WO1995025818A1

WO1995025818A1 - A support for a basic oxygen converter vessel

Info

Publication number: WO1995025818A1
Application number: PCT/GB1995/000599
Authority: WO
Inventors: Michael Hibbs
Original assignee: Davy Mckee (Stockton) Limited
Priority date: 1994-03-21
Filing date: 1995-03-17
Publication date: 1995-09-28
Also published as: AU1900395A; GB9405519D0; ZA952278B

Abstract

A support for a basic oxygen converter vessel wherein iron can be converted to steel comprises a trunnion ring (9) which engages the vessel (1) by means of three equally spaced suspension assemblies (17). Each suspension assembly (17) comprises a 'T' shaped claw which is bolted to the trunnion ring (9) and engages with a bracket member welded to the vessel (1).

Description

A SUPPORT FOR A BASIC OXYGEN CONVERTER VESSEL

A basic oxygen converter vessel for containing molten iron during its conversion to steel consists of a refractory-lined shell which has a base, a central cylindrical portion and an upper frusto-conical portion leading to an open top. The vessel is supported by a trunnion ring having a pair of diametrically opposed trunnion pins surrounds the cylindrical portion of the vessel and is rigidly secured thereto. Pivoting the trunnion ring about the trunnion pins enables the vessel to be tipped.

The support means for the vessel within the trunnion ring must be able to hold the vessel securely within the trunnion ring at any angle of rotation of the ring about the axis of the trunnion pins.

It will be appreciated that, in use, the vessel will expand and contract and the expansion and contraction is not uniform throughout the vessel. The temperature of the trunnion ring will be very much less than the temperature of parts of the vessel. The support means for the vessel have to be able to accommodate the changes in temperature between the vessel and the trunnion ring. Throughout the life of a steel converter in which such vessels are used permanent distortion of the vessel and trunnion ring occurs. This must be accommodated as well as the differential effects which occur during use.

According to the present invention there is provided: a support for a basic oxygen converter vessel, said vessel having a generally cylindrical wall portion supported within a surrounding ring having diametrically opposed trunnion pins about which the ring may pivot to tilt the vessel; at least three suspension assemblies deployed around the ring to suspend the vessel, each suspension assembly comprising, a bracket mounted on the vessel and a ^{nr ii} shaped claw adapted to be secured to the underside of the ring to engage the bracket and so to secure the vessel to the ring for suspension.

To suspend the vessel from the ring, the vessel is first inverted and located coaxially within the ring. The ring is then presented to the inverted brackets of the vessel so that the stem of each "T" shaped claw can be ■ secured to the ring with each arm of the cross bar of the claw overlying part of and hence retaining one of the brackets.

Preferably the "T" shaped claw is secured by bolts extending through a bottom wall of the ring and the stem.

An "L" shaped packing member may be introduced between each arm of the "T" shaped claw and the bracket.

Preferably there are only three suspension assemblies.

In a preferred embodiment of the invention having only three suspension assemblies the suspension assemblies are deployed circumferentially spaced from the trunnions to minimise the transfer of heat to them. In a preferred embodiment of the invention the suspension assemblies are spaced at 120 degrees from each other and one of the suspension assemblies is located equidistant from each of the trunnions.

Once secured the vessel support assembly can be turned the correct way up.

Embodiments of a support for a basic oxygen converter constructed in accordance with the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:-

Figure 1 is a side view of a converter vessel and support assembly;

Figure 2 is a view from underneath the converter vessel assembly shown in figure 1, i.e, on the arrow "A";

Figure 3 is a partially sectioned perspective view of a suspension assembly; and

Figure 4 is a partially sectioned enlarged view of part of a second embodiment of a suspension assembly.

Referring to Figure 1, a basic oxygen converter vessel 1 comprises a refractory-lined metal shell having a base portion, a central cylindrical portion 3, a frusto- conical upper portion 5 and an open top 7. The vessel is located within a substantially circular trunnion ring 9 having a bottom wall 11 and a pair of diametrically opposed outwardly extending trunnion pins 13. An annular slag shedder 15 is connected to the top of the trunnion ring and to the vessel to protect the trunnion ring from molten metal.

The vessel is supported within the trunnion ring by three suspension assemblies 17 which are described in detail below and which enable the vessel to be- rigidly held within the ring 9 when the ring is rotated about the trunnion pins 13. The suspension assemblies 17 have to be able to accommodate relative expansion between the vessel and the trunnion ring and also enable the vessel to be removed from the ring if this becomes necessary.

Each suspension assembly 17 comprises a thickened back plate 20 which is welded into the cylindrical portion 3. In some applications the back plate 20 may be secured to the cylindrical portion by means other than welding e.g. by bolts. A pair of spaced side walls 22 are welded to the back plate 20 to extend radially outwards and parallel to the axis of the vessel. A circumferentially and radially extending brace 24 is welded to the back plate 20 and to the lowermost ends (shown uppermost in figure 3) of each of the side walls 22. Additional bracing members 26 are welded to inclined outer edges of the side walls 22.

A peripheral brace 27 is welded to extend between the upper radially outer edges of the side walls 22.

Each side wall 22 braces a bracket member 28 which extends radially and circumferentially from the back plate and has a thicker section than the side walls 22 or brace 24. The bracket member 28 is welded to the back plate 20 and to an upper edge of each of the side walls 22.

A bracket brace 30 is welded between the outer face of each side wall 22 and the underside of the associated bracket member 28. A circumferentially and radially extending gap is provided in the bracket member 28 between the side walls 22 to receive a stem 32 of a "T" shaped claw 34 when the bracket member 28 is presented to the underside of the trunnion ring 9. The upper side of each cross arm 36 of the "T" shaped claw engages the lower side of the bracket member 28. The circumferentially facing edges of the stem 32 closely engage the circumferentially facing edges of the gap in the bracket member 28. The underside of the ring 9 is provided with a radially extending groove 38 to receive a corresponding radially extending ridge 40 in the upper side of the stem 32. The "T" shaped claw 34 is secured in place by four bolts 42 which extend through the stem 32 and through the bottom wall 11.

In the second embodiment of the invention shown in figure 4 an "L" shaped packing section 44 is located between each arm 36 of the "T" shaped claw 34 and the bracket member 28.

The suspension assemblies 17 are located so that one suspension assembly is located equidistant from each of the trunnions 13 and the other two suspension assemblies 17 are each spaced substantially 120 degrees from all the others. Thus the suspension assemblies are all spaced from the trunnions and consequently heat transfer to the trunnions is kept to a minimum.

To suspend the vessel 1 within the trunnion ring 9, the vessel is first inverted. The trunnion ring is then located coaxially with the trunnion ring 9 and the trunnion ring presented to the bracket members 28 so that the gaps and the grooves 38 are coincident. The "T" shaped claws 34 are then bolted into place, thus clamping the trunnion ring to the vessel. The trunnion ring and vessel can then be turned upright for use.

The number of stiffening plates such as the claw brace 30 built into the claw may vary according to the size of the converter vessel to be suspended.

Claims

1. A support for a basic oxygen converter vessel; said vessel (1) having a cylindrical wall portion supported within a surrounding ring (9) , said ring (9) having diametrically opposed trunnion pins (13) about which the ring (9) can pivot to tilt the vessel (1) ; at least three suspension assemblies (17) deployed around the ring to suspend the vessel (1) , each suspension assembly (17) comprising, a bracket mounted on the vessel and a "T" shaped claw (34) adapted to be secured to the underside of the ring (9) to engage the bracket (34) and so to secure the vessel (1) to the ring (9) for suspension.

2. A support according to claim 1 wherein the 'T' shaped claw (34) is secured by bolts (42) extending through a bottom wall (1) of the ring (9) and a stem (32) of the "T¹- shaped claw (34) .

3. A support according to claim 1 or claim 2 wherein an 'L' shaped packing member (44) may be introduced between each arm (36) of the "T" shaped claw (34) and the bracket.

4. A support according to any one of the preceding claims having only three suspension assemblies (17) .

5. A support according to claim 4 wherein each of the suspension assemblies (17) is spaced from the trunnions which pins (13) .

6. A support according to claim 4 wherein each suspension assembly is spaced 120° from each other suspension assembly.