Ammonia-air mixer for denitration system

Abstract

The utility model relates to the field of environmental protection, and discloses an ammonia-air mixer for a denitration system, which comprises a diffusion pipe and an ammonia gas input pipe positioned in the diffusion pipe, and the middle part of the diffusion pipe is a throat part; one end of the diffusion pipe is an inlet for inputting hot air; the other end of the diffusion pipe is an outlet communicated with an external ammonia-air mixed gas input pipe; an outlet of the ammonia gas input pipe is positioned at a position close to the throat part; and the throat part is provided with a plurality of guide plates with the same inclination direction. The mixer integrates the advantages of a traditional scheme, and the simple turbulent flow structure is arranged at the throat part, so that the ammonia-air mixing effect can be obviously improved.

Description

Technical Field

[0001] The utility model relates to the technical field of environmental protection equipment, in particular to an ammonia-air mixer for a denitration system. Background Art

[0002] CN118001954A discloses a high-performance ammonia-air mixer, comprising a mixer shell, one end of which is connected to an air supply channel and an ammonia supply channel, the other end of which is a mixed gas outlet, and a turbulent device is arranged on the inner wall of the mixer shell.

[0003] CN220496046U discloses an ammonia-air mixer for a urea hydrolysis and denitrification system, comprising: a mixing tube, which is composed of a conical tube 1, a pipeline 1, and a conical tube 2 in sequence and is arranged horizontally; a dilution air inlet pipe, which is composed of a flange 1 and a pipeline 3, and the pipeline 3 is connected to the conical tube 1 of the mixing tube; a mixed gas outlet pipe, which is composed of a pipeline 4 and a flange 2, and the pipeline 4 is connected to the conical tube 2 of the mixing tube; an ammonia injection pipe, which is composed of a flange 3, a pipeline 5, a bend pipe, a pipeline 6, and a head, and the ammonia injection pipe extends into the pipeline 3.

[0004] The above two are the more commonly used ammonia-air mixers in this field. The former performs mixing through an additional turbulent device; the latter performs mixing through a Venturi-like structure.

[0005] The former has a complex structure; the latter's spoiler effect needs to be further optimized. Utility Model Content

[0006] The utility model aims to solve the above problems and provides an ammonia-air mixer for a denitration system. The mixer concentrates the advantages of traditional solutions and sets a simple turbulent structure at the throat, which can significantly improve the ammonia-air mixing effect.

[0007] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0008] An ammonia-air mixer for a denitration system comprises a diffusion tube and an ammonia gas input pipe located in the diffusion tube, wherein the middle portion of the diffusion tube is a throat; one end of the diffusion tube is an inlet for inputting hot air; the other end of the diffusion tube is an outlet connected to an ammonia-air mixed gas input pipe; the outlet of the ammonia gas input pipe is located near the throat; and the throat is provided with a plurality of guide plates with the same inclination direction.

[0009] Compared with the prior art, the beneficial effects of the utility model are:

[0010] The utility model utilizes the high flow velocity of the throat of the venturi tube and realizes high-speed and thorough mixing of ammonia and air by adding a flow disturbance structure at the throat. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic structural diagram of Example 1;

[0012] Figure 2 is a schematic diagram of the coordination of the ammonia gas inlet pipe and the conical head of Example 1;

[0013] Figure 3 It is an axial cross-sectional view of the ammonia inlet pipe and the conical head of Example 1. DETAILED DESCRIPTION

[0014] 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 them. 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.

[0015] Example 1

[0016] refer to Figures 1 to 3 , an ammonia-air mixer for a denitration system, comprising a diffusion tube 1, an ammonia gas input pipe 2 located in the diffusion tube 1, the middle part of the diffusion tube 1 being a throat 3; one end of the diffusion tube 1 being an inlet for inputting hot air; the other end of the diffusion tube 1 being an outlet connected to an external ammonia-air mixed gas input pipe; the outlet of the ammonia gas input pipe 2 being located near the throat 3; the throat 3 being provided with a plurality of guide plates 4 having the same inclination direction. The number of guide plates 4 is preferably 8 to 16, and in this embodiment, 10 are selected, and the angle between the guide plates 4 and the axis of the diffusion tube is about 15°;

[0017] In practical applications, the diameter of the throat 3 is much smaller than the diameter of other positions of the diffuser 1. In this embodiment, the inner diameter of the throat 3 is approximately 0.4 to 0.5 times; in the optimal solution of this embodiment, its inner diameter is approximately 0.47 times the inner diameter of other positions. Ammonia is input from the ammonia input pipe 2, and hot air is input from one end of the diffuser 1 close to the ammonia input pipe 2. The mixing position is at the entrance of the throat 3. At this time, the two airflows are not fully mixed. They enter the throat 3 and begin to mix violently to achieve a better mixing effect. After leaving the throat 3, a vortex is formed to further achieve air-ammonia mixing.

[0018] Through the above optimization, the ammonia-air mixing effect can be improved, but the further improvement of the mixing effect should be further optimized for the input of ammonia. In the traditional scheme, a small hole is mostly opened at the end of the ammonia inlet pipe 2, and a low-pressure area is formed by the airflow flowing at the end of the ammonia inlet pipe 2. The ammonia is brought out and mixed by the flowing hot air. This mixing is suitable for ammonia with a low flow rate. However, when the amount of ammonia is large and the flow rate is fast, ammonia will be ejected from the ammonia inlet pipe 2 perpendicular to the flow direction of the hot air, which is not conducive to the subsequent efficient mixing based on the venturi tube. As a further optimization, the output end of the ammonia inlet pipe 2 is parallel to or coincides with the axis of the diffusion tube 1, and a conical head 5 is provided at the outlet position of the ammonia inlet pipe 2, and the tip of the conical head 5 extends to the inside of the ammonia inlet pipe 2. There is a gap 6 between the conical head 5 and the inner wall of the ammonia inlet pipe 2.

[0019] Taking the specifications of a safety input tube of this embodiment as an example, its inner diameter is 89mm, and the narrowest position of its gap 6 is 25mm; when the ammonia flow rate increases significantly, it can still output ammonia in time, and its flow rate increase is not too significant compared to outputting ammonia through a small hole. Ammonia will mix with hot air outside the conical head 5 and flow along the outer wall of the conical head 5. Then it will be ejected to all sides by the conical head 5; the ejected high-speed airflow will smoothly enter the throat 3 for secondary mixing. This gas mixing method is not only stable but also efficient.

[0020] More preferably, the conical head 5 and the ammonia gas inlet pipe are connected via a plurality of connecting plates 7; two adjacent connecting plates 7 form a gas passage, and the edge of the connecting plate 7 and the edge of the thick end of the conical body are located on the same plane.

[0021] The outer surface of the conical head 5 is further separated by the connecting plate 7, so that the ammonia can be divided into multiple portions. Each portion of ammonia does not interfere with each other, and is mixed and ejected with the hot air on the outer wall of the conical head 5 to form four jets flowing in the direction of the hot air and entering the throat.

[0022] Preferably, in the application process of this embodiment, the axial section of the conical head 5 is an equilateral triangle, and the diameter of the thick end of the conical head 5 is L1; the outer diameter of the ammonia inlet pipe 2 is L2; ​​the depth of the tip of the conical head 5 extending into the inside of the ammonia inlet pipe 2 is L3; the ratio of L1 to L2 is 170-175:105-110; the ratio of L3 to L1 is 30-35:170-175, and the inner diameter of the ammonia inlet pipe 2 is L4; the ratio of L4 to L2 is 85-90:105-110.

[0023] More specifically, L1 is 172mm, L2 is 109mm, L3 is 33.7mm, and L4 is 89mm.

[0024] Through this specific size structure, it achieves effective mixing of ammonia and hot air.

[0025] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements or modifications without departing from the principle of the present invention. These improvements or modifications should also be regarded as within the protection scope of the present invention.

Claims

1. An ammonia-air mixer for a denitration system, comprising a diffusion tube and an ammonia gas inlet pipe located in the diffusion tube, characterized in that: The middle part of the diffuser is the throat; one end of the diffuser is an inlet for inputting hot air; the other end of the diffuser is an outlet connected to an external ammonia-air mixed gas input pipe; the outlet of the ammonia input pipe is located near the throat; the throat is provided with a plurality of guide plates with the same inclination direction.

2. The ammonia-air mixer for a denitration system according to claim 1, characterized in that: The output end of the ammonia gas input pipe is parallel to or coincides with the axis of the diffusion pipe.

3. The ammonia-air mixer for a denitration system according to claim 2, characterized in that: A conical head is provided at the outlet of the ammonia gas inlet pipe, and the tip of the conical head extends into the interior of the ammonia gas inlet pipe; there is a gap between the conical head and the inner wall of the ammonia gas inlet pipe.

4. The ammonia-air mixer for a denitration system according to claim 3, characterized in that: The axial section of the conical head is an equilateral triangle.

5. The ammonia-air mixer for a denitration system according to claim 4, characterized in that: The diameter of the thick end of the conical head is L1; the outer diameter of the ammonia inlet pipe is L2; ​​the depth of the tip of the conical head extending into the inside of the ammonia inlet pipe is L3; the ratio of L1 to L2 is 170-175:105-110; the ratio of L3 to L1 is 30-35:170-175.

6. The ammonia-air mixer for a denitration system according to claim 5, characterized in that: The inner diameter of the ammonia gas inlet pipe is L4; the ratio of L4 to L2 is 85-90:105-110.

7. The ammonia-air mixer for a denitration system according to any one of claims 3 to 6, characterized in that: The conical head and the ammonia gas inlet pipe are connected via a plurality of connecting plates; two adjacent connecting plates form a gas channel.

8. The ammonia-air mixer for a denitration system according to claim 7, characterized in that: The edge of the connecting plate and the edge of the thick end of the cone are located on the same plane.

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