Rear isolation sealing device for compressor dry gas sealing

Abstract

The utility model relates to a rear isolation sealing device for dry gas sealing of a compressor. The rear isolation sealing device is installed between a dry gas seal main sealing assembly and a bearing box and comprises a static assembly, an isolation sealing assembly and an isolation sealing rotating assembly. Wherein the static assembly is fixed to a compressor shell, an oil blocking device for blocking bearing oil is arranged on a cavity of the static assembly, the isolation sealing assembly is arranged in the cavity of the static assembly and close to the outer side of a main seal, the rotating assembly is arranged on the outer side of a main shaft and rotates at a high speed along with the main shaft, and an oil throwing device is arranged on a rotating shaft sleeve of the rotating assembly. Compared with the prior art, the isolation sealing device has the advantages that the axial length of the compressor can be saved, the dynamic performance of a main shaft rotor of the compressor can be improved, and the consumption of isolation sealing isolation gas can be saved by more than 40%.

Description

Technical Field

[0001] The utility model belongs to the technical field of dry gas seals for compressors, and particularly relates to a rear isolation seal device for dry gas seals of compressors. Background Art

[0002] Centrifugal compressors are one of the core equipment in industries such as petroleum and chemical industries. Dry gas seals, namely dry-running, gas-lubricated, non-contact mechanical seals, are widely used as shaft-end seals on compressors in the petrochemical industry. A dry gas seal consists of a primary seal and a rear isolation seal. The main function of the primary seal is to seal process media; the main function of the rear isolation seal is to prevent the lubricating oil in the bearing box from axially diffusing to the outside of the primary seal and contaminating the primary seal on the outside.

[0003] Currently, the commonly used form of the isolation seal is a non-contact labyrinth seal, also known as a comb seal. The labyrinth seal realizes the sealing function of the fluid through the throttling and pressure reduction of the comb teeth. The biggest features are non-contact, large radial clearance, simple structure, low manufacturing cost, and reliable operation. However, its disadvantage is that in order to block the bearing oil and prevent the bearing oil from entering the primary seal, a large amount of isolation gas needs to be consumed, that is, by setting the flow rate of the isolation gas through the comb teeth to ensure complete blocking of the bearing oil and prevent the dry gas seal from being contaminated by the bearing oil. The higher the flow rate of the isolation gas through the comb teeth, the better the effect of blocking the bearing oil, and the more the consumption of the isolation gas, resulting in a higher operating cost of the compressor unit. And the higher the flow rate of the isolation gas through the comb teeth, the more the bearing oil sprayed from the bearing box oil injection hole is blown away from the bearing by a large amount of isolation gas, so that the bearing cannot be lubricated and there is a risk of bearing failure. Summary of the Utility Model

[0004] In order to solve the above problems, the purpose of the patent application of the utility model is to reduce the consumption of the isolation gas of the dry gas seal, reduce the operating cost of the compressor unit, and also ensure that the bearing at the shaft end of the compressor has sufficient bearing oil lubrication to avoid bearing failure.

[0005] The utility model is realized through the following technical solutions:

[0006] The purpose of this application is to provide a rear isolation seal device for dry gas seals of compressors, including an isolation seal assembly, which is installed between the main shaft of the compressor and the stationary assembly. One axial end of the isolation seal assembly is fixedly connected to the stationary assembly through a second connecting piece, and the other end is communicated with the air outlet channel of the primary seal assembly of the dry gas seal;

[0007] An isolation seal rotating assembly, which is installed between the main shaft of the compressor and the isolation seal assembly, and the isolation seal rotating assembly is fixedly connected to the main shaft of the compressor;

[0008] A plurality of radial air inlet channels are arranged on the stationary assembly;

[0009] An annular groove is provided on the inner wall of the stationary component near one end of the dry gas seal main seal component for installing a baffle, and one end face of the isolation seal component abuts against the baffle;

[0010] The stationary component is connected to the compressor housing through a first connecting piece;

[0011] A plurality of radial air inlet holes are provided on the isolation seal component, and the air inlet holes are communicated with the air inlet channel.

[0012] Furthermore, the stationary component includes a first ring body and a second ring body, and the first ring body and the second ring body are integrally formed.

[0013] Furthermore, an oil baffle ring is provided on the end face of the second ring body away from the first ring body, and the cross section of the oil baffle ring is trumpet-shaped.

[0014] Furthermore, an annular groove is provided on the inner wall of the first ring body for installing a baffle; the inner side end face of the second ring body abuts against the outer side end face of the isolation seal component.

[0015] An installation hole is provided on the end face of the second ring body away from the first ring body.

[0016] Furthermore, a sealing gasket is provided between the first connecting piece and the stationary component;

[0017] A plurality of first sealing rings are provided between the stationary component and the compressor housing.

[0018] Furthermore, a plurality of second sealing rings are provided between the isolation seal component and the stationary component.

[0019] Furthermore, the isolation seal rotating component includes a rotating shaft sleeve, which is fixedly connected to the compressor main shaft through a torque transmission device;

[0020] The torque transmission device is fixedly connected to the compressor main shaft through a fourth connecting piece;

[0021] The compressor main shaft is provided with a connection hole for cooperating with the fourth connecting piece.

[0022] Furthermore, the rotating shaft sleeve is in an annular structure, one side end face of which abuts against the outer end face of the dry gas seal main seal component, and an oil throwing device is provided on the end face of the rotating shaft sleeve away from the dry gas seal main seal component, and the cross section of the oil throwing device is dovetail-shaped; the distance between the inner wall of the second ring body and the outer wall of the rotating shaft sleeve is 0.8 - 2.6 mm.

[0023] Furthermore, the torque transmission device is disconnected in the diameter direction to form two semi-circular structures;

[0024] The rotating shaft sleeve and the torque transmission device are connected to the dry gas seal main seal component through a third connecting piece.

[0025] Further, a third sealing ring is provided between the inner wall of the side of the rotary shaft sleeve away from the main dry gas seal assembly and the outer wall of the compressor main shaft, a fourth sealing ring is provided between the inner wall of the rotary shaft sleeve and the outer wall of the torque transmission device, and a fifth sealing ring is provided between the inner wall of the rotary shaft sleeve and the main dry gas seal assembly.

[0026] Compared with the prior art, the present utility model has the following advantages and beneficial effects:

[0027] The post-isolation seal device for the compressor dry gas seal provided by the embodiment of the present utility model has a reasonable structural design and is applicable to the existing compressor cavity. The structure of the isolation seal device is provided with an oil baffle device integrated with the cavity on the stationary component to block the bearing oil sprayed from the bearing box oil injection hole, and most of the bearing oil is blocked by the oil baffle ring. A oil throwing device integrated with the rotary shaft sleeve is provided on the rotating component of the isolation seal. Under the dual action of having an oil baffle device above and an oil throwing device below, by setting the flow rate of the isolation gas passing through the isolation seal comb teeth, on the one hand, it ensures that the bearing oil sprayed from the bearing box oil injection hole is thrown to the bearing area to ensure the lubrication of the bearing; on the other hand, it ensures that the main seal will not be contaminated by the lubricating oil and gas on the bearing side, thereby ensuring the normal operation of the seal.

[0028] In the prior art, it is usually necessary to set the flow rate of the isolation gas passing through the isolation seal comb teeth to be 40 m / s - 50 m / s. For the isolation seal device provided by the embodiment of the present utility model, the flow rate of the isolation gas passing through the isolation seal comb teeth can be set to be 20 m / s - 30 m / s. On the premise of ensuring that the main seal is not contaminated by the lubricating oil and gas on the bearing side and the shaft end bearing can be well lubricated, a large amount of isolation gas consumption is saved, and the operation cost of the compressor unit is greatly reduced.

[0029] In addition, the design advantages of this integrated structure make the isolation seal have a compact structure, reasonable design, save the axial length of the compressor main shaft, and greatly improve the rotor dynamics performance of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0031] Figure 1 It is a schematic structural diagram of the post-isolation seal device for the compressor dry gas seal provided by the embodiment of the present utility model;

[0032] Figure 2Structural schematic diagram of the stationary component provided by an embodiment of the present utility model;

[0033] Figure 3 Structural schematic diagram of the torque transmission device structure provided by an embodiment of the present utility model;

[0034] Figure 4 Cross-sectional view of the torque transmission device structure provided by an embodiment of the present utility model;

[0035] Figure 5 Cross-sectional view of the oil baffle device structure provided by an embodiment of the present utility model;

[0036] Figure 6 Cross-sectional view of the oil slinger device structure provided by an embodiment of the present utility model;

[0037] Figure 7 Schematic diagram of the distance between the inner diameter of the oil baffle device and the outer diameter of the oil slinger device provided by an embodiment of the present utility model;

[0038] Wherein: 1 - stationary component, 2 - first connecting piece, 3 - sealing gasket, 4 - first sealing ring, 5 - compressor housing, 6 - isolation sealing component, 7 - baffle, 8 - second connecting piece, 9 - second sealing ring, 10 - rotating shaft sleeve, 11 - third connecting piece, 12 - torque transmission device, 13 - fourth connecting piece, 14 - third sealing ring, 15 - fourth sealing ring, 16 - fifth sealing ring, 17 - compressor main shaft, 18 - first ring body, 19 - second ring body, 20 - third ring body, 21 - fourth ring body, 22 - air inlet passage, 23 - mounting hole, 24 - air inlet hole, 25 - dry gas seal main sealing component, 26 - oil slinger device, 27 - oil baffle ring. Detailed implementation manners

[0039] To make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below in combination with embodiments and drawings. The illustrative embodiments and descriptions thereof of the present utility model are only used to explain the present utility model and shall not be construed as limiting the present utility model.

[0040] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and illustrated herein can be arranged and designed in various different configurations.

[0041] It should be noted that similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Without conflict, the embodiments in this application and the features in the embodiments can be combined with each other.

[0042] In the application description of this utility model patent, all inner sides are the medium side (left side) in the attached Figure 1 , that is, the side where the main dry gas seal assembly is located, and all outer sides are Figure 1 the bearing side (right side), that is, the side where the bearing housing is located.

[0043] As Figures 1 - 7 shown, this embodiment provides a rear isolation seal device for the dry gas seal of a compressor, which is installed between the main dry gas seal assembly 25 of the compressor and the bearing housing. A high-speed rotating compressor main shaft 17 is provided on the compressor, and it includes three parts: a stationary component 1 of the isolation seal, an isolation seal component 6, and a rotating component of the isolation seal. Among them, the stationary component 1 of the isolation seal is fixed to the compressor housing 5, the isolation seal component 6 is arranged in the cavity of the stationary component 1, close to the outside of the main dry gas seal assembly 25 of the compressor, the rotating component of the isolation seal is arranged outside the compressor main shaft 17 and rotates at a high speed together with the compressor main shaft 17. A torque transmission device 12 is arranged on the rotating component of the isolation seal to realize the torque transmission function of the dry gas seal;

[0044] Specifically: The rear isolation seal device of the compressor dry gas seal includes an isolation seal component 6, which is installed between the compressor main shaft 17 and the stationary component 1. One axial end of the isolation seal component 6 is fixedly connected to the stationary component 1 through a second connecting piece 8, and the other end is communicated with the air outlet channel of the main dry gas seal assembly 25; In this embodiment, the second connecting piece 8 is preferably a pin, and the function of the pin is to prevent the isolation seal component 6 from rotating.

[0045] The interior of the stationary component 1 has a cavity, which is annularly arranged outside the main dry gas seal assembly 25, and the isolation seal component 6 is installed in this cavity;

[0046] The isolation seal rotating component, which is installed between the compressor main shaft 17 and the isolation seal component 6, close to the atmosphere end (attached Figure 1 right side), the isolation seal rotating component is fixedly connected to the compressor main shaft 17;

[0047] A plurality of radial isolation gas inlet channels 22 are arranged on the stationary component 1, and the isolation gas enters the isolation seal component 6 through the plurality of inlet channels 22 to realize the functions of blocking bearing oil and blocking the leakage gas of the outer seal of the main seal;

[0048] The inner wall of the stationary component 1 near one end of the dry gas seal main seal component 25 is provided with an annular groove for installing the baffle 7, and one end face of the isolation seal component 6 abuts against the baffle 7;

[0049] The stationary component 1 is connected to the compressor housing 5 through the first connecting piece 2;

[0050] The isolation seal component 6 is provided with a plurality of radial air inlet holes 24. The isolation gas enters the comb teeth on both sides of the inner wall of the isolation seal component 6 through the air inlet holes 24. The isolation gas is divided into two strands. One strand leaks to the seal cavity outside the dry gas seal main seal component 25 through the inner comb teeth, playing a role in isolating the leakage gas outside the main seal of the dry gas seal. The leakage gas entering the outer seal is discharged at high altitude; the other strand leaks to the bearing box through the outer (right side) comb teeth under the action of throttling and pressure reduction, realizing the function of blocking the bearing oil. Figure 1 The right side) comb teeth leak into the bearing box to realize the function of blocking the bearing oil.

[0051] In another embodiment of the present application, the stationary component 1 includes a first ring body 18 and a second ring body 19, and the first ring body 18 and the second ring body 19 are integrally formed; the front end (left side) of the first ring 18 abuts against the outer side (right side) of the dry gas seal main seal component 25, and the inner end face (left side) of the second ring body 19 abuts against the outer end face (right side) of the isolation seal component 6. An annular groove is provided in the inner diameter of the first ring body 18 for installing the baffle 7, and the function of the baffle 7 is to prevent the axial movement of the isolation seal component 6.

[0052] In another embodiment of the present application, an oil baffle device integrated with the cavity is provided on the outer side of the second ring body 19, that is, an oil baffle ring 27 is provided on the end face of the second ring body 19 far from the first ring body 18. Most of the bearing oil sprayed from the bearing box oil injection hole is blocked by the oil baffle ring. The cross section of the oil baffle ring 27 is trumpet-shaped, and the sectional view of the oil baffle ring 27 is as Figure 5 shown. It can be seen from the sectional view that the structure of the oil baffle ring 27 is like a hook shape, the hook handle is trumpet-shaped, and the angle with the vertical direction is 30°-40°. The tail of the hook handle inclines towards the compressor housing 5 direction, which is convenient for blocking the bearing oil. The remaining bearing oil will be received by the bottom of the hook to avoid the migration of the bearing oil to the outside of the main seal.

[0053] An installation hole 23, preferably a threaded hole, is provided on the end face of the second ring body 19 far from the first ring body 18 for connecting the disassembly and assembly tool of the isolation seal, which is convenient for the disassembly and assembly of the isolation seal.

[0054] In another embodiment of the present application, refer to Figure 2, a counterbore is provided on the outer end face of the stationary component 1, and a sealing gasket 3 is provided in the counterbore. In this embodiment, the first connecting member 2 is preferably an internal hexagonal countersunk head screw, and the stationary component 1 is connected to the compressor housing 5 through the internal hexagonal countersunk head screw. The sealing gasket 3 serves to prevent bearing oil from entering the main seal;

[0055] A plurality of first sealing rings 4 are provided between the outer peripheral wall of the stationary component 1 and the compressor housing 5 to seal the gap between the compressor housing 5 and the stationary component 1.

[0056] In another embodiment of the present application, a plurality of second sealing rings 9 are provided between the inner wall of the cavity of the isolation sealing component 6 and the stationary component 1 to ensure the sealing performance at the contact position between the isolation sealing component 6 and the stationary component 1.

[0057] In another embodiment of the present application, the isolation sealing rotating component includes a rotating shaft sleeve 10, which is fixedly connected to the compressor main shaft 17 through a torque transmission device 12. The torque transmission device 12 is fixedly connected to the compressor main shaft 17 through a fourth connecting member 13. In this embodiment, the fourth connecting member 13 is preferably a pin (refer to Figure 3 and Figure 4 ). A torque transmission pin hole is provided on the compressor main shaft 17, and the pin cooperates with the pin hole on the compressor main shaft 17 to achieve the torque transmission function, so that the torque transmission device 12 rotates together with the compressor main shaft 17;

[0058] The rotating shaft sleeve 10 has an annular structure and includes an integrated third ring body 20 (the left side in Figure 1 ) and a fourth ring body 21 (the right side in Figure 1 ). The front end (left side) of the third ring body 20 abuts against the outer side (right side) of the dry gas seal main seal assembly 25. The inner diameter of the third ring body 20 is larger than the inner diameter of the fourth ring body 21. Therefore, a space for installing the torque transmission device 12 is formed between the dry gas seal main seal assembly 25 and the fourth ring body 21.

[0059] In another embodiment of the present application, an oil throwing device integrated with the rotating shaft sleeve 10 is provided on the outer side of the fourth ring body 21. An oil throwing device 26 (refer to Figure 6 ) is provided on the end face of the rotating shaft sleeve 10 away from the dry gas seal main seal assembly 25. The cross-section of the oil throwing device 26 is dovetail-shaped; the sectional view of the oil throwing device 26 is as shown in Figure 6 . It can be seen from the sectional view that the structure of the oil throwing device 26 is like a dovetail, and the dovetail forms an angle of 45° with the horizontal direction and inclines towards the compressor housing 5, as shown in Figure 7As shown, the distance L between the inner diameter of the oil baffle ring 27 and the outer diameter of the oil slinger 26 increases with the increase of the compressor shaft diameter. The range of L is between 0.8 mm and 2.6 mm (i.e., the distance between the inner wall of the second ring body and the outer wall of the rotating shaft sleeve 10), and the specific value depends on the specific design. The smaller the value of L, the greater the flow rate of the isolating gas passing through the annular region of L, and the better the effect of blocking the bearing oil.

[0060] In another embodiment of the present application, the torque transmission device 12 is disconnected in the diameter direction to form two semi-circular structures, namely split rings; the rotating shaft sleeve 10 and the torque transmission device 12 are connected to the dry gas seal main seal assembly 25 through a third connecting member 11. In this embodiment, the third connecting member 11 is preferably an internal hexagonal countersunk head screw.

[0061] In another embodiment of the present application, a third sealing ring 14 is provided between the inner wall of the rotating shaft sleeve 10 on the side away from the dry gas seal main seal assembly 25 and the outer wall of the compressor main shaft 17, a fourth sealing ring 15 is provided between the inner wall of the rotating shaft sleeve 10 and the outer wall of the torque transmission device 12, and a fifth sealing ring 16 is provided between the inner wall of the rotating shaft sleeve 10 and the dry gas seal main seal assembly 25.

[0062] The above specific embodiments further elaborate on the purpose, technical solutions, and beneficial effects of the present utility model. It should be understood that the above are only specific embodiments of the present utility model and are not used to limit the protection scope of the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A post-isolation seal device for a compressor dry gas seal, characterized in that: It includes an isolation seal assembly (6) which is installed between the compressor main shaft (17) and the stationary assembly (1). One axial end of the isolation seal assembly (6) is fixedly connected to the stationary assembly (1) through a second connecting piece (8), and the other end is communicated with the air outlet channel of the dry gas seal main seal assembly (25); An isolation seal rotating assembly is installed between the compressor main shaft (17) and the isolation seal assembly (6), and the isolation seal rotating assembly is fixedly connected to the compressor main shaft (17); A plurality of radial air inlet channels (22) are arranged on the stationary assembly (1); An annular groove is provided on the inner wall of the stationary assembly (1) near one end of the dry gas seal main seal assembly (25) for installing a baffle (7), and one end face of the isolation seal assembly (6) abuts against the baffle (7); The stationary assembly (1) is connected to the compressor housing (5) through a first connecting piece (2); A plurality of radial air inlet holes (24) are provided on the isolation seal assembly (6), and the air inlet holes (24) are communicated with the air inlet channels (22).

2. The post-isolation seal device for the dry gas seal of a compressor according to claim 1, characterized in that: The stationary assembly (1) includes a first ring body (18) and a second ring body (19), and the first ring body (18) and the second ring body (19) are integrally formed.

3. The post-isolation seal device for the dry gas seal of a compressor according to claim 2, characterized in that: An oil baffle ring (27) is machined on the end face of the second ring body (19) away from the first ring body (18), and the cross section of the oil baffle ring (27) is trumpet-shaped.

4. The post-isolation seal device for the dry gas seal of a compressor according to claim 2, characterized in that: An annular groove is provided on the inner wall of the first ring body (18) for installing a baffle (7); the inner side end face of the second ring body (19) abuts against the outer side end face of the isolation seal assembly (6); An installation hole (23) is provided on the end face of the second ring body (19) away from the first ring body (18).

5. The post-isolation seal device for the dry gas seal of a compressor according to claim 1, characterized in that: A sealing gasket (3) is provided between the first connecting piece (2) and the stationary assembly (1); A plurality of first sealing rings (4) are provided between the stationary assembly (1) and the compressor housing (5).

6. The post-isolation seal device for the dry gas seal of a compressor according to claim 1, characterized in that: A plurality of second sealing rings (9) are provided between the isolation seal assembly (6) and the stationary assembly (1).

7. The post-isolation seal device for the dry gas seal of a compressor according to claim 1, characterized in that: The isolation seal rotating assembly includes a rotating shaft sleeve (10) which is fixedly connected to the compressor main shaft (17) through a torque transmission device (12); The torque transmission device (12) is fixedly connected to the compressor main shaft (17) through a fourth connecting piece (13); The compressor main shaft (17) is provided with a connection hole for cooperating with the fourth connecting piece (13).

8. The post-isolation seal device for the dry gas seal of a compressor according to claim 7, characterized in that: The rotating shaft sleeve (10) is of an annular structure, one side end face of which abuts against the outer end face of the dry gas seal main seal assembly (25). A oil throwing device (26) is provided on the end face of the rotating shaft sleeve (10) away from the dry gas seal main seal assembly (25), and the cross section of the oil throwing device (26) is dovetail-shaped. The distance between the inner wall of the second ring body (19) and the outer wall of the rotating shaft sleeve (10) is 0.8 - 2.6 mm.

9. The post-isolation seal device for the dry gas seal of a compressor according to claim 7, characterized in that: The torque transmission device (12) is disconnected from the diameter direction to form two semi-circular structures; The rotating shaft sleeve (10) and the torque transmission device (12) are connected to the dry gas seal main seal assembly (25) through a third connecting piece (11).

10. The post-isolation seal device for the dry gas seal of a compressor according to claim 7 or 9, characterized in that: A third sealing ring (14) is provided between the inner wall on the side of the rotating shaft sleeve (10) away from the primary dry gas seal assembly (25) and the outer wall of the compressor main shaft (17). A fourth sealing ring (15) is provided between the inner wall of the rotating shaft sleeve (10) and the outer wall of the torque transmission device (12). A fifth sealing ring (16) is provided between the inner wall of the rotating shaft sleeve (10) and the primary dry gas seal assembly (25).

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