Double insulation pipe with electric wires flexible pipes that can easily install and replace heating wires and their manufacturing method

Abstract

The present invention relates to a 'double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires,' which is installed inside the double-insulated pipe to prevent freezing of the double-insulated pipe, and a method for manufacturing the same; In particular, damage to the heating wire caused by the expansion of the insulation material and heat filling between the inner and outer tubes of the double-insulated pipe is prevented, and when connecting heating wires to multiple double-insulated pipes, work convenience is ensured and overheating or disconnection of the heating wire joints is prevented, while heat supply is easy, thereby facilitating the prevention of freezing and thawing of the double-insulated pipe; A heating wire pull wire is provided on the heating wire installed inside the flexible conduit for electrical wires, which is provided on the outer surface of the inner conduit of the double-walled insulated pipe, thereby improving the heat transfer rate, and providing convenience of construction and safety of the heating wires by allowing the heating wires installed inside each unit of the flexible conduit for electrical wires to be assembled in one go without joints; The flexible conduit and inner tube for electrical wires are fixed with metal sheet tape, thereby further improving thermal conductivity, enhancing the fixing support strength of the flexible conduit and inner tube, and making the fixing work easier; Since on-site insulation work is unnecessary, construction costs and construction time are further reduced; The invention relates to a 'double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires and a method for manufacturing the same,' which has a configuration that reduces maintenance costs (operating costs) by having almost no heat loss and eliminates the need for regular replacement of insulation materials and repairs.

Description

Technology Field

[0001] The present invention relates to a 'double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires, and a method for manufacturing the same,'

[0002] More specifically, the invention relates to a ‘double-insulated pipe equipped with a flexible wire pipe that facilitates the installation and replacement of a heating wire,’ which is installed inside the double-insulated pipe to prevent freezing of the double-insulated pipe, and a method for manufacturing the same;

[0003] In particular, a flexible conduit for electrical wires is provided between the inner and outer tubes of the double-insulated pipe, so that when connecting heating wires to multiple double-insulated pipes, there are no connection points for the heating wires, thereby ensuring work convenience and preventing overheating or disconnection at the joints of the heating wires, while simultaneously facilitating heat supply and preventing damage to the heating wires caused by expansion and heat from polyol and MDI (Methylene Diphenyl Diisocyanate), which are the raw materials of the insulation material used for filling; and the facilitation of heat supply makes it easy to prevent freezing and thaw the double-insulated pipes;

[0004] A heating wire puller (jig) is provided on the heating wire installed inside the flexible conduit for wires, which is provided on the outer surface of the inner conduit, thereby improving the heat transfer rate and providing convenience in construction and safety of the heating wire, wherein the heating wires installed inside each unit of the flexible conduit for wires are connected and assembled in one go without joints;

[0005] The flexible conduit and inner tube for electrical wires are fixed with metal sheet tape, thereby further improving thermal conductivity, enhancing the fixing support strength of the flexible conduit and inner tube, and making the fixing work easier;

[0006] Since on-site insulation work is unnecessary, construction costs and construction time are further reduced;

[0007] The invention relates to a 'double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates easy installation and replacement of heating wires and a method for manufacturing the same,' which solves problems arising from heating wire connections by having a configuration without heating wire connections, reduces construction time and costs due to aging and damage of heating wires, and facilitates easy replacement and repair of heating wires. Background Technology

[0008] Generally, double-insulated pipes exposed to the outside of the inner pipe, which is a water supply pipe, are used to supply water for water supply, water pipes, and industrial water to various regions including apartment complexes, commercial buildings, industrial and residential areas through the Water Resources Corporation, water supply systems, and combined heat and power supply systems.

[0009] In addition, the double-walled insulated pipe is composed of an inner pipe including a steel pipe, copper pipe, stainless steel pipe, aluminum (AL) pipe, or synthetic resin pipe through which water flows, an outer pipe made of synthetic resin material including polyethylene (PE) or an aluminum (AL) pipe that wraps the outer surface of the inner pipe, and an insulating material filled between the inner pipe and the outer pipe.

[0010] Polyurethane is primarily used as an insulating material, and the piping lines constituting district heating or water supply systems are formed by connecting multiple double-insulated pipes.

[0011] As illustrated in FIG. 1, the double thermal insulation pipe (200) of the prior art is;

[0012] The double insulation pipe (200) comprises an inner pipe (201) which is a steel pipe, an outer pipe (202) which is a polyethylene pipe provided on the upper part of the inner pipe (201), a cylindrical heat shrink casing (203) which surrounds the outer pipe (202) of the plurality of double insulation pipes (200) composed of the inner and outer pipes (201, 202), and a heat shrink casing (203) which includes a heat shrink casing (203) filled with a heat shrink casing (203) and an insulating material which is urethane foam that insulates the inner pipe (201).

[0013] In addition, conventional piping for transporting various fluids, including the double-insulated pipe (200) of the above configuration, uses a method of winding a freeze-prevention heater around the outer circumference of the pipe and a method of embedding a heater in the pipe itself to prevent freezing.

[0014] Utility Model Registration No. 219527, which uses nichrome wire as a heating element; Utility Model Registration No. 293218, which winds fine nichrome wire onto a fiber bundle; and Utility Model Registration No. 137043, which discloses a polymer heater with self-regulating temperature, are known as anti-freeze heaters;

[0015] These are in the form of cords with a thickness of about 2 to 3 mm and a width of about 10 mm, and because they are thick, they have low flexibility, resulting in poor adhesion and workability when wound onto pipes; as a result, problems arise such as low heat transfer efficiency in which heat generated from the heating wire is transferred to the pipes, and excessive manufacturing and installation costs.

[0016] Meanwhile, regarding the electric heating insulation pipe structure of Utility Model Registration No. 367343, which is a pipe with a built-in heater to prevent freezing, the structure includes:

[0017] A technology is disclosed in which a carbon heating wire coated with carbon and silicon on the outer surface of a fiber is manufactured in a mesh form with a certain width and length together with an auxiliary wire made of fiber, and then a carbon heating element coated with an insulating material such as silicon is wound onto the outer surface of a pipe, and the outer surface is wrapped with an insulating material.

[0018] However, the above-mentioned thermal pipe is manufactured by weaving a carbon heating wire, coated with carbon and silicon on the outer surface of a fiber yarn to form a ribbon-shaped carbon heating element with a certain surface area, into a mesh of a certain width and length together with an auxiliary wire, and then coating it with an insulating material. Consequently, the manufacturing process is complex, resulting in excessive manufacturing costs and significantly reduced workability during installation.

[0019] As described above, conventional pipes for freeze protection mostly utilize a heating element made of nichrome wire or heating wire material with a circular cross-section, and thus require an insulation layer to cover it. Consequently, the pipe thickness is relatively thick, and as a result, heat transfer efficiency is reduced, leading to a decrease in thermal insulation performance. Consequently, problems arise where the double-insulated pipe freezes or bursts when the ambient temperature is below freezing;

[0020] In particular, the heating wire for preventing freezing of double-insulated pipes in the prior art is fixed to the outer surface of the inner pipe provided inside each of multiple double-insulated pipes with a band or tape, and then, when the urethane foam used as an insulating material is foamed, the heating wire is damaged due to expansion and heat caused by polyol and MDI (Methylene Diphenyl Diisocyanate), which are the raw materials of the insulating material; there is the inconvenience of the work of connecting the heating wire to each of the multiple double-insulated pipes, and the problem that the heating wire joints overheat or break due to high heat;

[0021] The problem that the insulation performance of the double-insulated pipe is also reduced because it is composed only of the inner and outer tubes, which are the tubular bodies, and the insulation material is not uniformly filled between the inner and outer tubes;

[0022] The current situation involves problems such as increased construction costs and duration due to the need for separate insulation work at the construction site, excessive manufacturing costs, significantly reduced work efficiency because it is inconvenient to install heating cables on the outside of the pipes, increased labor costs, and inconvenience of use. The problem to be solved

[0023] By means of the ‘double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires and a method for manufacturing the same’ of the present invention, the problems of the prior art are solved and:

[0024] In particular, the flexible wire tube provided on the outer surface of the inner tube is fixed with a metal sheet tape, thereby further improving thermal conductivity and further improving the fixing support strength between the flexible wire tube and the inner tube;

[0025] Between the inner and outer tubes, a thermal insulation material, which is a rigid polyurethane foam with low thermal conductivity composed of a foaming agent that is a polyol and a compounding agent that is MDI (Methylene Diphenyl Diisocyanate) in the composition and composition ratio of the present invention, is uniformly filled by centering, thereby providing even better thermal insulation;

[0026] Damage to heating wires caused by expansion and heat from polyol and MDI (Methylene Diphenyl Diisocyanate), which are raw materials for insulation, is prevented; when connecting heating wires to multiple double-walled insulated pipes, work convenience is ensured and overheating or disconnection at the wire joints is prevented; at the same time, heat supply is easy, making it easy to prevent freezing and thaw the double-walled insulated pipes;

[0027] A heating wire puller (jig) is provided on the heating wire installed inside the flexible conduit for electrical wires, which is provided on the outer surface of the inner conduit of the double-walled insulated pipe, thereby improving the heat transfer rate and providing convenience in construction and safety of the heating wires, wherein the heating wires installed inside each unit of the flexible conduit for electrical wires are assembled in one go without joints;

[0028] The flexible conduit and inner tube for electrical wires are fixed with metal sheet tape, thereby further improving thermal conductivity, enhancing the fixing support strength of the flexible conduit and inner tube, and making the fixing work easier;

[0029] Since on-site insulation work is unnecessary, construction costs and construction time are further reduced;

[0030] The objective of the present invention and the technical problem to be achieved by the present invention is to provide a 'double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires, and a method for manufacturing the same,' which has a configuration that reduces maintenance costs (operating costs) due to almost no heat loss and eliminates the need for regular replacement of insulation materials and repairs. means of solving the problem

[0031] of the composition of the present invention, 『Composed of 65 to 80 weight% high-density polyethylene and 20 to 35 weight% linear low-density polyethylene, or composed of 100 weight% high-density polyethylene, or an inner and outer surface made of polyvinyl chloride or polypropylene material;

[0032] A flexible pipe for electrical wires made of metal material, provided on the outer surface of an inner pipe, in close contact with the outer surface of the inner pipe so that heat is directly transferred to the outer surface of the inner pipe;

[0033] A heating wire, which is a wire equipped with a heating wire pull wire on one side for the movement of +, - power and heating wires, provided inside a flexible conduit for electrical wires, and

[0034] A metal sheet tape made of a metal material including aluminum, provided on the outer surface of a flexible conduit for electrical wires and an inner conduit;

[0035] A plurality of centerings made of polyethylene or polyvinyl chloride material, provided on the inner tube and the outer and outer sides of the flexible tube for electrical wires, such that the spacing between the inner and outer tubes and the flexible tube for electrical wires is maintained at a constant level and insulation material is uniformly filled between the inner and outer tubes;

[0036] A thermal insulation material comprising a rigid polyurethane foam with low thermal conductivity of 0.182 W / Mk to 0.0256 W / Mk, composed of 30 to 65 parts by weight of a foaming agent, which is a polyol containing 8 to 25 weight% of a foaming catalyst Dichloro-1-fluoroethane or HFO, injected and filled between the inner and outer layers, and 35 to 70 parts by weight of a compounding agent, which is MDI (Methylene Diphenyl Diisocyanate). 』 Composed of;

[0037] In addition, the + and - power of the heating wire is connected to a temperature control device for power supply and temperature control of the heating wire installed on the outside of the double-insulated pipe of the present invention, so that power is supplied to or cut off to the heating wire; 'a double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of the heating wire' and;

[0038] of the composition of the present invention,『 S1 Step: A step in which the inner and outer tubes of the double-insulated pipe body and the flexible pipe for electrical wires are manufactured; and,

[0039] S2 Step: A step in which a flexible conduit for electrical wires is installed on the outer surface of the inner tube, which is a double-insulated pipe body, and a metal sheet tape is bonded; and,

[0040] S3 Step: A step in which a heating wire is installed inside a flexible conduit for electrical wires; and,

[0041] S4 Step: A step in which centering is installed on the exterior and interior of the outer casing of the inner conduit and the flexible conduit for wires; and,

[0042] S5 Step: A step in which an insulating material, such as a rigid polyurethane foam with a low thermal conductivity of 0.182 W / Mk to 0.0256 W / Mk, is injected and filled between the inner and outer tubes; 』 The above problem is to be solved by the ‘installation method of a double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires’ manufactured by the present invention. Effects of the invention

[0043] By means of the ‘double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires and a method for manufacturing the same’ of the present invention, the problems of the prior art are solved and:

[0044] In particular, the flexible wire tube provided on the outer surface of the inner tube is fixed with a metal sheet tape, thereby further improving thermal conductivity and further improving the fixing support strength between the flexible wire tube and the inner tube;

[0045] A thermal insulation material, which is a rigid polyurethane foam with low thermal conductivity composed of a foaming agent that is a polyol and a compounding agent that is MDI (Methylene Diphenyl Diisocyanate) in the composition and composition ratio of the present invention, is uniformly filled by centering between the inner and outer tubes, thereby providing the effect of having even better thermal insulation;

[0046] Damage to heating wires caused by expansion and heat from polyol and MDI (Methylene Diphenyl Diisocyanate), which are raw materials for insulation, is prevented; when connecting heating wires to multiple double-insulated pipes, work convenience is ensured and overheating or disconnection of the wire joints is prevented; at the same time, heat supply is easy, providing the effect of preventing freezing and facilitating thawing of the double-insulated pipes;

[0047] A heating wire puller (jig) is provided on the heating wire installed inside the flexible conduit for electrical wires, which is provided on the outer surface of the inner conduit of a double-walled insulated pipe, thereby improving the heat transfer rate and providing the effect of construction convenience and safety of the heating wires, wherein the heating wires installed inside the unit flexible conduit for electrical wires are assembled in one go without joints;

[0048] By means of a metal sheet tape provided on the outer surface of the flexible tube for wires and the inner tube, the heat transferred to the flexible tube for wires (30) by the heat generated by the heating wire is further improved when transferred to the inner tube, the fixing strength of the flexible tube for wires and the inner tube is strengthened, and the fixing work is made easier;

[0049] The effect of further reducing construction costs and construction period by eliminating the need for on-site insulation work;

[0050] This is a very useful invention that reduces maintenance costs (operating costs) due to almost no heat loss and eliminates the need for regular replacement of insulation materials and repairs. Brief explanation of the drawing

[0051] FIG. 1 is a cross-sectional view of a conventional double-walled pipe. FIGS. 2 and FIGS. 3 are reference cross-sectional views of the double thermal insulation pipe of the present invention. FIGS. 4 and FIGS. 5 are photographs of the double-insulated pipe of the present invention. FIG. 6 is a schematic diagram illustrating the method of manufacturing a double-insulated pipe of the present invention in steps. FIGS. 7 and FIGS. 8 are accredited institution test reports of the double-insulated pipe of the present invention. Specific details for implementing the invention

[0052] Hereinafter, the "double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires and a method for manufacturing the same" of the present invention will be described in detail with reference to the attached drawings;

[0053] In addition, the "double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates easy installation and replacement of heating wires and a method for manufacturing the same" constituting the present invention The corresponding component is;

[0054] As clearly stated in the embodiments of the present invention and the test results of the test report from the accredited institution, the Korea Construction & Living Environment Testing Institute (KCL) (see FIG. 7 and FIG. 8):,

[0055] 『 Solving the problems of the prior art and,

[0056] In particular, between the inner and outer tubes, a thermal insulation material, which is a rigid polyurethane foam with low thermal conductivity composed of a foaming agent which is a polyol and a compounding agent which is MDI (Methylene Diphenyl Diisocyanate) in the composition and composition ratio of the present invention, is uniformly filled by centering, thereby providing even better thermal insulation;

[0057] Damage to heating wires caused by expansion and heat from polyol and MDI (Methylene Diphenyl Diisocyanate), which are raw materials for insulation, is prevented; when connecting heating wires to multiple double-walled insulated pipes, work convenience is ensured and overheating or disconnection at the wire joints is prevented; at the same time, heat supply is easy, making it easy to prevent freezing and thaw the double-walled insulated pipes;

[0058] A heating wire puller (jig) is provided on the heating wire installed inside the flexible conduit for electrical wires, which is provided on the outer surface of the inner conduit of the double-walled insulated pipe, thereby improving the heat transfer rate and providing convenience in construction and safety of the heating wires, wherein the heating wires installed inside each unit of the flexible conduit for electrical wires are assembled in one go without joints;

[0059] A flexible wire tube provided on the outer surface of the inner tube is fixed with a metal sheet tape, thereby further improving thermal conductivity, enhancing the fixing support strength between the flexible wire tube and the inner tube, and making the fixing work easier;

[0060] Since on-site insulation work is unnecessary, construction costs and construction time are further reduced;

[0061] It is clarified that it consists of a "double-insulated pipe equipped with a flexible conduit for electrical wires that facilitates the installation and replacement of heating wires, and a method for manufacturing the same," having an appropriate configuration that reduces maintenance costs (operating costs) as there is almost no heat loss and eliminates the need for regular replacement and repair of insulation materials;

[0062] Furthermore, the numerical values ​​mentioned in the "Double insulation pipe equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires and a method for manufacturing the same" of the present invention are not merely limited to numerical values, but are composed of the appropriate corresponding components and numerical values ​​possessing the aforementioned inventive step, which were determined by the applicant through considerable time and effort;

[0063] The embodiments mentioned below are preferred examples, and the present invention is not limited by these examples, but consists of ' " Double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates easy installation and replacement of heating wires, and a method for manufacturing the same " It is clarified that is included in these rights.

[0064] FIGS. 2 and FIGS. 3 are reference cross-sectional views of the double thermal insulation pipe of the present invention, and

[0065] FIGS. 4 and 5 are photographs of the double-insulated pipe of the present invention,

[0066] FIG. 6 is a schematic diagram illustrating the method of manufacturing a double-insulated pipe of the present invention in steps, and

[0067] Figures 7 and 8 are accredited test reports of the double-walled pipe of the present invention.

[0068] As illustrated in FIGS. 2 and FIGS. 3; ( Refer to the photos of the product in Figs. 4 and 5. )

[0069] For preventing freezing and thawing of double-insulated pipes, the present invention The ‘double-insulated pipe (100)’ equipped with a flexible pipe for electrical wires that allows for easy installation and replacement of heating wires is;

[0070] An inner and outer casing (10, 20) composed of 65 to 80 weight% high-density polyethylene and 20 to 35 weight% linear low-density polyethylene, or composed of 100 weight% high-density polyethylene, or made of polyvinyl chloride or polypropylene material;

[0071] A flexible pipe (30) for wires made of metal material, provided on the outer surface of the inner pipe (10), in which the pipe body is in close contact with the outer surface of the inner pipe (10) and heat is directly transferred to the outer surface of the inner pipe (10);

[0072] A heating wire (40) which is a wire having a heating wire pulling wire (41) provided on one side of the heating wire (40) for moving +, - power and heating wire, provided inside the above-mentioned flexible conduit (30) for electrical wires, and

[0073] A metal sheet tape (50) made of a metal material including aluminum, provided on the outer surface of the above-mentioned flexible tube (30) for wires and inner tube (10);

[0074] A plurality of centerings (60) made of polyethylene or polyvinyl chloride material, provided inside the inner tube (10) and the outer and outer tubes (20) of the flexible tube (30) for wires, such that the spacing between the inner and outer tubes (10, 20) and the flexible tube (30) for wires is maintained at a constant level and the insulation material (70) is uniformly filled between the inner and outer tubes (10, 20);

[0075] It is composed of a thermal insulation material (70) which is a rigid polyurethane foam with a low thermal conductivity of 0.182 W / Mk to 0.0256 W / Mk, comprising 30 to 65 parts by weight of a foaming agent which is a polyol containing 8 to 25 weight% of a foaming catalyst Dichloro-1-fluoroethane or HFO, and 35 to 70 parts by weight of a compounding agent which is MDI (Methylene Diphenyl Diisocyanate), which is injected and filled between the inner and outer tubes (10, 20).

[0076] In addition, the + and - power of the heating wire (40) is connected to a temperature control device (80) for power supply and temperature control of the heating wire installed outside the double insulation tube (100) of the present invention, so that power is supplied to or cut off to the heating wire.

[0077] As illustrated in FIGS. 4 and FIGS. 5;

[0078] The inner and outer tubes (10, 20) of the above double-walled pipe body are;

[0079] It is composed of an inner and outer tube (10, 20) which is a synthetic resin tube made of polyvinyl chloride or polypropylene, composed of 65 to 80 weight% high-density polyethylene and 20 to 35 weight% linear low-density polyethylene, or composed of 100 weight% high-density polyethylene.

[0080] Also, as needed,

[0081] The inner and outer tubes (10, 20) may be composed of metal materials including steel tubes, copper tubes, stainless steel tubes, or aluminum tubes.

[0083] Accordingly, when heat generated from a heating wire (40) installed in a flexible pipe (30) for electrical wires provided on the outer surface of an inner pipe (10) is transferred to an inner pipe (10) made of synthetic resin or metal material, the heat transfer is further enhanced;

[0084] When composed of inner and outer tubes made of polyethylene synthetic resin, the inner and outer tubes (10, 20) are composed of a composition in which the inherent properties of high-density polyethylene or composite polyethylene resin are maintained, and durability, thermal stability, and processability are further improved.

[0085] The above flexible pipe (30) for the wire is;

[0086] A flexible pipe (30) for wires made of a metal material including aluminum, provided on the outer surface of an inner pipe (10),

[0087] A heating wire is provided inside the body of the flexible pipe (30) for wires, and heat generated from the heating wire is transferred to the body of the flexible pipe (30) for wires, and the body of the flexible pipe (30) for wires is in close contact with the outer surface of the inner pipe (10), thereby directly transferring heat to the outer surface of the inner pipe (10), so that the heat transfer rate is improved, and the flexible pipe (30) for wires is configured such that the heating wire is provided inside the body of the flexible pipe (30) for wires.

[0088] In addition, the heating wire (40) is configured with the convenience of assembly in one go without joints inside the body of the flexible pipe (30) for wires, and the heating wire (40) is prevented from overheating, damage, or disconnection.

[0089] The above heating wire (40) is;

[0090] A heating wire (40) consisting of a wire composed of + and - power sources, provided inside the above-mentioned flexible conduit (30) for electrical wires, and a heating wire (40) having a heating wire pulling wire (jig: 41) made of polyethylene material provided on one side of the heating wire (40) for moving the heating wire;

[0091] It is provided inside the body of the flexible pipe (30) for the wire, so that heat generated from the heating wire is transferred to the body of the flexible pipe (30) for the wire, and damage or disconnection of the heating wire (40) is prevented by the body of the flexible pipe (30) for the wire.

[0092] A heating wire (40) is configured such that a heating wire pulling wire (fix: 41)) is provided on one side of the heating wire (40), allowing for movement of distance by means of the heating wire pulling wire (41). By moving to a length equal to the length of the flexible pipe (30) for the wire in each unit, the heating wire (40) is assembled in one go without joints inside the flexible pipe for the wire, thereby providing convenience in the work and preventing overheating or disconnection of the heating wire (40), while also facilitating heat supply so that freezing of the double insulation pipe (100) is prevented.

[0093] In addition, the heating wire (40) is connected to a temperature control device (80) for power supply and temperature control of the heating wire (40) provided on the outside of the double-walled insulation tube (100) of the present invention, and is configured as a heating wire (40) to which power is supplied or power is cut off.

[0094] The above metal sheet tape (50) is;

[0095] With a metal sheet tape (50), which is a metal sheet containing aluminum, provided on the outer surface of the flexible pipe (30) for wires and the inner pipe (10);

[0096] It is composed of a metal sheet tape (50) made of a metal material including aluminum, such that when heat transferred to the flexible pipe (30) by the heat generated by the heating wire (40) provided inside the flexible pipe (30) is transferred to the inner pipe (10), the thermal conductivity is further improved by the metal sheet containing aluminum, the fixing strength of the flexible pipe (30) and the inner pipe (10) is strengthened, and the fixing work of the flexible pipe (30) and the inner pipe (10) is made easier.

[0097] The above centering (60) is;

[0098] With a plurality of centerings (60) made of polyethylene (PE) or polyvinyl chloride (PVC) resin material, provided inside the inner tube (10) and the outer and outer tubes (20) of the flexible tube (30) for wires, such that the spacing between the inner and outer tubes (10, 20) and the flexible tube (30) for wires is maintained at a constant level and the insulation material (70) is uniformly filled between the inner and outer tubes (10, 20);

[0099] A cylindrical body (61) inserted into the outside of the inner tube (10) and the flexible tube (30) for wires, and a first support member (62) fastened to the outer surface of the inner tube (10) and the flexible tube (30) for wires inside the cylindrical body (61) to prevent movement of the inner tube (10) and the flexible tube (30) for wires and to maintain a constant gap are provided.

[0100] It is composed of a centering member (60) having a second support member (63) that is fastened to the inner surface of the outer surface (20) on the outside of the cylindrical body (61) to prevent movement of the inner and outer tubes (10, 20) and the flexible tube (30) for wires and to maintain a constant gap. (See FIG. 4)

[0101] Accordingly, the spacing between the inner and outer tubes (10, 20) of the double-insulated pipe body is maintained at a constant level, and the insulating material (70) is uniformly filled between the inner and outer tubes (10, 20), thereby further enhancing the thermal insulation (insulation) performance and durability performance of the double-insulated pipe (100) of the present invention, making the filling work of the insulating material (70) easier, and preventing movement of the inner and outer tubes (10, 20) and the flexible pipe (30) for wires, thereby improving installation workability, is configured with a centering (60)), and preferably, a plurality of centerings are installed at intervals of 600 to 1200 mm inside the double-insulated pipe (100) of the present invention.

[0102] The above thermal insulation material (70) is;

[0103] By centering (60) of the present invention, the spacing between the inner and outer tubes (10, 20), which are double-walled pipe bodies, is maintained at a constant level, and the space between the inner and outer tubes (11, 12) is filled with injection.

[0104] The thermal insulation material (70) is composed of a rigid polyurethane foam with a low thermal conductivity of 0.182 W / Mk to 0.0256 W / Mk, which is composed of 30 to 65 parts by weight of a foaming agent that is a polyol containing 8 to 25 parts by weight of Dichloro-1-fluoroethane or HFO, which is an eco-friendly foaming catalyst, and 35 to 70 parts by weight of a compounding agent that is MDI (Methylene Diphenyl Diisocyanate);

[0105] Insulating material (70) is uniformly filled between the inner and outer pipes (10, 20), and the thermal insulation performance of the double insulating pipe (100) of the present invention is enhanced, workability is significantly improved, and it is environmentally friendly.

[0106] Sealing caps are sealed at both ends of the inner and outer tubes (10, 20) with cylinders, and an insulating material (70) is injected and filled between the inner and outer tubes (10, 20).

[0107] The insulation material is composed of an insulation material (70) that has the lowest thermal conductivity among existing insulation materials, specifically a rigid polyurethane foam insulation material with a thermal conductivity of 0.0182W / Mk to 0.0256W / Mk, and has superior thermal insulation properties (temperature drop of less than 1℃ when transporting 120℃ hot water for 40km).

[0108] The above power supply temperature control device (80) is;

[0109] A power supply temperature control device (80) installed on the outside of the double thermal insulation tube (100) of the present invention, connected to the + and - power sources of the heating wire (40) for power supply and temperature control of the heating wire;

[0110] It is composed of an automatic control switch (81) that turns the power on and off manually or automatically according to the user's set temperature, and an on / off switch (82, 83);

[0111] The heating element (40) is connected to a manual and automatic control switch (81), and the heating element is turned on and off manually or automatically according to the user's set temperature, and the power supply temperature control device (80) is configured.

[0112] Accordingly, the ‘double-insulated pipe (100) equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires’ of the present invention solves the problems of the prior art and:

[0113] In particular, a flexible pipe (30) for wires is fixed to the outer surface of an inner pipe (10) with a metal sheet tape (50) which is a metal sheet containing aluminum, thereby further improving thermal conductivity and further improving the fixing support strength of the flexible pipe (30) for wires and the inner pipe (10);

[0114] Between the inner tube (10) and the outer tube (20), a thermal insulation material (70) is uniformly filled, which is a rigid polyurethane foam with a low thermal conductivity of 0.182 W / Mk to 0.0256 W / Mk, composed of 30 to 65 parts by weight of a foaming agent which is a polyol containing 8 to 25 weight% of Dichloro-1-fluoroethane or HFO, an eco-friendly foaming catalyst, and 35 to 70 parts by weight of a compounding agent which is MDI (Methylene Diphenyl Diisocyanate), so that the thermal insulation is even better, and

[0115] A technical configuration that prevents damage to the heating wire caused by expansion and heat from polyol and MDI (Methylene Diphenyl Diisocyanate), which are raw materials for the insulation material (70) filled between the inner tube (10) and the outer tube (20) of the double insulation pipe (100), and at the same time, facilitates the convenience of work and prevents overheating or disconnection of the heating wire when connecting heating wires (40) to multiple double insulation pipes (100), and facilitates heat supply, thereby preventing freezing and facilitating thawing of the double insulation pipe (100);

[0117] A heating wire pulling wire (jig; 41) is provided on the outer surface of the inner tube (10) of the double-walled insulation tube and on the heating wire (40) installed inside the flexible tube for wires, thereby further enhancing the heat transfer rate and providing a technical configuration that offers convenience of construction and safety of the heating wire, wherein the heating wire (40) installed inside the flexible tube (30) for wires in each unit is assembled at once without joints;

[0118] A technical configuration in which, by means of a metal sheet tape (50) which is a metal sheet containing aluminum of the present invention, the heat transferred to the flexible pipe (30) for a wire by the heating wire (40) provided inside the flexible pipe (30) for a wire is further improved when transferred to the inner pipe (10), the fixing strength of the flexible pipe (30) for a wire and the inner pipe (10) is strengthened, and the fixing work of the flexible pipe (30) for a wire and the inner pipe (10) is made easier;

[0119] A technical configuration that further reduces construction costs and construction time by eliminating the need for on-site insulation work;

[0120] A technical configuration that reduces maintenance (operating) costs due to minimal heat loss and eliminates the need for regular insulation replacement and repairs;

[0121] By centering (60) of the present invention, the inner and outer tubes (10, 20) which are double-insulated pipe bodies and the flexible pipe (30) for wires are prevented from moving and the spacing is maintained at a constant level, so that an insulating material (70) which is an insulating material is uniformly filled between the inner and outer tubes (10, 20), thereby further strengthening the thermal insulation performance and durability performance of the double-insulated pipe (100) of the present invention, making the filling work of the insulating material (70) easier, and preventing movement of the inner and outer tubes (10, 20) and the flexible pipe (30) for wires, thereby improving installation workability; the invention is configured as a ‘double-insulated pipe (100) equipped with a flexible pipe for wires that facilitates easy installation and replacement of heating wires.’

[0122] Also, as needed;

[0123] When configured as a double-insulated pipe with multiple configurations for extending the length of the double-insulated pipe: the joints of the inner pipe (10), the outer pipe (20), and the flexible pipe (30) for the wire may be welded or connected by a fitting, and the 'double-insulated pipe (100) equipped with a flexible pipe for the wire that facilitates easy installation and replacement of the heating wire' may be configured;

[0124] The joint of the multiple inner tubes (10) or outer tubes (20) may be composed of inner and outer tubes (10, 20) having an 'L'-shaped flared surface;

[0125] It may also be composed of a ‘double-insulated pipe (100) equipped with a flexible pipe for electrical wires that facilitates installation and replacement of heating wires,’ which is composed of an inner and outer pipe (10, 20) that is a double-insulated pipe body with the above-mentioned centering (60) excluded, a flexible pipe (30) for electrical wires, a heating wire (40), a metal sheet tape (50), and an insulating material (70).

[0126] Hereinafter, the ‘method for manufacturing a double-insulated pipe (100) equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires’ of the present invention will be explained.

[0127] As shown in FIG. 6;

[0128] The present invention, which prevents freezing of a double-insulated pipe and prevents damage, overheating, and disconnection of a freezing prevention heating wire installed inside the double-insulated pipe, and improves workability The ‘method for manufacturing a double-insulated pipe (100) equipped with a flexible pipe for electrical wires that facilitates easy installation and replacement of heating wires’ is;

[0129] It consists of the following steps S1 to S6. Product composition diagram and installation state diagram: Refer to FIGS. 2 to 5 )

[0130] S1 Step: A step in which the inner and outer tubes of the double-insulated pipe body and the flexible pipe for electrical wires are manufactured;

[0131] The above S1 step is,

[0132] A step of manufacturing an inner tube (10) made of one type of material selected from a synthetic resin tube made of polyethylene or polyvinyl chloride resin, a steel tube, a copper tube, a stainless steel tube, or an aluminum (AL) tube, which is a double-insulated pipe body, an outer tube (20) made of one type of material selected from a synthetic resin tube made of polyethylene or polypropylene resin, a steel tube, a copper tube, a stainless steel tube, or an aluminum (AL) tube, and a flexible pipe (30) for electrical wires made of metal material;

[0133] When the inner and outer tubes (10, 20) of the double-insulated pipe body are manufactured as synthetic resin pipes made of polyethylene,

[0134] It is composed of an inner and outer casing (10, 20) composed of 100% by weight of high-density polyethylene, or 65 to 80% by weight of high-density polyethylene (HDPE) and 20 to 35% by weight of linear low-density polyethylene (LLDPE).

[0135] S2 Step: Install a flexible conduit for electrical wires on the outer surface of the inner tube, which is the double-insulated pipe body, and a metal sheet Step of bonding the tape;

[0136] The above S2 step is,

[0137] A step in which the heat conductivity transmitted from the heating wire (40) installed inside the flexible pipe (30) is further improved by the metal sheet tape (50) bonded to the outer surface of the inner pipe (10) and the flexible pipe (30) for wires, and the fixing support force of the flexible pipe (30) and the inner pipe (10) is strengthened;

[0138] It is manufactured in the step of installing a flexible pipe (30) for wires in close contact with the outer surface of the inner pipe (10), and bonding a metal sheet tape (50) to the outer surface of the inner pipe (10) and the flexible pipe (30) for wires.

[0139] S3 Step: Step in which a heating wire is installed inside the flexible conduit for electrical wires;

[0140] The above S3 step is,

[0141] The metal sheet tape (50) of step S2 is bonded Heating wire inside the flexible conduit for electrical wires As a step in which this is installed;

[0142] It is manufactured in the step of installing a heating wire (40), which is a wire composed of + and - power sources, inside a flexible tube (30) for electrical wires, and a heating wire pulling wire (jig: 41) made of polyethylene material on one side of the heating wire (40) for moving the heating wire.

[0143] S4 Step: A step in which centering is installed on the exterior and interior of the inner tube and the flexible tube for wires;

[0144] The above S4 step is,

[0145] The invention is manufactured in the step of installing a plurality of centerings (60) made of polyethylene or polyvinyl chloride resin material, in which the spacing between the inner and outer pipes (10, 20) and the flexible pipe (30) for wires is maintained at a constant level and an insulating material (70) is uniformly filled between the inner and outer pipes (10, 20), and preferably, a plurality of centerings are installed at intervals of 600 to 1200 mm inside the double insulating pipe (100) of the present invention.

[0146] S5 Step: A step in which an insulating material, such as a rigid polyurethane foam with a low thermal conductivity of 0.182 W / Mk to 0.0256 W / Mk, is injected and filled between the inner and outer tubes;

[0147] The above S5 step is,

[0148] A step in which a thermal insulation material (70), which is a rigid polyurethane foam with a low thermal conductivity of 0.182 W / Mk to 0.0256 W / Mk, is filled between the inner and outer surfaces (10, 20) where the centering of the S4 step is installed. The thermal insulation material (70) is composed of 30 to 65 parts by weight of a foaming agent which is a polyol containing 8 to 25 weight% of Dichloro-1-fluoroethane or HFO, which is an eco-friendly foaming catalyst, and 35 to 70 parts by weight of a compounding agent which is MDI (Methylene Diphenyl Diisocyanate).

[0149] A double-walled insulation pipe (100) equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires according to the present invention is manufactured.

[0150] In addition, the double-insulated pipe (100) of the present invention, which is equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires and manufactured in steps S1 to S5 above, is configured by a manufacturing method in which power is supplied to or cut off to the heating wire (40) in step S6 below.

[0151] S6 Step: A step in which a heating wire installed inside a flexible conduit for electrical wires is connected to a temperature control device for power supply, thereby supplying or cutting off power;

[0152] A heating wire (40) installed inside a flexible conduit (30) for electrical wires is connected to an automatic control switch (81) of a power supply temperature control device (80) composed of an automatic control switch (81) that turns power on and off manually or automatically according to the user's set temperature, and an ON / OFF switch (82, 83), thereby supplying or cutting off power to the heating wire (40) manually or automatically according to the user's set temperature.

[0153] Accordingly, the "method for manufacturing a double-insulated pipe (100) equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires" of the present invention is as follows:

[0154] In particular, a manufacturing method in which, through steps S1 and S2, the inner tube (10) and the flexible tube (30) for wires are fixed with a metal sheet tape (50) which is a metal sheet containing aluminum, thereby further improving the thermal conductivity, improving the fixing support strength of the inner tube (10) and the flexible tube (30) for wires, and making the fixing work of the inner tube (10) and the flexible tube (30) for wires easier;

[0155] A manufacturing method in which, by step S3, a heating wire pulling wire (jig; 41) is provided on the heating wire (40) installed inside the flexible pipe (30) for wires provided on the outer surface of the inner pipe (10) of the double-walled pipe, thereby enhancing the heat transfer rate and providing convenience of construction and safety of the heating wire by allowing the heating wire (40) installed inside the flexible pipe (30) for wires to be assembled at once without joints;

[0156] A manufacturing method in which, by the centering (60) of the present invention in step S4, the inner and outer tubes (10, 20) which are double-insulated pipe bodies and the flexible pipe (30) for wires are kept constant and the gap between them is maintained so that an insulating material (70) which is an insulating material is uniformly filled between the inner and outer tubes (10, 20), thereby further enhancing the thermal insulation performance and durability performance of the double-insulated pipe (100) of the present invention, making the filling work of the insulating material (70) easier, and preventing movement of the inner and outer tubes (10, 20) and the flexible pipe (30) for wires, thereby further improving installation workability;

[0157] A manufacturing method having even better thermal insulation, wherein, by step S5, a thermal insulation material (70) is a rigid polyurethane foam with a low thermal conductivity of 0.182 W / Mk to 0.0256 W / Mk, composed of 30 to 65 parts by weight of a foaming agent which is a polyol containing 8 to 25 weight% of Dichloro-1-fluoroethane or HFO, an eco-friendly foaming catalyst, and 35 to 70 parts by weight of a compounding agent which is MDI (Methylene Diphenyl Diisocyanate), and is uniformly filled between an inner tube (10) and an outer tube (20).

[0158] A manufacturing method in which damage to the heating wire is prevented due to expansion and heat caused by polyol and MDI (Methylene Diphenyl Diisocyanate), which are raw materials for the insulation material (70) filled between the inner tube (10) and the outer tube (20) of the double insulation pipe (100), and when connecting heating wires (40) to multiple double insulation pipes (100), the convenience of work and prevention of overheating or disconnection of the heating wires are achieved, while heat supply is easy, thereby facilitating the prevention of freezing and thawing of the double insulation pipe (100);

[0159] The method of manufacturing a 'double insulation pipe (100) equipped with a flexible pipe for electrical wires that facilitates easy installation and replacement of heating wires' comprises steps S1 to S5, wherein on-site insulation work is unnecessary, thereby further shortening construction costs and construction periods, and there is almost no heat loss, thereby reducing maintenance costs (operating costs), and eliminating the need for regular replacement and repair of insulation materials.

[0160] As needed,

[0161] When manufacturing a double-insulated pipe with multiple configurations for extending the length of the double-insulated pipe: the joints of the inner pipe (10) and outer pipe (20) of the above S1 step and the flexible pipe (30) for wires may be welded, or the joints may be connected by a fitting;

[0162] Additionally, the joint of the inner tube (10) or outer tube (20) of the above S1 step may be manufactured as an inner or outer tube (10, 20) having an 'L'-shaped flared surface;

[0163] The centering (60) of the above S4 step may be manufactured with an inner and outer tube (10, 20) which is a double-walled pipe body, a flexible pipe (30) for wires, a heating wire (40), a metal sheet tape (50), and an insulating material (70), in a configuration where the centering (60) of the above S4 step is not installed.

[0164] As shown in the test results of the test report from the Korea Construction & Living Environment Testing Institute (KCL), an accredited institution in Figs. 7 and 8;

[0165] The ‘double-insulated pipe (100) equipped with a flexible pipe for electrical wires that facilitates easy installation and replacement of heating wires and a method for manufacturing the same’ of the present invention will be explained in more detail with reference to specific embodiments.

[0166] An example comprises a plurality of inner tubes with welded joints of composite polyethylene tubes composed of 68% by weight of high-density polyethylene with an outer diameter of 200 mm and 32% by weight of linear low-density polyethylene, a flexible wire tube made of aluminum metal with an outer diameter of 70 mm installed in close contact with the outside of the inner tubes, and an aluminum metal sheet tape adhered to the outer surfaces of the inner tubes and the flexible wire tubes;

[0167] A plurality of centering rings made of polyethylene material are installed on the exterior of the inner tube and the flexible tube for wires, maintaining a gap between the inner tube and the outer tube, and a plurality of outer tubes made of high-density polyethylene resin, each having a joint with an outer diameter of 300 mm welded to the exterior of the inner tube and the flexible tube for wires with the centering rings installed, after which,

[0168] After sealing the inner and outer tubes with cylinders at both ends, a thermal insulation composition consisting of 42 parts by weight of a polyol containing 15% by weight of the foaming catalyst Dichloro-1-fluoroethane in a rigid polyurethane resin and 58 parts by weight of the compounding agent Methylene Diphenyl Diisocyanate, which is a rigid polyurethane foam with a thermal conductivity of 0.187 W / Mk, is injected between the inner and outer tubes through the sealing caps and the foamed rigid polyurethane foam is filled.

[0169] A heating wire composed of a + and - power supply unit for a polyethylene heating wire provided inside the above-mentioned flexible conduit for wires, and a heating wire puller wire formed on one side for the movement of the heating wire, is inserted, and by pulling the heating wire puller wire, the heating wire moves to the other side of a plurality of flexible conduits for wires, so that the heating wire moves to a length equal to the length of the plurality of flexible conduits for wires,

[0170] The power connection part of the heating wire is connected to the manual and automatic control switch (81) of the temperature control device for power supply, and + and - power is supplied to the power connection part of the heating wire so that heat is generated in the heating wire. ;The present invention manufactured a double-insulated pipe equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of heating wires.

[0171] Test methods and physical property results;

[0172] a. Density, absorption rate:

[0173] It was measured using the test method of EN 253, and the results are listed in Table 1.

[0174] B. Flexural Test:

[0175] Measurements were taken using the test method of KSM ISO 1209-2, and the results are listed in Table 1.

[0176] All 10% compressive strength:

[0177] Measurements were taken using the test method of KSM ISO 844, and the results are listed in Table 1.

[0178] D. Adhesion test (inner, outer):

[0179] Measurements were taken using the test method of KSM ISO 1922, and the results are listed in Table 1.

[0180] E. Independent bubble ratio:

[0181] Measurements were taken using the test method of the Hannan Standard (Specifications for Heat Transport Equipment), and the results are listed in Table 1.

[0182] B. Thermal conductivity:

[0183] Measurements were taken using the test method of KSL 9016, and the results are listed in Table 1.

[0184] G. Shear strength:

[0185] Measurements were taken using the test method of KSM ISO 1922, and the results are listed in Table 1.

[0186] Test items unit Standard value Test results density ㎏ / ㎥ 60 or more 80 / Pass absorption rate % 10% or less 1.6 / Passed Flexural strength kPa 300 or more 1,171 / Passed 10% compressive strength kPa 300 or more 756 / Passed Adhesion test (internal) kPa 200 or more 362 / Passed Adhesion test (appearance) kPa 100 or more 446 / Passed Independent bubble rate % 88 or higher 93 / Passed Thermal conductivity W / mK 0.0256 or less 0.0218 / Passed Shear strength kPa 200 or more 568 / Passed

[0187] As shown in Table 1 above, an embodiment of the present invention is;

[0188] In particular, it was found that durability has been further enhanced, as flexural strength, 10% compressive strength, adhesion, and shear strength were significantly superior compared to the insulation material standards (Standard: Korea District Heating Corporation insulation material standards).

[0189] It was found that the density, water absorption rate, closed-cell ratio, and thermal conductivity were significantly superior to the insulation material standards, proving that the thermal insulation performance has been further enhanced. (Standard: Korea District Heating Corporation insulation material standards)

[0190] A. Product Composition and Workability: (Judgmented by product composition and manufacturing method)

[0191] In addition, by means of an article configuration and manufacturing method in which a flexible conduit for electrical wires is installed in close contact with the outer surface of an inner tube and a heating wire is installed inside the flexible conduit for electrical wires;

[0192] At the same time, the problems of damage to heating wires caused by expansion and heat from polyol and MDI, which are the raw materials of the insulation material of the conventional technology, the inconvenience of connecting heating wires to each of multiple double-insulated pipes, and overheating or disconnection of the heating wire joints are resolved,

[0193] In particular, the flexible conduit for electrical wires is fixed to the outer surface of the inner conduit with a metal sheet tape, which is an aluminum metal sheet, thereby further improving thermal conductivity and further improving the fixing support strength between the flexible conduit for electrical wires and the inner conduit;

[0194] Between the inner and outer layers, a thermal insulation material is uniformly filled in the form of a rigid polyurethane foam with a low thermal conductivity of 0.182 W / Mk to 0.0256 W / Mk, composed of 30 to 65 parts by weight of a foaming agent which is a polyol containing 8 to 25 wt% of an eco-friendly foaming catalyst, Dichloro-1-fluoroethane or HFO, and 35 to 70 parts by weight of a compounding agent which is MDI (Methylene Diphenyl Diisocyanate), thereby providing superior thermal insulation; (Example: Performed with a thermal insulation material composition which is a rigid polyurethane foam with a thermal conductivity of 0.187 W / Mk, composed of 42 parts by weight of a polyol containing 15 wt% of Dichloro-1-fluoroethane and 58 parts by weight of Methylene Diphenyl Diisocyanate).

[0195] Centering is installed on the outer and outer surfaces of the inner tube and the flexible conduit for electrical wires to maintain a gap between the inner tube and the outer surface, thereby preventing movement and maintaining a constant gap between the inner and outer tubes and the flexible conduit for electrical wires, so that an insulating material is uniformly filled between the inner and outer tubes;

[0196] When connecting heating wires to multiple double-insulated pipes, work convenience is ensured and overheating or disconnection of the wires is prevented, while heat supply is easy, thereby facilitating the prevention of freezing and thawing of the double-insulated pipes;

[0197] A heating wire puller (jig) is provided on the heating wire installed inside the flexible conduit for electrical wires, which is provided on the outer surface of the inner tube of the double-walled insulated tube, thereby further enhancing the heat transfer rate and providing convenience of construction and safety of the heating wire, in which the heating wire installed inside each unit of the flexible conduit for electrical wires is assembled in one go without joints;

[0198] The inner tube and the flexible conduit for wires are fixed with a metal sheet tape containing aluminum, thereby further improving thermal conductivity, enhancing the fixing support strength of the flexible conduit for wires and the inner tube, and making the fixing work of the inner tube and the flexible conduit for wires easier;

[0199] As a double-insulated pipe equipped with a flexible pipe for electrical wires featuring a heating element on the outside of the inner pipe, it is manufactured and supplied at the factory, making installation easier;

[0200] Unlike the conventional method of individually connecting multiple heating wires to multiple double-insulated tubes through connecting parts, the heating wires can be installed inside unit flexible conduits for electrical wires all at once without joints. It was found that the construction period and costs are significantly reduced, and the product and manufacturing method enable perfect insulation work.

[0201] Although the present invention has been described in detail through specific embodiments, the present invention is not limited to the above embodiments, and various modifications can be made by those skilled in the art within the scope of the technical concept of the present invention. Explanation of the symbols

[0202] 100 : Double-insulated pipe (double-insulated pipe) equipped with a flexible pipe for electrical wires that facilitates the installation and replacement of the heating wire of the present invention 10: Interior 20: Exterior 30: Flexible conduit for electrical wires 40: Heating wire 41: Heating wire puller (jig) 50: Metal sheet tape (metal sheet) 60: Centering 61: Cylindrical main body 62: First Earth District 63: Second Earth District 70: Insulation material 80: Temperature controller for power supply 81: Automatic control switch 82: ON switch 83: OFF switch 200 Prior art double-insulated pipe 201: Interior 202: Exterior 203: Heat Shrink Casing

Claims

Claim 1 For preventing freezing and thawing of the double-insulated pipe, the inner and outer pipes (10, 20) which are double-insulated pipe bodies made of polyvinyl chloride or polypropylene, and which allow for easy installation and replacement of heating wires, are composed of 65 to 80 weight percent high-density polyethylene and 20 to 35 weight percent linear low-density polyethylene, or are composed of 100 weight percent high-density polyethylene, and are easy to install and replace; and: a flexible pipe (30) for electrical wires made of metal material, which is provided on the outer surface of the inner pipe (10), and the pipe body is in close contact with the outer surface of the inner pipe (10) so that heat is directly transferred to the outer surface of the inner pipe (10); and a heating wire (40) which is a wire provided inside the flexible pipe (30) for electrical wires, having a heating wire pull wire (41) provided on one side of the heating wire (40) for moving +, - power and heating wires, and a heating wire pull wire (41); and on the outer surface of the flexible pipe (30) for electrical wires and the inner pipe (10). A metal sheet tape (50) made of a metal material including aluminum, provided therein; and an inner tube (10) and an outer tube (20) provided therein, with the spacing between the inner and outer tubes (10, 20) and the flexible tube (30) for wires maintained constant so that an insulating material (70) is uniformly filled between the inner and outer tubes (10, 20). A double-insulated pipe (100) equipped with a flexible pipe for electrical wires that facilitates easy installation and replacement of heating wires, wherein the insulation material (70) is composed of a plurality of centerings (60) made of polyethylene or polyvinyl chloride and an insulating material (70) injected and filled between the inner and outer pipes (10, 20); wherein the insulating material (70) is composed of a rigid polyurethane foam with a low thermal conductivity of 0.182 W / Mk to 0.0256 W / Mk, composed of 30 to 65 parts by weight of a foaming agent which is a polyol containing 8 to 25 weight% of a foaming catalyst Dichloro-1-fluoroethane or HFO, and 35 to 70 parts by weight of a compounding agent which is MDI (Methylene Diphenyl Diisocyanate). Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 delete Claim 8 delete Claim 9 delete Claim 10 delete

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