Ethylene unit magnetic suspension expansion compressor

Abstract

The invention relates to the technical field of turbine expansion recompression, and particularly discloses an ethylene unit magnetic suspension expansion compressor which comprises a nozzle outlet ring and a mounting end cover and further comprises a plurality of bolt assemblies arranged in an array mode in the circumferential direction of the nozzle outlet ring and used for fixing the nozzle outlet ring to the mounting end cover. A plurality of bolt holes matched with the bolt assemblies are formed in the nozzle outlet ring, each bolt assembly comprises a bolt body installed on the inner side of the corresponding bolt hole, each bolt body comprises a screw part and a tapered end part, a driving connector is formed in the inner side of each tapered end part, and an anti-loosening structure is arranged on each tapered end part. Through the design of the anti-loosening structure, in the operation process of the device, the bolt body is prevented from loosening due to impact, vibration and variable load as much as possible, the bolt body is not prone to rotating, and therefore the phenomenon that after the bolt body is loosened, a gap exists between the end cover and the nozzle outlet ring is avoided.

Description

Technical Field

[0001] This invention relates to the field of turbine expansion and recompression technology, and in particular to a magnetic levitation expansion compressor for an ethylene plant. Background Technology

[0002] In the modern ethylene industry, with the increasing size of ethylene plants, their cryogenic separation processes all use high-pressure demethanization technology. The high-pressure tail gas produced is mainly composed of methane and hydrogen, accounting for more than 90% (mole fraction), with pressures above 0.5 MPa. Usually, the process expands this high-pressure tail gas to recover it and provide cooling for the cold box, which is the key to the operation of the cryogenic separation system.

[0003] There are generally two methods for expansion refrigeration of tail gas from high-pressure demethanizers: One method is to use a Joule-Thomson expansion valve to achieve refrigeration. However, this method is based on isenthalpic expansion and cannot perform any work other than refrigeration, resulting in energy loss and low efficiency.

[0004] Another method is to use expansion mechanisms for refrigeration. This is isentropic expansion, which has a better cooling effect and can also recover energy for external work.

[0005] Therefore, in the current process, the expansion recompressor has become the key equipment for obtaining cold energy in the cryogenic separation process. Its cooling effect is far superior to that of the throttling expansion valve, and its performance has an important impact on improving ethylene yield and reducing the energy consumption level of the unit.

[0006] In recent years, with the rapid development of the energy and chemical industry and the increasing scale of ethylene plants, the market demand for expansion recompressors has been expanding. However, it should be noted that the expansion recompressors used in ethylene plants are currently heavily reliant on imports. Given the current international situation, research on domestic production is imperative.

[0007] The main structure of an expansion recompressor is generally fixed and sealed using a combination of multiple sets of bolts and sealing strips. Because it works for a long time in an environment of impact, vibration and variable load, the bolt structure is prone to loosening, which will affect the sealing of the device and may even cause gas leakage.

[0008] Based on this, those skilled in the art have proposed a magnetic levitation expansion compressor for ethylene plants, which provides a new solution to the above-mentioned technical problems. Summary of the Invention

[0009] Therefore, it is necessary to provide a magnetic levitation expansion compressor for an ethylene plant to address the problems raised in the background art.

[0010] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The magnetic levitation expansion compressor for an ethylene plant specifically includes a nozzle outlet ring and a mounting end cover, and further includes a plurality of bolt assemblies arranged in a circumferential array along the nozzle outlet ring for fixing the nozzle outlet ring to the mounting end cover. The nozzle outlet ring has a plurality of bolt holes adapted to the bolt assemblies. The bolt assembly includes a bolt body installed inside the bolt holes. The bolt body includes a threaded portion and a locking head. The locking head has a drive interface inside and an anti-loosening structure.

[0011] Optionally, the anti-loosening structure includes a positioning screw hole formed on the inner wall of the drive interface, a positioning pin threaded inside the positioning screw hole, and a polygonal groove formed on the end face of the positioning pin facing the inner side of the drive interface.

[0012] Optionally, a rubber layer is provided on the end of the positioning pin away from the polygonal groove.

[0013] Optionally, the inner wall of the bolt hole is provided with a plurality of toothed grooves. The anti-loosening structure includes a positioning ring inserted into the inner side of the bolt hole and sleeved on the outer side of the locking head of the bolt body. The outer side of the positioning ring is provided with an external connecting tooth that matches the toothed groove. The positioning ring engages with the nozzle outlet ring through the cooperation of the external connecting tooth and the toothed groove.

[0014] Optionally, the outer wall of the lock head is provided with a plurality of toothed grooves, and the inner wall of the positioning ring is provided with an inner connecting tooth that matches the toothed grooves. The positioning ring engages with the lock head through the cooperation of the inner connecting tooth and the toothed grooves.

[0015] Optionally, an anti-loosening damping ring is fixed inside the positioning ring, and a plurality of anti-loosening protrusions are provided on the outer wall of the lock head. The anti-loosening damping ring is sleeved on the outer side of the lock head and engages with the anti-loosening protrusions.

[0016] Optionally, an anti-loosening damping ring is fixed inside the positioning ring, and a plurality of damping grooves are formed on the outer wall of the lock head. The connection between the damping groove and the outer wall of the lock head is provided with a protective rounded corner. The anti-loosening damping ring is sleeved on the outer side of the lock head. The anti-loosening damping ring protrudes inward at the damping groove to form a damping protrusion. The damping protrusion is embedded in the inner side of the damping groove. The anti-loosening damping ring is engaged with the lock head through the cooperation between the damping protrusion and the damping groove.

[0017] Optionally, a ratchet is fixed to the bottom outer side of the lock head, the positioning ring is rotatably connected to the outside of the lock head, and a plurality of locking blocks are rotatably connected to the bottom inner side of the positioning ring. The locking blocks are adapted to the ratchet, and a second spring is provided between the locking block and the inner wall of the positioning ring. The two ends of the second spring are respectively connected to the inner wall of the positioning ring and the corresponding locking block. When the second spring is in its natural state, the locking block engages with the ratchet.

[0018] Optionally, the top of the positioning ring is closed, and an installation cylinder is provided on the closed end of the positioning ring and inside the positioning ring. When the positioning ring is sleeved on the outside of the lock head, the installation cylinder is inserted into the inside of the drive interface. An installation hole is provided on the inside of the installation cylinder, and a base plate is sleeved on the bottom of the inside of the installation hole. An adjustment plate is slidably connected to the inside of the installation cylinder, and an adjustment groove is provided on the adjustment plate. A spring is provided between the base plate and the adjustment plate, and the two ends of the spring are respectively connected to the base plate and the adjustment plate. Axial retaining strips are fixed on both sides of the adjustment plate near the base plate. The end of the axial retaining strip away from the adjustment plate extends out of the base plate and outward to form a retaining foot. A clearance channel adapted to the retaining foot is provided on the inner walls of both sides of the drive interface. A movable groove is provided on the inner side of the drive interface and at the bottom of the clearance channel. Several sets of axial retaining grooves adapted to the two retaining feet are provided on the side wall of the drive interface and above the movable groove.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention, through the design of the anti-loosening structure, minimizes the loosening of the bolt body due to impact, vibration and variable load during the operation of the device, making it less prone to rotation, thereby avoiding the gap between the rear end cover and the nozzle outlet ring caused by the loosening of the bolt body.

[0020] 2. By setting up an anti-loosening structure, the present invention can effectively prevent the bolt body from rotating circumferentially during the operation of the device by simultaneously engaging the positioning ring with the bolt body and the bolt hole, thereby achieving the anti-loosening effect.

[0021] 3. The present invention uses the engagement of the snap-fit ​​foot and the axial snap-fit ​​groove to effectively prevent the positioning ring from axially displacing and falling off under working conditions of impact, vibration and variable load, thereby improving the anti-loosening effect.

[0022] 4. The present invention has a simple and reasonable anti-loosening structure design, which can achieve the anti-loosening effect without external power, and has a low cost. It can effectively ensure the preload of the bolt body during long-term machine operation and improve the service life of the device. Attached Figure Description

[0023] To more clearly illustrate the solutions in this invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a cross-sectional structural diagram of the present invention; Figure 3 This is a cross-sectional axial view of the structure of the present invention; Figure 4 This is a schematic front view of the nozzle outlet ring and bolt assembly of the present invention; Figure 5 This is a schematic axial view of the nozzle outlet ring and mounting end cap of the present invention. Figure 6 This is an exploded structural diagram of the nozzle outlet ring, bolt body, and positioning pin of the present invention. Figure 7 This is an enlarged structural diagram of point A in the figure of the present invention; Figure 8 This is a schematic diagram of the positioning pin and rubber layer of the present invention; Figure 9 This is a schematic diagram of the nozzle outlet ring, bolt body, and positioning ring of the present invention; Figure 10 This is a schematic diagram of the positioning ring, anti-loosening damping ring, and anti-loosening protrusion of the present invention; Figure 11 This is a schematic diagram of the anti-loosening damping ring and anti-loosening protrusion of the present invention; Figure 12 This is a schematic diagram of the damping groove of the present invention; Figure 13 This is a schematic diagram of the anti-loosening damping ring and damping groove of the present invention; Figure 14 This is a schematic diagram of the damping groove, protective fillet, and damping protrusion of the present invention; Figure 15 This is an axial view structural schematic diagram of the positioning ring, bolt body, ratchet, and locking block of the present invention; Figure 16 This is a schematic diagram of the main structure of the positioning ring, bolt body, ratchet, and locking block of the present invention; Figure 17 This is an exploded structural diagram of the positioning ring, bolt body, ratchet, and locking block of the present invention; Figure 18 This is an exploded structural diagram of the adjusting plate, base plate, positioning ring, and bolt body of the present invention; Figure 19 This is a schematic diagram of the structure of the adjusting plate and adjusting groove of the present invention; Figure 20 This is a cross-sectional structural schematic diagram of the adjusting plate, base plate, positioning ring, and bolt body of the present invention; Figure 21 This is a schematic diagram of the structure of the clearance channel and axial groove of the present invention; Figure 22 This is a cross-sectional view of the bolt body and axial retaining strip of the present invention; Figure 23 This is a schematic diagram of the structure of the movable groove, the avoidance channel, and the axial slot of the present invention.

[0025] The markings in the diagram are explained as follows: 1. Housing; 2. Nozzle outlet ring; 3. Mounting end cover; 4. Impeller; 5. Control ring; 6. Nozzle blade; 10. Bolt assembly; 11. Bolt hole; 12. Bolt body; 13. Positioning screw hole; 14. Positioning pin; 15. Drive interface; 16. Positioning ring; 17. Tooth groove one; 18. Tooth groove two; 19. External connecting tooth; 20. Internal connecting tooth; 21. Anti-loosening damping ring; 22. Anti-loosening ridge; 23. Damping groove; 24. Protective fillet; 25. Damping protrusion; 26. Ratchet; 27. Locking block; 28. Mounting cylinder; 29. ​​Base plate; 30. Adjusting plate; 31. Spring one; 32. Axial locking strip; 33. Locking foot; 34. Adjusting groove; 35. Movable groove; 36. Clearance channel; 37. Axial locking groove; 38. Rubber layer; 39. Spring two. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0027] Please refer to Figure 1-23 The present invention provides a magnetic levitation expansion compressor for an ethylene plant, comprising a nozzle outlet ring 2 and a mounting end cover 3, and further comprising a plurality of bolt assemblies 10 arranged in a circumferential array along the nozzle outlet ring 2 for fixing the nozzle outlet ring 2 to the mounting end cover 3. The nozzle outlet ring 2 is provided with a plurality of bolt holes 11 adapted to the bolt assemblies 10. The bolt assembly 10 includes a bolt body 12 installed inside the bolt holes 11. The bolt body 12 includes a screw portion and a locking head. The locking head is provided with a drive interface 15 inside and an anti-loosening structure.

[0028] In the prior art, multiple nozzle blades 6 are rotatably connected to the nozzle outlet ring 2. The nozzle outlet ring 2 is coaxially arranged with the rotor and impeller 4, and multiple nozzle blades 6 are evenly arranged around the rotor. A gas channel is formed between multiple structures on the housing 1 (housing, nozzle outlet ring 2, etc.). Multiple nozzle blades 6 are located in the gas channel. The two sides of the nozzle blades 6 are respectively attached to the nozzle outlet ring 2 and the other end cover plate, so that the gas needs to flow to the rotor through the gap between two adjacent nozzle blades 6. When multiple nozzle blades 6 rotate synchronously, the flow area of ​​the gas in the device (i.e., the cross-sectional area through which the gas passes) can be adjusted. Multiple nozzle blades 6 are mounted on the control ring 5, and the control ring 5 is used to synchronously adjust multiple nozzle blades 6. In the prior art, the installation and positioning requirements of the nozzle outlet ring 2 are very high. That is, it is important to fasten the nozzle outlet ring 2 to the mounting end cover 3 with bolts. During installation, the bolts are tightened to the pre-set pre-tightening position. During long-term machine operation, when the connecting bolts loosen due to impact, vibration or variable load, the force of the bolts will also change. Long-term use may affect the performance and service life of the equipment, affect the sealing of the device, and even cause gas leakage.

[0029] It should be noted that the drive interface 15 is usually an internal hexagon, spline, or other drive interface used to receive torque.

[0030] Example 1 Please refer to Figure 6-8 The anti-loosening structure includes a positioning screw hole 13 formed on the inner wall of the drive interface 15. Positioning screw holes 13 can be formed on one or more inner walls of the drive interface 15 to improve the anti-loosening effect. Preferably, positioning screw holes 13 can be formed on one or two opposite inner walls of the drive interface 15 to ensure the strength of the locking head while providing circumferential positioning for the bolt body 12. A positioning pin 14 is threaded into the inner side of the positioning screw hole 13. A polygonal groove is formed on the end face of the positioning pin 14 facing the inner side of the drive interface 15. The polygonal groove can be set as an internal hexagonal groove for receiving... During installation, the operator can first install the bolt body 12 into the bolt hole 11 and tighten it to the pre-set preload. Then, replace it with a smaller hex wrench or other torque tool that is compatible with the polygonal groove of the positioning pin 14, insert it into the drive interface 15, and insert it into the polygonal groove. By continuously rotating the positioning pin 14, it will continuously extend out of the locking head of the bolt body 12 and press against the inner wall of the bolt hole 11, thereby positioning the bolt body 12 to a certain extent in the circumferential direction and preventing it from loosening during equipment operation.

[0031] Please refer to Figure 8In the above embodiments, the positioning pin 14 is usually made of metal, which is prone to frictional wear during long-term contact with the inner wall of the bolt hole 11. Long-term use may affect the anti-loosening effect. Therefore, in a preferred embodiment, a rubber layer 38 is provided on the end of the positioning pin 14 away from the polygonal groove. The rubber layer 38 is fixed on the positioning pin 14, and the positioning pin 14 abuts against the inner wall of the bolt hole 11 through the rubber layer 38. This can improve the friction between the positioning pin 14 and the inner wall of the bolt hole 11, improve the anti-loosening effect, and at the same time protect the inner wall of the bolt hole 11 and improve the service life.

[0032] Example 2 In Embodiment 1, the bolt body 12 is prevented from loosening by the abutting friction between the locating pin 14 and the inner wall of the bolt hole 11. However, during long-term use, vibration may cause the locating pin 14 to shift position, resulting in slight loosening of the bolt body 12. Therefore, in this embodiment, as an alternative to Embodiment 1, please refer to... Figure 9 The inner wall of the bolt hole 11 is provided with several grooves 17. The anti-loosening structure includes a positioning ring 16 inserted into the inner side of the bolt hole 11 and sleeved on the outer side of the locking head of the bolt body 12. The outer side of the positioning ring 16 is provided with an external connecting tooth 19 that matches the groove 17. The positioning ring 16 is engaged with the nozzle outlet ring 2 through the cooperation of the external connecting tooth 19 and the groove 17. The positioning ring 16 is inserted between the groove 17 and the locking head, and a limiting structure is provided between the positioning ring 16 and the locking head to prevent relative rotation in its natural state. In this way, the groove 17 limits the positioning ring 16, and the positioning ring 16 limits the bolt body 12. This can effectively prevent the bolt body from loosening during equipment operation, effectively reduce the number of maintenance operations, and improve service life.

[0033] The outer wall of the lock head is provided with several toothed grooves 18, and the inner wall of the positioning ring 16 is provided with inner connecting teeth 20 that are adapted to the toothed grooves 18. The positioning ring 16 is engaged with the lock head through the cooperation of the inner connecting teeth 20 and the toothed grooves 18. When the positioning ring 16 is inserted between the inner wall of the bolt hole 11 and the lock head, the positioning ring 16 is engaged with the bolt hole 11 and the lock head simultaneously through the cooperation of the outer connecting teeth 19 and the toothed grooves 17, and the cooperation of the inner connecting teeth 20 and the toothed grooves 18, thereby circumferentially limiting the bolt body 12 and effectively preventing the bolt body 12 from loosening during long-term operation of the equipment.

[0034] Example 3 In Embodiment 2, the positioning ring 16 engages with the bolt hole 11 and the lock head via the outer connecting teeth 19 and the inner connecting teeth 20. In actual use, this may result in over-tightening or under-tightening due to misalignment of the teeth, affecting assembly accuracy to some extent. Furthermore, the presence of the positioning ring 16 may affect the preload of the bolt body 12. This is clearly not ideal. Therefore, this embodiment is further optimized; please refer to [reference needed]. Figure 10-11 An anti-loosening damping ring 21 is fixed inside the positioning ring 16. The anti-loosening damping ring 21 can be made of rubber. Several anti-loosening protrusions 22 are provided on the outer wall of the lock head. The anti-loosening damping ring 21 is sleeved on the outside of the lock head and is engaged with the anti-loosening protrusions 22. When the positioning ring 16 and the anti-loosening damping ring 21 are sleeved on the outside of the lock head of the bolt body 12, the anti-loosening damping ring 21 is deformed by the compression of the anti-loosening protrusions 22. The anti-loosening protrusions 22 are embedded in the inside of the anti-loosening damping ring 21 and form a snap-fit ​​connection with it. Thus, when the positioning ring 16 and the anti-loosening damping ring 21 are inserted between the bolt hole 11 and the lock head, the positioning ring 16 is engaged with the bolt hole 11 through the cooperation of the external connecting tooth 19 and the tooth groove 17, and at the same time, the anti-loosening damping ring 21 is engaged with the bolt hole 11. The anti-loosening ring 21 engages with the locking head through the engagement of the anti-loosening protrusion 22, thereby achieving circumferential limiting of the bolt body 12 and effectively preventing it from loosening. On the other hand, compared with Embodiment 2, this embodiment, through the setting of the anti-loosening damping ring 21, allows the outer connecting tooth 19 to be aligned with the tooth groove 17 when the bolt body 12 is in a pre-tightening state. Then, the positioning ring 16, together with the anti-loosening damping ring, is inserted into the outside of the locking head, thereby circumferentially limiting the locking head when the bolt body is in a target torque pre-tightening state, thus improving assembly accuracy. During equipment operation, due to the effect of the anti-loosening damping ring 21 on the anti-loosening protrusion 22, the bolt body 12 is not easy to rotate, thereby preventing it from loosening. It should be noted that the design of the anti-loosening damping ring 21 can alleviate some of the vibrations generated during the operation of the equipment.

[0035] Example 4 Please refer to Figure 12-14As an alternative to Embodiment 3, an anti-loosening damping ring 21 is fixed inside the positioning ring 16. The anti-loosening damping ring 21 can be made of rubber. Several damping grooves 23 are provided on the outer wall of the lock head. The connection between the damping grooves 23 and the outer wall of the lock head is provided with a protective rounded corner 24. The anti-loosening damping ring 21 is sleeved on the outer side of the lock head. The anti-loosening damping ring 21 protrudes inward at the damping groove 23 to form a damping protrusion 25. The damping protrusion 25 is embedded in the inner side of the damping groove 23. The anti-loosening damping ring 21 is engaged with the lock head through the cooperation of the damping protrusion 25 and the damping groove 23. In this embodiment, the outer surface of the lock head is smooth, and the damping grooves 23 are only provided on the circumferential outer wall. This facilitates the assembly of the positioning ring 16 and the anti-loosening damping ring 21. The positioning ring 16 and the anti-loosening damping ring 21 can be directly inserted into the outer side of the lock head. During this process, the portion of the anti-loosening damping ring 21 located inside the damping groove 23 forms a damping protrusion 25. The damping protrusion 25 and the damping groove 23 form a snap-fit ​​relationship. The anti-loosening damping ring 21 engages with the lock head through the cooperation of the damping protrusion 25 and the damping groove 23. By setting the anti-loosening damping ring 21, when the bolt body 12 is in the pre-tightening state, the outer connecting tooth 19 can be aligned with the tooth groove 17 first, and then the positioning ring 16 together with the anti-loosening damping ring is inserted into the outside of the lock head. This allows for circumferential limiting of the lock head when the bolt body is in the target torque pre-tightening state, thereby improving assembly accuracy. During equipment operation, due to the interaction between the damping protrusion 25 of the anti-loosening damping ring 21 and the damping groove 23, the bolt body 12 is not easy to rotate, thus preventing it from loosening. It should be noted that the design of the protective rounded corner 24 can protect the anti-loosening damping ring 21, preventing it from shearing and breaking or being severely worn during relative rotation with the lock head, which would affect its fit with the lock head and thus affect the anti-loosening effect.

[0036] Example 5 Please refer to Figure 15-17 As an alternative to Embodiment 3 or Embodiment 4, a ratchet 26 is fixed to the bottom outer side of the lock head, a positioning ring 16 is sleeved on the outer side of the lock head, and a plurality of locking blocks 27 are rotatably connected to the bottom inner side of the positioning ring 16. The locking blocks 27 are adapted to the ratchet 26, and a second spring 39 is provided between the locking blocks 27 and the inner wall of the positioning ring 16. The two ends of the second spring 39 are respectively connected to the inner wall of the positioning ring 16 and the corresponding locking block 27. When the second spring 39 is in its natural state, the locking block 27 is engaged with the ratchet 26. It should be noted that the ratchet teeth of the ratchet 26 are configured such that when the locking block engages with the ratchet 26, the ratchet 26 can rotate in the same direction as the tightening direction of the bolt body 12.

[0037] In this embodiment, the assembly process of the bolt assembly 10 is as follows: First, the bolt assembly 10 is placed into the bolt hole 11 as a whole, so that the outer connecting teeth 19 on the outside of the positioning ring 16 are aligned with the tooth groove 17. Then, the positioning ring is inserted into the inside of the bolt hole 11, so that the outer connecting teeth 19 are engaged with the tooth groove 17. Then, a tool (such as a hex wrench) is inserted into the inside of the drive interface 15 to gradually tighten the bolt body 12 to the specified target torque. During this process, the positioning ring 16 will also gradually enter the inside of the bolt hole 11.

[0038] It should be noted that, through the design of ratchet 26 and locking block 27, the positioning ring 16 can be installed inside the bolt hole 11 first, and then the bolt body 12 can be tightened to near the target torque. When the number of ratchet teeth of ratchet 26 is set to be large, the assembly accuracy of bolt body 12 will be higher and closer to the target torque.

[0039] Example 6 In the above embodiments two to four, the bolt body 12 can be prevented from rotating circumferentially due to vibration during equipment operation to a certain extent. However, they all lack axial limiting of the positioning ring 16, and there is a probability that the positioning ring 16 will fall off axially when the equipment is running for a long time. Therefore, this embodiment is further optimized.

[0040] Please refer to Figure 18-23 One end of the positioning ring 16 is closed, and an installation cylinder 28 is provided on the closed end and inside the positioning ring 16. When the positioning ring 16 is sleeved on the outside of the lock head, the installation cylinder 28 is inserted into the inside of the drive interface 15. There is no interference between the outer wall of the installation cylinder 28 and the inner wall of the drive interface 15. An installation hole is provided on the inner side of the installation cylinder 28, and a base plate 29 is rotatably connected to the bottom of the inner side of the installation hole. An adjusting plate 30 is slidably connected to the inner side of the installation cylinder 28. An adjusting groove 34 is provided on the adjusting plate 30. A spring 31 is provided between the base plate 29 and the adjusting plate 30, and the two ends of the spring 31 are respectively connected to the base plate 29. On the adjusting plate 30, axial retaining strips 32 are fixed on both sides of the end of the adjusting plate 30 near the bottom plate 29. The axial retaining strips 32 are inserted into and slidably connected to the bottom plate 29. The end of the axial retaining strip 32 away from the adjusting plate 30 extends out of the bottom plate 29 and extends outward to form a retaining foot 33. The inner walls on both sides of the drive interface 15 are provided with clearance channels 36 that are adapted to the retaining foot 33. The inner side of the drive interface 15 and the bottom of the clearance channel 36 are provided with a movable groove 35. The side wall of the drive interface 15 and the upper part of the movable groove 35 are provided with several sets of axial retaining grooves 37 that are adapted to the two retaining feet 33. In this embodiment, when the positioning ring 16 is installed on the outside of the lock head, it can first be inserted into the inner side of the adjustment groove 34 by a tool and the adjustment plate 30 can be rotated. The adjustment plate 30 will rotate together with the base plate 29 through the axial locking strip 32. When the locking foot 33 rotates to be aligned with the clearance channel 36, the adjustment plate 30 is pressed, so that the locking foot 33 moves along the clearance channel 36 toward the movable groove 35. When the locking foot 33 moves to the inner side of the movable groove 35, the adjustment plate 30 is rotated, so that the locking foot 33 rotates inside the movable groove 35 and rotates to the position aligned with the axial locking groove 37. Then the adjustment plate 30 is released. Under the action of the spring 31, the adjustment plate 30 drives the locking foot 33 to move and lock into the axial locking groove 37. In this way, the bolt body 12 and the positioning ring 16 can be axially connected. The bolt body 12 axially limits the positioning ring 16, and the positioning ring 16 and other components circumferentially limit the bolt body 12. The two interact to effectively prevent loosening and greatly improve the stability of the connection.

[0041] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," 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, an electrical connection, or a connection that allows communication between them; 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] Obviously, the embodiments described above are merely some embodiments of the present invention, not all embodiments. The accompanying drawings show preferred embodiments of the present invention, but do not limit the patent scope of the present invention. The present invention can be implemented in many different forms; rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of 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 specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this invention.

Claims

1. A magnetic levitation expander compressor for an ethylene plant, comprising a nozzle outlet ring (2) and a mounting end cap (3), characterized in that, It also includes a plurality of bolt assemblies (10) arranged in a circumferential array along the nozzle outlet ring (2) for fixing the nozzle outlet ring (2) on the mounting end cap (3). The nozzle outlet ring (2) is provided with a plurality of bolt holes (11) adapted to the bolt assemblies (10). The bolt assembly (10) includes a bolt body (12) installed inside the bolt hole (11). The bolt body (12) includes a screw part and a locking head. The locking head is provided with a drive interface (15) inside and an anti-loosening structure is provided on the locking head.

2. The magnetic levitation expander compressor for an ethylene plant according to claim 1, characterized in that, The anti-loosening structure includes a positioning screw hole (13) opened on the inner wall of the drive interface (15), and a positioning pin (14) is threadedly connected to the inner side of the positioning screw hole (13). A polygonal groove is opened on the end face of the positioning pin (14) facing the inner side of the drive interface (15).

3. A magnetic levitation expander compressor for an ethylene plant according to claim 2, characterized in that, The positioning pin (14) has a rubber layer (38) on the end away from the polygonal groove.

4. A magnetic levitation expander compressor for an ethylene plant according to claim 1, characterized in that, The inner wall of the bolt hole (11) is provided with a plurality of toothed grooves (17). The anti-loosening structure includes a positioning ring (16) inserted into the inner side of the bolt hole (11) and sleeved on the outer side of the locking head of the bolt body (12). The outer side of the positioning ring (16) is provided with an external connecting tooth (19) that is adapted to the toothed groove (17). The positioning ring (16) is engaged with the nozzle outlet ring (2) through the cooperation of the external connecting tooth (19) and the toothed groove (17).

5. A magnetic levitation expander compressor for an ethylene plant according to claim 4, characterized in that, The outer wall of the lock head is provided with a plurality of toothed grooves (18), and the inner wall of the positioning ring (16) is provided with an inner connecting tooth (20) that is adapted to the toothed grooves (18). The positioning ring (16) is engaged with the lock head through the cooperation of the inner connecting tooth (20) and the toothed grooves (18).

6. A magnetic levitation expansion compressor for an ethylene plant according to claim 4, characterized in that, The positioning ring (16) has an anti-loosening damping ring (21) fixed inside. The outer wall of the lock head is provided with several anti-loosening protrusions (22). The anti-loosening damping ring (21) is sleeved on the outer side of the lock head and is engaged with the anti-loosening protrusions (22).

7. A magnetic levitation expander compressor for an ethylene plant according to claim 4, characterized in that, The positioning ring (16) has an anti-loosening damping ring (21) fixed inside. The outer wall of the lock head has several damping grooves (23). The connection between the damping groove (23) and the outer wall of the lock head has a protective rounded corner (24). The anti-loosening damping ring (21) is sleeved on the outer side of the lock head. The anti-loosening damping ring (21) protrudes inward at the damping groove (23) to form a damping protrusion (25). The damping protrusion (25) is embedded in the inner side of the damping groove (23). The anti-loosening damping ring (21) is engaged with the lock head through the cooperation of the damping protrusion (25) and the damping groove (23).

8. A magnetic levitation expander compressor for an ethylene plant according to any one of claims 4, characterized in that, A ratchet (26) is fixed to the bottom outer side of the lock head. The positioning ring (16) is rotatably connected to the outside of the lock head. Several locking blocks (27) are rotatably connected to the bottom inner side of the positioning ring (16). The locking blocks (27) are adapted to the ratchet (26). A second spring (39) is provided between the locking block (27) and the inner wall of the positioning ring (16). The two ends of the second spring (39) are respectively connected to the inner wall of the positioning ring (16) and the corresponding locking block (27). When the second spring (39) is in its natural state, the locking block (27) engages with the ratchet (26).

9. A magnetic levitation expander compressor for an ethylene plant according to any one of claims 4-8, characterized in that, The top of the positioning ring (16) is closed, and an installation cylinder (28) is provided on the closed end of the positioning ring (16) and inside the positioning ring (16). When the positioning ring (16) is sleeved on the outside of the lock head, the installation cylinder (28) is inserted into the inside of the drive interface (15). An installation hole is provided inside the installation cylinder (28), and a base plate (29) is rotatably connected to the bottom of the installation hole. An adjusting plate (30) is slidably connected to the inside of the installation cylinder (28). An adjusting groove (34) is provided on the adjusting plate (30). A spring (31) is provided between the base plate (29) and the adjusting plate (30). The two ends of the spring (31) are respectively connected to the base plate (29) ... 9) On the adjustment plate (30), axial retaining strips (32) are fixed on both sides of the adjustment plate (30) near the bottom plate (29). The axial retaining strips (32) extend out of the bottom plate (29) away from the adjustment plate (30) and extend outward to form a retaining foot (33). The inner walls on both sides of the drive interface (15) are provided with clearance channels (36) that are adapted to the retaining foot (33). The inner side of the drive interface (15) and the bottom of the clearance channel (36) are provided with a movable groove (35). The side wall of the drive interface (15) and the upper part of the movable groove (35) are provided with several sets of axial retaining grooves (37) that are adapted to the two retaining feet (33).

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