GB2037971A

GB2037971A - Heating pipe

Info

Publication number: GB2037971A
Application number: GB7908140A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-12-09
Filing date: 1979-03-08
Publication date: 1980-07-16
Also published as: NL7901881A; GB2037971B; FR2443656A1; PT69197A; GR68480B; DE2853234A1; LU80860A1; SE7902112L; ES241862U; BE875112A; IT1123998B; IT7912489A0; ES241862Y

Abstract

A heating pipe (12) for use in floor, wall and ceiling heating and made of a flexible, heat-resistant, thermally conducting plastics material is formed with metal fins 14 which extend laterally therefrom. The fins (14) are integral with a central strip (16) which is bent so as to conform to the cross-sectional shape of the pipe (12) and where the pipe is circular in cross-section may extend therearound by mole than 180 DEG so as to be a snap fit therearound. The strip (16) may in addition or alternatively be stuck to the pipe or welded thereto. By staggering the fins (14) so that they extend alternately first from one side and then the other side of the central strip (16) an even distribution of heat and even strengthening is provided around the pipe section. The integral central strip and fins are preferably formed from aluminium or an aluminium alloy. <IMAGE>

Description

SPECIFICATION Heating pipe FIELD OF INVENTION The invention relates to a heating pipe made of a flexible, heat-resistant and thermally conducting plastics material, of the type used in floor, wall and ceiling heating.

BACKGROUND TO THE INVENTION Pipes of the type referred to can be used for heating by passing hot water through them. If desired and required, they can also be used for cooling or for general air-conditioning, in which event cold water or a cooling medium is passed through them. They can equally well be installed internally in floors, walls and/or ceilings of rooms and externally in areas of concrete or asphalt for heating or cooling same. These can include airfields, traffic areas or other surfaces the temperature of which is to be controlled usually to free them from ice by heating.

The heating pipes are usually laid, using holding clips, clamps or the like, in the shape of loops, Sbends or the like. Internally they are laid on supporting base structure, and are then covered over and embedded in with a composition floor, concrete or some other floor covering. When this forms the floor of a room, a floor covering of this kind is then typically covered over again with plastic tiles or the like.

The transference of heat from the heating pipes into the composition floor, concrete or the like in which they are embedded is effected by thermal conduction. The same is true when the heating pipes are used for cooling purposes. The amount of heat transferred depends chiefly on the thermal conductivity of the plastics material used for the heating pipes. The ability of plastics to conduct heat is limited, and only low values of thermal conductivity usually apply. The selection of a suitable plastics material is usually also governed by the requirement that the material will exhibit a high degree of flexibility to facilitate laying. Other factors such as a long life and resistance to ageing must also be taken into account.

As a resuit, the transfer of heat from such heating pipes by conduction into a composition floor or concrete or other material in which they are embedded, rarely reaches the high value of conduction which, from the point of view of heating technology, is desirable.

Another point which should be mentioned is that the composition floor, concrete or the like in the immediate vicinity of the heating pipe is usually found to be heated particularly strongly.

The flow of heat away from the pipe and immediately surrounding floor material can be improved by adding agents which increase the conduction of heat into the composition floor or concrete. In spite of this, the temperature in the floor material immediately adjacent to the heating pipes is invariably higher than the mean temperature elsewhere in the floor. The temperature differences arising from this can lead to stresses, which in turn may cause cracks to appear in the composition floor or concrete over and adjacent to the heating pipes.

OBJECT OF THE INVENTION The present invention seeks to provide a heating pipe which will more effectively transfer heat into a surrounding material, and also of providing means which will counteract the tendency to form cracks in the material due to temperature differentials therein around the pipe.

THE INVENTION According to the present invention, a heating pipe is formed with metal fins extending out laterally theretrom.

Metals generally have high thermal conductivity, usually considerably higher than that of plastics material. The heat flowing from the plastics material of the heating pipe into the fins is therefore quickly conducted away in the fins and transmitted to the composition floor, concrete or the like which surrounds them. A s a result of a close, direct contact between the plastics material of the heating pipe and the fins which lie directly on it, the heat flows directly and quickly from the heating pipe into the fins to be conducted away laterally by the fins and transmitted to the surrounding material such as a composition floor, concrete or the like.

If the plastics heating pipe and the fins extending from it are considered as a single unit from a heat transfer point of view, then the fins not only increase the overall thermal conductivity of the heating pipe, but also its effective surface area. Preferably the fins are thin.

With the improved dispersion of heat which results from this, temperature peaks in the immediate vicinity of the heating pipe are avoided and the floor is heated more evenly. Due to the reduction orthe complete absence of temperature peaks, the danger that cracks will form is also reduced. Indeed the possibility of cracks forming due to local heating is very greatly decreased with a heating pipe constructed according to the invention, since the fins extending into the surrounding material, such as a composition floor, concrete or the like, serve to strengthen or reinforce the latter. In this connection, the fins perform a function similar to that of the steel inserts in steel-reinforced concrete structures. The invention, therefore, combats the formation of cracks in two ways.

Whilst the fins may simply be laid on the upper surface of the heating pipe to make contact therewith, they are preferably attached to the pipe.

There are several possible ways of doing this, some of which will now be described.

In one preferred embodiment of the invention, the fins are spaced out along the length of the heating pipe at intervals corresponding to the width of the fins. With a plurality of such fins with this kind of mutual spacing, the overall internal effect in surrounding material is not interrupted.

The formation of hollows or pockets in the composition floor or concrete which might otherwise arise under one, large-surface fins is also avoided.

Advantageously, the fins extend alternately on opposite sides of the heating pipe. To simplify their attachment to the heating pipe, the fins form an integral part of a central strip and extend from opposite sides thereof, the central strip being bent round to conform to the outer curved surface of the heating pipe. The central strip is laid on the pipe during the formation of the floor (wall or ceiling) and makes contact therewith.

This central strip bearing the fins may be a simple, stamped part, made from sheet metal. A large or small number of fins may extend from a single central strip, but whether large or small, this number of fins can be laid on the heating pipe and connected to it in a single operation.

A close fit between the central strip and the heating pipe to ensure good heat transference is enhanced by bending the central strip around to conform to the shape of the heating pipe.

Preferably the central strip is bent through an arc of 1 800, so that it encircles half the circumference of the heating pipe.

However, the central strip may be bent around through more than 1800, in which event the central strip has to be forced over the heating pipe, the heating pipe being slightly compressed in the process, so that the strip is a snap fit on the heating pipe.

Preferably the fins extend alternately from the two sides of the central strip and lie in mutual interstices. A fin on one side of the strip therefore always lies opposite a free space on the other side of the strip. Production is thereby simplified, since several central strips with integral fins can be stamped out, without any waste, from one large piece of metal sheet, in a single operation, the fins on one central strip being disposed in the interstices (i.e. intermediate spaces) between the fins of adjacent strips.

The central strip may be attached to the pipe by gluing, welding, or pressing or forcing.

The number of fins on a single central strip is not limited, but to simpiify production and assembly, the dimensions of a single strip are preferably selected so that the overall bounding shape of the central strip and the fins is square.

The central strip and the fins are made of a metal with high thermal conductivity. Silver and copper are metals with particularly high thermal conductivity but are normally excluded on the grounds of cost. Aluminium or aluminium alloys also have high thermal conductivity and are usually cheaper and therefore to be preferred.

Whether the central strip with the fins should be laid on and connected to a heating pipe already laid, or whether it should be attached to the heating pipe in advance, coiled with it on a drum or the like and delivered to the installation site in this state, as a structural unit, depends on the local situation at the installation or embedding site.

The invention will now be described by way of example with reference to the accompanying drawings.

IN THE DRAWINGS Fig. 1 is a perspective view of a section of heating pipe having attached thereto a central strip with integral, laterally extending fins, Fig. 2 is a plan view of the section of heating 'pipe shown in Fig. 1, Fig. 3 is a cross-section on the line 3-3 in Fig.

2, Fig. 4 is a cross-section similar to that shown in Fig. 3 of an embodiment of the invention in which the central strip is bent round through more than 1800, Fig. 5 is a perspective view of heating pipes which have been laid and fixed with battens and clamps and have fins attached to them, Fig. 6 is a cross-section through a floor as shown in Fig. 5 after the heating pipes have been embedded in material forming a composition floor, Fig. 7 is a perspective view, partially cut away and partially sectioned, of a composition floor with heating pipes bearing fins laid therein.

DETAILED DESCRIPTION OF THE DRAWINGS Figs. 1 to 4 show a section of heating pipe 12 with the fins 14 extending laterally from a central strip 1 6 laid thereon. The fins 14 and the central strip 1 6 form a single component. The central strip 1 6 is bent around to conform to the circular shape of the heating pipe 12. In the embodiment shown in Figs. 1 to 3 the central strip 1 6 is bent through an arc of 1 800 and therefore lies over the upper half of the heating pipe 1 2.

In the embodiment shown in Fig. 4 the central strip 1 6 extends further around the pipe and covers an arc of more than 1800. Owing to its resilience and the resilience of the heating pipe, this form of central strip 1 6 can be clamped around the heating pipe 12.

Figs. 5 to 7 show battens 1 8 extending across a base 22 for a floor. Clamps 20 are placed on the battens 18. The base 22 may for example be a layer of concrete. The heating pipes 1 2 are inserted in their turn in the clamps 20 and are thereby held and secured as required.

In Figs. 6 and 7 the heating pipes 12 with the fins 14 and the battens 18 and clamps 20 which hold them are shown embedded in a composition floor 24. This is covered over on top with a floor covering 26, such as plastics tiled, for instance.

Figs. 5 to 7 show particularly clearly how the fins 1 4, which extend into the composition floor 24, acts as reinforcing elements. The fins extend on opposite sides of the heating pipes 1 2 into the material of the floor in which the temperatures are highest during heating, so as to strengthen the composition flooring 24 and counteract the tendency to form cracks.

It is to be understood that the foregoing is merely illustrative of the invention described herein and the scope of the invention is determined by the following claims.

Claims

1. A heating pipe of flexible, heat-resistant and thermally conducting plastics material which is formed with metal fins which extend laterally therefrom to improve the dissipation of heat from the pipe into a surrounding material.

2. A heating pipe as claimed in claim 1 in which the fins are attached to the upper surface of the heating pipe.

3. A heating pipe as claimed in claim 1 or 2 in which the fins are spaced out along the length of the pipe at intervals corresponding to their width.

4. A heating pipe as claimed in any of claims 1 to 3 in which the fins extend on both sides of the pipe.

5. A heating pipe as claimed in claim 4 in which the fins are integral with a central strip and extend laterally therefrom, the central strip being bent round to conform to the cross-sectional shape of the heating pipe to facilitate the location of the central strip on the pipe and its connection thereto.

6. A heating pipe as claimed in claim 5 in which the pipe is circular and in which the central strip is bent round through an arc of more than 1800 to allow it to be clamped onto the heating pipe.

7. A heating pipe as claimed in claim 5 or 6 in which the fins extend alternately from one side and then the other along the length of the pipe, so that the fins on one side lie in the interstices of the other.

8. A heating pipe as claimed in any of claims 1 to 7 in which the central strip is glued to the heating pipe.

9. A heating pipe as claimed in any of claims 1 to 7 in which the central strip is welded onto the heating pipe.

10. A heating pipe as claimed in any of claims 1 to 7 in which the central strip is pressed over the heating pipe.

11. A heating pipe as claimed in any of claims 1 to 10 in which the length of the pipe section and the length of the fins is such that the pipe and fins have the shape of a square.

12. A heating pipe as claimed in any of claims 1 to 11 in which the central strip and the fins are formed from aluminium or an aluminium alloy.

13. A heating pipe as claimed in any of the preceding claims when embedded in a floor or wall or ceiling.

14. A heating pipe constructed and arranged substantially as herein described with reference to and as illustrated in Figs. 1 to 3 or Fig. 4 of the accompanying drawings.