WO2018224817A1

WO2018224817A1 - Heating unit

Info

Publication number: WO2018224817A1
Application number: PCT/GB2018/051532
Authority: WO
Inventors: Keith LAWLEY
Original assignee: Lawley Keith
Priority date: 2017-06-06
Filing date: 2018-06-05
Publication date: 2018-12-13
Also published as: GB201708964D0; GB2563225A

Abstract

This invention is directed to a water heating unit that is safer to use with low manufacturing costs. The heating apparatus comprising an electrical resistance heating element (12) that is sealed inside a heating element container (3) fully or partially filled with a heat transfer medium that is a thermally conductive material that also functions as a protective medium for the heating element. The heating element is thus kept separate from the rest of the system, especially the water being heated, protecting it from hard water lime scale, corrosion or any other such damage.

Description

HEATING UNIT

This invention is directed to a heating unit, and in particular, although not exclusively, a portable electric water boiler.

Background of the Invention

Water heating systems for use in domestic and industrial settings operate on a variety of fuels, in particular gas, oil and electricity. They typically consist of an apparatus which actually heats the water (a boiler), a circulating pump and a network of pipes to distribute the heated water to where it is required (e.g. hot water tank, radiator, etc).

Boilers occasionally malfunction. This is generally extremely inconvenient for the user, particularly during the winter, when maintaining the interior temperature is paramount. Usually, the services of a plumber are required to affect repairs.

It often transpires that the plumber tasked with repairing the boiler is unable to affect an immediate repair, because they require spare parts that are not always to hand. This is especially vexatious for the user, as it may result in a delay of several days before the relevant part can be sourced and installed.

During such a hiatus, it would be extremely desirable to have access to a temporary boiler, which could be installed relatively quickly, and removed when the plumber was in the position to carry out a repair of the actual boiler.

Electric water heaters, also known as immersion heaters, have been used in domestic and industrial contexts for many years but not known to be used for radiators. In the simplest terms, they consist of a heating element immersed within a water storage tank. The heating elements of these boilers often become damaged due to corrosion or limescale, losing efficiency and ultimately failing. Additionally, the tanks containing heated water become get very hot, reducing the safety of such systems. The danger is particularly envisaged when the heating is on while the tank is empty, causing the system to explode.

Other tankless systems have continuous flow-through arrangements that operate at mains pressure. These are complex in structure and require costly installation. Breakdown of such systems can cause delays in their repair due to their complex nature.

Summary of the Invention

In one aspect, the invention relates to a heating apparatus for heating a liquid, comprising:

a housing adapted to receive cold water to be heated;

a heating element container formed of a thermally conductive material and containing a heat transfer medium and a heating element;

one or more water inlets in fluid connection with the interior of the housing;

one or more water outlets in fluid communication with the interior of the housing; wherein the heating element is substantially within the heating element container, and the heating element container is substantially within the housing and, in use, in contact with the water to be heated.

Brief Description of the Figures

Fig. 1 is a schematic view of the elements of the heating apparatus.

Fig. 2 is a top view of the heating apparatus. Fig. 3 is a cross-section view of the heating apparatus. Fig. 4 is the lid of the heating apparatus.

Fig. 5 is a closed version of the heating apparatus. Fig. 6 is the heating apparatus with the safety plug socket.

Detailed Description of the Preferred Embodiments

The present invention provides a water heating unit that is safer to use with a longer lifespan than known water storage tank boilers. This system is compact, with low manufacturing costs. It is particularly suitable as an emergency replacement boiler where the primary boiler has failed, and provision of hot water and radiator must be restored without undue delay. The water heating apparatus has an electrical resistance heating element that is sealed inside a heating element container fully or partially filled with a heat transfer medium that is a thermally conductive material that also functions as a protective medium for the heating element. The heating element is thus kept separate from the rest of the system, especially the water being heated, protecting it from hard water lime scale, corrosion or any other such damage.

The heat transfer medium may include solids such as sand or any other thermally conductive small grain substances. The heat transfer medium is preferably a liquid, such as ethylene glycol (EG),1 ,3 propanediol (PDO), diethylene glycol (DEG), distilled water and mixtures of these.

The heating element container may be fashioned from any thermally conductive material. Preferably, it is made of a metal. Preferred metals include copper, brass, steel, aluminium and zinc. Copper and brass are especially preferred.

In a preferred embodiment, the housing is made from an engineering plastic thereby making it light weight for easy transportation and reducing manufacturing cost. The thermal gradient across the thickness of the plastic walls substantially prevents heating of the outer surfaces, rendering the unit safe to touch and acceptable in a domestic setting. Suitable engineering plastics include polypropylene, polyethylene, polystyrene and PET. Optionally, the housing may be provided with an outer layer of insulating material, such as rock or slag wool, asbestos, vermiculite or perlite. The housing, in some embodiments, comprises a double wall construction, wherein the gap may be filled with the materials listed. In such an embodiment, the outer skin may be of metal or other durable material.

The system can be operated to provide hot water and central heating

simultaneously. In particular, it has the capacity to provide both continuous heating of central heating fluid and contain a reservoir of hot water for supply to taps, shower heads etc. This makes the apparatus of the invention especially suitable for emergency or temporary use.

In one embodiment, the heating apparatus incorporates a pump to circulate central heating fluid. However, circulation may be provided by a separate pump at low speed, such as the one already present in a domestic central heating system, may be used. This is appropriate when the heating apparatus is used in a temporary situation, and the installed circulating pump is functional. Various pumps are known to those skilled in the art, and typical of these are electrically powered centrifugal pumps.

The heating apparatus is provided with one or more water inlets in fluid connection with the interior of the housing, and one or more water outlets in fluid communication with the interior of the housing. A typical and preferred arrangement will be that the heating apparatus is provided with an inlet and an outlet adapted to be connected to a central heating system, and an inlet and an outlet adapted to be connected to a hot water system, for the supply of taps, shower heads, appliances etc.

In a preferred embodiment, the central heating inlet and central heating outlet are connected via a tube having thermally conductive walls, which is in thermal contact with the heating element container. Such an arrangement allows central heating fluid to circulate through the heating apparatus, becoming heated as it does so, and so maintain the central heating fluid circulating in the remainder of the system to which it is connected at a more or less constant temperature. In order to increase the efficiency of heat transfer between the heating element container and the tube, the design of the tube preferably maximises the contact area between the two.

Preferably, the tube is generally in the form of a helix, wound about the exterior of the heating element container inside the housing. The heating element container is preferably cylindrical or generally cylindrical in shape.

The housing preferably has sufficient volume to act as a storage vessel for hot water, i.e. to act as a hot water tank. Generally, the size will be smaller than a standard domestic hot water tank, in the interest of portability of the overall device. Typically, the device may have a usable volume for receiving hot water of up to 50 L, such as up to 30 L or up to 10 L. The devise also functions to provide central heating without exploding even when there is no water in the housing. The heating element inside the heating element container is in an air tight seal with a heat transfer medium which protects it from explosion.

In a typical arrangement, the running water cold inlet comprises a cold water dip tube, having an open end disposed near the bottom of the housing. This allows cold water to fill the housing from the bottom. The heating element container is in contact (direct or indirect, e.g. via a surrounding tube) with the water filling the housing, and heated water rises to the top of the container. This may be drawn off via a running water hot outlet, suitably comprising a tube having an open end disposed near the top of the housing.

In some embodiments, the apparatus is provided with a safety plug with an

illuminated on/off switch for safe functioning of the unit.

Optionally, a drain valve at the bottom of the heating allows the content of the unit to be siphoned off so as to empty the unit when not in use. The size of the heating unit and the rating of the heating apparatus and the heating element are such that an adequate individual shower and heat supply for the radiators is provided. Figure 1 -6 illustrate the heating apparatus and the heating element of the present invention.

Fig 1 shows an embodiment of the invention. The heating apparatus (20) comprises a housing (1 ), in this case a drum made from an engineering plastic material and a lid (2).

The lid (2) of the heating apparatus (20) has inlets (5,7) for cold water, outlets for hot water (6,8) and the heating element container (3) attached to it.

Fig. 2 is a top view of the lid showing all the water outlets.

Fig. 3 shows the heating apparatus (20) which is made up of a heating element container (3) enclosing a heat transferring medium and a heating element (12). The heating element container is made up of any heat conducting material, preferably copper. The purpose of the heat transferring medium is not only to transfer heat from the heating element (12) to the walls of the heating element container (3), but also to protect the heating element (12) from any damage of lime scale or corrosion. As shown in Fig. 4, the lid (2) contains a running water cold inlet (5), a central heating cold inlet (7), running water hot outlet (6), a central heating hot outlet (8) and a heating element container (3). The inlet (7) and outlet (8) for connection to the central heating system are connected via a tube (4), which is wound in a helix around a heating element container (3). Inlet (5) extends via a dip tube (9) inside the heating apparatus (20) so that the cold water is transferred to the bottom of the tank.

As shown in Fig. 5, the drum (1 ) has a drain valve (1 1 ) attached at the bottom of the apparatus which is used to empty the contents of the apparatus.

The heating element (12) is sealed with the heat transferring medium in the heating element container (3) and is connected to the lid (2) such that the heating element is exposed on the outer side of the lid (2) where it is provided with contacts (10) for connection to an electricity supply. For safety, the exposed element and its circuit is covered in a safety case (14) with a safety plug (1 5) as shown in Fig. 6. An illuminated switch (13) provides a means of controlling the device, together with a visual indication of operation. The drum (1 ) and the lid (2) form an airtight seal to become a working heating apparatus (20).

In a preferred embodiment, the heating element (12) is configured with a thermostat for selected temperature range and an added safety measure which stops the heating apparatus (20) form over-heating.

In another embodiment, the heating apparatus (20) is provided with an integrated pump for inflow regulation in the absence of the householder's own pump. The heating element container (3) can be used in any system that requires safe heating and can also be incorporated into the conventional boilers so as to increase the lifetime of the heating elements.

Claims

1 . A heating apparatus for heating a liquid, comprising:

a housing adapted to receive cold water to be heated;

a heating element container formed of a thermally conductive material and

containing a heat transfer medium and a heating element;

one or more water inlets in fluid connection with the interior of the housing;

2. A heating apparatus according to claim 1 wherein, the heat transfer medium is a liquid.

3. A heating apparatus according to claim 2, wherein the heat transfer medium comprises ethylene glycol (EG), 1 ,3 propanediol (PDO), diethylene glycol (DEG), distilled water and mixtures thereof.

4. A heating apparatus according to any one of the preceding claims, wherein the heating element is an electrical resistance heating element.

5. A heating apparatus according to any of the preceding claims wherein the heating element is thermostatically controlled.

6. A heating apparatus according to any preceding claim, wherein there are two water inlets, being a central heating cold inlet and a running water cold inlet, and two water outlets, being a central heating hot outlet and a running water hot outlet.

7. A heating apparatus according to claim 6, wherein the central heating cold inlet and central heating hot outlet are connected via a tube having thermally conductive walls, which is in thermal contact with the heating element container.

8. A heating apparatus according to claim 7, wherein the tube forms a helical coil around the heating element container.

9. A heating apparatus according to one of claims 6, 7 or 8 wherein the running water cold inlet comprises a cold water dip tube, having an open end disposed near the bottom of the housing.

10. A heating apparatus according to any one of claims 6 to 9 wherein the running water hot outlet comprises a tube having an open end disposed near the top of the housing.

1 1 . A heating apparatus according to any preceding claim, wherein the heating apparatus further comprises a lid.

12. A heating apparatus of claim 1 1 , wherein the lid is adapted to receive the inlets and outlets.

13. A heating apparatus according to claim 1 1 or 12, wherein the lid is adapted to receive the heating element container.

14. A heating apparatus according to any preceding claim, wherein the housing is provided with a drain valve disposed near the bottom.

15. A heating apparatus according to any preceding claim, comprising an integrated water pump.