Preparation method of thermal insulation integrated flexible composite pipe

Abstract

The invention discloses a preparation method of a heat-preservation integrated flexible composite pipe. The preparation method comprises the following steps: (1) plasticizing and then extruding to obtain a high-temperature pipe blank I; (2) cooling the high-temperature pipe blank I to obtain an inner pipe; (3) performing cross spiral winding on the inner pipe by using a reinforcing material to obtain the reinforced and wound inner pipe; (4) plasticizing and then extruding to obtain a high-temperature pipe blank II; meanwhile, the surface of a reinforcing material is coated with the high-temperature pipe blank II, and a pipe I is obtained; (5) cooling the surface of the pipe I by using cooling water; (6) forming a closed space between the outer surface of the pipe I and the inner surface of the forming mold for injecting and filling a foaming material; (7) cooling and shaping through heat conduction to obtain a pipe II; (8) the surface of the pipe II is coated with the high-temperature pipe blank III, and a pipe III is obtained; (9) cooling the surface of the pipe III by using cooling water; and (10) the pipe III is wound around a winding disc. A one-step method is adopted for production, and the initial ovality of a final finished product is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of flexible composite pipe preparation, and in particular to a method for preparing a thermal insulation integrated flexible composite pipe. Background Art

[0002] Flexible composite pipes (three-layer structure, inner pipe + reinforcement layer + outer pipe) are widely used in the field of oil and gas gathering and transportation due to their advantages such as long single length (up to thousands of meters), coiling, convenient construction, excellent anti-corrosion performance, and low life cycle cost. In actual use, flexible composite pipes often need to be insulated. At present, the commonly used method for prefabricating and insulating flexible composite pipes in factories is as follows: (1) The flexible composite pipe coiled on the winding reel is unwound and pulled into a mold wrapped with insulation material. After wrapping, it is coiled onto another winding reel; (2) The pipe wound in the above steps is unwound and pulled into a coating mold. A protective cover is extruded on the outside of the insulation material, and then cooled and wound. The coil diameter required for prefabricating the insulation flexible pipe by this method is relatively large, and the domestic road transportation width limit is 4.2 meters. Therefore, this method is only applicable to small-diameter pipes (DN100mm or less), which limits its scope of application.

[0003] The factors that affect the coil diameter of the insulation pipe are generally the following: 1) the initial ovality of the pipe, that is, the ovality before coiling. Under the same conditions, the smaller the initial ovality, the smaller the coil diameter; 2) the cross-sectional configuration of the insulation material. Generally, the corrugated type has a smaller bending radius than the flat type. Therefore, how to effectively reduce the bending radius and expand the prefabricated insulation diameter in the factory to more than DN100mm has become a problem that needs to be solved urgently. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing an integrated thermal insulation flexible composite pipe, which adopts a one-step production method, that is, except for the winding of the final finished product, the winding and unwinding operations of the semi-finished products are no longer performed between the other adjacent processes, thereby reducing the initial ovality of the final product and the bending radius. The prefabricated insulation diameter in the factory can be expanded to DN150mm, and the application range is wide.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solution: A method for preparing a thermal insulation integrated flexible composite pipe of the present invention, the innovation of which is that it comprises the following steps: (1) Inner tube extrusion: polymer material I is first plasticized by screw barrel I, and then extruded through extrusion die I to form high-temperature tube blank I; (2) Cooling and shaping: Use negative pressure shaping to attach the high-temperature tube blank I to the inner surface of the sizing sleeve, and use cooling water to cool the sizing sleeve and the high-temperature tube blank I, so as to obtain the inner tube with the required outer diameter; (3) Reinforced winding: The cooled and shaped inner tube is transferred to the winding unit through the traction machine I, and is cross-spirally wound with reinforcing materials to obtain a reinforced wound inner tube; (4) Extrusion of outer tube: polymer material II is first plasticized by screw barrel II, and then extruded through T-type extrusion die I to form high-temperature tube blank II; at the same time, the inner tube after reinforcement winding obtained in the above steps enters the T-type die, and the high-temperature tube blank II is coated on the surface of the reinforcement material, thereby obtaining tube material I; (5) Cooling and shaping: Use cooling water to cool the surface of the pipe material I obtained in the above step; (6) Filling the insulation layer: According to the outer diameter of the pipe I and the required thickness of the insulation layer, select an insulation forming mold of corresponding size, and then lay a layer of high-strength film on the inner hole of the forming mold, so as to form a certain closed space between the outer surface of the pipe I and the inner surface of the forming mold for injection and filling of the foaming material; (7) Shaping of the insulation layer: The inner wall of the forming mold is a corrugated metal mold, and the corrugated metal mold is cooled by a water medium or an oil medium; then the pipe material I obtained in the above step contacts the corrugated metal mold and is cooled and shaped by heat conduction, thereby obtaining the pipe material II; (8) Extrusion of outer sheath: polymer material III is first plasticized by screw barrel III, and then extruded through T-type extrusion die II to form high-temperature tube blank III; at the same time, the tube II obtained in the above steps enters the T-type die, and the high-temperature tube blank III is coated on the surface of the tube II, thereby obtaining the tube III; (9) Cooling and shaping of the outer sheath: Use cooling water to cool the surface of the pipe III obtained in the above step; (10) Coiling: After being fully cooled in the above step, pipe III is coiled onto a coiling reel through a coiling device.

[0006] Preferably, in the above step (1), the polymer material I used is HDPE, PE-RT, XLPE, PA11, PA12 or PVDF; the working temperature of the screw barrel I is 180°C~230°C; and the working temperature of the extrusion die I is 180°C~250°C.

[0007] Preferably, in the above step (3), the number of winding units is an even number, and the reinforcement materials used are polyester yarns, polyester tapes, aramid yarns, aramid tapes, steel cord yarns, steel cord tapes, glass fiber yarns, glass fiber tapes or carbon fiber tapes; and the winding angle of the cross-helical winding is 0-90°.

[0008] Preferably, in the above step (4), the polymer material II used is HDPE, PE-RT, XLPE, PA11, PA12 or PVDF; the working temperature of the screw barrel II is 180°C~230°C; the working temperature of the T-type extrusion die I is 180°C~250°C.

[0009] Preferably, in the above step (6), the inner hole size of the molding die is the outer diameter of the pipe I + 2*the required thickness of the insulation layer / foaming shrinkage rate, and the material used for the high-strength film to be laid is PE, PA, PVC or EVA; the foaming material is an easy-to-foam material.

[0010] Preferably, the foaming material is PU or XPE.

[0011] Preferably, in the above step (6), the pipe I needs to enter the forming mold before it is completely cooled, and the forming mold is a series of mutually interlocking ones.

[0012] Preferably, in the above step (6), the insulation layer is filled by continuous foaming, and in order to form a continuously filled space, the moving speed of the high-strength film needs to be consistent with the moving speed of the pipe I.

[0013] Preferably, in the above step (8), the polymer material III used is HDPE, LLDPE or LDPE; the working temperature of the screw barrel III is 180°C to 230°C; and the working temperature of the T-type extrusion die II is 180°C to 250°C.

[0014] Beneficial effects of the present invention: The present invention adopts a one-step production method, that is, except for the final product being rolled up, the semi-finished product is no longer rolled up or unrolled between other adjacent processes, thereby reducing the initial ovality of the final product and the bending radius, and the prefabricated insulation diameter in the factory can be expanded to DN150mm, with a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 The present invention is a flow chart of a method for preparing a thermal insulation integrated flexible composite pipe. DETAILED DESCRIPTION

[0017] The technical solution of the present invention will be clearly and completely described below through specific implementation methods.

[0018] A method for preparing a thermal insulation integrated flexible composite pipe according to the present invention, Figure 1 As shown, the following steps are included: (1) Inner tube extrusion: polymer material I is first plasticized by screw barrel I, and then extruded through extrusion die I to form high-temperature tube blank I.

[0019] In the above steps, the polymer material I used is HDPE, PE-RT, XLPE, PA11, PA12 or PVDF; the working temperature of the screw barrel I is 180°C~230°C; the working temperature of the extrusion mold I is 180°C~250°C.

[0020] (2) Cooling and shaping: Use negative pressure shaping to attach the high-temperature tube blank I to the inner surface of the sizing sleeve, and use cooling water to cool the sizing sleeve and the high-temperature tube blank I, so as to obtain the inner tube with the required outer diameter.

[0021] (3) Reinforced winding: The cooled and shaped inner tube is transferred to the winding unit through the traction machine I, and is cross-spirally wound with reinforcing materials to obtain a reinforced wound inner tube.

[0022] In the above steps, the number of winding units is an even number, and the reinforcement materials used are polyester yarn, polyester tape, aramid yarn, aramid tape, steel cord yarn, steel cord tape, glass fiber yarn, glass fiber tape or carbon fiber tape; the winding angle of the cross spiral winding is 0~90°.

[0023] (4) Extrusion of outer tube: polymer material II is first plasticized by screw barrel II, and then extruded through T-type extrusion die I to form high-temperature tube blank II; at the same time, the reinforced wound inner tube obtained in the above steps enters the T-type die, and the high-temperature tube blank II is coated on the surface of the reinforcement material to obtain tube material I.

[0024] In the above steps, the polymer material II used is HDPE, PE-RT, XLPE, PA11, PA12 or PVDF; the working temperature of the screw barrel II is 180°C~230°C; the working temperature of the T-type extrusion die I is 180°C~250°C.

[0025] (5) Cooling and shaping: Use cooling water to cool the surface of the pipe I obtained in the above steps.

[0026] (6) Filling the insulation layer: According to the outer diameter of pipe I and the required thickness of the insulation layer, select an insulation molding mold of corresponding size, and then lay a layer of high-strength film on the inner hole of the molding mold, so as to form a certain closed space between the outer surface of pipe I and the inner surface of the molding mold for injection and filling of the foaming material.

[0027] In the above steps, the inner hole size of the molding mold is the outer diameter of pipe I + 2*the required thickness of the insulation layer / foaming shrinkage rate, and the material used for the high-strength film to be laid is PE, PA, PVC or EVA; the foaming material is an easy-to-foam material, and PU or XPE is selected.

[0028] In the above steps, the pipe I needs to enter the forming mold before it is completely cooled, and the forming mold is a series of mutually interlocking ones.

[0029] In the above steps, the insulation layer is filled by continuous foaming, and in order to form a continuously filled space, the moving speed of the high-strength film needs to be consistent with the moving speed of the pipe I.

[0030] (7) Shaping of the insulation layer: The inner wall of the molding mold is a corrugated metal mold, and the corrugated metal mold is cooled by a water medium or an oil medium; then the pipe material I obtained in the above step is contacted with the corrugated metal mold and cooled and shaped by heat conduction, thereby obtaining the pipe material II.

[0031] (8) Extrusion of outer sheath: polymer material III is first plasticized by screw barrel III, and then extruded through T-type extrusion die II to form high-temperature tube blank III; at the same time, the tube II obtained in the above steps enters the T-type head, and the high-temperature tube blank III is coated on the surface of the tube II, thereby obtaining the tube III.

[0032] In the above steps, the polymer material III used is HDPE, LLDPE or LDPE; the working temperature of the screw barrel III is 180°C~230°C; the working temperature of the T-type extrusion die II is 180°C~250°C.

[0033] (9) Cooling and shaping of the outer sheath: Use cooling water to cool the surface of the pipe III obtained in the above steps.

[0034] (10) Coiling: After being fully cooled in the above step, pipe III is coiled onto a coiling reel through a coiling device.

[0035] Beneficial effects of the present invention: The present invention adopts a one-step production method, that is, except for the final product being rolled up, the semi-finished product is no longer rolled up or unrolled between other adjacent processes, thereby reducing the initial ovality of the final product and the bending radius, and the prefabricated insulation diameter in the factory can be expanded to DN150mm, with a wide range of applications.

[0036] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineering technicians in the field should fall within the protection scope of the present invention. The technical contents for which protection is sought in the present invention have been fully recorded in the technical requirements.

Claims

1. A method for preparing a thermal insulation integrated flexible composite pipe, characterized in that The following steps are involved: (1) Inner tube extrusion: polymer material I is first plasticized by screw barrel I, and then extruded through extrusion die I to form high-temperature tube blank I; (2) Cooling and shaping: Use negative pressure shaping to attach the high-temperature tube blank I to the inner surface of the sizing sleeve, and use cooling water to cool the sizing sleeve and the high-temperature tube blank I, so as to obtain the inner tube with the required outer diameter; (3) Reinforced winding: The cooled and shaped inner tube is transferred to the winding unit through the traction machine I, and is cross-spirally wound with reinforcing materials to obtain a reinforced wound inner tube; (4) Extrusion of outer tube: polymer material II is first plasticized by screw barrel II, and then extruded through T-type extrusion die I to form high-temperature tube blank II; at the same time, the inner tube after reinforcement winding obtained in the above steps enters the T-type die, and the high-temperature tube blank II is coated on the surface of the reinforcement material, thereby obtaining tube material I; (5) Cooling and shaping: Use cooling water to cool the surface of the pipe material I obtained in the above step; (6) Filling the insulation layer: According to the outer diameter of the pipe I and the required thickness of the insulation layer, select an insulation forming mold of corresponding size, and then lay a layer of high-strength film on the inner hole of the forming mold, so as to form a certain closed space between the outer surface of the pipe I and the inner surface of the forming mold for injection and filling of the foaming material; (7) Shaping of the insulation layer: The inner wall of the forming mold is a corrugated metal mold, and the corrugated metal mold is cooled by a water medium or an oil medium; then the pipe material I obtained in the above step contacts the corrugated metal mold and is cooled and shaped by heat conduction, thereby obtaining the pipe material II; (8) Extrusion of outer sheath: polymer material III is first plasticized by screw barrel III, and then extruded through T-type extrusion die II to form high-temperature tube blank III; at the same time, the tube II obtained in the above steps enters the T-type die, and the high-temperature tube blank III is coated on the surface of the tube II, thereby obtaining the tube III; (9) Cooling and shaping of the outer sheath: Use cooling water to cool the surface of the pipe III obtained in the above step; (10) Coiling: After being fully cooled in the above step, pipe III is coiled onto a coiling reel through a coiling device.

2. The method for preparing a thermal insulation integrated flexible composite pipe according to claim 1, characterized in that: In the above step (1), the polymer material I used is HDPE, PE-RT, XLPE, PA11, PA12 or PVDF; the working temperature of the screw barrel I is 180°C~230°C; and the working temperature of the extrusion die I is 180°C~250°C.

3. The method for preparing a thermal insulation integrated flexible composite pipe according to claim 1, characterized in that: In the above step (3), the number of winding units is an even number, and the reinforcement materials used are polyester yarn, polyester tape, aramid yarn, aramid tape, steel cord yarn, steel cord tape, glass fiber yarn, glass fiber tape or carbon fiber tape; the winding angle of the cross spiral winding is 0~90°.

4. The method for preparing a thermal insulation integrated flexible composite pipe according to claim 1, characterized in that: In the above step (4), the polymer material II used is HDPE, PE-RT, XLPE, PA11, PA12 or PVDF; the working temperature of the screw barrel II is 180°C~230°C; the working temperature of the T-type extrusion die I is 180°C~250°C.

5. The method for preparing a thermal insulation integrated flexible composite pipe according to claim 1, characterized in that: In the above step (6), the inner hole size of the molding die is the outer diameter of the pipe I + 2*the required thickness of the insulation layer / foaming shrinkage rate, and the material used for the high-strength film to be laid is PE, PA, PVC or EVA; the foaming material is an easy-to-foam material.

6. The method for preparing a thermal insulation integrated flexible composite pipe according to claim 5, characterized in that: The foaming material is PU or XPE.

7. The method for preparing a thermal insulation integrated flexible composite pipe according to claim 1, characterized in that: In the above step (6), the tube I needs to enter the forming mold before it is completely cooled, and the forming mold is a series of mutually interlocking ones.

8. The method for preparing a thermal insulation integrated flexible composite pipe according to claim 1, characterized in that: In the above step (6), the insulation layer is filled by continuous foaming, and in order to form a continuously filled space, the moving speed of the high-strength film must be consistent with the moving speed of the pipe I.

9. The method for preparing a thermal insulation integrated flexible composite pipe according to claim 1, characterized in that: In the above step (8), the polymer material III used is HDPE, LLDPE or LDPE; the working temperature of the screw barrel III is 180°C~230°C; and the working temperature of the T-type extrusion die II is 180°C~250°C.

Images