GB2341668A

GB2341668A - Steelmaking sublance

Info

Publication number: GB2341668A
Application number: GB9820097A
Authority: GB
Inventors: Christopher Barnes; John Barnes
Original assignee: British Steel PLC
Current assignee: British Steel PLC
Priority date: 1998-09-15
Filing date: 1998-09-15
Publication date: 2000-03-22
Also published as: GB9820097D0

Abstract

A sublance for use in an oxygen blown steelmaking process, the sublance including a sublance tip 2', a probe holder 3', a disposable probe 4' and a flexible ring 5' for protecting the interface between the sublance tip and the probe, the arrangement being such that the flexible ring traverses and seals the interface 8 between the sublance tip and the probe.

Description

2341668 1 STEELMAKING SUBLANCE This invention relates to sublances for use

in steelmaking and especially to sublances for use in the Basic Oxygen Steelmaking process. More especially, but not exclusively, the invention relates to a method and apparatus for facilitating the repeatable and reliable replacement of a disposable probe on a sublance.

A sublance is a mechanical sampling device which dips into molten slag or steel in a basic oxygen steelmaking converter during oxygen blowing. For each sampling, a disposable probe is mounted on the lower end of the sublance. Electrical contacts connect the probe to the sublance; therefore, good contact is required between the sublance and the probe.

A conventional subiance 1 is illustrated in Figure 1. The arrangement includes a sublance tip 2, a probe holder 3, a disposable probe 4 and a protective resilient ring 5 of, for example, rubber which encircles the probe and the probe holder. The lowermost face 6 of the sublance tip 2 is of greater cross-sectional area than the probe 4 attached to the probe holder 3. Therefore, a protruding lip 7 creates an area between the sublance tip 2 and the probe 4 which is prone to filling with molten metal. The protective ring 5 is usually of elliptical cross-section and does not therefore fit intimately against the interface between the sublance tip 2 and the probe 4, thereby providing poor protection against intruding molten steel.

As a result of the nature of the steelmaking process, the sublance is, 2 in use, periodically splashed with molten metal. The conventional design of sublance described in Figure 1 suffers the disadvantage that notwithstanding the protective ring, a ring or "skull" of metal often builds up on the bottom surface of the sublance tip. This metal skull prevents the trouble-free connection of subsequent probes until the tip is manually de-skulled. Hence, there is a reduction in productivity and potentially an increase in quality defects.

An object of the present invention is to provide a sublance which substantially avoids, or at least alleviates, the problems discussed above.

Accordingly, in one aspect the invention provides a sublance for use in an oxygen blown steelmaking process, the sublance including a sublance tip, a probe holder, a disposable probe and a radial flexible ring for protecting the interface between the sublance tip and the probe, the arrangement being such that the flexible ring traverses and seals the interface between the sublance tip and the probe.

Preferably, the flexible ring lies flush to the external radial surface of the probe.

Typically, the radial surface of the sublance tip meets the radial surfaceof the probe atthe interface betweenthe sublancetip and the probe. Thus, the sublance tip does not overhang the probe at their interface.

In another aspect, the invention provides a sublance for use in a basic oxygen steelmaking process, the sublance including a tip, a probe holder, a disposable probe and a radial flexible ring, wherein:- (a) the radial surface of the sublance tip meets the radial surface of the probe at the interface between the sublance tip and the probe; and, (b) the flexible ring traverses and seals the interface between the sublance tip and the probe.

3 in one example, the flexible ring lies flush to the external radial surface of the probe.

It is preferred that the radial flexible ring is made of rubber or like polymeric material.

In a further aspect, the invention provides a mechanical sampling device for use in a basic oxygen steelmaking process which includes a sublance as described in the preceding six paragraphs.

In a still further aspect, the invention provides a method for mounting a disposable probe onto a sublance for use in a basic oxygen steelmaking process, the method comprising the provision of a sublance including a sublance tip, a probe holder, a disposable probe and a radial flexible ring, wherein the radial flexible ring traverses and seals the interface between the sublance tip and the probe, so that molten steel is prevented from forming a ring of metal around the probe and the sublance tip, The invention will now be described with reference to the accompanying diagrammatic drawing which illustrates one embodiment of the invention.

Figure I shows a section of a conventional sublance for use in the BOS process; Figure 2 shows a section through a sublance for use in the BOS process according to one embodiment of the invention; and Figure 3 shows the sublance of Figure 2 in use in a basic oxygen steelmaking vessel.

The conventional sublance has already been described. A sublance 4 according to the present invention is illustrated in Figure 2. The sublance 1 includes a tip 2', a probe holder 3', a disposable probe 4' and a protective rubber ring 5' which encircles the probe and the probe holder. However, the protective rubber ring now traverses the interface between the sublance tip 2' and the probe 4', thereby providing a protective barrier against the formation of a metal skull between the tip and the probe. Furthermore, the rubber ring has an angular cross-section to ensure an intimate fit between the ring and the tip and/or probe. The sublance tip has been modified so that the radial surface of the sublance tip meets the radial surface of the probe at the interface 8 between the sublance tip and the probe. This also prevents the presence of any angular niches in which molten metal could collect.

The sublance 1' is shown in use in a basic oxygen steelmaking vessel 10 in Figure 3. As will be seen, the probe holder 3' is supported by a rail mounted lifting winch 11 positioned above the vessel 10 and can be moved vertically by winch to move the probe 4' into and out of the liquid metal present within the vessel. The probe is secured to the holder automatically at a charging station 12. A lance 14 discharges oxygen into the liquid metal and slag.

It is to be understood that the foregoing is merely exemplary of one embodiment of the invention and that modifications may be made thereto without departing from the scope of the invention.

Claims

Claims:-

1 A sublance for use in an oxygen blown steelmaking process, the sublance including a sublance tip, a probe holder, a disposable probe and a radial flexible ring for protecting the interface between the sublance tip and the probe, the arrangement being such that the flexible ring traverses and seals the interface between the sublance tip and the probe.

2. A sublance as claimed in claim 1 wherein the flexible ring lies flush to the external radial surface of the probe.

3. A sublance as claimed in claim 1 or claim 2 wherein the radial surface of the sublance tip meets the radial surface of the probe at the interface between the sublance tip and the probe such that the sublance tip does not overhang the probe at their interface.

4. A sublance for use in a basic oxygen steelmaking process, the sublance including a tip, a probe holder, a disposable probe and a radial flexible ring, wherein:- (a) the radial surface of the sublance tip meets the radial surface of the probe at the interface between the subiance tip and the probe; and, (b) the flexible ring traverses and seals the interface between the sublance tip and the probe.

5. A subiance as claimed in claim 4 wherein the flexible ring lies flush to the external radial surface of the probe.

6. A sublance as claimed in any one of the preceding claims wherein the radial flexible ring is made of rubber or like polymeric material.

6

7. A sublance substantially as defined hereinabove and with reference to the accompanying drawings.

S. A mechanical sampling device for use in a basic oxygen steelmaking process which includes a sublance as defined in any one of the preceding claims.

9. A mechanical sampling device substantially as defined in claim 8 and with reference to the accompanying drawings.

10. A method for mounting a disposable probe onto a sublance for use in a basic oxygen steelmaking process, the method comprising the provision of a sublance including a sublance tip, a probe holder, a disposable probe and a radial flexible ring, wherein the radial flexible ring traverses and seals the interface between the sublance tip and the probe, so that molten steel is prevented from forming a ring of metal around the probe and the sublance tip.