US2296059A - Stopper for metallurgical ladles - Google Patents

Description

sept.15,1942. F. L. AGE 2,296,059

` STOPPER' FOR METALLURMCAL LADLES Filed June 9, 1942 i Immun l 76 Patented Sept. 942 y s'rorrna 'Fort l 2.396,05?I y METALLURGICAL llantasV y y Frederick Sage, Chicago, Ill. Applicatioasunee, 1941, seria1-No.397,1e1

This invention relates to improvements in s toppers for ladles used for conveying molten metal,

suchas steel, from converters,l melting furnaces, A

etc., and vpouring' it into molds.` Such Stoppers work from the inside 'of the ladles to open and close the passage through the pouring lnozzle which extends .vertically through the'bottom of the lad1`e,and .tol control the ilow of the `molten metal therethrough."y 5

As usually constructed` the stopper comprises a long central 2=inch iron rod closely-surrounded by tubularV sleeves of refractory material, such asilre clay, extending up through Lthe molten steelin the ladle. Thelower end: of the stopper is provided with a head-of agraphite and :dreclay mixture, which is adapted to rest upon the depressed annular seat in the upper end of the and dropping `ol. thehead` "during a pour is avoided. i

Another objectvis to provide a `const`ruction having the effect to break up orfprevent\the swirl of the hot `metal which tends to developin the ladle aroundthe stopper and nozzle `in pouring, and to do this in a way which also permits pouringwith the` cooler molten metals. This is commonly referred to as cold pouring.` t

Other objects are to provide an improved `construction universal in its application to the various conditions of such pouring, which may be standardized in its own. and associatedparts, su'ch as the nozzle, for the industry, which may result in a shortened nozzle-'a most desirable end-and in which the head may be made of less expensive and more readily obtainable grades voi? pouring nozzle in the bottom ofthe'ladle to close the passage therethrough,` like a valve, and when raised from the seat to open the passage. Suitf ablel mechanical connections atvthe upper end of the stopper and extending down over the outside of the ladle enable the stopper to be raised and lowered manually as desired. v

These stoppers are subjected to the high heat, 2600.o to 3100 F., of the steel bath, and as usually constructed are more or less rapidly destroyed, particularly at their lower ends where the' heads aresecured to the iron rod. It notinfrequently happens lthat the heads burn off, as it is called, from the remainder of the stopper and drop intoV the ladle, with consequent trouble and expense. 'I'he longer time for which the lower end and material vand a less percentage of the more expensive ingredient.

vFurther objectsr and'advantages will appear from the detailed description and claims to fol- A low, in connection-with the drawing which illusproportions, with an embodiment head of the stopper are necessarily subjected to the high heat of the bath, the relatively high Vheatfconductivity-of the head, and the mechanil cal and erosive action ofthe flowing metal contribute to the increase of these diiliculties at this point.

n It is found in practice, also, that when the ordinary stopper is raised to open 'the nozzle the flowing metal tends to swirl about the lower endv off-,the stopper, something like the water vin a` s wash-bowl when the stopper isv removed, which cuts thenozzle and interferesrwith the' proper flow into and out of the nozzle and causes spraying or fanning of the metal as it issues from the nozzlejall of which is objectionable.

Anobject of the present invention is to imtrates an embodiment ofthe invention, andjn Whic/hv Figure 1 is a vertical section through the lower end of a stopper of the usual construction and I of the present invention attached;v v

Figure 2 is a cross-section of the improved stopper on the line 2-f-2 of Figure 1; and

Figure 3 isl a cross-section of the stopperon the line 3-3 of Figure 1. f

, It will be understood that the ladles here involved are of comparatively large size, usually 15 to 20 feet in height and v10 feet or more in diameter, and take in onev filling the charge output prove the construction of 'the lower end of they stopper, wherebythe essential connections and y parts are `better protected from the destructive effects of the highlyheate'd liquid metal-and the danger o f-theirv destructionor the breaking oi 5 5 of a furnace, commonly 15.0 tons of molten metal.

lThe ladle after being so lled is conveyed to the f pouring location by an overhead crane and the `contents thereof poured usually into vertical ingot molds, of whichthere maybe 40 or 50, spaced a few feet apart, to be poured successively from -a 'single illlingvof the ladle. The Aladle is of the bottom pouring type, a vertical pouring nozzle `being secured in vthe bottom. wall of the ladle,

whichy is brought over each mold for the pouring. The nozzle .isopened and closeclfor theV w filling and pouring by an insidew stopper, that is,

a stopperV located and working inside of the ladle, and therefore subjected tothe high temperature of the molten metal.

Such' stoppers ordinarily comprise Aa central supporting-Z-inch iron rod extending from the bottom to the top of the ladle and which is covered with refractory tubular sleeves of re fliquid metal. The sleeves ,closely surround the rod, with .only a small clearance therebetween for ease of assembling and providing a,thin layer lof air around the rod for heat-insulation purposes. These sleeves are thick-walled,- to obstruct as much as possible the passage of the heat to the rod. v y

Figure l of the drawing shows, at the top, the lower end of such a sleeve Ill and therod II of the usual dimensions and proportions.

These sleeves ordinarily extend down to the head of the stopper and are .of the same diameter throughout. The head, as it'is called, located ately beneath the lowermost or bottom sleeve, is that part which contacts the pouring nozzle to close the opening therethrough. The material is usually graphite bonded with nre clay,` the graphite content running from 18 to 30 per cent, and both ingredients being of the imported 'variety andtherefore difllcult andd expensive to obtain.

. Graphite is usedl because it does not melt in contact with the fire-clay nozzle and weld and stick thereto, like other materials whichhave been tried. But the graphiteI and graphitic mix--v ture is of relatively high heat conductivity, andas heretofore constructed and attached to the supporting rod the latter was not sulciently protected from the high heat and frequently-burnedl off and dropped the head.

In the present invention, the bottom sleeve I2 of the stopper, which is of refractory material. such as fire clay, likeAthe sleeves above it, is of the usual` size and construction at its upper end suitably to conform and co-operate with the bottom 6i the ordinary-sleeve above. .As shown, vthis bottom sleeve I2 is enlarged toward the lower end to provide room therein for an enlarged ,recess I3 in the lower end' and still `maintain a thick wall of refractory materialthereabout. An

internal shoulder or ledge I4 is formed atthe upper end of this recess between the central b'ore of the sleeve and the walls of the recess. The central iron supporting rod'l I, which extends down through' the usual central bore or passage of the sleeve to this point, is provided with a lateral projection which may be in the form of a collar I5 secured thereto or formed thereon in any desired way, or other forms of lateral projection or projections may be provided on which the shoulder or ledge Il of the bottom sleeve may rest.

The head I6 is of a size and shape to flt into and fill the enlarged recess I3 inthe bottom sleeve. This is preferably in thel form of a truncated cone. A peripheral ledge I1 at'its midsection underlies or underlaps the edge of the bottom sleeve I? and its generally rounded, substantially hemispherical bottom forms the end of the stopper, the lower face of which engages the nozzle seat with a line -contact to stop the ilow ofmetal therethrough and to permit. its flow when raised. This head is secured tothe supporting rod II through the-medium of an extension of the rod, preferably inthe form of aT smaller rod I8,` the upper4 end of which' is inserted in a. hole in the lower end ofthe rod II and is securely keyed therein by key I9 driven lower end of this rod I8 projects ,into a porreinto the transverse openings therethrough. The

immedisponding hole in the upper part of the head and the latter is secured thereto by a cross-pin 20. preferably square or rectangular, in cross-section, with the flat side up for better bearing surface. ,This pin' projects at its ends from the rod I8 sufliciently to sustain the load, if need be,` of the head, the bottom sleeveand the sleeves above it, thoughfthe shoulder Il, may sharethe load.

In assembling the stopper. the extension I8 is placed in the rod and-keyed therein. The head is next secured tightly in position and the hole at the end of the pin filled with refractory cement V or plug. The sleeves are then .slipped over the rod II from the other` end, the' bottom sleeve being brought down intov position over thehead as shown. `All meeting faces of^the head and.y sleeve, and of the sleeves themselves, 'are, of course, coated or provided with a layer of refractory cement or equivalentmaterial, as is intended to be indicated by the double lines in the drawing. This tends to make a more rigid construction and prevents the liquid liron from seeping through the joints and reaching the metal rod and connections. V

By this construction an imperforate', solid 'bottomed head is provided, while the upper truncated half is surrounded and protected by the refractory material of the walls of the sleeve, and the part so encompassed is suilicient in size ands strength to receive the metallic supporting connections with the rod, thereby enabling the lower exposed portion of the head to be a relatively thick solid, unbroken block of material. This increases the strength of the head, which must/bear the weight of the entire stopper when closed and ,the shocks and Jars due to normal closing, and its violent closing to .shut oil any endw trickles of the hot metal, and affords greater heat protection for the embedded metallic lsupports. The greater protection to the metallic parts thus afforded by this construction from the highheat lof the bath and its rugged strength enable a less and fire clay, suchl as the domestic varieties, to be employed for the head and a less percentage of graphite may be used -in the. mixture and more vof the fire clay, which still further reduces the expense and simultaneously decreasesthe heat conductivity of the mixture, thereby further protecting the metallic parts. Engineeringspecications for such materiartor these new heads now call lfor as low as an 8% graphite content of the domestic type and may well be reduced with safety to 4%.

The pouring nozzle 2l is ofthe usual construction and material, to wit, fire clay, except that it may be shorter than heretofore, due to the true stream flow obtained therethrough as later explained. A slightly depressed seat 22 is ,formed in the upper -end in which the head of the stopper v engages by line contact, as shown in Fig. 1. Such of the ladle, indicated at 21, and are suitably sea nozzles extend vertically through the bottom wall cured therein. The upper end is frequently in a shallow well or sloping depression inthe upper /face of the bottom of the ladle or it may be ilush with the at face. y

The dilculty in bottom pouring with stoppers having substantially straight'sides, that is, of substantiallythe same diameter throughout, is the` tendency of themetal to-swirl when pouring. The erosive actionon the nozz'le tends to cut it, the desired free, fulliiow through the nozzle is interrupted, and' the .hot metal tends to,spray and fan out as it emits from the nozzle. The nozzles assenso soinf'of this, funtilnow theyare usually"1' 3or I4 inches -inlengtln` Long nozzles, 'lioweveL-sare obtendfto produce a swirl within themselvesi In his invention, the 's'wirlflis prevented by the frQmtnetp' f the lsleevet'o near theibqttom: vand at al point 24 near" the bottoni off-the sleeve by the inwardislope at aA comparatively sharp`y angle and steeper slopeg'fas shown in the drawing kand indicated-fat] ,25:17 The outer. surface?` 2s for! the headrben'eath ffthe-shqulderm ismadento :om a dent-inname orf'this inward' slope of the: bottom in'iierforate ,bottomf of the head;

f By 'this contour of the sleeve'thedescending hot metal aboutfthe stopper is caused to change its direction ofwflow', to break .up and prevent the tendency to swirl, and the Vsharp inward slope `at to constitute what is termed a cold pour. The

result, too, -is that a shorter nozzle may be used,y

since there is no spraying or tanning of themetal as it issues from the nozzle. A nozzle of 9 inches in length may be satisfactorily used. The design 4 and proportions shown in the drawing are preferred for, average conditions and temperature of metal to be poured and average characteristics of the metal such as are met with in the average plant doing general work of this nature.V For specialconditions and characteristics slight v ariations'may be desired. as will be understood by those skilled in the art. y It is intended, of course, that 'the invention should not be limited to the specific embodiment (or embodiments) disclosed herein, since modifications masr be made, .and it is contemplated, therefore, by the. appended claims, to cover any such modifications as fall within the true spirit and scope of this invention,

Having thus described this invention, what is claimed and desired to be secured by -Letters Patent is: y A

1. In an inside bottom pouring ladle stopper having theusual central metal supporting and4 nozzle, said sleeve lhaving in its expanded lower end l-anfenlarged andv deep l,recessfa head extending and )fitting .intensa-icl,` l`recess and having a molten menu and permitirse-now ,thereof tothe rounded-solid` imperforate bottom for-fengag-' 1 ment byline contact withfthefnozzle seat, and metallic'securinglandsupporting,connectlons-of f said ro'dzwith said-,head embedded in'v the upper partof said headx. l l, ,Y y 3.` In anffinside-bcttom pouring ladle-stopper having' the-usual. central metal supportingv and operating-1rod'surrounded b y the usualV refractory tiibularsleeves, a` refractryj bottom sleeve'=co.=" operatingat theupper endwith-the sleeve above Ait and having" anv exterior infthe forma-uffa truncated-'cone throughout its greaterzlengtmethe Aremainder dof its length `being inwardlyfsloped' exteriorlyat a.y sharp anglel with the surface above and at a.l steeper slope,l to prevent swirl`l of the molten metal and permit free ow' thereofito vthe nozzle, said sleeve rhaving-.in its vexpanded lower end anenlargedand deep recess, ahead having its upperV half, extending and tting into said 'recessand having a' mid-sectional, circumferential ledge or shoulder underlying the end of the sleeve and a rounded lowersolid and lmperforate lower half for engagement by line contact with the nozzle-seat, and metallic connections of the said rod with the head embedded in the said upper half of the head within said recess.

4; In an inside bottom pouring ladle stopper having the usualcentral metal supporting and operating rod surrounded by the usual refractory tubular sleeves,A a refractory `bottom sleeve cooperating at the upper end with the vsleeve above it and having an exterior in the form of a truncated cne throughout its greater length, the

'operating rod surrounded by the usualrefractory tubularlsleeves, a refractory bottom sleeve cooperating at the upper end with the sleeve above git and having an exterior in the form of a truncated cone throughout its greater length, the remainder oi! its length being inwardly sloped exteriorly at a sharp angle with the surface above and at a lsteeper slope, to prevent swirl of the molten metal and permit free flowv thereof to the nozzle, said sleeve having in its expanded lower end an enlarged and deep recess for the reception of a correspondingly shaped head with its metallic connections to the rod above and a rounded projecting bottom for engagement `by line contact with thel nozzle seat.

2. Inaninside b ottoinV pouring ladle stopper having the usual central metal supporting and remainder of its length being inwardly sloped exteriorly at' a 4sharp .angle with the surface,

above and at a steeper slope, to prevent swirl of Vthemolten metal and permit free flow thereof to the nozzle, said sleeve having'in its expanded lower end an enlarged and deep recess, a head having its upper half extending and fitting into said recess and having a mid-sectional,v circumferential ledge or shoulder underlying the end of Vthe sleeve and a rounded lower solid and imperforate half for engagement by line contact with the nozzle seat, said lower half having a surface contour forming a continuance of the inward slope of the lower part ofthe sleeve, and metallic connections ofthe said rod with the head embedded in the said upper half of the head within said recess.

5. In an inside bottom pouring ladle stopper l having the usuallcentral metal supporting and operating rod surrounded'by the usual refractory u having its upper half extending into and fitting operating rod surrounded by the usual refractory tubularsleeves', .a4 refractory bottom sleeve cocated .cone throughout its greater length, the reniainder of its .length being inwardly sloped ex- Y teriorly at a sharp angle with the surface above and "at a'st'eper slope, to prevent swirl of the 1 within said recess, an extension of the supporting rod entering a-central bore in the said upper half of the head,` and a cross-pin inserted through aligning apertures in said upper haii!l I of the head and the rod extension andl connecting said head to said rod, said head having a soliduimperforate bottoml half extending beneath the said sleeve and rounded to form a bottom to engage by' line contact with the ladle nozzle seat.

6. An inside bottom pouring ladle stopper hav-v ing a central metal supporting rod surrounded by refractory tubular sleeves anda head at the lower' end forfengagement with the nozzle seat,

. the extension, and said the lower end o! said rod having a central hole,

Vcentral 4bore at its lower end, an extension` of the rod having its upper endtting into saidbore, a transverse locking key through the rod and extension to secure the latter' to the rod, the lower end of the extension projecting and fitting into an'aperture in the upper part of the head, a cross-pin inserted after assernbly of the head and imperforate.

on the rod extension through aligning ,apertures in the head and extension to secure' the head to headliaving an imperforate solid depending lower .end to engage the nozzle. seat of the ladle.v

8. In an inside bottom pouring ladle stopper having a central metal supporting rod surrounded by refractoryl tubular sleeves, a head for use vat the lower end of the stopper for valve engagef ment with the nozzle seat, said head having its upper half in the form o1 atruncated cone to tit within a corresponding recess in the bottoni sleeve andhaving a mid-sectional 'outwardly extending ledge to' receive the lower end Qt the bottom sleeve andua substantially hemispherlcal lower half forming from the periphery of said ledge an inwardly sloping surfacevand'a rounded bottom forD engagement by line contact with the nozzle seat, said .upper halt being of: sumcient size to commodate the metal connections from the central rod to the head and its anchoring means .thereto and said lower half being? solid FREDERICg L. SAGE,

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