RU2318154C1 - Heat insulated pipe - Google Patents

Abstract

FIELD: pipeline engineering.

SUBSTANCE: heat insulated pipe comprises pressure-tight piping shell made of composition material. The outer side of the shell is provided with a heat insulation made of a material composed of heat insulating foamed solidified material and filler made of fiber glass particles mixed with sand. The length of the fibers ranges from 1 to 5 cm. The foamed solidified material is made of foamed polyepoxide.

EFFECT: simplified structure.

5 cl, 6 dwg

Description

The invention relates to heat-insulated pipes, which contain a sealed tubular shell made of composite material with at least two-component thermal insulation deposited on its outer surface, one of the components being the basis of thermal insulation and made of foam material, and the second component is a filler.

Known heat-insulated pipes, each of which contains a sealed tubular shell made of composite material, on the outer surface of which there is thermal insulation [1, 2, 5, 8, 11, 15, 16, 17].

In order to increase the strength in some pipe designs, bulk material is used as a filler, for example, sand with cement [9], gunpowder [4] for the purpose of its smokeless utilization, longitudinal and transverse fillers [7]. In other technical solutions, fiberglass is used as a filler, which is used in glass-polymer composite materials [10]. In the insulating material for pipes using fibers associated with the cured filler [12]. Technical solutions are also known in which the glass fiber strands of the heat-shielding sheath are reinforced with elastic fiber strands in order to increase the strength and bearing capacity of the pipe [13].

Of the known technical solutions close to the claimed technical solution are insulated pipes, each of which contains a tubular shell, on the outer surface of which is fixed thermal insulation from the cured material [11, 15]. In the technical solution of the pipe for district heating [11], the layer of thermal insulation material is made of polyurethane foam.

In the technical solution [15] for transporting hot liquids, the insulating material contains ceramic fiber, mineral fiber, silicate fiber or fiberglass.

A prototype of the invention is a thermally insulated pipe containing a sealed tubular shell, on the outer surface of which a thermal insulation is fixed, made of a material including components, one of which is the basis of the heat-insulating material and is made of foamed cured material, and the second component is a filler [11].

In the device of this pipe, the heat-insulating material performs heat-insulating functions, while mechanical stresses are perceived mainly by the inner and outer tubular shells, which significantly complicates the design of the pipe and increases the complexity and material consumption of its manufacture.

Solved and achievable technical objective of the invention is to simplify the design of the insulated pipe, increasing its bearing capacity and insulating properties.

To obtain the specified technical result in a heat-insulated pipe containing a sealed tubular shell made of composite material, on the outer surface of which a thermal insulation is fixed, made of a material including components, one of which is the basis of the heat-insulating material and is made of foamed cured material, and the second component is a filler; particles of chopped glass basalt fiber mixed with sand are used as filler, the length of each of which is in the range from 1 to 5 cm, as a foamed cured material, polyethylene foam with closed-cell structure is used, for example, polyethylene foam of the ETAL-PPE-407 brand, while the thermal insulation includes components, parts by weight: sand - 0 , 1-0.5, chopped glass basalt fiber - 0-0.25.

It is envisaged that the larger side of each chopped glass basalt fiber particle is located along the pipe. The large side of each chopped glass basalt fiber particle is located across the pipe. The large side of each chopped glass basalt fiber particle is inclined to the longitudinal axis of the pipe. Each particle of chopped glass basalt fiber has a bent shape in at least one plane.

It is envisaged that the glass-basalt fiber particles in the filler are arranged in a mixed manner such that the large sides of the chopped glass-basalt fiber particles are located along the pipe, across the pipe, obliquely to the longitudinal axis of the pipe, and also have a curved shape in at least one plane.

Figure 1 shows a thermally insulated pipe,

Figure 2-4 - arrangement of particles of chopped glass basalt fiber, respectively, along the pipe, across the pipe, obliquely to the longitudinal axis of the pipe.

Figure 5 - arrangement of curved particles of chopped glass basalt fiber in thermal insulation.

Figure 6 is a mixed arrangement of these particles of chopped glass basalt fiber in thermal insulation.

The heat-insulated pipe contains a sealed tubular shell 1 made of composite material, on the outer surface of which a thermal insulation 2 is made, made of a material including components. One component is the basis of the heat-insulating material and is made of foamed cured material 3, and the second component includes a filler.

As a filler, 4 particles of 5 chopped glass-basalt fiber mixed with sand, each of which is in the range of 1 to 5 cm in length, were used with sand. Polyfoam with closed-cell structure, for example, ETAL-PPE-407 polystyrene foam, was used as foamed cured material.

The composition of the thermal insulation includes components, parts by weight: sand - 0.1-0.5, chopped glass basalt fiber - 0-0.25, while in one version of the pipe, the larger side 6 of each particle 5 of chopped glass basalt fiber is located along the longitudinal axis 7 of the pipe .

In the second and third versions of the pipe, the large sides 6 of each particle 5 of the chopped glass basalt fiber are located transversely and, accordingly, obliquely to the longitudinal axis 7 of the pipe. Each particle 5 chopped glass basalt fiber may have a curved shape in at least one plane. In a mixed or combined application of the variously arranged above particles of chopped glass-basalt fiber, the particles are located in the filler so that their large sides are located along the pipe axis 7, transversely and inclined to the axis, and also have a curved shape in at least one plane.

The tubular shell 1 is made of a composite glass-basalt-plastic material. The manufacturing technology of a thermally insulated pipe provides for the process of applying to the tubular shell 1 a mixture of a thermal insulation layer 2 of the above components of a material that is in a state before it is cured. As a result, the thermal insulation components at the molecular level adhere to the composite layer of the glass-basalt-plastic sheath 1 during the curing of the foam epoxy, which creates the structural integrity of the boundary layer between the sheath 1 and the thermal insulation 2. As a result, after the thermal insulation is cured, it together with the tubular sheath presents a strong pipe construction with high heat insulating properties. Moreover, the possibility of delamination of thermal insulation 2 from the shell 1 during operation of the pipe is reduced.

When a thermally insulated pipe is used, loads are perceived by the tubular shell 1 and the thermal insulation layer 2, which, in terms of compressive and bending strength properties, have large indicators in comparison with the tubular shell. This is due to the fact that when bending the pipe, particles 5 of chopped glass-basalt fiber, which are located along the pipe axis 7 and are reinforcing elements, work on bending and reduce the formation of microcracks, particles 5 located across the pipe axis 7 receive compression forces directed across the pipe , curved particles 5 work well for tube-twisting forces. As a result, these types of loads to a greater extent perceive themselves as a layer of thermal insulation, which largely unloads the shell 1 of the pipe, operating under severe conditions of temperature and pressure difference of the transported medium from the inside of the pipe, as well as in ground conditions of constantly changing external loads.

By selecting the indicated ratios of the components, the particle sizes of the chopped glass basalt fiber, choosing the shape of the particles, and also due to the location of the particles in the thermal insulation, we obtained the optimal pipe option that satisfies the requirements of thermal insulation, strength, material consumption and the laboriousness of the production of heat-insulated glass-basalt plastic pipes used in district heating and water supply systems . At the same time, environmentally friendly waste-free production is achieved by harmless disposal of glass-basalt fiber waste, which is used for the manufacture of tubular shells of these thermally insulated pipes.

In this case, the use of polyepoxide in combination with sand and chopped particles of glass-basalt fiber allows, in addition to the listed advantages, to obtain a strong thermal insulation structure with closed, not interconnected, cells, as well as to obtain a durable waterproof crust on the outer surface of the thermal insulation, which significantly increases the water resistance of the insulated pipe and eliminates the penetration water into the zone of the boundary layer between the tubular shell and thermal insulation.

Information sources

1.SU 675261 A, 07.25.1997.

2. SU 365516 A, 01/08/1973.

3. SU 891461 A, 12/23/1981.

4. RU 2127393 C1, 03/10/1999.

5. RU 2204757 C2, 05.20.2003.

6. RU 2200269 C1, 03/10/2003.

7. RU 2221183 C2, 01/10/2004.

8. RU 2221184 C1, 01/10/2004.

9. RU 2232333 C2, 07/10/2004.

10. RU 2245477 C1, 01.27.2005.

11. WO 4003423 A1, 01/08/2004.

12. DE 19906734 C1, 07.27.2000.

13. US 6045884 A, 04/04/2004.

14.JP 3022677 B2, 03.21.2000.

15. DE 19908897 A1, 09/07/2000.

16.JP 3207297 B2, 09/10/2001.

17. DE 10248781 B3, 02.19.2004.

Claims (6)

1. A heat-insulated pipe containing a sealed tubular shell made of composite material, on the outer surface of which a heat insulation is fixed, made of a material including components, one of which is the basis of the heat-insulating material and is made of foamed cured material, and the second component is a filler, characterized in that, as a filler, particles of chopped glass-basalt fiber mixed with sand, the length of each of which is found, are mixed with sand it ranges from 1 to 5 cm, as a foamed cured material, a closed-cell foam epoxy foam is used, for example, ETAL-PPE-407 foam polyepoxide, the composition of the thermal insulation includes components, parts by weight: foam 0.5–0.9 foam, sand 0.1-0.5, chopped glass basalt fiber 0-0.25. 2. The heat-insulated pipe according to claim 1, characterized in that the large side of each particle of chopped glass basalt fiber is located along the pipe. 3. The insulated pipe according to claim 1, characterized in that the large side of each particle of chopped glass basalt fiber is located across the pipe. 4. The heat-insulated pipe according to claim 1, characterized in that the large side of each particle of chopped glass basalt fiber is inclined to the longitudinal axis of the pipe. 5. The heat-insulated pipe according to claim 1, characterized in that each particle of chopped glass basalt fiber has a bent shape in at least one plane. 6. The insulated pipe according to claim 1, characterized in that the particles of glass-basalt fiber in the filler are located in a mixed manner so that the large sides of the particles are located along the pipe, across the pipe, inclined to the longitudinal axis of the pipe and have at least one curved shape in at least one plane .

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