US3786856A - Method for controlling a continuous casting installation in the event of molten metal breakout - Google Patents

Method for controlling a continuous casting installation in the event of molten metal breakout Download PDF

Info

Publication number
US3786856A
US3786856A US00223674A US3786856DA US3786856A US 3786856 A US3786856 A US 3786856A US 00223674 A US00223674 A US 00223674A US 3786856D A US3786856D A US 3786856DA US 3786856 A US3786856 A US 3786856A
Authority
US
United States
Prior art keywords
breakout
light intensity
continuous casting
metal
threshold value
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
US00223674A
Other languages
English (en)
Inventor
T Nishikawa
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.)
SMS Concast AG
Original Assignee
Concast 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
Application filed by Concast AG filed Critical Concast AG
Application granted granted Critical
Publication of US3786856A publication Critical patent/US3786856A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/16—Controlling or regulating processes or operations
    • B22D11/20—Controlling or regulating processes or operations for removing cast stock
    • B22D11/207—Controlling or regulating processes or operations for removing cast stock responsive to thickness of solidified shell
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/14—Plants for continuous casting
    • B22D11/148—Safety arrangements

Definitions

  • the present invention relates to a new and improved method of controlling a continuous casting installation in the event ofmolten metal breakout, wherein the metal flowing out of the partially solidified strand produces a breakout signal by means of which the continuous casting installation can be controlled in accordance with requirements.
  • Breakout of molten metal can arise during continuous casting with the liquid core or crater protruding past the end of the mold, especially during the continuous casting of steel.
  • liquid metal flows out of the partially solidified strand through an opening in the thin peripheral skin or wall of the strand.
  • causes leading to breakout such as slag inclusions embedded in the peripheral wall of the strand, fissures, improper strand cooling, defects in the mold and so forth.
  • This stage of breakout is referred to in the art as a starting or incipient breakout.
  • Breakouts not only'cause longer standstill or downtime of the continuous casting installation or plant but they also impose expensive repair and replacement work and costs.
  • An operator at the mold can only first ascertain a breakout when the level of the molten metal in the mold quickly sinks, so that the above-mentioned starting or incipient breakouts are not readily discernible by the operator because the level of the molten metal bath does not visibly change.
  • a considerable quantity of metal has alreadly flowed into the secondary cooling zone, resulting in interruption in the casting operation and expensive repair and replacement work. It has been found that such interruptions and repairs can be prevented if incipient breakouts can be ascertained and suitable measures initiated to cure same by freezing or solidifying the breakout opening.
  • the prior art has already proposed a method for controlling a continuous casting installation upon the occurrence of disturbances of the type which cause lowering of the metal bath level within the mold.
  • components such as thermal indicators or fusible elements, arranged at the secondary cooling zone, generate signals for controlling the continuous casting installation upon the occurrence of a breakout.
  • a primary objective of the present invention is to provide a new and improved method of controlling a continuous casting installation in the event of molten metal breakout which effectively and reliably fulfills the existing need in the art and is not associated with the aforementioned drawbacks and limitations of the heretofore advanced proposals.
  • Still a further significant object of the present invention relates to a new and improved method for controlling a continuous casting installation in the event of a breakout and which overcomes the previously discussed drawbacks of the state-of-the-art techniques and importantly is capable of determining a breakout at the moment such arises and then in accordance with its order of magnitude and to practically eliminate or reduce the damaging effects thereof.
  • the method aspects of this development propose measuring the light intensity in the secondary cooling zone during the casting operation by means of at least one photoelectric transmitter, comparing changes in such light intensity with predetermined threshold values thereof, and obtaining signals by the comparison step which are then used for control purposes.
  • the light intensity of the metal flowing out of the continuously cast strand during breakout is approximately proportional to the size or magnitude of the breakout opening at the strand skin or wall.
  • the cooling chamber is only illuminated in a spark-like fashion by a number of metal or steel sprays.
  • the third threshold value is exceeded owing to the light emission of the outflowing metal jet as well as the glowing metal in the cooling compartment or chamber.
  • the measures which are then undertaken are directed towards protecting the equipment from damage as well as those concerning safety.
  • the withdrawal of the strand is interrupted, an alarm signal produced for informing an operator about the condition of the breakout and simultaneously the continuous casting installa' tion is switched over to manual control.
  • the metal infeed into the mold is interrupted upon the occurrence of the first light beam produced by the starting or incipient breakout, so that even if there is present a breakout which cannot be repaired only the smallest quantity of metal can flow-out.
  • the installation is switched back in stages, that is stepwise, to the casting parameters which were present prior to breakout.
  • FIG. 1 is a vertical sectional view through a schematically illustrated continuous casting installation, depicting enough of the hardware thereof necessary for understanding the inventive method;
  • FIG. 2 is a block circuit diagram of equipment employed in the continuous casting installation depicted in FIG. 1;
  • FIG. 3 is a graph showing the course of the light intensity curves for three different types of molten metal breakouts.
  • FIG. 1 more specifically 4 it is to be understood that an intermediate vessel or container 4 is equipped with a stopper 5 which controls its outflow or discharge opening 5a.
  • a partially solidifled continuous cast strand 7 is formed at the openended casting mold 6, this strand 7 being supported at the secondary cooling zone 8 by rollers or rolls 9 and cooled by spray water emanating from nozzles 10.
  • Photoelectric transmitter means such as for instance conventional photoelectric cells 14 are arranged at the secondary cooling zone 8 in such a manner that it is possible to measure a small increase in the light intensity caused by a starting or incipient breakout.
  • the photoelectric cells 14 could be arranged internally or externally of such spray compartment 15.
  • FIG. 2 there will be once again recognized the photoelectric cells 14. Depending upon the prevailing light intensity these photoelectric cells will deliver a corresponding signal or voltage to a conventional amplifier 40 which is provided at its input with a standard gain control or maximum value selector.
  • the amplified signal or voltage is delivered to any suitable threshold value indicators 41 to 44, wherein the threshold value indicator 41 can be adjusted to a first threshold value, the threshold value indicator 42 to a second threshold value, the threshold value indicator 43 to a third threshold value and the threshold value indicator 44 to normal light intensity 22 (FIG. 3).
  • the respective threshold values for the threshold value indicators 41, 42 and 43 have been graphically depicted by reference characters 1, 2 and 3 in FIG. 3.
  • Any suitable control 49 may be provided for controlling the process steps associated with the individual threshold values 1 to 3 and the normal light intensity 22 with regard to the regulation mechanism 51 for controlling the intermediate container stopper 5, the roll withdrawal unit 12, the secondary cooling zone water control 53 and the alarm mechanism 54 which may be acoustical or visual. Sincev the hardware for regulating the various components of the continuous casting installation just discussed are conventional and appear at standardcontinuous casting plants it is unnecessary to discuss same further, particularly since the invention is not concerned with any improvements in such structure or the details thereof.
  • FIG. 3 a graph, along the ordinate of which there is plotted the light intensity and along the abscissa 21 of which there is plotted time.
  • the first, second and third threshold values have been plotted on this graph, 'and specifically the predetermined light intensity of the first, second and third threshold values have been respectively indicated by the horizontally extending lines 1, 2 and 3.
  • the first threshold value 1 which, on the one hand, appears during a starting or incipient breakout, and on the other hand, to be able to distinguish such from a small breakout which is already flowing
  • a few drops of liquid steel are poured into the cooling compartment 15 during casting and thus the light intensity is measured.
  • the third threshold value 3 can be easily determined outside of the cooling zone in that there is measured the light intensity of a quantity of metal which has flowed-out and which approximately corresponds to one-third to one-half of the mold content.
  • the curve 23 illustrates the course of the light intensity of a starting breakout which has frozen or resolidified.
  • the light intensity fluctuates in the cooling compartment 15 about a low value which can be designated as the normal light intensity 22.
  • the first threshold value 1 At the point in 25 there begins a small breakout which at time point 26 reaches the first threshold value 1.
  • the delivery or feed of metal into the mold 6 is blocked by the control 51 and the withdrawal of the strand is briefly interrupted, that is to say for about up to approximately twenty seconds, by shutting-down the withdrawal unit 12.
  • reference character 30 represents a curve of the light intensity for a small breakout which can be cured or repaired.
  • the already described measures are initiated.
  • the light intensity attains the value of the second threshold value 2. Consequently, the already reduced withdrawal speed is still further reduced by about 50 percent.
  • the strand is therefore now moved only with about 25 percent of the normal withdrawal speed.
  • the quantity of cooling water is increased to about 1.5 fold.
  • the light intensity curve 33 represents a breakout which cannot be repaired or cured.
  • the corresponding light intensity curve 33 of such breakout exceeds the third threshold value 3.
  • the already abovediscussed measures have been initiated, without however bringing about a freezing together or resolidification of the breakout.
  • an alarm signal is triggered and the continuous casting installation is switched-over to manual operation.
  • a method of controlling a continuous casting installation in the event of metal breakout comprising the steps of continuously casting a strand, determining incipient metal breakout by monitoring during the casting operation the light intensity at the secondary cooling zone for the continuously cast strand at the location of such secondary cooling zone where cooling of the strand with water spray occurs, comparing changes in the light intensity with predetermined threshold values, obtaining electrical signals in response to the light intensity exceeding a threshold value owing to incipient metal breakout, and controlling the continuous casting operation to counteract against metal breakout in response to the electrical signals, said step of controlling the continuous casting operation including:
  • a method of controlling a continuous casting installation in the event of metal breakout comprising the steps of continuously casting a strand, monitoring during the casting operation the light intensity at the secondary cooling zone for the continuously cast strand, comparing changes in the light intensity with predetermined threshold values, upon exceeding a threshold value obtaining electrical signals by means of which it is possible to control the continuous casting operation and to counteract against metal breakout, wherein said predetermined threshold values comprise a first threshold value and wherein upon exceeding said first threshold value interrupting the feed of metal to the casting mold, briefly interrupting the withdrawal of the continuously cast strand, thereafter further moving the strand at a reduced withdrawal speed, and when the light intensity falls below said first threshold value continuing the casting operation with throttled feed of metal to the mold.
  • said predetermined threshold values include a second threshold value, and upon exceeding said second threshold value further reducing the smaller withdrawal speed and increasing the supply of water into the secondary cooling zone.
  • said predetermined threshold values include a third threshold value, and upon exceeding said third threshold value completely interrupting the withdrawal of the continuously cast strand, triggering an alarm signal and switching-over the continuous casting installation to manual operation.
  • a method of monitoring a continuous casting installation for the presence of breakout of molten metal from the continuously cast strand comprising the steps of determining the light intensity prevailing at a predetermined zone of the continuous casting installation where cooling of the strand with water spray occurs, comparing the momentarily prevailing light intensity with at least one predetermined threshold value, producing an electrical control signal in response to the light intensity exceeding a threshold value owing to incipient metal breakout, and controlling further operation of the continuous casting installation to act against metal breakout in response to said control signal, said step of controlling the continuous casting operation including:

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
US00223674A 1971-02-22 1972-02-04 Method for controlling a continuous casting installation in the event of molten metal breakout Expired - Lifetime US3786856A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP884371 1971-02-22

Publications (1)

Publication Number Publication Date
US3786856A true US3786856A (en) 1974-01-22

Family

ID=11704033

Family Applications (1)

Application Number Title Priority Date Filing Date
US00223674A Expired - Lifetime US3786856A (en) 1971-02-22 1972-02-04 Method for controlling a continuous casting installation in the event of molten metal breakout

Country Status (6)

Country Link
US (1) US3786856A (de)
BE (1) BE779677A (de)
BR (1) BR7200953D0 (de)
DE (1) DE2208205C3 (de)
FR (1) FR2126310B2 (de)
ZA (1) ZA721074B (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3886991A (en) * 1972-04-18 1975-06-03 Concast Ag Method and apparatus for controlling the withdrawal of heat in molds of continuous casting installations
US4311186A (en) * 1980-09-18 1982-01-19 Antonio Spaccarotella Method for quickly repairing break-outs in continuous casting plants
US4542781A (en) * 1983-01-07 1985-09-24 Klockner-Werke Aktiengesellschaft Breakout warning method, utilizing acoustics, in a continuous casting installation and apparatus for its implementation
US4556099A (en) * 1981-01-08 1985-12-03 Nippon Steel Corporation Abnormality detection and type discrimination in continuous casting operations
EP0209059A2 (de) * 1985-07-16 1987-01-21 Concast Service Union Ag Verfahren und Vorrichtung zum Antreiben eines gegossenen Stranges in einer Stranggiessanlage

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2923900C2 (de) * 1979-06-13 1984-09-13 Hoesch Werke Ag, 4600 Dortmund Verfahren zum Verhindern von Durchbrüchen des Strangs in Stranggießanlagen

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2206930A (en) * 1938-07-29 1940-07-09 William R Webster Continuous molding machine
US2825104A (en) * 1954-03-16 1958-03-04 Askania Regulator Co Method and apparatus for controlling gravity liquid flow, and for continuous metal billet casting
US3478808A (en) * 1964-10-08 1969-11-18 Bunker Ramo Method of continuously casting steel
US3510057A (en) * 1967-05-19 1970-05-05 Bailey Meter Co Signal scanning discriminator

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2206930A (en) * 1938-07-29 1940-07-09 William R Webster Continuous molding machine
US2825104A (en) * 1954-03-16 1958-03-04 Askania Regulator Co Method and apparatus for controlling gravity liquid flow, and for continuous metal billet casting
US3478808A (en) * 1964-10-08 1969-11-18 Bunker Ramo Method of continuously casting steel
US3510057A (en) * 1967-05-19 1970-05-05 Bailey Meter Co Signal scanning discriminator

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Mark s Mechanical Engineers Handbook, 6th Edition, McGraw Hill, N.Y., 1958, TJ151M37 1958 C.9. Pages 16 17. *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3886991A (en) * 1972-04-18 1975-06-03 Concast Ag Method and apparatus for controlling the withdrawal of heat in molds of continuous casting installations
US4311186A (en) * 1980-09-18 1982-01-19 Antonio Spaccarotella Method for quickly repairing break-outs in continuous casting plants
US4556099A (en) * 1981-01-08 1985-12-03 Nippon Steel Corporation Abnormality detection and type discrimination in continuous casting operations
US4542781A (en) * 1983-01-07 1985-09-24 Klockner-Werke Aktiengesellschaft Breakout warning method, utilizing acoustics, in a continuous casting installation and apparatus for its implementation
EP0209059A2 (de) * 1985-07-16 1987-01-21 Concast Service Union Ag Verfahren und Vorrichtung zum Antreiben eines gegossenen Stranges in einer Stranggiessanlage
US4735253A (en) * 1985-07-16 1988-04-05 Concast Service Union Ag Method of and apparatus for conveying a continuously cast strand
EP0209059A3 (de) * 1985-07-16 1989-01-25 Concast Service Union Ag Verfahren und Vorrichtung zum Antreiben eines gegossenen Stranges in einer Stranggiessanlage

Also Published As

Publication number Publication date
FR2126310B2 (de) 1979-08-03
BR7200953D0 (pt) 1973-05-03
BE779677A (fr) 1972-08-22
DE2208205A1 (de) 1973-03-22
ZA721074B (en) 1972-10-25
DE2208205C3 (de) 1975-08-28
DE2208205B2 (de) 1974-05-09
FR2126310A2 (de) 1972-10-06

Similar Documents

Publication Publication Date Title
HU180686B (en) Method and apparatus for direct die casting non-ferrous metals
KR870002051B1 (ko) 로울사이에서 스트립의 연속주조를 위한 장치의 작동매개변수의 감시 및 제어방법
KR101421841B1 (ko) 하이브리드 냉각노즐장치 및 이를 이용한 연속주조설비의 냉각노즐 제어방법
US3786856A (en) Method for controlling a continuous casting installation in the event of molten metal breakout
CN109420747B (zh) 一种高收得率的板坯连铸机自动封顶工艺
EP2386366B1 (de) Verfahren und Vorrichtung zur kontinuierlichen Erfassung des Schlackenniveaus in Elektroschlacke-Umschmelzanlagen mit kurzen Gleitkokillen
CN105251978A (zh) 一种用于圆坯连铸机中包水口的事故切断装置及其维护方法
KR19990036021A (ko) 연속주조설비를 작동시키기 위한 방법 및 장치
US3502133A (en) Continuous casting method and apparatus for controlling freeze line location
US4306610A (en) Method of controlling continuous casting rate
US4501315A (en) Method of controlling and regulating operational parameters of a machine for continuously casting bands between cylinders, allowing adhesion to be avoided
US4317482A (en) Method for preventing damage to strand guide elements of a continuous casting installation for steel
US3931848A (en) Method and apparatus for cooling a strand cast in an oscillating mold during continuous casting of metals, especially steel
JPS5946705B2 (ja) 連鋳モ−ルド内の溶融金属レベル制御方法
US4300620A (en) Method of monitoring the mold geometry during the continuous casting of metals, especially steel
KR100843937B1 (ko) 턴디쉬 용강온도 연속 감시장치
KR101204943B1 (ko) 몰드 코팅층의 결함 진단장치 및 그 방법
JP2914817B2 (ja) 連続鋳造における欠落鋳造方法
US10758971B2 (en) System and method for controlling the casting of a product
JP6387914B2 (ja) 連続鋳造設備におけるブレークアウト拡大の防止方法
KR100530464B1 (ko) 돌발적인 탕면레벨변화에 대응하기 위한 탕면레벨제어방법
KR101927769B1 (ko) 주조방법
KR20010057450A (ko) 쌍롤식 박판주조기를 이용한 박판제조방법
US5482106A (en) Process for the casting of metals in a continuous casting installation with continuous strand withdrawal
KR20040059505A (ko) 몰드 진동 및 마찰력 측정을 통한 연주공정의 주편파단예측장치