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(11) | EP 0 838 654 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Modular radiator |
| (57) A radiator, specifically a household radiator, of the type consisting of a plurality
of metal heating elements, each one formed by manifold elements and at least one radiant
element, which are obtained separately and then connected together. According to the
invention, the radiant element (6) is connected with the manifold elements (5) by
a male-female coupling and mechanical means (17,22) are provided, which prevent the
female acting element (23 or 15) to withdraw from the male acting element (15 or 23). |
[0001] The present invention relates to a radiator, specifically a household radiator, of the kind consisting of a plurality of metal heating elements, each one formed by manifold elements and at least one radiant element, which are realized separately and then connected together.
[0002] Household radiators are conventionally obtained by connecting in series a plurality of heating bodies, each one obtained by casting, wherein water or the fluid used as the vector for the thermal energy are flowing. Said heating bodies consist in main line of a plurality of upright tubes acting as radiant elements to ensure thermal exchange with the environment; said upright tubes end up in hollow manifold elements usually provided with a large diameter hole in a middle position. Through the arrangement in series of a plurality of heating elements and connecting them through said holes in the manifolds, two conduits are obtained, i.e. an upper and a lower pipe, the upper conduit usually representing the fluid inlet conduit to the radiator and the lower one the outlet conduit.
[0003] The holes on the manifolds forming each conduit are usually coupled by means of threaded bore plugs of the so-called "GAS" type, as used for the coupling of water pipes or through blind plugs.
[0004] Composable or sectional radiators are also known, where the manifold elements and the heating tubes of one same heating body are manufactured separately and subsequently coupled together during assembly.
[0005] Coupling is usually done by welding the tubes on proper protrusions provided on the manifold elements.
[0006] The welding process carried out at temperatures dependent on the kind of materials involved, however in the order of several hundreds of centigrade degrees, has several drawbacks.
[0007] First of all, the induced expansion of metal elements during welding, specifically in the manifold elements, causes some permanent deformations that will impair a subsequent alignment of the manifolds when the radiator inlet and outlet conduits have to be formed. As a result, pipes will not be straight and due to their segmented structure they are also weaker to mechanical stresses, introducing resistances in the hydraulic circuit and having an unsightly appearance, above all when used for household applications.
[0008] Secondly, since welding has not the same degree of efficiency for all materials, only a restricted range of metals is available for the production of tubes and manifolds.
[0010] For instance, oxygen available in water tends to dissociate with heating, thus favoring oxidation and corrosion.
[0011] Microsuspensions in water tend to deposit within the hydrothermal circuit where there is a lower fluid rate (typically the manifolds); such a deposit of microsuspensions causes an initial oxidation of the iron contained either in the steel or alloy being used.
[0012] Following the above considerations, manifold elements - wherein as said above microsuspensions accumulate and corrosion is started - are needed, which are made of alloys where iron oxidation is difficult, such as cast iron or iron-free alloys, e.g. brass.
[0013] On the contrary, upright tubes are subject to little corrosion or no corrosion at all, since, due to their particular arrangement, microsuspensions will not deposit on their walls.
[0014] Therefore, selection of materials to make upright tubes should be made according to other parameters, such as maximization of the radiant power or material costs for low-cost radiators.
[0015] However, as already mentioned above for welded couplings, this opportunity is not merely reached with the use of composable or sectional structures, since there are also technical problems associated with the nature of welds. It should be noted, for instance, that iron content in cast iron cannot be arbitrarily reduced in order to minimize corrosion without jeopardizing welding quality.
[0016] Other methods are also known, where welding is not used, to obtain mechanical couplings for the execution of radiator heating bodies.
[0017] For instance, an outspread method is to use forced couplings, i.e. with the manifold provided with holes whose diameter is slightly smaller than the outside diameter of the upright tubes, thus causing a certain interference between the tube and the hole. Then, upright tubes are inserted by exerting a pressure on the coupling site through the use of proper instruments.
[0018] Since the sealing of such couplings is obviously poor, ring seals and similar metal flanges will have to be added outside to improve sealing and mechanical strength. It is obvious that the use of such couplings is not very successful for radiators, such as household radiators, which have to comply with aesthetic requirements, wherein pressurized fluids are flowing and likely mechanical high stresses occur. In addition, a coupling usually requires special presses to operate on the tube ends, which is a rather complex operation.
[0019] Other solutions are also known, for instance from the German patent application DE-24 41 990, where bolts are used to connect some protrusions of the manifold elements on the upright tubes ends. To this purpose, a flat seal ring is inserted between the walls of each coupling for hydraulic sealing.
[0020] To achieve such a connection method, the protrusions of the manifold element and upright tube end have to be bored for bolt insertion, which affects sealing of the hydrothermal circuit in spite of seal insertion.
[0021] It is the object of this invention to solve the above problems and provide a radiator made of metal material, specifically a household radiator, of the composable type, which is improved if compared to the known solutions.
[0022] Therefore, it is the main object of the present invention to provide a radiator made of metal material, specifically a household radiator, whose simple and cost-effective manufacture is obtained through an efficient mechanical coupling, also warranting hydraulic sealing.
[0023] A further object of the present invention is to provide a radiator, specifically a household radiator, which is not subject to corrosion, though maintaining a high radiant power.
[0024] To achieve such purposes, it is the object of the present invention a radiator, specifically a household radiator, incorporating the characteristics of the annexed claims.
[0025] Further aims, characteristics and advantages of the present invention will be apparent from the following detailed description and annexed drawings, which are only supplied by way of non limiting example, wherein:
- Fig. 1 shows schematically a radiator according to the present invention;
- Fig. 2 shows schematically an assembly detail of the radiator of Fig. 1;
- Fig. 3 shows schematically some details of the radiator of Fig. 1;
- Fig. 4 shows in a partial section an element of the radiator of Fig. 1;
- Fig. 5 shows a section of a detail of the element shown in Fig. 1.
[0026] Fig. 1 shows a radiator 1 made of metal material suitable for household heating systems, consisting of a plurality of elements 2, which may be formed either by two columns elements 3 or three columns elements 4.
[0027] Elements 2 consist of two headers 5 acting as a lower and upper manifold respectively, and two or more upright columns 6.
[0028] Headers 5 have each one a threaded bore 7 with a large diameter; thus, as it can also be seen from Fig. 2, when the elements 2 are connected in series, the threaded holes 7 of the elements 2 are all on the same axis and define conduits 8. Said elements 2 are connected through threaded connectors 9 (see Fig. 2), which are inserted on the threaded holes 7. The holes of the farthest elements 2 are engaged by threaded plugs 10 (see Fig. 3), which may be either threaded plugs 11 or blind plugs 12, as to whether they are used for connection with an hydraulic pipeline - not shown here - or as terminals for the hydrothermal circuit.
[0029] Operation of said radiator is in itself known: the vector fluid of thermal energy conveys into the radiator 1 through the conduits 8, generally the upper conduits, and is distributed by each upper header 5 to the respective columns 6. Said columns 6 operate both as heat exchangers with the environment and as radiant elements, distributing thermal energy to the environment. The lower conduits 8 defined by the various lower headers 5 will then provide for fluid outlet.
[0030] Fig. 4 shows a partial section of the three-columns element 4 represented in fig. 1. This element 4 shows, for clarification's sake, an upper header 5A and a lower header 5B. Three lengthwise axis A, B, C can also be identified.
[0031] Headers 5A and 5B have some protrusions 15 (three in the specific case) provided with telescopic ends 16 (males). Each protrusion 15 has two seats obtained by punching, whose form is substantially that of a circular flaring 17 (blind).
[0032] A ring seal gasket 18 is provided for each protrusion 15, made of rubber or other material normally used for hydraulic sealing of household heating systems; said ring seal gasket 18 is housed on a depression 20 of the telescopic end 16, as it can be seen looking at the protrusion 15 of the header 5A on axis A.
[0033] On the axis C of the same header 5A the protrusion 15 is seen as a section and also the second flaring 17 can be seen, whose convex surface diametrically opposite to the other one is in sight. Also the corresponding gasket 18 is sectioned as well.
[0034] On the axis B, which is the section axis, the protrusions 15 are partially sectioned with reference to said axis B, showing a whole view with the gasket 18 mounted on the depression 20 and both flarings 17 visible.
[0035] Each column 6, as it can be seen by carefully watching protrusion 15 on the header 5A along the axis B, is coupled with each protrusion 15 by a mechanical coupling, wherein an end 23 of the column 6 is a female to interact with the male formed by the protrusion 15. The end 23 has a larger diameter compared to the outside diameter of protrusion 15, whereas the internal surface of the end 23 of column 6 and the outside surface of the upper portion 24 of protrusion 15 are substantially complementary, save for the area where flarings 17 are located. The end 23 of column 6 is inserted on the protrusion 15 and stops on a shoulder 21, as better seen in Fig. 5.
[0036] Thus, the gasket 18 is compressed between the extreme 23 of column 6 and the telescopic end 16. The function of the telescopic end 16 is to provide, through the depression 20, a proper seat to prevent the gasket 18 from being stressed over its own flexibility limits, with the risk of being subject to permanent distortions that would affect hydraulic sealing with time.
[0037] With reference to Fig. 5, when the column 6 is connected with the protrusion 15 of the header 5, a compression is exerted on the column 6, in line with the flarings 17 by means of a proper spherical shaped punch not shown here.
[0038] Therefore, the wall of the column 6 enters the flarings 17 and forms some flarings 22, thus ensuring a mechanical coupling.
[0039] The coupling between columns 6 and protrusions 15 can be advantageously a hot coupling, by preheating the column 6 at a temperature that is 40-50°C higher than the temperature of the protrusion 15, so that the interference in the coupling may help mechanical sealing on the protrusion 15. In this way, when the radiator 1 is subject to stress from thermal shocks and irregular hydraulic pressures, resistance to extraction is improved.
[0040] The characteristics of the present invention as well as its advantages are clear from the above description.
[0041] The heating bodies of the radiator can be obtained with a limited number of standardized components, specifically two equal headers, two or more equal tubes (depending upon the number of columns) and a couple of equal gaskets for each column.
[0042] The radiator described by way of example is quite simple and fast to manufacture from a mechanical machining standpoint and only requires a proper spherical punch for assembly. More specifically, if it is wished to have product quality improved, all operations can be carried out on automatic numerically controlled machines based on "total quality" criteria to prevent manufacturing rejects.
[0043] Hydraulic sealing is also ensured through a gasket, arranged between the internal wall of the various columns and the telescopic end of the headers protrusions, in a simple way and with a fast assembly.
[0044] Mechanical coupling strength to the maximum pressures that should be borne by the radiator is ensured by the coupling of the flarings.
[0045] Finally, the materials to be used can be freely chosen to obtain highest enhancement of the functional characteristics of each element (corrosion proof, radiant power, bactericide properties, recycling properties, aesthetic features ....). As a matter of fact, the headers can be made using a corrosion-proof material, whereas radiant and thermal exchange properties are preferred for the columns. For instance, in a preferred embodiment of the invention, the headers can be made of nodular cast iron, offering adequate mechanical strength guaranties, when thinner thickness (e.g. 2,5-4 mm) are used, and resistance to corrosion; on the other hand, columns can be made with steel alloys, such as extruded tubes or welded die-bent rolled elements offering a good radiant result (about 400 W/m2).
[0046] In a possible variant embodiment, the header can be made of brass casting, whereas the columns can be obtained with copper or copper-alloy materials, which have a high radiant power and bactericide properties, should the inlet pipelines be made in polyethylene. In this way, a radiator with a high radiant capacity (750 W/m2) can be obtained, though more expensive than the previous one.
[0047] In general, it is advantageously possible to associate any material suitable for radiators, by the same simple mechanical coupling.
[0048] It is obvious that many changes to the radiator, specifically a household radiator as described by way of example are possible for the man skilled in the art, without departing from the novelty spirit of the innovative solution, and it is also clear that in practical actuation of the invention the components may often differ in form and size from the ones described and be replaced with technical equivalent elements.
[0049] As an example, according to another possible embodiment, to prevent that the seal ring may be dissolved, due to the use of excessively hot fluids or diathermal oils, it can be replaced by one or more O-rings, housed in proper seats obtained on the telescopic end.
[0050] Another embodiment may provide for spreading the seal ring with silicone oils or graphitic grease, when fluids with a pH value from 5 to 6,5 are used.
[0051] A further embodiment refers to the type of the seats which can be obtained: on the protrusions of the headers, flarings and notches can be obtained in any way as provided by the present state of art, whose configurations differ from the circular one; also collars engraved all over the protrusion circumference could be obtained. In main line, it is possible to obtain different embodiments changing the means that hinder the female element from withdrawing from the male element.
[0052] A further embodiment provides for the use of upright or vertical columns to form the male element, i.e. having proper telescopic ends, and headers protrusions to form the female elements for the mechanical coupling and the relevant realization of flarings on the upright columns, with a subsequent punching of the headers protrusions in said flarings.
1. Radiator, specifically a household radiator, of the type consisting of a plurality
of metal heating elements, each one formed by manifold elements and at least one radiant
element, which are separately realized and then connected together, characterized
in that the radiant element (6) is connected with the manifold elements (5) by means
of a male-female coupling and that mechanical means (17,22) are provided, which prevent
the female acting element (23,15) from withdrawing from the male acting element (15,23).
2. Radiator, specifically a household radiator, according to claim 1, characterized in
that said mechanical means (17,22) are obtained through a mechanical deformation of
the female acting element (15,23) and/or of the male acting element (23, 15).
3. Radiator, specifically a household radiator, according to claim 2, characterized in
that the female acting element (23,15) is mechanically deformed on the male acting
element (15,23).
4. Radiator, specifically a household radiator, according to claim 1, characterized in
that the male acting element (15) is provided with an external surface suited to mate
with the internal surface of the female acting element (23) and that said external
surface of said male acting element (15) has an interruption (17) onto which the female
acting element is deformed (23).
5. Radiator, specifically a household radiator, according to claim 4, characterized in
that the male acting element (15) belongs to the manifold element (5) and the female
acting element (23) belongs to the radiant element (6), or viceversa.
6. Radiator, specifically a household radiator, according to claim 4, characterized in
that said interruption (17) is a seat.
7. Radiator, specifically a household radiator, according to claim 4, characterized in
that said interruption (17) is a protrusion.
8. Radiator, specifically a household radiator, according to claim 4, characterized in
that said interruption (17) is configured as a flaring with a substantially circular
shape.
9. Radiator, specifically a household radiator, according to at least one of the previous
claims, characterized in that the male acting element (15 or 23) comprises a telescopic
end (16).
10. Radiator, specifically a household radiator, according to Claim 9, characterized in
that a depression or lowering (20) is provided on the telescopic end (16) to house
a seal ring (18).
11. Radiator, specifically a household radiator, according to at least one of the previous
claims, characterized in that the coupling of the male acting element (15) with the
female acting element (23) is executed under hot conditions.
12. Radiator, specifically a household radiator, according to at least one of the previous
claims, characterized in that the coupling of the male acting element (15) with the
female acting element (23) is executed by a spherical punch.
13. Radiator, specifically a household radiator, according to claim 1, characterized in
that the manifold element (5) is obtained with a material differing from the material
used for the radiant element (6).
14. Radiator, specifically a household radiator, according to claim 13, characterized
in that the manifold element (5) is obtained with nodular cast iron, whereas the radiant
element (6) is obtained through extruded tubes or welded die-bent rolled elements.
15. Radiator, specifically a household radiator, according to claim 13, characterized
in that the manifold element (5) is obtained by brass casting, whereas the radiant
element (6) is obtained with copper or copper alloy tubes.
16. Method for obtaining radiators of metal material, specifically household radiators,
of the type comprising a plurality of heating elements obtained through mutual mating
of a couple of manifolds elements with one or more radiant elements, characterized
by the following steps:
• realizing the manifold element using the most suitable manufacturing techniques and adequate materials, providing it with a male or female protrusion;
• realizing the radiant element using the most suitable manufacturing methods and adequate materials, providing it with male or female type ends;
• realizing an interruption over the surface of the male element;
• coupling the protrusion of each manifold element with and the ends of the radiant element, interposing hydraulic seal elements between the parts;
• deforming the female elements on the interruption of the surface of the male element.