An external insulation device for oil pipeline using cast-in-place foamed cement without removing formwork

Abstract

The invention discloses an external thermal insulation device for an oil pipeline of cast-in-place foamed cement without dismantling a template, comprising an inner pipeline and a thermal insulation layer, wherein the inner pipeline is the oil pipeline and is placed in an outer protective shell, and the thermal insulation layer is formed by filling the cast-in-place foamed cement in the annular space between the outer protective shell and the inner pipeline. The cast-in-place foamed cement is used to achieve the purpose of thermal insulation and corrosion prevention of the oil pipeline in severely cold areas, which is prone to corrosion and frost cracking due to climate and soil freeze-thaw conditions. The thermal insulation device has excellent scalability due to good thermal insulation material performance and convenient installation technology and method. The fixing ring fixes the inner pipeline and the outer pipe to ensure that the thickness of the thermal insulation layer of the outer pipe will not be uneven due to external force when pouring the foamed cement, thereby solving the thermal insulation problem of pipelines in severely cold areas and having convenient construction technology and good thermal insulation effect.

Description

Technical Field

[0001] The invention relates to industrial thermal insulation technology, in particular to an external thermal insulation device for an oil pipeline using cast-in-place foamed cement without dismantling a formwork. Background Art

[0002] As a pipeline for oil loading and unloading and transportation, oil pipelines are mostly formed by steel pipes through welding, flanges and other connecting devices, and are opened and closed and flow regulated by delivery valves. However, in the cold northern regions, the winter is long and the temperature is extremely low. Exposed pipelines are prone to frost cracking and corrosion. Pipelines buried in the soil will also be damaged by the soil that freezes and melts periodically with the temperature. Therefore, it is particularly important to set up external insulation devices for oil pipelines. Polyurethane rigid foam has now developed into the largest pipeline insulation material in the country. Polyurethane foam will age over time. After aging, the thermal conductivity of polyurethane foam will increase and the shear strength will decrease. At the same time, due to process constraints, most polyurethane insulation pipelines are buried underground and bear the pressure of the soil. The deformation of the foam over time is relatively large, resulting in a large deformation, which will gradually reduce the thickness of the insulation layer and reduce the insulation coefficient of the foam, which will significantly reduce the insulation performance and poor insulation effect. Summary of the invention

[0003] The present invention aims to overcome the deficiencies of the prior art and provides an external insulation device for an oil pipeline using cast-in-place foamed cement without dismantling a formwork.

[0004] The invention discloses an external insulation device for an oil pipeline of cast-in-situ foamed cement without removing formwork, comprising an inner pipeline and an insulation layer. The inner pipeline is an oil pipeline and is placed in an outer protective shell. The insulation layer is formed by filling the cast-in-situ foamed cement in the annular space between the outer protective shell and the inner pipeline.

[0005] As a further improvement of the present invention, the outer protective shell includes an outer tube and a connecting flange. The outer tube is two semicircular tubes made of fiberglass. A longitudinal groove is opened on the inner wall of one of the semicircular tubes, and a longitudinal groove is opened on the outer wall of the other semicircular tube so that they can be connected to each other to form a bayonet. The two semicircular tubes are combined and spliced ​​to form a complete tube; connecting flanges are fixed at both ends of the outer tube.

[0006] As a further improvement of the present invention, the outer protective shell also includes a fixing ring, which is arranged on the inner side of both ends of the outer tube; the fixing ring is composed of a metal outer ring and a metal inner ring connected by elastic nuts, and sealing rings are provided on the outer wall of the metal outer ring and the inner wall of the metal inner ring, and the fixing ring is placed between the inner pipe and the outer tube.

[0007] As a further improvement of the present invention, the metal outer ring and the metal inner ring are connected by more than three elastic nuts.

[0008] The invention discloses an external thermal insulation device for oil pipelines of cast-in-place foamed cement without dismantling formwork. The device uses cast-in-place foamed cement to achieve the purpose of thermal insulation and corrosion prevention of oil pipelines in severely cold regions, which are prone to corrosion and frost cracking due to climate and soil freeze-thaw conditions. The thermal insulation device has excellent scalability due to good thermal insulation material performance and convenient installation technology and method. The fixing ring fixes the inner pipe and the outer pipe to ensure that the thickness of the thermal insulation layer of the outer pipe will not be uneven due to external force when pouring the foamed cement. The thermal insulation problem of pipelines in severely cold regions is solved, and the device has convenient construction technology and good thermal insulation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the straight pipeline structure of the present invention;

[0010] Figure 2 It is a schematic diagram of the curved pipeline structure of the present invention;

[0011] Figure 3 It is a schematic diagram of the T-shaped pipeline structure of the present invention;

[0012] Figure 4 is a schematic diagram of a complete outer tube of the present invention;

[0013] Figure 5 It is a schematic diagram of the fixing ring structure of the present invention. DETAILED DESCRIPTION

[0014] Example 1

[0015] The present invention discloses an external insulation device for an oil pipeline of cast-in-place foamed cement without removing formwork, comprising an inner pipeline 1 and an insulation layer 2, wherein the inner pipeline 1 is an oil pipeline and is placed in an outer protective shell 3, and the insulation layer 2 is formed by filling the annular space between the outer protective shell 3 and the inner pipeline 1 with cast-in-place foamed cement.

[0016] Example 2

[0017] The present invention discloses an external insulation device for an oil pipeline of cast-in-place foamed cement without removing formwork, comprising an inner pipeline 1 and an insulation layer 2. The inner pipeline 1 is an original oil pipeline, the outer wall of the pipeline is coated with an anti-corrosion coating 4, and is placed in an outer protective shell 3. The insulation layer 2 is formed by filling the annular space between the outer protective shell 3 and the inner pipeline 1 with cast-in-place foamed cement. Foamed cement is a prior art, and the publication number is CN103274719A.

[0018] The outer protective shell 3 includes an outer tube 5, a connecting flange 7 and a fixing ring 6. The outer tube 5 is two semicircular tubes made of glass fiber reinforced plastic. A longitudinal groove is opened on the inner wall of one of the semicircular tubes, and a longitudinal groove is opened on the outer wall of the other semicircular tube so that they can be connected to each other to form a bayonet 8. The two semicircular tubes are combined and spliced ​​to form a complete tubular outer tube 5; connecting flanges 7 are fixed at both ends of the outer tube 5, and the connecting flanges are arranged on the outer side of both ends of the outer tube to form a connection between the outer protective shells. A fixing ring 6 is arranged between the inner pipe 1 and the outer pipe 5 at both ends. The fixing ring 6 is composed of a metal outer ring 9 and a metal inner ring 10 connected by four elastic nuts 11. The inner pipe is fixed in the metal inner ring 10 by the elastic nuts 11, and an equidistant annular space is formed with the metal outer ring 9, and the outer tube 5 is fixed outside the metal outer ring 9. A sealing ring 12 is arranged on the outer wall of the metal outer ring 9 and the inner wall of the metal inner ring 10. The fixing ring in the device can be adapted to inner pipes of various sizes through the adjustability of the elastic nut. The setting of the fixing ring solves the stability of the outer pipe and avoids the possibility that the outer pipe may be offset due to external force when pouring foamed cement, thereby causing uneven thickness of the insulation layer.

[0019] The above-mentioned external insulation device for oil pipeline of cast-in-place foamed cement without dismantling formwork can be realized by the following steps:

[0020] a. Pre-treat the surface of the inner pipe 1 and apply anti-corrosion coating 4 (epoxy resin composite material AP370PLC);

[0021] b. Use glass fiber cloth tape to wrap the inner pipe, and brush the anti-corrosion coating 4 (AP370PLC) onto the outside of the wrapping tape again and wait for it to cure;

[0022] c. Set the fixing ring 6 to its fixed position according to the length of the outer tube 5, insert the inner pipe 1 into the metal inner ring 10 of the fixing ring 6, and adjust the size of the metal inner ring 10 by the elastic nut 11, so as to fix the inner pipe 1 in the center of the fixing ring;

[0023] d. Two semicircular outer tubes 5 are connected by internal buckles 8 to form a complete outer tube, and the inner part of the outer tube is combined with the metal outer ring 9 of the fixing ring 6;

[0024] e. Connecting flanges 7 are arranged on the outer walls of both ends of the complete outer pipe to form an outer protective shell 3. Foamed cement is poured into the annular space between the outer protective shell 3 and the inner pipe 1 to form an insulation layer 2. The whole device is easy to install and has excellent insulation performance.

Claims

1. A method for preparing an external insulation device for an oil pipeline made of cast-in-place foamed cement without removing the formwork, characterized in that: This is achieved through the following steps: a. Pre-treat the surface of the inner pipe (1) and apply an anti-corrosion coating (4); b. Use glass fiber cloth tape to wrap the inner pipe, and brush the anti-corrosion coating (4) onto the outside of the wrapping tape again and wait for it to cure; c. Setting the fixing ring (6) to a fixed position according to the length of the outer tube (5), inserting the inner tube (1) into the metal inner ring (10) of the fixing ring (6), and adjusting the size of the metal inner ring (10) by means of the elastic nut (11), thereby fixing the inner tube (1) at the exact center of the fixing ring; d. The two semicircular outer tubes (5) are connected by means of an internal buckle (8) to form a complete outer tube, and the inner part of the outer tube is combined with the metal outer ring (9) of the fixing ring (6); e. Connecting flanges (7) are arranged on the outer walls of both ends of the complete outer pipe to form an outer protective shell (3), and foamed cement is poured into the annular space between the outer protective shell (3) and the inner pipe (1) to form an insulation layer (2); The oil pipeline external insulation device comprises an inner pipeline (1) and an insulation layer (2); the inner pipeline (1) is an oil pipeline and is placed inside an outer protective shell (3); the insulation layer (2) is formed by filling the annular space between the outer protective shell (3) and the inner pipeline (1) with cast-in-place foamed cement; The outer protective shell (3) comprises an outer tube (5) and a connecting flange (7), wherein the outer tube (5) is two semicircular tubes made of glass fiber reinforced plastic, wherein a longitudinal groove is provided on the inner wall of one of the semicircular tubes, and a longitudinal groove is provided on the outer wall of the other semicircular tube so that the two semicircular tubes can be connected to each other to form a bayonet (8), and the two semicircular tubes are combined and spliced ​​to form a complete tube; connecting flanges (7) are fixed at both ends of the outer tube (5); The outer protective shell (3) also includes a fixing ring (6), which is arranged on the inner side of both ends of the outer tube (5); the fixing ring (6) is composed of a metal outer ring (9) and a metal inner ring (10) connected by an elastic nut (11), and a sealing ring (12) is provided on the outer wall of the metal outer ring (9) and the inner wall of the metal inner ring (10), and the fixing ring (6) is placed between the inner tube (1) and the outer tube (5); The metal outer ring (9) and the metal inner ring (10) are connected via more than three elastic nuts (11).

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