US3479550A - Device and method for reducing blackening in a lamp - Google Patents

Device and method for reducing blackening in a lamp Download PDF

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Publication number
US3479550A
US3479550A US558824A US3479550DA US3479550A US 3479550 A US3479550 A US 3479550A US 558824 A US558824 A US 558824A US 3479550D A US3479550D A US 3479550DA US 3479550 A US3479550 A US 3479550A
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United States
Prior art keywords
filament
grid
gas
vaporization
lamp
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Expired - Lifetime
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US558824A
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English (en)
Inventor
Klaus Frohner
Horst Horster
Hans Jurgen Lydtin
Otto Reifenschweiler
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US Philips Corp
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US Philips Corp
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Publication date
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01K—ELECTRIC INCANDESCENT LAMPS
    • H01K1/00—Details
    • H01K1/52—Means for obtaining or maintaining the desired pressure within the vessel
    • H01K1/54—Means for absorbing or absorbing gas, or for preventing or removing efflorescence, e.g. by gettering

Definitions

  • the invention relates to a gas-filled device such as an incandescent lamp, in which a member to prevent blackening surrounds a filament body and which consists at least partially of a grid.
  • the grid is at a higher temperature than the bulb wall.
  • a known arrangement has for its object to decrease the vaporization of filaments in gas-filled filament lamps and the associated blackening of the bulb by arranging in the proximity of the filaments, namely outside the filament construction or between the filaments, an electrode which consists, for example, of thin wires extending parallel to the filaments.
  • the object of the said electrode is to return the vaporized tungsten which is assumed to be charged electrically to the filament or to collect it on the electrode by suitably applied voltages.
  • the electrode In the case of negative polarity of the electrode with respect to the filament, the electrode must be heated at a high temperature to obtain emission of electrons to cause the charging of the vaporized tungsten.
  • none of these proposals has proved to be useful for practical purposes.
  • a hydrogen isotope replenisher for low pressure ranges can readily be obtained by evaporating a suitable metal in a rare gas atmosphere at a pressure of approximately 1 to 100 torr. A precipitation of metal soot is formed, which after pumping away the rare gas, is charged with deuterium/tritium mixtures at a pressure of approximately 40 torr. In this case so much gas is admitted that the atomic ratio between hydrogen isotope atoms and metal atoms is from 0.5 to 0. With such a ice replenisher the gas pressure in a vacuum system may be adjusted at a given value of for example 10- to 10 mm.
  • the soot deposits at undesired places, on the contrary it is the very invention that the soot is maintained in a small gas-permeable vessel, the member for preventing vaporization being required to prevent emergence of the soot during vaporization without forming a resistance to fiow for the mixture of hydrogen isotopes.
  • an absorption pump it may be required to deposit finely divided metal on a given surface and to keep the remainder of the surface of the pumping vessel free from deposits. If metal sheets are used as members for preventing the vaporization which sheets terminate in the proximity of the desired place of deposition, they may constitute a considerable resistance to flow for the gases to be absorbed and as a result prevent the gases from being absorbed rapidly by the absorption layer consisting of finely divided metal.
  • a member to prevent vaporization surrounds a filament and consists at least partially of a grid which is at a higher temperature than the wall of the device
  • the temperature of the grid is so high and consequently the temperature gradient between the filament and the grid is so low and the grid has such a mesh size with respect to its distance to the filament that at a short distance from the filament nuclei formed by supersaturation in the metal vapour formed by atomic vaporization and the conglomerates grown therefrom are hampered in their movement by radiometer force, the difference in voltage between the grid and the filament being either zero or so small that the electric field has no noticeable influence on the movements of the conglomerates.
  • the invention is based on the recognition-"of the fact that, the vaporization of the filament in a gas not attacking the filament body, for example, the vaporization of a filament in a gas-filled incandescent lamp taking place atomically on the surface of the filament, at a short distance thereof (less than 2 mm.) nuclei formation occurs on the bases of high super-saturations. These nuclei grow into metal drops having diameters of from 30 to 200 A. The presence of such metal drops could be proved with electron-optical records of metal deposited in lamps. By reducing the temperature gradient between the filament and the grid which is at a high temperature, the movement of the material particles and consequently also the mass transport are hampered.
  • the forces, which in a, gas act upon particles suspended in the gas under the influence of temperature differences are known as the radiometer effect.
  • the radiometer forces are proportional to the temperature gradient.
  • the temperature gradient is reduced and thus the material transport decreased by the conglomerates formed. Since it can be demonstrated that under the conditions occurring in incandescent lamps diffusion by concentration differences is negligible with respect to material transport by conglomerates under the influence of radiometer forces, the device according to the invention provides a considerable reduction of the material transport and con sequently of the blackening of the bulb.
  • the grid may be connected in parallel with the filament to raise its temperature.
  • a gas replenisher according to the invention comprises a metal vaporizer in a metal beaker, which comprises on its open side a metal net which can be heated.
  • FIG. 1 is a diagrammatic view of a projection lamp
  • FIG. 2 is a sectional view of an automobile headlight lamp
  • FIG. 3 is a sectional view of a gas replenisher, for a nuclear physical apparatus
  • FIG. 4 is a diagrammatic illustration of a vaporizing device for directed vaporization
  • FIG. 5 is a diagrammatical representation of a "Schlieren-photograph.
  • a glass bulb 30 mm. in cross-section 80 mm. in length is denoted by 1.
  • the tungsten filament 2 for 12 volt and 100 watt is surrounded at a distance of approximately 7 mm. by a tantalum wire 3, diameter 0.1 mm. and the turns spaced 2 mm. apart.
  • the tantalum wire 3 is connected parallel to the filament 2 and is heated at a temperature of approximately 1800 C.
  • the filament 2 has a temperature of 3000 C.
  • the total energy consumption of filament and grid is not larger than for a filament without grid. Whereas a very strong blackening of the bulb occurred within a period of hours when no grid was used, blackening was no longer observable when a grid was used.
  • reference numeral 4 denotes a headlight with a filament 5 of 6 volts and 150 watt.
  • the filament is surrounded by a helically wound tantalum wire 6 of A mm. thickness and the turn spaced 2.5 mms. apart.
  • the tantalum wire reaches a temperature of 1500 C.
  • the filament and the tantalum wire are supported by three supporting wires 7. No blackening was observed in the lamp after prolonged burning.
  • FIG. 3 shows a part of a bulb 8 of a physical apparatus which during operation is filled with a mixture of the hydrogen isotopes, deuterium and tritium under a pressure of 10" torr.
  • a nickel cylindrical receptacle 9 which comprises a vaporization spiral 10.
  • the vaporization spiral 10 consists of a tungsten wire, on which titanium wire is wound.
  • a gauze 11 is arranged manufactured from molybdenum wire, 25 microns thickness with apertures of 200 microns.
  • titanium soot is to be prepared by vaporization of the spiral 10, the bulb 8 being filled with argon gas at a pressure of 20 mm. mercury column.
  • the gauze 11 is heated at a temperature of approximately 1500 C. while the spiral has a temperature of approximately 2000 C. As a result of the heating of the gauze, no noticeable vaporization through the gauze takes place in contrast with the case in which the gauze is not heated.
  • FIG. 4 shows a vaporization device which may be used, for example, in absorption pumps.
  • a filament 13 coated with a layer of titanium is arranged in a conical grid 14. During the vaporization of the titanium from the spiral 13, said grid is heated to such a high temperature that the titanium deposits only on the surface 15 and i not scattered in other directions.
  • FIG. 5 is a Schlieren-photograph of a projection lamp with flat spiral 16, which in the photograph is substantially entirely hidden behind the supporting pole 17.
  • the fiat spiral 16 is surrounded by a wide spiral 18 consisting of thin wire and also heated only to a somewhat lower'temperature.
  • the principal Schlieren occurring in this lamp according to the invention is denoted by 19, the arrow 20 indicating the direction of the vertical.
  • a gas filled device including a sealed housing for use in conjunction with a source of electric current, comprising: (a) a filament disposed Within the sealed housing, (b) circuit means for conducting electric current from the source to the filament for heating the filament from which particulate matter is emittable as partial vaporization thereof, (c) a grid means disposed between at least a part of filament and the housing wall, and (d) circuit means for conducting electric current from the source to the grid for heating the grid to a temperature higher than that of the housing wall and lower than that of the filament with a smaller temperature gradient between the filament and grid, than between the grid and the wall, whereby radiometric forces from the heated grid inhibit the outward movement of said particulate matter emitted from the filament toward the grid.
  • a device as defined in claim 2 further comprising a plate disposed adjacent said aperture in the grid, whereby particulate matter flowing through the aperture becomes deposited on the plate.
  • a device as defined in claim 1 for use as a gas replenisher further comprising a metal receptable generally surrounding the filament and having one open side, the grid being disposed adjacent said open side, whereby said emitted particulate matter (inhibited from flowing out of the receptacle toward the grid) is permitted to flow toward and become deposited on the inner walls of the receptacle.
  • a device as defined in claim 1 further comprising means for maintaining the voltage differential between the filament and the grid sufficiently small that movement of said particles is substantially unaffected by the electric field.
  • a gas filled device including a sealed housing for use in conjunction with a source of electric current, comprising: (1) a filament disposed within the sealed housing, (2) circuit means for conducting electric current from the source to the filament for heating the filament from which particulate matter is emittable as partial vaporization thereof, (3) a grid disposed between the filament and the housing wall and substantially surrounding the filament on all sides, and (4) circuit means for conducting electric current from the source to the grid for heating the grid to a temperature higher than that of the housing wall and lower than that of the filament, whereby radiometric forces from the heated grid inhibit the outward movement of said particulate matter emitted from the filament, and reduces blackening of the bulb walls by said matter.
  • a device as defined in claim 8 used as a lamp wherein the grid comprises wires and the distances between the grid wires are at least as small as the distance between the grid and the filament, and the loss of light in the direction of use is smaller than 10% 10.
  • a method as defined in claim 10 comprising the further step of maintaining a voltage difference between the grid and the filament sufiiciently small such that the electric field has no noticeable influence on the movement of the conglomerates.
  • a method for reducing the deposition onto the interior walls of a sealed, gas-filled device of metal particulate vaporized from the filament therein comprising the steps:

Landscapes

  • Resistance Heating (AREA)
  • Physical Vapour Deposition (AREA)
  • Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
US558824A 1965-06-29 1966-06-20 Device and method for reducing blackening in a lamp Expired - Lifetime US3479550A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEN0026964 1965-06-29

Publications (1)

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US3479550A true US3479550A (en) 1969-11-18

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US558824A Expired - Lifetime US3479550A (en) 1965-06-29 1966-06-20 Device and method for reducing blackening in a lamp

Country Status (9)

Country Link
US (1) US3479550A (enrdf_load_stackoverflow)
BE (1) BE683228A (enrdf_load_stackoverflow)
CH (1) CH461635A (enrdf_load_stackoverflow)
DE (1) DE1489438A1 (enrdf_load_stackoverflow)
ES (1) ES328415A1 (enrdf_load_stackoverflow)
GB (1) GB1137434A (enrdf_load_stackoverflow)
NL (1) NL6608780A (enrdf_load_stackoverflow)
NO (1) NO120326B (enrdf_load_stackoverflow)
SE (1) SE309810B (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3683226A (en) * 1970-09-30 1972-08-08 Gen Electric Electric lamp apparatus having diffusion barrier
US5646483A (en) * 1995-05-30 1997-07-08 Matsushita Electronics Corporation Discharge lamp having cesium compound
US20040261265A1 (en) * 2003-06-25 2004-12-30 General Electric Company Method for improving the wear resistance of a support region between a turbine outer case and a supported turbine vane
RU2761175C1 (ru) * 2020-07-09 2021-12-06 Юрий Михайлович Ермаков Электрическая лампа

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2232817A (en) * 1938-10-20 1941-02-25 Sherwin Williams Co Preparation of pure titanium oxide
US2605440A (en) * 1951-06-04 1952-07-29 Westinghouse Electric Corp Incandescent electric lamp
US2692350A (en) * 1948-01-15 1954-10-19 Westinghouse Electric Corp Discharge lamp and electrode
US2725497A (en) * 1951-04-25 1955-11-29 Westinghouse Electric Corp Floating grids for fluorescent lamps
US2763814A (en) * 1952-04-22 1956-09-18 Sebel S A Electronic fluorescent illuminating lamp
US2812465A (en) * 1954-05-10 1957-11-05 Kenneth J Germeshausen Gaseous-discharge device
US2917650A (en) * 1955-06-29 1959-12-15 Hyperion Sa Electrode for discharge tubes
US2933632A (en) * 1957-10-28 1960-04-19 Gen Electric Incandescent lamp with blackening collector screen

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2232817A (en) * 1938-10-20 1941-02-25 Sherwin Williams Co Preparation of pure titanium oxide
US2692350A (en) * 1948-01-15 1954-10-19 Westinghouse Electric Corp Discharge lamp and electrode
US2725497A (en) * 1951-04-25 1955-11-29 Westinghouse Electric Corp Floating grids for fluorescent lamps
US2605440A (en) * 1951-06-04 1952-07-29 Westinghouse Electric Corp Incandescent electric lamp
US2763814A (en) * 1952-04-22 1956-09-18 Sebel S A Electronic fluorescent illuminating lamp
US2812465A (en) * 1954-05-10 1957-11-05 Kenneth J Germeshausen Gaseous-discharge device
US2917650A (en) * 1955-06-29 1959-12-15 Hyperion Sa Electrode for discharge tubes
US2933632A (en) * 1957-10-28 1960-04-19 Gen Electric Incandescent lamp with blackening collector screen

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3683226A (en) * 1970-09-30 1972-08-08 Gen Electric Electric lamp apparatus having diffusion barrier
US5646483A (en) * 1995-05-30 1997-07-08 Matsushita Electronics Corporation Discharge lamp having cesium compound
US20040261265A1 (en) * 2003-06-25 2004-12-30 General Electric Company Method for improving the wear resistance of a support region between a turbine outer case and a supported turbine vane
RU2761175C1 (ru) * 2020-07-09 2021-12-06 Юрий Михайлович Ермаков Электрическая лампа

Also Published As

Publication number Publication date
CH461635A (de) 1968-08-31
BE683228A (enrdf_load_stackoverflow) 1966-12-27
NL6608780A (enrdf_load_stackoverflow) 1966-12-30
ES328415A1 (es) 1967-04-01
NO120326B (enrdf_load_stackoverflow) 1970-10-05
SE309810B (enrdf_load_stackoverflow) 1969-04-08
GB1137434A (en) 1968-12-18
DE1489438A1 (de) 1969-04-24

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