US2137841A - Electric discharge device - Google Patents

Electric discharge device Download PDF

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Publication number
US2137841A
US2137841A US86800A US8680036A US2137841A US 2137841 A US2137841 A US 2137841A US 86800 A US86800 A US 86800A US 8680036 A US8680036 A US 8680036A US 2137841 A US2137841 A US 2137841A
Authority
US
United States
Prior art keywords
envelope
anode
tube
metal
temperature
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
US86800A
Other languages
English (en)
Inventor
John H Hutchings
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.)
General Electric Co
Original Assignee
General Electric 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
Priority to BE422235D priority Critical patent/BE422235A/xx
Priority to FR794258D priority patent/FR794258A/fr
Priority to DEA91704A priority patent/DE715438C/de
Application filed by General Electric Co filed Critical General Electric Co
Priority to US86800A priority patent/US2137841A/en
Priority to GB17482/37A priority patent/GB487460A/en
Priority to FR48549D priority patent/FR48549E/fr
Application granted granted Critical
Publication of US2137841A publication Critical patent/US2137841A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/20—Manufacture of screens on or from which an image or pattern is formed, picked up, converted or stored; Applying coatings to the vessel
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
    • H01J19/42—Mounting, supporting, spacing, or insulating of electrodes or of electrode assemblies
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J5/00—Details relating to vessels or to leading-in conductors common to two or more basic types of discharge tubes or lamps
    • H01J5/02—Vessels; Containers; Shields associated therewith; Vacuum locks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J5/00—Details relating to vessels or to leading-in conductors common to two or more basic types of discharge tubes or lamps
    • H01J5/02—Vessels; Containers; Shields associated therewith; Vacuum locks
    • H01J5/08—Vessels; Containers; Shields associated therewith; Vacuum locks provided with coatings on the walls thereof; Selection of materials for the coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
    • H01J2893/0002—Construction arrangements of electrode systems
    • 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
    • Y10S165/00—Heat exchange
    • Y10S165/904—Radiation

Definitions

  • My invention relates to electric discharge devices, and more particularly to electric discharge devices which are provided with metal enclosing envelopes.
  • the operating temperature of the electrode parts with a given energy input can be substantially reduced by providing the interior of the metal envelope with a blackened surface adapted to increase its ability to Aabsorb heat.
  • blackened I intend to designate not only true black body surfaces but also oth-er surfaces such as dark brown or blue gray which fairly approximate black body characteristics.
  • a surface of the desired characteristics is provided by a method which involves oxidizing the envelope walls after assembly of the various envelope parts but before exhaust.
  • FIG. 1 shows an elevational view in partial section of an electron .discharge device to which my invention is applicable;
  • Fig. 2 is a section on line 2--2 of Fig. 1 and
  • Fig. 3 is a longitudinal section of a controllable mercury pool tube also embodying the invention.
  • Aa metal enclosing envelope comprising an elongated tubular portion I of a readily workable metal, such as steel oi' .005 inch thickness, closed at the bottom by a anged header 2 hermetically sealed thereto.
  • a cathode 3 Within the envelope'and insulatingly supported therefrom are provided a cathode 3, a grid or control electrode 4, and an anode 5.
  • the cathode may suitably comprise a long cylinder of a metal such as nickel coated exteriorly with a layer of electron emissive mate- Irial such as a mixture of barium and strontium oxide.
  • This cathode is surrounded by the grid il which as shown takes the form of a helical ,spiral of thin wire, preferably of molybdenum,
  • anode Surrounding both these electrodes and adapted to receive a discharge from the cathode is provided an anode in the form of an imperforate sleeve suitably of carbon-coated nickel. 'Ihe electrode parts are supported and maintained in proper alinement by vertical rods 'l of a conducting material, for example, copper. Partial compensation for the electrostatic field distortion caused by these last-named elements is effected by making the grid and anode of generally elliptical shape. as best shown in Fig. 2.
  • the Various conducting parts are insulated from one another and from the envelope by spaced disks 8 of a non-conducting material, for example, mica.
  • Lead-in connections for the electrodes, as well as for a resistance heater l0 arranged coaxially within the cathode, are supplied through conductors H brought to the outside of the tube through suitable glass-to-metal seals l2.
  • Such a surface will have its greatest effect when applied in a region exposed to direct heat radiation from the anode. In the construction illustrated in Fig. 1 this will obviously comprise the area bounded by the insulating disks 8.
  • the Wall surfaces above the upper disk and below the lower disk need not be treated since they are so shielded as to play little part in the absorption of heat from the electrodes.
  • a method of blackening which is advantageous in the routine fabrication of metal tubes consists in oxidizing the desired region of the tube wall surface thus producing a blackening coating chemically bonded with the envelope material. This process may be carried out before the tube is exhausted and While it still contains a quantity of air. Under these conditions the central portion of the envelope, particularly in the vicinity of the anode, may be heated either by application of a flame or by high frequency induction to a temperature Well above the oxidation temperature of iron, that is, at least to 400 C. and preferably to about 900 C. This heating, especially at the high temperature specified, should be very brief, being long enough to produce oxidation of the surface of the envelope but not4 sufliciently long to heat the electrode parts to an oxidizing temperature.
  • the thermal absorptivity of the metal wall may be increased as much as 200 to 500 per cent depending on its original condition.
  • Particular tubes which before treatment had been observed to operate at normal voltages and currents with an anode temperature of 435 C. were found to operate with an anode temperature of less than 325 C. after application of an oxide coating as specified.
  • enclosing envelope comprises a pair of concentric slightly spaced cylinders I8 and I9 closed at their ends by stepped metal headers 20 and 2
  • An anode 22 preferably in the form of a large block of graphite is supported at the top of the discharge vessel and is insulated from the main portion of the vessel by a glass cylinder 23.
  • a heavy cable 24 indirectly attached to the anode as shown is provided for convenient connection to an external source of potential (not illustrated)
  • a pool of liquid cathode material 26, for example mercury adapted to cooperate with the anode 22 in conducting an electric discharge therebetween.
  • a makealive electrode 21 of a semi-conducting material as, for example, boron carbide mixed with clay.
  • the cathode header 2I may be connected to the same or a different source of potential through a heavy lug 32 Vwelded or soldered to the lower surface of the header.
  • the spaced cylinders I8 and I9 define a jacket or chamber therebetween adapted to receive a cooling uid 33, for example, water.
  • This jacket is provided with inlet and outlet conduits 34 and 35, respectively, which permit continuous circulation of the cooling medium.
  • the power load which will be effective to produce this limiting temperature may be substantially increased after application of a blackening coating to the inner surface of the cylinder I9.
  • This coating should be applied in a region adjacent the anode and serves to improve the transmission of heat to the cooling fluid 33, thereby lowering the ternperature at which the electrode parts will operate for a given voltage and current.
  • the blackening material may suitably be applied above the more or less arbitrary boundary line 31.
  • a coating. of the desired quality may be provided by the method outlined in the foregoing description.
  • the coating may be produced while the tube is being exhausted by operating the tube for a brief interval at an excessive overload.
  • an overload which may be in the neighborhood of 300 per cent, small particles of carbon will be thrown off the anode surface and will form a sooty deposit on the envelope walls, thus effecting the blackening desired.
  • objectionable gases generated during this process will be carried off to the exhaust pump through the exhaust tubulation 38 and will not render the tube inoperative as they might if generated during its later operation.
  • one may coat the surfaces desired to be darkened with a colloidal suspension of carbon in water.
  • the method of fabricating an electrical device of the type comprising a ferrous metal envelope enclosing electrode parts includes assembling the envelope and electrode parts, heating the wall of the envelope in an oxidizing atmosphere to provide a black oxide coating on the interior surface thereof and thereafter exhausting and sealing the envelope.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Lasers (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
  • Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
US86800A 1936-06-23 1936-06-23 Electric discharge device Expired - Lifetime US2137841A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
BE422235D BE422235A (cs) 1936-06-23
FR794258D FR794258A (fr) 1936-06-23 1935-08-29 Dispositifs à décharge à enveloppes métalliques
DEA91704A DE715438C (de) 1936-06-23 1935-09-02 Elektrisches Entladungsgefaess mit Metallwandung
US86800A US2137841A (en) 1936-06-23 1936-06-23 Electric discharge device
GB17482/37A GB487460A (en) 1936-06-23 1937-06-23 Improvements in and relating to electric discharge devices
FR48549D FR48549E (fr) 1936-06-23 1937-06-23 Dispositifs à décharge à enveloppes métalliques

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US86800A US2137841A (en) 1936-06-23 1936-06-23 Electric discharge device

Publications (1)

Publication Number Publication Date
US2137841A true US2137841A (en) 1938-11-22

Family

ID=22201015

Family Applications (1)

Application Number Title Priority Date Filing Date
US86800A Expired - Lifetime US2137841A (en) 1936-06-23 1936-06-23 Electric discharge device

Country Status (5)

Country Link
US (1) US2137841A (cs)
BE (1) BE422235A (cs)
DE (1) DE715438C (cs)
FR (2) FR794258A (cs)
GB (1) GB487460A (cs)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3254702A (en) * 1959-08-25 1966-06-07 Harry E Thomason Heat (or cold) storage apparatus

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE763641C (de) * 1938-06-16 1953-10-12 Aeg Elektrisches Entladungsgefaess mit Metallwandung und parallel zur Roehrenachse angeordnetem Elektrodensystem

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3254702A (en) * 1959-08-25 1966-06-07 Harry E Thomason Heat (or cold) storage apparatus

Also Published As

Publication number Publication date
GB487460A (en) 1938-06-21
FR794258A (fr) 1936-02-12
FR48549E (fr) 1938-03-08
DE715438C (de) 1941-12-22
BE422235A (cs)

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