WO2014181236A1

WO2014181236A1 - Thermally isolated pipeline for the transport of fluids

Info

Publication number: WO2014181236A1
Application number: PCT/IB2014/061205
Authority: WO
Inventors: Alessandro Sala; Riccardo Sala; Paolo Spinelli; Michaela Stellato; Giacomo Manenti; Giuseppe VITALI
Original assignee: Aktarus Group S.R.L.
Priority date: 2013-05-08
Filing date: 2014-05-05
Publication date: 2014-11-13
Also published as: EP2994687A1; ITBG20130013A1

Abstract

Thermally insulated solar pipeline for the transport of fluids comprising: a first conduit (11, 12); an insulating layer wrapped around said first conduit (11, 12) and coaxial thereto; said insulating layer comprising a support layer (13) treated with aerogel; characterized in that said support layer (13) treated with aerogel is completely coated with a containment layer (20, 21) before being wrapped around said first conduit (13); and that an outer layer (15) wraps and is coaxial to said insulating layer of said first conduit (11, 12); said outer layer (15) comprising at least one longitudinal lateral flap (25).

Description

"THERMALLY ISOLATED PIPELINE FOR THE TRANSPORT OF

FLUIDS"

DESCRIPTION

The present invention relates to a thermally insulated pipeline for the transport of fluids and to the implementation method thereof. In particular relating to a pipeline for the connection of solar heating panels.

The pipes for the connection of solar heating panels are used to send a fluid at lower temperature to a solar panel and receive a hotter return fluid.

For this purpose pairs of pipes normally of stainless steel, copper or other similar materials, thermally insulated by an insulating material wrapped around the pipes are normally used.

The patent IT1397040 describes a solar pipeline, consisting of two parallel pipes characterized in that the two pipes are insulated with a support insulating layer treated with aerogel.

The insulating layer is fixed to the pipeline with a mechanical fastening means, such as wire of high toughness nylon material.

The pipes are then wrapped by a PVC layer, which encloses them both and acts as an external finish and junction means between the two isolated pipes.

Purpose of the present invention is to provide a thermally insulated pipeline for the transport of fluids more suitable than that of the prior art.

Another purpose is to provide a pipeline whose production is simplified compared to the known art, in consideration of the fact that the production, today, is costly and inflexible.

Further object is to provide a pipeline whose thermal insulation is further improved.

In accordance with the present invention, these and other objects are achieved by a thermally insulated solar pipeline for the transport of fluids comprising: a first conduit; an insulating layer wrapped around said first conduit and coaxial thereto; said insulating layer comprising a support layer treated with aerogel; characterized in that said support layer treated with aerogel is completely coated with a containment layer before being wrapped around said first conduit; and an outer layer that wraps and is coaxial to said insulating layer of said first conduit; said outer layer comprising at least one longitudinal side flap.

Said objectives are also achieved by a method for producing a solar pipeline for the transport of fluids comprising the steps of: coating with a metalized containment layer a support layer treated with aerogel, to form a wrapped insulating layer; wrapping said wrapped insulating layer on a first conduit; wrap an outer layer on said wrapped insulating layer; providing said outer layer with at least one longitudinal side flap.

Further characteristics of the invention are described in the dependent claims.

The advantages of this solution compared to the solutions of the prior art are various. The support layer treated with aerogel is wrapped by a protective layer which contains the powder therein during the processing steps and subsequent use.

The support layer treated with aerogel, and protected, may be wrapped by a further layer which increases the thermal properties.

The pipes can be joined together with a detachable and modular connection, that is why implementation is easy to achieve without the aid of specific tools or machines, a multi-pipe battery, consisting of more than two pipes, for multiple installations.

The single pipe is characterized by one or more "wings" arranged in a longitudinal manner. In particular, this solution will be useful during assembly in order to join and separate the pipes without the aid of specific tools.

The solar pipeline according to the present invention, by being more compact, is easier to manufacture because the aerogel does not disperse, it has better performance in use, during processing and when the pipe cuts are made. The thermal performance and the dispersion limitations are also increased due to the possible additional layer.

The characteristics and advantages of the present invention will become apparent from the following detailed description of an embodiment thereof, that is illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 shows thermally insulated pipes for the transport of fluids, according to the present invention; Figure 2 shows a first implementation step of thermally insulated pipes for the transport of fluids, according to the present invention;

Figure 3 shows thermally insulated pipes for the transport of fluids, according to a second embodiment of the present invention;

Figure 4 shows a thermally insulated pipe for the transport of fluids, according to a third embodiment of the present invention;

Figure 5 shows a set of thermally insulated pipes for the transport of fluids, according to a third embodiment of the present invention.

Referring to the attached drawings, a thermally insulated pipeline for the transport of fluids, according to the present invention, comprises a first conduit 11 or 12, respectively wrapped by a first insulating material 13 and 14. The insulating material 13 and 14 is wrapped by a containment layer 20, is then wrapped around each pipe and 12. The containment layer 20 is a layer that wraps completely and longitudinally the insulating material 13 and/or 14. The end edges 22 of the containment layer 20 are overlapped with each other to completely wrap the insulating material 13 and/or 14, that thus contained is wrapped around the pipe 11 and/or 12.

Externally to the insulating material 13 and/or 14, a further layer 21 is preferably arranged, wrapped in the containment layer 20.

Externally, each pipe is then coated with a layer 15 of a stretched techno-polymer for example with an extruder or a PVC layer or similar material is arranged. The pipes, preferably, also comprise one or more cables 16 arranged between the layer 21 and the coating layer 15.

The cable 16 is an electrical cable with more conductive wires if necessary, for the operation of the solar system and its accessories if any. Note that it is possible to use individual wires coated with insulation, or wires can be inserted with the function of heaters to avoid condensation, or for further active heating. The conductive wires of the cable 16 are set to be parallel to the two pipes 11 and 12 or coiled around the layer 13 or 14 coated with the layer 21 or 15.

The conduits 11 and 12 are normally pipes made of stainless steel, preferably corrugated, of variable diameter according to requirements and normally of diameters 10-12-16-20-25-32-40 mm, and other diameters. Alternatively, copper or plastic or polymeric material pipes can be used.

The insulating layers 13 and 14 are constituted by a support layer treated with aerogel.

As support layer a high toughness polyester of reduced thickness fabric is used, and is comprised between 2 and 10 mm, of weight approximately 170 g/cm².

The support layer is treated with aerogel in an amount of about 150 grams per square centimeter.

Aerogel is a substance in the solid state similar to a gel in which the liquid component is substituted by a gas. The result is a solid foam with multiple properties.

Aerogel is normally made of 99.8% air and 0.2% trimetyl silylated silica. There are also alumina, carbon, organic based aerogels.

Each of the insulating layers 13 and 14, already treated with aerogel, is composed of a strip as wide as the outer circumference of the conduits 1 and 12.

Each of the insulating layers 13 and 14 are enclosed in a containment layer 20 that wraps it completely. The end edges 22 of the layer 20 are joined together by glue or welding, and said layer 20 forms a longitudinal containment sack.

Different methods for fixing the layer 13 to the pipes 1 and

12, comprising the layer 20 and 21 , can be used, for example having the foresight, during the laying of layer 21 , to leave a longitudinal weld tail that can be glued or welded and thus provide a solid structure without the aid of binding means. In this way the industrial process is greatly simplified and streamlined, in comparison to the known art.

The layer 21 preferably comprises a base plastic film that can be coupled with a thin aluminum foil that creates a reflective thermal barrier. In one advantageous embodiment it is possible to resort to a film (base or forming the multilayer) treated with the known metallization technique (sputtering, plasma treatment in a vacuum chamber, PVD or other). As a non-limiting example, a multilayer layer consisting of Alu 25 μιη/neutral Pet + 12 pm/Ldpe 30 pm, defined by the Code art. 1046 and produced by Roncoroni Spa, or of a PET film (polyethylene terephthalate) aluminized and, if necessary polythene of the Company Metalvuoto S.p.a.

Said layer 21 , due to the physical characteristics, acts as an infrared barrier (reflects infrared radiation) by increasing the insulating power. It is noted that, unlike what is applied in the prior art, the use of such a film has countless advantages, first of all the use of a single and not coupled film, the possibility of having insignificant thicknesses (of 12 pm for the PET film and a few tens of Armstrong for the aluminization), to avoid the use of a metal leaf which is pure and thick (aluminum) and thus of low thermal inertia and the tendency not to create a thermal storage, the antistatic properties donated by the film, etc..

In an alternative embodiment, instead of the two layers 20 and 21 a single layer can be used, for example of the type of the layer 21 but wrapped on the insulating layer 13 as the layer 20, so that this single layer performs both the physical containment function of the inner layer 13 and the thermal reflective function of the layer 2 .

The outer layer 15 is made on each pipe comprising thermal insulation, according to a first embodiment of the invention, so as to overlap the ends towards the outside so as to form a, longitudinal side flap 25 (for the entire length of the pipe) that extends from said pipe perpendicular to the tangent to the circumference of said pipe.

Said flap 25 is joined to a flap 25 of another pipe so as to form a pair of parallel pipes.

The joining of the flaps 25 can be obtained by glue, autogenous welding, and therefore without the contribution of external materials, or by means of rivets.

In a second embodiment of the present invention, during the wrapping of the outer layer 15, two strips are used of a width such as in wrapping, each one on both sides of the pipe, the ends overlap each other and two opposing lateral flaps 26 are formed.

In this way it is possible to join more than two pipes to form a battery of parallel pipes joined together.

The joining of the flaps 26 one to the other and with the flaps 25 can be obtained by glue, welding, or by means of rivets.

Each pipe 11 and 12, already coated with the layer 20 which encloses the layer 13, possibly including the layer 21 , passes inside an extrusion mouth and is coated with a thermoplastic sheath made of techno-polymer which forms the layer 15 comprising the flaps 25 or 26.

The layer 15 of techno-polymer is of an approximate thickness between 0.5 mm and 5 mm, made with an extruder, allows to obtain a product which is compact, flexible, resistant to external agents, attractively aesthetic having a slender profile, and with high capacity of insulation.

The flaps 25 and 26 have an approximate length that results to be comprised between 0.5 cm and 15 cm each depending on the application.

The flaps 25 and 26 are intended to be fixed by screws or other to the installation wall, they can also be cut in the center to separate the pipes one from the other. The length of the same allows to have, even after separation of the two pipes, the space for fixing single pipes.

In an advantageous embodiment, the flaps 25 and 26 comprise at the ends thereof a male element 27 and on the other end a female element 28, to facilitate the union, by fitting one into the other. With said jointing system the separation of the conduits, if necessary, in the mounting case is also facilitated.

Said elements 27 and 28 can be made by co- extrusion, or by the insertion, in the extruded polymer of profiles suitable for the purpose.

The containment layer 20 of the insulating layer 13 treated with aerogel (or more commonly with a nano-porous solid for example based on silicon dioxide, carbon dioxide, or similar even organic) also has the containment function of the powder in an intimate and direct way, which releases considerable amounts of the aerogel, it can be made with a thermoplastic material or similar. Being cited purely representatively the TNT coupled or coated to polyethylene, polymeric films, fabrics, films or layers that with the appropriate choice of materials allow the welding without the use of support materials.

The welding is realized with known techniques (example: two hot wheels or similar, with a temperature range between 70°C and 350X).

These aerogel strips, webbing or tape 13 coated (or wrapped) from both upper and lower sides, have a width such as to allow the wrapping along the perimeter of the pipeline to be insulated. The use of the layer 20, is to retain the powder during the processing steps and during subsequent use, and not to penalize the loss of aerogel in powder form. This choice allows to have a support treated with aerogel that has now cleared its dustiness and in this step can already be treated as a semi-finished product, unlike the prior art, where the processing must be realized in a simultaneous way and in sequence in this case it is possible to store a mono-semi-finished product.

The aerogel strips thus composed can be preferably coated with an additional layer or film 21 arranged longitudinally. Said layer can be advantageously made to obtain a technical device that meets additional requirements, such as the reflectance and the dampening of the range of said Infrared radiation (l/R) and that represents a substantial portion in the calculation of the thermal dispersion which moves towards the external environment from the heat transfer fluid (contained in the conduit). In this regard, it is recalled that the small and reduced mass of added metallic material has a thermal inertia and a heat storage capacity equal to zero, but a great reflection of the portion of thermal energy that otherwise would be lost.

Although a semi-finished product much more complex and detailed is achieved, compared to the prior art, the latter facilitates and speeds up the production, and despite the use of several materials and machine steps, the production costs will be decreased, as to date the greater implementation problem is that of the aerogel dust dispersed during the processing, which, thanks to the invention, is cleared completely. Note that, thanks to the already described heat-sealing properties of the film used in the assembly and coating phase of the aerogel webbing, it is possible to make integral with the coupling flaps through a thermal action (fusion) of said film.

Also, thanks to the elimination of aerogel dust, which would make any adhesion impossible, only now it is possible to work with glues, adhesive tapes, pre-impregnated, chemically or thermally activable or photosensitive, autogenous or non-autogenous depositions, stitching, or any other known or innovative techniques that allow to join two edges in a stable manner (for subsequent machining or in a permanent way).

The solar pipeline thus conceived is susceptible of numerous modifications and variations, all within the scope of the inventive concept; moreover, all details can be substituted by technically equivalent elements.

For example it is possible to use an insulation layer of a lesser or greater type or thickness to insulate a conduit (e.g. the cold one) and a different type of insulating layer or a greater thickness for the other conduit (e.g. the hot one). A similar possibility is to create different insulating layers one with respect to the other in relation to thickness and materials.

Claims

1. A thermally insulated solar pipeline for the transport of fluids comprising: a first conduit (11 , 12); an insulating layer wrapped around said first conduit (11 , 12) and coaxial thereto; said insulating layer comprising a support layer (13) treated with aerogel; characterized in that said support layer (13) treated with aerogel is completely coated with a containment layer (20, 21) before being wrapped around said first conduit (13); and that an outer layer (15) wraps and is coaxial to said insulating layer of said first conduit (11 , 12); said outer layer (15) comprising at least one longitudinal lateral flap (25).

2. The pipeline according to claim 1 characterized in that said containment layer (20, 21) is a metalized layer.

3. The pipeline according to one of the preceding claims characterized in that said metalized containment layer (20, 21) comprises a containment layer (20) and a layer (21) with infrared radiation reflection properties.

4. The pipeline according to one of the preceding claims characterized in that said containment layer (20) is made with a thermoplastic material.

5. The pipeline according to one of the preceding claims characterized in that said layer (21) with infrared radiation reflection properties is an aluminized PET film.

6. The pipeline according to one of the preceding claims characterized in that said outer layer (15) comprises two lateral opposed longitudinal flaps (25, 26).

7. The pipeline according to claim 6 characterized in that said two flaps (25, 26) comprise a first flap (25) and a second flap (26); said first flap (25) at its outer end comprises a male connection element (27) and said second flap (26) at its outer end comprises a female connection element (28); said male connection element (27) is of the type adapted to be coupled in a removable manner with a corresponding female connection element (28).

8. The pipeline according to one of the preceding claims characterized in that said at least one flap (25) extending from said pipeline perpendicular to the tangent to the circumference thereof.

9. The pipeline according to one of the preceding claims characterized in that said at least one flap (25) is formed by the union of the extreme edges of said outer layer (15).

10. The pipeline according to one of the preceding claims characterized in that a flap (25) of said pipeline can be joined to a flap (25, 26) of a further pipeline by means of glue, welding, or by means of rivets.

11. A method for manufacturing a solar pipeline for the transport of fluids comprising the steps of: coating with a metalized containment layer (20, 21) a support layer (13) treated with aerogel, to form a wrapped insulating layer; wrapping said wrapped insulating layer on a first conduit (11 , 12); wrapping an outer layer (15) on said wrapped insulating layer; providing said outer layer (15) with at least one lateral longitudinal flap (25, 26).

12. Method according to claim 10 characterized in that the step of coating with a metalized containment layer (20, 21) a support layer (13) treated with aerogel comprises the steps of: coating with a containment layer (20) a support layer (13) treated with aerogel to form said support layer (13) wrapped by said containment layer (20); wrapping said support layer (13) wrapped by said containment layer (20) to said first conduit ( , 12) to form a first insulating layer arranged around said first conduit (11 , 12); wrapping a layer (21) with infrared radiation reflection properties outside of said first insulating layer.