A SELF-SUPPORTING PLASTIC MATERIAL WATER HEATER

Abstract: A self-supporting plastic material water heater, comprises an inner container (1) and an outer container (3) located inside said inner container (1) with an insulating material (5) being disposed between said containers (1, 2). The inner container (1) comprises peripheral surfaces (6, 10; 22, 23, 25) and a plurality of partitioning walls (9) intersecting with each other to form a stiffening grid structure (15) defining a plurality of compartments (11) together with said peripheral surfaces of said containers (1, 2). Opening (13) are provided in said partitioning walls (9) to form passages between adjacent compartments (11).

Description: "A SELF-SUPPORTING PLASTIC MATERIAL WATER HEATER" The present invention relates to plastic material water heaters of the self-supporting type. EP-A-0 668 984 in the name of the present applicant discloses a self-supporting plastic material water heater which is quite different from the conventional enamelled sheet steel water heaters and achieves a real innovatory improvement over the prior art. Although the water heater disclosed in the above mentioned EP-A-0 668 984 has proved to be generally satisfactory, some limitations were found in respect of the pressure-resistance and the manufacturing costs. In view of the above the applicant carried out tests and investigations on several plastic materials and structures. It is an object of the present invention to provide a water heater formed of a plastic material that is both simple and effective and has a larger pressure resistance than the known devices and is easy and convenient to be manufactured. This object, together with additional characteristics and advantages that will become clear from the following disclosure are achieved through a water heater as claimed in claim 1. Additional advantageous characteristics are recited in the dependent claims. The self-supporting plastic material water heater according to the invention comprises an inner container and an outer container housing said inner container. Both container are of a plastic material and an insulating material is disposed in the space between said containers. The inner container comprises peripheral surfaces and a plurality of internal partitioning walls intersecting each other to form a stiffening grid structure defining a plurality of compartments together with the peripheral surfaces of the container. Openings are provided in said partitioning walls to form passages between adjacent compartments . In accordance with a first embodiment of the invention, the inner container is formed by heat sealing together two half-shells of plastic material, each comprising side surfaces, a bottom surface and a grid structure (15) formed by intersecting walls and provided with communication openings. All said surfaces and structure of a half-shell are integrally formed, and the two half-shells are sealingly hot joined to each other along the free edges of said grid and surfaces to define inner compartments that are in turn fluidly connected to each other. In accordance with a second embodiment of the invention, the inner container is formed by heat sealing together a one-piece structure - formed by a grid of intersecting partitioning walls and lateral surfaces extending around said grid - to a front (23) and a rear (25) walls. The front and rear walls are sealingly joined to said one-piece structure along the free edges of said grid and the free edges of said lateral surfaces to define inner compartments that are in turn fluidly connected to each other. In both embodiments of the invention, there are provided additional and conventional fittings and components of a water heater, such as an electric resistor, inlet and outlet ducts, a safety valve, a pressure reducer and members adapted to fix the water heater to a mounting frame and to a wall. The invention will now be illustrated with more details referring to the attached drawings, only supplied to show not-limiting embodiments of the invention, in which: - Fig. 1 is a perspective view of a first embodiment of an inner container according to the invention; - Fig. 2 is a perspective view from the opposite side of the inner container shown in Fig. 1; - Fig. 3 is a perspective view of a second embodiment of an inner container according to the invention; and - Fig. 4 is a side cross-section view of a water heater illustrating the inner container mounted within the outer container. In the Figures the water heater is shown as having a parallelepipedal shape, but this is not to be construed as a limitation since the inner container is generally formed as a solid having at least two facing surfaces, the expression including a plurality of solids, such as a parallelepiped, a polygonal prism, a cylinder and so on. In the last mentioned solid the opposite surfaces are formed by the two bases of the cylinder and by the plurality of infinitesimal surfaces forming the cylinder curved (lateral) surface. As shown in the Figures, the subject water heater substantially comprises an inner container 1 of a suitable plastic material and having a substantially parallepipedal shape and an outer container 3, also this latter being of a suitable plastic material. The inner container is fitted inside the outer container 3, with an insulating material 5 being disposed between the containers 1 e 3. As shown in Fig. 4, the water heater according to the invention is provided with the conventional fittings of a water heater such as a heating resistance 27, water inlet and outlets ducts, 29 and 31, respectively, a safety valve and a pressure reducer (this latter not shown) similar to those disclosed in the above mentioned patent. According to a first embodiment shown in Figures 1 and 2, the inner container 1, is formed by two substantially equal half-shells 7 that can be hot joined together to form a single inner container 1. Each of said half-shells 7 has opposite faces or surfaces 6 and a bottom surface 10. The opposite surfaces 6 are internally connected by a plurality of septa or partitioning walls 9 intersecting each other so as to form a plurality of compartments or partitions 11 having a shape depending on the relative inclinations of said walls 9. The grid of walls shown in the Figure defines spaces 11 that are substantially rectangular. The main difference between the two half-shells is that the lateral surface 6 of one of them carries ducts and fittings for the connection of the water heater. Such ducts and fittings can be formed or applied after the half-shell has been formed. In correspondence of the center line of each compartment 11, the walls 9 are provided with indentations or notches 13, formed as a half-circle for allowing the water passage through said walls 9 and therefore a water circulation inside the container 1. Moreover the grid 15 of the intersecting walls 9 constitutes a stiffening frame extending between opposite faces of the container 1 along three orthogonal directions X, Y and Z. By hot joining together said two half-shells 7 along the edges of the grid 15 (i.e. along the edges of the partitioning walls and the container walls) , a complete inner container 1 is formed, provided with peripheral walls 6 and partitioning walls 9 sealed to each other to define inner compartments that are in turn fluidly connected to each other by openings formed by adjacent pairs of holes 13. In accordance with a second embodiment shown in Figure 3, the inner container 1 is formed as a structure 21 provided with lateral walls 22 and a grid 15 fixed to said lateral walls 22, without the front and real walls (a parallepiped as shown in Figure 3) . The front wall 23 and the rear wall 25 are formed as separate components and are shaped as two simple and substantially flat plates, adapted to be heat sealed to the structure 21 for closing it. This way a container similar to the one of the first embodiment is obtained, with the grid 15 extending through and connecting the opposite walls of the drawn structure 21 and the front wall 23 and rear wall 25. The grid 15 constitutes a reinforcement or stiffening frame of the inner container 1 along the directions X, Y and Z. The outer container 3 has the same shape (parallelepipedal as shown in the Figures) of the inner container and its size is such as to house said inner container 1, with an insulating material 5, such as foamed polyurethane or the like, disposed in the hollow space between the two containers 1, 3. Members 17, 19 either of a plastic material or not, can be provided between the two containers 1, 3, as spacing or positioning members. In both the above disclosed embodiments of water heaters according to the invention, conventional fittings of a water heater such as a heating resistance 27, water inlet and outlets ducts, 29 and 31, respectively, a safety valve and a pressure reducer (not shown) similar to those disclosed in the above mentioned patent, are provided. These components are provided in a surface of the inner container 1 mounted in sleeves integrally formed with the container during the moulding thereof in the first embodiment, and applied later to the solid 21 in the second embodiment . In both embodiments the half-shells and the structure can be obtained by drawing or extruding a plastic material, or through other suitable process for forming plastic materials . It is also to be noted that the structure is formed of a suitable plastic material so as to be inexpensive both in respect of its manufacturing and its operation, as well as energy-saving. Such plastic material is preferably adapted to be fully recyclable. Thanks to the grid constituted by the inner reinforcement walls extending along three orthogonal directions X, Y and Z, the inner container is adapted to withstand higher pressures than those withstood by the conventional plastic material water heater. The invention is not limited to the disclosed embodiments, but comprises several changes and modifications that will be evident to the skilled of the art and fall within its scope.

Claims: CLAIMS A self-supporting water heater, comprising an inner container (1) and an outer container (3) located inside said inner container (1), both said containers (1, 3) being of a plastic material and with an insulating material (5) being disposed in the space between them; characterized in that said inner container (1) comprises peripheral surfaces (6, 10; 22, 23, 25) and a plurality of partitioning walls (9) intersecting each other to form a stiffening grid structure (15) defining a plurality of compartments (11) together with the peripheral surfaces of said containers (1, 2), openings (13) being provided in said partitioning walls (9) to form passages between adjacent compartments (11) . 2. A self-supporting plastic material water heater as claimed in claim 1, characterized in that said inner container (1) comprises at least two facing surfaces (6, 6, 10, 10; 23, 25, 22, 22) between which said stiffening grid structure (15) extends. 3. A self-supporting plastic material water heater as claimed in claim 1 or 2, characterized in that both said inner (1) and outer (3) containers have a substantially parallelepipedal shape, and in that spacing or positioning members (17, 19) are provided in the space between said containers (1, 3) . 4. A self-supporting plastic material water heater as claimed in any of claims 1 to 3, characterized in that said inner container (1) is formed by heat sealing two half- shells (7) of plastic material, each comprising lateral surfaces (6), a bottom surface (10) and a grid structure (15) formed by intersecting walls (9) and provided with openings (13), all said surfaces (6, 10) and structure (15) being integrally formed, and in that said two half-shells (7) are sealingly joined to each other along the free edges of said grid (15) and surfaces (6, 10) . 5. A self-supporting plastic material water heater as claimed in claim 4, characterized in that each of said intersecting wall (9) is provided with an indentation or notch (13) formed as a half-circle. 6. A self-supporting plastic material water heater as claimed in any of claims 1 to 3, characterized in that said inner container (1) is formed by heat sealing together a one-piece structure (21) - formed by a grid (15) of intersecting partitioning walls (9) and lateral surfaces (22) around said grid - with a front (23) and a rear (25) walls, and in that said front (23) and rear (25) walls are sealingly joined to said one-piece structure (21 ) along the free edges of said grid (15) and the free edges of said lateral surfaces (22). 7. A self-supporting plastic material water heater as claimed in claim 6, characterized in that said partitioning walls (9) are provided with apertures (13) between adjacent compartments (11). 8. A self-supporting plastic material water heater as claimed in claims 4 to 7, characterized in that said grid (15) constitutes a stiffening frame along three orthogonal directions (X, Y and Z) between said opposite surfaces (6, 6, 10, 10; 23, 25, 22, 22) of the inner container (1) . 9. A water heater as claimed in the preceding claims, characterized in that said half-shells (7) and said one- piece structure (21) are obtained through drawing or extrusion of a plastic material.

Inventors: MASSARI ALESSANDRO, NARDI ROMANO, MASSARI, ALESSANDRO, NARDI, ROMANO
Applicants: GOITRE TIZIANA, MAGRETTI ANGELA, MASSARI ALESSANDRO, NARDI ROMANO, GOITRE, TIZIANA, MAGRETTI, ANGELA, MASSARI, ALESSANDRO, NARDI, ROMANO
Application year: 1999
Main classification: F24H1
IPC codes: F24H1