US2826405A - Converter vessel - Google Patents

Description

March 11, 1958 H. L. MOFEATERS 2,326,405

CONVERTER VESSEL Filed Nov. 10, 1955 2 Sheets-Sheet 1 /7/'s Afforweys.

March 11, 1958 v H. L. M FEATERS 2,

CONVERTER VESSEL Filed Nov. 10, 1955 2 Sheefs-Sheet 2 Jig. 4 5; 1:1 .3

INVENTOR. f/arry/L'Mc/ eafefis United States Patent CONVERTER VESSEL Harry L McFeaters, New Castle, Pa., assignor to Pennsylvanla Engineering Corporation, New Castle, Pa, a corporation of Pennsylvania Application November 10, 1955, Serial No. 546,233

4 Claims. (Cl. 266-36) This invention relates to an improved converter construction having separable parts or sectors and particularly, to an improved top blow construction for a metal refining converter or vessel of a type suitable for a socalled oxygen blow processing of metals, such as steel.

It has been my experience that a converter of the socalled top blow type and particularly, one of the oxygen blow type presents entirely diiierent and exacting factors in its utilization and construction as compared to conventional converters of the so-called side or bottom blow types. The two-way fiow of gas within a top blow converter, the intense heat of the reaction, e. g., in the neighborhood of 3500 F., the intensity and thus the limited time factor of the refining operation, and requirements for larger and larger capacities, in the neighborhood of 60 tons or more, have all contributed to the complexity of the probelm of providing a converter or vessel. The need is for a top blow vessel that can be provided at a reasonable cost, with further desired processing of the metal, and will have a relatively low maintenance cost, and particularly, one which will minimize and facilitate repair operations, for example, of the refractory lining.

My study and work in this particular field has indicated that the problem involved in producing a practical and improved top blow type of converter or vessel and essentially, one that will be practical for present-day so-called intense-heat oxygen-blow processing, arises out of the need for making the construction, assembly and disassembly of the converter in the form of sectors or segments. A practical solution to the problem centers about the need to provide a joint between the sectors such that they can be properly aligned, securely held together, held together without damage and, at the same time, easily formed and separated, and when in position will provide an efficient and efiective closure seal between adjacent refractories. Since converters of this type, like the Bessemer converters, are adapted to be rotated to pour the refined metal, the refractory material about the joint has to withstand the molten pour, molten metal spatter from the bottom portion, and the scarifying, agitated flow of gases, fumes and flame during the blowing or refining operation.

It has thus been an object of my invention to provide a new and improved converter or refining vessel construction and one that is suitable for top-blow operations;

Another object has been to devise a converter of a construction mounting and utilization that will be practical for and that will better withstand the rough usage involved in a so'called oxygen blow process;

A further object has been to devise an improved joint construction between converter sections or sectors and particularly, from the standpoint of increasing the life of the refractories, of facilitating the repair of the construction, and of assuring an accurately-aligned strainminimized re-assembly of the parts of the construction;

A still further object of my invention has been to minimize wear, stresses and strains as set up in a converter construction and to provide an over-all improved vessel;

aster-as Patented Mar. 11, 1958 iice ' These and many other objects of my invention will appear to those skilled in the art from the illustrated embodiment, as shown in the drawings and as described in the specification.

In the drawings,

Figure 1 is a side view in elevation, partially broken away, illustrating somewhat generally the construction of the coverter or vessel of my invention; this view somewhat diagrammatically shows a typical type of molten metal-induced erosion which may occur in the refractory lining of a bottom sector;

Figure 2 is a top plan view of the construction of Figure 1 and on the same scale as such figure;

Figure 3 is a greatly enlarged sectional detail of my joint assembly or construction as taken along line III- III of Figure 2 of the drawings;

Figure 4 is a somewhat diagrammatic view in elevation on the scale of Figures 1 and 2, illustrating how an upper part or sector may be removed after the sector has been raised off the lower sector and, of course, after securing bolts and aligning pins have been removed, but while trunnion bearing bolts are still in position as to the lower sector or half;

Figure 5 is a vertical side view in elevation on the same scale as Figure 4, showing the position of a bottom sector after it has been rotated about degrees and illustrating how it may be lifted clear of the bearings for transportation to a repair station; the full lines show the bottom sector in its normal or lower position and the dot and dash lines show it in its upper 180 degree position. Such dot and dash lines also show how the bearing means and the gear for the trunnions may be removed;

And, Figure 6 is a fragmental section of the same scale as and taken on the line VI-VI of Figure 3.

A vessel or converter of the type of utilization here involved is periodically subjected to intense heat and to temperature variations. It is thus apparent that the parts and particularly, the refractory lining and shell and flange portions thereof will tend to expand and contract in accordance with the particular temperatures. I thus found that it is highly essential to minimize stresses and strains between the joint portions, members or parts of the construction and at the same time to protect the metal parts or portions at or adjacent the joint from the intense inner heat to which the vessel is subjected.

In accordance with my present invention, I provide a sectored vessel or converter, as shown in the drawings, of two parts or sections which may be readily removed with respect to each other to not only speed up the cooling for repair purposes, but to also facilitate repair and, if desired, to provide for immediate replacement by spare sectors or halves, so that production of time lost due to maintenance and repair will be minimized. The construction is such that the bottom or top sector may be removed from the other or, in other words, lifted out or" position with respect to the other and by employing the same type of handling equipment or hoist mechanism.

Importantly, in carrying out my present invention, and as illustrated particularly in Figures 3 and 4 of the drawings, I have devised a shell construction whose parts are provided both with aligning and with securing means. The securing means has one positioning point or flange located in a spaced or slightly remote relationship with respect to the joint, so as to not only aid in pulling up and securing the joint, in the aligned relationship set by the aligning means, but to also reinforce and strengthen the structure or the structural halves or parts adjacent to and along the joint therebetween.

The inner or refractory wall lining of the vessel may comprise refractory brick tile which, as to the top sector half, extends vertically from an open mouth portion sesame downwardly to a position and adjacent the joint; As to the bottom sector or half of the vessel, a second and segregated refractory wall lining projects from a position adjacent the joint, downwardly into a cooperating relationship with a bottom refractory lining. The wall linings of the two halves at their joint. endportionsare. held. and supported in a widely spaced-apart. position by. shelf.- flanges and reinforcing ribs therefor andessentially, in such a manner that they terminate in a vertically spaced relationship. with each other circumferentially of. the vessel and above and below the actual partinglineor plane between the adjacent'joint edges of the. shellportions. of the upper and lower halves: or. sectors...

A central refractory girdle, annular band oncylindrical sealing refractory part is positioned between opposed: reaches of the adjacent end portions. ofthe WalLrefEactories of the upper and lower halves ofithe vesselto tightly. abut or cooperate with them to provide the. inner portions of the joint. tive vertical'extent and projects circumferentially about andin av substantially centrally-aligned relationship. with the joint (between the outer metal'shell'portions of the upper and lower sectors or halves) to. in effect, close-off. or isolate the latter from the standpoint of the inner portion of the vessel.

Thus, the refractory girdle or band presents a solid face to the immediate joint of the metal shell-portions and defines two, tightly-fitting, and spaced-apart. joints between the end portions of the upper and lower wall halves of'the refractory wall lining. Such band may, be rammed" in position and thus, will operate as an intermediatestrain and stress-resisting refractory which bears stress or strain set up by the expansion and contraction of the halves or members ofthe vessel during its operation. It further fully protects the metal members and particularly, the outer securing and aligning flanges of their joint from the hot gases and intense heat of'the interior of the vessel.

In the drawings, I have. illustrated a converter or refining vessel constructed in accordance with my invention. This vessel carries trunnions 11 that project from its opposite sides and are rotatably mounted within bearing halves 13 and 14. The latter are secured by bolt and nut assemblies 13a to upright stands 12. As shown particularly in Figure 5', the bearing assembly comprises a lower portion 13 of semicircular shape which carries projecting bolts 14a and is adapted to receive and cooperate with an. upper bearing half. 14, also of' semicircular shape. The bolts 1'421 projectthrough the upper halfv 14 and are removably secured in position, thereon by nuts 1412.

As shown in Figures 1 and 5, a bull gear wheel 15. is feathered on one trunnion at 15a. The gear 15 is adapted to mesh in the ordinary manner with a drive pinion, so as to turn or rotate the vessel or converter 10- on the stands 12 from, for example, an upright vertical blow position of Figure 1 to tilted, molten-metal pouring, and charge-receiving, somewhat horizontal positions, and to an inverted or 180 position to lift a bottom part or sector 30 off the stands, compare Figures 1' and 5 of'the drawings;

Referring particularly to Figure 1 of the drawingS,- I have shown a vessel 10oftwo' halves, sectors or parts comprising an upper part 17 and a lower part 30. The

upper part or sector halfl7'has, as shown, an integraL, upper metal shell consisting of an upper cone-shaped;

nose portion 17a, an intermediate transition portion 17b, and a lower cylindrical bodyor wall portion 170: A

radially-inwardly projectingannular top flange; refractory support rim, metal nose or mouth ledge 20': is secured about an upper end ofthe'upper metal shell and. about the charging opening. Also,- as shown particularlyin- Figures 1, 2 and 4, a pouring lip-or bib21 projectsdown-- wardly along the pouring side of the converter fromthe rim 20. Lift trunnions 18' for theupperstructureonhalf:

This refractory, girdle or bandhasQ aneifecprojecting bottom flange; or metal ledge23 that is secured to the shell portion 170. 3, a series of circumferentially=spaced-apart" upright angle pieces 24'serve as reinforcing; ribs for: theledge 23 and project into the refractory wall 25. Also, as shown in Figure 3;, theledge 23 has an. upwardly-spaced.relationship with respect to the bottom edgeof the metal shell portion 17c which is to define the joint.

The outer reaches or circumference of the upper shell is reinforced by and carries an outer cage or frame structure, see. Figure 1.. This: frame orcage. is-Jmade up; of

vertically-spaced-apart radially-outwardly extendinggupperand. lower banding rings or flanges 27 and 28.- Theuppjer ring 27 issecuredto the outer sidevof the shell portion above. the ledgev 23 and in a substantially remote, up-- wardly-spaced relationship. with respect to the lower jointforming edgeof such shell portion. The lower ring 28: is secured. to. the. shellportionx17c. below the ledge23 and.- centrally to theimmediate edgeof- 17c which forms: the. joint.. Vertical. cross-tie, pieces 26, are. secured, as bywelding, between the upper and lower rings 27: and 28.

As shown inFigure 1, the upperand lower rings 27' and.

28. are split to. provide expansion joints in arcircumferentialdirection. A. pair. ofv bar key, pieces 29 areshown wedged. in position betweenthesplitends of the ringsand' secured thereto, as by weld metal.

The other or-lowerhalf 3110f the converter 10'has an integral metal. shell made up of a bottom portion 30a and an. upper cylindrical. body or'wall portion 30!). A refractory wall lining 35 is. shown as of the. same typev of construction and of the same diameter as: the upper refractory wall- 25 and, at its lower end, provides. and is. supported by a concave refractory bottom 35a, see Figure 6. The lining35 is limited. and supportedat itsupper end by a continuous or annular, radially-inwardly projecting, top. flange ormetal ledge 33 which is. secured to'the. shell portion 30b in a"- downwardly-spaced relationshipv from'its-joint edge, and in: substantially the same spaced relationship asthe ledge 23. hasv with respect to thejoint edge of its. shell portion 17c., Reinforcing ribs or webs.

34 of similar construction and spacedmonntinggasihe:

websi24- aresecured to theledge 33'to project into. the lower refractory wall lining 35.

As shownparticularly in Figures 1 and 3,, the inner; extent of the joint formedbetwecn the. upper and lower halves 17 and 30-is defined by acentral girdle or annular refractory sealingv band 22 which may be, in effect, rammed. or tightly fitted in anabutting relationship be tween. the opposed end portions of the upper and lower refractory. walls 25'and- 35. It is. thusapparent. that the. refractory band 22' has a vertically-centralized relation-.

ship with the joint between the edges of the shell portions.

17c and] 30b to thusseal them ofi. The sealingband 22 provides: or defines two parting lines, one, of' which is:

above: themetal joint and: one of which is below it, but;

both of which are out of or off-set with respect to the plane of the joint. As shown in Figure 3 to further seal off the joint; a-light gauge plate'mernber 32 of'ferrous or non-ferrous metal may be inset within the outer face of the refractory band 22 in substantial central-vertical alignment both withitand' the joint definedlby themembers 17c andfflb.

Aswillbenotedfrom Figures 1- and 3',,tlie lower-metal. shell construction consisting of portions. 30a and 30b" may. be. of heavier: metalv thickness. or. plate than the; upper part-consisting; of portions-17a, 17b. and 17c. Like the.

As shown particularly in Figure 7 upper part, the lower part also has a reinforcing films or cage construction 36.

The cage 36 projects between and is secured to upper and lower, radially-outwardly-projecting, banding flanges or rings 37 and 38. It will be noted that the ring 38 is secured to the outer side of the shell portion 30b above the ledge 33 and somewhat centrally of the immediate edge which forms the joint. The ring 38 is in a relatively close and opposed relationship with and cooperates with the ring 28 which is similarly secured to the shell portion 170. As disclosed particularly in Figure 3, the rings 28 and 38 are of suificient thickness or vertical extent to project above and below or beyond the relatively wide joint or seam between the opposed edges of the shell portions 17c and 30b.

The rings 28 and 38 have a circumferentially spacedapart series of aligned holes therethrough (about five spaced as shown) to receive assembly guide and alignment wedge pins 42 (see Figures 1, 2, 3 and 6). Although the rings 28 and 38 are adapted to be held in a rather closely spaced and opposed relationship with each other, an upwardly-projecting face flange or plate ring or rim 39 is secured to the outer edge face of the ring 38 to project above or across the joint between opposed faces of the rings 28 and 38 and along the front edge or face of the upper ring 28 in a slightly spaced relationship with respect thereto. The ring 28 may be slightly beveled at 28a (see Figure 3) to form an overflow pocket for sealing mud or ganister 40, as employed to seal off the joint between the metal rings 28 and 38.

To secure the joint between the upper and lower halves of the converter in their aligned relationships under compression, the rings 27 and 38 are provided with a series of vertically-aligned holes for receiving and mounting take-up or tension bolts 43 that extend therebetween. The bolts 43 also extend through aligned holes in the ring 28, so that they have a three-point support along their extent and project between upper and lower reaches of the upper cage, the upper reaches of the lower cage 36, along the upper shell portion 17c and considerably beyond the joint. Locking nut pairs 44 are adapted to be secured on upper threaded ends 43a of the bolts to cooperate with nuts 45 on lower threaded end portions 43b. The nuts 45 are shown secured in position by cotter pins 46 and although they are not normally removed during a disassembly, may be removed if there is any tendency for the nut and bolt assembly to stick or jam.

It may be noted that the lower half or sector 30 is also provided with a pair of lift trunnions 31 that are secured to bottom shell portion 30a, so that, as illustrated for example in Figures 4- and 5, the bottom half 39 may also be lifted off the stands by rotating the converter after the upper half 17 has been removed.

In Figure 1, I have somewhat diagrammatically indicated how molten metal M in a converter will, in time, tend to eat-out or slutf-oif the refractory lining, as at A. This emphasizes the need for a reinforced and stronger bottom half of the vessel, as well as the importance of facilitating the removal of the lower half from the upper half 17. The latter, being for the most part subjected to the hot gases and only during the pouring operation to molten metal, has a longer life. However, the intense heat involved in a refining or blowing operation and the temperature variations involved in the processing steps, all tend to cause distortions due to expansion and contraction. Thus, it is highly important that the vessel or converter 16 be capable of withstanding such forces and particularly so from the standpoint of a joint between its upper and lower halves or sectors.

In accordance with my present invention, temperature variations at the immediate area of the joint are minimized by a compression fit of the refractory material 22 and a new type of positioning of such material, as well as a new type of construction of the joint. The construction is such as to avoid an over-centralization or concentration of stresses and strains of the metal parts in the immediate joint area and a more or less uniform distribution of them throughout the extent of the vessel or converter. The construction is also such as to minimize stresses and strains in the refractory walls of the upper and lower halves (as isolated by their angle shelves 23 and 33) and to concentrate those present in an easilyreplaceable, banding or central refractory wall part 22.

From thestandpoint of minimizing stresses and strains, I have found that it is highly essential to provide means for aligning the two parts of the vessel and for maintaining them in alignment without entire reliance upon the securing assemblies. The construction is such that the aligning means aids in the securing operation and enables the securing to be effected at points of wider spacing with respect to each other for better force distribution and also, in such a manner as to further distribute the stresses and strains and prevent their localization at the immediate cross plane of the joint.

However, as to the inner or refractory wall linings, the construction protects the lining of the upper and lower halves, so that their maximum operative life will be attained. The tightening-down of the upper and lower halves 17 and 3t) and the maintenance of them in a sealed relationship from the standpoint of the interior of the vessel is accomplished on a rather wide width of sealing refractory band or girdle 22 that lies intermediate the refractories of the upper and lower halves and bears the brunt of wear and tear of periodic joint disassembly and assembly.

For the purpose of illustration, I have shown a vessel or converter of about 60 net tons capacity that can be operated under an oxygen blow of about 300 cubic feet per minute and about 400 pounds of melt per cubic feet, by employing an oxygen lance that is adapted to be moved vertically downwardly through its mouth to a point adjacent the surface of its melt M. This indicates that my invention provides a vessel and particularly, a joint construction that may be used in larger tonnage installations and for maximum capacities that may be required.

The upper and lower halves of the vessel are independent in the sense of their inner refractory linings and the secure mounting of such linings within and along their respective shell halves. The metal shell of each sector or half, at its joint end portion, projects beyond the end portion of its supporting refractory wall or lining in such a manner as to define an annular joint area or spacing between opposed end portions of the refractory walls of each sector or half and adjacent to the end portions of the metal shells that provide the joint. The refractory band is securely and in a flush relationship mounted in position in such spacing area to seal off the furnace interior and in such a tight fitting sealing relationship with respect to end portions of the refractory walls as to eliminate the necessity for sealing material therebetween. This band provides an offset type of joint construction with respect to adjacent ends of the metal shells. The band, at its upper and lower faces, is out of alignment with the joint spacing or opening between adjacent end portions of the metal shells to avoid a through-type of joint. The spacing at the joint outwardly in front of the plate 32 and between the opposed edge-s of the members and 3011 may, as shown, be filled with an outer refractory band 22a (see Figure 3). However, if desired, the sealing mud or ganister 40 may be employed to fill such spacing.

Normally in a Bessemer converter, a bottom portion being subjected to the most severe wear may average only about 25 to 35 blows. Deterioration may be at a relatively fast rate or as much as an inch per minute after a so-called initial boring or cavitation has been effected. I have discovered that initial deterioration is greatly hastened if the refractory portion is, at the time, being subjected to stress and strain and particularly, to

aeeaaos;

it a localized type and that this follows .through,as.to subV-- sequent.deterioration.. By .way offlexample,'a.slight.fail= ure or'cracking ofLja portion ofiaref'r'actorynstarts the. iiritialboring or cavitation and iflsucliuportion isstill.

under" stress and strain of a more localized nature, it furthers" a' spread of such cavitation and a. more. rapid over=all"deterioration of the lining.

'In' accordance with the invention of my constructiom thewmain lining portio nstof' the .vessel are independently supportedwith respectto each. other, ,butidependently supported'ga's totheir' respective outer metal's'liells. Any 1ecalizedjbint-stress and strain .is concentrated in aseparate and interm'ediatel'y'positionedrefractory lining means or band part which; by reason of its location, sizeand towardsa similar joint portion of-the'other'shelland' in a: vertically-spaced relationship 'beyond'a joint-defining end portion of its respectiveinner refractory wall to define ametal outer jointand aninner 'relatively wide jointspacing areabetween opposed joint-defining end portions of the-inner refractory walls;- a metal shelf flange projecting radially-inwardly from each metal shell in a supporting: relationship along the joint-defining end portion of its respective refractory wall to independently support each: refractory; wall in position with: respect to itsrrespective'.metal -shell; t a refractory band securely po sitionedi withimsaid inner= joint.spacing area and'irr abutment: against said opposed joint de'fining end portions of the: inner refractorywallsitoclose-off the interior of the converter-,1 saidishelf fianges being insetwit'hin said refractory walls toxsmoothly abut: said refractory band,

a pair; of; opposed and cooperating joint rings secured to' projeotcradiallyi-outwardlyfrom said'metal joint portions I to. further define the metal i outer joint, meanscooperating between said pair of joint rings to positiontthem inan aligned relationship with each otherysaidrefractory band beingipositionedt. above. the meltleveL of: the converte'r. and? substantially midway-across the metal outer joiiitttowdefineta -pairz ofrefractory joints withtheopposedend'porti'onsofJsaidrefractory wallsthat are verticallyoffset withrespect toeach. other andwith respect to: the metallouter joint a thirdtmetal ringv secured about one of I said' metal shell sfitoproject radiallyoutwardly there'- fi'om in a vertically-spaced" relationship with the metal outer joint and' take-up assemblies. betweenvsaid third ring and said-pair 'of joinhrings to: securely hold the body halves in an aligned.and"tens'ioned relationship I with each other and to holdf said refractory band under substantially uniform compressiori'between theopposed jointdefining end portions of said refractory walls.

2. A converter construction as defined in. claim 1 wherein a series of vertical reiiiforcin'gwebs are secured between; said. metal shells. and their respective shelf flanges to project into their respective refractory walls.

3i.A converter construction as defined in claim 1 wherein; atsupport' cage projects downwardly from a lower one of said joint rings, and trunnions are carried bysai'd cage beneath" said'metal outer joint to rotatably positionthe'conve'rter.

4. A converter construction. as defined in claim 1 wherein; sealingmu'd 'is'positione'dibetwe'en opposed joint defining faces'ofsaid'pa'ir' of jo'int ring-s to extend from saidrefractory band; and a vertical metal end rim is secured to project from one" of saidjoint rings along the other joint ring and across" the joint the'rebetween toretain the-sealing mud inposition:

Referenees' Cited in the file of this patent UNITED STATES'PATENTS 94,997 Bessemer Sept. 21-,v 1869 314,551 Wilcox Mar. 24; 1885 3355613 Murdock Feb. 9, 1886 358,559 Laureau Mar. 1; 1887' l;042,876 Blackwood July 28 1910 1;479',9'97' M'cCaflery Jan. 8, 1924'

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