Adaptor for hot water storage tank and method of use thereof

Abstract

An adapter allows a hot water storage tank of the kind having an electrical immersion heater fitted into a base of the tank via a flange. The adapter includes a flange having peripheral holes corresponding to holes in the flange of the electrical immersion heater. A cold water outlet mounted project through the flange and allows connection to a cold water inlet of an external heater. A hot water inlet projects through the flange and allows connection to a hot water outlet of the external heater. The hot water inlet is configured so that in use hot water entering therethrough is directed to an uppermost location of the tank.

Description

RELATED APPLICATION

This application is a c-i-p of U.S. Ser. No. 11/820,866 filed Jun. 20, 2007 entitled “Water Heating and Storage System” and due to issue as U.S. Pat. No. 7,726,263 on Jun. 1, 2010 the contents of which are wholly incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a hot water storage tank that stores water heated by an external heater.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 7,726,263 discloses a thermosyphonic water heating and storage system, comprising a heat-insulated main heated water storage tank for storing hot water. As shown in FIG. 1 of this patent, the storage tank has top, side and bottom walls, a hot water inlet close to the top wall of the tank for heated water entering the tank, a cold water inlet, and a consumer hot water outlet. Hot water is heated in an external water heater of a capacity up to several liters having top and side walls and a base, and a controlled electrical heating unit protrudes into an interior of the heater from the top wall thereof. An outlet port of the heater is connectable to the inlet of the main storage tank and a water inlet port of the heater is connectable to the mains water supply.

A first valve is connected between a non-consumer outlet of the storage tank and the water inlet port of the external water heater for allowing prevention of water flow from the storage tank to the external water heater during maintenance, and a second valve is connected between the hot water inlet of the storage tank and the outlet of the external water heater for allowing prevention of hot water flow from the storage tank to the external water heater during maintenance. The base of the heater is detachably affixed on to the side walls for easy maintenance of the external water heater including maintenance and replacement of the electrical heating unit.

It emerges from the foregoing and from FIG. 1 of U.S. Pat. No. 7,726,263 that the main storage tank requires four ports altogether: a first for entry of cold water and a second for outlet of hot water as are standard fittings in hot water storage tanks However, there are additionally required a third port for coupling to the hot water outlet of the external heater and a fourth port for coupling to the cold water inlet of the external heater. These additional ports are non-standard thus requiring that a custom water storage tank be provided in order to enjoy the benefit of the system shown in U.S. Pat. No. 7,726,263.

The need for two additional ports militates against connection of an external heater to conventional water storage tanks having only a single inlet and outlet and, in practice, means that in order to benefit from the teachings of U.S. Pat. No. 7,726,263 in an existing water system, the water storage tank must be replaced with a customized tank having the requisite four ports. This is wasteful of both material and expense.

There are two different types of hot water storage tank. One uses so-called indirect heating such as shown in U.S. Pat. No. 2,016,746 (Ireland) where very hot water is fed from an external boiler through a closed tube and heats cold water that is circulated through a circulating unit in the tank. The closed tube has connections mounted in a side of the tank for coupling to the boiler. The other type of hot water tank uses directs heating, whereby an electrical immersion heater is mounted in a base of the tank. It is with such types of tank that the present invention is concerned.

FIGS. 1 and 2 of the present application show pictorially in partially cut-away section a hot water storage tank 10 of the kind manufactured by Chromagen of Sha'ar Ha'amakim, Israel. The tank 10 has an outer casing 11 in a base 12 of which there are a cold water inlet 13 and a hot water outlet 14 that is directed toward the top of the tank where the water is hottest. The tank 10 may be mounted vertically as shown in FIG. 1 when there is sufficient headroom, as is common in solar heating applications, or it may be mounted horizontally as shown in FIG. 2 when headroom is at a premium. In the case where it is mounted vertically, the hot water outlet 14 curves inwardly towards an apex of the storage tank, as shown albeit schematically in the figure. The apex of the tank is not visible in the figure, since the storage tank is covered by insulating material, only the wall of the lower part of the tank being shown in partial section.

In the case where the tank is mounted horizontally, the hot water outlet 14 is shorter and directed to an upper surface of the tank, the cold water inlet 13 being taken from the same connection as shown in FIG. 1. In both cases, the hot water outlet 14 is higher than the cold water inlet 13 and its highest end reaches to where the water in the tank is hottest. For the sake of completeness, it should be noted that hot water tanks are known having three ports in the base: one being the cold water inlet shown as 13 in FIGS. 1 and 2; the second being a hot water outlet that is disposed toward a center of the base and reaches the apex for use when the tank is mounted vertically as shown in FIG. 1; and the third being a hot water outlet that is disposed toward an upper part of the base as shown in FIG. 2 when the tank is mounted horizontally. Such an arrangement allows the same tank to be mounted in either orientation, the unused hot water outlet being sealed.

An electrical immersion heater element 15 having an integral thermostat 16 is mounted via a flange 17 in the base 12 of the tank 10. Typically the lifetime of such heaters is less than that of the tank and, if necessary, the heater can be replaced by removing the flange whereupon the immersion heater and thermostat are withdrawn and can be replaced. Of course, prior to doing this, water must be drained from the tank and this, indeed, is one of the drawbacks associated with such tanks, which is overcome by the arrangement in U.S. Pat. No. 7,726,263.

However, the hot water storage tank as required in U.S. Pat. No. 7,726,263 has an additional two ports that are not provided in the tank 10 shown in FIGS. 1 and 2. It would therefore be desirable to convert a conventional tank having two ports for use with an external heater of the kind taught in U.S. Pat. No. 7,726,263.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to obviate the need to replace the storage tank in a conventional water system when utilizing an external heater of the kind taught in U.S. Pat. No. 7,726,263.

To this end there is provided in accordance with the invention an adapter for converting a hot water storage tank of the kind having an electrical immersion heater fitted into a base of the tank via a flange so as to provide a cold water outlet for coupling to an external heater and a hot water inlet for coupling to the external heater, said adapter comprising:

• • a flange having peripheral holes corresponding to holes in the flange of the electrical immersion heater,
  • a cold water outlet mounted in said flange so as to project therethrough and allow connection to a cold water inlet of the external heater,
  • a hot water inlet mounted in said flange so as to project therethrough and allow connection to a hot water outlet of the external heater, said hot water inlet being configured so that in use hot water entering therethrough is directed to an uppermost location of the tank.

In accordance with another aspect of the invention, a conventional hot water storage tank having an electrical immersion heater is adapted for use with an external heater by:

• • removing the electrical immersion heater from the base of the tank; and
  • mounting the adapter in the base of the tank instead of the heater while ensuring that the hot water inlet of the adapter is directed to an uppermost location of the tank.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carried out in practice, an embodiment will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

FIGS. 1 and 2 are pictorial representations showing partially cut-away views of a known hot water storage tank mounted respectively vertically and horizontally and being suitable for use with the present invention;

FIG. 3 is a pictorial representation of an adapter according to the present invention; and

FIG. 4 is a schematic representation of a modified hot water storage tank coupled to an external heater via the adapter shown in FIG. 3.

In the drawings, identical components that appear in more than one figure or that share similar functionality are referenced by identical reference symbols.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 3 shows an adapter 20 for converting a hot water storage tank of the kind having a cold water inlet and a hot water outlet and an electrical immersion heater fitted into a base of the tank via a flange for use with an external heater as taught by U.S. Pat. No. 7,726,263. The adapter 20 comprises a flange 21 having peripheral holes 22 corresponding to holes in the flange of the electrical immersion heater. A cold water outlet 23 is mounted in the flange 21 so as to project therethrough and allow connection to a cold water inlet 31 of an external heater 30 shown in FIG. 4.

A hot water inlet 24 is mounted in the flange 21 so as to project therethrough and allow connection to a hot water outlet 32 of the external heater 30. The hot water inlet 24 is configured such that it projects into the tank via a tube 25 and reaches toward the highest point of the tank where the water is hottest. This is important in order to prevent the hot water entering the storage tank from mixing with cold water in the storage tank and thereby cooling. Thus, in the case where the adapter 20 is intended for use in a vertical tank as shown in FIG. 1, the tube 25 is elongated relative to the cold water outlet so that a far end 26 of the tube remote from the flange reaches the top of the tank 10. On the other hand, if the adapter 20 is intended for use in a horizontal tank as shown in FIG. 2, the tube 25 need not be elongated but should be curved toward the far end 26 so that in use the far end 26 curves upwardly toward the highest point of the tank. Alternatively, a universal adapter may employ an elongated tube 25 that is curved toward a free end 26 thereof so as to be suitable regardless of whether the hot water storage tank is mounted horizontally or vertically.

FIG. 4 shows schematically and not to scale a modified hot water storage tank 11 coupled to an external heater 30 via the adapter 20 in a thermosyphonic water heating and storage system. Double arrowheads depict the connection of the cold water outlet 23 of the adapter 20 to the cold water inlet 31 of the external heater 30 and of the hot water inlet 24 of the adapter 20 to the hot water outlet 32 of the external heater 30. Water flow between the external heater 30 and the storage tank 11 is thermosyphonic such that hot water entering the storage tank via the hot water inlet 24 displaces cold water in the tank which flows from the cold water outlet 23 to the cold water inlet of 31 the heater 30. The cold water entering the cold water inlet 31 is heated and rises, so that the hot water reaches the hot water outlet 32 and flows into the storage tank via convection.

The invention also contemplates retrofitting a conventional hot water storage tank of the type shown in FIGS. 1 and 2 with the adapter 20 such that the tank may be modified after manufacture and sold integral with the adapter in place of an electrical immersion heater. This is done by replacing the electrical immersion heater with the adapter 20 with the end 26 of the hot water inlet 24 directed to where the water in the tank is hottest. Typically, this requires removal of the immersion heater from the base of the tank by removing the securing screws; and then mounting in the base of the tank instead of the heater the flange of the adapter whose peripheral holes correspond to those in the flange of the electrical immersion heater.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrated embodiments and may be embodied in other forms without departing from the essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated only by the appended claims and equivalents thereof.

Claims

1. An adapter for converting a hot water storage tank having an electrical immersion heater fitted into a base of the tank via a first flange so as to provide a cold water outlet for coupling to an external heater and a hot water inlet for coupling to the external heater, said adapter comprising:

A second flange having peripheral holes corresponding to holes in the first flange of the electrical immersion heater,

a cold water outlet mounted in said second flange so as to project therethrough and allow connection to a cold water inlet of the external heater, and

a hot water inlet mounted in said second flange so as to project therethrough and allow connection to a hot water outlet of the external heater, said hot water inlet being configured so that in use hot water entering therethrough is directed to an uppermost location of the tank.

2. The adapter according to claim 1, wherein the hot water inlet comprises an elongated tube that is configured to reach toward the uppermost location of a vertically-mounted tank.

3. The adapter according to claim 1, wherein the hot water inlet comprises a tube that is curved toward an end thereof inside the tank so that, when used in a horizontally-mounted tank, said end curves upwardly toward the uppermost location of the tank.

4. The adapter according to claim 1, wherein the hot water inlet is configured to reach toward the uppermost location of the tank regardless of whether the hot water storage tank is mounted vertically or horizontally.

5. The adapter according to claim 4, wherein the hot water inlet comprises an elongated tube that is curved toward a free end thereof.

6. The adapter according to claim 1, being integrally fitted to a hot water storage tank in place of an electrical immersion heater.

7. A method for adapting a hot water storage tank having an electrical immersion heater fitted into a base of the tank via a first flange for use with an external heater, said method comprising:

removing said electrical immersion heater from the base of the tank; and

mounting an adaptor in the base of tank instead of the heater, comprising: providing a second flange having peripheral holes corresponding to holes in the first flange of the electrical immersion heater, mounting a cold water outlet in said second flange so as to project therethrough and allow connection to a cold water inlet of the external heater, and mounting a hot water inlet in said second flange so as to project therethrough and allow connection to a hot water outlet of the external heater, said hot water inlet being configured so that in use hot water entering therethrough is directed to an uppermost location of the tank.