EP0228615A2 - Arrangement for heating a billet of electrically conductive material - Google Patents

Arrangement for heating a billet of electrically conductive material Download PDF

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Publication number
EP0228615A2
EP0228615A2 EP86117107A EP86117107A EP0228615A2 EP 0228615 A2 EP0228615 A2 EP 0228615A2 EP 86117107 A EP86117107 A EP 86117107A EP 86117107 A EP86117107 A EP 86117107A EP 0228615 A2 EP0228615 A2 EP 0228615A2
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EP
European Patent Office
Prior art keywords
strand
capacitor plates
capacitor
frequency generator
heating
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.)
Granted
Application number
EP86117107A
Other languages
German (de)
French (fr)
Other versions
EP0228615A3 (en
EP0228615B1 (en
Inventor
Eckhard Schulz
Georg Zimmermann
Franz Wosnitza
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sicowa Verfahrenstechnik fuer Baustoffe GmbH and Co KG
Original Assignee
Sicowa Verfahrenstechnik fuer Baustoffe GmbH and Co KG
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 Sicowa Verfahrenstechnik fuer Baustoffe GmbH and Co KG filed Critical Sicowa Verfahrenstechnik fuer Baustoffe GmbH and Co KG
Priority to EP92101680A priority Critical patent/EP0486472B1/en
Priority to EP92101681A priority patent/EP0485363B1/en
Priority to EP92101679A priority patent/EP0487504B1/en
Priority to AT86117107T priority patent/ATE81434T1/en
Publication of EP0228615A2 publication Critical patent/EP0228615A2/en
Publication of EP0228615A3 publication Critical patent/EP0228615A3/en
Application granted granted Critical
Publication of EP0228615B1 publication Critical patent/EP0228615B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B3/00—Producing shaped articles from the material by using presses; Presses specially adapted therefor
    • B28B3/20—Producing shaped articles from the material by using presses; Presses specially adapted therefor wherein the material is extruded
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B11/00—Apparatus or processes for treating or working the shaped or preshaped articles
    • B28B11/24—Apparatus or processes for treating or working the shaped or preshaped articles for curing, setting or hardening
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B7/00—Moulds; Cores; Mandrels
    • B28B7/40—Moulds; Cores; Mandrels characterised by means for modifying the properties of the moulding material
    • B28B7/42—Moulds; Cores; Mandrels characterised by means for modifying the properties of the moulding material for heating or cooling, e.g. steam jackets, by means of treating agents acting directly on the moulding material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/0088—Lubricating means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/34—Heating or cooling presses or parts thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B5/00—Presses characterised by the use of pressing means other than those mentioned in the preceding groups
    • B30B5/04—Presses characterised by the use of pressing means other than those mentioned in the preceding groups wherein the pressing means is in the form of an endless band
    • B30B5/06—Presses characterised by the use of pressing means other than those mentioned in the preceding groups wherein the pressing means is in the form of an endless band co-operating with another endless band
    • 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
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/46—Dielectric heating
    • H05B6/60—Arrangements for continuous movement of material

Definitions

  • the invention relates to a device for heating a strand of electrically conductive material, preferably solidified by the heating, in a channel which is delimited by walls made of electrically insulating material, adjacent to which a capacitor plate arrangement, which is connected to a high-frequency generator, is provided.
  • Such a device is known from EU-B-0085318, in which two capacitor plates are arranged on two opposite sides of the channel offset by approximately their length from one another, which are connected to a non-potential-free connection of the high-frequency generator, while on both sides adjacent to the two capacitor plates In each case two further capacitor plates are arranged, which are connected to the potential-free connection of the high-frequency generator and extend along the channel to such an extent that the strand is no longer at potential outside the heating range.
  • the heating of the strand is not sufficiently uniform and, as a result, can lead to shell formation within the strand, which causes the homogeneity of the end product and thus its strength, if it is, for example building materials to be hardened by heating is impaired.
  • the object of the invention is therefore to provide a device of the type mentioned at the outset which enables more uniform heating of the strand and prevents shell formation within the strand.
  • This object is achieved in that the four middle capacitor plates - on two opposite sides of the strand, two adjacent in the longitudinal direction of the strand - are all connected to the non-potential-free connection of the high-frequency generator and additionally to the two remaining sides of the strand in the middle region of the strand and the extension of these capacitor plates, an auxiliary capacitor plate, which is also connected to the non-potential-free connection of the high-frequency generator, is provided.
  • the object is further achieved in that the four middle capacitor plates - each arranged on two opposite sides of the string - are connected to two uncorrelated high-frequency generators. This also ensures that the field inside the strand becomes more homogeneous and concentrated.
  • the object is also achieved in that the distance between the capacitor plates arranged adjacent in the longitudinal direction of the strand is at least equal to the distance between the capacitor plates opposite each other with respect to the strand.
  • the distance between the floating outer capacitor plates is and to select the adjacent, middle, non-potential-free capacitor plates at least equal to the distance of the capacitor plates opposite one another with respect to the strand, while the distance between the middle neighboring capacitor plates can be narrower.
  • the distance between the potential-free outer capacitor plates and the adjacent middle capacitor plates is at least equal to the distance between the capacitor plates opposite one another with respect to the strand, while the distance between the middle neighboring capacitor plates is narrower and in each case on one side of the line has potentials applied symmetrically to the zero potential.
  • a cylindrical capacitor consisting of a capacitor electrode surrounding the strand and at least one capacitor electrode located in the interior of the strand, which is arranged in the area of the surrounding capacitor electrode and has a different polarity than the surrounding capacitor electrode, is provided, which at least when the surrounding capacitor electrode is not potential-free, it is expediently arranged between outer capacitor plates which are adjacent in the strand direction and are at zero potential.
  • the skin effect in heating devices using high-frequency electrical energy is normally a second-order disturbance, it can become a dominant effect depending on the size of the capacitor plate.
  • the capacitor plates each from a plurality of, preferably two, partial plates which are at the same potential and whose adjacent edges are separated by a slot which is preferably kept as small as possible.
  • the 1 comprises four belts 10, 11, 12 and 13 which are arranged such that they form a rectangular channel 14 between them.
  • the belts 10 to 13 are guided around rollers 15 and driven synchronously by means of a drive, not shown.
  • the tapes 10 to 13 are, if necessary, also supported adjacent to the channel 14 by support gratings, not shown, while the vertical tapes 12 and 13 can additionally be guided at their edges via slide rails.
  • the lower horizontal belt 10 is extended beyond the outlet end of the channel 14 and guided to the belt running control via a dancer roller 16.
  • a filling device e.g. a filling funnel 17, which is expediently arranged such that it can be moved out of the entry region of the channel 14 by means of a piston-cylinder unit for the purpose of cleaning.
  • the outlet opening of the filling funnel 17 is located in the inlet area of the channel 14.
  • a cutting device 18 is provided, which can be moved in the feed direction of the strip 10 from an initial position synchronously with the feed speed of the strip 10 and can be returned to the initial position after the cutting process has been carried out.
  • the cutting device 18 has a bracket 19, which receives a cutting wire 19a to and fro and is adjustable in the vertical direction in accordance with the cutting progress and can be moved with a carriage 20.
  • a belt weighing section can follow the cutting device 18 be provided.
  • the tapes 10 to 13 consist of an electrically non-conductive plastic, while adjacent to the tapes 12 and 13, namely on the outside of the tape parts, which form the entrance area of the channel 14, a schematically illustrated capacitor plate arrangement 21 is provided, which is connected via corresponding lines 22 a high frequency generator 23 are connected.
  • a raw mixture for example consisting of quartz sand, lime, water, cement with an accelerator / retarder system and foam for the production of lime silicate stones
  • the raw mixture passes into the channel 14 and is conveyed through the belts 10 to 13 on the predetermined channel cross section kept.
  • the raw mixture in the duct 14 is heated, for example, to a temperature of 50 ° C. via the capacitor plate arrangement 21, so that the raw mixture solidifies due to the strengthening reactions of the cement that are set in motion.
  • the solidifying strand of raw mixture in channel 14 is conveyed through belts 10 to 13 to the outlet end of channel 14. A relative movement between the strand and the tapes 10 to 13 and between the tapes 10 to 13 does not take place here, so that the wear problems are minimal.
  • the tapes 10 to 13 are sprayed with a separating agent by spray devices 24 before they are deflected to the channel 14.
  • scrapers 25 are provided, which remove any adhering material from the belts 10 to 13.
  • the solidified strand After the solidified strand emerges from the channel 14, it is transported further through the lower belt 10 and divided into individual stone blanks 26 by means of the cutting device 18.
  • the separated stone blanks 26 can then optionally be weighed on a belt weighing line in order to be able to readjust the composition of the raw mixture in this way in order to ensure that the blends are as uniform as possible To achieve cullet bulk density of the stone blanks 26.
  • the waste heat from the high-frequency generator 23 can be used by blowing warm air generated by the generator cooling, for example by means of a hood, onto the stone blanks 26 in order to harden them, so that these have a sufficiently high strength for subsequent transport to an autoclave, but they do not must be fully generated by the heating in the region of the capacitor plate assembly 21.
  • the length of the channel 14 is dimensioned such that the emerging strand has a desired strength, which may be increased to the necessary value by reheating with warm air from the generator cooling or another heat source.
  • the area of the channel 14 is expediently accommodated in a housing (not shown) which is at ground potential and which extends from the filling funnel 17 to the cutting device 18.
  • the belts 10 to 13 with their rollers 15 as well as support grids and sliding guides can be adjusted with respect to their belt levels so that the cross section of the channel 14 can be changed.
  • the length of the blanks 26 can be changed by the cycle of the cutting device 18.
  • the feed rate of the belts 10 to 13 is expediently adjustable, in particular continuously adjustable, in order to be able to adapt the feed rate to the heating rate and the size of the capacitor plate arrangement 21 accordingly.
  • the belt strand system is suitable, for example, for the production of blanks for wall blocks, in particular lightweight blocks, for example based on lime silicate, gas or foam concrete or from coarse-ceramic material, the raw mixture containing large proportions of foam and water, so that body density down to 0.2 g / cm 'can be achieved.
  • two pairs of mutually opposite capacitor plates 30 are provided adjacent to the belts 12 and 13 at a distance from one another, between which two further pairs of mutually opposite capacitor plates 31 are arranged, so that in the longitudinal direction of the channel 14 a capacitor plate 30, two capacitor plates 31 and a capacitor plate 30 follow one another in the longitudinal direction of the channel 14 on the two opposite sides.
  • the outer capacitor plates 30 are connected to the potential-free connection (0) of the high-frequency generator 23 and extend so far along the channel 14 that the stray fields emanating from the inner capacitor plates 31 are picked up by the capacitor plates 30 on both sides, so that the strand inside of the channel 14 is free of contact voltage outside the heating region.
  • the capacitor plates 31 are shorter than the capacitor plates 30 and connected to the other non-potential-free connection (+) of the high-frequency generator 23.
  • two auxiliary capacitor plates 32 which are connected to the non-potential-free connection (+) of the high-frequency generator 23, are provided adjacent to the bands 10 and 11 opposite one another approximately in the middle between the four middle capacitor plates 31.
  • the auxiliary capacitor plates 32 can be approximately as long as the capacitor plates 31, but are narrow in relation to the distance d between the capacitor plates 30 and 31 and are directed with their longitudinal axis in the direction of the longitudinal axis of the channel 14.
  • the auxiliary capacitor plates 32 together with the same-polarized capacitor plates 31 lead between the outer, differently polarized capacitor plates 30 to a field line distribution which, in addition to the entire heating of the strand, particularly supports surface heating, which contributes to a shortening of the heating distance, the auxiliary capacitor plates 32 providing additional heating in the area of the adjacent strand. In the above-mentioned applications, this leads to an additional hardening in this area and thus to a better detachment of the hardened strand from the belts 10, 11.
  • two high-frequency generators 23 of half the total power are provided, the uncorrected are related.
  • a pair of mutually opposite middle capacitor plates 31 is connected to the floating and the non-floating connection of one of the two high-frequency generators 23 (floating supply to the capacitor plates), the adjacent capacitor plates 31 of opposite polarity in the longitudinal direction of the strand, however, are each connected to a different high-frequency generator 23.
  • a distance between the capacitor plates 30, 31 in the longitudinal direction of the strand is at least approximately equal to the distance d between capacitor plates 30 or 31 located opposite one another.
  • the polarity of the capacitor plates 30, 31 is as in FIG. 3, but only one high-frequency generator 23 is used.
  • Auxiliary capacitor plates 32 can be provided in the middle between the four middle capacitor plates 31 as in FIG. 2, but in such a way that they are also approximately at a distance d from the adjacent capacitor plates 31.
  • the auxiliary capacitor plates 32 can also be round or oval.
  • the capacitor plates 30 adjacent to a pair of capacitor plates 31 must be connected to the zero potential of the respective high-frequency generator 23, since guaranteed with no contact voltage.
  • the distance between adjacent capacitor plates 30, 31 lying at zero potential can be chosen to be smaller than d, as shown in FIG. 5.
  • the auxiliary capacitor plates 32 of the embodiment of FIG. 4 can also be connected to a further non-correlated high-frequency generator 23, in which case the distance between the capacitor plates 31 and 32 can be chosen to be correspondingly small.
  • the capacitor plate arrangement is as in FIG. 5, but only one high-frequency generator 23 is used.
  • the opposing pairs of capacitor plates 31 are subjected to voltage symmetrically to the zero potential, in that a capacitor plate 31 is connected to an output connection of the high-frequency generator 23 and the opposite capacitor plate 31 is connected to the latter via a phase-shifting lambda / 2 bypass line 34 or a phase shift network, which is one Phase shift caused by half a period.
  • a high-frequency generator 23 with a symmetrical output can also be used.
  • the opposing pairs of capacitor plates 31 are subjected to voltage symmetrically to the zero potential by connecting a capacitor plate 31 to one output connection of the high-frequency generator 23 and the capacitor plate 31 opposite with respect to the string to the other output connection of the high-frequency generator 23, which causes the opposite electrodes to be driven in phase .
  • the capacitor plates 30 are then connected to the zero potential of the high-frequency generator 23.
  • the capacitor plate 31 connected to the ungrounded connection of the high-frequency generator overlaps a small piece across the bands 10, 11 at both ends transversely to the longitudinal direction of the strand, either by means of a bend 35 or by its own narrow auxiliary capacitor plate 36 realized, whereby the field in the upper and lower region of the strand is slightly compressed for local surface heating. If this is followed by a further pair of capacitor plates 31 of reversed polarity, the more inhomogeneous field is located on the other side of the strand, so that overall a good homogeneous surface heating results.
  • the capacitor plates 31 can consist of several partial plates 31a, 31b arranged adjacent to one another in order to keep the skin effect in the strand material as low as possible.
  • the partial plates 31a, 31b are at the same potential and their adjacent edges are separated by a slot 37, which can be as narrow as possible due to the same potential.
  • a cylindrical capacitor in which the opposite capacitor plates 31 are closed to form a box 38 which surrounds the channel 14 and the bands 10, 11, 12, 13.
  • a capacitor electrode 39 Inside the channel 14 there is at least one capacitor electrode 39 in the area of the box 38, protected from the strand material in the channel 14 by a sleeve 40 made of insulating plastic, the outer box-shaped capacitor electrode 38 and the inner electrode (s) 39 being at different potentials , e.g. as indicated in Fig. 9.
  • the concavity of the capacitor plate 30, 31 can be filled with a material 41 with the highest possible dielectric constant, so that its surface facing the corresponding band 10, 11, 12 or 13 is flat and abuts against it.
  • plastics have a dielectric constant of the order of about 2 to 4 (with a loss factor tg G that is extremely low, so that the plastic practically does not heat up)
  • materials such as calcium titanate are provided here, the dielectric constant of which is very much greater than 1 is. Also show these materials have high dimensional stability and a low coefficient of thermal expansion.
  • the strand material has a dielectric constant of approximately 40 to 80 and a significant loss factor tg , ie the continuous material can be heated particularly well by means of a high-frequency field.
  • the capacitor plates are expedient to provide with a plastic layer on the sides facing the strips or to embed the capacitor plates in plastic in order to keep the wear on the strips moving along the capacitor plates low.
  • this plastic coating should be as thin as possible so as not to influence the stress profile too much.
  • the material 41 can be ground and polished on the side facing the belt.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Electromagnetism (AREA)
  • Physics & Mathematics (AREA)
  • Structural Engineering (AREA)
  • Constitution Of High-Frequency Heating (AREA)
  • Resistance Heating (AREA)
  • Drying Of Solid Materials (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
  • General Induction Heating (AREA)
  • Control Of Resistance Heating (AREA)

Abstract

The invention relates to a device for heating a billet being passed in a duct. The billet consists of an electrically conductive material, preferably material that hardens as a result of the heating, for example a raw mixture containing a binder for production of building materials; a capacitor plate arrangement connected to at least one RF generator being arranged so that it is electrically insulated from the billet. The capacitor plate arrangement is designed so as to permit as uniform heating of the billet material as possible and so as to prevent formation of a skin within the billet. <IMAGE>

Description

Die Erfindung betrifft eine Vorrichtung zum Erwärmen eines Strangs aus elektrisch leitfähigem, sich vorzugsweise durch die Erwärmung verfestigendem Material in einem Kanal, der durch Wände aus elektrisch isolierendem Material begrenzt ist, benachbart zu denen eine Kondensatorplattenanordnung, die an einen Hochfrequenzgenerator angeschlossen ist, vorgesehen ist.The invention relates to a device for heating a strand of electrically conductive material, preferably solidified by the heating, in a channel which is delimited by walls made of electrically insulating material, adjacent to which a capacitor plate arrangement, which is connected to a high-frequency generator, is provided.

Eine derartige Vorrichtung ist aus der EU-B-0085318 bekannt, bei der auf zwei gegenüberliegenden Seiten des Kanals um etwa ihre Länge zueinander versetzt zwei Kondensatorplatten angeordnet sind, die mit einem nicht potentialfreien Anschluß des Hochfrequenzgenerators verbunden sind, während beidseitig benachbart zu den beiden Kondensatorplatten jeweils zwei weitere Kondensatorplatten angeordnet sind, die mit dem potentialfreien Anschluß des Hochfrequenzgenerators verbunden sind und sich soweit entlang des Kanals erstrecken, daß der Strang außerhalb des Erwärmungsbereichs nicht mehr auf Potential liegt. Wie sich jedoch gezeigt hat, ist die Erwärmung des Strangs nicht genügend gleichmäßig und kann infolgedessen zu einer Schalenbildung innerhalb des Strangs führen, wodurch die Homogenität des Endprodukts und damit dessen Festigkeit, wenn es sich beispielsweise um durch Erwärmung zu erhärtende Baustoffe handelt, beeinträchtigt wird. Dies dürfte darauf zurückzuführen sein, daß sich die Felder in der Mitte des Strangs in etwa kompensieren können, während zwischen nebeneinander befindlichen Kondensatorplatten unterschiedlicher Polarität im Randbereich des Strangs sehr starke Felder auftreten, so daß die Feldverteilung zur Symmetrieachse in Längsrichtung des Strangs stark unsymmetrisch ist. Wegen der relativ ungleichmäßigen Erwärmung ist außerdem eine sehr große Erwärmungsstrecke erforderlich.Such a device is known from EU-B-0085318, in which two capacitor plates are arranged on two opposite sides of the channel offset by approximately their length from one another, which are connected to a non-potential-free connection of the high-frequency generator, while on both sides adjacent to the two capacitor plates In each case two further capacitor plates are arranged, which are connected to the potential-free connection of the high-frequency generator and extend along the channel to such an extent that the strand is no longer at potential outside the heating range. However, as has been shown, the heating of the strand is not sufficiently uniform and, as a result, can lead to shell formation within the strand, which causes the homogeneity of the end product and thus its strength, if it is, for example building materials to be hardened by heating is impaired. This may be due to the fact that the fields in the middle of the strand can compensate approximately, while very strong fields occur between adjacent capacitor plates of different polarity in the edge region of the strand, so that the field distribution with respect to the axis of symmetry in the longitudinal direction of the strand is highly asymmetrical. Because of the relatively uneven heating, a very large heating section is also required.

Aufgabe der Erfindung ist es daher, eine Vorrichtung der eingangs genannten Art zu schaffen, die eine gleichmäßigere Erwärmung des Strangs ermöglicht und eine Schalenbildung innerhalb des Strangs verhindert.The object of the invention is therefore to provide a device of the type mentioned at the outset which enables more uniform heating of the strand and prevents shell formation within the strand.

Diese Aufgabe wird dadurch gelöst, daß die vier mittleren Kondensatorplatten - auf zwei gegenüberliegenden Seiten des Strangs jeweils zwei in Längsrichtung des Strangs benachbarte - sämtlich an den nicht potentialfreien Anschluß des Hochfrequenzgenerators angeschlossen sind und zusätzlich an den beiden verbleibenden Seiten des Strangs im mittleren Bereich des Strangs und der Erstreckung dieser Kondensatorplatten jeweils eine Hilfskondensatorplatte, die ebenfalls an den nicht potentialfreien Anschluß des Hochfrequenzgenerators angeschlossen ist, vorgesehen ist.This object is achieved in that the four middle capacitor plates - on two opposite sides of the strand, two adjacent in the longitudinal direction of the strand - are all connected to the non-potential-free connection of the high-frequency generator and additionally to the two remaining sides of the strand in the middle region of the strand and the extension of these capacitor plates, an auxiliary capacitor plate, which is also connected to the non-potential-free connection of the high-frequency generator, is provided.

Die Aufgabe wird ferner dadurch gelöst, daß die vier mittleren Kondensatorplatten - jeweils zwei auf zwei gegenüberliegenden Seiten des Strangs angeordnete - mit zwei unkorrelierten Hochfrequenzgeneratoren verbunden sind. Hierdurch wird ebenfalls erreicht, daß das Feld im Inneren des Strangs homogener und konzentrierter wird.The object is further achieved in that the four middle capacitor plates - each arranged on two opposite sides of the string - are connected to two uncorrelated high-frequency generators. This also ensures that the field inside the strand becomes more homogeneous and concentrated.

Die Aufgabe wird außerdem dadurch gelöst, daß der Abstand der in Längsrichtung des Strangs benachbart angeordneten Kondensatorplatten mindestens gleich dem Abstand der sich bezüglich des Strangs gegenüberliegenden Kondensatorplatten ist.The object is also achieved in that the distance between the capacitor plates arranged adjacent in the longitudinal direction of the strand is at least equal to the distance between the capacitor plates opposite each other with respect to the strand.

Wenn man zwei unkorrelierte Hochfrequenzgeneratoren verwendet, ist der Abstand zwischen den potentialfreien äußeren Kondensatorplatten und den benachbarten, mittleren, nicht potentialfreien Kondensatorplatten mindestens gleich dem Abstand der sich bezüglich des Strangs gegenüberliegenden Kondensatorplatten zu wählen, während der Abstand zwischen den mittleren benachbarten Kondensatorplatten enger sein kann.If you use two uncorrelated high frequency generators, the distance between the floating outer capacitor plates is and to select the adjacent, middle, non-potential-free capacitor plates at least equal to the distance of the capacitor plates opposite one another with respect to the strand, while the distance between the middle neighboring capacitor plates can be narrower.

Die Aufgabe wird zudem dadurch gelöst, daß bei einem Hochfrequenzgenerator der Abstand zwischen den potentialfreien äußeren Kondensatorplatten und den benachbarten mittleren Kondensatorplatten mindestens gleich dem Abstand der sich bezüglich des Strangs gegenüberliegenden Kondensatorplatten ist, während der Abstand zwischen den mittleren benachbarten Kondensatorplatten enger ist und diese jeweils auf einer Seite des Strangs symmetrisch zum Nullpotential potentialbeaufschlagt sind.The object is also achieved in that, in the case of a high-frequency generator, the distance between the potential-free outer capacitor plates and the adjacent middle capacitor plates is at least equal to the distance between the capacitor plates opposite one another with respect to the strand, while the distance between the middle neighboring capacitor plates is narrower and in each case on one side of the line has potentials applied symmetrically to the zero potential.

Außerdem wird die Aufgabe dadurch gelöst, daß ein Zylinderkondensator bestehend aus einer den Strang umschließenden Kondensatorelektrode und mindestens einer im Inneren des Strangs befindlichen Kondensatorelektrode, die im Bereich der umschließenden Kondensatorelektrode angeordnet ist und eine andere Polarität als die umschließende Kondensatorelektrode aufweist, vorgesehen ist, der zumindestens dann, wenn die umschließende Kondensatorelektrode nicht potentialfrei ist, zweckmäßigerweise zwischen in Strangrichtung benachbarten auf Nullpotential befindlichen äußeren Kondensatorplatten angeordnet ist.In addition, the object is achieved in that a cylindrical capacitor consisting of a capacitor electrode surrounding the strand and at least one capacitor electrode located in the interior of the strand, which is arranged in the area of the surrounding capacitor electrode and has a different polarity than the surrounding capacitor electrode, is provided, which at least when the surrounding capacitor electrode is not potential-free, it is expediently arranged between outer capacitor plates which are adjacent in the strand direction and are at zero potential.

Zwar ist der Skin-Effekt bei Erwärmungsvorrichtungen mittels hochfrequenter elektrischer Energie normalerweise eine Störung 2. Ordnung, jedoch kann er in Abhängigkeit von der Kondensatorplattengrösse zu einem dominanten Effekt werden. Um seine Auswirkung möglichst gering zu halten, ist es daher zweckmäßig, die Kondensatorplatten jeweils aus mehreren, vorzugsweise zwei Teilplatten aufzubauen, die auf gleichem Potential liegen und deren benachbarte Kanten durch einen Schlitz getrennt sind, der vorzugsweise so klein wie möglich gehalten ist.Although the skin effect in heating devices using high-frequency electrical energy is normally a second-order disturbance, it can become a dominant effect depending on the size of the capacitor plate. In order to keep its impact as low as possible, it is therefore expedient to construct the capacitor plates each from a plurality of, preferably two, partial plates which are at the same potential and whose adjacent edges are separated by a slot which is preferably kept as small as possible.

Weitere Ausgestaltungen der Erfindung sind der nachfolgenden Beschreibung und den Ansprüchen zu entnehmen.Further embodiments of the invention can be found in the following description and the claims.

Die Erfindung wird nachstehend anhand der in den beigefügten Abbildungen dargestellten Ausführungsbeispiele näher erläutert.

  • Fig. 1 zeigt im wesentlichen schematisch und perspektivisch eine Bandstranganlage mit einer Vorrichtung zum Erwärmen des Strangs.
  • Fig. 2 bis 10 zeigen im wesentlichen schematisch Ausführungsformen von Kondensatoranordnungen.
The invention is explained in more detail below on the basis of the exemplary embodiments illustrated in the attached figures.
  • 1 shows an essentially schematic and perspective view of a strip strand system with a device for heating the strand.
  • 2 to 10 show essentially schematic embodiments of capacitor arrangements.

Die in Fig. 1 dargestellte Bandstranganlage umfaßt vier Bänder 10, 11, 12 und 13, die derart angeordnet sind, daß sie zwischen sich einen rechteckigen Kanal 14 bilden. Die Bänder 10 bis 13 sind um Rollen 15 geführt und mittels eines nicht darstellten Antriebs synchron angetrieben. Die Bänder 10 bis 13 werden, soweit erforderlich, ferner benachbart zum Kanal 14 durch nicht dargestellte Tragroste abgestützt, während die vertikalen Bänder 12 und 13 zusätzlich über Gleitschienen an ihren Kanten geführt sein können. Das untere horizontale Band 10 ist über das Austrittsende des Kanals 14 hinaus verlängert und über eine Tänzerwalze 16 zur Bandlaufregelung geführt.1 comprises four belts 10, 11, 12 and 13 which are arranged such that they form a rectangular channel 14 between them. The belts 10 to 13 are guided around rollers 15 and driven synchronously by means of a drive, not shown. The tapes 10 to 13 are, if necessary, also supported adjacent to the channel 14 by support gratings, not shown, while the vertical tapes 12 and 13 can additionally be guided at their edges via slide rails. The lower horizontal belt 10 is extended beyond the outlet end of the channel 14 and guided to the belt running control via a dancer roller 16.

Zwischen den Bändern 10 bis 13 mündet im Eintrittsbereich des Kanals 14 eine Befüllungseinrichtung, z.B. ein Fülltrichter 17, der zweckmäßigerweise etwa mittels einer Kolben-Zylinder-Einheit zwecks Reinigung aus dem Eintrittsbereich des Kanals 14 herausfahrbar angeordnet ist. Die Austrittsöffnung des Fülltrichters 17 befindet sich im Eintrittsbereich des Kanals 14.Between the belts 10 to 13, a filling device, e.g. a filling funnel 17, which is expediently arranged such that it can be moved out of the entry region of the channel 14 by means of a piston-cylinder unit for the purpose of cleaning. The outlet opening of the filling funnel 17 is located in the inlet area of the channel 14.

Am Austrittsende des Kanals 14 ist eine Schneideeinrichtung 18 vorgesehen, die in Vorschubrichtung des Bandes 10 aus einer Ausgangsstellung synchron mit der Vorschubgeschwindigkeit des Bandes 10 verfahrbar und nach Durchführung des Schneidvorgangs in die Ausgangsstellung zurückfahrbar ist. Die Schneideeinrichtung 18 besitzt in der dargestellten Ausführungsform einen Bügel 19, der einen Schneidedraht 19a hin- und herbeweglich sowie in vertikaler Richtung entsprechend dem Schneidfortgang verstellbar aufnimmt und mit einem Schlitten 20 verfahrbar ist.At the outlet end of the channel 14, a cutting device 18 is provided, which can be moved in the feed direction of the strip 10 from an initial position synchronously with the feed speed of the strip 10 and can be returned to the initial position after the cutting process has been carried out. In the embodiment shown, the cutting device 18 has a bracket 19, which receives a cutting wire 19a to and fro and is adjustable in the vertical direction in accordance with the cutting progress and can be moved with a carriage 20.

Nachfolgend zur Schneideeinrichtung 18 kann eine Bandwiegestrecke vorgesehen sein.A belt weighing section can follow the cutting device 18 be provided.

Die Bänder 10 bis 13 bestehen aus einem elektrisch nichtleitenden Kunststoff, während benachbart zu den Bändern 12 und 13, und zwar auf Außenseiten der Bandteile, die den Eingangsbereich des Kanals 14 bilden, eine schematisch dargestellte Kondensatorplattenanordnung 21 vorgesehen ist, die über entsprechende Leitungen 22 mit einem Hochfrequenzgenerator 23 verbunden sind.The tapes 10 to 13 consist of an electrically non-conductive plastic, while adjacent to the tapes 12 and 13, namely on the outside of the tape parts, which form the entrance area of the channel 14, a schematically illustrated capacitor plate arrangement 21 is provided, which is connected via corresponding lines 22 a high frequency generator 23 are connected.

Wird eine Rohmischung, beispielsweise bestehend aus Quarzsand, Kalk, Wasser, Zement mit einem Beschleuniger/Verzögerer-System und Schaum zur Herstellung von Kalksilikatsteinen in den Fülltrichter 17 eingefüllt, gelangt die Rohmischung in den Kanal 14 und wird durch die Bänder 10 bis 13 auf dem vorbestimmten Kanalquerschnitt gehalten. Über die Kondensatorplattenanordnung 21 erfolgt die Erwärmung der Rohmischung im Kanal 14 beispielsweise auf eine Temperatur von 50°C, so daß sich die Rohmischung aufgrund der dadurch in Gang gesetzten festigkeitsbildenden Reaktionen des Zements verfestigt.If a raw mixture, for example consisting of quartz sand, lime, water, cement with an accelerator / retarder system and foam for the production of lime silicate stones, is filled into the filling funnel 17, the raw mixture passes into the channel 14 and is conveyed through the belts 10 to 13 on the predetermined channel cross section kept. The raw mixture in the duct 14 is heated, for example, to a temperature of 50 ° C. via the capacitor plate arrangement 21, so that the raw mixture solidifies due to the strengthening reactions of the cement that are set in motion.

Der sich verfestigende Strang aus Rohmischung im Kanal 14 wird durch die Bänder 10 bis 13 zum Austrittsende des Kanals 14 gefördert. Eine Relativbewegung zwischen dem Strang und den Bändern 10 bis 13 sowie unter den Bändern 10 bis 13 untereinander findet hierbei nicht statt, so daß auch die Verschleißprobleme minimal sind.The solidifying strand of raw mixture in channel 14 is conveyed through belts 10 to 13 to the outlet end of channel 14. A relative movement between the strand and the tapes 10 to 13 and between the tapes 10 to 13 does not take place here, so that the wear problems are minimal.

Um am Austrittsende des Kanals 14 ein leichtes Lösen der Bänder 10 bis 13 von dem verfestigten Strang zu erreichen, werden die Bänder 10 bis 13, bevor sie zum Kanal 14 umgelenkt werden, durch Sprüheinrichtungen 24 mit einem Trennmittel besprüht. Außerdem sind Abstreifer 25 vorgesehen, die eventuell anhaftendes Material von den Bändern 10 bis 13 entfernen.In order to achieve a slight detachment of the tapes 10 to 13 from the solidified strand at the exit end of the channel 14, the tapes 10 to 13 are sprayed with a separating agent by spray devices 24 before they are deflected to the channel 14. In addition, scrapers 25 are provided, which remove any adhering material from the belts 10 to 13.

Nach Austritt des verfestigten Strangs aus dem Kanal 14 wird dieser durch das untere Band 10 weitertransportiert und mittels der Schneideeinrichtung 18 in einzelne Steinrohlinge 26 zerteilt. Die vereinzelten Steinrohlinge 26 können dann gegebenenfalls auf einer Bandwiegestrecke gewogen werden, um auf diese Weise die Zusammensetzung der Rohmischung nachregeln zu können, um eine möglichst gleichmäßige Scherbenrohdichte der Steinrohlinge 26 zu erzielen.After the solidified strand emerges from the channel 14, it is transported further through the lower belt 10 and divided into individual stone blanks 26 by means of the cutting device 18. The separated stone blanks 26 can then optionally be weighed on a belt weighing line in order to be able to readjust the composition of the raw mixture in this way in order to ensure that the blends are as uniform as possible To achieve cullet bulk density of the stone blanks 26.

Ferner läßt sich die Abwärme des Hochfrequenzgenerators 23 nutzen, indem durch die Generatorkühlung erzeugte Warmluft etwa mittels einer Haube auf die Steinrohlinge 26 geblasen wird, um diese nachzuhärten, so daß diese eine für einen nachfolgenden Transport zu einem Autoklaven ausreichend hohe Festigkeit besitzen, die jedoch nicht voll durch die Erwärmung im Bereich der Kondensatorplattenanordnung 21 erzeugt werden muß. Die Länge des Kanals 14 ist derart bemessen, daß der austretende Strang eine gewünschte Festigkeit aufweist, die gegebenenfalls durch die Nachwärmung mit Warmluft von der Generatorkühlung oder auch einer sonstigen Wärmequelle auf den notwendigen Wert erhöht wird.Furthermore, the waste heat from the high-frequency generator 23 can be used by blowing warm air generated by the generator cooling, for example by means of a hood, onto the stone blanks 26 in order to harden them, so that these have a sufficiently high strength for subsequent transport to an autoclave, but they do not must be fully generated by the heating in the region of the capacitor plate assembly 21. The length of the channel 14 is dimensioned such that the emerging strand has a desired strength, which may be increased to the necessary value by reheating with warm air from the generator cooling or another heat source.

Der Bereich des Kanals 14 wird zweckmäßigerweise in einem nicht dargestellten auf Erdpotential befindlichen Gehäuse untergebracht, das vom Fülltrichter 17 bis zur Schneideeinrichtung 18 reicht.The area of the channel 14 is expediently accommodated in a housing (not shown) which is at ground potential and which extends from the filling funnel 17 to the cutting device 18.

Um andere Formate herstellen zu können, ist es zweckmäßig, wenn die Bänder 10 bis 13 mit ihren Rollen 15 sowie Tragrosten und Gleitführungen in bezug auf ihre Bandebenen verstellbar sind, um so den Querschnitt des Kanals 14 ändern zu können. Die Länge der Rohlinge 26 kann durch den Takt der Schneideeinrichtung 18 verändert werden.In order to be able to produce other formats, it is expedient if the belts 10 to 13 with their rollers 15 as well as support grids and sliding guides can be adjusted with respect to their belt levels so that the cross section of the channel 14 can be changed. The length of the blanks 26 can be changed by the cycle of the cutting device 18.

Zweckmäßigerweise ist die Vorschubgeschwindigkeit der Bänder 10 bis 13 regelbar, und zwar insbesondere stufenlos regelbar, um die Vorschubgeschwindigkeit an die Aufheizgeschwindigkeit und die Größe der Kondensatorplattenanordnung 21 entsprechend anpassen zu können.The feed rate of the belts 10 to 13 is expediently adjustable, in particular continuously adjustable, in order to be able to adapt the feed rate to the heating rate and the size of the capacitor plate arrangement 21 accordingly.

Die Bandstranganlage eignet sich beispielsweise zur Herstellung von Rohlingen für Wandbausteine, insbesondere Leichtbausteine, etwa auf Basis von Kalksilikat, Gas- oder Schaumbeton oder aus grobkeramischem Material, wobei die Rohmischung große Anteile Schaum und Wasser enthält, so daß Scherbenrohdichten bis herab zu 0,2 g/cm' erzielt werden.The belt strand system is suitable, for example, for the production of blanks for wall blocks, in particular lightweight blocks, for example based on lime silicate, gas or foam concrete or from coarse-ceramic material, the raw mixture containing large proportions of foam and water, so that body density down to 0.2 g / cm 'can be achieved.

Bei der in Fig. 2 dargestellten Kondensatorplattenanordnung 21 sind an den Bändern 12 bzw. 13 anliegend mit Abstand zueinander zwei Paare von einander gegenüberliegenden Kondensatorplatten 30 vorgesehen, zwischen denen zwei weitere Paare von einander gegenüberliegenden Kondensatorplatten 31 angeordnet sind, so daß in Längsrichtung des Kanals 14 auf den beiden gegenüberliegenden Seiten jeweils eine Kondensatorplatte 30, zwei Kondensatorplatten 31 und eine Kondensatorplatte 30 aufeinander in Längsrichtung des Kanals 14 folgen. Die äusseren Kondensatorplatten 30 sind an den potentialfreien Anschluß (0) des Hochfrequenzgenerators 23 angeschlossen und erstrecken sich dabei soweit entlang des Kanals 14, daß die von den inneren Kondensatorplatten 31 ausgehenden Streufelder von den Kondensatorplatten 30 auf beiden Seiten aufgenommen werden, so daß der Strang innerhalb des Kanals 14 außerhalb des Erwärmungsbereichs berührungsspannungsfrei ist. Die Kondensatorplatten 31 sind kürzer als die Kondensatorplatten 30 und an den anderen nicht potentialfreien Anschluß (+) des Hochfrequenzgenerators 23 angeschlossen. Außerdem sind zwei Hilfskondensatorplatten 32, die an den nicht potentialfreien Anschluß (+) des Hochfrequenzgenerators 23 angeschlossen sind, benachbart zu den Bändern 10 und 11 einander gegenüberliegend etwa in der Mitte zwischen den vier mittleren Kondensatorplatten 31 vorgesehen. Die Hilfskondensatorplatten 32 können etwa so lang wie die Kondensatorplatten 31 sein, sind jedoch im Verhältnis zum Abstand d zwischen den Kondensatorplatten 30 bzw. 31 schmal und mit ihrer Längsachse in Richtung der Längsachse des Kanals 14 gerichtet. Die Hilfskondensatorplatten 32 führen zusammen mit den gleichgepolten Kondensatorplatten 31 zwischen den äußeren anders gepolten Kondensatorplatten 30 zu einer Feldlinienverteilung, die neben der gesamten Erwärmung des Strangs besonders die Oberflächenerwärmung unterstützt, was zu einer Verkürzung der Erwärmungsstrecke beiträgt, wobei die Hilfskondensatorplatten 32 eine zusätzliche Erwärmung im Bereich des hierzu benachbarten Strang bewirken. Dies führt bei den vorstehend erwähnten Anwendungsfällen zur einer zusätzlichen Verfestigung in diesem Bereich und damit auch zu einem besseren Lösen des verfestigten Strangs von den Bändern 10, 11.In the capacitor plate arrangement 21 shown in FIG. 2, two pairs of mutually opposite capacitor plates 30 are provided adjacent to the belts 12 and 13 at a distance from one another, between which two further pairs of mutually opposite capacitor plates 31 are arranged, so that in the longitudinal direction of the channel 14 a capacitor plate 30, two capacitor plates 31 and a capacitor plate 30 follow one another in the longitudinal direction of the channel 14 on the two opposite sides. The outer capacitor plates 30 are connected to the potential-free connection (0) of the high-frequency generator 23 and extend so far along the channel 14 that the stray fields emanating from the inner capacitor plates 31 are picked up by the capacitor plates 30 on both sides, so that the strand inside of the channel 14 is free of contact voltage outside the heating region. The capacitor plates 31 are shorter than the capacitor plates 30 and connected to the other non-potential-free connection (+) of the high-frequency generator 23. In addition, two auxiliary capacitor plates 32, which are connected to the non-potential-free connection (+) of the high-frequency generator 23, are provided adjacent to the bands 10 and 11 opposite one another approximately in the middle between the four middle capacitor plates 31. The auxiliary capacitor plates 32 can be approximately as long as the capacitor plates 31, but are narrow in relation to the distance d between the capacitor plates 30 and 31 and are directed with their longitudinal axis in the direction of the longitudinal axis of the channel 14. The auxiliary capacitor plates 32 together with the same-polarized capacitor plates 31 lead between the outer, differently polarized capacitor plates 30 to a field line distribution which, in addition to the entire heating of the strand, particularly supports surface heating, which contributes to a shortening of the heating distance, the auxiliary capacitor plates 32 providing additional heating in the area of the adjacent strand. In the above-mentioned applications, this leads to an additional hardening in this area and thus to a better detachment of the hardened strand from the belts 10, 11.

Bei der in Fig. 3 dargestellten Ausführungsform sind zwei Hochfrequenzgeneratoren 23 der halben Gesamtleistung vorgesehen, die unkorreliert sind. Jeweils ein Paar von einander gegenüberliegenden mittleren Kondensatorplatten 31 ist an den potentialfreien und an den nicht potentialfreien Anschluß eines der beiden Hochfrequenzgeneratoren 23 angeschlossen (potentialfreie Zuführung zu den Kondensatorplatten), wobei in Längsrichtung des Strangs die benachbarten Kon':' densatorplatten 31 von entgegengesetzter Polarität, jedoch an jeweils einen anderen Hochfrequenzgenerator 23 angeschlossen sind. Hierdurch wird ein insgesamt bezüglich des Strangquerschnitts recht homogenes Feld erzeugt, so daß auch das Stranginnere gut erwärmt und Schalenbildung vermieden wird.In the embodiment shown in Fig. 3, two high-frequency generators 23 of half the total power are provided, the uncorrected are related. A pair of mutually opposite middle capacitor plates 31 is connected to the floating and the non-floating connection of one of the two high-frequency generators 23 (floating supply to the capacitor plates), the adjacent capacitor plates 31 of opposite polarity in the longitudinal direction of the strand, however, are each connected to a different high-frequency generator 23. As a result, a field which is quite homogeneous overall with respect to the strand cross section is generated, so that the interior of the strand is also warmed well and shell formation is avoided.

Bei der in Fig. 4 dargestellten Ausführungsform ist zur Erzeugung eines homogeneren Feldes vorgesehen, daß zwischen den Kondensatorplatten 30, 31 in Längsrichtung des Strangs jeweils ein Abstand mindestens etwa gleich dem Abstand d zwischen einander gegenüberliegenden Kondensatorplatten 30 oder 31 ist. Die Polung der Kondensatorplatten 30, 31 ist wie bei Fig. 3, jedoch wird nur ein Hochfrequenzgenerator 23 verwendet.In the embodiment shown in FIG. 4, in order to generate a more homogeneous field, it is provided that a distance between the capacitor plates 30, 31 in the longitudinal direction of the strand is at least approximately equal to the distance d between capacitor plates 30 or 31 located opposite one another. The polarity of the capacitor plates 30, 31 is as in FIG. 3, but only one high-frequency generator 23 is used.

In der Mitte zwischen den vier mittleren Kondensatorplatten 31 können wie bei Fig. 2 Hilfskondensatorplatten 32 vorgesehen sein, jedoch derart, daß sie sich ebenfalls etwa im Abstand d von den benachbarten Kondensatorplatten 31 befinden. Die Hilfkondensatorplatten 32 können auch rund oder oval sein.Auxiliary capacitor plates 32 can be provided in the middle between the four middle capacitor plates 31 as in FIG. 2, but in such a way that they are also approximately at a distance d from the adjacent capacitor plates 31. The auxiliary capacitor plates 32 can also be round or oval.

Wenn man bei der in Fig. 4 dargestellten Ausführungsform zwei Hochfrequenzgeneratoren 23 verwendet, die unkorreliert sind, genügt es, wenn nur der Abstand zwischen den auf unterschiedlichem Potential befindlichen Kondensatorplatten 30 und 31 mindestens etwa gleich d ist, wie in Fig. 5 dargestellt. Die Kondensatorplatten 30 sind hierbei jeweils mit dem potentialfreien Ausgangs des Hochfrequenzgenerators 23 verbunden, der auch mit der benachbarten potentialfreien Kondensatorplatte 31 verbunden ist.If two high-frequency generators 23 which are uncorrelated are used in the embodiment shown in FIG. 4, it is sufficient if only the distance between the capacitor plates 30 and 31, which are at different potential, is at least approximately equal to d, as shown in FIG. 5. The capacitor plates 30 are each connected to the floating output of the high-frequency generator 23, which is also connected to the adjacent floating capacitor plate 31.

Werden zwei Hochfrequenzgeneratoren 23 verwendet, deren Ausgänge symmetrisch zum Nullpotential sind, sind die dem an ein Paar von Kondensatorplatten 31 benachbarten Kondensatorplatten 30 auf das Nullpotential des jeweiligen Hochfrequenzgenerators 23 zu legen, damit Berührungsspannungsfreiheit gewährleistet ist.If two high-frequency generators 23 are used, the outputs of which are symmetrical to the zero potential, the capacitor plates 30 adjacent to a pair of capacitor plates 31 must be connected to the zero potential of the respective high-frequency generator 23, since guaranteed with no contact voltage.

Zwischen benachbarten auf Nullpotential liegenden Kondensatorplatten 30, 31 kann der Abstand kleiner als d gewählt werden, wie in Fig. 5 dargestellt ist.The distance between adjacent capacitor plates 30, 31 lying at zero potential can be chosen to be smaller than d, as shown in FIG. 5.

Man kann auch die Hilfkondensatorplatten 32 der Ausführungsform von Fig. 4 an einen weiteren nichtkorrelierten Hochfrequenzgenerator 23 anschließen, wobei dann der Abstand zwischen den Kondensatorplatten 31 und 32 entsprechend gering gewählt werden kann.The auxiliary capacitor plates 32 of the embodiment of FIG. 4 can also be connected to a further non-correlated high-frequency generator 23, in which case the distance between the capacitor plates 31 and 32 can be chosen to be correspondingly small.

Bei der in Fig. 6 dargestellten Ausführungsform ist die Kondensatorplattenanordnung wie in Fig. 5, jedoch wird nur ein Hochfrequenzgenerator 23 verwendet. Dafür werden aber die einander gegenüberliegenden Paare von Kondensatorplatten 31 symmetrisch zum Nullpotential spannungsbeaufschlagt, indem eine Kondensatorplatte 31 mit einem Ausgangsanschluß des Hochfrequenzgenerators 23 verbunden und die gegenüberliegende Kondensatorplatte 31 mit letzterer über eine phasenverschiebende lambda/2-Umwegleitung 34 oder ein Phasenschiebemetzwerk verbunden ist, das eine Phasenverschiebung um eine halbe Periode bewirkt.In the embodiment shown in FIG. 6, the capacitor plate arrangement is as in FIG. 5, but only one high-frequency generator 23 is used. For this purpose, however, the opposing pairs of capacitor plates 31 are subjected to voltage symmetrically to the zero potential, in that a capacitor plate 31 is connected to an output connection of the high-frequency generator 23 and the opposite capacitor plate 31 is connected to the latter via a phase-shifting lambda / 2 bypass line 34 or a phase shift network, which is one Phase shift caused by half a period.

Stattdessen kann aber auch ein Hochfrequenzgenerator 23 mit symmetrischem Ausgang verwendet werden. Die einander gegenüberliegenden Paare von Kondensatorplatten 31 werden dabei symmetrisch zum Nullpotential spannungsbeaufschlagt, indem eine Kondensatorplatte 31 mit einem Ausgangsanschluß des Hochfrequenzgenerators 23 und die bezüglich des Strangs gegenüberliegende Kondensatorplatte 31 mit dem anderen Ausgangsanschluß des Hochfrequenzgenerators 23 verbunden wird, was eine gegenphasige Ansteuerung der gegenüberliegenden Elektroden bewirkt. Die Kondensatorplatten 30 sind dann mit dem Nullpotential des Hochfrequenzgenerators 23 verbunden.Instead, a high-frequency generator 23 with a symmetrical output can also be used. The opposing pairs of capacitor plates 31 are subjected to voltage symmetrically to the zero potential by connecting a capacitor plate 31 to one output connection of the high-frequency generator 23 and the capacitor plate 31 opposite with respect to the string to the other output connection of the high-frequency generator 23, which causes the opposite electrodes to be driven in phase . The capacitor plates 30 are then connected to the zero potential of the high-frequency generator 23.

Gemäß Fig. 7 kann vorgesehen sein, daß die an den nicht geerdeten Anschluß des Hochfrequenzgenerators angeschlossene Kondensatorplatte 31 an beiden Enden quer zur Längsrichtung des Strangs eine kleines Stück über die Bänder 10, 11 übergreift, entweder durch eine Abwinkelung 35 oder durch eine eigene schmale Hilfskondensatorplatte 36 realisiert, wodurch das Feld im Ober- und Unterbereich des Strangs zur lokalen Oberflächenerwärmung leicht komprimiert wird. Wenn sich daran ein weiteres Kondensatorplattenpaar 31 umgekehrter Polung anschließt, befindet sich dort das inhomogenere Feld auf der anderen Seite des Strangs, so daß sich insgesamt eine gute homogene Oberflächenerwärmung ergibt. Hierbei kann man mit einem oder mit zwei unkorrelierten Hochfrequenzgeneratoren 23 oder mit symmetrischen oder unsymmetrischen Potential (bezüglich des Nullpotentials) arbeiten.According to FIG. 7, it can be provided that the capacitor plate 31 connected to the ungrounded connection of the high-frequency generator overlaps a small piece across the bands 10, 11 at both ends transversely to the longitudinal direction of the strand, either by means of a bend 35 or by its own narrow auxiliary capacitor plate 36 realized, whereby the field in the upper and lower region of the strand is slightly compressed for local surface heating. If this is followed by a further pair of capacitor plates 31 of reversed polarity, the more inhomogeneous field is located on the other side of the strand, so that overall a good homogeneous surface heating results. One can work with one or two uncorrelated high-frequency generators 23 or with symmetrical or asymmetrical potential (with respect to the zero potential).

Gemäß Fig. 8 können die Kondensatorplatten 31 (und eventuell auch 30) aus mehreren, benachbart zueinander angeordneten Teilplatten 31a, 31b bestehen, um den Skin-Effekt im Strangmaterial so gering wie möglich zu halten. Die Teilplatten 31a, 31b liegen auf gleichen Potential und ihre benachbarten Kanten sind durch einen Schlitz 37 getrennt, der infolge gleichen Potentials so eng wie möglich sein kann.According to FIG. 8, the capacitor plates 31 (and possibly also 30) can consist of several partial plates 31a, 31b arranged adjacent to one another in order to keep the skin effect in the strand material as low as possible. The partial plates 31a, 31b are at the same potential and their adjacent edges are separated by a slot 37, which can be as narrow as possible due to the same potential.

Bei der in Fig. 9 dargestellten Ausführungsform ist ein Zylinderkondensator vorgesehen, bei dem die gegenüberliegenden Kondensatorplatten 31 zu einem Kasten 38 geschlossen sind, der den Kanal 14 und die Bänder 10, 11, 12, 13 umgreift. Im Inneren des Kanals 14 befindet sich im Bereich des Kastens 38 wenigstens eine Kondensatorelektrode 39, gegenüber dem im Kanal 14 befindlichen Strangmaterial durch eine Hülle 40 aus isolierendem Kunststoff geschützt, wobei die äußere kastenförmige Kondensatorelektrode 38 und die Innenelektrode(n) 39 auf unterschiedlichem Potential liegen, z.B. wie in Fig. 9 angegeben.In the embodiment shown in FIG. 9, a cylindrical capacitor is provided, in which the opposite capacitor plates 31 are closed to form a box 38 which surrounds the channel 14 and the bands 10, 11, 12, 13. Inside the channel 14 there is at least one capacitor electrode 39 in the area of the box 38, protected from the strand material in the channel 14 by a sleeve 40 made of insulating plastic, the outer box-shaped capacitor electrode 38 and the inner electrode (s) 39 being at different potentials , e.g. as indicated in Fig. 9.

Wie in Fig. 10 dargestellt, ist es zweckmäßig, in Bezug auf den Strang etwas konkav ausgebildete Kondensatorplatten 30, 31 zu verwenden, wodurch ebenfalls ein Beitrag zur Homogenisierung des Feldes erhalten wird. Außerdem kann die Konkavität der Kondensatorplatte 30, 31 mit einem Material 41 mit möglichst hoher Dielektrizitätskonstante ausgefüllt sein, so daß ihre dem entsprechenden Band 10, 11, 12 oder 13 zugewandte Fläche plan ist und an diesem anliegt. Während Kunststoffe eine Dielektrizitätskonstante in der Größenordnung von etwa 2 bis 4 aufweisen (bei einem Verlustfaktor tg G, der extrem niedrig ist, so daß sich der Kunststoff praktisch auch nicht erwärmt), sind hier Materialien wie Calciumtitanat vorgesehen, deren Dielektrizitätskonstante sehr viel größer als 1 ist. Außerdem zeigen diese Materialien hohe Formstabilität und einen geringen Temperaturausdehnungskoeffizienten. Fig. 11 zeigt den normierten Potentialverlauf zwischen zwei gegenüberliegenden Kondensatorplatten für eine Kunststoffschicht zwischen Strang und Kondensatorplatte (gestrichelt) und für ein Material mit hoher Dielektrizitätskonstante zwischen Strang und Kondensatorplatte (durchgezogen). Ersichtlich ergibt sich im letzteren Falle ein sehr viel kleinerer Spannungsabfall über den Kondensatorplatten, was die Betriebssicherheit deutlich erhöht. Das Stranggut hat zumindestens bei den vorstehend angesprochenen Anwendungsfällen eine Dielektrizitätskonstante von ca. 40 bis 80 und einen nennenswerten Verlustfaktor tg

Figure imgb0001
, d.h. das Stranggut ist mittels eines Hochfrequenzfeldes besonders gut erwärmbar.As shown in FIG. 10, it is expedient to use somewhat concave capacitor plates 30, 31 with respect to the strand, which also contributes to the homogenization of the field. In addition, the concavity of the capacitor plate 30, 31 can be filled with a material 41 with the highest possible dielectric constant, so that its surface facing the corresponding band 10, 11, 12 or 13 is flat and abuts against it. While plastics have a dielectric constant of the order of about 2 to 4 (with a loss factor tg G that is extremely low, so that the plastic practically does not heat up), materials such as calcium titanate are provided here, the dielectric constant of which is very much greater than 1 is. Also show these materials have high dimensional stability and a low coefficient of thermal expansion. 11 shows the normalized potential curve between two opposing capacitor plates for a plastic layer between the strand and the capacitor plate (dashed) and for a material with a high dielectric constant between the strand and the capacitor plate (solid). Obviously there is a much smaller voltage drop across the capacitor plates in the latter case, which significantly increases operational reliability. At least in the above-mentioned applications, the strand material has a dielectric constant of approximately 40 to 80 and a significant loss factor tg
Figure imgb0001
, ie the continuous material can be heated particularly well by means of a high-frequency field.

Außerdem ist es zweckmäßig, die Kondensatorplatten an der den Bändern zugewandten Seiten mit einer Kunststoffschicht zu versehen bzw. die Kondensatorplatten in Kunststoff einzubetten, um den Verschleiß der sich an den Kondensatorplatten entlang bewegenden Bänder gering zu halten. Diese Kunststoffbeschichtung sollte jedoch so dünn wie möglich sein, um das Spannungsprofil nicht zu stark zu beeinflussen. Zum selben Zweck kann das Material 41 an der dem Band zugekehrten Seite geschliffen und poliert sein.In addition, it is expedient to provide the capacitor plates with a plastic layer on the sides facing the strips or to embed the capacitor plates in plastic in order to keep the wear on the strips moving along the capacitor plates low. However, this plastic coating should be as thin as possible so as not to influence the stress profile too much. For the same purpose, the material 41 can be ground and polished on the side facing the belt.

Claims (18)

1. Vorrichtung zum Erwärmen eines in einem Kanal (14) geführten Strangs aus einem elektrisch leitfähigen, vorzugsweise sich durch die Erwärmung verfestigenden Materials, wobei eine Kondensatorplattenanordnung (21), die an einen Hochfrequenzgenerator (23) angeschlossen ist, elektrisch isoliert gegenüber dem Strang angeordnet ist, und wobei die Kondensatorplattenanordnung (21) zwei benachbarte Paare von Kondensatorplatten (31) aufweist, zu deren beiden Seiten zwei weitere Paare von Kondensatorplatten (30) angeordnet sind, die mit dem potentialfreien Anschluß des Hochfrequenzgenerators (23) verbunden sind, dadurch gekennzeichnet, daß die Kondensatorplatten (31) sämtlich an den nicht potentialfreien Anschluß des Hochfrequenzgenerators (23) angeschlossen und an den beiden gegenüberliegenden Seiten des Strangs, an denen keine Kondensatorplatten (31) anliegen, im mittleren Bereichs des Strangs und der Erstreckung der Kondensatorplatten (31) jeweils eine Hilfskondensatorplatte (32) vorgesehen ist, die ebenfalls an den nicht potentialfreien Anschluß des Hochfrequenzgenerators (23) angeschlossen ist.1. Device for heating a strand in a channel (14) made of an electrically conductive material, preferably solidifying through the heating, wherein a capacitor plate arrangement (21), which is connected to a high-frequency generator (23), is arranged electrically insulated from the strand and wherein the capacitor plate arrangement (21) has two adjacent pairs of capacitor plates (31), on the two sides of which two further pairs of capacitor plates (30) are arranged, which are connected to the floating connection of the high-frequency generator (23), characterized in that that the capacitor plates (31) are all connected to the non-potential-free connection of the high-frequency generator (23) and on the two opposite sides of the line, on which no capacitor plates (31) are present, in the central region of the line and the extension of the capacitor plates (31) in each case an auxiliary capacitor plate (32) is provided is, which is also connected to the non-potential-free connection of the high-frequency generator (23). 2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die Hilfskondensatorplatten (32) in Längsrichtung des Strangs schmal sind.2. Device according to claim 1, characterized in that the auxiliary capacitor plates (32) are narrow in the longitudinal direction of the strand. 3. Vorrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Hilfskondensatorplatten (32) etwa gleiche Länge wie die Kondensatorplatten (31) haben.3. Apparatus according to claim 1 or 2, characterized in that the auxiliary capacitor plates (32) have approximately the same length as the capacitor plates (31). 4. Vorrichtung zum Erwärmen eines in einem Kanal (14) geführten Strangs aus einem elektrisch leitfähigen, vorzugsweise sich durch die Erwärmung verfestigenden Materials, wobei eine Kondensatorplattenanordnung (21), die an einen Hochfrequenzgenerator (23) angeschlossen ist, elektrisch isoliert gegenüber dem Strang angeordnet ist, und wobei die Kondensatorplattenanordnung (21) zwei benachbarte Paare von Kondensatorplatten (31) aufweist, zu deren beiden Seiten zwei weitere Paare von Kondensatorplatten (30) angeordnet sind, die mit dem potentialfreien Anschluß des Hochfrequenzgenerators (23) verbunden sind, dadurch gekennzeichnet, daß ein weiterer, mit dem ersten Hochfrequenzgenerator nicht korrelierter Hochfrequenzgenerator (23) vorgesehen und jeweils ein Paar von Kondensatorplatten (31) mit den Ausgängen jeweils eines Hochfrequenzgenerators (23) verbunden ist.4. Device for heating a strand guided in a channel (14) made of an electrically conductive material, preferably solidified by the heating, a capacitor plate arrangement (21) connected to a high-frequency generator (23) is arranged in an electrically insulated manner from the strand, and wherein the capacitor plate arrangement (21) has two adjacent pairs of capacitor plates (31), on the two sides of which two further pairs of capacitor plates (30) are arranged, which are connected to the potential-free connection of the high-frequency generator ( 23), characterized in that a further high-frequency generator (23) which is not correlated with the first high-frequency generator is provided and a pair of capacitor plates (31) is connected to the outputs of one high-frequency generator (23). 5. Vorrichtung nach Anspruch 4, dadurch gekennzeichnet, daß zwei der einander schräg gegenüberbefindlichen Kondensatorplatten (31) an die potentialfreien Anschlüsse der Hochfrequenzgeneratoren (23) angeschlossen sind.5. The device according to claim 4, characterized in that two of the obliquely opposite capacitor plates (31) to the floating connections of the high frequency generators (23) are connected. 6. Vorrichtung nach Anspruch 4 oder 5, dadurch gekennzeichnet, daß zwischen in Längsrichtung des Strangs benachbarten Kondensatorplatten (30, 31) ein Abstand etwa mindestens gleich dem Abstand (d) der sich bezüglich des Strangs gegenüberbefindlichen Kondensatorplatten (30 bzw. 31) vorgesehen ist.6. Apparatus according to claim 4 or 5, characterized in that between adjacent in the longitudinal direction of the strand capacitor plates (30, 31) a distance approximately at least equal to the distance (d) with respect to the strand opposite capacitor plates (30 and 31) is provided . 7. Vorrichtung zum Erwärmen eines in einem Kanal (14) geführten Strangs aus einem elektrisch leitfähigen, vorzugsweise sich durch die Erwärmung verfestigenden Materials, wobei eine Kondensatorplattenanordnung (21), die an einen Hochfrequenzgenerator (23) angeschlossen ist, elektrisch isoliert gegenüber dem Strang angeordnet ist, und wobei die Kondensatorplattenanordnung (21) zwei benachbarte Paare von Kondensatorplatten (31) aufweist, zu deren beiden Seiten zwei weitere Paare von Kondensatorplatten (30) angeordnet sind, die mit dem potentialfreien Anschluß des Hochfrequenzgenerators (23) verbunden sind, insbesondere nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß der Abstand der in Längsrichtung des Strangs benachbart angeordneten Kondensatorplatten (30, 31) etwa mindestens gleich dem Abstand (d) der sich bezüglich des Strangs gegenüberbefindlichen Kondensatorplatten (30 bzw. 31) ist.7. Device for heating a strand, which is guided in a channel (14) and is made of an electrically conductive material, preferably solidifying as a result of the heating, wherein a capacitor plate arrangement (21), which is connected to a high-frequency generator (23), is arranged in an electrically insulated manner from the strand and wherein the capacitor plate arrangement (21) has two adjacent pairs of capacitor plates (31), on the two sides of which two further pairs of capacitor plates (30) are arranged, which are connected to the potential-free connection of the high-frequency generator (23), in particular according to one of claims 1 to 3, characterized in that the distance between the capacitor plates (30, 31) arranged adjacent in the longitudinal direction of the strand is approximately at least equal to the distance (d) of the capacitor plates (30 and 31) located opposite one another with respect to the strand. 8. Vorrichtung nach Anspruch 7, dadurch gekennzeichnet, daß an den beiden gegenüberbefindlichen Seiten des Strangs, an denen keine Kondensatorplatten (31) anliegen, im mittleren Bereich des Strangs jeweils eine Hilfskondensatorplatte (32) vorgesehen ist, die zu den benachbarten Kanten der Kondensatorplatten (31) einen Abstand etwa gleich dem Abstand (d) der sich bezüglich des Strangs gegenüberbefindlichen Kondensatorplatten (30 bzw. 31) hat.8. The device according to claim 7, characterized in that on the two opposite sides of the strand, on which no Kon contact the capacitor plates (31), an auxiliary capacitor plate (32) is provided in the central region of the strand, which is a distance from the adjacent edges of the capacitor plates (31) approximately equal to the distance (d) of the capacitor plates (30 or 31) has. 9. Vorrichtung zum Erwärmen eines in einem Kanal (14) geführten Strangs aus einem elektrisch leitfähigen, vorzugsweise sich durch die Erwärmung verfestigenden Materials, wobei eine Kondensatorplattenanordnung (21), die an einen Hochfrequenzgenerator (23) angeschlossen ist, elektrisch isoliert gegenüber dem Strang angeordnet ist, und wobei die Kondensatorplattenanordnung (21) zwei benachbarte Paare von Kondensatorplatten (31) aufweist, zu deren beiden Seiten zwei weitere Paare von Kondensatorplatten (30) angeordnet sind, die mit dem potentialfreien Anschluß des Hochfrequenzgenerators (23) verbunden sind, insbesondere nach einem der Ansprüche 4 bis 8, dadurch gekennzeichnet, daß der Abstand zwischen den auf Nullpotential befindlichen Kondensatorplatten (30) und den in Längsrichtung des Strangs benachbarten Kondensatorplatten (31) etwa mindestens gleich dem Abstand (d) der sich bezüglich des Strangs gegenüberbefindlichen Kondensatorplatten (30 bzw. 31) ist, während die Kondensatorplatten (31) die sich bezüglich des Strangs gegenüberliegen, symmetrisch zum Nullpotential beaufschlagt sind.9. Device for heating a strand guided in a channel (14) from an electrically conductive material, preferably solidifying by the heating, wherein a capacitor plate arrangement (21), which is connected to a high-frequency generator (23), is arranged electrically insulated from the strand and wherein the capacitor plate arrangement (21) has two adjacent pairs of capacitor plates (31), on the two sides of which two further pairs of capacitor plates (30) are arranged, which are connected to the potential-free connection of the high-frequency generator (23), in particular according to one of claims 4 to 8, characterized in that the distance between the capacitor plates (30) located at zero potential and the capacitor plates (31) adjacent in the longitudinal direction of the strand is approximately at least equal to the distance (d) of the capacitor plates (30 or . 31) is while the capacitor plates (31), which are opposite each other with respect to the string, are applied symmetrically to the zero potential. 10. Vorrichtung nach Anspruch 9, dadurch gekennzeichnet, daß eine Kondensatorplatte (31) mit der bezüglich des Strangs gegenüberliegenden über eine Lambda/2-Umwegleitung (34) oder ein Phasenschiebernetzwerk verbunden ist.10. The device according to claim 9, characterized in that a capacitor plate (31) with the opposite with respect to the strand via a lambda / 2 detour line (34) or a phase shifter network is connected. 11. Vorrichtung nach Anspruch 9, dadurch gekennzeichnet, daß der Hochfrequenzgenerator (23) symmetrische Ausgangsanschlüsse bezüglich des Nullpotentials aufweist.11. The device according to claim 9, characterized in that the high-frequency generator (23) has symmetrical output connections with respect to the zero potential. 12. Vorrichtung zum Erwärmen eines in einem Kanal (14) geführten Strangs aus einem elektrisch leitfähigen, vorzugsweise sich durch die Erwärmung verfestigenden Materials, wobei eine Kondensatorplattenanordnung (21), die an einen Hochfrequenzgenerator (23) angeschlossen ist, elektrisch isoliert gegenüber dem Strang angeordnet ist, und wobei gegebenenfalls die Kondensatorplattenanordnung (21) zwei Paare von Kondensatorplatten (30) aufweist, die mit dem potentialfreien Anschluß des Hochfrequenzgenerators (23) verbunden sind, dadurch gekennzeichnet, daß ein Zylinderkondensator bestehend aus einer den Strang umschließenden Kondensatorelektrode (38) und mindestens einer im Inneren des Strangs befindlichen Kondensatorgegenelektrode (39) besteht, die im Bereich der umschließenden Kondensatorelektrode (38) angeordnet ist.12. Device for heating a strand, which is guided in a channel (14) and is made of an electrically conductive material, preferably solidifying as a result of the heating, a capacitor plate arrangement (21) which is connected to a high-frequency generator (23) being arranged in an electrically insulated manner with respect to the strand is and where appropriate, the capacitor plate arrangement (21) has two pairs of capacitor plates (30) which are connected to the potential-free connection of the high-frequency generator (23), characterized in that a cylindrical capacitor consists of a capacitor electrode (38) enclosing the strand and at least one inside of the strand located capacitor counterelectrode (39), which is arranged in the area of the surrounding capacitor electrode (38). 13. Vorrichtung nach einem der Ansprüche 1 bis 12, dadurch gekennzeichnet, daß die Kondensatorplatten (31, 38 und gegebenenfalls 30) aus mindestens zwei Teilplatten (31a, 31b), die durch einen Spalt13. Device according to one of claims 1 to 12, characterized in that the capacitor plates (31, 38 and optionally 30) from at least two partial plates (31a, 31b) through a gap (37) getrennt sind, bestehen.(37) are separate. 14. Vorrichtung nach einem der Ansprüche 1 bis 13, dadurch gekennzeichnet, daß die Kondensatorplatten (31 und gegebenenfalls 30) in Richtung auf den Strang konkav ausgebildet sind, wobei die Konkavität mit einem elektrisch isolierenden Material ausgefüllt ist.14. Device according to one of claims 1 to 13, characterized in that the capacitor plates (31 and optionally 30) are concave in the direction of the strand, the concavity being filled with an electrically insulating material. 15. Vorrichtung nach Anspruch 14, dadurch gekennzeichnet, daß das elektrisch isolierende Material eine Dielektrizitätskonstante sehr viel größer als 1, vorzugsweise größer als 100 aufweist.15. The apparatus according to claim 14, characterized in that the electrically insulating material has a dielectric constant very much greater than 1, preferably greater than 100. 16. Vorrichtung nach einem der Ansprüche 1 bis 11 gegebenenfalls zusammen mit einem der Ansprüche 13 bis 15, dadurch gekennzeichnet, daß die nicht auf Nullpotential befindlichen Kondensatorplatten (31) an beiden sich in Längsrichtung des Strangs erstreckenden Kanten den Strang auf seinen freien Seiten mittels einer Abwinkelung (35) oder einer getrennten Hilfskondensatorplatte (36) ein kleines Stück im Vergleich zur Strangbreite übergreifen.16. Device according to one of claims 1 to 11, optionally together with one of claims 13 to 15, characterized in that the capacitor plates (31) which are not at zero potential on both edges extending in the longitudinal direction of the strand, the strand on its free sides by means of a Angle (35) or a separate auxiliary capacitor plate (36) overlap a small piece compared to the strand width. 17. Vorrichtung nach einer der Ansprüche 4 bis 9 oder 12 bis 16, dadurch gekennzeichnet, daß die sich bezüglich des Strangs gegenüberliegenden Kondensatorplatten (31) bzw. -elektroden (38, 39) symmetrisch zum Nullpotential beaufschlagbar sind.17. Device according to one of claims 4 to 9 or 12 to 16, characterized in that the capacitor plates (31) or electrodes (38, 39) lying opposite one another with respect to the strand can be applied symmetrically to the zero potential.
EP86117107A 1985-12-10 1986-12-09 Arrangement for heating a billet of electrically conductive material Expired - Lifetime EP0228615B1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP92101680A EP0486472B1 (en) 1985-12-10 1986-12-09 Device for heating a length of electrically conductive material
EP92101681A EP0485363B1 (en) 1985-12-10 1986-12-09 Device for heating a long product of electrical conductive material
EP92101679A EP0487504B1 (en) 1985-12-10 1986-12-09 Arrangement for heating an elongated piece of electrically conductive material
AT86117107T ATE81434T1 (en) 1985-12-10 1986-12-09 DEVICE FOR HEATING A STRING OF ELECTRICALLY CONDUCTIVE MATERIAL.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19853543569 DE3543569A1 (en) 1985-12-10 1985-12-10 DEVICE FOR HEATING A STRAND OF ELECTRICALLY CONDUCTIVE MATERIAL
DE3543569 1985-12-10

Related Child Applications (4)

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EP92101680A Division EP0486472B1 (en) 1985-12-10 1986-12-09 Device for heating a length of electrically conductive material
EP92101680.4 Division-Into 1992-02-01
EP92101679.6 Division-Into 1992-02-01
EP92101681.2 Division-Into 1992-02-01

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EP0228615A2 true EP0228615A2 (en) 1987-07-15
EP0228615A3 EP0228615A3 (en) 1988-06-08
EP0228615B1 EP0228615B1 (en) 1992-10-07

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EP92101681A Expired - Lifetime EP0485363B1 (en) 1985-12-10 1986-12-09 Device for heating a long product of electrical conductive material
EP92101680A Expired - Lifetime EP0486472B1 (en) 1985-12-10 1986-12-09 Device for heating a length of electrically conductive material
EP92101679A Expired - Lifetime EP0487504B1 (en) 1985-12-10 1986-12-09 Arrangement for heating an elongated piece of electrically conductive material
EP86117107A Expired - Lifetime EP0228615B1 (en) 1985-12-10 1986-12-09 Arrangement for heating a billet of electrically conductive material

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EP92101681A Expired - Lifetime EP0485363B1 (en) 1985-12-10 1986-12-09 Device for heating a long product of electrical conductive material
EP92101680A Expired - Lifetime EP0486472B1 (en) 1985-12-10 1986-12-09 Device for heating a length of electrically conductive material
EP92101679A Expired - Lifetime EP0487504B1 (en) 1985-12-10 1986-12-09 Arrangement for heating an elongated piece of electrically conductive material

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EP (4) EP0485363B1 (en)
AT (4) ATE112129T1 (en)
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Cited By (2)

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Publication number Priority date Publication date Assignee Title
DE3817831A1 (en) * 1988-05-26 1989-11-30 Sicowa Verfahrenstech Process for producing blocks
EP0413975A2 (en) * 1989-08-21 1991-02-27 General Electric Company High dielectric constant material to shape electric fields for heating plastics

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102021121013A1 (en) 2021-08-12 2023-02-16 KB Engineering GmbH Process for the production of single or multi-layer shaped elements, in particular wall or stone elements, and associated plant

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US2288269A (en) * 1941-06-04 1942-06-30 Compo Shoe Machinery Corp Electrostatic heating apparatus
DE858868C (en) * 1951-02-18 1952-12-11 Siemens Ag Method for treating a e.g. B. piece-shaped goods by the action of an alternating field
EP0085318B1 (en) * 1982-01-30 1987-09-09 SICOWA Verfahrenstechnik für Baustoffe GmbH & Co. KG Device for heating an extrusion moulding track of electrically conductive material, and the use thereof

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GB726359A (en) * 1952-05-23 1955-03-16 Bostadsforskning Ab Improvements in or relating to high frequency heating systems
DE933046C (en) * 1953-04-19 1955-09-15 Siemens Ag Device for treating particularly grainy bulk material by means of a high-frequency field
AT184997B (en) * 1954-08-09 1956-03-10 Bostadsforskning Ab Device for high-frequency heating of workpieces that are transported in carriages, slides or the like through a heating system

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Publication number Priority date Publication date Assignee Title
US2288269A (en) * 1941-06-04 1942-06-30 Compo Shoe Machinery Corp Electrostatic heating apparatus
DE858868C (en) * 1951-02-18 1952-12-11 Siemens Ag Method for treating a e.g. B. piece-shaped goods by the action of an alternating field
EP0085318B1 (en) * 1982-01-30 1987-09-09 SICOWA Verfahrenstechnik für Baustoffe GmbH & Co. KG Device for heating an extrusion moulding track of electrically conductive material, and the use thereof

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3817831A1 (en) * 1988-05-26 1989-11-30 Sicowa Verfahrenstech Process for producing blocks
EP0413975A2 (en) * 1989-08-21 1991-02-27 General Electric Company High dielectric constant material to shape electric fields for heating plastics
EP0413975A3 (en) * 1989-08-21 1991-08-21 General Electric Company High dielectric constant material to shape electric fields for heating plastics

Also Published As

Publication number Publication date
DE3543569A1 (en) 1987-06-11
EP0487504B1 (en) 1994-10-26
ATE114212T1 (en) 1994-12-15
DE3650141D1 (en) 1994-12-22
EP0485363B1 (en) 1994-11-17
DE3686938D1 (en) 1992-11-12
EP0487504A1 (en) 1992-05-27
DE3650115D1 (en) 1994-12-01
EP0486472A2 (en) 1992-05-20
EP0486472B1 (en) 1994-09-21
EP0485363A2 (en) 1992-05-13
ATE112129T1 (en) 1994-10-15
EP0228615A3 (en) 1988-06-08
EP0485363A3 (en) 1992-05-27
ATE113434T1 (en) 1994-11-15
EP0486472A3 (en) 1992-05-27
DE3650076D1 (en) 1994-10-27
EP0228615B1 (en) 1992-10-07
ATE81434T1 (en) 1992-10-15

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