EP0742370B1 - Heating assembly for getter pumps and gas purifiers - Google Patents

Heating assembly for getter pumps and gas purifiers Download PDF

Info

Publication number
EP0742370B1
EP0742370B1 EP96830262A EP96830262A EP0742370B1 EP 0742370 B1 EP0742370 B1 EP 0742370B1 EP 96830262 A EP96830262 A EP 96830262A EP 96830262 A EP96830262 A EP 96830262A EP 0742370 B1 EP0742370 B1 EP 0742370B1
Authority
EP
European Patent Office
Prior art keywords
flange
heating element
seats
heating
heating assembly
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
EP96830262A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0742370A1 (en
Inventor
Sergio Carella
Fortunato Belloni
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.)
SAES Getters SpA
Original Assignee
SAES Getters SpA
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 SAES Getters SpA filed Critical SAES Getters SpA
Publication of EP0742370A1 publication Critical patent/EP0742370A1/en
Application granted granted Critical
Publication of EP0742370B1 publication Critical patent/EP0742370B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B37/00—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00
    • F04B37/02—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for evacuating by absorption or adsorption

Definitions

  • the present invention deals with a heating assembly for devices operating under vacuum or in gases different from air, such as the gas purificators or the getter pumps which for the sake of simplicity will be referred to in the following description.
  • the getter pumps are well known in the vacuum technology since about thirty years and are much appreciated due to the fact of not having moving mechanical parts. Thanks to this feature they do not need for their operation the use of lubricants which could contaminate the chamber to be evacuated; furthermore these pumps do not transmit vibrations, often undesired, to the system connected thereto.
  • NEG materials non-evaporable getter materials
  • the main NEG materials are zirconium or titanium-based alloys in combination with elements such as aluminum, vanadium, iron, nickel or other transition elements or their combinations.
  • St101 R the alloy of composition Zr 84% - Al 16% by weight, manufactured and sold by the applicant under the name St101 R
  • St 707 the alloy of composition Zr 70% - V 24.6% - Fe 5.4% by weight, manufactured and sold by the applicant under the name St 707.
  • the active elements of these pumps can be produced by making the NEG material in powder form to adhere, generally by rolling, onto a suitable metallic support; pumps of this type are described for example in the U.S. patent 4,137,012 assigned to the applicant and in the published patent application JP-A-04/45480, in the name of the company Japan Steel Works. More recently there have been proposed getter pumps in which the getter elements are formed of bodies obtained by sintering powders of NEG materials, as described e.g. in the U.S. patents 5,320,496 and 5,324,172 both assigned to the applicant.
  • the getter material requires an initial "activation" treatment at temperatures of up to 900°C during a time of 10-30 minutes.
  • an essential element of these getter pumps is a heating element integrated in the pump itself. Furthermore, as the heating element can have a life shorter than that of the pump as a whole, this element must be interchangeable, possibly in a simply manner.
  • the heating element may be of various types, particularly advantageous is the use of IR lamps or of metallic resistances embedded in the pump body.
  • the size and the location of the heating element are critical parameters for the pump operation, especially in pumps of small size.
  • this can be placed at the outside of the chamber containing the getter elements rather than at the inside thereof.
  • the getter elements within the chamber can be placed in the most different ways, such as by simply filling the chamber of sintered pellets obtained from powders.
  • the getter elements are generally fixed to a support and in a preferred embodiment the support is provided by the inner wall portion itself which is extending into the chamber and houses the heating elements in the recess formed by the wall to the outside; such an arrangement is described e.g. in the mentioned patent application JP-A-04/45480.
  • the heating element is there integral with the support of the getter elements and its replacement requires much work.
  • the sheath in which the heating element is housed is in contact with the environment.
  • a breakage of the sheath wall may occur for various reasons, such as by melting or mechanical weakening due to an excessive heating, phenomena connected to an oversizing of the heater; or also the sheath wall may break due to the increasing oxidation caused by the presence of air at high temperature at its inside.
  • object of the present invention is that of providing a heating assembly to be introduced in the body of a getter pump so that the heating element can be easily replaced and furthermore can be reduced to a minimum both the problem due to the wall oxidation of the sheath that houses the heating element itself, and the possible consequences of a breakage or melting of the wall of such a sheath.
  • the first flange is made of a material which must show a good mechanical resistance, resistance to the operation temperature of the heater as well as a good thermally insulation.
  • a metal for example steel
  • plastic materials it is preferred the use of plastic materials, as they are lighter and less expensive.
  • the plastic materials allow to use, for coupling the flange to the heating element, a process that is particularly simple and affords advantages of hermetic sealing of the sheath housing the heater, as described in the following.
  • the thermo-resistant plastic materials which is possible to use can be of various types, among which for example phenolic, epoxy, acrylic, polyamidic resins, etc.
  • This flange is provided with means for its fastening to the second flange. Additionally, this flange may show one or more seats for the correct positioning of the sealing gaskets.
  • the heating element integrally fixed to the first flange may be of different types: for example it may be a heating quartz lamp.
  • electrical resistance heaters are used, which are well known in the art, being formed of a metallic resistance embedded in a ceramic material within a metallic housing. Heating elements of this type are manufactured e.g. by the company Watlow of St. Louis, Missouri, USA.
  • the heating element can be fastened to the flange in general with a thermo-resistant adhesive or by welding when flange and housing of the heating element are made of a metallic material.
  • the flange is obtained locally, with a thermosetting plastic material, thus providing at the same time the assembly of the flange itself to the heating element.
  • a thermosetting plastic material is obtained with a process in which the heating element is placed co-axially in a mould having essentially the complementary shape of the final flange and by pouring into the mould the thermosetting plastic material in liquid form.
  • the hardened plastic material can be then worked to obtain the finished flange with a seat for the fastening means to the second flange (generally screws), the possible seat of the gaskets or other finishing workings.
  • the thermosetting plastic materials it is preferred to use epoxy and acrylic resins.
  • the second flange is always made of metal as one of its surfaces provides a wall of the pump chamber.
  • the preferred material for making the second flange is AISI 316 steel.
  • This second flange is welded to the sheath wherein the heating element is housed; also the sheath itself can have the function of supporting the getter elements, as previously described.
  • the size of the sheath is such to leave a minimum air volume between the inner wall and the heating element.
  • the sealing gaskets may be made of metal if the two flanges are both metallic; in this case the metal of the gaskets will be of less hardness than that of the two flanges, for example there may be gaskets of copper, aluminum, nickel or other sufficiently soft metals with flanges of steel.
  • the gaskets will be in turn made of plastic material such as Teflon or Viton; alternatively, should the temperature of the flange not exceed 150°C it is also possible to use gaskets of indium.
  • the two main access passages of air to the sheath are the zone of contact between the two flanges, which is hermetically sealed by the gaskets; and the zone of connection between the first flange and the heating element, which is also hermetically sealed, in particular by means of the above described process in which the flange is "formed" about the heating element itself.
  • the last possible way of air entering the sheath is through the wires for feeding electric power to the heater, which generally are not air-tight: the gas conductance through this way is however extremely low and also to have air entering the pump chamber through this way is necessary that both the sheath and the heater housing break at the same time.
  • the first flange 10 has a seat 12 in which the heating element 14 is inserted in an air-tight manner.
  • the seat 12 is obtained locally in the same process of forming the flange 10.
  • This flange has also through holes 16, 16' in case that screws are used as fastening means between flange 10 and the second flange.
  • a seat 20 is formed for gasket 30.
  • the wires for the electrical supply of the heating element 14 are shown.
  • the second flange 40 is integral with support 42 of the getter elements; this structure is preferably obtained by welding together the two portions to the support base in the region 44.
  • the getter elements (not shown) are fixed to the outer surface 46 of the support, while the inner surface 48 defines a sheath 50 for housing the heating element 14.
  • On the same surface 52 also the seat 56 for gas-tight gasket 30 is formed.
  • the seats 20 and 56 for the gasket 30 are here shown on both the surfaces 18, 52 but in alternative they can be on one surface only or even on none of said surfaces; in particular the gaskets in Teflon with rectangular cross-section, having the two main faces flat, do not require generally the formation of seats.
  • the seats 60, 60' are formed for the fastening means (generally screws, shown in figure 2) and, on the surface 62 of flange 40 the seat 64 for high-vacuum sealing gasket 122 (shown in Figure 2).
  • these high-vacuum gaskets are made of metal, generally electrolytic copper.
  • Figure 2 schematically shows in cross-section a possible getter pump with heating element assembled according to the invention.
  • the pump 100 comprises a housing 102 with an opening 104 for the connection with the chamber to be evacuated.
  • a flange 106 is fixed to the housing 102, generally by welding, with seats 108, 108' corresponding to the seats 60, 60' on the flange 40 for the fastening means 110, 110'.
  • the volume 112 defined by the inner walls of housing 102, the surface 62 of flange 40 and surface 46 of support 42 is the operating chamber of the pump, containing the getter elements 120, 120', 120",....; this chamber is hermetically sealed by means of the gasket 122.
  • the getter elements are kept at the operation temperature by the heating element 14 protruding into the chamber 124 that corresponds to said sheath 50 at the inside of support 42.
  • figure 2 represents a particular type of pump, in which the getter elements are connected to the support 42, particularly in form of disks perpendicular to the support, it is possible that the getter elements are made as blades fixed to the support parallel thereto and extending radially into the chamber or even simply introduced into the chamber in a non-supported form, e.g. as sintered pellets.
  • the heating assembly has been described in particular for an application to the getter pumps, the same assembly can be advantageously adopted also in other devices showing the same technical problems, in particular the risks of destruction of the device in case that the heater housing breaks.
  • Another type of devices in which the heating system of the invention can be applied are for example the gas purifiers based on the use of getter materials, which show a construction and operative principles quite similar to those illustrated herewith for the getter pumps.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
  • Compressor (AREA)
  • Resistance Heating (AREA)
EP96830262A 1995-05-11 1996-05-07 Heating assembly for getter pumps and gas purifiers Expired - Lifetime EP0742370B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITMI950954 1995-05-11
ITMI950954A IT1274478B (it) 1995-05-11 1995-05-11 Insieme di riscaldamento per pompe getter e purificatori di gas

Publications (2)

Publication Number Publication Date
EP0742370A1 EP0742370A1 (en) 1996-11-13
EP0742370B1 true EP0742370B1 (en) 1999-03-17

Family

ID=11371578

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96830262A Expired - Lifetime EP0742370B1 (en) 1995-05-11 1996-05-07 Heating assembly for getter pumps and gas purifiers

Country Status (4)

Country Link
EP (1) EP0742370B1 (it)
JP (1) JPH08315961A (it)
DE (1) DE69601746T2 (it)
IT (1) IT1274478B (it)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT237018Y1 (it) * 1995-07-10 2000-08-31 Getters Spa Pompa getter perfezionata in particolare per uno strumento dianalisi chimiche portatile
ITMI20121732A1 (it) 2012-10-15 2014-04-16 Getters Spa Pompa getter
TWI660125B (zh) * 2014-04-03 2019-05-21 義大利商沙斯格特斯公司 吸氣泵
US9685308B2 (en) 2014-06-26 2017-06-20 Saes Getters S.P.A. Getter pumping system
CN112169528B (zh) * 2020-09-24 2022-07-12 有研工程技术研究院有限公司 一种内加热式吸气剂片及其制备方法
WO2024028240A1 (en) 2022-08-01 2024-02-08 Saes Getters S.P.A. Snap-on getter pump assembly and its use

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH597514A5 (it) * 1976-09-07 1978-04-14 Balzers Patent Beteilig Ag
US4137012A (en) * 1976-11-03 1979-01-30 S.A.E.S. Getters S.P.A. Modular getter pumps
US5154582A (en) * 1991-08-20 1992-10-13 Danielson Associates, Inc. Rough vacuum pump using bulk getter material
IT1255438B (it) * 1992-07-17 1995-10-31 Getters Spa Pompa getter non evaporabile

Also Published As

Publication number Publication date
DE69601746D1 (de) 1999-04-22
ITMI950954A1 (it) 1996-11-11
EP0742370A1 (en) 1996-11-13
IT1274478B (it) 1997-07-17
DE69601746T2 (de) 1999-09-02
JPH08315961A (ja) 1996-11-29
ITMI950954A0 (it) 1995-05-11

Similar Documents

Publication Publication Date Title
JP6585229B2 (ja) 高圧ハーメチック端子
US11204127B2 (en) Vacuum insulated structure with end fitting and method of making same
US5404078A (en) High-pressure discharge lamp and method of manufacture
US5215639A (en) Composite sputtering target structures and process for producing such structures
EP0742370B1 (en) Heating assembly for getter pumps and gas purifiers
JP5302386B2 (ja) ゲッタポンプ及びイオンポンプを具備する複合排気システム
EP0910106B1 (en) Getter pump with high velocity of gas sorption
US20040234033A1 (en) Rotary positive pole type x-ray tube
JP2002531690A (ja) インサートターゲットアセンブリとそれを製造する方法
US4874339A (en) Pumping tubulation getter
EP0136864A2 (en) Method for assembling a high vacuum rotating anode x-ray tube
EP0183403B1 (en) Lead wires in pinch seals
KR100544591B1 (ko) 터보분자 펌프에 동축으로 그 부근의 상류에서 사용하기 위한 게터 펌프
EP3048634B1 (en) X-ray tube vacuum assemblies and methods of vacuum formation
US20050254969A1 (en) Vacuum pump
KR100799092B1 (ko) 디스플레이 디바이스들을 밀봉하는 방법
US5515412A (en) Method of producing frit-sealed x-ray tube
JP2518962B2 (ja) セラミックスヒ―タ―
WO2019083645A2 (en) MODULAR REACTOR SYSTEM FOR EXOTHERMIC REACTIONS
JP2805022B2 (ja) 炭素材の接合方法その方法による接合物及びその接合物を用いた材料
JPS6236773B2 (it)
US10945311B1 (en) High temperature substrate heater for use in high and ultra-high vacuum systems
JPH11195358A (ja) 真空インタラプタ
JP3652899B2 (ja) 電池
JPH07134958A (ja) 回転陽極型ｘ線管及びその製造方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB NL SE

17P Request for examination filed

Effective date: 19970113

17Q First examination report despatched

Effective date: 19980407

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB NL SE

REF Corresponds to:

Ref document number: 69601746

Country of ref document: DE

Date of ref document: 19990422

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20010502

Year of fee payment: 6

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20020507

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20020529

Year of fee payment: 7

Ref country code: NL

Payment date: 20020529

Year of fee payment: 7

Ref country code: FR

Payment date: 20020529

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20020617

Year of fee payment: 7

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20020507

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030508

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031201

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031202

EUG Se: european patent has lapsed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040130

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20031201

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST