GB2523404A

GB2523404A - Heat transfer device

Info

Publication number: GB2523404A
Application number: GB1403286.6A
Authority: GB
Inventors: Michael Reid; Robert Johnson
Original assignee: HEATLIGHT Ltd
Current assignee: HEATLIGHT Ltd
Priority date: 2014-02-25
Filing date: 2014-02-25
Publication date: 2015-08-26
Also published as: GB201403286D0

Abstract

A heat transfer device for heating or cooling a fluid comprises a sealed container housing a phase change material. The container has a first configuration when the phase change material is in a first phase and moves to a second configuration when the phase change material changes to a second phase. The sealed container is preferably partially or fully formed from a resilient material. In use, the heat transfer device is particularity suited for use when the fluid is a drink.

Description

HEAT TRANSFER DEVICE

The present invention relates to a heat transfer device comprising a sealed container containing phase change material and which heats or cools fluids.

Hot or cold fluids, in particular drinks, that are intended to be cooled or heated prior S to consumption, take time to prepare. Typically, a consumer may wait some time before the drink reaches a temperature within the desired temperature range or consumption Devices to neat or cool orinks are known in the art For example, to cool a drink that has not been refrigerated, and for which it is not desirable to use ice cubes in the drink, an ice sleeve can be placed around and in contact with the vesseL The sleeve cools the vessel which in turn cools the drink. Similarly, insulating, heated sleeves can heat a drink in the same way.

However, the irne taken to cool or heat the think using these devices is prolonged owing to the initial cooling or heating of the vessel. Thermal energy can also be absorbed or released by the sleeve to or from the external environment.

The present invention seeks to provide a heat transfer device that can be provided into a fluid, in particular a drink, to improve efficiency and rapidity of heating or cooflng a drink. It would also be desirable to provide a device that indicates when the heat transfer process has completed.

According to a first aspect of the present invention, there is provided a heat transfer device for heating or cooling a fluid, in particular a drink, comprising a sealed container containing a phase change material such that the container is in a first configuration when the phase change material is in a first phase and is moved to a second configuration by the phase change material wnen the phase change material changes to a second pnase The sealed contav'er is advantageously part'ay or fully formed from a resilient materia In the first configuration the sealed container is preferably in an unstressed state and in the second con'guration is in a stressed state the sealed container preferably returns to the irst configuration in the absence of any appled stress Alternatively the sealed container may be bi-stable, with first and second confgurations both being stable configurations Resilient in this context means able to recoil or spring back rio siape after bending, stretching, or being compressed The sealed container may be completely filled by the phase change material or filled to a level such tha' expansion of the phase change material when the phase change material changes phase forces a change of shape of the sealed container The phase change material has a first material volume when in the first phase. The sealed container in the first configuration has a first internal volume equal to or greater than the first material volume In the second phase the phase change matena has a second material volume that is greater than the first internal volume Expansion of the ohase change material to the second material volume forces the sealed container to change shape to increase is internal volume to a second internal volume that is equal to, or greater than, the second material volume.

A change of shape from the first configuration to the second configuration may comprise a straightening of one or more walls of the sealed container Alternatively or in addition, the change of shape may comprise relative movement between different portions of the sealed container, such as the expansion of a piston and cylinder type arrangement Alternatively, or in addition, the change of shape may comprise a stretching of one or more waDs of the sealed container.

The container is preferably made from a material with high thermal conductivity, resistant to oxidation, non-corrosive and not brittle within the intended range of operating temperatures. The container can be made of, but not limited to, metal or a polymer. The container can be made of a material treated with a coating, anodised, or plated in order to improve resistance to oxidation.

The phase change material is advantageously non-toxic The phase change matenal may be an incompressible fluid. The phase change material may be, but is not limited to, organic wax-like rnatenal, salt hydrates soW-sold phase change materials or water Advantageously, water changes phase beween soid and liquid states at around 0°C a temperature close to the temperature range cold drinks are refrigerated at (+2 to ÷5 degrees C), it is non-toxic and innocuous.

Prior to use, the heat transfer device is heated or cooled to bring the phase change is material into the desired phase. In one embodiment, the device is configured for cooling drinks and the phase change material is water In this embodiment, in the first configuration of the sealed container, the water is in the liquid phase. Prior to use, the device is placed in a freezer cabinet to bring the water into the second phase, i.e. ice. The expansion of the water as it turns to ice forces the sealed container into a second configuration prior to use, The device is then removed from the freezer cabinet and placed in a drink to be cooled. As heat is transferred from the dnnk o the device, the water is returned to the liquid phase and so reduces in volume. This removes stress on the sealed container and it returns to the first configuration, which is its rest state.

The shape change of the container between a first configuration and a second configuration indicates the piase change of the phase change material is complete Advantageously, this identifies when the heat transfer device is ready for use, or is spent.

This indication reduces unnecessary waiting times In the embodiment described above, using water as the phase change material, when the cevice is in the second configuration t is ready for use and when it has returned to the first configuration the phase change cooling has completed.

The heat transfer device preferably has a large surface area to volume ratio in order to maxirnise the rate of heat transfer. For example, the device may be shaped in a spiral or a convoluted tube. A spiral shape or convoluted tube also advantageously provides for an easily detected change of shape from the first configuration to the second configuration when the phase change material changes from a first phase o a second phase As the phase change material expands the spiral wiP unwind and the radius of a spiral shaped container will increase.

The heat transfer device can comprise a handle. A handle allows the device to be easily inserted into and removed from a fluid without a user needing to contact the fluid The handle preferably comprises a good thermal insulator, and may comprise a polymer material or may comprise stainless steel with a polyneric sleeve Advantageously, thermal energy lost from the handle or absorbed by the handle is kept to a minimum resulting in more efficient heating or cooling of the fluid. The handle can be detachable from the container.

This means that the handle does not need to be cooled or heated prior to use.

The heat transfer device may comprise one or more markers that indicate when the sealed contaner is in the flrst configuration or the second conf guration For example, a irst marker may be provided that is visible only when the sealed container is in the second configuration, Alternatively, or in addition, a marker may be provided that is only concealed when the sealed container is in the first configuration The marker advantageously inaicates to the user that the change in shape of the heat transfer device is complete, so that the device is either ready for use or has completed heat transfer. The one or more markers may comprise, for example, coloured surface markings, printed text or surface textures.

The heat transfer device advantageously has dimensions typically, but not limited to, approximately 500 mm long by 50 mm wide, that allow it to be inserted into a standard wine or beer glass.

According to a second aspect of the present invention, there is provided a method for cooling or heating a fluid by absorbing or releasing thermal energy from or to a fluid comprising dispensing a fluid into a vessel, for example a glass, a drinking mug or cup, carafe etc, and inserting the heat transfer device in accordance with the first aspect into the fluid such that the fluid in the vessel is in thermal contact with the heat transfer device.

The method may require the heat transfer device to be pre-teated by heating or cooling, prior to fluid contact within a vessel.

The invention will be further described, by way of example only, with reference to the accompanying drawings in which: Figure la is an exploded view of the components of a first embodiment of the present invention.

Figure lb is a persoective view of a first embodiment of the present invention in a first configuration; Figure ic s a perspective view of a first embodiment of the present invention in a second configuration; Figure 2a is a perspective view of a second embodiment of the present invention in a first configuration; Figure 2b is a perspective view of a second embodiment of the present invention in a second configuration.

Figure la is an exploded view of the components of a first embodiment of the heat transfer device, configured for cool ng drinks, such as wine and beer The device has dimensions typically, but not limited to, 500 mm long by 50 mm wide, that allow it to fit into standard glasses. All components of the first embodiment of the heat transfer device are made of steel The sheet 11 is joined at one end to a tube handle 12 by welding The punched holes 13 are provided to communicate between the interior of the tube handle 12 and sheet 11. The end of the tube handle proximal to sheet 11 is sealed by welding. The edges of sheet 11 and 14 are welded together to create a central cavity, Figure lb shows the assembly of Figure is in a spiral shape. The spiral shape provides for a large surface area to volume ratio between the phase change matenal and the fluid, for fluid contact and cooling the fluid more quickly. The greater the surface area between the phase change material and the fluid, the quicker the fluid will cool. Conjoined sheets 11 and 14 are wound round the sealed tube handle 12 The heat transfer device is compleely filled with water via t"e open end of tube handle 12 to allow for expansion o' water between the solid and liquid phases forcing a shape change. Once filled, the open end of tube handle 12 is subsequently sealed by welding.

The heat transfer device is in a first configuration 15, when the water is in a liquid phase at room temperature, A first marker 17 is visible in the first configuration 15 (see Figure ic) Transfer of the heat transfer device into a freezer cabinet causes a phase change of the water from a liquid phase to a sohd phase Tne phase change of the water from a liquid to a aol d phase causes the container to expand leading to an increase in the radius of the spiral shape and a change in shace of the container from a first configuration 15 to a second configuration 16. A second marker 18 is visible in the second configuration indicating the phase change of water from a liquid to a solid is complete and the heat transfer device is ready to use.

When the second marker 18 is visible, the heat transfer device is transfrred frorr the freezer into a vessel of fluid The heat transfer device absorbs the thermal energy from the fluid thereby cooling 4he fluid Thermal absorption causes the watei to change phase from a sokd phase to a liquid phase The phase change of the water from a solid to a liquid causes the container to contract leading to a decrease in the radius of the spiral shape and a change in shape of he container from a first configuration 15 to a second configLration 16 Only the first marker 17 is visible in this configuration.

The heat transfer device can be re-used when in the first configuration 15 by putting it back into the freezer cabinet and repeating the process.

Figure 2a shows another embodiment of the present invention wherein the heat transfer device is a convoluted steel tube. One end of the convoluted steel tube 24 is wound round the opposite straightened end of the convoluted steel tube 22 in a shape which would allow for t to be positioned in a vessel of fluid. The shape of the convoluted steel tube provides for a large surface area to volume ratio between the phase change material and the fluid, for fluid contact and cooling the fluid more quickly. Convoluted steel tube end 24 is sealed by welding. The convoluted steel tube can be completely filled with water via open eno of the convoluted steel tube 22 to allow for expanson of water between the solid ard liquid phases forcing a shape change. Once filled, the open end of the convoluted steel tube 22 is sealed by welding.

The convoluted steel tube can cool a fluid in the same way as described for the first errbodirne"t of the invention The convolutod steel tube is in a first configuration 23 when the water is in a liquid phase and a marker 21 is visible In a second configura*ion 25 (Figure 2b) when the phase change of the water from a liquid to solid phase is complete, the marker 21 is not visible,

Claims

Claims 1. A heat transfer device for heating or cooling a fluid comprising: a sealed container containing a phase change material such that the container is in a first configuration when the phase change material is in a first S phase and is moved to a second configuration by the phase change mater al when the phase change material changes to a second phase.
2 The heat transfer device of claim wherein the container is shaped in a spiral or convoluted tube.
3. The heat transfer device of claim 1 or 2, wherein the sealed container is partially or fully formed from a resikent material.
4. The heat transfer device of any preceding claim, wherein in the first configuration the sealed container is in an unstressed state and in the second configuration the sealed container is in a stressed state.
5, The heat transfer device of any preceding claim, wherein the sealed container is completely filled by the phase change material or filled to a level such that expansion of the phase change material when the phase change material changes phase forces a change of shape of the sealed container.
6. The heat transfer device of any preceding claim wherein as the sealed container is moved from the first configuration to the second configuration one or more walls of the sealed container straightens or stretches 7 The heat transfer device of any preceding claim wherein the phase change matenal is water.8 The heat transfer device of claim 7, wherein the first phase is liqwd water 9 The heat transfer device of any preceding claim wherein the container comprises a handle.The heat transfer device of any preceding clam wherein the container comprises one or more markers that indicate when the sealed container is ri the first configuration or the second configuration.11. The heat transfer device of claim 10, wherein the one or more markers comprises a first marker that is visible only when the sealed container is in the second configuration.12. The heat transfer device of claim 10 or 11, wherein the one or more markers comprises a second marker that is concealed from view only when the sealed container is in the first configuration.13. A method of cooling or heating a fluid by absorbing or releasing thermal energy from or to a fluid comprising: irserting the heat transfer device of any Dreceding clam into the fluid such that the heat transfer device is in therma contact with the fluidS14, The method of claim 13 wherein the heat transfer device is cooled or thermafly pre treated prior to insertion into the fluid.15. A heat transfer device substantially as described herein with reference to Figures la to lc.16. A heat transfer device substantially as described herein with reference to Figures 2a and 2b.