WO1994023549A2 - Electrical heater - Google Patents
Electrical heater Download PDFInfo
- Publication number
- WO1994023549A2 WO1994023549A2 PCT/EP1994/000987 EP9400987W WO9423549A2 WO 1994023549 A2 WO1994023549 A2 WO 1994023549A2 EP 9400987 W EP9400987 W EP 9400987W WO 9423549 A2 WO9423549 A2 WO 9423549A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- electrical
- tube
- previous
- heaters
- liquid
- Prior art date
Links
- 239000000463 material Substances 0.000 claims abstract description 19
- 239000007788 liquid Substances 0.000 claims abstract description 9
- 238000010438 heat treatment Methods 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 229920003023 plastic Polymers 0.000 claims description 3
- 239000004033 plastic Substances 0.000 claims description 3
- 229910000831 Steel Inorganic materials 0.000 claims description 2
- 239000000919 ceramic Substances 0.000 claims description 2
- 238000004140 cleaning Methods 0.000 claims description 2
- 239000010959 steel Substances 0.000 claims description 2
- 239000000126 substance Substances 0.000 claims description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims 1
- 239000000956 alloy Substances 0.000 claims 1
- 229910045601 alloy Inorganic materials 0.000 claims 1
- 230000000694 effects Effects 0.000 claims 1
- 229910021645 metal ion Inorganic materials 0.000 claims 1
- 150000002739 metals Chemical class 0.000 claims 1
- 230000000063 preceeding effect Effects 0.000 claims 1
- 230000001105 regulatory effect Effects 0.000 claims 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims 1
- 229910010271 silicon carbide Inorganic materials 0.000 claims 1
- 238000009413 insulation Methods 0.000 abstract description 2
- 239000012530 fluid Substances 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 238000010276 construction Methods 0.000 description 2
- 238000010411 cooking Methods 0.000 description 2
- 229910052755 nonmetal Inorganic materials 0.000 description 2
- 239000003921 oil Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- VVNCNSJFMMFHPL-VKHMYHEASA-N D-penicillamine Chemical compound CC(C)(S)[C@@H](N)C(O)=O VVNCNSJFMMFHPL-VKHMYHEASA-N 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 229940075911 depen Drugs 0.000 description 1
- 230000002500 effect on skin Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
- H05B3/40—Heating elements having the shape of rods or tubes
- H05B3/42—Heating elements having the shape of rods or tubes non-flexible
-
- 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
- H05B3/12—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material
- H05B3/14—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material the material being non-metallic
-
- 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
- H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
- H05B2203/021—Heaters specially adapted for heating liquids
Definitions
- a resistance material from a conducting metal in form of wires is wound in or on insulating basements. These basements are usually contained in tubelike heat exchangers. These heat exchangers ar to be immersed into a medium which is contained in a vessel. There the heat exchanger conducts thermal energy into the medium.
- Different equipements are heating plates of a kitchen oven where the insulating base ⁇ ment is below a metal or glass plate through which the ther- mal energy from the resistance wires is sent to a pot con ⁇ taining a medium or the like.
- the pot has here the function of a heat exchanger.
- a heater should be found which reduces energy loss on the path of the thermal energy from its source to a medium.
- the tempera- ture of the heat source should be almost the same as the temperature on the surface of a known heat exchanger.
- the main points are:
- heater units as described above which are deposited into the medium inside the tube or heating elements attached to the outer side of the tube are used.
- heaters immersed in the medium need a relative big surface and in this connection a big area. Expensive and special materials are needed.
- Heaters installed on the outer surface of the tube need to produce relatively high temperatures, because of the insula ⁇ tion basement mounted between the heat source and the tube. A great loss of heat results (inefficiency) .
- This invention proposes the solution by using known mate ⁇ rials and technologies in a way, that has essential advanta ⁇ ges in relation to conventional heaters and solutions, and that is for example:
- the inventive heater is in direct connection with the medium that is to be warmed up, and also has the func ⁇ tion to carry or to disconnect the medium from the surroun- ding.
- Conventional heaters, installed outside the medium, have in comparison a big loss of heat.
- the inventive heater is on one side connected directly with the medium, and on the other side in direct contact with the energy source (electrical connection) , while conventional heaters installed inside the medium need a lot of space for insulation . They show difficult and inconvenient constructive interventions for electrical energy connecting.
- Figure 1 shows a tube-like heater consisting of metal (e.g. alloyed steel) or non metal (e.g. ceramic, silicon or con- ductively doped plastic) tubes, of suitable thickness and length - depending on specific electric resistance of its material (e.g. with a specific electrical resistance of 10 " 4 to 1 Ohmmeter) .
- metal e.g. alloyed steel
- non metal e.g. ceramic, silicon or con- ductively doped plastic
- Figure 2 shows a similar construction as in Fig.l, but with stretched surface, in which the slab-like heater is received.
- Figure 3 shows a tube-like exchanger rolled into a spiral on outside part the entrance for the cold medium, so that los ⁇ ses of the heat, on the exit of hot medium from the tube, are warming up outside spiral, the reason why the loss of heat is almost zero.
- the tube can be additionally insulated with a material of good thermal insulating characteristics and of great electrical insulating hardness.
- Figure 4 shows an inventive heater tube-like or slab-like, connected over a suitable transformer or electronic device such as a voltage regulator, by which a better relation bet ⁇ ween the characteristic and the dimensions of the heater material is achievable.
- the transformer and/or the electro- nic device may protect from too high touch voltage.
- Figure 5 shows several tube-like heatexchangermodules of Fig.3 connected in serial.
- Figure 6 shows an additional device for dosing a cleaning substance against unwanted coatings or the like on the inner wall of the tube-like heater.
- Tube-like heat exchangers are sometimes immersed into liquid as electrical tube-like heaters around which the liquid may circulate.
- the basic problem with all these known heaters is the loss of thermal energy which occurs when thermal energy on its way to warm up a medium passes materials with bad thermal conductive properties.
- the invention provides a tube or slab made of metal or semi- conductive non-metal of suitable length, shape and volume, connectable to an electrical energy source, directly with complete width of a given surface, whereby the electric energy circulation through the whole volume of heat exchan ⁇ ger is obtained, and realized thermal energy directly trans- fered over the whole surface to the medium (fluid) to be heated up.
- the complete thermal energy is transfered into the medium with a minimum of energy losses, relatively to minimum losses from emittation.
- the inventive heaters can be used with better effi ⁇ ciency.
- the most effective way of using the inventive heaters is in lower power devices, particulary in those that use lower voltage.
- Tube-like exchangers would be especially usefull with: -rapid water heaters in households, public baths, or the like;
- the invention can be connected to any level voltage, depen ⁇ ding on material dimension and characteristic.
- the normal power from the mains (220/380V) can be used directly, but as a rule for other heat exchangers low voltage or some known separation systems from the mains (transformers) can be used.
- the heat exchangers material as well as its dimensions, are the results of in-out parameters (requirements) i.e. mate ⁇ rial will be chosen depending on:
- Electrical heater comprising a resistance-heater connectable to an electrical energy source, and a body carrying the object or guiding the medium to be heated respectively, characterized in that the carrying respectively power leading body is the resistance- heatele ent itself.
- Electrical heating unit characte ⁇ rized in that the body connectable to an electrical energy source consists of a material, preferably semicon ⁇ ducting material with a specific electrical resistance of 10 " to 1 Ohmmeter.
Landscapes
- Resistance Heating (AREA)
- Pipe Accessories (AREA)
Abstract
Conventional electrical heaters, tube- or plate-like, change electric energy into thermal energy and transmit it from wires or some other materials supported on an insulation basement to a heat exchanger (in many cases also through insulating air). Tube-like heat exchangers are sometimes immersed into liquid as electrical tube-like heaters around which the liquid may circulate. The basic problem with all these known heaters is the loss of thermal energy which occurs when thermal energy on its way to warm up a medium passes materials with bad thermal conductive properties. This problem is avoided with the invention.
Description
Electrical Heater Description of the Invention:
Field of Technology: IPC H05B 3/14, Electrical Resistance
Heaters
«
Technical Problem:
Conventional electrical heaters, tube- or slab-like resis¬ tance heaters use electric energy and convert it into ther- " mal energy. A resistance material from a conducting metal in form of wires is wound in or on insulating basements. These basements are usually contained in tubelike heat exchangers. These heat exchangers ar to be immersed into a medium which is contained in a vessel. There the heat exchanger conducts thermal energy into the medium. Different equipements are heating plates of a kitchen oven where the insulating base¬ ment is below a metal or glass plate through which the ther- mal energy from the resistance wires is sent to a pot con¬ taining a medium or the like. The pot has here the function of a heat exchanger.
These technical constructions of the above mentioned and known heaters lead to the following basic problem: Thermal energy on its way to warm up a medium (fluid e.g.) must pass from the resistor through materials which have different - and in many cases bad - thermal conductivity. Therefore energy is lost and a low degree of heat level on the surface between the heatexchanger and the medium is achieved.
To solve this problem is the aim of this invention. A heater should be found which reduces energy loss on the path of the thermal energy from its source to a medium. And the tempera- ture of the heat source (resistance wire or the like) should be almost the same as the temperature on the surface of a known heat exchanger.
The solution of the mentioned technical problem is achieved if the heater is built according to the invention disclosed later in the specification and in the claims.
The main points are:
a) bring then thermal energy source in direct contact with the medium which should be warmed up.
b) make the surface which connects the thermal energy source with the medium as big as possible but do not increase the total size of the heater over certain limits.
Existing heaters cannot fulfill these main requirements, or they need too much area or space.
State of Technology:
In all electrical tube-like heaters of fluids, for example Durchlauferhitzer, for heating up a medium which flows through the heater, heater units as described above which are deposited into the medium inside the tube or heating elements attached to the outer side of the tube are used.
To transfer thermal energy well, quickly and not disturbed, heaters immersed in the medium need a relative big surface and in this connection a big area. Expensive and special materials are needed.
Heaters installed on the outer surface of the tube need to produce relatively high temperatures, because of the insula¬ tion basement mounted between the heat source and the tube. A great loss of heat results (inefficiency) .
For heaters with good energy saving a great deal of research has been done in the past.
Until nowadays no heater is known with the properties of the invention. Heat exchangers tube- or slab-like directly connecteα to a suitable elctro-energy source, are not known.
Description of the Solution of the Technical Problem:
This invention proposes the solution by using known mate¬ rials and technologies in a way, that has essential advanta¬ ges in relation to conventional heaters and solutions, and that is for example:
1) The inventive heater is in direct connection with the medium that is to be warmed up, and also has the func¬ tion to carry or to disconnect the medium from the surroun- ding. Conventional heaters, installed outside the medium, have in comparison a big loss of heat.
2) The inventive heater is on one side connected directly with the medium, and on the other side in direct contact with the energy source (electrical connection) , while conventional heaters installed inside the medium need a lot of space for insulation . They show difficult and inconvenient constructive interventions for electrical energy connecting.
Figure 1 shows a tube-like heater consisting of metal (e.g. alloyed steel) or non metal (e.g. ceramic, silicon or con- ductively doped plastic) tubes, of suitable thickness and length - depending on specific electric resistance of its material ( e.g. with a specific electrical resistance of 10" 4 to 1 Ohmmeter) .
Figure 2 shows a similar construction as in Fig.l, but with stretched surface, in which the slab-like heater is received.
Figure 3 shows a tube-like exchanger rolled into a spiral on outside part the entrance for the cold medium, so that los¬ ses of the heat, on the exit of hot medium from the tube, are warming up outside spiral, the reason why the loss of heat is almost zero. The tube can be additionally insulated with a material of good thermal insulating characteristics and of great electrical insulating hardness.
Figure 4 shows an inventive heater tube-like or slab-like, connected over a suitable transformer or electronic device such as a voltage regulator, by which a better relation bet¬ ween the characteristic and the dimensions of the heater material is achievable. The transformer and/or the electro- nic device may protect from too high touch voltage.
Figure 5 shows several tube-like heatexchangermodules of Fig.3 connected in serial.
Figure 6 shows an additional device for dosing a cleaning substance against unwanted coatings or the like on the inner wall of the tube-like heater.
More details are described in the claims.
Brief:
Conventional electrical heaters, tube- or plate-like, change electric energy into thermal energy an transmit it from wires or some other materials supported on an insula¬ tion basement to a heat exchanger (in many cases also through insulating air) .
Tube-like heat exchangers are sometimes immersed into liquid as electrical tube-like heaters around which the liquid may circulate.
The basic problem with all these known heaters is the loss of thermal energy which occurs when thermal energy on its way to warm up a medium passes materials with bad thermal conductive properties.
The invention provides a tube or slab made of metal or semi- conductive non-metal of suitable length, shape and volume, connectable to an electrical energy source, directly with complete width of a given surface, whereby the electric energy circulation through the whole volume of heat exchan¬ ger is obtained, and realized thermal energy directly trans- fered over the whole surface to the medium (fluid) to be heated up.
With a sufficient small thickness of the heater (heat exchanger respectively) , the complete thermal energy is transfered into the medium with a minimum of energy losses, relatively to minimum losses from emittation.
The best way of Economic use of the Invention:
Economic use in many devices of electric heat exchangers (tube- or slab-like) is easy also for a man skilled in the art of known heaters.
Almost everywhere, where fluids are warmed up using electric energy, the inventive heaters can be used with better effi¬ ciency. The most effective way of using the inventive heaters is in lower power devices, particulary in those that use lower voltage.
Tube-like exchangers would be especially usefull with:
-rapid water heaters in households, public baths, or the like;
-free flow oil heaters in machines, oil industry, on ships, or the like;
-free flow heaters in household devices like washing machines for clothes and dishes;
-slab-like heaters in household devices like washing machines, cooking or grilling devices;
-heaters in ovens and cooking surfaces for the household;
-heaters in pots with integrated electrical heater;
■heaters in water- or oil-radiators;
The invention can be connected to any level voltage, depen¬ ding on material dimension and characteristic.
The most suitable is direct voltage, but alternate voltage can be used only with lower frequencies (up to 150Hz or to 150kHz) , because with higher skin effect (by tube like exchangers) the heat is produced on the outer side of the tube and that is quite opposite to the intention of the invention.
In closed systems (where the heater cannot be touched by tubes through which the medium is circulated) or in systems, where the medium is an insulator, the normal power from the mains (220/380V) can be used directly, but as a rule for other heat exchangers low voltage or some known separation systems from the mains (transformers) can be used.
The heat exchangers material as well as its dimensions, are the results of in-out parameters (requirements) i.e. mate¬ rial will be chosen depending on:
a) corrosion of the medium b) quickness of flowing through c) pressure d) necessary temperature as follows : lower limit upper limit t (K)
Dimensions of the heater will depend on:
a) specific electric resistance of material b) hardness of material and pressure c) quickness of medium flow through and necessary temperature (t) d) coefficient of heat spreading e) coefficient of heat transfer on medium and in medium f) form of the exchanger.
Claims
1. Electrical heater comprising a resistance-heater connectable to an electrical energy source, and a body carrying the object or guiding the medium to be heated respectively, characterized in that the carrying respectively power leading body is the resistance- heatele ent itself.
2. Electrical heating unit according to claim 1 characte¬ rized in that the body connectable to an electrical energy source consists of a material, preferably semicon¬ ducting material with a specific electrical resistance of 10" to 1 Ohmmeter.
Claims
3. Electrical heating unit according to claim 2, characte¬ rized in that the body consists of siliconcarbide or of highquality-plastic doted with carbon-, graphite- or metal-ions.
4. Electrical heating unit according to any of the pre¬ vious claims, characterized in that the body has the form of a tube preferably with a heat isolating coat on this side of the tube which is opposite the side which bears a heat exchanging surface.
5. Electrical heating unit according to any of the pre¬ vious claims, characterized in that the heating part is coated at least partially with a heat-leading but electrically insulating coat.
6. Cooking-plate (hot plate) consisting of a body according to any of the previous claims.
7. Tube-like shaped electrical heater with a hollow body through which a medium may flow or in which a medium may be contained, bearing a heat exchanging surface, electri¬ cal contacts to be connected to an electrical source and an electrical resistance material between those contacts, characterized in that said contacts are electrically connected with said body and that said body is as a whole made of said electrically resistance material which is chosen of the group of metals, alloys of steel, se icon- ductors, graphits, electrically conducting or semiconduc¬ ting ceramics and plastics.
8. Electrical heater according to claim 7,characterized in that the body is flat so that said heat exchanging surface is slab like.
9. Electrical heater with an entrance and an exit for a liquid according to any of the previous claims, characte¬ rized in that the body is spirally wound and that the
entrance for said liquid is on the outer side of said spiral whereby the exit is on its inner side.
10. Electrical heater according to any of the previous claims, characterized in that the contacts are connected to a secondary coil of a transformer or to an output of an elctronic voltage regulating device, whereby the out¬ put of said transformer and the output of said electronic device are related to the dimensions and specifications of said material of said body in order to avoid too high touch voltage.
11. Electrical heater according to any of the previous claims, characterized in that it is divided into at least two mechanically coupled units of heaters with the fea¬ tures of any of the preceeding claims whereby the con- tacts of said units are connected in serial or parallel whereby in the later case the contacts are separatly connectable to the electric source.
12. Electrical heater with a tube shaped body according to any of the previous claims, characterized in that at its entrance for a liquid to be heated means for dosing a cleaning substance into said liquid or on said heat exchanger surface are arranged.
13. Tube-like electrical heater according to any of the previous claims connected to an entrance and and exit of a vessel characterized in that the heater is mounted in such a way that when it is supplied with electrical energy liquid coming from the vessels exit will climb along the heatexchanger surface according to the thermo- siphone effect and will enter the vessels entrance.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| HRP930576 HRP930576A2 (en) | 1993-03-29 | 1993-03-29 | Electric heat exchanger |
| HRP930576A | 1993-03-29 | ||
| CH2083/93-2 | 1993-07-12 | ||
| CH208393A CH688328A5 (en) | 1993-07-12 | 1993-07-12 | Electrical heating. |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| WO1994023549A2 true WO1994023549A2 (en) | 1994-10-13 |
| WO1994023549A3 WO1994023549A3 (en) | 1994-12-08 |
Family
ID=25689464
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP1994/000987 WO1994023549A2 (en) | 1993-03-29 | 1994-03-29 | Electrical heater |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO1994023549A2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2299005A (en) * | 1995-03-17 | 1996-09-18 | Draegerwerk Ag | Vaporising liquids |
| WO2008081123A1 (en) * | 2006-12-21 | 2008-07-10 | Revtech | Method for the thermal treatment of powdery materials |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH138805A (en) * | 1926-04-28 | 1930-03-31 | Max Dr Hauser | Electrical resistance body and method of making the same. |
| US2371275A (en) * | 1945-03-13 | heating element | ||
| US3309643A (en) * | 1964-01-02 | 1967-03-14 | Massachusetts Inst Technology | Electric heating element |
| DE1239416B (en) * | 1960-04-26 | 1967-04-27 | Siemens Electrogeraete Ges Mit | Electric instantaneous water heater with ceramic heating resistor |
| DE2049977A1 (en) * | 1970-10-12 | 1972-04-20 | Danfoss As | High temp electrical resistance - based on aluminium oxycarbide for stability and thermal shock resistance |
| FR2167267A1 (en) * | 1972-01-11 | 1973-08-24 | Klima Technik | Resistance compsn - for heating panels eg in muffles baking ovens and cooking appliances |
| FR2197295A1 (en) * | 1972-08-25 | 1974-03-22 | Bailey Barbara | |
| DE2347766A1 (en) * | 1972-09-22 | 1974-03-28 | Inventum Koninklijke Fab | HEATING ELEMENT |
| US4384192A (en) * | 1981-03-02 | 1983-05-17 | Teledyne Still-Man Manufacturing | Electric heating element |
| WO1991001617A1 (en) * | 1989-07-18 | 1991-02-07 | Matsusita Electric Works, Ltd. | Heat generating member |
-
1994
- 1994-03-29 WO PCT/EP1994/000987 patent/WO1994023549A2/en active Application Filing
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2371275A (en) * | 1945-03-13 | heating element | ||
| CH138805A (en) * | 1926-04-28 | 1930-03-31 | Max Dr Hauser | Electrical resistance body and method of making the same. |
| DE1239416B (en) * | 1960-04-26 | 1967-04-27 | Siemens Electrogeraete Ges Mit | Electric instantaneous water heater with ceramic heating resistor |
| US3309643A (en) * | 1964-01-02 | 1967-03-14 | Massachusetts Inst Technology | Electric heating element |
| DE2049977A1 (en) * | 1970-10-12 | 1972-04-20 | Danfoss As | High temp electrical resistance - based on aluminium oxycarbide for stability and thermal shock resistance |
| FR2167267A1 (en) * | 1972-01-11 | 1973-08-24 | Klima Technik | Resistance compsn - for heating panels eg in muffles baking ovens and cooking appliances |
| FR2197295A1 (en) * | 1972-08-25 | 1974-03-22 | Bailey Barbara | |
| DE2347766A1 (en) * | 1972-09-22 | 1974-03-28 | Inventum Koninklijke Fab | HEATING ELEMENT |
| US4384192A (en) * | 1981-03-02 | 1983-05-17 | Teledyne Still-Man Manufacturing | Electric heating element |
| WO1991001617A1 (en) * | 1989-07-18 | 1991-02-07 | Matsusita Electric Works, Ltd. | Heat generating member |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2299005A (en) * | 1995-03-17 | 1996-09-18 | Draegerwerk Ag | Vaporising liquids |
| GB2299005B (en) * | 1995-03-17 | 1999-04-14 | Draegerwerk Ag | Electrically-heated heat exchanger |
| WO2008081123A1 (en) * | 2006-12-21 | 2008-07-10 | Revtech | Method for the thermal treatment of powdery materials |
Also Published As
| Publication number | Publication date |
|---|---|
| WO1994023549A3 (en) | 1994-12-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2745438B2 (en) | Heat transfer material and heating element for heating and heating device using the same | |
| EP2186380B1 (en) | Electric heater | |
| WO2007091749A1 (en) | Induction heating element for electric hot air heater and electric heater using the same | |
| WO2011005684A1 (en) | Non-metal electric heating system and method, and tankless water heater using the same | |
| KR0180211B1 (en) | Floor heater with water tube and thin copper electric heating element inserted therein | |
| US20040146289A1 (en) | Electric water heater, liquid heater, steam generator | |
| CN101025288A (en) | Electric water-heating device adopting electromagnetic heating technology | |
| CN112586996A (en) | Steam generation assembly and cooking device | |
| WO1994023549A2 (en) | Electrical heater | |
| CN205980339U (en) | Outer hot type water heater and watering device overflow | |
| JP2002005522A (en) | Rapid rise electric water heater | |
| IL145426A (en) | Electrical water heating device with large contact surface | |
| CN201875873U (en) | Electromagnetic instant-heating water heater | |
| JPH0668993B2 (en) | Low frequency electromagnetic induction heater | |
| CN201331187Y (en) | Liquid and gas heating device | |
| CN100491862C (en) | Skin effect electric water heater | |
| RU80218U1 (en) | FUEL HEATER | |
| RU223462U1 (en) | Coolant heating device | |
| CN2311910Y (en) | Ring double-side heating tube | |
| WO2018000497A1 (en) | Vapour generator and vapour device | |
| CN211744773U (en) | Energy-saving safe electric heating meal warm-keeping plate | |
| RU195772U1 (en) | Tank heater | |
| RU2392547C1 (en) | Fluid convective heater | |
| CN2193974Y (en) | Indirect heating type electric water heater | |
| CN2238515Y (en) | Electrothermal film universal heating plate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AK | Designated states |
Kind code of ref document: A2 Designated state(s): CA JP RU UA US |
|
| AL | Designated countries for regional patents |
Kind code of ref document: A2 Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE |
|
| AK | Designated states |
Kind code of ref document: A3 Designated state(s): CA JP RU UA US |
|
| AL | Designated countries for regional patents |
Kind code of ref document: A3 Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE |
|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
| 122 | Ep: pct application non-entry in european phase | ||
| NENP | Non-entry into the national phase in: |
Ref country code: CA |