SOLAR WATER HEATER

Abstract: A solar water heater comprising a collector (11) and a storage tank (14) characterised in that the collector (11) and the storage tank (14) are formed integrally as a single unit. The heater may be formed of suitable plastics material by a roto-moulding technique.

Description: "Solar Water Heater" THIS INVENTION relates to a solar water heater. The object of the invention is to provide a solar water heater which is simple to construct in relation to existing designs of solar water heaters. The majority of solar water heater units in production at the present time comprise a collector and a separate tank which may be located close to the upper end of the collector or remote therefrom. The production of these units and particularly the collector is labour intensive. It has now been found that if the collector and the tank are formed integrally as a single unit from a suitable material there are significant reductions in cost. Thus in one form the invention resides in a solar water heater in which the collector and the tank are formed integrally as a single unit. It will be appreciated that the surface of the collector exposed to the sun should be covered with glass in the normal manner and the underside of the collector and the tank suitably insulated with a suitable insulating material such as polyurethane foam. If desired the exposed surface of the collector may be ribbed parallel to the sides to increase the contact area, promote upward convective flow and stiffen the surface. The collector portion of the integral unit may be wedge shaped, the mouth of the wedge merging with the tank portion which is circular in cross section. Alternatively the upper and lower surfaces of the collector portion may be parallel. In each case the surface of the collector which is exposed to solar radiation is in direct contact with the water. It is preferable that the unit of the present invention be formed of a suitable plastic material such as polypropylene using a roto-moulding technique. Any one of a wide range of plastics which retain their strength and rigidity at temperature of the order of 30° - 90°C, and which are substantially unaffected by prolonged exposure to the sun and other elements may be used. The invention will be better understood by reference to the following description of one specific embodiment shown in the accompanying drawings of which: Fig. 1 is an isometric view of one embodiment of the invention; Fig. 2 is a sectional side elevation of the embodiment of Fig. 1; Fig. 3 is a fragmentary sectional view showing details of construction of the first embodiment; and Fig. 4. is a sectional elevation of a second embodiment. As shown in Figs. 1, 2 and 3 of the drawing the unit is moulded from polypropylene compounded with suitable pigments and UV retarders. The collector 11 has a parallel upper and lower faces when viewed in side elevation and the upper surface thereof covered with a sheet of glass 12. The upper end of the collector merges with and is integral with a tank 14 which is generally circular in cross section. The collector is provided with a water inlet 15 adjacent the end of the collector remote from the tank. The water inlet is connected to a water supply through a header tank fitted with a float control valve or some similar low pressure source. The tank has a hot water outlet 16 which is located in the upper half of the tank portion of the unit and in addition a relief vent to relieve any undue build up of pressure in the unit. As will be seen from Fig. 3 of the drawings the body of the unit is provided with insulation 18 on all surfaces except the surface of the collector portion. The insulation is encased in a metal casing 19 whilst the absorption surface is covered with the sheet of glass 12. In the embodiment shown in Fig. 4 of the drawings, the collector portion 21 is formed as a wedge shape which merges with the tank 22. The two embodiments described above are for particularly suitable for production from a plastic material such as polypropylene by a roto-moulding technique. It may also be fabricated from metal or other suitable materials. It has been found that the unit of the present invention is particularly suitable for use in areas having a high ambient temperature. It may be used to supply hot water directly or as a preheating unit for other types of low pressure hot water storage units.

Claims: THE CLAIMS defining the invention are as follows: 1. A solar water heater comprising a collector and a storage tank characterised in that the collector and the storage tank are formed integrally as a single unit. 2. A solar water heater as claimed in claim 1 wherein the upper and lower surfaces of the collector portion are parallel. 3. A solar water heater as claimed in claim 1 wherein the collector portion is wedge shaped in section with the wider portion of the wedge merging with the tank. 4. A solar water heater as claimed in claim 1, 2 or 3 formed from a suitable plastic material by a roto-moulding technique. 5. A solar water heater as claimed in any one of claims 1 to 4 wherein the upper surface of the collector is ribbed. 6. A solar water heater substantially as herein described and as shown in Fig. 1, 2 and 3 of the drawings. 7. A solar water heater substantially as herein described and as shown in Fig. 4 of the drawings.

Inventors: GRAHAM KEITH STUART PAMPLIN, WILLIAMSON KENNETH GEORGE, GRAHAM, KEITH, STUART, PAMPLIN, WILLIAMSON, KENNETH, GEORGE
Applicants: K & K HOLDINGS
Application year: 1985
Main classification: F24J2
IPC codes: F24J2