Pipeline with polytetrafluoroethylene lining

Abstract

The invention relates to the technical field of metallurgical chemical engineering pipelines, in particular to a lining polytetrafluoroethylene pipeline which comprises a metal outer pipe, a pipe lining is arranged on the inner wall of the metal outer pipe, and the lining outer cover is formed by bending one end of the pipe lining towards the periphery after extending out of the interior of the metal outer pipe; the first flange plate is fixedly connected to the outer side surface, close to the left end opening of the metal outer pipe, of the metal outer pipe; the outer wall of the end, away from the metal outer pipe, of the pipe sleeve is fixedly sleeved with a second flange plate. And a buffer sealing rubber ring fixedly attached to the inner wall of the pipe sleeve is arranged in the sealing protrusion, and the interior of the sealing protrusion is divided into a water inlet cavity and an extrusion cavity through the buffer sealing rubber ring. By means of the structural design, the influence of the water hammer effect on the lining pipe of the pipeline can be effectively reduced, the service life of the lining pipe is prolonged, and meanwhile the sealing effect at the joint of the pipeline can be effectively enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical and chemical industry pipelines, and in particular to a polytetrafluoroethylene lined pipeline. Background Art

[0002] Existing polytetrafluoroethylene pipes have excellent chemical stability, can withstand all strong acids, strong alkalis, strong oxidants, and various organic solvents. They are also resistant to high temperatures and negative pressures. Therefore, polytetrafluoroethylene pipes are more suitable for transporting special gases and liquids. However, existing polytetrafluoroethylene pipes still have the following defects: When a larger diameter polytetrafluoroethylene pipe opens and closes its valve, the flow velocity and fluid kinetic energy in the pipe will change suddenly. This sudden change in flow velocity will form a pressure wave in the pipe, resulting in a relatively serious water hammer effect. The inner lining of the polytetrafluoroethylene pipe is made of polytetrafluoroethylene. When the water hammer effect occurs, the inner lining is subjected to greater stress and pressure. If the material strength of the inner lining pipe is not sufficient to withstand such pressure, it is prone to rupture or damage, especially at the joints of the pipes. The water hammer effect will cause the seals at the pipe joints to be subjected to additional pressure or vibration, thereby increasing the risk of wear and damage to the seals.

[0003] In order to solve this problem and enhance the sealing effect of the pipe joint, the present application proposes a polytetrafluoroethylene lined pipe. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned shortcomings in the prior art and to propose a polytetrafluoroethylene lined pipe.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A polytetrafluoroethylene lined pipe comprises a metal outer pipe, the inner wall of which is provided with a pipe lining, and further comprises: The lining outer package is formed by bending one end of the tube lining around after extending out of the metal outer tube, and the lining outer package is fixedly attached to the outer wall of the left end port of the metal outer tube; A first flange, the first flange being fixedly connected to the outer surface of the metal outer tube near the left end port thereof; A pipe sleeve, the pipe sleeve is fixedly connected to the right end surface of the metal outer pipe, and a second flange is fixedly provided on the outer wall of one end of the pipe sleeve away from the metal outer pipe; A sealing protrusion is arranged at the middle position of the pipe sleeve, and a buffer sealing rubber ring fixedly fitted to the inner wall of the pipe sleeve is arranged inside the sealing protrusion, and the buffer sealing rubber ring divides the inside of the sealing protrusion into a water inlet chamber and an extrusion chamber, the water inlet chamber is located on the left side of the buffer sealing rubber ring, and the extrusion chamber is located on the right side of the buffer sealing rubber ring. An injection hole is provided on the sealing protrusion, one end of the injection hole is connected to the outside, and the other end of the injection hole is connected to the inside of the extrusion chamber, and a sealing plug is provided in a sealing sliding connection inside the injection hole.

[0006] Preferably, a thermal insulation layer is fixedly installed between the inner wall of the metal outer tube and the tube lining.

[0007] Preferably, the second flange has completely the same specifications as the first flange, and the second flange is threadedly connected with a plurality of bolts in an annular array.

[0008] Preferably, a thread fixedly connected to the outer surface of the metal outer tube is provided between the left end port of the metal outer tube and the first flange.

[0009] Preferably, a sealing thread groove is formed on the inner wall of one end of the tube sleeve away from the metal outer tube, and the sealing thread groove matches the thread.

[0010] Preferably, the right side of the extrusion cavity is communicated with the gap formed between the sealing thread groove and the thread.

[0011] Preferably, a sealing ring is fixedly attached to an end of the tube sleeve away from the metal outer tube.

[0012] Preferably, a buffer tube fixedly connected to the metal outer tube is arranged on the left side of the tube sleeve, one end of the buffer tube is communicated with the inside of the metal outer tube, and the other end of the buffer tube is sealed.

[0013] Preferably, a sealing plate is sealingly and slidably connected inside the buffer tube, and a spring is fixedly connected between the sealing plate and the inner top wall of the buffer tube.

[0014] Preferably, a plurality of retarding belts are provided on the inner wall of the pipe lining.

[0015] Compared with the prior art, the advantages of the present invention are: 1. In the present application, by setting up the insulation layer, the insulation layer can, on the one hand, reduce the temperature difference between the external environment and the liquid temperature of the pipe lining, thereby increasing the service life of the pipe lining; on the other hand, it can also allow the outer side of the pipe lining to contact the insulation layer with a certain elasticity, so that the pipe lining will not directly contact the hard metal outer pipe, thereby reducing the risk of the pipe lining being damaged when it is under pressure.

[0016] 2. In the present application, by setting up the sealing protrusion, water inlet chamber and extrusion chamber, when the water flow in the pipeline enters the water inlet chamber through the reserved gap, the water inlet chamber can buffer the water flow, reduce the pressure and impact of the water hammer effect on the pipe lining, and at the same time, the buffer sealing rubber ring in the water inlet chamber will absorb the pressure generated by the inertia of the water, move slightly to one side of the extrusion chamber, and squeeze the sealing grease in the extrusion chamber into the gap between the sealing thread groove and the thread, thereby enhancing the sealing effect.

[0017] 3. In the present application, a buffer tube, a spring and a sealing plate are arranged. When the water pressure inside the pipeline is relatively high, the water can enter the buffer tube. The water entering the buffer tube will squeeze the sealing plate and move the sealing plate. Under the action of the spring, the water flow can be buffered, thereby reducing the damage to the pipe lining caused by the water hammer effect.

[0018] 4. In the present application, multiple retarding strips are provided, which can increase the contact area between the inner lining of the pipe and the liquid, slow down the change of flow velocity when the pipeline is opened and closed, weaken the water hammer effect, and prevent damage to the inner wall of the pipe lining.

[0019] In summary, the present application can effectively reduce the impact of the water hammer effect on the pipeline liner through the design of the above-mentioned structure, increase the service life of the liner, and at the same time effectively enhance the sealing effect of the pipeline connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the overall axial structure of a polytetrafluoroethylene lined pipe proposed by the present invention.

[0021] Figure 2 The present invention provides a schematic diagram of the overall top view of the polytetrafluoroethylene lined pipe.

[0022] Figure 3 This is a schematic diagram of the pipe sleeve and sealing protrusion structure of a polytetrafluoroethylene lined pipe proposed by the present invention.

[0023] Figure 4 This is a schematic diagram of the injection hole and sealing ring structure of a polytetrafluoroethylene lined pipe proposed by the present invention.

[0024] Figure 5 This is a schematic diagram of the first flange and insulation layer structure of a polytetrafluoroethylene lined pipe proposed by the present invention.

[0025] Figure 6 This is a schematic diagram of the buffer tube and retarder structure of a polytetrafluoroethylene lined pipe proposed by the present invention.

[0026] Figure 7 The present invention provides a schematic diagram of a half-section structure of a connection between two adjacent polytetrafluoroethylene lined pipes.

[0027] Figure 8 This is an enlarged schematic diagram of the structure at point A of a polytetrafluoroethylene lined pipe proposed by the present invention.

[0028] In the figure: 1 metal outer pipe, 2 insulation layer, 3 pipe lining, 4 retarder, 5 lining outer package, 6 first flange, 7 second flange, 8 bolts, 9 pipe sleeve, 10 sealing protrusion, 11 sealing plug, 12 injection hole, 13 buffer pipe, 14 spring, 15 sealing plate, 16 sealing ring, 17 buffer sealing rubber ring, 18 reserved gap, 19 water inlet cavity, 20 extrusion cavity, 21 sealing thread groove, 22 thread. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] Reference Figures 1 to 8 A polytetrafluoroethylene lined pipe comprises a metal outer pipe 1, the inner wall of the metal outer pipe 1 is sequentially glued with an insulation layer 2 and a pipe lining 3 from the inside to the outside. The insulation layer 2 can reduce the temperature difference between the external environment and the liquid temperature of the pipe lining 3 on the one hand, thereby increasing the service life of the pipe lining 3. On the other hand, the outer side of the pipe lining 3 can be allowed to contact the insulation layer 2 with a certain elasticity, so that the pipe lining 3 will not directly contact the hard metal outer pipe 1, thereby reducing the risk of damage to the pipe lining 3 when it is under pressure. One end of the pipe lining 3 is bent around after extending out of the metal outer pipe 1 to form an inner lining outer package 5, and the inner lining outer package 5 is in contact with the outer wall of the left end port of the metal outer pipe 1.

[0031] A first flange 6 is welded and fixed to the outer surface of the metal outer tube 1 near its left end port, and a thread 22 welded and fixed to the outer surface of the metal outer tube 1 is provided between the left end port of the metal outer tube 1 and the first flange 6 .

[0032] A pipe sleeve 9 is welded and fixed on the right end surface of the metal outer tube 1. A sealing thread groove 21 is opened on the inner wall of the end of the pipe sleeve 9 away from the metal outer tube 1. The sealing thread groove 21 matches the thread 22. A second flange 7 is welded and fixed on the outer wall of the end of the pipe sleeve 9 away from the metal outer tube 1. The specifications of the second flange 7 are exactly the same as those of the first flange 6. A plurality of bolts 8 are threadedly connected in an annular array on the second flange 7. A sealing ring 16 is glued to the end of the pipe sleeve 9 away from the metal outer tube 1.

[0033] A sealing protrusion 10 is provided at the middle position of the pipe sleeve 9, and a buffer sealing rubber ring 17 glued to the inner wall of the pipe sleeve 9 is provided inside the sealing protrusion 10. The buffer sealing rubber ring 17 divides the inside of the sealing protrusion 10 into a water inlet chamber 19 and an extrusion chamber 20. The water inlet chamber 19 is located on the left side of the buffer sealing rubber ring 17, and the extrusion chamber 20 is located on the right side of the buffer sealing rubber ring 17 and close to the sealing thread groove 21. An injection hole 12 is provided on the sealing protrusion 10, one end of the injection hole 12 is connected to the outside, and the other end of the injection hole 12 is connected to the inside of the extrusion chamber 20. A sealing plug 11 is sealingly and slidably connected inside the injection hole 12, and sealing grease can be injected into the extrusion chamber 20 through the injection hole 12. The sealing grease can penetrate into the gap between the sealing thread groove 21 and the thread 22 to enhance the sealing effect of the sealing thread groove 21.

[0034] When two pipes are connected to each other, a reserved gap 18 will be formed at the connection (unavoidable), and the reserved gap 18 is connected to the inside of the water inlet chamber 19. When the water flow in the pipe enters the water inlet chamber 19 through the reserved gap 18, the water inlet chamber 19 can buffer the water flow, reduce the pressure and impact of the water hammer effect on the pipe lining 3, and at the same time, the buffer sealing rubber ring 17 in the water inlet chamber 19 will absorb the pressure generated by the inertia of the water, move slightly to the side of the extrusion chamber 20, and squeeze the sealing grease in the extrusion chamber 20 to the gap between the sealing thread groove 21 and the thread 22, thereby enhancing the sealing effect.

[0035] A buffer tube 13 is arranged on the left side of the pipe sleeve 9. The buffer tube 13 is welded and fixed on the metal outer tube 1, and one end of the buffer tube 13 is connected to the inside of the metal outer tube 1, and the other end of the buffer tube 13 is sealed. A sealing plate 15 is sealingly and slidingly connected inside the buffer tube 13, and a spring 14 is fixedly connected between the sealing plate 15 and the inner top wall of the buffer tube 13. When the water pressure inside the pipeline is relatively high, the water can enter the buffer tube 13. The water entering the buffer tube 13 will squeeze the sealing plate 15 and move the sealing plate 15. Under the action of the spring 14, the water flow can be buffered, thereby reducing the damage of the pipe lining 3 caused by the water hammer effect.

[0036] Reference Figure 6 to Figure 7 A plurality of retarding strips 4 are arranged on the inner wall of the pipe liner 3, which can increase the contact area between the inner wall of the pipe liner 3 and the liquid, slow down the change of flow velocity when the pipeline is opened and closed, weaken the water hammer effect, and prevent damage to the inner wall of the pipe liner 3.

[0037] The specific working principle of the present invention is as follows: when opening and closing the valve in a large flow pipeline, the flow velocity and fluid kinetic energy in the pipeline will suddenly change. This sudden change in flow velocity will form a pressure wave in the pipeline, resulting in a more serious water hammer effect. The lining material of the liner pipe is softer or more easily damaged than ordinary metal pipes. When the water hammer effect occurs, the pipe wall is subjected to greater stress and pressure. If the material strength of the liner pipe is not sufficient to withstand such pressure, it is prone to rupture or damage, especially at the connection of the pipeline. The water hammer effect will cause the seals at the connection of the pipeline to be subjected to additional pressure or vibration, thereby increasing the wear and damage risk of the seals. This device can effectively alleviate the water hammer effect, increase the service life of the liner pipe, and enhance the sealing effect of the connection.

[0038] Align the two pipes, position and connect them along the sealing spiral 21, and place the buffer sealing rubber ring 17 on the right side of the liner outer package 5. Ensure that the connection is installed in place, and then use the bolts 8 to firmly fix the first flange 6 and the second flange 7 together (according to Figure 7 The sealing ring 16 is located between the second flange 7 and the pipe sleeve 9. The sealing ring 16 is clamped to provide auxiliary sealing effect. A reserved gap 18 is left at the outer package 5 of the inner lining of the two pipes to effectively compensate for the interface hidden dangers caused by displacement due to non-vertical cuts, oblique cuts, socket failure, thermal expansion and contraction during installation, and to prepare for alleviating the water hammer effect.

[0039] A trapezoidal sealing protrusion 10 is provided in the middle of the pipe sleeve 9, and a buffer sealing rubber ring 17 is tightly pressed and installed in the middle of the trapezoidal sealing protrusion 10. The buffer sealing rubber ring 17 and the trapezoidal sealing protrusion 10 leave space for a water inlet chamber 19 on the left side and leave space for an extrusion chamber 20 on the right side.

[0040] Pull out the sealing plug 11 in the injection hole 12, and inject sufficient sealing grease into the extrusion cavity 20 from the injection hole 12. A small amount of sealing grease will penetrate into the gap between the sealing thread groove 21 and the thread 22 to enhance the sealing effect of the sealing thread groove 21. At the same time, the space of the extrusion cavity 20 provides more buffer space for the buffer sealing rubber ring 17.

[0041] When the connection work is completed, the retarding strip 4 provided on the inner wall of the pipe liner 3 can increase the contact area between the inside of the pipe liner 3 and the liquid, slow down the change of flow velocity when opening and closing the gate, weaken the water hammer effect, and prevent damage to the inner wall of the pipe liner 3.

[0042] When water flows through the reserved gap 18, due to the relatively fast flow rate of water and the small spacing of the reserved gap 18, under the action of the surface tension of water, water will not flow out of the reserved gap 18, but will form a small liquid bridge at the reserved gap 18, and will continue to flow without flowing out of the reserved gap 18, which will not affect the normal liquid transmission. However, when the valve is opened to form a water hammer effect, due to the inertia of water, a huge water pressure is formed at the reserved gap 18, which is greater than the surface tension of water, breaking through the liquid surface of the reserved gap 18 and entering the water inlet chamber 19, and the water inlet chamber 19 can play a buffering role, reducing the pressure and impact of the water hammer effect on the pipe lining 3; the buffer sealing rubber ring 17 in the water inlet chamber 19 will absorb the pressure generated by the inertia of water, and at the same time slightly move to the side of the extrusion chamber 20, and squeeze the sealing grease in the extrusion chamber 20 to the gap between the sealing thread groove 21 and the thread 22, thereby enhancing the sealing effect; that is, the negative feedback on the sealing effect caused by the water hammer effect is transformed into a positive feedback that is beneficial to the pipeline sealing.

[0043] When the valve is opened again, the water flow rate in the pipe lining 3 rises instantly. Due to Bernoulli's law, the faster the flow rate, the lower the pressure. The initial flow rate of the liquid in the water inlet chamber 19 is zero, so the pressure in the water inlet chamber 19 is greater than the pressure of the pipe lining. At the same time, the buffer sealing rubber ring 17 also has a force to restore deformation. Under the action of the two forces, the liquid in the water inlet chamber 19 is discharged from the water inlet chamber 19. The lining outer package 5 can prevent the liquid from contacting the metal outer tube 1 to prevent corrosion, etc. The insulation layer 2 has the following effects: first, it reduces the temperature difference between the external environment and the liquid temperature of the pipe lining 3, and increases the service life of the pipe lining 3; second, it allows the outer side of the pipe lining 3 to contact the insulation layer 2 with a certain elasticity, so that the pipe lining 3 will not directly contact the hard metal outer tube 1, reducing the risk of damage to the pipe lining when it is under pressure.

[0044] When the water hammer effect occurs, the water inlet chamber 19 absorbs part of the pressure, and part of the pressure is absorbed by the buffer tube 13. Under the action of the water pressure, the sealing plate 16 is pushed upward to squeeze the spring 14, absorbing the water pressure while increasing the space for accommodating water, weakening the water hammer effect and preventing the pipe lining 3 from being damaged. After the water hammer effect ends, the sealing plate 16 returns to its original position under the action of the rebound force of the spring 14, and the water is discharged by itself under the action of gravity.

[0045] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A polytetrafluoroethylene lined pipe, comprising a metal outer pipe (1), the inner wall of the metal outer pipe (1) being provided with a pipe lining (3), characterized in that: Also included are: The lining outer package (5) is formed by bending one end of the tube lining (3) in all directions after extending out of the metal outer tube (1), and the lining outer package (5) is fixedly attached to the outer wall of the left end port of the metal outer tube (1); A first flange (6), the first flange (6) being fixedly connected to the outer surface of the metal outer tube (1) near its left end port; A pipe sleeve (9), the pipe sleeve (9) being fixedly connected to the right end surface of the metal outer pipe (1), and a second flange (7) being fixedly sleeved on the outer wall of one end of the pipe sleeve (9) away from the metal outer pipe (1); A sealing protrusion (10) is arranged at a middle position of the pipe sleeve (9), a buffer sealing rubber ring (17) fixedly fitted to the inner wall of the pipe sleeve (9) is arranged inside the sealing protrusion (10), the buffer sealing rubber ring (17) divides the inside of the sealing protrusion (10) into a water inlet chamber (19) and an extrusion chamber (20), the water inlet chamber (19) is located on the left side of the buffer sealing rubber ring (17), and the extrusion chamber (20) is located on the right side of the buffer sealing rubber ring (17), an injection hole (12) is provided on the sealing protrusion (10), one end of the injection hole (12) is communicated with the outside, and the other end of the injection hole (12) is communicated with the inside of the extrusion chamber (20), and a sealing plug (11) is sealingly and slidably connected inside the injection hole (12).

2. A polytetrafluoroethylene lined pipe according to claim 1, characterized in that: A thermal insulation layer (2) is fixedly installed between the inner wall of the metal outer tube (1) and the tube lining (3).

3. The polytetrafluoroethylene lined pipe according to claim 1, characterized in that: The second flange (7) has completely the same specifications as the first flange (6), and the second flange (7) is threadedly connected with a plurality of bolts (8) in an annular array.

4. The polytetrafluoroethylene lined pipe according to claim 1, characterized in that: A thread (22) fixedly connected to the outer surface of the metal outer tube (1) is provided between the left end port of the metal outer tube (1) and the first flange (6).

5. The polytetrafluoroethylene lined pipe according to claim 4, characterized in that: A sealing thread groove (21) is formed on the inner wall of one end of the pipe sleeve (9) away from the metal outer pipe (1), and the sealing thread groove (21) matches the thread (22).

6. The polytetrafluoroethylene lined pipe according to claim 5, characterized in that: The right side of the extrusion cavity (20) is communicated with the gap formed between the sealing thread groove (21) and the thread (22).

7. The polytetrafluoroethylene lined pipe according to claim 1, characterized in that: A sealing ring (16) is fixedly attached to an end of the pipe sleeve (9) away from the metal outer pipe (1).

8. The polytetrafluoroethylene lined pipe according to claim 1, characterized in that: A buffer tube (13) fixedly connected to the metal outer tube (1) is arranged on the left side of the tube sleeve (9); one end of the buffer tube (13) is communicated with the interior of the metal outer tube (1), and the other end of the buffer tube (13) is sealed.

9. The polytetrafluoroethylene lined pipe according to claim 8, characterized in that: A sealing plate (15) is sealingly and slidably connected inside the buffer tube (13), and a spring (14) is fixedly connected between the sealing plate (15) and the inner top wall of the buffer tube (13).

10. The polytetrafluoroethylene lined pipe according to claim 1, characterized in that: A plurality of retarding strips (4) are arranged on the inner wall of the pipe lining (3).

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