High efficiency flue gas static mixer
By optimizing the mixing of ammonia and flue gas by setting paddle fins around the ammonia injection grid and baffles and guide plates in the mixer, the problem of uneven mixing in static mixers is solved, the denitrification efficiency and reducing agent utilization are improved, and ammonia slip is reduced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING GUONENG HUARUI ENVIRONMENTAL PROTECTION TECH DEV CO LTD
- Filing Date
- 2025-08-11
- Publication Date
- 2026-07-07
AI Technical Summary
In existing SCR denitrification systems, when the static mixer and ammonia injection grid are arranged vertically, the ammonia and flue gas do not mix evenly, leading to ammonia escape and affecting denitrification efficiency.
Design a high-efficiency flue gas static mixer, including an ammonia injection grid and a mixer. The ammonia injection grid is surrounded by paddle fins, and the mixer is equipped with a flow deflector and a flow guide plate. The mixing is enhanced by changing the flue gas flow pattern. The arrangement of the nozzles and the flow guide plate optimizes the mixing of ammonia and flue gas.
It improves the mixing uniformity of ammonia and flue gas, enhances denitrification efficiency, reduces ammonia slip rate, and improves the utilization rate of reducing agent.
Smart Images
Figure CN224462566U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of flue gas denitrification, and in particular to a high-efficiency flue gas static mixer. Background Technology
[0002] SCR (Selective Catalytic Reduction) denitrification, also known as selective catalytic reduction, is currently the most widely used flue gas denitrification technology internationally. This method primarily uses ammonia (NH3) as a reducing agent to selectively reduce NOx to N2. In an SCR denitrification system, ammonia, after being injected through an ammonia injection grid, needs to be mixed with the flue gas through a static mixer. However, in existing SCR denitrification system designs, the static mixer and the ammonia injection grid are arranged vertically, with a certain distance between the grid and the mixer. When ammonia is injected through the grid, the ammonia concentration at the nozzle is higher than the flue gas concentration. Combined with the difference in flow rates, this results in uneven mixing of ammonia and flue gas as they pass through the static mixer, causing ammonia escape and affecting denitrification efficiency. Utility Model Content
[0003] Based on the above problems, the purpose of this utility model is to provide a high-efficiency static flue gas mixer. The technical solution adopted by this utility model is as follows:
[0004] This utility model provides a high-efficiency flue gas static mixer, including an ammonia injection grid and a mixer. The ammonia injection grid includes a number of grid tubes arranged in parallel at intervals. A number of nozzles are arranged along the length of the upper part of the grid tubes, and a number of blades are arranged in a ring around the nozzles.
[0005] The mixer includes a first spoiler and a second spoiler arranged at intervals. The first spoiler includes a first baffle, and a plurality of first guide plates are arranged at intervals on both sides of the first baffle. Each first guide plate is inclined towards the upper right direction. The second spoiler includes a second baffle, and a plurality of second guide plates are arranged at intervals on both sides of the second baffle. Each second guide plate is inclined towards the upper left direction.
[0006] Preferably, a diverter plate is provided at the bottom of the grid tube along its length.
[0007] Preferably, the diverter plate is an angular plate.
[0008] Preferably, the upper part of the grid tube is provided with two rows of nozzles arranged in a V-shape.
[0009] Preferably, the first guide plates on both sides of the first partition correspond one-to-one with each other; the second guide plates on both sides of the second partition correspond one-to-one with each other.
[0010] Preferably, the first guide plate in the first spoiler and the second guide plate in the second spoiler are arranged in a staggered manner.
[0011] Preferably, each of the grid pipes is connected to the main pipe on the outer wall of the flue via a branch pipe.
[0012] Compared with the prior art, the beneficial technical effects of this utility model are as follows:
[0013] The fins arranged around the nozzle in this invention can change the incoming flue gas from a laminar flow state to a turbulent flow state, thereby enhancing and accelerating the mixing of flue gas and ammonia. At the same time, after the initial mixing, the flue gas and ammonia are further mixed in the mixer, which improves the denitrification efficiency and the utilization rate of the reducing agent, and reduces the ammonia escape rate. Attached Figure Description
[0014] The present invention will be further described below with reference to the accompanying drawings.
[0015] Figure 1 This is a schematic diagram of the structure of the high-efficiency static flue gas mixer of this utility model;
[0016] Figure 2 This is a schematic diagram of the structure of the ammonia injection grid of this utility model;
[0017] Figure 3 This is a schematic diagram of the mixer of this utility model.
[0018] Explanation of reference numerals in the attached drawings: 1. Ammonia injection grid; 101. Grid pipe; 102. Nozzle; 103. Blade fin; 104. Diverter plate; 105. Branch pipe; 2. Mixer; 201. First spoiler; 201-1. First baffle; 201-2. First guide plate; 202. Second spoiler; 202-1. Second baffle; 202-2. Second guide plate; 3. Main pipe. Detailed Implementation
[0019] To make the technical problems, technical solutions and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.
[0020] like Figures 1 to 3 As shown, this embodiment discloses a high-efficiency flue gas static mixer, including an ammonia injection grid 1 and a mixer 2. The mixer 2 and the ammonia injection grid 1 are fixed in the flue in an up-down arrangement in the SCR denitrification system.
[0021] The ammonia injection grid 1 includes several grid tubes 101 arranged side by side at intervals. Several nozzles 102 are arranged along the length of the upper part of the grid tubes 101. Several blades 103 are arranged in a ring around the nozzles 102. The axes of the blades 103 and the nozzles 102 have a certain angle. The function of the blades 103 is the same as that of the propeller blades, which turbulentize the airflow.
[0022] The mixer 2 includes a first spoiler 201 and a second spoiler 202 arranged at intervals. The first spoiler 201 includes a first baffle 201-1, and a plurality of first guide plates 201-2 arranged at intervals are provided on both sides of the first baffle 201-1. Each first guide plate 201-2 is inclined towards the upper right direction. The second spoiler 202 includes a second baffle 202-1, and a plurality of second guide plates 202-2 arranged at intervals are provided on both sides of the second baffle 202-1. Each second guide plate 202-2 is inclined towards the upper left direction.
[0023] The working principle of this invention is as follows: When flue gas flows through the ammonia injection grid 1, the blades 103 fixed around the nozzle 102 change the incoming flue gas from a laminar flow to a turbulent flow, enhancing and accelerating the mixing of flue gas and ammonia, improving denitrification efficiency and reducing agent utilization, and lowering ammonia escape rate. After preliminary mixing, the flue gas and ammonia undergo further mixing after passing through the mixer 2. The second guide plate 202-2 and the first guide plate 201-2 in the mixer 2 promote the mixing of flue gas and ammonia.
[0024] In this embodiment, two rows of nozzles 102 arranged in a V-shape are provided on the upper part of the grille pipe 1. The nozzles 102 are inclined to the side, and a flow divider 104 is provided along the length of the bottom of the grille pipe 101. The flow divider 104 is an angular plate. After the flue gas passes through the flow divider 104, it can flow towards the nozzles 102. At the same time, the flow divider 104 is in direct contact with the flue gas, which can effectively reduce the wear of the pipe when the flue gas passes through the grille pipe 1.
[0025] In this embodiment, the first guide plates 201-2 on both sides of the first partition 201-1 correspond one-to-one with each other; the second guide plates 202-2 on both sides of the second partition 202-1 correspond one-to-one with each other. The first guide plates 201-2 in the first spoiler 201 and the second guide plates 202-2 in the second spoiler 202 are arranged in a staggered manner.
[0026] In this embodiment, each grid pipe 101 is connected to the main pipe 3 on the outer wall of the flue through a branch pipe 105. A regulating valve and a flow measuring device are installed on the branch pipe 105. The regulating valve can adjust the flow of each grid pipe 101 to ensure the NH3 / NO in each area. x The molar ratio is uniformly distributed.
[0027] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.
Claims
1. A high-efficiency static flue gas mixer, comprising an ammonia injection grid (1) and a mixer (2), characterized in that: The ammonia injection grid (1) includes a number of grid tubes (101) arranged in parallel at intervals. A number of nozzles (102) are provided on the upper part of the grid tubes (101) along the length direction. A number of blades (103) are arranged in a ring around the nozzles (102). The mixer (2) includes a first spoiler (201) and a second spoiler (202) arranged at intervals. The first spoiler (201) includes a first partition (201-1), and a plurality of first guide plates (201-2) are arranged at intervals on both sides of the first partition (201-1). Each first guide plate (201-2) is inclined towards the upper right direction. The second spoiler (202) includes a second partition (202-1), and a plurality of second guide plates (202-2) are arranged at intervals on both sides of the second partition (202-1). Each second guide plate (202-2) is inclined towards the upper left direction.
2. The high-efficiency static flue gas mixer according to claim 1, characterized in that: A flow divider (104) is provided at the bottom of the grid tube (101) along its length.
3. The high-efficiency static flue gas mixer according to claim 2, characterized in that: The diverter plate (104) is an angular plate.
4. The high-efficiency static flue gas mixer according to claim 1, characterized in that: The upper part of the grid tube (101) is provided with two rows of nozzles (102) arranged in a V-shape.
5. The high-efficiency static flue gas mixer according to claim 1, characterized in that: The first guide plates (201-2) on both sides of the first partition (201-1) correspond one-to-one with each other; the second guide plates (202-2) on both sides of the second partition (202-1) correspond one-to-one with each other.
6. The high-efficiency static flue gas mixer according to claim 5, characterized in that: The first guide plate (201-2) in the first spoiler (201) and the second guide plate (202-2) in the second spoiler (202) are arranged in a staggered manner.
7. The high-efficiency static flue gas mixer according to claim 1, characterized in that: Each of the grid pipes (101) is connected to the main pipe (3) on the outer wall of the flue through a branch pipe (105).