EP0216978B1 - Method and device for extruding carbon masses, in particular carbon electrodes - Google Patents

Method and device for extruding carbon masses, in particular carbon electrodes Download PDF

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Publication number
EP0216978B1
EP0216978B1 EP19850890266 EP85890266A EP0216978B1 EP 0216978 B1 EP0216978 B1 EP 0216978B1 EP 19850890266 EP19850890266 EP 19850890266 EP 85890266 A EP85890266 A EP 85890266A EP 0216978 B1 EP0216978 B1 EP 0216978B1
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European Patent Office
Prior art keywords
cylinder
press
mouthpiece
pressure
strand
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EP19850890266
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German (de)
French (fr)
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EP0216978A1 (en
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Aktiengesellschaft Voest-Alpine
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Voestalpine AG
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Voestalpine AG
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B11/00—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses
    • B30B11/22—Extrusion presses; Dies therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B11/00—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses
    • B30B11/22—Extrusion presses; Dies therefor
    • B30B11/224—Extrusion chambers

Definitions

  • the invention relates to a method for extruding carbon masses, in particular carbon electrodes, wherein the carbon mass introduced into a press cylinder with a closable mouthpiece is first compressed by means of a press ram with the mouthpiece closed and then pressed out of the press cylinder with the mouthpiece open, and to a device to carry out the method (DE-A-28 55 899).
  • the carbon mass Before carbon electrodes can be burned, the carbon mass must be shaped and compressed accordingly.
  • the carbon sleeve is placed in a press cylinder with a lockable mouthpiece and pre-compressed in this press cylinder with the mouthpiece closed using a press ram before the actual shaping and compression process can take place by squeezing out the carbon mass through the mouthpiece.
  • the quality of the later electrodes depends among other things on a uniform grain orientation of the mass particles in the press strand and on sufficient compression of the press strand. As has been shown, one of the conditions for a uniform grain alignment can be seen in an at least approximately constant exit speed of the press strand from the die of the press cylinder.
  • this exit speed of the press strand from the mouthpiece of the press cylinder depends on the press pressure exerted on the carbon mass via the press ram, so that only a certain press pressure may be applied for an advantageous exit speed range.
  • a desired grain orientation in the press strand can therefore only be ensured if a certain pressing force and, depending on it, a certain compression are maintained.
  • this compaction is generally not sufficient, so that in such cases vibration compaction in closed molds is adopted, although grain orientation cannot be achieved.
  • the invention is therefore based on the object of avoiding these deficiencies and of specifying a method for extruding carbon masses in which, in spite of good grain orientation, any desired compression of the extruded strand can be ensured.
  • the invention solves this problem in that a counter pressure to the pressing pressure is exerted on the strand of carbon mass emerging from the mouthpiece.
  • the exit speed when a back pressure is applied depends on the difference between the press pressure and the back pressure and this pressure difference can be easily adapted to the desired exit speed of the press strand from the mouthpiece, a compression pressure that is independent of the exit speed can be exerted on the carbon mass.
  • the increase in the exit speed, which is otherwise caused by an increase in the pressing pressure, is prevented by the correspondingly selected counter pressure, so that the pressing strand can emerge from the mouthpiece of the pressing cylinder at a speed which is advantageous for the desired orientation.
  • the effective squeezing pressure in the mouthpiece area increases with increasing press ram stroke, which results in an increasing exit speed.
  • the application pressure of the press ram would have to be controlled as a function of the press ram stroke. If it is not the action of the press ram but the counterforce that is controlled, namely in the sense of an increase in the counterpressure with increasing length of the press run, a constant exit speed for the press run can be achieved even if the press ram is acted on consistently.
  • a known device can be used (DE-A-28 55 899), which provides a guide sleeve arranged at a distance from the mouthpiece of the press cylinder for the press strand emerging from a vertically arranged press cylinder, in order to prevent deformation of the press strand during its removal avoid.
  • the press strand received by the guide sleeve is namely conveyed along with the guide sleeve.
  • the guide sleeve of such a device is designed as an axially displaceable pressure cylinder which can be tightly connected to the mouthpiece of the press cylinder and has a pressure stamp guided therein, a desired counterpressure to the pressure can be exerted on the press strand emerging from the mouthpiece of the press cylinder be because the jacket of the pressure cylinder effectively prevents radial deflection of the press strand.
  • the pressure stamp must of course be able to be pushed back over the emerging press strand without changing the position of the pressure cylinder. Is the ge reaches the desired length of the press strand, the pressure cylinder can be withdrawn axially from the mouthpiece in order to be able to sever the press strand.
  • the jacket of the pressure cylinder can have lubrication openings connected to at least one pressure line for a lubricant, through which the lubricant is pressed between the jacket of the pressure cylinder and the press strand.
  • the press strand In the case of a horizontal press cylinder arrangement, the press strand must be supported appropriately when pulling off the pressure cylinder.
  • adjustable support supports can be arranged outside the printing cylinder, which are pivoted or raised when the printing cylinder is pulled off the strand into the working position.
  • a particularly advantageous support of the press strand is obtained, however, when a support beam forming part of the inner wall for the press strand is guided axially displaceably in the jacket of the pressure cylinder, because in this case the press strand can remain on the support beam when the pressure cylinder is removed.
  • the support bracket is held stationary when the printing cylinder is removed and pulled out of the printing cylinder jacket.
  • the device shown for the extrusion of carbon electrodes essentially consists of a press cylinder 1 which has a mouthpiece 3 which can be closed by means of a cover 2 and which receives a press ram 4 in a displaceable manner.
  • a press cylinder 1 which has a mouthpiece 3 which can be closed by means of a cover 2 and which receives a press ram 4 in a displaceable manner.
  • an axially displaceable pressure cylinder 5 is provided, which can be connected tightly to the mouthpiece 3 of the press cylinder 1 and is provided with a pressure stamp 6.
  • the plunger 6 guided in the pressure cylinder 5 is acted upon accordingly and pressed against the carbon mass 7 in the region of the mouthpiece, as is indicated in FIG. 2. If the press ram 4 is now acted upon, the carbon mass 7 is pressed out of the mouthpiece 3 against the force of the pressure ram 6, the emerging press strand 8 being guided through the pressure cylinder 5, so that a corresponding counter pressure to the press pressure can be exerted via the pressure ram 6 .
  • a compression pressure which depends on the size of the pressing pressure and the size of the counterpressure by the pressure stamp 6, thus acts on the carbon mass 7 or the press strand 8.
  • the exit speed of the press strand 8 from the mouthpiece 3 is, however, independent of this compression pressure, because only the pressure difference between the back pressure and the pressure in the area of the mouthpiece 3 is decisive for the exit speed.
  • a comparatively low exit speed can therefore be ensured at very high compression pressures, so that the press strand 8 not only has a high compression rate, but also a desired grain orientation.
  • lubrication openings 9 are provided in the jacket of the pressure cylinder 5, which are connected to a pressure line 10 for a lubricant, so that the lubricant is conducted under the necessary pressure between the cylinder jacket and the press line 8 can be.
  • the pressure ram 6 is lifted off the press strand 8 and the pressure cylinder 5 is withdrawn from its working position according to FIG. 3 from the press strand 8 into the position according to FIG. 4 in order to be able to sever the press strand 8 with the help of the knives 11.
  • lifting supports 12 are provided according to FIG. 4, which are placed on the press strand 8 as soon as it is released by the pressure cylinder 5.
  • a support bracket 13 can also be provided, which is guided axially displaceably in an axial groove 14 of the jacket of the printing cylinder 5 and forms part of the inner wall of the printing cylinder 5, as shown in FIGS. 5 and 6.
  • the support bracket 13 therefore only needs to be held by means of a holder 15 when the pressure cylinder 5 is withdrawn from the mouthpiece 3 of the press cylinder 1 in order to pull it out of the pressure cylinder 5.
  • the press strand 8 consequently remains on the support bracket 13 without any relative movement during the pulling off of the pressure cylinder 5, so that uninterrupted support of the press strand 8 can be achieved.
  • the pressure cylinder 5 can be provided with an end recess 16 for the holder 15.
  • the arrangement must, of course, be such that the knives 11 can be used unhindered for severing the press strand 8. For this purpose, it may be necessary to shift the holder 15 in certain areas.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Press-Shaping Or Shaping Using Conveyers (AREA)

Description

Die Erfindung bezieht sich auf ein Verfahren zum Strangpressen von Kohlenstoffmassen, insbesondere von Kohlenstoffelektroden, wobei die in einen Presszylinder mit verschliessbarem Mundstück eingebrachte Kohlenstoffmasse mit Hilfe eines Pressstempels zunächst bei verschlossenem Mundstück angestaucht und dann bei geöffnetem Mundstück aus dem Presszylinder herausgedrückt wird, sowie auf eine Vorrichtung zur Durchführung des Verfahrens (DE-A-28 55 899).The invention relates to a method for extruding carbon masses, in particular carbon electrodes, wherein the carbon mass introduced into a press cylinder with a closable mouthpiece is first compressed by means of a press ram with the mouthpiece closed and then pressed out of the press cylinder with the mouthpiece open, and to a device to carry out the method (DE-A-28 55 899).

Bevor Kohlenstoffelektroden gebrannt werden können, muss die Kohlenstoffmasse entsprechend geformt und verdichtet werden. Zu diesem Zweck wird die Kohlenstoffmansse in einen Presszylinder mit einem verschiessbaren Mundstück eingebracht und in diesem Presszylinder bei verschlossenem Mundstück mit Hilfe eines Pressstempels vorverdichtet, bevor der eigentliche Form- und Verdichtungsvorgang durch das Auspressen der Kohlenstoffmasse durch das Mundstück erfolgen kann. Die Qualität der späteren Elektroden hängt dabei unter anderem von einer gleichmässigen Kornorientierung der Masseteilchen im Pressstrang und von einer ausreichenden Verdichtung des Pressstranges ab. Wie sich gezeigt hat, ist eine der Bedingungen für eine gleichmässige Kornausrichtung in einer zumindest angenähert konstanten Austrittsgeschwindigkeit des Pressstranges aus dem Mundstück des Presszylinders zu sehen. Diese Austrittsgeschwindigkeit des Pressstranges aus dem Mundstück des Presszylinders hängt aber von dem über den Pressstempel auf die Kohlenstoffmasse ausgeübten Pressdruck ab, so dass für einen vorteilhaften Austrittsgeschwindigkeitsbereich nur ein bestimmter Pressdruck aufgebracht werden darf. Für einen bestimmten Elektrodenquerschnitt kann folglich nur dann eine erwünschte Kornorientierung im Pressstrang sichergestellt werden, wenn eine bestimmte Presskraft und davon abhängig eine bestimmte Verdichtung eingehalten wird. Für hohe Ansprüche reicht diese Verdichtung jedoch im allgemeinen nicht aus, so dass man in solchen Fällen auf eine Vibrationsverdichtung in geschlossenen Formen übergeht, wobei allerdings keine Kornorientierung erreicht werden kann.Before carbon electrodes can be burned, the carbon mass must be shaped and compressed accordingly. For this purpose, the carbon sleeve is placed in a press cylinder with a lockable mouthpiece and pre-compressed in this press cylinder with the mouthpiece closed using a press ram before the actual shaping and compression process can take place by squeezing out the carbon mass through the mouthpiece. The quality of the later electrodes depends among other things on a uniform grain orientation of the mass particles in the press strand and on sufficient compression of the press strand. As has been shown, one of the conditions for a uniform grain alignment can be seen in an at least approximately constant exit speed of the press strand from the die of the press cylinder. However, this exit speed of the press strand from the mouthpiece of the press cylinder depends on the press pressure exerted on the carbon mass via the press ram, so that only a certain press pressure may be applied for an advantageous exit speed range. For a certain electrode cross section, a desired grain orientation in the press strand can therefore only be ensured if a certain pressing force and, depending on it, a certain compression are maintained. For high demands, however, this compaction is generally not sufficient, so that in such cases vibration compaction in closed molds is adopted, although grain orientation cannot be achieved.

Der Erfindung liegt somit die Aufgabe zugrunde, diese Mängel zu vermeiden und ein Verfahren zum Strangpressen von Kohlenstoffmassen anzugeben, bei dem trotz einer guten Kornorientierung eine beliebig hohe Verdichtung des Pressstranges sichergestellt werden kann.The invention is therefore based on the object of avoiding these deficiencies and of specifying a method for extruding carbon masses in which, in spite of good grain orientation, any desired compression of the extruded strand can be ensured.

Die Erfindung löst die gestellte Aufgabe dadurch, dass auf den aus dem Mundstück austretenden Strang der Kohlenstoffmasse ein Gegendruck zum Pressdruck ausgeübt wird.The invention solves this problem in that a counter pressure to the pressing pressure is exerted on the strand of carbon mass emerging from the mouthpiece.

Da die Austrittsgeschwindigkeit bei der Anwendung eines Gegendruckes von der Differenz des Pressdruckes und des Gegendruckes abhängt und diese Druckdifferenz in einfacher Weise auf die gewünschte Austrittsgeschwindigkeit des Pressstranges aus dem Mundstück angepasst werden kann, kann auf die Kohlenstoffmasse ein von der Austrittsgeschwindigkeit unabhängiger Verdichtungsdruck ausgeübt werden. Die sonst durch eine Vergrösserung des Pressdruckes bedingte Steigerung der Austrittsgeschwindigkeit wird ja durch den entsprechend gewählten Gegendruck unterbunden, so dass der Pressstrang mit einer für die gewünschte Orientierung vorteilhaften Geschwindigkeit aus dem Mundstück des Presszylinders austreten kann.Since the exit speed when a back pressure is applied depends on the difference between the press pressure and the back pressure and this pressure difference can be easily adapted to the desired exit speed of the press strand from the mouthpiece, a compression pressure that is independent of the exit speed can be exerted on the carbon mass. The increase in the exit speed, which is otherwise caused by an increase in the pressing pressure, is prevented by the correspondingly selected counter pressure, so that the pressing strand can emerge from the mouthpiece of the pressing cylinder at a speed which is advantageous for the desired orientation.

Da sich der Reibungswiderstand zwischen der Kohlenstoffmasse und dem Presszylinder mit zunehmendem Pressstempelhub, also mit wachsender Länge des aus dem Mundstück austretenden Pressstranges verringert, vergrössert sich bei einer gleichbleibenden Pressstempelbeaufschlagung der im Mundstückbereich wirksame Auspressdruck mit wachsendem Pressstempelhub, was eine steigende Austrittsgeschwindigkeit zur Folge hat. Um eine gleichmässige Austrittsgeschwindigkeit für den Pressstrang sicherzustellen, müsste daher der Beaufschlagungsdruck des Pressstempels in Abhängigkeit vom Pressstempelhub gesteuert werden. Wird nicht die Beaufschlagung des Pressstempels, sondern die Gegenkraft gesteuert, und zwar im Sinne einer Vergrösserung des Gegendruckes mit wachsender Länge des Pressstranges, so kann auch bei einer gleichbleibenden Beaufschlagung des Pressstempels eine konstante Austrittsgeschwindigkeit für den Pressstrang erreicht werden.Since the frictional resistance between the carbon mass and the press cylinder decreases with increasing press ram stroke, i.e. with increasing length of the press strand emerging from the mouthpiece, with a constant press ram application, the effective squeezing pressure in the mouthpiece area increases with increasing press ram stroke, which results in an increasing exit speed. In order to ensure a uniform exit speed for the press strand, the application pressure of the press ram would have to be controlled as a function of the press ram stroke. If it is not the action of the press ram but the counterforce that is controlled, namely in the sense of an increase in the counterpressure with increasing length of the press run, a constant exit speed for the press run can be achieved even if the press ram is acted on consistently.

Aufgrund der sich bei einem Pressstempelhub ändernden Reibungskräfte innerhalb des Presszylinders wird sich unter Wahrung einer konstanten Austrittsgeschwindigkeit für den Pressstrang eine Änderung des Verdichtungsdruckes ergeben. Diese Änderung hat aber auf die Qualität der Rohelektrode keinen wesentlichen Einfluss, weil ja im wesentlichen der gesamte Pressstrang dieser Änderung des Verdichtungsdruckes unterworfen ist.Due to the changing friction forces within the press cylinder during a press ram stroke, a change in the compression pressure will result while maintaining a constant exit speed for the press strand. However, this change has no significant influence on the quality of the raw electrode, because essentially the entire press line is subjected to this change in the compression pressure.

Zur Durchführung des Verfahrens kann von einer bekannten Vorrichtung ausgegangen werden (DE-A-28 55 899), die für den aus einem vertikal angeordneten Presszylinder austretenden Pressstrang eine mit Abstand vom Mundstück des Presszylinders angeordnete Führungshülse vorsieht, um Deformationen des Pressstranges bei seinem Abtransport zu vermeiden. Der von der Führungshülse aufgenommene Pressstrang wird nämlich zusammen mit der Führungshülse weitergefördert.To carry out the method, a known device can be used (DE-A-28 55 899), which provides a guide sleeve arranged at a distance from the mouthpiece of the press cylinder for the press strand emerging from a vertically arranged press cylinder, in order to prevent deformation of the press strand during its removal avoid. The press strand received by the guide sleeve is namely conveyed along with the guide sleeve.

Wird zur Durchführung des erfindungsgemässen Verfahrens die Führungshülse einer solchen Vorrichtung als an das Mundstück des Presszylinders dicht anschliessbarer, axial verschiebbarer Druckzylinder mit einem darin geführten Druckstempel ausgebildet, so kann über diesen Druckstempel auf den aus dem Mundstück des Presszylinders austretenden Pressstrang ein gewünschter Gegendruck zum Pressdruck ausgeübt werden, weil der Mantel des Druckzylinders ein radiales Ausweichen des Pressstranges wirksam verhindert. Der Druckstempel muss dabei selbstverständlich über den austretenden Pressstrang zurückgeschoben werden können, ohne die Lage des Druckzylinders zu verändern. Ist die gewünschte Länge des Pressstranges erreicht, so kann der Druckzylinder vom Mundstück axial zurückgezogen werden, um den Pressstrang durchtrennen zu können.If, for carrying out the method according to the invention, the guide sleeve of such a device is designed as an axially displaceable pressure cylinder which can be tightly connected to the mouthpiece of the press cylinder and has a pressure stamp guided therein, a desired counterpressure to the pressure can be exerted on the press strand emerging from the mouthpiece of the press cylinder be because the jacket of the pressure cylinder effectively prevents radial deflection of the press strand. The pressure stamp must of course be able to be pushed back over the emerging press strand without changing the position of the pressure cylinder. Is the ge reaches the desired length of the press strand, the pressure cylinder can be withdrawn axially from the mouthpiece in order to be able to sever the press strand.

Um den Einfluss von Reibungskräften im Bereich des Druckzylinders weitgehend ausschliessen zu können, kann der Mantel des Druckzylinders an wenigstens eine Druckleitung für ein Gleitmittel angeschlossene Schmieröffnungen aufweisen, durch die das Gleitmittel zwischen den Mantel des Druckzylinders und den Pressstrang gedrückt wird.In order to be able to largely rule out the influence of frictional forces in the area of the pressure cylinder, the jacket of the pressure cylinder can have lubrication openings connected to at least one pressure line for a lubricant, through which the lubricant is pressed between the jacket of the pressure cylinder and the press strand.

Bei einer horizontalen Presszylinderanordnung muss der Pressstrang beim Abziehen des Druckzylinders entsprechend unterstützt werden. Hierfür können ausserhalb des Druckzylinders vorgesehene, anstellbare Stützauflagen angeordnet werden, die beim Abziehen des Druckzylinders vom Strang in die Arbeitsstellung eingeschwenkt oder angehoben werden. Eine besonders vorteilhafte Unterstützung des Pressstranges erhält man jedoch, wenn im Mantel des Druckzylinders ein einen Teil der Innenwandung bildender Stützträger für den Pressstrang axial verschiebbar geführt ist, weil in diesem Falle der Pressstrang auf dem Stützträger beim Abziehen des Druckzylinders aufliegen bleiben kann. Der Stützträger wird beim Abziehen des Druckzylinders ortsfest gehalten und aus dem Druckzylindermantel ausgezogen.In the case of a horizontal press cylinder arrangement, the press strand must be supported appropriately when pulling off the pressure cylinder. For this purpose, adjustable support supports can be arranged outside the printing cylinder, which are pivoted or raised when the printing cylinder is pulled off the strand into the working position. A particularly advantageous support of the press strand is obtained, however, when a support beam forming part of the inner wall for the press strand is guided axially displaceably in the jacket of the pressure cylinder, because in this case the press strand can remain on the support beam when the pressure cylinder is removed. The support bracket is held stationary when the printing cylinder is removed and pulled out of the printing cylinder jacket.

An Hand der Zeichnung wird das erfindungsgemässe Verfahren näher erläutert. Es zeigen

  • Fig.1 ein Ausführungsbeispiel einer erfindungsgemässen Vorrichtung zur Durchführung des Verfahrens in einem schematischen Längsschnitt mit verschlossenem Mundstück des Presszylinders,
  • Fig. 2 eine der Fig. 1 entsprechende Darstellung, jedoch mit an das Mundstück des Presszylinders angeschlossenem Druckzylinder,
  • Fig. 3 die Vorrichtung während des Auspressens eines Pressstranges gegen einen Gegendruck,
  • Fig. 4 die Vorrichtung nach der Beendigung des Pressvorganges vor dem Durchtrennen des Pressstranges,
  • Fig. 5 eine der Fig. 4 entsprechende Darstellung einer Konstruktionsvariante, und
  • Fig. 6 einen Schnitt nach der Linie VI-VI der Fig. 5.
The method according to the invention is explained in more detail with reference to the drawing. Show it
  • 1 shows an embodiment of an inventive device for performing the method in a schematic longitudinal section with the mouthpiece of the press cylinder closed,
  • 2 shows a representation corresponding to FIG. 1, but with a pressure cylinder connected to the mouthpiece of the press cylinder,
  • 3 shows the device during the pressing of a press strand against a counter pressure,
  • 4 shows the device after completion of the pressing process before severing the press strand,
  • 5 shows a representation of a construction variant corresponding to FIG. 4, and
  • 6 shows a section along the line VI-VI of FIG. 5th

Die dargestellte Vorrichtung zum Strangpressen von Kohlenstoffelektroden besteht im wesentlichen aus einem Presszylinder 1, der ein mit Hilfe eines Deckels 2 verschliessbares Mundstück 3 aufweist und einen Pressstempel 4 verschiebbar aufnimmt. In axialer Verlängerung des Mundstükkes 3 ist ein axial verschiebbarer Druckzylinder 5 vorgesehen, der dicht an das Mundstück 3 des Presszylinders 1 angeschlossen werden kann und mit einem Druckstempel 6 versehen ist. Nach dem Anstauchen der in den Presszylinder 1 eingebrachten Kohlenstoffmasse 7, was bei verschlossenem Mundstück 3 über den Pressstempel 4 gemäss Fig. 1 durchgeführt wird, wird der Deckel 2 vom Verschlussstück 3 abgenommen und der Druckzylinder 5 an das Mundstück 3 dicht angeschlossen. Vor dem eigentlichen Strangpressen wird der im Druckzylinder 5 geführte Druckstempel 6 entsprechend beaufschlagt und gegen die Kohlenstoffmasse 7 im Bereich des Mundstückes gedrückt, wie dies in Fig. 2 angedeutet ist. Wird nun der Pressstempel 4 beaufschlagt, so wird die Kohlenstoffmasse 7 gegen die Kraft des Druckstempels 6 aus dem Mundstück 3 herausgedrückt, wobei der austretende Pressstrang 8 durch den Druckzylinder 5 geführt wird, so dass über den Druckstempel 6 ein entsprechender Gegendruck zum Pressdruck ausgeübt werden kann. Auf die Kohlenstoffmasse 7 bzw. den Pressstrang 8 wirkt somit ein Verdichtungsdruck, der von der Grösse des Pressdruckes und der Grösse des Gegendrukkes durch den Druckstempel 6 abhängt. Die Austrittsgeschwindigkeit des Pressstranges 8 aus dem Mundstück 3 ist allerdings von diesem Verdichtungsdruck unabhängig, weil für die Austrittsgeschwindigkeit lediglich die Druckdifferenz zwischen dem Gegendruck und dem Druck im Bereich des Mundstückes 3 massgebend ist. Es kann daher bei sehr hohen Verdichtungsdrücken eine vergleichsweise geringe Austrittsgeschwindigkeit sichergestellt werden, so dass der Pressstrang 8 nicht nur eine hohe Verdichtung, sondern auch eine erwünschte Kornorientierung aufweist. Durch eine Steuerung der Beaufschlagung des Druckstempels 6 und/oder des Pressstempels 4 können dabei sehr unterschiedliche Verhältnisse berücksichtigt werden.The device shown for the extrusion of carbon electrodes essentially consists of a press cylinder 1 which has a mouthpiece 3 which can be closed by means of a cover 2 and which receives a press ram 4 in a displaceable manner. In the axial extension of the mouthpiece 3 an axially displaceable pressure cylinder 5 is provided, which can be connected tightly to the mouthpiece 3 of the press cylinder 1 and is provided with a pressure stamp 6. After the carbon mass 7 introduced into the press cylinder 1 has been compressed, which is carried out with the mouthpiece 3 closed via the press die 4 according to FIG. 1, the cover 2 is removed from the closure piece 3 and the pressure cylinder 5 is tightly connected to the mouthpiece 3. Before the actual extrusion, the plunger 6 guided in the pressure cylinder 5 is acted upon accordingly and pressed against the carbon mass 7 in the region of the mouthpiece, as is indicated in FIG. 2. If the press ram 4 is now acted upon, the carbon mass 7 is pressed out of the mouthpiece 3 against the force of the pressure ram 6, the emerging press strand 8 being guided through the pressure cylinder 5, so that a corresponding counter pressure to the press pressure can be exerted via the pressure ram 6 . A compression pressure, which depends on the size of the pressing pressure and the size of the counterpressure by the pressure stamp 6, thus acts on the carbon mass 7 or the press strand 8. The exit speed of the press strand 8 from the mouthpiece 3 is, however, independent of this compression pressure, because only the pressure difference between the back pressure and the pressure in the area of the mouthpiece 3 is decisive for the exit speed. A comparatively low exit speed can therefore be ensured at very high compression pressures, so that the press strand 8 not only has a high compression rate, but also a desired grain orientation. By controlling the application of the pressure ram 6 and / or the press ram 4, very different conditions can be taken into account.

Um die Reibungskräfte im Bereich des Druckzylinders 5 möglichst klein zu halten, sind im Mantel des Druckzylinders 5 Schmieröffnungen 9 vorgesehen, die an eine Druckleitung 10 für ein Gleitmittel angeschlossen sind, so dass das Gleitmittel unter dem nötigen Druck zwischen den Zylindermantel und den Pressstrang 8 geleitet werden kann.In order to keep the frictional forces in the area of the pressure cylinder 5 as small as possible, lubrication openings 9 are provided in the jacket of the pressure cylinder 5, which are connected to a pressure line 10 for a lubricant, so that the lubricant is conducted under the necessary pressure between the cylinder jacket and the press line 8 can be.

Nach der Beendingung des Pressvorganges wird der Druckstempel 6 vom Pressstrang 8 abgehoben und der Druckzylinder 5 aus seiner Arbeitsstellung gemäss Fig. 3 vom Pressstrang 8 in die Stellung nach Fig. 4 zurückgezogen, um den Pressstrang 8 mit Hilfe der Messer 11 durchtrennen zu können. Beim Zurückziehen des Druckzylinders 5 vom Pressstrang 8 muss dieser entsprechend unterstützt werden. Zu diesem Zweck sind nach Fig. 4 anhebbare Stützauflagen 12 vorgesehen, die an den Pressstrang 8 angestellt werden sobald dieser vom Druckzylinder 5 freigegeben wird.After the pressing process has ended, the pressure ram 6 is lifted off the press strand 8 and the pressure cylinder 5 is withdrawn from its working position according to FIG. 3 from the press strand 8 into the position according to FIG. 4 in order to be able to sever the press strand 8 with the help of the knives 11. When the pressure cylinder 5 is withdrawn from the press strand 8, it must be supported accordingly. For this purpose, lifting supports 12 are provided according to FIG. 4, which are placed on the press strand 8 as soon as it is released by the pressure cylinder 5.

An Stelle der Stützauflagen 12 kann auch ein Stützträger 13 vorgesehen werden, der in einer Axialnut 14 des Mantels des Druckzylinders 5 axial verschiebbar geführt ist und einen Teil der Innenwandung des Druckzylinders 5 bildet, wie dies in den Fig. 5 und 6 dargestellt ist. Der Stützträger 13 braucht daher beim Zurückziehen des Druckzylinders 5 vom Mundstück 3 des Presszylinders 1 lediglich mittels einer Halterung 15 festgehalten zu werden, um ihn aus dem Druckzylinder 5 herauszuziehen. Der Pressstrang 8 bleibt folglich ohne Relativbewegung während des Abziehens des Druckzylinders 5 auf dem Stützträger 13 liegen, so dass eine ununterbrochene Unterstützung des Pressstranges 8 erreicht werden kann. Um einen dichten Anschluss des Druckzylinders 5 an das Mundstück 3 des Presszylinders sicherzustellen, ohne die Halterung 15 abnehmen zu müssen, kann der Druckzylinder 5 mit einer stirnseitigen Aufnahmeaussparung 16 für die Halterung 15 versehen werden. Die Anordnung muss dabei selbstverständlich so getroffen werden, dass die Messer 11 zum Durchtrennen des Pressstranges 8 unbehindert eingesetzt werden können. Zu diesem Zweck kann eine bereichsweise Verschiebung der Halterung 15 notwendig sein.Instead of the support pads 12, a support bracket 13 can also be provided, which is guided axially displaceably in an axial groove 14 of the jacket of the printing cylinder 5 and forms part of the inner wall of the printing cylinder 5, as shown in FIGS. 5 and 6. The support bracket 13 therefore only needs to be held by means of a holder 15 when the pressure cylinder 5 is withdrawn from the mouthpiece 3 of the press cylinder 1 in order to pull it out of the pressure cylinder 5. The press strand 8 consequently remains on the support bracket 13 without any relative movement during the pulling off of the pressure cylinder 5, so that uninterrupted support of the press strand 8 can be achieved. To one To ensure the tight connection of the pressure cylinder 5 to the mouthpiece 3 of the press cylinder without having to remove the holder 15, the pressure cylinder 5 can be provided with an end recess 16 for the holder 15. The arrangement must, of course, be such that the knives 11 can be used unhindered for severing the press strand 8. For this purpose, it may be necessary to shift the holder 15 in certain areas.

Claims (5)

1. A process for extruding carbon compositions, more particularly carbon electrodes, a carbon composition (7) which has been introduced into a pressing cylinder (1) having a closable mouthpiece (3) first being squeezed by a pressing ram (4) with the mouthpiece (3) closed, then expelled from the cylinder (4) with the mouthpiece (3) open, characterised in that a back pressure opposing the forward pressure (pressing pressure) is exerted on the carbon strand (8) issuing from the mouthpiece (3).
2. A process according to claim 1, characterised in that the back pressure increases with increasing strand length.
3. An apparatus for performing the process according to claim 1 or 2 and comprising: a pressing cylinder (1) which receives a pressing ram (4) and has a closable mouthpiece (3) ; and a guide sleeve forthe strand (8) issuing from the mouthpiece (3), characterised in that the guide sleeve is in the form of an axially movable pressing cylinder (5) which can be sealingly connected to the pressing cylinder mouthpiece (3) and in which a pressing ram (6) is guided.
4. An apparatus according to claim 3, characterised in that the outer envelope of the cylinder (5) is formed with lubricating orifices (9) connected to at least one pressure line (10) for a lubricant.
5. An apparatus according to claim 3 or 4, characterised in that a support (13) for the strand (8) forms a part of the inner wall and is guided for axial movement in the casing envelope of the cylinder (5).
EP19850890266 1985-01-04 1985-10-24 Method and device for extruding carbon masses, in particular carbon electrodes Expired EP0216978B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT0001785A AT382897B (en) 1985-01-04 1985-01-04 METHOD AND DEVICE FOR EXTRUDING CARBON MATERIALS, ESPECIALLY CARBON ELECTRODES
AT17/85 1985-01-04

Publications (2)

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EP0216978A1 EP0216978A1 (en) 1987-04-08
EP0216978B1 true EP0216978B1 (en) 1988-06-01

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EP19850890266 Expired EP0216978B1 (en) 1985-01-04 1985-10-24 Method and device for extruding carbon masses, in particular carbon electrodes

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EP (1) EP0216978B1 (en)
AT (1) AT382897B (en)
DD (1) DD240702A5 (en)
DE (1) DE3562998D1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103737954A (en) * 2013-12-31 2014-04-23 一重集团大连设计研究院有限公司 Rotary carbon electrode extruder and extruding method thereof

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10000165A1 (en) * 2000-01-05 2001-07-12 Sgl Technik Gmbh Process and device for the production of components and semi-finished products made of synthetic graphite or ceramic granulate, in particular for the production of graphite pipes
CN108749100A (en) * 2018-06-06 2018-11-06 河南中烟工业有限责任公司 A kind of rod-pressing machine extrusion molding caput

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Publication number Priority date Publication date Assignee Title
US1881397A (en) * 1930-05-31 1932-10-04 Potlatch Forests Inc Briquetting machine
DE2853748C2 (en) * 1978-12-13 1981-02-19 Mannesmann Demag Ag, 4100 Duisburg Device for closing the outlet opening of an electrode press
DE2855899C2 (en) * 1978-12-23 1983-11-10 Mannesmann AG, 4000 Düsseldorf Holding device for a carbon electrode line

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103737954A (en) * 2013-12-31 2014-04-23 一重集团大连设计研究院有限公司 Rotary carbon electrode extruder and extruding method thereof

Also Published As

Publication number Publication date
ATA1785A (en) 1986-09-15
DE3562998D1 (en) 1988-07-07
AT382897B (en) 1987-04-27
EP0216978A1 (en) 1987-04-08
DD240702A5 (en) 1986-11-12

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