AU2017220393A1

AU2017220393A1 - An instant boiling water heater system

Info

Publication number: AU2017220393A1
Application number: AU2017220393A
Authority: AU
Inventors: Brian Lionel CHERTKOW
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-02-17
Filing date: 2017-02-17
Publication date: 2018-08-30
Also published as: GB2563529B; WO2017139851A1; CN107091526A; CN107091526B; GB201814173D0; GB2563529A

Abstract

An instant boiling water heater system for dispensing boiling water comprising a first tank in fluid communication with a water supply, a heating device in fluid communication with the first tank, and a dispensing outlet in fluid communication with the heating device. The first tank comprises a first heating element for heating water from the water supply and the heating device comprises a body having a high thermal mass and a passageway extending through the body to receive water from the first tank.

Description

FIELD OF THE INVENTION [0001] The present invention relates to an instant boiling water heater system. In particular, although not exclusively, the invention relates to an instant boiling water heater system for dispensing boiling water.

BACKGROUND TO THE INVENTION [0002] There are a number of different brands of instant boiling water appliances on the market today. These products are all aimed at providing the user with having instant access to boiling water for making hot beverages such as tea and coffee, without the need to wait for a kettle to boil. Such appliances first found favour in offices and workplaces due to their convenience whilst ensuring employees did not waste time waiting for a kettle to boil.

[0003] Almost all, if not all, of these appliances use an electrical heating element to heat water in a chamber or tank, to a temperature that is considered to be boiling or close enough to boiling. At Standard Sea-Level Atmospheric Pressure and Temperature, water boils at 100^sC. Most of the commercially available appliances operate at just below 100^sC if they have vented storage tanks, while some operate just above 100^QC if they have pressurised storage tanks.

[0004] The higher the altitude above sea level, the lower the temperature at which the water will boil in a system that is vented to atmosphere. As the

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PCT/AU2017/050141 temperature at which the water boils varies with atmospheric pressure and altitude above sea level, it is difficult to develop one solution that will work at any location across the planet. To compensate for this, some of the more sophisticated appliances have built in calibration systems that determine the boiling point of water at the time of installation and then use this local boiling temperature as a future reference for determining the appliances operating set point, which is often 1^SC to 3^SC below the local boiling temperature. Other appliances simply have their operating set temperature below the minimum expected boiling point. This often leads to lower than optimum temperatures at sea level conditions.

[0005] Pressurised systems, which allow the temperature of the water in the tank to be raised above normal boiling point, do not suffer from this problem, but do have other drawbacks in their design systems. One such drawback is that when the water is released from the pressure vessel, because it is now well above the normal boiling point of water, the water comes out with a combination of excessive steam and bubbling water, increasing the risk of scalding. Another drawback is that extra energy is required to raise the water temperature to that above the boiling point, which is unnecessary and wasteful. Additionally, as a result of creating a pressure vessel, additional safety features are required. Further, a significant quantity of water is wasted through both the pressure relief system as well as when water is dispensed. A significant volume of water instantly converts to steam when released and is wasted into the atmosphere as a result.

[0006] A further drawback common to many appliances is that as water is heated close to boiling point, the relationship between energy in to

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PCT/AU2017/050141 temperature rise is not linear. As water gets closers to boiling point, an increasing amount of energy is required per degree rise in temperature. The reason is that when water begins to boil, the additional energy applied converts water from a liquid phase to a gaseous phase and this is done without change to the temperature. It is only after all the liquid is converted to gas that the temperature will begin to rise. So, as water is heated close to boiling point, some of that energy is converted to small pockets of gas or vapour without any significant increase to the overall temperature, hence the bubbling that begins to occur close to boiling point.

[0007] A further drawback of boiling water heaters is the lime scale present in hard water areas that forms inside the boiling water storage tank and on the heating elements. The formation requires regular maintenance as well as forming an insulating layer over the heating element. This insulating layer reduces the efficiency of the heating element resulting in more electrical power being required to achieve the same result as well as reducing the life of the element.

[0008] Some appliances pump their boiling water out of the storage tank. As the water temperature gets close to boiling point, this can cause cavitation in the pump resulting in poor flow or water delivery.

[0009] There are two main methods of delivering the boiling water to the outlet faucet. The simple version is a “push through” system in which the incoming cold water displaces and therefore pushes boiling water out of the tank. This is a simple concept that is often controlled by a solenoid valve. There are two main drawbacks of this simple system. The major drawback on such a system is that the incoming cold water mixes with the boiling water in

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PCT/AU2017/050141 the tank at the rate that the water is being dispensed. The cold water entering the tank mixes with the boiling water at the rate of the water being dispensed. This can cause a rapid cooling of the stored boiling water in the tank resulting in a noticeable drop in dispensed water temperature, especially in high use applications. The second drawback is that this system normally leaves water in the tube leading from the tank to the outlet faucet. This water in the tube cools down over time to the ambient air temperature, so when the next delivery of boiling water is required; a quantity of cooled water is delivered into the cup prior to boiling water. Users who are familiar with this problem will often dispense a quantity of water to waste before the usable boiling water is delivered into the cup or pot.

[0010] The more sophisticated systems separate the incoming water supply from the delivery system. They usually dispense the water from the boiling tank by pumping the water out. They also only allow incoming water into the tank at the rate that the heating element can keep up with maintaining the water at an acceptable temperature. The result of such a system is that any water being dispensed will normally be close to boiling temperature. However, when the tank empties, no water will be dispensed until the tank has recovered sufficient boiling water to allow more to be dispensed. The pumped system also has the advantage of allowing the water in the delivery tube from the tank to the faucet to drain back into the tank after use, thereby preventing a quantity of water in the tube to cool down. The result is that the first drop of water dispensed should be close to the desired water temperature.

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OBJECT OF THE INVENTION [0011] It is an object of the present invention to overcome and/or alleviate one or more of the disadvantages of prior art systems or provide the consumer with a useful or commercial choice.

SUMMARY OF THE INVENTION [0012] In one aspect, although not necessarily the only aspect or the broadest aspect, the invention resides in an instant boiling water heater system for dispensing boiling water, the system comprising:

a first tank in fluid communication with a water supply, the first tank comprising a first heating element for heating water from the water supply;

a heating device in fluid communication with the first tank, the heating device comprising a body having a high thermal mass and a passageway extending through the body to receive water from the first tank; and a dispensing outlet in fluid communication with the heating device.

[0013] Preferably, the body of the heating device comprises a metal block. Preferably, the body comprises a cast aluminium block.

[0014] Preferably, the heating device comprises a second heating element. Preferably, the second heating element is a stainless steel or Incoloy coil.

[0015] Preferably, the first heating element is an electric heating element. Preferably, the second heating element is an electric heating element.

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PCT/AU2017/050141 [0016] Preferably, the second heating element is cast in an aluminium block. Preferably, the passageway is a stainless steel tubular coil cast in the aluminium block.

[0017] The system normally includes a conduit providing the fluid communication between the water supply and the first tank, and the first tank and the heating device. The system also normally includes a conduit providing the fluid communication between the heating device and the dispensing outlet.

[0018] Preferably, the system further comprises an expansion tank connected to the dispending outlet of the first tank.

[0019] Preferably, the system further comprises a venturi tube within the expansion tank in fluid communication between the first tank and the heating device.

[0020] Preferably, water is discharged from the first tank to the heating device as the first tank fills with water from the water supply. Preferably, the first tank comprises a pump for pumping the heated water to the heating device.

[0021] Preferably, the dispensing outlet is in fluid communication with the first tank for dispensing hot water.

[0022] Preferably, the first tank and the heating device comprise a controller for controlling the first and second heating elements. Preferably, the water in the first tank is maintained between about 70^sC-90^sC. Preferably, the heating device is heated to between about 110^sC-140^sC.

[0023] Preferably, the first tank includes a first temperature measurement device for monitoring a temperature of the water in the first tank.

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PCT/AU2017/050141 [0024] Preferably, the heating device comprises a second temperature measurement device for monitoring a temperature of the aluminium block in the heating device.

[0025] Preferably, the first and second temperature measurement devices are thermistors or thermocouple devices.

[0026] Preferably, the controller is an electronic circuit board control system.

[0027] Preferably, the dispensing outlet is a faucet. Preferably, the outlet faucet further comprises a ceramic disc cartridge for controlling the flow of water from the water supply to the first tank.

[0028] Preferably, the faucet dispenses boiling water. Preferably, the faucet dispenses boiling water and at least one of chilled water, cold water and hot water.

[0029] Preferably, the first tank and heating device are thermally insulated. Preferably, the thermally insulated tank and heating device comprise vacuum jackets. Preferably, the thermally insulated tank and heating device comprise a thermal insulating material.

[0030] Preferably, the faucet comprises an indicator element. Preferably, the indicator element is a light for indicating the system has achieved its operating temperature. Preferably, the faucet comprises an indicator light for indicating the status of a filter.

[0031] In another form, although not necessarily the only or broadest form, the invention resides in a method for heating water in an instant boiling water heater system, comprising:

heating the water in a first tank to a first temperature;

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PCT/AU2017/050141 transferring the heated water from the first tank to a heating device;

transferring heat from the heating device to heat the water to a second temperature; and dispensing the heated water from the heating device to the dispensing outlet.

[0032] Preferably, water is received in the first tank, wherein the first tank is in fluid communication with a water supply.

[0033] Preferably, the first tank and the heating device are heated simultaneously, and the controller provides a first portion of total available electrical power to the first tank and a second portion of total available electrical power to the heating device wherein the sum of the first and second portions does not exceed the total available power.

[0034] Preferably, the first tank is not heating while the heating device is heating. Preferably, the heating device is not heating while the first tank is heating.

[0035] Preferably, the first temperature is between about 70^sC-90^sC.

[0036] Preferably, the second is temperature is between about 110^sC140^sC [0037] Further features of the invention will become apparent from the detailed description below.

BRIEF DESCRIPTION OF THE DRAWINGS [0038] To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, preferred

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PCT/AU2017/050141 embodiments of the invention will be described by way of example only with reference to the accompanying drawing, in which:

FIG. 1 illustrates a schematic diagram of an embodiment of a boiling water heater system.

DETAILED DESCRIPTION OFTHE INVENTION [0039] The present invention relates to an instant boiling water heater system. Elements of the invention are illustrated in concise outline form in the drawings, showing only those specific details that are necessary to understanding the embodiments of the present invention, but so as not to clutter the disclosure with excessive detail that will be obvious to those of ordinary skill in the art in light of the present description.

[0040] In this specification, adjectives such as first and second, and the like may be used solely to distinguish one element or action from another element or action without necessarily requiring or implying any actual such relationship or order. Words such as “comprises” or “includes” are intended to define a non-exclusive inclusion, such that, a method or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed, including elements that are inherent to such a method, or device.

[0041] FIG. 1 shows an embodiment of an instant boiling water heater system 10 for dispensing boiling water. The system 10 includes a water supply conduit 11 to be linked to a mains water supply 12, a water filtration system 13 including double check valves 13a and a pressure limiting valve

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13b, a water flow meter 14 and an outlet faucet 15. In this embodiment, the outlet faucet 15 dispenses boiling water as well as dispensing hot, cold and chilled water. The system is powered by a power source 16, such as a mains electrical supply.

[0042] The outlet faucet 15 is linked to the first tank 17 of the boiling water system 10 by a conduit 18a. The system 10 further includes a conduit 18b which connects the water supply 12 from the filter 13 to the faucet 15 and a conduit 18c which connects the faucet 15 to the first tank 17 for supplying cold water into the first tank 17. As shown, the boiling water system 10 is located under a bench top 19.

[0043] The first tank 17 includes a heating element 20. This is typically an electric heating element but other suitable types of heating elements, such as gas, may be used. Furthermore, the first tank 17 includes a temperature measuring device 21 such as a thermocouple, thermistor or negative temperature coefficient thermistor (NTC). The first tank 17 also includes a dispending outlet 24 for dispensing hot water through the faucet 15. The first tank 17 also includes an insulation chamber 17a such as a vacuum chamber or thermal insulating barrier.

[0044] As shown in FIG. 1, the system 10 includes a controller 22 which connects the temperature measuring device 21 and the heating element 20 such that the controller 22 controls the heating element 20 based on the measurements taken by the temperature measuring device 21.

[0045] The system 10 further includes an expansion tank 23 having an inlet conduit 24 and an outlet conduit 25. The expansion tank 23 is connected

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PCT/AU2017/050141 to the first tank 17 via the inlet conduit 24 of the expansion tank 23.

Furthermore, the expansion tank 23 includes a venturi tube 26 located between and connecting the inlet 24 to the outlet 25 of the expansion tank 23.

The first tank 17 dispenses hot water through outlet conduit 25 and out through the faucet 15 via the venturi 26 and heating device 27.

[0046] The boiling water heater system 10 also includes a heating device 27 including a body 27a, a heating element (not shown), an inlet conduit 25 and an outlet conduit 18a.

[0047] The heating device 27 comprises a cast aluminium body into which a helical stainless steel passageway and a stainless steel or Incoloy heating element are cast. However, the heating element can be made from any suitable metal. Aluminium provides an ideal metal for the body 27a of the heating device 27 due to the low specific heat (0.91kJ/kg K) properties and low melting temperature of aluminium relative to other metals. It will be appreciated that the body can be made from any suitable material with a high thermal mass, low specific heat and low melting temperature.

[0048] The heating element of the heating device 27 is typically an electric heating element but may be any suitable heating element. The heating device 27 also includes a temperature measuring device (not shown) such as a thermistor or NTC. The heating device 27 also includes an insulation chamber 30 such as a vacuum chamber or thermal insulating barrier. As discussed above, the system 10 includes a controller 22 which connects the temperature measuring device and the heating device 27 such that the controller 22 controls the heating device 27 based on the measurements taken by the temperature measuring device.

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PCT/AU2017/050141 [0049] A typical mains general purpose outlet (GPO) in Australia is rated at 10A. At 240V, this nominally means that the maximum power can only be 2400W. The controller 22 can be configured to control the first heating element 20 in the first tank 17 and the second heating element in heating device 27 such that the controller directs power to an element as it is needed. As a result, each individual element could be rated up to 2400W. In an example, during the initial start-up of the system, the primary objective is to heat the water in the first tank to 80^sC as quickly as possible and therefore a majority of the electrical power is directed to the first heating element 20 by the controller 22. The heating device 27 heats up very fast so less electrical power is directed to the heating device 27 by the controller 22. The controller 22 monitors the temperature of the first tank 17 and the heating device 27 until sufficient temperatures have been reached. At this stage, the first heating element 20 and heating device 27 only need to be occasionally supplied with electrical power to maintain their respective temperatures. As soon as the flow meter 14 detects water starts flowing, the controller 22 can direct, for example, 75% of the available electrical power to the heating device 27 while the remaining 25% of the electrical power is directed to the heating element 20 of the first tank 17. As the temperatures of the first tank 17 and the heating device 27 are constantly monitored, power can be applied to the element most in need, while at all times ensuring the total current draw is at or less than the total available power supply.

[0050] The faucet 15 further includes an indicator light 28 for indicating when the water is at the correct temperature for dispensing. In some

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PCT/AU2017/050141 embodiments, the indicator light 28 also indicates the status of the filtration system 13.

[0051] In use, the water supplied to the system 10 is filtered through the water filtration system 13. The water passing through the filter 13 to a ceramic disc cartridge (not shown) passes through a water flow meter 14 to measure the volume of water used. In contrast to typical systems, the flow control does not use any solenoid valves, but uses a standard ceramic disc cartridge commonly used in mixer taps available today. Advantageously, this design ensures that only when the ceramic cartridge is operated can incoming water enter the system. As a result, there is a minimised risk of accidental flooding if the system is left unattended. The system therefore does not require a flood sensor.

[0052] In operation, the first tank 17 heats up the water via the heating element 20 to around 80^sC for example. The heating device 27 is empty of water but is heated to, for example, 120^sC. The heating device 27 acts as a heat sink or storage medium for heat to rapidly heat water that passes through the stainless steel conduit. The temperature of the stainless steel water conduit also rises to the temperature of the aluminium block. This facilitates rapid boiling of the water in the system 10. Activation of the faucet 15 causes cold water to flow through conduit 18b to the faucet 15 and then from the faucet 15 through conduit 18c into the first tank 17. The flow of cold water into the first tank 17 causes hot water to be discharged from the first tank 17 through the outlet conduit 25 and through the venturi 26 of the expansion tank

23.

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PCT/AU2017/050141 [0053] The hot water then passes through the venturi tube 26 located in the expansion tank 23 causing any residual hot water in the expansion chamber 23 to be drawn into the heating device 27. As mentioned above, the heating device 27 is heated and maintained at a high temperature at all times. A person skilled in the art will appreciate that the water could also be transferred from the first tank 17 to the heating device 27 by a pump (not shown).

[0054] As the heating element in the heating device 27 is at a higher temperature, the water is rapidly raised to boiling point. The boiling water leaving the heating device 27 passes through the faucet 15 delivering boiling water. Once the desired volume of water has been dispensed and the ceramic cartridge is shut off, the water in the conduits from the expansion chamber 23, the heating device 27 and the conduit 18a to the faucet 15 drains back through the venturi 26 and into the expansion chamber 23 to be kept at the same temperature as the first tank 17. When the next dispensing of water is required, the water that is dispensed out of the first tank 17 passes through the venturi 26 to the heating device 27 and in so doing draws with it the water that was allowed to drain back into the expansion chamber 23. This process empties the water in the expansion chamber 23 which then allows for the water to drain back through the venturi 26 in the expansion chamber 23 once again after use. Advantageously, the use of the expansion chamber 23 and venturi 26 prevents any water that would typically remain in the conduit 18a between the first tank 17 and the faucet 15 from boiling overly high. Further advantageously, no water remains in the conduits or faucet to cool.

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PCT/AU2017/050141 [0055] Advantageously, there is no need for any level, leakage or flood sensors. Further advantageously, the use of a ceramic disc cartridge eliminates the need for solenoid valves. Furthermore, the controller simply switches the heating elements on and off based on temperature sensing inputs, dispensing with the need for a boiling water calibration system.

[0056] Further advantageously, the size of the system is reduced as the elimination of all valves and pumps results in a more compact system. There are also minimal moving parts. Only the impellor in the flow meter and the ceramic disc are moving parts. This can greatly improve reliability as compared to traditional units. In the event that the flow meter was to breakdown, the overall unit will still operate and deliver boiling water.

[0057] A further advantage lies in operating the first tank at a lower temperature which reduces the rate of lime scale build up on the heating element thereby increasing the heating efficiency over a longer period and extending the operating life of the heating element.

[0058] Advantageously, reducing the storage tank temperature from 98^SC to 80^sC can significantly reduce energy consumption resulting in lower operating costs. Furthermore, the flow meter measures the consumption of water to determine when the filter needs changing, while also acting as an indicator for the system to activate the heating element of the heating device before the temperature of the water in the system begins to drop. Advantageously, this design increases the boiling water capacity of the system.

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PCT/AU2017/050141 [0059] Advantageously, utilising a cast aluminium block around the water pipe prevents the heated water from cooling rapidly and maintains the boiling water temperature.

[0060] The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. The invention is intended to embrace all alternatives, modifications, and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention.

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Claims

1. An instant boiling water heater system for dispensing boiling water, the system comprising:

2. The instant boiling water heater system of claim 1, the heating device comprising a second heating element.

3. The instant boiling water heater system of claim 1 or 2, wherein the second heating element is cast in an aluminium block.

4. The instant boiling water heater system of any one of claims 1-3, the system further comprising a conduit providing the fluid communication between the water supply and the first tank, and the first tank and the heating device.

5. The instant boiling water heater system of any one of claims 1-4, the system further comprising a second conduit providing the fluid communication between the heating device and the dispensing outlet.

6. The instant boiling water heater system of any one of claims 1-5, the system further comprising an expansion tank connected to an outlet conduit of the first tank.

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7. The instant boiling water heater system of any one of claims 1-6, the system further comprising a venturi tube within the expansion tank in fluid communication between the first tank and the heating device.

8. The instant boiling water heater system of any one of claims 1-7, the first tank comprising a pump for pumping heated water to the heating device.

9. The instant boiling water heater system of any one of claims 1-8, the system further comprising a control for controlling the heating element of the first tank and the heating device.

10. The instant boiling water heater system of any one of claims 1-9, the first tank comprising a first temperature measurement device for monitoring a temperature of the water in the first tank.

11. The instant boiling water heater system of any one of claims 1-10, the heating device comprising a second temperature measurement device for monitoring a temperature of the heating device.

12. The instant boiling water heater system of any one of claims 1-11, wherein the first and second temperature measurement devices are thermistors or thermocouple devices.

13. The instant boiling water heater system of any one of claims 1-12, the dispending outlet comprising a ceramic disc cartridge for controlling the flow of water from the water supply to the first tank.

14. The instant boiling water heater system of any one of claims 1-13, wherein the first tank and heating device are thermally insulated.

15. A method for heating water in an instant boiling water heater system, comprising:

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PCT/AU2017/050141 heating the water in a first tank to a first temperature;

transferring the heated water from the first tank to a heating device;

16. The method of claim 15, wherein water is received in the first tank, wherein the first tank is in fluid communication with a water supply.

17. The method of claim 15 or 16, wherein the first tank and the heating device are heated simultaneously, and the controller provides a first portion of total available electrical power to the first tank and a second portion of total available electrical power to the heating device wherein the sum of the first and second portions does not exceed the total available power.

18. The method of any one of claims 15-17, wherein the first tank is not heating while the heating device is heating or the heating device is not heating while the first tank is heating.

19. The method of any one of claims 15-18, wherein the first temperature is between about 70^sC-90^sC.

20. The method of any one of claims 15-19, wherein the second temperature is between about 110^sC-140^sC.

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1/1

FIG. 1