Heating assembly for a kitchen device

Abstract

A heating assembly (100) for a kitchen device (10) is provided, the heating assembly (100) being mounted in a cavity (12) for receiving water to be heated, and including a heating element (120) for heating the water in the cavity (12), an electrode (130) for contact with the water in the cavity (12), a power source (140) connected to the heating element (120) and the electrode (130) for creating an electric potential between the heating element (120) and the electrode (130) with the heating element (120) having an anodic potential. A kitchen device (10) having the heating assembly (100) is also provided as well as a method of operating the kitchen device (10).

Description

HEATING ASSEMBLY FOR A KITCHEN DEVICE FIELD

[0001] The present invention relates to a heating assembly for a kitchen device.BACKGROUND

[0002] Heating assemblies for heating water are used in a variety of applications. In most applications, the water being heated is untreated, in the sense that the water will contain a variety of mineral salts, such as calcium carbonate and magnesium hydroxide. A common problem for heating assemblies for heating water is that the solubility of such salts may be inversely proportional to the temperature of the water, meaning that the salts may precipitate out of solution when the water is heated. The effect is especially pronounced proximate the heating assembly, as the water is typically hotter and hotter for longer in those locations. The deposits are commonly referred to as “scale” and the problem as “scaling”.

[0003] The presence and accumulation of scale is a problem for the heating assembly, as the scale acts to thermally insulate the heating element from the water, meaning that the heating element itself reaches higher temperatures, reducing the expected life of the component.Additionally, in temperature-sensitive applications such as the extraction of coffee or tea, the lag introduced between power applied to the heating element and subsequent change in temperature of the water leads to less precise control over the water temperature.

[0004] There are existing approaches to control scale deposits on heating elements. For example, US 11,129,489 B2 describes a methodology of treating water electrochemically to control the mineral salt content of the water before the water is admitted to the cavity in which the water is heated. However, such approaches typically require an additional liquid cavity in which the water is treated before being admitted to the heating cavity, increasing the size of the kitchen device.SUMMARY

[0005] It is an object of the present invention to substantially overcome, or at least ameliorate, one or more of the disadvantages of the above-mentioned heating assemblies, or at least provide a useful alternative to the heating assemblies discussed above.

[0006] There is disclosed herein a heating assembly for a kitchen device, the heating assembly being mounted in a cavity for receiving water to be heated, and including:a heating element for heating the water in the cavity;an electrode for contact with the water in the cavity;a power source connected to the heating element and the electrode for creating an electric potential between the heating element and the electrode with the heating element having an anodic potential.

[0007] Preferably, the heating element includes an electrically conductive anti-corrosion coating.

[0008] Preferably, the electrode has an electrically conductive anti-corrosion coating.

[0009] Preferably, the electrode is mounted to the heater using an electrically insulating standoff.

[0010] There is also disclosed a heating assembly for a kitchen device, the heating assembly being mounted in a cavity for receiving water to be heated, and including:a heating element for heating the water in the cavity;a first electrode for contact with the water in the cavity;a second electrode for contact with the water to be heated;a power source connected to the first electrode and second electrode for creating an electric potential between the electrodes,wherein, when the electric potential is applied, the first electrode has an anodic potential, and wherein the first electrode includes an electrically conductive anti-corrosion coating.

[0011] Preferably, the second electrode includes an electrically conductive anti-corrosion coating.

[0012] Preferably, the heating element is an element of the first electrode.

[0013] Preferably, the second electrode is mounted to the first electrode using an electrically insulating standoff.

[0014] Preferably, the power source is configured to provide an electric potential of about 2 V.

[0015] Preferably, the anti-corrosion coating includes one or more of:a conductive ceramic,an amorphous carbon,a diamond like carbon.

[0016] The heating assembly of claim 10, wherein the anti-corrosion coating includes doping elements, the doping elements including one or more of silicon, tungsten, chromium, gold, and platinum.

[0017] Preferably, the power source is a first power source, and the heating element is connected to a second power source for powering the heating element for heating the water.

[0018] There is further disclosed a kitchen device having the disclosed heating assembly.

[0019] There is also disclosed a method of operating the disclosed kitchen device, the method including the steps of:operating the heating element for heating the water without operating the power source creating the anodic potential;operating the power source creating the anodic potential without operating the heating element for heating the water and subsequently discarding the water.BRIEF DESCRIPTION OF THE DRAWINGS

[0020] For a more complete understanding of the present invention, exemplary embodiments of the invention are explained in more detail in the following description with reference to the accompanying drawing figures, in which like reference signs designate like parts and in which:

[0021] FIG. 1 is a perspective view of a heating assembly according to a first embodiment of the invention, used with a kettle.

[0022] FIG. 2 is a section view of the heating assembly of FIG. 1.

[0023] FIG. 3 is an exploded perspective view of a heating assembly according to a second embodiment of the invention, used with a thin film heater.

[0024] FIG. 4 is a bottom view of the heating assembly of FIG. 3.

[0025] FIG. 5 is a top view of the heating assembly of FIG. 3.

[0026] FIG. 6 is a side elevation view of the heating assembly of FIG. 3.

[0027] FIG. 7 is a section view of the heating assembly of FIG. 6.DETAILED DESCRIPTION

[0028] As shown in FIGS. 1 and 2, a heating assembly 100 according to a first embodiment of the invention may be implemented with a kitchen device 10, such as a kettle 10. A second exemplary embodiment in which the kitchen device 10 is an espresso machine is shown in FIGS. 3 to 7.

[0029] The heating assembly 100 is mounted in a cavity 12 of the kitchen device 10 that is adapted to receive water to be heated by the heating assembly 100. For example, in FIG. 1, the kettle 10 includes a base 20 and side wall 22 defining the cavity 12, with an opening 24 providing access to the cavity 12 for adding water to, or removing water from, the cavity 12. The heating assembly 100 includes a heating element 120 locatable in the cavity 12 for heating the water in the cavity 12. As shown in FIG. 2, the heating element 120 may take the form of a resistive heating plate 120. The heating assembly 100 further includes an electrode 130 locatable in the cavity 12 for contact with the water to be heated. The electrode 130 may, as shown in FIG. 2, be embodied as a plate having a top surface 132 and a bottom surface 134, with a thickness 136. Preferably, the top and / or bottom surface 132, 134 are much greater than the thickness 136, such that the plate is a thin plate to increase the contact area between the electrode 130 and the water. The top and / or bottom surfaces 132, 134 may further include apertures 138 to further increase the contact area between the electrode 130 and the water. The electrode 130 may further include a central aperture 131 to avoid inhibiting water flow of heated water by the heating element 120 away from the heating element 120 under the influence ofconvection. The heating assembly 100 further includes a power source 140 connected to the heating element 120 and the electrode 130 for creating an electric potential between the heating element 120 and the electrode 130, when water is located in the cavity 12. Water located in the cavity 12 typically includes mineral salts making the water at least weakly conductive, closing an electric circuit between the power source 140, the heating element 120, and the electrode 130. Preferably, in conditions reflective of typical tap water, the power source 140 is configured to maintain an electric potential between the heating element 120 and the electrode 130 of about 2 V. The power source 140 is configured such that the heating element 120 has an anodic potential. In this way, H+ions are formed in the water proximate the heating element 120 by action of the anodic potential of the heating element 120 on the water. The presence of H+ions decreases the pH of the water close to the heating element 120, which increases the solubility of common scale-forming mineral salts, such as calcium carbonate and magnesium hydroxide. The increased solubility decreases the tendency for these mineral salts to precipitate out of the water when the water is heated by the heating element 120.

[0030] A potential problem created by the presence of H+ ions proximate the heating element 120 is that most metals corrode much more quickly in low-pH environments. Thus, the heating element 120 may include an electrically conductive anti-corrosion coating 150. The coating 150 should be electrically conductive such that the heating element 120 is in electrical contact with the water to act as the anode and cause the presence of H+ions in the water. In some embodiments, the electrode 130 may also include an electrically conductive anti-corrosion coating 150, preferably the same coating 150 as included by the heating element 120. The coating 150 may include one or more of a conductive ceramic, an amorphous carbon, more preferably a diamond-like carbon. To provide conductivity, the coating 150 may be doped with elements such as silicon, tungsten, chromium, gold, or platinum. The coating 150 is preferably applied to the heating element 120 and / or the electrode 130 using plasma vapour deposition processes (PVD), such as arc deposition, sputter deposition, or plasma assisted chemical vapour deposition.

[0031] As shown in FIG. 2, the electrode 130 may be mounted to the heating element using an insulating standoff 160, to control a distance 162 between the electrode 130 and the heating element 120, which is one of the variables controlling the electric potential between the electrode 130 and the heating element 120.

[0032] The power source 140 may be a first power source 140, and the heating element 120 may be connected to a second power source 170 for powering the heating element 120 for heating the water. The second power source 170 is thus preferably rated to a much higher power delivery than the first power source 140, since the power required to maintain an electric potential between the heating element 120 and the electrode 130 of about 2 V is typically much lower than the typically 1800 W or 2400 W of power delivered by the second power source 170 to the heating element 120 for heating the water.

[0033] Use of the heating assembly 100 of the embodiment shown in FIGS. 1 and 2 will now be discussed. The scale-controlling function of the heating assembly 100 may be applied substantially every time the kitchen device 10 is used. When operated in this manner, the power source 140 will operate every time the second power source 170 is operated to heat water, and will create the anodic potential at the heating element 120 to decrease the precipitation of mineral salts near the heating element 100 when the water is heated. Depending on the kitchen device 10, and the level of water hardness, the scale-controlling function of the heating assembly 100 may be applied periodically to control scale deposition on the heating element 120. When operated in this manner, the heating element 120 is operated in most, or at least some, instances, using the second power source 170, for heating the water without operating the power source 140, and thus no anodic potential is created. In periodic scale control operations, the power source 140 may then be operated, with or without operation of the second power source 170 for heating the water, to create the anodic potential at the heating element 120, which lowers the pH of the water near the heating element and may dissolve scale deposited on the heating element. The water in the cavity 12 may then be discarded to remove the scale from the system.

[0034] FIGS. 3 to 7 show a second embodiment of the heating assembly 100 in which the heating assembly 100 is applied to a kitchen device 10 with a flow-through style heater, in which water is heated as it flows through the cavity 12, rather being heated in bulk in the cavity 12 and then dispensed, as shown in FIGS. 1 and 2. Like reference numerals will be used for like integers, and the mechanism of function between the embodiments is substantially similar.

[0035] As shown in FIG. 3 the heating assembly 100 may include a heating element 120, in this exemplary embodiment the heating element 120 includes a thin film heater having a resistive heater etched on a circuit board. The heating element 120 is locatable for heating water in thecavity 12 of the kitchen device 10. The heating assembly 100 also includes a first electrode 110 locatable for contact with the water in the cavity 12, and a second electrode 130 locatable for contact with the water in the cavity 12. In the preferred embodiment, the cavity 12 is defined by one or more of the heating element 120, the first electrode 110, the second electrode 130, and an insulating standoff 160. In this embodiment, the insulating standoff 160 may take the form of a spacer 160 defining a flow path 164 for the water from an inlet 166 to and outlet 168. The flow path 164, bounded by the electrodes 110, 130 and the heating element 120, define the cavity 12. The power source 140 remains connected to the electrodes 110, 130 to create an electric potential between the electrodes, with the first electrode 110 having an anodic potential and the second electrode 130 having a corresponding cathodic potential. In preferred embodiments, the first electrode 110 includes the electrically conductive anti-corrosion coating 150. In some embodiments, the second electrode 130 also includes the coating 150.

[0036] As shown in FIG. 3, the heating element 120 may be an element of the first electrode 110. For example, the resistive heating trace may be printed on the first electrode 110, or the circuit board containing the resistive heating trace may be mounted on the first electrode 110. The second electrode 130 may be mounted to the first electrode 110 using the insulating standoff 160, to create the distance 162 between the electrodes 110, 130 and define the cavity 12.

[0037] Various forms of the heating assembly 100 described above may have one or more of the following advantages. Due to the use of the heating element 120 as an anode and / or the first electrode 110 with an electrical potential produced by the power source 140, scale-depositing mineral salts may be inhibited from precipitating out of the water as it is heated by the heating element 120, due to the presence of H+ions caused by the anodic potential. The use of the electrically conductive anti -corrosion coating 150 helps to protect the heating element 120 and / or the electrodes 110, 130 from the higher corrosion in the low pH environment caused by the anodic potential. The use of the insulating standoff 160 allows the careful control of distance 162 between the anode and cathode, while ensuring that the circuit between them is closed through the water. The use of the heating element 120 as the anode allows the protection of the heating element 120 from the water as it is being heated, rather than requiring water to be treated for mineral content before being admitted to the cavity 12, reducing the size of the kitchen device 10. The use of a diamond-like carbon coating, in particular, is preferential due to the associated hardness and possibility for appropriate doping to provide electrical conductivity.

[0038] Because the heating element 120 is less likely to be exposed to scale, the fluid temperature surrounding the heating element 120 may be raised higher than previous kitchen devices might be designed for, as the precipitation rate correlates with increasing temperature. A higher fluid temperature causes faster precipitation of mineral salts, especially in the water closest to the electrodes 110, 130. Thus, mineral salts are precipitated from the water relatively quickly, which is beneficial in particular for the flow-through embodiment of FIGS. 3 to 7 to reduce precipitation of mineral salts in components of the kitchen device 10 after the water has left the flow path 164. Water with a lower mineral salt content is also beneficial in the embodiment of FIGS. 1 and 2, as the “softer” water enhances taste and overall user experience, especially for coffee or tea beverages.

[0039] It will also be appreciated that in this document the terms “comprise”, “comprising”, “include”, “including”, “contain”, “containing”, “have”, “having”, and any variations thereof, are intended to be understood in an inclusive (i.e. non-exclusive) sense, such that the process, method, device, apparatus or system described herein is not limited to those features or parts or elements or steps recited but may include other elements, features, parts or steps not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, the terms “a” and “an” used herein are intended to be understood as meaning one or more unless explicitly stated otherwise. Moreover, the terms “first”, “second”, etc. are used merely as labels, and are not intended to impose numerical requirements on or to establish a certain ranking of importance of their objects.

[0040] Integers:10 kitchen device 136 thickness12 cavity 138 apertures20 base 140 power source22 sidewall 150 anti-corrosion coating24 opening 160 insulating standoff100 heating assembly 162 distance120 heating element / first electrode 164 flow path130 second electrode 166 inlet132 top surface 168 outlet134 bottom surface 170 second power source

Claims

CLAIMS:

1. A heating assembly for a kitchen device, the heating assembly being mounted in a cavity for receiving water to be heated, and including:a heating element for heating the water in the cavity;an electrode for contact with the water in the cavity;a power source connected to the heating element and the electrode for creating an electric potential between the heating element and the electrode with the heating element having an anodic potential.

2. The heating assembly of claim 1, wherein the heating element includes an electrically conductive anti-corrosion coating.

3. The heating assembly of claim 1, wherein the electrode has an electrically conductive anti-corrosion coating.

4. The heating assembly of claim 1, wherein the electrode is mounted to the heater using an electrically insulating standoff.

5. A heating assembly for a kitchen device, the heating assembly being mounted in a cavity for receiving water to be heated, and including:a heating element for heating the water in the cavity;a first electrode for contact with the water in the cavity;a second electrode for contact with the water to be heated;a power source connected to the first electrode and second electrode for creating an electric potential between the electrodes,wherein, when the electric potential is applied, the first electrode has an anodic potential, and wherein the first electrode includes an electrically conductive anti-corrosion coating.

6. The heating assembly of claim 5, where the second electrode includes an electrically conductive anti-corrosion coating.

7. The heating assembly of claim 5, wherein the heating element is an element of the first electrode.

8. The heating assembly of claim 6, wherein the second electrode is mounted to the first electrode using an electrically insulating standoff.

9. The heating assembly of any one of claims 1 to 8, wherein the power source is configured to provide an electric potential of about 2 V.

10. The heating assembly of any one of claims 1 to 9, wherein the anti-corrosion coating includes one or more of:a conductive ceramic,an amorphous carbon,a diamond like carbon.

11. The heating assembly of claim 10, wherein the anti-corrosion coating includes doping elements, the doping elements including one or more of silicon, tungsten, chromium, gold, and platinum.

12. The heating assembly of any one of claims 1 to 11, wherein the power source is a first power source, and the heating element is connected to a second power source for powering the heating element for heating the water.

13. A kitchen device having the heating assembly of any one of claims 1 to 12.

14. A method of operating the kitchen device of claim 13, the method including the steps of:operating the heating element for heating the water without operating the power source creating the anodic potential;operating the power source creating the anodic potential without operating the heating element for heating the water and subsequently discarding the water.Breville Pty LimitedPatent Attorneys for the Applicant / Nominated PersonGLMR

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