US2494425A - Electrolytically polished graphite anode - Google Patents

Electrolytically polished graphite anode Download PDF

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Publication number
US2494425A
US2494425A US681124A US68112446A US2494425A US 2494425 A US2494425 A US 2494425A US 681124 A US681124 A US 681124A US 68112446 A US68112446 A US 68112446A US 2494425 A US2494425 A US 2494425A
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United States
Prior art keywords
graphite
anode
graphite anode
electrolytically polished
anodes
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Expired - Lifetime
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US681124A
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Bakker Jan
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Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
    • C25F3/00—Electrolytic etching or polishing
    • C25F3/16—Polishing
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/042—Electrodes formed of a single material
    • C25B11/043—Carbon, e.g. diamond or graphene
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2893/00—Discharge tubes and lamps
    • H01J2893/0048—Tubes with a main cathode
    • H01J2893/0051—Anode assemblies; screens for influencing the discharge

Definitions

  • a graphite cylinder having a length of 8 cms. and a diameter of 2 cms. is arranged as the anode in an electrolysis bath of molten potassium hydrofiuoride KI-IFz which is not entirely anhydrous. At a voltage of volts the anode is loaded for half an hour with a current of 15 amperes. The graphite anode is then as smooth as a mirror. If the graphite rod is housed in a current-converting tube to form the anode and is deprived of gases in the usual manner, the current-converting tube is free from arcing back to a high extent.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)

Description

Patented Jan. 10, 1950 ELECTROLYTICALLY POLISHED GRAPHITE AN ODE Jan Bakker, Eindhoven, Netherlands, assignor to Hartford National Bank and Trust Company, Hartford, Conn, as trustee No Drawing. Application July 2, 1946, Serial No. 681,124. In the Netherlands March 15, 1943 Section 1, Public Law 690, August 8, 1946 Patent expires March 15, 1963 2 Claims.
This invention relates to a gasand/or vapourfilled current-converting tube Whose anode is of graphite.
Graphite has been used fora long time as material for anodes in gas or vapour-filled current-converting tubes. It has a lot of good properties, such as high load capacity on account of the low specific emission, even at very high temperatures, low volatilisation and a high coefficient of radiation so that the anode leads need conduct away less heat by conduction. In addition, graphite anodes are materially less liable to arcing back than metal anodes, because of glow discharge on a graphite surface as the cathode does not readily pass into an arc.
Nevertheless, in spite of the good properties of graphite it was frequently difficult to render the anodes of a current-converting tube free from arcing-back under all conditions. The back discharges which occur at any frequency. are put down by divers testers to gas-enclosures in the graphite, impurities in the surface of the anode, for example pieces of ashes or metal mercury or activating material that may condense on the anodes after having found its way from the cathode to the anodes.
According to the invention, gas and/or vapour filled current-converting tubes comprise anodically polished graphite anodes. Anodically polished graphite is as smooth as a mirror and is devoid of grinding or polishing scratches. Anodically polished surfaces may exhibit certain undulations due to irregularities in the starting material but they only become manifest as a certain moir on the surface. It has been found by the applicant that anodically polished anode surfaces are by far less liable to arcing back than coarse surfaces. Probably, there are on an anodically polished surface fewer impurities capable of bringing about arcing back and new impurities do not readily adhere to the surface.
Especially suitable electrolytes for anodically polishing graphite are molten fluorides. The current density is preferably chosen to range between 0.1 and 1 a./cm. and the duration between 1 minute and 1 hour.
In order that the invention may be clearly understood and readily carried into effect it will 2 now be described more fully with reference to the following example.
A graphite cylinder having a length of 8 cms. and a diameter of 2 cms. is arranged as the anode in an electrolysis bath of molten potassium hydrofiuoride KI-IFz which is not entirely anhydrous. At a voltage of volts the anode is loaded for half an hour with a current of 15 amperes. The graphite anode is then as smooth as a mirror. If the graphite rod is housed in a current-converting tube to form the anode and is deprived of gases in the usual manner, the current-converting tube is free from arcing back to a high extent.
What I claim is:
1. An ion discharge tube comprising an electrolytically polished graphite anode.
2. A method of polishing graphite anodes for ion discharge tubes which comprises the steps of positioning the graphite anode as an anode of an electrolytic bath consistin of molten potassium hydrofiuoride KHFz, applying a potential of approximately 130 volts to the said anode, and loading the said anode with a current density of between about 0.1 and 1 a./cm. for about 1 minute to 1 hour.
JAN BAKKER.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,484,733 Mathers Feb. 26, 1924 1,866,969 Fredenhagen July 12, 1932 2,329,317 Atlee Sept. 14, 1943 FOREIGN PATENTS Number Country Date 401,471 Great Britain Nov. 16, 1933 455,256 Great Britain Oct. 16, 1936 OTHER REFERENCES The Electrochemical Society, Preprint 91-3 (1947), Electrolytic Fluorine Production In Germany, by Neumark; pages 37 through 44. (Copy in Division 56.)

Claims (1)

1. AN ION DISCHARGE TUBE COMPRISING AN ELECTROLYTICALLY POLISHED GRAPHITE ANODE.
US681124A 1943-03-15 1946-07-02 Electrolytically polished graphite anode Expired - Lifetime US2494425A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL628129X 1943-03-15

Publications (1)

Publication Number Publication Date
US2494425A true US2494425A (en) 1950-01-10

Family

ID=19788649

Family Applications (1)

Application Number Title Priority Date Filing Date
US681124A Expired - Lifetime US2494425A (en) 1943-03-15 1946-07-02 Electrolytically polished graphite anode

Country Status (4)

Country Link
US (1) US2494425A (en)
GB (1) GB628129A (en)
NL (1) NL65822C (en)
SE (1) SE115949C1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2876190A (en) * 1955-04-18 1959-03-03 Union Carbide Corp Duct anode
US3432411A (en) * 1965-12-08 1969-03-11 Weyerhaeuser Co Method of operating an electrolytic chlorine production cell
US4602985A (en) * 1985-05-06 1986-07-29 Eldorado Resources Limited Carbon cell electrodes
US20150247255A1 (en) * 2014-02-28 2015-09-03 Boe Technology Group Co., Ltd. Electrochemical polishing solution, process for electrochemically polishing graphite gate electrode and graphite gate electrode

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1484733A (en) * 1919-06-30 1924-02-26 Frank C Mathers Method of making fluorine
US1866969A (en) * 1928-07-17 1932-07-12 Fredenhagen Karl Electrolytic production of fluorine
GB401471A (en) * 1931-09-12 1933-11-16 Philips Nv Improvements in or relating to gasfilled discharge tubes, particularly incandescent cathode rectifier tubes
GB455256A (en) * 1934-11-08 1936-10-16 British Thomson Houston Co Ltd Improvements in and relating to electrodes for electric discharge devices
US2329317A (en) * 1941-03-19 1943-09-14 Gen Electric X Ray Corp Method of conditioning anodes

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1484733A (en) * 1919-06-30 1924-02-26 Frank C Mathers Method of making fluorine
US1866969A (en) * 1928-07-17 1932-07-12 Fredenhagen Karl Electrolytic production of fluorine
GB401471A (en) * 1931-09-12 1933-11-16 Philips Nv Improvements in or relating to gasfilled discharge tubes, particularly incandescent cathode rectifier tubes
GB455256A (en) * 1934-11-08 1936-10-16 British Thomson Houston Co Ltd Improvements in and relating to electrodes for electric discharge devices
US2329317A (en) * 1941-03-19 1943-09-14 Gen Electric X Ray Corp Method of conditioning anodes

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2876190A (en) * 1955-04-18 1959-03-03 Union Carbide Corp Duct anode
US3432411A (en) * 1965-12-08 1969-03-11 Weyerhaeuser Co Method of operating an electrolytic chlorine production cell
US4602985A (en) * 1985-05-06 1986-07-29 Eldorado Resources Limited Carbon cell electrodes
US20150247255A1 (en) * 2014-02-28 2015-09-03 Boe Technology Group Co., Ltd. Electrochemical polishing solution, process for electrochemically polishing graphite gate electrode and graphite gate electrode
US9551085B2 (en) * 2014-02-28 2017-01-24 Boe Technology Group Co., Ltd. Electrochemical polishing solution, process for electrochemically polishing graphite gate electrode and graphite gate electrode

Also Published As

Publication number Publication date
SE115949C1 (en) 1946-03-05
NL65822C (en)
GB628129A (en) 1949-08-23

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