An expansion joint with compensation and noise reduction functions

Abstract

The present invention provides an expansion joint with compensation and noise reduction functions, comprising at least three deformation units. The end of the first deformation unit is connected to an end tube, a ring plate is provided on the circumferential outer side of the end tube, and a universal ring is provided on the circumferential outer side of the bellows of the first deformation unit. The first deformation unit also includes a first universal hinge plate, which is arranged parallel to the axial direction of the expansion joint. One end of the first universal hinge plate is connected to the ring plate, and the other end of the first universal hinge plate is connected to the universal ring via a first pin. The first deformation unit and the second deformation unit are connected via an intermediate tube, and the universal ring of the first deformation unit and the universal ring of the second deformation unit are connected via a second universal hinge plate, which is parallel to the axial direction of the expansion joint. A sound insulation net is provided on the outside of the bellows, and a heat insulation layer is provided between the sound insulation net and the bellows. A non-metallic friction-reducing sleeve is provided between the pin and the hinge plate to enhance the noise reduction and sound insulation effect of the bellows and achieve acoustic isolation between the load-bearing structural components.

Description

Technical Field

[0001] The present invention relates to the field of metal bellows expansion joints, in particular to an expansion joint with compensation and noise reduction functions, which is used for flexible compensation and sound insulation and noise reduction of pipelines connected to moving equipment. Background Art

[0002] For pipelines connected to reciprocating sensitive dynamic equipment such as pumps and steam turbines, in addition to compensating for thermal expansion and contraction displacement, measures must also be taken to reduce vibration and noise.

[0003] The existing technology adopts the method of using a constrained expansion joint displacement compensation that can constrain the pressure thrust of the bellows. The core component, the metal bellows, adopts a multi-layer thin-wall structure to improve the flexibility of the bellows and reduce the force on the nozzle of the reciprocating sensitive moving equipment. At the same time, during the displacement compensation process, the relative friction between the layers of the multi-layer bellows plays a certain role in sound insulation and noise reduction. Figures 1 to 3 As shown, the types of constrained expansion joints used in the prior art include compound tie rod type expansion joints, elbow pressure balanced expansion joints, straight pipe pressure balanced expansion joints, etc. These constrained expansion joints have the following shortcomings: vibration noise is still transmitted through the tie rod of the load-bearing structure on the expansion joint that constrains the pressure thrust of the bellows, that is, the tie rod of the load-bearing structure on the expansion joint is connected to the end plate on the end pipe of the expansion joint through a metal gasket, nut, etc., and the rigid contact of the metal material causes an acoustic circuit breakage, which seriously affects the vibration reduction and sound insulation effect of the pipeline system. Summary of the Invention

[0004] In view of this, the present invention aims to propose an expansion joint with compensation and noise reduction functions to solve the problem in the prior art that the expansion joint has poor compensation and sound insulation functions, which affects the vibration reduction and sound insulation effect of the pipeline system.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] An expansion joint with compensation and noise reduction functions comprises at least three deformation units, wherein a first deformation unit, a second deformation unit and a third deformation unit are connected in sequence along the axial direction of the expansion joint, an end portion of the first deformation unit is connected to an end pipe, a ring plate is provided on the circumferential outer side of the end pipe, a universal ring is provided on the circumferential outer side of the bellows of the first deformation unit, the first deformation unit also comprises a first universal hinge plate, the first universal hinge plate is arranged parallel to the axial direction of the expansion joint, one end of the first universal hinge plate is connected to the ring plate, the other end of the first universal hinge plate is connected to the universal ring through a first pin shaft, the first deformation unit and the second deformation unit are connected through an intermediate tube, the first deformation unit and the second deformation unit are mirror-symmetrical, the universal ring of the first deformation unit and the universal ring of the second deformation unit are connected through a second universal hinge plate, the second universal hinge plate is arranged parallel to the axial direction of the expansion joint, a sound insulation net is provided on the outside of the bellows, and a heat insulation layer is provided between the sound insulation net and the bellows.

[0007] Furthermore, anti-friction sleeves with anti-friction function are installed in the inner holes of the first universal hinge plate, the second universal hinge plate and the universal ring, and anti-friction friction pairs are formed between the anti-friction sleeves and the contact surfaces of the first pin shaft.

[0008] Furthermore, a friction-reducing pad is provided between the first universal hinge plate, the second universal hinge plate and the universal ring, and a clearance is reserved between the inner diameter of the friction-reducing pad and the first pin shaft.

[0009] Furthermore, fixing members are provided at the front and rear ends of the outer side of the sound insulation net, and the fixing members are used to fix the sound insulation net.

[0010] Furthermore, an intermediate ring plate is provided on the circumferential outer side of the intermediate tube, and the intermediate ring plate is used to fix the second universal hinge plate.

[0011] Furthermore, a first limiting plate is provided on the universal ring of the first deformation unit and the universal ring of the second deformation unit, and two ends of the second universal hinge plate are connected to the first limiting plate via a second pin shaft.

[0012] Furthermore, the expansion joint includes five deformation units, with the midpoint in the axial direction as the center, and both ends of the expansion joint are symmetrical, and both ends of the third deformation unit are connected to the second deformation unit.

[0013] Furthermore, a first single-type hinge plate and a second single-type hinge plate are provided on the circumferential outer side of the third deformation unit, one end of the first single-type hinge plate is connected to one end of the second single-type hinge plate through a third pin shaft, the other end of the first single-type hinge plate is connected to the ring plate of the second deformation unit, and the other end of the second single-type hinge plate is connected to the ring plate of the second deformation unit at the other end.

[0014] Furthermore, a second limiting plate is provided between the first single hinge plate and the second single hinge plate, and the second limiting plate is used to limit the rotation angle of the first single hinge plate and the second single hinge plate.

[0015] Furthermore, a second limiting plate is provided between the first single hinge plate and the second single hinge plate, and the second limiting plate is used to limit the rotation angle of the first single hinge plate and the second single hinge plate.

[0016] Furthermore, the same first pin shaft is connected to two first universal hinge plates, and the two first universal hinge plates are respectively located on the inner and outer sides of the universal ring.

[0017] Compared with the prior art, the expansion joint with compensation and noise reduction functions of the present invention has the following advantages:

[0018] 1) In terms of the action principle, based on the deformation coordination action principle of the bellows and the universal structural parts, through the ingenious combination design of the bellows and the structural parts, the expansion joint described in the present invention can effectively compensate for the axial, lateral, angular and multi-directional displacements of the straight pipe section and has smaller external dimensions and rigidity. On the basis of meeting the displacement compensation performance, the overall rigidity of the expansion joint is reduced, that is, the flexibility of the expansion joint is improved. At the same time, a bellows deformation limiting device is provided, which can control the deformation amount of each bellows to ensure that each will not become unstable due to excessive deformation.

[0019] 2) While the bellows still uses multiple layers of thin-walled material, multiple layers of stainless steel wire mesh (generally more than 5 layers) are laid on the outside of the bellows, and a layer of high-temperature resistant ceramic fiber felt is laid between the wire mesh and the bellows. The friction between the thin-walled bellows layers and the frictional heat between the stainless steel wire mesh layers during bellows compensation are used to reduce the transmission of vibration noise and improve the sound insulation and noise reduction effect of the bellows. At the same time, the high-temperature resistant ceramic fiber felt laid between the wire mesh and the bellows can not only effectively protect the bellows from damage, but more importantly, it plays a role in heat insulation, reducing the heat loss of the bellows and ensuring that the temperature of the non-metallic friction-reducing sleeve is within the permitted range.

[0020] 3) The pin shaft is made of stainless steel, and ultra-high molecular polyethylene, a non-metallic material with anti-friction function, is added between the hinge plate of the load-bearing component and the pin shaft. At the same time, a friction pair with anti-friction is also added between the universal ring and the hinge plate to achieve sound isolation while reducing the movement friction resistance between the components. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a compound tie rod type expansion joint in the prior art;

[0022] Figure 2 It is a elbow pressure balance expansion joint in the prior art;

[0023] Figure 3 It is a straight pipe pressure balanced expansion joint in the prior art;

[0024] Figure 4 This is a schematic diagram of a constrained expansion joint according to an embodiment of the present invention;

[0025] Figure 4a for Figure 4 A partial enlarged view of the part selected in the middle box;

[0026] Figure 5 This is a schematic diagram of the pre-deformation of the constrained expansion joint when only axial displacement is compensated according to an embodiment of the present invention;

[0027] Figure 6 This is a simplified schematic diagram of a constrained expansion joint according to an embodiment of the present invention.

[0028] Description of reference numerals:

[0029] 1-end tube, 2-ring plate, 3-first universal hinge plate, 4-universal ring, 5-first pin, 6-bellows, 7-second universal hinge plate, 8-middle tube, 9-middle ring plate, 10-first limit plate, 11-first single hinge plate, 12-second limit plate, 13-second single hinge plate, 14-fixing part, 15-sound insulation net, 16-thermal insulation layer, 17-anti-friction pad, 18-anti-friction sleeve, 19-pin retaining ring DETAILED DESCRIPTION

[0030] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Furthermore, a brief explanation of the directions or positional relationships involved in the following specific embodiments is provided: The directions or positional relationships indicated by terms such as "front," "back," "upper," "lower," "left," "right," "top," and "bottom" mentioned in the embodiments refer to the directions or positional relationships shown in the accompanying drawings. The term "on" refers to being directly supported by an element or indirectly supported by an element via another element integrated into or supported by that element.

[0031] It should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections, electrical connections, or mutual communication; they may refer to direct connections or indirect connections through an intermediate medium; they may refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0032] like Figures 4-6 As shown, an expansion joint with compensation and noise reduction functions includes at least three deformation units. The first, second, and third deformation units are connected in sequence along the axial direction of the expansion joint. The end of the first deformation unit is connected to an end pipe 1, which is circumferentially provided with a ring plate 2. A universal ring 4 is circumferentially provided with a bellows 6 of the first deformation unit. The first deformation unit also includes a first universal hinge plate 3, which is arranged parallel to the axial direction of the expansion joint. One end of the first universal hinge plate 3 is connected to the ring plate 2, and the other end of the first universal hinge plate 3 is connected to the universal ring 4 via a first pin 5. The first and second deformation units are connected by an intermediate tube 8. The first and second deformation units are mirror-symmetrical. The universal ring 4 of the first and second deformation units are connected by a second universal hinge plate 7, which is arranged parallel to the axial direction of the expansion joint. A sound insulation net 15 is provided on the outside of the bellows 6, and a heat insulation layer 16 is provided between the sound insulation net 15 and the bellows 6. When the temperature of the pipeline rises and thermal expansion occurs, the constrained expansion joint is subjected to the thrust of the displacement change caused by the thermal expansion of the pipeline or equipment. The deformation unit bellows of the constrained expansion joint will produce angular deformation around the pin axis based on the direction of displacement. The intermediate tube of the constrained expansion joint will deflect accordingly, so that the center line between two adjacent deformation units becomes a broken line relative to the initial axis. The combination of different directions of the broken line can achieve compensation and absorption of axial, lateral and angular displacement, effectively meeting the needs of compensating high-pressure straight pipe sections in confined spaces with high requirements on the expansion joint's external dimensions and pipe rack stress. That is, a metal bellows expansion joint with smaller external dimensions is used to compensate for the multi-directional thermal expansion deformation of pipelines and equipment, reducing space occupancy and reducing the stress on the pipe and equipment nozzles. It can be used for flexible compensation of straight pipe sections in confined spaces. At the same time, the friction between the thin-walled bellows layers and the frictional heat between the sound insulation mesh layers during bellows compensation are used to absorb the transmission of vibration and noise, thereby improving the sound insulation and noise reduction effect of the bellows expansion joint. The high-temperature resistant heat-insulating layer 16 laid between the sound-insulating net 15 and the bellows 6 can effectively protect the bellows 6 from damage. At the same time, the heat-insulating layer 16 can also play a role in heat insulation, reduce heat loss in the pipeline, and ensure that the temperature of the stress-bearing structural parts such as the pin shaft 5, hinge plate, universal ring 4 and friction-reducing sleeve 18 is within the range allowed by their physical properties and can function normally. The expansion joint described in the present invention has both compensation and sound insulation functions, improves the noise reduction and sound insulation effect of the bellows, and can achieve sound isolation between stress-bearing structures, effectively improving the vibration reduction, sound insulation and noise reduction effect of the expansion joint of the pipeline connected to reciprocating sensitive dynamic equipment such as pumps and steam turbines, and meets the system's compensation and sound insulation and noise reduction requirements for pipelines and expansion joints.

[0033] In this embodiment, the first pin shaft 5 is made of stainless steel, and a friction-reducing sleeve 18 with a friction-reducing function is installed in the inner holes of the first universal hinge plate 3, the second universal hinge plate 7 and the universal ring 4. A friction-reducing friction pair is formed between the friction-reducing sleeve 18 and the contact surface of the first pin shaft 5. At the same time, a stainless steel friction-reducing pad 17 is added between the first universal hinge plate 3, the second universal hinge plate 7 and the universal ring 4. A gap is reserved between the inner diameter of the stainless steel friction-reducing pad 17 and the first pin shaft 5. In this way, on the one hand, sound isolation is achieved between the load-bearing structural parts of the expansion joint, and on the other hand, the relative movement resistance and noise of the load-bearing structural parts are greatly reduced.

[0034] The sound insulation net 15 is configured as a stainless steel wire mesh. The sound insulation net 15 can be configured as multiple layers. The number of layers of the sound insulation net is determined according to a vibration reduction and noise reduction index test, and is generally more than 5 layers.

[0035] Fixings 14 are provided at the front and rear ends of the outer side of the sound insulation net 15. Fixings 14 are configured as fixed steel wires and are used to secure the sound insulation net 15. Thermal insulation layer 16 is configured as ceramic fiber felt, effectively protecting the corrugated pipe 6 from damage. The ceramic fiber felt 16 also provides thermal insulation, reducing heat loss in the pipeline. Friction-reducing sleeve 18 is configured as an ultra-high molecular weight anti-friction sleeve, preferably a non-metallic ultra-high molecular weight polyethylene anti-friction sleeve.

[0036] Furthermore, the first universal hinge plate 3 is welded to the ring plate.

[0037] The two ends of the second universal hinge plate 7 are respectively connected to the universal rings 4 of the first deformation unit and the second deformation unit. An intermediate ring plate 9 is provided on the circumferential outer side of the intermediate tube 8. The intermediate ring plate 9 is used to fix the second universal hinge plate 7. When in use, the intermediate ring plate 9 is preferably welded to the second universal hinge plate 7.

[0038] Furthermore, first limiting plates 10 are provided on both the universal ring 4 of the first deformation unit and the universal ring 4 of the second deformation unit, and the ends of the second universal hinge plate 7 are connected to the first limiting plates 10 via second pins. This allows the universal ring 4 to be fixed to the outside of the deformation unit via the first universal hinge plate 3 and the second universal hinge plate 7, achieving vertical and horizontal fixation. At the same time, the first limiting plates 10 limit the rotation angle of the second universal hinge plate 7, thereby limiting the bending angle of the expansion joint.

[0039] As part of the embodiment of the present invention, the expansion joint of the present invention may include 5 deformation units, with the midpoint in the axial direction as the center, and the two ends of the expansion joint are symmetrical. The two ends of the third deformation unit are connected to the second deformation unit. A first single hinge plate 11 and a second single hinge plate 13 are provided on the circumferential outer side of the third deformation unit. One end of the first single hinge plate 11 is connected to one end of the second single hinge plate 13 through a third pin shaft, and the other end of the first single hinge plate 11 is connected to the ring plate 2 of the second deformation unit, and the other end of the second single hinge plate 13 is connected to the ring plate 2 of the second deformation unit at the other end. Furthermore, a second limit plate 12 is provided between the first single hinge plate 11 and the second single hinge plate 13, and the second limit plate 12 is used to limit the rotation angle of the single hinge plate.

[0040] Furthermore, when the constrained expansion joint only compensates for axial displacement, it is necessary to follow Figure 5 As shown, during installation, the deformation units at both ends of the expansion joint are pre-displaced in an angular direction of θ=0.5-1° in advance to enable the expansion joint to quickly respond to and coordinate the thermal expansion changes of the deformed pipeline and effectively absorb the axial displacement.

[0041] Furthermore, according to the pressure of the straight pipe section compensated by the constrained expansion joint, when the pressure of the straight pipe section compensated by the constrained expansion joint is large, the bellows can be a reinforced U-shaped bellows, wherein the reinforced U-shaped bellows is a bellows with a reinforcement ring added at the trough.

[0042] Furthermore, the same first pin 5 is connected to two first universal hinge plates 3, which are respectively located on the inner and outer sides of the universal ring 4 to clamp and fix the universal ring. A pin retaining ring 19 is provided at the inner end of the first pin 5 to prevent the first pin 5 from loosening.

[0043] As part of the embodiment of the present invention, when the axial and lateral displacements to be compensated are small, the expansion joint of the present invention can be designed to include a structure of three deformation units, such as Figure 6 shown.

[0044] Through the rotation of the hinge plate around the pin, each bellows undergoes moderate angular deformation. The straight-line connection between the deformation units is transformed into a broken-line connection, shortening the distance between the deformation units and, in turn, the length of the expansion joint, absorbing the axial displacement of the deformed pipe. When the pin rotates, driving one end of the expansion joint downward and the other end upward, the lateral displacement of the deformed pipe is absorbed. When the pin rotates, causing the angle between the two ends of the expansion joint to change, the angular displacement of the deformed pipe is absorbed. The axial force that drives the deformation of the constrained expansion joint is equal to the axial stiffness of one bellows multiplied by the axial displacement; the lateral force is equal to the lateral stiffness of two adjacent bellows multiplied by the lateral displacement; and the angular deformation force is equal to the angular stiffness of one bellows multiplied by the angular displacement.

[0045] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. An expansion joint with compensation and noise reduction functions, characterized in that: The invention comprises at least three deformation units, wherein a first deformation unit, a second deformation unit and a third deformation unit are connected in sequence along the axial direction of the expansion joint, an end of the first deformation unit is connected to an end tube (1), a ring plate (2) is provided on the circumferential outer side of the end tube (1), a universal ring (4) is provided on the circumferential outer side of the bellows (6) of the first deformation unit, and the first deformation unit further comprises a first universal hinge plate (3), the first universal hinge plate (3) is arranged parallel to the axial direction of the expansion joint, one end of the first universal hinge plate (3) is connected to the ring plate (2), and the other end of the first universal hinge plate (3) is connected to the ring plate (2). A pin (5) is connected to the universal ring (4), the first deformation unit and the second deformation unit are connected through an intermediate tube (8), the first deformation unit and the second deformation unit are mirror-symmetrical, the universal ring (4) of the first deformation unit and the universal ring (4) of the second deformation unit are connected through a second universal hinge plate (7), the second universal hinge plate (7) is arranged parallel to the axial direction of the expansion joint, a multi-layer sound insulation net (15) is arranged outside the bellows (6), the sound insulation net (15) is arranged as a stainless steel wire mesh, and a heat insulation layer (16) is arranged between the sound insulation net (15) and the bellows (6), An intermediate ring plate (9) is provided on the circumferential outer side of the intermediate tube (8), and the intermediate ring plate (9) is used to fix the second universal hinge plate (7). A first limiting plate (10) is provided on both the universal ring (4) of the first deformation unit and the universal ring (4) of the second deformation unit, and both ends of the second universal hinge plate (7) are connected to the first limiting plate (10) via a second pin shaft.

2. The expansion joint with compensation and noise reduction functions according to claim 1, characterized in that: A friction-reducing sleeve (18) having a friction-reducing function is assembled in the inner holes of the first universal hinge plate (3), the second universal hinge plate (7) and the universal ring (4), and a friction-reducing pair is formed between the contact surface of the friction-reducing sleeve (18) and the first pin shaft (5).

3. The expansion joint with compensation and noise reduction functions according to claim 1, characterized in that: A friction-reducing pad (17) is provided between the first universal hinge plate (3), the second universal hinge plate (7), and the universal ring (4), and a clearance is reserved between the inner diameter of the friction-reducing pad (17) and the first pin shaft (5).

4. The expansion joint with compensation and noise reduction functions according to claim 1, characterized in that: Fixing members (14) are provided at the front and rear ends of the outer side of the sound insulation net (15), and the fixing members (14) are used to fix the sound insulation net (15).

5. The expansion joint with compensation and noise reduction functions according to claim 1, characterized in that: The expansion joint includes five deformation units, with the midpoint in the axial direction as the center, and the two ends of the expansion joint are symmetrical, and both ends of the third deformation unit are connected to the second deformation unit.

6. The expansion joint with compensation and noise reduction functions according to claim 1, characterized in that: A first single hinge plate (11) and a second single hinge plate (13) are provided on the circumferential outer side of the third deformation unit, one end of the first single hinge plate (11) is connected to one end of the second single hinge plate (13) via a third pin shaft, the other end of the first single hinge plate (11) is connected to the ring plate (2) of the second deformation unit, and the other end of the second single hinge plate (13) is connected to the ring plate (2) of the second deformation unit at the other end.

7. The expansion joint with compensation and noise reduction functions according to claim 6, characterized in that: A second limiting plate (12) is further provided between the first single hinge plate (11) and the second single hinge plate (13), and the second limiting plate (12) is used to limit the rotation angle of the first single hinge plate (11) and the second single hinge plate (13).

8. The expansion joint with compensation and noise reduction functions according to claim 1, characterized in that: The same first pin shaft (5) is connected to two first universal hinge plates (3), and the two first universal hinge plates (3) are respectively located on the inner and outer sides of the universal ring (4).

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