EP0130960A2 - Verfahren zum Überwachen des Schäumens von Schlacke - Google Patents

Verfahren zum Überwachen des Schäumens von Schlacke Download PDF

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Publication number
EP0130960A2
EP0130960A2 EP84870068A EP84870068A EP0130960A2 EP 0130960 A2 EP0130960 A2 EP 0130960A2 EP 84870068 A EP84870068 A EP 84870068A EP 84870068 A EP84870068 A EP 84870068A EP 0130960 A2 EP0130960 A2 EP 0130960A2
Authority
EP
European Patent Office
Prior art keywords
intensity
foam
sound
frequency band
difference
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.)
Withdrawn
Application number
EP84870068A
Other languages
English (en)
French (fr)
Other versions
EP0130960A3 (de
Inventor
Daniel Léon Ramelot
Jean-Paul François Fischbach
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.)
Centre de Recherches Metallurgiques CRM ASBL
Original Assignee
Centre de Recherches Metallurgiques CRM ASBL
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 BE6/47835A external-priority patent/BE896980A/fr
Application filed by Centre de Recherches Metallurgiques CRM ASBL filed Critical Centre de Recherches Metallurgiques CRM ASBL
Publication of EP0130960A2 publication Critical patent/EP0130960A2/de
Publication of EP0130960A3 publication Critical patent/EP0130960A3/de
Withdrawn legal-status Critical Current

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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
    • 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
    • C21C5/30—Regulating or controlling the blowing
    • 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
    • C21C5/36—Processes yielding slags of special composition
    • C21C2005/366—Foam slags

Definitions

  • the present invention relates to a process for monitoring the foaming of slag in pig iron refining converters with the blowing of an oxidizing gas such as, for example, enriched air or industrially pure oxygen.
  • an oxidizing gas such as, for example, enriched air or industrially pure oxygen.
  • a method for determining the foaming of the slag in which, on the one hand, the intensity of the sound coming from the converter is continuously measured in a determined frequency band, and on the other hand, the gases contained in the converter and the flow of C0 2 leaving the converter is determined.
  • a law of variation of the height of the foam above the metal bath is established for the duration of the blowing.
  • This method has provided interesting results, but it nevertheless has the disadvantage of requiring the simultaneous measurement of several quantities; namely the intensity of the sound, the com position of the gases and the flow of C0 2 . It imposes a large volume of calculations which indirectly provide the value of the height of foam.
  • the subject of the present invention is a method making it possible to remedy this drawback.
  • the first frequency band is advantageously between 150 Hz and 1000 Hz, preferably between 300 Hz and 500 Hz
  • the second frequency band is advantageously between 5 Hz and 40 Hz, preferably between 15 Hz and 30 Hz.
  • the Applicant has found that the intensity SI of sound measured in the first frequency band increases rapidly, then undergoes a rapid decrease, until it is covered by the background noise from the steelworks. According to the Applicant's observations, the rapid attenuation of this intensity corresponds to the moment when the foam reaches the nose of the blowing lance.
  • the signal corresponding to the intensity S 2 measured in the second frequency band is very sensitive to the variation in the level of the foam. It therefore makes it possible to precisely determine the level of the foam in the converter at any time, provided that the installation has been previously calibrated.
  • a limit value corresponding to a level that the foam cannot exceed is fixed at the intensity of the sound measured in said second frequency band, and the conditions of souf setting so that said measured sound intensity does not exceed this limit value.
  • this limit value is fixed between 80% and 90% of the value of the intensity of the sound measured when the foam reaches the level of the nozzle of the converter.
  • This signal S 2 is also influenced by other parameters, in particular the height of the blowing lance, the flow of oxygen blown and the configuration of the installation.
  • the configuration of the installation includes, without limitation, the possible presence of a movable skirt at the mouth of the converter, the position and orientation of the microphone and the geometry of the converter.
  • a correction coefficient taking account of the influence of the various disturbing factors is applied to the signal representative of the measured intensity S 2 .
  • this coefficient can be written: in which a, b, c and d are coefficients specific to each installation.
  • the signal S 2 is not clearly distinguished from the background noise. We then say that the signal / noise ratio is low. The Applicant has found that the detection of the rise of the foam was particularly difficult when this signal / noise ratio was less than 4.
  • This limit value is advantageously fixed between 80% and 90% of the value reached by this difference (S 2 - SI) when the foam reaches the level of the converter nozzle.
  • the limit value is advantageously fixed between 80% and 90% of the value reached by the difference ( S 2 corr. S 1 ) when the foam reaches the level of the nozzle of the converter.
  • FIG. 1 represents the evolution of the sound intensities S 1 and S 2 as a function of time, in the case of a refining operation with foam formation (fig. La) and without foam formation (fig. Lb).
  • FIG. 2 illustrates the effect of the correction applied to the signal S 2 , also during refining with foaming (fig. 2.a) and without foaming of the slag (fig. 2.b).
  • a microphone In a top-blown oxygen converter, a microphone has been installed which picks up a wide spectrum of frequencies, for example up to 1000 Hz. After amplification, the raw signal is subdivided by appropriate filters into two signals SI and S 2 corresponding respectively to the frequency bands chosen, ie from 300 Hz to 500 Hz for S 1 and from 15 Hz and 30 Hz for S 2 .
  • Figure 1 shows records obtained under good conditions.
  • the signal S 1 increases very quickly to a high maximum, then decreases almost as quickly to a point where it remains substantially constant. This point is reached after about 4 minutes; it reflects the moment when the foam reaches the nose of the blowing lance and acts as an absorbent screen with regard to the high frequency sound waves emitted by the lance.
  • the signal S 2 evolves very differently.
  • the signal S 2 increases rapidly when the foam reaches the nose of the lance, and it retains a high value during most of the ripening.
  • FIG. 1 clearly illustrates the representative character of the signal S 2 with regard to the foaming of the slag and the value of the measurement of this signal for monitoring this phenomenon.
  • FIG. 2 represents recordings of the same nature, but obtained under unfavorable conditions. It reflects the effect of the correction applied to the signal S 2 , in accordance with one of the variants of the present invention.
  • the signal S 2 corr. is dissociated from the signal S 2 , but it remains nested in the signal SI and therefore does not allow any significant measurement with regard to the foam (fig. 2.b).
  • FIG. 2 confirms the advantage of the signal S 2 for monitoring the level of the foam. It also reflects the beneficial effect of the correction of the signal S 2 .
  • monitoring of the signal S 2 makes it possible to determine at any time the level of foam in the converter, to assess the risks of overflow and to modify the conditions blowing properly.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)
EP84870068A 1983-06-06 1984-05-30 Verfahren zum Überwachen des Schäumens von Schlacke Withdrawn EP0130960A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
BE6047835 1983-06-06
BE6/47835A BE896980A (fr) 1983-06-06 1983-06-06 Procede pour surveiller le moussage de la scorie

Publications (2)

Publication Number Publication Date
EP0130960A2 true EP0130960A2 (de) 1985-01-09
EP0130960A3 EP0130960A3 (de) 1986-04-02

Family

ID=3874927

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84870068A Withdrawn EP0130960A3 (de) 1983-06-06 1984-05-30 Verfahren zum Überwachen des Schäumens von Schlacke

Country Status (1)

Country Link
EP (1) EP0130960A3 (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0402344A1 (de) * 1989-06-05 1990-12-12 VOEST-ALPINE Industrieanlagenbau GmbH Verfahren zur Schlackenführung in einem Blasstahlkonverter
EP0692544A1 (de) * 1994-07-15 1996-01-17 ISPAT, Hamburger Stahlwerke GmbH Verfahren zur Steuerung der Schaumschlackebildung im Drehstromlichtbogenofen
EP0735147A1 (de) * 1995-03-30 1996-10-02 VOEST-ALPINE STAHL Donawitz GmbH (HRB Nr. 502) Verfahren und Vorrichtung zur Begrenzung des Schaumschlackenvolumens in einem metallurgischen Gefäss
EP1306451A2 (de) 2001-10-24 2003-05-02 SMS Demag AG Verfahren und Vorrichtung zur Bestimmung der Schaumschlackenhöhen beim Frischvorgang in einem Blasstahlkonverter
DE10111394B4 (de) * 2001-03-09 2008-12-18 Sms Demag Ag Verfahren und Einrichtung zur Steuerung eines metallurgischen Prozesses mit Bildung von Schlacke auf einer Schmelzbadoberfläche
CN113061684A (zh) * 2021-03-11 2021-07-02 莱芜钢铁集团银山型钢有限公司 一种基于音频化渣的转炉动态底吹方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB976158A (en) * 1961-09-13 1964-11-25 Centre Nat Rech Metall The control of steel manufacturing processes
FR1430843A (fr) * 1965-04-29 1966-03-04 Centre Nat Rech Metall Installation pour le contrôle de l'opération d'affinage de la fonte
IT1055688B (it) * 1974-11-28 1982-01-11 Rech Metallurg Ct Voor Res Ass Procedimento per controllare l affinazione della ghisa
LU81740A1 (fr) * 1979-09-28 1981-04-17 Arbed Systeme de mesure de l'epaisseur de la couche de scorie dans un recipient metallurgique et pour l'appreciation de son etat physique

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0402344A1 (de) * 1989-06-05 1990-12-12 VOEST-ALPINE Industrieanlagenbau GmbH Verfahren zur Schlackenführung in einem Blasstahlkonverter
EP0692544A1 (de) * 1994-07-15 1996-01-17 ISPAT, Hamburger Stahlwerke GmbH Verfahren zur Steuerung der Schaumschlackebildung im Drehstromlichtbogenofen
EP0735147A1 (de) * 1995-03-30 1996-10-02 VOEST-ALPINE STAHL Donawitz GmbH (HRB Nr. 502) Verfahren und Vorrichtung zur Begrenzung des Schaumschlackenvolumens in einem metallurgischen Gefäss
DE10111394B4 (de) * 2001-03-09 2008-12-18 Sms Demag Ag Verfahren und Einrichtung zur Steuerung eines metallurgischen Prozesses mit Bildung von Schlacke auf einer Schmelzbadoberfläche
EP1306451A2 (de) 2001-10-24 2003-05-02 SMS Demag AG Verfahren und Vorrichtung zur Bestimmung der Schaumschlackenhöhen beim Frischvorgang in einem Blasstahlkonverter
DE10152371A1 (de) * 2001-10-24 2003-05-15 Sms Demag Ag Verfahren und Vorrichtung zur Bestimmung der Schaumschlackenhöhen beim Frischvorgang in einem Blasstahlkonverter
DE10152371B4 (de) * 2001-10-24 2004-04-15 Sms Demag Ag Verfahren und Vorrichtung zur Bestimmung der Schaumschlackenhöhen beim Frischvorgang in einem Blasstahlkonverter
EP1306451A3 (de) * 2001-10-24 2007-09-05 SMS Demag AG Verfahren und Vorrichtung zur Bestimmung der Schaumschlackenhöhen beim Frischvorgang in einem Blasstahlkonverter
CN113061684A (zh) * 2021-03-11 2021-07-02 莱芜钢铁集团银山型钢有限公司 一种基于音频化渣的转炉动态底吹方法
CN113061684B (zh) * 2021-03-11 2022-04-22 莱芜钢铁集团银山型钢有限公司 一种基于音频化渣的转炉动态底吹方法

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Publication number Publication date
EP0130960A3 (de) 1986-04-02

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Inventor name: RAMELOT, DANIEL LEON

Inventor name: FISCHBACH, JEAN-PAUL FRANCOIS