High-uniformity low-energy-consumption static nozzle ring device

Abstract

The utility model relates to the technical field of coal mills, and discloses a high-uniformity low-energy-consumption static nozzle ring device which comprises a nozzle ring, a wear-resistant block and a pressing and blocking piece. The nozzle ring is fixed in the machine shell, the nozzle ring and a millstone supporting ring in the machine shell are coaxially arranged, a through-flow area of the nozzle ring is provided with a first airflow channel, a second airflow channel and a third airflow channel which are sequentially communicated from bottom to top, and a plurality of first blades are arranged in the second airflow channel to divide the second airflow channel into a plurality of first nozzles. The through-flow area of the first nozzle is gradually increased from the position close to the primary air outlet to the position far away from the primary air outlet; and the wear-resistant block is limited in the third airflow channel of the nozzle ring through the pressing and blocking piece. The airflow velocity distribution of a through-flow area is simulated through an experiment, and the through-flow area of a runner is adjusted by using a spline curve, so that the flow velocity of a flow field in a whole nozzle ring area is more uniform, the abrasion condition of an abrasion-resistant block and a machine shell is effectively improved, and the overall service life is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of coal mill technology, specifically to a high-uniformity, low-energy-consumption static nozzle ring device. Background Technology

[0002] Coal mills have advantages such as low noise, low power consumption, small footprint, and compact equipment, and are widely used in the power generation, chemical, and metallurgical industries. The ZGM coal mill designed by Beijing Electric Power Equipment General Factory and the coal mill designed by Changchun Power Equipment Co., Ltd. are commonly seen in the market. At present, the conventional design of the nozzle annular flow channel has a consistent upper and lower flow area. The nozzle ring is attached to the grinding disc support ring and rotates with the grinding disc support ring, which is also called a rotating nozzle ring. Conventional rotating nozzle rings have the advantage of uniform wear. However, rotating nozzle rings cannot solve the problem of uneven nozzle annular flow field caused by the asymmetry of primary air. Multiple field reports indicate that the wear-resistant plate of the casing on the right side near the primary air inlet of the coal mill is severely damaged by wind. In severe cases, the inner wall of the casing is even worn through in a short time, resulting in serious losses. Utility Model Content

[0003] The purpose of this invention is to provide a highly uniform, low-energy-consumption static nozzle ring device to solve the problems of uneven flow field in conventional rotating nozzle rings mentioned above.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A highly uniform, low-energy-consumption static nozzle ring device, comprising:

[0006] The nozzle ring is fixed inside the housing and is coaxially arranged with the grinding disc support ring inside the housing, and is located outside the grinding disc support ring. The flow passage area of ​​the nozzle ring has a first airflow channel, a second airflow channel and a third airflow channel connected sequentially from bottom to top. A plurality of first blades are arranged inside the second airflow channel. The plurality of first blades are spaced apart along the circumferential direction of the nozzle ring to divide the second airflow channel into a plurality of first nozzles. The flow passage area of ​​the first nozzles gradually increases from near the primary air outlet to far away from the primary air outlet.

[0007] The wear-resistant block is detachably embedded in the third airflow channel of the nozzle ring. The wear-resistant block is located on the outside of the grinding disc support ring. The flow area of ​​the wear-resistant block is separated into second nozzles corresponding to the first nozzles by the second blades. Each set of corresponding first nozzles and second nozzles are interconnected. The flow area of ​​each second nozzle is equal. The primary airflow passes through the first airflow channel, the first nozzle and the second nozzle in sequence and is then ejected.

[0008] The pressure-blocking component includes a first pressure ring and a second pressure ring. The first pressure ring is detachably mounted on the nozzle ring and abuts against the outer wall of the wear-resistant block to confine the wear-resistant block within the third airflow channel of the nozzle ring. The second pressure ring is detachably mounted on the grinding disc support ring and makes dynamic frictional contact with the inner wall of the wear-resistant block. This configuration adjusts the flow area of ​​each second nozzle on the circumference of the nozzle ring, lowering it in the high-speed region and compensating for it in the low-speed region, resulting in a more uniform flow velocity across the entire nozzle ring area. This gives the nozzle ring device low resistance and high uniformity. Furthermore, the wear-resistant block is replaceable, reducing maintenance and manufacturing costs.

[0009] Furthermore, the opening size of each of the first nozzles is the same along the circumferential direction of the nozzle ring, and the opening size of each of the first nozzles gradually increases from near the primary air outlet to far away from the primary air outlet. With this setting, the thickness of the first blade remains unchanged during the adjustment of the flow area of ​​the first nozzle, which facilitates the determination of the thickness of the second blade and the docking of the second blade with the first blade.

[0010] Furthermore, the maximum flow area among the several first nozzles is 1.5 to 2.5 times the minimum flow area. This data is derived from software simulation.

[0011] Furthermore, the nozzle ring includes an outer upper guard plate, an outer lower guard plate, and an inner lower guard plate; the outer upper guard plate is located above the outer lower guard plate, and the inner lower guard plate is located inside the outer lower guard plate and spaced apart, so that a first airflow channel and a second airflow channel are formed between the outer lower guard plate and the inner lower guard plate from bottom to top; the inner region of the first end of the outer upper guard plate is a third airflow channel; the second end of the outer upper guard plate is fixedly connected to the inner wall of the housing; and the bottom end of the outer lower guard plate is fixedly connected to the housing. The nozzle ring is composed of multiple parts, which facilitates a streamlined inner wall and reduces airflow resistance.

[0012] Furthermore, the outer upper guard plate includes an inclined guard plate and an annular expansion plate; the first end of the annular expansion plate is connected to the inclined guard plate, the second end of the annular expansion plate is fixedly connected to the inner wall of the housing, the inclined guard plate is connected to the outer lower guard plate, the inner side of the inclined guard plate is a third airflow channel, and the inclined guard plate has an angle of 10° to 20° with the vertical direction, preferably 15°. This arrangement can fix the nozzle ring inside the housing, and the inclined guard plate can effectively reduce airflow resistance.

[0013] Furthermore, it also includes an annular support plate, which is fixed to the inner wall of the housing, and the outer lower guard plate is fixedly connected to the housing through the annular support plate.

[0014] Furthermore, the wear-resistant block includes an inner protective plate and an outer protective plate; the inner protective plate is located inside the outer protective plate and is spaced apart to form the flow passage area of ​​the wear-resistant block; the second blade is located between the inner and outer protective plates; the inner protective plate is in dynamic frictional contact with the second pressure ring; the outer protective plate abuts against the first pressure ring; when the wear-resistant block is embedded in the third airflow channel, the inner protective plate connects with the inner lower protective plate to form the inner wall of the flow channel; the second blade connects with the first blade to form a guide blade; and the outer protective plate connects with the outer lower protective plate to form the outer wall of the flow channel. The seamless connection between the inner and inner lower protective plates, the outer and outer lower protective plates, and the second and first blades effectively reduces airflow loss and lowers airflow resistance.

[0015] Furthermore, when the wear-resistant block is embedded in the third airflow channel, the edge line of the longitudinal section of the inner wall of the channel is a combination of a straight line and a spline curve from top to bottom. The upper 1 / 4 section is a straight line at an angle of 10° to 20° with the vertical direction, and the upper 1 / 4 to the bottom is a spline curve, with the center of curvature all located outside the flow area. This arrangement conforms to fluid dynamics design, effectively alleviates fluid turbulence, and reduces fluid pressure loss.

[0016] Furthermore, when the wear-resistant block is embedded in the third airflow channel, the edge line of the longitudinal section of the outer wall of the channel is a combination of a straight line and a spline curve from top to bottom. The upper 1 / 5 section is a straight line at an angle of 10° to 20° with the vertical direction, and the upper 1 / 5 to the bottom is a spline curve, with the center of curvature located entirely outside the flow passage area. This arrangement conforms to fluid dynamics design, effectively alleviates fluid turbulence, and reduces fluid pressure loss.

[0017] Furthermore, when the wear-resistant block is embedded in the third airflow channel, the edge line of the guide vane in contact with the outer wall of the channel is a combination of a straight line and a spline curve from top to bottom. The upper 1 / 4 section is a straight line at an angle of 40° to 50° with the horizontal direction, and the upper 1 / 4 to the bottom is a spline curve, with the bottom tangent direction making an angle of 0° to 15° with the vertical direction. This arrangement conforms to fluid dynamics design, effectively alleviates fluid turbulence, and reduces fluid pressure loss.

[0018] Furthermore, both the inner and outer protective plates have an angle of 10° to 20° with the vertical direction, preferably 15°. This arrangement ensures that the inner and outer protective plates have the same inclination angle as the inclined protective plate, facilitating the installation of the wear-resistant block within the third airflow channel.

[0019] Furthermore, the first pressure ring is fitted to the annular expansion plate, the outer top outer side of the outer protective plate has a chamfered surface, the first end of the first pressure ring abuts against the chamfered surface of the outer protective plate, the second end of the first pressure ring abuts against the inner wall of the housing, and the first pressure ring and the annular expansion plate are connected by bolts. This arrangement can effectively prevent the wear-resistant block from shifting during rotation.

[0020] Furthermore, the upper surface of the second blade is an inclined plane of 0° to 30°, and the side of the upper surface of the second blade closer to the inner liner is lower than the side closer to the outer liner. This configuration optimizes the stress distribution of the wear-resistant block and effectively reduces stress concentration in the wear-resistant block.

[0021] Furthermore, the inner protective plate is lower in the vertical direction than the outer protective plate, and the outer protective plate is higher than the second blade. This arrangement, based on the opening, effectively reduces the ventilation resistance of the nozzle ring.

[0022] This invention has the following advantages over the prior art:

[0023] 1. This utility model relates to a high-uniformity, low-energy-consumption static nozzle ring device. The nozzle ring is fixed to the mill housing and does not rotate with the mill disc support ring, effectively reducing power consumption and saving operating costs during operation. Due to the asymmetry of the primary air duct, the gas velocity varies in the nozzle ring's flow area, resulting in different degrees of wear at different locations. This nozzle ring adjusts the flow area of ​​each first nozzle on the circumference of the nozzle ring, with the flow area of ​​the first nozzle gradually increasing from near the primary air outlet to far away from the primary air outlet. This makes the flow velocity in the entire nozzle ring area more uniform, giving the nozzle ring high uniformity, effectively improving wear on the wear-resistant blocks and the mill housing, and increasing the overall service life.

[0024] 2. The high uniformity and low energy consumption static nozzle ring device of this utility model is equipped with replaceable wear-resistant blocks. Experiments have shown that the wear of the nozzle ring is caused by the long-term impact of coal powder particles in the airflow on the metal surface. Extensive practice has shown that when the airflow passes through the lower part of the nozzle ring (first airflow channel and second airflow channel), there are no coal powder particles in the airflow, and no wear will occur during operation. Therefore, during operation, the wear area is mainly distributed in the upper half of the entire flow channel (third airflow channel). Therefore, a replaceable wear-resistant block is designed in the third airflow channel. When wear occurs during the operation of the coal mill, it is not necessary to replace the entire nozzle ring, but only the wear-resistant block needs to be replaced, which reduces maintenance and manufacturing costs.

[0025] 3. The high-uniformity, low-energy-consumption static nozzle ring device of this invention adopts a design combining straight lines and spline curves. Compared with the straight cylindrical inner walls of the flow passage in the prior art, this device can effectively reduce the local resistance of the nozzle ring and reduce wear. In this invention, the upper outer wall of the nozzle ring is an annular expansion plate. Airflow enters from the bottom of the nozzle ring and exits from the top of the wear-resistant block, effectively increasing the gas diffusion area at the outlet of the wear-resistant block and effectively reducing the wear of the casing. Attached Figure Description

[0026] Figure 1This is a longitudinal cross-sectional schematic diagram of the high uniformity, low energy consumption static nozzle ring device and the grinding disc support ring in an embodiment of this utility model.

[0027] Figure 2 This is a schematic longitudinal section of the high uniformity, low energy consumption static nozzle ring device in an embodiment of this utility model;

[0028] Figure 3 This is a schematic cross-sectional view of the second airflow channel of the nozzle ring in the high uniformity and low energy consumption static nozzle ring device in this embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram of the guide vanes in the high uniformity, low energy consumption static nozzle ring device in this embodiment of the present invention.

[0030] In the diagram: 1. Nozzle ring; 101. First airflow channel; 102. Second airflow channel; 103. Third airflow channel; 104. First blade; 105. First nozzle; 106. Outer lower guard plate; 107. Inner lower guard plate; 108. Inclined guard plate; 109. Annular expansion plate; 2. Housing; 3. Grinding disc support ring; 4. Wear-resistant block; 401. Second blade; 402. Inner guard plate; 4021. Limiting right angle; 403. Outer guard plate; 4031. Beveled surface; 4032. Chamfer; 5. First pressure ring; 6. Second pressure ring; 7. Annular support plate; 8. Bolt; 9. Low resistance area; 10. High resistance area. Detailed Implementation

[0031] 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.

[0032] It should be noted that in the description of this utility model, the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0033] Furthermore, it should be understood that, for ease of description, the dimensions of the various components shown in the accompanying drawings are not drawn to actual scale.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined or described in one figure, it will not need to be further discussed and described in the description of the subsequent figures.

[0035] Example:

[0036] like Figure 1 and Figure 2 As shown, a highly uniform, low-energy-consumption static nozzle ring device includes:

[0037] Nozzle ring 1 is fixed inside the housing 2. The nozzle ring 1 is coaxially arranged with the grinding disc support ring 3 inside the housing 2 and is located outside the grinding disc support ring 3. The flow area of ​​the nozzle ring 1 has a first airflow channel 101, a second airflow channel 102 and a third airflow channel 103 connected sequentially from bottom to top. A plurality of first blades 104 are arranged in the second airflow channel 102. The plurality of first blades 104 are distributed at intervals along the circumferential direction of the nozzle ring 1 to divide the second airflow channel 102 into a plurality of first nozzles 105. The flow area of ​​the first nozzles 105 gradually increases from near the primary air outlet to far away from the primary air outlet.

[0038] Preferably, such as Figure 3 As shown, the opening size of each of the first nozzles 105 along the circumferential direction of the nozzle ring 1 is the same, while the opening size of each of the first nozzles 105 along the radial direction of the nozzle ring 1 gradually increases from near the primary air outlet to far away from the primary air outlet. By adjusting the radial size of the first nozzles 105 along the nozzle ring 1, the flow area of ​​the first nozzles 105 gradually increases from near the primary air outlet to far away from the primary air outlet, making the flow velocity of the entire nozzle ring area more uniform, giving the nozzle ring high uniformity, effectively improving the wear of the wear-resistant block and the housing, and increasing the overall service life. In this embodiment, the radial opening size is adjusted, rather than the circumferential opening size, to achieve uniform thickness of each first blade, facilitating docking with the second blade. According to software simulation, the maximum flow area among several first nozzles is 1.5 to 2.5 times the minimum flow area.

[0039] Wear-resistant block 4 is detachably embedded in the third airflow channel 103 of nozzle ring 1. Wear-resistant block 4 is located on the outside of grinding disc support ring 3. The flow area of ​​wear-resistant block 4 is separated by second blade 401 to form second nozzles that correspond one-to-one with the first nozzle 105. Each set of corresponding first nozzles 105 and second nozzles are interconnected. The flow area of ​​each second nozzle is equal. The primary airflow passes through the first airflow channel 101, the first nozzle 105 and the second nozzle in sequence and is then ejected. By adjusting the flow area of ​​each first nozzle 105, the airflow velocity at the outlet of each second nozzle in the circumferential direction of nozzle ring 1 is made more uniform.

[0040] The pressure-blocking component includes a first pressure ring 5 and a second pressure ring 6. The first pressure ring 5 is detachably installed on the nozzle ring 1 and abuts against the outer wall of the wear-resistant block 4 to confine the wear-resistant block 4 within the third airflow channel 103 of the nozzle ring 1. The second pressure ring 6 is detachably installed on the grinding disc support ring 4 and makes dynamic frictional contact with the inner wall of the wear-resistant block 4. By setting the first pressure ring 5 and the second pressure ring 6, the wear-resistant block 4 can be replaced, while improving the stability of the wear-resistant block 4 fitted within the third airflow channel 103. The second pressure ring 6 also has a height compensation function. The outer edge of the second pressure ring 6 is vertically aligned with the inner edge of the inner protective plate 402 of the wear-resistant block. The setting of the second pressure ring 6 does not change the outlet size of the second nozzle. The top of the inner protective plate 402 of the wear-resistant block 4 has a horizontal gap dynamic sealing contact with the second pressure ring 6, and the outer side of the inner protective plate 402 has a vertical gap dynamic sealing contact with the grinding disc support ring 3.

[0041] The wear-resistant block 4 is made of wear-resistant material and is replaceable. The overall flow channel of the nozzle ring 1 adopts a streamlined design that conforms to fluid dynamics. Due to the asymmetry of the primary air channel, the gas flow velocity inside each channel on the cross-section of the nozzle ring is different at different positions on the circumference during actual operation, which leads to different degrees of wear on the casing at different positions. To solve this problem, the nozzle ring 1 in this utility model uses spline curves to adjust the airflow velocity on different curves (different positions) on the circumference. The internal flow channel of the wear-resistant block is connected to the flow channel of the nozzle ring. Since the nozzle ring is changed to a static open structure, the nozzle has the characteristics of low resistance, high uniformity, replaceability, and low power consumption.

[0042] In this invention, the nozzle ring 1 determines the velocity distribution of the entire flow area through numerical simulation. Based on the different velocities of each flow channel, spline curves are used to adjust the flow area. The gas velocity is referenced to the outlet of the wear-resistant block. The nozzle ring is adjusted downwards in the high-speed region (reducing the flow area) and upwards in the low-speed region (increasing the flow area), resulting in a more uniform flow field velocity across the entire nozzle ring region (uniform velocity at the outlet of the second nozzle). This nozzle ring incorporates wear-resistant blocks made of wear-resistant material. Wear on the nozzle ring is caused by the long-term impact of coal dust particles in the airflow on the metal surface. Extensive practical experience shows that when the airflow passes through the lower part of the nozzle ring, there are no coal dust particles, and no wear occurs during operation. Therefore, during operation, the wear area is mainly distributed in the upper half of the entire flow channel. This design incorporates replaceable wear-resistant blocks. When wear occurs during the operation of the coal mill, it is not necessary to replace the entire nozzle ring; only the wear-resistant blocks need to be replaced, reducing maintenance and manufacturing costs.

[0043] like Figure 2As shown, the nozzle ring 1 includes an outer upper guard plate, an outer lower guard plate 106, and an inner lower guard plate 107. The outer upper guard plate is located at the upper end of the outer lower guard plate 106, and the inner lower guard plate 107 is located inside the outer lower guard plate 106 and spaced apart, so that a first airflow channel 101 and a second airflow channel 102 distributed from bottom to top are formed between the outer lower guard plate 106 and the inner lower guard plate 107. The inner area of ​​the first end of the outer upper guard plate is a third airflow channel 103. The second end of the outer upper guard plate is fixedly connected to the inner wall of the housing 2, and the bottom end of the outer lower guard plate 106 is fixedly connected to the housing 2. Specifically, an annular support plate 7 is welded to the inner wall of the housing 2, and the bottom end of the outer lower guard plate 106 is fixedly connected to the housing 2 through the annular support plate 7. This configuration allows the nozzle ring 1 to be fixed inside the housing, giving it a stationary open design. The inner walls of the first airflow channel 101, the second airflow channel 102, and the third airflow channel 103 are designed with a streamlined shape, effectively reducing airflow resistance.

[0044] In this embodiment, the outer upper guard plate includes an inclined guard plate 108 and an annular expansion plate 109; the first end of the annular expansion plate 109 is connected to the inclined guard plate 108, the second end of the annular expansion plate 109 is fixedly connected to the inner wall of the housing 2, the inclined guard plate 108 is connected to the outer lower guard plate 106, the inner side of the inclined guard plate 108 is a third airflow channel, and the inclined guard plate 108 has an angle of 10° to 20° with the vertical direction, preferably 15°.

[0045] According to the structural design of the outer upper protective plate, the wear-resistant block 4 is configured as a combination of an inner protective plate 402 and an outer protective plate 403; the inner protective plate 402 is located inside the outer protective plate 403 and is spaced apart to form the flow area of ​​the wear-resistant block 4, and the second blade 401 is located between the inner protective plate 402 and the outer protective plate 403. When the wear-resistant block 4 is embedded in the third airflow channel 103, the first pressure ring 5 is set along the annular expansion plate 109 and fixed to the annular expansion plate 109 by bolts. The bottom of 5 abuts against the outer protective plate 403, thereby confining the wear-resistant block 4 within the third airflow channel 103. The inner protective plate 402 is in dynamic frictional contact with the second pressure ring 6, and the outer protective plate 403 is attached to the inclined protective plate 108, both having the same inclination angle. The inner protective plate 402 is connected to the inner lower protective plate 107 to form the inner wall of the flow channel. The second blade 401 is connected to the first blade 104 to form a guide blade. The outer protective plate 403 is connected to the outer lower protective plate 106 to form the outer wall of the flow channel.

[0046] In this embodiment, in order to facilitate the placement of the wear-resistant block 4 into the third airflow channel 103, the bottom of the outer protective plate 403 of the wear-resistant block 4 is provided with a chamfer 4032 along a vertical direction, and a limiting right angle 4021 is designed on the outer side of the bottom of the inner protective plate 402 of the wear-resistant block. This limiting right angle 4021 and the top of the inner lower protective plate 107 of the nozzle ring are mating surfaces.

[0047] Meanwhile, in order to better fix the wear-resistant block 4, the outer outer side of the top end of the outer protective plate 403 has a beveled surface 4031, and the first end of the first pressure ring 5 abuts against the beveled surface 4031 of the outer protective plate 403. The angle of the beveled surface is 30° to 50°, and in this embodiment it is preferably 40°.

[0048] Specifically, the upper surface of the second blade 401 is an inclined plane of 0° to 30°, and the side of the upper surface of the second blade 401 near the inner guard plate 402 is lower than the side near the outer guard plate 403. This arrangement optimizes the stress distribution of the wear-resistant block and effectively reduces stress concentration. The gas outlet direction of the wear-resistant block flow channel is perpendicular to the outlet cross-section, ensuring uniform wear of the wear-resistant block during operation.

[0049] The inner protective plate is lower in height than the outer protective plate in the vertical direction, while the outer protective plate is higher than the second blade. By setting a second pressure ring 6 to compensate for the height of the inner protective plate, this setting increases the length of the air leakage channel between the nozzle ring and the grinding disc tray, which can effectively reduce the amount of air leakage.

[0050] In this embodiment, the inner wall of the nozzle annular flow region is adjusted to a streamlined shape as follows:

[0051] When the wear-resistant block 4 is embedded in the third airflow channel 103, the inner guard plate 402 is connected to the inner lower guard plate 107 to form the inner wall of the flow channel. The edge line of the longitudinal section of the inner wall of the flow channel is a combination of a straight line and a spline curve from top to bottom. The upper 1 / 4 section is a straight line at an angle of 10° to 20° with the vertical direction, preferably 15°. The upper 1 / 4 to the bottom is a spline curve, and the center of curvature is all outside the flow area.

[0052] When the wear-resistant block 4 is embedded in the third airflow channel 103, the outer protective plate 403 is connected to the outer lower protective plate 106 to form the outer wall of the flow channel. The edge line of the longitudinal section of the outer wall of the flow channel is a combination of a straight line and a spline curve from top to bottom. The upper 1 / 5 section is a straight line at an angle of 10° to 20° with the vertical direction, preferably 15°. The upper 1 / 5 to the bottom is a spline curve, and the center of curvature is all outside the flow area.

[0053] When the wear-resistant block 4 is embedded in the third airflow channel 103, the second blade 401 abuts with the first blade 104 to form a guide blade. The edge line of the guide blade in contact with the outer wall of the flow channel is a combination of a straight line and a spline curve from top to bottom. The upper 1 / 4 section is a straight line at an angle of 40° to 50° with the horizontal direction, preferably 45°, and the upper 1 / 4 to the bottom is a spline curve, with the bottom tangent direction making an angle of 0° to 15° with the vertical direction. This above arrangement conforms to fluid dynamics design, effectively alleviates fluid turbulence, and reduces fluid pressure loss.

[0054] In this utility model:

[0055] Nozzle ring 1 is an open flow channel. The first airflow channel of the nozzle ring has a large flow area, resulting in low local resistance. The cross-section of the first nozzle of the nozzle ring is a contraction section, and the contraction area is adjusted according to the airflow resistance. The specific contraction area is adjusted based on numerical simulation results to balance the local resistance of all nozzle ring flow channels. For example, when all flow channel cross-sections (first nozzle) of the nozzle ring are the same, when the nozzle ring flow channel is close to the primary air inlet (low resistance region 9), the local resistance from the primary air inlet to the nozzle ring flow channel is low. Therefore, it is necessary to reduce the flow area of ​​the first nozzle to increase resistance and reduce the flow velocity. Conversely, when the nozzle ring flow channel is far from the primary air inlet (high resistance region 10), the local resistance from the primary air inlet to the nozzle ring outlet is high. Therefore, it is necessary to increase the flow area of ​​the first nozzle to reduce resistance and increase the flow velocity. See [link to relevant documentation]. Figure 4 The regions are divided into low-resistance region 9 and high-resistance region 10. Therefore, the flow area of ​​the first nozzle gradually increases from near the primary air outlet to far away from it, ensuring a uniform airflow velocity at the second nozzle outlet. The flow channels of each second nozzle within the wear-resistant block, divided by the second blades, are gas flow channels with equal cross-sections, and the gas velocity passing through the second nozzles remains unchanged.

[0056] This utility model's high-uniformity, low-energy-consumption static nozzle ring device adopts a static open design. During use, it is fixed inside the coal mill casing, and the nozzle ring does not rotate with the grinding disc support ring. This effectively reduces power consumption and saves operating costs during operation. The primary airflow sequentially passes through the first, second, and third airflow channels from bottom to top. The second airflow channel is divided into several first nozzles by the first blade. Due to the asymmetry of the primary air duct, the flow area of ​​each first nozzle on the circumference of the nozzle ring is adjusted through software simulation during actual operation. Specifically, the flow area of ​​the first nozzle gradually increases from near the primary air outlet to far away from the primary air outlet. After adjustment, the flow velocity in the nozzle ring area is more uniform, giving the nozzle ring a high uniformity characteristic. Simultaneously, the wear-resistant blocks are replaceable, reducing maintenance and manufacturing costs.

[0057] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A highly uniform, low-energy-consumption static nozzle ring device, characterized in that, include: The nozzle ring is fixed inside the housing and is coaxially arranged with the grinding disc support ring inside the housing, and is located outside the grinding disc support ring. The flow passage area of ​​the nozzle ring has a first airflow channel, a second airflow channel and a third airflow channel connected sequentially from bottom to top. A plurality of first blades are arranged inside the second airflow channel. The plurality of first blades are spaced apart along the circumferential direction of the nozzle ring to divide the second airflow channel into a plurality of first nozzles. The flow passage area of ​​the first nozzles gradually increases from near the primary air outlet to far away from the primary air outlet. The wear-resistant block is detachably embedded in the third airflow channel of the nozzle ring. The wear-resistant block is located on the outside of the grinding disc support ring. The flow area of ​​the wear-resistant block is separated into second nozzles corresponding to the first nozzles by the second blades. Each set of corresponding first nozzles and second nozzles are interconnected. The flow area of ​​each second nozzle is equal. The primary airflow passes through the first airflow channel, the first nozzle and the second nozzle in sequence and is then ejected. The pressure block includes a first pressure ring and a second pressure ring; the first pressure ring is detachably installed on the nozzle ring and abuts against the outer wall of the wear-resistant block to confine the wear-resistant block within the third airflow channel of the nozzle ring; the second pressure ring is detachably installed on the grinding disc support ring and makes dynamic frictional contact with the inner wall of the wear-resistant block.

2. The high uniformity, low energy consumption static nozzle ring device according to claim 1, characterized in that: The opening size of each of the first nozzles is the same along the circumferential direction of the nozzle ring, and the opening size of each of the first nozzles along the radial direction of the nozzle ring gradually increases from near the primary air outlet to far away from the primary air outlet.

3. The high uniformity, low energy consumption static nozzle ring device according to claim 1, characterized in that: The maximum flow area among several first nozzles is 1.5 to 2.5 times the minimum flow area.

4. The high uniformity, low energy consumption static nozzle ring device according to claim 1, characterized in that: The nozzle ring includes an outer upper guard plate, an outer lower guard plate, and an inner lower guard plate; the outer upper guard plate is located at the upper end of the outer lower guard plate, and the inner lower guard plate is located inside the outer lower guard plate and is spaced apart, so that a first airflow channel and a second airflow channel are formed between the outer lower guard plate and the inner lower guard plate from bottom to top; the inner area of ​​the first end of the outer upper guard plate is a third airflow channel; the second end of the outer upper guard plate is fixedly connected to the inner wall of the housing; and the bottom end of the outer lower guard plate is fixedly connected to the housing.

5. The high uniformity, low energy consumption static nozzle ring device according to claim 4, characterized in that: The outer upper guard plate includes an inclined guard plate and an annular expansion plate; the first end of the annular expansion plate is connected to the inclined guard plate, the second end of the annular expansion plate is fixedly connected to the inner wall of the housing, the inclined guard plate is connected to the outer lower guard plate, the inner side of the inclined guard plate is a third airflow channel, and the inclined guard plate has an angle of 10° to 20° with the vertical direction.

6. The high uniformity, low energy consumption static nozzle ring device according to claim 5, characterized in that: The wear-resistant block includes an inner protective plate and an outer protective plate; the inner protective plate is located inside the outer protective plate and is spaced apart to form the flow passage area of ​​the wear-resistant block; the second blade is located between the inner and outer protective plates; the inner protective plate is in dynamic frictional contact with the second pressure ring; the outer protective plate abuts against the first pressure ring; when the wear-resistant block is embedded in the third airflow channel, the inner protective plate is connected to the inner lower protective plate to form the inner wall of the flow channel; the second blade is connected to the first blade to form a guide blade; and the outer protective plate is connected to the outer lower protective plate to form the outer wall of the flow channel.

7. The high uniformity, low energy consumption static nozzle ring device according to claim 6, characterized in that: When the wear-resistant block is embedded in the third airflow channel, the edge line of the longitudinal section of the inner wall of the channel is a combination of a straight line and a spline curve from top to bottom. The upper 1 / 4 section is a straight line at an angle of 10° to 20° with the vertical direction, and the upper 1 / 4 to the bottom is a spline curve, and the center of curvature is all outside the flow area.

8. The high uniformity, low energy consumption static nozzle ring device according to claim 6, characterized in that: When the wear-resistant block is embedded in the third airflow channel, the edge line of the longitudinal section of the outer wall of the channel is a combination of a straight line and a spline curve from top to bottom. The upper 1 / 5 section is a straight line at an angle of 10° to 20° with the vertical direction, and the upper 1 / 5 to the bottom is a spline curve, with the center of curvature of the circle all located outside the flow area.

9. The high uniformity, low energy consumption static nozzle ring device according to claim 6, characterized in that: When the wear-resistant block is embedded in the third airflow channel, the edge line of the guide vane in contact with the outer wall of the channel is a combination of a straight line and a spline curve from top to bottom. The upper 1 / 4 section is a straight line at 40° to 50° with the horizontal direction, and the upper 1 / 4 to the bottom is a spline curve, and the angle between the bottom tangent direction and the vertical direction is 0° to 15°.

10. The high uniformity, low energy consumption static nozzle ring device according to claim 6, characterized in that: Both the inner and outer protective plates have an angle of 10° to 20° with the vertical direction.

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