A high-pressure mechanical seal device suitable for wax oil

Abstract

The utility model discloses a kind of high-pressure mechanical seal devices suitable for wax oil, belong to sealing device technical field, specifically relate to.The utility model mechanical seal adopts spring external, spring does not contact medium, and the wax oil leaked in standard range does not affect the compensation performance of spring.Meanwhile section adopts hard to hard end face design, and hard to hard end face pairing is as follows: mechanical seal dynamic ring and static ring are ceramic hard material, and hard to hard end face can make wax oil liquid film between end face thin, effectively reduce leakage amount.Leaked wax oil can be discharged without spring, can make mechanical seal keep compensation performance.Prolong the service life of mechanical seal.Moreover, ceramic has good heat conductivity, and wax oil permeated into inner hole does not condense, and it will flow out in time after exceeding inner hole edge, and will not produce jam to compensation ring.

Description

Technical Field

[0001] This utility model relates to the field of sealing device technology, and more specifically to a high-pressure mechanical seal device suitable for wax oil. Background Technology

[0002] The working principle of a mechanical seal is to prevent media leakage by utilizing the friction generated between the sealing surfaces. A mechanical seal is a shaft sealing device for rotating machinery. Besides requiring good machining accuracy of the sealing end faces, it also needs to maintain contact and relative sliding through the action of fluid pressure, the elastic force of the compensation mechanism, and the cooperation of auxiliary seals to prevent fluid leakage. A common mechanical seal structure consists of a stationary ring, a rotating ring, an elastic element spring seat, a set screw, auxiliary sealing rings for the rotating and stationary rings, etc., with an anti-rotation pin fixed to the gland to prevent the stationary ring from rotating. There are four possible leakage paths in a mechanical seal. Two of these are the seals between the stationary ring and the gland, and between the gland and the housing, both of which are static seals. The other path is the seal between the rotating ring and the shaft; after the end faces wear down due to friction, it can only move slightly axially following the compensation ring, effectively remaining a relatively static seal. Therefore, these leakage paths are relatively easy to seal. The last channel is the dynamic seal, where the end faces of the rotating ring and the stationary ring slide relative to each other. It is the main seal in the mechanical seal device and is the key to determining the performance and life of the mechanical seal.

[0003] The mechanical seal is a static bellows seal. The original mechanical seal's usage status and defects include: 1) Usage status: The original bellows mechanical seal typically showed leakage exceeding the standard leakage rate after half a month of use, with the leakage gradually increasing. 2) Design defects of the original mechanical seal: Because the mechanical seal has a certain leakage rate within the standard range, the leaked wax oil from the original seal had to pass through the bellows, filling the gap between the bellows and the water jacket before flowing out. During this process, the leaked wax oil would gradually solidify, causing the bellows' compensation performance to gradually decrease until it failed. For example, the applicant's 400,000-ton / year tail oil isomerization dewaxing and hydrogenation unit's high-pressure pump previously used mechanical seals from major brands like Dandong Kron or John Crane. Leaks began to appear one month after installation, and the seals were generally not used for more than three months. In 2023, a Dandong Chenghai high-pressure pump mechanical seal was used, put into operation on December 25th, and leaked after 15 days of use on January 10th, 2024. After the leak, the high-pressure pump was switched to the standby machine and the seal of the machine in use was replaced. It was also a mechanical seal of the high-pressure pump from Dandong Chenghai. However, after being put into use on February 22, 2024, it leaked again after only one day of use.

[0004] Therefore, redesigning the high-pressure seal to ensure its continuous and stable operation for a longer period of time is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] This utility model aims to at least partially solve one of the aforementioned technical problems in the prior art.

[0006] Therefore, one objective of this utility model is to provide a high-pressure mechanical seal device suitable for wax oil, comprising a bushing fixed on a shaft and rotating with the shaft via a transmission device.

[0007] The bushing has a groove at one end, and the transmission device is fixed to the other end of the bushing; at least one third auxiliary sealing ring is provided on the outer surface of the bushing groove.

[0008] The bushing has a spring, a push ring, and a moving ring arranged sequentially from the inside to the outside in the groove, wherein the spring, push ring, and moving ring abut against each other in sequence;

[0009] The other end of the rotating ring abuts against a stationary ring, and a first auxiliary sealing ring is provided between the rotating ring and the inner wall of the groove of the bushing;

[0010] The other end of the stationary ring is fixedly abutted against the gland, and a second auxiliary sealing ring is provided at the connection between the stationary ring and the gland; the stationary ring is fixed to the sealing cavity of the gland by a nut and a double-ended stud;

[0011] The gland surface is also provided with a fourth auxiliary sealing ring;

[0012] An anti-rotation pin is also provided between the stationary ring and the gland, and the anti-rotation pin is fixed above the second sealing ring;

[0013] The other end of the pressure cap is provided with a limiting plate, and the limiting plate is fixed on the bushing. The limiting plate and the pressure cap are fixedly connected by bolts.

[0014] Furthermore, the transmission device includes an expansion ring 2, a transmission ring A 4, a transmission ring B 5, and a transmission ring bolt 19;

[0015] The expansion ring is fixed to one end of the bushing, and the transmission ring A4 and transmission ring B5 are symmetrically fixed above the expansion ring; the transmission ring bolt is connected to the transmission ring B bolt and passes through the transmission ring A and transmission ring B, and the transmission ring bolt fixes the transmission ring A and transmission ring B.

[0016] After tightening the transmission ring bolts, remove the limit plate.

[0017] In this utility model, the limiting plate is inserted into the bushing to fix the relative position of the bushing and the pressure cover. The limiting plate is tightened onto the pressure cover by bolts. After the transmission ring bolts are tightened and fixed, the limiting plate is removed after the nut and double-ended stud are tightened.

[0018] In this invention, the bushing is fixed to the shaft under the action of the transmission device and rotates with the shaft. The moving ring rotates synchronously with the bushing via the push ring, and under the combined action of the auxiliary sealing ring and the spring, it is tightly fitted with the stationary ring and rotates relative to it, thus sealing the process medium. The spring acts as a compensator, pushing the push ring assembly to push the stationary ring into tight contact with it. The stationary ring is installed on the gland and becomes an integral part with the auxiliary sealing ring, and is fixed to the sealing cavity by a nut and double-ended studs. An anti-rotation pin prevents the stationary ring and the gland from rotating relative to each other. A limiting plate is inserted and fixed on the bushing by bolts, keeping the bushing and the gland in a fixed relative position. The limiting plate is removed after the transmission ring bolts are tightened.

[0019] In the solution of this utility model:

[0020] 1) External spring: The spring does not contact the medium, and the leakage of wax oil within the standard range does not affect the compensation performance of the spring.

[0021] 2) Hard-to-hard end face design: Hard-to-hard end face design can make the wax oil film between the end faces thinner, effectively reducing leakage.

[0022] 3) Leaked wax oil can be discharged without passing through the spring, which allows the mechanical seal to maintain its compensating performance.

[0023] This utility model relates to the modification of the high-pressure pump mechanical seal for a 400,000-ton / year tail oil isomerization dewaxing and hydrogenation unit. Designed by Dandong Runhe Co., Ltd., the system was installed and commissioned on April 26, 2024, and has accumulated over 6,000 hours of operation to date. This utility model's solution saves 106,000-294,000 yuan annually per high-pressure pump mechanical seal.

[0024]

[0025] The results show that the mechanical seal of this invention uses an externally mounted spring, which does not contact the medium. Within the standard range, leaked wax oil does not affect the spring's compensation performance. Simultaneously, the cross-section adopts a hard-to-hard end-face design. The hard-to-hard end-face pairing involves both the dynamic and stationary rings of the mechanical seal being made of hard ceramic material. This hard-to-hard end-face design thins the wax oil film between the end faces, effectively reducing leakage. Leaked wax oil can be discharged without passing through the spring, maintaining the mechanical seal's compensation performance and extending its service life. Furthermore, ceramic has good thermal conductivity; wax oil that seeps into the inner hole does not solidify and flows out promptly after exceeding the inner hole edge, preventing jamming of the compensation ring. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 The attached figure is a schematic diagram of the high-pressure mechanical seal device for wax oil provided by this utility model.

[0028] The following is a list of structures represented by each number in the attached diagram: 1-Sleeve, 2-Expansion ring, 3-Third auxiliary seal ring, 4-Drive ring A, 5-Drive ring B, 6-Limiting plate, 7-Fourth auxiliary seal ring, 8-Bolt, 9-Glander cap, 10-Nut, 11-Double-ended stud, 12-Push ring, 13-Moving ring, 14-Stationary ring, 15-First auxiliary seal ring, 16-Second auxiliary seal ring, 17-Spring, 18-Anti-rotation pin, 19-Drive ring bolt. Detailed Implementation

[0029] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0030] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., 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.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0034] Example 1

[0035] A high-pressure mechanical seal device suitable for wax oil includes a bushing 1 that is fixed on a shaft and rotates with the shaft via a transmission device;

[0036] The bushing has a groove at one end, and the transmission device is fixed at the other end of the bushing; at least one third auxiliary sealing ring 3 is provided on the outer surface of the bushing groove.

[0037] The bushing groove is provided with a spring 17, a push ring 12 and a moving ring 13 from the inside to the outside, wherein the spring 17, the push ring 12 and the moving ring 13 abut against each other in sequence;

[0038] The other end of the rotating ring 13 is abutted against the stationary ring 14, and a first auxiliary sealing ring 15 is provided between the rotating ring 13 and the inner wall of the groove of the bushing 1;

[0039] The other end of the stationary ring 14 is fixedly abutted against the gland 9, and a second auxiliary sealing ring 16 is provided at the connection between the stationary ring 14 and the gland 9; the stationary ring 14 is fixed to the sealing cavity of the gland by a nut 10 and a double-ended stud 11.

[0040] The surface of the pressure cap 9 is also provided with a fourth auxiliary sealing ring 7;

[0041] An anti-rotation pin 18 is also provided between the stationary ring 14 and the gland 9, and the anti-rotation pin 18 is fixed above the second sealing ring 16;

[0042] The other end of the pressure cap 9 is provided with a limiting plate 6, and the limiting plate 6 is fixed on the bushing 1. The limiting plate 6 and the pressure cap 1 are fixedly connected by bolts 8.

[0043] In some embodiments, the transmission device includes an expansion ring 2, a transmission ring A 4, a transmission ring B 5, and a transmission ring bolt 19;

[0044] The expansion ring 2 is fixed at one end of the bushing 1, and the transmission ring A 4 and transmission ring B 5 are symmetrically fixed above the expansion ring 2; the transmission ring bolt 19 is bolted to the transmission ring B 5 and passes through the transmission ring A 4 and transmission ring B 5, and the transmission ring bolt 10 fixes the transmission ring A 4 and transmission ring B 5.

[0045] Experimental Example 1

[0046] Before the modification of the mechanical seal TD70-250X10 for the high-pressure pump of the 400,000-ton hydrogenation unit at Panjin Northern Asphalt Co., Ltd.:

[0047] Operating medium: wax oil, temperature 160℃, inlet pressure 0.6MPa, outlet pressure 16MPa.

[0048] TD70-250X10 Hydrocracking Tail Oil Specifications for High-Pressure Pump Mechanical Seal of 400,000-ton Unit

[0049]

[0050]

[0051] After the modification of the mechanical seal TD70-250X10 for the high-pressure pump of the 400,000-ton hydrogenation unit of Panjin Northern Asphalt Co., Ltd.:

[0052]

[0053] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0054] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A high-pressure mechanical seal device for a wax oil, characterized by, This includes a bushing that is fixed to the shaft and rotates with the shaft via a transmission device; The bushing has a groove at one end, and the transmission device is fixed to the other end of the bushing; at least one third auxiliary sealing ring is provided on the outer surface of the bushing groove. The bushing has a spring, a push ring, and a moving ring arranged sequentially from the inside to the outside in the groove, wherein the spring, push ring, and moving ring abut against each other in sequence; The other end of the rotating ring abuts against a stationary ring, and a first auxiliary sealing ring is provided between the rotating ring and the inner wall of the groove of the bushing; The other end of the stationary ring is fixedly abutted against the gland, and a second auxiliary sealing ring is provided at the connection between the stationary ring and the gland; the stationary ring is fixed to the sealing cavity of the gland by a nut and a double-ended stud; The gland surface is also provided with a fourth auxiliary sealing ring; An anti-rotation pin is also provided between the stationary ring and the gland, and the anti-rotation pin is fixed above the second auxiliary sealing ring; The other end of the pressure cap is provided with a limiting plate, and the limiting plate is fixed on the bushing. The limiting plate and the pressure cap are fixedly connected by bolts.

2. A high pressure mechanical seal device for use with wax oil according to claim 1, wherein The transmission device includes an expansion ring, a transmission ring A, a transmission ring B, and a transmission ring bolt; The expansion ring is fixed to one end of the bushing, and the transmission ring A and transmission ring B are symmetrically fixed above the expansion ring; the transmission ring bolt is bolted to the transmission ring B and passes through the transmission ring A and transmission ring B, and the transmission ring bolt fixes the transmission ring A and transmission ring B.

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