Flow-equalizing anti-blocking nozzle structure
By designing a flow-to-blocking anti-blocking nozzle structure, using components such as a variable diameter tube and cone, the problems of uneven mixing of ammonia and flue gas and easy blockage of nozzles are solved, and more efficient NOX emissions and nozzle protection are achieved.
Patent Information
- Application Number
- CN202421544758.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-02
- Publication Date
- 2025-05-16
- Estimated Expiration
- 2034-07-02
AI Technical Summary
The uneven mixing of ammonia and flue gas in the existing SCR system makes it difficult to meet the NOX emission standards, and the nozzle is prone to clogging, which increases ammonia consumption and catalyst ash accumulation.
A flow-equilibrium-proof nozzle structure is designed, including a variable diameter tube, a straight tube, a cone and a circular plate. The variable diameter tube forms a flaring to reduce the nozzle flow rate. The cone and a circular plate structure are used to spray ammonia at the nozzle at 360°, increasing the contact area with the flue gas.
A more uniform mixing of ammonia and flue gas is achieved, heat transfer efficiency is improved, and the wear and blockage of nozzles is reduced, and dust is prevented from falling into the nozzle during the furnace shutdown.
Smart Images
Figure CN222872436U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of SCR ammonia nozzles, and in particular to a uniform flow anti-blocking nozzle structure. Background Art
[0002] As domestic power environmental protection emission standards become increasingly stringent, the state requires coal-fired units to discharge NO X The emission concentration shall not exceed 50mg / Nm 3 Many power plants have defects in the design of the SCR inlet flue gas diversion and mixing device due to rapid changes in boiler load, which leads to uneven mixing of ammonia and flue gas. At the same time, the primary air used to dilute ammonia contains a lot of ash, and the nozzle is seriously blocked. In order to ensure NO X In order to meet the emission standards, excessive ammonia injection is often used, which increases ammonia consumption and generates ammonium sulfate due to ammonia leakage, resulting in serious catalyst dust accumulation and reduced denitrification efficiency. At the same time, the air preheater is frequently blocked, the outlet resistance of the induced draft fan increases, and the unit's operating energy consumption is high. Utility Model Content
[0003] The utility model aims to provide a uniform flow anti-clogging nozzle structure, which not only increases the contact area between ammonia and flue gas to make the heat transfer efficiency higher, but also prevents dust from falling into the nozzle and causing blockage when the furnace is shut down.
[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:
[0005] A uniform flow anti-clogging nozzle structure comprises a reducer, a straight pipe, a cone and a circular plate; the reducer is arranged vertically, and the diameter of its upper port is larger than the diameter of its lower port; the lower port of the straight pipe is butt-connected with the upper port of the reducer; the cone is vertically inverted in the upper port of the straight pipe with a gap between the two so as to spray ammonia water; the bottom surface of the cone extends to above the upper port of the straight pipe, the circular plate is horizontally fixed on the bottom surface of the cone and the two are arranged concentrically, so that a gap is formed between the circular plate and the upper port of the straight pipe, and the diameter of the circular plate is larger than the diameter of the straight pipe.
[0006] Preferably, the angle between the cone surface and the horizontal direction is 50-60°.
[0007] Preferably, the upper surface of the circular plate is a conical structure. Optionally, the angle between the conical surface of the conical structure and the horizontal direction is 10-15°.
[0008] Preferably, the distance between the cone tip and the lower end of the straight tube is 40-50% of the bottom diameter of the cone.
[0009] Preferably, the diameter of the circular plate is 5-10 mm larger than the diameter of the straight tube.
[0010] Compared with the prior art, the utility model has the following beneficial effects:
[0011] (1) The uniform flow anti-clogging nozzle structure of the utility model can make ammonia gas spray 360 degrees at the nozzle. After being sprayed out, ammonia gas will be deflected by the top conical circular plate and mixed with the high-temperature flue gas, so that the distribution of ammonia gas in the flue cross section is larger and more uniform, and the contact area between ammonia gas and flue gas is increased, so that the heat transfer efficiency is higher; at the same time, the circular plate also helps to prevent dust from falling into the nozzle and causing blockage when the furnace is shut down;
[0012] (2) The flow-averaging and anti-clogging nozzle structure of the utility model forms an expanded mouth through a reducer, thereby reducing the nozzle flow rate, which not only helps to reduce nozzle wear, but also effectively reduces nozzle clogging. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 The utility model is a schematic structural diagram of an embodiment.
[0014] Figure 2 It is a structural schematic diagram of the circular plate in the utility model.
[0015] Figure 3 It is a schematic diagram of the uniform flow anti-clogging nozzle structure of the utility model spraying ammonia gas flow.
[0016] In the figure: 1- reducer, 2- straight pipe, 3- cone, 4- circular plate. DETAILED DESCRIPTION
[0017] 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 of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.
[0018] refer to Figure 1 The uniform flow anti-clogging nozzle structure described in this embodiment mainly includes a reducer 1, a straight tube 2, a cone 3 and a circular plate 4 made of 316L material. Specifically, the reducer 1 is arranged vertically, and the diameter of its upper port is larger than the diameter of the lower port. The diameter of the straight tube 2 is 5mm, and the lower port of the straight tube 2 is butt-connected to the upper port of the reducer 1 to form a flared form, but the flow rate of the ammonia flow is reduced when it enters the straight tube 2 from the reducer 1, which not only helps to reduce the wear on the nozzle, but also effectively reduces the clogging of the nozzle.
[0019] The cone 3 is vertically inverted in the upper end of the straight tube 2 with a gap between the two to spray ammonia water. The angle between the cone surface of the cone 3 and the horizontal direction is 50-60°, such as 50°, 55°, 60°, etc. The distance between the cone tip of the cone 3 and the lower end of the straight tube 2 is 40-50% of the bottom diameter of the cone 3, such as 40%, 45%, 50%, etc.
[0020] The bottom surface of the cone 3 extends to above the upper end of the straight tube 2, and the circular plate 4 is horizontally fixed on the bottom surface of the cone 3 and the two are concentrically arranged, so that a gap is formed between the circular plate 4 and the upper end of the straight tube 2, and the diameter of the circular plate 4 is larger than the diameter of the straight tube 2 by 5~10mm, such as 5mm, 8mm, 10mm.
[0021] In another embodiment, reference Figure 2 The upper surface of the circular plate 4 of the above-mentioned uniform flow anti-blocking nozzle structure is a conical structure, which is helpful for guiding the ammonia flow. The angle between the cone surface of the conical structure and the horizontal direction is 10-15°, such as 10°, 12°, 15°, etc.
[0022] The special uniform flow anti-blocking nozzle structure of the above embodiment can make the ammonia gas spray 360 degrees at the nozzle. After the ammonia gas is sprayed out, it will be deflected by the top conical circular plate 4 and mixed with the high-temperature flue gas (refer to Figure 3 ), so that the distribution of ammonia in the flue cross section is larger and more uniform, and the contact area between ammonia and flue gas is increased, so that the heat transfer efficiency is higher. At the same time, the circular plate 4 also helps to prevent dust from falling into the nozzle and causing blockage when the furnace is shut down.
[0023] Finally, it should be noted that any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model. Although the above describes the specific implementation of the utility model in conjunction with the drawings, it is not a limitation on the protection scope of the utility model. Those skilled in the art should understand that on the basis of the technical solution of the utility model, various modifications or deformations that can be made by those skilled in the art without creative labor are still within the protection scope of the utility model.
Claims
1. A uniform flow anti-blocking nozzle structure, characterized in that: It comprises a reducer, a straight tube, a cone and a circular plate; the reducer is arranged vertically, and the diameter of its upper port is larger than the diameter of its lower port; the lower port of the straight tube is butt-jointed with the upper port of the reducer; the cone is vertically inverted in the upper port of the straight tube with a gap therebetween; the bottom surface of the cone extends to above the upper port of the straight tube, the circular plate is horizontally fixed on the bottom surface of the cone and the two are arranged concentrically, so that a gap is formed between the circular plate and the upper port of the straight tube, and the diameter of the circular plate is larger than the diameter of the straight tube.
2. The flow-averaging and anti-clogging nozzle structure according to claim 1 is characterized in that: The angle between the cone surface and the horizontal direction is 50-60°.
3. The flow-averaging and anti-clogging nozzle structure according to claim 1 is characterized in that: The upper surface of the circular plate is in a conical structure.
4. The flow-averaging and anti-clogging nozzle structure according to claim 3 is characterized in that: The angle between the cone surface of the conical structure and the horizontal direction is 10-15°.
5. The flow-averaging and anti-clogging nozzle structure according to any one of claims 1 to 4, characterized in that: The distance between the cone tip and the lower end of the straight pipe is 40-50% of the bottom diameter of the cone.
6. The flow-averaging and anti-clogging nozzle structure according to any one of claims 1 to 4, characterized in that: The diameter of the circular plate is 5-10 mm larger than the diameter of the straight tube.