A corrugated tube expansion joint type with a pressure increasing device and a method of use

Abstract

This invention discloses a type of bellows expansion joint with a pressurizing device and its usage method, including a first connecting pipe, a second connecting pipe, a first bellows, a second bellows, and a pressurizing device. The first bellows is located between the inner ends of the first connecting pipe and the second connecting pipe, and the second bellows is located around the second connecting pipe. The pressurizing device includes an outer sheath structure, an automatic pressurizing circuit, a pressurizing valve, and a pressure relief valve. The outer sheath structure includes a long connecting pipe and end plates on both sides. The automatic pressurizing circuit is located on one end plate, the pressurizing valve is located on the automatic pressurizing circuit, and the pressure relief valve is located on the long connecting pipe. The outer sheath structure is connected to the first connecting pipe through the end plate, and the outer sheath structure is connected to one end of the second bellows through the other end plate. The other end of the second bellows is connected to the outer end of the second connecting pipe near its outer side. A sealed cavity is formed between the outer sheath structure and the first bellows. This invention has an ingenious structure, and the pressurizing device outside the bellows improves the pressure-bearing capacity of the bellows.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pressure pipeline elements and equipment, in particular to a bellows expansion joint type with a pressure increasing device and a use method. BACKGROUND

[0002] The bellows expansion joint is a kind of expansion joint made of metal bellows as the main element, which can stretch along the pipeline axis direction, and also allows a small amount of bending and transverse deformation. The bellows expansion joint is widely used in pressure pipelines and containers, which not only bears the pipeline pressure, but also meets the compensation of thermal expansion displacement. Its deformable feature determines its thin wall thickness. Due to the thin wall feature, the pressure bearing capacity is relatively weak, which makes the expansion joint have great limitations and risks in high pressure occasions, and failure occurs from time to time. SUMMARY

[0003] In view of the insufficient pressure bearing capacity of the bellows, the present application provides a bellows expansion joint type with a pressure increasing device and a use method, which can greatly improve the pressure bearing capacity of the bellows without additional air source on the basis of meeting the original compensation capacity.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a bellows expansion joint type with a pressure increasing device, comprising a first connecting pipe, a second connecting pipe, a first bellows, a second bellows and a pressure increasing device, the first bellows is located between the inner side end of the first connecting pipe and the second connecting pipe, and is connected with the inner side end of the first connecting pipe and the second connecting pipe through the two ends of the first bellows, the second bellows is located on the periphery of the second connecting pipe, the outer side end of the first connecting pipe and the second connecting pipe is respectively connected with other components, the pressure increasing device is located on the periphery of the first bellows, and the pressure increasing device moves together with the first bellows;

[0005] The pressure increasing device comprises an outer sheath structure, an automatic pressure increasing circuit, a pressure increasing valve and a pressure relief valve, the outer sheath structure comprises a long connecting pipe and two side end plates, the automatic pressure increasing circuit is located on one side of the end plate, the pressure increasing valve is located on the automatic pressure increasing circuit, and the pressure relief valve is located on the long connecting pipe, the outer sheath structure is connected with the first connecting pipe through one side of the end plate, the outer sheath structure is connected with one end of the second bellows through the other side of the end plate, the other end of the second bellows is connected with the second connecting pipe close to the outer side end, and a sealed cavity is formed between the outer sheath structure and the first bellows, and the actual pressure load borne by the first bellows is reduced through the sealed cavity.

[0006] Preferably, a flow guide is arranged between the first connecting pipe and the inner end of the second connecting pipe, and the flow guide is arranged inside the first bellow, one end of the flow guide is connected with the inner wall of the first connecting pipe, and the other end of the flow guide extends into the second connecting pipe, and the flow guide is used to prevent the medium inside from impacting the first bellow.

[0007] Preferably, the first bellow is connected with the first connecting pipe and the second connecting pipe by welding.

[0008] Preferably, the end plate on one side of the outer sheath structure is connected with the inner end surface of the first connecting pipe by welding, and the end plate on the other side of the outer sheath structure is connected with the second bellow near the inner end by welding.

[0009] Preferably, the end plate near the first connecting pipe is provided with an inflation port, and the inflation port is arranged on the surface of the end plate, and air or other gas with corresponding pressure is filled into the sealing cavity through the inflation port.

[0010] Preferably, the surface of the long connecting pipe is provided with a pressure alarm for monitoring the air pressure of the sealing cavity.

[0011] Preferably, the automatic pressure increasing circuit is connected with the inside of the first connecting pipe and the inside of the sealing cavity respectively.

[0012] The application also provides a use method of the bellow expansion joint type with the pressure increasing device, which comprises the following steps:

[0013] S1, first, air or other gas with corresponding pressure is filled into the sealing cavity through the inflation port, so that the pressure in the sealing cavity reaches a set value;

[0014] S2, the medium is introduced into the pipeline, and the actual bearing pressure of the first bellow in contact with the medium is the difference between the pressure of the medium and the set value;

[0015] S3, the outer sheath structure between the first connecting pipe and the second connecting pipe moves together with the first bellow to compensate the displacement of the pipeline;

[0016] S4, when the pipeline is expanded or compressed, the first bellow and the second bellow move synchronously and in the same direction to compensate the thermal expansion of the pipeline;

[0017] S5, the pressure in the sealing cavity is detected by the pressure alarm, and when the pressure is lower than a certain value or higher than a certain value, an alarm signal is sent to timely find out whether the pressure relief valve or the pressure increasing valve is out of order;

[0018] S6, when the sealing cavity pressure drops due to the working temperature change or displacement movement, the pressure of the sealing cavity between the outer side of the first bellows and the outer sheath structure is kept constant through the pressure increasing valve and the pressure relief valve in the automatic pressure increasing circuit, and the actual pressure load of the first bellows is reduced.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] 1. According to the principle that the forces in the positive and negative directions can offset each other, a sealing pressure increasing device which can move synchronously with the inner bellows is arranged on the outer side of the bellows, and the internal pressure of the bellows is offset by the external pressure of the sealing cavity, so that the bellows can bear greater internal pressure, the sealing cavity has constant pressure, can move in the same direction with the inner bellows to compensate displacement, and can automatically increase pressure to keep the pressure constant.

[0021] 2. According to the present application, the automatic pressure increasing circuit and the pressure relief valve are arranged to keep the outer side of the first bellows at constant pressure, so as to offset the influence of part of the internal pressure, reduce the actual pressure load of the bellows, and improve the safety of the bellows and expand the use range of the bellows.

[0022] 3. The present application has simple and reliable structure, and the automatic pressure increasing circuit is ingenious, easy to manufacture, controllable in cost and high in practicality. DETAILED DESCRIPTION

[0023] The accompanying drawings are used to provide further understanding of the present application, and constitute a part of the specification, which is used together with embodiments of the present application to explain the present application, and do not constitute a limitation of the present application.

[0024] In the drawings:

[0025] Figure 1 is a structure diagram of the expansion joint of the automatic pressure increasing device of the present application;

[0026] Figure 2 is a schematic diagram of the pressure bearing state of the ordinary bellows;

[0027] Figure 3 is a schematic diagram of the pressure bearing state of the bellows of the device of the present application;

[0028] In the drawings, 1 is a first connecting pipe, 2 is an automatic pressure increasing circuit, 3 is a pressure increasing valve, 4 is an inflation port, 5 is a flow guide cylinder, 6 is a pressure relief valve, 7 is a first bellows, 8 is a pressure alarm, 901 is a long connecting pipe, 902 is an end plate, 10 is a second bellows, and 11 is a second connecting pipe. DETAILED DESCRIPTION

[0029] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0030] Example: Figure 1 As shown, a bellows expansion joint with a pressurizing device includes a first connecting pipe 1, a second connecting pipe 11, a first bellows 7, a second bellows 10, and a pressurizing device. The first bellows 7 is located between the inner ends of the first connecting pipe 1 and the second connecting pipe 11, and is connected to the inner ends of the first connecting pipe 1 and the second connecting pipe 11 by welding at both ends. A guide tube 5 is provided between the inner ends of the first connecting pipe 1 and the second connecting pipe 11, and the guide tube 5 is located inside the first bellows 7. One end of the guide tube 5 is connected to the inner wall of the first connecting pipe 1 by welding, and the other end of the guide tube 5 extends into the interior of the second connecting pipe 11. The guide tube 5 is used to prevent the internal medium from impacting the first bellows 7. The second bellows 10 is located outside the second connecting pipe 11. The outer ends of the first connecting pipe 1 and the second connecting pipe 11 are respectively connected to other components. The pressurizing device is located outside the first bellows 7, and the pressurizing device moves with the first bellows 7.

[0031] The pressure increasing device comprises an outer sheath structure, an automatic pressure increasing circuit 2, a pressure increasing valve 3 and a pressure relief valve 6, the outer sheath structure comprises a long connecting pipe 901 and end plates 902 on both sides, the automatic pressure increasing circuit 2 is located on the end plate 902 on one side, the pressure increasing valve 3 is located on the automatic pressure increasing circuit 2, and the automatic pressure increasing circuit 2 is in communication with the inside of the first connecting pipe 1 and the inside of the sealing cavity respectively, wherein the automatic pressure increasing circuit 2 can adapt to the working conditions of frequent changes in temperature and displacement, such as temporarily adding a little gas through the gas inlet 4, and in specific working conditions, such as constant working temperature, it can not be needed or replaced by other forms, and the automatic pressure increasing circuit 2 can also be replaced by other forms, such as setting a gas source outside to supplement pressure, the pressure relief valve 6 is located on the long connecting pipe 901, a pressure alarm 8 is arranged on the surface of the long connecting pipe 901, the pressure alarm is located on one side of the pressure relief valve 6 and is used for monitoring the air pressure of the sealing cavity, the outer sheath structure is connected with the first connecting pipe 1 through the end plate 902 on one side in a welding mode, the outer sheath structure is connected with one end of the second bellows 10 through the end plate 902 on the other side in a welding mode, the other end of the second bellows 10 is connected with the second connecting pipe 11 close to the outer side end in a welding mode, the sealing cavity is formed between the outer sheath structure and the first bellows 7, and a gas inlet 4 is arranged on the surface of the end plate 902 close to the first connecting pipe 1, the gas inlet 4 is located on the surface of the end plate 902 and is used for filling the sealing cavity with air or other gas with corresponding pressure through the gas inlet 4.

[0032] The application also provides a use method of the bellows expansion joint type with the pressure increasing device, comprising the following steps:

[0033] S1, first, before work, filling the sealing cavity with air or other gas with corresponding pressure through the gas inlet 4, so that the pressure in the sealing cavity reaches a set value P2, wherein the pressure value can be adjusted and controlled through the pressure relief valve 6, and during work, the expansion joint can discharge part of the gas through the pressure relief valve 6 due to the expansion of the gas in the sealing cavity caused by the temperature rise of the pipeline, so as to ensure that the pressure in the sealing cavity remains constant;

[0034] S2, as shown in Figure 2 and Figure 3 shown, the medium is introduced into the pipeline, wherein the pressure of the medium is P1, the actual bearing pressure of the ordinary bellows is P1, and according to the principle that the forces in the positive and negative directions can be offset, the actual bearing pressure of the first bellows 7 contacting the medium is P1'=P1-P2, so that the pressure load of the bellows is effectively reduced, the internal gas source is used for automatically increasing pressure to keep the external air pressure constant, and the internal and external pressure actions can be offset, so that the first bellows 7 can bear greater internal pressure;

[0035] S3, the outer sheath structure between the first connecting pipe 1 and the second connecting pipe 11 moves together with the first bellows 7 to compensate the pipeline displacement;

[0036] S4, when the pipeline expands or compresses, the expansion joint is compressed or stretched, the first bellows 7 and the second bellows 10 move synchronously and in the same direction to compensate the thermal expansion of the pipeline;

[0037] S5, the pressure inside the sealed cavity is detected by the pressure alarm 8, when the pressure is lower than a certain value or higher than a certain value, an alarm signal is sent, whether the pressure relief valve or the pressure increasing valve fails can be found in time, and the pressure alarm 8 can also be used to prevent the valve from being blocked or the pipeline from leaking, which can effectively improve the safety of the equipment;

[0038] S6, when the pressure inside the sealed cavity is lower than the set value due to temperature change or displacement movement, the pressure increasing valve 3 is automatically opened to automatically increase the pressure of the sealed cavity to the set value from the automatic pressure increasing circuit 2, when the pressure inside the sealed cavity is too large due to temperature change or displacement movement, the pressure relief valve can discharge part of the gas, so as to keep the pressure of the sealed cavity between the outer side of the first bellows 7 and the outer sheath structure constant, and reduce the actual pressure load of the first bellows 7.

[0039] Finally, it should be noted that: the above only for the preferred examples of the present application, and not for limiting the present application, although the present application is described in detail with reference to the foregoing examples, for those skilled in the art, the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A bellows expansion joint type with a pressure intensifier, characterized by: The application relates to a pipeline expansion joint, which comprises a first pipe, a second pipe, a first bellows, a second bellows and a booster device, the first bellows is arranged between the inner end of the first pipe and the second pipe, and the two ends of the first bellows are connected with the inner end of the first pipe and the second pipe; the second bellows is arranged on the periphery of the second pipe; the outer end of the first pipe and the second pipe is respectively connected with a pipeline component; the booster device is arranged on the periphery of the first bellows and moves along with the first bellows. The booster device comprises an outer sheath structure, an automatic booster loop, a booster valve and a pressure relief valve; the outer sheath structure comprises a long pipe and end plates on both sides; the automatic booster loop is arranged on one of the end plates; the booster valve is arranged on the automatic booster loop; the pressure relief valve is arranged on the long pipe; the outer sheath structure is connected with the first pipe through one of the end plates; the outer sheath structure is connected with one end of the second bellows through the other end plate; the other end of the second bellows is connected with the second pipe close to the outer end; a sealed cavity is formed between the outer sheath structure and the first bellows, and the actual pressure load borne by the first bellows is reduced through the sealed cavity. The two ends of the automatic booster loop are respectively connected with the inner part of the first pipe and the sealed cavity.

2. A bellows expansion joint of the type having a pressure intensifier according to claim 1, characterized in that: A flow guide cylinder is arranged between the inner end of the first pipe and the second pipe, and the flow guide cylinder is arranged in the first bellows; one end of the flow guide cylinder is connected with the inner wall of the first pipe; the other end of the flow guide cylinder extends into the second pipe; the flow guide cylinder is used for preventing the internal medium from impacting the first bellows.

3. A bellows expansion joint of the type having a pressure boosting device as defined in claim 1, characterized in that: The first bellows is connected with the first pipe and the second pipe through welding.

4. A bellows expansion joint of the type having a pressure boosting device as defined in claim 1, characterized in that: The end plate on one side of the outer sheath structure is connected with the inner end surface of the first pipe through welding; the end plate on the other side of the outer sheath structure is connected with the second bellows close to the inner end through welding.

5. A bellows expansion joint of the type having a pressure boosting device as defined in claim 1, characterized in that: An air inlet is arranged on the surface of the end plate close to the first pipe; the air inlet is arranged on the surface of the end plate; air with corresponding pressure is filled into the sealed cavity through the air inlet.

6. A bellows expansion joint of the type having a pressure intensifier according to claim 1, characterized in that: A pressure alarm is arranged on the surface of the long pipe and used for monitoring the air pressure of the sealed cavity.

7. A method of using a bellows expansion joint type with a booster according to any one of claims 1-6, characterized in that, The application further discloses a pipeline expansion joint operation method, which comprises the following steps: S1, air with corresponding pressure is filled into the sealed cavity through the air inlet, so that the pressure in the sealed cavity reaches a set value; S2, the medium is introduced into the pipeline, and the actual pressure borne by the first bellows in contact with the medium is the difference between the pressure of the medium and the set value; S3, the outer sheath structure arranged between the first pipe and the second pipe moves along with the first bellows to compensate the displacement of the pipeline; S4, when the pipeline expands or is compressed, the first bellows and the second bellows move synchronously and in the same direction to compensate the thermal expansion of the pipeline; S5, the pressure alarm is used for detecting the pressure in the sealed cavity; when the pressure is lower than a certain value or higher than a certain value, an alarm signal is sent, so that whether the pressure relief valve or the booster valve is out of order can be found in time. S6. When the pressure in the sealing cavity is lower than the set value during operation, the pressure boosting valve will automatically open and pressurize the sealing cavity through the automatic pressure boosting circuit to maintain a constant pressure in the sealing cavity between the outer side of the first bellows and the outer sheath structure, thereby reducing the actual pressure load on the first bellows.

Images