US3602297A - Heat transfer tube assembly - Google Patents

Heat transfer tube assembly Download PDF

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Publication number
US3602297A
US3602297A US826956A US3602297DA US3602297A US 3602297 A US3602297 A US 3602297A US 826956 A US826956 A US 826956A US 3602297D A US3602297D A US 3602297DA US 3602297 A US3602297 A US 3602297A
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US
United States
Prior art keywords
heat transfer
transfer tube
oxygen
tube assembly
tantalum
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
US826956A
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English (en)
Inventor
Gunther Kraft
Manfred Potzschke
Claus Busse
Franz Geiger
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.)
GEA Group AG
Original Assignee
Metallgesellschaft AG
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
Priority claimed from DE19681751411 external-priority patent/DE1751411C3/de
Application filed by Metallgesellschaft AG filed Critical Metallgesellschaft AG
Application granted granted Critical
Publication of US3602297A publication Critical patent/US3602297A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
    • F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
    • F28D15/04—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes with tubes having a capillary structure
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C27/00—Alloys based on rhenium or a refractory metal not mentioned in groups C22C14/00 or C22C16/00

Definitions

  • a heat transfer tube assembly (heat pipe) using lithium as its working fluid is provided with 5-500 ppm. of an oxygen-stabilizing agent in the refractory alloy of the wall material to prevent oxygen corrosion at operating conditions.
  • HEAT TRANSFER TUBE ASSEMBLY The present invention relates to the use of refractory metals or their alloys, which contain oxygen-stabilizing addition elements, as wall material for heat transfer tubes which carry molten metallic lithium as a heat transfer fluid.
  • Heat transfer tubes are tubes which are hermetically sealed on all sides and which contain a capillary system formed on the inside surfaces by ribs and grooves and which are partly filled with a heat transfer fluid. When one end of such tube is heated, the heat transfer fluid will form a liquid-vapor cycle between the heating zone and a remote cooling zone. The heat transfer fluid transfers heat in that direction with such low losses that the temperature of the entire heat transfer tube may be considered virtually constant.
  • Such heat transfer tubes are often used to transfer heat to the emitter and to transfer heat from the collector of thermionic energy-converting devices. Operating temperatures of about l400-l600 C. are required for a cooperation of such tubes with the emitters of thermionic converters so that the selection of the heat transfer fluid and the wall material of the heat transfer tube is restricted.
  • Refractory metals such as columbium, zirconium, molybdenum, tungsten, tantalum, or their alloys, such as columbium and 1 percent zirconium, tantalum and 5 percent tungsten, have been used as wall materials. Bismuth, lead, thallium, barium and the alkali metals are known as metallic heat transfer fluids.
  • the known wall materials such as molybdenum or tungsten have proved unsatisfactory in many cases because they are too brittle.
  • the corrosion process is critically influenced by the oxygen content of the wall material of high-temperature heat transfertubes. This corrosion process involves a dissolving of the oxygen out of the wall material by molten lithium, which flows along the inside wall under the operating conditions. The molten lithium transfers the oxygen into the heating zone, where the oxygen is deposited in the form of oxides of lithium and of the metal of the wall material.
  • The'corrosion can be controlled only if the tube material contains less than 1 p.p.m. oxygen. It has hardly been possible before to meet these requirements in commercial operation.
  • a commercially available tantalum has a small content of yttrium and is known as so-called SGS tantalum or grain-stabilized tantalum.
  • the invention teaches to use oxygen-stabilized refractory metals.
  • the invention resides in the use of refractory metals or their alloys and 5-500 p.p.m. oxygen-stabilizing elements as wall material for heat transfer tubes containing liquid metallic lithium.
  • the heat transfer tube assembly comprises a horizontally disposed tube 1, which is sealed at opposite ends by plugs 2 and 3, respectively.
  • the tube 1 is formed on its inside surface with a plurality of axial grooves 4 which are circumferentially spaced apart and may be covered with a screen.
  • the screen is not shown in the drawing for the sake of clarity.
  • the tube 1 contains some metallic lithium which at operating temperature fills the grooves 4, whereas lithium vapor fills the inner part of the tube.
  • the tube 1 has a heating zone 5 adapted to be supplied with heat and a cooling zone 6, from which heat can be withdrawn.
  • the tube 1 and any screen therein consists of a refractory alloy which contains 5-500 p.p.m. of an oxygen-stabilizing element,
  • a preferred material for tube 1 is known as $68 tantalum, a commercially available, grain-stabilizing tantalum alloy which contains a small percentage of yttrium.
  • the tube 1 may consist of a columbium alloy containing 1 percent zirconium.
  • tantalum which contains yttrium or rare earth element metals, such as cerium or lanthanum has proved satisfactory, e.g., as a wall material in lithium-operated heattransfer tubes.
  • the tantalum suitably contains said additional elements in amounts of 5-500 p.p.m.
  • the use of tantalum which contains 5-500 p.p.m. yttrium as a wall material in lithium-operated heat-transfer tubes has proved particularly suitable.
  • Tantalum alloys, such as tantalum and 5 percent tungsten as well as additions of oxygen-stabilizing elements in amounts of 5-500 p.p.m. e.g., yttrium or rare earth elements metals may also be used as a wall material according to the invention.
  • Columbium or its alloys such as columbium and 1 percent zir conium as well as additions of oxygen-stabilizing elements in amounts of 5-500 p.p.m. are also suitable as a wall material according to the invention.
  • the use of refractory metals which contain oxygen-stabilizing elements as wall material in lithium-operated heat-transfer tubes involves advantages. These additions, such as yttrium or rare earth element metals, reduce the oxygen-diffusion rate of the oxygen in the wall material to such an extent that oxygen is no longer presented to lithium, which as a result of the continuous evaporation-condensation cycle has an extremely low oxygen content so that it has a high free linkage enthalpy for oxygen.
  • a heat transfer tube consisting of tantalum and 5-l00 p.p.m. yttriums has been successfully used according to the invention at 1600 C. for more than 1000 hours without damage to the capillary structure.
  • a heat transfer tube assembly which comprises a heat transfer tube consisting of a refractory alloy containing 5-500 p.p.m.of an oxygen-stabilizing agent, means sealing said tube at both ends, and a body of metallic lithium partly filling said tube.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Sustainable Development (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
US826956A 1968-05-25 1969-05-22 Heat transfer tube assembly Expired - Lifetime US3602297A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19681751411 DE1751411C3 (de) 1968-05-25 Verwendung von Refraktär-Metallen . mit Zusätzen an Sauerstoff-stabilisierenden Elementen als Wandmaterial für Wärmerohre

Publications (1)

Publication Number Publication Date
US3602297A true US3602297A (en) 1971-08-31

Family

ID=5692295

Family Applications (1)

Application Number Title Priority Date Filing Date
US826956A Expired - Lifetime US3602297A (en) 1968-05-25 1969-05-22 Heat transfer tube assembly

Country Status (6)

Country Link
US (1) US3602297A (xx)
BE (1) BE732959A (xx)
CH (1) CH512715A (xx)
FR (1) FR2009951A1 (xx)
GB (1) GB1194530A (xx)
NL (1) NL6907567A (xx)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4087893A (en) * 1974-11-08 1978-05-09 Nippon Gakki Seizo Kabushiki Kaisha Process for producing a heat pipe
US4109131A (en) * 1976-04-30 1978-08-22 E. Schluter Fachhandel Fur Schweisstechnik Welding-, cutting-, or heating torch
US4372377A (en) * 1981-03-16 1983-02-08 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Heat pipes containing alkali metal working fluid
US4681995A (en) * 1986-04-04 1987-07-21 Ahern Brian S Heat pipe ring stacked assembly
US4703796A (en) * 1987-02-27 1987-11-03 Stirling Thermal Motors, Inc. Corrosion resistant heat pipe
US20060222423A1 (en) * 2005-03-31 2006-10-05 Xerox Corporation Heat-pipe fuser roll with internal coating

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL7612360A (nl) * 1976-11-08 1978-05-10 Philips Nv Warmtepijp.
ES509334A0 (es) * 1981-02-14 1982-12-16 Teves Thompson Gmbh Valvula hueca para maquinas motrices de combustion.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Deverall et al, JE High Thermal Conductance Devices Utilizing The Boiling of Lithium or Silver, Los Alamos Scientific Laboratory, Los Alamos, New Mexico, 4/1965, 37 pgs. *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4087893A (en) * 1974-11-08 1978-05-09 Nippon Gakki Seizo Kabushiki Kaisha Process for producing a heat pipe
US4109131A (en) * 1976-04-30 1978-08-22 E. Schluter Fachhandel Fur Schweisstechnik Welding-, cutting-, or heating torch
US4372377A (en) * 1981-03-16 1983-02-08 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Heat pipes containing alkali metal working fluid
US4681995A (en) * 1986-04-04 1987-07-21 Ahern Brian S Heat pipe ring stacked assembly
US4703796A (en) * 1987-02-27 1987-11-03 Stirling Thermal Motors, Inc. Corrosion resistant heat pipe
US20060222423A1 (en) * 2005-03-31 2006-10-05 Xerox Corporation Heat-pipe fuser roll with internal coating

Also Published As

Publication number Publication date
DE1751411A1 (de) 1971-02-18
BE732959A (xx) 1969-10-16
DE1751411B2 (de) 1976-03-25
CH512715A (de) 1971-09-15
FR2009951A1 (fr) 1970-02-13
NL6907567A (xx) 1969-11-27
GB1194530A (en) 1970-06-10

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