US2294044A - Ladle - Google Patents

Description

Al'lg1f25, 1942- P. D. NlELsEN l 2,294,044

l LADLE Filed March 9, 1940 Patented Aug. 25, 1942 LADLE Peer D'. Nielsen, Lorain, Ohio, assignor to National Tube Company, a corporation of New Jersey Application March 9, 1940, Serial No. 323,182

(Cl. 26S-39) 2 Claims.

This invention relates to improvements in the details of construction and arrangement of ladles peculiarly well suited for handling molten slag.

One object of the invention is to provide, in a large ladle, a structural assemblage of parts which will effectively resist the enormous stresses imposed by the rapid and uneven heating and cooling cycles encountered in normal use, so as to eiectively prevent deformation and breakage of the parts.

Another object is to provide a construction and arrangement whereby various parts of the ladle can be readily replaced in the event that warpage occurs or such parts become unfit for further use due to improper handling.

The ability to replace component parts of the improved ladle is an important one because it makes possible the salvaging or continued use of the undamaged parts thereof. The invention, by its dimensional arrangement, provides a ladle which will conserve the iioor space required to accommodate it, and is of a height sufficient to furnish the necessary cubical capacity for practical operations in conventional steel mills.

An additional object is to provide a ladle whose component parts are of such shape and form as to simplify the molding and casting procedure and thus avoid the inherent difficulties encountered in the manufacture of large ladles made in one piece and also to eliminate the necessity for normalizing such large castings.

A further and more detailed object of the invention is to design and construct the component parts of the ladle hereinafter described with particularity in such a manner that they singly and jointly perform the functions herein set forth in a practical and efncient manner.

An embodiment of the invention is illustrated in the accompanying drawing, in which:

Figure 1 is an end view with parts broken away and shown in section.

Figure 2 is a side view.

Figure 3 is a plan view.

Figure 4 is a horizontal detail section illustrating the juncture of side elements of the ladle.

Figure 5 is a vertical section illustrating the juncture of a side and a bottom section of the ladle.

Referring in detail to the drawing, the ladle illustrated includes four side sections l-I and 2-2 and a bottom section 3. The inner surfaces of all of these sections arc flat or plane surfaces. The outer faces of the side sections l-l and 2-2 are provided with stiiening ribs la and 2a,

in order to provide adequate strength to resist ,55

warping or deformation. The side sections I-l are provided with trunniorls l0 by means of which the ladle can be suspended from a spreader-type sling operated from an overhead crane by means of which the ladle can be moved from place to place, as desired. In teeming the ladle contents, the trunnions l0 are used in the conventional manner, the ladle being rocked about the axis of the trunnions while suspended in a sling by means of an auxiliary hoist on the overhead crane, this hoist carrying a suitable cable having a hook or other grappling device adapted to be engaged with the dumping lugs Il. The trunnions l0 also serve as means to support the ladle in a suitable ladle stand either at the location where it is to receive slag or on the cars which transport it. Stands on the car, however, are not essential, as a ladle built in accordance with the present invention has a flat bottom which provides adequate and suitable support and will thus rest lirmly on a conventional narrow gauge ladle car such as indicated at C.

As clearly shown in Figure 4, each side section 2 is provided with an angular liange 2b which is adapted to be assembled in abutting relationship with the adjacent portion of a respective side section I, these sections being heavily ribbed at their outer surfaces to provide substantial flanges t which extend from end to end of their oblique edges. The heavy flanges and ribs, together with the substantial trunnion construction, endow the sections with great strength, thus making them highly resistant to breakage and deformation. This construction is provided for the express purpose of making these sections I-I stronger than the others, so that if deformation or warpage of the ladle does occur to any extent, it will occur in those parts which are less costly to replace. The side sections l-l and 2-2 are secured to one another by suitable bolts 6 which pass through bolt holes 5.

As shown in Figure 5, the bottom section 3 is bolted to the side sections by means of bolts 9 passing through suitable bolt holes 8 in a flange l formed at the base of the side sections. The bolt holes 5 and 8 are made appreciably larger in diameter than the bolts 6 and 9 which pass through them, so as to provide a looseness or clearance which is deemed essential Ifor a proper functioning of the ladle so as to compensate for relative movement of the parts under the inuence of expansion and contraction. Y

The assembled ladle, as shown, is squared in plan and tapered in elevation. This provides a Acavity in the form of a truncated pyramid, from which solidified slag can be readily removed. While the square section as viewed in plan is preferable, the same principles of the invention may be embodied in a ladle of rectangular plan.

The adjacent contacting surfaces of the various ladle sections are machined to provide a proper ft to inhibit leakage of molten contents and to allow a relative creeping movement under the influence of expansion and contraction. The loose engagement of the bolts with the holes and the smooth machined surfaces of the various sections in contact thus provides for relief of stresses set up by expansion and contraction by unequal heating and cooling of the ladle in service. Such construction is of importance, as it prolongs the useful life of the ladle. When ladles are cast in one piece, even though heavily reinforced, failure eventually takes place because of the excessive deformation from warpage caused by contraction and expansion stresses. in ladles of circular form in plan. Heretofore Various circular ladles have been designed with removable top and bottom sections. Some of these circular top sections formerly proposed have been of a segmental design. Such prior ladles, however, have not accomplished the desired result, since, upon failure of one of the parts replacement has been very dicult and frequently impossible due to deformation of other parts, being of such magnitude that the proper fit of new and old parts could not be readily obtained. The reasons for the practical impossibility of effecting replacement of parts of such prior art ladles is that the superimposed circular sections have a rigid periphery, and a proper match between the old and new sections can not be made nor can one distorted section be properly drawn into alignment with a new undistorted section by connecting bolts, as each section is much too rigid to permit the necessary change or deflection required to bring about a proper fit.

The various sections of a ladle of the present invention can be readily replaced if damaged, for thereason that each section is a substantially. flat plate and the vertical corner joints extending for the entire height of the ladle can be effectively drawn together by tightening the bolts 6. Similarly, the bottom section 3 of the ladle is a plate of either rolled or cast steel, and because of its flat character it can be readily drawn to a tight ft with the base flanges 'I of the sections I and 2 by tightening the bolts 9.

In Figures 1 and 2, the ladle is shown mounted on a car C for ready transportation, with its flat bottom resting on skids secured to the bottom of the car. However, if desired, the car can be provided with stands at each end for engagement with the trunnions l0, or suitable lugs can be provided on the ladle below the trunnion so that it can be supported on such lugs resting on suitable stands at each end of the car.

The square or rectangular cross section of the ladle has certain structural advantages over a ladle of circular cross section. In many existing furnace installations, which this ladle has been designed to serve, space is at a premium. Fixed furnace dimensions such as the height of slag hole above ground level, the size of car suitable for transporting the ladle over existing tracks, building clearances, etc., definitely limit the maximum dimensions to which the ladle can be built. In such cases a ladle of square section This is particularly true can be made with a greater volume than a ladle of round section. In either case, the height must be the same and the ladle whose section is .that of a square superscribed upon a circle has the greater cross-sectional area and thus a greater volume.

A ladle having a square or rectangular sectional cross-section as described, with plate-like sections bolted together to allow for movement at the joints, such movement being provided for by the smooth character of adjoining surfaces and bolts loosely fitted in their holes, results in an assembly in which the parts are free to move one upon the other to the extent necessary to relieve the stresses set up by alternate heating and cooling and the accompanying expansion and contraction of the various sections. In a ladle of that design, the periphery at any point of its cross-section is free to change by movement at the joints, and the unequal stresses, caused by partially filling the ladle and resulting in the top portion of the ladle being considerably cooler than the bottom section, are relieved no matter at which point they occur. The ladle is made preferably square in section to take advantage of equal linear expansion or contraction for equal temperature changes on all four sides, this arrangement resulting in less unequal stresses than if one side of the ladle were longer than the other.

At stated previously, one of the objects of the invention is to simplify the founding of such large ladles. Few foundries are equipped to manufacture castings of the size required if the ladle is made in one piece, and practically none of the furnace plants in which the ladles are used is equipped to make such castings. The sectional character of the ladle and the atness of the parts described permits relatively simple foundry procedure in casting, and, -due to the stressrelieving feature incorporated in the assembled ladle, normalizing heat treatment of the castings is not required.

Various modifications may be made by those skilled in the art without departure from the invention as defined in the appended claims.

I claim:

1. A sectional ladle substantially as described comprising a plurality of flat faced side sections and a flat bottom section, all said sections being secured by bolts passing through holes of larger diameter than the bolts so as to permit movement of any section relative to its neighbor and thus relieve the assemblage of stresses normally set up as an incident to expansion and contraction induced by the radical temperature variations to which ladles of this character are subjected in practice.

2. A sectional ladle comprising a plurality of readily replaceable flat plate-like sections consisting of a rectangular flat bottom section and four trapezoidal flat plate-like side sections, all the sections being secured together by bolts passing through holes thereinof larger diameter than the bolts so as to permit movement of any section relative to its neighbor to thus relieve the assemblage of stresses normally set up as an incident to expansion and contraction induced by the radical temperature variations to which ladles of this character are subjected in practice.

PEER D. NIELSEN.

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