WO1994017646A1 - Microwavable heating device - Google Patents

Microwavable heating device Download PDF

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Publication number
WO1994017646A1
WO1994017646A1 PCT/GB1993/002560 GB9302560W WO9417646A1 WO 1994017646 A1 WO1994017646 A1 WO 1994017646A1 GB 9302560 W GB9302560 W GB 9302560W WO 9417646 A1 WO9417646 A1 WO 9417646A1
Authority
WO
WIPO (PCT)
Prior art keywords
heating device
microwavable
component
microwavable heating
core
Prior art date
Application number
PCT/GB1993/002560
Other languages
French (fr)
Inventor
Colin Michael Clifford
Original Assignee
Colin Michael Clifford
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Colin Michael Clifford filed Critical Colin Michael Clifford
Priority to AU57049/94A priority Critical patent/AU5704994A/en
Publication of WO1994017646A1 publication Critical patent/WO1994017646A1/en

Links

Classifications

    • AHUMAN NECESSITIES
    • A47FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47JKITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
    • A47J36/00Parts, details or accessories of cooking-vessels
    • A47J36/24Warming devices
    • A47J36/2483Warming devices with electrical heating means
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00Heating by electric, magnetic or electromagnetic fields
    • H05B6/64Heating using microwaves

Definitions

  • This invention concerns the use of a microwavaole heating device to provide a useful souce of energy. 5. Specifically. this invention relates to a microwavable heating device for use in heating food or keeping food warm.
  • Present divices for heating food may comprise a grill with candles lit underneath on which are 10. placed the items to he kept warm.
  • this arrangement has the disadvantage that the candles must be lit and replaced and there are some situations where a naked flame is not advisable.
  • a hotplate may also be used at present to keep food warm.
  • the food or other items 15. to be kept warm are placed on a ceramic top which has an element within it which is plugged into an electricity and also results in unsightly power leads.
  • This present invention seeks to provide a 20. microwavable heating apparatus which is easy and simple to use, portable, and which uses microwave energy, is efficient and cheap.
  • a microwavable heating device including a first or third component which converts microwave energy into heat, a second component to allow the transfer of heat,and the third component also acting to to insulate both first and second component's.
  • This arrangement enables part of the external surfaces to be maintained at a relativelv cool 30. temperature, enabling the device to be handled easily.while providing a source of heat through the second surface region.
  • the first component of 35. the microwavable heating device would contain varying ammounts of minerals. This enables the first surface region to become hotter more eas ly.
  • the second surface region of the microwavable heating device may be glazed or unglazed.
  • microwavable heating device may have a core formed from the first component, and an 10. insulating material around the core with the second surface region being located outwardly of the insulating material.
  • the insulating material is porous. Tnis 15. allows the microwave energy to pass more freely to the first surface region.
  • Figure 1 shows a plan view of a microwave heating device according to the invention.
  • Figure 2 shows a cross-section through line A-A in Figure 1;
  • Figure 3 is a plan view of a heating device in accordance with a further alternative embodiment of the invention.
  • Figure 4 is a cross-section through the device
  • Figure 5 shows a further alternative with the cere material as the heating surface.
  • the microwave heating device comprises a microwave activated core.
  • This core is made out of a material suitable for converting microwave energy into heat.
  • the core may be made from any fired clay. This material is typically a mixture of silica, alumina and ferric oxide, plus other components present in small amounts. It will be apparent that other materials could be used for this purpose.
  • the core may be made of a material which 10. is unaffected by microwave energy, but which has a large heat capacity and can be heated indirectly by the microwave energy.
  • the core 1 is partially surrounded by a moulded insulating material 2.
  • This insulating material is preferably made out of a porous material .
  • the edges of the material are preferably left unglazed, although they may be coated with an acrylic-based material.
  • the use of a porous insulating material 2 with unglazed surfaces means that heat can easily escape from the insulating
  • the moulded material material may in particular be made from a polyurethane prepolymer, normally used as a binding agent or an adhesive, together with a "fly ash" filler.
  • the polymer and the filler are present in the ratio approximately 1:4, i.e.
  • This material may be easily moulded into the 35. desired shape for the insulating means.
  • the material may be moulded so that it is easy to handle. Moulding is carried out by packing the mixture of prepolymer and filler into a mould and compressing it, either by hand or by machine. The mould can then be lifted off the moulded product.
  • the grains of ash are each similar to a microsphere containing a small amount of gas, which becomes hot when exposed to microwave energy.
  • the gaps between the grains of the 10. filler are left . unfilled. This means that air, moisture and microwaes can pass freely through the material.
  • this material has the advantage that it is a good insulator, and is resistant to heat, 15. including temperatures of at least 150c. As a result, it is able to withstand being in contact with the hot core without damage, and without becoming too hot to handle.
  • the core material has a surface which is intended 20. to provide the heating surface. This surface may be flat. If the heating device is to be used for keeping plates and food warm a protective tile 2 may be placed in thermal contact with the care matrial.
  • the tile 2 may advantageously be made from 25. a ceramic material, and have a glazed surface 3a. This tile might rest upon the moulded material for support, or sit directly on the core.
  • a heating device in accordance with the 30. invention may be used for purposes other than warming plates or food, for example a bottle warmer, and in this case the core and surrounding moulding material will be suitably shaped.
  • the heating device may also be used in other heating situations, and the shape of the 35. heating surface together with the dimensions of the device, may be chosen in accordance
  • the porous insulating may be saturated, or substantially saturated, with water before the device is exposed to the microwave energy.
  • the apparatus may be removed from the microwave oven and used in the desired manner.
  • the core After microwaving the core will retain its heat and 15. provide heat through the heat conducting material. However the insulating material will cool rapidly due to the porosity and the evopration of the moisture, this will make it easy to handle.
  • Figure 2 is a cross section through the device 20 in accordance with the invention .
  • This device has a core 21 surrounded by an insulating material 22 and a heating surface 23. This device may be used without the addition of water.
  • FIG. 25 Figures 3 and 4 show an alternative device 40 having a core 41. and an outer layer of insulating material 42. This device has an internal in the form of a tube 43. for example made of glass. nd connected to other pipes, a liquid is pumped round the system while been heated by the microwaves.
  • figure 5. shows a further alternative 30 showing the core material protruding from the insulating material 32. and acting as the heating surface.
  • figure 6. shows yet a further alternative 50. with the core 51. material surrounded by the insulating material 52. This device would allow the heat to escape only through the pores of the insulating material, giving a lower heat over a longer period.
  • FIG. 3 is a cross-section through an alternative device 20 in accordance with the invention.
  • This device has a core 21, a layer of insulating 5. material 22 surrounding most of the core, and a heating surface 23.
  • This device may be used without addition of water, or alternatively the insulating material may be saturated with water to speed up the rate at which the device is heated when exposed to microwave energy.
  • Figures 4 and 5 show a futher alternative device 40, having a core 41 and an outer layer of insulating material 42.
  • This device has an internal surface in the form of a tube 43, for example made of glass. The device can be heated by exposure to microwave energy and can then be used to heat a liquid flowing through the tube 43,

Abstract

This invention concerns the use of microwave energy to create a portable source of heat, which is used to keep food or other products hot without the need for candles, or electric leads. It is made by using a core material that contain varying ammounts of minerals which are activated by the microwave energy. A ceramic tile can be bonded direct to the core and the whole unit is moulded into a resin and filler mix. The tile being, on the outside, this acts like a hot-plate absorbing the heat from the core, while the resin mix insulates.

Description

MICROWAVAB E HEATING DEVICE,
This invention concerns the use of a microwavaole heating device to provide a useful souce of energy. 5. Specifically. this invention relates to a microwavable heating device for use in heating food or keeping food warm.
Present divices for heating food may comprise a grill with candles lit underneath on which are 10. placed the items to he kept warm. However, this arrangement has the disadvantage that the candles must be lit and replaced and there are some situations where a naked flame is not advisable.
A hotplate may also be used at present to keep food warm. In this arrangement the food or other items 15. to be kept warm are placed on a ceramic top which has an element within it which is plugged into an electricity and also results in unsightly power leads.
This present invention seeks to provide a 20. microwavable heating apparatus which is easy and simple to use, portable, and which uses microwave energy, is efficient and cheap.
According to this invention there is provided a microwavable heating device including a first or third component which converts microwave energy into heat, a second component to allow the transfer of heat,and the third component also acting to to insulate both first and second component's.
This arrangement enables part of the external surfaces to be maintained at a relativelv cool 30. temperature, enabling the device to be handled easily.while providing a source of heat through the second surface region.
In a preferred arrangement the first component of 35. the microwavable heating device would contain varying ammounts of minerals. This enables the first surface region to become hotter more eas ly.
Furthermore, the second surface region of the microwavable heating device may be glazed or unglazed.
5. This enables the second surface to radiate heat stored in the first surface region.
Additionally the microwavable heating device may have a core formed from the first component, and an 10. insulating material around the core with the second surface region being located outwardly of the insulating material.
Preferably the insulating material is porous. Tnis 15. allows the microwave energy to pass more freely to the first surface region.
For a better understanding of the present. 20. invention, and to show how it may be brought into effect, reference will now be made, by way of example, to the drawings, in which:
Figure 1 shows a plan view of a microwave heating device according to the invention.
25. Figure 2 shows a cross-section through line A-A in Figure 1;
Figure 3 is a plan view of a heating device in accordance with a further alternative embodiment of the invention; and
30. Figure 4 is a cross-section through the device
Figure 5. shows a further alternative with the cere material as the heating surface.
35. Figure 6. yet another device with the core material been completely surrounded by the insulating material and having no visible heating surface. shown in Figure 4.
The microwave heating device comprises a microwave activated core. This core is made out of a material suitable for converting microwave energy into heat.
5. For example, the core may be made from any fired clay. This material is typically a mixture of silica, alumina and ferric oxide, plus other components present in small amounts. It will be apparent that other materials could be used for this purpose. Provided that the device includes a component capable of converting microwave energy to heat, the core may be made of a material which 10. is unaffected by microwave energy, but which has a large heat capacity and can be heated indirectly by the microwave energy.
15. The core 1 is partially surrounded by a moulded insulating material 2. This insulating material is preferably made out of a porous material . The edges of the material are preferably left unglazed, although they may be coated with an acrylic-based material. The use of a porous insulating material 2 with unglazed surfaces means that heat can easily escape from the insulating
20. material and hence that its surfaces remain relatively cool since air and moisture can escape therefrom.
25. The moulded material material may in particular be made from a polyurethane prepolymer, normally used as a binding agent or an adhesive, together with a "fly ash" filler. The polymer and the filler are present in the ratio approximately 1:4, i.e.
30. approximately 250 grams of the polymer to 2.4 litres of ash or other non- absorbing filler.
This material may be easily moulded into the 35. desired shape for the insulating means. In particular the material may be moulded so that it is easy to handle. Moulding is carried out by packing the mixture of prepolymer and filler into a mould and compressing it, either by hand or by machine. The mould can then be lifted off the moulded product.
5. The grains of ash are each similar to a microsphere containing a small amount of gas, which becomes hot when exposed to microwave energy. In addition, because of the relatively small proportion of the resin which is used, compared to most moulding materials, the gaps between the grains of the 10. filler are left . unfilled. This means that air, moisture and microwaes can pass freely through the material.
Moreover, this material has the advantage that it is a good insulator, and is resistant to heat, 15. including temperatures of at least 150c. As a result, it is able to withstand being in contact with the hot core without damage, and without becoming too hot to handle.
The core material has a surface which is intended 20. to provide the heating surface. This surface may be flat. If the heating device is to be used for keeping plates and food warm a protective tile 2 may be placed in thermal contact with the care matrial. The tile 2 may advantageously be made from 25. a ceramic material, and have a glazed surface 3a. This tile might rest upon the moulded material for support, or sit directly on the core.
However, a heating device in accordance with the 30. invention may be used for purposes other than warming plates or food, for example a bottle warmer, and in this case the core and surrounding moulding material will be suitably shaped. In addition the heating device may also be used in other heating situations, and the shape of the 35. heating surface together with the dimensions of the device, may be chosen in accordance
with the intended use of the device.
5. Alternatively, the porous insulating may be saturated, or substantially saturated, with water before the device is exposed to the microwave energy.
10 The apparatus may be removed from the microwave oven and used in the desired manner.
After microwaving the core will retain its heat and 15. provide heat through the heat conducting material. However the insulating material will cool rapidly due to the porosity and the evopration of the moisture, this will make it easy to handle.
20. Figure 2 is a cross section through the device 20 in accordance with the invention .This device has a core 21 surrounded by an insulating material 22 and a heating surface 23. This device may be used without the addition of water.
25. Figures 3 and 4 show an alternative device 40 having a core 41. and an outer layer of insulating material 42. this device has an internal in the form of a tube 43. for example made of glass. nd connected to other pipes, a liquid is pumped round the system while been heated by the microwaves.
30. figure 5. shows a further alternative 30 showing the core material protruding from the insulating material 32. and acting as the heating surface.
35. figure 6. shows yet a further alternative 50. with the core 51. material surrounded by the insulating material 52. this device would allow the heat to escape only through the pores of the insulating material, giving a lower heat over a longer period.
Figure 3 is a cross-section through an alternative device 20 in accordance with the invention. This device has a core 21, a layer of insulating 5. material 22 surrounding most of the core, and a heating surface 23. This device may be used without addition of water, or alternatively the insulating material may be saturated with water to speed up the rate at which the device is heated when exposed to microwave energy.
10. Figures 4 and 5 show a futher alternative device 40, having a core 41 and an outer layer of insulating material 42. This device has an internal surface in the form of a tube 43, for example made of glass. The device can be heated by exposure to microwave energy and can then be used to heat a liquid flowing through the tube 43,
15. which can of course be connected to other liquid-containing pipes. Meanwhile the outer surface of the insulating material 42 remains relatively cool.
There is thus provided a convenient source of heat for use, for example, as a food warmer.

Claims

5. 1. A microwavable heating device including a first component which converts microwave energy into heat and having second and third components the first component becoming hotter than the second when the device is exposed to microwave energy.
2. A microwavable heating device as claimed in claim 1, wherein the first component is glazed.
10. 3. A microwavable heating device as claimed in claim 1 or 2, wherein the second component is unglazed.
4. A microwavable heating device as claimed in claim 1, 2 or 3, having a core formed from the
15. first component, the third component been insulating material around the core with the second component being located outwardly of the insulating material.
5. A microwavable heating device as claimed in 20 claim 1, 2, 3, or 4, having only a first and third component.
6. A microwavable heating device as claimed in claim 5, when dependent on claim 4 wherin thee insulating material is porous.
25. 7. A microwavable heating device, the only component been the insulating moulded material
θ. A microwavable heating device as claimed in claim 4, or clai;m 5, 6 or 7 when dependent on claim 4, wherein the insulating means is made of a 30. moulded polymer.
9. A microwavable heating device as claimed in 35. claim 7,and 8, wherein the insulating means is made from a moulded polyurethane resin using a refined fly ash filler. 11. A microwaable heating device as claimed in any preceding claim wherein the first surface region is flat.
5. 12. A microwavable heating device as claimed in claim 11 wherein the first surface region is covered by a protective means.
13. A microwavable heating device as claimed in 10. claim 12 wherein the protective means is made frcan glazed ceramic.
15. 14 . A microwavable heating device, for warming products,other than food
20. 15. A microwavable heating device as claimed in any preceding claim for heating or warming food.
16. A microwavable heating device substantially as 25. herein described with reference to Figures 1 and 2. or figure 3 or Figure 4 or figures 5 and 6 of the accompanying drawings.
PCT/GB1993/002560 1993-01-21 1993-12-15 Microwavable heating device WO1994017646A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU57049/94A AU5704994A (en) 1993-01-21 1993-12-15 Microwavable heating device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9301102.1 1993-01-21
GB9301102A GB2274567A (en) 1993-01-21 1993-01-21 Microwavable heating device

Publications (1)

Publication Number Publication Date
WO1994017646A1 true WO1994017646A1 (en) 1994-08-04

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Application Number Title Priority Date Filing Date
PCT/GB1993/002560 WO1994017646A1 (en) 1993-01-21 1993-12-15 Microwavable heating device

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AU (1) AU5704994A (en)
GB (1) GB2274567A (en)
WO (1) WO1994017646A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9247848B2 (en) 2007-11-21 2016-02-02 Mastrad, S.A. Temperature-retaining device

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3701872A (en) * 1968-02-09 1972-10-31 Melvin L Levinson Heating and loading implement for microwave energy
US4567877A (en) * 1984-07-30 1986-02-04 Bahman Sepahpur Heat storage food container
GB2186478A (en) * 1986-02-04 1987-08-19 Commercial Decal Inc Microwave heating utensil
US4914717A (en) * 1989-02-13 1990-04-03 Jmk International, Inc. Microwave actuable heating pad and method
US4931608A (en) * 1988-12-16 1990-06-05 Ran Free Microwave-heatable hot pad
US5052369A (en) * 1985-12-13 1991-10-01 Johnson Kendrick A Heat retaining food container
US5070223A (en) * 1989-03-01 1991-12-03 Colasante David A Microwave reheatable clothing and toys
US5155319A (en) * 1991-01-17 1992-10-13 Chiu Sou Kuein Heat-conducting film for absorbing electromagnetic wave and microwave energy

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01501166A (en) * 1986-07-01 1989-04-20 セカ・ゲーエムベーハー Vibratory weight measuring device
US4849593A (en) * 1986-10-14 1989-07-18 Hughes Thomas E Microwave-activated heating element
US4880953A (en) * 1988-12-23 1989-11-14 Prism Technologies, Inc. Method of recharging a heat pack by microwave energy
US4983798A (en) * 1989-04-18 1991-01-08 Eckler Paul E Warming devices and method using a material with a solid-solid phase change

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3701872A (en) * 1968-02-09 1972-10-31 Melvin L Levinson Heating and loading implement for microwave energy
US4567877A (en) * 1984-07-30 1986-02-04 Bahman Sepahpur Heat storage food container
US5052369A (en) * 1985-12-13 1991-10-01 Johnson Kendrick A Heat retaining food container
GB2186478A (en) * 1986-02-04 1987-08-19 Commercial Decal Inc Microwave heating utensil
US4931608A (en) * 1988-12-16 1990-06-05 Ran Free Microwave-heatable hot pad
US4914717A (en) * 1989-02-13 1990-04-03 Jmk International, Inc. Microwave actuable heating pad and method
US5070223A (en) * 1989-03-01 1991-12-03 Colasante David A Microwave reheatable clothing and toys
US5155319A (en) * 1991-01-17 1992-10-13 Chiu Sou Kuein Heat-conducting film for absorbing electromagnetic wave and microwave energy

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9247848B2 (en) 2007-11-21 2016-02-02 Mastrad, S.A. Temperature-retaining device

Also Published As

Publication number Publication date
GB9301102D0 (en) 1993-03-10
GB2274567A (en) 1994-07-27
AU5704994A (en) 1994-08-15

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