GB2479574A - Electric fire also burning a fluid fuel to generate flames - Google Patents

Abstract

A domestic electric fire has electrical heating elements 101 and a burner assembly 108a for a combustible fuel supply (e.g. an environmentally-friendly ethanol-based bio-fuel) to generate flames. A heating element 101 can be provided in a removable cassette (104a, fig 5) supported by a ceramic cylinder 102. Imitation logs or coals 103 can be provided. Heat from the elements 101 or a spark form igniter 111 can ignite the fuel. The fuel can be in an integral reservoir 109 above or below (figs 9 and 12) the heating elements 101. The fire may be in a housing 113, or free standing (fig 7). There may be a full of partial transparent guard 117. Thus the fire has a heating function while emulating the appearance of a solid fuel fire.

Description

A HYBRID ELECTRIC FIRE

The present invention relates to improvements in heating appliances and particularly relates to a hybrid electric fire comprising a real flame effect.

Conventional domestic electric fires may generally be categorised into one of two different types: (i) radiant, where heat from a heating element is predominantly transferred by radiative processes, and (ii) convective, where heat is typically transmitted to the heating environment (e.g. a room etc.) by a fan or blower, which circulates warm air, heated by an element of the fire.

Both types of electric fire conventionally comprise some form of resistive heating element, which when subjected to an electric current exhibits Ohmic heating. In radiant electric fires, the one or more heating elements are usually of the cylindrical spiral wound' type, typically referred to as electric bar heaters'. Such heating elements generally only transmit heat linearly (radiatively) directly in front of the fire, and due to their somewhat old-fashioned' appearance are usually quite aesthetically unpleasing to look at, both when in use and when turned off.

Therefore, manufacturers of electric fires have made significant efforts to produce aesthetically pleasing electric fires for domestic environments (such as living rooms and front rooms etc.). Hence, in addition to providing ornate housings, many manufacturers have also incorporated various mechanisms within the fires to simulate real flame effects', to thereby give the fire a more natural' and satisfying appearance. Many of these mechanisms are based on some form of coloured bulb or coloured light projector that is modulated, either mechanically or electronically, to simulate flickering flames'. In addition, some of the fires also make use of ribbons or the like disposed behind a vertical screen to emulate the appearance of moving flames.

However, such mechanisms typically require periodic maintenance (e.g. to replace the bulb or modulation device -such as a fan etc.), while many also suffer from the undesirable effects of ambient air currents or draughts, which can interfere with the simulated flame effect.

Moreover, and most importantly, very few of the simulated effects actually look like a real flame, and consequently, despite the efforts of the manufacturers, virtually all existing electric files simply do not have the appearance and feel of a real fire'.

It is an object of the present invention to address at least some, or all, of the above problems and to provide an electric fire that has a more realistic appearance.

According to an aspect of the present invention there is a provided a hybrid electric fire, comprising: at least one electrical heating element; and a burner assembly; wherein the assembly is in fluid communication with a combustible fuel supply, such that in use, the assembly is operable to controllably generate one or more flames via combustion of the supplied fuel.

The provision of both an electric heating element and a burner assembly for controllably generating one or more flames via combustion of a combustible fuel supply, enables the hybrid electric fire of the present invention to have the appearance of a real fire'. By real fire' we mean, a fire that burns via natural combustible processes and which produces living flames that both provide heat and light. An example of a real fire' is therefore a solid fuel (e.g. coal, coke or wood) fire, but is not limited thereto.

Moreover, the provision of both an electrical heating element and a real flame' burner assembly, allows the hybrid electric fire to provide a dual heating function, in that heat can be supplied to the heating environment (e.g. a front room) both through radiative and convective processes via electrical heating and combustion. In addition, due to the real living flame effect, the fire of the present invention is more natural in appearance, as compared to an existing electric fire with simulated flames, and hence is found to be significantly more aesthetically pleasing than conventional fires.

In one embodiment, the hybrid electric fire may comprise a plurality of electrical heating elements. The heating elements may be resistive heating elements, either of a conventional electric bar heater type or otherwise bespoke heating elements depending on the application.

Preferably, the burner assembly may be disposed in spaced relation to the heating element, this is to prevent any potential damage to the one or more electrical heating elements by the flames. In one embodiment, the burner assembly may be disposed above the one or more heating elements.

In preferred embodiments, the burner assembly may comprise a fluid conduit having at least one aperture at which the fuel can be ignited.

Preferably, the fluid conduit of the burner assembly may comprise a plurality of apertures. In one embodiment, the fluid conduit may be substantially circular in form, while in another embodiment it may be substantially S'-shaped in form. However, it is to be appreciated that the fluid conduit and the burner assembly may take any suitable form or configuration depending on the particular arrangement of the fire and the desired real flame effect.

The hybrid electric fire preferably further comprises a reservoir to hold the combustible fuel supply. In preferred embodiments, the reservoir may be integral to the electric fire itself, while in other embodiments, the reservoir may be external to the electric fire, but may be connected via a fuel supply or feed tube to the burner assembly.

Preferably, the burner assembly and reservoir are connected by at least one fuel feed tube, but may alternatively be connected by a plurality of feed tubes, depending on the particular arrangement.

The combustible fuel supply is preferably a bio-fuel, and is most preferably an ethanol-based bio-fuel. An advantage of using a bio-fuel is that the CO2 footprint is significantly lower than other liquid-based fuels, such as hydrocarbon fuels (e.g. paraffin etc.). Hence, in addition to aesthetically pleasing appearance of the present electric fire, it is also more environmentally-friendly than solid-fuel fires or paraffin heaters etc. Therefore, a homeowner can enjoy the benefits of a real flame fire, but without having a large CO2 environmental footprint.

Moreover, due to the low CO2 emission from the combustion of the bio-fuel, it is found that no flue or chimney is required for operation of the fire in a normally ventilated room or environment (e.g. such as a living room etc). Hence, no specialist installation is required to install the fire in a domestic setting, nor is any special certification required.

In some embodiments, the one or more heating electrical elements may be mounted within a replaceable heating element cassette. An advantage of this is that the heating elements may be easily replaced should they burn out' after prolonged use. The heating element cassette may be made from a relatively lightweight low thermal mass insulation material, such as a porous ceramic etc. In this way, the heating elements may be further protected from damage by the flames from the burner assembly.

To maintain a constant flow of fuel to the burner assembly during use, the hybrid electric fire may further comprise a pump. Any conventional electrical or mechanical pump may be used. Alternatively, or additionally, the reservoir may be disposed so that it is relatively higher that than the burner assembly, so that the fuel may be supplied to the assembly under the action of its own weight (i.e. by gravity). Such an arrangement may also be assisted by a pump.

Preferably, the hybrid electric fire may also comprise a deflector plate configured to deflect radiative and/or convective heat components away from the electric fire. The deflector plate may be a planar arrangement disposed behind the electrical heating elements and burner assembly, or it may be curved or angled, or any combination thereof, depending on the desired heat deflection. The deflector plate may be opaque and/or reflective, or alternatively, at least partially transparent.

In preferred embodiments, the hybrid electric fire may also comprise a transparent guard screen disposed at the forward-facing portion of the electric fire. By forward-facing' we mean the face or portion of the fire that faces outwards towards the heating environment.

Preferably, the hybrid electric fire comprises an outer housing, which preferably contains the heating elements and the burner assembly. In some preferred embodiments, the deflector plate and the guard screen may form part of the housing.

The housing may comprise at least one ventilation grill to facilitate convective air flow through the electric fire. In preferred embodiments, the housing comprises an upper grill and a lower grill disposed on the forward-facing portion of the housing.

In some embodiments, the housing may comprise one or more at least partially transparent walls to enable the homeowner to view the flames from oblique angles relative to the forward-facing portion of the fire. In this way, the aesthetic appearance of the fire is further enhanced.

It is to be appreciated that the transparent guard screen and housing walls may be made from any suitable high-melting temperature material, such as toughened safety glass or other silicate materials.

To further facilitate the circulation of air through the hybrid electric fire, at least one electric fan may be included within the housing.

Preferably, the hybrid electric fire further comprises an igniter to controllably ignite the fuel when the burner assembly is turned on. The igniter is most preferably an electric spark igniter, such as piezo-electric device, which can ignite the fuel vapour at the one or more apertures of the burner assembly.

To control the operation of the one or more heating elements and/or the burner assembly, a controller is preferably provided. The controller may be electronic or mechanical, or a combination of both, and may be configured to automatically limit the current to the heating elements and/or vary the flow of fuel to the burner assembly. In one embodiment, the controller may comprise one or more thermostats, which contain a bi-metallic strip to limit the current to the heating elements. In addition, the controller may further comprise a closure valve which may vary the fuel flow to the burner assembly.

The controller may be manually manipulated by a homeowner or alternatively, or additionally, may be remotely controlled using a remote control device, such as an infra-red transmitter etc. Preferably, the controller may also control the igniter to ignite the fuel at the aperture(s) of the burner assembly.

The hybrid electric fire of the present invention may be free-standing, partially wall mounted or fully wall mounted depending on the particular arrangement and desired domestic configuration.

In addition, to further enhance the aesthetic appeal and appearance of the hybrid electric fire, imitation coals or logs etc. may also be mounted proximal to the burner assembly. Alternatively, in some embodiments, the burner assembly is embedded, or otherwise covered by, the imitation coals or logs. Preferably the imitation coals are fabricated from a ceramic material, which visibly glows when heated, to thereby further emulate the appearance of a solid-fuel fire.

It is to be understood that elements or features of any of the embodiments can be used with or interchanged for elements or features of any of the other embodiments, without limitation.

Embodiments of the present invention will now be described in detail by way of example and with reference to the accompanying drawings in which: Figure 1 -shows a perspective view of a hybrid electric fire according to a preferred embodiment of the present invention; Figure 2 -shows a plan view of part of the fire of the embodiment of Figure 1, illustrating an example grate arrangement; Figure 3 -shows a side sectional view of the fire of the embodiment of Figure 1; Figure 4 -shows a front view of the fire of the embodiment of Figure 1; Figures 5A & 5B -show respective perspective and cut-away views of an example heating element cassette according to a preferred embodiment of the invention; Figures 6A to 6C -show respective plan and cross-sectional views of the heating element cassette of the embodiment of Figures 5A and SB; Figure 7 -shows a perspective view of another embodiment of the hybrid electric fire according to the invention, illustrating an example free-standing fire grate; Figure 8 -shows a plan view of the fire of the embodiment of Figure 7; Figure 9 -shows a side cross-section view of an alternative embodiment of the hybrid electric fire according to the invention; Figure 10 -shows a front view of the fire of the embodiment of Figure 9; Figure 11 -shows a side cross-section view of a example fuel supply arrangement according to an embodiment of the invention; Figure 12 -shows a side cross-section view of a example fuel supply arrangement according to another embodiment of the invention; For the purposes of clarity, in some of the figures features have been omitted or simplified in order not to obscure other features in the illustration. Features referred to in one embodiment may be interchanged with or replaced by those of another embodiment, without limitation.

Referring to Figure 1, there is a shown a particularly preferred embodiment of a hybrid electric fire 100 according to the present invention. The electric fire 100 comprises a plurality of electrical heating elements 101 arranged in a planar parallel configuration. The electrical heating elements are of a conventional electric heating bar type and during operation glow red-hot' to radiatively transmit heat to the heating environment (e.g. a domestic living room etc.).

The electric fire 100 further comprises a burner assembly in fluid communication with a combustible fuel supply, the assembly comprising a fluid conduit 108a having a plurality of apertures at which the fuel can be ignited (see Figure 3). In this way, the electric fire 100 is capable of generating a plurality of real flames via combustion of the fuel, while also providing a dual heating function by way of the electrical heating elements 101.

Hence, it is apparent that the electric fire 100 differs from existing simulated flame fires, which typically require the use of ribbons or projections or the like behind a vertical screen to provide the flame effect, as the fire of the present invention generates real living flames.

In the example of Figure 1, each electrical heating element 101 is supported by a respective ceramic cylinder 102, which passes through the internal volume of the element (see Figure 2). The ceramic supports are made from a high percentage sintered Alumina, or similar ceramic material.

As shown in Figure 1, the electric fire 100 further comprises an outer housing or enclosure 113, which is generally box-like' in form.

However, it is to be appreciated that any suitable shape or structure for the housing or enclosure may be adopted for the electric fire of the present invention depending on the desired application and aesthetic requirement.

In the example of Figure 1, the housing comprises a deflector plate 106, opaque sidewalls and a front panel 117, serving as a transparent guard screen. It is perceived that the sidewalls may also be manufactured in an at least partially transparent material, so as to provide a more aesthetic view of the fire from oblique side angles as well as from the front.

The deflector plate 106 serves two main functions, to deflect the convective air flow and radiated heat into the heating environment (see Figure 3) and to provide a contrasting background for the real flame effects. Hence, the deflector plate 106 may be have a blackened surface to enhance the brightness and/or colour of the flames generated by the burner assembly to further improve the aesthetic appearance of the fire.

This is found to be particularly beneficial in rooms that have a lot of natural light or are otherwise generally well-lit.

Alternatively, a polished (reflective) deflector plate may instead be used to reflect the light and heat of the flames into the heating environment.

Referring now to Figure 2, there is shown a plan view of the resistive heating elements 101 of the electric fire 100 of Figure 1. As indicated above, in this example the heating elements 101 are mounted on ceramic supports 102, which are then arranged in a planar parallel configuration, with each of the heating elements being spaced from each other.

However, it is to be appreciated that any suitable arrangement or array of heating elements may be used with the electric fire of the present invention.

As shown in Figures 2 and 3, a light-weight low thermal mass insulation material, such as a porous ceramic, is preformed into a planar matrix 104 that overlies the heating elements 101. The matrix 104 comprises a plurality of apertures, which can be arranged into a specific pattern across the surface of the matrix or alternatively can be randomly distributed. The function of the matrix 104 is to provide support for imitation coals or logs etc. so that they may be disposed above and/or in contact with the heating elements 101.

The imitation parts 103 may be made from a low thermal mass insulation material, such as porous ceramic, and can be shaped into any desired form to simulate coals, cokes or logs etc. or any other desired aesthetic shape, for example, pebbles etc. Upon heating, the imitation parts 103 will be at such a temperature that they will begin to glow and emit light. Hence, in this way the visual appearance more closely resembles that of a solid fuel fire, which also has the additional advantage that the imitation parts assist with radiating heat in different directions into the heating environment.

Referring now to Figure 3, the fluid conduit 108a of the burner assembly is supplied with an environmentally friendly bio-fuel, ideally an ethanol-based bio-fuel, via a feed tube 108 from an integral storage reservoir 109.

The reservoir 109 is positioned at the rear, upper portion of the electric fire 100. However, it is to be appreciated that the reservoir 109 may be disposed at any convenient location within the fire, as required by the particular design and configuration of the housing 113.

It should be understood that although an ethanol-based bio-fuel is the preferred combustible fuel for the electric fire of the present invention, any other suitable fuel derived from sustainable and renewable plant extracts or any other suitable variant may alternatively be used, provided that when it is combusted it produces only relatively small or negligible quantities of CO2.

To maintain the fluid flow to the fluid conduit 108, an electric fuel pump is incorporated into the reservoir 109.

Although not explicitly shown in Figure 3, the fluid conduit 108a includes a plurality of apertures at which the fuel can be ignited to generate real flames. The fluid conduit 108a can have any desired shape, which in the example of Figure 3, is simply a linear pipe.

The fuel can be ignited by the heat coming from the electrical heating elements 101, when the fire is operated in a dual heating mode. However, it is found that more control over the flame effects can be obtained if the fuel is ignited by way of an electric spark igniter 111 located proximal to the apertures in the fluid conduit 108a. Any suitable igniter, and any number thereof, may be used with the electric fire of the present invention.

From a practical point of view, since the electric fire in these examples uses a liquid fuel the housing 113 incorporates adjustable feet 120 to facilitate horizontal levelling of the fire relative to the ground. To assist the homeowner with the task of levelling the fire, a visual level gauge, such as a spirit-level type device (not shown), may be incorporated into the housing 113. Any suitable levelling gauge may be used, e.g. a mechanical or electrical device etc. In addition, a fuel quantity gauge or meter l2lmay also be associated with the reservoir and incorporated into a surface of the housing 113 to enable the homeowner to monitor the supply of bio-fuel remaining in the reservoir.

As shown in Figure 3, the whole heating unit, i.e. the heating elements 101, burner assembly and imitation parts 103 can be angled relative to the horizontal base of the housing 113. In this way, the fire may then present a more preferred viewing angle to the homeowner, which can further enhance the aesthetic appearance of the fire.

The operation of the fire is controlled by way of a manually manipulated controller 107, as shown in Figures 1 and 2. The function of the controller 107 is to control the electrical current to the heating elements 101 and also to the vary the flow of fuel to the burner assembly. Hence, the controller 107 can alter the heat output of the heating elements 101 and increase or decrease the flame height.

The controller 107 may comprise two separate control devices or may be an integrated device which can control all the functions of the fire. In particular, in some examples the controller may be responsive to remote control signals, so that the fire can be operated remotely from within the heating environment.

The heating elements 101 can be adjusted via a proportional power control, using variable current pulses. This can be achieved using a power regulator such as a bi-metallic switching device or an electronically controlled power modulated circuit.

An adjustable bi-metallic switch can turn the heating elements on and off for predetermined amounts of time; while a burst fire type' modulated circuit provides trigger pulses, coincident with the mains polarity crossover, ensuring complete sine wave cycles are passed through to the resistive load. This prevents fast changes in load currents and inhibits radio frequency interference (RFI).

To further enhance safety, an over temperature' protection thermostat (not shown) can be incorporated into the electric fire, which would isolate the current to the heating elements and/or isolate the fuel to the flame, via a closure (stop) valve, if the temperature exceeded a predetermined threshold.

To protect the controller 107 and the fuel supply arrangement (i.e. reservoir 109 and feed tube 108 etc.) from undesirable heating, an insulation layer or shield 105 is fitted inside the electric fire, as shown in Figure 3. This shield 105 may be made from a low thermal conductivity material, such as a composite aggregate or relatively dense silicate or ceramic material. The shield 105 can also prevent undue heating of the housing 113 itself, preventing or otherwise minimising the risk of the homeowner burning themselves upon touching the surface of the housing.

Referring to Figure 4, the housing 113 also includes vents in the form of a bottom grill 115 and a top grill 116, which facilitate air flow 118, 119 through the fire and enable heat from the fire to be convectively transmitted to the heating environment. The bottom grill 115 and the top grill 116 may have any suitable aesthetic shape or form as desired.

The transparent guard screen 117 at the front of the electric fire can be a full height panel (i.e. from bottom to top) or else can be a partial height screen as shown in Figures 1 and 4. The screen 117 allows the homeowner to view the fire, while increasing safety by shielding him/her from the flames and the electrical heating elements.

Where a full height screen 117 is used, convective air flow 119 can pass through the top grill 116. The bottom grill 115 thereby inducing ambient air 118 from the heating environment into the fire. To facilitate air movement a fan 114 can be incorporated within the fire, as shown in Figure 3. The fan 114 can be used in conjunction with any of the embodiments of the present invention.

If desired, the electric fire may additionally comprise one or more guards or shields in the form of metal grills etc. to overlay any openings or vents.

It is to be appreciated that all embodiments of the hybrid electric fire 100 of the present invention require no chimney, flue, or other form of specific ventilation and consequently, the fire may be a free-standing appliance in any normally ventilated room.

Hence, the present electric fire is suitable for all domestic properties, with or without chimneys, where a fire with a real living flame is desired.

Referring to Figures 5A & 5B, there are shown examples of a heating element cassette 104a. The function of the cassette 104 is to support the plurality of heating elements 101, while permitting easily replacement of the heating elements after one or more have burned out'. The cassette comprises a matrix 104, similar in form and function to that described in relation to Figures 1 to 3, which is attached or moulded or otherwise bonded to a base insulation block 105. However, it is to be appreciated that the matrix 104 may be a separate component to that of the cassette and may be removable or permanently fixed, as required.

In the examples of Figures 5A & SB, the cassette 104a has been moulded into a form that allows the heating elements 101 to be mounted above the block 105 and close to or touching the upper matrix 104. This matrix is made up of a plurality of apertures, which allow the heated air 119 to pass through unimpeded. As shown, the apertures can be regularly spaced and located across the surface of the matrix 104, and may have any regular or irregular shape covering a large or small percentage of the matrix 104.

The cassette 104a may be made from a low thermal mass, high temperature insulation material, such as a porous ceramic. The block 105 may also have apertures or slots (not shown) to further enhance the airflow over the element.

Figure SB shows a cross-section view of the cassette 104a along line X-X' and is shown with a series of electric bar type' heating elements 101 mounted on ceramic supports 102. As shown the heated airflow 119 flows upwardly through the apertures in the matrix 104 at the top of the cassette 104a.

The use of a removable cassette is highly advantageous, as the inventor realised that the electrical heating elements are likely to require replacement over prolonged use of the electric fire. Therefore, the cassette can be changed as one complete unit, thereby significantly reducing the complexity of replacing the elements within the fire.

It is to be appreciated that the cassette may be used with any of the embodiments of the present invention.

Referring to Figures 6A to 6C, there are shown other views of the cassette 104a as described above, generally illustrating the convective air currents 119 that emanate from the heating elements 101 through the matrix 104. In Figure 6B, the cassette is shown in conjunction with overlying imitation parts 103 (e.g. coals), which illustrates the convective air movement through the imitation parts 103. In some examples, the cassette 104a and imitation parts 103, or the matrix 104 and imitation parts 103 may be moulded as an integral component.

In Figure 7, there is shown an alternative embodiment of the hybrid electric fire of the present invention. In this embodiment, the electric fire is in the form of a free-standing fire grate.

The fire grate has no deflector plate and is open both at the sides and behind. A transparent guard screen 215 is located at the front of the fire grate. However, if the fire grate were to be situated in the centre of a room etc. the fire grate could be provided with a guard screen that is disposed circumferentially around the grate, if desired.

The operation and functionality of the fire grate 200 is essentially the same as that described in relation to the preceding embodiments.

However, the fuel reservoir is now located beneath the heating element cassette and the burner assembly (see Figure 9).

As before, a bottom grill 213 is provided to allow air into the base of the fire grate to facilitate convective heat flow, which would pass through the matrix 204 and permeate upwardly through the imitation parts 203 (e.g. coals).

The operation of the fire grate is controlled by way of controller 207, in the manner as described in the preceding embodiments.

Figure 8 shows a plan view of the fire grate of Figure 7, the grate utilises the heating element cassette as shown in Figures 5A & SB above. It is intended that this fire grate would be ideally suited for location within a traditional fireplace or could alternatively be used as a central feature (e.g. such as in the centre of a room), where access and viewing from all sides is desirable.

Since no chimney or flue is required the grate could be viewed from all angles without any obstruction.

Referring now to Figure 9, there is shown a modified version of the fire grate of Figure 7. In this example, a deflector plate 206 has been added to enhance the background contrast relative to the foreground flames. In this way, when viewing the fire, the flames and glow of the imitation parts 203 appear brighter and more defined, which significantly improves the aesthetic appeal of the fire, especially in well-lit rooms.

In addition, the deflector plate 206 also serves to deflect the convective air currents 219 from the fire into the heating environment.

The transparent guard screen 206 allows the homeowner to view the fire directly from the front and above without any obscuration, when the grate is placed in a traditional fireplace setting.

The bottom grill 216 acts to induce air 218 into the fire. To facilitate this air movement a fan 214 is incorporated into the fire to promote the flow of air into the cassette, whereby heating of the air can be effected.

The ethanol-based bio-fuel is stored in reservoir 209, which is located within the grate housing 213 at the bottom portion of the fire. A fuel pump 210 is used to ensure that the fuel flow to the burner assembly is maintained during use of the fire.

The fuel flows through the insulated feed tube 208 and into the fluid conduit 208a, whereupon it is ignited at a plurality of apertures (not shown) in the conduit via a electric spark igniter 211.

Figure 10 shows a front view of the fire grate of Figure 9. The grill 213 may be of a horizontal slat or a chequer design as desired. However, any required shape or configuration may be used depending on the particular aesthetic requirement.

The fire grate of Figures 7 to 10 may be controlled by way of a controller as described in detail in relation to any of the preceding embodiments.

Referring to Figure 11, there is shown a gravitational fuel feed system which may be used in conjunction with any of the embodiments of the present invention, unless it is necessary to locate the reservoir beneath the burner assembly, such as in the fire grate examples of Figures 7 to 10.

Where the fuel reservoir can be mounted higher than the burner assembly, fuel can be permitted to flow under the action of its own weight. Hence, when the closure valve 312 is opened, during use, fuel can flow down the fed tube 308 and into the fluid conduit 308a. The fuel at the apertures of the fluid conduit 308 can then be ignited by an electric spark igniter 311, whereupon flames are generated until the control valve is switched off or the reservoir 309 becomes depleted.

If, however, the pressure of the fuel flow drops during use, such as when the reservoir 309 is becoming nearly depleted, a pump 310 can be configured to automatically turn on to ensure that the flow is maintained to the burner assembly. An audible and/or visual alarm (not shown) can be used to indicate that the fuel is running low and/or requirements re-filling.

Depending on the particular configuration of the fluid conduit 308a, some apertures can be arranged to allow fuel to drip into the areas occupied by the imitation parts 103, which when ignited give the effect that the coals or logs etc. themselves are actually burning. The resulting flames are found to be more generally dispersed and possess a wider girth than is achievable by a single aperture of the fluid conduit.

By introducing the fuel in this way gives the fire an even more realistic appearance and consequently further enhances the aesthetic appeal of the fire.

Figure 12 shows an alternative arrangement for the fuel feed system, which may be used with any of the embodiments of the present invention.

In this arrangement, the reservoir 409 is situated beneath the heating element cassette and burner assembly.

The fluid conduit 408a is in the form of a channel having a single open slot that runs longitudinally along the length of the channel. During use, closure valve 412 is opened, which permits fuel to be supplied via pump 410 through feed tube 408 into conduit 408a. An electric spark igniter 411 ignites the fuel at the slot and a wide continuous flame is generated along the length of the conduit 408a.

Although the hybrid electric fire of the present invention is ideally suited for domestic purposes in respect of emulating a solid fuel fire, it will be recognised that one or more of the principles of the invention may extend to other heating and/or aesthetic display applications both within domestic and commercial environments, whereby it would be advantageous to have a dual heating function with a controllable real flame fire but without the inconvenience, and/or environmental impact, of a solid fuel fire, e.g. in retailer/shop window displays or in theatrical productions etc. Moreover, although each of the embodiments of the electric fire have been described in relation to the use of a liquid bio-fuel, it is to be appreciated that other fluid fuels, such as gases etc. may alternatively be used in some embodiments.

The above embodiments are described by way of example only. Many variations are possible without departing from the invention.

Claims (23)

1. CLAIMS1. A hybrid electric fire, comprising: at least one electrical heating element; and a burner assembly; wherein the assembly is in fluid communication with a combustible fuel supply, such that in use, the assembly is operable to controllably generate one or more flames via combustion of the supplied fuel.
2. 2. The electric fire of Claim 1, further comprising a plurality of electrical heating elements.
3. 3. The electric fire of Claim 2, wherein the one or more electrical heating elements are resistive heating elements.
4. 4. The electric fire of any preceding claim, wherein the burner assembly is disposed in spaced relation to the heating element.
5. S. The electric fire of any preceding claim, wherein the burner assembly comprises a fluid conduit having at least one aperture at which the fuel can be ignited.
6. 6. The electric fire of Claim 5, wherein the fluid conduit of the burner assembly comprises a plurality of apertures.
7. 7. The electric fire of any preceding claim, further comprising a reservoir to hold the combustible fuel supply.
8. 8. The electric fire of Claim 7, wherein the reservoir is integral to the electric fire.
9. 9. The electric fire of Claim 7 or Claim 8, wherein the assembly and reservoir are connected by at least one fuel feed tube.
10. 10. The electric fire of any preceding claim, wherein the combustible fuel supply is a bio-fuel.
11. 11. The electric fire of any preceding claim, wherein the one or more heating elements are mounted within a replaceable element cassette.
12. 12. The electric fire of any preceding claim, further comprising a pump to maintain the flow of fuel to the burner assembly during use of the electric fire.
13. 13. The electric fire of any preceding claim, further comprising a deflector plate configured to deflect radiative and/or convective heat components away from the electric fire.
14. 14. The electric fire of any preceding claim, further comprising a transparent guard screen disposed at the forward-facing portion of the electric fire.
15. 15. The electric fire of any preceding claim, further comprising a housing, in which the heating element and burner assembly are disposed.
16. 16. The electric fire of Claim 15, wherein the housing comprises at least one ventilation grill to facilitate convective air flow through the electric fire.
17. 1?. The electric fire of Claim 15 or Claim 16, wherein the housing comprises one or more at least partially transparent walls.
18. 18. The electric fire of any preceding claim, further comprising at least one fan to facilitate the circulation of air through the electric fire.
19. 19. The electric fire of any preceding claim, further comprising an igniter to controllably ignite the fuel when the burner assembly is turned on.
20. 20. The electric fire of Claim 19, wherein the igniter is an electric spark igniter.
21. 21. The electric fire of any preceding claim, further comprising a controller to control the operation of the one or more heating elements and/or the burner assembly.
22. 22. The electric fire of any preceding claim, wherein the electric fire is free-standing.
23. 23. A hybrid electric fire substantially as hereinbefore described with reference to Figures 1 to 12 of the accompanying drawings.