Packing structure of polyolefin reciprocating compressor

Abstract

The utility model relates to a packing structure of a reciprocating compressor, in particular to a packing structure of a polyolefin reciprocating compressor. Comprising a water jacket shell, an end flange, a piston shaft, a packing box and sealing ring sets, the water jacket shell is arranged on the outer side of the piston shaft, the end flange is arranged at one end of the water jacket shell, the packing box is arranged between the water jacket shell and the piston shaft, the sealing ring sets comprise the first sealing ring set and the normally-sealed ring set, and the first sealing ring set is arranged on the side, away from the water jacket shell, of the end flange; the first sealing ring set comprises two tangential rings arranged in parallel. According to the first sealing ring set, the sealing effect of the packing structure can be greatly improved through two tangential rings arranged in parallel, when the inner diameter of packing is abraded, good self-compensation performance can be provided, and the reliability of the sealing effect is improved; the damage to the filler structure is smaller; the friction surface is almost not increased under the condition that an additional filler box is not added, the heat generation is reduced, the manufacturing is simpler, the cost is lower, and the effect is better.

Description

Technical Field

[0001] The utility model relates to a reciprocating compressor packing structure, in particular to a polyolefin reciprocating compressor packing structure. Background Art

[0002] In order to prevent the compressed gas from leaking along the gap between the piston rod and the inner wall of the cylinder, a polyolefin reciprocating compressor generally needs to set a sealing structure between the inner wall of the cylinder and the piston rod. This sealing structure is also called a stuffing box. During the use of polyolefin reciprocating compressors, a large amount of heat is often generated due to the friction between the piston packing and the piston. If it is not removed in time, the stuffing box will soften and fail due to the high temperature, causing polyolefin leakage; the copper flow ring will also wear the piston rod and packing that expand due to heat, causing more serious equipment failures, shutting down for maintenance and replacing equipment components, bringing great risks to safe and environmentally friendly operation, and failing to meet the relevant requirements for long-term operation of polyolefin units.

[0003] In the prior art, patent CN201820768847.8 discloses a compressor stuffing box structure that is easy to dissipate heat. In order to solve the problem of drilling holes in the stuffing boxes to inject cooling water, a screw structure that penetrates each stuffing box is used to introduce cooling water, and a plurality of heat dissipation holes are added to fill heat dissipation silica gel. It is still necessary to introduce cooling water into the piston structure, which poses a risk of water leakage. In addition, the screw holes that penetrate the stuffing and the complex multi-heat dissipation hole structure increase the difficulty of processing and significantly increase the processing cost, which is not conducive to widespread application. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the shortcomings of the prior art and provide a polyolefin reciprocating compressor packing structure which is easy to dissipate heat, has a simple structure, causes little damage to the packing structure and has a more reliable sealing effect.

[0005] The utility model adopts a technical solution to solve the technical problem: a polyolefin reciprocating compressor packing structure, comprising a water jacket shell, an end flange, a piston shaft, a packing box and a sealing ring group, wherein the water jacket shell is arranged on the outside of the piston shaft, the end flange is arranged at one end of the water jacket shell, the packing box is arranged between the water jacket shell and the piston shaft, and the sealing ring group is arranged on the outer wall of the piston shaft, and is characterized in that: the sealing ring group comprises a first sealing ring group and a normal sealing ring group, the first sealing ring group is arranged on the side of the end flange away from the water jacket shell, and the first sealing ring group comprises two tangential rings arranged in parallel; a plurality of the packing boxes are arranged in parallel with each other, and the normal sealing ring groups are respectively and correspondingly arranged between the packing boxes and the piston shaft.

[0006] The common sealing ring group is generally composed of a radial ring and a tangential ring. Its function is to seal when the compressor is exhausted and to reflux the leaked ethylene gas when it is inhaled. The first sealing ring group can greatly increase the sealing effect of the packing structure through two parallel tangential rings. When the inner diameter of the packing is worn, it can provide good self-compensation and improve the reliability of the sealing effect. It also causes less damage to the packing structure. Without adding an additional stuffing box, there is almost no increase in friction surface, which reduces heat generation, is simpler to manufacture, has lower cost and better effect.

[0007] Preferably, a groove is provided on a side of the end flange away from the water jacket shell, and the first sealing ring assembly is correspondingly arranged in the groove.

[0008] Preferably, a top sealing cover is provided on the side of the first sealing ring assembly away from the end flange, and the top sealing cover is fixedly connected to the end flange.

[0009] Preferably, it also includes a second sealing ring group, which is arranged between the stuffing box near the end flange and the piston shaft; the second sealing ring group includes two parallel tangential rings. Inside the stuffing box, two parallel tangential rings are added to the end of the sealing structure to further improve the terminal sealing performance, make full use of the sealing effect and reflux effect of the normal sealing ring group at the high-pressure end (the side away from the end flange), avoid gas leakage, and facilitate the reflux of leaked gas.

[0010] Further preferably, the tangential openings of the two parallel tangential rings are opposite to each other, thereby improving the sealing effect.

[0011] Preferably, the stuffing box includes a sealing stuffing box and a bottom stuffing box; wherein the bottom stuffing box is arranged at one end of the water jacket shell away from the end flange, the sealing stuffing box is arranged between the bottom stuffing box and the end flange, and the side of the bottom stuffing box away from the end flange is turned outward to the end edge of the water jacket shell. The turned outward structure of the bottom stuffing box makes it easier for the bottom stuffing box to directly contact the external heat dissipation surface, thereby greatly improving the heat dissipation effect of the entire polyolefin reciprocating compressor stuffing structure and extending its service life.

[0012] Further preferably, the sealing stuffing boxes are provided with 6 to 8 pieces, so as to achieve a good sealing effect and a long service life.

[0013] Preferably, the normally sealed ring set includes a radial ring and a tangential ring which are arranged in parallel.

[0014] Further preferably, the tangential ring is arranged on the side of the radial ring close to the end flange. When the sealed working cylinder end is compressed, the packing seal ring is moved toward the low-pressure side due to the gas force, and the gas enters the outer side of the packing from the axial gap between the packing seal ring and the packing box cup groove and the cut gap of the radial ring. Under the action of the gas force, three sealing surfaces are formed: the radial ring and the tangential ring cutouts are staggered to form a sealing surface, the tangential ring and the piston shaft surface form a sealing surface, and the tangential ring and the side of the packing box groove form a sealing surface, thus preventing the leakage of ethylene gas and playing a sealing role; when the cylinder inhales, the gas flows back into the cylinder through the cut gap part of the radial ring (generally not less than 1mm).

[0015] Preferably, it also includes an injection hole and a recovery hole; the injection hole and the recovery hole are both connected to the piston shaft through the end flange and the stuffing box, and the injection hole is arranged on the side of the recovery hole away from the end flange.

[0016] The gas injection hole and the recovery hole are connected to a nitrogen pipeline. The gas injection can play an auxiliary sealing role during compression. After compression, stable nitrogen can be recovered through the recovery hole.

[0017] Compared with the prior art, the utility model has the following beneficial effects: the first sealing ring group can greatly increase the sealing effect of the packing structure through two parallel tangential rings, and can provide good self-compensation when wear occurs on the inner diameter of the packing, thereby improving the reliability of the sealing effect; and the damage to the packing structure is less; without adding an additional packing box, there is almost no increase in the friction surface, which reduces heat generation, is simpler to manufacture, has lower cost, and has better effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the packing structure of a polyolefin reciprocating compressor.

[0019] Among them, 1. water jacket shell; 2. end flange; 3. piston shaft; 4. bottom stuffing box; 5. top sealing cover; 6. first sealing ring group; 7. second sealing ring group; 8. normal sealing ring group; 9. sealing stuffing box; 10. coolant tank; 11. air injection hole; 12. recovery hole. DETAILED DESCRIPTION

[0020] Figure 1 It is the best embodiment of the utility model, and the following Figure 1 The utility model is further described.

[0021] See attached Figure 1 : A polyolefin reciprocating compressor packing structure, including a water jacket shell 1, an end flange 2, a piston shaft 3, a stuffing box and a sealing ring group; wherein the sealing ring group includes a first sealing ring group 6, a second sealing ring group 7 and a normal sealing ring group 8, and the stuffing box includes a sealing stuffing box 9 and a bottom stuffing box 4.

[0022] The water jacket housing 1 is sleeved on the outside of the piston shaft 3 and is spaced apart from the piston shaft 3; the end flange 2 is arranged at one end of the water jacket housing 1, and a groove is provided on the side of the end flange 2 away from the water jacket housing 1, and the first sealing ring group 6 is correspondingly arranged in the groove, and a top sealing cover 5 is provided at a position corresponding to the groove, and the top sealing cover 5 is fixedly connected to the end flange 2, so that the first sealing ring group 6 is fixed in the groove; the first sealing ring group 6 includes two tangential rings arranged in parallel, and the tangential openings of the tangential rings are opposite.

[0023] The stuffing box is arranged between the water jacket housing 1 and the piston shaft 3. There are seven groups of stuffing boxes arranged in parallel. The bottom stuffing box 4 is arranged at the end of the water jacket housing 1 away from the end flange 2, and the side of the bottom stuffing box 4 away from the end flange 2 is turned outward to the end edge of the water jacket housing 1. The sealing stuffing box 9 is arranged between the bottom stuffing box 4 and the end flange 2; the second sealing ring group 7 is arranged between the sealing stuffing box 9 closest to the end flange 2 and the piston shaft 3, and the second sealing ring group 7 includes two tangential rings arranged in parallel and with opposite tangential openings. Two parallel tangential rings are added to the end of the stuffing box end flange 2 and the end of the sealing structure respectively, so as to further improve the terminal sealing performance, make full use of the sealing effect and reflux effect of the normal sealing ring group 8 at the high-pressure end (away from the end flange 2), avoid gas leakage, and easily prevent the reflux of leaked gas. The sealing effect is improved with the smallest friction surface, and the heat damage is reduced.

[0024] There are six sets of regular sealing rings 8, corresponding to the other six stuffing boxes respectively, and arranged between the stuffing box and the piston shaft 3. The regular sealing rings 8 include a radial ring and a tangential ring arranged in parallel, and the tangential ring is arranged on the side of the radial ring close to the end flange 2. When the sealed working cylinder end is compressed, the packing sealing ring is close to the low-pressure side due to the effect of gas force, and the gas enters the outer side of the packing from the axial gap between the sealing ring and the cup groove of the stuffing box and the cut gap of the radial ring. Under the action of gas force, three sealing surfaces are formed: the radial ring and the tangential ring cut are staggered to form a sealing surface, the tangential ring and the surface of the piston shaft 3 form a sealing surface, and the tangential ring and the side of the stuffing box form a sealing surface, so that the leakage of ethylene gas is prevented, thereby playing a sealing role; when the cylinder inhales, the gas flows back into the cylinder through the cut gap part of the radial ring (generally not less than 1mm).

[0025] The end flange 2 and the stuffing box are also provided with an injection hole 11 and a recovery hole 12, both of which pass through the end flange 2 and the stuffing box to be connected to the piston shaft 3, and the injection hole 11 is arranged on the side of the recovery hole 12 away from the end flange 2. The injection hole 11 and the recovery hole 12 are externally connected to a nitrogen pipeline, and the injection of gas can play a role of auxiliary sealing during compression. After compression, stable nitrogen can be recovered through the recovery hole 12 and enter the compression chamber, providing compression stability and reducing leakage.

[0026] In addition, a cooling liquid tank 10 penetrating through the five middle sealing stuffing boxes 9 is provided in the water jacket housing 1 on one side of the piston shaft 3. The cooling liquid tank 10 can be filled with water or other cooling liquid to cool the middle sealing stuffing box 9, thereby improving the cooling effect and extending the service life.

[0027] The above is only the preferred embodiment of the utility model, and does not limit the utility model in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the utility model without departing from the technical solution of the utility model still belongs to the protection scope of the technical solution of the utility model.

Claims

1. A polyolefin reciprocating compressor packing structure, comprising a water jacket shell (1), an end flange (2), a piston shaft (3), a packing box and a sealing ring group, wherein the water jacket shell (1) is arranged outside the piston shaft (3), the end flange (2) is arranged at one end of the water jacket shell (1), the packing box is arranged between the water jacket shell (1) and the piston shaft (3), and the sealing ring group is arranged on the outer wall of the piston shaft (3), characterized in that: The sealing ring group comprises a first sealing ring group (6) and a normal sealing ring group (8); the first sealing ring group (6) is arranged on a side of the end flange (2) away from the water jacket shell (1); the first sealing ring group (6) comprises two tangential rings arranged in parallel; the stuffing box comprises a plurality of stuffing boxes arranged in parallel with each other; the normal sealing ring groups (8) are respectively arranged between the stuffing boxes and the piston shaft (3).

2. The polyolefin reciprocating compressor packing structure according to claim 1, characterized in that: A groove is provided on the side of the end flange (2) away from the water jacket shell (1), and the first sealing ring assembly (6) is correspondingly arranged in the groove.

3. The polyolefin reciprocating compressor packing structure according to claim 1, characterized in that: A top sealing cover (5) is provided on the side of the first sealing ring assembly (6) away from the end flange (2), and the top sealing cover (5) is fixedly connected to the end flange (2).

4. The polyolefin reciprocating compressor packing structure according to claim 1, characterized in that: It also comprises a second sealing ring group (7), which is arranged between a stuffing box close to the end flange (2) and the piston shaft (3); the second sealing ring group (7) comprises two tangential rings arranged in parallel.

5. The polyolefin reciprocating compressor packing structure according to claim 1 or 4, characterized in that: The tangential openings of the two parallel tangential rings are opposite to each other.

6. The polyolefin reciprocating compressor packing structure according to claim 1, characterized in that: The stuffing box comprises a sealing stuffing box (9) and a bottom stuffing box (4); wherein the bottom stuffing box (4) is arranged at an end of the water jacket shell (1) away from the end flange (2), the sealing stuffing box (9) is arranged between the bottom stuffing box (4) and the end flange (2), and a side of the bottom stuffing box (4) away from the end flange (2) is turned outward to the end edge of the water jacket shell (1).

7. The polyolefin reciprocating compressor packing structure according to claim 6, characterized in that: The sealing stuffing boxes (9) are provided in 6 to 8 pieces.

8. The polyolefin reciprocating compressor packing structure according to claim 1, characterized in that: The constant sealing ring set (8) comprises a radial ring and a tangential ring which are arranged in parallel.

9. The polyolefin reciprocating compressor packing structure according to claim 8, characterized in that: The tangential ring is arranged on a side of the radial ring close to the end flange (2).

10. The polyolefin reciprocating compressor packing structure according to claim 1, characterized in that: It also includes an air injection hole (11) and a recovery hole (12); the air injection hole (11) and the recovery hole (12) both pass through the end flange (2) and the stuffing box to be connected to the piston shaft (3), and the air injection hole (11) is arranged on a side of the recovery hole (12) away from the end flange (2).

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