US2087054A - Ladle - Google Patents

Description

July 13, 1937. w. w WALLACE 2,087,054y

' LADLE Filed OCT.. l5, 1936 Patented July 13, 1937 UNITED STTl LADLE William W. Wallace, Pittsburgh, Pa., assignor to rllreadwell Construction Company, Midland, Pa., a corporation of Pennsylvania Application October 15, 1936, -Serial No. 105,787

3 Claims.

The present invention relates to ladles and particularly to ladles of the type made use of in and around steel plants in the handling and transportation of molten materials such as molten iron and steel. Y

Ladles now in use are formed in various ways depending upon the specic uses to which they are put, a common type of ladle, generally designated the open-hearth type, comprising essentially a cylindrical shell, bottom, and opposed trunnions secured to the shell, or to a band encircling the shell adjacent the upper end thereof, which end is open, the shell and bottom being lined With a suitable refractory. Ladles of this type may be emptied by top or bottom pouring operations and are moved from place to place by means of trunnion engaging hooks swung from overhead cranes. Other types of ladles are designed and constructed of somewhat dierent shape and mounted upon ladle supports, especially mobile supports by means of which the ladle may be transported from point to point. The contours of both types of ladles may vary considerably, the open-hearth ladle being either round or oval in horizontal crossesection and the ladles adapted to be permanently mounted upon mobile transportation means also varying .considerably in design and capacity. Insofar as details and method of ladle construction go, ladles fall into tWo main classifications, i. e., those which are formed by casting processes and those which are built up of sectionsand the several sections suitably secured together, as by welding, or by means of rivets, or by combined welding and riveting operations.

Essentially the present invention deals with ladles of the built-up type, Which type is now coming into increasing use in the steel industry in that it presents certain advantages of substantial nature over the well-known and widely used ladle fabricated by casting processes. A built-up ladle may be fabricated so as to be considerably lighter than the cast ladle, for a given ladle capacity, is less expensive to fabricate, may be more easily and less expensively repaired, and while containing less metal, is quite sufficiently `rigid and durable for its vintended purposes.

Such ladles of the built-up type as have heretofore been designed, suggested or placed in use have not been constructed in such manner as to avoid substantial criticism and it is the purpose of the present invention to provide an improved built-up ladle having a design superior to those previously suggested and by means of which the cost of ladle manufacture, maintenance and operation may be still further minimized.

Thus a ladle constructed in accordance with the present invention comprises only relatively inexpensive commercial sheets or forged plates oi moderate weight or thickness, which constructional elements are of comparatively low cost, and the method of assembly of these elements is such that the resulting ladle, while being quite suiciently strong Where strength is needed, embodies no portions or sections in which the weight of metal is excessive when the tensional, torsional or shearing stresses to which such portions or sections are subjected, are taken into account. At the same time a ladle constructed in accordance with the present design is amply strong at all points, not only having the necessary strength to resist failure but also the strength and stiffness necessary to resist excessive deformation under load.

As noted before, the principles of the invention may be embodied in ladles which differ quite considerably in contour and may be embodied in the construction of ladles to be put to widely different uses. By way of example there is illustrated in the accompanying drawing one form oi ladle constructed in accordance with the invention, this ladle being of the open-hearth type. It will be fully appreciated by those skilled in the art that in certain of its aspects the invention may be readily incorporated in ladles of other types and that the form of the invention which has been selected for illustration is b way of example only.

The ladle is seen to comprise a bottom, shell or side wall, and spreader encircling the shell, one or more pairs of trunnions being attached to the spreader. The bottom may be formed in any suitable manner but the shell is formed in a novel manner, as is the spreader, and by means oi the securing means employed these parts of the ladle are so secured together as to enter into a cooperative relationship not heretofore realized with other types of ladles. The shell comprises a plurality of shell plates the lower edges of which are suitably attached to the bottom and the adjacent lateral edges of which are suitably secured to each other, the number of individual shell plates employed depending upon the size and capacity of the ladle to. be built. The spreader likewise comprises a plurality of plates which, taken together, form an encircling band, the meeting edges of these plates being suitably secured together, and the several plates of the spreader being rigidly aixed to the shell. The,

trunnions may be of ordinary construction formed for instance by casting and are secured to the spreader as by rivets or welds, the weights or thicknesses of the several plates which together form the spreader varying in thickness, if desired, around the periphery of the shell, the trunnions being preferably secured to plates of greater thickness and rigidity than the remaining plates of the spreader. Each plate which forms a portion of the spreader is rigidly secured to the shell at a plurality of points 'and the axis of the trunnions is below the horizontal plane of the upper edge of the shell.

By means of the construction just above briey described, various stresses imposed upon the several portions of the ladle by reason of the lifting of the ladle by crane hooks when loaded or filled are amply taken care of, the lifting loads imposed upon the trunnions being transmitted horizontally into the spreader and thence vertically downwardly through the shell plates to the bottom without the development of excessive, tensional, torsional or shearing stresses at any point. A more detailed description of that form of the invention selected for disclosure will now be given.

In the drawing:

Figure 1 is a side elevation of a ladle of the open-hearth type embodying the features of the invention;

Figure 2 is a horizontal section on line 2-2 of Figure 1;

Figure 3 is a section on line 3 3 of Figure 1; and

Figure 4 is a section generally similar to that shown in Figure 3 but showing a modified means for attaching the spreader to the shell.

The ladle bottom is indicated at I0 and this portion of the ladle may be formed in any desired manner, preferably comprising a latslightly inclined plate with upturned or cupped edges and having a sufficient stiffness to withstand without buckling or excessive deformation the weight of a full charge oi" molten iron, slag or other material. The ladle shell is generally indicated at S and is seen to be somewhat oval-shaped in horizontal section. It comprises a plurality of shell plates II the number of which may vary in accordance with the size and capacity of the ladle, a ladle of moderate size having for instance four such plates, and a ladle of larger capacity six or more, the exact number of shell plates not being material to the invention. 'Ihe lower edge of each plate is suitably secured to the bottom I0, as by means of rivets or by welding, or by both rivets and welds. The lateral edges of each plate, which extend substantially vertically, are in abutting relationship with the ad jacent edges of the plates on either side thereof, and these adjacent margins are secured together by suitable means, preferably by welds such as indicated at I2. The shell plates II may extend upwardly various distances, in the case of the ladles shown in Figures l and 2, these plates terminating at II and in the case of the ladle shown in Figure 4 the shell plates being somewhat longer vertically and terminating at II2. In any event the spreader, which is generally indicated at P is so positioned that its inner surface is either in full and complete contact with the shell, as shown in Figure 4, or contacts with the shell over the major portion of its surface, as indicated in Figure 3, so that the trunnion axis is well below the upper edge of the shell, as will be apparent from an inspection of Figure 3 in which one of the trunnions is indicated at I4.

The spreader P comprises a plurality of plates in end to end abutting relationship. The number of plates which together comprise the spread* er may vary, depending upon the size and capacity of the ladle, the spreader shown in the drawing having fom such plates, two of which, indicated at I6, are trunnion carrying plates and the remaining two, indicated at II, are interposed between the trunnion carrying plate IG. The adjacent edges or" spreader plates I6 and Il may be connected by means of welds I8 to unite these plates into a continuous band. Furthermore by means of a plurality of rivets I9 each spreader plate is securely attached at a plurality of points to the shell, a built-up structure of great rigidity against twisting and horizontal distortion being thereby created. The trunnion members III may be of a type heretofore commonly known, 'formed by a casting process and the inner ends of the trunnions maybe enlarged to form spreader engaging plates Id which plates may be in turn secured to the trunnion bearing plates I of the spreader by rivets, welds or by both rivets and welds.

The ladle structure so far described is operative after a suitable refractory lining indicated at 2E) is applied but in the case of the ladle shown in Figures l and 2 I preferably add an upwardly L extending top portion 2l, which may comprise either a single plate or a number of plates welded together end to end, this top being of less thickness than the shell and boing attached to that portion of the spreader which projects above the shell by the upper row or rivets i9, a ller plate 22 being preferably interposed between the spreader and top section 2 l. A top ring of angle section is indicated at it being the function of this ring to protect and retain the lining 23. In the form of the invention disclosed in Figure 4 the spreader is sho-wn to be secured to the shell by means of plug welds 24 and the top ring 25 is shown to be welded to the upper edge of the light weight top extension 25, the lower edge of the top ring 26 being welded to the upper edge of the shell. Welding is employed wherever convenient or economical but in fabricating the ladle rivets may be substituted where deemed advisable. It will be perceived from inspection of Figures 1 and 2 that the welds I8 in the spreader plate are considerably removed from the welds I2 in the shell, care being taken to so space the various welded joints in order that maximum strength at all sections may be realized.

The ladle just described may be readily fabricated of commercial plates and at less cost than ladles of the built-up type heretofore designed. It likewise may be repaired at any point with greater ease and, while of light weight, possesses all the necessary strength and rigidity. The spreader P is so designed, and is so secured to the shell S that the section of the ladle taken in a horizontal plane of the trunnion axis is of great strength and this section is quite suliciently stiff and rigid to resist the torsional, bending and shearing stresses imposed thereon by the trunnion members when the ladle is lifted while fully charged. When the ladle lifted, the greatweight of the metal which rests upon the bottom is transmitted by the bottom to the several shell plates II, thence vertically upwardly to the zone of the spreader P. By means of the rivets shown, the load is transmitted from the shell to lit the spreader and from the spreader to the trunnions. It will be appreciated, of course, that inasmuch as both the ladle shell and spreader flare upwardly and there is close contact between the outer surface of the shell and inner surface of the spreader, a substantial portion of the weight of the ladle and contents may be transmitted to the spreader because of the frictional engagement of the mutually contacting faces of these two members. The joints between the several component plates of the spreader are sufficiently strong to withstand any tensional forces which may be developed therein at any time by reason of possible downward movement of the shell relatively to the spreader. The various metal sections are so designed that no excessive stress is met with at any point while at the same time no section or portion of the ladle contains any metal over and above that necessary for strength requirements.

While I prefer to make use of trunnions of the cast type, such as illustrated, forged or machined trunnions may also be employed and these may be attached to the spreader or to the spreader and shell in various ways, as for instance by passing the trunnions through aligned cylindrical apertures formed in the spreader and shell, and welding the trunnions iirmly in such positions.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In a ladle of the built-up type, in combination, a bottom, a plurality of plates extending upwardly from the bottom, the lower edges of said plates being secured to said bottom and the vertically extending adjacent lateral edges being secured together to form a horizontally `continuous shell, a spreader horizontally encircling and closely contacting the shell thus formed and comprising a horizontally extending series of plates the adjacent vertically extending edges of which are secured together, means rigidly securing the spreader plates individually to the shell plates which they overlie, the joints between the shell plates and those between the spreader plates being non-coincident, and trunnions secured to the spreader at diametrically opposite points and each to one plate only of said spreader, said spreader varying in thickness circumferentially, the trunnions being attached to the thickest portions thereof.

2. In a ladle of the built-up type, in combination, a bottom, a plurality of plates extending upwardly from said bottom, the lower edges of said plates being secured to said bottom and the vertically extending adjacent lateral edges being welded together to form a horizontally continuous shell, a spreader horizontally encircling the shell thus formed, said spreader being relatively wide vertically and the inner face thereof closely fitting against the outer surface of the shell, rivets securing all areas of the spreader to the shell, to bind the spreader and shell into a rigid unitary relatively stiif structure, and trunnions carried by the spreader in the zone of interconnection of the spreader and shell, said s preader comprising a circumferentially extending series of plates of varying thickness, the adjacent ends of which are attached to each other, the plates to which the trunnions are attached being of greater thickness than the remaining plates.

3. In a ladle, in combination, a bottom, a shell comprising a number of arcuate plates the lower edges of which are secured to said bottom, and the adjacent vertically extending edges of which are secured together, each of said arcuate plates subtending an angle of considerably less than 180, a spreader horizontally encircling the shell, said spreader being relatively wide vertically and the inner face thereof closely fitting against the outer surface of the shell, a multiplicity of means securing substantially all areas of the spreader to the shell to bind the shell and its enveloping spreader into a rigid unitary relatively stiff structure, and trunnions secured to said spreader, the plates of said shell extending upwardly to and beyond the horizontal center line of said trunnions, the latter being thus attached to the ladle in the zone of interconnection of the spreader and the shell.

WILLIAM W. WALLACE.

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