WO1995022236A1

WO1995022236A1 - System for generating heat by electric current through conducting bodies of micrometric thickness but large in area

Info

Publication number: WO1995022236A1
Application number: PCT/IT1994/000039
Authority: WO
Inventors: Aldo Stabile
Original assignee: Adara Engineering
Priority date: 1994-02-15
Filing date: 1994-03-30
Publication date: 1995-08-17
Also published as: JPH09512944A; RU2126605C1; EP0745312A1; ITMI940268A0; CA2182954A1; ITMI940268A1; AU6688594A; IT1273308B

Abstract

System for generating heat by converting electric energy into thermal energy by passing electric current through conducting bodies (12, 16-18) of high conductivity, their thickness being measurable in microns and with a large ratio between width of the section and said thickness, said bodies being laid flat on their supports (11, 15) to create heat-emitting surfaces which not only heat but which diffuse as well.

Description

SYSTEM FOR GENERATING HEAT BY ELECTRIC CURRENT THROUGH CONDUCTING BODIES OF MICROMETRIC THICKNESS BUT LARGE IN AREA

Systems that use electricity for generating heat are in- numerable .

These systems are based on the use of materials of high resistivity which reach very high temperatures when elec¬ tric current is passed through them producing great concen¬ trations of heat. Such temperatures are nearly always very much eater than those required by what has to be heated, whether this is a room, an oven, a hotplate or something else. Heat must be diffused where the thermal head is so high and such diffusion requires means for the purpose which are both costly and complex. Wires carrying great heat need supporting materials of a special kind, such as cera¬ mics, difficult to produce and fragile when made, as well as complex structures for insulating and coating them. High temperatures also mean hard wear on such structures while efficiency is low compared with direct energy pro¬ duced by fuel. Resistive materials are costly and this too increases purchasing and running costs. The above invention shows how electric energy can be trans¬ formed into heat by means of simple and practical structures, inexpensive to produce and to run, as will be fully explained be low . The invented system is based on the use of extremely thin conducting bodies, whose thickness is measured in microns, compatible with their formation and with the resistance nee¬ ded to withstand stresses during use, there being a high ratio between the width of the cross section and said fine thick- ness .

Said conducting bod-ies are laid flat on their support, in lengths placed side by side but insulated one from another so as to obtain substantially continuous heat-emitting surfaces. The material used to make the conducting bodies is a highly conductive one, such as copper or aluminium.

The length is established according to temperatures and to the desired concentration or diffusion of heat. Strength of mains current can be intensified by transformers to increase the amount of heat generated. Due to minimum thickness of the conductors and consequently large area covered by the source of heat, said source of heat also acts as a diffuser drastically reducing the thermal head compared with the temperature required to make the heat¬ ing equipment function efficiently. As the case may require, conducting bodies can take the form of sheets, bands and the like, or be layers formed for elec¬ troplating or similar processes.

The conducting bodies are preferably placed serpent inewise or spirally on their means of support. The serpentine can^'ibe formed from a sheet in which parallel cuts are made alterna ingly in one edge or in the edge oppo¬ site. The spiral may be circular, square, rectangular or of some other shape.

Along the lengths of conducting bodies the cross section may remain constant or may differ according to the amount of heat and to the temperature to be reached in the various lengths. Variations in size may be gradual or sudden, con¬ tinuous or intermittent, as the particular case and prefer¬ ences may dictate. The conducting bodies may receive electric current at their ends or at intermediate points.

Values of current tljat supply the ends or intermediate points may be equal or different.

Variations in values may be gradual or sudden, continuous or intermittent as the particular case or preference may de- cide .

This system can be used for a vast number of applications. The heat-emitting surfaces can be placed around enclosed spa¬ ces in which temperatures higher than ambient temperatures are required for physical or chemical transformation of ma- terials, so creating static ovens.

In tunnel, ring-shaped or similarly shaped equipment, in in¬ stallations generally where material to be baked or treated passes through slowly, such as in impregnating systems, said heat-emitting surfaces can create the most suitable thermal radiations achieving optimum disclocations and intensities. The heat-emitting surfaces-can be placed on internal walls, including the bottom surface, of baths, tanks and the like in which fluid materials are poured for physical or chemical ransformations, such as electrolytic baths, or else placed on the flat parts of equipment and devices generally which must give off heat such as hotplates, or else inside vehicles in their side walls or on floors or roofs. Various alimentary items can be cooked or physically or chemically transformed by placing or creating said heat- -emitting surfaces on the inside walls or on the base of different types of cooking or frying pans or of suitable receptacles in general.

By associating the heat-emitting surfaces to panels and the like, fixed or mobile radiators, stoves and the like can be created for heating indoor rooms. The advantages of the invention are evident. The system here described makes it possible to have gene¬ rators of heat, par icularly useful in all those cases - which form the majority - where high concentrations of heat are unnecessary, such as in living and working rooms, in heating or cooking food, as well as in a great many indus- trial processes.

Heat is produced almost instantaneously and the surfaces obtained by the system emit uniform heat.

The cost of the heating bodies is much lower than that of those at present in use. The heat diffuser, today an essential item, is not needed as a single body is, at one and the same time, heater, emit¬ ter and diffuser.

The source of heat is easily created, whether it consists of sheets, bands or is to be used for electroplating. The heating bodies are also in direct contact with the struc¬ ture to be heated, consequently evoiding a thermal chain. If the equipment requires a transformer for stronger cur¬ rent, the lower voltage makes for greater operational safety. Characteristics and purposes of the invention will be made still clearer by the following examples of its execution il¬ lustrated by diagrammatically drawn figures. Fig. 1 Wall-mounted radiator. Fig. 2 Static oven . Fig . 3 Hotplate .

Fig. 4 Heated tunnel for impregnating work. Fig. 5 Tank for an electrolytic bath.

Fig. 6 Heating system for motor vehicles.

Fig. 7 Heated tank.

Fig. 8 Domestic heating.

Fig. 9 Detail of the radiator in Fig. 8. The radiator 10 comprises an insulating lamina 11 on which an extremely thin band, the thickness of which is measurable in microns, is laid flat, said band being of copper and be¬ ing arranged in the form of a serpentine 12 supported by a framework 15 for which any material may be used. The end 16 of the serpentine is connected to a terminal 19 while the other end 17 is joined by a connecting section 18 to a second terminal 20 this in turn connected to the elec¬ tric main . Said terminals are connected by the wire 21 to the plug 22. The serpentine 12 is covered by a sheet of anodized alumin¬ ium 13.

Said radiator is mounted directly onto the wall 24 of the room 25, an apparatus clearly of the greatest simplicity. Being so thin and yet so large in area the heat-emitter en- sures almost immediate and direct transfer of heat to the room with no need for supporting materials of high thermal resistance such as ceramic for example; neither is there any need for diffusers. Bulk and weight of the apparatus are practically negligible. Neither are the framework and anodized aluminium cover real¬ ly necessary since the insulating and supporting lamina alone could be sufficient. Maximum temperature of the radiator can be maintained at a low level, only a little above ambient temperature.

This radiator ofers a high degree of efficiency and is easily adaptable to any room and to any kind of furnishing.

The parallelepiped static oven 30 contains heat-emi ting surfaces inside its walls 31, said surfaces 32-34 consist¬ ing of a serpentine of copper band, similar to that previous¬ ly described, or equivalent means. The generator 35 of electric current is connected by wires 36 and 37 to the terminals 38, 39.

On the stove top 40 is a hotplate 41 formed by the heat-emitter 42 consisting of a copper lamina of the kind already described. Electricity from the mains reaches the hotplate 41 through the transformer 45 which increases intensity and upgrades heat. From the transformer the wires 46, 47 connect to terminals 48,49. Uniform and direct heat is applied to the pan 43.

The impregnating system 50 comprises a tunnel 51.

The walls 52,53 of refractary material carry the heat-emitting surfaces 54,55 of copper laminae; these radiate heat straight onto the two faces of- the band 56 moving slowly between the reels 57, 58 drawn along by the pair of rollers 59. Said heat-emitting surfaces 54, 55 are connected respectively by the pairs of wires 60,61 and 62, 63 to the current genera¬ tors 64 , 65. The bath 70 has walls 71 of refractary material, the inner ones being lined with a layer 72 of electrolytic copper. The tank filled with liquid 75 contains the chmicals needed for operations carried out in the electrolytic bath. Said layer of copper is connected by terminals 76, 77 and by wires 78, 79 to the electricity generator 80. In the motor vehicle 81, comfortable and uniform warmth is given out from the heat-emitting surfaces 82 consisting of fine copper bands arranged serpent inewise in.the inner sides of the doors 83. Said heat-emitting surfaces are connected to the generator

84 installed under the vehicle's bonnet 85 by the terminals

86, 87 and wires 88, 89.

The cylindrical tank 90 has walls 91 of refractary material, inside which is mounted the cylindrical ..heat-emitting sur- face 92 formed of a lamina whose lower ends are fitted with the terminals 93.

The wires 94, 95 lead off from said terminals and are then connected to the transformer 96 for receiving main current.

By means of this transformer the heat level is increased, intensity of current being thereby raised.

In the room 100, below the window 101, a radiator is fitted

102, a more detailed view of which is shown in Fig. 9.

Mains electricity for the radiator is increased in intensity after passing through the transformer 103. Through the terminals 104 and wires 105, 106, transformed current is sent to the two ends of the conducting aluminium cover 107 which clothes the two sides of the insulating plate 108.

Claims

CLA IMS

1. System for generating heat to convert electric energy into thermal energy by passing electric current through one or more conducting bodies ( 12, 16-18, 32-34, 42, 54, 55, 72, 82, 92, 107) characterized in that said conducting bodies are extremely thin, their thickness being measurable in microns, compa¬ tible with their formation and with resistance to stresses during use, and that there is a high ratio between width of the section and said thickness.

2. System as in claim 1, characterized in that the conducting bodies ( 12, 16-18, 32-34, 42, 54, 55, 72, 82, 92, 107) are placed flat on their supports ( 11, 15, 32, 53) and in lengths laid side by side but insula- ted one from another so as to offer heat-emitting surfaces (42, 54, 55) that are substantially continuous.

3. System as in claim 1, characterized in that the conducting bodies ( 12, 16-18, 32-34, 42, 54, 55, 72, 82, 92, 107) are of highly conductive material such as copper and aluminium.

4. System as in claim 1, characterized in that intensity of mains electricity is in¬ creased by means of transformers (45, 96, 103).

5. System as in claim 1, characterized in that the conducting bodies ( 12, 16-18, 32-34, 42, 54, 55, 72, 82, 92, 107) are in the form of laminars.

6. System as in claim 1, characterized in that the conducting bodies are films (72) made by electroplating or similar processes. 7. System as in claim 1, characterized in that the conducting bodies ( 12, 16-18,32-34) are laid in the form of a serpentine. 8. System as in claim 7, characterized in that the serpentine ( 12, 16- 18) is formed from a sheet in which parallel cuts are made alternat ingly on one of the two opposite edges and on the other. 9. System as in claim 1, characterized in that the conducting bodies are laid in the form or a circular, square or rectangular spiral, or dif¬ ferently shaped.

10. Heat . generators ( 10, 30, 40, 50, 70, 90, 102) obtained by converting electric energy into thermal energy by passing electric current through one or more conducting bodies ( 12, 16- 18, 32-34, 42, 54, 55, 72, 82, 92, 107) characterized in that said conducting bodies are extremely thin, their thickness being measurable in microns, compati- ble with their formation and with resistance to stresses during use, and that there is a high ratio between width of the section and said thickness, and that by laying said bo¬ dies flat on their supports and in lengths placed side by side, substantially continuous heat-emitting surfaces can be obtained.

11. Generators as in claim 10, characterized in that the heat-emitting surfaces (32-34) are placed around enclosed spaces in which they must reach temperatures higher than ambient temperature to bring about physical or chemical transformation of materials, so creating static ovens (30).

12. Generators as in claim 10, characterized in that the heat-emitting surfaces (54,55) are placed in installat ions , tunne1 (51) or ring-shaped, or simi- lar, around spaces through which material (56) is slowly moved for baking or some other treatment such .as impregna¬ ting installations (50). 13. Generators as in claim 10, characterized in that the heat-emitting surfaces are placed in internal walls (71) or on the bottom, of baths (70), anks and the like, into which fluid materials (75) are poured to obtain physical or chemical transformations, such as in electroplating baths.

14. Generators as in claim 10, characterized in that the heat-emitting surfaces (42) are placed on the flat areas (40) of equipment, devices general- ly whose purpose is to give off heat, such as hotplates (41) and the 1ike .

15. Generators as in claim 10, characterized in that the heat-emitting surfaces (82) are placed in those parts of vehicles (81) from which warmth can can suitably be given off, such as in their sides, floors, roofs (83) generally.

16. Generators as in claim 10, characterized in that the heat-emitting surfaces ( 12, 107), if necessary associated to panels ( 11, 15) and the like, create radiators ( 10, 102), stoves and the like, both fixed and moveable, for heating indoor environments (LQ0) generally. J7. Generators as in claim 10, charac erized in that the heat-emitting surfaces are placed or created on the inner surfaces of cooking pans, containers generally for cooking and for physically and chemically trans¬ forming materials.

18. Generating system-as in claim 1, characterized in that the conducting bodies ( 12, 16- 18, 32- 34, 42, 54, 55, 72, 82, 92, 107) have along their length transversal sections that are constant or differ according to the quantity of heat and the temperatures to be reached in the various lengths, differences in dimensions being gradual or sudden, continuous or discon inuous according to the particular case concerned or to preferences.

19. Generating system as in claim 1, characterized in that the conducting bodies ( 12, 16- 18, 32-34, 42, 54, 55, 72, 82, 92, 107) are supplied with el¬ ectric current at the ends or at intermediate points, values of current supplying the end or intermediate zones being equal or different, variations in values being gradual or sudden, continuous or discontinuous according to the particular case concerned or to preferences.