SYSTEM AND APPARATUS FOR HEATING BY ELECTRICITY WITH HEAT DIFFUSED AT A VERY HIGH TEMPERATURE A great number of systems exist for heating by electric current It is known that said systems are based on the use of highly resistant mateials that heat up to very high temperatures when electric current is passed through them producing an enormous concentration of heat
Such temperatures are nearly almost much greater that those required for heating rooms, ovens, hotplates and for other purposes Heat must therefore be diffused in the utilizing means with differences of temperature that can be very high and having to resort to specially made diffusers of a complex and costly kind
The high temperatures reached in heat-resisting materials require means of support made of special products, ceramic and others, difficult to construct, fragile and with complex forms of insulation and covering At such high temperatures these structures quickly wear out while, com- pared with direct utilization in which energy is obtained by burning fuels, efficiency is very low
Allowing for the considerable cost of heat resisting materials, all this determines great expense on purchase, installation and operation apart from the fact that utilization is limited compared with that theoretically possible on account of structural complications especially due to excessively high temperatures, to concentration of heat and to fragility of
insulating bodies, as well as to the need for creating insulating means that are placed between the source of heat and the body that must use such heat
The limitations are therefore caused by both economic and structural problems
Purpose of the above invention is to obtain a system whereby electric energy can be transformed into diffused heat, even at very high temperatures with simple and practical structures avoiding intermediate means of insulation and avoiding the difference between the very high tempera- tures produced and those actually used, as will be explained below
Subject of the invention are systems and means of electric heating obtained by closing the electric circuit using a band of very thin material, of a thickness measured in microns, highly conductive and wound in the form of a serpentine Inside each bend in the band are metal laminae the external surfaces of which are treated with insulating means
In this way compact panels are formed, serving both to generate and to diffuse heat, substantially at use temperature, both for heating and for other purposes The band can be continuous or in lengths connected one to another, interrupting the flow of electricity and heat
This interruption can be realized by means made of conducting material The band is preferably of copper though it may also be of aluminium or in any case of some highly conductive material Thickness of the band is advantageously that of 10-20 microns
The metal laminae placed between one bend in the serpentine and the next can be of steel coated with thermally insulating paint or with some other metal Said laminae may be of anodized aluminium on both faces Strong metal sheets are laid at the two ends of the panel, said sheets being connected together by suitable mechanical means to create pressure against the various components of said panel and ensure greater structural and thermal compactness
Said means of pressure and connection may be bolts or their equivalent In one type of execution the panel is laid in a strongly made flat box with a strong smooth base and with an upward curving front end In this way the box can be hauled along, for example over weedy ground Haulage can be done by motor-driven means, tractors and the like The ground can thus be cleared of weeds by dragging the box over it This method offers all the advantages of speed, simplicity and efficiency One or more sets of panels can be placed against the inner sides of ovens Inside these ovens heat is generated at high temperature and diffused for a variety of purposes
The invention offers evident advantages
Generation of heat by means of resistance and diffusion make possible elimination of a thermal head and of complex and costly insulating parts The large area of the heat generator, its possible planar form compact- ness and strength associated to an exceptional degree of efficiency, comparable to that obtained with known forms of gas and coal heating, mean that it can be used in a vast number of cases with beneficial effects of cost and easy application such as can bring about a decided change in the use of electricity for generation of heat It is in fact just the low level of efficiency of electric heating that has made it impossible hitherto to extend its use to highly interesting fields, as indicated by the examples given in this description
Applications are of course innumerable both in the field of electric heating itself and in that of utilization of high temperatures for other purposes, as for example, clearing of weedy ground as already mentioned
Characteristics and purposes of the invention will be made still clearer by the following examples of its application illustrated by diagrammatic drawings
Fig 1 Panel composed according to the invented method, in perspective Fig 2 Side view of the panel in Fig 2
Fig 3 The invented method of clearing weedy ground
Fig 4 Application of the invented system to an oven, front perspective
The panel 10 exhibits a copper band 1 1 , bent in the form of a serpentine to form curves 12.
Brass bars 15, 16 are fixed at the two ends 13, 14.
At the ends of said bars are terminals 17, 18 for connection by wires 19, 20 to the generator of current 21 .
Metal laminae 30 are placed between one bend in the copper band and the next, their external surfaces being coated with an anodized layer
31 ,32.
At the two ends of the panel 10 are two metal sheets 40, 41 of the same size as the laminae 30, said sheets being joined together with bolts 45 tightened by nuts 46.
The internal surfaces of said sheets are coated with anodized layers 42,
43.
On closing the electric circuit, the various bends 12 in the copper band 1 1 warm up generating heat and at the same time diffusing it from the large surface, from the metal laminae 30 and matching sheets 40 41 .
The combined heat diffused from each band in the serpentine generates directly utilizable heat at a very high temperature.
In Fig 3 the tractor 50, by its linkage means 51 , pulls along the body 60 containing the panel 72 substantially the same as the panel 10 described above.
The body 60 is joined to the linkage 51 by drawbars 52 articulated on the linkage 51 by the pin 53.
Over the body 60 is a cover 61 and underneath it is a base 62 joined to the lower plane 65 by an upward curving front 64.
The electric cable 70 connects the copper band 71 in the panel 72 to the generator of electric current 75 comprising a dynamo 76 driven by the engine of the tractor.
On moving the tractor 50 over the ground 80 covered with weeds 81 , said weeds are quickly burned and destroyed as shown by the length 82 of ground freed of weeds when the tractor has passed on.
Weeds 81 are therefore removed by a dragging process with all the enormous advantages of speed, area coverage and great ease.
Fig. 4 shows an oven 90 with door 91 turning on hinges 94 and with internal sides 92, 93 on which panels 95 are placed, substantially the same as the panels 10 already described.
The ends 97 of the copper band 96 are connected by terminals 98 to a generator of current using wiring 99, 100, 101.
Heating is regulated and controlled by switch 102 and pilot light 103.
The high temperatures generated by the opposing heating panels 95 is diffused directly into the oven 105 with maximum efficiency.