Arbed S.a.

Arbed Acieries Reunies De Burbach-eich-dudelange S.a.

Jean Baumert

Romain Henrion

Francois Schleimer

Ferdinand Goedert

Lucien Lorang

A steel refining system has a crucible having an upwardly open mouth and containing a steel melt covered by slag, an oxygen lance directed downwardly into the mouth at the melt, a hood fitting downwardly over the mouth and having a hood wall formed by a multiplicity of coolant tubes, and an arrangement for circulating a coolant through these tubes. The tubes form a tubular hood-wall extension that has an outer end and is centered on an axis trained on the melt on the crucible. A holder is mounted on the outer end of this extension and contains a sound transducer carried by the holder and directed along the axis at the melt. A circuit is connected to this transducer for determining slag thickness by means of the sound detected by the transducer. The holder itself comprises a circularly annular hollow cell fixed by means of a collar to the extension and a transducer housing that is fixed to this cell and therethrough to the extension. The cell defines a passage aligned with the axis and is connected to a separate coolant circuit to prevent overheating of the transducer.

System for monitoring slag thickness and consistency in refining crucible

A method of and an apparatus for determining the level of slag above a metallurgical melt, especially a steel melt, and for determining a physical characteristic or property of the slag, such as its viscosity or consistency, utilizes a plurality of nozzles opening into the bath-containing vessel at different levels above the melt and supplied with inert gas. The difference in hydrostatic pressures at the nozzles can be ascertained by measurement of the pressures upstream thereof and the measured values are converted into indications of slag level and consistency.

Method of and apparatus for measuring level and characteristics of a

A ferrous melt, e.g. of steel, is refined beneath a slag layer by blowing from above with an oxygen-containing gas through a lance and by bubbling an inert gas through the melt from the bottom. According to the invention, the consistency of the slag layer and/or its level is continuously detected on the one hand and the rate of decarburation of the bath is detected on the other hand and in response to these measurements the volume rate of flow of the bubbling gas is controlled on the one hand to maintain a predetermined spacing of the slag layer from the head of the lance and, on the other hand, a fluid consistency of the slag.

Apparatus for refining ferrous melt with slag conditioning

Slag is conditioned during blowing from above with oxygen of an iron melt by bubbling an inert gas into the melt from the bottom of the crucible in response to measurements made of the flowability of the slag layer and the speed of decarburization.

Process for conditioning slag during the refining of a metal bath

An apparatus for controlling the level of liquid steel in a continuous-casting mold wherein the position of the molten steel level within the mold is detected by a coil juxtaposed therewith and forming part of a resonant circuit controlling an oscillator. The capacitor portion of this resonant circuit is formed at least in part by a coaxial cable connecting the coil to the balance of the oscillator circuit. The output frequency of the oscillator is combined with the signal of a reference oscillator in a modulator, the low-frequency passband of this signal is then transformed into an analog voltage proportional to frequency and is used to control a servomotor which regulates the feed of molten metal to the mold.

Apparatus for measuring and controlling the level of molten steel in a

An acoustic tube having several resonant frequencies is directed into the mouth of a rafining crucible and is heated to above 100.degree. C. A microphone at the remote end of this tube receives sound passing through the tube and generates an electrical output corresponding to the sound received. This electrical output is linearized over a band width including several of the resonant frequencies of the tube and the signal is then passed through a low pass filter to eliminate parasitic oscillations and through a mixer where it is combined with a signal from a local oscillator. The intermediate-frequency signal thus produced is passed through either of a pair of band-pass filters and is displayed. The signal strength at the output is inversely proportional to the depth of slag in the crucible, as the deeper the slag the more sound is absorbed in the crucible.

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Esch, Alzette, Luxembourg

Jean Baumert