GB2147777A - Electrical heaters - Google Patents
Electrical heaters Download PDFInfo
- Publication number
- GB2147777A GB2147777A GB08423976A GB8423976A GB2147777A GB 2147777 A GB2147777 A GB 2147777A GB 08423976 A GB08423976 A GB 08423976A GB 8423976 A GB8423976 A GB 8423976A GB 2147777 A GB2147777 A GB 2147777A
- Authority
- GB
- United Kingdom
- Prior art keywords
- heater
- incorporating
- electrical
- electric
- electric heater
- Prior art date
- Legal status (The legal status 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 status listed.)
- Withdrawn
Links
- 229910052751 metal Inorganic materials 0.000 claims abstract description 32
- 239000002184 metal Substances 0.000 claims abstract description 32
- 239000000758 substrate Substances 0.000 claims abstract description 19
- 238000005524 ceramic coating Methods 0.000 claims abstract description 16
- 238000010438 heat treatment Methods 0.000 claims abstract description 5
- 210000003298 dental enamel Anatomy 0.000 claims description 19
- 239000000463 material Substances 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- FUJCRWPEOMXPAD-UHFFFAOYSA-N Li2O Inorganic materials [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 claims description 3
- KKCBUQHMOMHUOY-UHFFFAOYSA-N Na2O Inorganic materials [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 claims description 3
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 claims description 3
- 229910002113 barium titanate Inorganic materials 0.000 claims description 3
- 238000000151 deposition Methods 0.000 claims description 3
- 230000008021 deposition Effects 0.000 claims description 3
- XUCJHNOBJLKZNU-UHFFFAOYSA-M dilithium;hydroxide Chemical compound [Li+].[Li+].[OH-] XUCJHNOBJLKZNU-UHFFFAOYSA-M 0.000 claims description 3
- 239000011888 foil Substances 0.000 claims description 3
- 238000005507 spraying Methods 0.000 claims description 3
- 238000004544 sputter deposition Methods 0.000 claims description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 2
- 239000004411 aluminium Substances 0.000 claims description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical group [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 2
- 229910052782 aluminium Inorganic materials 0.000 claims description 2
- 229910052799 carbon Inorganic materials 0.000 claims description 2
- 239000010949 copper Substances 0.000 claims description 2
- 229910052802 copper Inorganic materials 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 238000007639 printing Methods 0.000 claims description 2
- 239000007788 liquid Substances 0.000 claims 2
- 229910000838 Al alloy Inorganic materials 0.000 claims 1
- 229910000881 Cu alloy Inorganic materials 0.000 claims 1
- 238000007750 plasma spraying Methods 0.000 abstract description 2
- 229910018404 Al2 O3 Inorganic materials 0.000 abstract 1
- 238000000034 method Methods 0.000 description 6
- 239000004020 conductor Substances 0.000 description 5
- 239000000919 ceramic Substances 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000000037 vitreous enamel Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000002730 additional effect Effects 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910000272 alkali metal oxide Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 235000000396 iron Nutrition 0.000 description 1
- 239000000615 nonconductor Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/10—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
Landscapes
- Resistance Heating (AREA)
Abstract
An electrical heater comprises a metal substrate having a ceramic coating deposited on one or both sides, preferably by plasma spraying Al2 O3, and an electrically conductive heating element deposited on the face of one of the ceramic coatings remote from the metal substrate.
Description
SPECIFICATION
Electrical heaters
This invention relates to electrical heaters, and is applicable particularly, but not exclusively, to domestic types of electrical heaters.
According to one aspect of the invention, there is provided an electrical heater including a metal substrate, a ceramic coating deposited on the metal substrate and an electrically conductive heating element deposited on the face of the ceramic coating remote from the metal substrate.
Conveniently the element is deposited by vapour deposition, metal spraying, sputtering, printing, electroplating or as a foil.
Preferably the ceramic coating is selected to have a high electrical resistance at high temperatures. For this purpose it may have a relatively low content of Li2O or Na2O.
According to another aspect of the invention such an electrical heater may be incorporated into a water heater, kettle, oil heater, deep fryer, space heater, radiator, building panel, electric iron, oven or hot plate.
The invention is described hereafter, by way of example only. A suitable metal substrate, which could be a casting but is preferably in wrought form such as in sheet form, and of an appropriate grade of steel, copper or aluminium and their alloys is prepared, in known manner, to receive a coating of a ceramic, such as a vitreous enamel.
The composition of the metal substrate may be chosen to be satisfactory for forming into the final product and also for adhesion of the required ceramic. The compatibility of the metal and the ceramic and the required surface treatment of the metal will be well known to those versed in the art of vitreous enamelling.
One or more coats of vitreous enamel are then applied to the metal substrate and fused using known enamelling techniques. For some applications both sides of the substrate will be enamelled and different grades of enamel may be used on opposite sides to satisfy the different functional needs of those sides. For example, on one side of the metal the enamel may serve only to protect the metal from corrosion, whereas on the other side the enamel may need the different or additional property of being an electrical insulator at high temperatures, for reasons explained below.
On selected areas of the enamel an electrical element is then deposited and fixed by an appropriate method. The materials of suitable electrical conductors for the element and the methods of their application may be already well known in themselves. For example, an ink of the type used for thick-film electronic circuits may be screen printed onto the enamel. A typical ink is a mixture of a metal powder such as silver and frit, which fuses when heated to bond to the enamel surface. Similar techniques are used for applying heating elements to vehicle windscreens. Alternative conductors may be carbon, metal foils, or semiconductors and deposition may be by sputtering, metal spraying or the like or by evaporation and condensation of the metal or other conductor material.
The conductor shape may be developed by additive or subtractive methods.
For some embodiments if may be advantageous to use a conductor material of higher resistivity than relatively pure metal, so that a thick and hence more robust element may be used.
Clearly, the element must be adequately insulated electrically from the metal substrate. Thus the enamel must be substantially free from pin holes which may reduce the dielectric strength of the insulating enamel. Furthermore it has been found that certain vitreous enamels have lower electrical resistivity at temperatures above ambient. Thus the enamel must be chosen to satisfy the requirements of porosity, resistivity and cost. Multiple coats of the same or different types of enamel may be needed to achieve those requirements.
For some low temperature applications conventional vitreous enamels will be satisfactory. However, such enamels have been found to conduct electricity unacceptably at temperatures above about 130 C. Such temperatures could be reached in the enamel in a water heater where one side of the heater is in intimate contact with the water, for example, where the metal forms part of the wall or base of a kettle. For such purposes an enamel having low content of alkali oxides and especially Li2O and Na2O has been found preferable.
Heaters using ceramic coatings suitable for operating temperatures up to 500 may be incorporated into a wide range of devices such as immersion heaters, kettles and water heaters, fryers, slow cookers, electric radiators, wall, ceiling or floor panels, ovens, toasters, grills, hot plates, hair curlers, irons, trouser presses, engine sump heaters, de-icers, fan heaters and so on.
Where the heater is used to heat water and the element is on the water side of the metal substrate, or in other applications where insulation or protection of the element is needed, a further coating of a suitable enamel or other protective material may be applied over the element.
The opposite side of the metal substrate from the element may be protected by a ceramic coating.
The enamels used are preferably of a devitrifying type which tend to be more stable at high temperatures.
In place of vitreous enamels it may be advantageous for some applications, especially for high temperature work, to use other appropriate ceramics, such as a plasma sprayed coating of Al2 or 02.
Furthermore, the process described above enables the use of materials for the element in which the electrical resistivity increases with increasing temperature, thereby providing a self-regulating form of heater. One such material is barium titanate which can be ground into a powder, mixed with a frit, applied in the required pattern and then fused by heat. Alternatively, the barium titanate may be applied by plasma spraying.
Claims (34)
1. An electrical heater including a metal substrate, a ceramic coating deposited on the metal substrate and an electrically conductive heating element deposited on the face of the ceramic coating remote from the metal substrate.
2. An electrical heater, according to Claim 1, in which the element is deposited by vapour deposition, metal spraying, sputtering, printing or as a foil.
3. An electrical heater, according to Claim 1 or 2, in which the ceramic coating is selected to have a high electrical resistance at high temperatures.
4. An electrical heater, according to any of
Claims 1 to 3, in which the ceramic coating has a relatively low content of Li2O or Na2O.
5. An electrical heater according to any of
Claims 1 to 4 in which the ceramic coating is a plasma sprayed ceramic coating.
6. An electrical heater, according to any of
Claims 1 to 5 in which the ceramic coating is largely or entirely Al2 Oa.
7. An electrical heater, according to any of
Claims 1 to 4, in which the ceramic coating is a devitrifying enamel.
8. An electrical heater, according to any of
Claims 1 to 7, in which the metal is cast metal.
9. An electrical heater, according to any of
Claims 1 to 8, in which the metal substrate is copper or copper alloy.
10. An electrical heater, according to any of
Claims 1 to 8, in which the metal substrate is aluminium or aluminium alloy.
11. An electrical heater, according to any preceding Claim, in which the element includes or is composed of a material of which the electrical resistivity increases with increasing temperature.
12. An electrical heater, according to Claim 11 in which the material is barium titanate.
13. An electrical heater, according to any of
Claims 1 to 10 in which the element includes or is composed of carbon.
14. An electrical heater, according to any preceding Claims, in which the face of the metal substrate remote from the heating element is also protected by a ceramic coating.
15. A liquid heater, according to any preceding
Claim, in which the conductive element is on the liquid side of the metal substrate.
16. A water heater incorporating an electrical heater according to any of Claims 1 to 14.
17. An electric kettle incorporating an electric heater according to any of Claims 1 to 14.
18. An oil heater incorporating an electric heater according to any of Claims 1 to 14.
19. A space heater incorporating an electric heater according to any of Claims 1 to 14.
20. A radiator incorporating an electric heater according to any of Claims 1 to 14.
21. A building panel incorporating an electric heater according to any of Claims 1 to 14.
22. An electric iron incorporating an electric heater according to any of Claims 1 to 14.
23. An electric oven incorporating an electric heater according to any of Claims 1 to 14.
24. An electric hot plate incorporating an electric heater according to any of Claims 1 to 14.
25. A fryer incorporating an electric heater according to any of Claims 1 to 14.
26. A slow cooker incorporating an electric heater according to any of Claims 1 to 14.
27. A toaster incorporating an electric heater according to any of Claims 1 to 14.
28. A grill incorporating an electric heater according to any of Claims 1 to 14.
29. A hair curler incorporating an electric heater according to any of Claims 1 to 14.
30. A trouser press incorporating an electric heater according to any of Claims 1 to 14.
31. An engine sump heater incorporating an electric heater according to any of Claims 1 to 14.
32. A de-icer incorporating an electric heater according to any of Claims 1 to 14.
33. A fan heater incorporating an electric heater according to any of Claims 1 to 14.
34. An electrical heater constructed and arranged and adapted to operate substantially as described
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB838326122A GB8326122D0 (en) | 1983-09-29 | 1983-09-29 | Electrical heaters |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8423976D0 GB8423976D0 (en) | 1984-10-31 |
| GB2147777A true GB2147777A (en) | 1985-05-15 |
Family
ID=10549478
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB838326122A Pending GB8326122D0 (en) | 1983-09-29 | 1983-09-29 | Electrical heaters |
| GB08423976A Withdrawn GB2147777A (en) | 1983-09-29 | 1984-09-21 | Electrical heaters |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB838326122A Pending GB8326122D0 (en) | 1983-09-29 | 1983-09-29 | Electrical heaters |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB8326122D0 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1986006241A1 (en) * | 1985-04-15 | 1986-10-23 | Email Limited | Heating element |
| US4808490A (en) * | 1983-12-28 | 1989-02-28 | Hitachi Metals, Ltd. | Plasma sprayed film resistor heater |
| GB2253551A (en) * | 1991-03-05 | 1992-09-09 | Electrolux Cookers | Heating element in cooking vessel wall |
| EP0772954A1 (en) * | 1994-07-29 | 1997-05-14 | Thermal Dynamics U.S.A., Ltd. Co. | Resistance heating element with large-area, thin film and method |
| US6370327B1 (en) * | 1999-07-21 | 2002-04-09 | Aerospatiale Matra Missiles | Emitter of infrared radiation in band III and composite allowing the emission of such radiation |
| WO2006101498A1 (en) * | 2005-03-18 | 2006-09-28 | Powerpulse Technologies, L.P. | Cutaneous heating element |
| CN104525460A (en) * | 2014-12-16 | 2015-04-22 | 刘桂芹 | Surface treatment method for smoke-free electric heating wire of cutting machine |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB743322A (en) * | 1949-10-04 | 1956-01-11 | Wmf Wuerttemberg Metallwaren | Electrically-heated appliance, in particular a vessel for cooking, roasting or baking |
-
1983
- 1983-09-29 GB GB838326122A patent/GB8326122D0/en active Pending
-
1984
- 1984-09-21 GB GB08423976A patent/GB2147777A/en not_active Withdrawn
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB743322A (en) * | 1949-10-04 | 1956-01-11 | Wmf Wuerttemberg Metallwaren | Electrically-heated appliance, in particular a vessel for cooking, roasting or baking |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4808490A (en) * | 1983-12-28 | 1989-02-28 | Hitachi Metals, Ltd. | Plasma sprayed film resistor heater |
| WO1986006241A1 (en) * | 1985-04-15 | 1986-10-23 | Email Limited | Heating element |
| GB2253551A (en) * | 1991-03-05 | 1992-09-09 | Electrolux Cookers | Heating element in cooking vessel wall |
| EP0772954A1 (en) * | 1994-07-29 | 1997-05-14 | Thermal Dynamics U.S.A., Ltd. Co. | Resistance heating element with large-area, thin film and method |
| EP0772954A4 (en) * | 1994-07-29 | 1998-10-14 | Thermal Dynamics U S A Ltd Co | Resistance heating element with large-area, thin film and method |
| US6370327B1 (en) * | 1999-07-21 | 2002-04-09 | Aerospatiale Matra Missiles | Emitter of infrared radiation in band III and composite allowing the emission of such radiation |
| WO2006101498A1 (en) * | 2005-03-18 | 2006-09-28 | Powerpulse Technologies, L.P. | Cutaneous heating element |
| CN104525460A (en) * | 2014-12-16 | 2015-04-22 | 刘桂芹 | Surface treatment method for smoke-free electric heating wire of cutting machine |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8423976D0 (en) | 1984-10-31 |
| GB8326122D0 (en) | 1983-11-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4587402A (en) | Planar heating unit | |
| US6736997B2 (en) | Sol-gel derived resistive and conductive coating | |
| JP3929068B2 (en) | Resistance heating element with large area thin film | |
| US6118102A (en) | Immersion heating element sandwiched between two substrates | |
| JP2661994B2 (en) | Glass-ceramic heating element and method of manufacturing the same | |
| FI87964B (en) | UPPVAERMNINGSELEMENT OCH UPPVAERMNINGSENHET | |
| US5888429A (en) | Method for providing high temperature conductive-resistant coating, medium and articles | |
| US3679473A (en) | Method of making a heating element | |
| JPH11514792A (en) | Heating element | |
| US9493906B2 (en) | Thin-film heating element | |
| US5940579A (en) | Capacitive leakage current cancellation for heating panel | |
| JPS6344792A (en) | Electric parts and manufacture of the same | |
| GB2147777A (en) | Electrical heaters | |
| US5679273A (en) | Cooktop having a flat surface, suitable for flush-mounting | |
| EP0967838B1 (en) | Thin film heating assemblies | |
| JPS6325465B2 (en) | ||
| US5718946A (en) | Induction heating substrate for ceramic or vitreous ceramic receptacles | |
| DE19817194A1 (en) | Cooking plate with electrically conductive ceramic plate | |
| JP2857408B2 (en) | Insulation or heating plate | |
| JPS54112981A (en) | Article having self-cleaning coat | |
| JPS6129090A (en) | Article having panel heater | |
| JP2943248B2 (en) | Planar heating element | |
| RU1787429C (en) | Electric liquid-heating device | |
| JPS6259428B2 (en) | ||
| JPS62150685A (en) | Manufacture of panel heater |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |