US3609064A - Getter pump with direct resistance heating of getter strip - Google Patents

Getter pump with direct resistance heating of getter strip Download PDF

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Publication number
US3609064A
US3609064A US87812*[A US3609064DA US3609064A US 3609064 A US3609064 A US 3609064A US 3609064D A US3609064D A US 3609064DA US 3609064 A US3609064 A US 3609064A
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United States
Prior art keywords
substrate
getter material
pump
particulate
getter
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Expired - Lifetime
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US87812*[A
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English (en)
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Tiziano A Giorgi
Bruno Ferrario
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SAES Getters SpA
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SAES Getters SpA
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J7/00—Details not provided for in the preceding groups and common to two or more basic types of discharge tubes or lamps
    • H01J7/14—Means for obtaining or maintaining the desired pressure within the vessel
    • H01J7/18—Means for absorbing or adsorbing gas, e.g. by gettering
    • H01J7/186—Getter supports
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J7/00—Details not provided for in the preceding groups and common to two or more basic types of discharge tubes or lamps
    • H01J7/14—Means for obtaining or maintaining the desired pressure within the vessel
    • H01J7/18—Means for absorbing or adsorbing gas, e.g. by gettering

Definitions

  • Getter pumps employing nonevaporable getter materials embedded in a substrate are known and have found wide acceptance for producing and maintaining a vacuum is closed vessels and especially in electronic tubes such as klystron tubes, image intensifier tubes and cathode-ray tubes. Such pumps employing getter materials are especially suited for the pumping of active gases.
  • the substrate coated with the getter material is generally pleated and coaxially disposed around a separate central resistance heater. In operation heat is radiated from the resistance heater to the getter material on the substrate.
  • the sorptive rate of gases increases with temperature as is well known in the art. If the surface of the getter material is partially or fully saturated with sorbed gases, the heat drives the gas-reaction products, through diffusion, into the center of the particles of the getter material and exposes a fresh surface.
  • Unfortunately such devices suffer from a number of disadvantages.
  • the presence of the necessary separate resistance heater increases production costs. Uniform heating of the getter material is difi'rcult or impossible to obtain for example, because varying portions of the coated substrate are at varying distances from the heater. While it is desirable to coat both sides of the substrate with the getter material only the side next to the heater is heated by radiation whereas the side away from the heater must be heated by conduction through the substrate. Because of the above, relatively long heating periods are required in order to activate the getter material.
  • Another object is to provide getter pumps which require no separate heater.
  • a further object is to provide getter pumps wherein the getter material can be easily and uniformly heated.
  • a still further object is to provide getter pumps employing a substrate having a getter material on both sides which is heated uniformly and simultaneously.
  • Still another object is to provide a getter pump which requires only a short period of time to activate the getter material.
  • Still another object is to provide a novel process for activating a nonevaporable getter material which is embedded in a substrate.
  • FIG. I is a sectional view of a getter pump of the present invention taken along line l-l of FIG. 2;
  • FIG. 2 is a sectional view of a getter pump of the present invention taken along line 2-2 of FIG. 1.
  • a getter pump having a nonevaporable getter material embedded in a substrate of high ohmic resistance and means for causing an electrical current to flow through the substrate to heat the getter material.
  • FIG. 1 there is shown a nonlimiting preferred embodiment of the present invention in the form of a getter pump I0 comprising a glass, gastight envelope 11 having a rim 12 which defines an opening 13.
  • the getter pump is rendered attachable to any vessel in which it is desired to maintain a vacuum.
  • Fixedly attached to and extending through the envelope 10 are three support members 14, I5 and 16(See FIG. 2).
  • the support member 14 has near the end nearest to the envelope 11 a first flanged washer I7 electrically spot welded to the support member 14 and acting as a stop.
  • a second flanged washer 18 Near the end of the support member 14 which is furthest from the point of attachment of the support member 14 and the envelope 11 is a second flanged washer 18.
  • a cylindrical sleeve 19 of heat and electrical insulative material surrounds the portion of the support I4 between the first flanged washer l7 and the second flanged washer 18.
  • the support members 15 and 16 have similar flanged washers and sleeves.
  • a first retainer 20 having a hole through which the support member 14 passes, the diameter of the hold being less than the diameter of the sleeve 19 such that the retainer 20 is fixedly clamped on the support 14 between the first flanged washer 17 and the sleeve 19.
  • the retainer 20 has a flat portion 21 attached to an outer rim 22 and an inner rim 23. The flat portion 21 in the inner and outer rims 22 and 23 together form an annular groove.
  • a second retainer 24 identical to the first retainer 20 but with its annular groove facing the annular groove of the retainer 20.
  • the second retainer 24 is fixedly held on the support member 14 by the second flanged washer l8 and the sleeve 19.
  • Slidably mounted on the sleeve 19 is an intermediate retainer 25 having annular grooves on opposite faces.
  • a pleated strip 26 comprising a substrate 27 having thereon a particulate nonevaporable getter material 28.
  • a similar pleated strip 29 is between the second retainer 24 and the intermediate retainer
  • a first electrode 30 extends through the envelope 11 and is electrically spot welded to the pleated strip 26 forming an electrical contact therewith.
  • a second electrode 31 which is likewise spot welded to the pleated strip 29.
  • conductor 33 connects the end of the pleated strip 26 with the beginning of the pleated strip 29.
  • the pleated strips 26 and 29 comprise two electrical resistances connected in series with electrodes 30 and 31.
  • the strips 26 and 29 can be connected in parallel but series is the preferred arrangement because of the lower current required for equivalent heating.
  • the retainers 20, 24 and 25; and the sleeves l9 and 32 can be of any heat resistant dielectric material but are preferably ceramic.
  • the substrate 27 can be any material of high ohmic resistance such that passage of current therethrough heats the getter material 28 to within the desired temperature range.
  • the substrate 27 is generally formed of a material having a resistivity of l to 200 and preferably 10 to I50 microhm-centimeters when measured at 20 C. Within these limits of resistivity practical current values can be employed.
  • suitable substrate materials include among others stainless steel containing 18 degrees chromium and 8 degrees nickel, balance consisting essentially of iron; as well as the widely used high resistance material available under the trade name Nichrome.” Other suitable materials will immediately be apparent to those skilled in the art.
  • any nonevaporable getter material can be employed such as titanium, zirconium, tantalum or niobium as well as alloys and/or mixtures of two or more of the above.
  • the preferred nonevaporable getter material is an alloy of 5 to 30 weight percent aluminum, balance zirconium, and especially that alloy of 16 weight percent aluminum, balance zirconium, available as St lOl from S.A.E.S. Getters S.p.A., Milan, Italy.
  • the getter material 28 is applied to the substrate 27 in the form of a powder in order to have a high surface area to mass ratio facilitating gas sorption.
  • the powder is preferably one which passes through a U.S. Standard screen of I40 mesh/inch.
  • the powder is attached to the strips 26 and 29 by any suitable means such as rolling or pressing which does not materially reduce the total surface area of the powder.
  • the getter pump 10 is attached to a vessel to be evacuated by sealing the rim 12 to the vessel.
  • the vessel is then evacuated by any convenient means such as a mechanical pump or a zeolite pump.
  • the electrodes 30 and 31 are connected to a source of alternating or direct current whereby current flows through the pleated strip 26 and the pleated strip 29 activating the getter material, ohmically generating heat in the substrate 27, conducting the heat to the particulate nonevaporable getter material 28 and driving the sorbed gases into the interior of each particle of getter material.
  • Current is passed through the strips 26 and 29 such that the temperature of the getter material 28 is held at 600 to 900 and preferably 700 to 800 C.
  • the getter material 28 is gas sorptive at room temperature but the rate of gas sorption can be increased by heating the getter material 28 as described above or more preferably at temperatures of 250 to 400 C. in order to avoid the evolution of hydrogen. which can be present in the getter material 28 as a solid solution due to previous hydrogen sorption.
  • the getter material 28 remains gas sorptive after heating is terminated and continues to sorb active gases evolved during the life of the vessel. Should an undesirable increase in gas pressure in the vessel occur, it is only necessary to connect the electrodes 30 and 31 to a source of power in order to reactivate the getter material 28. In this manner, a very high vacuum can be maintained in a vessel throughout its life and until the getter material 28 becomes saturated with gases.
  • the getter pumps of the present invention find utility as supplements to sputter ion pumps and diffusion pumps and can be used to create and maintain vacuum in continuously pumped vacuum systems and in sealed off vacuum systems. These pumps can be permanently installed for example in klystron tubes and image intensifier tubes as so called appendage pumps.
  • Example i This example illustrates the construction of a substrate having embedded therein a nonevaporable getter material which substrate is useful in the present invention.
  • Finely ground Stll nonevaporable getter material is passed through as screen having 140 mesh/inch and is retained on a screen having 600 mesh/inch. This material is then placed on the center of a strip of 18-8 stainless steel 8 mm. wide and 0.2 mm. thick leaving a getter material free margin near the edges of the strip.
  • On top of the powder is placed a strip of common soft iron of the same dimensions.
  • the two strips with the StlOl alloy between them are then pressed together by a roller whereupon the strip of soft iron is removed leaving the StlOl alloy adhering to the strip of stainless steel.
  • a plurality of slits are then made at intervals of 6 mm. across the strip and extending into the margin which is free of StlOl alloy.
  • the strip is then folded adjacent to the slits to form a pleated strip which is then circularly curved to be employed in the getter pump of the present invention.
  • EXAMPLE Il A substrate having a getter material embedded thereon is produced as described in US. application Ser. No. 527,906, filed Feb. 16, 1966. The substrate is then pleated as in example 1.
  • EXAMPLE Iii A substrate coated on both sides with Stl0l alloy is purchased from S.A.E.S. Getters S.p.A. of Milan, Italy, under stock number Stl0l1Ct/86/D6O and pleated as described in example l.
  • EXAMPLE IV A substrate coated on both sides with Stl0l alloy is purchased from S.A.E.S. Getters S.p.A. of Milan, Italy under stock number StlOl/Ct/l 5X6/Dl 50.
  • EXAMPLE V The pleated strip of example III is circularly formed as shown in FIGS. 1 and 2, attached to electrodes 30 and 31 and placed in a getter pump 10 as shown in FIGS. 1 and 2.
  • the getter pump 10 is then attached to a glass vessel of about i liter in volume whose pressure is reduced to l0 torr using zeolites whereupon a current of 7 amps is passed through the electrodes 30 and 31 for a period of 10 minutes activating the getter material and reducing the pressure of active gases in the vessel to 10 torr in an overall time of 20 minutes. Similar results are obtained with the pleated strips of examples 1, ll and IV.
  • a getter pump comprising a substrate of high ohmic resistance; a particulate nonevaporable getter material embedded in the substrate; and means for causing an electrical current to flow through the substrate wherein the substrate is of a material having a resistivity of l to 200 microhm-centimeters when measured at 20 C.
  • the pump of claim 1 wherein the nonevaporable getter material is an alloy of 5 to 30 weigh percent aluminum, balance zirconium.
  • the pump of claim 2 wherein the nonevaporable getter material is an alloy of 16 weight percent aluminum, balance zirconium.
  • a getter pump ofclaim 1 comprising:
  • second retainer having an annular groove facing the annular groove of the first retainer
  • E. means for causing an electrical current to flow through the substrate, whereby imposing a potential across the electrodes causes current to flow through the pleated strip heating and activating the embedded getter material thereby increasing the rate of sorption of gas within the vessel.
  • a getter pump comprising a substrate of high ohmic resistance; a particulate nonevaporable getter material embedded in the substrate; and means for causing an electrical current to flow through the substrate wherein the substrate is of a material having a resistivity of l0 to microhm-centimeters when measured at 20 C.
  • a process for increasing the sorptive rate of particulate nonevaporable getter material embedded in a substrate comprising the step of passing an electrical current through the substrate thereby ohmically generating heat in the substrate and conducting the heat to the pafiiculate nonevaporable getter material wherein the electrical current is passed at a sorb active gases at a maximum rate while avoiding evolution of hydrogen.
  • a getter pump comprising a substrate of high ohmic resistance; a particulate nonevaporable getter metal embedded in the substrate and means for imposing a potential across the substrate in order to cause an electrical current to flow through the substrate heating it and conducting the heat to the particulate nonevaporable getter metal embedded therein.
  • Line 46 delete "degrees” and insert -percent- (both occurrences) 3, Example III, Line 74, delete "Stl0llCt/86/D60” and insert --St l0l/Ct/8 x 6/D60.

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  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
US87812*[A 1968-11-20 1969-11-21 Getter pump with direct resistance heating of getter strip Expired - Lifetime US3609064A (en)

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Application Number Priority Date Filing Date Title
IT2409068 1968-11-20

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US (1) US3609064A (enExample)
FR (1) FR2023966A1 (enExample)
GB (1) GB1274909A (enExample)

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3961897A (en) * 1973-10-01 1976-06-08 S.A.E.S. Getters S.P.A. Getter pump
US4050914A (en) * 1976-07-26 1977-09-27 S.A.E.S. Getters S.P.A. Accelerator for charged particles
DE2747186A1 (de) * 1976-11-03 1978-05-18 Getters Spa Modulare getter-pumpe
US4306887A (en) * 1979-04-06 1981-12-22 S.A.E.S. Getters S.P.A. Getter device and process for using such
US4789309A (en) * 1987-12-07 1988-12-06 Saes Getters Spa Reinforced insulated heater getter device
US5154582A (en) * 1991-08-20 1992-10-13 Danielson Associates, Inc. Rough vacuum pump using bulk getter material
US5161955A (en) * 1991-08-20 1992-11-10 Danielson Associates, Inc. High vacuum pump using bulk getter material
US5320496A (en) * 1992-07-17 1994-06-14 Saes Getters Spa High-capacity getter pump
US5628819A (en) * 1995-09-28 1997-05-13 Calgon Carbon Corporation Method and apparatus for continuous adsorption of adsorbable contaminates and adsorber regeneration
RU2202707C1 (ru) * 2001-08-28 2003-04-20 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева" Адсорбционный насос
RU2203436C1 (ru) * 2001-08-28 2003-04-27 Открытое акционерное общество Ракетно-космическая корпорация "Энергия" им. С.П.Королева Адсорбционный насос
RU2203437C1 (ru) * 2001-08-28 2003-04-27 Открытое акционерное общество Ракетно-космическая корпорация "Энергия" им. С.П.Королева Адсорбционный насос
RU2203438C1 (ru) * 2001-08-28 2003-04-27 Открытое акционерное общество Ракетно-космическая корпорация "Энергия" им. С.П.Королева Адсорбционный насос
RU2203439C1 (ru) * 2001-08-28 2003-04-27 Открытое акционерное общество Ракетно-космическая корпорация "Энергия" им. С.П.Королева Адсорбционный насос
RU2206790C1 (ru) * 2001-12-06 2003-06-20 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева Адсорбционный насос
RU2206789C1 (ru) * 2001-10-12 2003-06-20 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева Адсорбционный насос
RU2208182C1 (ru) * 2001-12-05 2003-07-10 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева" Адсорбционный насос
RU2208181C1 (ru) * 2001-10-29 2003-07-10 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева" Адсорбционный насос
RU2215901C2 (ru) * 2002-01-21 2003-11-10 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева" Адсорбционный насос
RU2215900C2 (ru) * 2002-01-21 2003-11-10 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева" Адсорбционный насос
US20040051507A1 (en) * 2000-08-10 2004-03-18 Gabrys Christopher W. Long-life vacuum system for energy storage flywheels
US20160069338A1 (en) * 2014-08-08 2016-03-10 Vaclab Inc. Non-evaporable getter and non-evaporable getter pump
CN106224202A (zh) * 2016-08-31 2016-12-14 兰州空间技术物理研究所 一种利用电加热激活的非蒸散型吸附泵

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2965218A (en) * 1956-08-16 1960-12-20 Rand Dev Corp Getter
US3469375A (en) * 1967-10-16 1969-09-30 Nasa Sorption vacuum trap

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2965218A (en) * 1956-08-16 1960-12-20 Rand Dev Corp Getter
US3469375A (en) * 1967-10-16 1969-09-30 Nasa Sorption vacuum trap

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3961897A (en) * 1973-10-01 1976-06-08 S.A.E.S. Getters S.P.A. Getter pump
US4050914A (en) * 1976-07-26 1977-09-27 S.A.E.S. Getters S.P.A. Accelerator for charged particles
DE2747186A1 (de) * 1976-11-03 1978-05-18 Getters Spa Modulare getter-pumpe
FR2370357A1 (fr) * 1976-11-03 1978-06-02 Getters Spa Dispositif d'absorption modulaire a getter ou a substance d'absorption de gaz residuels
US4137012A (en) * 1976-11-03 1979-01-30 S.A.E.S. Getters S.P.A. Modular getter pumps
US4306887A (en) * 1979-04-06 1981-12-22 S.A.E.S. Getters S.P.A. Getter device and process for using such
US4789309A (en) * 1987-12-07 1988-12-06 Saes Getters Spa Reinforced insulated heater getter device
US5154582A (en) * 1991-08-20 1992-10-13 Danielson Associates, Inc. Rough vacuum pump using bulk getter material
US5161955A (en) * 1991-08-20 1992-11-10 Danielson Associates, Inc. High vacuum pump using bulk getter material
US5320496A (en) * 1992-07-17 1994-06-14 Saes Getters Spa High-capacity getter pump
US5324172A (en) * 1992-07-17 1994-06-28 Saes Getters S.P.A. High-capacity getter pump
US5628819A (en) * 1995-09-28 1997-05-13 Calgon Carbon Corporation Method and apparatus for continuous adsorption of adsorbable contaminates and adsorber regeneration
US7053589B2 (en) * 2000-08-10 2006-05-30 Gabrys Christopher W Long-life vacuum system for energy storage flywheels
US20040051507A1 (en) * 2000-08-10 2004-03-18 Gabrys Christopher W. Long-life vacuum system for energy storage flywheels
RU2203437C1 (ru) * 2001-08-28 2003-04-27 Открытое акционерное общество Ракетно-космическая корпорация "Энергия" им. С.П.Королева Адсорбционный насос
RU2203436C1 (ru) * 2001-08-28 2003-04-27 Открытое акционерное общество Ракетно-космическая корпорация "Энергия" им. С.П.Королева Адсорбционный насос
RU2203439C1 (ru) * 2001-08-28 2003-04-27 Открытое акционерное общество Ракетно-космическая корпорация "Энергия" им. С.П.Королева Адсорбционный насос
RU2202707C1 (ru) * 2001-08-28 2003-04-20 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева" Адсорбционный насос
RU2203438C1 (ru) * 2001-08-28 2003-04-27 Открытое акционерное общество Ракетно-космическая корпорация "Энергия" им. С.П.Королева Адсорбционный насос
RU2206789C1 (ru) * 2001-10-12 2003-06-20 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева Адсорбционный насос
RU2208181C1 (ru) * 2001-10-29 2003-07-10 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева" Адсорбционный насос
RU2208182C1 (ru) * 2001-12-05 2003-07-10 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева" Адсорбционный насос
RU2206790C1 (ru) * 2001-12-06 2003-06-20 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева Адсорбционный насос
RU2215901C2 (ru) * 2002-01-21 2003-11-10 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева" Адсорбционный насос
RU2215900C2 (ru) * 2002-01-21 2003-11-10 Открытое акционерное общество "Ракетно-космическая корпорация "Энергия" им. С.П.Королева" Адсорбционный насос
US20160069338A1 (en) * 2014-08-08 2016-03-10 Vaclab Inc. Non-evaporable getter and non-evaporable getter pump
US9945368B2 (en) * 2014-08-08 2018-04-17 Vaclab Inc. Non-evaporable getter and non-evaporable getter pump
CN106224202A (zh) * 2016-08-31 2016-12-14 兰州空间技术物理研究所 一种利用电加热激活的非蒸散型吸附泵
CN106224202B (zh) * 2016-08-31 2018-06-22 兰州空间技术物理研究所 一种利用电加热激活的非蒸散型吸附泵

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FR2023966A1 (enExample) 1970-08-21
GB1274909A (en) 1972-05-17

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