Packing sealing structure applied to high-pressure medium

Abstract

The invention discloses a packing sealing structure applied to a high-pressure medium, and relates to the technical field of fluid mechanical sealing, the packing sealing structure comprises a pump body and a shaft body, the pump body is internally provided with a pump cavity, the upper end of the pump body is detachably provided with a stuffing box body, the stuffing box body is internally provided with a stuffing shaft sleeve, and the sealing cavity is internally provided with three groups of packing bodies; a lower water seal ring is installed between every two adjacent groups of packing bodies on the lower portion, a middle water seal ring is installed between every two adjacent groups of packing bodies on the upper portion, a packing gland is detachably installed on the surface of the shaft body above the uppermost packing body, and a pressure relief hole is formed in the surface of the packing box body on one side of the middle water seal ring. The lower water seal ring and the higher middle water seal ring are arranged in a grading mode, high-pressure media can be decompressed, gathered and integrated step by step, the pressure of the media is gradually attenuated to micro pressure from high pressure of a pump cavity, medium and low pressure leakage media are discharged in time in cooperation with the pressure relief holes, and the problems that a traditional single laminated packing is difficult to resist impact of the high-pressure media and prone to leakage are solved.

Description

Technical Field

[0001] This invention relates to the field of fluid mechanical seal technology, specifically to a packing seal structure applied to high-pressure media. Background Technology

[0002] Packing seals (also known as packing seals) are a traditional and widely used form of contact seal. Due to their simple structure, low manufacturing cost, and convenient disassembly and maintenance, they have long held an important position in shaft end sealing of fluid conveying equipment. Their core working principle involves applying axial pressure to the packing gland, causing radial expansion of the packing, which then tightly adheres to the surface of the rotating shaft and the inner wall of the sealing cavity, forming a sealing surface and blocking the leakage path of the medium. Currently, when the conveying medium is under high pressure (usually referring to pressure ≥10MPa), traditional packing seal structures are gradually revealing many insurmountable defects: First, poor sealing reliability and easy leakage: High-pressure media will exert strong radial impact and penetration on the packing. Traditional packings mostly use a single material or a simple stacked structure, making it difficult to guarantee the uniformity of radial expansion and the stability of compression. This easily leads to leakage channels at the fit gaps between the packing and the shaft, and between the packing and the sealing cavity, resulting in high-pressure media leakage. This not only wastes the media but may also cause safety accidents (such as leakage of flammable, explosive, or corrosive high-pressure media). Second, rapid packing wear and short service life: Under high-pressure conditions, the contact pressure between the packing and the rotating shaft increases significantly, and the scouring of the high-pressure media will exacerbate the wear of the packing. In addition, traditional packings... The packing has poor thermal conductivity, and the heat generated by friction cannot be dissipated in time, which can easily lead to local carbonization and aging of the packing, further shortening its service life. Third, the risk of shaft wear is high: under high pressure, the interference fit between the packing and the shaft increases, and the accumulation of frictional heat can easily lead to wear, scoring and other damage on the shaft surface. If impurities are mixed in the packing, a "grinding effect" will also be formed, which will accelerate the wear of the shaft. In severe cases, the drive shaft needs to be replaced, which further increases the equipment maintenance cost. Fourth, in order to improve the sealing effect under high pressure, traditional packing seals need to apply a large axial clamping force. This not only requires the gland mechanism to have sufficient strength, but also places extremely high demands on the accuracy of clamping force control during the installation process. Insufficient clamping force will cause the seal to fail, while excessive clamping force will aggravate the wear of the packing and shaft, increase rotational resistance, and reduce equipment energy efficiency. Based on this, developing a new type of packing seal structure that can adapt to high-pressure media conditions, has high sealing reliability, low wear, long service life, and is easy to install and maintain has become a technical problem that still needs to be solved in the field of sealing technology for water pumps and fluid conveying equipment. Summary of the Invention

[0003] The purpose of this invention is to provide a packing seal structure for use with high-pressure media, so as to solve the problems mentioned in the background art. To achieve the above objectives, the present invention provides the following technical solution: a packing seal structure for high-pressure media, comprising a pump body and a shaft, wherein a pump chamber is provided inside the pump body, a stuffing box is detachably installed at the upper end of the pump body, a stuffing sleeve is installed inside the stuffing box, the shaft is located inside the stuffing sleeve, a sealing cavity is formed between the stuffing sleeve and the stuffing box, three sets of packing bodies are installed inside the sealing cavity, a lower water seal ring is installed between two adjacent sets of packing bodies at the bottom, a middle water seal ring is installed between two adjacent sets of packing bodies at the top, a packing gland is detachably installed on the surface of the shaft above the uppermost packing body, a pressure relief hole is provided on the surface of the stuffing box on one side of the middle water seal ring, a liquid collection groove is provided at the upper end of the stuffing box, a discharge hole is provided at one end of the liquid collection groove, and a drain hole is provided on the surface of the packing gland above the liquid collection groove. Preferably, the upper end of the stuffing box has three through holes arranged in a circumferential array, and each through hole is fitted with a connecting bolt. One end of each connecting bolt extends into the pump body through a screw hole. Positioning posts are installed on both sides of the lower end of the stuffing box, and one end of each positioning post extends into the pump body. Preferably, the height of the lower water seal ring is less than the height of the middle water seal ring. Preferably, each group of the disk bases consists of two disk bases, and the interfaces of the multiple disk bases are staggered. Preferably, both the bottom end of the sealing cavity and the lower end of the packing gland are provided with inclined surfaces. Preferably, the packing gland is a split design, consisting of two half-glanders connected and fixed by screws. Each half-glander has a mounting plate installed on its surface, and a connecting stud is installed at the upper end of the packing gland below the mounting plate. The upper end of the connecting stud penetrates the mounting plate, and a nut is installed on the surface of the connecting stud. Compared with the prior art, the beneficial effects of the present invention are: This packing seal structure, applied to high-pressure media, employs a combination design of "three sets of packing bodies + graded water seal rings." Each set of packing bodies consists of two packings with staggered interfaces. The staggered interfaces can block the medium's permeation channels, forming multiple sealing barriers. At the same time, the graded arrangement of the lower water seal ring and the taller middle water seal ring can gradually reduce and consolidate the high-pressure medium, causing the medium pressure to gradually decrease from the high pressure in the pump cavity to a low pressure. Combined with the pressure relief hole, it can promptly discharge medium and low-pressure leaked media, fundamentally solving the problem that traditional single-layer packing is unable to withstand the impact of high-pressure media and is prone to leakage. This packing seal structure, applied to high-pressure media, features a beveled structure at the bottom of the sealing cavity and the lower end of the packing gland. During compression, the beveled structure guides the outer packing body to distribute force evenly, while the inner packing body expands moderately. This ensures a tight seal and avoids excessive compression that could cause hard friction between the packing and the packing sleeve, thus reducing the packing wear rate. This packing seal structure, applied to high-pressure media, features a split-type packing gland design. It is secured by two half-gland glands that snap together. When replacing the packing, it is not necessary to disassemble the entire packing gland body; only the half-gland glands need to be separated to remove the old part and install the new part, thus solving the problem of cumbersome disassembly and assembly of traditional sealing structures. Attached Figure Description Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a front cross-sectional view of the present invention; Figure 3 For the present invention Figure 2 Enlarged view of point A in the middle; Figure 4 For the present invention Figure 2 Enlarged view of point B in the middle. In the diagram: 1. Pump body; 2. Shaft; 3. Pump chamber; 4. Stuffing box; 5. Packing sleeve; 6. Sealing chamber; 7. Lower water seal ring; 8. Middle water seal ring; 9. Packing gland; 10. Pressure relief hole; 11. Liquid collection tank; 12. Discharge hole; 13. Connecting bolt; 14. Positioning pin; 15. Inclined surface; 16. Half gland; 17. Screw; 18. Mounting plate; 19. Connecting stud; 20. Nut; 21. Base body; 22. Drain hole. Detailed Implementation The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for 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 invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. like Figures 1 to 4As shown, this embodiment applies to a packing seal structure for high-pressure media, including a pump body 1 and a shaft 2. The pump body 1 serves as the main support of the entire sealing structure, while the shaft 2 transmits power to achieve the rotational movement of the equipment. It is the power transmission component for media transportation or related operations. A pump chamber 3 is provided inside the pump body 1, which is the space for media flow or related operations. A stuffing box 4 is detachably installed on the upper end of the pump body 1. The stuffing box 4 provides installation space for sealing elements such as the packing body 21 and also protects and fixes the internal components. A stuffing sleeve 5 is installed inside the stuffing box 4, with the shaft 2 located inside the stuffing sleeve 5. The stuffing sleeve 5 guides and supports the shaft 2, forming a sealing cavity between the stuffing sleeve 5 and the stuffing box 4. 6. Three sets of disc bodies 21 are installed inside the sealing cavity 6. A lower water seal ring 7 is installed between two adjacent sets of disc bodies 21 at the bottom, and a middle water seal ring 8 is installed between two adjacent sets of disc bodies 21 at the top. A packing gland 9 is detachably installed on the surface of the shaft body 2 above the uppermost disc body 21. A pressure relief hole 10 is provided on the surface of the stuffing box 4 on one side of the middle water seal ring 8. A liquid collection tank 11 is provided at the upper end of the stuffing box 4. The liquid collection tank 11 collects a small amount of medium that may leak, preventing the medium from flowing out and polluting the environment or causing waste. A discharge hole 12 is provided at one end of the liquid collection tank 11. The discharge hole 12 is used to discharge the medium collected in the liquid collection tank 11 for unified treatment. A drain hole 22 is provided on the surface of the packing gland 9 above the liquid collection tank 11. The drain hole 22 is used to discharge medium and low pressure leaked medium. Specifically, the upper end of the stuffing box 4 has three through holes arranged in a circular array, and each through hole is fitted with a connecting bolt 13. One end of the connecting bolt 13 extends into the pump body 1 through a screw hole. The lower end of the stuffing box 4 has two positioning pins 14 installed on both sides. One end of the positioning pin 14 extends into the pump body 1. When installing the stuffing box 4, the positioning pin 14 is inserted into the pump body 1, which facilitates the connection of the stuffing box 4 and the pump body 1 using the connecting bolts 13. Furthermore, the height of the lower water seal ring 7 is smaller than that of the middle water seal ring 8, increasing the size of the subsequent water seal ring and forming a large collection cavity, effectively reducing the pressure of the leaking medium. Furthermore, each set of disc bodies 21 consists of two, with the interfaces of multiple disc bodies 21 arranged in an alternating pattern. The multiple disc bodies 21 are closely arranged with their interfaces interlaced, and under pressure, they tightly fit the shaft body 2 and stuffing box body 4, forming a reliable sealing barrier to prevent leakage of high-pressure media. Furthermore, both the bottom end of the sealing cavity 6 and the lower end of the packing gland 9 are provided with inclined surfaces 15. The inclined surfaces 15 can press the outer disc body 21 tightly, and the inner disc body 21 will expand. This can reduce leakage and reduce wear on the packing bushing 5, thereby increasing its service life. Furthermore, the packing gland 9 is a split design, consisting of two half-gland 16 connected and fixed by screws 17. Each half-gland 16 has a mounting plate 18 installed on its surface. The upper end of the stuffing box 4 below the mounting plate 18 is equipped with a connecting stud 19, which penetrates the mounting plate 18. A nut 20 is installed on the surface of the connecting stud 19. The two half-gland 16 are combined into the packing gland 9 by using screws 17. The packing gland 9 is connected to the stuffing box 4 by the connecting stud 19 and the nut 20, making it convenient to replace the packing body 21. The usage method of this embodiment is as follows: During installation, align the positioning pin 14 at the lower end of the stuffing box 4 with the corresponding positioning hole of the pump body 1 and insert it to achieve precise alignment; then, insert the three connecting bolts 13 into the through hole at the upper end of the stuffing box 4, align them with the screw holes of the pump body 1 and tighten them to complete the fixed assembly of the stuffing box 4 and the pump body 1. Then, put the stuffing sleeve 5 into the shaft 2, and install the two disc bases 21-lower water seal ring 7-two disc bases 21-middle water seal ring 8-two disc bases 21 into the sealing cavity 6 in sequence. Then, symmetrically fasten the two half-caps 16 on the surface of the shaft 2 and use screws 17 to combine and fix them to form the stuffing cap 9. Then, align the mounting plate 18 on the assembled stuffing cap 9 with the connecting stud 19 at the upper end of the stuffing box 4 and put it on. Tighten the nut on the upper end of the connecting stud 19. 20. The inclined surface 15 at the lower end of the packing gland 9 presses the outer packing body 21 tightly, so that the inner packing body 21 expands appropriately to fit the shaft 2 and the stuffing box 4, completing the sealing and pressing, and completing the installation operation. When in use, the high pressure in the pump chamber 3 directly enters the sealing chamber 6 after the first throttling of the stuffing box 4. After passing through two packing rings, it gathers in the lower water seal ring 7 to form a secondary high pressure liquid. After passing through two packing bodies 21, it enters the cavity of the middle water seal ring 8. The middle water seal ring 8 is larger than the lower water seal ring 7, mainly to collect and integrate the leaked medium. At this time, the medium pressure is already very low. Then it is discharged from the pressure relief hole 10 on the left side. Finally, it leaks through the two packing bodies 21 at the top and leaks from the vent hole 22 on the surface of the packing gland 9. At this time, the leakage amount is negligible. Finally, it gathers in the collection tank 11 and is led away by the discharge hole 12 on the right side. Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A packing seal structure for high-pressure media, comprising a pump body (1) and a shaft (2), characterized in that: The pump body (1) has a pump chamber (3) inside. A stuffing box (4) is detachably installed on the upper end of the pump body (1). A stuffing sleeve (5) is installed inside the stuffing box (4). The shaft (2) is located inside the stuffing sleeve (5). A sealing cavity (6) is formed between the stuffing sleeve (5) and the stuffing box (4). Three sets of disc base bodies (21) are installed inside the sealing cavity (6). A water seal ring (7) is installed between two adjacent sets of disc base bodies (21) below. A water seal ring (7) is installed between two adjacent sets of disc base bodies (21) above. A water seal ring (8) is installed between the base bodies (21) of the group. A packing gland (9) is detachably installed on the surface of the shaft body (2) above the uppermost base body (21). A pressure relief hole (10) is provided on the surface of the packing gland (4) on one side of the water seal ring (8). A liquid collection tank (11) is provided at the upper end of the packing gland (4). A discharge hole (12) is provided at one end of the liquid collection tank (11). A drain hole (22) is provided on the surface of the packing gland (9) above the liquid collection tank (11).

2. The packing seal structure for high-pressure media according to claim 1, characterized in that: The stuffing box (4) has three through holes arranged in a circular array at its upper end. Each through hole is fitted with a connecting bolt (13). One end of the connecting bolt (13) extends into the pump body (1) through a screw hole. Positioning pins (14) are installed on both sides of the lower end of the stuffing box (4). One end of the positioning pin (14) extends into the pump body (1).

3. The packing seal structure for high-pressure media according to claim 1, characterized in that: The height of the lower water seal ring (7) is less than the height of the middle water seal ring (8).

4. The packing seal structure for high-pressure media according to claim 1, characterized in that: The number of each set of the disk body (21) is two, and the interfaces of the multiple disk bodies (21) are staggered.

5. The packing seal structure for high-pressure media according to claim 1, characterized in that: The bottom end of the sealing cavity (6) and the bottom end of the packing gland (9) are both provided with inclined surfaces (15).

6. The packing seal structure for high-pressure media according to claim 1, characterized in that: The packing gland (9) is a split design. The packing gland (9) is composed of two half glands (16). The two half glands (16) are connected and fixed by screws (17). The surface of each half gland (16) is equipped with a mounting plate (18). The upper end of the packing gland (4) below the mounting plate (18) is equipped with a connecting stud (19). The upper end of the connecting stud (19) penetrates the mounting plate (18). The surface of the connecting stud (19) is equipped with a nut (20).

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