US2089690A - Electric furnace - Google Patents

Electric furnace Download PDF

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Publication number
US2089690A
US2089690A US2003A US200335A US2089690A US 2089690 A US2089690 A US 2089690A US 2003 A US2003 A US 2003A US 200335 A US200335 A US 200335A US 2089690 A US2089690 A US 2089690A
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Prior art keywords
furnace
electrodes
heat
electrode
throat
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US2003A
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Yngve R Cornelius
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D11/00—Arrangement of elements for electric heating in or on furnaces
    • F27D11/02—Ohmic resistance heating
    • F27D11/04—Ohmic resistance heating with direct passage of current through the material being heated
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B5/00—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
    • C03B5/02—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in electric furnaces, e.g. by dielectric heating
    • C03B5/027—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in electric furnaces, e.g. by dielectric heating by passing an electric current between electrodes immersed in the glass bath, i.e. by direct resistance heating
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
    • C03B5/00—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
    • C03B5/02—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in electric furnaces, e.g. by dielectric heating
    • C03B5/033—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in electric furnaces, e.g. by dielectric heating by using resistance heaters above or in the glass bath, i.e. by indirect resistance heating
    • C03B5/0332—Tank furnaces

Definitions

  • the present invention relates to the construction and operation of electric furnaces of the single or polyphase type such as may be used for the manufacture of glass, sodium silicate or other products.
  • the principal object of the invention is to construct and operate a furnace of the above type so as to maintain the charge or other material in the fusion zone at a uniform temperature without localized overheating or the formation therein of overheated zones.
  • Another object of the invention is the arrangement of electrodes within such a furnace so that they will influence the flow of material from the reaction or melting zone.
  • the material flowing from the melting chamber or fusing zone through the submerged throat into the tapping or refining chamber tends to have a suction effect on the melt surrounding the throat in the melting chamber. This causes the melt closest to the throat to move faster downwardly toward the throat than in other parts of the melt. Consequently, more raw material moves in this bath and will be fused at this point.
  • the fusing process which requires heat, results in cooling the molten mass, which, in turn, causes increased electrical resistance and less heat to be generated, thus further intensifying the cooling effect.
  • furnace walls should be placed as far away from this current path as possible, this path generally being theoretically not materially outside a semi-circle drawn from the center point of one electrode to the center point of an opposite electrode. If this semi-circle touches or tends to touch a wall, means should be provided for cooling this particular part of the wall. This may be done by providing cooling ducts in the wall at that place or by substituting for insulation there, a material which will readily diss pate developed heat such as cast refractory or the like.
  • the raw material fed to the furnace may be used as a means to decrease or increase the electrical conductivity of the resistance of the molten bath itself and this feature is also described in my copending application above mentioned.
  • the raw material blanket covering the surface of the melt should have such a minimum thickness that gases penetrating the same leave the blanket at substantially the temperature of the fresh raw material. It must, however. be thick enough that there will be no gas pockets between the bottom. of the blanket and the surface of the melt.
  • This raw material may be evenly spread over the furnace by a motor driven charging car capable of being raised or lowered, all as described in my above mentioned copending application.
  • the invention contemplates, with respect both to single and polyphase furnaces, means for applying heat to the bottom of the melt, both in and outside of the reaction or melting chamber to compensate for heat losses through radiation or conduction.
  • the invention also contemplates the provision of cooling means to avoid wall deterioration for those portions of the side walls through which the current flow passes or tends to flow.
  • the invention further revolves about the use of electrodes having an upstanding plate-like extension, the volume of which has a certain proportion to the volume of that portion of the electrode submerged or in contact with the melt; also about having the connector bars of the electrodes located or extending out of or above the melt.
  • the invention contemplates with particular respect to polyphase furnaces, an arrangement of electrodes whereby locally overheated zones are avoided and a uniform melt temperature may be maintained. Where there is a tendency for heat 70 loss to occur at or near the submerged throat or outlet from the melting or reaction zone, the
  • invention contemplates the arrangement of electrodes so that this heat loss may be avoided and the discharge from the furnace melting chamber 75 will proceed with uniformity without in any of course, between the way detracting from the desirable temperature uniformity of the entire melt.
  • Fig. 1 is a diagrammatic plan view of a polyphase furnace showing certain undesirable heat zones
  • Fig. 3 is a diagrammatic plan view of a modifled form of polyphase furnace
  • Fig. 4 is a diagrammatic plan view of still another form of polyphase furnace
  • Fig, 5 is a plan view through a preferred form of furnace
  • Fig. 6 is a diagrammatic furnace hook-up
  • Fig. 7 is a diagrammatic plan view showing a modified form of electrode arrangement:
  • Fig. 8 is a diagrammatic plan view showing a modified form of electrode arrangement
  • Fig. 9 is a diagrammatic plan view showing a modified form of electrode arrangement
  • Fig. 10 is a diagrammatic plan view showing a modified form of electrode arrangement
  • Fig. 11 is a plan View of a complete furnace constructed according to this invention.
  • Fig. 13 is a sectional elevation along the line i3--l3 of Fig. 11;
  • Fig. 14 is an elevation partly in section along the line i l-44 in Fig. 11;
  • Fig. 15 is a side view of one form of electrode
  • Fig. 16 is an end view of the electrode of Fig. 15;
  • F1Figisl'l is a bottom plan view of the electrode of Fig. 18 is a side view of a modified form of electrode;
  • Fig. 19 is an end view of the electrode of Fig. 18; v
  • Fig. 20 is a bottom plan view of Fig. 18.
  • a three electrode polyphase furnace is diagrammatically illustrated ashaving walls or wall-sections I forming with a bottom-section a melting or reaction chamber 2 therebetween with a submerged throat 3, a refining chamber 4 and overflow 5.
  • Electrodes 8, I and 8 which are substantially horizontally disposed and are suitably connected to a polyphase electric circuit are also provided.
  • the normal location of these electrodes is one in which a horizontal triangle connecting the cam ters of the electrodes comprises a triangle whose angles are so that they are directed toward a generally common center, electrode 1 being on a longitudinal center line of the furnace and in line with the submerged throat 3, the remaining electrodes being on each side thereof. Under these circumstances, a most unsatisfactory heat distribution occurs. 1
  • the coolest zone which is over i the furnace throat, iscaused by the more rapid outflow of fused material through the throat causing additional quantities of the raw charge to be drawn down, and the fusion of the larger quantities of raw charge at this point absorbs heat to produce a cooling action on the charge at this point.
  • the warmer zone ll the warmer zone
  • Fig. 2 illustrates a furnace of the type shown in Fig. 1 but in which the heat balance has been vastly improved
  • the furnace layout is shown similar in some respects to that of the furnace of Fig. 1, except that immediately within the walls l a platform i2 is built up on the furnace bottom and electrodes l3, l4 and
  • the platform i2 is not completely circular but is provided with spaced apart ends immediately adjacent the submerged throat 3. This produces a stepped melting or reaction chamber indicated generally at l6.
  • the gap between electrodes l3 and 15 has been shortened as compared with the gaps between electrodes l3 and M and I4 and l 5. This tends to increase the heat generated be-- 40 tween electrodes l3 and I5. This increased heat tends to overcome the cooling effect of the indrawn raw material produced as a result of the suction effect of the melt passing through the submerged throat 3. It also results in a merging 45 of all three heat zones between the electrodes into a single zone illustrated diagrammatically by the line H.
  • 75 may be used to serve the same function as the cooling duct, this material being particularly efficacious in conducting heat away from the melting zone at that point. This material is also particularly resistant to the current flow itself, but rather than construct the entire inner lining of this material, which would be rather expensive, blocks thereof may be inserted at the points of greatest wear.
  • Cooling ducts 22 may also be provided in the platform l2 to overcome any local overheating. It is to be noted that these ducts pass immediately beneath the electrodes and serve to maintain those parts of the furnace adjacent thereto at a' desirable temperature.
  • Fig. 3 illustrates a polyphase furnace having four electrodes in which the walls are indicated generally at I, the melting chamber or reaction zone at 2, the submerged throat 3 leading to the refining chamber 4 and overflow 5.
  • a platform (2 is built up on the furnace bottom to receive the electrodes 23, 24, 25 and 26.
  • Electrodes 23 and 25 may be of larger volume and extent than electrodes 24 and 26 where desirable. In this arrangement, electrodes 23 and 25 are in line with the furnace center line A-A while electrodes 24 and 26 are in line with the furnace center line B-B. Electrodes 23 and 25 are each connected with a different phase in a three phase electrical circuit while electrodes 24 and'26 are connected to the same and remaining phase.
  • the submerged throat 3 is in line with the gap between electrodes 23 and 25 and also passes beneath the former. This makes for a. better heat control.
  • the uniformity of heating effect may likewise be controlled.
  • the furnace dimension along the center line B--B is materially shortened over that of Fig. 3. This brings the electrodes 24 and 26 closer together with the result that the gaps be.- tween those electrodes and electrodes 23 and 25 are materially shortened. This has a tendency to bring the zones 2'1 closer together and the limits of zone 23 closer to the throat 3 which, as a consequence, materially decreases the cold zone immodiately surrounding the throat. This enlargement of the hot zone in the center of the furnace is very desirable.
  • the angle between the lines connecting the centers of electrodes connected to different phases should be approximately 90. This may be expressed by saying that the length of the gapbetween the electrodes on the furnace center line AA should be /2 times that of the average of the shorter gaps.
  • furnace wall to current flow should be observed with respect to that described in connection with Fig. 2 as well as the various cooling means or ducts there provided.
  • an electrode arrangement as shown in Fig. 5 is preferred.
  • the top of this zone is illustrated by the line 29 and the bottom thereof by the line 33.
  • the relationship in Fig. 5 as to electrode gap should be the same as above set forth 1 in connection with Fig. 4. This adjustment is so sensitive that even a small movement of the electrodes out of the furnace center line B-B' results in appreciable heat uniformity.
  • a three phase furnace is diagrammatically illustrated showing the walls I and the electrodes 23, 24, 25 and 26 in which electrode 23 is connected to phase A, electrode 25 with phase B, electrodes 24 and 26 with phase C.
  • the effective area of electrodes 23 and 25 and their volume is materially greater than that of electrodes 24 and 26.
  • This larger effective area and volume may be secured in other ways than by making an integrally larger electrode.
  • Fig. 7 the same furnace is shown in which the electrode 23 is subdivided into two individual electrodes both, however, connected with phase A as in the case of Fig. 6.
  • both electrodes 23 and are of the s 30 multiple type connected, however, in the manner shown in Fig. 6.
  • either or both of the electrodes 24 and 26 may be subdivided as shown in Figs. 9 and 10, respectively, wherein electrodes 24 and/or 2B are of the multiple variety.
  • Figs. 9 and 10 respectively, wherein electrodes 24 and/or 2B are of the multiple variety.
  • Fig. 11 the furnace shell is shown at 31 enclosing a composite wall made up of insulation material 32 with refractory lining 33.
  • the major portion of the bottom of the furnace chamber between the side walls is composed of refractory 33 mounted upon suitable insulation 32 rested upon supporting blocks 34.
  • a portion of this refractory 33 surrounds the bottom immediately adjacent to said walls to form the platform i2 upon which the electrodes rest.
  • Cooling ducts 35 are located in various parts of the furnace construction in order to produce the desired cooling eifect where needed.
  • the bottom of the furnace immediately beneath and on each side of the submerged throat 3 is made of a more efilcient heat conductor such as fused refractory 36.
  • a more efilcient heat conductor such as fused refractory 36.
  • metallic blocks 31 such as iron or the like through which passes heating means such as carbon resistance 33 connected at the ends by carbon leads 39 to a suitable source of electric current.
  • the bottom of the melting chamber is inclined toward the center to form a trough 40, leading to the throat I.
  • the raw material is fed to the melting or reaction chamber by means of a charging car 4i suitably mounted for movement on rails 42 on the top of the furnace wall, this car being also mounted for vertical adjustment so as to maintain a desired thickness or blanket of raw material 43 on top of the melt.
  • the level of the molten material in the furnace should preferably be such that the major portions of the electrodes are submerged therein while the connector bars of the electrodes are not.
  • the upper portion of the electrode which extends toward and outside of the furnace walls, desirably should be completely surrounded by the raw material blanket.
  • the melt flows through the submerged throat to the refining chamber 4, the level of which is maintained at the level of the discharge outlet 5 under the pressure action of the raw material blanket 43.
  • the walls of the refining chamber or zone may be provided with apertures 44 through which a flame from any desired source such as a gas burning flame may be projected to maintain the surface of the material therein at the desired temperature for eliminating the un desirable bubbles, grains or seed and thereby making the melt substantially homogeneous.
  • heating means are provided for both top and bottom sections of the melt in the refining zone. For retaining this zone against excessive heat losses it is also desirable to provide a cover 45 for the refining chamber.
  • cooling ducts II or their equivalent are provided in the furnace walls to prevent wall deterioration where the current flow between electrodes touches or tends to touch such walls.
  • such electrodes have a substantially cylindrical portion 46 provided with an upstanding connection plate 41 having a portion 48 for connection outside the furnace to the electrical bus bars.
  • the connection for each electrode between the submerged portion and the furnace wall is above the molten material.
  • the electrodes are shown as having a modified contact contour as at 49.
  • the connecting plate of the electrodes should have a volume not less than that of the parts 46 and 49.
  • furnaces have been descrbed with reference to particular embodiments, yet it is to be understood that the invention is not to be restricted thereto but is to be construed broadly and limited only by the scope of the claims.
  • a polyphase electric furnace comprising a chamber for the material to be melted and in which the material acts as a resistance, spaced horizontally disposed electrodes therein directed toward a generally common center, two of said electrodes being opposite each other, each of which is connected to a different phase in a three phase electrical system, and two additional electrodes opposite each other and on a line at right angles to a line connecting the first two electrodes, the two latter electrodes being connected to the third. phase in the said three phase electrical system.
  • a polyphase electric furnace comprising a $5 chamber for the material to be melted and in which the material acts as a resistance, spaced horizontally disposed electrodes therein directed toward a generally common center, two of said electrodes being opposite each other along a center line of the furnace, each of which is con.- nected with a different phase in a three phase electrical system, and two additional electrodes one on each side of the former and along a center line transverse to the first mentioned center line, both of said electrodes being connected to the third phase in the said three phase electrical system.
  • a polyphase electric furnace for the material to be melted and in which the material acts as a resistance comprising a chamber, two electrodes therein opposite each other along the center line 46 of the furnace, each of which is connected with a different phase in a three phase electrical system, and two additional electrodes on each side of the former, both of which are connected to the third phase in the said three phase system, the furnace s so having a submerged outlet throat through one of the side walls crossed by the center line, the two additional electrodes being located between the transverse center line and the side wall of the furnace through which the submerged outlet passes and all of said electrode entering the melt.
  • the furnace of claim 8 provided with a refining chamber and a submerged throat connecting the two chambers, heat accumulating blocks beneath the floor of the throat and the refining chamber and heating means associated with said blocks.
  • An electric furnace comprising side walls and a bottom forming a treating chamber there- 'between, platforms placed on the furnace bottom and in proximity to the side walls, electrodes resting on said platforms, said electrodes having a plate-shaped connection rising from the top thereof and extending horizontally out beyond the side wall to a suitable electrical connection, the plate-shaped connection being adapted to be covered by a raw material blanket formed on the top of the molten mass within the furnace by the raw material fed thereto, the major portion of the electrode being adapted to be submerged in the molten mass.
  • connection plate of the electrode represents at least one third of the weight of the electrode part adapted to be below the surface of the molten mass.
  • a polyphase electric furnace comprising a chamber, a submerged throat for the discharge of material treated therein, an electrode on each side of said throat, a third electrode on the other side of said chamber and in line with said throat, the gap between the two electrodes on each side of the throat being so much less than that between said electrodes and the third electrode, that the temperature throughout a horizontal section of the fusing zone will be practically equal.
  • a polyphase electric furnace comprising a chamber, a submerged throat for the discharge of material treated therein, an electrode on each side of said throat, a third electrode on the other side of said chamber and in line with said throat, the gap between the two electrodes on each side of the throat being so much less than that between said electrodes and the third electrode, that the temperature throughout a horizontal section of the fusing zone will be practically equal, the molten charge in the chamber being covered by a thick raw material blanket which is continuously fed to the furnace.
  • An electric furnace comprising furnace walls and a furnace bottom defining a space adapted for containing a conductive bath formed from a superposed layer of raw material to be treated in the furnace, a plurality of electrodes between which current is adapted to flow through the conductive bath, and electrical connections for said electrodes entering the raw material layer for being cooled thereby.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Furnace Details (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
US2003A 1934-12-24 1935-01-16 Electric furnace Expired - Lifetime US2089690A (en)

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CA2089690X 1934-12-24

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US (1) US2089690A (enMihai)
BE (1) BE414770A (enMihai)
FR (1) FR804356A (enMihai)
GB (1) GB477027A (enMihai)
NL (1) NL46073C (enMihai)

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2415493A (en) * 1944-11-27 1947-02-11 Artemas F Holden Salt bath furnace
US2523030A (en) * 1948-10-30 1950-09-19 Glass Fibers Inc Electric glass furnace
US2559683A (en) * 1949-03-15 1951-07-10 Ferro Enamel Corp Electric enamel furnace
US2589301A (en) * 1949-06-07 1952-03-18 Kaiser Aluminium Chem Corp Electric melting furnace
US2636913A (en) * 1943-07-01 1953-04-28 Saint Gobain Method and apparatus for the manufacture of glass by electric heating
US2636914A (en) * 1945-09-15 1953-04-28 Saint Gobain Furnace for making glass
US2658095A (en) * 1944-05-05 1953-11-03 Saint Gobain Process and apparatus for making glass
US2658094A (en) * 1950-05-10 1953-11-03 Gen Electric Combined electrode and skimmer for electric glass melting furnaces
US2680772A (en) * 1950-12-02 1954-06-08 Ferro Corp Method for producing porcelain enamel
US2749378A (en) * 1954-01-08 1956-06-05 Harvey L Penberthy Method and apparatus for glass production
US2749379A (en) * 1952-06-06 1956-06-05 Jenaer Glaswerk Schott & Gen Means and method for the electric melting of glass
US2761890A (en) * 1952-03-15 1956-09-04 Saint Gobain Method and arrangement in the heating of electric furnaces
US2928887A (en) * 1955-07-28 1960-03-15 Jenaer Glaswerk Schott & Gen Method and apparatus for refining glass
US2972651A (en) * 1956-04-13 1961-02-21 Ajax Electric Company Electrode arrangement in a salt bath furnace
DE3207250A1 (de) * 1981-03-04 1982-09-16 Manville Service Corp., 80217 Denver, Col. Elektroofen und verfahren fuer ein optimiertes mischen und schmelzen
US4494974A (en) * 1981-10-19 1985-01-22 B.H.F. (Engineering) Ltd. Forehearth for conditioning glass
US6044667A (en) * 1997-08-25 2000-04-04 Guardian Fiberglass, Inc. Glass melting apparatus and method
US6125658A (en) * 1997-07-22 2000-10-03 Isover Saint-Gobain Glass furnace and installation comprising same
US6178777B1 (en) 1997-08-25 2001-01-30 Guardian Fiberglass, Inc. Side-discharge melter for use in the manufacture of fiberglass, and corresponding method
US20030210731A1 (en) * 2002-03-14 2003-11-13 Japan Super Quartz Process and device for producing a quartz glass crucible by ring-like arc, and its quartz glass crucible
US20040050099A1 (en) * 2002-08-15 2004-03-18 Japan Super Quartz Corporation Reforming process of quartz glass crucible
US20240262734A1 (en) * 2022-03-29 2024-08-08 Jinzhou Youxin Quartz Technology Co., Ltd Manufacturing method of large-outer-diameter quartz crucible for czochralski (cz) single crystal

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2636913A (en) * 1943-07-01 1953-04-28 Saint Gobain Method and apparatus for the manufacture of glass by electric heating
US2658095A (en) * 1944-05-05 1953-11-03 Saint Gobain Process and apparatus for making glass
US2415493A (en) * 1944-11-27 1947-02-11 Artemas F Holden Salt bath furnace
US2636914A (en) * 1945-09-15 1953-04-28 Saint Gobain Furnace for making glass
US2523030A (en) * 1948-10-30 1950-09-19 Glass Fibers Inc Electric glass furnace
US2559683A (en) * 1949-03-15 1951-07-10 Ferro Enamel Corp Electric enamel furnace
US2589301A (en) * 1949-06-07 1952-03-18 Kaiser Aluminium Chem Corp Electric melting furnace
US2658094A (en) * 1950-05-10 1953-11-03 Gen Electric Combined electrode and skimmer for electric glass melting furnaces
US2680772A (en) * 1950-12-02 1954-06-08 Ferro Corp Method for producing porcelain enamel
US2761890A (en) * 1952-03-15 1956-09-04 Saint Gobain Method and arrangement in the heating of electric furnaces
US2749379A (en) * 1952-06-06 1956-06-05 Jenaer Glaswerk Schott & Gen Means and method for the electric melting of glass
US2749378A (en) * 1954-01-08 1956-06-05 Harvey L Penberthy Method and apparatus for glass production
US2928887A (en) * 1955-07-28 1960-03-15 Jenaer Glaswerk Schott & Gen Method and apparatus for refining glass
US2972651A (en) * 1956-04-13 1961-02-21 Ajax Electric Company Electrode arrangement in a salt bath furnace
DE3207250A1 (de) * 1981-03-04 1982-09-16 Manville Service Corp., 80217 Denver, Col. Elektroofen und verfahren fuer ein optimiertes mischen und schmelzen
US4351054A (en) * 1981-03-04 1982-09-21 Manville Service Corporation Optimized mixing and melting electric furnace
US4494974A (en) * 1981-10-19 1985-01-22 B.H.F. (Engineering) Ltd. Forehearth for conditioning glass
US6125658A (en) * 1997-07-22 2000-10-03 Isover Saint-Gobain Glass furnace and installation comprising same
US6418755B2 (en) 1997-08-25 2002-07-16 Guardian Fiberglass, Inc. Glass melting apparatus and method including exhausting the furnace atmosphere by removal of a heating element
US6178777B1 (en) 1997-08-25 2001-01-30 Guardian Fiberglass, Inc. Side-discharge melter for use in the manufacture of fiberglass, and corresponding method
US6314760B1 (en) 1997-08-25 2001-11-13 Guardian Fiberglass, Inc. Glass melting apparatus and method
US6044667A (en) * 1997-08-25 2000-04-04 Guardian Fiberglass, Inc. Glass melting apparatus and method
US20030210731A1 (en) * 2002-03-14 2003-11-13 Japan Super Quartz Process and device for producing a quartz glass crucible by ring-like arc, and its quartz glass crucible
US6853673B2 (en) * 2002-03-14 2005-02-08 Japan Super Quartz Corporation Process and device for producing a quartz glass crucible by ring-like arc, and its quartz glass crucible
US20040050099A1 (en) * 2002-08-15 2004-03-18 Japan Super Quartz Corporation Reforming process of quartz glass crucible
US7905112B2 (en) 2002-08-15 2011-03-15 Japan Super Quartz Corporation Reforming process of quartz glass crucible
US20240262734A1 (en) * 2022-03-29 2024-08-08 Jinzhou Youxin Quartz Technology Co., Ltd Manufacturing method of large-outer-diameter quartz crucible for czochralski (cz) single crystal
US12060294B1 (en) * 2022-03-29 2024-08-13 Jinzhou Youxin Quartz Technology Co., Ltd Manufacturing method of large-outer-diameter quartz crucible for Czochralski (CZ) single crystal

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BE414770A (enMihai) 1936-04-30
NL46073C (enMihai) 1939-07-15
FR804356A (fr) 1936-10-22
GB477027A (en) 1937-12-20

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