Compressor sealing device

Abstract

The utility model provides a compressor sealing device, and relates to a compressor sealing device, which comprises a moving ring fixed on a shaft sleeve of a compressor and provided with a fluid dynamic pressure groove, and a static ring supported by a spring, and the moving ring and the static ring are matched to form a sealing surface. Sealing gas with the pressure higher than that of process gas is injected, fluid dynamic pressure is generated in combination with rotation of the movable ring and balanced with static pressure, a gas film is formed, and non-contact sealing is achieved. In addition, the device is designed to be a main seal and an auxiliary seal which are connected in series, leakage gas of the main seal is reused as sealing gas of the auxiliary seal, only single-stage sealing gas and leakage gas are needed, a traditional two-stage sealing system is optimized, gas waste is reduced, the number of accessories and the failure rate are reduced, and meanwhile the size of the sealing device is reduced. The isolation gas prevents lubricating oil pollution and sealing gas leakage, and the reliability of a sealing system is guaranteed. The utility model provides a sealing solution which is more economical, environment-friendly and efficient, and is particularly suitable for a gas compression process in chemical production.

Description

Technical Field

[0001] The utility model relates to the technical field of compressors, in particular to a compressor sealing device. Background Art

[0002] In the industrial application of gas compressors, especially in chemical production processes, efficient and reliable sealing devices are key components to ensure safe production. The special properties of the compressed medium constitute the primary difficulty. These media, such as natural gas, methane, hydrogen, olefins, ammonia, chlorine and mixed gases, are not only highly flammable, toxic and even explosive, but also place extremely high isolation requirements on the sealing system. Once a leak occurs, it will not only seriously threaten the life safety of the operator, but also cause immeasurable pollution to the surrounding environment. Traditional compressor sealing technology faces several technical challenges that need to be solved urgently, mainly focusing on the following aspects:

[0003] The complexity of the sealing structure and maintenance cost of existing sealing technologies are the pain points of the industry. Traditional dry gas sealing designs usually use multi-stage sealing gas and leakage gas systems, which means more components, more complex pipeline layouts, and higher maintenance costs. Too many components not only increase the failure rate of the system, but also pose challenges to the compact and lightweight design of the equipment.

[0004] Furthermore, the existing technology has obvious deficiencies in resource utilization. During the operation of the traditional dry gas sealing system, the leaked gas is often directly discharged and burned through a torch, which wastes precious resources and is not conducive to the realization of energy conservation, emission reduction and sustainable development goals. Utility Model Content

[0005] The utility model aims to provide a compressor sealing device, which can effectively seal high-pressure, flammable and explosive gases, improve resource utilization, simplify the structure and reduce costs.

[0006] To achieve the above purpose, the utility model is implemented through the following technical solutions:

[0007] A compressor sealing device, comprising a sealing shell base sleeved on a compressor main shaft, characterized in that: it also comprises a sealing part and an isolating part respectively installed at two ends of the sealing shell base, an isolating plate is arranged between the sealing part and the isolating part, the isolating plate is fixed to the sealing shell base, and a gap is arranged between the isolating plate and the main shaft;

[0008] The sealing part comprises a main sealing part, which comprises a dynamic ring, a static ring and a spring which are sequentially distributed from the outside to the inside. The dynamic ring is fixedly mounted on the main shaft of the compressor, and the static ring is fixedly mounted in the sealing shell base through the spring. A fluid dynamic pressure groove is opened on the dynamic ring towards the static ring, and the opening direction of the fluid dynamic pressure groove on the side of the dynamic ring is the same as the rotation direction of the dynamic ring; a sealing air hole is opened on the sealing shell base shell corresponding to the sealing part;

[0009] An isolation air hole is provided on the sealing shell base shell corresponding to the isolation part.

[0010] Furthermore: comb teeth are provided between the gap between the isolation plate and the main shaft, and the comb teeth are attached to the isolation plate.

[0011] Furthermore: the sealing part also includes a secondary sealing part, which is arranged between the main sealing part and the isolation part, and the structure of the secondary sealing part is the same as that of the main sealing part; the secondary sealing part is connected to the main sealing part, and the secondary sealing part is connected to the isolation part.

[0012] Furthermore, a leakage part is provided between the sealing part and the isolation part, and a leakage air hole is provided on the sealing shell base shell corresponding to the leakage part.

[0013] Furthermore: the spring is a chromium-nickel-iron alloy spring.

[0014] Compared with the original technology, the utility model has the following beneficial effects:

[0015] 1. The sealing device is installed on both sides of the compressor cylinder along the axial direction to seal the process gas leaking along the axis on both sides. The sealing gas comes from the process gas. The sealing device recycles the leaked gas to avoid waste.

[0016] 2. Traditionally, the dry gas seal system contains two independent sealing gas flows - primary and secondary sealing gas, and corresponding leakage gas flows - primary and secondary leakage gas. The primary sealing gas is used for the primary seal, while the secondary sealing gas is used for the secondary seal. The primary leakage gas is drawn from the gas after the primary seal and eventually discharged into the flare system; similarly, the secondary leakage gas is also drawn from the secondary seal after passing through the primary seal and is also sent to the flare for combustion.

[0017] However, the new utility model simplifies the original two-stage sealing gas and two-stage leakage gas into only a single-stage sealing gas and a single-stage leakage gas through innovative structural design, simplification and optimization. Specifically, the gas flow channel inside the dry gas seal is re-planned so that the gas leaked from the main seal can be collected and reused to serve as the sealing gas of the secondary seal. In this way, only one set of sealing gas and leakage gas system can support the normal operation of the main seal and the secondary seal. The total amount of leaked gas is significantly reduced, avoiding the waste of resources.

[0018] 3. The overall sealing structure of the sealing device is streamlined and optimized, reducing the number of required accessories, thereby reducing the failure rate of the entire system, reducing the customer's cost of pipeline layout, and reducing the overall size of the sealing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the device;

[0020] Figure 2 It is a schematic diagram of the structure of the fluid dynamic pressure groove on the dynamic ring;

[0021] In the figure:

[0022] 1. Main shaft; 2. Sealing shell base; 3. Main sealing part; 3.1. Sealing pore; 3.2. Moving ring; 3.21. Fluid dynamic pressure groove; 3.3. Stationary ring; 3.4. Spring; 4. Secondary sealing part; 5. Leakage part; 5.1. Leakage pore; 6. Isolation part; 6.1. Isolation pore; 7. Isolation plate; 7.1. Comb teeth. DETAILED DESCRIPTION

[0023] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0025] like Figure 1 As shown: A compressor sealing device includes a sealing shell base 2 sleeved on the compressor main shaft 1, characterized in that it also includes a sealing part and an isolating part 6 respectively installed at both ends of the sealing shell base 2, an isolating plate 7 is provided between the sealing part and the isolating part 6, the isolating plate 7 is fixed to the sealing shell base 2, and a gap is provided between the isolating plate 7 and the main shaft 1; comb teeth 7.1 are provided between the gap between the isolating plate 7 and the main shaft 1, and the comb teeth 7.1 are attached to the isolating plate 7.

[0026] A leakage portion 5 is further provided between the sealing portion and the isolating portion 6 , and a leakage air hole 5 . 1 is opened on the shell of the sealing shell base 2 corresponding to the leakage portion 5 .

[0027] An isolation air hole 6.1 is opened on the shell of the sealing shell base 2 corresponding to the isolation part 6.

[0028] The sealing part includes a main sealing part 3, and the main sealing part 3 includes a dynamic ring 3.2, a static ring 3.3 and a spring 3.4 which are distributed in sequence from the outside to the inside. The dynamic ring 3.2 is fixedly installed on the main shaft 1 of the compressor, and the static ring 3.3 is fixedly installed in the sealing shell base 2 through the spring 3.4. The spring 3.4 is a chromium-nickel-iron alloy spring. A fluid dynamic pressure groove 3.21 is opened on the side of the dynamic ring 3.2 facing the static ring 3.3, and the opening direction of the fluid dynamic pressure groove 3.21 on the side of the dynamic ring 3.2 is the same as the rotation direction of the dynamic ring 3.2; a sealing air hole 3.1 is opened on the shell of the sealing shell base 2 corresponding to the sealing part; the sealing part also includes a secondary sealing part 4, and the secondary sealing part 4 is arranged between the main sealing part 3 and the isolation part 6, and the structure of the secondary sealing part 4 is the same as that of the main sealing part 3; the secondary sealing part 4 is connected to the main sealing part 3, and the secondary sealing part 4 is connected to the isolation part 6.

[0029] The leakage pore 5.1, the isolation pore 6.1 and the sealing pore 3.1 are all connected with a pressure gauge and a flow meter.

[0030] The working principle of the utility model is as follows:

[0031] Before the compressor is started, the dynamic ring 3.2 and the static ring 3.3 are in contact, and no air film is formed at this time. In order to prevent dry friction damage, dry nitrogen needs to be injected through the isolation air hole 6.1 to push the dynamic ring 3.2 open to form a certain gap between it and the static ring 3.3 to prevent dry friction with the static ring 3.3 when the compressor starts to rotate; and the isolation air introduced at this time also forms an initial isolation layer.

[0032] Sealing gas injection: When the compressor is started, sealing gas (usually process gas or high-pressure nitrogen) is injected into the sealing part from the sealing gas hole 3.1. The pressure of the sealing gas is set to be higher than the pressure of the process gas sealed inside the compressor to prevent the process gas from leaking outward along the axial direction.

[0033] Rotation of the dynamic ring 3.2 and formation of the air film: As the compressor main shaft 1 rotates, the dynamic ring 3.2 rotates at high speed. Figure 2 As shown: the fluid dynamic pressure groove 3.21 on the surface of the dynamic ring 3.2 guides the sealing gas to enter, and the gas flow is subjected to the shear force in the groove and moves from the outer diameter to the center. The flow resistance provided by the sealing dam causes the gas to be compressed and the pressure to rise, which causes the dynamic ring 3.2 to separate from the static ring 3.3 and form a 3-5 micron thick gas film. At this time, the formation of the gas film realizes the non-contact sealing between the dynamic ring 3.2 and the static ring 3.3.

[0034] Sealing and isolation: The air film formed between the dynamic ring 3.2 and the static ring 3.3 of the main sealing part 3 undertakes the main sealing task to prevent the process gas from leaking. At the same time, the secondary sealing part 4 is located between the main sealing part 3 and the isolation part 6, as a second line of defense, to further enhance the sealing effect and prevent any possible leakage. The leaked gas of the main sealing part 3 is reused as the sealing gas of the secondary sealing part 4. Through such a series operation, the maintenance of single-stage sealing gas and leaked gas is achieved, the number of accessories is reduced, the failure rate is reduced, and the volume of the sealing device is also reduced.

[0035] Isolation gas circulation: Isolation gas (usually dry nitrogen) is injected into the isolation part 6 through the isolation gas hole 6.1 to prevent lubricating oil or other impurities from entering the sealing area and to prevent the sealing gas from leaking to the lubricating oil side.

[0036] Leakage gas treatment: A leakage part 5 is provided between the sealing part and the isolation part 6, wherein the leakage gas is discharged through the leakage gas hole 5.1. The leakage gas is the gas leaked from the main sealing part 3 and the secondary sealing part 4. After passing through the pressure switch, the flow limiting orifice plate and the flow meter, this part of the gas is discharged to the main venting port, and then returns to the compressor inlet for recycling, rather than simply discharged into the atmosphere.

[0037] Continuous monitoring: During the entire process, parameters such as the flow and pressure of the sealing gas, isolation gas and leakage gas are continuously monitored to ensure the normal operation of the sealing device and avoid damage to the dry gas seal caused by abnormal parameters.

[0038] The above implementation is only to illustrate the technical concept and features of the utility model, and its purpose is to enable people familiar with this technology to understand the content of the utility model and implement it accordingly, and it cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A compressor sealing device, comprising a sealing shell base sleeved on a compressor main shaft, characterized in that: It also includes a sealing part and an isolating part respectively installed at two ends of the sealing shell base, an isolating plate is arranged between the sealing part and the isolating part, the isolating plate is fixed to the sealing shell base, and a gap is arranged between the isolating plate and the main shaft; The sealing part comprises a main sealing part, which comprises a dynamic ring, a static ring and a spring which are sequentially distributed from the outside to the inside. The dynamic ring is fixedly mounted on the main shaft of the compressor, and the static ring is fixedly mounted in the sealing shell base through the spring. A fluid dynamic pressure groove is opened on the dynamic ring towards the static ring, and the opening direction of the fluid dynamic pressure groove on the side of the dynamic ring is the same as the rotation direction of the dynamic ring; a sealing air hole is opened on the sealing shell base shell corresponding to the sealing part; An isolation air hole is provided on the sealing shell base shell corresponding to the isolation part.

2. A compressor sealing device according to claim 1, characterized in that: Comb teeth are arranged between the gap between the isolation plate and the main shaft, and the comb teeth are attached to the isolation plate.

3. A compressor sealing device according to claim 1, characterized in that: The sealing part further comprises a secondary sealing part, which is arranged between the main sealing part and the isolation part, and the structure of the secondary sealing part is the same as that of the main sealing part; The secondary sealing portion is communicated with the primary sealing portion, and the secondary sealing portion is communicated with the isolation portion.

4. A compressor sealing device according to claim 1, characterized in that: A leakage part is also arranged between the sealing part and the isolating part, and a leakage air hole is opened on the sealing shell base shell corresponding to the leakage part.

5. A compressor sealing device according to claim 1, characterized in that: The spring is a chromium-nickel-inconel spring.

6. A compressor sealing device according to any one of claims 1 to 5, characterized in that: Also included are several flow meters and pressure meters connected to the sealing shell base.

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