High efficiency static ammonia air mixer

Abstract

The utility model relates to flue gas denitration equipment technical field, concretely is a kind of efficient static ammonia air mixer, it includes: mixer, and the front end of mixer is equipped with premixing pipe, and premixing pipe is equipped with ammonia injection assembly.The utility model, by connecting pipe to the inclination of flue gas flow direction, reduce the direct impact of flue gas, improve the service life of ammonia injection assembly;Nozzle is designed into streamline, can reduce the resistance of nozzle to flue gas, and flue gas flows along nozzle surface, cooperate the nozzle of horizontal and oblique setting, can improve mixing efficiency;By separating the premixing pipe and mixer, cooperate the nozzle of split design, can be convenient nozzle maintenance and replacement, and can reduce replacement cost.

Description

Technical Field

[0001] This utility model relates to the technical field of flue gas denitrification equipment, specifically a high-efficiency static ammonia-air mixer. Background Technology

[0002] In SCR denitrification systems, commonly used reducing agents include liquid ammonia, ammonia water, and urea. In SCR denitrification systems using liquid ammonia as the reducing agent, the ammonia-air mixer is one of the most critical pieces of equipment, playing a vital role in uniformly mixing ammonia with flue gas. Its core function is to optimize the flow field distribution to ensure sufficient contact between ammonia and flue gas before entering the SCR reactor, thereby improving the efficiency of the denitrification reaction.

[0003] In the existing technology, static mixing generally includes three schemes. Among them, the Jintai mixer with built-in spiral blades has a better mixing effect and a higher pressure drop. In order to improve the mixing efficiency and reduce the pressure drop, an ammonia injection pipe is usually inserted vertically at the front of the mixer to mix the flue gas and ammonia gas in advance, thereby reducing the length of the mixer.

[0004] However, in actual operation, the ammonia injection pipe and nozzle occupy the internal space of the pipeline, generating additional resistance and affecting the mixing efficiency. Furthermore, the direct impact of flue gas on the ammonia injection pipe and nozzle will cause structural wear. Secondly, the ammonia gas or ammonia water sprayed from the nozzle mixes well with the central airflow, but the airflow at the edge mixes poorly, and the premixing effect cannot meet expectations. Utility Model Content

[0005] To overcome the above shortcomings, this utility model provides a high-efficiency static ammonia-air mixer.

[0006] The technical solution of this utility model is:

[0007] A high-efficiency static ammonia-air mixer, comprising:

[0008] A mixer, wherein a premixing pipe is provided at the front end of the mixer, and an ammonia injection assembly is provided inside the premixing pipe;

[0009] The mixer is used to mix flue gas and a reducing agent, wherein the reducing agent includes at least one of ammonia, ammonia water, or urea solution;

[0010] The premixing pipe includes a premixing shell, an ammonia inlet pipe is provided in the middle of the premixing shell, the ammonia injection assembly is connected to the ammonia inlet pipe, flue gas enters axially from one end of the premixing shell, and reducing agent enters from the ammonia inlet pipe;

[0011] The ammonia injection assembly includes a connecting pipe inclined in the direction of flue gas flow, and a streamlined nozzle is provided at the end of the connecting pipe and at the position of the premixing pipe axis. The nozzle end section is provided with several horizontal and inclined nozzles.

[0012] Preferably, the mixer includes a mixer housing, with a venturi tube at the front and mixing blades at the rear.

[0013] Preferably, the ammonia inlet pipe is inclined in the direction of flue gas flow, with an inclination angle between 30 and 60°.

[0014] Preferably, the connecting pipe is connected to the ammonia inlet pipe, and the inclination angle of the connecting pipe is the same as that of the ammonia inlet pipe.

[0015] Preferably, the nozzle includes a nozzle pipe, the top of which is connected to a connecting pipe, a hemispherical end cap is provided on the front end face of the nozzle pipe, and a conical tail plug is provided at the end of the nozzle pipe. The end cap, nozzle pipe and tail plug are combined to form a teardrop shape.

[0016] Preferably, the end cap and the nozzle are connected by fixing screws, and the screw holes on the end cap for fixing screw installation are sealed with plugs.

[0017] Preferably, the outer diameter of the end cap is no greater than 60% of the inner diameter of the premixed housing, and the total length of the nozzle is 2.5-3 times the outer diameter of the end cap.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] This invention reduces the direct impact of flue gas by tilting the connecting pipe in the direction of flue gas flow, thereby improving the service life of the ammonia injection assembly. The streamlined nozzle design reduces the resistance of the nozzle to the flue gas, and the flue gas flows along the nozzle surface. Combined with the horizontal and inclined nozzle settings, the mixing efficiency can be improved. By separating the premixing pipe and the mixer, and with the split-type nozzle design, the maintenance and replacement of the nozzle can be facilitated, and the replacement cost can be reduced. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0021] Figure 2 This is a cross-sectional view of the overall structure of this utility model;

[0022] Figure 3 This is a cross-sectional view of the premixed pipe structure in this utility model;

[0023] Figure 4 This is an exploded view of the ammonia injection component structure in this utility model.

[0024] The meanings of the labels in the diagram are as follows:

[0025] 1. Mixer; 11. Mixer housing; 12. First end face flange; 13. Mixing blade; 131. First mixing blade; 132. Second mixing blade; 133. Limiting ring; 14. Venturi tube;

[0026] 2. Premixed pipe; 21. Premixed shell; 22. Ammonia inlet pipe; 23. Second end flange;

[0027] 3. Ammonia injection assembly; 31. Connecting pipe; 32. Injection pipe; 33. End cap; 34. Tail plug; 35. First nozzle; 36. Second nozzle; 37. Fixing screw; 38. Plug cap. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] Example 1:

[0030] Please see Figure 1-4 The present invention will describe the above technical solution in detail through the following embodiments:

[0031] A high-efficiency static ammonia-air mixer, comprising:

[0032] Mixer 1, with a premixing pipe 2 at its front end, and an ammonia injection assembly 3 inside the premixing pipe 2. Mixer 1 is used for mixing flue gas and a reducing agent, the reducing agent including at least one of ammonia gas, ammonia water, or urea solution.

[0033] The mixer 1 includes a mixer housing 11, with a venturi tube 14 at the front and a mixing blade 13 at the rear.

[0034] The mixing blade 13 includes a plurality of first mixing blades 131 and second mixing blades 132. The first mixing blades 131 and second mixing blades 132 are spiral plates with opposite spiral directions and are arranged at intervals. The first mixing blades 131 and second mixing blades 132 are inserted into the mixer housing 11, and the ends of the mixing blades 13 are fixed to the end of the mixer housing 11 by limiting rings 133.

[0035] The Venturi tube 14 is used to increase the flow rate of the mixture of flue gas and ammonia.

[0036] The mixer housing 11 has first end face flanges 12 welded to both ends.

[0037] The premixing pipe 2 includes a premixing shell 21, with an ammonia inlet pipe 22 in the middle of the premixing shell 21. The ammonia injection assembly 3 is connected to the ammonia inlet pipe 22. Flue gas enters axially from one end of the premixing shell 21, and the reducing agent enters from the ammonia inlet pipe 22.

[0038] The premixed shell 21 has a second end face flange 23 welded to both ends, and the second end face flange 23 is fixedly connected to the first end face flange 12 by bolts.

[0039] In this embodiment, ammonia is used as the reducing agent.

[0040] The ammonia inlet pipe 22 is inclined in the direction of flue gas flow, with an inclination angle between 30 and 60°.

[0041] In this example, the inclination angle of the ammonia inlet pipe 22 is 45°.

[0042] The ammonia injection assembly 3 includes a connecting pipe 31 that is inclined in the direction of flue gas flow. A streamlined nozzle is provided at the end of the connecting pipe 31 and at the position of the axis of the premixing pipe 2. The nozzle end section is provided with several horizontal and inclined nozzles.

[0043] The connecting pipe 31 is connected to the ammonia inlet pipe 22, and the tilt angle of the connecting pipe 31 is the same as that of the ammonia inlet pipe 22.

[0044] The connecting pipe 31 is inclined at 45° towards the direction of flue gas flow, which can reduce the direct impact of flue gas. In addition, the connecting pipe 31 is at the same angle as the ammonia inlet pipe 22, which can reduce the pressure loss of ammonia gas.

[0045] The nozzle includes a nozzle pipe 32, the top of which is connected to a connecting pipe 31. A hemispherical end cap 33 is provided on the front end face of the nozzle pipe 32, and a conical tail plug 34 is provided at the end of the nozzle pipe 32. The end cap 33, the nozzle pipe 32 and the tail plug 34 are combined to form a teardrop shape.

[0046] The nozzle is teardrop-shaped, which minimizes its own resistance and reduces pressure loss of the flue gas. It also reduces the impact of the flue gas on the nozzle.

[0047] The end cap 33 and the nozzle 32 are connected by a fixing screw 37, and the screw hole on the end cap 33 for installing the fixing screw 37 is sealed with a plug 38.

[0048] The end cap 33 is designed to be detachable, allowing it to be replaced when it is heavily worn. Replacing the end cap 33 separately can reduce replacement and maintenance costs.

[0049] The plug 38 is made of the same material as the end cap 33. It is used to seal the screw hole, reduce the resistance caused by the screw hole, and protect the fixing screw 37, making it easy to disassemble later.

[0050] The outer diameter of the end cap 33 is no greater than 60% of the inner diameter of the premixed housing 21, and the total length of the nozzle is 2.5-3 times the outer diameter of the end cap 33.

[0051] In this embodiment, the total length of the nozzle is 2.5 times the outer diameter of the end cap 33. If the length is too short, it will cause airflow separation; if it is too long, it will increase airflow resistance.

[0052] The nozzle includes several first nozzles 35 and several second nozzles 36. The first nozzles 35 are located at the rear of the nozzle 32 and are arranged radially around the axis of the nozzle 32. The second nozzles 36 are arranged circumferentially around the axis of the tail plug 34 and horizontally penetrate the tail plug 34.

[0053] Working principle:

[0054] Flue gas enters from the end of the premixed shell 21, while ammonia gas enters from the ammonia inlet pipe 22.

[0055] Ammonia gas enters the connecting pipe 31 from the ammonia inlet pipe 22, then enters the nozzle 32, and is then ejected from the first nozzle 35 and the second nozzle 36.

[0056] The flue gas is premixed at the nozzle end with radially and horizontally injected ammonia gas. It then enters mixer 1.

[0057] After entering mixer 1, the flow is accelerated by venturi tube 14, and then encounters mixing blade 13. When the flow is blocked by the first mixing blade 131 and the second mixing blade 132, the flow direction changes and the flow is fully mixed.

[0058] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency static ammonia-air mixer, characterized in that, include: A mixer (1) is provided at the front end of the mixer (1) with a premixing pipe (2) and an ammonia injection assembly (3) is provided inside the premixing pipe (2); The mixer (1) is used for mixing flue gas and a reducing agent, wherein the reducing agent includes at least one of ammonia, ammonia water, or urea solution; The premixed pipe (2) includes a premixed shell (21), and an ammonia inlet pipe (22) is provided in the middle of the premixed shell (21). The ammonia injection assembly (3) is connected to the ammonia inlet pipe (22). Flue gas enters axially from one end of the premixed shell (21), and reducing agent enters from the ammonia inlet pipe (22). The ammonia injection assembly (3) includes a connecting pipe (31) inclined in the direction of flue gas flow. A streamlined nozzle is provided at the end of the connecting pipe (31) and at the position of the axis of the premixing pipe (2). The end section of the nozzle is provided with several horizontal and inclined nozzles.

2. The high-efficiency static ammonia-air mixer as described in claim 1, characterized in that: The mixer (1) includes a mixer housing (11), with a venturi tube (14) at the front and a mixing blade (13) at the rear.

3. The high-efficiency static ammonia-air mixer as described in claim 1, characterized in that: The ammonia inlet pipe (22) is inclined in the direction of flue gas flow, with an inclination angle between 30 and 60°.

4. The high-efficiency static ammonia-air mixer as described in claim 3, characterized in that: The connecting pipe (31) is connected to the ammonia inlet pipe (22), and the tilt angle of the connecting pipe (31) is the same as that of the ammonia inlet pipe (22).

5. The high-efficiency static ammonia-air mixer as described in claim 1, characterized in that: The nozzle includes a nozzle pipe (32), the top of which is connected to a connecting pipe (31). The nozzle pipe (32) has a hemispherical end cap (33) on its front end face and a conical tail plug (34) at its end. The end cap (33), nozzle pipe (32) and tail plug (34) are combined to form a teardrop shape.

6. The high-efficiency static ammonia-air mixer as described in claim 5, characterized in that: The end cap (33) and the nozzle (32) are connected by fixing screws (37), and the screw holes on the end cap (33) for fixing screws (37) are sealed with plugs (38).

7. The high-efficiency static ammonia-air mixer as described in claim 5, characterized in that: The outer diameter of the end cap (33) is no greater than 60% of the inner diameter of the premixed shell (21), and the total length of the nozzle is 2.5-3 times the outer diameter of the end cap (33).

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