US3864232A - Apparatus for Monitoring the Oxygen Content of High Temperature Fluids - Google Patents

Apparatus for Monitoring the Oxygen Content of High Temperature Fluids Download PDF

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Publication number
US3864232A
US3864232A US356669A US35666973A US3864232A US 3864232 A US3864232 A US 3864232A US 356669 A US356669 A US 356669A US 35666973 A US35666973 A US 35666973A US 3864232 A US3864232 A US 3864232A
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United States
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solid electrolyte
electrochemical cell
molten metal
tubular
electrolyte electrochemical
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Expired - Lifetime
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US356669A
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English (en)
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Lawrence M Handman
Charles E Spangler
Raymond F Thompson
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Westinghouse Electric Corp
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Westinghouse Electric Corp
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Priority to US356669A priority Critical patent/US3864232A/en
Priority to CA196,753A priority patent/CA985742A/en
Priority to JP4890074A priority patent/JPS5343434B2/ja
Application granted granted Critical
Publication of US3864232A publication Critical patent/US3864232A/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/406—Cells and probes with solid electrolytes
    • G01N27/411—Cells and probes with solid electrolytes for investigating or analysing of liquid metals
    • G01N27/4118—Means for protecting the electrolyte or the electrodes

Definitions

  • solid electrolyte electrochemical cell is preheated under controlled conditions to a temperature equiva- [22] Fil d; M 2, 1973 lent to the temperature of a high temperature oxygen containing fluid such as a gas or molten metal prior to Appl 356669 insertion of the probe into the fluid for measuring the oxygen concentration of the fluid.
  • the oxygen content of molten copper is controlled by blowing either a reducing gas or an oxidizing gas stream on the copper as it flows from the holding furnace tothe tundish. If the oxygen content is low, air is blown into the copper. High oxygen is corrected by blowing the hydrogen rich gas stream into the copper. Tundish samples taken periodically are removed and analyzed in a remote laboratory. During the 5 to minute period required to sample and analyze the molten metal an additional 2,500 to 5,000 pounds of copper can be cast at the typical rate of l5 tons/- hour. There exists an urgent need for an in situ oxygen measuring technique which will not only provide an accurate oxygen content measurement of high temperature fluids but which will eliminate the time consuming practice of removing samples for analysis in a remote laboratory.
  • the traditional fully stabilized solid electrolyte is replaced with a partially stabilized solid electolyte to improve the physical characteristics of the electrolyte to enable it to better withstand elevated temperatures.
  • the solid electrolyte electrochemical cell is incorporated into a probe assembly and is controllably preheated to a temperature representative of the fluid to be monitored for oxygen content.
  • the preheating of the solid electrolyte electrochemical cell prior to insertion into the fluid eliminates the occurrence of thermal shock when the cell contacts the fluid thus avoiding physical deterioration of the cell.
  • the specific embodiment of the invention described below with reference tothe accompanying drawings refers to an oxygen ion conductive solid electrolyte electrochemical cell which is controllably preheated to the temperature of the molten metal under consideration and subsequently positioned within a thermal insulating tubular member for insertion directly into the molten metal.
  • the thermal insulating tubular member is a part of a probe assembly capable of being mounted directly on the tundish within which the molten metal is contained.
  • a vertical positioning mechanism associated with the probe assembly functions to lower the solid electrolyte electrochemical cell assembly'through the tubular insulating member and into the molten metal for direct contact measurement of the oxygen concentration in the molten metal.
  • Suitable thermal insulating devices within the probe assembly permit subsequent retraction of the solid electrolyte electrochemical cell to a position within the tubular thermal shield member and the subsequent removal of the probe assembly from the tundissh.
  • FIG. 1 is a sectioned illustration of a probe assembly embodying the invention
  • FIG. 2 is a detailed sectioned illustration of the solid electrolyte electrochemical cell assembly of the probe assembly of FIG. 1;
  • FIG. 3 is a schematic illustration of an alternate configuration of the solid electrolyte electrochemical cell assembly for use in the probe assembly of FIG. 1;
  • FIG. 4 is a modification of the configuration of FIG. 3.
  • FIG. I there is illustrated an oxygen probe assembly 10 inserted through a flange member F in the top ofa tundish T containing molten copper C.
  • the oxygen measuring probe assembly is supported on the flange F by tubular housing 12.
  • tubular thermal shield l4 composed of a thermal insulating material capable of withstanding the temperature of the molten copper which is typically in the range of 2,000 to 2,500F.
  • a clay-graphite composition has proven to be most suitable for fabrication of the tubular shield 14.
  • the tubular solid electrolyte member 20 having a closed end forming an electrochemical cell 22 extends through the tubular stainless steel member 30 to connector assembly 38 which is secured to mounting plate 36.
  • the tubular stainless steel member 30 extends from the connector assembly 38 through the stuffing gland 32.
  • the vertical position of the mounting plate 36 and consequently the vertical position of the combination of the solid electrolyte electrochemical cell 22, which as seen in FIG. 2, is comprised of the solid electrolyte material forming the closed end of the electrolyte member 20 and the electrode 23, and the tubular stainless steel member 30 is controlled by knob 40 and gear train 42.
  • tubular stainless steel member 30 Extending from the tubular stainless steel member 30 is a closed end tubular screen member 44 which surrounds the solid electrolyte member 20 and the electrochemical cell 22.
  • the tubular screen member functions l. dislogdge the thermal plug element 46 prior to the insertion of the electrochemical cell 22 into the molten copper,
  • a collar of thermal insulating material 50 is secured to the tubular screen member 44 and moves vertically within the tubular shield member 14 to maintain alignment of the solid electrolyte member 20 within the thermal shield 14.
  • the thermal plug element 46 serves to prevent hot metal and gases from rising within the probe assembly before insertion of the electrochemical cell 22 into the molten metal.
  • the solid electrolyte electrochemical cell 22 corresponds essentially in method of operation to the solid electrolyte oxygen analyzer described in US. Pat. No. 3,400,054, issued Sept. 3, 1968 and assigned tothe assignee of the present invention.
  • An oxygen reference of known oxygen concentration is established within the solid electrolyte member 20 at the closed end by an air supply source 54.
  • the solid electrolyte electrochemical cell assembly transmits an EMF signal to signal measuring circuit 56.
  • the magnitude of EMF signal is a function of the difference in oxygen partial pressure between the oxygen reference established by the air supply and the oxygen concentration of the molten copper C.
  • the EMF signal is an indication of the oxygen concentration of the molten copper C.
  • the probe assembly 10 Prior to positioning the probe assembly 10 on flange F, the probe assembly 10 is positioned on preheat furnace PF such that the thermal shield 14 and solid electrolyte member 20 are inserted within the furnace PF.
  • the electrochemical cell 22 is subjected to a controlled heating process by temperature controller TC to pre-
  • temperature controller TC When the oxygen concentration measurements of the molten copper are desired, the combination of the solid electrolyte member 20 and the tubular stainless steel member 30 are lowered through the thermal shield member 14 by the adjustment of knob 40.
  • the closed end tubular metallic screen member 44 dislodges the thermal plug element 46, which then assumes a floating position on the surface of the molten copper and is subsequently removed as part of the slag.
  • the assembly After the oxygen probe assembly 10 has been heated to the desired temperature by the preheat furnace PF the assembly is installed on the tundish T with the bottom of the tubular housing 12 position in the flange F. With the assembly 10 in position on the tundish T, the tubular thermal shield member 14 extends inside the tundish T through the gas burner flame to a position below the molten copper level.
  • the stuffing gland 32 which provides a slidable seal for the vertical movement of the tubular stainless steel member 30, also functions to reduce the natural convection inside the tubular thermal shield member 14 thus minimizing heat losses while also preventing tundish burner flames from rising up through the probe assembly 10.
  • the requirement for removing the probe assembly 10 for preheating in a remote preheater furnace PF can be eliminated'by incorporating a preheating furnace PF as part of the probe assembly 10 of H6. 1.
  • the incorporation of a tubular preheating furnace within the tubular thermal shield element 14 coupled with a temperature control circuit can provide direct heating of the electrochemical cell 22 while the probeassembly 10 is positioned in the tundish T.
  • the solid electrolyte electrochemical cell 22 as including the closed end of the oxygen ion conductive solid electrolyte member 20 and the electrode 23 disposed on the inner surface of the closed end to serve as the oxygen reference electrode in response to the air flow introduced into the interior of the solid electrolyte member 20 by the air supply source 54.
  • the essential requirement for the material composition of the solid electrolyte material is that it support substantial oxygen ion conductivity while withstanding relatively high temperatures. While this material requirement can be satisfied by the numberous fully stabilized compositions described in the above-referenced US. Patent, such as the calcium stabilized zirconia composition represented as Zr0 15 mol percent CaO, experimental analysis indicates that partially stabilized electrolyte compositions offer additional advantages.
  • the partial stabilization in contrast to complete stabilization provides for improved physical strength and is therefore desirable for the relatively severe environmental operating conditions to which the solid electrolyte material of a molten metal sensor is subjected.
  • a particularly useful partially stabilized calcia-zirconia electrolyte composition is represented as ZrO 3.5 mol percent CaO.
  • the conical top of the solid electrolyte member 20 sits inside connector 60, to which the tubular stainless steel member 30 is affixed.
  • Washer 62 is made of a high temperature insulating material and serves as a cushion for the solid electrolyte member 20.
  • Reference oxygen from the oxygen supply 54 enters the solid electrolyte member 20 through the connector 70 which mates with connector 60.
  • Washer 68 provides a mechanical cushion between the connector 70 and the solid electrolyte member 20.
  • Electrode 23 and the connector 41 mounted on the mounting plate Electrical continuity between the electrode 23 and the connector 41 mounted on the mounting plate is provided by electrical lead members 72 and 73 which extend through longitudinal passages in a tubular feed through member 75 inserted within the solid electrolyte member 20 to which is attached a metallic mesh electrode 76 which is maintained in intimate contact with electrode 23.
  • the metallic mesh electrode 76 which can be typically fabricated from platinum wire mesh, provides positive electrical contact with the electrode 23 while also isolating the solid electrolyte member 22 from direct mechanical contact by the tubular feed-through member 75.
  • thermocouple combination with the electrical leads 72 and 73.
  • a particular useful thermocouple for monitoring temperatures in the range of molten copper is formed by using platinum for the electrical lead wires 72 and 73 and a platinum per cent rhodium material for wire 74. The thermocouple signal produced is transmitted through the electrical connector 41 to a temperature monitoring circuit 82 illustrated in FIG. 1.
  • FIG. 3 An alternate solid electrolyte electrochemical cell assembly is illustrated in FIG. 3.
  • the tubular electrolyte member of FIG. 1 has been replaced by a tubular stainless steel member 80 which supports a dish shape solid electrolyte electrochemical cell 82.
  • the stainless steel tubular member functions as an electrical lead when in contact with the molten metal and functions in combination with the electrical lead 84 which contacts the inner electrode 85 to transmit the EMF signal developed by the cell 82 to a suitable monitoring circuit.
  • FIG. 3 can be modified as shown in FIG. 4 to monitor high temperature gas environments by adding an external electrode 86 for contacting the gas enviroment and extending the stainless steel tube 80 to contact the electrode 86 and thus functions as an electrical lead wire from the electrode 86.
  • Apparatus for monitoring the oxygen content of molten metal comprising, an open ended tubular member, a solid electrolyte electrochemical cell cell means including an oxygen ion conductive solid electrolyte having an external surface and an internal surface, an electrode means disposed in intimate contact with said internal surface and a reference medium of known oxygen content in contact with said internal surface, said solid electrolyte electrochemical cell means being slidably positioned within said tubular member, said tubular thermal insulating member being adapted for positioning relative to said molten metal, adjustment means for slidably positioning said solid electrolyte electro-.

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  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Molecular Biology (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating And Analyzing Materials By Characteristic Methods (AREA)
  • Measuring Oxygen Concentration In Cells (AREA)
US356669A 1973-05-02 1973-05-02 Apparatus for Monitoring the Oxygen Content of High Temperature Fluids Expired - Lifetime US3864232A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US356669A US3864232A (en) 1973-05-02 1973-05-02 Apparatus for Monitoring the Oxygen Content of High Temperature Fluids
CA196,753A CA985742A (en) 1973-05-02 1974-04-03 Apparatus for monitoring the oxygen content of high temperature fluids
JP4890074A JPS5343434B2 (enrdf_load_stackoverflow) 1973-05-02 1974-05-02

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US356669A US3864232A (en) 1973-05-02 1973-05-02 Apparatus for Monitoring the Oxygen Content of High Temperature Fluids

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JP (1) JPS5343434B2 (enrdf_load_stackoverflow)
CA (1) CA985742A (enrdf_load_stackoverflow)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4003814A (en) * 1974-08-02 1977-01-18 Noranda Mines Limited Apparatus for the continuous measurement of the oxygen content of molten copper or alloys thereof
US4007106A (en) * 1973-06-22 1977-02-08 Canadian Patents And Development Limited Device for measuring oxygen concentration in molten-metal
US4166019A (en) * 1975-09-26 1979-08-28 General Electric Company Electrochemical oxygen meter
US4198279A (en) * 1977-11-10 1980-04-15 Corning Glass Works Oxygen sensor mounting structure
US4414093A (en) * 1981-12-30 1983-11-08 Laszlo Redey Multifunctional reference electrode
US4818366A (en) * 1987-07-30 1989-04-04 The United States Of America As Represented By The United States Department Of Energy Long life reference electrode
US5596134A (en) * 1995-04-10 1997-01-21 Defense Research Technologies, Inc. Continuous oxygen content monitor
US6083368A (en) * 1996-04-20 2000-07-04 Kawaso Electric Industrial Co., Ltd. Probe device for continuous measurements of oxygen in running molten metal
US6551498B2 (en) * 2001-02-13 2003-04-22 Delphi Technologies, Inc. Lower protective shield for an exhaust sensor and method for making the same
US20050029100A1 (en) * 2003-02-17 2005-02-10 Dongsub Park Solid-state electrochemical hydrogen probe for the measurement of hydrogen content in the molten aluminum
US20090166520A1 (en) * 2007-11-09 2009-07-02 The Regents Of The University Of California In-situ soil nitrate ion concentration sensor
US20110003400A1 (en) * 2008-02-22 2011-01-06 The Johns Hopkins University Methods and systems for ground and surface water sampling and analysis

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5361670U (enrdf_load_stackoverflow) * 1976-10-28 1978-05-25
JPS5897545U (ja) * 1981-12-25 1983-07-02 住友ベークライト株式会社 分取容器
JPH0447653Y2 (enrdf_load_stackoverflow) * 1985-08-28 1992-11-10
JPH06105238B2 (ja) * 1986-02-06 1994-12-21 新日本製鐵株式会社 高炉内ガスの酸素分圧測定方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3619381A (en) * 1968-12-23 1971-11-09 George R Fitterer Determining oxygen content of materials
US3652427A (en) * 1969-12-22 1972-03-28 Little Inc A Method for monitoring the oxygen and carbon contents in a molten metal
US3719574A (en) * 1970-07-06 1973-03-06 Metallurgie Hoboken Apparatus for measuring in a continuous manner the oxygen in a molten metal

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3864231A (en) * 1972-01-31 1975-02-04 Metallurgie Hoboken Apparatus for measuring in a continuous manner oxygen in a molten metal

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3619381A (en) * 1968-12-23 1971-11-09 George R Fitterer Determining oxygen content of materials
US3652427A (en) * 1969-12-22 1972-03-28 Little Inc A Method for monitoring the oxygen and carbon contents in a molten metal
US3719574A (en) * 1970-07-06 1973-03-06 Metallurgie Hoboken Apparatus for measuring in a continuous manner the oxygen in a molten metal

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4007106A (en) * 1973-06-22 1977-02-08 Canadian Patents And Development Limited Device for measuring oxygen concentration in molten-metal
US4003814A (en) * 1974-08-02 1977-01-18 Noranda Mines Limited Apparatus for the continuous measurement of the oxygen content of molten copper or alloys thereof
US4166019A (en) * 1975-09-26 1979-08-28 General Electric Company Electrochemical oxygen meter
US4198279A (en) * 1977-11-10 1980-04-15 Corning Glass Works Oxygen sensor mounting structure
US4414093A (en) * 1981-12-30 1983-11-08 Laszlo Redey Multifunctional reference electrode
US4818366A (en) * 1987-07-30 1989-04-04 The United States Of America As Represented By The United States Department Of Energy Long life reference electrode
US5596134A (en) * 1995-04-10 1997-01-21 Defense Research Technologies, Inc. Continuous oxygen content monitor
US6083368A (en) * 1996-04-20 2000-07-04 Kawaso Electric Industrial Co., Ltd. Probe device for continuous measurements of oxygen in running molten metal
US6551498B2 (en) * 2001-02-13 2003-04-22 Delphi Technologies, Inc. Lower protective shield for an exhaust sensor and method for making the same
US20050029100A1 (en) * 2003-02-17 2005-02-10 Dongsub Park Solid-state electrochemical hydrogen probe for the measurement of hydrogen content in the molten aluminum
US7396443B2 (en) * 2003-02-17 2008-07-08 Dongsub Park Solid-state electrochemical hydrogen probe for the measurement of hydrogen content in the molten aluminum
US20090166520A1 (en) * 2007-11-09 2009-07-02 The Regents Of The University Of California In-situ soil nitrate ion concentration sensor
US7927883B2 (en) * 2007-11-09 2011-04-19 The Regents Of The University Of California In-situ soil nitrate ion concentration sensor
US8444937B2 (en) 2007-11-09 2013-05-21 The Regents Of The University Of California In-situ soil nitrate ion concentration sensor
US20110003400A1 (en) * 2008-02-22 2011-01-06 The Johns Hopkins University Methods and systems for ground and surface water sampling and analysis

Also Published As

Publication number Publication date
CA985742A (en) 1976-03-16
JPS5343434B2 (enrdf_load_stackoverflow) 1978-11-20
JPS5015598A (enrdf_load_stackoverflow) 1975-02-19

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