A thermal fan

Abstract

A thermal fan (1) comprises a base section (2) configured to locate onto a heated surface in use; a central body section (3); a TEG (5) configured to locate between the base section (2) and central body section (3) to connect the base and central body sections (2,3), the TEG (5) configured to power a fan (6) in use; the central body section (3) extending upwards from the base section (2), the fan (6) located so that the fan blades rotate in front of or behind the base and central body sections (2,3) in use, the thermal fan (1) further comprising at least one side section (4a,4b) connected to the base section (2) and configured to at least partly shield the central body section (3) from radiative heat from the stove top on at least one side of the central body section (3).

Description

[0001] A THERMAL FAN

[0002] FIELD

[0003] The present invention relates to a thermal fan. The present invention further relates to a thermal fan having a fragrance dispenser.

[0004] BACKGROUND

[0005] Wood burning stoves and similar work well at warming an area directly in front or around the stove, but tend to be less effective at projecting heat further into a room. This can cause areas in the space that they are installed in to be either too cold or too hot.

[0006] A particular type of thermal fan - generally referred to in this context as a stove fan - is a type of device that is commonly used to assist with this issue. A ‘thermal fan’ in this context generally refers to a freestanding fan that sits on top of a hot body, such as a radiator, stove, or similar, and which uses the transference of heat between the surface of the hot body and the body of the fan (via the base) to power the fan’s motor and blades. When the fan is operating, the warm air from the hot body is circulated around the room rather than this air remaining directly around or adjacent to the hot body. A ‘stove fan’ is a particular variation of this.

[0007] As noted above, stove fans use the heat generated by the stove to power the fan. When the stove fan is placed on top of a stove, heat is transferred to the base of the fan from the stove top. The heat travels up from the base of the fan to a thermoelectric generator, which produces thermoelectric energy, which is used to turn the fan blades and circulate the warm air around the room.

[0008] US5,544,488 shows and describes a self-powered fan for circulating air for use in cooperation with a heat source. The fan comprises a heat transfer member having a heat transfer surface operably co-operable with the heat source, an electric motor, fan blades, a thermocouple means co-operable with the electric motor and the heat transfer member. The heat transfer member is of suitable size, mass and shape so as to provide a suitable temperature gradient between the thermocouple means and the heat source to operably allow sufficient heat transfer from the heat transfer member to the thermocouple means to generate sufficient power to effect rotation of the blades but not to cause thermal damage to said thermocouple means.

[0009] Air fresheners or similar are generally formed either as passive units that contain a scent reservoir (e.g. a scented oil or gel) that gradually evaporates into a room under normal day-to-day conditions, or active units that are powered either by an integral battery or which plug into an electrical power socket in order to drive the evaporative and distribution process. The passive type relies on the ambient conditions being suitable for evaporation and distribution as required, and the active type requires a power source.

[0010] In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.

[0011] SUMMARY

[0012] It is an object of the present invention to provide a thermal fan which goes some way to overcoming the abovementioned disadvantages or which at least provides the public or industry with a useful choice.

[0013] It is a further object of the invention to provide a thermal fan having a fragrance dispenser which goes some way to overcoming the abovementioned disadvantages or which at least provides the public or industry with a useful choice.

[0014] The term “comprising” as used in this specification and indicative independent claims means “consisting at least in part of”. When interpreting each statement in this specification and indicative independent claims that includes the term “comprising”, features other than that or those prefaced by the term may also be present. Related terms such as “comprise” and “comprises” are to be interpreted in the same manner.

[0015] As used herein the term “and / or” means “and” or “or”, or both.

[0016] As used herein “(s)” following a noun means the plural and / or singular forms of the noun.

[0017] Accordingly, in a first aspect the present invention may broadly be said to consist in a thermal fan, comprising: a base section configured to locate onto a heated surface top in use; a central body section; a TEG configured to locate between the base section and central body section to connect the base and central body sections, the TEG configured to power a fan in use; the central body section extending upwards from the base section, the fan located so that the fan blades rotate in front of or behind the base and central body sections in use; the thermal fan further comprising at least one side section connected to the base section and configured to at least partly shield the central body section from radiative heat from the stove top on at least one side of the central body section.

[0018] In an embodiment, the at least one side section comprises multiple side sections configured to connect to the base section and extend to at least partly shield each side of the central body section from radiative heat from the stove top.

[0019] In an embodiment, the at least one side section is configured to connect to the base section so that there is direct contact between at least a portion of the base section and the at least one side section.

[0020] In an embodiment, the at least one side section is configured to connect to the base section so that the base section and side section are spaced apart from one another.

[0021] In an embodiment, the thermal fan further comprises a connector configured to connect the base section and side section and to space these apart from one another in use.

[0022] In an embodiment, the connector comprises a bolt and sleeve.

[0023] In an embodiment, the sleeve is formed in sizes of 1 mm, 3mm, 5mm, and 10mm.

[0024] In an embodiment, the outer part of the at least one side section is curved to follow the path of the tips of the fan blade.

[0025] In an embodiment, the base section comprises a lower section with a substantially flat lower face, and a plurality of legs extending upwards from the lower section, the side sections and outer ones of the legs configured for connection.

[0026] In an embodiment, the plurality of legs are substantially evenly spaced from one another.

[0027] In an embodiment, the legs comprise three legs.

[0028] In an embodiment, the legs comprise a substantially central leg and two outer legs to each side of the central leg.

[0029] In an embodiment, the central body section comprises a flat base section configured to contact the upper surface of the TEG in use, and a plurality of substantially evenly- spaced apart fins extending upwards from the base.

[0030] With respect to the above description then, it is to be realised that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

[0031] This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

[0032] Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

[0033] BRIEF DESCRIPTION OF THE FIGURES

[0034] Further aspects of the invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings which show an embodiment of the device by way of example, and in which:

[0035] Figure 1 shows a stove fan of the known prior art type.

[0036] Figure 2 shows an exploded perspective view of the central portion of a prior art stove fan, the fan having a base section, a fan section, and a thermoelectric generator that is in use located between the two, the figure also showing schematically the temperature differences between the base and fan sections, and how this temperature gradient powers the thermoelectric generator.

[0037] Figure 3 shows a front view of an embodiment of thermal fan of the present invention, with the bladed section of the fan not shown, the thermal fan having a base section, a central section connected to and extending from the top of the base section, and two side sections connected one to each side of the base section and extending up and around the sides of the central section, a thermoelectric generator located in the central section and configured for connection to the bladed section of a fan in use, the side sections shown connected to but spaced away from the base section by the connector so that there is no direct contact between the side sections and the base section.

[0038] Figure 4 shows a front view of the embodiment of the thermal fan of figure 3, the bladed section of the fan shown in this figure, with the direction of rotation of the blades also shown, arrows showing the direction of heat transfer from the base section along the side sections.

[0039] Figure 5 shows a rear view of the embodiment of thermal fan of figures 3 and 4.

[0040] Figure 6 shows a variation of the thermal fan of the present invention, lower portions of the side sections of the thermal fan in this embodiment in direct contact with the central section.

[0041] Figure 7 shows a prior art stove fan, showing detail of temperature variations of the output caused by differential warming from the stove.

[0042] Figure 8 shows a perspective rear view of the base of a variation of the thermal fan of the present invention, the base configured to receive a long oil tray that in use holds a fragranced oil that is heated from the heated of the base, and which evaporates to fragrance a room.

[0043] Figure 9 shows a perspective front view of a further variation of the thermal fan of the present invention, the base configured to receive a short oil tray that in use holds a fragranced oil that is heated from the heated of the base, and which evaporates to fragrance a room.

[0044] DETAILED DESCRIPTION

[0045] Embodiments of the invention, and variations thereof, will now be described in detail with reference to the figures.

[0046] An embodiment of thermal fan 1 is shown in figure 3. The thermal fan 1 has a base section 2, a central section 3 connected to and extending from the top of the base section 2, and two side sections 4a, 4b connected one to each side of the base section 2, the side sections, 4a, 4b extending up and around the sides of the central section 2. A thermoelectric generator (TEG) 5 is located in and forms part of the central section 3. A fan 6 is connected to the TEG 5 in use, the TEG powering the fan 6, the fan 6 not shown in figure 3.

[0047] The separate parts of the thermal fan 1 will now be described in detail.

[0048] Base Section

[0049] As shown in the figures, the base section 2 comprises a flat lower section 201 that is configured to in use rest on top of a stove or wood burner or similar. In variations, the base section 2 could also be configured to rest on top of a radiator, a convection heater, or any other similar type of heating unit. The underside or bottom surface of the flat lower section 201 is flat or substantially flat so that there is good contact and heat transfer between the stove top and the flat lower section. The flat lower section 201 is substantially rectangular in plan view in this embodiment.

[0050] Three legs 202 extend upwards from the flat lower section 201 , the outer two of the legs 202 located at or towards each end of the flat lower section 201 , and a central leg that extends straight up. The end legs are angled inwards towards the centre.

[0051] The upper ends of the legs 202 connect with a flat upper plate 203 that is smaller than the flat lower section 201 .

[0052] In this embodiment, the base section 2 is formed as a single one-piece or integral item.

[0053] In some variations, the flat lower section 201 is configured so that it can be bolted to a stove top or similar, as this allows better conductive transfer between the stove top and the flat lower section 201.

[0054] In this embodiment, and the other embodiments described, the legs 202 are substantially evenly spaced from one another. Even spacing of the legs allows an even distribution of heat to the upper plate 203, which in turn means that heat is evenly distributed across the under-surface of the TEG. This helps to ensure that the TEG works as efficiently as possible.

[0055] Central Section

[0056] The central section 3 is connected to the flat upper plate 203 and extends upwards from the flat upper plate 203. The central section 3 comprises a body 301 and a thermoelectric generator 5. The body 301 comprises a base portion 302, four spaced-apart fins 303 that extend upwards from the base portion 302, and an upper portion 304. The body 301 is formed as a single one-piece or integral item.

[0057] The thermoelectric generator 5 is in use located between the base portion 302 and the flat upper plate 203 of the base section 2, so that there is thermal or heat transfer from the flat upper plate 203 of the base section 2 to the thermoelectric generator 5 and heat transfer from the thermoelectric generator 5 to the base portion 302.

[0058] A fan motor 305 is located partway up the central section 3 between the two central ones of the fins 303, the motor 305 connected to the fins. The thermoelectric generator 5 is connected to the motor 305 to provide power to the motor 305.

[0059] The base portion 301 is flat, and the fins 303 are substantially evenly-spaced across the upper surface. Similarly to the base section, even spacing allows an even distribution of heat to the base portion 301 , which in turn means that heat is evenly distributed across the under-surface of the TEG. This helps to ensure that the TEG works as efficiently as possible.

[0060] Side Sections

[0061] Each of the side sections 4a, 4b is connected to the base section 2, the side sections 4a, 4b, connected one each to each of the outer two of the legs 202.

[0062] The side sections 4a, 4b are formed so that each side section has a connecting lower section 401 that in use parallels the leg 202 to which it is connected, and sides 402, 403 that extend one from each end of the connecting section so that in use when connected to the base section 2 the sides 402, 403 curve upwards and inwards (towards the top of the central section, the upper ends of the sides 402, 403 meeting at an inwardly and upwardly facing point. Each of the side sections 4a, 4b is formed as a one-piece or unitary item. The outer one of the sides 403 is shaped so that in front or rear view the outer perimeter of the thermal fan 1 has the appearance of the upper part of a circle. The upper portion 304 of the central section is also curved so as to continue this circular perimetrical curvature appearance.

[0063] As shown in figures 3 and 4, the side sections are connected to the base section 2 in this embodiment via a single bolt or similar, with a sleeve or spacer 10 or similar around the body of the bolt that allows a gap to be made in use between the connecting section 401 and the outer leg 202 to which it is connected - the only contact between the side section and the base section is via the connector (the bolt and sleeve in combination). The sleeve or similar spacer 10 controls the distancing. The spacers 10 can be formed in a variety of sizes, to allow a gap of e.g. 3mm, 5mm, 10mm etc. It should be noted that any other suitable combination other than a bolt and sleeve could be used to achieve the same effect, and where ‘connector’ is used in this specification, this should be taken to mean any element or combination of elements that can achieve the effect of connection and spacing. These could be built into the base and side sections, and do not have to be separate elements. This could also refer to the bolt by itself.

[0064] In the variation shown in figure 4, the connecting lower section 401 is in contact with the outer / upper surface of the leg 202 along the length of the lower section 401 .

[0065] Another variation of this connecting arrangement is shown in figure 5. In this variation, the connecting lower section 401 and outer side of the base section 2 (the upper and outer surface of the leg 202 and flat lower section 201 at that part) are mutually shaped so as to be in contact along the length of the lower section 401 . It is preferred that for all of the elements described above - the base, the central section, and the side sections, that the surfaces of these are kept smooth. It is known in the prior art to use a textured or ‘rippled’ surface for some or all of the elements that form the upper section, in order to increase the surface area available for cooling in the upper section. However, a smooth surface increases the effectiveness of the fan and the air flow, and therefore a smooth surface is preferred in the embodiments of the present invention.

[0066] Operation

[0067] In use, it is desirable that the base of the thermal fan is as hot as possible, and the upper section is as cool as possible. Because of the way in which a TEG operates, the larger the temperature difference between the base and upper section, the more power is generated, and the TEG (and therefore the fan) operates more effectively.

[0068] There is always a compromise between heat extraction from stove top and the speed of the fan.

[0069] In the thermal fan of the present invention, the use of multiple legs (three, in the embodiments described above) allows a greater amount of heat transfer from the flat lower base that is in contact with the stove top, to the TEG. The outer legs also allow the side sections to be connected. The side sections shield the central section from reflected / radiated heat from the stove top, allowing the upper section to remain cooler in use than would otherwise be the case.

[0070] In use, heat is transmitted through the legs quickly, and the amount of heat then diverted to the side sections can be altered by using spacers, as outlined above. Using a single longer spacer (as shown in figures 3 and 4) means that less heat is transferred to the side sections, and a greater amount of heat is therefore transferred directly upwards to the TEG (there is less direct contact as the only contact is via the spacer and connector, and the air gap is larger). Using two spacers as shown in figure 5, with the spacers a smaller size than for figures 3 and 4, so that there is a narrower air gap, means that there is relatively more heat transfer from the base to the side sections than there is for the figures 3 and 4 embodiments.

[0071] Direct contact, as shown in the embodiment of figure 6, means that a larger proportion of the heat from the base is transferred into the side sections than if spacers are used.

[0072] If the stove fan of the present invention is operated with no spacer present (e.g. figure 6), the output temperature of the air from the fan is higher. However, the fan speed is lower than if a spacer is used, as heat is ‘pulled’ out of the base section and into the side sections. Therefore the temperature of the base where it is in contact with the TEG is lower, and therefore the temperature difference between the upper and lower parts of the TEG is lower, and therefore the amount of power generated is lower, leading to a lower fan speed.

[0073] If a spacer is used, there is less heat transfer to the side sections, and therefore the base where it is in contact with the TEG is hotter, leading to a larger temperature difference between the top and bottom of the TEG, leading to greater power generation, leading to a faster fan speed.

[0074] In short, adding spacers gives a higher fan speed output with less heat output. More spacers and a greater air gap width increases the speed output and decreases the heat output. Direct contact with no spacers can lead to a temperature output that is 20 degrees Centigrade higher than a variation with spacers.

[0075] Another issue with prior art designs is where the output air from the fan is drawn from. With reference to figure 7, it can be seen that as the fan rotates clockwise, it pulls hot air through the blades at the lower left quadrant. However, at the upper right quadrant, cooler air is drawn through the blades, as this area is higher, and further away from the stove top.

[0076] Using a thermal fan such as the one from the present invention, where side sections are used, the temperature of the output air is much more even, as the side sections extend around and over the perimeter of rotation of the fan. As the side sections are heated due to heat transfer from the base section, the air around them becomes heated, and therefore the air in the top quadrants which is drawn through the fan is hotter than it would otherwise be.

[0077] In variations of the design outlined above, the fan could be located behind the central and side sections. The fan could also be enclosed, or located in the middle of a support structure formed by the central and side sections.

[0078] Fragrance Dispenser

[0079] In a variation of the embodiment described above, the thermal fan is configured to also act as a fragrance dispenser.

[0080] As shown in figures 8 and 9, in this variation, the flat lower section 201 of the base of the thermal fan is configured to receive a container - in these variations tray 50a (figure 8) or oil tray 50b (figure 9), the trays configured to hold a fragrance solution (‘solution tray’). The solution tray is an open-topped container that in use holds a fragranced solution, most preferably a water-soluble fragrance material . In use, heat from the flat lower section 201 heats the solution tray, which causes the contents to become heated and gradually evaporate. The evaporating vapours from the solution mix with the atmospheric air around the solution tray and fan, and this air and vapour mixture is distributed to the wider environment as the fan blades rotate and mix the air passing through the fan throughout the room in which the fan is located.

[0081] The solution trays described above and as shown in figures 8 and 9 could be substituted for any suitable container - any container that can contain a liquid and which can both conduct heat and be heat-resistant (e.g. will not melt or otherwise become damaged when heated), and which has an opening though which vapours form the heated contents can exit the container.

[0082] In use, the fan recycles the heated and scented air round the room. Heated air is less dense than cold air, and therefore circulates better than cold air. This assists with spreading the fragrance. The use of the fan helps to extend the life of the solution, so it does not burn oft as fast.

[0083] In contrast with scented candles, which burn wax in order to give of volatile organic compounds for the scent, the scent is distributed via evaporation of the solution. This is safer and present less of a fire hazard.

Claims

Claims1. A thermal fan, comprising: a base section configured to locate onto a heated surface in use; a central body section; a TEG configured to locate between the base section and central body section to connect the base and central body sections, the TEG configured to power a fan in use; the central body section extending upwards from the base section, the fan located so that the fan blades rotate in front of or behind the base and central body sections in use; characterised in that the thermal fan further comprises at least one side section connected to the base section and configured to at least partly shield the central body section from radiative heat from the stove top on at least one side of the central body section.

2. A thermal fan as claimed in claim 1 wherein the at least one side section comprises multiple side sections configured to connect to the base section and extend to at least partly shield each side of the central body section from radiative heat from the stove top.

3. A thermal fan as claimed in claim 1 or claim 2 wherein the at least one side section is configured to connect to the base section so that there is direct contact between at least a portion of the base section and the at least one side section.

4. A thermal fan as claimed in claim 1 or claim 2 wherein the at least one side section is configured to connect to the base section so that the base section and side section are spaced apart from one another.

5. A thermal fan as claimed in claim 4 further comprising a connector configured to connect the base section and side section and to space these apart from one another in use.

6. A thermal fan as claimed in claim 5 wherein the connector comprises a bolt and sleeve.

7. A thermal fan as claimed in claim 6 wherein the sleeve is formed in sizes of 1 mm, 3mm, 5mm, and 10mm.

8. A thermal fan as claimed in any one of claims 1 to 7 wherein the outer part of the at least one side section is curved to follow the path of the tips of the fan blade.

9. A thermal fan as claimed in any one of claims 2 to 8 wherein the base section comprises a lower section with a substantially flat lower face, and a plurality of legs extending upwards from the lower section, the side sections and outer ones of the legs configured for connection.

10. a thermal fan as claimed in claim 9 wherein the plurality of legs are substantially evenly spaced from one another.

11. A thermal fan as claimed in claim 9 or claim 10 wherein the legs comprise three legs.

12. A thermal fan as claimed in claim 11 wherein the legs comprise a substantially central leg and two outer legs to each side of the central leg.

13. A thermal fan as claimed in any one of claims 1 to 12 wherein the central body section comprises a flat base section configured to contact the upper surface of the TEG in use, and a plurality of substantially evenly-spaced apart fins extending upwards from the base.

14. A thermal fan as claimed in any one of claims 1 to 13 further comprising a container, the base section and container mutually configured so that the container can locate onto the base section in use, the container configured to in use hold a fragranced liquid or solid, the container further configured to receive heat from the base in use so that the fragranced liquid or solid is heated and gradually evaporates.

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