Uniform mixing device in front of inlet of SCR (selective catalytic reduction) system

Abstract

The utility model discloses a uniform mixing device in front of an inlet of an SCR (Selective Catalytic Reduction) system and belongs to the technical field of flue gas denitration. Comprising a boiler, a first preheater is arranged on the upper portion of the boiler and connected with a material mixing barrel through a pipeline, the material mixing barrel is connected with an ammonia storage tank and comprises a barrel body, a stirring shaft, a plurality of stirring blades, a closed piston and a sliding net barrel, and the stirring shaft is rotationally arranged on the upper portion of an inner cavity of the barrel body; the stirring blades are uniformly distributed on the outer wall of the stirring shaft, the sliding net barrel is fixedly arranged in the middle of an inner cavity of the barrel body through the isolation plate and is communicated with the isolation plate, the closed piston is arranged in the sliding net barrel in a sliding manner, and a spring is arranged at the bottom of the closed piston. According to the mixing barrel disclosed by the utility model, oxygen can be fully fused into ammonia water under the action of stirring and air pressure, and the ammonia water fused with the oxygen is sprayed into the SCR reactor by utilizing the air pressure, so that the ammonia water fused with the oxygen is fully contacted with and reacts with N0x gas in flue gas, and the removal effect of the N0x gas is improved.

Description

Technical Field

[0001] The utility model relates to a pre-inlet homogenizing device for an SCR system, belonging to the technical field of flue gas denitration. Background Art

[0002] SCR (selective catalytic reduction) is a technology that has developed rapidly in recent years and has been widely used in Western Europe and Japan. Currently, ammonia catalytic reduction is the most widely used technology. It has no by-products, does not form secondary pollution, has a simple device structure, and has high removal efficiency (up to more than 90%), reliable operation, and is easy to maintain.

[0003] Selectivity means that under the action of a catalyst and in the presence of oxygen, NH3 preferentially undergoes a reduction removal reaction with NOx to generate nitrogen and water, rather than an oxidation reaction with oxygen in the flue gas.

[0004] In the prior art, the selective catalytic reduction technology is to directly introduce oxygen and ammonia into the SCR reactor, which results in that oxygen and ammonia cannot fully contact with the NOx gas in the flue gas, resulting in that the NOx gas cannot fully absorb and react, thereby affecting the removal effect of the NOx gas.

[0005] In summary, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the invention

[0006] The technical problem to be solved by the utility model is to provide a pre-inlet homogenizing device of an SCR system capable of fully contacting and reacting oxygen and ammonia with NOx gas in flue gas in view of the above shortcomings.

[0007] An optimization scheme, a pre-inlet mixing device of the SCR system, comprising a boiler, a first preheater is provided on the upper part of the boiler, a mixing cylinder is connected to the first preheater pipeline, and the mixing cylinder is connected to the ammonia storage tank;

[0008] The mixing cylinder comprises a cylinder body, a stirring shaft, stirring blades, a sealing piston and a sliding mesh cylinder.

[0009] The stirring shaft is rotatably arranged at the upper part of the inner cavity of the cylinder, and a plurality of stirring blades are provided, which are evenly distributed on the outer wall of the stirring shaft. The sliding mesh cylinder is fixedly arranged at the middle part of the inner cavity of the cylinder through an isolation plate, and the sliding mesh cylinder is connected to the isolation plate. The closing piston is slidably arranged in the sliding mesh cylinder, and a spring is provided at the bottom of the closing piston.

[0010] Furthermore, a top block is rotatably provided on the upper part of the sealing piston, and the top block can be arranged in close contact with the bottom of the stirring shaft.

[0011] Furthermore, a placement groove is provided at the bottom of the cylinder, and the end of the spring is fixedly arranged in the placement groove.

[0012] Furthermore, the stirring shaft is fixedly connected to a motor, and the motor is fixedly arranged on the upper part of the cylinder.

[0013] Furthermore, the first preheater is connected to the upper inner cavity and the lower inner cavity of the cylinder through a pipeline.

[0014] Furthermore, a feed pipe is provided at the lower part of the cylinder, and a solenoid valve is provided on the feed pipe.

[0015] Furthermore, the feed pipe is connected to an SCR reactor, and the upper part of the SCR reactor is connected to the smoke outlet pipe of the boiler;

[0016] A second preheater is provided at the lower part of the boiler, and the second preheater is connected to the bottom pipeline of the SCR reactor.

[0017] Furthermore, a gas outlet pipe is provided on one side of the SCR reactor, and a solenoid valve is provided on the gas outlet pipe.

[0018] Compared with the prior art, the utility model has the following advantages after adopting the above technical solution:

[0019] The mixing barrel of the utility model can fully blend oxygen into ammonia water through stirring and air pressure, and use air pressure to spray the ammonia water blended with oxygen into the SCR reactor, so that the ammonia water blended with oxygen can fully contact and react with NOx gas in the flue gas, thereby improving the NOx gas removal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of the pre-inlet homogenizing device of the SCR system of the utility model;

[0021] Figure 2 This is a schematic diagram of the cross-sectional structure of the mixing cylinder of the pre-inlet homogenizing device of the SCR system of the utility model;

[0022] In the figure, 1-boiler, 2-first preheater, 3-mixing cylinder, 4-ammonia storage tank, 5-cylinder, 6-stirring shaft, 7-stirring blade, 8-closing piston, 9-sliding mesh cylinder, 10-isolating plate, 11-spring, 12-top block, 13-placing groove, 14-motor, 15-feeding pipe, 16-solenoid valve, 17-SCR reactor, 18-second preheater, 19-exhaust pipe. DETAILED DESCRIPTION

[0023] In order to have a clearer understanding of the technical features, purposes and effects of the utility model, the specific implementation methods of the utility model are now described with reference to the accompanying drawings.

[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0025] In the description of the present invention, it should be understood that the terms "upper", "lower", "top surface", "bottom surface" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the positions or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations of the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0026] Examples, such as Figure 1 and 2 As shown, the utility model provides a pre-inlet homogenizing device for an SCR system, comprising a boiler 1, a first preheater 2 is provided on the upper part of the boiler 1, a mixing cylinder 3 is connected to the first preheater 2 through a pipeline, and the mixing cylinder 3 is connected to an ammonia storage tank 4;

[0027] The mixing cylinder 3 comprises a cylinder body 5, a stirring shaft 6, a stirring blade 7, a sealing piston 8 and a sliding mesh cylinder 9.

[0028] The stirring shaft 6 is rotatably arranged in the upper part of the inner cavity of the cylinder 5, and a plurality of stirring blades 7 are provided, and the stirring blades 7 are evenly distributed on the outer wall of the stirring shaft 6. The sliding mesh cylinder 9 is fixedly arranged in the middle part of the inner cavity of the cylinder 5 through the isolation plate 10, and the sliding mesh cylinder 9 is connected to the isolation plate 10. The closing piston 8 is slidably arranged in the sliding mesh cylinder 9, and a spring 11 is provided at the bottom of the closing piston 8.

[0029] The upper part of the closing piston 8 is rotatably provided with a top block 12 , and the top block 12 can be arranged in close contact with the bottom of the stirring shaft 6 .

[0030] The bottom of the cylinder 5 is provided with a placement groove 13 , and the end of the spring 11 is fixedly disposed in the placement groove 13 .

[0031] The stirring shaft 6 is fixedly connected to a motor 14 , and the motor 14 is fixedly arranged on the upper part of the cylinder 5 .

[0032] The first preheater 2 is connected to the upper inner cavity and the lower inner cavity of the cylinder 5 through a pipeline.

[0033] A feed pipe 15 is provided at the lower part of the cylinder 5 , and a solenoid valve 16 is provided on the feed pipe 15 .

[0034] The feed pipe 15 is connected to the SCR reactor 17, and the upper part of the SCR reactor 17 is connected to the smoke outlet pipe of the boiler 1;

[0035] A second preheater 18 is disposed at the lower portion of the boiler 1 , and the second preheater 18 is connected to a bottom pipeline of the SCR reactor 17 .

[0036] An outlet pipe 19 is provided on one side of the SCR reactor 17 , and an electromagnetic valve 16 is provided on the outlet pipe 19 .

[0037] The working principle of this utility model:

[0038] The ammonia storage tank 4 passes ammonia water into the cylinder 5, and the motor 14 drives the stirring shaft 6 and the stirring blade 7 to rotate. At the same time, the first preheater 2 passes heated oxygen and air, and the stirring shaft 6 and the stirring blade 7 are used to fully dissolve oxygen into the ammonia water. As the oxygen and air passing into the cylinder 5 increase, the pressure of the cylinder 5 increases. Under the influence of the gravity of the pressure ammonia water, the sealing piston 8 descends, and the ammonia water with sufficient dissolved oxygen enters the bottom of the cylinder 5 through the sliding mesh cylinder 9. The solenoid valve 16 of the feed pipe 15 is opened, and is sprayed into the SCR reactor 17 under the action of the air pressure at the bottom of the cylinder 5. At the same time, the second preheater 18 passes the heated air into the SCR reactor 17;

[0039] The flue gas from the boiler 1 is introduced into the SCR reactor 17 and fully reacts with the oxygen and ammonia water in the SCR reactor 17 . The solenoid valve 16 of the SCR reactor 17 is opened, and the flue gas after the reaction is discharged through the outlet pipe 19 .

[0040] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the article or device including the above elements.

[0041] This article uses specific examples to illustrate the principles and implementation methods of the utility model. The above examples are only used to help understand the core idea of ​​the utility model. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

Claims

1. The homogenous mixing device before the inlet of the SCR system is characterized by: It comprises a boiler (1), a first preheater (2) is provided on the upper part of the boiler (1), a mixing cylinder (3) is connected to the first preheater (2) via a pipeline, and the mixing cylinder (3) is connected to an ammonia storage tank (4); The mixing cylinder (3) comprises a cylinder body (5), a stirring shaft (6), stirring blades (7), a sealing piston (8) and a sliding mesh cylinder (9). A stirring shaft (6) is rotatably arranged at the upper part of the inner cavity of the cylinder (5); a plurality of stirring blades (7) are provided, and the stirring blades (7) are evenly distributed on the outer wall of the stirring shaft (6); a sliding net cylinder (9) is fixedly arranged at the middle part of the inner cavity of the cylinder (5) through an isolation plate (10); the sliding net cylinder (9) is connected to the isolation plate (10); a closing piston (8) is slidably arranged in the sliding net cylinder (9); and a spring (11) is provided at the bottom of the closing piston (8).

2. The SCR system pre-inlet homogenizing device according to claim 1, characterized in that: The upper part of the sealing piston (8) is rotatably provided with a top block (12), and the top block (12) can be arranged in close contact with the bottom of the stirring shaft (6).

3. The SCR system pre-inlet homogenizing device according to claim 1, characterized in that: The bottom of the cylinder (5) is provided with a placement groove (13), and the end of the spring (11) is fixedly arranged in the placement groove (13).

4. The SCR system pre-inlet homogenizing device according to claim 1, characterized in that: The stirring shaft (6) is fixedly connected to a motor (14), and the motor (14) is fixedly arranged on the upper part of the cylinder (5).

5. The SCR system pre-inlet homogenizing device according to claim 1, characterized in that: The first preheater (2) is connected to the upper inner cavity and the lower inner cavity of the cylinder (5) through a pipeline.

6. The SCR system pre-inlet homogenizing device according to claim 1, characterized in that: A feed pipe (15) is provided at the lower part of the cylinder (5), and the feed pipe (15) is provided with a solenoid valve (16).

7. The SCR system pre-inlet homogenizing device according to claim 6, characterized in that: The feed pipe (15) is connected to an SCR reactor (17), and the upper part of the SCR reactor (17) is connected to the smoke outlet pipe of the boiler (1); A second preheater (18) is provided at the bottom of the boiler (1), and the second preheater (18) is connected to the bottom pipeline of the SCR reactor (17).

8. The SCR system pre-inlet homogenizing device according to claim 7, characterized in that: An air outlet pipe (19) is provided on one side of the SCR reactor (17), and the air outlet pipe (19) is provided with a solenoid valve (16).

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