US3652068A - Refractory hollow body - Google Patents

Refractory hollow body Download PDF

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Publication number
US3652068A
US3652068A US874258A US3652068DA US3652068A US 3652068 A US3652068 A US 3652068A US 874258 A US874258 A US 874258A US 3652068D A US3652068D A US 3652068DA US 3652068 A US3652068 A US 3652068A
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United States
Prior art keywords
hollow body
refractory
outer layer
set forth
percent
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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
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US874258A
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English (en)
Inventor
Meinhard Truppe
Matthias Schernthaner
Gunter Poferl
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Voestalpine AG
Voest AG
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Voestalpine AG
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Publication date
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/42—Constructional features of converters
    • C21C5/46—Details or accessories
    • C21C5/4673—Measuring and sampling devices

Definitions

  • ABSTRACT The invention relates to a refractory hollow body serving especially as protection for probes or lances with which the progress of metallurgical processes is tested, to a method for producing such hollow body and to a device useful in carrying out such method.
  • the high demands placed in such protection jacket are met by providing two layers for the refractory hollow body, i.e., an inner layer of unsintered refractory mass, containing 25 35 percent of fine particles and 30 40 percent of coarser particles, and a dense, sintered outer layer of the same material, the thickness of said outer layer amounting to preferably from one-sixth to one-tenth of the wall thickness of said body.
  • Such jacket body whose total porosity preferably amounts to 15 20 percent is produced by forming a hollow cylindrical body out of a granular, refractory mass under the addition of water and consolidation by shaking, drying said body and burning said outer layer to become dense at a temperature higher than the sintering temperature, while said inner layer is cooled by a coolant.
  • the invention relates to a refractory hollow body, particularly for the protection of probes or lances such as temperature measuring lances having a cooling arrangement in their interior and destined to be immersed into hot liquid media.
  • lances and the like comprising a sensing portion which is entirely or partly cooled, which lances are immersed into hot metal baths in order to observe the progress of metallurgical processes.
  • Devices of this kind are e.g. temperature measuring lances, in the sensing portion of which a thermocouple with a sheath tube is encased.
  • the sheath tube with the thermocouple has to be protected against the influence of slag and metal by means of a refractory jacket; when such temperature measuring devices are employed e.g. in top blowing converters it is desired that the life of the device lasts for a larger number of heats.
  • the refractory protection jacket is required to be resistant against the specific thermal stresses which arise from the great temperature gradient from the hot outside to the interior which is entirely or partly cooled; to be resistant against the chemical attack of liquid slag and metal; and to show firstrate fireproof properties as well as a good resistance to thermal shocks.
  • the relevant temperature gradient is much greater than that which may occur in refractory bricks used for lining an open-hearth furnace or a converter; a stationary distribution of temperature cannot occur because the measuring lance remains but shortly in the bath, e.g. for 20-25 minutes during a refining heat, after which the measuring lance is drawn out again.
  • the present invention is aimed at avoiding the drawbacks and difficulties described by creating a refractory hollow body, particularly for the protection of probes or lances, such as temperature measuring lances having a cooling arrangement in their interior and destined to be immersed into hot liquid media, which is characterized in that the hollow body comprises an inner layer of unsintered refractory mass and a dense, sintered outer layer of the same material.
  • the dense outer layer of the hollow body according to the invention is resistant against chemical and mechanical corrosion by liquid slag and liquid steel up to temperatures of about 1,700" C. and even more.
  • the inner layer which is unsintered and carries the outer layer is deformable and therefore may follow heat tensions which occur as a result of temperature fluctuation stresses. Owing to this deformability the occurrence of cracks is avoided.
  • the life of the lance lasts for a plurality of refining heats, e.g. more than 10.
  • a certain ratio is to be maintained between the thickness of the sintered outer layer and the wall-thickness of the inner layer.
  • the inner layer at any rate has to be considerably thicker than the outer layer.
  • the thickness of the sintered outer layer amounts to one-fourth or less of the wall thickness of the entire hollow body, especially one-sixthonetenth of the wall thickness. ln this connection it is essential that the inner layer has a certain degree of porosity for only then it remains deformable and, so to speak, suitable as an elastic carrier for the dense outer layer. The best results are obtained when the total porosity of the hollow body amounts to -20 percent.
  • the invention further comprises a process for the production of the described hollow body, which process resides in that a hollow cylindrical moulded body is formed out of a granular, refractory material under addition of water and consolidation by shaking, which body is dried and its outer layer is burnt to become dense at a temperature higher than the sintering temperature while its inner layer is cooled by a coolant.
  • the body is dried in two steps, namely by air-drying at room temperature and subsequent drying at increased temperature in the range of 200 to 650 C, preferably 400-450 C.
  • Reinforcement rods, wires or nets may be incorporated into the body in the mould.
  • the refractory mass should contain 25-35 percent of fine particles having a grain size of up to 0.10 mm. and 30-40 percent of coarser particles having a grain size of 2.5-5 mm.
  • FIG. 1 is a vertical longitudinal section through the refractory hollow body according to the invention receiving the sensing portion of a temperature measuring lance.
  • FIG. 2 a device for producing a hollow body is shown.
  • the hollow body 1 is provided with a central bore which is enlarged approximately in the upper third, i.e. it has a greater diameter there, to receive the probe head 11.
  • the probe comprises three concentrical tubes 7, 8 and 9; the compensating line, namely two conductors encased in a sleeve 10, being arranged in the inner tube 7, said conductors serving for the connection to the outside of the thermocouple limbs situated in the sensing portion of the apparatus.
  • the tube 8 ends short of the probe head. It represents a guide tube for the formation of a coolant circulation.
  • the sensing portion which is connectable with the probe head is generally denoted by numeral 12 in FIG. 1.
  • thermocouple 14 with its hot juncture 15 is encased, and the hollow body 1 according to the invention which surrounds the sheath tube and, when the measuring lance is inserted into the bath, comes to lie in the area of the slag layer 3 floating on the bath 2. In this region of the slag layer the greatest stresses occur, as is well known.
  • the tip 4 of the sensing portion in which the hot juncture is situated projects from the hollow body 1 in downward direction.
  • the hollow body 1 comprises an inner layer 5 consisting of unsintered, refractory granulated mass, and a dense, sintered outer layer 6 consisting of the same material.
  • a basic ramming mass of preferably the following composition is suitable as refractory mass:
  • the hollow body is produced in that after the addition of 5-7 percent by weight of water the mass is filled into a mould under slight shaking where it is consolidated by further, stronger shaking. In the mould a reinforcement body made of steel wire may be inserted.
  • the hollow body is then predried at room temperature for 24 hours in the mould and for 48 hours outside the mould. At temperatures of about 450 C. it is further dried for about 48 hours during which the hollow body is suspended in the kiln. After these two drying steps the hollow body shows the following characteristics:
  • the dense sintered outer layer is produced by burning the hollow body at a temperature of about l,600 C. for about 2 hours.
  • the device according to FIG. 2 may be used.
  • the predried hollow body 1 is suspended on a watercooled carrier 16, whose shape corresponds to the inner contour of the hollow body, and is inserted into the burning chamber 17 ofa kiln 18.
  • the burning chamber is covered by a lid 19.
  • Arrows indicate the supply and draining of water.
  • the outer layer is sintered, the inner part of the hollow body is continuously cooled. Instead of water also air may be used as coolant.
  • the total wall thickness of a hollow body produced according to the invention may amount to e.g. 60 mm., the thickness of the sintered outer layer amounting to about mm.
  • Hollow bodies according to the invention have proved highly satisfactory in practice. When used in top blowing oxygen converters service periods lasting for more than ten charges have been achieved without difficulties, the measuring lance having been in use for the overall blowing period and exposed to cooling off by air in the intervals between blowing, which meets the severest conditions that may occur in a steelmaking plant. If, instead of exposing it to cooling off by air in the intervals between blowing, the measuring lance is brought into a warming chamber kept at a temperature of about l,00O C., the life of the hollow body according to the invention will be considerably increased, so that it will last e.g. for more than 20 charges.
  • a refractory hollow body for the protection of heat-sensitive instruments against severe thermal stresses comprising an inner layer of unsintered refractory mass and a dense, sintered outer layer of the same material, said body being composed throughout said inner and outer layers of a packed mass of granular refractory material all of which is capable of being sintered but which has only said outer layer thereof sintered with said outer layer merging into and carried by said inner layer, the latter being substantially thicker than said outer layer and having a degree of porosity greater than said outer layer.
  • hollow body set forth in claim 1, wherein said hollow body has an exposed outer surface formed in its entirety by said outer layer and said body being formed with a bore which defines the hollow interior of said body, said bore having a pair of opposed end regions where said outer layer is located and being defined between said end regions by a surface of said inner layer.
  • the hollow body set forth in claim 1 which is adapted for protectively encasing an internally cooled, thermocouple-type temperature measuring lance destined to be immersed into hot liquid media.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Measuring Temperature Or Quantity Of Heat (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)
  • Compositions Of Oxide Ceramics (AREA)
  • Investigating And Analyzing Materials By Characteristic Methods (AREA)
US874258A 1968-11-18 1969-11-05 Refractory hollow body Expired - Lifetime US3652068A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AT1117968A AT303782B (de) 1968-11-18 1968-11-18 Feuerfester Hohlkörper sowie Verfahren und Vorrichtung zur Herstellung desselben

Publications (1)

Publication Number Publication Date
US3652068A true US3652068A (en) 1972-03-28

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ID=3627254

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Application Number Title Priority Date Filing Date
US874258A Expired - Lifetime US3652068A (en) 1968-11-18 1969-11-05 Refractory hollow body

Country Status (12)

Country Link
US (1) US3652068A (fr)
AT (1) AT303782B (fr)
BE (1) BE741771A (fr)
CS (1) CS152466B2 (fr)
DE (1) DE1956012A1 (fr)
ES (2) ES372713A1 (fr)
FR (1) FR2023564A1 (fr)
GB (1) GB1283233A (fr)
LU (1) LU59822A1 (fr)
NL (1) NL6916897A (fr)
PL (1) PL80535B1 (fr)
SE (1) SE347816B (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4352486A (en) * 1981-04-02 1982-10-05 Pennsylvania Engineering Corp. Pressure probe for metallurgical vessels
US4676107A (en) * 1986-04-23 1987-06-30 Baumco, Inc. Pressure sensing probe
US4721534A (en) * 1985-09-12 1988-01-26 System Planning Corporation Immersion pyrometer
US4746534A (en) * 1985-09-12 1988-05-24 System Planning Corporation Method of making a thermocouple
US5147137A (en) * 1991-01-22 1992-09-15 The United States Of America As Represented By The United States Department Of Energy Refractory thermowell for continuous high temperature measurement of molten metal
US6071466A (en) * 1996-10-17 2000-06-06 Voest Alpine Industries, Inc. Submergible probe for viewing and analyzing properties of a molten metal bath
CN104515407A (zh) * 2014-12-09 2015-04-15 济源赛孚工业陶瓷有限公司 烧结窑测温热电偶保护装置
US20230313340A1 (en) * 2022-04-05 2023-10-05 Doggone Investment Co. LLC Apparatus and method for production of high purity copper-based alloys

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8313343D0 (en) * 1983-05-14 1983-06-22 Hamblin M J Heat resistant means
US4659679A (en) * 1985-01-25 1987-04-21 Falk Richard A Insulative composition and method of making articles therefrom

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3468780A (en) * 1965-04-08 1969-09-23 Forderung Der Eisenhuttentechn Apparatus for determining the oxygen content of molten metal

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3468780A (en) * 1965-04-08 1969-09-23 Forderung Der Eisenhuttentechn Apparatus for determining the oxygen content of molten metal

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4352486A (en) * 1981-04-02 1982-10-05 Pennsylvania Engineering Corp. Pressure probe for metallurgical vessels
US4721534A (en) * 1985-09-12 1988-01-26 System Planning Corporation Immersion pyrometer
US4746534A (en) * 1985-09-12 1988-05-24 System Planning Corporation Method of making a thermocouple
US4676107A (en) * 1986-04-23 1987-06-30 Baumco, Inc. Pressure sensing probe
US5147137A (en) * 1991-01-22 1992-09-15 The United States Of America As Represented By The United States Department Of Energy Refractory thermowell for continuous high temperature measurement of molten metal
US6071466A (en) * 1996-10-17 2000-06-06 Voest Alpine Industries, Inc. Submergible probe for viewing and analyzing properties of a molten metal bath
CN104515407A (zh) * 2014-12-09 2015-04-15 济源赛孚工业陶瓷有限公司 烧结窑测温热电偶保护装置
US20230313340A1 (en) * 2022-04-05 2023-10-05 Doggone Investment Co. LLC Apparatus and method for production of high purity copper-based alloys
US11851730B2 (en) 2022-04-05 2023-12-26 Doggone Investment Co. LLC Apparatus and method for production of high purify copper-based alloys
US11993828B2 (en) 2022-04-05 2024-05-28 Doggone Investment Co. LLC Apparatus and method for production of high purity copper-based alloys

Also Published As

Publication number Publication date
ES372713A1 (es) 1972-03-16
CS152466B2 (fr) 1973-12-19
SE347816B (fr) 1972-08-14
DE1956012A1 (de) 1970-06-04
GB1283233A (en) 1972-07-26
ES173183Y (es) 1972-10-16
LU59822A1 (fr) 1970-01-14
AT303782B (de) 1972-12-11
PL80535B1 (fr) 1975-08-30
NL6916897A (fr) 1970-05-20
ES173183U (es) 1972-03-01
BE741771A (fr) 1970-05-04
FR2023564A1 (fr) 1970-08-21

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