Wear-resistant composite pipe, composite pipe processing method and wear-resistant main pipe processing unit

Abstract

The present invention discloses a wear-resistant composite pipe, a composite pipe processing method and a wear-resistant main pipe processing unit, which belong to the technical field of composite pipes. It comprises a wear-resistant main pipe, an intermediate reinforcement layer, a buffer layer and a pressure-bearing layer. The wear-resistant main pipe comprises a wear-resistant inner layer, which is composed of nitrile rubber and modified ceramic particles mixed, kneaded, extruded and vulcanized in a mass ratio of 8:2; the intermediate reinforcement layer is a multi-layer glass fiber winding layer wound on the outer surface of the wear-resistant main pipe; the buffer layer is arranged outside the intermediate reinforcement layer, and the buffer layer is composed of polyurethane foam; the pressure-bearing layer is arranged outside the buffer layer, and the pressure-bearing layer is bonded and fixed to the buffer layer; the wear-resistant main pipe also comprises an end wear-resistant layer, which is arranged at both ends of the wear-resistant inner layer, and the end wear-resistant layer and the wear-resistant inner layer are extruded together through the same extruder. The wear-resistant composite pipe of the present invention has excellent wear resistance and can be used in high-wear transmission occasions.

Description

Technical Field

[0001] The present invention particularly relates to a wear-resistant composite pipe, a composite pipe processing method and a wear-resistant main pipe processing unit, and belongs to the technical field of composite pipes. Background Art

[0002] Wear-resistant pipes are a special type of industrial pipes, mainly used in mining, metallurgy, chemical industry and electric power, such as slurry beneficiation transportation and long-distance pipeline transportation of tailings, transportation of concentrate slurry, metallurgical waste slag and coal powder; transportation of solid-liquid mixtures such as salt slurry and alkali slurry; ash removal, slag discharge, powder feeding, powder return and desulfurization process pipelines in thermal power plants; therefore, wear-resistant pipes have been widely used in many industrial fields; traditional wear-resistant pipes are mainly metal pipes, but they have serious corrosion and wear problems. Therefore, in the existing technology, ultra-high molecular weight polyethylene pipes are used in many occasions, but their wear resistance is insufficient under harsh working conditions; for this reason, China Patent Grant Patent Announcement No.: CN108561636B discloses a wear-resistant composite pipe, comprising: a pipe body and a wear-resistant layer, wherein the wear-resistant layer is a thermoplastic elastomer material; the composite pipe is manufactured by molding, sizing, cooling and drawing, but the overall cost is high, the impact resistance is average, and the wear-resistant layer still suffers from large wear in situations with high flow rate and high solid content; another example is Chinese Patent Authorization Announcement No.: CN113045810B, which discloses a super wear-resistant composite pipe and a preparation method thereof; the super wear-resistant composite pipe is co-extruded by polyethylene for the outer layer and wear-resistant material for the inner layer; however, the composite pipe still suffers from large wear rate in high wear transmission situations. Summary of the Invention

[0003] To solve the above problems, the present invention proposes a wear-resistant composite pipe, a composite pipe processing method and a wear-resistant main pipe processing unit, which have excellent wear resistance and can be used in high-wear transmission occasions.

[0004] The wear-resistant composite pipe of the present invention comprises:

[0005] A wear-resistant main pipe comprising a wear-resistant inner layer formed by mixing, kneading, extruding, and vulcanizing nitrile rubber and modified ceramic particles in a mass ratio of 8:2. The modified ceramic particles enhance interfacial bonding with the rubber matrix, and the inner wall of the pipe assembly supported by the mixture of nitrile rubber and modified ceramic particles, kneading, extrusion, and vulcanization, exhibits excellent wear resistance.

[0006] An intermediate reinforcement layer, which is a multi-layer glass fiber wound layer wound around the outer surface of the wear-resistant main pipe; the intermediate reinforcement layer has high axial tensile strength;

[0007] A buffer layer is provided outside the intermediate reinforcement layer and is composed of polyurethane foam with a steel mesh provided at the center of the polyurethane foam. The polyurethane foam and the steel mesh can absorb more than 85% of the instantaneous impact energy caused by the fluid inside the wear-resistant main pipe.

[0008] The pressure-bearing layer is arranged outside the buffer layer and is bonded and fixed to the buffer layer; the pressure-bearing layer can bear external impact, protect the wear-resistant main pipe, and prevent the wear-resistant main pipe from deformation.

[0009] Furthermore, the wear-resistant main pipe also includes an end wear-resistant layer, which is arranged at both ends of the wear-resistant inner layer. The end wear-resistant layer is composed of nitrile rubber, modified ceramic particles, and silane-grafted modified thermoplastic elastomer mixed and dynamically kneaded in a mass ratio of 5:1:4; the end wear-resistant layer and the wear-resistant inner layer are extruded together through the same extruder; since the composite pipes need to be connected to form a pipeline, and since the axial center lines between the composite pipes are prone to deviation, fluid resistance and turbulence are easily generated at the ends of the pipelines, causing the composite pipes to wear too quickly near the end areas, resulting in eccentric wear and shortening the service life of the composite pipes; for this reason, the end wear-resistant layers are integrally extruded at both ends of the wear-resistant inner layer and vulcanized to form an integrated structure The end wear-resistant layer is made of nitrile rubber with a silane-grafted modified thermoplastic elastomer and modified ceramic particles. Since the thermoplastic elastomer itself has excellent wear resistance and is tightly combined with the thermoplastic elastomer through the modified ceramic particles, it has stronger wear resistance than the wear-resistant inner layer. During the entire use of the pipeline, the wear process of the entire pipe wall is close, which avoids excessive wear in the end area and affects the service life, and can extend the replacement cycle of the wear-resistant composite pipe; and the wear-resistant main pipe is only composited with the end wear-resistant layer at both ends of the wear-resistant inner layer, so the overall cost is lower, and the end wear-resistant layer and the wear-resistant inner layer are vulcanized with the common nitrile rubber and the common vulcanization system, so that the end wear-resistant layer and the wear-resistant inner layer can form an integrated structure.

[0010] Furthermore, the pressure-bearing layer is an outer tube body with a continuous spiral protrusion structure formed on the surface thereof, which is made of polyvinyl chloride or thermoplastic polyurethane as a base material and is extruded through a rotary die.

[0011] Furthermore, the pressure-bearing layer is a steel pipe, and the inner wall of the steel pipe is sequentially sandblasted and sprayed with a silane coupling agent coating.

[0012] A wear-resistant composite pipe processing method is used to process the wear-resistant composite pipe. The processing method is specifically as follows:

[0013] First, a wear-resistant inner layer is processed. The preparation process of the wear-resistant inner layer is as follows: alumina ceramic particles with a purity of ≥99% and a particle size of 50-200 μm are selected, and the surface is modified with a silane coupling agent to obtain modified ceramic particles. Then, the modified ceramic particles and nitrile rubber are added to an internal mixer according to a set mass ratio, and a vulcanization system and a plasticizer are simultaneously added for mixing to obtain a rubber compound. Then, the rubber compound is extruded into a tube blank through a screw extruder, and the tube blank is then vulcanized to obtain the wear-resistant inner layer.

[0014] Next, the middle reinforcement layer is processed. The processing steps of the middle reinforcement layer are as follows: first, the glass fiber yarn is pre-impregnated with epoxy resin emulsion and heated for pre-curing. Then, the treated glass fiber yarn is wound onto the outer surface of the wear-resistant main pipe through a four-axis winding machine, and multiple layers are wound. After the winding is completed, the wear-resistant inner layer and the middle reinforcement layer are heated and cured into one.

[0015] Next, the buffer layer is processed. The processing procedure of the buffer layer is as follows: the wear-resistant main pipe and the middle reinforcement layer that are solidified into one are sent into a foaming mold, and a steel mesh is pre-embedded in the foaming mold. Then, polyurethane foam is injected into the foaming mold. The polyurethane foam is made of a mixture of polyether polyurethane prepolymer and chain extender in a ratio of 100:12. After the polyurethane foam is injected, it is foamed to form a foam structure with a closed-cell rate of ≥90%.

[0016] Finally, the wear-resistant composite pipe processing is completed, and the core pipe is bonded and cured to the inner wall of the pressure-bearing layer to obtain a finished wear-resistant composite pipe.

[0017] A wear-resistant main pipe processing unit is used to process a wear-resistant main pipe. The wear-resistant main pipe is extruded through an extrusion unit to obtain a pipe blank. The extrusion unit includes a first screw extruder for extruding a wear-resistant inner layer raw material and a second screw extruder for extruding a terminal wear-resistant layer raw material. The output ends of the first screw extruder and the second screw extruder are connected to an extrusion head through a heated extrusion switching pipeline. The first screw extruder and the second screw extruder each complete the feeding and plasticizing stages of the wear-resistant inner layer raw material and the terminal wear-resistant layer raw material, and press the molten rubber material into the heated extrusion switching pipeline. The heated extrusion switching pipeline intermittently injects the rubber material of the terminal wear-resistant layer into the rubber material of the wear-resistant inner layer according to the length requirement of the wear-resistant main pipe, so that the rubber material of the terminal wear-resistant layer is located at the end of the wear-resistant inner layer. Finally, the entire wear-resistant main pipe is extruded through the extrusion head. The truncation position of the wear-resistant main pipe is the middle position of the rubber material extruded from the terminal wear-resistant layer. After truncation, the ends of two adjacent wear-resistant main pipes are processed to obtain the terminal wear-resistant layer.

[0018] Furthermore, the heating extrusion switching pipeline includes a square slide, a first input port and a first output port are provided opposite to each other at the lower part of the slide, a second input port is provided above the first input port, a cutting port is provided opposite to the second input port, and a pneumatic cutting knife is provided outside the cutting port; a heating plate is provided on the inner side of the slide for sliding, two material storage holes are provided on the heating plate, the first input port and the second input port are respectively connected to the output ends of the first screw extruder and the second screw extruder; the first output port is connected to the extrusion head through a heating pipe; A lifting hydraulic cylinder connected to the heating plate is fixed on the top of the slide; during processing, the first input port and the first output port are first aligned. At this time, the first screw extruder extrude the material into the first input port and enters the first output port through the storage hole below the heating plate. Then, the wear-resistant inner layer raw material is sent into the extrusion head through the heating material pipe to extrude the tube blank. At the same time, the second screw extruder continuously feeds the material to the second input port and the other storage hole. Since the other storage hole is closed by the pneumatic cutting knife at one end away from the second input port, the rubber material of the end wear-resistant layer is heated and kept warm by the heating plate. Temperature, when the rubber material of the end wear-resistant layer needs to be fed into the heating material pipe, the lifting hydraulic cylinder is activated to drive the heating plate downward to the lower limit position. At this time, the lower storage hole carries the rubber material of the wear-resistant inner layer downward. At the same time, the upper storage hole is facing the first input port and the first output port; and the wear-resistant inner layer raw material extruded by the first screw extruder is used as the extrusion force to push the rubber material of the end wear-resistant layer in the storage hole into the heating material pipe. At this time, the second input port is closed by the heating plate, and then the lifting hydraulic cylinder is activated to drive the heating plate upward to the upper limit position. The lower storage hole is facing the first input port and the first output port. To the first input port and the first output port; at this time, the wear-resistant inner layer raw material is extruded and transported again; the upper storage hole is realigned with the second input port, and the rubber material of the end wear-resistant layer extruded by the second screw extruder is used as the extrusion force to push the rubber material of the wear-resistant inner layer in the upper storage hole outward, and the pushed-out rubber material is cut off as waste material through the pneumatic cutting knife, and the upper storage hole is closed at the same time, and the rubber material of the end wear-resistant layer is received again; in order to prevent the extrusion position deviation of the end wear-resistant layer and the wear-resistant inner layer, a sufficient amount of rubber material of the end wear-resistant layer is fed in advance to ensure the length of the end wear-resistant layer.

[0019] Furthermore, the heating extrusion switching pipeline includes a disc jacket, and a rotating disc with a heating function is installed inside the disc jacket through a drive shaft, and the rotating disc is tightly fitted to the disc jacket; a ring of storage holes is arranged at intervals on the rotating disc; a stamping through hole, a third input port and a fourth input port connected to the storage hole are arranged on one side of the disc jacket; a second output port connected to the storage hole is arranged on the other side of the rotating disc; the third input port and the second output port are opposite to each other, and the third input port and the fourth input port are connected to the output ends of the first screw extruder and the second screw extruder respectively; the second output port is connected to the extrusion head through a heating material pipe; a transposition motor connected to the drive shaft is fixed to the outside of the rotating disc; a pneumatic punch head is fixed on the disc jacket opposite the stamping through hole.

[0020] During processing, first align the third input port, a storage hole on the rotating disk and the second output port. At this time, the first screw extruder extrudes the material into the third input port and enters the second output port through a storage hole on the rotating disk. Then, the wear-resistant inner layer material is fed into the extruder through the heated material pipe to extrude the tube blank. At the same time, the second screw extruder continues to feed the material to the other storage hole. Since the other storage hole is far away from the third input port and is closed by the disc jacket, the rubber material of the end wear-resistant layer is heated and kept warm by the rotating disk. When the end wear-resistant layer needs to be heated, the rubber material of the end wear-resistant layer is heated and kept warm. When the rubber material is fed into the heating material pipe, the transposition motor drives the rotating disk to transpose, so that the rubber material of the loading end wear-resistant layer is aligned with the second output port, and the wear-resistant inner layer raw material extruded by the first screw extruder is used as the extrusion force to push the rubber material of the end wear-resistant layer in the storage hole into the heating material pipe. At this time, the new hollow storage hole receives the rubber material of the end wear-resistant layer, and the wear-resistant inner layer raw material separated from the storage hole of the heating material pipe is cooled until it reaches the punching through hole, and the cooled wear-resistant inner layer is punched out of the storage hole by the pneumatic punch head, and the cooled wear-resistant inner layer is recovered.

[0021] Furthermore, the heating extrusion switching pipeline includes a heating material pipe, an injection head is embedded in the middle of the heating material pipe, the injection head is connected to the output end of the second screw extruder through a pipe valve, one end of the heating material pipe is connected to the output end of the first screw extruder, and the other end is connected to the extrusion head; the bottom of the injection head is embedded in the axis of the heating material pipe; a heating sleeve is provided on the outside of the injection head; during processing, the first screw extruder injects the rubber material of the wear-resistant inner layer into the heating material pipe, and sends the rubber material to the heating material pipe through the heating material pipe. The rubber material of the end wear-resistant layer is fed into the extrusion head for tube extrusion. When the rubber material feeding position of the end wear-resistant layer is reached, the first screw extruder drives the rubber material of the end wear-resistant layer into the inner side of the heated material pipe through the pipe valve and the extrusion head, and fills it to the center line of the rubber material of the wear-resistant inner layer. The rubber material of the end wear-resistant layer is wrapped by the rubber material of the wear-resistant inner layer and fed into the extrusion head for extrusion. After the rubber material of the end wear-resistant layer is fed, the pipe valve is closed. At the same time, the first screw extruder maintains the temperature control state. At the same time, the drive motor of the extruder enters the low frequency or standby state.

[0022] Compared with the prior art, the wear-resistant composite pipe of the present invention adopts a wear-resistant inner layer as the wear-resistant main body, has excellent overall wear resistance, and can be used in high-wear transmission occasions. The intermediate reinforcement layer and the wear-resistant main pipe are integrally wound and heat-cured into one. The intermediate reinforcement layer is formed by multiple layers of glass fiber winding layers to form a mesh structure, which can serve as the internal skeleton of the buffer layer, so that the wear-resistant main pipe, the intermediate reinforcement layer and the buffer layer are cured into one. Each layer has strong anti-peeling ability, and the buffer layer is composed of polyurethane foam and steel wire mesh, which can absorb more than 85% of the instantaneous impact energy brought by the fluid inside the wear-resistant main pipe; in addition, the wear resistance of both ends of the wear-resistant main pipe is further improved, and the wear process of the entire pipe wall is close, which avoids excessive wear in the end area affecting the service life, and can extend the replacement cycle of the wear-resistant composite pipe; and the cost of the entire wear-resistant composite pipe is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of Example 1 of the wear-resistant composite pipe of the present invention.

[0024] Figure 2 This is a schematic diagram of the overall structure of Example 2 of the wear-resistant composite pipe of the present invention.

[0025] Figure 3 This is a structural schematic diagram of the wear-resistant composite pipe processing equipment according to Example 2 of the present invention.

[0026] Figure 4 This is a schematic diagram of the first extrusion unit structure of the present invention.

[0027] Figure 5 This is a schematic diagram of the second extrusion unit structure of the present invention.

[0028] Figure 6 This is a schematic diagram of the third extrusion unit structure of the present invention.

[0029] Figure markings: 1. wear-resistant inner layer, 2. middle reinforcement layer, 3. buffer layer, 4. pressure-bearing layer, 5. end wear-resistant layer, 6. first screw extruder, 7. second screw extruder, 8. heating extrusion switching pipeline, 9. extrusion head, 10. slide, 11. first input port, 12. first output port, 13. second input port, 14. cutting port, 15. pneumatic cutting knife, 16. heating plate, 17. storage hole, 18. lifting hydraulic cylinder, 19. heating material pipe, 20. disc jacket, 21. rotating disk, 22. punching hole, 23. third input port, 24. fourth input port, 25. second output port, 26. transposition motor, 27. pneumatic punch head, 28. injection head, 29. pipe valve, 30. heating sleeve, 31. wire mesh. DETAILED DESCRIPTION

[0030] Example 1:

[0031] like Figure 1 The wear-resistant composite pipe shown includes:

[0032] A wear-resistant main pipe, comprising a wear-resistant inner layer 1, which is formed by mixing, kneading, extruding, and vulcanizing nitrile rubber and modified ceramic particles in a mass ratio of 8:2; the modified ceramic particles can improve the interfacial bonding strength with the rubber matrix; the inner wall of the pipe group supported by the nitrile rubber and modified ceramic particles after mixing, kneading, extruding, and vulcanization has excellent wear resistance;

[0033] The intermediate reinforcement layer 2 is a multi-layer glass fiber wound layer wound around the outer surface of the wear-resistant main pipe; the intermediate reinforcement layer 2 has high axial tensile strength;

[0034] A buffer layer 3 is disposed outside the intermediate reinforcement layer 2 and is composed of polyurethane foam with a steel mesh 31 disposed at the center of the polyurethane foam. The polyurethane foam and the steel mesh 31 can absorb more than 85% of the instantaneous impact energy caused by the fluid inside the wear-resistant main pipe.

[0035] The pressure-bearing layer 4 is arranged outside the buffer layer 3 and is bonded and fixed to the buffer layer 3 ; the pressure-bearing layer 4 can bear external impact, protect the wear-resistant main pipe, and prevent the wear-resistant main pipe from deformation.

[0036] The pressure-bearing layer 4 is an outer tube body with a continuous spiral protrusion structure formed on the surface, which is made of polyvinyl chloride or thermoplastic polyurethane as a base material and is extruded through a rotary die.

[0037] The pressure-bearing layer 4 is a steel pipe, and the inner wall of the steel pipe is sequentially sandblasted and sprayed with a silane coupling agent coating.

[0038] Example 2:

[0039] like Figures 2 to 4The wear-resistant composite pipe shown in the figure, the wear-resistant main pipe also includes an end wear-resistant layer 5, the end wear-resistant layer 5 is arranged at both ends of the wear-resistant inner layer 1, and the end wear-resistant layer 5 is composed of nitrile rubber, modified ceramic particles, and silane-grafted modified thermoplastic elastomer mixed and dynamically kneaded in a mass ratio of 5:1:4; the end wear-resistant layer 5 and the wear-resistant inner layer 1 are co-extruded through the same extruder; since the composite pipes need to be connected to form a pipeline, since the axial center lines between the composite pipes are prone to deviation, fluid resistance and turbulence are prone to occur at the end of the pipeline, causing the composite pipe to wear too quickly near the end area, resulting in eccentric wear and shortening the service life of the composite pipe; for this reason, the end wear-resistant layer 5 is integrally extruded at both ends of the wear-resistant inner layer 1, and vulcanized to form an integral The structure of the end wear-resistant layer 5 is a composite silane-grafted modified thermoplastic elastomer and modified ceramic particles inside the nitrile rubber. Since the thermoplastic elastomer itself has excellent wear resistance and is tightly combined with the thermoplastic elastomer through the modified ceramic particles, the wear resistance is stronger than that of the wear-resistant inner layer 1. During the entire use of the pipeline, the wear process of the entire pipe wall is close, avoiding excessive wear in the end area that affects the service life, and can extend the replacement cycle of the wear-resistant composite pipe; and the wear-resistant main pipe is only composited with the end wear-resistant layer 5 at both ends of the wear-resistant inner layer 1, so the overall cost is lower, and the end wear-resistant layer 5 and the wear-resistant inner layer 1 are vulcanized with the common nitrile rubber and common vulcanization system, so that the end wear-resistant layer 5 and the wear-resistant inner layer 1 can form an integrated structure.

[0040] A wear-resistant main pipe processing unit is used to process wear-resistant main pipes. The wear-resistant main pipe is extruded into a pipe blank through an extrusion unit. The extrusion unit includes a first screw extruder 6 for extruding the raw material of the wear-resistant inner layer 1, and a second screw extruder 7 for extruding the raw material of the end wear-resistant layer 5. The output ends of the first screw extruder 6 and the second screw extruder 7 are connected to the extrusion head 9 through a heated extrusion switching pipeline 8; the first screw extruder 6 and the second screw extruder 7 each complete the extrusion of the raw material of the wear-resistant inner layer 1 and the end wear-resistant layer 5 raw material feeding and plasticizing section, and presses the molten rubber into the heating extrusion switching pipeline 8. The heating extrusion switching pipeline 8 intermittently injects the rubber of the end wear-resistant layer 5 into the rubber of the wear-resistant inner layer 1 according to the length requirement of the wear-resistant main pipe, so that the rubber of the end wear-resistant layer 5 is located at the end of the wear-resistant inner layer 1; finally, the entire wear-resistant main pipe is extruded through the extrusion head 9. The truncation position of the wear-resistant main pipe is the middle position of the rubber extrusion of the end wear-resistant layer 5. After truncation, the ends of the two adjacent wear-resistant main pipes are processed to obtain the end wear-resistant layer 5.

[0041] The heating extrusion switching pipeline 8 includes a square slide 10, and a first input port 11 and a first output port 12 are provided opposite to each other at the lower part of the slide 10. A second input port 13 is provided above the first input port 11, and a cutting port 14 is provided opposite to the second input port 13. A pneumatic cutting knife 15 is provided outside the cutting port 14; a heating plate 16 is provided on the inner side of the slide 10 for sliding, and two storage holes 17 are provided on the heating plate 16. The first input port 11 and the second input port 13 are connected to the output ends of the first screw extruder 6 and the second screw extruder 7 respectively; the first output port 12 is connected to the extruder 6 through a heating pipe 19. Head 9; a lifting hydraulic cylinder 18 connected to a heating plate 16 is fixed on the top of the slide 10; during processing, the first input port 11 and the first output port 12 are first aligned. At this time, the first screw extruder 6 extrudes the material into the first input port 11 and enters the first output port 12 through the storage hole 17 below the heating plate 16. Then, the raw material of the wear-resistant inner layer 1 is fed into the extrusion head 9 through the heating material pipe 19 to extrude the tube blank. At the same time, the second screw extruder 7 continues to feed the material to the second input port 13 and the other storage hole 17. Since the other storage hole 17 is closed by the pneumatic cutting knife 15 at one end away from the second input port 13, the rubber material of the end wear-resistant layer 5 is heated. The plate 16 is heated and kept warm. When the rubber material of the end wear-resistant layer 5 needs to be fed into the heating material pipe 19, the lifting hydraulic cylinder 18 is actuated to drive the heating plate 16 downward to the lower limit position. At this time, the lower storage hole 17 carries the rubber material of the wear-resistant inner layer 1 downward. At the same time, the upper storage hole 17 is facing the first input port 11 and the first output port 12; and the raw material of the wear-resistant inner layer 1 extruded by the first screw extruder 6 is used as the extrusion force to push the rubber material of the end wear-resistant layer 5 in the storage hole 17 into the heating material pipe 19. At this time, the second input port 13 is closed by the heating plate 16. Then, the lifting hydraulic cylinder 18 is actuated to drive the heating plate 16 upward to the upper limit position. The lower storage hole 17 is opposite to the first input port 11 and the first output port 12; at this time, the raw material of the wear-resistant inner layer 1 is extruded and transported again; the upper storage hole 17 is realigned with the second input port 13, and the rubber material of the end wear-resistant layer 5 extruded by the second screw extruder 7 is used as the extrusion force to push the rubber material of the wear-resistant inner layer 1 in the upper storage hole 17 outward, and the pushed-out rubber material is cut off as waste material by the pneumatic cutting knife 15, and the upper storage hole 17 is closed at the same time to receive the rubber material of the end wear-resistant layer 5 again; in order to prevent the extrusion position deviation of the end wear-resistant layer 5 and the wear-resistant inner layer 1, a sufficient amount of rubber material of the end wear-resistant layer 5 is fed in advance to ensure the length of the end wear-resistant layer 5.

[0042] Example 3:

[0043] like Figure 5As shown, the heated extrusion switching pipeline 8 includes a disc jacket 20, and a rotating disc 21 with a heating function is installed inside the disc jacket 20 through a drive shaft, and the rotating disc 21 fits tightly with the disc jacket 20; a ring of storage holes 17 is arranged at intervals on the rotating disc 21; a stamping through hole 22, a third input port 23 and a fourth input port 24 connected to the storage hole 17 are provided on one side of the disc jacket 20; a second output port 25 connected to the storage hole 17 is provided on the other side of the rotating disc 21; the third input port 23 and the second output port 25 are opposite to each other, and the third input port 23 and the fourth input port 24 are respectively connected to the output ends of the first screw extruder 6 and the second screw extruder 7; the second output port 25 is connected to the extrusion head 9 through a heating material pipe 19; a transposition motor 26 connected to the drive shaft is fixed to the outside of the rotating disc 21; a pneumatic punch head 27 is fixed to the disc jacket 20 opposite the stamping through hole 22.

[0044] During processing, first align the third input port 23, a storage hole 17 on the rotating disk 21, and the second output port 25. At this time, the first screw extruder 6 extrudes the material into the third input port 23 and enters the second output port 25 through a storage hole 17 on the rotating disk 21. Then, the wear-resistant inner layer 1 raw material is fed into the extrusion head 9 through the heating material pipe 19 to extrude the tube blank. At the same time, the second screw extruder 7 continues to feed the material to the other storage hole 17. Since the other storage hole 17 is closed by the disc jacket 20 at one end away from the third input port 23, the rubber material of the end wear-resistant layer 5 is heated and kept warm by the rotating disk 21. When the end wear-resistant layer needs to be heated, the rubber material of the end wear-resistant layer 5 is heated and kept warm. When the rubber material of 5 is fed into the heating material pipe 19, the shifting motor 26 drives the rotating disk 21 to shift, so that the rubber material of the loading end wear-resistant layer 5 is aligned with the second output port 25, and the raw material of the wear-resistant inner layer 1 extruded by the first screw extruder 6 is used as the extrusion force to push the rubber material of the end wear-resistant layer 5 in the storage hole 17 into the heating material pipe 19. At this time, the new hollow storage hole 17 receives the rubber material of the end wear-resistant layer 5, and the raw material of the wear-resistant inner layer 1 separated from the storage hole 17 of the heating material pipe 19 is cooled until it reaches the punching through hole 22, and the cooled wear-resistant inner layer 1 is punched out of the storage hole 17 by the pneumatic punch head 27, and the cooled wear-resistant inner layer 1 is recovered.

[0045] Example 4:

[0046] like Figure 6As shown, the heating extrusion switching pipeline 8 includes a heating material pipe 19, and an injection head 28 is embedded in the middle of the heating material pipe 19. The injection head 28 is connected to the output end of the second screw extruder 7 through a pipe valve 29. One end of the heating material pipe 19 is connected to the output end of the first screw extruder 6, and the other end is connected to the extrusion head 9; the bottom of the injection head 28 is embedded in the axis of the heating material pipe 19; a heating sleeve 30 is provided on the outside of the injection head 28; during processing, the first screw extruder 6 injects the rubber material of the wear-resistant inner layer 1 into the heating material pipe 19, and through the heating material pipe 1 9 feeds the rubber into the extrusion head 9 for tube extrusion. When the rubber feeding position of the end wear-resistant layer 5 is reached, the first screw extruder 6 drives the rubber of the end wear-resistant layer 5 into the inner side of the heating material pipe 19 through the pipe valve 29 and the extrusion head 9, and fills it to the center line of the rubber of the wear-resistant inner layer 1. The rubber of the end wear-resistant layer 5 is wrapped by the rubber of the wear-resistant inner layer 1 and fed into the extrusion head 9 for extrusion. After the rubber of the end wear-resistant layer 5 is completed, the pipe valve 29 is closed. At the same time, the first screw extruder 6 maintains a temperature control state. At the same time, the drive motor of the extruder enters a low frequency or standby state.

[0047] The preparation process of the wear-resistant inner layer 1 is as follows: alumina ceramic particles with a purity of ≥99% and a particle size of 50-200 μm are selected, and surface-modified with a silane coupling agent to obtain modified ceramic particles. Then, the modified ceramic particles and nitrile rubber are added to an internal mixer according to a set mass ratio, and a vulcanization system and a plasticizer are simultaneously added for mixing to obtain a rubber mixture. Then, the rubber mixture is extruded into a tube blank through a screw extruder, and the tube blank is then vulcanized to obtain the wear-resistant inner layer 1.

[0048] The processing steps of the intermediate reinforcement layer 2 are as follows: first, the glass fiber yarn is pre-impregnated with epoxy resin emulsion and heated for pre-curing, then the treated glass fiber yarn is wound onto the outer surface of the wear-resistant main pipe through a four-axis winding machine, and multiple layers are wound. After the winding is completed, the wear-resistant inner layer 1 and the intermediate reinforcement layer 2 are heated and cured into one.

[0049] The processing steps of the buffer layer 3 are as follows:

[0050] The wear-resistant main pipe and the intermediate reinforcement layer 2 that have been solidified into one are fed into a foaming mold, and a steel mesh 31 is pre-embedded in the foaming mold. Then, polyurethane foam is injected into the foaming mold. The polyurethane foam is made by mixing a polyether polyurethane prepolymer and a chain extender in a ratio of 100:12. After the polyurethane foam is injected, it is foamed to form a foam structure with a closed-cell rate of ≥90%.

[0051] Example 5:

[0052] A method for processing a wear-resistant composite pipe is provided, which is used to process the wear-resistant composite pipe. The wear-resistant composite pipe does not include an end wear-resistant layer 5. The processing method is specifically as follows:

[0053] High-purity alumina ceramic particles (purity ≥99%, particle size 50-200μm) were selected and surface-modified with a silane coupling agent (KH-550). The modified ceramic particles can improve the interfacial bonding strength with the rubber matrix. Nitrile rubber and modified ceramic particles were added to the internal mixer at a mass ratio of 7:3, and the vulcanization system (1.2 parts sulfur, 5 parts zinc oxide, and accelerator CZ) was added simultaneously. The rubber compound was then extruded into a tube blank through a screw extruder (L / D=20:1). The extrusion temperature zones were set as follows: 95°C for the feeding section, 110°C for the plasticizing section, and 150°C for the die head. The tube blank was then vulcanized using a staged temperature increase process: pre-vulcanization at 125°C for 30 minutes in the first stage, and high-temperature vulcanization at 165°C for 45 minutes in the second stage at a pressure of 3.2±0.2MPa. The staged temperature increase process was used to balance the ceramic hardness and rubber elasticity to avoid brittle cracking. Multiple groups of wear-resistant inner layers 1 with a thickness of 3mm were obtained according to the above process. Hardness tests were performed on the wear-resistant inner layer 1, and the hardness was found to be HRA85±2, meeting the wear-resistant hardness requirements.

[0054] Next, an intermediate reinforcement layer 2 is processed on the outer surface of the wear-resistant main pipe. The processing process of the intermediate reinforcement layer 2 is as follows: first, glass fiber yarn (single filament diameter 11±0.5μm) is pre-impregnated with epoxy resin emulsion to an impregnation rate of ≥75%, and pre-cured in an 80°C oven for 15 minutes. Then, a four-axis winding machine is used, with the winding angle set to 55°±5°, the tension controlled to 25-30N / bundle, and the interlayer offset angle of 10° to avoid stress concentration. The winding thickness of each layer is 0.8mm, and the total number of layers is 4. After winding, the wear-resistant inner layer 1 and the intermediate reinforcement layer 2 are heated and cured at 145°C for 60 minutes to fully cross-link the resin and increase the axial tensile strength to above 48MPa.

[0055] Next, the buffer layer 3 is processed. The pipe material obtained in the previous step is fed into a foaming mold, and a steel mesh 31 (mesh size 3mm×3mm) is pre-embedded in the foaming mold. Then, polyurethane foam is injected into the foaming mold for foaming. The polyurethane foam uses a polyether polyurethane prepolymer (NCO content 25±2%) and is mixed with a chain extender (MOCA) in a ratio of 100:12. The foaming density is set to 85±5kg / m³, the foaming temperature is 125±5°C, and the foaming time is 15 minutes. The foaming pressure is 1.0MPa, forming a foam structure with a closed-cell ratio of ≥90%. The buffer layer 3 has a thickness of 5mm. The buffer layer 3 and the steel mesh 31 can absorb more than 85% of the instantaneous impact energy caused by the fluid inside the wear-resistant main pipe.

[0056] Finally, the pressure-bearing layer 4 is processed. The pressure-bearing layer 4 is made of polyvinyl chloride and is extruded through a rotary die to obtain an outer tube body with a continuous spiral protrusion structure on the surface; the thickness is 5 mm, and it is bonded to the buffer layer 3 by hot melt adhesive to form an integral body; after the pressure-bearing layer 4 is processed, it can be plasma sprayed to form a 50μm alumina ceramic coating, so that its surface hardness can reach above HV1200. The wear-resistant composite pipe obtained above is subjected to performance tests, including bursting pressure test (GB / T15560 standard), drop hammer impact test (ASTMD2444) and wear resistance test (GB / T3960); the test results meet the requirements that when the bursting pressure is ≥15Mpa, there is no impact and no cracks, and the volume wear is ≤0.02cm³ / 1.61km.

[0057] In addition, a steel pipe can also be used as the pressure-bearing layer 4. The inner wall of the steel pipe is successively sandblasted (sandblasting Sa2.5 level) and sprayed with a silane coupling agent coating to increase the bonding strength between the buffer layer 3 and the pressure-bearing layer 4. Subsequently, a polyurethane-based adhesive (solid content ≥60%) is applied with a coating amount of 40 g / m², and the buffer layer 3 and the steel pipe are thermally bonded at a heating temperature of 80°C. After the bonding is cured, the peel strength between the buffer layer 3 and the steel pipe is ≥8 N / mm.

[0058] Application Example 1:

[0059] The processed wear-resistant composite pipe is used for mortar conveying pipeline. The pressure-bearing layer 4 of the wear-resistant composite pipe is made of steel pipe. The inner diameter of the wear-resistant composite pipe is 200mm and the length is 6m. The steel pipes are connected by flanges. The conveyed mortar is a slurry containing 30% quartz sand (particle size 5~8mm, flow rate 2.5~3m / s); after 1200 hours of continuous conveying, the wear-resistant composite pipe is disassembled and inspected by ultrasonic detection, and the following test results are obtained: the maximum wear of the input end of the wear-resistant composite pipe (length within 0.3m) is 1.1mm, the maximum wear of the output end of the wear-resistant composite pipe (length within 0.3m) is 0.9mm, and the maximum wear of the rest of the wear-resistant composite pipe is 0.8mm; therefore, compared with the existing polypropylene and polyethylene composite pipes of the same diameter (maximum wear 2.8mm), the wear of the wear-resistant composite pipe is low and can adapt to high-wear transmission pipeline occasions.

[0060] Example 6:

[0061] A wear-resistant composite pipe processing method is used to process a wear-resistant composite pipe, which includes an end wear-resistant layer 5. When the wear-resistant main pipe is processed, the end wear-resistant layer 5 and the wear-resistant inner layer 1 are extruded synchronously, and the intermediate reinforcement layer 2, the buffer layer 3 and the pressure-bearing layer 4 are processed according to the processing method of Example 5 to obtain another wear-resistant composite pipe. Then, the wear-resistant composite pipe obtained in this embodiment is tested for performance according to the process of Application Example 1, and the following test results are obtained: the maximum wear amount of the wear-resistant composite pipe input end (length within 0.3m) is 0.7mm, and the wear amount of the wear-resistant composite pipe output end (length is 0.3m) is 0.7mm. The maximum wear amount at the rest of the wear-resistant composite pipe is 0.6 mm (within the range of 0.3 m), and the maximum wear amount at the rest of the wear-resistant composite pipe is 0.7 mm; therefore, compared with the wear-resistant composite pipe obtained by processing in Example 1, the wear resistance of both ends is further improved, and the wear process of the entire pipe wall is close, which avoids excessive wear in the end area and affects the service life, and can extend the replacement cycle of the wear-resistant composite pipe. Among them, the fluctuation amount formed by the maximum wear amount of the rest of the wear-resistant composite pipe of Example 1 being 0.8 mm and the maximum wear amount of the rest of the wear-resistant composite pipe of Example 2 is affected by the fluctuation of the particle size and flow rate of the conveying mortar.

[0062] The above embodiments are only preferred implementations of the present invention. Therefore, any equivalent changes or modifications made according to the structures, features and principles described in the scope of application of the present invention are included in the scope of application of the present invention.

Claims

1. A wear-resistant composite pipe, characterized by: include: A wear-resistant main pipe, comprising a wear-resistant inner layer, wherein the wear-resistant inner layer is formed by mixing nitrile rubber and modified ceramic particles in a mass ratio of 8:2, kneading, extruding and vulcanizing; An intermediate reinforcement layer, wherein the intermediate reinforcement layer is a multi-layer glass fiber winding layer wound around the outer surface of the wear-resistant main pipe; A buffer layer is provided outside the middle reinforcement layer, the buffer layer is composed of polyurethane foam, and a steel mesh is provided at the center of the polyurethane foam; A pressure-bearing layer, the pressure-bearing layer being arranged outside the buffer layer and being bonded and fixed to the buffer layer; The wear-resistant main pipe also includes an end wear-resistant layer, which is arranged at both ends of the wear-resistant inner layer. The end wear-resistant layer is composed of nitrile rubber, modified ceramic particles, and silane-grafted modified thermoplastic elastomer mixed in a mass ratio of 5:1:4 and dynamically kneaded; the end wear-resistant layer and the wear-resistant inner layer are jointly extruded through the same extruder.

2. The wear-resistant composite pipe according to claim 1, characterized in that: The pressure-bearing layer is a steel pipe.

3. The wear-resistant composite pipe according to claim 1, characterized in that: The pressure-bearing layer is made of polyvinyl chloride or thermoplastic polyurethane as a base material, and is extruded through a rotary die to obtain an outer tube body with a continuous spiral protrusion structure formed on the surface.

4. A method for processing a wear-resistant composite pipe, used for processing the wear-resistant composite pipe according to claim 1, characterized in that: The processing method is specifically as follows: First, a wear-resistant inner layer is processed. The wear-resistant inner layer is prepared as follows: alumina ceramic particles with a purity of ≥99% and a particle size of 50-200 μm are selected and surface-modified with a silane coupling agent to obtain modified ceramic particles. Then, the modified ceramic particles and nitrile rubber are added to an internal mixer according to a set mass ratio, and a vulcanization system and a plasticizer are simultaneously added and mixed to obtain a rubber mix. Then, the rubber mix is ​​extruded into a tube blank through a screw extruder, and the tube blank is vulcanized to obtain the wear-resistant inner layer. Next, the intermediate reinforcement layer is processed. The processing steps of the intermediate reinforcement layer are as follows: First, the glass fiber yarn is pre-impregnated with epoxy resin emulsion and heated for pre-curing. Then, the treated glass fiber yarn is wound onto the outer surface of the wear-resistant main pipe through a four-axis winding machine. Multiple layers of winding are completed. After the winding is completed, the wear-resistant inner layer and the middle reinforcement layer are heated and cured into one. Next, the buffer layer is processed. The buffer layer processing steps are as follows: The wear-resistant main pipe and the middle reinforcement layer that have been solidified into one are fed into a foaming mold, and a steel mesh is pre-embedded in the foaming mold. Then, polyurethane foam is injected into the foaming mold for foaming to obtain a core pipe; Finally, the wear-resistant composite pipe processing is completed, and the core pipe is bonded and cured to the inner wall of the pressure-bearing layer to obtain a finished wear-resistant composite pipe.

5. The method for processing a wear-resistant composite pipe according to claim 4, characterized in that: The polyurethane foam is prepared by mixing a polyether polyurethane prepolymer and a chain extender in a ratio of 100:

12. The polyurethane foam is foamed after injection to form a foam structure with a closed cell rate of ≥90%.

6. A wear-resistant main pipe processing unit for processing the wear-resistant main pipe according to claim 2, characterized in that: The wear-resistant main pipe is extruded into a pipe blank through an extrusion unit. The extrusion unit includes a first screw extruder for extruding the wear-resistant inner layer raw material and a second screw extruder for extruding the end wear-resistant layer raw material. The output ends of the first screw extruder and the second screw extruder are connected to the extrusion head through a heated extrusion switching pipeline.

7. The wear-resistant main pipe processing unit according to claim 6, characterized in that: The heating extrusion switching pipeline includes a square slide, a first input port and a first output port are provided opposite to each other at the lower part of the slide, a second input port is provided above the first input port, a cutting port is provided opposite to the second input port, and a pneumatic cutting knife is provided outside the cutting port; a heating plate is provided on the inner side of the slide for sliding, two material storage holes are provided on the heating plate, the first input port and the second input port are respectively connected to the output ends of the first screw extruder and the second screw extruder; the first output port is connected to the extrusion head through a heating pipe; A lifting hydraulic cylinder connected to the heating plate is fixed on the top of the slide.

8. The wear-resistant main pipe processing unit according to claim 6, characterized in that: The heating extrusion switching pipeline includes a disc jacket, in which a rotating disc with a heating function is rotatably installed via a drive shaft, and the rotating disc is tightly fitted to the disc jacket; a ring of material storage holes is provided on the rotating disc at intervals; a punching through hole, a third input port, and a fourth input port are provided on one side of the disc jacket, which are connected to the material storage holes; a second output port, which is connected to the material storage holes, is provided on the other side of the rotating disc; the third input port and the second output port are directly opposite to each other, and the third input port and the fourth input port are connected to the output ends of the first screw extruder and the second screw extruder, respectively; the second output port is connected to the extrusion head via a heating pipe; A transposition motor connected to a driving shaft is fixed on the outside of the rotating disk.

9. The wear-resistant main pipe processing unit according to claim 6, characterized in that: The heating extrusion switching pipeline includes a heating material pipe, an injection head is embedded in the middle of the heating material pipe, and the injection head is connected to the output end of the second screw extruder through a pipe valve. One end of the heating material pipe is connected to the output end of the first screw extruder, and the other end is connected to the extrusion head; the bottom of the injection head is embedded in the axis of the heating material pipe; A heating jacket is provided outside the injection head.

Images