US3695602A

US3695602A - Metal converting furnace apparatus

Info

Publication number: US3695602A
Application number: US65651A
Authority: US
Inventors: Ernst A Mevissen
Original assignee: Dravo Corp
Current assignee: Dravo Corp
Priority date: 1970-08-20
Filing date: 1970-08-20
Publication date: 1972-10-03
Anticipated expiration: 1989-10-03

Abstract

The combination of a metal converting furnace and a pair of diametrically opposed support assemblies mounted thereon is disclosed. Each of the support assemblies includes brackets mounted directly on the outer surface of the furnace and arranged to define a central pocket and slots extending radially outwardly from the pocket. A shaft has a hub formed on the inner end thereof and is shaped and sized to fit within the pocket, and lugs extending radially outwardly from the hub and shaped and sized to be received in the slots. The slots and lugs are shaped and sized to permit a reasonable amount of misalignment therebetween whereby mating of the shaft to the brackets is in the nature of a flexible connection. A heat shield is mounted on the outer surface of the furnace with the shield surrounding the tap spout of the furnace and enclosing an area around the spout. The shield serves as a heat sink for the heat radiated from molten metal poured into a ladle. Finally, the metal shell of the furnace is thickened in the area surrounding the tap spout. The thickened wall serves to resist distortion due to the thermal expansion concentrated in the area of the wall where the molten metal flows during tap off.

Description

United States Patent Mevissen 154] METAL CONVERTING FURNACE APPARATUS [72] Inventor: Ernst A. Mevissen, Robinson Township, Allegheny County, Pa.

[73] Assignee: Dravo Corporation, Pittsburgh, Pa.

[22] Filed: Aug, 20, 1970 [21] Appl. No: 65,651

Primary Examiner-Gerald A. Dost Attorney-Parmelee, Utzler & Welsh [5 7 ABSTRACT The combination of a metal converting furnace and a [451 Oct. 3, 1972 pair of diametrically opposed support assemblies mounted thereon is disclosed. Each of the support assemblies includes brackets mounted directly on the outer surface of the furnace and arranged to define a central pocket and slots extending radially outwardly from the pocket. A shaft has a hub formed on the inner end thereof and is shaped and sized to fit within the pocket, and lugs extending radially outwardly from the hub and shaped and sized to be received in the slots. The slots and lugs are shaped and sized to permit a reasonable amount of misalignment therebetween whereby mating of the shaft to the brackets is in the nature of a flexible connection. A heat shield is mounted on the outer surface of "the furnace with the shield surrounding the tap spout of the furnace and enclosing an area around the spout. The shield serves as a heat sink for the heat radiated from molten metal poured into a ladle. Finally, the metal shell of the furnace is thickened in the area surrounding the tap spout. The thickened wall serves to resist distortion due to the thermal expansion concentrated in the area 25 Claims, 8 Drawing Figures METAL CONVERTING FURNACE APPARATUS This invention relates to metal converting furnace apparatus, and more particularly to the combination of a metal converting furnace and support assemblies therefor.

BOF and other converting furnaces used in refining metal have customarily used a trunnion ring fixed around a central portion of the furnace, with opposed trunnion shafts fixed to the ring. The trunnion shafts are usually supported for rotation, with one of the shafts being coupled with a drive motor through reduction gearing, thus enabling the furnace to be tilted for molten metal or slag tap off. Converting furnaces of this type generate tremendous quantities of heat at extremely high temperatures during refining operations. The high temperatures cause the metal shell of the furnace to expand resulting in distortion of the shell and high local stresses. Because of the expansion of the shell, the trunnion ring is also subject to expansion and resulting permanent distortion. Accordingly, the shell and trunnion ring must be periodically repaired and sometimes replaced. The trunnion ring is also subject to physical abuse, as for example during shipment, which causes distortion, necessitating repair. Also, the ring by its very nature, is very costly to fabricate and the expense is compounded since the ring requires elaborate attachment arrangements with the furnace vessel which must be designed to accommodate the radial and axial expansion of the vessel. Additionally, tedious and time consuming field fitting and aligning of the trunnion ring to the support structure on the furnace is necessary.

Another undesireable feature of a trunnion ring support arrangement is the fact that the ring is very heavy and, thus, prevents, for all practical purposes, added weight to the furnace. For example, distortion of the metal shell of the furnace may be minimized by increasing the thickness of the metal wall or by adding radiation heat shields to the furnace. Doing this, however, would necessitate a larger, and therefore heavier, trunnion ring as well as an increase in the size of the trunnion shafts and bearings therefor, and usually an increase in the capacity of the drive motors and gear train used to tilt the furnace. Because these increases are very expensive, design of the furnace to avoid distortion may be compromised with resulting unnecessary distortion of the furnace shell. 7

Various attempts have been made to avoid damage to the trunnion ring due to the thermal expansion between the furnace and the ring. Means have been provided between the furnace and the trunnion ring to allow the furnace to expand independently of the ring. That is, the furnace is allowed to expand without transmitting that expansion directly to the trunnion ring. Such means usually involve complicated and costly sliding brackets and guides, requiring careful selection of clearances which are often upset due to the physical abuse given to the trunnion ring, making alignment a cumbersome procedure. The sliding brackets and guide arrangements are also subject to damage from thermal expansion of the furnace when the clearances are improperly selected or are changed because of physical abuse.

Direct mounting of the trunnion shafts to the furnace has been suggested for overcoming the trunnion ring problems. Such direct mounting, however, has its problems also, especially with high local stresses around the mounting structure on the furnace created by the thermal expansion of the metal shell. In addition there is the problem of aligning the shafts to the shaft support structure on the furnace. This alignment problem exists when new shafts are mounted to new furnaces, but becomes considerably greater when a used shaft must be remounted to a used furnace. The high local stresses to the support structure on the furnace will frequently result in distortion of the various elements forming the structure. Thus, alignment of the shafts to the support structure becomes virtually impossible without major reworking or replacement of the distorted elements. If a new vessel replaces an old one, most likely new trunnion shafts will also be provided.

l overcome those problems stated above by providing a support arrangement for metal converting furnaces which does not use a trunnion ring. My support arrangement is direct furnace mounted, but avoids the direct mounting alignment and local stress distortion problems. More particularly, I provide a combination of a metal converting furnace and a pair of opposed support assemblies, with each assembly preferably comprising: ground supported shaft means coupled to the furnace for supporting the furnace above ground level; and flexible connection means on the shaft and furnace, respectively, engaging each other for supporting the furnace on the shaft. Since the connections between the shafts andfurnace are flexible connections, a certain degree of misalignment caused, for example, by distortion of parts resulting from thermal expansion or fabrication error is allowed. Also, the flexible connection will allow the connection structure on the furnace to move with the furnace during thermal expansion, and independently of the mating connection on the trunnion shaft. Because the support structures move relative to each other the high local stresses otherwise resulting in the support structures of rigidly furnace mounted trunnion shafts are virtually eliminated. In my preferred form I achieve these results by providing a spline type of a connection which I illustrate as including four brackets fixed to the metal shell of the furnace and arranged to define four slots spaced ninety degrees apart and extending radially from a central pocket. The inner end portion of each of my trunnion shafts has a hub which is shaped and sized to fit in the pocket, and also has four lugs extending radially from the hub; The lugs are fitted into the slots, with the shape and size of the slots and lugs being selected to permit a certain degree of misalignment therebetween typical of any spline-type flexible coupling. Thus, misalignment is compensated for. Local stresses from heat expansion will also be eliminated since the brackets on the furnace wall will move with the furnace to open the slots. My invention contemplates either a fixed orientation furnace or one that is tiltable. With a tiltable arrangement a drive motor would be coupled to one of the trunnion shafts through suitable reduction gearing. In both the tiltable and stationary furnace arrangements, one of the shafts would be supported for limited axial movement so that the expansion of the furnace will be taken up by that shaft.

By eliminating the heavy trunnion ring, the furnace may be made larger and heavier without any necessity of changing the size of the trunnion shafts, and bearings supports, and drives therefor. Thus, my invention permits addition of weight to the critical points of the furnace for the purpose, for example, of resisting distortion resulting from thermal expansion. One area of a tiltable furnace subject to the greatest distortion from thermal expansion is that area of the metal shell around a molten metal tap. When the metal is being tapped off it will be concentrated on the inner wall of the furnace surrounding the tap and the metal shell will tend to creep and enlarge in time, more so than the rest of the shell, and to become, as is said in the trade, pregnant. The distorted portion of the shell is either replaced or, if the distortion is too great, the entire furnace is scrapped. The external area of the furnace around the tap is also subjected to radiant heat from the molten metal as it is being poured into a ladle. The radiant heat further adds to the distortion of the metal shell around the tap. I considerably reduce the distortion problems just mentioned by providing, in one instance, a thickened metal shell in the area of the furnace around the tap, and, in a second instance, providing a heat shield mounted on the outer wall of the metal shell and covering the area around the tap which would be subject to the radiation from a ladle into which molten metal was being poured. The thickened shell will resist distortion resulting from the concentrated volume of metal thereon, while the heat shield will prevent distortion by serving as a heat sink between the shell and the ladle of molten metal. The heat shield would be subject to distortion but it could be easily and more cheaply replaced as compared to replacing a section of metal shell.

Other details and advantages of this invention will become apparent as the following descriptions of certain present preferred embodiments thereof proceed.

In the accompanying drawings I have shown certain present preferred embodiments of this invention in which:

FIG. 1 is a side elevation view partly in section of a combination metal converting furnace and support assemblies therefor, embodying one form of the present invention;

FIG. 2 is a view looking along the line IIlI of FIG. 1 with certain portions of the furnace being cut away and heat shield around one of the tap spouts being in section, to show details of construction;

FIG. 3 is a top plan view of the furnace and supports of FIG. 1 and including drive motors and primary gear reduction boxes coupled with one of the trunnion shafts;

FIG. 4 is an enlarged elevation view, partly in section, of the trunnion shaft and support members Referring now to the drawings, and especially to FIGS. 1-6, there is shown a typical open-mouthed metal converting furnace 10 as would be used in the basic oxygen refining of steel. The furnace 10 has an outer metal shell 11 and a refractory block inner shell 12. The furnace 10 is shown in its upright metal charging or refining position; that is, with its longitudinal centerline being vertical, and location of elements hereinafter will be described in reference to the upright position. The furnace 10 is a tiltable one, being supported above ground level for rotation about a generally horizontal axis by a pair of diametrically opposed support assemblies 14, and 16, respectively. Identical molten metal tap spouts 18 and 20 are arranged on opposite sides of the furnace at upper portions thereof, thereby allowing the furnace to be tilted in two directions for metal tap-off.

Both support assemblies 14 and 16 are arranged for direct connection with the outer wall of the furnace. That is, the support assemblies 14 and 16 are not coupled to a trunnion ring mounted on the furnace. Support assembly 14 is coupled to power means for supplying the driving force needed to tilt the furnace. Support assembly 14 includes an elongated trunnion shaft member 21 having a generally frusto-conical shape, and is supported for rotation with its axis horizontally oriented by spaced

bearings

22 and 24, both of which are arranged in housing 26 resting on and anchored to a reinforced concrete foundation 28. The right end, as viewed in FIG. 1, of trunnion shaft 21 is connected to the furnace in a manner to be described hereinafter. Since it is the same essential coupling arrangement as is used with the other support assembly 16 only one description for both will be made in the interest of avoiding redundant description. Trunnion shaft 21 of support assembly 14 is driven by power means 30 and 32, shown in FIG. 3, arranged for selectively driving the shaft in reverse directions. Each power means 30 and 32 includes a pair of

motors

34 and 36 connected with a source of electrical power, not shown, both of which motors are coupled to a primary reduction gear arranged in housings 38. The primary reduction gear is coupled with a drive shaft 40 which is supported in housing 26 as shown in FIG. 1, which drive shaft 40 has a pinion gear 42 mounted on an intermediate portion thereof. The pinion gear 42 engages a second reduction gear 44 arranged on an intermediate portion of trunnion shaft 21.

Support assembly 16 includes an elongated trunnion shaft 50 of generally frusto-conical shape having its longitudinal axis coaxial with the axis of trunnion shaft 21, and supported for rotation by bearings 52 and 54 arranged on a bearing stand 56 which rests on and is anchored to a reinforced concrete foundation 58. A cover 59 is placed over the bearings 52 and 54 to protect them from damage. Trunnion shaft 50 serves as an idler shaft and is arranged to move a fixed distance along its horizontal axis so that axial thermal expansion of the furnace 10 will be taken up by shaft 50.

The right end of trunnion shaft 21 and left end of trunnion shaft 50 as viewed in FIG. 1, are both identically connected to the furnace. As stated earlier, one description of both connections will be made with the understanding that it refers to both support assemblies 14 and 16. Referring now to the connection arrangement for support assembly 16, there is provided four identically shaped brackets 60 fixed to the outer wall of the metal shell 11 of furnace 10. Each bracket 60 is suitably curved to conform with the curvature of furnace and is joined to a supporting pin 61, shown in FIG. 5, and fixed to the metal shell 11 by a series of fasteners such as bolts, for example. Each bracket 60 is appropriately shaped and sized in the manner shown clearly in FIG. 4, so that when the four brackets are fixed to the metal shell 11 as shown, they define with portions of metal shell 11 a central pocket 62 with four

slots

63, 64, 65, 66 extending radially from the pocket and having their centerline spaced generally 90 apart. Slots 63 and 65 are identically shaped and are located at the 12 and 6 oclock positions respectively; while

slots

64 and 66 are identical and are located at 3 and oclock respectively. However, the shape of all the

slots

63, 64, 65, 66 adjacent to pocket 62 is the same for all, for reasons which will become apparent as the description continues.

The left or inner end portion 70 of trunnion shaft 50 is formed to include a hub portion 72 shaped to fit within pocket 62 defined by brackets 60. Four identically shaped lugs 74 extend radially outwardly from hub portion 72 and have their centerlines spaced generally ninety degrees apart. Each lug 74 is shaped and sized to fit within the identically shaped portions of the

slots

63, 64, 65, 66 defined by brackets 60. Hardened steel wear plates 78 are arranged between the side faces of lugs 74 and the wall of the

slots

63, 64, 65, 66. The wear plates 78 are sized to permit a slidable fit between the lugs and the slots. As shown in FIGS. 5 and 6, a clearance exists between the face or left end portion 70 of shaft 50 and the furnace. Limited axial movement of the shaft 50 toward and away from the furnace is thus permitted but is restricted by four identical retention brackets 80, one each of which is mounted, as with removable bolts for example, to the metal shell 11 of the furnace 10 in each of the

slots

63, 64, 65, 66 defined by brackets 60. Each retention bracket 80 has parallel tabs 81 and 82, shown clearly in FIG. 6, which serve as stops for lugs 74 to limit the axial movement of trunnion shaft 50. A clearance is also provided between the free ends of lugs 74 and the inner face 84 formed between the tabs 81 and 82 of the retention brackets 80. By virtue of the clearances just described, the shaft 50 has a certain degree of movement relative to the brackets 60. Thus, the connection of the shaft 50 at the inner end portion 70 thereof to the brackets 60 is in the nature of a flexible splined connection-the lugs 74 being external splines and the

slots

63, 64, 65, 66 being internal splines defined by the four brackets 60. The clearances between the lugs 74 and the surfaces of the slots as defined by brackets 60 and retention brackets 80 allows a reasonable degree of misalignment therebetween thus permitting the trunnion shaft 50 to be flexibly connected to brackets 60 (i.e., connected to furnace 10).

Brackets 60 will move and expand with the metal shell 11 of furnace 10 when it thermally expands during refining of metal. As the metal shell 11 expands circumferentially so will the brackets 60 to thereby widen the

slots

63, 64, 65, 66. By virtue of this widening of the slots, local stresses are prevented between the brackets 60 and the inner end portion 70 of shaft 50. The

loosening of the slots can be controlled to avoid any adverse consequences, by making a tight fit between the sides of lugs 74 and slots. Proper sizing of the wear plates 78 will provide the desired tight fit. In any event the opening of the clearances between the lugs and slots will be very small, as compared with a trunnion ring bracket arrangement, since the dimensions of the slots are small compared to the trunnion ring bracket axial spacing. Stress on the trunnion shafts 21 and 50 due to radial expansion of the vessel is avoided since trunnion shaft 50 is supported to move a limited amount along its horizontal axis, thus allowing the radial expansion of the vessel 10 to be taken up by the shaft 50. Another advantage of the flexible connection arrangement, is that a very small force is transmitted to the vessel, as compared with the force which would be transmitted to the vessel by rigidly connected shaft ar-.

rangements. in a rigidly connected shaft arrangement, the moment arm acting on the vessel would be the length of the shaft. In the present invention-the trunnion shafts will not act directly on the vessel wall since they are flexibly connected with the vessel. The only moment arms acting on the vessel in this invention are the brackets, which are considerably shorter in length than rigidly connected trunnion shafts. The large moment arm of the rigid connection could possibly damage the vessel wall. Thus, I diminish this possibility by decreasing the moment arms to a very small value.

When the furnace 10 is in the charge or refining position shown in the drawings, the 3 and 9 oclock lugs 74 carry the load while the 12 and 6 oclock lugs are under no-load but do serve to stabilize the furnace. When the furnace is tilted the load on the lugs will shift. it should be noted at this juncture that the orientation of the centerlines of the lugs and slots as described and illustrated is not critical and may be arranged as desired with reference to the longitudinal centerline of the furnace. For example, as compared with the previously described structure, all of the lugs 74 could be shifted 45 out of phase and the brackets 60 arranged accordingly to define slots 45 out of phase. Any other shifting could be selected as desired. Also it is' noted that four external splines (lugs 74) and internal splines (slots) are not critical, and any number may be selected as desired. Four splines is a practical number, but anywhere from two and up to a practical number may be used. Moreover, my flexible connection between the trunnion shafts and the vessel need not be aspline arrangement but may take on any other form which those skilled in the art would readily recognize.

FlGS.7 and 8 illustrate another flexible connection arrangement between the trunnion shafts and the furnace in accordance with the present invention. In this arrangement the splines are reversed, the external splines being formed on brackets mounted on the furnace and the internal splines being formed on the trunnion shaft. As shown, inner end portion of trunnion shaft 50' which is supported for rotation in the same general manner as trunnion shaft 50, has four identical slots 92 formed therein and spaced with their centerlines being ninety degrees apart. Four identically shaped brackets 96 are secured to the metal shell of a furnace, each bracket having a lug 97 depending from a main body portion and received in a slot 92 of sleeve member 90. Hardened steel wear plates are arranged between the side face of the lugs 97 and the opposite faces of the slots 92. A clearance exists between the face of inner portion 90 of shaft 50 and the opposite wall portion of the furnace. Some axial movement by the trunnion shaft 50' toward and away from the furnace is thus provided and the extent of such movement is limited by trunnion retention brackets 98 fixed to the furnace and arranged to fit loosely over the inner end portion 90. A clearance is also provided between the radial outer end of each lug 97 and the end of the slot 92 facing the lug. The clearances mentioned in this paragraph thus provide the necessary freedom of movement to provide reasonable degree of misalignment between the lugs 97 and slots 92, much in the same manner as the embodiment of FIGS. 1-6.

The brackets 96 of the embodiment of FIGS. 7 and 8 will tend to expand with the metal shell of the furnace during metal refining. During circumferential expansion the mating between the lugs 97 and slots 92 will become tighter, whereas in the first embodiment the mating between the lugs and slots became looser. Nevertheless, the coupling arrangement between trunnion shaft 50' and the furnace will be devoid of local stresses caused by thermal expansion. Any damaging stress between the lugs 97 and trunnion shaft 50' may be simply avoided by proper size selections of wear plates 95 for giving a suitable clearance between the side faces of the lugs 97 and the opposite faces of the slots 92, which clearance will allow for the expansion of the lugs 97 without causing distortion of the sleeve 90. In any event, whatever stresses are created between the lugs 97 and the shaft 50' will be very low since the degree of expansion of the lugs will be small because of their small sizes (i.e., as compared to a trunnion ring and bracket arrangement, for example).

Referring again to the first embodiment of this invention, there is provided, as shown in FIGS. 1-3, slag shields 100 and 102 suitably fixed to the furnace and covering the flexible connections (i.e., brackets 60 and inner end portion 70 of trunnion shaft 50) to protect them from molten metal and slag spatter. The slag shields 100 and 102 are opened, as shown, so that the vessel may be easily accessible for inspection or service.

As mentioned earlier in the introductory portion of this description, the area of the furnace 10 subject to the greatest distortion due to thermal expansion is the area surrounding the tap spouts 18 and 20. This area may extend from the top to a lower portion of the furnace, and to an arcuate distance covering maybe 120 measured 60 degrees on each side of the tap spouts l8 and 20. The dimensions of the area are governed by the lines of radiation from the hot metal ladle into which the vessel is being tapped, and are not restricted to any absolute values such as those mentioned above. The distortion in the area around the tap spouts 18 and 20 is resisted by providing a metal shell section lla (See FIG. 2) having a thickness greater than that of the remainder of the shell. The thickness of the portion 1 1 a may be chosen as desired taking into consideration the overall design of the furnace 10. The thickness should not be so great as to reduce the volume of the furnace. Most often the thickness of portion 1 1a will be selected on the basis of standard plate size. For example if standard 2 inch plate is used in fabricating metal shell 11, standard 6 inch plate might be used for portion 1 la.

The external areas of the vessel surrounding the tap spouts 18 and 20 are exposed to the radiation of the molten metal as it is poured from the spouts into a ladle. The radiation also causes higher expansion to the metal shell 11 in the area of the tap spouts 18 and 20 as compared with the rest of the shell. In order to reduce the distortion effect from the molten metal radiation, 1 provide heat shields covering the area around the tap spouts 20. As shown, each heat shield 110 has a lower portion 110a shaped generally in the form of a section of a cylinder and an upper portion 110b shaped generally in the form of a section of a truncated cone. Together the lower and upper portions 110a and 1l0b cover an area of the furnace. A preferred area of each heat shield would be slightly more than the mouth area of the ladle into which the metal will be poured. Thus, if a shield 110 were laid on top of the ladle, it would completely cover the mouth of the ladle. Upper portion 1 10b has an opening cut therethrough to fit around tap spout 18 or 20. A pair of clevis connections 114 located at the lower end of each heat shield 110 serve to pivotally mount each heat shield to the metal shell 11 of the furnace 10. A pair of wedge type locks 116 fixed between the top ends of each heat shield 110 locks the heat shields to the furnace. The heat shields 110 thus act as heat sinks for the heat of radiation emitted from the molten metal as it is being poured into a ladle and thereby decreases the thermal expansion of the metal shield 11 compared with expansion of the shell caused by direct radiation from the molten metal to the shell. The heat shields 1 10 may be pivoted into a horizontal position in which case they may be used as work platforms.

Since this invention eliminates the need for a heavy trunnion ring improvements such as the thickened shell and the heat shields may be made to the furnace without concern for adding too much weight to the supports. Other improvements could also be made, as for example, attaching stiffeners to the outer periphery of the furnace to reinforce the metal shell against thermal expansion. The stiffeners would also function as heat transfer radiating surfaces and would add to decreasing the temperature of the metal shell. Even without stiffeners the metal shell of the furnace would tend to be cooler since elimination of the trunnion ring exposes more heat transfer surface of the shell to the atmosphere.

It should be readily apparent that connecting and disconnecting the trunnion shafts 21 and 50 to the furnace is simplified by the virtue of the arrangement of elements as described. Each trunnion shaft and its bearing supports may be connected and disconnected as a unit from the furnace. This permits the trunnion shafts and bearing supports to be assembled or disassembled in a shop away from the furnace.

While I have shown and described various embodiments of my present invention it should be clear that various changes and modifications may be made in this invention within the contemplation of the following claims. Examples of such changes and modification have already been noted hereinbefore. Also, there are various other advantages to the flexible connection support arrangement of my invention over trunnion ring and direct shaft connection arrangements, as those skilled in the art could readily see.

lclaim:

1. In combination with a metal converting firnace, a pair of opposed support assemblies, each of which comprises:

ground supported shaft means coupled directly to an external portion of the furnace shell for supporting the furnace above ground level;

first and second connection means on said shaft means and the furnace shell, respectively, and flexibly engaging each other for supporting the furnace on said shaft means; and

one of said connection means having multiple external splines defined thereon, and the other of said connection means having multiple internal splines defined therein, said splines mating with each other and being shaped and sized with clearances to permit a certain degree of misalignment therebetween.

2. The combination as set forth in claim 1 wherein a clearance space is provided between the free ends of the external splines and the ends of the internal splines.

3. The combination as set forth in claim 1 wherein said first connection means includes the external splines and said second connection means includes the internal splines.

4. The combination as set forth in claim 3 including stop members disposed in the internal splines adjacent the free ends of the external splines. v

5. The combination as set forth in claim 1 including separate means for selectively securing said first and second connection means in engagement with each other.

6. The combination as set forth in claim 1 wherein said second connection means includes four similarly shaped brackets mounted on the wall of the furnace and arranged thereon to define a central pocket and four slots generally 90 apart extending radially from the pocket; and said first connection means having a hub shaped and sized to fit within said pocket and four lugs generally ninety degrees apart and shaped and sized to be received in said slots, with said slots and lugs being shaped and sized to permit a certain degree of misalignment therebetween.

7. The combination as set forth in claim 6 including wear plate members arranged in abutting relationship between the sides of said lugs and said slots.

8. The combination as set forth in claim 6 including retaining plates mounted on the wall of the furnace within the confines of said slots and arranged adjacent the free ends of said lugs.

9. The combination as set forth in claim 1 wherein said shaft means of each of the support assemblies is supported for rotation about a generally horizontal axis with one of said shaft means being an idler shaft and arranged in bearing supports for limited movement along the horizontal axis thereof toward and away from the furnace, and the other of said shaft means being a driven shaft; and including power means engageable with said driven shaft for driving same about the axis of rotation thereof.

10. In combination with an open-mouth metal converting furnace, a pair of opposed support assemblies, each of which comprises:

ground supported shaft means with one end thereof being disposed adjacent an outer wall portion of the furnace and coupled to the furnace for supporting the furnace above ground level;

a plurality of bracket members fixed to the wall of the furnace and arranged thereon in spaced relationship with each other to define a plurality of slots;

said shaft means having lugs thereon received in and engaging the walls of said slots; and

said slots and lugs being shape-d and sized to permit certain degree of misalignment therebetween whereby the bracket members and said lugs serve as a flexible connection between the furnace and the shaft means.

l l. The combination as set forth in claim 10 wherein each support assembly includes four bracket members fixed to the wall of the furnace and arranged thereon to define four slots generally apart; and said shaft means has four lugs generally 90 apart.

12. The combination as set forth in claim 10 wherein each support assembly includes four bracket members fixed to the wall of the furnace and arranged thereon to define a central pocket and four slots generally 90 apart extending radially from the pocket; and said shaft means has a hub shaped and sized to fit within said pocket and four lugs generally 90 apart.

13. The combination as set forth in claim 10 wherein when the furnace is in the metal charge position the centerline of one pair of diametrically opposed slots and lugs lie in a generally vertical plane and the centerline of the other pair of diametrically opposed slots and lugs lies in a generally horizontal plane.

14. The combination as set forth in claim 10 wherein the shaft means of both support assemblies are supported for rotation about a common generally horizon tal axis, with one of said shaft means being an idler shaft and arranged in bearing supports for limited movement along the horizontal axis thereof toward and away from the furnace, and the other of said shaft means being a driven shaft; and including power means engageable with said driven shaft for driving same about the axis of rotation thereof.

15. The combination as set forth in claim 10 including a stop means detachably mounted on the furnace for engaging at least one of said lugs to secure said lugs in engagement with the walls of said slots.

16. In combination with an open-mouth metal con verting furnace, a pair of opposed support assemblies, each of which comprises:

a plurality of bracket members fixed to the wall of the furnace, each of said bracket members having a lug thereon extending in the direction of said shaft means;

said shaft means having a plurality of slots formed therein at said one end portion thereof, each of said slots being shaped and sized to receive one of said lugs; and

said slots and lugs being shaped and sized to permit a certain degree of misalignment therebetween, whereby the bracket members and said one end of said shaft means serve as a flexible connection between the furnace and the shaft means.

17. The combination as set forth in claim 16 including stop means detachably mounted on the furnace for engaging said one end portion of said shaft means to secure said lugs in engagement with said slots.

18. The combination as set forth in claim 16 wherein each of said support assemblies includes four bracket members fixed to the wall of the furnace with the lugs thereof being generally in a circular pattern about 90 apart; and said shaft means has four slots generally 90 apart.

19. The combination as set forth in claim 16 wherein the shaft means of both support assemblies are supported for rotation, about a common generally horizontal, with one of said shaft means being an idler shaft and arranged in bearing supports for limited movement along the horizontal axis thereof toward and away from the furnace, and the other of said shaft means being a driven shaft; and including power means engageable with said driven shaft for driving same about the axis of rotation thereof.

20. The combination as set forth in claim 1 wherein said shaft means are ground supported such that the longitudinal axes thereof are horizontally fixed when the shaft means are disconnected from the furnace.

21. The combination as set forth in claim wherein said shaft means are ground supported such that the longitudinal axes thereof are horizontally fixed when the shaft means are disconnected from the furnace.

22. The combination as set forth in claim 16 wherein said shaft means are ground supported such that the longitudinal axes thereof are horizontally fixed when the shaft means are disconnected from the furnace.

23. The combination as set forth in claim 1 wherein said first and second connection means are so constructed and arranged that the furnace portion thereof will expand with the furnace during thermal expansion and away from said shaft means whereby overstressing between the engaging parts of the first and second connection means is avoided during thermal expansion of the furnace.

24. The combination as set forth in claim 1 wherein the furnace includes at least one metal tap spout; and including a heat shield plate member supported by the furnace and spaced radially outwardly therefrom; said plate member being shaped and sized to surround said tap spout and to cover a surface area of the furnace extending from the tap spout circumferentially away from both sides thereof and from an upper portion of the furnace to a lower portion thereof.

25. The combination as set forth in claim 1 wherein the furnace includes at least one metal tap spout; and wherein the metal shell of the portion has a thickened portion in the area of said tap spout with said thickened portion extending circumferentially away from both sides of the tap spout and from an upper portion to a lower portion of the furnace.

Claims

1. In combination with a metal converting firnace, a pair of opposed support assemblies, each of which comprises: ground supported shaft means coupled directly to an external portion of the furnace shell for supporting the furnace above ground level; first and second connection means on said shaft means and the furnace shell, respectively, and flexibly engaging each other for supporting the furnace on said shaft means; and one of said connection means having multiple external splines defined thereon, and the other of said connection means having multiple internal splines defined therein, said splines mating with each other and being shaped and sized with clearances to permit a certain degree of misalignment therebetween.

4. The combination as set forth in claim 3 including stop members disposed in the internal splines adjacent the free ends of the external splines.

6. The combination as set forth in claim 1 wherein said second connection means includes four similarly shaped brackets mounted on the wall of the furnace and arranged thereon to define a central pocket and four slots generally 90* apart extending radially from the pocket; and said first connection means having a hub shaped and sized to fit within said pocket and four lugs generally ninety degrees apart and shaped and sized to be received in said slots, with said slots and lugs being shaped and sized to permit a certain degree of misalignment therebetween.

10. In combination with An open-mouth metal converting furnace, a pair of opposed support assemblies, each of which comprises: ground supported shaft means with one end thereof being disposed adjacent an outer wall portion of the furnace and coupled to the furnace for supporting the furnace above ground level; a plurality of bracket members fixed to the wall of the furnace and arranged thereon in spaced relationship with each other to define a plurality of slots; said shaft means having lugs thereon received in and engaging the walls of said slots; and said slots and lugs being shaped and sized to permit certain degree of misalignment therebetween whereby the bracket members and said lugs serve as a flexible connection between the furnace and the shaft means.

11. The combination as set forth in claim 10 wherein each support assembly includes four bracket members fixed to the wall of the furnace and arranged thereon to define four slots generally 90* apart; and said shaft means has four lugs generally 90* apart.

12. The combination as set forth in claim 10 wherein each support assembly includes four bracket members fixed to the wall of the furnace and arranged thereon to define a central pocket and four slots generally 90* apart extending radially from the pocket; and said shaft means has a hub shaped and sized to fit within said pocket and four lugs generally 90* apart.

14. The combination as set forth in claim 10 wherein the shaft means of both support assemblies are supported for rotation about a common generally horizontal axis, with one of said shaft means being an idler shaft and arranged in bearing supports for limited movement along the horizontal axis thereof toward and away from the furnace, and the other of said shaft means being a driven shaft; and including power means engageable with said driven shaft for driving same about the axis of rotation thereof.

16. In combination with an open-mouth metal converting furnace, a pair of opposed support assemblies, each of which comprises: ground supported shaft means with one end thereof being disposed adjacent an outer wall portion of the furnace and coupled to the furnace for supporting the furnace above ground level; a plurality of bracket members fixed to the wall of the furnace, each of said bracket members having a lug thereon extending in the direction of said shaft means; said shaft means having a plurality of slots formed therein at said one end portion thereof, each of said slots being shaped and sized to receive one of said lugs; and said slots and lugs being shaped and sized to permit a certain degree of misalignment therebetween, whereby the bracket members and said one end of said shaft means serve as a flexible connection between the furnace and the shaft means.

18. The combination as set forth in claim 16 wherein each of said support assemblies includes four bracket members fixed to the wall of the furnace with the lugs thereof being generally in a circular pattern about 90* apart; and said shaft means has four slots generally 90* apart.

21. The combination as set forth in claim 10 wherein said shaft means are ground supported such that the longitudinal axes thereof are horizontally fixed when the shaft means are disconnected from the furnace.