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

Abstract

The invention discloses a wear-resistant composite pipe, a composite pipe machining method and a wear-resistant main pipe machining unit, and belongs to the technical field of composite pipes. Comprising a wear-resistant main pipe, a middle reinforcing layer, a buffer layer and a pressure-bearing layer, the wear-resistant main pipe comprises a wear-resistant inner layer, and the wear-resistant inner layer is formed by mixing, banburying, extruding and vulcanizing nitrile rubber and modified ceramic particles according to the mass ratio of 8: 2; the middle reinforcing 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 middle reinforcing layer and is made of polyurethane foam, the pressure-bearing layer is arranged outside the buffer layer, and the pressure-bearing layer and the buffer layer are bonded and fixed; the wear-resistant main pipe further comprises end wear-resistant layers, the end wear-resistant layers are arranged at the two ends of the wear-resistant inner layer, and the end wear-resistant layers and the wear-resistant inner layer are co-extruded through the same extrusion head. The wear-resistant composite pipe is excellent in wear resistance and can be applied to high-wear transmission occasions.

Description

Technical Field

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

[0002] As a special industrial pipe, wear-resistant pipes are mainly used in mines, metallurgy, chemical industry, and power generation, such as the conveying of ore pulp for beneficiation and the long-distance pipeline conveying of tailings, the conveying of concentrated ore pulp, metallurgical waste slag, pulverized coal, etc.; the conveying of solid-liquid mixtures such as salt slurry and alkali slurry; the ash removal, slag discharge, powder feeding, powder return, and desulfurization process pipelines in thermal power plants, etc. 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 prior art, ultra-high molecular weight polyethylene pipes are used in many occasions, but their wear resistance is insufficient under harsh working conditions. For this reason, the Chinese patent authorization publication number: CN108561636B, discloses a wear-resistant composite pipe, including: a pipe body and a wear-resistant layer, and the wear-resistant layer is a thermoplastic elastomer material; the composite pipe is made by forming, sizing, cooling, and traction, but the overall cost is high, the impact resistance is average, and there is still large wear on the wear-resistant layer in the case of high flow rate and high solid content. Another example is the Chinese patent authorization publication number: CN113045810B, which discloses a super wear-resistant composite pipe and its preparation method; the super wear-resistant composite pipe is co-extruded with polyethylene on the outer layer and wear-resistant material on the inner layer; however, this composite pipe still has a large wear rate in high-wear transmission occasions. Summary of the Invention

[0003] To solve the above problems, the present invention provides 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 applied to high-wear transmission occasions.

[0004] The wear-resistant composite pipe of the present invention includes: A wear-resistant main pipe, the wear-resistant main pipe includes a wear-resistant inner layer, and the wear-resistant inner layer is composed of nitrile rubber and modified ceramic particles mixed, kneaded, extruded, and vulcanized in a mass ratio of 8:2; the modified ceramic particles can improve the interfacial bonding force with the rubber matrix, and the inner wall of the pipe group formed by mixing, kneading, extruding, and vulcanizing nitrile rubber and modified ceramic particles has excellent anti-wear performance; An intermediate reinforcement layer, the intermediate reinforcement layer is a multi-layer glass fiber winding layer wound around the outer surface of the wear-resistant main pipe; the intermediate reinforcement layer has high axial tensile strength; A buffer layer, the buffer layer is arranged outside the intermediate reinforcement layer, the buffer layer is composed of polyurethane foam, and a steel wire mesh is arranged at the center of the polyurethane foam; the polyurethane foam and the steel wire mesh cooperate to absorb more than 85% of the instantaneous impact energy brought by the fluid inside the wear-resistant main pipe; The pressure-bearing layer is arranged outside the buffer layer and is adhesively fixed to the buffer layer; the pressure-bearing layer can bear external impacts, protect the wear-resistant main pipe, and prevent the wear-resistant main pipe from deforming.

[0005] Furthermore, the wear-resistant main pipe further includes end wear-resistant layers arranged at both ends of the wear-resistant inner layer. The end wear-resistant layers are 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 layers and the wear-resistant inner layer are co-extruded through the same extrusion head. Since the composite pipes need to be connected to form a pipeline, the axis lines of the composite pipes are prone to deviation, and fluid resistance and turbulence are likely to occur at the pipe ends, causing the area near the ends of the composite pipes to wear rapidly, resulting in eccentric wear and shortening the service life of the composite pipes. Therefore, by integrally extruding the end wear-resistant layers at both ends of the wear-resistant inner layer and vulcanizing them into an integral structure, the nitrile rubber inside the end wear-resistant layers is compounded with silane-grafted modified thermoplastic elastomer and modified ceramic particles. Since the thermoplastic elastomer itself has excellent wear resistance and is closely combined with the modified ceramic particles, its wear resistance is stronger than that of the wear-resistant inner layer. During the use of the entire pipeline, the wear process of the entire pipe wall is similar, avoiding excessive wear in the end area and affecting the service life, and being able to extend the replacement cycle of the wear-resistant composite pipe. Moreover, the wear-resistant main pipe only has end wear-resistant layers compounded at both ends of the wear-resistant inner layer, with a lower overall construction cost. And through the common nitrile rubber and common vulcanization system of the end wear-resistant layers and the wear-resistant inner layer for vulcanization, the end wear-resistant layers and the wear-resistant inner layer can form an integral structure.

[0006] Furthermore, the pressure-bearing layer is an outer pipe body with a continuous spiral convex structure formed on its surface by extrusion using a rotating die with polyvinyl chloride or thermoplastic polyurethane as the base material.

[0007] Furthermore, the pressure-bearing layer is a steel pipe, and the inner wall of the steel pipe is successively treated by sandblasting and coated with a silane coupling agent coating.

[0008] A processing method for a wear-resistant composite pipe, which is used to process the wear-resistant composite pipe. The specific processing method is as follows: First, process the wear-resistant inner layer. The preparation process of the wear-resistant inner layer is as follows: Select alumina ceramic particles with a purity ≥ 99% and a particle size of 50 - 200 μm, and perform surface modification treatment with a silane coupling agent to obtain modified ceramic particles. Then, add the modified ceramic particles and nitrile rubber to a kneader according to a set mass ratio, and synchronously add a vulcanization system and a plasticizer for mixing to obtain a mixed rubber. Then, extrude the mixed rubber through a screw extruder into a pipe blank, and then vulcanize the pipe blank to obtain the wear-resistant inner layer.

[0009] Next, process the intermediate reinforcement layer. The processing procedure of the intermediate reinforcement layer is as follows: First, pre-impregnate the fiberglass yarn with epoxy resin emulsion and perform heat pre-curing. Then, wind the treated fiberglass yarn onto the outer surface of the wear-resistant main pipe through a four-axis winding machine for multiple layers. After winding, heat-cure the wear-resistant inner layer and the intermediate reinforcement layer into one body.

[0010] Next, process the buffer layer. The processing procedure of the buffer layer is as follows: Feed the wear-resistant main pipe and the intermediate reinforcement layer that have been cured into one body into a foaming mold, and embed a steel wire mesh in the foaming mold. Then, inject polyurethane foam into the foaming mold. The polyurethane foam is a mixture of polyether-type polyurethane prepolymer and chain extender in a ratio of 100:12. After the polyurethane foam is injected, it foams to form a foam structure with a closed-cell rate ≥ 90%.

[0011] Finally, complete the processing of the wear-resistant composite pipe. Bond and cure the core pipe to the inner wall of the pressure-bearing layer to obtain the finished product of the wear-resistant composite pipe.

[0012] A processing unit for a wear-resistant main pipe is used to process the wear-resistant main pipe. The wear-resistant main pipe is obtained by extrusion through an extrusion unit. The extrusion unit includes a first screw extruder for extruding the raw material of the wear-resistant inner layer and a second screw extruder for extruding the raw material of the end wear-resistant layer. The output ends of the first screw extruder and the second screw extruder are connected to the extrusion head through a heating extrusion switching pipeline. The first screw extruder and the second screw extruder respectively complete the feeding and plasticizing sections of the raw materials of the wear-resistant inner layer and the end wear-resistant layer, and press the molten rubber into the heating extrusion switching pipeline. According to the length requirement of the wear-resistant main pipe, the heating extrusion switching pipeline intermittently injects the rubber of the end wear-resistant layer between the rubber of the wear-resistant inner layer, so that the rubber of the end wear-resistant layer is located at the end of the wear-resistant inner layer. Finally, extrude the entire wear-resistant main pipe through the extrusion head. The cutting position of the wear-resistant main pipe is the middle position where the rubber of the end wear-resistant layer is extruded. After cutting, the ends of adjacent two wear-resistant main pipes are processed to obtain the end wear-resistant layer.

[0013] Furthermore, the heating and extrusion switching pipeline includes a square sliding cylinder. A first input port and a first output port are oppositely arranged at the lower part of the sliding cylinder. A second input port is arranged above the first input port. A cutting port is oppositely arranged corresponding to the second input port. A pneumatic cutting knife is arranged outside the cutting port. A heating plate is slidably arranged inside the sliding cylinder. Two material storage holes are formed in the heating plate. The first input port and the second input port are respectively communicated with the output ends of a first screw extruder and a second screw extruder. The first output port is connected to an extrusion head through a heating material pipe. A lifting hydraulic cylinder connected to the heating plate is fixed at the top of the sliding cylinder. During processing, first, the first input port and the first output port are made to face each other. At this time, the material extruded by the first screw extruder is fed into the first input port and enters the first output port through the material storage hole below the heating plate. Then, the wear-resistant inner layer raw material is fed into the extrusion head through the heating material pipe to extrude a pipe blank. At the same time, the second screw extruder continuously feeds materials into the second input port and the other material storage hole. Since one end of the other material storage hole far away from the second input port is closed by the pneumatic cutting knife, the rubber material of the end wear-resistant layer is heated and insulated by the heating plate. When it is necessary to feed the rubber material of the end wear-resistant layer into the heating material pipe, the lifting hydraulic cylinder acts to drive the heating plate to move downward to the lower limit position. At this time, the lower material storage hole carries the rubber material of the wear-resistant inner layer downward. At the same time, the upper material storage hole faces the first input port and the first output port. And using the wear-resistant inner layer raw material extruded by the first screw extruder as the extrusion force, the rubber material of the end wear-resistant layer in the material storage hole is pushed into the heating material pipe. At this time, the second input port is closed by the heating plate. Then, the lifting hydraulic cylinder acts to drive the heating plate to move upward to the upper limit position. The lower material storage hole faces the first input port and the first output port. At this time, the extrusion and transmission of the wear-resistant inner layer raw material are restarted. The upper material storage hole is re-aligned with the second input port. The rubber material of the end wear-resistant layer extruded by the second screw extruder is used as the extrusion force to push out the rubber material of the wear-resistant inner layer in the upper material storage hole. And the pushed-out rubber material is cut off as waste by the pneumatic cutting knife. At the same time, the upper material storage hole is closed and re-receives the rubber material of the end wear-resistant layer. In order to prevent the deviation of the extrusion positions of the end wear-resistant layer and the wear-resistant inner layer, enough surplus rubber material of the end wear-resistant layer is fed in advance to ensure the length of the end wear-resistant layer.

[0014] Furthermore, the heating extrusion switching pipeline includes a disc jacket, inside which a rotating disc with a heating function is rotatably installed 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; one side of the disc jacket is provided with a stamping through hole connected to the storage hole, a third input port and a fourth input port; the other side of the rotating disc is provided with a second output port connected to the storage hole; 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 respectively connected to the output ends of the first screw extruder and the second screw extruder; 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; and a pneumatic punching head is fixed to the disc jacket opposite the stamping through hole.

[0015] During processing, firstly, the third input port, a storage hole on the rotating disk and the second output port are aligned. At this time, the extruded material of the first screw extruder is sent to the third input port, and enters the second output port through a storage hole on the rotating disk. Then, the wear-resistant inner layer raw material is sent to the extruder through the heating 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 insulated 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 insulated. When the rubber material is fed into the heating material pipe, the shifting motor drives the rotating disk to shift the rubber material of the loading end wear-resistant layer to 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 moves to the punching through hole, and the cooled wear-resistant inner layer is punched out of the storage hole by the pneumatic punching head, and the cooled wear-resistant inner layer is recovered.

[0016] Furthermore, the heating extrusion switching pipeline includes a heating material pipe, a material injection head is embedded in the middle of the heating material pipe, the material 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 material injection head is embedded in the axis of the heating material pipe; a heating sleeve is arranged on the outside of the material 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 tube 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, and 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.

[0017] Compared with the prior art, the wear-resistant composite pipe of the present invention uses a wear-resistant inner layer as the wear-resistant main body, with excellent overall wear resistance, and can be applied to high-wear transmission occasions. The middle reinforcing layer and the wear-resistant main pipe are integrally wound and heat-cured into one. The middle reinforcing 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 middle reinforcing 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 internal fluid of the wear-resistant main pipe; in addition, the wear resistance at both ends of the wear-resistant main pipe is further improved, and the wear process of the entire pipe wall is close, avoiding too fast wear in the end area and 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 relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of Embodiment 1 of the wear-resistant composite pipe of the present invention.

[0019] Figure 2 It is a schematic diagram of the overall structure of Embodiment 2 of the wear-resistant composite pipe of the present invention.

[0020] Figure 3 It is a schematic diagram of the structure of the processing equipment for the wear-resistant composite pipe of Embodiment 2 of the present invention.

[0021] Figure 4 It is a schematic diagram of the structure of the first extrusion unit of the present invention.

[0022] Figure 5 It is a schematic diagram of the structure of the second extrusion unit of the present invention.

[0023] Figure 6 It is a schematic diagram of the structure of the third extrusion unit of the present invention.

[0024] Reference numerals: 1, wear-resistant inner layer; 2, middle reinforcing 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, sliding cylinder; 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 outer sleeve; 21, rotating disc; 22, punching through hole; 23, third input port; 24, fourth input port; 25, second output port; 26, transposition motor; 27, pneumatic punching head; 28, injection head; 29, pipe valve; 30, heating sleeve; 31, steel wire mesh. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] Embodiment 1: AsFigure 1 The wear-resistant composite pipe shown in the figure includes: A wear-resistant main pipe, the wear-resistant main pipe includes a wear-resistant inner layer 1, and the wear-resistant inner layer 1 is composed of nitrile rubber and modified ceramic particles mixed, kneaded, extruded and vulcanized according to a mass ratio of 8:2; the modified ceramic particles can improve the interfacial bonding force with the rubber matrix, and the inner wall of the pipe group formed by mixing, kneading, extruding and vulcanizing nitrile rubber and modified ceramic particles has excellent anti-wear performance; An intermediate reinforcing layer 2, the intermediate reinforcing layer 2 is a multi-layer glass fiber winding layer wound around the outer surface of the wear-resistant main pipe; the intermediate reinforcing layer 2 has high axial tensile strength; A buffer layer 3, the buffer layer 3 is arranged outside the intermediate reinforcing layer 2, the buffer layer 3 is composed of polyurethane foam, and a steel wire mesh 31 is arranged at the center of the polyurethane foam; the polyurethane foam and the steel wire mesh 31 cooperate to absorb more than 85% of the instantaneous impact energy brought by the fluid inside the wear-resistant main pipe; A pressure-bearing layer 4, the pressure-bearing layer 4 is arranged outside the buffer layer 3, and the pressure-bearing layer 4 is adhesively fixed to the buffer layer 3; the pressure-bearing layer 4 can bear external impacts, protect the wear-resistant main pipe, and prevent the wear-resistant main pipe from deforming.

[0026] The pressure-bearing layer 4 is an outer pipe body with a continuous spiral convex structure formed on the surface by extrusion through a rotary die with polyvinyl chloride or thermoplastic polyurethane as the base material.

[0027] The pressure-bearing layer 4 is a steel pipe, and the inner wall of the steel pipe is sequentially treated by sandblasting and coated with a silane coupling agent coating.

[0028] Example 2: As Figures 2 to 4The wear-resistant composite pipe shown, the wear-resistant main pipe further 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 in a mass ratio of 5:1:4 and dynamically kneaded; the end wear-resistant layer 5 and the wear-resistant inner layer 1 are co-extruded through the same extrusion head; Since the composite pipes need to be connected to form a pipeline, and the axis lines between the composite pipes are prone to deviation, fluid resistance and turbulence are likely to occur at the pipe ends, causing the area near the end of the composite pipe to wear too quickly, 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 structure. The nitrile rubber inside the end wear-resistant layer 5 is compounded with silane-grafted modified thermoplastic elastomer and modified ceramic particles. Since the thermoplastic elastomer itself has excellent wear resistance and is closely combined with the modified ceramic particles, its wear resistance is stronger than that of the wear-resistant inner layer 1. During the use of the entire pipeline, the wear process of the entire pipe wall is similar, avoiding excessive wear in the end area and affecting the service life, and being able to extend the replacement cycle of the wear-resistant composite pipe; Moreover, the wear-resistant main pipe only has the end wear-resistant layer 5 compounded at both ends of the wear-resistant inner layer 1, with a lower overall cost, and through the common nitrile rubber and common vulcanization system of the end wear-resistant layer 5 and the wear-resistant inner layer 1 for vulcanization, the end wear-resistant layer 5 and the wear-resistant inner layer 1 can form an integral structure.

[0029] A processing unit for a wear-resistant main pipe, used to process the wear-resistant main pipe. The wear-resistant main pipe is obtained by extruding 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 heating extrusion switching pipeline 8; The first screw extruder 6 and the second screw extruder 7 each complete the feeding and plasticizing sections of the raw materials of the wear-resistant inner layer 1 and the end wear-resistant layer 5, and press the molten rubber into the heating extrusion switching pipeline 8. The heating extrusion switching pipeline 8 intermittently injects the rubber material of the end wear-resistant layer 5 between the rubber materials of the wear-resistant inner layer 1 according to the length requirement of the wear-resistant main pipe, so that the rubber material 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 where the rubber material of the end wear-resistant layer 5 is extruded. After truncation, the ends of adjacent two wear-resistant main pipes are processed to obtain the end wear-resistant layer 5.

[0030] The heating and extrusion switching pipeline 8 includes a square sliding cylinder 10. A first input port 11 and a first output port 12 are oppositely arranged and opened at the lower part of the sliding cylinder 10. A second input port 13 is arranged above the first input port 11. A material cutting port 14 is oppositely arranged corresponding to the second input port 13. A pneumatic material cutting knife 15 is arranged outside the material cutting port 14. A heating plate 16 is slidably arranged inside the sliding cylinder 10. Two material storage holes 17 are opened on the heating plate 16. The first input port 11 and the second input port 13 are respectively communicated with the output ends of a first screw extruder 6 and a second screw extruder 7. The first output port 12 is connected to an extrusion head 9 through a heating material pipe 19. A lifting hydraulic cylinder 18 connected to the heating plate 16 is fixed at the top of the sliding cylinder 10. During processing, first, the first input port 11 and the first output port 12 are made to face each other. At this time, the material extruded by the first screw extruder 6 is fed into the first input port 11 and enters the first output port 12 through the material 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 a pipe blank. At the same time, the second screw extruder 7 continuously feeds materials into the second input port 13 and the other material storage hole 17. Since one end of the other material storage hole 17 far from the second input port 13 is closed by the pneumatic material cutting knife 15, the rubber material of the end wear-resistant layer 5 is heated and kept warm through the heating plate 16. When it is necessary to feed the rubber material of the end wear-resistant layer 5 into the heating material pipe 19, the lifting hydraulic cylinder 18 acts to drive the heating plate 16 to descend to the lower limit position. At this time, the lower material storage hole 17 carries the rubber material of the wear-resistant inner layer 1 and descends. At the same time, the upper material storage hole 17 faces the first input port 11 and the first output port 12. And taking the raw material of the wear-resistant inner layer 1 extruded by the first screw extruder 6 as the extrusion pressure, the rubber material of the end wear-resistant layer 5 in the material storage hole 17 is pushed 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 acts to drive the heating plate 16 to ascend to the upper limit position. The lower material storage hole 17 faces the first input port 11 and the first output port 12. At this time, the extrusion and transmission of the raw material of the wear-resistant inner layer 1 are carried out again. The upper material storage hole 17 is re-aligned with the second input port 13. The rubber material of the end wear-resistant layer 5 extruded by the second screw extruder 7 is used as the extrusion pressure to push out the rubber material of the wear-resistant inner layer 1 in the upper material storage hole 17, and the pushed-out rubber material is cut off as waste through the pneumatic material cutting knife 15. At the same time, the upper material storage hole 17 is closed and re-receives the rubber material of the end wear-resistant layer 5. In order to prevent the deviation of the extrusion positions of the end wear-resistant layer 5 and the wear-resistant inner layer 1, enough surplus rubber material of the end wear-resistant layer 5 is fed in advance to ensure the length of the end wear-resistant layer 5.

[0031] Example 3: As Figure 5As shown, the heating and extrusion switching pipeline 8 includes a disc outer sleeve 20. Inside the disc outer sleeve 20, a rotating disc 21 with a heating function is rotatably installed through a driving shaft. The rotating disc 21 is in close fit with the disc outer sleeve 20. A ring of material storage holes 17 are spaced apart on the rotating disc 21. On one side of the disc outer sleeve 20, a stamping through hole 22, a third input port 23, and a fourth input port 24 communicating with the material storage holes 17 are provided. On the other side of the rotating disc 21, a second output port 25 communicating with the material storage holes 17 is provided. The third input port 23 and the second output port 25 are facing each other. The third input port 23 and the fourth input port 24 are respectively communicated with 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 commutation motor 26 connected to the driving shaft is fixed outside the rotating disc 21. An air-powered stamping head 27 is fixed to the disc outer sleeve 20 opposite to the stamping through hole 22.

[0032] During processing, first, align the third input port 23, one of the material storage holes 17 on the rotating disc 21, and the second output port 25. At this time, the material extruded by the first screw extruder 6 is fed into the third input port 23 and enters the second output port 25 through one of the material storage holes 17 on the rotating disc 21. 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 pipe blank. At the same time, the second screw extruder 7 continuously feeds material into another material storage hole 17. Since one end of another material storage hole 17 away from the third input port 23 is closed by the disc outer sleeve 20, the rubber material of the end wear-resistant layer 5 is heated and insulated through the rotating disc 21. When it is necessary to feed the rubber material of the end wear-resistant layer 5 into the heating material pipe 19, the commutation motor 26 drives the rotating disc 21 to change positions, so that the rubber material of the loaded 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 material storage hole 17 into the heating material pipe 19. At this time, a new hollow material 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 in the material storage hole 17 separated from the heating material pipe 19 is cooled until it reaches the stamping through hole 22, and the cooled wear-resistant inner layer 1 is punched out of the material storage hole 17 by the air-powered stamping head 27, and the cooled wear-resistant inner layer 1 is recycled.

[0033] Example 4: As Figure 6As shown in the figure, the heating and extrusion switching pipeline 8 includes a heating material pipe 19, in the middle of which a material injection head 28 is fitted. The material 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 material injection head 28 is embedded on the axis of the heating material pipe 19. A heating sleeve 30 is arranged outside the material 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 the rubber material is sent to the extrusion head 9 through the heating material pipe 19 for pipe blank extrusion. When reaching the feeding position of the rubber material of the end wear-resistant layer 5, the first screw extruder 6 injects the rubber material 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 on the center line of the rubber material of the wear-resistant inner layer 1. The rubber material of the end wear-resistant layer 5 is sent into the extrusion head 9 for extrusion by being wrapped by the rubber material of the wear-resistant inner layer 1. After the large amount of rubber material 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 the temperature control state, and at the same time, the drive motor of the extruder enters the low-frequency or standby state.

[0034] The preparation process of the wear-resistant inner layer 1 is as follows: Select alumina ceramic particles with a purity ≥ 99% and a particle size of 50 - 200 μm, and perform surface modification treatment with a silane coupling agent to obtain modified ceramic particles. Then, add the modified ceramic particles and nitrile rubber to a mixer according to a set mass ratio, and synchronously add a vulcanization system and a plasticizer for mixing to obtain a mixed rubber. Then, extrude the mixed rubber through a screw extruder to form a pipe blank, and then vulcanize the pipe blank to obtain the wear-resistant inner layer 1.

[0035] The processing procedure of the intermediate reinforcement layer 2 is as follows: First, pre-impregnate glass fiber yarns with an epoxy resin emulsion and perform heat pre-curing. Then, wind the treated glass fiber yarns onto the outer surface of the wear-resistant main pipe through a four-axis winding machine in multiple layers. After winding, heat-cure the wear-resistant inner layer 1 and the intermediate reinforcement layer 2 into one body.

[0036] The processing procedure of the buffer layer 3 is as follows: Send the wear-resistant main pipe and the intermediate reinforcement layer 2 cured into one body into a foaming mold, and embed a wire mesh 31 in the foaming mold. Then, inject polyurethane foam into the foaming mold. The polyurethane foam is a mixture of a polyether-type polyurethane prepolymer and a chain extender in a ratio of 100:12. After the polyurethane foam is injected, it foams to form a foam structure with a closed cell rate ≥ 90%.

[0037] Example 5: A processing method for a wear-resistant composite pipe, used to process a wear-resistant composite pipe that does not include an end wear-resistant layer 5. The specific processing method is as follows: High-purity alumina ceramic particles (purity ≥ 99%, particle size 50 - 200 μm) are selected and surface-modified with a silane coupling agent (KH-550). The modified ceramic particles can improve the interfacial bonding force with the rubber matrix. Nitrile rubber and the modified ceramic particles are added to a mixer at a mass ratio of 7:3, and a vulcanization system (1.2 parts of sulfur, 5 parts of zinc oxide, 1.5 parts of accelerator CZ) and a plasticizer (18 parts of dioctyl phthalate) are added synchronously. The mixing temperature is controlled at 95°C for 20 min to obtain a mixed rubber. Then, the mixed rubber is extruded into a tube blank by a screw extruder (L / D = 20:1). The extrusion temperature zones are set as follows: the feeding section is 95°C, the plasticizing section is 110°C, and the die head is 150°C. Then, the tube blank is vulcanized. During vulcanization, a segmented heating process is adopted: in the first stage, it is pre-vulcanized at 125°C for 30 min, and in the second stage, it is high-temperature vulcanized at 165°C for 45 min, with a pressure of 3.2 ± 0.2 MPa. The segmented heating process is used to balance the hardness of the ceramic and the elasticity of the rubber to avoid brittle cracking. Multiple groups of wear-resistant inner layers 1 with a thickness of 3 mm are processed according to the above process, and their hardness is tested. The hardness of the wear-resistant inner layer 1 is HRA85 ± 2, meeting the wear-resistant hardness requirements. Then, a middle reinforcing layer 2 is processed on the outer surface of the wear-resistant main pipe. The processing procedure of the middle reinforcing layer 2 is as follows: First, glass fiber yarns (single fiber diameter 11 ± 0.5 μm) are pre-impregnated with an epoxy resin emulsion, and the impregnation rate is ≥ 75%. Then, they are pre-cured in an 80°C oven for 15 min. Then, a four-axis winding machine is used, and the winding angle is set at 55° ± 5°, the tension is controlled at 25 - 30 N / strand, and the interlayer misalignment angle is 10° to avoid stress concentration. The thickness of each winding layer is 0.8 mm, and the total number of layers is 4. After winding, it is heated at 145°C for 60 min to heat-cure the wear-resistant inner layer 1 and the middle reinforcing layer 2 into one body, so that the resin is completely cross-linked, and the axial tensile strength is increased to more than 48 MPa. Then, a buffer layer 3 is processed. The tube material obtained in the previous step is sent into a foaming mold, and a wire mesh 31 (mesh size 3 mm × 3 mm) is embedded in the foaming mold. Then, polyurethane foam is injected into the foaming mold for foaming. The polyurethane foam uses a polyether-type polyurethane prepolymer (NCO content 25 ± 2%) and is mixed with a chain extender (MOCA) at a ratio of 100:12. The foaming density is set at 85 ± 5 kg / m³, the foaming temperature is 125 ± 5°C, and the foaming time is 15 min. The foaming pressure is 1.0 MPa to form a foam structure with a closed-cell rate ≥ 90%. The thickness of the buffer layer 3 is 5 mm. Through the buffer layer 3 and the wire mesh 31, more than 85% of the instantaneous impact energy brought by the fluid inside the wear-resistant main pipe can be absorbed. Finally, the pressure-bearing layer 4 is processed. The pressure-bearing layer 4 is made of polyvinyl chloride, and an outer pipe body with a continuous spiral convex structure on the surface is obtained by extrusion through a rotary die; the thickness is 5 mm, and it is bonded to the buffer layer 3 by hot melt adhesive to form a whole; after the pressure-bearing layer 4 is processed, plasma spraying treatment can be carried out to form an alumina ceramic coating with a thickness of 50 μm, so that the surface hardness can reach above HV1200. The prepared wear-resistant composite pipe is subjected to performance tests, including burst pressure test (GB / T15560 standard), drop hammer impact test (ASTM D2444), and wear resistance test (GB / T3960); the test results meet the requirements that when the burst pressure ≥ 15 Mpa, there is no impact and no crack, and the volume wear amount ≤ 0.02 cm³ / 1.61 km.

[0038] In addition, a steel pipe can also be used as the pressure-bearing layer 4. The inner wall of the steel pipe is successively treated by sandblasting (sandblasting grade Sa2.5) and coated with a silane coupling agent coating to increase the bonding force between the buffer layer 3 and the pressure-bearing layer 4. Then, a polyurethane-based adhesive (solid content ≥ 60%) is coated with a coating amount of 40 g / m², and the buffer layer 3 and the steel pipe are thermally bonded. The heating temperature is 80 °C. After bonding and curing, the peel strength between the buffer layer 3 and the steel pipe ≥ 8 N / mm.

[0039] Application Example 1: The processed wear-resistant composite pipe is used for a mortar conveying pipeline. The pressure-bearing layer 4 of the wear-resistant composite pipe is made of a steel pipe. The inner diameter of the wear-resistant composite pipe is 200 mm and the pipe length is 6 m. The steel pipes are connected by flanges. The conveyed mortar is a slurry containing 30% quartz sand (particle size 5 - 8 mm, flow rate 2.5 - 3 m / s); after continuous conveying for 1200 hours, the wear-resistant composite pipe is disassembled and detected. The detection method is ultrasonic detection, and the following test results are obtained: the maximum wear amount at the input end (within a length range of 0.3 m) of the wear-resistant composite pipe is 1.1 mm, the maximum wear amount at the output end (within a length range of 0.3 m) of the wear-resistant composite pipe is 0.9 mm, and the maximum wear amount at the remaining positions of the wear-resistant composite pipe is 0.8 mm; therefore, compared with the existing polypropylene and polyethylene composite pipes of the same pipe diameter (maximum wear amount 2.8 mm), the wear-resistant composite pipe has a low wear amount and can adapt to high-wear transmission pipeline occasions.

[0040] Example 6: A processing method for wear-resistant composite pipes, which is used to process wear-resistant composite pipes. The wear-resistant composite pipe includes an end wear-resistant layer 5. When processing the wear-resistant main pipe, the end wear-resistant layer 5 and the wear-resistant inner layer 1 are extruded synchronously, and the middle reinforcing 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, according to the process of Application Example 1, the wear-resistant composite pipe obtained in this embodiment is subjected to performance testing, and the following test results are obtained: the maximum wear amount at the input end of the wear-resistant composite pipe (within a length range of 0.3 m) is 0.7 mm, the maximum wear amount at the output end of the wear-resistant composite pipe (within a length range of 0.3 m) is 0.6 mm, and the maximum wear amount at the remaining positions of the wear-resistant composite pipe is 0.7 mm; therefore, compared with the wear-resistant composite pipe processed in Example 1, the wear resistance at both ends is further improved, and the wear process of the entire pipe wall is close, avoiding the too-fast wear in the end area from affecting the service life and being able to extend the replacement cycle of the wear-resistant composite pipe. Among them, the maximum wear amount at the remaining positions of the wear-resistant composite pipe in Example 1 is 0.8 mm, and the fluctuation amount formed by the maximum wear amount at the remaining positions of the wear-resistant composite pipe in Example 2 is affected by the fluctuation of the particle size and flow rate of the conveyed mortar.

[0041] The above embodiments are only preferred embodiments of the present invention. Therefore, any equivalent changes or modifications made according to the structures, features and principles described in the scope of the present invention application are included in the scope of the present invention application.

Claims

1. A wear-resistant composite pipe, characterized in that: Including: A wear-resistant main pipe, the wear-resistant main pipe includes a wear-resistant inner layer, and the wear-resistant inner layer is composed of nitrile rubber and modified ceramic particles mixed, kneaded, extruded and vulcanized according to a mass ratio of 8:2; An intermediate reinforcing layer, the intermediate reinforcing layer is a multi-layer glass fiber winding layer wound around the outer surface of the wear-resistant main pipe; A buffer layer, the buffer layer is arranged outside the intermediate reinforcing layer, the buffer layer is composed of polyurethane foam, and a steel wire mesh is arranged at the center of the polyurethane foam; A pressure-bearing layer, the pressure-bearing layer is arranged outside the buffer layer, and the pressure-bearing layer is adhesively fixed to the buffer layer.

2. The wear-resistant composite pipe according to claim 1, wherein: The wear-resistant main pipe further includes end wear-resistant layers, the end wear-resistant layers are arranged at both ends of the wear-resistant inner layer, and the end wear-resistant layers are composed of nitrile rubber, modified ceramic particles and silane-grafted thermoplastic elastomer mixed and dynamically kneaded according to a mass ratio of 5:1:4; the end wear-resistant layers and the wear-resistant inner layer are co-extruded through the same extrusion head.

3. The wear-resistant composite pipe according to claim 1, wherein: The pressure-bearing layer is a steel pipe.

4. The wear-resistant composite pipe according to claim 1, wherein: The pressure-bearing layer uses polyvinyl chloride or thermoplastic polyurethane as a base material, and an outer pipe body with a continuous spiral convex structure formed on the surface is obtained by extrusion through a rotary die.

5. A processing method for wear-resistant composite pipes, which is used to process the wear-resistant composite pipes described in claim 1, and is characterized in that, The specific processing method is as follows: First, process the wear-resistant inner layer. The preparation process of the wear-resistant inner layer is as follows: Select alumina ceramic particles with a purity ≥ 99% and a particle size of 50 - 200 μm, and perform surface modification treatment with a silane coupling agent to obtain modified ceramic particles. Then, add the modified ceramic particles and nitrile rubber to a kneading machine according to a set mass ratio, and synchronously add a vulcanization system and a plasticizer for kneading to obtain a kneaded rubber. Then, extrude the kneaded rubber through a screw extruder to form a pipe blank, and then vulcanize the pipe blank to obtain the wear-resistant inner layer; Next, process the intermediate reinforcing layer. The processing procedure of the intermediate reinforcing layer is as follows: First, pre-impregnate the glass fiber yarn with an epoxy resin emulsion for heating and pre-curing. Then, wind the treated glass fiber yarn onto the outer surface of the wear-resistant main pipe through a four-axis winding machine, winding multiple layers. After winding, heat-cure the wear-resistant inner layer and the intermediate reinforcing layer into one body; Next, process the buffer layer. The processing procedure of the buffer layer is as follows: Feed the wear-resistant main pipe and the intermediate reinforcing layer cured into one body into a foaming mold, and pre-bury a steel wire mesh in the foaming mold. Then, inject polyurethane foam into the foaming mold for foaming to obtain a core pipe; Finally, complete the processing of the wear-resistant composite pipe. Bond and cure the core pipe to the inner wall of the pressure-bearing layer to obtain a finished product of the wear-resistant composite pipe.

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

12. After the polyurethane foam is injected, it foams to form a foam structure with a closed cell rate ≥ 90%.

7. A wear-resistant main pipe processing unit for processing the wear-resistant main pipe described in claim 2, characterized in that: 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 the raw materials of the wear-resistant inner layer and a second screw extruder for extruding the raw materials of the end wear-resistant layer. The output ends of the first screw extruder and the second screw extruder are connected to the extrusion head through a heating extrusion switching pipeline.

8. The wear-resistant main pipe processing unit according to claim 7, wherein: The heating extrusion switching pipeline includes a square slide, a first input port and a first output port are provided opposite the lower part of the slide, a second input port is provided above the first input port, a cutting port is provided opposite the second input port, and a pneumatic cutting knife is provided outside the cutting port; a heating plate is slidably provided on the inner side of the slide, 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 material pipe; a lifting hydraulic cylinder connected to the heating plate is fixed on the top of the slide.

9. The wear-resistant main pipe processing unit according to claim 7, characterized in that: The heating extrusion switching pipeline includes a disc jacket, inside which a rotating disc with a heating function is rotatably installed through a driving shaft, and the rotating disc is tightly fitted to the disc jacket; a ring of material storage holes is arranged at intervals on the rotating disc; one side of the disc jacket is provided with a stamping through hole connected to the material storage hole, a third input port and a fourth input port; the other side of the rotating disc is provided with a second output port connected to the material storage hole; 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 respectively connected to the output ends of the first screw extruder and the second screw extruder; the second output port is connected to the extrusion head through a heating material pipe; a transposition motor connected to the driving shaft is fixed to the outside of the rotating disc.

10. The wear-resistant main pipe processing unit according to claim 7, wherein: 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 axial center line of the heating material pipe; a heating sleeve is arranged on the outside of the injection head.

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