US3892394A

US3892394A - Metallurgical vessel having restraining means

Info

Publication number: US3892394A
Application number: US385993A
Authority: US
Inventors: Richard P Krause; Harry T Montgomery
Original assignee: Pennsylvania Engineering Corp
Current assignee: Pennsylvania Engineering Corp
Priority date: 1973-08-06
Filing date: 1973-08-06
Publication date: 1975-07-01
Anticipated expiration: 1992-07-01
Also published as: JPS5072803A; JPS5729530B2; CA1039501A; GB1448804A

Abstract

A refractory lined converter vessel for converting ferrous metals to steel is supported in a trunnion ring and constrained against the rocking movement which can result from the swirling and slopping of molten metal in the vessel during various stages of the metallurgical refining cycle. The constraint means of the invention includes a plurality of restraint arms operated by double acting air cylinders which press the arms against the lower section of the vessel during the oxygen blow period and retract them during other stages of the refining operation when the vessel needs to be tilted for charging, deslagging or molten metal pouring.

Description

'United States Patent n91 Krause et al.

July 1, 1975 i 1 METALLURGICAL VESSEL HAVING RESTRAINING MEANS [73] Assigneei Pennsylvania Engineering Corporation, Pittsburgh, Pa.

[22] Filed: Aug. 6, 1973 [21] Appl, No: 385,993

[52] U5. 266/36 P [51] Int. Cl. CZlc 5/46 [58] Field of Search 266/35, 36 P {56] Reierences Cited UNITED STATES PATENTS 855,603 6/l907 Adams 266/36 P 3,502,3l3 3/l970 Pastorius 266/36 P FOREIGN PATENTS OR APPLICATIONS 204,0l8 5/l966 Sweden 266/35 Primary ExaminerGerald A. Dost Attorney, Agent, or FirmFred Wiviott [57] ABSTRACT A refractory lined converter vessel for converting fer rous metals to steel is supported in a trunnion ring and constrained against the rocking movement which can result from the swirling and slopping of molten metal in the vessel during various stages of the metallurgical refining cycle. The constraint means of the invention includes a plurality of restraint arms operated by double acting air cylinders which press the arms against the lower section of the vessel during the oxygen blow period and retract them during other stages of the refining operation when the vessel needs to be tilted for charging, deslagging or molten metal pouring,

23 Claims, 4 Drawing Figures METALLURGICAL VESSEL HAVING RESTRAINING MEANS BACKGROUND OF THE INVENTION In the process of refining molten iron in pneumatic process vessels, process gases such as oxygen may be injected beneath the level of molten metal so as to create turbulence within the molten metal bath. Because the bath level is lower than the pivotal axis of the trunnion ring which supports the vessel, the metal agitation produces reaction forces tending to rock the vessel but this is normally restricted by the drive unit restraining means. The resulting torque forces are transmitted from the vessel shell to the supporting trunnion ring through the drive side trunnion pin into the vessel drive assembly and down through the torsion restraining devices and into the concrete or steel supporting foundation for the converter vessel. During oxygen blowing periods, deflection may result in the torsion restraint devices of the drive system which can become sympathetic with vessel movement and actually aggravate the problem. The torsion restraint devices are designed normally to protect drive gears and support bearing from torque shocks during the starting and stopping of vessel tilting while the rotational or rocking forces occur during the oxygen blow period when the vessel is normally at rest.

OBJECTS OF THE INVENTION It is a primary object of this invention to provide a system for restraining the rocking motion of converter vessels resulting from the injection of oxygen into baths of molten metal.

It is another object of this invention to provide a converter restraint system which will not interfere with normal vessel tilting for charging, deslagging and pouring operations.

It is yet another object of the invention to provide a converter vessel restraint system which is readily adaptable to existing furnaces and which requires no modification in the vessel drive and support assembly.

A further object of the invention is to provide a restraining device for metallurgical vessels which reduce the thrust forces along the trunnion axis.

How these and other more specific objects of the invention are accomplished will appear from the follow ing detailed description of a preferred embodiment of the invention taken in conjunction with the drawings. Generally, however, the invention comprises disposing restraint arms in the walls ofa converter pit at approximately 90 angles around the lower portion of the converter vessel. Bumper plates attached to the furnace are similarly arranged so as to be in position for receiving the restraint arms when they are extended. The arms are bidirectionally activated by suitable power supply means such as air or hydraulic cylinders which press one end of each restraint arm firmly against its associated bumper plate and hold it there during the oxygen blow cycle. The contacting surface of each restraint arm is preferably ball and socket mounted to the remainder of the arm so as to insure proper contact between the restraint arm and the bumper plate. The restraint arms are designed so as to be retractable away from the vessel and out of the are through which the bottom ofthe converter passes during normal tilting for charging, deslagging or molten metal pouring.

DESCRIPTION OF THE DRAWINGS FIG. I is a top plan view ofa converter vessel having restraining means according to the invention;

FIG. 2 is a side elevational view of the converter shown in FIG. 1;

FIG. 3 is a fragmentary view showing the restraining means of the invention in an alternate position; and

FIG. 4 is a fragmentary view of a portion of the restraining means according to a preferred embodiment of the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT FIG. 1 illustrates a metallurgical vessel 10 having a refractory lining 11 and metallic shell 12. According to this invention, vessel 10 may also have an open upper end 13 for charging, deslagging and the evolution of hot gases during refining and pouring spout 14 may be provided adjacent the upper end for deslagging or pouring of the final melt. Surrounding vessel 10 is a generally annular trunnion ring 16 having trunnion shafts l6 and I7 extending from its opposite sides for being supported in

bearings

18 and 19.

As those skilled in the art will appreciate, one of the trunnion shafts is engaged by a drive assembly 20 for tilting vessel 10 as described above. The drive assembly 20 includes a bull gear (not shown) affixed to shaft 17 and disposed within a housing 21 and a plurality of motors 26, may be mounted on housing 21. As those skilled in the art will also appreciate, each motor 26 is suitably coupled to the bull gear for effective pivotal movement of vessel 10 and may be provided with brakes, speed reducers and the like. The

trunnion bearings

18, 19, drive system 20 and motors 26 have not been described in detail since they are ancillary to the invention and as such will not be described in detail. For a more specific description of a drive system 20, reference is made to United States patent application Ser. No. 213,610 filed Dec. 29, 1971, now U.S. Pat. No. 3,771,777 and assigned to the assignee of the pres ent application.

Trunnion bearings

18 and 19 rest on

support piers

28 and 29 respectively which in turn are supported by a concrete or steel foundation 32 which defines a pit 33 for containing the lower portion of converter I0. The vessel 10 may include a gas injection system 40 which may be of any well known type for injecting process gases such as oxygen, argon, air, nitrogen and the like into the molten metal bath. For example, the gas distribution system may include a plurality of tuyeres, not shown, extending through the bottom or side of the ves sel with their inner ends below the level of molten metal. In an exemplary gas injection system, the tuyeres may be of the type having a pair of concentric pipes wherein oxygen or an oxygen containing gas may be injected during the main blowing period and a shielding fluid, such as hydrocarbon containing gas or a light oil, is delivered through the outer pipe for the purpose of prolonging tuyere and refractory life. Also inert gases such as argon or nitrogen may be delivered through one or both pipes during various portions of the process cycle such as during vessel turn-up or turn-down or during desulfurization or recarburization. Particulate material such as lime, may be entrained in one or more of the gas streams and injected through the tuyeres if desired. The outer ends of the tuyeres may be coupled to a gas distribution system (not shown) but which is well known in the art. A housing 43 may surround the gas system and a pair of

gas pipes

44 and 45 are coupled through housing 43 to the individual gas distribu tion systems, not shown.

In metallurgical vessels where process gases are injected below the surface of the molten metal, the tuyeres are often arranged in an asymmetrical manner so as to produce a stirring action within the melt. As those skilled in the art will appreciate, for example, the tuycres may be inclined, or a majority may be located on one side of the vessel's center line. As an alternative, the tuyeres may extend through the side wall of the vessel. Such tuyere arrangements are illustrated in US Pat. No. 3,706,549, issued Dec. 19, 1972 to H. Knup' ple et al. In any event, the asymmetrical insertion of process gases and other materials causes agitation and turbulence within the melt which may produce reaction forces within the support and drive assembly. Restraining means 30 according to the invention, are provided to protect the drive assembly bearings and supports from torque shock loading which occurs during the starting and stopping of the rotational forces which occur within the vessel during gas blowing periods.

As seen in FIG. 2 the illustrated embodiment employs four restraining devices 30 which are spaced apart at about 90 intervals around the periphery of the vessel with each pair at about 45 relative to the center line of the trunnion shafts l7 and 18. It will be appreciated, however, that while four such devices or a lesser or greater number may be also employed.

Each of the restraint devices 30 includes a restraint arm assembly 60 pivotally mounted adjacent the vessel 10 and a coacting bumper assembly 70 affixed to the metallic shell 12 of vessel 10.

As best illustrated in FIG. 3, each of the bumper assemblies 70 includes a bumper plate 7] affixed to a tubular support 72 which in turn is suitably affixed to the metallic shell 12 of vessel 10 at a point below the trunnion ring 16. The support 72 may have a radially extending flange 73 affixed to one end and having a curvature generally conforming to that of the vessel 10 whereby flange 73 may be suitably affixed as by welding to the vessel shell 12. The opposite end of tubular member 72 may be formed at an oblique angle relative to its longitudinal axis for supporting bumper plate 71 in a plane which is generally tangential to the shell of vessel 10 and generally vertical when vessel 10 is in an untilted position. The bumper plate 71 may take any convenient shape and is shown to be circular in the preferred embodiment solely for purposes of illustration.

The restraint arm assembly 60 includes an arm 81 pivotally mounted on one end on bracket 82 which is suitably affixed to the walls of the pit 33 and an articulated bumper head 83 mounted on its other end. Suitable means, such as a fluid operated, double acting cylinder 84 may be provided for pivoting the arms 81 into and out of cooperative engagement with the bumper assembly 70.

Each of the arms 81 may have any convenient crosssectional configuration such as a rectangular member which is pivotally mounted between the legs ofa generally U-shapcd support bracket 82 by means of a pin 84 which extends through suitably aligned openings in bracket 82 and arm 8]. The end of arm 80 adjacent the wall of pit 33 may be configured so as to permit unimpeded pivotal motion.

The bumper heads 83 are preferably mounted on the free end of their respective arms 81 in any suitable manner which permits a slight degree of misalignment with the bumper plate 71. For example, each bumper head 83 may be mounted on an arm 8] by means of a ball joint assembly 85 as shown in FIG. 4. Each assembly 85 includes a socket member 86 having a radially extended flange 87 on one side for being secured to a mating flange 88 mounted on the end of arm 81 in any suitable manner such as by bolts 89. Socket member 86 has a hemispheric concave surface 90 on the side oppo site the flange 87 for receiving a ball 92 therein. A restraining plate 93 having a spherical opening 94 is affixed to the opposite side of socket member 86 and in surrounding relation to ball 92 to retain the latter in position. A stem 95 extends axially from one side of ball 92 and through the opening 94 in plate 93 and is threaded at its free end for being received within mating threads formed in the body portion 96 of bumper head 83. Body 96 may take any convenient configuration such as a solid cylindrical member which is truncated at its end remote from the threads for having attached thereto a plate 97 which may have the same general configuration as bumper plate 7!.

Each cylinder 84 includes a cylinder body pivotally mounted at one end to a bracket I06 affixed to a recess 107 formed in the concrete wall 32 of pit 33. A rod 107 extends axially from cylindrical body 105 and is pivotally connected by a pin 108 to a bracket 109 affixed to the side of arm 81.

Those skilled in the art will appreciate that the vessel 10 will normally be pivoted by drive assembly 20 for the purpose of being charged by hot metal and/or scrap, for deslagging and for discharging the molten metal after the completion of a process cycle. During such periods, the double acting cylinder 84 will be pressurized to pivot each of the arm assemblies 60 from their positions shown in FIGS. 1 and 2 to the retracted position shown in FIG. 3. This moves the bumper heads 83 out of an interfering position relative to bumper assemblies 70 whereby the vessel may then be freely pivoted about its trunnion shaft axis.

When it is desired to blow oxygen or other process gases into the molten metal bath within vessel 10, the vessel will normally be in an upright position as shown in FIGS. 1 and 2. Prior to the commencement of such blowing operations, each of the cylinder assemblies 84 will be actuated to pivot arm assemblies 60 away from the walls of pit 33 to move the plates 97 on bumper heads 83 into engagement with the bumper assemblies 70.

The cylinder controls (not shown) for delivering pressurized fluid to cylinders 84 may be interlocked with the drive controls of the bull gear so as to prevent tilting of the furnace when the arms are in an extended position, Such interlocking apparatus is not shown but is well known in the art.

The contact between the arm assemblies 60 and the bumper assemblies 70 prevents the vessel 10 from rocking during the blowing of process gases. As a result, transfer of torque forces to the drive assembly 20, bearings l8 and 19 and supports 28 and 29 are mini mized.

An additional advantage of the system just described is that the dampening device on the lower portion of the vessel 10 can help to reduce the thrust forces which oscillate or hammer in a linear direction along the trunnion axis and tend to brinell the bearing races and rollers in the fixed side trunnion support bearing [9. The thrust force is periodically reversed thereby tending to damage both sides of a typical double row bearing, the kind most commonly employed in support bearings such as 19. The thrust forces, besides damaging the trunnion bearings, can be transmitted through the trunnion bearings and housing into the bearing foundation pier 29 and eventually cause damage in this structure. The restraining devices of the invention help to reduce the damaging effects of thrust forces as well as the rocking action caused by the swirling and spitting of molten metal in the vessel.

Although the invention has been described in connection with drawings illustrating a single preferred embodiment, such description should not be taken as limiting the invention to specific restraint configurations, numbers, or specific placements thereof. For example. the exact placement ofthe restraint arms 60 and the bumper assemblies 70 is a design choice which could be made by one skilled in the art, having knowledge of the particular vessel, tuyere placements and the particular metallurgical refining operations. Also the movable portion of the assemblies 30 could be mounted upon the vessel and the stationary portion mounted on the stationary support structure or the bumper plate 7] or bumper 70 could be flexibly mounted and the plate 97 or arm 81 could be fixed or both plates could be flexibly arranged.

Also, while one particular type of gas distribution is illustrated in the drawings, it will be appreciated that the invention has application to other types of pneumatic steel making vessels as well, For example, the vessel 10 could be one in which argon and oxygen, either as a mixture or delivered through separate tuyere pipes, could be injected through the vessel and beneath the level of molten metal as is done in one well known type of steel making process. The invention could also be employed in basic oxygen type vessels wherein reaction forces of the type described are induced during injection of oxygen through a top lance. it is not intended, therefore, to limit the invention to the forego ing preferred embodiment but only by the scope of the appended claims.

We claim:

I. A metallurgical vessel,

support means for said vessel,

pivot means coupled to said vessel for pivoting the same about a generally hor zontal axis,

means for delivering at least one process gas to said vessel, and

a plurality of restraint means including a first portion mounted on said vessel and a second portion relatively movable into and out of engagement with said first portion for stabilizing the vessel against rocking motion when said portions are in engagement and allowing said vessel to pivot when said portions are out of engagement, said second re straint portion including at least one arm means pivotally mounted adjacent said vessel for pivotal movement into and out of engagement with said first portion of said restraint means,

2. The invention as claimed in claim I wherein said first portion includes plate means mounted on said vesscl and facing outwardly therefrom.

3. The invention set forth in claim I and including a plurality of said restraint means located in equi-spaced relation around the periphery of said vessel.

4. The invention set forth in claim 3 and wherein said support means includes shaft means mounted on said vessel and extending from the opposite sides thereof, bearing means for supporting said shaft means for pivoting said vessel on said bearing means, at least a pair of said restraint means being disposed on the opposite sides of said shaft means.

5. The invention set forth in claim 4 wherein said restraint means are displaced 45 from the axis of said shaft means.

6. The invention as claimed in claim 4 wherein each of said plurality of restraint means is located below the axis of said shaft means.

7. A metallurgical vessel.

generally horizontal shaft means mounted on said vessel and extending from the opposite sides thereof, bearing means supporting said shaft means for pivotal movement,

pivot means coupled to said shaft means for pivoting said vessel about a generally horizontal axis,

means for delivering at least one process gas to said vessel, and

a plurality of restraint means disposed in equi-spaced relation about the periphery of said vessel and below said pivotal axis, at least a pair of said restraint means being disposed on the opposite sides of said shaft means, each of said restraint means including a first portion mounted on said vessel and a second portion relatively movable into and out of engagement with said first portion for stabilizing the vessels against rocking motion when said portions are in engagement and allowing said vessel to pivot when said portions are out of engagement, each of said second restraint portions including at least one arm means pivotally mounted adjacent said vessel for pivotal movement into and out of engagement with one of said first portions of said restraint means.

8. The invention as claimed in claim 7 and including fluid operated means for moving said second portion into and out of engagement with said first portion.

9. In combination,

a metallurgical vessel means for delivering process fluids to said vessel to cause agitation of molten metal disposed therein,

support means for said metallurgical vessel,

said support means including a trunnion support ring having trunnion shafts extending substantially horizontally from the opposite sides thereof,

support bearing means for said trunnion shafts,

vessel tilting drive means connected to one of said trunnion shafts, and

restraint means disposed below said trunnion ring and arranged for restraining motion of the vessel during the delivery of said process fluids for disengagement with said vessel to permit tilting of said vessel. said restraint means comprising:

a. four bumper plate means affixed to said vessel and disposed at angles with respect to the vertical axis of said vessel and at 45 angles with respect to the axis of said trunnion shaft,

b. four restraint arms pivotally mounted adjacent said vessel for movement into and out ofengagement with said bumper plate means,

c. means for pivoting said restraint arms.

10. The invention as claimed in claim 9 wherein said means for pivoting said restraint arms are fluid operated cylinder means.

11. The invention as claimed in claim 9 wherein at least one of said restraint arms or said bumper plate means are flexibly mounted so as to permit misalign ment of the contacting portions of said restraint arms with said bumper plate means.

12. A metallurgical vessel,

support means for said vessel,

pivot means coupled to said vessel for pivoting the same about a generally horizontal axis.

means for delivering at least one process gas to said vessel. and

a plurality of restraint means disposed adjacent said vessel, said restraint means including a first portion mounted on said vessel and having a plate means facing outwardly therefrom and a second portion relatively movable into and out of engagement with b said first portion for stabilizing the vessel against rocking motion when said portions are in engagement and allowing said vessel to pivot when said portions are out of engagement, and including plate means mounted on said second portion, one of said plate means being flexibly mounted to permit misalignment therebetween.

13. The invention as claimed in claim 12 including fluid operated means for moving said plate means of said second portion into and out of engagement with said plate means of said first portion.

M. A metallurgical vessel,

support means, said vessel being mounted on said support means for pivotal movement about a generally horizontal axis,

means for delivering at least one process gas to said vessel,

a plurality of spaced apart restraint means, at least one of said restraint means being disposed on each of the opposite sides of a vertical plane containing said axis, each of said restraint means including a first portion mounted on said vessel and a second portion mounted on said support means, each of said second portions having a first and second position, said second means being out of the pivotal path of said vessel when in its first position thereby allowing said vessel to pivot about said axis, said second means being disposed in the pivotal path of said vessel and in engagement with said first portion when in its second position for stabilizing said vessel against rocking motion,

and means for moving each of said second portions between said first and second positions each of said second portions being pivotally mounted adjacent said vessel and about a fixed axis.

15. The invention as claimed in claim 14 wherein said first portion includes plate means mounted on said vessel and facing outwardly therefrom.

16. The invention as claimed in claim l5 and includ ing plate means mounted on each of said second portions, at least one of said plate means being flexibly mounted to permit misalignment therebetween.

17. The invention as claimed in claim 16 wherein each of said plurality of restraint means is located below said pivotal axis.

18. The invention as claimed in claim 17 wherein each of said second restraint portions includes an arm means pivotally mounted adjacent said vessel for pivotal movement into and out of engagement with said first portion of said restraint means.

19. The invention set forth in claim 18 and including shaft means mounted on said vessel and extending from the opposite sides thereof, said support means includ ing bearing means for supporting said shaft means for pivotal movement, at least a pair of said restraint means being disposed on the opposite sides of said shaft means.

20. The invention as claimed in claim 19 including fluid operated means for moving said plate means of said second portion into and out of engagement with said plate means of said first portion.

21. The invention set forth in claim 20 and including a plurality of said restraint means located in equispaced relation around the periphery of said vessel.

22. ln combination.

a metallurgical vessel, means for delivering process fluids to said vessel to cause agitation of molten metal disposed therein,

support means for said metallurgical vessel,

said support means including a trunnion support ring having trunnion shafts extending substantially hori zontally from the opposite sides thereof,

support bearing means for said trunnion shafts,

vessel tilting drive means connected to one of said trunnion shafts, and

restraint means disposed below said trunnion ring and arranged for restraining motion of the vessel during the delivery of said process fluids for disengagement with said vessel to permit tilting of said vessel, said restraint means comprising:

a. a plurality of bumper plate means affixed to said vessel and spaced apart therearound.

b. a plurality of restraint arms each pivotally mounted adjacent said vessel,

c. means for pivoting each of said restraint arms into and out of engagement with one of said bumper plate means.

23. The invention as claimed in claim 22 wherein at least one of said restraint arms or said bumper plate means are flexibly mounted so as to permit misalignment of the contacting portions of said restraint arms with said bumper plate means.

l l k i Patent No.

3,892,394 Dated July 1, 1975 lnventofls) Richard P. Krause and Harry T. Montgomery It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Claim Claim 4, Column 6, Line 10, after "of" insert --a plane containing the axis of-.

5, Column 6, Line 12, after "displaced" insert -through a horizontal angle of-; before "the" insert -a generally vertical plane containing-.

Claim 6, Column 6, Line 15, after "below" insert --a generally horizontal plane containing-.

Claim 7, Column 6, Line 28, after "below" insert --a generally horizontal plane containing-; Line 30, after "of" (first occurrence) insert -a vertical plane containing the axis of--.

Claim 9, Column 6, Line 64, after "respect to" insert --a generally vertical plane containing-.

Claim 14, Column 7, Line 44, after 'and" insert '--8.'-'.-; Line 45,

cancel "means" and substitute -portion--; Line 48, cancel "means" and substitute --portion-.

Claim 17, Column 8, Line 8, after "below" insert -a generally horizontal plane containing-- Claim 19, Column 8, Line 19, after "sides of" insert --a generally vertical plane containing the axis of-.

Signed and Scaled this tenth D3) Of February 1976 [SEAL] Arrest.

RUTH C. MASON Commissioner of Parents and Trademarks

Claims

1. A metallurgical vessel, support means for said vessel, pivot means coupled to said vessel for pivoting the same about a generally horizontal axis, means for delivering at least one process gas to said vessel, and a plurality of restraint means including a first portion mounted on said vessel and a second portion relatively movable into and out of engagement with said first portion for stabilizing the vessel against rocking motion when said portions are in engagement and allowing said vessel to pivot when said portions are out of engagement, said second restraint portion including at least one arm means pivotally mounted adjacent said vessel for pivotal movement into and out of engagement with said first portion of said restraint means.

2. The invention as claimed in claim 1 wherein said first portion includes plate means mounted on said vessel and facing outwardly therefrom.

3. The invention set forth in claim 1 and including a plurality of said restraint means located in equi-spaced relation around the periphery of said vessel.

5. The invention set forth in claim 4 wherein said restraint means are displaced 45* from the axis of said shaft means.

7. A metallurgical vessel, generally horizontal shaft means mounted on said vessel and extending from the opposite sides thereof, bearing means supporting said shaft means for pivotal movement, pivot means coupled to said shaft means for pivoting said vessel about a generally horizontal axis, means for delivering at least one process gas to said vessel, and a plurality of restraint means disposed in equi-spaced relation about the periphery of said vessel and below said pivotal axis, at least a pair of said restraint means being disposed on the opposite sides of said shaft means, each of said restraint means including a first portion mounted on said vessel and a second portion relatively movable into and out of engagement with said first portion for stabilizing the vessels against rocking motion when said portions are in engagement and allowing said vessel to pivot when said portions are out of engagement, each of said second restraint portions including at least one arm means pivotally mounted adjacent said vessel for pivotal movement into and out of engagement with one of said first portions of said restraint means.

9. In combination, a metallurgical vessel means for delivering process flUids to said vessel to cause agitation of molten metal disposed therein, support means for said metallurgical vessel, said support means including a trunnion support ring having trunnion shafts extending substantially horizontally from the opposite sides thereof, support bearing means for said trunnion shafts, vessel tilting drive means connected to one of said trunnion shafts, and restraint means disposed below said trunnion ring and arranged for restraining motion of the vessel during the delivery of said process fluids for disengagement with said vessel to permit tilting of said vessel, said restraint means comprising: a. four bumper plate means affixed to said vessel and disposed at 90* angles with respect to the vertical axis of said vessel and at 45* angles with respect to the axis of said trunnion shaft, b. four restraint arms pivotally mounted adjacent said vessel for movement into and out of engagement with said bumper plate means, c. means for pivoting said restraint arms.

11. The invention as claimed in claim 9 wherein at least one of said restraint arms or said bumper plate means are flexibly mounted so as to permit misalignment of the contacting portions of said restraint arms with said bumper plate means.

12. A metallurgical vessel, support means for said vessel, pivot means coupled to said vessel for pivoting the same about a generally horizontal axis, means for delivering at least one process gas to said vessel, and a plurality of restraint means disposed adjacent said vessel, said restraint means including a first portion mounted on said vessel and having a plate means facing outwardly therefrom and a second portion relatively movable into and out of engagement with said first portion for stabilizing the vessel against rocking motion when said portions are in engagement and allowing said vessel to pivot when said portions are out of engagement, and including plate means mounted on said second portion, one of said plate means being flexibly mounted to permit misalignment therebetween.

14. A metallurgical vessel, support means, said vessel being mounted on said support means for pivotal movement about a generally horizontal axis, means for delivering at least one process gas to said vessel, a plurality of spaced apart restraint means, at least one of said restraint means being disposed on each of the opposite sides of a vertical plane containing said axis, each of said restraint means including a first portion mounted on said vessel and a second portion mounted on said support means, each of said second portions having a first and second position, said second means being out of the pivotal path of said vessel when in its first position thereby allowing said vessel to pivot about said axis, said second means being disposed in the pivotal path of said vessel and in engagement with said first portion when in its second position for stabilizing said vessel against rocking motion, and means for moving each of said second portions between said first and second positions each of said second portions being pivotally mounted adjacent said vessel and about a fixed axis.

16. The invention as claimed in claim 15 and including plate means mounted on each of said second portions, at least one of said plate means being flexibly mounted to permit misalignment therebetween.

19. The invention set forth in claim 18 and including shaft means mounted on said vessel and extending from the opposite sides thereof, said support means including bearing means for supporting said shaft means for pivotal movement, at least a pair of said restraint means being disposed on the opposite sides of said shaft means.

21. The invention set forth in claim 20 and including a plurality of said restraint means located in equi-spaced relation around the periphery of said vessel.

22. In combination, a metallurgical vessel, means for delivering process fluids to said vessel to cause agitation of molten metal disposed therein, support means for said metallurgical vessel, said support means including a trunnion support ring having trunnion shafts extending substantially horizontally from the opposite sides thereof, support bearing means for said trunnion shafts, vessel tilting drive means connected to one of said trunnion shafts, and restraint means disposed below said trunnion ring and arranged for restraining motion of the vessel during the delivery of said process fluids for disengagement with said vessel to permit tilting of said vessel, said restraint means comprising: a. a plurality of bumper plate means affixed to said vessel and spaced apart therearound, b. a plurality of restraint arms each pivotally mounted adjacent said vessel, c. means for pivoting each of said restraint arms into and out of engagement with one of said bumper plate means.