Coal mill nozzle ring

Abstract

The utility model relates to the technical field of coal mill, specifically is coal mill nozzle ring, including dynamic ring and static ring, wherein: dynamic ring and static ring adopt up and down installation mode, static ring is located above dynamic ring, and the clearance between both is 5mm, further, the dynamic ring outer wall board is changed to curved arc board from traditional vertical flat plate, and the whole is horn mouth shape, the curved arc board design of dynamic ring effectively reduced the flow resistance of hot air in nozzle ring, and the air volume and air pressure of hot air were strengthened, specifically, the shape of curved arc board makes hot air more smoothly flow when passing through nozzle ring, avoids the problem that hot air flow efficiency reduces because of too big wind resistance in the traditional vertical flat plate design, especially, the thickness of dynamic ring is 12mm, guarantees the structural strength and lightens the overall weight simultaneously, thereby reduces the energy consumption when the equipment runs.

Description

Technical Field

[0001] This utility model relates to the field of coal mill technology, specifically to a coal mill nozzle ring. Background Technology

[0002] In industrial sectors such as thermal power plants, chemical plants, and steel smelters, medium-speed coal mills are key equipment. The design and performance of their core component, the nozzle ring, directly affect the processing quality of pulverized coal and the operating efficiency of the equipment. The main function of the nozzle ring is to evenly introduce hot air around the grinding disc through an annular channel, thereby drying the pulverized coal and transporting it to the boiler for combustion. At the same time, impurities that are difficult to break cannot be blown away by the hot air and fall into the lower part of the mill through the annular channel of the nozzle ring, and are eventually discharged into the stone coal box.

[0003] However, the existing nozzle ring design and installation methods have many shortcomings. The traditional nozzle ring installation method makes the direction of hot air blowing out from the annular channel tend to be vertical, causing the blown coal powder to directly impact the cylinder and lower support, resulting in severe wear. In addition, the problem of coal powder not being blown away in time is also prominent, resulting in the coal powder being over-ground and becoming too fine, which in turn leads to a series of problems such as large amount of coal powder return, uneven coal distribution in the conveying pipe and difficulty in adjustment. What is even more inconvenient is that when adjusting the gap between the moving ring and the stationary ring of the nozzle ring, the traditional method requires welding a whole ring of round steel between the stationary ring and the cylinder. If the gap is less than 5mm, the edge of the stationary ring needs to be cut off on-site to complete the adjustment. This process is complicated and difficult to operate, which seriously affects the maintenance efficiency and operational stability of the equipment. Therefore, there is an urgent need for a nozzle ring design and installation scheme that can effectively reduce hot air resistance, optimize coal powder conveying and drying effects, and simplify the gap adjustment process, so as to solve the above-mentioned problems in the existing technology and improve the overall performance of the coal mill. Utility Model Content

[0004] This invention addresses the shortcomings of existing coal mill nozzle rings in terms of hot air resistance, uneven coal powder fineness, large amount of returned coal, and uneven coal distribution in the conveying pipe. It proposes an improved coal mill nozzle ring, which solves the above-mentioned technical problems by optimizing the installation method and structural design of the moving and stationary rings.

[0005] The technical solution adopted by this utility model to solve its technical problem is a coal mill nozzle ring, including a moving ring and a stationary ring. The moving ring and the stationary ring are installed in an upper and lower configuration, with the stationary ring located above the moving ring and a gap of 5mm between them. Furthermore, the outer wall plate of the moving ring is changed from a traditional vertical flat plate to a curved arc plate, which is flared in shape and has a thickness of 12mm. Three sets of airflow baffles are provided on the stationary ring, each with a height of 5mm, and their positions correspond to the gap area between the three sets of grinding rollers. The airflow baffles are used to guide air and achieve an air seal function, guiding some hot air to the grinding area of ​​the grinding rollers.

[0006] Specifically, the curved arc plate design of the moving ring effectively reduces the flow resistance of hot air within the nozzle ring, enhancing the airflow and air pressure of the hot air. In particular, the shape of the curved arc plate allows the hot air to flow more smoothly through the nozzle ring, avoiding the problem of reduced hot air flow efficiency caused by excessive wind resistance in traditional vertical flat plate designs. In particular, the thickness of the moving ring is 12mm, which reduces the overall weight while ensuring structural strength, thereby reducing the energy consumption during equipment operation.

[0007] Specifically, the airflow baffle on the stationary ring achieves an air-sealing function for the grinding area of ​​the grinding rollers by guiding the hot air. Specifically, the airflow baffle guides part of the hot air to the gap area between the grinding rollers, which on the one hand promptly blows out the ground coal powder to prevent the coal powder from becoming too fine due to excessive grinding; on the other hand, the hot air pre-dries and heats the coal powder, shortening the drying time of the coal powder and improving the coal grinding efficiency. In particular, the height of the airflow baffle is 5mm, which can effectively guide the air without causing additional obstruction to the mainstream direction of the hot air.

[0008] Specifically, the gap between the stationary ring and the rotating ring is maintained at 5mm, which is easy to adjust and meets the requirements of actual working conditions. In particular, the gap adjustment is achieved by adjusting the vertical position of the stationary ring, without the need for on-site cutting or other complex operations on the stationary or rotating ring. Compared with the existing technology that requires welding round steel or cutting off the edge of the stationary ring, this utility model greatly simplifies the gap adjustment process and significantly improves maintenance efficiency.

[0009] The beneficial effects of this utility model are as follows: The improved coal mill nozzle ring is compatible with existing equipment specifications, wherein the diameter of the grinding roller tray is Φ2150mm and the width of the grinding roller is 284mm. Furthermore, the overall structural design of the nozzle ring fully considers the actual operating conditions of the equipment, ensuring stable operation under various working conditions. It has high practical value and promising prospects for promotion. Through the curved arc plate design of the moving ring and the air guiding function of the airflow baffle of the stationary ring, the resistance of hot air in the nozzle ring is significantly reduced, and the flow efficiency of hot air is improved. In particular, the improved nozzle ring can... The pulverized coal is blown out of the grinding area to prevent it from becoming too fine due to excessive grinding, thus solving the problem of uneven coal fineness. Furthermore, because the hot air can be distributed more evenly in the grinding area, the pulverized coal is promptly blown out and transported to the boiler for combustion, significantly reducing the amount of coal returned. In particular, the improved nozzle ring makes the hot air flow more uniform, and the distribution of pulverized coal in the conveying pipe is more balanced, reducing the risk of blockage in the conveying pipe. In addition, during actual operation, the operating current of the coal mill is reduced by 8-10A compared to the original installation method, achieving energy saving and consumption reduction. Attached Figure Description

[0010] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0011] Figure 1 This is a schematic diagram of the modified nozzle ring of this utility model;

[0012] Figure 2 A schematic diagram of the nozzle ring of an existing coal mill;

[0013] Figure 1 In the middle: 2. stationary ring; 3. moving ring; grinding roller grinding gap; 7. airflow baffle;

[0014] Figure 2 In the middle: 11. Round steel; 12. Stationary ring; 13. Moving ring; 14. Liner plate; 15. Grinding roller tray; 16. Grinding roller. Detailed Implementation

[0015] To make the technical means, creative features, objectives, and effects of this utility model easier to understand, in conjunction with the appendix... Figure 1 and attached Figure 2 The specific implementation methods are described in detail in the appendix. Figure 2 The image illustrates the installation method of the nozzle ring in the prior art. In this method, the hot air is blown out through the annular channel in a direction that tends to be vertical, causing the hot air to directly impact the cylinder and lower support, resulting in severe wear and problems such as the inability to promptly remove pulverized coal, excessive pulverized coal return, and uneven pulverized coal distribution in the conveying pipe. To solve these problems, this invention optimizes the structure of the moving and stationary rings of the nozzle ring, as well as the installation method. Figure 1 The improved nozzle ring mounting method and the specific structure of key components are shown.

[0016] like Figure 1 As shown, the coal mill nozzle ring of this utility model includes a moving ring 3 and a stationary ring 2. The moving ring 3 and the stationary ring 2 are installed in an upper and lower configuration, with the stationary ring 2 located above the moving ring 3. The gap between the stationary ring 2 and the moving ring 3 is 5mm. The outer wall plate of the moving ring 3 is a curved arc plate, and the moving ring 3 is shaped like a trumpet. The thickness of the moving ring 3 is 12mm. Three sets of airflow baffles 7 are provided on the stationary ring 2. The height of each set of airflow baffles 7 is 5mm, and the position of the airflow baffles 7 corresponds to the gap area between the grinding rollers.

[0017] In use, the improved nozzle ring of this application includes a moving ring 3 and a stationary ring 2, which are installed in an upper and lower configuration. The stationary ring 2 is located above the moving ring 3, and the gap between the stationary ring 2 and the moving ring 3 is set to 5mm. This gap can be adjusted by adjusting the upper and lower position of the stationary ring 2 without the need for complex operations such as on-site cutting or welding of round steel. The stationary ring 2 is fixed to the upper housing of the coal mill with bolts, while the moving ring 3 is fixed to the outside of the grinding roller tray. When it is necessary to adjust the gap, simply loosen the fixing bolts of the stationary ring 2 and change the height of the stationary ring 2 by increasing or decreasing the thickness of the shims, thereby achieving precise gap control. This design significantly simplifies the maintenance process and improves the reliability and efficiency of equipment operation.

[0018] This invention also includes a curved arc plate of the moving ring 3 whose radius of curvature is determined according to actual fluid dynamics calculations to ensure that the hot air forms a stable airflow distribution when passing through the nozzle ring.

[0019] This utility model also includes a curved arc plate design for the moving ring 3, which avoids the problem of reduced hot air circulation efficiency caused by excessive wind resistance in traditional vertical flat plate structures.

[0020] This invention also includes an airflow baffle 7 on the stationary ring 2 that guides some of the hot air to the grinding area of ​​the grinding roller by directing the hot air flow.

[0021] In use, the airflow baffle 7 on the stationary ring 2 serves to guide airflow and achieve an air seal function, directing some of the hot air to the grinding area of ​​the grinding roller. By guiding the hot air, the airflow baffle 7 promptly blows out the ground coal powder, preventing it from becoming too fine due to excessive grinding. On the other hand, the hot air pre-dries and heats the coal powder, shortening the drying time and improving the grinding efficiency. The height of the airflow baffle 7 is precisely calculated to effectively guide airflow without obstructing the main direction of the hot air, ensuring a more uniform hot air flow.

[0022] The working process of the coal mill of this utility model is as follows: After hot air enters the coal mill from the outside, it first passes through the annular channel of the nozzle ring and is guided by the curved arc plate of the moving ring 3 to form a stable airflow distribution. The hot air is further guided by the airflow baffle 7 on the stationary ring 2 to the grinding area of ​​the grinding roller. In the grinding area, the grinding roller grinds the coal powder. The coal powder that meets the fineness requirements is blown out by the hot air and transported to the boiler for combustion through the coal powder conveying pipe. The coal powder that does not meet the fineness requirements continues to remain in the grinding area for further processing until the requirements are met. Due to the airflow baffle 7, the hot air can be distributed more evenly in the grinding area, and the coal powder is blown out and transported to the boiler for combustion in time, which greatly reduces the amount of coal powder returned.

[0023] This invention improves the nozzle ring to adapt to existing equipment specifications. The overall structural design of the nozzle ring fully considers the actual operating conditions of the equipment, ensuring stable operation under various working conditions. For example, in the application scenario of thermal power plants, coal mills usually need to operate continuously for a long time. The optimized design of the nozzle ring can improve the energy saving and consumption reduction effect. The improved nozzle ring makes the hot air flow more uniform and the coal powder distribution in the conveying pipe more even, reducing the risk of conveying pipe blockage and further improving the operating efficiency of the equipment.

[0024] In the actual installation process, the moving ring 3 is first fixed to the outside of the existing coal mill's grinding roller tray, ensuring that its curved plate is aligned with the outer edge of the grinding roller tray. Then, the stationary ring 2 is installed on the upper housing of the coal mill. The gap between the stationary ring 2 and the moving ring 3 is maintained at 5mm by adjusting the vertical position of the stationary ring 2. After installation, the overall structure of the nozzle ring is inspected to ensure that the connection of each component is firm and there is no looseness. The coal mill is started for trial operation to observe the flow of hot air and the conveying effect of coal powder, confirming that the performance of the improved nozzle ring meets the design requirements.

[0025] This utility model optimizes the installation method and structural design of the moving ring 3 and the stationary ring 2 in the nozzle ring, fully considers the actual operating conditions of the equipment, and ensures stable operation under various working conditions, providing reliable technical support for medium-speed coal mill equipment in thermal power plants, chemical plants or steel smelting plants.

[0026] 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 descriptions of the above embodiments and specifications are merely illustrative of the principles of this 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 protection claimed by this utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A coal mill nozzle ring characterised in that, It includes a moving ring (3) and a stationary ring (2). The moving ring (3) and the stationary ring (2) are installed in an up-down manner, with the stationary ring (2) located above the moving ring (3). The gap between the stationary ring (2) and the moving ring (3) is 5mm. The outer wall plate of the moving ring (3) is a curved arc plate.

2. The coal mill nozzle ring of claim 1, wherein, The moving ring (3) is shaped like a trumpet, and the thickness of the moving ring (3) is 12mm.

3. The coal mill nozzle ring of claim 2, wherein, The stationary ring (2) is provided with three sets of airflow baffles (7), and the height of each set of airflow baffles (7) is 5mm.

4. The coal mill nozzle ring of claim 3, wherein, The airflow baffle (7) is located at the top inside the stationary ring (2), and the bottom of the moving ring (3) forms a grinding gap (6) between the airflow baffle (7) and the stationary ring (2).

5. The coal mill nozzle ring of claim 4, wherein, The airflow baffle (7) on the stationary ring (2) guides the hot air, so that part of the hot air is guided from the grinding gap (6) to the grinding area of ​​the grinding roller.

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