US3401296A - Mercury vapor generating means for discharge tubes - Google Patents

Mercury vapor generating means for discharge tubes Download PDF

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Publication number
US3401296A
US3401296A US449004A US44900465A US3401296A US 3401296 A US3401296 A US 3401296A US 449004 A US449004 A US 449004A US 44900465 A US44900465 A US 44900465A US 3401296 A US3401296 A US 3401296A
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US
United States
Prior art keywords
mercury
mercury vapor
tube
pyrophosphate
vapor
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
US449004A
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English (en)
Inventor
Rigot Roger
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.)
Thales SA
Original Assignee
CSF Compagnie Generale de Telegraphie sans Fil SA
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 CSF Compagnie Generale de Telegraphie sans Fil SA filed Critical CSF Compagnie Generale de Telegraphie sans Fil SA
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Publication of US3401296A publication Critical patent/US3401296A/en
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Expired - Lifetime legal-status Critical Current

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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
    • H01J17/22—Means for obtaining or maintaining the desired pressure within the tube
    • H01J17/26—Means for producing, introducing, or replenishing gas or vapour during operation of the tube
    • 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
    • H01J9/38—Exhausting, degassing, filling, or cleaning vessels
    • H01J9/395—Filling vessels

Definitions

  • the present invention relates to discharge tubes having an enclosure containing mercury vapor either in relatively large quantity for operational purposes, or in the state of traces for stimulating some predetermined properties. It is known in the prior art to introduce mercury vapor into these tubes by providing within the evacuated enclosure an auxiliary vessel containing some amount of mercury from which vapor is released under the action of heat, thereby generating the mercury vapor medium which is required for normal operation of the tube.
  • the metallic mercury used in the prior art release its vapor also during the manufacturing step of removal of gas from the tube, i.e., during the period when the tube exposed to heat still remains connected to the pumping means. Some quantity of mercury vapor is then evacuated by the pumping means, causing a substantial loss of mercury vapor before the tube is delivered for normal operation. Therefore, at the beginning of normal service of the tube, the mercury vapor atmosphere within the closed or sealed enclosure becomes poor, so that the lifetime of the tube is reduced.
  • Another object of the invention is to provide a mercury vapor tube having a relatively long lifetime.
  • a further object of the invention is the provision of a mercury vapor tube wherein the mercury vapor medium is generated only after the termination of the manufacturing step of removing the gas, when the evacuated enclosure is already disconnected from the pumping means and is closed.
  • a still further object of the invention is the provision of a mercury vapor tube in which gases are removed by applying temperatures up to about 600 C., substantially without any mercury vapor generation during this treat ment.
  • FIGURE 1 shows a characteristic of loss of Weight in dependence of temperature for the substance used for generating mercury vapor according to the present invention
  • FIGURE 2 shows diagrammatically a mercury vapor tube using the improvement according to the present invention.
  • the present invention essentially consists in the use, for generating or producing mercury vapor within closed or sealed enclosures of tubes requiring such an environment, of a substance containing at least in part a chemical product known as mercury pyrophosphate and having the chemical formula Hg P O
  • a curve is plotted showing along ordinates the loss of weight G (in percent) of mercury pyrophosphate in vacuum in dependence on temperature T (in C.) along abscissae, then a curve shown in FIGURE 1 is obtained.
  • mercury pyrophosphate has the feature of substantially not releasing mercury vapor below about 600 C., further of beginning to release more and more mercury vapor between about 600 and 800 C., and finally of becoming exhausted near 800 C., and the loss of weight at this temperature attaining 70%, a proportion corresponding to theoretical content of Hg in Hgzpgoq.
  • mercury pyrophosphate can be successfully applied to the tubes in which the step of gas removal is effected at temperatures lower than about 600 C.
  • FIGURE 2 shows as an example only a diagrammatic view of a tube including within an evacuated enclosure 1 a system of electrodes 2 supported by the rods 3.
  • auxiliary vessel 4 composed of two shells connected together by a plurality of welding points and containing several milligrams of a substance composed at least in part of mercury pyrophosphate.
  • the tube Prior to closing or sealing of the enclosure 1, the tube was connected to pumping means (not shown) and subjected to action of heat at a temperature lower than about 600 C. During this period, there was substantially no release of mercury vapor from the pyrophosphate.
  • the vessel 4 is exposed to a heating action at a temperature between about 600 and 800 C., by means of any known method, such as for instance, high frequency.
  • the mercury vapor is then released from the pyrophosphate and passes through the nontight junction between the edges of two shells composing the vessel 4, to fill the enclosure 1, so that the tube is ready for normal operation.
  • the release of vapor should also be controlled by acting on the source of heat.
  • the mercury pyrophosphate for this use should be preferably very pure, with a proportion of impurities not in excess of several parts per million, and rigorously dry at the instant of its introduction into the vessel4.
  • the mercury pyrophosphate can be used without mixture with any other substance. If, however, such a limit is exceeded during the operation or during a manufacturing treatment, or if the tube is subjected to the danger of such excess temperatures during its treatment, even if only for a short duration, then there is a risk that not only mercury but also oxygen is released from the pyrophosphate, this being harmful for certain electrodes of the tube.
  • the mercury pyrophosphate will be used in such a case in mixture with an oxygen reducing substance, for instance, a powder of metal such as aluminum, aluminum-j-magnesium, titanium, zirconium, columbium and the like, the proportion being thereof chosen for instance between 25% and by weight of the total mass of the mixture.
  • an oxygen reducing substance for instance, a powder of metal such as aluminum, aluminum-j-magnesium, titanium, zirconium, columbium and the like, the proportion being thereof chosen for instance between 25% and by weight of the total mass of the mixture.
  • This composition enables mercury pyrophosphate to be dissociated at temperatures above 750 C., without any trace of oxygen accompanying the release of mercury.
  • a method for producing a mercury vapor environment within an evacuated closed enclosure, particularly discharge devices comprising the steps of locating within said enclosure a substance consisting at least in part of mercury pyrophosphate, applying heat at a first temperature to said substance, and subsequently applying heat to said substance at a second temperature higher than said first temperature.
  • means for producing a mercury vapor environment comprising within an evacuated enclosure of the discharge tube a substance consisting at least in part of mercury pyrophosphate.
  • means-for producing a mercury vapor environment comprising within an evacuated enclosure of the discharge tube an auxiliary vessel intercommunicating with the interior of said enclosure, and a substance consisting at least in part of mercury pyrophosphate, located within said vessel.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
US449004A 1964-04-29 1965-04-19 Mercury vapor generating means for discharge tubes Expired - Lifetime US3401296A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR972773A FR1402090A (fr) 1964-04-29 1964-04-29 Perfectionnements aux tubes à vapeur de mercure

Publications (1)

Publication Number Publication Date
US3401296A true US3401296A (en) 1968-09-10

Family

ID=8828956

Family Applications (1)

Application Number Title Priority Date Filing Date
US449004A Expired - Lifetime US3401296A (en) 1964-04-29 1965-04-19 Mercury vapor generating means for discharge tubes

Country Status (6)

Country Link
US (1) US3401296A (de)
CH (1) CH420393A (de)
DE (1) DE1258984B (de)
FR (1) FR1402090A (de)
GB (1) GB1034024A (de)
NL (1) NL6505544A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3605036A (en) * 1967-10-17 1971-09-14 Laser Sciences Inc Method and apparatus for thermochemically controlling the gas atmosphere of a gas coherent radiation generator
US3722976A (en) * 1970-10-07 1973-03-27 Getters Spa Mercury generation
US4553067A (en) * 1982-02-10 1985-11-12 Gte Products Corporation Method of dispensing mercury into a fluorescent lamp and lamp to operate with method
US5026311A (en) * 1983-03-10 1991-06-25 Gte Products Corporation Arc tube fabrication process

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5500567A (en) * 1994-02-10 1996-03-19 General Electric Company Apparatus for securing an amalgam at the apex of an electrodeless fluorescent lamp

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2930921A (en) * 1954-05-28 1960-03-29 Patelhold Patentverwertung Process of filling a discharge chamber with mercury and product
US3230027A (en) * 1962-03-28 1966-01-18 Hivac Ltd Method of constructing cold cathode gas discharge tubes

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE916552C (de) * 1943-12-09 1954-08-12 Patra Patent Treuhand Verfahren zum Einbringen von Quecksilber in elektrische Entladungsgefaesse
FR1351908A (fr) * 1962-03-28 1964-02-07 Hivac Ltd Perfectionnement aux tubes à décharge à cathode froide

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2930921A (en) * 1954-05-28 1960-03-29 Patelhold Patentverwertung Process of filling a discharge chamber with mercury and product
US3230027A (en) * 1962-03-28 1966-01-18 Hivac Ltd Method of constructing cold cathode gas discharge tubes

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3605036A (en) * 1967-10-17 1971-09-14 Laser Sciences Inc Method and apparatus for thermochemically controlling the gas atmosphere of a gas coherent radiation generator
US3722976A (en) * 1970-10-07 1973-03-27 Getters Spa Mercury generation
US4553067A (en) * 1982-02-10 1985-11-12 Gte Products Corporation Method of dispensing mercury into a fluorescent lamp and lamp to operate with method
US5026311A (en) * 1983-03-10 1991-06-25 Gte Products Corporation Arc tube fabrication process

Also Published As

Publication number Publication date
GB1034024A (en) 1966-06-29
CH420393A (fr) 1966-09-15
DE1258984B (de) 1968-01-18
NL6505544A (de) 1965-11-01
FR1402090A (fr) 1965-06-11

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