US2822591A - Hot top casing - Google Patents

Description

Feb. 11, 1958 H. c. HAMPE Ho'r TOP CASING Filed mig. 2,V 1954 AFIG] He.

.wat

United States Patent() HOT TOP CASING Harry C. Hampe, University City, Mo., assigner to Oswald Refractories Company, Brentwood, Mo., a corporation of Missouri Application August 2, 1954, Serial No. 447,331

2 Claims. (Cl. 22-147) This invention relates to hot top casings.

Itis customary to provide at the top of a vertical ingot mold a so-called hot top casing. The function of such a casing is to retard the cooling of molten metal at the upper end of the mold, so as to provide a reservoir of molten metal, feeding by gravity into the interstices of the cooling metal, in order to produce a sound and solid ingot. The preservation of a molten pool at the top also permits dross to rise to the top. Traditionally, such hot top casings rest on top of the mold and are destroyed when the ingot is removed from the mold.

It has been proposed heretofore to construct an ingot mold with an enlarged cavity or recess at its upper end, the base of the recess being defined by an annular shoulder, and to line the enlarged cavity with refractory blocks supported by the shoulder. However, these prior art insert-type refractory hot top casings have also had a very limited life, having to be replaced after one to four pourings, because they have broken 'under the strains exerted upon them, and molten metal has made its way into joints between the various blocks. Y

One of the objects of this invention is to provide a refractory hot top casing which is capable of repeated use without replacement, and which can be tightly fitted into a roughly finished mold cavity enlargement.

Other objects will become apparent to those skilled in the art in the light of the following description and accompanying drawing.

In accordance with this invention, generally stated, a refractory hot top casing is provided for use in an ingot mold having an enlarged top cavity or recess the base of which is defined by an annular shoulder. The refractory hot top is made sectionally, with wedge-shaped corner blocks by which the casing may be tightened so as to present an unbroken surface to the metal in the mold and to accommodate any irregularities in the walls of the recessed portion of the mold.

In the drawing,

Figure 1 is a top plan view of an ingot mold in whichy a refractory hot top casing, -constructed in accordance with one embodiment of this invention, is installed;-

Figure 2 is a sectional View taken along the line 2-2 of Figure 1;

Figure 3 is a top plan view of a wall block of the hot top casing shown in Figures 1 and 2;

Figure 4 is a view in end elevation of the wall block shown in Figure 3;

Figure 5 is a view in front elevation of the wall block shown in Figure 3; Y

nFigure 6-is -aplan View of acorner wedge block of the hot top casing shown in Figures'l and'2;V

Figure 7 is a view in front elevation of the Wedge block shown in Figure 6; and

Figure 8 is a view in side elevation of the wedge block shown in Figure 6.

Referring now to the drawing for an illustrative embodiment of this invention, reference numeral 1 indicates an ingot mold having a mold cavity 2. The mold cavity 2 consists of 1an upper cavity 3 and a lower cavity 4. The upper cavity 3 is larger laterally than the upper end of' the lower cavity 4, so that an annular shoulder 6 is provided at the juncture of the lower cavity 4 and the upper cavity 3. The upper cavity 3 is approximately square in cross-section, being defined by plane walls 7, substantially perpendicular to one another, and by rounded corners 5 connecting contiguous walls.

Resting on the shoulder 6, and extending through the height of the upper cavity 3 is a hot top casing 10 of this invention. shown, is made in twelve parts. Along each of the four flat sides 7 of the upper cavity are a left-hand wall block` 12, shown in detail in Figures 3 through 5, and a righthand wall block 14 which is a mirror image of the leftend 25. The square ends 15 and 25 abut one another tightly.

The chamfered sections 20 and 30 are wide at. their tops and taper along the front faces 18 and 28. Thus` the front faces 18 and 28 are wider :at their bottom-than,

at their top, as shown in Figures 4.and 5.

In each corner between the Wall blocks 12 and 14`of` contiguous sides is a corner wedge block 40.Y Each ofV the wedge blocks 40 has a flat vertical backV 41, a front face 42 which inclines toward the back 41 downwardly, and sides 43 and 44, extending convergently from the back 41 to the front face 42. Thus the corner blocks 40 are wedge-shaped both in plan view and in side elevation. The corner wedge blocks may be made in different Widths, so that if an upper mold cavity is oversize or undersize, or is slightly out of square, one or more widejorrnarrow corner wedge blocks may be used to give a tight iit.

lThe wall blocks 12 and 14 and the wedge blocks 40 are of the same height, and are flat on the top and bottom. The arris between the back of each of the blocks and its bottom is preferably chamfered as shown at 46 in Figures 4 and 8.

The downward convergence of the front faces of the wall and wedge blocks is preferably substantially the same as the downward outward air of the lower cavity 4, and the width of the blocks at their lower ends is the same as the width lof the shoulder 6, so that the front faces of the blocks form substantially uninterrupted continuations of the walls of the lower cavity 4, as indicated in Figure 2.

In preparing an ingot mold for use, the Wall blocks 12 and`14 are placed in position as shown inFigure 1, with their square ends 15 and 25 abutting. The corner wedge blocks 40 arethen inserted with their backs 41 as close to the'corners of the upper cavity 3 as possible, solas to give the greatest possible amount of 'clearance between them :and the wall blocks. 'The wedge blocks 40 are then 'Patented Feb. 11, 195s The hot top casing 10, in the embodiment and Iwedge blocks may be used. The preferred embodiment described is convenient to make and to install and produces excellent results. It ismore ilexiblethanvother,

arediicult to manufacture, inordinately heavy, and liable to break from the strains set up in use. t

The wail blocks and wedge blocks of the hot top casing of thisV invention are preferably made of refractory clays having low density, slag resistant and thermal shock resistant characteristics. First quality or better tire clay may be used. However, those skilled in the refractories art will understand that proper blends of rst quality, super-duty or special super-duty refractory clays can be made up to have the particular characteristics desired. In actual practice, dry press, super-duty grade fire clay blocks used in casings of this invention have consistently been used for sixteen to twenty pours. High burned superduty fire clay blocks, red at approximately 2750" F, will also give excellent results.

While the particular dimensions form no part of this invention, the following detailed description will serve to illustrate a practical device.

In an ingot mold 75 inches high, 32 inches square at thebottom and 30 inches square at the top, with a mold cavity tapering from 20% inches square at the bottom to 195/8 inches square at the shoulder, and with a recess 15 inches high and 23% inches square, leaving a shoulder approximately 25/s inches wide, the following dimensions have been found to be satisfactory for the blocks of the hot top casing:

Wall blocks: Inches Height of blocks 15 Thickness of blocks at base (without the bottom chamfer) 2% Thickness at top 3% Thickness of dat end 1%: Width of bottom chamfer 1/2 Width of chamfer section between front and flat end:

At top 3 At bottom 1% Width of front face between square end and chamfer:

At top.' 6%.

t At bottom 7%; `Width of back 8% Wedge blocks: Inches Height 15 Thickness at base i 3 Thickness at top 41A Y Width kof back 2% Width yof front face: Y

At top 1% At bottom 2 Width of sides:

' At top;v 41A YAt bottom 3 Numerous variations in the construction of the hot top casing-of this invention within the scope of the appended and two short sides, as compared with the square mold,

Wall blocks along the short sides.

are presently being used. In order to adapt the hot top casing of this invention Yto such a mold, it is only necessary to increase the width of the Wall blocks positioned along the long sides and to decrease the width of the The use of a plurality of Wall blocks along each side makes the hot top casing of this invention readily adaptable to various shapes, since individual wall blocks may be made of various different widths and configurations, so long as they are provided with camming end surfaces. So also, the configuration of the wedge blocks may be changed, so long as they are so constructed as'to perform their wedging function.

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

1. In an ingot mold having an enlarged upper mold cavity, defined by generally at Walls and an internal annular shoulder, a refractory hot top casing comprising: wall blocks resting on said shoulder and extending along the wallsdening the sides of the enlarged mold cavity but terminating short of the meeting corners thereof; said wall blocks having a plane substantially rectangular vertical back, a front face extending convergently downwardly Vtoward said back, and a chamfered section of uniform angularity from top to bottom with respect to the said back, said chamfered section extending along the inner edge of the wall block adjacent the corner of the enlarged mold cavity; :and corner wedge blocks, in corners of said enlarged cavity between the chamfered sections of adjacent wall blocks; said corner wedge blocks having a substantially rectangular flat back, a front face which extends convergently downwardly toward theflat back and sides which diverge in a direction away from the interiorA of the enlarged mold cavity, said sides being of uniform angularty with respect to the back of the corner Wedge blocks, there being suthcient clearance between the back of the corner wedge blocks and the wal-l of the enlarged mold cavity to permit the insertion of the wedge blocks after the wall blocks are in place, the divergence of the sides of the wedge blocks permitting them to bear againstV the chamfered sections of the wall blocks when the corner wedge blocks are moved inwardly, so that the wall blocks and wedge blocks constituting the hot top casing are forced tightly together.

2. A refractory hot top casing of the character described in claim 1 wherein the wall blocks along each wall are made up of a left-hand block and a right-hand block,

Y. said left-v and right-hand blocks being mirror images of one another, with abutting square ends opposite the hat ends adjacent the corners of the enlarged upper mold cavity.

References Cited in the file of this patent UNITED STATES PATENTS 1,804,205 Charman May 5, 1931 2,046,043 Urmetz June 30, 1936 2,433,175 Urmetz Dec. 23, 1947 FOREIGN PATENTS Great Britain Mar. 25, 1953;

Images