US3876744A - Compacting step by step - Google Patents

Compacting step by step Download PDF

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Publication number
US3876744A
US3876744A US262247A US26224772A US3876744A US 3876744 A US3876744 A US 3876744A US 262247 A US262247 A US 262247A US 26224772 A US26224772 A US 26224772A US 3876744 A US3876744 A US 3876744A
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United States
Prior art keywords
mold
composition
cavity
segments
axis
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.)
Expired - Lifetime
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US262247A
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English (en)
Inventor
Harald Onder
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.)
Alcan Holdings Switzerland AG
Original Assignee
Alusuisse Holdings AG
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Publication date
Application filed by Alusuisse Holdings AG filed Critical Alusuisse Holdings AG
Priority to US376340A priority Critical patent/US3901641A/en
Application granted granted Critical
Publication of US3876744A publication Critical patent/US3876744A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • B30B11/224—Extrusion chambers
    • B30B11/225—Extrusion chambers with adjustable outlet opening
    • 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
    • B30B11/007—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses using a plurality of pressing members working in different directions
    • 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

Definitions

  • My present invention relates to the continuous production of a continuous length of product by compacting a composition consisting of small particles (that is granular or composed of short fibres) and a binding agent.
  • a composition consisting of small particles (that is granular or composed of short fibres) and a binding agent.
  • moldings which must satisfy high requirements, are molded with a minimum possible addition of binding agent or plasticiser in block presses.
  • the addition of binding agent or plasticiser must be kept low so that no shrinkages or stresses occur in the subsequent firing.
  • the block presses have the disadvantage that they work discontinuously. In the case of molding by extruders a higher addition of binding agent or plasticiser is necessary, so that the moldings obtained cannot satisfy any high requirements after firing.
  • the green artificial carbonaceous composition is pressed in a mold with the aid of a plunger or of two oppositely acting plungers (block pressing).
  • the method offers the advantage that it is possible to work with a low addition of binding agent.
  • it has two disadvantages. Firstly it is not continuous and therefore does not fit well into the course of processing.
  • the finished blocks have a very great anisotropy. which is attributable to the long compression distances. An inhomogeneous resistance of the fired (baked) electrodes against oxidiation results from the anisotropy.
  • the green artificial carbonaceous composition is processed in an extruder.
  • the method is continuous and can be fitted well into the course of processing, but it is very expensive as regards the machines used and the composition requires substantially more binding agent than in block pressing. Further disadvantages derive from the very distinct radial anisotropy of the artificial carbonaceous blocks obtained. On the other hand the uniformity of the material quality over the length is advantageous.
  • the obtained artificial carbonaceous blocks are of course intended subsequently to be fired (baked).
  • the object of my invention is the combination of the advantages of both the main methods. that is block pressing and extrusion.
  • the composition in a method of continuously producing a continuous length of product by compacting a composition consisting of small particles and a binding agent, the composition is introduced continuously into one end of an open ended mold and in passing through the mold, the composition is compacted step by step into a continuous length by lateral pressure.
  • This method which is particularly applicable to the production of artificial carbonaceous products, is continuous and the requirement of binding agent or plasticiser is just as low as in the case of the conventional block pressing.
  • the composition is expediently introduced into a lon gitudinally divided mold the segments of which, in the axial direction of passage of the composition, firstly form a tapering mold cavity and then a cavity with walls parallel with the axis, the segments moving synchronously back and forth perpendicularly to the axis of the mold to produce the step by step compaction. At every movement of the mold segments apart the composition is moved forwards and at every movement together it is further compacted.
  • composition is most advantageously introduced into the wider end of the mold by means of a worm screw feeder which is arranged axially of the mold.
  • the filling pressure thus achieved is intended both to prevent the development of a force component in the direction against the material flow through the mold, so that the cross-sections in the continuous length remain even, and to effect the opening of the mold and thus the longitudinal movement of the continuous length.
  • the invention also includes a mold for use in the method, the mold being open ended and longitudinally divided into at least four segments and of polyhedral internal cross'section, the segments being movable synchronously inwards and outwards transversely to the axis of the mold and being shaped to provide in the axial direction firstly a mold cavity tapering in the direction and then a cavity with walls parallel with the axis.
  • the segments each provide one side of the polyhedron and are symmetrically arranged around the axis of the mold and abut one another across planes which are continuations of the sides of the polyhedron, the segments being movable linearly in guides substantially tangentially of the polyhedron.
  • a machine for carrying out the method will consist of such a mold together with a device for introducing the composition into the wider end of the mold.
  • FIGS. 1 to 6 are vertical axial sections ofa mold illustrating diagrammatically the steps in producing a continuous length of product from green synthetic carbon;
  • FIGS. 7 to 10 illustrate a mold having four segments
  • FIGS. 11 and 12 illustrate a mold having six segments.
  • FIG. 1 shows the first phase in the commencement of operation.
  • a mold 10 with its segments 11 is open and filled with green articicial carbonaceous composition 12.
  • the mold has a tapering zone 13 and a zone 14 with walls parallel with the axis.
  • the vertical arrow 15 indicates the axial filling pressure.
  • the mold 10 is closed at the bottom by a floor 16 for starting operation. At this stage the green artificial carbonaceous composition has the same density in the entire mold cavity.
  • FIG. 2 shows the condition after the first compacting operation.
  • the mold 10 has closed.
  • the horizontal arrows 17 indicate the direction of movement of the mold segments.
  • Compacting is indicated by the crosshatching.
  • the filling pressure 15, provided for example by a feed screw, has prevented material from moving back upwards.
  • FIG. 3 shows the condition after the re-opening of the mold 10, that is to say after the mold segments ll have moved apart again (arrows 18).
  • the floor 16 has been removed.
  • the compacted composition has been moved downwards by the filling pressure 15 until the pressing rests upon the walls of the tapering mold cavity l3. Refilling has then been effected with further uncompacted artificial carbonaceous composition 12.
  • FIG. 4 the mold is closed again.
  • the second compacting operation has taken place.
  • the filling pressure has prevented material from moving back upwards.
  • the twice-compacted artificial carbon composition is indicated by the cross-hatching and an additional horizontal hatching.
  • the part 19 of the car bonaceous body which has emerged from the mold is only cross-hatched. lt has been subjected to only one single compacting operation, and is waste from starting up operation.
  • FIG. 5 the mold 10 has opened again and the artificial carbonaceous body has been moved downwards a second time by the filling pressure 15. A further quantity of uncompacted artificial carbonaceous composition 12 has been added.
  • FIG. 6 shows the condition after the third closure of the mold 10.
  • the thrice-compacted composition is indicated by cross-hatching and additionally by horizontal and vertical hatching. in the case of the size ratios as sketched in the Figures this would be the usable final state of compacting; in this case only the lowermost part 19 of the carbonaceous body and the next following part 20 would be waste from starting operation.
  • the tool can have different dimensions and can achieve a final compacting for example only after closure of the mold five or six times or still more frequent closure, in which case that length of the carbonaceous body which comprises the insufficiently pressed parts is to be regarded as waste from starting operation.
  • the distinctive feature of the method as described with reference to FIGS. 1 to 6 consists in that the main proportion of the compacting is determined not by the magnitude of the tool movement but by the geometrical formation of the pressing tool (mold) itself.
  • the amplitude of the mold movement small and correspondingly to increase the frequency of the reciprocating movement of the mold segments, so that finally one can speak of a vibrating movement.
  • a pressure gradient establishes itself in the mold which is dependent directly upon the geometrical form of the tool and the compression curve (density/pressure function) of the artificial carbonaceous mixture.
  • HO 7 indicates the performance capacity of such an apparatus.
  • a is the angle of inclination of the walls of the tapering part of the mold cavity
  • A is the amplitude of the horizontal reciprocating movement
  • H the axial movement of the carbon length (feed movement) at every opening of the mold.
  • H corresponds to the value A/tana
  • the tapering part of the mold must have a length of about 1.200 mm. in the case of an artificial carbonaceous final cross-section of 500 X 500 mm. This has the result that the artificial carbonaceous composition has reached its final density of 1.6 t/cu.m. only after about 400 oscillations, and consequently that the length of waste from starting operation amounts to about 1.200 mm. plus the length of the mold part of constant cross-section (for example 250 mm.
  • An artificial carbonaceous mixture for the manufacture of anodes for aluminum fusion electrolysis has for example the following composition by weight:
  • Petroleum coke grain size 3.36 to 8.0 mm. l6.6% 1.68 to 3.36 mm. 12.5%
  • the binding agent In the processing of the green artificial carbonaceous composition according to the method in accordance with the invention (as also in block pressing and extruding) the binding agent must be plastic and therefore the entire composition must be warm. For this reason the composition is brought before processing to a temperature which is determined by the viscositytemperature function of the binding agent. In the case of coal tar medium-hard pitch the requisite temperature lies between l25 and C. The composition is introduced into the mold at such a temperature. it is advisable to keep the temperature of the mold approximately at the level of that of the introduced composition during operation.
  • pitch coke or anthracite the latter for the cathodes of aluminum electrolysis cells
  • coal tar medium-hard pitch any other cokable binding agent (such as petroleum pitch) may be considered.
  • the dry material consists of amorphous carbon with a minimum of inorganic impurities (10% in the case of anthracite, 0.5% in the case of pitch or petroleum coke).
  • the mold of the illustrated machine has a polyhedral internal cross-section with at least four corners.
  • lt consists for example of steel.
  • FIG. 8 shows a diagrammatic plan view of a mold 10 with four segments 11 which are tapered at 13 and have a constant cross-section with parallel walls at 14, namely in the open position, that is with segments drawn apart.
  • the arrows 17 indicate the direction for the closing movement of the segments 11.
  • the frame 21 contains the guides 22 for the movement of the segments 11 and takes up the deformation forces.
  • FIG. 9 shows diagrammatically the mold l0 with its segments 11 in the closed position.
  • 23 indicates the free cross-section which the lower part of the mold 10 (the part with parallel walls) then has and thus determines the cross-section of the continuous length to be produced.
  • the arrows 18 indicate the direction for the movement of the segments 11 apart.
  • FIG. 10 shows in perspective, partially in dot-anddash lines, one half of the mold of FIGS. 8 and 9, the frame 21 being omitted.
  • FIG. 11 shows diagrammatically in plan view a mold 24 with six segments 25 in the open position and FIG. 12 shows the same in the closed position.
  • the segments appear approximately like those of FIG. l0.
  • Each has a tapering part 26 and a part 27 which extends parallel with the axis of the mold on the mold cavity side and thus with the other segments produces a mold cavity having walls parallel with the axis. 28 designates the frame.
  • a method of continually producing, along an upright mold axis, a continuous length of product by repeatedly compacting a composition comprising small particles and a in an open ended mold having an inlet and outlet communicating with the mold cavity, said mold comprising a plurality of at least four segments disposed along said axis and defining said cavity, said cavity having an inwardly tapered portion in a direction from the inlet to the outlet and having a straight axial portion in the vicinity of the outlet, each individual compacting comprising the steps of:
  • a method, as claimed in claim 1 further comprising introducing the composition into said inlet by means of a worm screw feeder with a filling pressure sufficient to overcome any force opposing the material flow through the mold thereby restraining material from moving against the flow direction, and
  • composition is a green artificial carbonaceous composition.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Press-Shaping Or Shaping Using Conveyers (AREA)
  • Ceramic Products (AREA)
  • Electrolytic Production Of Metals (AREA)
US262247A 1971-06-24 1972-06-13 Compacting step by step Expired - Lifetime US3876744A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US376340A US3901641A (en) 1971-06-24 1973-07-05 Compacting step by step

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH923171A CH524451A (de) 1971-06-24 1971-06-24 Verfahren und Vorrichtung zum kontinuierlichen Herstellen eines Stranges aus kleinteiliger Masse

Publications (1)

Publication Number Publication Date
US3876744A true US3876744A (en) 1975-04-08

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ID=4349762

Family Applications (1)

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US262247A Expired - Lifetime US3876744A (en) 1971-06-24 1972-06-13 Compacting step by step

Country Status (5)

Country Link
US (1) US3876744A (enrdf_load_stackoverflow)
AT (1) AT330049B (enrdf_load_stackoverflow)
CH (1) CH524451A (enrdf_load_stackoverflow)
FR (1) FR2143411B1 (enrdf_load_stackoverflow)
GB (1) GB1388758A (enrdf_load_stackoverflow)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4435359A (en) 1982-06-21 1984-03-06 Huntington Alloys, Inc. Apparatus and method for fabricating tubes from powder
US4498858A (en) * 1982-08-23 1985-02-12 Philip Morris Incorporated Heated die for carbonized material
US4606876A (en) * 1982-09-30 1986-08-19 Kawasaki Steel Corporation Method of continuously producing compression molded coal
US5155146A (en) * 1991-03-29 1992-10-13 Reetz William R Thermoplastic composite and method and apparatus of making the same
US5356278A (en) * 1991-03-29 1994-10-18 Reetz William R Apparatus for making a thermoplastic composite
US5824246A (en) * 1991-03-29 1998-10-20 Engineered Composites Method of forming a thermoactive binder composite
US6231796B1 (en) * 1996-04-26 2001-05-15 Edward H. Allen Pulsed method for creating composite structures
US6398998B1 (en) * 1994-07-08 2002-06-04 3H Inventors Aps Method for producing bodies of consolidated particulate material
US6635198B1 (en) * 1998-04-24 2003-10-21 Elkem Asa Method for producing elongated carbon bodies
US20060103052A1 (en) * 1991-03-29 2006-05-18 Reetz William R Method of forming a thermoactive binder composite

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CS251907B1 (en) * 1980-08-22 1987-08-13 Gennadij P Kurilov Method of polydispersion materials pressing
CN107914411B (zh) * 2017-11-24 2019-08-06 吉林炭素有限公司 一种基于装料分界面避开掏孔区的石墨电极本体压制方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2289787A (en) * 1937-12-24 1942-07-14 Kaschke Kurt Production of shaped articles from metal powder
US2708770A (en) * 1952-11-20 1955-05-24 Allegheny Ludlum Steel Apparatus for making continuous electrode sticks
US2844845A (en) * 1955-12-20 1958-07-29 Schwarzkopf Dev Co Die structure for forming powder particles into strand-shaped bodies
US2902714A (en) * 1955-08-23 1959-09-08 Herbert G Johnson Rod extrusion press
US3674389A (en) * 1969-08-06 1972-07-04 British Iron Steel Research Apparatus for production of metal strip from metal powder

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2289787A (en) * 1937-12-24 1942-07-14 Kaschke Kurt Production of shaped articles from metal powder
US2708770A (en) * 1952-11-20 1955-05-24 Allegheny Ludlum Steel Apparatus for making continuous electrode sticks
US2902714A (en) * 1955-08-23 1959-09-08 Herbert G Johnson Rod extrusion press
US2844845A (en) * 1955-12-20 1958-07-29 Schwarzkopf Dev Co Die structure for forming powder particles into strand-shaped bodies
US3674389A (en) * 1969-08-06 1972-07-04 British Iron Steel Research Apparatus for production of metal strip from metal powder

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4435359A (en) 1982-06-21 1984-03-06 Huntington Alloys, Inc. Apparatus and method for fabricating tubes from powder
US4498858A (en) * 1982-08-23 1985-02-12 Philip Morris Incorporated Heated die for carbonized material
US4606876A (en) * 1982-09-30 1986-08-19 Kawasaki Steel Corporation Method of continuously producing compression molded coal
US5155146A (en) * 1991-03-29 1992-10-13 Reetz William R Thermoplastic composite and method and apparatus of making the same
US5356278A (en) * 1991-03-29 1994-10-18 Reetz William R Apparatus for making a thermoplastic composite
US5824246A (en) * 1991-03-29 1998-10-20 Engineered Composites Method of forming a thermoactive binder composite
US20060103052A1 (en) * 1991-03-29 2006-05-18 Reetz William R Method of forming a thermoactive binder composite
US6398998B1 (en) * 1994-07-08 2002-06-04 3H Inventors Aps Method for producing bodies of consolidated particulate material
US6231796B1 (en) * 1996-04-26 2001-05-15 Edward H. Allen Pulsed method for creating composite structures
US6635198B1 (en) * 1998-04-24 2003-10-21 Elkem Asa Method for producing elongated carbon bodies

Also Published As

Publication number Publication date
AT330049B (de) 1976-06-10
GB1388758A (en) 1975-03-26
DE2147333A1 (de) 1972-12-28
ATA521572A (de) 1975-08-15
DE2147333B2 (de) 1977-07-07
FR2143411A1 (enrdf_load_stackoverflow) 1973-02-02
CH524451A (de) 1972-06-30
FR2143411B1 (enrdf_load_stackoverflow) 1973-07-13

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