WO2006070273A1

WO2006070273A1 - Aluminium heating appliance with a new concept

Info

Publication number: WO2006070273A1
Application number: PCT/IB2005/003914
Authority: WO
Inventors: Stefano Ragaini
Original assignee: Rag-All S.P.A.
Priority date: 2004-12-31
Filing date: 2005-12-30
Publication date: 2006-07-06
Also published as: ITAN20040067A1

Abstract

An element (2) for space heating, preferably made of die-cast aluminium, is described in which the means (4, 5, 6) of transfer of the heat of the carrier fluid to the room consist exclusively of the structure of the element (2) itself. Said element (2) - can be pressed in a mould whose shells can open up parallel to the axes of said means (1.1, 3) through which the heat carrier fluid crosses, - and has no undercuts in the said mould opening direction. An end plate (2.t) that conceals the parts connecting the radiator to the heating system is also described. The invention can be used to form radiators with elements (2, 2.t) positioned both vertically or horizontally with a range of different shapes.

Description

RGL.005.PCT

ALUMINIUM HEATING APPLIANCE WITH A NEW CONCEPT

DESCRIPTION

The object of the present invention is a radiator, preferably in aluminium alloy, for space heating or similar applications obtained through casting or die-casting. There are three main types of heating appliances for space heating systems:

- radiant panels that mainly emit heat by radiation and usually consist of pipes laid in the floor or ceiling,

- fan coils that mainly emit heat by forced convection and consist of finned coils in which air circulates by way of a fan,

- radiators that, irrespective of their name, emit heat both by radiation and natural convection. The radiators usually consist of a sufficient number of similar elements placed side by side to guarantee the necessary thermal power. They can be obtained in a variety of ways:

- pressed sheet steel half-shells welded together,

- iron casting, - aluminium alloy die-casting,

- steel or aluminium tubular structures that are welded or mechanically connected together.

A characteristic common to all known radiators is the fact that the thermal carrier fluid crosses the entire heating appliance circulating in parallel in a series of distribution pipes that lead to two headers, one inlet and the other outlet, placed on the edges; these are connected to the heating system. Fig. 1 enclosed shows schematically a die-cast aluminium radiator.

Each element includes a section of each of the two headers and one or more distribution pipes, the ends of which lead to the said header sections. Moulding of the distribution pipes in the sheet steel radiators is not a problem since they can be easily obtained during pressing of the half-shells. However, this type of radiator has certain limitations due to its tendency to corrosion and significant difficulty in obtaining aesthetically pleasing shapes. With regard to tubular radiators, in addition to serving as headers and distribution pipes, they have structural, aesthetic and support functions; towel- warmer distribution pipe radiators, used in hotels for towels, are a well-known example. Tubular radiators are the most suitable for meeting the growing need for heating appliances that are also items ,of furniture and offer a variety of different shapes that are capable of emitting heat efficiently. The manufacturing of distribution pipes, on the other hand, presents technical problems in radiators obtained through casting since removable cores are required in the die. In cast-iron radiators, the internal cores are disposable and made of compacted sand that disintegrates with vibrating machines, hi those made of die-cast aluminium (hereon, simply referred to as aluminium radiators), the cores are usually metal and can be removed. As illustrated in Fig. 1, that will shortly be discussed in detail, the core outlet hole in aluminium radiators is then closed with a flash-welded plug. The first significant problem with distribution pipes is therefore that of production costs. On the other hand, there is no aesthetic problem with the welded plug since, according to the known state of the art, there are minimum aesthetic differences between one aluminium radiator model and another and elements are always positioned vertically; i.e. with distribution pipes positioned with a vertical axis. As a result, the plug is concealed. This standardization, that gives little space to aesthetic differences, is however only the result of the mistaken conviction that the known constructive limitations of die-cast radiators cannot be avoided and, as a result, this type of radiator is not suitable for strange or unusual shapes. Document GB1286214 shows radiator elements made of aluminium alloy that have been die-casted; the figures illustrate how the two parts (or shells) of the die-cast mould must open up orthogonally to the front side and the thermal carrier fluid distribution pipe axis and how the cavity of this pipe forms an undercut that requires a "movement" duct in the mould, i.e. a plug that can be removed parallel to the pipe axis.

Document EP1258694 shows a radiator made of pressed sheet steel the shape of which is dictated by production technology and operating principles and, as a result, is ill- suited to aesthetic differences. Documents EP0183211, DE3237351, DE9112267U and DE20006211U show radiators made of extruded aluminium sections with tubular elements as described above; they are suitable for some aesthetic solutions but not the type that will be described in this invention.

Document DE3915272 illustrates a electric radiator comprising a shell-type electrical resistance heater and pressed sheet steel that, as can be seen, is far removed from the means and aims of this invention.

A first aim of this invention is to simplify the production process for elements in metal alloy radiators that are casted or die-casted.

A second aim of this invention is to simplify the production process for elements comprising radiators that are obtained by aluminium alloy diecasting. A third aim of this invention is to reduce the constructive and geometrical limitations of said elements.

A fourth aim of this invention is to eliminate the aforementioned outlet hole of the core and plug in said elements. A fifth aim of at least some variants of this invention is to indicate elements that can be installed horizontally or, at least for some models, both horizontally and vertically.

A sixth aim of at least some variants of this invention is to indicate end plates that are suitable for concealing the heating system connection valves.

A seventh aim of at least some variants of this invention is that of indicating methods of constructing elements that are suitable for obtaining shapes that are very different from those according to the known state of the art. These and other aims are achieved with elements and radiators comprising these elements built as described below, in the enclosed claims that are an integral part of the description and as illustrated in the enclosed drawings.

Fig. 1 shows a side view, a front cross-section and a cross-section from above of an aluminium radiator according to the known state of the art.

Fig. 2 shows a side and rear view, and a possible first version of an element placed vertically of an aluminium radiator according to the invention.

Fig. 3 shows a side and front view of an aluminium radiator according to the invention consisting of elements illustrated in Fig. 2. Fig. 4 shows a side and front view of an aluminium radiator according to the invention consisting of elements illustrated in Fig. 2 as well as two end plates.

Fig. 5 shows a front, side and rear view of a second variant of an element, of an aluminium radiator according to the invention.

Fig. 6 shows a side view and a view from above of an aluminium radiator according to the invention consisting of elements positioned horizontally and shaped according to a third variant.

Fig. 7 shows a front view and a view from above of an aluminium radiator according to the invention consisting of elements that are horizontally positioned and shaped differently for special aesthetic effects. With reference to Fig. 1, an aluminium radiator element 1 according to the known state of the art includes two headers 1.1, one inlet and the other outlet of the thermal carrier fluid that crosses the entire body of the element 1 along one or more distribution pipes

1.2. These distribution pipes 1.2 are obtained during the die-casting process with special cores that are then extracted; the corresponding extraction hole is then sealed with a soldered plug 1.3. Fins 1.4 increase the efficiency of heat exchange by natural convection.

Clearly, this element must be placed vertically; more precisely, the axis of the two headers 1.1 must be horizontal and the plug 1.3 must be placed in the lower part and concealed. With reference to Fig. 2, element 2 according to the invention consists of one or more ducts 3 with parallel axes with a single inlet and single outlet 3.1 for connection in a known way to adjacent elements 2 and/or the heating system. Rib 4 mainly extends along the whole length of element 2 and is positioned mainly orthogonal to the axes of said ducts 3. Element 2 includes panelling 5 directed towards the room to be heated. Element 2 is obtained through pressing using a mould, the shells of which open up parallel to the axes of one or more ducts 3. It can be seen that element 2 has no undercuts in that direction: the rear and front surfaces of said panelling 5 are mainly parallel (except for a draft angle) to the axes of said one or more ducts 3 but can be flat, angular or curved. Using stricter geometric terminology, said panelling 5 (except for the draft angle) has ruled surfaces with the generating line parallel to the axes of one or more ducts 3 and a guide line that may be straight, split or curved. It should be noted that, according to the invention, heat is transferred by the thermal carrier fluid to the external surfaces of heat exchange with the room exclusively by conduction through the body made of conductive material of element 2 which does not have distribution pipes 1.2, that are present in radiators according to the known state of the art.

First of all, the production process of mould shaping has clearly been simplified because of the lack of undercut holes; the absence of welded plugs 1.3 that must be concealed also offers new aesthetic options. In the element 2 of Figure 2, as in the similar elements for other variants shown in subsequent figures, there are two ducts 3 symmetrically arranged in relation to the centre plane C - C and markedly distant from the edges; in the figure, the distance of the ducts 3 from the edges is equal to ¹A of the total height H of element 2. This arrangement, that is not essential for the invention but to be preferred, offers the advantage of a more uniform distribution of the heat flow from ducts 3 to the external surfaces. If total symmetry in relation to the centre plane C - C is preferred, element 2 can be assembled in reverse order.

The rib 4 shown in Figure 2 has a tapered profile; this may simply meet aesthetic needs but can also lead to a saving in material since the section of said rib 4 can be reduced in the areas with less heat flow running through them. This can be obtained by varying the thickness Sn and the width L of said rib 4.

Unlike Figure 2, there may be any number of ducts 3, even only one, depending on the dimensions of element 2, and they should always be placed symmetrically in relation to the centre plane C - C. Nonetheless, asymmetrical forms for the arrangement of the ducts 3 and/or shape of rib 4 and/or panelling 5 may be preferred especially for aesthetic reasons and it becomes clear that element 2 according to the invention is particularly suitable in said variants because there are no distribution pipes 1.2. If we examine Fig. 3, a radiator R according to the invention is obtained by placing several elements 2 next to each other; the entry of the thermal carrier fluid from the heating system via a thermal expansion valve (or simply an on-off valve) 8 is shown in the top right; the thermal carrier fluid crosses the whole radiator R passing in series through a first series of ducts 3; at the exit it encounters a bleeder valve 9 and via a return pipe 10 then flows along a second series of ducts 3 before it returns to the heating system via an on-off valve 11. If additional series of ducts 3 were present, these would also be crossed in series. However, there is nothing to prevent each series of ducts 3 being fed in parallel by way of distribution and collection pipes that run alongside said elements 2.

Fig. 4 illustrates a radiator R according to the invention with two possible end plates 2.t whose sole purpose is to close off the sides of radiator R in an aesthetically pleasing way. These end plates 2.t can be similar to elements 2 except that the ducts 3.t they contain extend from the side facing outwards less than the corresponding ducts 3 of said elements 2 so that said heating system connection elements (thermal expansion valve 8, bleeder valve 9, return pipes 10 and on-off valve 11) can be concealed behind the panelling 5 on the back of the rib 4. Fig. 5 illustrates how the efficiency of the heat exchange of an element 2 can be improved by using fins 6 that increase the exchange surface and can be attached to the rib 4 and/or panelling 5. Slits 7 that extend from the side edges 8 of the panelling 5 towards the central part can also be included. They improve air circulation from the rear part to the front. They improve air circulation from the rear part to the front. For both aesthetic reasons and heat efficiency, elements 2 can be positioned horizontally with the duct 3 axis placed vertically. This is perfectly possible with the elements 2 and end plates 2.t already shown; however, Fig. 6 illustrates an additional element 2 with holes 12 cut in the rib 4 to improve air circulation. Fig. 6 illustrates the wide range of shapes available according to the invention: note that the front surface 5.1 of element 2 has been designed by intersecting the lying plane 3.2 of the duct 3 axes; this would be impossible to achieve with aluminium radiators according to the known state of the art because of the presence of distribution pipes. Finally, always depending on the pressing method used, Fig. 7 illustrates how the side edges 8 can be curved in a variety of ways thus permitting an infinite range of aesthetic effects previously unheard of in the manufacturing of mass-produced elements 2. Using stricter geometric terminology, the side edges 8 of the ruled surfaces comprising said panelling 5 are obtained when said rules surfaces intercept general curved surfaces. Obviously the absence of distribution pipes slightly reduces the thermal power emitted by an element 2 according to the invention but this is perfectly acceptable given the advantages obtained in terms of ease of manufacturing and the very wide range of shapes available.

As an example, an element 2 as in Fig. 2, i.e. without fins 6, slits 7 and holes 12 positioned vertically with: - height H of 600 mm,

- depth A (maximum width of rib 4) of 60 mm,

- width L of panelling 5 of 85 mm,

- thickness Sn of rib 4 of 2 mm,

- thickness Sn of panelling 5 of 2 mm, - centre distance I between ducts 3 of 300 mm,

- inner diameter of ducts 3 of 1 ", supplied thermal power of 48 W when tested in accordance with the EN 442 standard whereas a state-of-the-art standard aluminium radiator element of the same height, 52 mm deep and 80 mm wide, supplied approximately 59 W when subjected to the same test procedure.

Claims

1. Radiator (R) element (2) for space heating with a thermally conductive material structure using a thermal carrier fluid supplied by a heating system as a source of heat obtained through metal casting and comprising

— means (1.1 ; 3) through which heat carrier fluid crosses said element,

- means (1.2; 4, 5, 6) for transfer of heat from inner surface of said one or more ducts to special heat exchange surfaces (1.4; 5, 6)

- said means (1.1; 3) for crossing said element consisting exclusively of one or more ducts (3), each one with only one inlet and only one outlet

(3.1)

- and said means (1.2; 4, 5, 6) of heat transfer consisting exclusively of said structures (4, 5, 6) of thermally conductive material. characterized in that said element (2)

— can be pressed in a mould whose shells can open up parallel to the axes of said means (1.1, 3) through which the heat carrier fluid crosses,

- and has no undercuts in the said mould opening direction.

2. Radiator (R) element (2) according to the previous claim characterized in that said structure in conductive material (4, 5, 6) includes a lying rib (4) that is positioned mainly orthogonal to the axis of one or more ducts (3).

3. Radiator (R) element (2) according to the previous claim characterized in that said rib (4) has area sections that vary from point to point since said area is mainly proportional to the heat flow that passes through these sections.

4. Radiator (R) element (2) according to the previous claim characterized in that said variations in section are obtained irrespective of variations in the thickness (Sn) and/or depth (A) of said rib (4). 5. Radiator (R) element (2) according to at least claim 2 characterized in that in said rib (4) holes (12) are cut to improve air circulation and consequently activate convective heat exchange. 6. Radiator (R) element (2) according to any claim from 1 to 5 characterized in that said structure in conductive material (4,

5,

6) includes lying fins (6) that are positioned mainly parallel to the axis of one or more ducts (3) and designed to improve convective heat exchange.

7. Radiator (R) element (2) according to any claim from 1 to 6 characterized in that said structure in conductive material (4, 5, 6) includes panelling (5) with ruled rear and front surfaces with the generating line parallel to the axes of one or more ducts (3) and a guide line that may be straight, split or curved.

8. Radiator (R) element (2) according to the previous claim characterized in that if there are two or more of said ducts (3), the front surface (5.1) of said panelling (5) can intersect the resting plane (3.2) of the axes of at least two of the said ducts (3).

9. Radiator (R) element (2) according to at least claim 7 characterized in that said panelling (5) has slits (7) that extend from the side edges of the panelling

(5) towards the central part to allow air circulation.

10. Radiator (R) element (2) according to one or more of the previous claims characterized in that one or more of said ducts (3) are symmetrically arranged in relation to the centre plane C - C.

11. Radiator (R) element (2) according to claim 10 characterized in that the entire element is symmetrical in relation to the centre plane C - C.

12. Radiator (R) element (2) according to any previous claim characterized in that said casting consists of die-casting of suitable aluminium alloys according to the known state of the art.

13. Radiator (R) element (2) according to any previous claim characterized in that the side edges (8) of the ruled surfaces comprising said panelling (5) are obtained when said rules surfaces intercept general curved surfaces.

14. End plate (2.t) for radiators (R) for heating with structure (4, 5, 6) in thermally conductive material using a thermal carrier fluid supplied by a heating system as a source of heat characterized in that it can be shaped and manufactured like an element (2) for radiators (R) according to one or more of the claims from 1 to 11 except that the ducts (3.t) they contain extend from the side facing outwards less than the corresponding ducts (3) of said elements (2) so that said heating system connection elements

(8, 9, 10, 11) can be concealed behind the panelling (5) close to the rib (4).

15. Radiator (R) for space heating using a thermal carrier fluid supplied by a heating system as a source of heat characterized in that it includes one or more elements (2) according to one or more claims from 1 to

13 and/or one or two end plates (2.t) according to claim 14.

16. Radiator (R) for space heating according to claim 15 characterized in that said ducts (3, 3.t) are arranged with a horizontal axis.

17. Method for the pressing of elements (2) or end plates (2.t) for radiators (R) for space heating where said elements (2, 2.t)

- are made of thermally conductive material

- use a thermal carrier fluid supplied by a heating system as a source of heat,

- consist of one or more ducts (3), each one with one inlet and one outlet (3.1) and a lying rib (4) that is positioned mainly orthogonal to the axis of one or more ducts (3), characterized in that the mould shells open up parallel to the axes of one or more ducts (3).