CONVERTER VESSEL SUPPORT ASSEMBLY

Abstract: A converter vessel support assembly consists of a basic oxygen converter vessel (1) for metals processing, suspended from a trunnion ring (9) which provides trunnions (13) for pivotally mounting the vessel (1) during use. The vessel (1) must be relatively immovably secured within the trunnion ring (9) by means which accomodate relative thermal expansion and contraction of the vessel (1) and the trunnion ring (9). This is achieved by two brackets (17) fastened to the vessel at diametrically opposite positions and which engage in clamping guides (31) fastened to the trunnion ring in diametrically opposed positions to allow relative radial displacement of the brackets (17) and a further bracket (19) which locates in simple guide in form of packing members to prevent circumferential movement of the bracket (19) but allow radial and axial movement.

Description: CONVERTER VESSEL SUPPORT ASSEMBLY This invention relates to a support assembly for a vessel, such as a basic oxygen converter vessel. 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 substantially circular trunnion ring, having a pair of outwardly extending diametrically opposed trunnions, surrounds the cylindrical portion of the vessel and is rigidly, but removably, secured thereto. Pivotting the trunnion ring about the trunnions enables the vessel to be tipped. The support assembly 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 trunnions. The support assembly must transmit rotational torques applied to the trunnion ring, via the trunnions, to the vessel. It will readily be appreciated that the vessel will expand and contract in the radial direction at a rate dissimilar to that of the trunnion ring due to the difference of temperature between the hot vessel and the trunnion ring. If the supports engaging between the vessel and trunnion ring are adapted to accommodate the relative radial expansion, as is desirabl ,allow relative radial expansion they will also allow undesirable relative displacement of the vessel and the trunnion ring. It is an object of the present invention to provide a vessel support assembly which alleviates the aforementioned technical problem; is simple to assemble and disassemble so that the trunnion ring can readily be separated and attached to the vessel for maintenance and has as few components and minimum weight possible. Accordingly there is provided a support assembly for a converter vessel comprising a trunnion ring having diametrically opposed trunnions projecting outwardly therefrom, the vessel being suspended in the trunnion ring characterised in that the vessel is suspended exclusively by a pair of suspension means, the suspension means being located, one below each of the trunnions and adapted to accommodate relative radial expansion and contraction of the vessel and trunnion ring and a guide means engaging between the vessel and the trunnion ring at a position circumferentially spaced from the suspension means to maintain the relative positions of the axes of the vessel and the trunnion ring. It will be appreciated that the assembly defined above will accommodate relative radial expansion of the trunnion ring and vessel but is of simple and hence relatively inexpensive construction. Because the number of components is kept to a minimum, amongst other reasons, the vessel and trunnion ring assembly is relatively light weight. The two suspension brackets and the associated suspension means secure the vessel within the trunnion ring and they support the whole weight of the vessel and its contents. The function of the guide means is to centralise the vessel in the trunnion ring and the guide means does not provide any support for the vessel. It does, however, prevent the vessel from being moved within the trunnion ring in the direction parallel to the common axis of the trunnion pins. According to another aspect of the present invention there is provided a method of assembling a trunnion ring and converter vessel for suspension thereof comprising the steps of locating the trunnion ring over the vessel so that a pair of coaxial trunnions on the trunnion ring overlie a pair of suspension brackets mounted on the vessel and engaging a radially projecting member of a guide bracket between guide members adapted to prevent only circumferential displacement of the guide bracket; and, clamping the suspension brackets to the trunnion ring by guide and claw members adapted to permit only radial displacement of the bracket relative to the trunnion ring. It will be appreciated from the above method that assembly and disassembly of the trunnion ring and vessel suspension construction is conveniently quick and simple. In order that the invention may be more readily understood, it 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 basic oxygen converter vessel incorporating a support arrangement in accordance with the present invention; Figure 2 is a front view of a suspension bracket forming part of the support arrangement; Figure 3 is a front view of a guide bracket forming part of the support arrangement; and Figure 4 is a side view of part of a basic oxygen converter vessel showing the trunnion pin and one of the suspension brackets of a support arrangement of the present invention. 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 and supported in a substantially circular trunnion ring 9 having a bottom flange 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 means which enable the vessel to be removed from the ring, if necessary. To this end, the support for the vessel comprises a pair of suspension brackets 17 mounted on the cylindrical part 3 of the vessel and located one beneath each of the trunnion pins 13. A guide bracket 19 is mounted on the cylindrical part of the vessel at a position substantially mid-way between the brackets 17. Referring particularly to Figures 2 and 4, it can be seen that each suspension bracket 17 has a vertical leg 21 which is shaped to conform to the outer surface of the vessel 1 and which is secured to the vessel by means of bolts 23 which pass through the wall of the vessel and the vertical leg 21. At the upper end of the vertical leg 21 there is a horizontal leg 25 which has thickened blocks 27 fabricated into each of its ends. The horizontal leg 25 is secured to the vertical leg by stiffening plates 26. To assemble the ring around the vessel, the vessel is positioned in the ring with the suspension plates 17 located beneath respective trunnion pins. The upper faces of the blocks 27 on the brackets have been dressed to ensure good bracket contact with the bottom flange 11 on the trunnion ring. A pair of stop members 29 are welded or otherwise secured to the underside of the flange 11. A pair of claw members 31 are bolted to the flange 11 by pre-stressed bolts 33 and each claw member has a projection which fits underneath the portion 27 on the bracket. As the bolts 33 are tightened, the claw members 31 are clamped to the underside of the flange 11. The claw members 31 are accurately machined so as to fit, with the minimum of clearance, between the bracket 17 and the stop members 29. Each claw member is secured to the flange 11 by an appropriate number of bolts and the flange member 11 may be strengthened, if necessary. A minimum clearance has to be provided between the claw members, the bracket and the stop members to allow for expansion when the vessel is filled with molten metal. Referring now to Figure 3, it can be seen that the guide bracket 19 is of similar construction to the suspension brackets 17 in that it comprises a vertical limb 21A and a horizontal limb 25A with thickened portions 27A at opposite ends of the horizontal portion. Stop members 29A are secured to the underside of the flange 11 and packing members 31A are located between the stop members 29A and the thickened portions 27A of the bracket 19. The packing members are bolted into position with the minimum of clearance between the bracket and the stop members 29A but the packing members do not have a claw which fits underneath the thickened portions 27A. The packing members 31A prevent lateral movement from occurring between the bracket 19 and the flange 11. In all positions of tilt, the vessel is rigidly supported within the trunnion ring by the suspension brackets and the suspension members. The guide bracket only serves to locate the vessel within the trunnion ring. In this arrangement, therefore, it will be appreciated that there is a two-point suspension of the vessel with an additional guide means between the vessel and the trunnion ring. Although the invention has been specifically exemplified in relation to a basic oxygen converter vessel, it will be appreciated that the support arrangement of this invention can be applied to other types of furnace vessel.

Claims: CLAIMS 1. A support assembly for a converter vessel (1) comprising a trunnion ring (9) having diametrically opposed trunnions (13) projecting outwardly therefrom, the vessel (1) being suspended in the trunnion ring (9) characterised in that the vessel is suspended solely by a pair of suspension means (17), the suspension means (17) being located, one below each of the trunnions (13) and adapted to accommodate relative radial expansion and contraction of the vessel (1) and trunnion ring (9) and a guide means (19) engaging between the vessel (1) and the trunnion ring (9) at a position circumferentially spaced from the suspension means (17) to maintain the relative positions of the axes of the vessel (1) and the trunnion ring (9) . 2. A support assembly according to claim 1 wherein each suspension means (17) and the guide means (19) comprises a bracket rigidly secured to the vessel (1), each bracket providing a radially projecting member (25, 25A) having radially extending edges abuted by paking members (31, 31A) which prevent displacement of the radially projecting members (25, 25A) in the circumferential direction only, each of the suspension means, only, having packing members (31 ) with a claw member to clamp the underside of the leg (25) to the trunnion ring (9). 3. A support assembly according to claim 2, wherein the packing members (31 , 31A) are bolted, to the underside of the trunnion ring (9). 4. A support assembly according to claim 3 wherein the resistance to circumferential displacement or deformation of the guide means (31, 31A) is reinforced by stop members (29, 29A) welded to the trunnion ring (9). 5. A support assembly according to any of claims 2 to 4 wherein the brackets (17, 19) are secured to the vessel wall be means of a vertical leg (21, 21A) bolted to the wall. 6. A support assembly according to any one of the preceding claims wherein the trunnion ring (9) has a horizontal flange (11) projecting from its lowermost edge and from which the vessel is suspended. 7. A method of assembling a trunnion ring and converter vessel for suspension thereof comprising the steps of: locating the trunnion ring over the vessel so that a pair of coaxial trunnions on the trunnion ring overlie a pair of suspension brackets mounted on the vessel and engaging a radially projecting member of a guide bracket between packing members secured to the trunnion ring and adapted to prevent circumferential displacement of the guide bracket only, and clamping the suspension brackets to the trunnion ring by packing members comprising guide and claw parts adapted to permit only radial displacement of the suspension bracket relative to the trunnion ring.

Inventors: BAILEY RALPH, HIBBS MICHAEL, BAILEY, RALPH, HIBBS, MICHAEL
Applicants: DAVY MCKEE STOCKTON, DAVY MCKEE (STOCKTON) LIMITED
Application year: 1991
Main classification: C21C5
IPC codes: C21C5