency and poor desulfurization effect.

Aiming at the problems of uneven mixing of the catalyst powder sprayed into the flue and the flue gas and lower desulfurization efficiency in the related technology, no effective solution is provided at present.

Therefore, the inventor provides the flue built-in type injection device by virtue of experience and practice of related industries for many years so as to overcome the defects in the prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a built-in jetting device of flue can improve the degree of consistency that the catalyst sprays in the flue greatly, guarantees catalyst and flue gas fully contact in the flue for SO in the flue gas₂The reaction is sufficient, the efficiency of the dry desulfurization of the flue gas is improved, and the pollution of the flue gas to the environment is avoided.

Another object of the utility model is to provide a built-in jetting device of flue, simple structure, simple to operate only need on the flue trompil connect can accomplish the installation to the jetting device, in the course of the work, this jetting device can make the catalyst dispersion of injection even through the flue gas that flows in the flue, need not to increase extra power, and is energy-concerving and environment-protective, is suitable for and uses widely.

The purpose of the utility model can be realized by adopting the following technical scheme:

the utility model provides a built-in jetting device of flue, the built-in jetting device of flue is including being used for carrying the distributing valve and many defeated powder branch pipes in the flue shell with catalyst powder, wherein:

the distribution valve is arranged on the flue shell, a powder spraying inlet of the distribution valve is communicated with the outside of the flue shell, a powder spraying outlet of the distribution valve is connected with each powder conveying branch pipe located in the flue shell, a plurality of nozzles are arranged on each powder conveying branch pipe, and the spraying direction of each nozzle to the catalyst powder is the same as the flow direction of flue gas in the flue shell.

In a preferred embodiment of the present invention, each of the powder conveying branch pipes is arranged in a divergent manner.

In a preferred embodiment of the present invention, each of the powder conveying branch pipes is located on the same cross section in the flue casing, so that the catalyst powder ejected from each of the nozzles can be uniformly distributed on the entire cross section in the flue casing.

In a preferred embodiment of the present invention, the powder injection inlet of the distribution valve is adapted to pass through the flue housing and extend to the outside of the flue housing.

The utility model discloses a in a preferred embodiment, be located every on the defeated powder branch pipe the nozzle includes a plurality of first nozzles and a second nozzle, defeated powder branch pipe one end with the distributing valve the exit linkage of dusting, the second nozzle set up in defeated powder branch pipe's the other end, each first nozzle is followed defeated powder branch pipe's extending direction is in succession and the interval is arranged.

In a preferred embodiment of the present invention, the distance between two adjacent first nozzles and the distance between the second nozzle and the adjacent first nozzle are equal.

In a preferred embodiment of the present invention, the air inlet end of the second nozzle is an arc structure which gradually inclines toward the flowing direction of the flue gas in the flue casing.

In a preferred embodiment of the present invention, the inner diameter of the second nozzle is gradually reduced from the air inlet end of the second nozzle to the air outlet end of the second nozzle.

In a preferred embodiment of the present invention, the distribution valve is disposed at the top of the flue housing, each of the powder conveying branch pipes is disposed along a vertical direction, and each of the powder conveying branch pipes is adjacent to each other.

The utility model discloses a in a preferred embodiment, the distributing valve includes distributing valve main part and many root branch pipes, the distributing valve main part is the tubular structure who sets up along vertical direction, the top of distributing valve main part is the inlet that dusts of distributing valve, the bottom of distributing valve main part and each the one end of root branch pipe is connected, each the root branch pipe is from top to bottom gradually to keeping away from distributing valve main part direction is the form of dispersing and arranges, each the other end of root branch pipe is respectively each the export of dusting of distributing valve.

The utility model discloses an in a preferred embodiment, each be provided with the fixed beam between the defeated powder branch pipe, the both ends of fixed beam be used for with the interior wall connection of flue shell, the middle part of fixed beam respectively with each defeated powder branch pipe's outer wall connection.

The utility model discloses an in a preferred embodiment, the quantity of fixed roof beam is many, each the fixed roof beam all sets up along the horizontal direction, and each the interval is arranged from top to bottom between the fixed roof beam.

In a preferred embodiment of the present invention, the inner cross-sectional area of the distribution valve is greater than the sum of the inner cross-sectional areas of the powder delivery branch pipes, and the sum of the inner cross-sectional areas of the powder delivery branch pipes is greater than the sum of the inner cross-sectional areas of the nozzles.

In a preferred embodiment of the present invention, a gap is left between each of the nozzles and the inner wall of the flue housing.

In a preferred embodiment of the present invention, the powder injection inlet of the distribution valve is connected to a compressed air line, and the compressed air line is connected to a bypass for injecting the catalyst powder.

From above, the utility model discloses a built-in jetting device of flue's characteristics and advantage are: the distribution valve is arranged on the flue shell, the powder spraying inlet of the distribution valve is connected with the compressed air pipeline positioned outside the flue shell, the powder spraying outlets of the distribution valve are connected with the powder conveying branch pipes positioned inside the flue shell, the distribution valve is simple in structure and convenient to install, the distribution valve and the powder conveying branch pipes can be installed only by connecting the powder spraying outlets with the powder conveying branch pipes positioned inside the flue shell through holes in the flue shell, the distribution valve and the powder conveying branch pipes are installed and used on the use site, and the distribution valve is high in practicability. In addition, each powder conveying branch pipe is provided with a plurality of nozzles, the spraying direction of each nozzle to the catalyst powder is the same as the flow direction of the flue gas in the flue shell, the catalyst powder sprayed by each nozzle can smoothly enter the inside of the flue shell and flow along with the flue gas, the condition that the catalyst powder impacts the inner wall of the flue shell and is accumulated on the inner wall is avoided, the diffusion efficiency of the catalyst powder is improved, the catalyst powder can be uniformly dispersed in the flue shell and fully contacted with the flue gas, and SO in the flue gas is enabled to be fully contacted with the flue gas₂When the gas can fully react with the catalyst powder, the efficiency of the dry desulfurization of the flue gas is improved, the good desulfurization effect is ensured, and SO in the flue gas is avoided₂When the gas pollutes the environment, in the flue gas purification process, the catalyst powder sprayed by the nozzles can be uniformly dispersed through the flue gas flowing in the flue shell, additional power does not need to be added, and the flue gas purification device is energy-saving, environment-friendly and suitable for popularization and use.

Drawings

The drawings are only intended to illustrate and explain the present invention and do not limit the scope of the invention. Wherein:

FIG. 1: is a three-dimensional view of the built-in blowing device of the flue in the flue.

FIG. 2: do the utility model discloses the built-in jetting device of flue elevation view in the flue.

FIG. 3: do the utility model discloses the built-in jetting device of flue is provided with the elevation view of fixed beam in the flue.

FIG. 4: do the utility model discloses the built-in jetting device's of flue structural schematic diagram.

FIG. 5: is a local sectional view of a distribution valve in the built-in flue blowing device of the utility model.

FIG. 6: is a local sectional view of a branch pipe in the built-in type flue blowing device of the utility model.

The utility model provides an reference numeral does:

1. a dispensing valve; 101. A dispensing valve body;

102. a root branch pipe; 2. A powder conveying branch pipe;

3. a nozzle; 301. A first nozzle;

302. a second nozzle; 3021. An air inlet end;

3022. an air outlet end; 4. A fixed beam;

10. a flue housing.

Detailed Description

In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in fig. 1 to 6, the utility model provides a built-in jetting device in flue, this built-in jetting device in flue include distributing valve 1 and many defeated powder branch pipes 2, and distributing valve 1 cooperatees with each defeated powder branch pipe 2 and is used for carrying catalyst powder to flue shell 10 in, wherein: the distribution valve 1 is arranged on the flue shell 10, a powder spraying inlet of the distribution valve 1 is communicated with the outside of the flue shell 10, a compressed air pipeline is arranged outside the flue shell 10, a bypass is connected to the compressed air pipeline, catalyst powder can be injected into the compressed air pipeline through the bypass, and the catalyst powder is fully mixed with compressed air in the compressed air pipeline and then enters the distribution valve 1. The powder spraying outlet of the distribution valve 1 is connected with each powder conveying branch pipe 2 positioned in the flue shell 10, a plurality of nozzles 3 are arranged on each powder conveying branch pipe 2, and the spraying direction of each nozzle 3 to the catalyst powder is the same as the flow direction of the flue gas in the flue shell 10.

The utility model discloses in set up distributing valve 1 on flue shell 10, distributing valve 1's the entry of dusting and the outside compressed air pipe connection that is located flue shell 10, distributing valve 1's a plurality of exports of dusting and many defeated powder branch pipes 2 that are located flue shell 10's inside are connected, simple structure, simple to operate, only need trompil connection on flue shell 10 can accomplish the installation to distributing valve 1 and each defeated powder branch pipe 2, use the on-the-spot installation and use, therefore, the clothes hanger is strong in practicability. In addition, each powder conveying branch pipe 2 is provided with a plurality of nozzles 3, the spraying direction of each nozzle 3 to the catalyst powder is the same as the flow direction of the flue gas in the flue shell 10, the catalyst powder sprayed by each nozzle 3 can smoothly enter the inside of the flue shell 10 and flow together with the flue gas, the condition that the catalyst powder impacts the inner wall of the flue shell 10 and is accumulated on the inner wall is avoided, the diffusion efficiency of the catalyst powder is improved, the catalyst powder can be uniformly dispersed in the flue shell 10 and fully contacted with the flue gas, SO that SO in the flue gas₂When the gas can fully react with the catalyst powder, the efficiency of the dry desulfurization of the flue gas is improved, the good desulfurization effect is ensured, and SO in the flue gas is avoided₂When the gas pollutes the environment, in the flue gas purification process, the catalyst powder sprayed by each nozzle can be uniformly dispersed through the flue gas flowing in the flue shell 10, additional power does not need to be added, and the method is energy-saving, environment-friendly and suitable for popularization and use.

Specifically, as shown in fig. 1 to 4, each nozzle 3 is disposed toward the same direction, and the direction of each nozzle 3 is the same as the flow direction of the flue gas in the flue housing 10, so that the injection direction from each nozzle 3 is the same as the flow direction of the flue gas in the flue housing 10, and therefore the catalyst powder ejected through each nozzle 3 can smoothly enter the inside of the flue housing 10 and flow together with the flue gas, the diffusion efficiency of the catalyst powder is improved, the catalyst powder can be uniformly dispersed in the flue housing 10 and fully contact with the flue gas, and further the reaction efficiency is improved. Therefore, during operation, it is necessary to make the flue gas flow inside the flue housing 10, and control each nozzle 3 to spray the catalyst powder into the flue housing 10.

Further, the catalyst powder used may be, but is not limited to, baking soda (i.e., sodium bicarbonate) powder.

In an alternative embodiment of the present invention, as shown in fig. 1 to 3, the powder conveying branch pipes 2 are arranged in a divergent manner. SO that the catalyst powder sprayed by the nozzles 3 on the powder conveying branch pipes 2 can be uniformly distributed in the flue shell 10 as much as possible, thereby increasing the contact area of the catalyst powder and the flue gas and increasing the SO in the flue gas₂And the gas and the catalyst powder react fully to ensure good desulfurization effect.

Further, as shown in fig. 1 to 3, each powder conveying branch pipe 2 is located on the same cross section in the flue housing 10, SO that the catalyst powder sprayed by each nozzle 3 can be uniformly distributed on the whole cross section in the flue housing 10, the uniformity of the catalyst powder sprayed in the flue housing 10 can be greatly improved, the catalyst powder and the flue gas can be fully contacted in the flue housing 10, and the SO in the flue gas₂Etc. can sufficiently react with the catalyst powder.

Further, as shown in fig. 1 to 3, the powder injection inlet of the distribution valve 1 passes through the flue housing 10 and protrudes to the outside of the flue housing 10, thereby facilitating connection of the powder injection inlet of the distribution valve 1 with the compressed air line.

Furthermore, the internal cross-sectional area of the distribution valve 1 is larger than the sum of the internal cross-sectional areas of the powder conveying branch pipes 2, and the sum of the internal cross-sectional areas of the powder conveying branch pipes 2 is larger than the sum of the internal cross-sectional areas of the nozzles 3, so that a certain pressure difference exists between the distribution valve 1 and each powder conveying branch pipe 2 and between each powder conveying branch pipe 2 and each nozzle 3, the flowing speed of the catalyst powder is ensured to be gradually increased in the process from the distribution valve 1 to each powder conveying branch pipe 2 and from each powder conveying branch pipe 2 to each nozzle 3, the catalyst powder is prevented from being retained in the flowing process in the whole spraying and blowing device, and the smooth spraying of the catalyst powder is ensured.

Furthermore, a gap is left between each nozzle 3 and the inner wall of the flue shell 10, so that the catalyst powder is prevented from being directly sprayed on the inner wall of the flue shell 10.

In an optional embodiment of the present invention, as shown in fig. 1 to 4 and 6, the nozzle 3 located on each powder conveying branch pipe 2 includes a plurality of first nozzles 301 and a second nozzle 302, one end of the powder conveying branch pipe 2 is connected to the powder spraying outlet of the distribution valve 1, the second nozzle 302 is disposed at the other end of the powder conveying branch pipe 2, each first nozzle 301 is continuously and intermittently arranged along the extending direction of the powder conveying branch pipe 2, so as to ensure that each nozzle 3 can be uniformly arranged on the same cross section in the flue shell 10 as much as possible, thereby enabling the catalyst powder sprayed by each nozzle 3 to be uniformly distributed inside the flue shell 10.

Further, as shown in fig. 1 to 4, the distance between each two adjacent first nozzles 301 and the distance between the second nozzle 302 and its adjacent first nozzle 301 are equal, so as to improve the uniform distribution effect of the catalyst powder.

In an optional embodiment of the present invention, as shown in fig. 6, the air inlet port 3021 of the second nozzle 302 to the air outlet port 3022 of the second nozzle 302 are arc structures gradually inclined toward the flowing direction of the flue gas in the flue housing 10, and the air inlet port 3021 to the air outlet port 3022 are smooth transitions inside the second nozzle 302, so as to ensure that the catalyst powder can be smoothly injected into the flue housing 10, and avoid blocking the air outlet port 3022 of the second nozzle 302.

Further, as shown in fig. 6, the turning angle of the arc-shaped structure formed by the gas inlet end 3021 of the second nozzle 302 to the gas outlet end 3022 of the second nozzle 302 may be, but is not limited to, 90 °, and it is sufficient to ensure that the direction of the catalyst powder sprayed by the second nozzle 302 is the same as the flow direction of the flue gas in the flue housing 10.

Further, as shown in fig. 6, the inner diameter of the second nozzle 302 gradually decreases from the gas inlet end 3021 of the second nozzle 302 to the gas outlet end 3022 of the second nozzle, so that a pressure difference is formed between the gas inlet end 3021 of the second nozzle 302 and the gas outlet end 3022 of the second nozzle, and the catalyst powder is gradually accelerated during the process of passing through the second nozzle 302, thereby further preventing the catalyst powder from being retained in the second nozzle 302 and blocking the second nozzle 302.

In an optional embodiment of the present invention, as shown in fig. 1 to 3, the distribution valve 1 is disposed on the top of the flue housing 10, each powder conveying branch pipe 2 is disposed along the vertical direction, and the distance between each two adjacent powder conveying branch pipes 2 is equal, so as to ensure that each powder conveying branch pipe 2 is uniformly distributed inside the flue housing 10 as much as possible.

Specifically, as shown in fig. 1 to 6, the distribution valve 1 includes a distribution valve main body 101 and a plurality of root branch pipes 102, the distribution valve main body 101 is a cylindrical structure arranged along a vertical direction, a powder injection inlet of the distribution valve 1 is formed at the top end of the distribution valve main body 101, the bottom end of the distribution valve main body 101 is connected with one end of each root branch pipe 102, each root branch pipe 102 is arranged in a divergent manner from top to bottom in a direction away from the distribution valve main body 101, and the other end of each root branch pipe 102 is respectively used as each powder injection outlet of the distribution valve 1.

In an optional embodiment of the utility model, as shown in fig. 3, be provided with fixed beam 4 between each defeated powder branch pipe 2, the both ends of fixed beam 4 and the interior wall connection of flue shell 10, the middle part of fixed beam 4 respectively with each defeated powder branch pipe 2's outer wall connection, through the setting of fixed beam 4, improve the stability between each defeated powder branch pipe 2 and the stability between defeated powder branch pipe 2 and flue shell 10.

Further, as shown in fig. 3, the number of the fixed beams 4 is multiple, each fixed beam 4 is arranged along the horizontal direction, and the fixed beams 4 are arranged at intervals from top to bottom.

A specific embodiment of the present invention is shown in fig. 1 to 3: the high-temperature flue gas generated by steel plant sintering and converter steelmaking contains a large amount of SO₂Gas and catalyst powder enter a distribution valve 1 arranged at the top of a flue shell 10 along with compressed air, then flow by the distribution valve 1 and then enter each powder conveying branch pipe 2, and then are sprayed into the flue shell 10 from a nozzle 3 arranged on each powder conveying branch pipe 2, and the catalyst powder and SO in flue gas₂The sulfate particles are generated by reaction and are collected by the dust remover together with fly ash in the flue gas, thereby having the effect of purifying the flue gas and having the total desulfurization efficiency of more than 95 percent. The smaller the catalyst powder is, the more sufficient the catalyst powder is contacted with the flue gas, and the higher the desulfurization efficiency isIn this example, the catalyst powder is pulverized to about 20 μm, and the desulfurization effect is most excellent. In the embodiment, the sum of the internal cross-sectional areas of the powder conveying branch pipes 2 is 97 percent of the internal cross-sectional area of the distribution valve 1, and the sum of the internal cross-sectional areas of the nozzles 3 on each powder conveying branch pipe 2 is 90 to 98 percent of the internal cross-sectional area of the powder conveying branch pipe 2, so that the catalyst powder is ensured not to be detained and blocked in the blowing device.

In the embodiment, four powder conveying branch pipes 2 are arranged in the flue shell 10 along the vertical direction, the four powder conveying branch pipes 2 are arranged in bilateral symmetry, and the distance between two adjacent powder conveying branch pipes 2 is about 1/4 of the inner diameter of the flue shell 10; in this embodiment, the distance between each nozzle 3 and the inner wall of the flue housing 10 is greater than 500mm, ensuring that the catalyst powder is not directly sprayed onto the inner wall of the flue housing 10.

The utility model discloses a built-in jetting device of flue's characteristics and advantage are:

the built-in blowing device for the flue is simple in structure and convenient to install, the distribution valve 1 and each powder conveying branch pipe 2 can be installed only by connecting the openings on the flue shell 10, and the built-in blowing device is installed and used on the using site, high in practicability, energy-saving, environment-friendly and suitable for popularization and use.

Secondly, the catalyst powder jetted by each nozzle 3 in the flue built-in type jetting device can be uniformly distributed on the whole cross section in the flue shell 10, the uniformity of the catalyst powder jetted in the flue shell 10 can be greatly improved, the catalyst powder and the flue gas can be ensured to be fully contacted in the flue shell 10, and SO in the flue gas can be ensured₂When the gas can fully react with the catalyst powder, the efficiency of the dry desulfurization of the flue gas is improved, the good desulfurization effect is ensured, and SO in the flue gas is avoided₂And the gas causes pollution to the environment.

The orientation of each nozzle 3 in the flue built-in type spraying and blowing device is the same as the flowing direction of the flue gas in the flue shell 10, so that the spraying direction of each nozzle 3 is the same as the flowing direction of the flue gas in the flue shell 10, the diffusion efficiency of the catalyst powder is improved, the catalyst powder can be uniformly dispersed in the flue shell 10 and fully contacted with the flue gas, and the reaction efficiency can be improved without adding extra power.

The above description is only exemplary of the present invention, and is not intended to limit the scope of the present invention. Any person skilled in the art should also realize that such equivalent changes and modifications can be made without departing from the spirit and principles of the present invention.

Claims

1. A blowing device with built-in flue is characterized by comprising a distribution valve (1) and a plurality of powder conveying branch pipes (2) for conveying catalyst powder into a flue shell (10), wherein:

the distribution valve (1) is arranged on the flue shell (10), a powder spraying inlet of the distribution valve (1) is communicated with the outside of the flue shell (10), a powder spraying outlet of the distribution valve (1) is connected with each powder conveying branch pipe (2) in the flue shell (10), a plurality of nozzles (3) are arranged on each powder conveying branch pipe (2), and the spraying direction of the catalyst powder by each nozzle (3) is the same as the flow direction of flue gas in the flue shell (10).

2. The in-flue blowing device according to claim 1, characterized in that each of the powder conveying branch pipes (2) is arranged divergently.

3. The in-flue blowing device according to claim 2, characterized in that each of said powder conveying branch pipes (2) is located on the same cross section in said flue housing (10) so that said catalyst powder ejected from each of said nozzles (3) is distributed uniformly over the entire cross section in said flue housing (10).

4. The in-flue blowing device according to claim 1, characterized in that the powder injection inlet of the distribution valve (1) is intended to pass through the flue housing (10) and project outside the flue housing (10).

5. The in-flue blowing device according to claim 1, characterized in that said nozzles (3) located in each of said powder delivery branch pipes (2) comprise a plurality of first nozzles (301) and a second nozzle (302), one end of said powder delivery branch pipe (2) is connected to said powder spraying outlet of said distribution valve (1), said second nozzle (302) is disposed at the other end of said powder delivery branch pipe (2), and said first nozzles (301) are arranged continuously and at intervals along the extension direction of said powder delivery branch pipe (2).

6. The in-flue blowing device of claim 5, wherein the distance between each two adjacent first nozzles (301) and the distance between the second nozzle (302) and the adjacent first nozzle (301) are equal.

7. The in-flue blowing device as claimed in claim 5, characterized in that the air inlet end (3021) of the second nozzle (302) to the air outlet end (3022) of the second nozzle (302) are of an arc structure gradually inclined toward the flow direction of the flue gas in the flue housing (10).

8. The in-flue blowing device of claim 7, wherein the inner diameter of the second nozzle (302) is gradually reduced from the air inlet end (3021) of the second nozzle (302) to the air outlet end (3022) of the second nozzle (302).

9. The in-flue blowing device according to claim 1, characterized in that the distribution valve (1) is arranged on the top of the flue housing (10), each powder conveying branch pipe (2) is arranged along the vertical direction, and the distance between each two adjacent powder conveying branch pipes (2) is equal.

10. The in-flue blowing device according to claim 9, characterized in that the distribution valve (1) comprises a distribution valve main body (101) and a plurality of root branch pipes (102), the distribution valve main body (101) is a cylindrical structure arranged along a vertical direction, the top end of the distribution valve main body (101) is the powder injection inlet of the distribution valve (1), the bottom end of the distribution valve main body (101) is connected with one end of each root branch pipe (102), each root branch pipe (102) is arranged in a manner of gradually diverging from the distribution valve main body (101) from top to bottom, and the other end of each root branch pipe (102) is respectively the powder injection outlet of the distribution valve (1).

11. The device for internally blowing in the flue as claimed in claim 1, wherein a fixed beam (4) is arranged between each powder conveying branch pipe (2), two ends of the fixed beam (4) are used for being connected with the inner wall of the flue shell (10), and the middle part of the fixed beam (4) is respectively connected with the outer wall of each powder conveying branch pipe (2).

12. The in-flue blowing device of claim 11, wherein the number of the fixed beams (4) is multiple, each fixed beam (4) is arranged along the horizontal direction, and the fixed beams (4) are arranged at intervals from top to bottom.

13. The in-flue blowing device according to claim 1, characterized in that the internal cross-sectional area of the distribution valve (1) is larger than the sum of the internal cross-sectional areas of the powder conveying branch pipes (2), and the sum of the internal cross-sectional areas of the powder conveying branch pipes (2) is larger than the sum of the internal cross-sectional areas of the nozzles (3).

14. The in-flue blowing device according to claim 1, characterized in that a gap is left between each nozzle (3) and the inner wall of the flue housing (10).

15. The in-flue blowing device according to claim 1, characterized in that the powder injection inlet of the distribution valve (1) is adapted to be connected to a compressed air line to which a bypass for injecting the catalyst powder is connected.