US3652072A

US3652072A - Support arrangement for metallurgical vessel such as steel mill converter

Info

Publication number: US3652072A
Application number: US98016A
Authority: US
Inventors: Siegfried Stresemann; Karl-Heinz Langlit; Karl-Heinz Mahringer
Original assignee: Demag AG
Current assignee: Mannesmann Demag AG
Priority date: 1967-07-01
Filing date: 1970-12-14
Publication date: 1972-03-28
Anticipated expiration: 1989-03-28
Also published as: AT278066B; NL162963C; ES349815A1; SE372288B; GB1218442A; BE716069A; DE1583232B1; JPS4827167B1; FR1550949A; NL6717587A

Abstract

A supporting ring for metallurgical vessel, such as a tiltable or revolvable steel mill converter, includes straps secured around the periphery of the vessel and in heat exchange relation therewith. These straps are connected to a support ring for the vessel, which also surrounds the vessel but is not in heat exchange contact therewith. The supporting arrangement includes adjustable connecting screws which have a hinge-like connection at one end to the supporting ring, for displacement in at least a radial plane, and the other ends of which screws are hingedly connected to the projections of the vessel shell or wall, such as projections on the straps.

Description

[ 51 Mar. 28, 1972 ited States Patent Stresemann et al.

[54] SUPPORT ARRANGEMENT FOR References Cited UNITED STATES PATENTS Johnson......................

Kramer...............................,

Eberhart....................,..........

a. .m s e u B 4568 666 999 HHHH 98 7 1 003 805w 6100i. 4089 r 333 f m o i e H Siegfried Stresemann, Rheinhausen; Karl- Heinz Langlit, Mulheim/Ruhr; Karl- Mahringer, Duisburg-Hamborn, all Germany 3,400,922 9/1968 Langlitz............................... [73] Assigneez Demag Aktiengesellschaft, Duisburg, Germany . Primary Examiner--Robert D. Baldwin Assistant Examiner-John S. Brown Attorney-McGlew & Toren [22] Filed: Dec. 14, 1970 [2i] Appl. No.:

ABSTRACT A supporting ring for metallurgical vessel, such as a tiltable or doned. revolvable steel mill converter, includes straps secured around the periphery of the vessel and in heat exchange relation [30] Foreign Application Priority Data therewith. These straps are connected to a support ring for the July 1, i967 cermanymwwmuunnunmnn 53503 vessel, which also surrounds the vesseLbut is not in heat exchange contact therewith. The supporting arrangement m- 52 vs. dudes adjustable Connecting Screws which have a hinge-like .......C2lc s/so .266/35, 36 P, 36 R, 39

connection at one end to the supporting ring, for displacement in at least a radial plane, and the other ends of which screws 7 are hingedly connected to the projections of the vessel shell or wall, such as projections on the straps.

[51] lnt.Cl.................

[58] Field of Search...........................

8 Claims, 5 Drawing Figures &

SUPPORT ARRANGEMENT FOR METALLURGICAL VESSEL SUCH AS STEEL MILL CONVERTER This application is a continuation of Ser. No. 734,592, filed June 5, 1968, and now abandoned.

BACKGROUND OFTI-IE INVENTION Steel mill converters are supported, as a unit with a surrounding supporting ring, by means of straps surrounding the converters and through the medium of screws, wedges, and so forth. A separation between the converter vessel and its suporting ring is provided to accommodate heat expansion between the vessel wall and the inside periphery of the supporting ring. Naturally, the amount of heat released during the metallurgical reaction varies in time, and heating of the converter vessel, with consequent temperature induced expansion, leads to displacement of the supporting components. The thermal stresses must not exceed the elastic limit, although permanent deformations will have to be accepted occasionally, since the operating conditions do not permit, at present, any other choice. The penetration of the tamping material between the refractory lining and the converter vessel wall into hair cracks of the permanent lining also leads to an expansion, the so-called growth of the vessel.

For charging, blasting, removing slag, casting and lining, the converter vessel must be tiltable. As a result, a deformation, although not a permanent deformation, appears because of the relatively thin wall of the vessel and depending on the inclined position.

During operation, it happens time and again that the lining is irregularly complete at several points because of the nonhomogeneous structure stemming partly from the constitution of the brickwork or refractory and partly from the melt. Refractory surfaces that have become particularly thin present a shorter path for heat transfer, so that heat transfer to the outer skin of the vessel occurs in a time which is relatively shorter than may be desired. In such cases, highly heated zones appear on the wall of the vessel, with some parts of the surface becoming even red hot. Generally, such parts will not withstand internal overpressure, so that at least permanent deformations of the outer shell of the vessel have to be acccpted.

It is not impossible that these highly heated zones coincide with the fastening points of the straps, so that the straps experience, under the most favorable conditions, a corresponding heat expansion. In most cases, however, the bearing surfaces of the straps will be twisted. All straps provided in the range of the supporting rings, as well as the vessel as a whole, are thus greatly stressed thermally and subjected to constant expansion, shrinkage and distortion.

Prior art supporting arrangements have provided that the converter vessels be supported rigidly on the support rings by means of screws. It has been considered that neither an axial nor a radial expansion is possible to any desired extent. Although some arrangements have been proposed to facilitate sliding of the straps on the support rings, such arrangements require a certain play by which the vessel can move during tilting. Such a freedom of movement may be quite tolerable in smaller vessels, but such a solution is not useable for larger vessels, of the order of several hundred tons of useful load.

In the support of a metallurgical vessel subjected to thermal stresses, a special difficulty is encountered with respect to the play that must be provided between the straps and stops arranged on the supporting rings, in order to provide freedom for heat expansion. In practice, it has been found that this play increases in tiltable vessels on one of the stop faces engaged with a respective strap, when the vessel performs a slight axial movement during erection from the inclined position. Even the insertion of bars enhancing the sliding friction can result only in an improvement which delays the wear. However, if surface pressures appear to an increasing extent at the stop faces, the predetermined heat expansion play increases rapidly, which is a considerable disadvantage in tilting the vessel. The vessel always moves inside its supporting ring in the range of the play, and thus wears out faster than desired, due to the reduced strength resulting from the thermal stress.

A completely rigid support of the vessel, however, results in such thermal stresses that material cracks are unavoidable. The resulting consequences, for an elastic support of the vessel, appear particularly in the load at the pivotal points, a stati cally undetermined support, that is, a plurality of pivotal points, leading to economically unacceptable solutions. The statically determined support, however, has the great advantage that fewer pivotal points are required, although the latter must have a corresponding operating safety and the required service life.

SUMMARY OF THE INVENTION This invention relates to the support of metallurgical vessels, such and/or tiltable and/or revolving steel mill converters, and, more particularly, to an improved supporting arrangement for. supporting such a vessel from a supporting ring through the medium of straps secured in heat conducting relation to the vessel.

The present invention is directed to improving the elastic connection between the vessel wall and the supporting ring or rings, and to take into consideration the possibility of free heat expansions as a superposition in radial and axial directions. The invention also takes into account the various positions of a tiltable vessel in which the essential causes of wear must be eliminated in advance.

In accordance with the invention, the supporting ring surrounding the vessel is provided with hinge-like fastening points for connecting screws or bolts which can be displaced in a radial plane, and whose other ends are connected to projections of the vessel wall, also in a hinge-like manner. In the expansion of the vessel, the initial consideration is that both the radial expansion and an axial expansion act as the main forces. These forces can vary, however, from zone-to-zone of the vessel circumference. For example, for reasons mentioned above, a temperature difference between two opposite sides of the converter is possible, and which results in a unilateral expansion.

In contrast to known solutions to the problem, wherein only the elasticity of the elements in one main direction is taken into consideration, the arrangement of the invention has the effect that the pivotal points of the connecting screws can be quite irregular in their movements. A supporting ring spaced from the vessel expands far less, because of the considerable difference, than a ring bearing on the vessel and in heat conductive contact therewith. In addition, it must be expected that projections secured on the vessel shell can perform torsion-like movements, and the connecting screws must follow this distortion to a far greater extent at their ends connected to the vessel than at their ends connected to the supporting ring. The arrangement of the present invention thus provides for expansion of connecting screw fulcrums to take place at different rates and to different extents.

In accordance with a principal feature of the invention, the connecting screws pass loosely through their fastening points, and their projections at their ring ends and on their vessel shell ends have end faces engaged with respective nuts in spherically shaped bearing disks. The size and accessibility of the fastening points and engaging points, respectively, of the forces on the ring and those on the vessel wall, can be easily improved without departing from the principal feature of the invention which is to transmit the force only at the pivotal points and to design the connecting screws as favorably as possible. That is, to design these screws so that they are stressed solely in tension. Thus, the connecting screws can be advantageously designed, as the principal requirement of expansion screws is expansion. The moving connections, designed as spherical shaped bearing members, offer the possibility of performing movements on a spherical shell, a slight deviation in the form of two superposed surfaces providing for the introduction of a heat-resistant lubricant between these surfaces and its retention during operation.

Another feature of the invention is the provision of additional spherical-shaped spacing disks, in relatively slidable relation with each other, between the fastening or anchoring points or projections on both the supporting ring and the vessel shell, the connecting screws extending through the spacing disks. The energy or forces thus acting between the support ring surrounding the converter vessel and the wall of the vessel are thus exerted in a force-locking and form-locking manner, despite the desired elasticity of the system, whereby a high safety of operation is insured.

The invention also provides for absorbing, in any manner, tensile or compressive forces, depending on the inclination of the vessel. An advantageous feature is that the tilting direction of the metallurgical vessel or the like can be selected to proceed in either direction. The force patterns in the material extend in a known manner, so that the invention arrangement can be used particularly easily, in practice, by virtue of exact calculation of the forces.

As another feature of the invention, the expansion screw connection, supported in ball sockets between the supporting ring fastening portions and the projections on the shell of the vessel, is provided at both sides of the radial axis of symmetry of the vessel considered in a horizontal direction. A substantial disadvantage of metallurgical vessels supported solely by straps, as mentioned above, is the also mentioned heat expansion play, which increases rapidly depending upon the prevailing operating conditions. Surprisingly, and due to the nature of known solutions, this play is doubled in these known solutions, because the stop faces of the supporting ring are arranged at both sides of the straps on the vessel, a particularly large spacing being selected, in most cases, between two adjacent straps. Thus, according to the mathematical determination, based on the size of the longitudinal expansion difference, the extent of the heat expansion increases considerably.

The present invention is also based on the concept of maintaining the size of the factor length, introduced into the calculation, as small as possible. In the present invention, this is attained by forming the fastening parts, between the vessel shell and the supporting ring, as short as possible, thus not providing any long reference dimensions as would be the case with a substantial spacing between two straps. Thus, the invention solution to the problem of supporting a metallurgical vessel or container departs completely from the principle of the strap support, and replaces this principle by a new one, which is namely that of a short hinge connection. This results in the additional advantage of being able to work with only slight heat expansion differences.

An object of the present invention is to provide an improved supporting arrangement for metallurgical vessels, particularly tiltable and/or revolving steel mill converters.

Another object of the invention is to provide such a supporting arrangement providing for substantially universal displacement of connecting elements between a supporting ring and a vessel supported by the supporting ring.

A further object of the invention is to provide such a supporting arrangement including expansion screws interconnecting the supporting ring and the vessel and passing loosely through fastening points and projecting therebeyond on either end.

Still another object of the invention is to provide such a supporting arrangement in which the projecting ends of the expansion screws or bolts are provided with spherically shaped bearing disks interposed between their associated nuts and the connecting portions of the supporting ring and the vessel.

A further object of the invention is to provide such a supporting arrangement including additional spherical-shaped spacing disks associated with the expansion bolts or screws and having sliding engagement with each other.

Yet, another object of the invention is to provide such a supporting arrangement characterized by relatively short fastening or securing parts extending between the vessel shell and its supporting ring.

A further object of the invention is to provide such a supporting arrangement which is capable of working with only very slight heat expansion differences.

BRIEF DESCRIPTION OF THE DRAWINGS For understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof, as illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a partial side elevation view of a converter embodying the support arrangement of the invention, the end sections of the converter being omitted for the sake of clarity;

FIG. 2 is a horizontal or diametric sectional view through the converter shown in FIG. 1;

FIG. 3 is a side elevation view, looking from the left of FIG.

FIG. 4 is a view, similar to FIG. 2, illustrating a modification of the invention; and

FIG. 5 is a sectional view taken on the line V-V of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In each of the figures, the converter vessel 1 has secured thereto so-called claw or strap rings 2, 3, 5 and 6.

Rings

2 and 3 are arranged above a supporting ring 4, and rings 5 and 6 are arranged beneath supporting ring 4. Ribs 7 form connections between

rings

2 and 3 and between

rings

5 and 6, providing suitable means for securing the

rings

2, 3, 5 and 6 to the vessel shell as by means of welded seams, threaded joints, and the like.

Rings

3 and 5 have bearing engagement with the surfaces 10 of supporting ring 4 through the medium of abutments 8 secured on

rings

3 and 5 and intermediate layers or shims 9 interposed between abutments 8 and the surfaces 10 of supporting ring 4.

As best seen in FIG. 2, rings 2, 3, 5 and 6 have additional reinforcement members 11 extending between the rings and the wall of the vessel 1. Thereby a compact ring surface is formed under which are arranged the intermediate layers or shims 9 and the abutments 8. The abutments 8 and layers or shims are additionally limited against displacement by laterally arranged projections or abutments 12, with bars 13 being inserted between projections 12 and abutments 8. These bars 13 are, as mentioned above, inserted with a certain play or relatively loosely. The support thus provided serves substantially for securing of the vessel 1 against axial displacement, but the vessel can move, in a certain range, because there is no rigid connection extending radially and axially between abutments 8 and projections 12.

In accordance with the invention, this loose support of vessel 1 on supporting ring 4 is restrained or constricted by an expansion screw or bolt connection. To this end, projections 14 are arranged on

rings

2, 3, 5 and 6, and are rigidly connected to these rings as by welding at 15 and through bracing ribs 16. The projections 14 consequently form elements on the vessel shell whose heat expansion is influenced substantially by the thickness of the vessel shell.

As will be further noted from FIG. 2, supporting ring 4 has a housing construction 17 formed of several walls 18 and designed, for example, by welding, as a continuous or integral fastening member which projects both upwardly and downwardly from supporting ring 4. Ring 4 thus provides, on both its upper side and its under side, support for the projections 14 on the shell of vessel 1.

Each projection 14 on the shell of the vessel is formed with a bore or aperture 20 extending completely therethrough, and the apertures 20 in projections 14 are aligned with apertures 20 extending completely through the support 17 forming a passage between the walls 18 of member 19. Threaded expansion or tension members 21, such as studs or screws, extend through the aligned bores 20 and have nuts 22 secured to opposite ends thereof, spherically shaped pairs of supporting disks or

washers

23 and 24 being interposed between one nut 22 and supporting member 19, the other nut 22 and a projection 14, and between projection 14 and the support 19. If supporting ring 4 thus expands, and the vessel 1 with the

rings

2, 3, 5 and 6 also expands, to greatly varying degrees, as in the majority of cases, or if, in other words, there is differential expansion between ring 4 and vessel l and its connected parts, expansion members 21 can be displaced, through the medium of the spherically shaped supporting disks or

washers

23 and 24, in a radial plane in respect to the axis 25 of the vessel 1.

The expansion members 21 are arranged on both sides of the radial plane of symmetry 26 of vessel 1, so that the lateral play provided for the bars 13 can be cancelled. The invention support thus has sufficient rigidity without offering, however, any resistance to heat expansion of vessel 1 and heat expansion of supporting ring 4. it is advisable to apply a heat-resistant lubricant in powder form, such as graphite or similar mixtures, to the surfaces of the spherically shaped supporting

disks

23 and 24. Thereby tension transmitted by expansion members 21, with resulting friction between the supporting disks or

washers

23 and 24, can be readily overcome.

Since housing construction 17 and projection 14 form, together with the supporting disks or

washers

23 and 24, a closed unit, there is no longer any free play at any point of the support between converter 1 and supporting ring 4, so that excessive movement during erection of converter 1 is effectively prevented. The arrangement of a pair of expansion members 21 on either side of the axis of symmetry 26 of vessel 1 is generally sufficient. However, several such expansion members can be provided for larger vessels, and particularly three expansion members to provide a statically determined support.

The support of the vessel by means of projections or claws is only one example where the invention can be applied. FIG. 4 illustrates a variation wherein expansion members 27, extending parallel to the axis 25 of vessel 1, can be provided between the

rings

2 and 3 and the

rings

5 and 6, respectively.

The invention can also be applied with advantage notonly in a horizontal plane, but also in planes parallel to the main axis of the vessel. Referring to FIG. 5, slots 28 are provided in the claw or strap ring secured to the vessel 1, and similar slots 29 are provided on the upper side of supporting ring 4. Threaded expansion members 27 extend through these slots, having nuts secured to opposite ends thereof. in the same manner as described, spherically shaped supporting disks or

washers

23 and 24 are interposed between the nuts and the adjacent bearing surfaces so that vessel 1 can perform a swinging movement about the underside of supporting ring 4, as at 31. Spherically shaped supporting

disks

23 and 24 are provided at the location 31 so that a movable joint is formed. It will be understood that the invention support arrangement can be applied in several variations, particularly with respect to the arrangement of the expansion member connections on the cir cumference of the vessel and insofar as position and number of the expansion members are concerned.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. A supporting arrangement for vessels used in metallurgical processing involving heat, such as tiltable, revolvable and tiltable and revolvable steelmill converters, of the type in which the vessel is supported in at least one supporting ring, said supporting arrangement comprising, in combination, support elements secured on the vessel wall and supporting the vessel on at least one axial end face of a supporting ring when the vessel is in an upright position; at least one first apertured projection member on the associated supporting ring; at least one second apertured projection member on the vessel wall; the apertures of associated first and second projection members being substantially aligned; respective tension rods extending through the apertures of associated first and second projection members and projecting beyond the two associated member, fastening means on the projecting ends of each rod cooperable with the two associated projection members to prestress the respective rods in tension when said vessel is in said upright position; and bearing means on the opposite projecting ends of each tension rod and engaged at least between the adjacent projection member and the adjacent fastening means to transmit tension stresses of the associated tension rod; said tension rods extending in a direction to suspend the vessel from the supporting ring when the vessel is tilted to at least the horizontal position; said bearing means providing for swinging displacement of the associated tension rods in a radial plane of the supported and tilted vessel.

2. A supporting arrangement for vessels used in metallurgical processing involving heat, as claimed in claim 1, in which each tension rod extends through its associated apertures loosely and with play.

3. A supporting arrangement for vessels used in metallurgical processing involving heat, such as tiltable, revolvable and tiltable and revolvable steelmill converters, of the type in which the vessel is supported in at least one supporting ring, surrounding the vessel, through the medium of support elements secured on the vessel wall, said supporting arrangement comprising, in combination, first means forming at least one hinge-like first fastening point on each supporting ring; second means forming at least one hinge-like second fastening point on each support element; and connecting elements extending between each first fastening point and a respective second fastening point, and displaceable radially of the supported vessel through the articulation provided by said fastening points; each first means includes a first apertured projection on the associated supporting ring, and each second means including a second apertured projection on the associated support element; each connecting element extending through substantially aligned apertures in the associated first and second projections; each connecting element extending through its associated apertures loosely and with play.

4. A supporting arrangement for vessels used in metallurgical processing involving heat, as claimed in claim 3, including spherically shaped annular disks interposed between each associated first and second projection and embracing the associated connecting element.

5. A supporting arrangement for vessels used in metallurgical processing involving heat, as claimed in claim 3, in which each threaded connecting element, the nuts threaded on opposite ends thereof, and the spherically shaped annular disks associated therewith constitute a connection unit; said connection units being arranged in pairs, and the connection units of each pair being disposed on opposite sides of the axis of symmetry of the supported vessel.

6. A supporting arrangement for vessels used in metallurgical processing involving heat, as claimed in claim 5, in which said support elements comprise rings secured to said vessel in heat conductive relation therewith and disposed on axially opposite sides of each supporting ring; and additional connection units interconnecting said last-named rings and extending parallel to the axis of symmetry of said vessel.

7. A supporting arrangement for vessels used in metallurgical processing involving heast, as claimed in claim 5, in which said support elements comprise rings secured to said vessel in heat conductive relation therewith on axially opposite sides of said supporting ring; and additional connection units extending between said supporting ring and said last-named rings and parallel to the axis of symmetry of said vessel.

8. A supporting arrangement for vessels used in metallurgical processing involving heat, such as tiltable, revolvable and tiltable and revolvable steelmill converters, of the type in which the vessel is supported in at least one supporting ring, surrounding the vessel, through the medium of support elements secured on the vessel wall, said supporting arrangement comprising, in combination, first means forming at least one hinge-like first fastening point on each supporting ring; second means forming at least one hinge-like second fastening point ment; each connecting element extending through substantially aligned apertures in the associated first and second projections; said connecting elements being arranged in pairs, the connecting elements of each pair being positioned on opposite sides of the axis of symmetry of the supported vessel.

* t i i

Claims

8. A supporting arrangement for vessels used in metallurgical processing involving heat, such as tiltable, revolvable and tiltable and revolvable steelmill converters, of the type in which the vessel is supported in at least one supporting ring, surrounding the vessel, through the medium of support elements secured on the vessel wall, said supporting arrangement comprising, in combination, first means forming at least one hinge-like first fastening point on each supporting ring; second means forming at least one hinge-like second fastening point on each support element; and connecting elements extending between each first fastening point and a respective second fastening point, and displaceable radially of the supported vessel through the articulation provided by said fastening points; each first means including a first apertured projection on the associated supporting ring, and each second means including a second apertured projection on the associated support element; each connecting element extending through substantially aligned apertures in the associated first and second projections; said connecting elements being arranged in pairs, the connecting elements of each pair being positioned on opposite sides of the axis of symmetry of the supported vessel.