US1572873A - High-frequency dielectric and magnetic furnace - Google Patents

High-frequency dielectric and magnetic furnace Download PDF

Info

Publication number
US1572873A
US1572873A US683375A US68337523A US1572873A US 1572873 A US1572873 A US 1572873A US 683375 A US683375 A US 683375A US 68337523 A US68337523 A US 68337523A US 1572873 A US1572873 A US 1572873A
Authority
US
United States
Prior art keywords
high frequency
mass
electric field
temperature
heated
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
Application number
US683375A
Inventor
Chester T Allcutt
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.)
CBS Corp
Original Assignee
Westinghouse Electric and Manufacturing Co
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 Westinghouse Electric and Manufacturing Co filed Critical Westinghouse Electric and Manufacturing Co
Priority to US683375A priority Critical patent/US1572873A/en
Application granted granted Critical
Publication of US1572873A publication Critical patent/US1572873A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • H05B11/00—Heating by combined application of processes covered by two or more of groups H05B3/00 - H05B7/00
    • 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
    • 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
    • C03B5/021—Melting in furnaces; Furnaces so far as specially adapted for glass manufacture in electric furnaces, e.g. by dielectric heating by induction heating
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S65/00—Glass manufacturing
    • Y10S65/04—Electric heat

Definitions

  • nmc'rmc a murac'runme comuuw, A coaromrron or rummvlmu.
  • the object of my invention is to provide a system for heatingmasses of material having a relativel hlgh negative temperature co-efiic'ient o reslstivity, by means of high frequency and. high voltage electric and electromagnetic fields.
  • Figure 1 is a schematic diagram of connections and of a furnace embodying my invention
  • I Fig.2 is a top plan view of the furnace illustrated in section in Fig- 1 of the drawing
  • I Fig. 3 is a schematic drawing of a furnace and system embodying my invention.
  • the subject-matter of the present application relates more particularly to the use of a high frequency electromagnetic field when combined with a high frequency electric field in order that material'having a negative temperature coeflicientof resistivity may be initiall heated by subjecting it to the action o the electric field and then further causing its temperature to rise by'subjecting it to the action of an electromagnetic field of high frequency.
  • oxides of metals are examples of such material and they may be operated upon by the means and the system embodying my invention, to cause the same to be heated to ermit of their commercial application, suc 1, for instance, as coatings or other material.
  • a suitable source of supply of high frequency alternating or oscillating current is intended to be represented by the transformer 14 and as such sources of supply are well known in the art, I do not consider it necessary to illustrate or describe them in detail.
  • a condenser 15 may be provided, and is preferably of such capacitance as to make the secondary circuit of the transformer resonant at the frequency of the source of current.
  • a pair of electrodes 16 and 17 are located in spaced relation and are operativcly associated with the container 11.
  • a transformer 18, comprising primary and second ary windings, is illustrated in the drawings as representing a suitable source of high frequency and high voltage current, the terminals of the secondary winding of the transformer being connected to the respective electrodes 16 and 17.
  • the source of supply 14 may be energized, thereby causing a high frequency electromagnetic field to be generated by-and within the coil 13.
  • This electromagnetic field causes a relatively large amount of energy loss in the non-conducting mass of materialand results in a much quicker rise of the temperature therein.
  • the inherent resistivity of the material decreases with an increase in temperature, it is apparent that it will require a short time only to cause the temperature thereof to be raised to a predetermined value.
  • Fig. 3 have illustrated a preferred form of device embodying my invention in which a single source of high voltage and high frequency electric current is connected to means for producing respectively an electric field and an electromagnetic field.
  • a transformer 14 has the terminals of secondary winding electrically connected to the terminals of a coil 13 to thereby produce a high frequency electromagnetic field.
  • Two spaced electrodes 19 and 21, located within the coil 13 are electrically connected to the terminals of the secondary winding of the transformer 14 and a container 22 is located therebetween.
  • the container 22 is preferably of shallow form, and of short length relatively to the axial length of the coil 13, to obtain the proper electric conditions when in operation. It is desirable and may become necessary to slot the electrodes 19 and 21 radially thereof to pre vent excessive temperature rise by reason of eddy current losses therein.
  • the device and system illustrated in Fig. 3 will operate automatically when employed to heat materials having a negative temperature coefficient of resistivity, in that the material will be, initially heated by the action of the electric field and will then be further heated mainly by the action of the electromagnetic field. Both fields are effective during the entire operation but their action is selective as stated-above.
  • tures comprising a part of dielectric material, that'may. be influenced tures may, for instance, comprise vacuumtubes, and where large numbers of such tubes are to be operated upon, the furnace structure may be so designed that the de sired heating effects may be obtained in each part of the tube.
  • I have referred to a source of sustained electric current of high frequency, 1 include frequencies not less than those usually employed in radio telegraphy and radio telephony and such higher frequencies as may be commercially produced for such applications.
  • a sustained alternating current of high frequency is particularly applicable for my purpose, as the discharge from a series of high frequency wave trains, such as produced by an oscillatory spark discharge, will not, in many cases, produce the desired heating effects.
  • a heating system the combination with a mass of material to be heated and a means for producing a high frequency electromagnetic field, of means for producing a high frequency electric field surrounding said mass.
  • a mass to be heated in combination, a mass to be heated,-said mass being pyromagnetic, means for producing, a high frequency electromagnetic field in said mass, and means for producing a high frequency electric field in said mass.
  • a heating system in combination, a mass of material to be heated, a coil, a source of high frequency current connected to said coil, and means for subjecting said mass of material to a high'frequency electric field.
  • a heating system in combination, a mass of material to be heated, a container therefor, means for producing a high frequency electromagnetic field surrounding said mass of material, and means for producing a high frequency electric field surrounding said mass of material.
  • a heating system in combination, a mass of material to beheated, a container therefor, a coil surrounding saidcontaincr, a source of high frequency current electrically connected to saidcoil, a pair of spaced electrodes operatively associated with said container, and means for producing a high frequency electric field between said electrodes.
  • the method of heating a mass of material having a relatively high negative temperature cocfiicient of resistivity comprises subjecting the mass of material to the action of a high frequency electric field to raise the temperature thereof, and then subjecting it to the action of a high frequency electromagnetic field until the desired temperature is reached.

Description

Feb. 1% 11926.,
C. T. ALLCUTT HIGH FREQUENCY DIELECTRIC AND MAGNETIC FURNACE Filed Dec. 29. 1923 W my Q M WITNESSES:
/ ATTORNEY em... Feb. '16, 192e,v
'- -'uN1TEnsrATEs PATENT OFFICE.
,. marlin. r. mourn orrrrrsnunen, rmmsnvnma, .nssmnoa 'ro. wns'rnwnous]: nmc'rmc a murac'runme comuuw, A coaromrron or rummvlmu.
HIGH- FREQUENCY DIELECTRIC AND MAGNETIC FURNACE.
Application filed December 28, 1928. Serial No. 683,875.
, To all whom it may concern:-
Be it known that I, CHESTER T. ALLoU'r'r, a citizen of the United States, and a resldent of Pittsburgh, in the'county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in High- Frequency Dielectric and Magnetic Furnaces, of which the following is a specificatio a My invention relates to electric furnaces and more particularly to furnaces that are heated by means of the action of dielectric and of electromagnetic fields.
The object of my invention is to provide a system for heatingmasses of material having a relativel hlgh negative temperature co-efiic'ient o reslstivity, by means of high frequency and. high voltage electric and electromagnetic fields.
In the single sheet of drawings,
Figure 1 is a schematic diagram of connections and of a furnace embodying my invention, I Fig.2 is a top plan view of the furnace illustrated in section in Fig- 1 of the drawing, and I Fig. 3 is a schematic drawing of a furnace and system embodying my invention.
In my copending application, Serial No.
671,113; filed Oct. 27, 1923, and assigned to the Westinghouse Electric and Manufacturing Company, I have disclosed and claimed more articularly the use of a high voltage and hlgh frequency electric field employed in combination with a member of dielectric material to therebyheat the same. The subject-matter of the present application relates more particularly to the use of a high frequency electromagnetic field when combined with a high frequency electric field in order that material'having a negative temperature coeflicientof resistivity may be initiall heated by subjecting it to the action o the electric field and then further causing its temperature to rise by'subjecting it to the action of an electromagnetic field of high frequency.
' A container 11 for a mass 12 of material to be heated may consist of any suitable or desired material that is an imperfect dielec tric, such as glass or quartz. It is, however, not necessary that the container consist of such material when the mass of material to sufliciently high temperature to be operatedupon consists of material, that has a relatively high inherent resistivit when cold and that has a relatively hig conductivity when hot.
The oxides of metals are examples of such material and they may be operated upon by the means and the system embodying my invention, to cause the same to be heated to ermit of their commercial application, suc 1, for instance, as coatings or other material.
A coil 13 of a suitable electric-conducting material, such as copper, surrounds the con-' tainer 11 and has the terminals thereof connected to the terminals of a suitable source of supply of high frequency electric current, here illustrated as a transformer 14, the secondary winding of which is connected to the coil 13 and the primary winding of which is connected to the terminals of a suitable source of supply. Any suitable source of supply of high frequency alternating or oscillating current is intended to be represented by the transformer 14 and as such sources of supply are well known in the art, I do not consider it necessary to illustrate or describe them in detail. A condenser 15 may be provided, and is preferably of such capacitance as to make the secondary circuit of the transformer resonant at the frequency of the source of current.
A pair of electrodes 16 and 17 are located in spaced relation and are operativcly associated with the container 11. A transformer 18, comprising primary and second ary windings, is illustrated in the drawings as representing a suitable source of high frequency and high voltage current, the terminals of the secondary winding of the transformer being connected to the respective electrodes 16 and 17.
In practicing my method of heating by consecutive or simultaneous subjection of the container and of the mass of material to be heated to the action of high frequency electric and electromagnetic fields,=the source of supply 18 is first energized in order that pyroelectric material 12 within the container 11 may be subjected to the action of the high frequency electric field,.thereby causing heat to be generated in the mass itself and resulting in a rise in temperature thereof.
When this temperature rise is sufficient to effect a substantial decrease in the inherent resistivity of .the material, the source of supply 14 may be energized, thereby causing a high frequency electromagnetic field to be generated by-and within the coil 13.
This electromagnetic field causes a relatively large amount of energy loss in the non-conducting mass of materialand results in a much quicker rise of the temperature therein. As the inherent resistivity of the material decreases with an increase in temperature, it is apparent that it will require a short time only to cause the temperature thereof to be raised to a predetermined value.
When it is desired to heat a mass of material that is conducting even when cold, it is desirable to employ a crucible or container of imperfect dielectric material. Heat is generated in the container 11 by subjecting it to the action of a high frequency electric field generated between the electrodes 16 and 17. The heat generated in the container 11 is imparted to the mass of material to be heated and, depending upon the characteristics of the mass of material, the electromagnetic field may be energized simultaneously with the electric field or after the temperature of the material has beenrai'sed a predetermined amount.
In Fig. 3, l have illustrated a preferred form of device embodying my invention in which a single source of high voltage and high frequency electric current is connected to means for producing respectively an electric field and an electromagnetic field.
A transformer 14 has the terminals of secondary winding electrically connected to the terminals of a coil 13 to thereby produce a high frequency electromagnetic field. Two spaced electrodes 19 and 21, located within the coil 13 are electrically connected to the terminals of the secondary winding of the transformer 14 and a container 22 is located therebetween. The container 22 is preferably of shallow form, and of short length relatively to the axial length of the coil 13, to obtain the proper electric conditions when in operation. It is desirable and may become necessary to slot the electrodes 19 and 21 radially thereof to pre vent excessive temperature rise by reason of eddy current losses therein.
The device and system illustrated in Fig. 3 will operate automatically when employed to heat materials having a negative temperature coefficient of resistivity, in that the material will be, initially heated by the action of the electric field and will then be further heated mainly by the action of the electromagnetic field. Both fields are effective during the entire operation but their action is selective as stated-above.
In case structures, comprising a part of dielectric material, that'may. be influenced tures may, for instance, comprise vacuumtubes, and where large numbers of such tubes are to be operated upon, the furnace structure may be so designed that the de sired heating effects may be obtained in each part of the tube.
I consider that the system embodying my invention will find a distinct field of usefulness in connection with the manufacture of small evacuated bulbs, such as are now used in radio communication work. It is evident that if a conducting material constitutes a part of such a bulb or vacuum tube, it may be-directly acted upon by the electromagnetic field, and that the glass of such a bulb will be heated by energy loss generated) therein when subjected to the action of the high frequency electric field. This makes it possible to effect selective heating of predetermined portions or parts of such apparatus or of similar apparatus and also makes it possible to heat portions thereof to a predetermined temperature by means of the high frequency electric field and to further increase the temperature of a predetermined part of the device by subjecting it to the action of the high frequency electromagnetic field.
Where I have referred to a source of sustained electric current of high frequency, 1 include frequencies not less than those usually employed in radio telegraphy and radio telephony and such higher frequencies as may be commercially produced for such applications. A sustained alternating current of high frequency is particularly applicable for my purpose, as the discharge from a series of high frequency wave trains, such as produced by an oscillatory spark discharge, will not, in many cases, produce the desired heating effects.
Various modifications and changes may be made herein without departing from the spirit and scope of the invention. I desire therefore, that only such limitations shall be placed thereon as are imposed by the prior art.
a I claim as my invention:
1. In a heating system, the combination with a mass of material to be heated and a means for producing a high frequency electromagnetic field, of means for producing a high frequency electric field surrounding said mass.
2. In a heating system, in combination, a mass to be heated,-said mass being pyromagnetic, means for producing, a high frequency electromagnetic field in said mass, and means for producing a high frequency electric field in said mass.
3. In a heating system, in combination, a mass of material to be heated, a coil, a source of high frequency current connected to said coil, and means for subjecting said mass of material to a high'frequency electric field.
4. In a heating system, in combination, a mass of material to be heated, a container therefor, means for producing a high frequency electromagnetic field surrounding said mass of material, and means for producing a high frequency electric field surrounding said mass of material.
5. In a heating system, in combination, a mass of material to beheated, a container therefor, a coil surrounding saidcontaincr, a source of high frequency current electrically connected to saidcoil, a pair of spaced electrodes operatively associated with said container, and means for producing a high frequency electric field between said electrodes.
6. The method of heating a mass of material having a relatively high negative temperature cocfiicient of resistivity that comprises subjecting the mass of material to the action of a high frequency electric field to raise the temperature thereof, and then subjecting it to the action of a high frequency electromagnetic field until the desired temperature is reached.
In testimony whereof, I have hereunto subscribed my name this 17th day of December 1923.
CHESTER 'r. ALLCUTT.
US683375A 1923-12-29 1923-12-29 High-frequency dielectric and magnetic furnace Expired - Lifetime US1572873A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US683375A US1572873A (en) 1923-12-29 1923-12-29 High-frequency dielectric and magnetic furnace

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US683375A US1572873A (en) 1923-12-29 1923-12-29 High-frequency dielectric and magnetic furnace

Publications (1)

Publication Number Publication Date
US1572873A true US1572873A (en) 1926-02-16

Family

ID=24743774

Family Applications (1)

Application Number Title Priority Date Filing Date
US683375A Expired - Lifetime US1572873A (en) 1923-12-29 1923-12-29 High-frequency dielectric and magnetic furnace

Country Status (1)

Country Link
US (1) US1572873A (en)

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2432491A (en) * 1939-03-06 1947-12-09 Hygrade Sylvania Corp Apparatus for lamp bulb sealing
US2475810A (en) * 1944-01-05 1949-07-12 Bell Telephone Labor Inc Preparation of silicon material
US2515211A (en) * 1947-01-24 1950-07-18 Armstrong Cork Co Method and apparatus for dielectric heating
US2555450A (en) * 1943-11-29 1951-06-05 Lee Foundation For Nutritional High-frequency dehydrating method and apparatus
US2608638A (en) * 1947-01-17 1952-08-26 Hoover Co Electrostatic dielectric heating apparatus
DE874939C (en) * 1948-10-02 1953-04-27 Telefunken Gmbh High frequency heating device
US2695475A (en) * 1949-10-21 1954-11-30 American Optical Corp Means and method of hardening glass articles
US2714785A (en) * 1950-11-21 1955-08-09 Hartford Nat Bank & Trust Co Method of sealing a vacuum vessel having a thick-walled exhaust tube
US2740184A (en) * 1951-03-01 1956-04-03 Albert G Thomas Electrically charged material
US2749379A (en) * 1952-06-06 1956-06-05 Jenaer Glaswerk Schott & Gen Means and method for the electric melting of glass
US2768226A (en) * 1954-08-27 1956-10-23 Inductotherm Corp Spark-gap converter, induction-heating and melting assembly
DE952376C (en) * 1940-02-17 1956-11-15 Siemens Ag Treatment of inhomogeneous masses in a capacitive high frequency field
DE971499C (en) * 1941-08-22 1959-02-05 Siemens Ag Device for the optional ultra-short wave treatment of any good in the electrical capacitor or coil field with defined capacitance and inductivity
US2875556A (en) * 1953-07-31 1959-03-03 Vig Corp Apparatus for molding refractory materials
US3205292A (en) * 1959-06-25 1965-09-07 Loing Verreries Heating and melting process of vitreous materials and furnace therefor
US3219787A (en) * 1963-04-08 1965-11-23 Julius W Mann Process and apparatus for heating dielectrics in high frequency extended toroidal electrode configurations
US3244850A (en) * 1963-06-03 1966-04-05 Mann Russell Electronics Inc Segmented extended toroidal electrode and process of dielectric heating therewithin
US3337675A (en) * 1963-02-02 1967-08-22 Loing Verreries Manufacture of glass
US3359399A (en) * 1963-07-25 1967-12-19 Chemetron Corp High frequency heating system
US3394007A (en) * 1966-05-19 1968-07-23 Campbell Richard Lincoln Method of thawing and cooking food
US3535481A (en) * 1969-03-24 1970-10-20 Plastics Eng Co High frequency induction heating of semiconductive plastics
US3598951A (en) * 1969-08-08 1971-08-10 Julius W Mann Self-excited, self-tuning and self-loading generator in which the load is an inherent part of the tank circuit capacitance and inductance
US3937625A (en) * 1973-08-30 1976-02-10 International Standard Electric Corporation Radio frequency preparation of pure glass
US4546484A (en) * 1982-11-16 1985-10-08 U.S. Philips Corporation Device for the continuous manufacture of elongated bodies starting from unmolten solid starting material
US4814567A (en) * 1987-07-08 1989-03-21 Darko Jorge Lazaneo Dragicevic Electro-thermic resonance system for heating liquid
EP0546617A1 (en) * 1991-12-09 1993-06-16 Koninklijke Philips Electronics N.V. Method of moulding products and device suitable for carrying out the method
FR2749524A1 (en) * 1996-06-06 1997-12-12 Curie Patrick Asbestos fibre insulation disposal
EP1563714A1 (en) * 2002-11-15 2005-08-17 Liquid Ceramics Technology Pty Ltd Method and apparatus for heating refractory oxides
WO2007109858A1 (en) * 2006-03-27 2007-10-04 Liquid Ceramics Technology Pty Ltd Method and apparatus for heating refractory oxides

Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2432491A (en) * 1939-03-06 1947-12-09 Hygrade Sylvania Corp Apparatus for lamp bulb sealing
DE952376C (en) * 1940-02-17 1956-11-15 Siemens Ag Treatment of inhomogeneous masses in a capacitive high frequency field
DE971499C (en) * 1941-08-22 1959-02-05 Siemens Ag Device for the optional ultra-short wave treatment of any good in the electrical capacitor or coil field with defined capacitance and inductivity
US2555450A (en) * 1943-11-29 1951-06-05 Lee Foundation For Nutritional High-frequency dehydrating method and apparatus
US2475810A (en) * 1944-01-05 1949-07-12 Bell Telephone Labor Inc Preparation of silicon material
US2608638A (en) * 1947-01-17 1952-08-26 Hoover Co Electrostatic dielectric heating apparatus
US2515211A (en) * 1947-01-24 1950-07-18 Armstrong Cork Co Method and apparatus for dielectric heating
DE874939C (en) * 1948-10-02 1953-04-27 Telefunken Gmbh High frequency heating device
US2695475A (en) * 1949-10-21 1954-11-30 American Optical Corp Means and method of hardening glass articles
US2714785A (en) * 1950-11-21 1955-08-09 Hartford Nat Bank & Trust Co Method of sealing a vacuum vessel having a thick-walled exhaust tube
US2740184A (en) * 1951-03-01 1956-04-03 Albert G Thomas Electrically charged material
US2749379A (en) * 1952-06-06 1956-06-05 Jenaer Glaswerk Schott & Gen Means and method for the electric melting of glass
US2875556A (en) * 1953-07-31 1959-03-03 Vig Corp Apparatus for molding refractory materials
US2768226A (en) * 1954-08-27 1956-10-23 Inductotherm Corp Spark-gap converter, induction-heating and melting assembly
US3205292A (en) * 1959-06-25 1965-09-07 Loing Verreries Heating and melting process of vitreous materials and furnace therefor
US3337675A (en) * 1963-02-02 1967-08-22 Loing Verreries Manufacture of glass
US3219787A (en) * 1963-04-08 1965-11-23 Julius W Mann Process and apparatus for heating dielectrics in high frequency extended toroidal electrode configurations
US3244850A (en) * 1963-06-03 1966-04-05 Mann Russell Electronics Inc Segmented extended toroidal electrode and process of dielectric heating therewithin
US3359399A (en) * 1963-07-25 1967-12-19 Chemetron Corp High frequency heating system
US3394007A (en) * 1966-05-19 1968-07-23 Campbell Richard Lincoln Method of thawing and cooking food
US3535481A (en) * 1969-03-24 1970-10-20 Plastics Eng Co High frequency induction heating of semiconductive plastics
US3598951A (en) * 1969-08-08 1971-08-10 Julius W Mann Self-excited, self-tuning and self-loading generator in which the load is an inherent part of the tank circuit capacitance and inductance
US3937625A (en) * 1973-08-30 1976-02-10 International Standard Electric Corporation Radio frequency preparation of pure glass
US4546484A (en) * 1982-11-16 1985-10-08 U.S. Philips Corporation Device for the continuous manufacture of elongated bodies starting from unmolten solid starting material
US4617041A (en) * 1982-11-16 1986-10-14 U.S. Philips Corporation Method for continuously manufacturing elongated bodies starting from unmolten solid starting material
US4814567A (en) * 1987-07-08 1989-03-21 Darko Jorge Lazaneo Dragicevic Electro-thermic resonance system for heating liquid
EP0546617A1 (en) * 1991-12-09 1993-06-16 Koninklijke Philips Electronics N.V. Method of moulding products and device suitable for carrying out the method
FR2749524A1 (en) * 1996-06-06 1997-12-12 Curie Patrick Asbestos fibre insulation disposal
EP1563714A1 (en) * 2002-11-15 2005-08-17 Liquid Ceramics Technology Pty Ltd Method and apparatus for heating refractory oxides
EP1563714A4 (en) * 2002-11-15 2006-03-08 Liquid Ceramics Technology Pty Method and apparatus for heating refractory oxides
WO2007109858A1 (en) * 2006-03-27 2007-10-04 Liquid Ceramics Technology Pty Ltd Method and apparatus for heating refractory oxides

Similar Documents

Publication Publication Date Title
US1572873A (en) High-frequency dielectric and magnetic furnace
US2444259A (en) Method of high-frequency induction heating
US1900573A (en) Electric heating apparatus
US2276994A (en) Electrotherapy
US2494716A (en) Method and apparatus for treating materials dielectrically
GB950742A (en) A process and apparatus for heating and fusing a vitreous material
US2314311A (en) Apparatus for starting and controlling electric discharge devices
US1555258A (en) High-frequency dielectric furnace
US2908739A (en) Water cooled crucible for high frequency heating
US1954678A (en) Electric heating apparatus
US3323010A (en) Monochromatic light source with temperature regulating means
US2465093A (en) High-frequency corona arc heating apparatus
US1998332A (en) Heating apparatus and system
US1555259A (en) High-frequency-corona-discharge furnace
US3644151A (en) Method and device for crucible-free zone melting a crystalline rod
US2381057A (en) Oscillator circuit for inductive heating
US1506320A (en) High-frequency electric arc
US2022465A (en) Electrical vacuum pump
US1813580A (en) Mercury vapor lamp
US1579009A (en) High-frequency apparatus and method of heating
US2151912A (en) High frequency generator
US1616431A (en) Treatment of vacuum devices to remove occluded gases therefrom
US2723366A (en) Starting and operating circuit for high pressure gaseous discharge device
US2100697A (en) Braun tube and method of producing braun tubes
US1506486A (en) Electric oscillator