US3611014A - Method and apparatus for starting a long arc between hollow electrodes - Google Patents

Method and apparatus for starting a long arc between hollow electrodes Download PDF

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Publication number
US3611014A
US3611014A US34382A US3611014DA US3611014A US 3611014 A US3611014 A US 3611014A US 34382 A US34382 A US 34382A US 3611014D A US3611014D A US 3611014DA US 3611014 A US3611014 A US 3611014A
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Prior art keywords
electrode
rod
chamber
gas
piston
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US34382A
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English (en)
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Harden Henry Troue
Ledford H Day Jr
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Union Carbide Corp
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Union Carbide Corp
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Assigned to MORGAN GUARANTY TRUST COMPANY OF NEW YORK, AND MORGAN BANK ( DELAWARE ) AS COLLATERAL ( AGENTS ) SEE RECORD FOR THE REMAINING ASSIGNEES. reassignment MORGAN GUARANTY TRUST COMPANY OF NEW YORK, AND MORGAN BANK ( DELAWARE ) AS COLLATERAL ( AGENTS ) SEE RECORD FOR THE REMAINING ASSIGNEES. MORTGAGE (SEE DOCUMENT FOR DETAILS). Assignors: STP CORPORATION, A CORP. OF DE.,, UNION CARBIDE AGRICULTURAL PRODUCTS CO., INC., A CORP. OF PA.,, UNION CARBIDE CORPORATION, A CORP.,, UNION CARBIDE EUROPE S.A., A SWISS CORP.
Assigned to UNION CARBIDE CORPORATION, reassignment UNION CARBIDE CORPORATION, RELEASED BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: MORGAN BANK (DELAWARE) AS COLLATERAL AGENT
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/02—Details
    • H01J17/30—Igniting arrangements
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/26—Plasma torches
    • H05H1/32—Plasma torches using an arc
    • H05H1/34—Details, e.g. electrodes, nozzles

Definitions

  • Terminello and Eugene Lieberstein ABSTRACT An arc is initiated between a pair of hollow elec- METHOD AND APPARATUS FOR STARTING A trodes spaced a relatively substantial distance apart and con- LONG ARC BETWEEN HOLLOW ELECTRODES It I t t b b d M Claims 30mm Figs. tune a opposi e en s 1n 4 quar z u e y passmg a ro through the bore of one electrode and into the bore of the U.S. Cl 3l5/lli, other electrode.
  • Electric arcs of high intensity have utility as sources of light and heat.
  • One such electric are light source is shown and described in US. Pat. No. 3,364,387 wherein the arc is constricted by means of a swirling gas injected into the arc chamber.
  • the gas spirals inwardly along the central axis of the chamber creating a low-pressure region for confining and concentrating the are thereby increasing the intensity thereof.
  • This swirl flow phenomenon is equally effective on both short and long arcs.
  • the length of the arc is evidenced by the spacing between the electrodes. Where the spacing between the electrodes is greater than about 1 inch in length, hereinafter defined as a long are, conventional are starting techniques such as high frequency become impractical.
  • FIG. 1 is a longitudinal sectional view broken along the line A-A illustrating a dual hollow electrode radiation source integrally coupled to the are starting apparatus of the present invention
  • FIG. 2 is a system flow diagram partly schematic and partly diagrammatic illustrating the arc starting sequence of the present invention
  • FIG. 3 is an electrical schematic block diagram illustrating a circuit arrangement for performing the desired timing sequence in accordance with the present invention.
  • the radiation source 10 shown in the illustrated apparatus of FIG. 1 comprises a pair of substantially similar manifold assemblies l2 and 14 supporting therebetwcen an elongated tubular envelope 16 forming a gastight chamber 18.
  • Tubular envelope 16 is surrounded by an outer tubular envelope 19 in coaxial and radially spaced relationship.
  • the envelopes 16 and 19. respectively, are formed from transparent material such as quartz.
  • Electrode 20 is detachably connected at one end to manifold assembly 14 while projecting into the chamber 18 from its opposite end. in a similar fashion.
  • electrode 22 is detachably connected at one end to manifold assembly 12 and projects from its opposite end into chamber l8.
  • Each electrode is of substantially cylindrical geometry having a central bore in coaxial relationship with one another and with the longitudinal axis of the chamber 18. The spacing between the electrodes is fixed and may represent for purposes of the present invention any predetermined distance; although, the advantages of the invention become more apparent for an electrode spacing of at least 1 inch in length.
  • the manifold assemblies 12 and 14 include fluid passages as shown in FIG. 1 for passing and withdrawing a cooling fluid such as water. Additional passages are provided for circulating a gas through the radiation source 10 in a closed cycle.
  • the gas provides a plurality of functions including cooling the quartz envelope, constricting the are once established and providing in a manner to be described hereafter the pneumatic energy for the starter assembly. The gas flow sequence will be discussed more thoroughly in connection with FIG. 2
  • the arc starter assembly 30 comprises a housing 32 including a cylindrical hollow body 34 defining therewithin a piston chamber 35. Mounted in chamber 35 is a piston 36 and starter rod 38.
  • the housing 32 is fixedly bolted to the frame of manifold assembly 14 with its cylindrical body 34 extending outwardly from manifold assembly 14 in coaxial alignment with the longitudinal axis of chamber 18.
  • the flanged termination 40 at the rear end of cylindrical body 34 has an inner surface 42 which functions as the outer piston stop.
  • Stem 44 of manifold assembly 14 extends into the mouth of cylindrical body 34 and functions as the forward piston stop.
  • the stem 44 has a central bore 45 which acts as a guide for the starter rod 38.
  • Piston 36 is represented by a conductive sleeve element 48 mounted about the starter rod 38 at its rearward end and threadably fastened to an outer nonconductive member 50 such as Teflon. Member 50 is sufficiently biased against the inner surface of body 34 to function as a fluid seal. The engaging surfaces of piston 36 and stem 44 are tapered in order to controllably brake piston 36.
  • Housing 32 of starter assembly 30 includes a gas passage 52 for passing a gas into the chamber 35 through openings 54 located at the far end of the cylindrical body 34.
  • the injected gas is confined to the area behind the piston 36.
  • piston 36 When sufficient pressure is built up piston 36 will advance downstream toward chamber 18 causing the starter rod 38 to proceed through the bore 60 of electrode 20 then axially across the chamber 18 and into the bore 62 of electrode 22 until the piston 36 is stopped by stem 44.
  • the length of the starter rod 38 is determined by the distance to be traversed between the electrodes 20 and 22, respectively.
  • the tip 46 of starter rod 38 should preferably extend only a short distance within bore 62 of electrode 22.
  • a power supply (not shown) is connected to a pair of terminal posts 68 and 70, respectively; with the negative side of the supply connected so as to render electrode 20 the cathode. It is preferred in accordance with the present invention to have the starter rod 38 function as an extension of the cathode in establishing an are between the electrodes. With this arrangement, reliable starting has been demonstrated without emitting spatter from the starter rod 38.
  • the cathode electrode 20 may be composed substantially of tungsten or may comprise a conductive outer body such as copper with a tungsten or thoriated tungsten inner layer at the end adjacent the arc chamber 18.
  • the anode electrode 22 may be fonned from any conductive material such as copper.
  • the starter rod 38 should be composed of a relatively strong conductive material such as tungsten or 2 percent thoriated tungsten. For proper operation, the diameter of the starter rod 38 must be smaller than the bore size of each electrode 20 and 22, respectively. To avoid possible contamination of chamber 18 during the starting period and to provide optimum starting reliability, cordance with the sequence as reference to FIGS. 1-3 inclusive.
  • supply source 78 delivers gas under pressure to radiation torch 10 and the starter assembly 30.
  • Any inert gas such as for example, argon, krypton or xenon may be used.
  • the direction of gas flow is determined by means of a plurality of conventional, electrically actuated, control valves SVl, SV2, SV3, 8V4, 8V5, and SV6, respectively.
  • Control valve SVll is a conventional three-way valve having two separate flow paths one of which opens supply line 84 into line 86 while the other vents line 86 into exhaust line 87. Additional gas control is provided by restricted orifices 80 and 82, respectively.
  • the retum path for the gas is shown in FIG. 2 in dotted linw. Although a closed return path to the supply source is shown, it should be apparent that the exhaust gas may be directly vented into the atmosphere.
  • the starter rod 38 is at rm in its fully withdrawn position with the piston 36 up against the outer stop 42, the power across the electrodes off, and all of the control valves closed.
  • the piston and starter rod assembly is then primed by energizing three-way control valve SVH opening supply line 84 into line 86.
  • the exhaust to line 87 is closed.
  • control valve SV2 is opened bypassing orifice 80 and bringing on full flow and maximum supply pressure behind piston 36 to firmly hold it in place.
  • Control valve V3 is then opened permitting gas to flow from supply source 78 into radiation torch 10.
  • the gas enters arc chamber 18 of torch through openings positioned about the circumference of electrode 20.
  • the gas spirals inwardly from electrode in a fashion similar to that of a tornado.
  • the buildup of swirl flow is controlled by restricted orifice 82.
  • a slow buildup of swirl flow is considered desirable to prevent the starter rod from being damaged.
  • the gas exhausts through the central bore of each electrode 20 and 22, respectively, passing through a pair of conventional heat exchangers 90 and 92 and then into line 94. From line 94 the exhaust gas passes through a pressure relief valve 96 and returns to the supply source 78.
  • Relief valve 96 performs the important function of constricting the exhaust flow for creating sufficient back pressure across the starter assembly and hence starter piston 36 to enable the starter rod 38 to be swiftly withdrawn as will be discussed hereinafter.
  • control valves 8V4 and SV5 are opened.
  • Control valve 5V4 pennits full swirl flow to develop in the arc chamber 18.
  • Pressure relief valve 93 located in series with control valve SVS is used to regulate the delivery pressure at electrode 20 and hence in chamber 18 by bleeding off a controlled amount of gas from line 99. By maintaining a reduced chamber pressure, the starting voltage requirement is minimized. A voltage of the order of i000 volts has been found satisfactory to start an are 4 inches long for example.
  • Solenoid control valves SVl through SV6 may be actuated automatically in the above-described preferred sequence using any number of different conventional timing circuits.
  • a simplified timing circuit for energizing the control valves in consecutive order is shown in FIG. 3.
  • the circuit includes a number of conventional time delay relays each of which is mechanically preset to actuate its contacts, upon energization, after a predetermined time delay.
  • TD time delay relay n
  • the alternating current source 100 is concurrently impressed across a plurality of similar paired parallel branches; where one branch of each pair contains a time delay relay and a contact of the time delay relay of the preceding parallel branch in series therewith and where the other branch of the pair contains a solenoid control valve in series with a time delay relay contact of the time delay relay in that branch.
  • the second paired parallel branch symbolically represents a string of such paired branches; one leg of each branch having a time delay relay TD in series with a time delay relay contact TDC, and the other leg having a solenoid control valve SV in series with a time delay relay contact TDC where n represents consecutive numbers and A is a integral step later.
  • any solenoid such as SV can be cancelled at a later point in the sequence by action of a normally closed contact such as TDC Aof time delay relay TD
  • TDC Aof time delay relay TD The amount of time that should elapse between each event in the starting sequence is not critical. A time period between events, where a time elapse has been indicated, is generally in the range of 4-l5 seconds.
  • a method of starting an electric are between spaced first and second electrodes contained within a chamber, each electrode having a central bore in substantially coaxial relation with each other and with the longitudinal axis of the chamber comprising the steps of:
  • a method as defined in claim 2 wherein said rod is connected to a piston and wherein gas is introduced behind said piston for developing a gas pressure to drive said rod through the bores of said electrodes.
  • a method as defined in claim 4 further comprising the steps of releasing the gas pressure from behind the piston and developing a pressure differential across the rod sufficient to cause the rod to be automatically withdrawn from the chamber after an arc has been established.
  • a method of starting an electric are between spaced first and second electrodes contained within a transparent chamber, each electrode having a central bore in substantially coaxial relation with each other and with the longitudinal axis of the chamber comprising the steps of:
  • Apparatus for generating a high intensity source of light radiation which comprises:
  • an elongated tubular envelope providing an arc chamber having a light transmitting portion;
  • first and second electrodes each having a central bore axially disposed at opposite ends of the chamber;
  • a piston assembly mounted in a cylinder extending from the first electrode external of the arc chamber;
  • Apparatus as defined in claim 8 wherein the gas is supplied from a common inert gas supply source and returned to said supply source.
  • Apparatus as defined in claim 8 wherein the piston assembly comprises an insulating member mounted about the end of the rod and biased against the inner surface of said cylinder thereby acting as a fluid seal.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Plasma Technology (AREA)
  • Discharge Heating (AREA)
US34382A 1970-05-04 1970-05-04 Method and apparatus for starting a long arc between hollow electrodes Expired - Lifetime US3611014A (en)

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Application Number Priority Date Filing Date Title
US3438270A 1970-05-04 1970-05-04

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US (1) US3611014A (pt)
AT (1) AT307564B (pt)
BE (1) BE766649A (pt)
BR (1) BR7102643D0 (pt)
CA (1) CA928372A (pt)
CH (1) CH550526A (pt)
DE (1) DE2121757C3 (pt)
FR (1) FR2091131A5 (pt)
GB (1) GB1347091A (pt)
NL (1) NL7106022A (pt)
NO (1) NO130291B (pt)
SE (1) SE373455B (pt)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2574165A1 (fr) * 1984-11-30 1986-06-06 Plasma Energy Corp Appareil de chauffage a arc-plasma pour chauffer de grandes quantites d'air, notamment a des fins de sechage de materiaux bruts
CN105755421A (zh) * 2016-04-20 2016-07-13 北京科技大学 一种直流氩弧等离子粉喷枪及制备方法

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3128967C2 (de) * 1981-07-22 1984-05-30 Leybold-Heraeus GmbH, 5000 Köln UV-Strahlungsquelle
US4448799A (en) * 1983-04-21 1984-05-15 Multi-Arc Vacuum Systems Inc. Arc-initiating trigger apparatus and method for electric arc vapor deposition coating systems
RU2093326C1 (ru) * 1995-10-09 1997-10-20 Общество с ограниченной ответственностью "МОГАСС" Устройство для пайки и сварки световым лучом
RU2169653C1 (ru) * 1999-12-29 2001-06-27 Гусев Эдуард Борисович Устройство для сварки световым лучом

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3218514A (en) * 1961-07-11 1965-11-16 Max Planck Gesellschaft Spectroscopic light source
US3501665A (en) * 1967-01-20 1970-03-17 Leitz Ernst Gmbh Plasma torch

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3218514A (en) * 1961-07-11 1965-11-16 Max Planck Gesellschaft Spectroscopic light source
US3501665A (en) * 1967-01-20 1970-03-17 Leitz Ernst Gmbh Plasma torch

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2574165A1 (fr) * 1984-11-30 1986-06-06 Plasma Energy Corp Appareil de chauffage a arc-plasma pour chauffer de grandes quantites d'air, notamment a des fins de sechage de materiaux bruts
CN105755421A (zh) * 2016-04-20 2016-07-13 北京科技大学 一种直流氩弧等离子粉喷枪及制备方法

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Publication number Publication date
GB1347091A (en) 1974-02-13
AT307564B (de) 1973-05-25
FR2091131A5 (pt) 1972-01-14
NO130291B (pt) 1974-08-05
BE766649A (fr) 1971-11-03
DE2121757C3 (de) 1975-11-06
BR7102643D0 (pt) 1973-04-10
CA928372A (en) 1973-06-12
DE2121757A1 (de) 1971-11-25
CH550526A (fr) 1974-06-14
DE2121757B2 (de) 1975-03-20
NL7106022A (pt) 1971-11-08
SE373455B (pt) 1975-02-03

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Owner name: MORGAN GUARANTY TRUST COMPANY OF NEW YORK, AND MOR

Free format text: MORTGAGE;ASSIGNORS:UNION CARBIDE CORPORATION, A CORP.,;STP CORPORATION, A CORP. OF DE.,;UNION CARBIDE AGRICULTURAL PRODUCTS CO., INC., A CORP. OF PA.,;AND OTHERS;REEL/FRAME:004547/0001

Effective date: 19860106

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Owner name: UNION CARBIDE CORPORATION,

Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:MORGAN BANK (DELAWARE) AS COLLATERAL AGENT;REEL/FRAME:004665/0131

Effective date: 19860925