Stove fan

Abstract

A stove fan is provided that comprises a bladed rotor, an electric motor for driving the bladed rotor, a thermoelectric generator arrangement operative to power the electric motor, and a housing forming ducting having an internal diameter that is greater than the diameter of the tip path of the bladed rotor. The thermoelectric generator arrangement comprises: a thermoelectric module to generate electricity from a temperature differential between a first surface and a second surface, a heat transfer element in contact with the first surface of the thermoelectric module, a heatsink in contact with the second surface of the thermoelectric module The heat transfer element is thermally isolated from the housing.

Description

[0001] STOVE FAN

[0002] Field of the Invention

[0003] The present invention relates to a fan for a stove, such as a wood-burning or multi-fuel stove.

[0004] Background of the Invention

[0005] A stove fan is a device for improving the output of heat from a stove, such as a wood burner or a multifuel burner. A known type of stove fan comprises a bladed rotor, which is supported by a base that allows the stove fan to be placed on the top of a stove, and a thermoelectric module that is designed to utilise heat generated by the stove to drive the bladed rotor, which circulates warm air in the vicinity of the stove. The stove fan operates using only the heat from the stove and the rotating blades function to distribute heat from the stove more effectively.

[0006] It is an object of the present invention to provide an improved stove fan.

[0007] Summary of the Invention

[0008] According to a first aspect there is provided a stove fan, comprising: a bladed rotor, an electric motor for driving the bladed rotor, a thermoelectric generator arrangement operative to power the electric motor, and a housing forming ducting having an internal diameter that is greater than the diameter of the tip path of the bladed rotor, the thermoelectric generator arrangement comprising: a thermoelectric module to generate electricity from a temperature differential between a first surface and a second surface, a heat transfer element in contact with the first surface of the thermoelectric module, a heatsink in contact with the second surface of the thermoelectric module, the heat transfer element thermally isolated from the housing.

[0009] In an example, the bladed rotor is enclosed by the housing. This provides efficiency and safety benefits. In an example, the bladed rotor is selectively operable in a stationary mode and in an oscillating mode. The bladed rotor may have any suitable number of blades. In an example, the blades of the bladed rotor are provided with an edging element over the free edge thereof. In a specific example, the bladed rotor comprises metal and the edging element is a silicone overmolding.

[0010] In an example, the heat transfer element extends through an opening defined by the housing, which may be an aperture defined in the housing. Thus, the heat transfer element is partially enclosed by the housing, for practical and aesthetic purposes, but is thermally isolated from the housing to inhibit the undesirable transfer of heat from the heat transfer element to the housing, and to encourage the transfer of heat from the heat transfer element to the thermoelectric module. In an example, the heat transfer element is formed as a unitary part. In an example, the housing is formed as a multi-component part.

[0011] I In an example, the heat transfer element forms a base of the stove fan for resting on a stove. In an example, the housing forms a base of the stove fan for resting on a stove. In an example, a front end of the housing is inclined downwards with respect to a rear end of the housing when the base is oriented on a horizontal plane. This serves to improve effectiveness by directing warm air downwards, the hotter air then rising naturally to distribute heat from the stove into a room.

[0012] In an example, the stove fan comprises a support arrangement for holding the housing in a position spaced above a lower base portion of the heat transfer element. In an example, the support arrangement comprises at least one securing element that extends through a channel defined within an upper platform portion of the heat transfer element. In an example, at least one spacer element comprising a thermally insulating material is disposed between the heat transfer element and the housing. The thermally insulating material may be a thermoplastic. In an example, the at least one spacer element comprises polyether- ether-ketone (PEEK).

[0013] In an example, the stove fan comprises a guiding arrangement to guide movement of the heat transfer element towards an outermost position, for contacting a surface of a stove in use; the thermoelectric module and the heatsink movable with the heat transfer element. In an example, the guiding arrangement comprises at least one guide element having a rail portion that the heat transfer element at least partially surrounds. In an example, the guiding arrangement comprises a pair of guide elements that are provided by a pair of shoulder bolts. In an example, the guiding arrangement comprises a resilient biasing arrangement. In an example, the resilient biasing arrangement comprises a pair of compression springs.

[0014] In an example, the stove fan comprises a control module, the control module comprising a controller and a power device. In an example, the power device comprises a rechargeable battery. In a specific example, the controller is configured to control charging of the rechargeable battery by energy generated by the thermoelectric module and the discharging of the rechargeable battery to power the electric motor. In an example, the controller is configured to control the speed of rotation of the bladed rotor with reference to a detected room temperature. In an example, the control module comprises a temperature sensor for sensing an operating temperature of the stove fan. In an example, the control module comprises a wireless communication device for communicating with a wireless communication network. In an example, the control module comprises g a visual indicator device for emitting light of at least one colour in accordance with at least one illumination pattern. In an example, the control module comprises an audio indicator device for generating at least one sound according to at least one activation pattern. In an example, the control module comprises an input device for allowing a user to control one or more functions of the stove fan. In an example, the stove fan is provided with a mounting arrangement for securing the stove fan to a flue of a stove. The mounting arrangement may comprise any suitable element or elements, and may at least one mechanical element, for example a bracket, and may comprise at least one magnetic element.

[0015] According to a second aspect there is provided, in combination, a stove and at least one stove fan according to the first aspect. In an example, the stove is a wood-burning stove. In an example, the stove is a multi-fuel stove.

[0016] Further particular and preferred aspects of the invention are set out in the accompanying dependent claims.

[0017] Brief Description of the Drawings

[0018] The present invention will now be more particularly described, with reference to the accompanying drawings, in which:

[0019] Figure I shows a stove fan according to the prior art, placed on a stove;

[0020] Figure 2 shows a perspective bottom view of a prior art stove fan;

[0021] Figure 3 shows a front view of the prior art stove fan of Figure I ;

[0022] Figure 4 shows a cross-sectional view of the prior art stove fan of Figure 2, along the line A-A of

[0023] Figure 3;

[0024] Figure 5 shows a perspective front view of a stove fan according to a first example;

[0025] Figure 6 shows a front view of the stove fan of Figure 5;

[0026] Figure 7 shows a cross-sectional view of the stove fan of Figure 5, along the line A-A of Figure 6;

[0027] Figures 8 & 9 show perspective rear and rear views respectively of the stove fan of Figure 5;

[0028] Figures 10, I I & 12 show top, side and bottom views respectively of the stove fan of Figure 5;

[0029] Figure 13 shows a cross-sectional view of a stove fan according to a second example;

[0030] Figures 14 & 15 show rear and perspective rear views respectively of the stove fan of Figure 13;

[0031] Figure 16 shows a perspective front view of a stove fan according to a third example;

[0032] Figure 17 shows a front view of the stove fan of Figure 16;

[0033] Figure 18 shows a cross-sectional view of the stove fan of Figure 16, along the line A-A of Figure 17;

[0034] Figures 19 & 20 show perspective bottom and rear views respectively of the stove fan of Figure 16;

[0035] Figures 21 , 22 & 23 show top, side and bottom views respectively of the stove fan of Figure 16;

[0036] Figure 24 shows a pair of stove fans according to the present invention, positioned for use on a stove, according to a first example scenario;

[0037] Figure 25 shows a stove fan according to the present invention, positioned for use on a stove, according to a second example scenario;

[0038] Figure 26 shows a cross-sectional view of a stove fan according to a fourth example; Figures 27, 28 & 29 show perspective front, perspective rear and perspective bottom views respectively of the stove fan of Figure 26;

[0039] Figure 30 shows a rear view of the stove fan of Figure 26; and

[0040] Figures 31 , 32 & 33 show top, side and bottom views respectively of the stove fan of Figure 26.

[0041] Description

[0042] Illustrative embodiments and examples are described below in sufficient detail to enable those of ordinary skill in the art to embody and implement the apparatus described herein. It is to be understood that embodiments and examples can be provided in many alternate forms and the invention should not be construed as limited to the embodiments and examples set forth herein but by the scope of the appended claims. Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. In addition, features referred to herein in the singular can number one or more, unless the context clearly indicates otherwise. Similarly, the terms “comprises”, “comprising”, “includes”, “including”, “has” and / or “having”, when used herein, specify the presence of the stated feature or features and do not preclude the presence or addition of one or more other features, unless the context clearly indicates otherwise. In the following description, all orientational terms, such as upper, lower, radially and axially, are used in relation to the drawings and should not be interpreted as limiting on the invention, unless the context clearly indicates otherwise. The drawings are not necessarily drawn to scale, and in some instances the drawings may have been exaggerated or simplified for illustrative purposes only.

[0043] A prior art stove fan 100 is shown in Figures I to 4. Figure I shows the prior art stove fan 100 located for use on a stove 200. Figures 2, 3 & 4 show details of the prior art stove fan 100. The prior art stove fan 100 comprises a carrier handle I (at the top of the main body), a bladed rotor 2 (with the rotor blades forward of the main body), an extruded aluminium heat sink (cold) 3 (upper side of main body), a DC electric motor 4, a thermoelectric module 5, an extruded aluminium heat sink (hot) 6 (lower side of main body), and a bimetallic strip 7 (at the bottom of the main body).

[0044] In use, heat from the stove 200 is transferred to the thermoelectric module 5 through the aluminium heat sink (hot) 6 and from the thermoelectric module 5 through the extruded aluminium heat sink (cold) 3. The thermoelectric module 5 utilises a temperature differential between hotter and colder sides of the thermoelectric module 5 to generate electricity (using the Seebeck effect), which is provided to the DC electric motor 4, which drives the bladed rotor 2. The greater the temperature differential between hot and cold sides of the thermoelectric module 5, the greater the power generated. The rotating blades function to move radiant heat into the room, in turn making the stove 200 more efficient, with the objective of saving fuel. Various design limitations have been identified in relation to the prior art stove fans such as prior art stove fan 100.

[0045] The optimum working temperature of a stove is up to around 300 °C, more typically around 200 °C. The majority of thermoelectric modules have a relatively low melting point, up to around 200 °C, more typically from around 50 °C to around 200 °C, and are at risk of malfunction through overheating. The bimetallic strip is provided to address this issue. When the bimetallic strip is heated above a particular temperature, it bends to lift the stove fan to reduce the amount of heat being transferred from the stove to the thermoelectric module. This results in the energy output by the thermoelectric module being throttled, reducing efficiency. The bending of the bimetallic strip also causes the airflow through the stove fan to be angled upwards and, as heat rises, this reduces efficiency further. Further, the stove fan being lifted by the bimetallic strip bending reduces its stability on the stove, leading to the stove fan vibrating and causing undesirable noise and sound annoyance.

[0046] The achievable airflow is related to the size of the blades and the speed they are rotated. Increasing the blade size and / or R.PM to improve airflow can exacerbate problems mentioned above. For example, increasing the size of the heat sink (cold) of the thermoelectric module to achieve a greater power output makes the stove fan more top heavy, which increases instability when the bimetallic strip bends to lift the stove fan to prevent overheating. The fan blades can easily be bent out of shape and become unbalanced, which can lead to excessive noise being created at higher R.PM. Increasing the blade size and render the blades more susceptible to warping. In addition, the heat sink (cold) is exposed to high radiant temperature, reducing efficiency.

[0047] The present invention provides improvements in relation to stove fan design.

[0048] A stove fan 501 according to a first example is shown in Figures 5 to 12. The stove fan 501 comprises a bladed rotor 502, an electric motor 503, the electric motor 503 for driving the bladed rotor 502, and a thermoelectric generator arrangement, indicated generally at 504, the thermoelectric generator arrangement 504 operative to power the electric motor 503. The stove fan 501 further comprises a housing 505, the housing forming ducting having an internal diameter 506 that is greater than the diameter 507 of the tip path of the bladed rotor 502.

[0049] The thermoelectric generator arrangement 504 comprises a thermoelectric module 508 to generate electricity from a temperature differential between a first surface 509 and a second surface 510, a heat transfer element 51 I in contact with the first surface 509 of the thermoelectric module 508, and a heatsink 512 in contact with the second surface 510 of the thermoelectric module 508. The thermoelectric generator arrangement 504 further comprises a guiding arrangement, indicated generally at 51 3, to guide the heat transfer element 51 I towards an outermost position (shown in Figures 6, 7, 9 & I I) for contacting a surface of a stove in use. The heat transfer element 51 I has a stove-facing surface 514. The stove-facing surface 514 may have any suitable shape and dimensions. In a specific example, the stovefacing surface 514 has dimensions of approximately 40 mm x 40 mm.

[0050] The thermoelectric module 508 and the heatsink 512 are movable with the heat transfer element 51 1. Thus, if the heat transfer element 51 I moves radially inwardly, the thermoelectric module 508 and the heatsink 512 will move radially inwardly in a corresponding manner so that the contact between the heat transfer element 51 I and the thermoelectric module 508 and between the thermoelectric module 508 and the heatsink 512 is maintained. This feature will be discussed further below.

[0051] The heat transfer element 51 I is thermally isolated from the housing 505. This feature will be discussed further below.

[0052] According to the shown example, the housing 505 forms a base of the stove fan 501 , indicated generally at 515. According to the specific example illustrated, the base 515 of the housing 505 comprises feet, such as foot 516. The base 515 is profiled to create a hollow 517, into which the heat transfer element 51 I projects. According to the shown example, the heat transfer element 51 I extends through an aperture 518 defined in the housing 505.

[0053] According to the present example, the guiding arrangement 51 3 comprises at least one guide element, such as guide element 519, which may be a mounting element. The or each guide element 51 may have any suitable form to guide smooth travel of the heat transfer element 51 I between an inward position and the outermost position. The or each guide element 519 may have a rail portion, for example as indicated at 520, that the heat transfer element 51 I at least partially surrounds. In this illustrated example, the guiding arrangement 51 3 comprises a pair of guide elements 519 that are provided by shoulder bolts. The shoulder bolts support precise movement, to enhance positioning of the heat transfer element 51 I and improve operational stability. In this specific illustrated example also, each guide element 519 extends through the heat transfer element 51 1. The heat transfer element 51 I moves along the guide elements 519, which guide the path of travel.

[0054] The mounting of the heat transfer element 51 I and the profile of the base 515 serves to concentrate heat transfer from the stove to the heat transfer element 51 I (and, in turn, to the thermoelectric module 508) and reduce the transfer of heat from the stove to the housing 505 via surface contact between the base 515 and the stove. As illustrated, the heat transfer element 51 I and heat sink 513 are connected with the thermoelectric module 508 disposed centrally therebetween. In an example, the heat transfer element 51 I and heat sink 512 are connected by one or more suitable mechanical fixings. In use, air flows through the housing in the direction indicated by arrow 521 (Figure 5) as the bladed rotors spins in the direction of rotation indicated by arrow 522 (Figure 5).

[0055] The thermoelectric generator arrangement 504 is designed to optimise contact with a stove and maintain a heat transfer path from the stove through the thermoelectric module 508 without compromising the stability of the stove fan 501 on the stove. The heat transfer element 51 I is held against the stove, under the action of gravity on the mass of the heat transfer element 51 1 , and of the housing 505, to provide a consistent surface-to-surface contact between the stove-facing surface 514 of the heat transfer element 51 I and the heated top plate of the stove.

[0056] The thermal isolation of the heat transfer element 51 I from the housing 505 is designed to concentrate heat transfer from the stove to the thermoelectric module 508. The separation of the heat transfer element 51 I from the housing 505 prevents the undesired transfer of heat to the housing 505 and other key components of the stove fan 501 .

[0057] According to the shown example, the housing 505 surrounds the bladed rotor 502. This feature serves to improve user safety and reduce the risk of accidental damage to the bladed rotor, by providing shielding for the blades as they rotate. The ducting formed by the housing 505 is designed to increase airflow (m3 / hr) across the heatsink 512 and through the blades. It also reduces noise from vortices that form at the tips of the blades as they rotate.

[0058] As shown, the electric motor 503 is enclosed by the housing 505. The electric motor 503 is protected from radiant heat emitted by the stove. As shown, the thermoelectric module 508 and the heatsink 512 are enclosed by the housing 505 (the heat transfer element 51 I is only partially enclosed by the housing 505). The heatsink 512 is protected from radiant heat emitted by the stove. By virtue of the airflow through the housing 505 when the stove fan 501 is in use, radiant heat is drawn from the heatsink 512 and transferred into the room. The airflow is channelled through the heatsink 512 which improves the transfer of heat from the second surface 510 (cool side) of the thermoelectric module 508. This serves to improve the temperature differential between the first surface 509 (hot side) and the second surface 510 (cool side) of the thermoelectric module 508, which results in more energy being generated by the thermoelectric module 508. In effect, a feedback loop is implemented within the design of the stove fan 501 , in which rotation of the bladed rotor 502 drives airflow through the housing 505, which draws more heat from the heatsink 512, which causes more cooling of the second surface 510 (cool side) of the thermoelectric module 508, which causes more power to be generated by the thermoelectric module 508 and provided to the electronic motor 503 that drives the bladed rotor 502. In this way, the design of the stove fan 501 promotes efficiency. In the shown example, the bladed rotor 502 comprises six blades, such as blade 523. It is to be appreciated however that any suitable number of blades may be used.

[0059] In the present example, the heatsink 512 is made from copper and incorporates aluminium nickel-plated sheets, which has been found to provide enhanced cooling, in turn improving the temperature difference between the first and second surfaces 509, 510 of the thermoelectric module 508.

[0060] In the present example, the thermoelectric module 508 is operational within a range of temperatures that accommodates the typical optimum working temperature of a stove of around 200 °c. In an example, the thermoelectric module 508 has a normal operating temperature range of from around 0 °C up to around 300 °C.

[0061] The housing 505 has a front end 524 and a rear end 525. According to the present example, the front end 524 of the housing 505 is inclined downwards with respect to the rear end 525 when the base 515 of the housing 505 is oriented on a horizontal plane. This serves to direct airflow issuing from the front end 524 of the housing 505 downwards, so that air is driven towards the ground. This serves to improve the effectiveness of the stove fan 501 .

[0062] In a specific example, the housing 505 comprises an extruded aluminium body. In a specific example, the heat transfer element 51 I is aluminium.

[0063] A stove fan 1001 according to a second example is shown in Figures 13 to 15. The stove fan 1001 is like the stove fan 501 of Figures 5 to 10 but features a different guiding arrangement.

[0064] According to the present example, the guiding arrangement 1002 comprises a resilient biasing arrangement, indicated generally at 1003, to radially bias the heat transfer element 1004 towards the outermost position for contacting a surface of a stove in use. Thus, if the heat transfer element 1004 is pushed radially inwardly, the thermoelectric module 1005 and the heatsink 1006 will move radially inwardly in a corresponding manner so that the contact between the heat transfer element 1004 and the thermoelectric module 1005 and between the thermoelectric module 1005 and the heatsink 1006 is maintained.

[0065] In this specific illustrated example, the resilient biasing arrangement 1003 comprises a pair of compression springs located around mounting elements, such as spring 1007 located around respective mounting element 1008. The thermoelectric generator arrangement 1009, including the resilient biasing arrangement 1003, is designed to optimise contact with a stove and maintain a heat transfer path from the stove through the thermoelectric module 1005 without compromising the stability of the stove fan 1001 on the stove. The spring-loaded heat transfer element 1004 is held against the stove, utilising the mass of the housing 1010, to provide a consistent surface-to-surface contact between the stove-facing surface 101 1 of the heat transfer element 1004 and the heated top plate of the stove. According to the present example, the springs 1004 of the resilient biasing arrangement 1003 are arranged relative to the housing 1010 to reduce the impact of vibration from the bladed rotor 1012 and quieten operation. In this example, a downward and forward inclination of the housing 1010 may be provided by the arrangement of the housing 1010 and / or the resilient biasing arrangement 1003 acting to urge the heat transfer element 1004 into contact with the stove.

[0066] Comparing the stove fan 1001 of the second example with the stove fan 501 of the first example, in the second example movement of the thermoelectric generator arrangement 1009 is influenced by the resilient biasing arrangement 1003 of the guiding arrangement 1002, but in the first example the thermoelectric generator arrangement 504 moves simply under its own weight. Hence, the guiding arrangement 513 of the first example does not use any resilient biasing in the positioning of the heat transfer element 51 1.

[0067] Through the omission of the resilient biasing arrangement 1003 of the second example (and any other additional componentry having the purpose of locating the heat transfer element 510 in an operative position), the design of the guiding arrangement 51 3 of the first example is less complex than the design of the guiding arrangement 1002 of the second example. This, in turn, provides for a simpler assembly, and lower manufacturing cost The guiding arrangement 51 3 of the first example still achieves the desired stability and heat transfer effectiveness.

[0068] A stove fan 1501 according to a third example is shown in Figures 16 to 23. The stove fan 1501 has features in common with the stove fan 501 of Figures 5 to 10 and the stove fan 1001 of Figures 13 to 15 but includes some optional features as will now be described. In Figures 16 to 23, stove fan 1501 is illustrated to have the guiding arrangement 1002 of stove fan 1001 but it is to be appreciated that it may alternatively have the guiding arrangement 513 of stove fan 501 .

[0069] According to the shown example, each of the blades 1523 of the bladed rotor I 502 is provided with an edging element, such as a silicone overmolding 1525, over the free edge thereof. Optimising the performance of the stove fan 1501 increases the maximum R.PM of the bladed rotor 1502. Providing the blades 1523 with the edging element 1525 serves to enhance the profile of the blade 1523 and generate greater airflow. In addition, the edging elements 1525 add weight to the blades 1523 that will slow down and steady the spinning bladed rotor 1502, increasing safety and reducing noise. According to the shown example, the bladed rotor 1503 is stationary (in other words, the axis around which the blades rotate does not move). In an example, the bladed rotor is configured to oscillate to vary the direction of airflow into the room (in other words, the axis around which the blades rotate moves relative to a pivot point). In an example, the bladed rotor is selectively operable in a stationary mode or in an oscillating mode.

[0070] In an example, the heatsink 1512 is designed with a round shape, but may have any suitable alternative shape. According to the shown example, a funnel 1526 within the housing 1505 is design to force the airflow through the heatsink 1512 (utilising the Venturi effect) and improve the transfer of heat from the heatsink 1512 into the room. This enhanced cooling increases the effectiveness of the stove fan 1501 , transferring more heat into the room and increasing the temperature differential across the thermoelectric module 1508. The heat transfer block 151 1 may be made from copper with a graphite layer to increase the heat throughput to the thermoelectric module 1508. It may then be possible to reduce the depth (in the direction indicated by arrow 1527) of the heat transfer block 151 1 without reducing performance.

[0071] According to the shown example, the stove fan 1501 is provided with a control module, indicated generally at 1528. According to a specific example, the control module 1528 comprises a controller, indicated at 1529, which may be any suitable device, for example a programmable logic controller (PLC). The controller 1529 may comprise, or otherwise have access to, a non-transitory computer-readable medium, with program instructions being stored on the non-transitory computer-readable medium that are executable by the controller to cause the controller to perform each of a plurality of functions.

[0072] According to the present example, the control module 1528 comprises a power device 1530 for providing power to at least the controller 1529. In a specific example, the power device 1530 comprises a rechargeable battery 1531. In a specific example, the controller 1529 is configured to control charging and discharging of the rechargeable so that excess energy generated by the thermoelectric module 1508 is stored in the rechargeable battery 1531 and used to drive the electric motor 1503 when the amount of heat being transferred to the thermoelectric generator 1508 is lower.

[0073] According to a specific example, the control module 1528 comprises a wireless communication device 1532 that is suitably arranged for communicating with a wireless communication network. In a preferred embodiment, the wireless communication device 1532 provides the capability of two-way data communication between the controller 1529 and a wireless network. The stove fan 1501 may be an “Internet of Things” device. In an example, the wireless communication device 1532 is configured for communication with a wireless-communication enabled user device, indicated at 1000. The user device 1000 may be a smartphone, or other electronic device capable of running a mobile or desktop application for the stove fan.

[0074] According to a specific example, the control module 1528 comprises an input device, indicated generally at 1533, allowing a user to control one or more functions of the stove fan 1501.

[0075] According to a specific example, the controller 1529 is configured to receive an indication of the temperature of the room, for example via an external temperature sensor 1534 and determine whether to initiate an adjustment to the speed at which the bladed rotor 1502 is spinning; a determination may be made to initiate a reduction in the R.PM of the bladed rotor 1502 when the room temperature is detected to be above a predetermined threshold temperature. Thus, the controller 1529 may be configured to control the speed of rotation of the bladed rotor 1502 with reference to a detected room temperature.

[0076] According to a specific example, the control module I 528 comprises a temperature sensor, indicated at 1535, for detecting an operational temperature of the stove fan 1501.

[0077] According to a specific example, the control module 1528 comprises a visual indicator device, indicated generally at 1536 for emitting light of at least one colour (for example, but not limited to, white, yellow, orange / amber, red) in accordance with at least one illumination pattern (for example, but not limited to, continuous, slow blink, fast blink). The visual indicator device 1536 may be used to indicate one or more conditions of the stove fan 1501. The visual indicator device 1536 may comprise one or more light emitting diodes (LEDs), the or each of which may be configured to emit light of one or more colours and in accordance with one or more illumination patterns.

[0078] In an example, the control module 1528 is configured to operate the visual indicator device 1536 to emit light of a first colour and according to an associated first illumination pattern to indicate a normal operating temperature (for example, continuous white to indicate an operating temperature within a predetermined normal operating temperature range from 0 °C to 240 °C), to emit light of a second, different colour and according to an associated second illumination pattern to indicate / warn of an operating temperature higher than a predetermined normal operating temperature range (for example, continuous yellow to indicate an operating temperature within a predetermined high operating temperature range from 240 °C to 280 °C), and to emit light of a third, different colour and according to an associated third illumination pattern to indicate / warn of an operating temperature that is higher than the predetermined high operating temperature range (for example, fast-blinking red to indicate an operating temperature at a dangerous operating temperature above 280 °C). In an example, a different LED is used to emit light of each different colour. In a specific example, the control module 1528 comprises an audio indicator device, indicated generally at 1537 for generating at least one sound (for example, but not limited to, buzzing, beeping, wailing) according to at least one activation pattern (for example, but not limited to, continuous, beeping, siren sound effect). The audio indicator device 1537 may be used to indicate one or more conditions of the stove fan 1501. The audio indicator device 1537 may comprise at least one speaker and / or at least one buzzer. In an example, the control module 1528 is configured to operate the audio indicator device 1537 to generate an audible sound to indicate / warn of an elevated operating temperature that is predetermined to be too hot / dangerous.

[0079] In an example comprising both the visual indicator device 1536 and the audio indicator device 1537, the control module 1528 is configured to contemporaneously operate the visual indicator device 1536 to emit a visual warning of an elevated operating temperature that is predetermined to be too high and operate the audio indicator device 1537 to generate an audible alert of an elevated operating temperature that is predetermined to be too high. In one example, an audible alert is raised whenever an operating temperature higher than a predetermined normal operating temperature range is detected; in another example, an audible alert is raised only when an operating temperature that is predetermined to be unsafe / dangerous is detected.

[0080] Thus, using a visual indicator device and / or an audio indicator device, the control module can provide feedback to a user regarding the operating temperature of the stove fan. It is to be appreciated that a visual indicator device and / or an audio indicator device may be utilised to provide feedback / indications to a user regarding one or more other operational parameters or functions of the stove fan. In examples in which the control module is configured for communication with a user device running an application for the stove fan, the control module may generate and send one or more notifications / alerts to the user device.

[0081] According to a specific example, the controller 1529 is configured to record data relating to operation of the stove fan 1501 , allowing analysis for use in optimising performance.

[0082] In an envisaged example, the stove fan 1501 may be provided with at least one additional bladed rotor (not shown in the Figures) arranged to improve airflow through the heatsink 1512.

[0083] Stove fans 500, 500’, 500” according to the present invention are shown in Figures 24 & 25 positioned for use on a stove 200. According to a first example scenario, shown in Figure 24, each of a pair of stove fans 500, 500’ according to the present invention is sited upon a top surface 201 of the stove 200, with one placed on each side of the flue 202 of the stove 200. According to a second example scenario, shown in Figure 25, stove fan 500” according to the present invention is shown sited on the flue 202. According to another example scenario, not illustrated, at least one stove fan according to the present invention is sited on a surface of the stove and at least one stove fan according to the present invention is sited on the flue.

[0084] It is to be appreciated that, in some applications, any suitable mounting arrangement may, optionally, be used to secure a stove fan according to the present invention in a suitable position on a stove, for use, for example, comprising one or more of at least one mechanical element, such as a bracket, and at least one magnetic element.

[0085] A stove fan 2001 according to a fourth example is shown in Figures 26 to 33. The stove fan 1501 has some features in common with the stove fan 501 of Figures 5 to 10, the stove fan 1001 of Figures I 3 to 15 and the stove fan 1501 of Figures 16 to 23 and some notable features of difference as will be clear from the following description.

[0086] The stove fan 2001 comprises a bladed rotor 2002, an electric motor 2003, the electric motor 2003 for driving the bladed rotor 2002, and a thermoelectric generator arrangement, indicated generally at 2004, the thermoelectric generator arrangement 2004 operative to power the electric motor 2003. The stove fan 2001 further comprises a housing 2005, the housing forming ducting having an internal diameter 2006 that is greater than the diameter 2007 of the tip path of the bladed rotor 2002.

[0087] The thermoelectric generator arrangement 2004 comprises a thermoelectric module 2008 to generate electricity from a temperature differential between a first surface 2009 and a second surface 2010, a heat transfer element 201 1 in contact with the first surface 2009 of the thermoelectric module 2008, and a heatsink 2012 in contact with the second surface 2010 of the thermoelectric module 2008.

[0088] The heat transfer element 201 I comprises a lower base portion 201 3. In this example, the stove fan 2001 comprises a support arrangement, indicated generally at 2014, for holding the housing 2005 in a position spaced above the lower base portion 201 3 of the heat transfer element 201 1. As shown in this Figure, the housing 2005 is floated over the lower base portion 2013 of the heat transfer element 201 1. Further, and according to this specific illustrated example, the housing 2005 is supported in a position relative to the lower base portion 201 3 such that it does not contact a stove on which the stove fan 2001 is placed, and only a stove-facing surface 2015 of the lower base portion 201 3 of the heat transfer element 201 I contacts the stove. Thus, the heat transfer element 201 I forms a base 201 of the stove fan. The stovefacing surface 2015 may have any suitable shape and dimensions. In a specific example, the stove-facing surface 2015 has dimensions of approximately 84 mm x 125 mm. In this example, the support arrangement 2014 comprises at least one fixing element, such as securing element 2017, that extends through a channel, such as channel 2018, defined within an upper platform portion 2019 of the heat transfer element 201 I , to be connected to the housing 2005. As shown, in this example, at least one spacer element comprising a thermally insulating material, such as spacer element 2020, is disposed between the heat transfer element 201 I and the housing 2005. The thermally insulating material may be a thermoplastic. In an example, the at least one spacer element comprises polyether- ether-ketone (PEEK).

[0089] In this specific example, the pair of securing elements 2017 comprises a pair of M4 machine screws, each of which is provided with a spacer element comprising a thermally insulating material 2020 in the form of a washer. In an example, a grub screw (not shown) is used against each securing element 2017, to stop unwanted vibration and association noise.

[0090] According to this illustrated example, a pair of securing elements 2017 is used to secure the heatsink 2012, thermoelectric module 2008 and heat transfer element 201 1 together and to secure the thermoelectric generator arrangement 2004 and housing 2005. This serves to provide structural integrity. Further, efficient use of securing elements, for example reducing the number of securing elements used in the assembly, serves to minimise heat transfer paths to the heat sink and optimise the performance of the thermoelectric module.

[0091] The thermal isolation of the heat transfer element from the housing prevents heat transfer to the housing, which serves to protect components within the housing, for example sensitive electronic equipment. The ducting formed by the housing supports consistent airflow through the stove fan, which serves to maintain a lower operational temperature, which, in turn, supports long-term reliability, even in demanding thermal environments. The floating housing design serves to reduce stress during thermal cycling while enhancing thermal isolation. The stove fan is designed to achieve a high degree of thermal efficiency and structural stability, rendering it suitable for use in application requiring precise temperature control and protection for embedded electronics.

[0092] In an example, and according to this illustrated example, the heat transfer element 201 1 is formed as a unitary part. In an example, and according to this illustrated example, the housing 2005 is formed as a multi-component part, comprising, for example, at least first, second and third modular sections 2021 , 2022, 2023. Providing the housing 2005 in a modular form serves to facilitate assembly.

[0093] Comparing stove fan 2001 to stove fan 501 , the stove-facing surface 2015 of the heat transfer element 201 1 of stove fan 2001 has greater dimensions than the stove-facing surface 514 of the heat transfer element 51 I of stove fan 501 , which serves to enhance the thermal energy capacity of the heat transfer element and the contact area between the heat transfer element and a stove.

[0094] Also, the stove fan 2001 does not feature physical contact between the housing 2005 and a stove, which serves to overcome undesired heat transfer from the stove to the housing and undesired vibration of the housing; the heat transfer element 201 1 of stove fan 2001 provides a base with improved stability.

[0095] Preferably, stove fan 2001 comprises a control module, indicated generally at 2019, which is like, or is arranged to provide one or more functions of, control module 1528 described above with reference to Figure 18,

[0096] The present invention provides an improved design of stove fan that offers various technical advantages and benefits when compared to the prior art.

[0097] Although illustrative embodiments and examples of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiment and examples shown and / or described and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims.

Claims

Claims1 . A stove fan, comprising: a bladed rotor, an electric motor for driving the bladed rotor, a thermoelectric generator arrangement operative to power the electric motor, and a housing forming ducting having an internal diameter that is greater than the diameter of the tip path of the bladed rotor, the thermoelectric generator arrangement comprising: a thermoelectric module to generate electricity from a temperature differential between a first surface and a second surface, a heat transfer element in contact with the first surface of the thermoelectric module, and a heatsink in contact with the second surface of the thermoelectric module; the heat transfer element thermally isolated from the housing.

2. The stove fan of claim I , wherein the bladed rotor is enclosed by the housing.

3. The stove fan of claim I or claim 2, wherein the heat transfer element extends through an opening defined by the housing.

4. The stove fan of claim 3, wherein the heat transfer element forms a base of the stove fan for resting on a stove.

5. The stove fan of claim 4, comprising a support arrangement for holding the housing in a position spaced above a lower base portion of the heat transfer element.

6. The stove fan of claim 5, wherein the support arrangement comprises at least one securing element that extends through a channel defined within an upper platform portion of the heat transfer element to be connected to the housing.

7. The stove fan of claim 5 or claim 6, wherein at least one spacer element comprising a thermally insulating material is disposed between the heat transfer element and the housing.

8. The stove fan of any one of claims I to 3, further comprising a guiding arrangement to guide movement of the heat transfer element towards an outermost position, for contacting a surface of a stove in use; the thermoelectric module and the heatsink movable with the heat transfer element,9. The stove fan of claim 8, wherein the housing forms a base of the stove fan for resting on a stove.

10. The stove fan of claim 9, wherein a front end of the housing is inclined downwards with respect to a rear end of the housing when the base is oriented on a horizontal plane.I I . The stove fan of any one of claims 8 to 10, wherein the guiding arrangement comprises at least one guide element having a rail portion that the heat transfer element at least partially surrounds.

12. The stove fan of claim I I , wherein the guiding arrangement comprises a pair of guide elements that are provided by a pair of shoulder bolts.I 3. The stove fan of any one of claims 8 to 12, wherein the guiding arrangement comprises a resilient biasing arrangement to radially bias the heat transfer element towards the outermost position.

14. The stove fan of claim I 3, wherein the resilient biasing arrangement comprises a pair of compression springs.

15. The stove fan of any one of claims I to 1 , wherein the blades of the bladed rotor are provided with an edging element over the free edge thereof.

16. The stove fan of claim 15, wherein the bladed rotor comprises metal and the edging element is a silicone overmolding.

17. The stove fan of any one of claims I to 16, comprising a control module, the control module comprising a controller, and a power device.

18. The stove fan of claim 17, wherein the power device comprises a rechargeable battery.

19. The stove fan of claim 18, wherein the controller is configured to control charging of the rechargeable battery by energy generated by the thermoelectric module and the discharging of the rechargeable battery to power the electric motor.

20. The stove fan of any one of claims 17 to 19, wherein the controller is configured to control the speed of rotation of the bladed rotor with reference to a detected room temperature.21 . The stove fan of any one of claims 17 to 20, the control module comprising a temperature sensor for sensing an operating temperature of the stove fan.

22. The stove fan of any one of claims 17 to 21 , the control module comprising a wireless communication device for communicating with a wireless communication network.

23. The stove fan of any one of claims 17 to 22, the control module further comprising a visual indicator device for emitting light of at least one colour in accordance with at least one illumination pattern.

24. The stove fan of any one of claims 17 to 23, the control module further comprising an audio indicator device for generating at least one sound according to at least one activation pattern.

25. The stove fan of any one of claims 17 to 24, the control module further comprising an input device for allowing a user to control one or more functions of the stove fan.

26. The stove fan of any one of claims I to 25, wherein the bladed rotor is selectively operable in a stationary mode and in an oscillating mode.

27. The stove fan of any one of claims I to 26, provided with a mounting arrangement for securing the stove fan to a flue of a stove.

28. In combination, a stove and at least one stove fan according to any one of claims I to 27.

29. The combination of claim 28, wherein the stove is a wood-burning stove.

30. The combination of claim 28, wherein the stove is a multi-fuel stove.

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