The present invention concerns a heating appliance consisting of a reservoir containing liquid, such as water, which is heatable with the aid of a heat source, such as an electric resistance.
The drawback of heating appliances of this kind known in the art, such as water heaters, boilers, etc., is that the water reservoir has been dimensioned to be large with the objective that the warmed household water should positively suffice for the needs even of several persons, such as their washing and showering in succession. The object of the present invention is to eliminate the drawback and to provide a new type of heating appliance in which the water reservoir has been dimensioned to be as small as possible. The heating appliance of the invention is characterized in that around the heat source installed in upright position there is an elongated tube open at its top as well as its bottom end and constituting a small, rapidly heating liquid volume separate from the reservoir, whence the liquid that is warming up rises into the upper part of the reservoir. With the aid of the invention, hot water is continuously supplied into the upper part of the heating appliance, because the water volume around the heat source is minimal and is very rapidly heated, the water ascends into the upper part of the heating appliance and can be withdrawn for household water. Hereby there is no necessity to heat any large water quantities: the water is heated accordingly as it is being consumed.
An advantageous embodiment of the invention is characterized in that the heat source is located in a separate tubular liquid volume closed off from the reservoir, such as a circulating water heating volume of the heating appliance, around which the tube is located. Therefore the heating appliance operates, with one and the same heat source, both as circulating water heating appliance and as household water heating appliance.
Another embodiment of the invention is characterized in that the heat source consists of the flue gas exhaust duct of an oil burner, around which the tube is located. This is a so-called oil-operated boiler in which according to the design taught by the present invention the capacity of the household water reservoir can be dimensioned to be exceedingly small.
The invention is described in the following with the aid of an example, referring to the attached drawing, wherein
FIG. 1 presents a heating appliance comprising both a water boiler for household water and a circulating water heating section.
FIG. 2 presents a simple water boiler.
FIG. 3 presents a boiler provided with an oil burner.
In FIGS. 1 and 2, the heating appliance consists of an elongated upright reservoir 1 containing household water 3 that is heatable with an electric resistance 2. Around the electric resistance 2 there is an elongated tube 4, open at its top as well as its bottom end and which constitutes a small, rapidly heating liquid volume separate from the reservoir 1, wherein the liquid being warmed up rises into the upper part of the reservoir 1, as indicated by arrows. In FIG. 1, the electric resistance is located in a separate tubular heating volume 5 for the circulating water of the heating appliance, closed off from the reservoir, around which the tube 4 is located. In this instance the electric resistance is in no direct connection with the household water; instead, the circulating water heating volume 5 very rapidly heats the water quantity present between the heating volume 5 and the tube 4, this water quantity rising to the upper part of the heating appliance. In the lower part of the reservoir 1 has been provided a cold water intake connector 6, and there is a connector 7 for the warm household water in the top part of the reservoir. The circulating water of the heating appliance has similarly been connected with the circulating water heating volume by connectors 8 and 9.
In FIG. 3, the heat source consists of an oil burner, and the flue gas exhaust duct 11 serves as heat source for the household water 12, the tube 4 being located therearound. The circulating water 13 becomes heated, in this case, around the firebox 14.
It is obvious to a person skilled in the art that the invention is not confined to the examples presented in the foregoing and that it may instead vary within the scope of the claims stated below.