US2107267A - Ladle - Google Patents

Description

C. P. ASTROM Feb.8,1938.

LADLE Filed March 14"., 1936 IJUlll Patented Feb. 8, 1938 UNITED STATES ATENT OFFICE Application March 14,

4 Claims.

This invention relates to ladles and particularly to ladles of the tubular open top type such as are used for the handling and transportation of molten materials in and around steel plants. 5 For the handling of molten materials, especially molten iron and steel, various types of ladles have heretofore been suggested and used. Qne type of widely used ladle comprises essentially a tubular shell or body, bottom and trunnions secured at diametrically opposed points upon the shell or body at or near the upper or open end thereof. Ladles of this type are frequently designed so as to have the capacity to receive large quantities of molten metal and are hence of large size and great weight. The structure of the ladle must be such that it is able not only to resist the outward pressure of the metal which the ladle contains when charged but also to resist distortion due to the application of lifting forces to the trunnions. As is well-known, the outwardly projecting trunnions to which the crane hooks are attached tend to tilt upwardly when lifting forces are applied thereto and to twist or distort those portions 25 of the shell of the ladle to which they are secured. Likewise, the application of lifting forces to the trunnions tends to cause the trunnions to move toward each other when the ladle is elevated and to distort the tubular shell of the ladle, 30 this being due to the fact that the center of gravity of the load is intermediate the trunnions.

Various expedients have heretofore been resorted to to render ladles of this type entirely rigid under the action of lifting hooks applied to the 35 trunnions but in each instance where a satisfactory degree of rigidity has been obtained it has been obtained by greatly thickening certain portions of the walls of the container or by providing the container shell with circumferen- 40 tially extending reinforcing or supporting members of very substantial design, the weight of the ladle being thereby rendered much greater than would be necessary were it only required to provide a shell of sufficient rigidity to withstand the internal pressure of its liquid contents.

It is the object of the present invention to provide a ladle of great strength and rigidity but which at the same time is lighter and less expensive to construct and manipulate than ladles of the same capacity of other types heretofore designed or suggested, In carrying out the invention various mechanical expedients may be resorted to but each embodiment of the invention is so constructed as to make use of the internal pressure of the liquid contents of the 1936, Serial No. 68,954

ladle to oppose distortion of the shell when lift.- ing forces are applied at the trunnions. As a result of making use of the outwardly directed forces developed by the contained molten material, or other liquid, to resist distortion, certain portions of the shell of the ladle may be made of considerably lighter section than would otherwise be necessary, without sacrifice of effective strength and with substantial savings in first cost. Likewise, substantial savings are also realized l0 throughout the useful life of the ladle due to the fact that less power than otherwise necessary need be used to lift and transport it, whether it be full or empty. 7

In the accompanying drawing two forms of 15 the invention are set forth by way of example and still further forms may readily be devised.

In the drawing:

Figure 1 is a side view of one form of ladle embodying the invention; a ,20

Figure 2 is likewise a side elevation of the same ladle but viewed from a different point, 90removed from the point from which the ladle shown in Figure 1 is used;

Figure 3 is a section on line 33 of Figure 1; 5

Figures l and 5 are views similar to Figures 1 and 2 but illustrate a second form of ladle constructed in accordance with the invention;

Figures 6 and '7 are diagrammatic views, Figure 6 illustrating diagrammatically the condition of the ladle shell when empty and resting upon its bottom, and Figure '7 illustrating the same shell when charged and elevated by the trunnions.

Each form of the ladle illustrated includes a, tubular shell, this shell being closed at one end by a bottom member, the oppositeend being open. In Figures 1, 2 and 3 the tubular shell is indicated generally at H] and is seen to comprise diametrically opposed, relatively thick plates 40 II and diametrically opposed, relatively thin plates !2, intermediate the plates ll, the adja cent edges of the plates II and i2 being welded together in a suitable manner. The bottom is indicated at IS, the edge of this bottom being welded to the inner face of the shell adjacent the lower end thereof.

Trunnions are indicated at M, these trunnions being secured to the plates H at points adjacent the upper ends of these plates, preferably having their inner ends tightly fitting in circular apertures formed in the plates and being firmly secured in such positions by welding. Encircling the trunnions and positioned just outside of the ladle shell are cast metallic trunnion supporting,

pads I5 also welded to plates II, respectively, these pads being designed and intended to assist in rigidly securing the trunnions to plates II. Encirclingthe shell I0, and disposed in parallel horizontal planes, are the two bracing ribs I6, these ribs being welded to the surface of the shell and also to the trunnion pads I5. It will be perceived from Figures 1 and 2 that the stiffened elements or plates I I, while extending completely to the bottom of the ladle, do not extend all the way to the top, terminating just above the trunnions I4. The portion ll of the shell which lies above the upper edge of each of the stiffened elements or plates II is relatively thin, as shown in Figure 2, and may comprise portion of either or both plates I2 or a separate plate, welded to the upper edge of the plate II immediately below.

In the form of the invention shown in Figures 1, 2 and 3, the diametrically opposed plates II are relatively thick as compared with the plates I2, and are substantially rectangular as shown in Figure 1. The thickness of these side plates will vary with the size and capacity of the ladle but in every instance should be such as to substantially resist deformation between the trunnions and the bottom I3 when lifting forces are applied to the trunnions. In other words, inasmuch as the lower edges of these plates or stiffened elements II are secured to and held in spaced relationship by the bottom I3 of the ladle, the bottom edges are therefore relatively immovable and the elements I I have such thickness that no substantial deformation thereof occurs when the ladle and its contents are lifted by crane hooks. Each of the plates I2, therefore, performs not only the function of retaining the lining of the ladle and resisting the outward pressure of the molten contents when loaded, but likewise functions as a relatively stiff and und-istortable beam anchored at its lower end to the bottom I3 and movable, if movable at all, only about its lower edge when transverse distortion of the ladle shell, between the trunnions, occurs.

As is well-known, all metallic structures when subjected to load will distort through measurable amounts and in the diagrammatic Figure 7 of the drawing a ladle such as the one illustrated in detail in Figures 1, 2 and 3 is shown as being distorted to a greatly exaggerated extent under load, the undistorted ladle being diagrammatically illustrated in Figure 6. Thus, due to the application of lifting forces, the trunnions have moved slightly toward each other, carrying with them the upper edges of the beam-like relatively stiff plates II, which plates or beams will have only insignificant distortions due to their heavy construction. .The amount of inward deflection of the upper ends of the plates II will be greatly minimized, however, due to the outwardly directed and opposing pressure of the contained liquid, the pressure of the liquid being effective to resist or oppose the inward deflection of the plates II over the entire areas of these plates, as will be readily apparent.

This being the case, it is readily apparent that, in order to reduce the distortion due to lifting to the absolute minimum, it is only necessary to brace the upper ends of the beam-like plates II apart by metallic members of much lighter weight than would be required were the pressure of the metal not made use of to resist this distortion. The circumferentially extending strengthening ribs I6, therefore, may be relatively light in cross-section and the intermediate plates I2 may be of considerably less thickness than would-be otherwise required. The net result of the construction is therefore to provide a ladle which is highly resistant to strain and deformation while at the same time having a minimum weight for a given capacity. It will be appreciated that the beam-like plates II may be formed in various shapes, that the members chosen for bracing the upper edges of these plates apart may be formed differently and that the lower edges of the plates may likewise be braced apart by means other than the bottom I3. The lining of the ladle is indicated by the chain lines I3 and this lining may be of conventional character.

In the form of the invention illustrated in Figures 4 and 5 the shell 20 is of uniform thickness throughout and the trunnions 21 are attached by radially extending arms 22 to the spaced vertically extending beams 23, respectively, and to the cross bracing 24 and the circumferentially extending ring 25, the several parts being preferably welded to each other and to the shell 20 of the ladle. The beam members 23 extend to the bottom of the ladle, which is indicated at 26 and preferably also extend to the top, although they may terminate short of the top if desired. The effect of the beams 23 is to render the diagrammatically opposed sides of the shell 29 to which they are immediately attached substantially undistortable and to cause these opposed portions of the shell to move, if they move at all, when the welded ladle is lifted by the trunnions, about the points of intersection of these portions with the portion 26. This inwardly swinging movement of the opposing sides of the ladle shell is resisted by the outwardly acting pressure of the metal, exactly as in the case of the first form of the invention described, and the pressure of the molten metal is therefore made use of to resist and minimize distortion of the metallic parts of the ladle. Hence it is possible to make the ladle shell 20 of minimum thickness for any specified capacity of ladle and the transverse upper bracing means, whether it be a ring such as indicated at 25, or other bracing device, may be very considerably reduced in size and weight.

It will be understood by those skilled in the art that the two forms of the invention described in detail and illustrated in the accompanying drawg steel plants, various types of specific structures may be evolved and used.

An improvement which I find useful when applied to all designs of ladles of the open topped type is also illustrated in the drawing. This improvement comprises the slag and molten metal deflecting member 30, a narrow plate encircling the ladle shell and suitably secured thereto at points above and spaced from the upper rib or ring I6. Member 30 is downwardly and outwardly inclined as shown and prevents any hot slag or metal spilling over the upper edge of the ladle from falling upon and overheating the upper ring I6. Devices of this general character have been employed heretofore but, when used, have been mounted upon the upper rings instead of upon the bodies or shells of the ladles with which they are associated. By mounting the deflecting member 30 above the ring, and spaced therefrom,

heating of the ring does not occur even though the deflecting member itself may become highly heated, thus preventing overheating and weakening of the upper ring.

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

1. A ladle comp-rising a tubular metallic shell having a bottom and an open top, the tubular wall of the shell having vertically extending trunnion carrying portions on opposite sides thereof and intermediate portions connecting the trunnion carrying portions, the trunnion carrying portions having their lower ends attached to and spaced apart by the bottom and being individually substantially resistant to flexure under the influence of lifting forces applied at the trunnions, and the intermediate portions, not subjected to such forces, being of lighter construction.

2. A ladle of the built-up type comprising a tubular shell open at the top and having a bottom closure, diametrically opposed trunnions adjacent the top of the shell, relatively thick diametrically opposed plates to the upper ends of which the trunnions are attached, respectively, said plates comprising portions of the shell and having their lower ends secured to the bottom, said plates being substantially inflexible under the influence of lifting forces applied at the trunnions, and other plates of lighter construction connecting the aforementioned plates.

3. In a built-up welded ladle of tubular type having a closed end and an open end, a bottom, a tubular shell or side Wall comprising opposed longitudinally extending trunnion supporting plates extending from the bottom toward the open end, and intermediate plates welded to said first mentioned plates and to the bottom, and opposed trunnions attached, respectively, to the said trunnion supporting plates at points remote from the bottom, the trunnion bearing plates being suificiently stiif to substantially resist distortion thereof at the trunnions and intermediate the trunnions and bottom due to the application of lifting forces at the trunnions, and intermediate plates being of lighter section.

4. A ladle of the built-up type comprising a tubular shell open at the top and having a bottom closure, diametrically opposed trunnions adjacent the top of the shell, and members to which the trunnions are rigidly secured, respectively, extending vertically downwardly from the trunnions to the ladle bottom, the lower ends of said members being rigidly maintained in fixed spaced relationship by the bottom structure, and said members being subtantially inflexible under the influence of lifting forces applied at the trunnions, the other portions of the ladle, not subjected to such forces, being of lighter construction.

CARL P. ASTROM.

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