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(11) | EP 4 772 802 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | AIR-COOLING DEVICE AND METHOD OF OPERATING THE SAME |
| (57) Provided is an air-cooling device (10) comprising an absorbent medium (12) configured
to absorb a liquid, and an agitator (14) for contacting a surface of the absorbent
medium. The absorbent medium and the agitator are moveable relative to each other
to cause the agitator to agitate the surface of the absorbent medium and thereby release
droplets of the liquid from the absorbent medium. Once released from the absorbent
medium, the droplets of the liquid can evaporate to cool air.
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FIELD OF THE INVENTION
[0001] The invention relates to an air-cooling device comprising an absorbent medium in which a liquid is absorbed. The invention further relates to a method of operating such an air-cooling device.
BACKGROUND OF THE INVENTION
[0002] Various types of air-cooling device are known. For example, a typical refrigerant-based air conditioner may utilize a refrigerant in a closed system which includes a compressor, a condenser, an evaporator and a fan. Such devices may draw in outside air which is passed over the evaporator to remove heat from the air, whilst warm air generated by the condenser is passed to the outside via a duct.
[0003] Whilst such refrigerant-based air coolers can provide highly effective cooling, they may consume large amounts of energy as well as taking up a lot of space. The need for a duct can pose challenges in terms of portability, and accordingly, such air conditioners are often implemented as permanent installations. Despite the highly effective cooling, the nature of the cooling process results in reduced humidity of the air, which can result in discomfort for some users.
[0004] Evaporative coolers on the other hand typically operate by using a fan to blow air through a wet absorbent medium. As the air passes through the wet medium, it will cause evaporation, which in turn removes heat from the air, resulting in a cooled airstream.
[0005] Evaporative coolers can have many advantages over typical refrigerant-based coolers. For example, the relative simplicity of such evaporative coolers means that they may be cheaper to purchase and maintain, as well as generally having lower energy consumption during use. Additionally, since evaporative cooling does not generate a waste flow of hot air, there may be no need for a duct, which can be advantageous in terms of portability.
[0006] Despite these advantages, evaporative coolers are typically less effective at cooling air than refrigerant-based systems. Accordingly, in order to achieve sufficient cooling, the absorbent medium and the fan may have to be relatively large, which can be inconvenient for a user of the device.
SUMMARY OF THE INVENTION
[0007] It would be desirable to provide an improved air-cooling device, for example an air-cooling device which provides an enhanced user experience.
[0009] According to examples in accordance with an aspect of the invention, there is provided an air-cooling device comprising an absorbent medium configured to absorb a liquid and an agitator for contacting a surface of the absorbent medium, wherein the absorbent medium and the agitator are moveable relative to each other to cause the agitator to agitate the surface of the absorbent medium and thereby release droplets of the liquid from the absorbent medium.
[0010] In the case of the air-cooling device according to the present disclosure, agitating the absorbent medium to release droplets of liquid may enable more efficient evaporative cooling, since the droplets released from the absorbent medium may be more susceptible to evaporation than liquid retained in the absorbent medium. Accordingly, this may facilitate use of a smaller absorbent medium to achieve a desired cooling effect.
[0011] Additionally, if the absorbent medium is left in a wet state after use, e.g. after using the device for cooling air, there is a risk that mold will grow on the absorbent medium. Thus, it may be desirable to dry the medium after use of the device. One solution would be to blow air through the medium, however, this may be undesirable because the user may not want the device to generate any airflow after use. By agitating the surface of the absorbent medium, it may be possible to dry the medium, by releasing droplets of water from the medium, without generating additional unwanted airflow.
[0012] It is noted that when the agitator is contacting the surface of the absorbent medium, the agitator may compress the surface of the absorbent medium and/or a portion of the agitator may be compressed by the absorbent medium.
[0013] The amount of compression may be fixed, e.g. during manufacture of the device, or may be variable, e.g. adjustable by a user of the device.
[0014] Varying the amount of compression in this way may allow for more precise control over the release of droplets, since depending on the amount of compression applied to the absorbent medium, more or less liquid may be released from the medium.
[0015] In some embodiments, the agitator comprises protruding elements configured to contact the surface of the absorbent medium during the movement of the absorbent medium and the agitator relative to each other.
[0016] Agitating the surface using protruding elements may result in enhanced release of droplets from the medium. For example, protruding elements may enable a greater number of droplets to be released and/or greater control over size of the droplets.
[0017] The protruding elements can take any suitable form, such as elongate protruding elements, such as fibers.
[0018] In some embodiments, at least some of the protruding elements are configured to flex when in contact with the surface of the absorbent medium so as to flick the surface during the movement of the absorbent medium and the agitator relative to each other.
[0019] Protruding elements configured to flex and flick the surface of the absorbent medium may present a particularly effective way of releasing droplets of liquid from the medium due to the increased velocity of the tip of the protruding element as it returns to its original shape after being flexed.
[0020] For example, in embodiments in which the agitator is rotatable about a rotational axis, the protruding elements, e.g. fibers, may be arranged radially around the agitator such that the flexible protruding elements flick the surface of the absorbent medium as the agitator rotates.
[0021] The protruding elements may comprise a plastic material, such as polyester or nylon. For example, the protruding elements may comprise flexible polyester fibres.
[0022] In some embodiments, the air-cooling device is configured to generate a gas flow for contacting the droplets.
[0023] By contacting the droplets with a gas flow, the droplets may evaporate, resulting in cooling of the gas flow, without the need for the gas to pass through the medium itself. This may help to reduce build-up of pollutants in the medium, as well as providing more efficient cooling of the gas flow due to the droplets being easier to vaporize.
[0025] The gas flow can be generated by the air-cooling device in any suitable manner. In some embodiments, the air-cooling device comprises an airflow generator, e.g. a fan, for generating an airflow.
[0026] In some embodiments, the agitator is configured such that movement of the agitator to agitate the surface of the absorbent medium generates an airflow for contacting the droplets.
[0027] By configuring the agitator to simultaneously generate the droplets and the airflow, cooled air may be provided without an additional airflow generator, e.g. a fan, being included in the device. This may allow for a simpler and more compact device.
[0028] In some embodiments, the agitator is rotatable about a rotational axis. In such embodiments, a periphery of the agitator that is located radially from the rotational axis may, for example, be configured to agitate the surface of the absorbent medium during rotation of the agitator about the rotational axis.
[0029] This may be a particularly effective way of agitating the surface of the absorbent medium, since the medium may be continuously and consistently agitated whilst the agitator rotates, resulting in a more consistent supply of droplets.
[0030] The periphery may include a portion, e.g. a tip, of at least some of the protruding elements. This may be a particularly desirable configuration when the protruding elements are configured to flex.
[0031] The air-cooling device may comprise a motorized drive system for causing the absorbent medium and the agitator to move relative to each other, e.g. to rotate the agitator about the rotational axis.
[0032] The motorized drive system may facilitate agitation of the absorbent medium and optionally generation of the airflow.
[0033] In some embodiments, the agitator is configured to rotate at a rotational speed of at least 2000rpm. Rotating the agitator at the rotational speed of at least 2000rpm may be particularly effective for releasing droplets and optionally displacing air to generate the air flow.
[0034] For example, the device may be configured to rotate the agitator at a rotational speed of at least 4000rpm, or at least 5000rpm, such as at 6000rpm.
[0035] In some embodiments, the agitator comprises one or more airflow element(s) configured to displace air during the rotation of the agitator. Airflow elements configured to displace air during the rotation of the agitator may enable an airflow to be generated in the direction of rotation of the agitator, and hence towards the released droplets to facilitate evaporation.
[0036] This may present a particularly convenient way of both generating the airflow and agitating the absorbent medium using the agitator to facilitate cooling of the air. Additionally, it may be possible to vary, e.g. increase or decrease, the amount of liquid released and the air flow rate by varying a single parameter, that being the rotational speed of the agitator. Thus, the amount of cooling provided by the device may be straightforwardly varied, whilst ensuring that the air flow rate and the amount of liquid released remain proportional to each other.
[0037] For example, the airflow element(s) may include a recessed portion and/or a protruding portion of the agitator, such as a trough-like recessed portion configured to displace air as the agitator rotates. Such airflow elements may displace air that would not otherwise be displaced during rotation of the agitator.
[0038] The absorbent material can be formed of any suitable material capable of absorbing the liquid and releasing the liquid via the contact with the agitator. In some embodiments, the absorbent medium comprises a porous material having pores for containing the liquid. In such embodiments, the porous material may be at least one of a woven fabric, a nonwoven fabric, and a foam.
[0039] A porous material may enable water to be retained by the absorbent medium in its pores, whilst also facilitating release of droplets by the agitator.
[0040] Utilising woven fabric, nonwoven fabric, and/or foam may enable straightforward cleaning, e.g. washing, and/or replacement of the absorbent medium. The absorbent medium may need to be cleaned and/or replaced due to, for example, mineral deposits from the liquid, e.g. water. Such materials may also be sufficiently durable to withstand agitation by the agitator, in comparison to, for example, paper or cardboard.
[0041] In some embodiments, the air-cooling device comprises sound proofing. The sound proofing may be arranged at least partly around where the agitator contacts the surface of the absorbent medium. This may enhance user experience, since the noise emanating from the air-cooling device due to (at least) the process of agitating the medium may be reduced.
[0042] For example, the air-cooling device may comprise an external housing, and the sound proofing arrangement, e.g. acoustic foam, may be included in the external housing.
[0043] In embodiments in which the device includes the motorized drive system, a motor included in the motorized drive system can include, for example, a brushless DC motor.
[0044] Such a motor, e.g. the brushless DC motor, may, for example, be arranged to rotate the agitator.
[0045] The air-cooling device may comprise a controller for controlling the motorized drive system, e.g. for controlling the rotary speed of a motor included in the motorized drive system.
[0046] The air-cooling device may comprise a liquid supply system for supplying liquid to the absorbent medium. The liquid supply system may, for example, comprise a reservoir for storing the liquid prior to the liquid being supplied to the absorbent medium.
[0047] The liquid reservoir may assist to make the device portable, since it may not be necessary to connect the device to an external water supply.
[0049] The term "portable" in this context may refer to the device being carriable by the user between different spaces in which the air-cooling device is operated/to be operated.
[0050] In some embodiments, the air-cooling device comprises a liquid collector arranged beneath the absorbent medium when the air-cooling device is orientated for use.
[0051] In some embodiments, the liquid collector is included in the liquid supply system, such that the liquid collected in the liquid collector may be recirculated to the absorbent medium.
[0053] In this way, excess water from the absorbent medium may be returned to the liquid reservoir without the need for a return pump, since the liquid may return under the force of gravity. This may be particularly advantageous not only when the device is being used to cool air, but when the agitator is being used to dry the absorbent medium after use.
[0054] The air-cooling device may comprise a pump. For example, the device may comprise a pump for conveying liquid from the reservoir to the absorbent medium, e.g. an inlet portion of the absorbent medium. Alternatively, or additionally, the device may comprise a pump for conveying liquid from the liquid collector to the liquid reservoir.
[0055] As an alternative or in addition to the pump for pumping liquid from the reservoir to the absorbent medium, the air-cooling device may comprise one or more valves for controlling the rate of flow of liquid from the liquid reservoir to the absorbent medium.
[0056] The air-cooling device may comprise one or more controllers for controlling the flow rate of the liquid conveyed by the pump(s).
[0057] According to another aspect of the invention, provided is a method of operating an air-cooling device, the device comprising an absorbent medium for absorbing a liquid and an agitator for contacting a surface of the absorbent medium, wherein the method comprises implementing an air-cooling operation comprising moving the absorbent medium and the agitator relative to each other to cause the agitator to agitate the surface of the absorbent medium and thereby release droplets of the liquid from the absorbent medium.
[0058] In some embodiments, a gas flow is generated by the air-cooling device during the air-cooling operation to evaporate the droplets.
[0059] The method may comprise, subsequently to the air-cooling operation, implementing a drying operation comprising moving the absorbent medium and the agitator relative to each other without further liquid being supplied to the absorbent medium.
[0061] In the drying operation, the absorbent medium and the agitator may be dried, so as to reduce the likelihood of mold and bacterial growth.
[0062] More generally, embodiments described herein in relation to the air-cooling device may be applicable to the method, and embodiments described herein in relation to the method may be applicable to the air-cooling device.
[0063] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0064] For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:
FIG. 1 provides a block diagram of an air-cooling device according to an example;
FIG. 2 provides a block diagram of an air-cooling device according to another example;
FIG. 3 provides a perspective view of an absorbent medium and an agitator of an air-cooling device according to an example;
FIG. 4 schematically depicts operation of the air-cooling device shown in FIG. 3;
FIG. 5 provides an example of an agitator of an air-cooling device with protruding elements; and
FIG. 6 provides an example of an agitator of an air-cooling device with protruding elements.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0066] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.
[0067] Provided is an air-cooling device comprising an absorbent medium configured to absorb a liquid, and an agitator for contacting a surface of the absorbent medium. The absorbent medium and the agitator are moveable relative to each other to cause the agitator to agitate the surface of the absorbent medium and thereby release droplets of the liquid from the absorbent medium. Once released from the absorbent medium, the droplets of the liquid can evaporate to cool air.
[0068] FIG. 1 provides a block diagram of an air-cooling device 10 according to an example. The air-cooling device 10 is configured to enable cooling of air, or another gas, by evaporating a liquid, e.g. water, to remove heat from the air or gas. To this end, the air-cooling device 10 includes an absorbent medium 12 configured to absorb a liquid, e.g. a liquid to be evaporated by the air or gas.
[0069] The absorbent medium 12 may include a porous material having pores for containing the liquid, such as one or more of a woven fabric, a non-woven fabric, and a foam. For example, the absorbent medium 12 may include a foam core which can absorb a relatively large amount of liquid, and a fabric outer layer, which may provide enhanced durability. Regardless of whether the absorbent medium includes foam, it may be desirable that the outer layer of the absorbent medium is a woven or non-woven fabric, e.g. a polyester or cotton-based fabric.
[0070] More generally, the absorbent medium 12 may comprise any type of material provided it is capable of absorbing a liquid.
[0071] The absorbent medium 12 may take the form of a relatively thin sheet like component, such that the length and width of the medium may be significantly larger than the thickness. The absorbent medium may be of any suitable size depending upon the particular requirements of the application, e.g. the required amount of cooling and/or the required size of the device.
[0072] The absorbent medium 12, or a portion of the absorbent medium 12 such as the outer layer, may be reversibly detachable from the air-cooling device 10. Thus, the absorbent medium 12 may be removed for replacement or cleaning.
[0073] The air-cooling device 10, such as the air-cooling device 10 of Figs. 1 of 2, may include a liquid supply system for supplying liquid to the absorbent medium 12. For example, the liquid supply system may include a reservoir 20 for storing the liquid prior to the liquid being supplied to the absorbent medium.
[0074] To this end, the liquid supply system may further include a pump 18 for conveying the liquid from the reservoir 20 to the absorbent medium 12. The pump may be, for example, a centrifugal pump.
[0075] The absorbent medium 12 may accordingly include an inlet for receiving liquid from the reservoir 20 via the pump 18. The inlet may be configured to withstand the pumping pressure provided by the pump 18, and/or to evenly distribute the liquid from the reservoir throughout the absorbent medium 12. For example, the inlet may include a manifold component for distributing the liquid, e.g. water, throughout the absorbent medium 12.
[0076] Alternatively, or additionally, the liquid supply system may include a connection for connecting the absorbent medium 12, e.g. the inlet of the absorbent medium 12, to a liquid supply, such as a tap or mains water supply. In such embodiments, there may be no need for a pump 18 to convey the liquid from the liquid supply to the absorbent medium 12 due to the water supply being pressurized.
[0077] The liquid supply system may further include a valve arrangement for controlling the flow of liquid from the reservoir 20 and/or water supply. For example, the air-cooling device 10 shown in Fig. 2 includes a valve 26, e.g. a one-way valve, between the reservoir 20 and the absorbent medium 12 to regulate the flow of liquid. This may ensure that the correct amount of liquid is supplied to the absorbent medium 12, to prevent the medium 12 from becoming too dry or too wet. In contrast, the air-cooling device 10 shown in Fig. 1 does not include a valve 26, and instead the flow rate of liquid supplied to the absorbent medium 12 is regulated by controlling the flow rate of the pump 18 alone.
[0078] Whilst the absorbent medium 12 may be orientated in any direction, it may be desirable that the medium is orientated vertically, as shown in Fig. 3, such that the thinnest dimension of the medium 12 is arranged substantially perpendicular to the vertical axis of the air-cooling device 10 when orientated for use. Accordingly, the water may be supplied by the liquid supply system to the top of the absorbent medium 12 such that the liquid flows downwards resulting in even absorption and distribution of the liquid in the medium 12.
[0079] Alternatively, the air-cooling device 10 may not include the liquid supply system and instead the user of the device may simply supply liquid to the absorbent medium 12 manually, e.g. by pouring a liquid over the absorbent medium 12.
[0080] The device may further include a liquid collector 30 arranged beneath the absorbent medium 12 when the air-cooling device is orientated for use. This may enable excess liquid from the absorbent medium 12 to be collected and re-circulated to the absorbent medium 12. For example, the liquid collector 30 may be an open reservoir beneath the absorbent medium 12 which is configured to collect liquid that drips from the absorbent medium 12.
[0081] In the example shown in Fig. 1, the reservoir 20 and the liquid collector 30 are the same component. That is, the reservoir is located beneath the absorbent medium during use and thus may serve the additional function of collecting the excess liquid. In practice, the pump 18 may pump liquid from the reservoir to the top of the absorbent medium 12 before said liquid flows downwards through the absorbent medium 12, and any excess liquid may be returned via gravity directly to the reservoir 20, e.g. the liquid collector 30.
[0082] In the example shown in Fig. 2, the reservoir 20 is instead arranged above the absorbent medium 12 when it is orientated for use. The liquid supply system includes a pump 18 and a valve 26, which together control the flow of liquid from the reservoir 20 to the absorbent medium 12, e.g. to the inlet of the absorbent medium 12. Whilst the pump 18 is included in this example, it is equally contemplated that the pump 18 could be omitted such that the liquid flows from the reservoir 20 to the absorbent medium 12 by gravity, with the flow rate of the liquid being controlled by the valve 26 alone.
[0083] Since the reservoir 20 of Fig. 2 is located vertically above the absorbent medium 12, a separate liquid collector 30 is arranged beneath the absorbent medium 12 such that excess liquid from the medium 12 may flow via gravity into the liquid collector. A second pump 28 may accordingly be included in the device 10 to return the liquid collected in the liquid collector 30 to the reservoir 20, so that the liquid can be recirculated to the absorbent medium 12.
[0084] The air-cooling device 10 may include a gas flow generator for evaporating liquid absorbed by the absorbent medium 12. For example, the device 10 may include a fan for blowing air towards the absorbent medium 12, or any other gas supply source, such as a compressed gas canister.
[0085] To achieve sufficient cooling using such an arrangement with an absorbent medium 12 and a gas flow generator, conventional evaporative air-cooling devices may require that the absorbent medium 12 is relatively large. This is to ensure that the surface area of the absorbent medium 12 is large enough to provide the desired amount of liquid evaporation, and hence, cooling. This may negatively impact the portability of the device, which can be inconvenient for the user.
[0086] Accordingly, the air-cooling device 10 according to the present disclosure includes an agitator 14 for contacting a surface of the absorbent medium 12. The absorbent medium 12 and the agitator 14 are moveable relative to each other to cause the agitator 14 to agitate the surface of the absorbent medium 12 and thereby release droplets of the liquid from the absorbent medium 12.
[0087] By agitating the absorbent medium 12 to release droplets, it may be possible for the size of the absorbent medium 12 to be reduced compared to a conventional evaporative air-cooling device as described above configured to provide the same amount of cooling. This is because droplets released from the absorbent medium 12 may be more susceptible to evaporation than liquid retained in the absorbent medium 12, due to, for example, the increased surface area to volume ratio of said droplets.
[0088] Additionally, using an agitator 14 to release droplets from the medium 14 may enable drying of the medium 12 after use, without the need for further air to be blown through the medium 12, which may be undesirable for the user.
[0089] The agitator 14 may utilise any suitable mechanism or device for providing agitation to the surface of the medium 12. For example, the agitator 14 may oscillate or rotate to agitate, e.g. vibrate, the surface of the medium 12 to release droplets from the surface. Alternatively, or additionally, it may be the absorbent medium 12 that is moveable to cause the agitation of the surface.
[0090] To this end, the device 10 may include a motorized drive system 16 for driving the movement of the absorbent medium 12 and the agitator 14 relative to each other, such as the motorized drive system 16 of Figs. 1 and 2. The motorized drive system 16 may include, for example, a motor, such as a brushless DC motor. Such a type of motor may be desirable due to its relatively quiet operation.
[0091] The air-cooling device 10 may further include one or more controllers 22, 24, 32 for controlling operation of the pump(s) 18, 26, motorized drive system 16, and/or valve 26, when included in the system.
[0092] For example, as in the air-cooling devices 10 of Figs. 1 and 2, the device 10 may include a controller 24 for controlling a rotational speed of the motor included in the motorized drive system 16. Thus, in embodiments in which the motor is employed to drive movement of the agitator 14, control may be exerted over movement of the agitator 14 such that agitation of the surface is controlled.
[0093] For example, as in the air-cooling devices 10 of Figs. 1 and 2, the device may include a controller 22 for controlling a flow rate of the liquid pumped by the pump 18 from the reservoir 20 to the absorbent medium 12. The flow rate may be controlled, for example, to ensure that the amount of liquid pumped to the absorbent medium 12 is equal to the amount of liquid removed from the absorbent medium by the agitator 14 and/or evaporation. Such a flow rate may be pre-set during manufacture of the device 10 such that the user is simply required to select a desired amount of cooling, e.g. via a user interface, and the controller 22 controls the flow rate of the pump and/or the motorized drive system 16 based on the user selection.
[0094] In some embodiments, such as that of Fig. 2 which includes a pump 28 for pumping liquid from the liquid collector 30 to the reservoir 20, the device 10 may include a controller 32 for controlling a flow rate of liquid pumped by the pump 28.
[0095] Whilst in the non-limiting examples of Figs. 1 and 2 the device 10 includes multiple controllers 24, 22, 28 for controlling operation of the motorized drive system 16 and pump(s) 18, 28, such examples may instead employ a single controller for controlling operation of the pumps, valves and motorized drive system 16 included in any particular configuration of the device 10.
[0096] The air-cooling device 10 may accordingly include a power supply unit for supplying power to any of the controller(s) 22, 24, 32, pump(s) 18, 28, valve(s) 26 and the motorized drive system 16. The power supply unit may be in the form of a battery pack, e.g. a rechargeable battery pack, or in the form of a corded power supply unit.
[0097] In some embodiments, such as those of Figs. 1 and 2, the agitator 14 may be rotatable about a rotational axis, a periphery of the agitator 14 that is located radially from the rotational axis being configured to agitate the surface of the absorbent medium 12 during the rotation. Such a configuration of the agitator 14 and the absorbent medium 12 is further illustrated in Figs. 3 and 4.
[0098] Fig. 3 accordingly provides an example of such a rotatable agitator 12 that may be included in the air-cooling devices 10 of Figs. 1 and 2. The agitator 14 of Fig. 3 has a cylindrical shape that is configured to rotate on its central axis, e.g. to rotate in the direction of curved arrow 40 on a shaft included in the air-cooling device 10. The agitator 14 is arranged such that a periphery of the agitator 14 contacts the surface of the medium 12 during rotation to provide the agitation.
[0099] As can be seen in Fig. 3 the agitator 14 and the absorbent medium 12 may be arranged relative to each other such that the agitator 14, e.g. the periphery of the agitator 12, compresses the absorbent medium slightly when the device 10 is assembled and whilst the agitator 14 rotates. In other words, the agitator 14 may be configured to indent on the absorbent medium 12. Alternatively, or additionally, depending upon the firmness of the agitator 14, the agitator 14 may also be compressed at the point of contact between the agitator 14 and the absorbent medium 12.
[0100] The amount of compression may be fixed, e.g. during manufacture of the device, or may be variable, e.g. adjustable by a user of the device via an adjustment mechanism, such as via an adjustment screw which pushes the agitator 14 away from the absorbent medium 12 or draws the agitator 14 towards the absorbent medium 12.
[0101] Controlling the amount of compression in this way may allow for more precise control over the release of droplets, since depending on the amount of compression applied to the absorbent medium 12, more or less liquid may be released from the medium 12.
[0102] The periphery of the agitator 14, such as the agitator 14 of Fig. 3, may be configured in any suitable way to provide agitation to the surface of the absorbent medium 14. For example, by varying a surface roughness, or a material, of the periphery, e.g. the radial surface of the agitator 14 shown in Fig. 3, it may be possible to vary the level of agitation applied to the surface.
[0103] Fig. 4 depicts operation of the agitator 14 and absorbent medium 12 arrangement of Fig. 3, further illustrating the agitation mechanism described above.
[0104] In Fig. 4 it can be seen that as the agitator 14 rotates in the direction of the curved arrow 40, the surface of the absorbent medium 12 will be agitated where the agitator 14 contacts the surface of the absorbent medium 12. Accordingly, liquid in the absorbent medium 12 will be released from the medium 12 to create a mist, e.g. droplets, approximately in the area designated by the dotted box 38. It is noted that the dotted box 38 is purely for illustrative purposes to indicate approximately where the droplets may be released. More generally, in embodiments in which the agitator 14 is rotational, the mist of liquid will be released, e.g. thrown, in the direction of rotation of the agitator 14.
[0105] The agitator 14 of Fig. 3 may be coupled to the motorized drive system 16 of Figs. 1 and 2, e.g. to a motor such as a brushless DC motor, to drive rotation of the agitator 14. For example, the motor may be directly coupled to the shaft of the agitator 14, or alternatively may be coupled to the agitator 14, e.g. the shaft of the agitator 14, via a gear system or a belt drive system.
[0106] In some embodiments, such as those of Figs. 1 and 2, the agitator 14 may be configured to rotate at a rotational speed of at least 2000rpm. For example, the motorized drive system 16 may be controlled to rotate the agitator 14 at a speed of at least 2000rpm, e.g. either directly via the shaft coupling, or via the belt drive or gear system.
[0107] It has been found that 2000rpm may be a suitable minimum speed for releasing droplets from the absorbent medium 12. However, depending upon the requirements of the particular device 10, the rotational speed of the agitator 14 may be controlled accordingly, e.g. controlled by controller 24. Thus, if greater release of droplets is required, the motorized drive system 16 may be controlled to rotate the agitator 14 at, for example, at least 3000rpm, at least 4000rpm or at least 5000rpm. For example, the motorized drive system 16 may be controlled to rotate the agitator 14 at 6000rpm.
[0108] In some embodiments, such as those of Figs. 1 and 2, the air-cooling device 10 may further include a user interface (not shown) for controlling operation of the device 10, e.g. for controlling operation, via the controller(s), of the motorized drive system 16, pump(s) 18, 28 and/or valve(s) 18. For example, the motorized drive system 16 may be controllable by a user via the interface, e.g. via a button, to select a rotational speed of the agitator 14 to provide the desired level of agitation, and hence cooling, when the gas flow, e.g. airflow, is passed through the droplets. When the agitator 14 is not rotational, e.g. when the agitator 14 includes an oscillating mechanism, the user interface may enable the user to control, for example, the frequency and/or amplitude of oscillation such that the level of agitation is controllable. Thus, the user may be able to control the level of agitation regardless of the particular mechanism which is employed by the agitator 14 to agitate the medium 12.
[0109] More generally, it is contemplated that the user may simply be able to select a desired level of cooling, e.g. via the user interface, to cause the controller(s) to control operation of the relevant motorized drive system, pump(s) and valve(s) accordingly.
[0110] Agitation of the medium 12 as described herein may produce noise during use, due to the physical interaction between the agitator 14 and the surface of the absorbent medium 12. This may be particularly noticeable when the agitator 14 is rotating at high rotational speeds or oscillating or vibrating at a high frequency and/or amplitude. Thus, in some embodiments, such as those of Figs. 1 and 2, the air-cooling device 10 may include sound proofing arranged at least partly around where the agitator 14 contacts the surface of the absorbent medium 12.
[0111] For example, the agitator 14 may include acoustic foam which surrounds the agitator 14 and/or the absorbent medium 12. For example, the device 10 may include an external housing to house the agitator 14 and the absorbent medium 12, and the sound proofing, e.g. acoustic foam, may be included on an interior surface of the housing. Alternatively, or additionally, components of the device 10, such as the agitator 14 and the motorized drive system 16, e.g. the motor, may be resiliently mounted to reduce vibration. For example, the motor and/or agitator 14 may be mounted on vibration absorbing mounts, such as rubber bushes.
[0112] In some embodiments, such as those of Figs. 1 and 2, the agitator 14 may comprise protruding elements 42 configured to contact the surface of the absorbent medium 12 during the movement of the absorbent medium 12 and the agitator 14 relative to each other.
[0113] Figs. 5 and 6 show examples of rotatable agitators 14 which include protruding elements 42, for use in the air-cooling devices of Figs. 1 and 2. The rotatable agitators 14 shown in Figs. 5 and 6 are similar to the agitators 14 shown in Figs. 3 and 4, and thus any features discussed in relation to the agitators 14 of Figs. 3 and 4 may be applied to the agitators 14 of Figs. 5 and 6, and any features discussed in relation the agitators 14 shown in Figs. 5 and 6 may be applied to the agitators 14 of Figs. 3 and 4.
[0114] Agitating the surface of the absorbent medium 12 using such protruding elements 42 may result in release of a greater number of droplets and allow greater control over the size and/or shape of the droplets released, compared to an agitator 14 which does not include such protruding elements 42, such as that of Fig. 3.
[0115] The protruding elements 42 may be arranged radially around the cylindrical agitator 14, as can be seen in Figs. 5 and 6. Thus, the periphery may include at least a portion, e.g. a tip, of the protruding elements 42 such that the tip of the protruding elements 42 contacts the surface of the absorbent medium 12.
[0116] The protruding elements 42 may be arranged in any pattern. For example, the protruding elements 42 of the agitator 14 of Fig. 5 are arranged uniformly in circumferential rows around the agitator 14, whilst the protruding elements 42 of Fig. 6 are arranged in a helical pattern.
[0117] Additionally, the number and/or density of protruding elements 42 may also be varied to control the level of agitation applied to the absorbent medium 12. For example, a large number of protruding elements 42 may be included such that the protruding elements 42 are densely arranged, or relatively fewer protruding elements 42 may be included such that there is greater empty space between the elements 42.
[0118] More generally, features such as the pattern, number, density, size and shape of the protruding elements 42 may be varied to achieve the desired level of agitation.
[0119] The protruding elements 42 may be made from any suitable material. For example, the protruding elements 42 may be made from a rigid plastic material such as nylon or polypropylene. The protruding elements 42 may be molded, e.g. injection molded. For example, the agitator 14 and the protruding elements 42 may be injection molded as a unitary component from the rigid plastic material. Alternatively, the protruding elements 42 themselves may be attachable and/or detachable to a main body of the agitator 14, such as a rotatable cylindrical main body through which the shaft passes. Thus, it may be possible to replace the protruding elements 42 if they become damaged.
[0120] Whilst in the embodiments of Figs. 3 to 6 the agitator 14 is shown as a rotatable component, the protruding elements 42 are equally applicable to embodiments in which the agitator is not a rotatable agitator 14, such as embodiments that employ an oscillating or vibrating agitator 14. In such embodiments, the protruding elements 42 may have the same effect of enabling release of a greater number of droplets and allowing more precise control over the size of the droplets released.
[0121] In some embodiments, at least some of the protruding elements 42 are configured to flex when in contact with the surface of the absorbent medium 12 so as to flick the surface during the movement of the absorbent medium 12 and the agitator 14 relative to each other.
[0122] Protruding elements 42 configured to flex and flick the surface of the absorbent medium 12 may present a particularly effective way of releasing droplets of liquid from the medium 12 due to the increased velocity of the tip of the protruding element 42 as it returns to its original shape after being flexed.
[0123] For example, the protruding elements 42 of the agitators 14 of Figs. 5 and 6 may be able to flex. Thus, as the agitator 14 rotates as shown in Fig. 4, the protruding elements 42 will be flexed, e.g. bent, as they are compressed against the surface of the absorbent medium 12. Once the agitator 14 has rotated past a certain point, the compressed protruding elements 42 will spring back to their original unflexed shape at an increased velocity. In doing so, the tip of the protruding element 42 may flick the surface of the absorbent medium 12, resulting in a small amount of liquid being released from the surface in the form of droplet(s), in the direction of rotation. Accordingly, if multiple protruding elements 42 that are configured to flex are included, the above-described phenomenon may result in the generation of a large number of droplets, e.g. a mist.
[0124] The protruding elements shown in Figs. 5 and 6 may be flexible fibers, such as flexible polyester or nylon fibers. More generally, the flexible protruding elements, or fibers, may be made from any suitable flexible material which is able to flick the absorbent medium 12 in the manner described above. The fibers of the agitator 14 may be thin fibers, such that the resulting agitator 14 essentially takes the form of a brush, e.g. a rotating brush.
[0125] The protruding elements 42 may be of a single type, e.g. made from a single type of material and have the same size. Alternatively, multiple different types of protruding element 42 may be included in the agitator 14. For example, the agitator 14 may include a combination of rigid protruding elements 42 and protruding elements 42 that are configured to flex. Alternatively, or additionally, the agitator may include different types of protruding element 42 that are configured to flex, such as protruding elements 42 that are compositionally different to each other, have a different stiffness, and/or have a different size, e.g. length and/or thickness.
[0126] As detailed herein, the air-cooling device 10 may be configured to generate a gas flow for contacting the droplets, and thereby evaporate at least some of the droplets to provide cooling.
[0127] In some embodiments, such as those shown in Figs. 1 and 2, the device 10 may be configured such that movement of the agitator 14 to agitate the surface of the absorbent medium 12 generates an airflow for contacting, and thereby evaporating, the droplets.
[0128] For example, when the agitator 14 is rotatable such as in Figs. 3 to 6, the rotation of the agitator 14 may generate the airflow. This is illustrated in Fig. 4, in which it can be seen that rotation of the agitator 14 in the direction of the arrow 40 may result in generation of an airflow in the direction of arrow 36. Due to the particular arrangement of the agitator 14 and the surface, the airflow may be towards the area 38 in which the droplets are released, thereby enabling evaporation of the droplets and cooling of the air by driving a single component, that being the agitator 14.
[0129] The agitator 14 may be configured in any suitable way to generate said airflow during rotation. For example, in some embodiments, such as those shown in Figs. 5 and 6, the protruding elements 42 themselves may be configured to displace air whilst the agitator 14 rotates, thereby generating the airflow 36 towards the droplets. Additionally, as the agitator 14 rotates, the protruding elements may cause rapid compression and relaxation of the absorbent medium 12, thereby generating further airflow towards the droplets. Such an airflow generation mechanism may be influenced by characteristics of the agitator 42, such as the arrangement of protruding elements 42 and the gap between each set of protruding elements 42. Similarly, the flexing and flicking action of the protruding elements 42 when said elements 42 are configured to flex may generate additional airflow in the direction of the droplets.
[0130] Accordingly, the flow rate of the air, and thus the cooling effect of the device 10, may be controlled by varying the rotational speed of the motor included in the motorized drive system 16. For example, as explained herein, the user may select a rotational speed of the agitator 14 depending upon their desired level of cooling.
[0131] Thus, varying the rotational speed of the agitator 14 may vary both the number of droplets released, e.g. the amount of liquid, and the flow rate of the air simultaneously. This may be particularly convenient, due to the proportional relationship between the amount of liquid released and the flow rate of air required to evaporate said droplets. Such embodiments may be particularly advantageous, since the device 10 may generate the cooled airflow without the need for an additional airflow generation device, such as a fan.
[0132] In some embodiments, such as those of Figs. 3 and 4, the agitator 14 may include one or more airflow elements 34 configured to displace air during the rotation of the agitator 14.
[0133] Airflow elements 34 may enable air to be displaced that would not otherwise be displaced during the rotation of the agitator 14, e.g. air displaced other than that displaced by the protruding elements 42.
[0134] For example, as illustrated in the non-limiting examples of Figs. 3 and 4, the agitator 14 may include a trough/trench-like recessed portion 34 that extends along the length of the agitator 14. Such a recessed portion may cause displacement of air from the volume of the recessed portion 34 whilst the agitator 14 rotates, causing air, e.g. additional air, to be directed towards the released droplets.
[0135] Whilst the airflow element 34 is illustrated as a single recessed portion in Figs. 3 and 4, the airflow element(s) may be configured in any suitable manner provided it/they displace(s) air as the agitator 14 rotates. For example, the airflow element 34 may include any number of airflow elements configured to displace air in the direction of the released droplets. The airflow elements 34 may, for example, be interspersed between the protruding elements 42 of Figs. 5 and 6, such as a void between the protruding elements 42 which causes displacement of air during rotation of the agitator 14.
[0136] It is noted that the dotted line extending across the airflow element 34 in FIGs. 3 and 4 is representative of an approximate shape of an agitator 14 which does not include an airflow element 34, such as the agitators 14 of FIGs. 5 and 6.
[0137] Testing has been carried out using the air-cooling device 10 described herein to demonstrate the cooling effect achievable by an air-cooling device 10 according to the present disclosure. During testing the air-cooling device 10 was employed to direct cooled air towards a mannequin fitted with 27 temperatures sensors, and the temperature reduction due to the cooled air measured at each sensor. Testing was carried out using both a clothed mannequin and a non-clothed mannequin.
[0138] The air-cooling device 10 used for the testing included a rotational agitator 12 in the form of a cylindrical brush-like agitator 14 as detailed herein. The agitator 12 included flexible polyester protruding elements 42, e.g. flexible fibers, at the periphery, much like the agitators 14 illustrated in Figs. 5 and 6. The agitator itself was approximately 44mm in diameter and 240mm in length.
[0139] The absorbent medium 12 included a woven fabric outer layer which was contactable by the polyester fibers of the agitator 14 during rotation. The achieved temperature reduction at each sensor location can be seen in Table 1 below.
Table 1
| Sensor location | Δ Temperature (°C) (clothed mannequin) | Δ Temperature (°C) (unclothed mannequin) |
| Forehead | -4.4 | -2.8 |
| Face | -8.6 | -6.4 |
| Neck | -5.3 | -3.5 |
| Chest | -9.7 | -9 |
| Upper arms | -6 | -5.8 |
| Stomach | -9 | -8.1 |
| Forearms | -7.7 | -4.2 |
| Pelvis | -10.5 | -9.7 |
| Hands | -6.2 | -4.5 |
| Front thighs | -0.7 | -1.4 |
| Shins | -3.1 | -2.1 |
| Feet | -3.1 | -2.2 |
[0140] Further provided is a method of operating the air-cooling device 10 of Figs. 1 and 2, the device 10 comprising the absorbent medium 12 for absorbing a liquid and the agitator 14 for contacting the surface of the absorbent medium 12, wherein the method comprises implementing an air-cooling operation comprising moving the absorbent medium 12 and the agitator 14 relative to each other to cause the agitator 14 to agitate the surface of the absorbent medium 12 and thereby release droplets of the liquid from the absorbent medium 12. In some embodiments, a gas flow is generated by the air-cooling device, e.g. via rotation of the agitator, during the air-cooling operation to evaporate the droplets.
[0141] The method may comprise, subsequently to the air-cooling operation, implementing a drying operation comprising moving the absorbent medium 12 and the agitator 14 relative to each other without further liquid being supplied to the absorbent medium 12.
[0142] It is reiterated that the gas flow, e.g. airflow, may be generated by the agitator 14, for instance by rotation of the agitator 14.
[0143] In the drying operation, the absorbent medium 12 and the agitator 14 may be dried, so as to reduce the likelihood of mold and bacterial growth.
[0144] More generally, embodiments described herein in relation to the air-cooling device 10 may be applicable to the method, and embodiments described herein in relation to the method may be applicable to the air-cooling device 10.
[0145] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.
[0146] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
1. An air-cooling device (10) comprising:
an absorbent medium (12) configured to absorb a liquid; and
an agitator (14) for contacting a surface of the absorbent medium, wherein the absorbent medium and the agitator are moveable relative to each other to cause the agitator to agitate the surface of the absorbent medium and thereby release droplets of the liquid from the absorbent medium.
2. The air-cooling device (10) of claim 1, wherein the agitator (14) comprises protruding
elements (42) configured to contact the surface of the absorbent medium (12) during
the movement of the absorbent medium and the agitator relative to each other.
3. The air-cooling device (10) of claim 2, wherein at least some of the protruding elements
(42) are configured to flex when in contact with the surface of the absorbent medium
(12) so as to flick the surface during the movement of the absorbent medium and the
agitator (14) relative to each other.
4. The air-cooling device (10) of any one of claims 1 to 3, wherein the air-cooling device
is configured to generate a gas flow (36) for contacting the droplets.
5. The air-cooling device (10) of any one of claims 1 to 4, wherein the agitator (14)
is configured such that movement of the agitator to agitate the surface of the absorbent
medium (12) generates an airflow for contacting the droplets.
6. The air-cooling device (10) of any one of claims 1 to 5, wherein the agitator (14)
is rotatable about a rotational axis, a periphery of the agitator that is located
radially from the rotational axis being configured to agitate the surface of the absorbent
medium (12) during rotation of the agitator about the rotational axis.
7. The air-cooling device (10) of claim 6, wherein the agitator (14) is configured to
rotate at a rotational speed of at least 2000rpm.
8. The air-cooling device (10) of any one of claims 1 to 7, wherein the agitator (14)
comprises one or more airflow element(s) (34) configured to displace air during the
rotation of the agitator.
9. The air-cooling device (10) of any one of claims 1 to 8, wherein the absorbent medium
(12) comprises a porous material having pores for containing the liquid; optionally
wherein the porous material is at least one of a woven fabric, a nonwoven fabric,
and a foam.
10. The air-cooling device (10) of any one of claims 1 to 9, wherein the air-cooling device
comprises sound proofing arranged at least partly around where the agitator (14) contacts
the surface of the absorbent medium (12).
11. The air-cooling device (10) of any one of claims 1 to 10, wherein the device comprises
a motorized drive system (16) for driving the movement of the absorbent medium (12)
and the agitator (14) relative to each other.
12. The air-cooling device (10) of any one of claims 1 to 11, comprising a liquid supply
system for supplying liquid to the absorbent medium (12); optionally wherein the liquid
supply system comprises a reservoir (20) for storing the liquid prior to the liquid
being supplied to the absorbent medium.
13. The air-cooling device (10) of any one of claims 1 to 12, comprising a liquid collector
(20, 30) arranged beneath the absorbent medium (12) when the air-cooling device is
orientated for use.
14. A method of operating an air-cooling device (10), the device comprising an absorbent
medium (12) for absorbing a liquid, and an agitator (14) for contacting a surface
of the absorbent medium, wherein the method comprises implementing an air-cooling
operation comprising moving the absorbent medium and the agitator relative to each
other to cause the agitator to agitate the surface of the absorbent medium and thereby
release droplets of the liquid from the absorbent medium.
15. The method of claim 14, wherein during the air-cooling operation a gas flow is generated
by the air-cooling device (10) to evaporate the droplets; and/or wherein the method
further comprises, subsequently to the air-cooling operation, implementing a drying
operation comprising moving the absorbent medium (12) and the agitator (14) relative
to each other without further liquid being supplied to the absorbent medium.