GB2344872A

GB2344872A - Converter vessel support assembly

Info

Publication number: GB2344872A
Application number: GB9823990A
Authority: GB
Inventors: Ian Mervyn Craig
Original assignee: Kvaerner Metals Davy Ltd
Current assignee: Kvaerner Engineering and Construction UK Ltd
Priority date: 1998-11-02
Filing date: 1998-11-02
Publication date: 2000-06-21
Also published as: GB9823990D0

Abstract

A support assembly is provided to support a converter 1 in a trunnion ring 2 to accommodate thermal and mechanical strain. The converter 1 is supported in the trunnion ring 2 by an array of flexible elongate members 3 to control lateral displacement of the converter 1 and articulated members 7 to support the weight of the converter 1. The elongate support members 3 are connected at an angle to the radial direction to the converter 1 and inclined upwards to allow for inspection. A pair 3& 3' is provided for each trunnion pin 6. Each pair are preferably connected to adjacent mounting points 4 & 4' on the converter vessel 1 from circumferentially spaced points 5 & 5' on the trunnion ring 2. The mounting points 4 & 4' on the vessel 1 preferably intersect the rotary axis of each trunnion. The elongate support member 3 may be a resilient strap of twisted laminate metal. The articulated member 7 comprises a rigid member 8 connected to mounting plates 11 on the vessel 1 and trunnion ring 2 by pinned hinges 9 & 10. Each hinge 10 is mounted perpendicular to the axis of the vessel 1 and parallel to a tangent of the vessel wall. An array of preferably 4 or 6 articulated supports 7 may be spaced circumferentially around the vessel. The elongate support members 3 may be mounted to an upper rim of the trunnion ring 2 with the articulated members 7 below to allow slag shredders to overlay the elongate supports 3 and trunnion ring 2.

Description

Converter Vessel Support Assembly The present invention concerns the support of a basic oxygen converter vessel in a trunnion ring. Such vessels are large and very heavy. In use they contain molten iron or steel and are therefore subject to extreme temperatures and loads. The invention may have applications in supporting other loads where there are similar demands.

A 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. A trunnion ring having a pair of diametrically opposed trunnion pins surrounds the cylindrical portion of the vessel and is rigidly secured to it. 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 temperatures to which parts of the vessel are subjected. The support means for the vessel have to be able to accommodate the changes in temperature between the vessel and the trunnion ring.

Continuing developments in the materials and design of the vessel itself, such as the improvements in the refractory lining, mean that the vessel shell and its support must operate under ever more arduous conditions, such as increased shell temperature with corresponding increases in thermal strain. There is therefore a demand for vessel supports able to safely endure prolonged and repeated exposure to such thermal strain which may lead to notable vessel distortion.

Accordingly the present invention provides a converter vessel support assembly comprising: a converter vessel, a trunnion ring, an array of elongate flexible lateral support members secured between the converter vessel and the trunnion ring and arranged to control lateral displacement of the vessel in a direction perpendicular to the axis of the vessel, and an array of articulated support members secured between the vessel and the trunnion ring to support the weight of the vessel.

Preferably the lateral support members extend between the vessel and the trunnion ring at an angle inclined to the radial direction and the tangential. This arrangement curbs the tendency for the vessel to swing of centre when tipped. Preferably the lateral support members are inclined up from the top rim of the trunnion ring this assists by rendering each lateral support accessible for inspection and installation. The lateral support members are preferably arranged in pairs, one pair being associated with each trunnion pin. Lateral support members of each pair extend one each from adjacent mounting points on the vessel to circumferentially spaced mounting points on the trunnion ring so that the upper lateral support members are in tension when supporting the overturning load as the vessel is tipped. Each vessel mounting point is preferably located on or immediately adjacent a vertical line on the vessel which intersects the rotary axis of each trunnion.

Each lateral support member may advantageously be provided by a strap with mounting means at each end. The strap may be resilient and advantageously can be formed of laminated metal strips twisted through an angle between the mounting point on the trunnion ring and the mounting point on the vessel. The lateral support members are able to flex to accommodate circumferential, radial and vertical strain.

Each articulated support member will comprise a rigid element connected at one end to the vessel by a vessel hinge and at the other end to the trunnion ring by a trunnion hinge. Each hinge is preferably formed with a pin joining the rigid element to a mounting member fastened to either the vessel, in the case of the vessel hinge, or the trunnion in the case of the trunnion hinge. Preferably each of the rigid element and the mounting members is provided by a stiff strong plate so that the articulated mounting member does not flex in the circumferential direction. Each hinge is arranged to articulate around an axis which is perpendicular to the axis of the vessel and trunnion ring and parallel to a tangent to the vessel wall. The array of articulated support members comprises several members located at circumferentially spaced positions around the vessel. Preferably the array comprises four or six articulated support members. The array of articulated support members is able to accommodate strain or displacement in any radial direction while supporting the weight of the vessel either in the upright condition or when inverted.

Preferably the lateral support members are mounted on an upper rim of the trunnion ring and the articulated support members are mounted between a lower rim of the trunnion ring and the vessel. Upper and lower are with reference to the vessel in the upright condition. This arrangement allows slag shedders to overlay the lateral supports and trunnion ring.

The converter vessel support assembly may be applied to an existing installation and accordingly a second aspect of the present invention provides a system for supporting a converter vessel comprising : an elongate flexible lateral support member adapted to be secured between a converter vessel and a trunnion ring to control lateral displacement of the vessel in a direction perpendicular to the axis of the vessel, and an articulated support member adapted to be secured between the vessel and the trunnion ring to support the weight of the vessel.

The converter vessel support system may also include lateral support member mounting brackets and articulated support member mounting brackets whereby the lateral support member and the articulated support member can be attached to the trunnion ring and the vessel.

An embodiment of a converter vessel support assembly constructed in accordance with the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig 1 is a diagrammatic elevation of the converter vessel assembly, Figures 2A and 2B are enlarged views at a tangent to the vessel of an articulated support member illustrating how the member is mounted and accommodates radial deformation of the vessel, Figure 3A is an enlarged perspective view of a lateral support member mounted in the assembly, Figure 3B is an enlarged view on A in Figure 3A, Figure 3C is a view of the lateral support on B in figure 3A, Figure 4 is a perspective view of a second embodiment of the lateral support member.

A converter vessel support assembly comprises a converter vessel 1, a trunnion ring 2, an array of elongate flexible lateral support members 3 secured between the converter vessel 1 and the trunnion ring 2 and arranged to control lateral displacement of the vessel 1 in a direction perpendicular to the axis of the vessel.

Each lateral support member 3 consists of a flat strap formed from laminated strips of steel or other suitable material twisted about its long axis through an angle which in this case is approximately ninety degrees.

The lateral support members 3,3'are mounted in pairs. Each pair of lateral support members 3,3' consists of a first lateral support member 3 having one end bolted to a first vessel mounting bracket 4 welded to the wall of the vessel 1. The other end of the support member 3 is bolted to a ring mounting bracket 5 welded to an upper rim of the trunnion ring 2. A second lateral support member 3' extends from a bracket 4'welded to the vessel 1 immediately adjacent the first vessel mounting bracket 4, to a second ring mounting bracket 5'. The location of the brackets 4,5 is such that with the vessel axis vertical a line drawn through the axis of a trunnion pin 6 will pass between the lateral support members 3,3' of the pair and preferably equidistant from each of the lateral support members 3,3'.

The array of lateral support members 3 includes a second pair on the opposite side of the vessel overlying the other trunnion pin 6.

Four articulated support members 7 are circumferentially spaced around the assembly and extend between the lower rim of the trunnion ring 2 and the vessel 1. Each articulated support member 7 comprises a rigid element 8 provided by a plate which may be a steel plate to resist buckling. The rigid element 8 is coupled by means of a hinge 9 at one end to a vessel mounting plate 10. The other end of the plate 8 is coupled by a similar hinge 9'to a ring mounting plate 10'so that the rigid element 8 is inclined to the vessel axis and the horizontal when the vessel is upright. A first triangular section mounting bracket 11 is welded to the outside wall of the vessel 1 and a second triangular section mounting bracket 11'is welded to the lower rim of the trunnion ring 3. The mounting plate 10 is then bolted to the vessel mounting bracket 11 and the mounting plate 10 is bolted to the ring mounting bracket 1 1'.

When the vessel 1 is upright as shown in figure 1 the weight of the vessel is supported by the articulated support members 7 which are stressed in tension. During use the vessel 1 is heated and therefore expands radially and axially. The radial expansion is accommodated by the articulated support members 7 articulating as shown in figure 2B. The lateral support members 3 flex resiliently about the twist to accommodate both axial expansion and radial expansion of the vessel but the array of lateral support members 3 acts to keep the vessel centred in the trunnion ring 3.

When the vessel 1 is tipped the array of lateral support members 3 continues to keep the vessel centred in the trunnion ring as the uppermost pair of lateral support members takes the weight of the vessel 1 in tension. Thus when the vessel is upright or tipping, and therefore when it is at its heaviest, the support members 3,7 are all stressed in tension and the risk of buckling is therefore obviated.

When the vessel 1 is fully inverted it is supported by the articulated support members 7 in compression.

However, in this condition the vessel, being empty, is lighter so that the risk of buckling of the support members is alleviated by the design of the substantial plate 8.

Figure 4 illustrates a second embodiment of the invention in which the pair of lateral support members 3,3' from the first embodiment is replaced by a single integrated lateral support member 3''. Apart from consequent modifications to the vessel mounting bracket 4''there are no other changes to the vessel support assembly.

Claims

CLAIMS 1. A converter vessel support assembly comprising : a converter vessel, a trunnion ring, an array of elongate flexible lateral support members secured between the converter vessel and the trunnion ring and arranged to control lateral displacement of the vessel in a direction perpendicular to the axis of the vessel, and an array of articulated support members secured between the vessel and the trunnion ring to support the weight of the vessel.
2. An assembly according to claim 1 wherein the lateral support members extend between the vessel and the trunnion ring at an angle inclined to the radial direction and the tangential direction.
3. An assembly according to claim 2 wherein the lateral support members are inclined up from the top rim of the trunnion ring to be accessible for inspection and installation.
4. An assembly according to any of claims 1 to 3 wherein the lateral supports are arranged in pairs, one pair being associated with each trunnion pin.
5. An assembly according to claim 4 wherein lateral support members of each pair extend one each from adjacent mounting points on the vessel to circumferentially spaced mounting points on the trunnion ring so that the upper lateral support members are in tension when supporting the overtuming load as the vessel is tipped.
6. An assembly according to claim 5 wherein each vessel mounting point is located on or immediately adjacent a vertical line on the vessel which intersects the rotary axis of each trunnion.
7. An assembly according to claim 1 wherein each lateral support member is provided by a strap with mounting means at each end.
8. An assembly according to claim 7 wherein the strap is resilient.
9. An assembly according to claim 8 wherein the strap is formed of laminated metal strips twisted through an angle between the mounting point on the trunnion ring and the mounting point on the vessel.
10. An assembly according to any one of claims 1 to 9 wherein each articulated support member comprises a rigid element connected at one end to the vessel by a vessel hinge and at the other end to the trunnion ring by a trunnion hinge.
11. An assembly according to claim 10 wherein each hinge is formed with a pin joining the rigid element to a mounting member fastened to either the vessel, in the case of the vessel hinge, or the trunnion in the case of the trunnion hinge.
12. An assembly according to claim 10 or 11 wherein each of the rigid element and the mounting members is provided by a stiff strong plate so that the articulated mounting member does not flex in the circumferential direction.
13. An assembly according to any of claims 10 to 12 wherein each hinge is arranged to articulate around an axis which is perpendicular to the axis of the vessel and trunnion ring and parallel to a tangent to the vessel wall.
14. An assembly according to any one of the preceding claims wherein the array of articulated support members comprises several members located at circumferentially spaced positions around the vessel.
15. An assembly according to claim 14 wherein the array comprises four or six articulated support members.
16. An assembly according to claim 15 wherein the lateral support members are mounted on an upper rim of the trunnion ring and the articulated support members are mounted between a lower rim of the trunnion ring and the vessel to allow slag shedders to overlay the lateral supports and trunnion ring.
17. A system for supporting a converter vessel comprising: an elongate flexible lateral support member adapted to be secured between a converter vessel and a trunnion ring to control lateral displacement of the vessel in a direction perpendicular to the axis of the vessel, and an articulated support member adapted to be secured between the vessel and the trunnion ring to support the weight of the vessel.
18. A system according to claim 17 comprising lateral support member mounting brackets and articulated support member mounting brackets whereby the lateral support member and the articulated support member can be attached to the trunnion ring and the vessel.