Sealing structure of hollow shaft of pre-pressing coal mill
Through the combined structure of the inner pressure plate, flexible sealing cover and external pressure plate, the seal failure problem of coal mill when the sealing air pressure is insufficient is solved, effective sealing and vibration protection under low pressure conditions is achieved, and material costs are reduced.
Patent Information
- Application Number
- CN202421642271.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-11
- Publication Date
- 2025-04-11
- Estimated Expiration
- 2034-07-11
AI Technical Summary
The special sealing structure of existing coal mills cannot contact the rotating metal ring when the sealing wind pressure is insufficient, resulting in high-frequency vibration and seal failure, making it impossible to effectively seal the mill.
The combined structure of the inner pressure plate, a flexible sealing cover and an outer pressure plate is adopted. The inner pressure plate is equipped with a radially extending pressing plate. Under the wind force of the sealing fan, the flexible sealing cover is bonded to the metal ring to form a pre-pressing effect and ensure the sealing effect.
It can still maintain an effective seal when the sealing wind pressure is insufficient, preventing the flexible sealing cover from being damaged by high-frequency vibration, reducing costs and improving sealing effect.
Smart Images
Figure CN222746605U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the structure of a steel ball coal mill, in particular to a sealing structure for pre-pressing a hollow shaft of the coal mill. Background Art
[0002] The coal mill of the boiler pulverizing system adopts a positive pressure direct-blowing steel ball coal mill. Since the coal mill runs in a positive pressure state, a special sealing structure is installed between the rotating hollow shaft of the mill and the stationary frame (hollow tube). The sealing wind provided by the sealing fan, which is higher than the primary air pressure in the mill, acts on the special sealing structure, making the special sealing structure tightly attached to the rotating metal ring fixed on the hollow shaft, thereby achieving the effect of mill sealing.
[0003] The above sealing structure has the following problems: when the sealing air pressure of the coal mill is insufficient, the special sealing structure cannot contact the rotating metal ring, causing high-frequency vibration of the special sealing structure, which cannot effectively seal the mill, and the high-frequency vibration will also damage the sealing cover. Utility Model Content
[0004] The technical problem to be solved by the utility model is that the special sealing structure has no pre-compression function. When the sealing wind pressure of the coal mill is insufficient, the special sealing structure cannot contact with the rotating metal ring, causing high-frequency vibration of the special sealing structure and failing to effectively seal the mill. The purpose is to provide a sealing structure for pre-compressing the hollow shaft of the coal mill, so as to solve the problem that the special sealing structure cannot effectively seal the mill when the sealing wind pressure of the coal mill is insufficient.
[0005] The utility model is realized by the following technical solutions:
[0006] A sealing structure for pre-compressing a hollow shaft of a coal mill comprises an inner pressure plate, a flexible sealing cover and an outer pressure plate, wherein the inner pressure plate, the flexible sealing cover and the outer pressure plate are connected in sequence, and a free end of the inner pressure plate is formed with a plurality of compression sheets extending along its radial direction, and the inner pressure plate is located on a side where a sealing fan is provided, and under the action of the wind force of the sealing fan, each of the compression sheets applies force to the free end of the flexible sealing cover, so that the free end of the flexible sealing cover fits with a metal ring connected to the hollow shaft.
[0007] The utility model adopts the above scheme, by arranging an inner pressure plate, a flexible sealing cover and an outer pressure plate which are fitted and connected in sequence, and forming a plurality of compression sheets extending radially thereof at the free end of the inner pressure plate, so that when the sealing wind pressure of the coal mill is insufficient, the compression sheet whose structure is smaller than that of the inner pressure plate can be deformed under the action of wind force, and force is applied to the free end of the flexible sealing cover so that the free end of the flexible sealing cover fits with the metal ring connected to the hollow shaft and is retained on the metal ring, thereby forming an effective seal for the mill and preventing the flexible sealing cover from being damaged due to high-frequency vibration when the wind pressure is insufficient.
[0008] Preferably, a sealed air box is connected to the frame, and an assembly formed by the inner pressure plate, the flexible sealing cover and the outer pressure plate is connected to the inner side of the sealed air box.
[0009] In this way, by connecting the sealing air box to the frame, the component can be easily attached to the metal ring and form an effective seal on the mill together with the sealing air box.
[0010] Preferably, the inner pressure plate, the flexible sealing cover and the outer pressure plate are all circular plates with the same diameter, and the outer sides of the circular plates are connected to the sealing air box.
[0011] In this way, the inner pressure plate, the flexible sealing cover and the outer pressure plate are all circular plates with the same diameter, and the outer side of the circular plates is connected to the sealing wind box, so that when the sealing structure is in contact with the metal ring, it can form an effective seal on the mill together with the sealing wind box.
[0012] Preferably, the inner side of the inner pressure plate is provided with a plurality of strip-shaped through holes extending in its radial direction, and the strip-shaped structure between two adjacent strip-shaped through holes constitutes the pressing plate.
[0013] In this way, by arranging a plurality of strip-shaped through holes extending radially along the inner side of the inner pressure plate, it is convenient to form a clamping sheet on the inner pressure plate through the strip-shaped through holes, thereby ensuring the connection strength and rigidity between the clamping sheet and the inner pressure plate.
[0014] Preferably, the compression sheet may be in the shape of a strip, a trapezoid or a triangle.
[0015] In this way, the flexible sealing cover is subjected to force by arranging the pressing piece in the shape of a long strip, a trapezoid or a triangle.
[0016] Preferably, the pressing pieces are evenly distributed in a circle with the center of the inner pressure plate.
[0017] In this way, by evenly distributing the compression pieces in a circle with the center of the inner pressure plate, the flexible sealing cover can be evenly stressed, so that the flexible sealing cover is completely fitted with the metal ring to achieve a satisfactory sealing effect.
[0018] Preferably, the flexible sealing cover is composed of several segments of arc-shaped plates connected together.
[0019] In this way, by connecting the flexible sealing cover with several arc-shaped plates, it is easy to prevent a part of the structure of the flexible sealing cover from warping when it is in contact with the metal ring, thereby affecting the sealing effect.
[0020] Preferably, a plurality of concave-convex structures are formed on both sides of the arc-shaped plate constituting the flexible sealing cover, and two adjacent arc-shaped plates are connected by matching the concave-convex structures.
[0021] In this way, the two adjacent arc-shaped plates are connected through the matching concave-convex structures, so as to prevent air leakage at the connection point.
[0022] Preferably, the flexible sealing cover is made of EP200 polyurethane flame retardant belt.
[0023] In this way, the cost can be reduced by making the flexible sealing cover with EP200 polyurethane flame retardant belt instead of the original imported material.
[0024] Preferably, a side of the metal ring close to the flexible sealing cover is formed with an inclined portion inclined toward the flexible sealing cover, and the flexible sealing cover can fit with the inclined portion.
[0025] In this way, by forming an inclined portion inclined toward the flexible sealing cover on the side of the metal ring close to the flexible sealing cover, the contact area between the flexible sealing covers is increased, thereby improving the sealing effect.
[0026] Compared with the prior art, the utility model has the following advantages and beneficial effects:
[0027] 1. By arranging a compression sheet on the inner pressure plate, when the sealing wind pressure of the coal mill is insufficient, the compression sheet whose structure is smaller than the inner pressure plate can be deformed under the action of wind force, and force is applied to the free end of the flexible sealing cover, so that the free end of the flexible sealing cover fits with the metal ring connected to the hollow shaft and is kept on the metal ring, thereby forming an effective seal for the mill.
[0028] 2. When the wind pressure is insufficient, the flexible sealing cover can also fit on the metal ring to prevent the flexible sealing cover from being damaged due to high-frequency vibration.
[0029] 3. Reduce costs by making the flexible sealing cover with EP200 polyurethane flame retardant belt instead of the original imported materials.
[0030] 4. An inclined portion inclined toward the flexible sealing cover is formed on one side of the metal ring close to the flexible sealing cover, so as to increase the contact area between the flexible sealing covers and improve the sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The drawings described herein are used to provide a further understanding of the embodiments of the present utility model, constitute a part of this application, and do not constitute a limitation of the embodiments of the present utility model.
[0032] In the attached picture:
[0033] Figure 1 It is a structural diagram of the utility model;
[0034] Figure 2 This is a structural diagram of the coal mill of the utility model when it is not started;
[0035] Figure 3 For this utility model Figure 1 A magnified view of part K in FIG.
[0036] Figure 4 This is a structural diagram of the inner pressure plate in the utility model;
[0037] Figure 5 This is a structural diagram of the flexible sealing cover in the utility model;
[0038] Figure 6 It is the structural diagram of the middle and outer pressure plates of the utility model.
[0039] Marks and corresponding parts names in the attached drawings:
[0040] The frame 10 , the sealing air box 11 , the inner pressure plate 20 , the pressing sheet 21 , the flexible sealing cover 30 , the outer pressure plate 40 , the metal ring 50 , the inclined portion 51 , and the hollow shaft 60 . DETAILED DESCRIPTION
[0041] In order to make the purpose, technical solutions and advantages of the utility model more clearly understood, the utility model is further described in detail below in conjunction with embodiments and drawings. The schematic implementation manner of the utility model and its description are only used to explain the utility model and are not intended to limit the utility model.
[0042] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any appropriate combination and / or sub-combination. In addition, it will be appreciated by those of ordinary skill in the art that the diagrams provided herein are for illustrative purposes, and the diagrams are not necessarily drawn to scale. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items.
[0043] In the description of the present invention, the terms "front", "rear", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the scope of protection of the present invention.
[0044] The terms "first", "second", etc. used in the present invention are only used to distinguish the corresponding components for the purpose of clarity of description, and are not intended to limit any order or emphasize importance, etc. In addition, the term "connected" used in this article can be directly connected or indirectly connected via other components without special explanation.
[0045] Example 1
[0046] This embodiment 1 provides a sealing structure for pre-compressing the hollow shaft 60 of the coal mill, such as Figure 1-Figure 6 As shown, it includes an inner pressure plate 20, a flexible sealing cover 30 and an outer pressure plate 40, and the inner pressure plate 20, the flexible sealing cover 30 and the outer pressure plate 40 are sequentially fitted and connected, and the free end of the inner pressure plate 20 is formed with a plurality of compression sheets 21 extending along its radial direction, and the inner pressure plate 20 is located on the side where the sealing fan is provided, and under the action of the wind force of the sealing fan, each of the compression sheets 21 applies force to the free end of the flexible sealing cover 30, so that the free end of the flexible sealing cover 30 fits with the metal ring 50 connected to the hollow shaft 60.
[0047] See also Figure 1-Figure 3 , further comprising a sealing air box 11, the sealing air box 11 is connected to the frame 10, and the sealing structure is connected to the inner side of the sealing air box 11. Specifically, the sealing structure is connected to the inner side of the sealing air box 11 by bolts.
[0048] See also Figure 1-Figure 3 The inner pressure plate 20 , the flexible sealing cover 30 and the outer pressure plate 40 are all circular plates with the same diameter, and the outer sides of the circular plates are connected to the sealing air box 11 .
[0049] The inner diameters of the outer pressure plate 40, the inner pressure plate 20 and the flexible sealing cover 30 decrease in sequence, so that the outer side of the flexible sealing plate can be supported by the outer pressure plate 40 to give it a certain rigidity, and a certain pre-pressure is applied to the flexible sealing cover 30 by the inner pressure plate 20, so that the flexible sealing plate exposed outside the outer pressure plate 40 can be kept in contact with the metal ring 50.
[0050] Specifically, the inner diameter of the outer pressure plate 40 can be set to be slightly smaller than the outer diameter of the hollow shaft 60 to reduce the gap between the outer pressure plate 40 and the hollow shaft 60 and prevent the metal ring from running out of the end surface of the hollow shaft 60 when the sealing pressure is too high.
[0051] See also Figure 4 The inner side of the inner pressure plate 20 is provided with a plurality of strip-shaped through holes extending in the radial direction thereof, and the strip structure between two adjacent strip-shaped through holes constitutes the pressing sheet 21. The pressing sheet 21 can be in the shape of a long strip, a trapezoid or a triangle.
[0052] Specifically, the pressing pieces 21 are evenly distributed in a circle with the center of the inner pressure plate 20 , so that when the mill is sealed, the flexible sealing plate is evenly stressed as a whole, so that it is completely fitted with the metal ring 50 .
[0053] See also Figure 1 and Figure 5 The flexible sealing cover 30 is composed of several arc-shaped plates connected to each other, so that the flexible sealing cover 30 can be fitted with the metal ring 50, and the flexible sealing plate is prevented from being partially lifted when being fitted with the metal ring 50, thereby affecting the sealing effect.
[0054] See also Figure 1 A plurality of concave-convex structures are formed on both sides of the arc-shaped plate constituting the flexible sealing cover 30, and two adjacent arc-shaped plates are connected by the matching concave-convex structures.
[0055] Specifically, the matching concave-convex structures can adopt a stepped structure or other concave-convex structures to match each other, so as to increase the strength of the connection and prevent air leakage.
[0056] See also Figure 1 and Figure 6 The flexible sealing cover 30 is made of EP200 polyurethane flame retardant belt, replacing the original imported materials to reduce costs. It is also convenient to utilize the sealing properties of the rubber on the surface of the polyurethane flame retardant belt, and the nylon meridian in the middle of the polyurethane flame retardant belt provides tensile resistance for the flexible sealing cover 30 to achieve the required sealing effect.
[0057] See also Figure 1 A sloped portion 51 inclined toward the flexible sealing cover 30 is formed on one side of the metal ring 50 close to the flexible sealing cover 30 , and the flexible sealing cover 30 can fit in the sloped portion 51 .
[0058] When working, Figure 1 As shown, at the initial start-up of the unit, when the sealing wind pressure is relatively low, the flexible sealing cover 30 relies on the compression sheet 21 on the inner pressure plate 20 to provide a certain pre-tightening force, so as to make close contact with the hollow shaft 60 of the coal mill, thereby eliminating the sealing wind leakage caused by insufficient sealing wind force at the initial start-up of the unit. The flow direction of the sealing wind force is shown in FIG. Figure 1-Figure 3 When the unit is operating normally, the pressure of the sealing air reaches the set value. At this time, the flexible sealing cover 30 is pressed again to make the flexible sealing cover 30 in close contact with the end surface of the hollow shaft 60 to achieve a long-term sealing effect.
[0059] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only the specific implementation method of the utility model and is not used to limit the protection scope of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.
Claims
1. A sealing structure for pre-compressing a hollow shaft of a coal mill, characterized in that: It includes an inner pressure plate, a flexible sealing cover and an outer pressure plate, which are connected in sequence, and the free end of the inner pressure plate is formed with several compression sheets extending along its radial direction. The inner pressure plate is located on the side where a sealing fan is provided. Under the action of the wind force of the sealing fan, each of the compression sheets applies force to the free end of the flexible sealing cover, so that the free end of the flexible sealing cover fits with the metal ring connected to the hollow shaft.
2. The sealing structure for pre-pressing the hollow shaft of a coal mill according to claim 1, characterized in that: It also includes a sealed air box, which is connected to the frame, and an assembly formed by the inner pressure plate, the flexible sealing cover and the outer pressure plate is connected to the inner side of the sealed air box.
3. The sealing structure for pre-pressing the hollow shaft of a coal mill according to claim 2, characterized in that: The inner pressure plate, the flexible sealing cover and the outer pressure plate are all circular plates with the same diameter, the outer side of the circular plate is connected to the sealed air box, and the inner diameters of the outer pressure plate, the inner pressure plate and the flexible sealing cover decrease in sequence.
4. The sealing structure for pre-pressing the hollow shaft of a coal mill according to claim 2, characterized in that: The inner side of the inner pressure plate is provided with a plurality of strip-shaped through holes extending in the radial direction thereof, and the strip-shaped structure between two adjacent strip-shaped through holes constitutes the pressing sheet.
5. The sealing structure for pre-pressing the hollow shaft of a coal mill according to claim 1, characterized in that: The compression piece can be in the shape of a strip, a trapezoid or a triangle.
6. The sealing structure for pre-pressing the hollow shaft of a coal mill according to claim 2, characterized in that: The pressing pieces are evenly distributed in a circle with the center of the inner pressure plate.
7. The sealing structure for pre-pressing the hollow shaft of a coal mill according to claim 1, characterized in that: The flexible sealing cover is composed of several segments of circular arc plates connected together.
8. The sealing structure for pre-pressing the hollow shaft of a coal mill according to claim 7, characterized in that: A plurality of concave-convex structures are formed on both sides of the arc-shaped plate constituting the flexible sealing cover, and two adjacent arc-shaped plates are connected by the matching concave-convex structures.
9. The sealing structure for pre-pressing the hollow shaft of a coal mill according to claim 1, characterized in that: The flexible sealing cover is made of EP200 polyurethane flame retardant belt.
10. The sealing structure for pre-pressing the hollow shaft of a coal mill according to any one of claims 1 to 9, characterized in that: An inclined portion inclined toward the flexible sealing cover is formed on one side of the metal ring close to the flexible sealing cover, and the flexible sealing cover can be fitted with the inclined portion.