WO2014188183A1

WO2014188183A1 - Polymeric foam pipe insulation

Info

Publication number: WO2014188183A1
Application number: PCT/GB2014/051552
Authority: WO
Inventors: Paul Jacobs; Karl Hewson; Luis CONCEICAO
Original assignee: Zotefoams Plc
Priority date: 2013-05-22
Filing date: 2014-05-21
Publication date: 2014-11-27
Also published as: GB201309243D0

Abstract

A helical elongate polymeric foam body is provided for insulating a water pipe, wherein the foam forming the helix has a thermal conductivity of less than 0.15 W/mK at 0°C.

Description

POLYMERIC FOAM PIPE INSULATION

FIELD OF THE INVENTION The present invention relates to polymeric foam insulation for pipes and ducts. The foam insulation is provided in the form of a semi-rigid spiral that can easily be helically wound around the pipe or duct to be insulated without the need for specialist tools.

BACKGROUND OF THE INVENTION

Piping and ducting systems are designed to transport a variety of fluids, some of which may be heated, such as a hot air, hot water or steam, and some of which may be chilled, such as a cold water, or in some instances the temperature of the fluids may alternate between hot and cold. When the fluid transported is at a different temperature to that of the ambient environment, it is desirable to insulate the piping to maintain the temperature of the fluid being transported, and to reduce overall energy losses in the system. In addition to this, the insulation may provide protection against burn or freeze injuries that could occur as a result of contact with uninsulated or insufficiently insulated pipework.

To address this need to insulate pipework, and in particular heated systems, a wide variety of thermal insulation products are available. These range from the relatively low operating temperature expanded polyethylene foam tubes that are slit along the length for ease of installation to the higher temperature mineral wool and fiberglass materials that have higher temperature performance but are inherently more difficult to handle and install because of their fibrous nature. In view of these limitations, a number of solutions involving the complex use of layers of different materials with different characteristics have been disclosed. In US5934338, for example, Perstnev et al describe the use of a layer of high temperature mineral wool adjacent to the pipe surface and an outer layer of a polymeric foam material (polyurethane). In US6403180, Barrall also teaches the use of two or more layers of insulation to achieve pipe insulation with the required temperature performance. In this disclosure the insulation is prepared in the form of semi-circular shaped lengths of material that must precisely match the dimensions of the pipe to be insulated in order for the mating surfaces to be abutted exactly. The need for ease of installation of the pipe insulation is widely recognized and insulation is provided in a number of formats including semi-circular half sections, tubes, strips, rolls and sheets. In patent application US2003/0234058, for example, Tippins describes a self-closing pipe insulation device that is designed to assume a tubular sleeve configuration when applied to the pipe to be insulated. As previously, the use of two or more layers of insulation to achieve the required level of insulation is contemplated. Tippins is also in agreement with Barrall regarding the need for accurate preparation of the insulation material in order to facilitate the even joining of the longitudinal edges of the material to form the tubular sleeve configuration. It is an advantage of the present invention that, unlike the teaching of Barrall and

Tippins, the semi-rigid foam spiral does not have to be of exactly the same dimensions as pipe to be insulated. Provided that the internal diameter (ID) of the foam spiral is smaller than the external diameter (OD) of the pipe to be insulated the semi-rigid nature of the foam means that it has sufficient "spring-back" to grip the pipe once installed. The spiral design also allows some latitude in the angle of winding and the gap between adjacent turns, particularly if the semi-rigid foam spiral is to be used in combination with an outer layer of insulating material. The fact that the spiral does not need to be bonded to the pipe or have its edges joined to form a tube has the additional advantage of allowing it to more easily accommodate any thermal expansion or contraction of the pipe being insulated.

While it is recognized that the helical winding of thermal insulation onto a pipe is already known to those skilled in the art, this method typically uses a flexible insulation in the form of a strip that is wound around the pipe and often requires specialized equipment to do this. For example, in US6283160 Hardy et al teach the helical winding of at least one strip of thermal insulation around a flexible pipe. One advantage of the semi-rigid foam spiral of the present invention is that it can easily be wound around the pipe or duct to be insulated without the need for specialist tools. A further advantage is that the pipe or duct to be insulated can be rigid or flexible, straight or curved.

US 4239064 (Gilman) discloses a tube which can be torn into a length of coiled insulation wrapping, which comprises at least two layers of a firm, foamed

thermoplastic polymer web which has been set into a coiled configuration.

US 2008/0128043 (Watkins) discloses a flexible insulating material which can be wound spirally around a length of pipe.

DE 102009053092 (Audi AG) discloses a stone chip protection unit for a spring element which has a protective hose encasing the spring element which is formed from a shock-absorbing and elastic material in the form of a spiral coiled tube having multiple windings.

DE 2412003 (Neumann) discloses a binding system for cables or rubber tubes which has a helically wound strip with interlocking edges.

GB 2373308 (Gresham Wood Industry Ltd) discloses an elongate spiral thermal guard for thermally isolating a member such as a pipe.

US 4,218,814 (Dart Industries Inc) discloses an elongate flexible tubular sheath having a longitudinal slit from end to end which can be helically wrapped around a conduit. SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, there is provided an elongate polymeric foam body for insulating a water pipe, wherein at least part of the body is in the form of a helix disposed around a longitudinal core, wherein the foam forming the helix has a thermal conductivity of less than 0.15 W/mK at 0°C and is sufficiently flexible to be able to move from a first configuration in which the longitudinal core has a first diameter to a second configuration in which the longitudinal core has a second diameter, the second diameter being greater than the first diameter, and wherein the foam forming the helix is resiliently biased into the first configuration, whereby in use the foam body can be moved from the first configuration to the second configuration to enable a water pipe to be disposed in the longitudinal core, the resilient bias of the foam causing the foam body to grip the water pipe.

None of the prior art documents employ a foam having a thermal conductivity of less than 0.15 W/mK at 0°C. The main advantage of the present invention is that by using a low thermal conductivity foam to form the semi-rigid foam spiral a reduced thickness of foam can be used to achieve the required level of thermal insulation or personal protection than if a higher thermal conductivity material were used. This reduction in the thickness of the insulation will make it easier to handle, install and maintain, particularly where the pipe or duct to be insulated is in a confined space, and it may also be accompanied by a reduction in weight. Any reduction in the weight of the insulation will reduce the overall weight of the pipe or ducting system and might allow the use of lighter weight brackets, hangers, fixings and the like. This would have significant benefits for pipe or ducting systems in mass transport applications, such as aircraft and trains, where weight savings can reduce fuel consumption, thereby reducing the environmental impact and making a significant contribution to reducing the operating costs over the lifetime of the vehicle.

The present invention is preferably a semi-rigid spiral of polymeric foam that can be used for the thermal or thermal acoustic insulation of pipework and ducting. The semirigid spiral can be fabricated from sheets, blocks, rolls, strips, tapes, tubes, rods or other shapes of foam, using techniques such as cutting, slitting, cold-forming, moulding, thermoforming or any other technique known to those skilled in the art. The foam can be heat welded or laminated by standard techniques to form spirals with any desired thickness length or thickness. Where thermal processes are used to form the spiral, as in the case of thermoforming for example, the surface of the foam may be provided with a closed skin due to a healing effect of the outermost cell walls, however, where cold- forming processes are used the surface of the foam may have a proportion of open cells from the cutting and slitting processes used to fabricate the material.

As regards the polymeric foam, polymeric foam insulation materials may be thermoplastic or thermoset and may have an open or a closed cell structure. Examples of polymeric foams used for pipe insulation include polyethylene, EPDM, polyurethane, polyisocyanurate, melamine, polyamide and polyvinylidene fluoride. They are typically characterised by their low density and low thermal conductivity, i.e. less than 0.04 W/mK at 0°C, although in certain specific applications thermal conductivities of up to 0.15 W/mK may be considered. In the present invention it is desirable for the foam to have sufficient rigidity to form a self-supporting spiral while retaining sufficient flexibility to allow it to be wrapped around the pipe or duct to be insulated.

It is contemplated that the semi-rigid spiral could also be formed from a composite structure of various layers, selected from any number of polymeric foams, films, foils, textiles, reinforcements and other materials known to those skilled in the art. Such a composite structure could be prepared by heat lamination, adhesive bonding, sewing or other techniques known to those skilled in the art. Individual layers could have different functional characteristics such as thermal conductivity, temperature resistance, weatherability, fire performance, colour or identification markings. It is further contemplated that the semi-rigid spiral could be used in combination with insulation in any of the other known formats described previously, including semi-circular half sections, tubes, strips, rolls and sheets. Although the present invention has been described with particular emphasis on the thermal or thermal acoustic insulation of pipework and ducting, there are many other applications wherein the inherent benefits of polymeric foam combined with ease of installation would be advantageous. For example, the cushioning properties of the foam make it suitable for impact protection on pipes, posts, barriers, handrails, scaffolding poles and the like. In addition to those examples given above, transportation applications including the protection of ship's railings and roll-bars and cages in vehicles are contemplated, and further applications include impact protection and cushioning on animal stalls, pens, cages and the like. The present invention can also be used on the support poles of swings, trampolines and other playground equipment to protect children from accidental injury. Sporting applications include impact protection on rugby and American football posts and the support poles of basketball hoops and the like. On a smaller scale, grips for bats, racquets, handlebars and other sporting equipment are also contemplated. Further applications include grips for canoe and kayak paddles and rowing oar handles, where the selection of a closed cell foam would impart additional buoyancy, and the handles of rowing machines and other gym equipment.

The present invention has use in medical applications as a wrap to provide localized support and impact protection, in planned or emergency situations, particularly in the area of orthopaedics and fractures. It could find similar applications in veterinary medicine, for example, in the protection or treatment of the legs of animals such as horses. In such applications the selection of a closed cell foam would provide a barrier to liquids, micro-organisms and dirt, and, if the polymer was selected from those known to those skilled in the art as breathable, for example a polyether block amide (PEBA), it would also allow sweat and moisture to pass through.

Another use of the present invention is that it can be used to provide protection to the trunks of newly planted trees and saplings that might otherwise be subject to attack by insects or animals. The nature of the present invention is such that it is easily installed and, once installed, it allows for some expansion of the trunk as the tree grows. It can also be designed such that the young tree or sapling can flex in the wind allowing the development of a strong root system. Further horticultural applications include grips for long handled tools and other gardening equipment.

The inherent insulation properties of the present invention also make it suitable for use as a beverage can, cup or bottle holder, commonly known as a koozie. In such applications the present invention could be decorated with advertising or promotional information. It is also contemplated that in this application the present invention might be considered disposable, for example at sporting events, concerts or festivals, and in such cases it would be advantageous if the polymer were selected from those known to be biodegradable or compostable. Further applications of the present invention include packaging, and in particular returnable packaging, for tubes, rods, bottles, cylinders and the like. The present invention can also be used to cover the framework of cages, stillages or racks to prevent the contents being scratched or damaged in some other way. The present invention can also find use in cable management and can further be used as an electrical insulation. Where the polymeric foam of the invention is closed cell, the present invention can also be used to impart buoyancy to an object as mentioned previously with regard to watersports. A semi-rigid spiral of polymeric foam may be provided that can be used for the thermal or thermal acoustic insulation of pipework and ducting. The semi-rigid spiral can be fabricated from sheets, blocks, rolls, strips, tapes, blocks, tubes, rods or other shapes of foam, using a variety of hot or cold forming techniques. The foam can be heat welded, laminated or adhesively bonded by standard techniques to form a spiral with any desired length or thickness. The semi-rigid foam spiral can easily be installed around the pipe or duct to be insulated by helical winding without the need for specialist tools.

The foam body in accordance with the invention can also be used: (a) as an impact protector for a bar, barrier, pipe or section of scaffolding, or on animal stalls, pens or cages, to reduce the risk of impact damage or injury to an individual or animal;

(b) as a grip for canoe or kayak paddles or rowing oar handles;

(c) as a wrap to provide localized support and impact protection in a medical or veterinary application or in personal protective equipment; (d) as a grip for tools or gardening equipment;

(e) as a beverage can, cup or bottle holder;

(f) as packaging;

(g) for cable management; or (h) as an electrical insulator.

In accordance with an alternative aspect of the invention, there is provided an elongate polymeric foam body for insulating a water pipe, wherein at least part of the body is in the form of a helix disposed around a longitudinal core, wherein the foam forming the helix has a density of less than 200kg/m³ and is sufficiently flexible to be able to move from a first configuration in which the longitudinal core has a first diameter to a second configuration in which the longitudinal core has a second diameter, the second diameter being greater than the first diameter, and wherein the foam forming the helix is resiliently biased into the first configuration, whereby in use the foam body can be moved from the first configuration to the second configuration to enable a water pipe to be disposed in the longitudinal core, the resilient bias of the foam causing the foam body to grip the water pipe.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of the tightly wound semi-rigid polymeric foam spiral insulation of the present invention prior to installation.

FIG. 2 shows a perspective view of the semi-rigid polymeric foam spiral insulation of the present invention installed on a length of pipe. EXAMPLES

Example 1

A 500mm x 25mm x 5mm strip of Zotek NB50 (Zotefoams) polyamide foam, thermal conductivity 0.036 W/m.K at 0°C, was wound tightly around a 25mm diameter mandrel heated to a temperature of 230°C and the foam and mandrel were then allowed to cool to room temperature. The mandrel was then removed to leave a self-supporting semirigid polyamide foam spiral. The foam spiral was then wound around a 50mm diameter pipe without the need for any additional adhesives, tapes or mechanical fixings.

Example 2

A 750mm x 25mm x 5mm strip of Zotek F38HT (Zotefoams) polyvinylidene fluoride (PVDF) foam, thermal conductivity 0.030 W/m.K at 0°C, was wound tightly around a 25mm diameter mandrel heated to a temperature of 170°C and the foam and mandrel were then allowed to cool to room temperature. The mandrel was then removed to leave a self-supporting semi-rigid PVDF foam spiral.

Example 3

A 1200mm x 25mm x 6mm strip of Plastazote LD45 (Zotefoams) low density polyethylene (LDPE) foam, thermal conductivity <0.042 W/m.K at 0°C, was wound tightly around a 25mm diameter mandrel heated to a temperature of 120°C and the foam and mandrel were then allowed to cool to room temperature. The mandrel was then removed to leave a self-supporting semi-rigid LDPE foam spiral.

Claims

1. An elongate polymeric foam body for insulating a water pipe, wherein at least part of the body is in the form of a helix disposed around a longitudinal core, wherein the foam forming the helix has a thermal conductivity of less than 0.15 W/mK at 0°C and is sufficiently flexible to be able to move from a first configuration in which the longitudinal core has a first diameter to a second configuration in which the longitudinal core has a second diameter, the second diameter being greater than the first diameter, and wherein the foam forming the helix is resiliently biased into the first configuration, whereby in use the foam body can be moved from the first configuration to the second configuration to enable a water pipe to be disposed in the longitudinal core, the resilient bias of the foam causing the foam body to grip the water pipe.

2. A foam body as claimed in claim 1 comprising a first layer of polymeric foam which has a thermal conductivity of less than 0.15 W/mK at 0°C and one or more additional layers selected from foams, films, foils, textiles and reinforcing material.

3. A foam body as claimed in Claim 1 or 2, wherein the polymeric foam has a thermal conductivity of less than 0.04 W/mK at 0°C.

4. A foam body as claimed in Claim 1 or 2, wherein the polymeric foam has a thermal conductivity of less than 0.15 W/mK at 150°C.

5. A foam body as claimed in Claim 4, wherein the polymeric foam has a thermal conductivity of less than 0.07 W/mK at 150°C.

6. A foam body as claimed in Claim 5, wherein the polymeric foam has a thermal conductivity of less than 0.055 W/mK at 150°C.

7. A foam body as claimed in any preceding claim, wherein the polymer is a thermoplastic.

8. A foam body as claimed in any preceding claim, wherein the polymeric foam has a density of less than 200kg/m³.

9. A foam body as claimed in Claim 8, wherein the polymeric foam has a density of less than 100kg/m³.

10. A foam body as claimed in Claim 9, wherein the polymeric foam has a density of less than 60kg/m³.

11. A foam body as claimed in any preceding claim, wherein the polymeric foam is closed cell.

12. A foam body as claimed in any preceding claim, wherein the polymeric foam is crosslinked.

13. The preparation of the multilayer structure according to Claim 2 by heat lamination or adhesive bonding.

14. The transformation of the polymeric foam insulation according to Claim 1 or 2 into a continuous or semi-continuous spiral of any desired length by welding, laminating or adhesive bonding.

15. The use of a foam body as claimed in any of claims 1 to 12 as insulation for rigid or flexible pipes and ducts in industrial process equipment and installations.

16. The use of a foam body as claimed in any of claims 1 to 12 as insulation for rigid or flexible oil and gas pipelines.

17. The use of a foam body as claimed in any of claims 1 to 12 as insulation for rigid or flexible pipes and ducts in buildings.

18. The use of a foam body as claimed in any of claims 1 to 12 as insulation for rigid or flexible pipes and ducts in vehicles.

19. The use of a foam body as claimed in any of claims 1 to 12 to protect sapling or tree trunks or branches from damage.

20. The use of a foam body as claimed in any of claims 1 to 12 as an impact protector for a bar, pipe or section of scaffolding, to reduce the risk of impact damage. A pipe having a foam body as claimed in any of claims 1 to 12 fitted thereon.