US2988793A - Composite hot top and method of manufacture - Google Patents

Description

June 20, 1961 R. E. WITHEE ETAL 2,

COMPOSITE HOT TOP AND METHOD OF MANUFACTURE Filed Oct. 8, 1958 2 Sheets-Sheet 1 P76. 2 F/Cil 63 3 -17) 44 40 6m im I, I 3 1, Q i :1,

H 4- INVENTORS ROBERT E. I/V/THEE BE/WAM/A/ FAA/7740M 7 :M I g I ATTOR/VE Y5 June 20, 1961 R. E. WITHEE ET AL 2,988,793

COMPOSITE HOT TOP AND METHOD OF MANUFACTURE Filed Oct. 8, 1958 2 Sheets-Sheet 2 III I U iwd S a s t n V 2,988,793" COMPOSITE H T TOP AND METHOD OF MANUFACTURE i Robert-E. Withee and Benjamin F. Anthony, Cleveland Heights, Ohio, assignors to Oglebay Norton Company, Cleveland, Ohio, a corporation of Delaware Filed Oct. 8, 1958, Ser. No. 766,048 3 Claims. (Cl. 22-'147) rThepresent inventionrelat'es to hot tops of therefractory-lined, m'etal casing and, more particularly, to such a hot topand a method-and apparatus for readying thehot topfor use with an ingot fi'nold.

In one method of casting anin'got of steel, ahot top is associated with. the upper "end of t-heingot mold and molten steel is'pouredinto the ingot mold through a central opening in thehottop. Sufficient molten steel is Ipou'red to fill the mold and, at least, part of the hot top. The hot top is a heatiiris'ulator and maintains the molten steel therein ina, mo'lten condition. while the steel in the ingot mold.solidifies,.thereby providing a sinkhead of molten steel for satisfying the shrinkage in the solidifying ingot. v

The general type pfhot top to which the'present invention relates is c'onipiisedof afmetal casing lined with refractory brick to protect the casing from the heat of themolten steel. Tihe bottom of the casing is prevented from coming into contact with the'steelin the ingot mold during the casting operation by alr efractory band or ring whichis replaced after each casting. One type of brick lining iscomprised of a commercial "insulating fire brick which has its exposed face gprot ected'by a veneer preferably of refractory material. Structurally, insulating firebrick is soft, porous and weak. .Another type of refractory liningis comprised of commercial fire-clay brick which is relatively hard, dense and strong.

After-the'hot top has been used and has been stripped from the ingot, it is reconditioned before it is again used. The heat ofthe molten steel and the stripping of the'hot'top generallydamages the lining of the hot top. In the caseof hot tops whichhave relatively hard fireclay 'br'ick lininggxthe linings are patched Withpatching material tha't'is applied in fictile or plastic form and then dried. In the casc'of hot tops having an insulating firebrick'lining protected by -a layer of veneer, the veneer must be replacedafter each use. In both types of hot tops, a new ring must be applied to the bottom of the hot top with each use. The user of the hot top must, therefore, maintain on hand an inventory of bottom rings and'eitherpatching material or veneer compound as the case may be. Theshipping, stocking, and handling of the bottom rings involves problems to both the user and niamifacttirer.

The principal objectof the present invention is to provide a new and improved method of readying a metal casing-type hot topfor use in a casting operation, which method does not 'reqilire the user of the hot top to maintain'an inventory of bottom rings, as has heretofore been the case, thereby eliminating the problems in shipping, storing, and handling therings.

Another object of-the present invention is to provide a new and improved iiiethod of readying a hot top for use including the conditioning of the refractory lining of thefho t top andthe providing of a protective wall on the bottom of the'casing'which functions as the conventional bottom refractory ring, which method is simplified over the prior'art methods "and which'requires fewer parts to condition the'hot top for use; as wellas preferably providing a novel and improved manner of securing conventionalwiper strips to the'hottop.

A further object of the -present invention is the provision of a novel and improved apparatus for applying a veneer to the brick lining of a hot top and for simultaneously forming in situ a protective wall simulating a refractory bottom ring at one end of the hot top.

A still further object of the present invention is to provide a new and improved hot top having a protective veneer for protecting the brick lining thereof and a bottom protective ring molded in situ as a single unit.

It is also an object to eliminate the spring clips conventionally used to clip a bottom ring to a hot top casing.

It is still another object of the present invention to providean apparatus for forming a bottom ring in situ on the hot top and, preferably, for forming the bottom ring and applying a protective veneer to the lining of'the o n- In accordance with the present invention, the bottom ring of the hot top is formed in situ, preferably while the refractory lining thereof is being conditioned for use by molding fictile material; and the wiper strips, conventionally associated with the hot top, are preferably, if used, secured to'the hot top by inserting one edge thereof into the 'materialformirlg the ring while the latter is plastic. According to onefeature of the present invention, a removable form member for facilitating the molding of theringis "provided and preferably comprises a member adaptedto be supported on'the hot top in a position wherethe member'circumscribes the bottom end wall of the hot top'adja'cent'the outer edge thereof and wherein it forms a prolongation of the outer side of the hot top, the inner sideof the form member preferably forming the prolongation of the outer side of the hot top. The form veneer and bottom ring, the ring and veneer preferably being formed as a single unit.

Further objects'and advantages of the present invention will be apparent from the following detailed description thereof made with reference to the accompanying drawings forming a part of this specification and in which:

FIG. 1 is a sectional view of a hot top supported on a stand in an inverted position;

FIG. 2 is a fragmentary sectional view of a part of the hot top as shownin FIG. lbut after the setting of the refractory ring formed thereon and the attachment of clips for securing the ring in its position;

FIG. 3 is a vertical sectional view of an apparatus for applying a refractory veneer to the lining of a hot top comprised of a brick-lined, metal casing and for simultaneously forming abottom ring with the application of the veneer; and

FIG. 4 is a fragmentary view of a portion of FIG. 3 showinga modification.

The type of hot top to which the present invention relates is shown in FIG. 1 supported in an inverted position by a stand 10, the stand comprising two vertically extending supports between which the hot top is supported, only one of the supports appearing in the drawing. The hot top shown in FIG. 1 is comprised of a metal casing 12 open at .both ends and interiorly lined with a fireclay lining 13. The metal casing 12 has an inwardly extending ledge 14 which extends under the brick lining at what is its loweredge when the hot top is in use,the inwardly extending ledge 14 appearing in the drawings at the top of and over the brick lining '13 since the hot top is shown in an inverted position. The normally bottom portion'of the hot top casing 12 is of reduced cross-section as indicated at 15 and is adapted to be received within the ingot mold, When the hot top is in 'use the reduced port'ion 15 provides an annular shoulder 16 which is used "to 'sfip-,

Patented June 20, 1961 port the hot top in position on the ingot mold while the molten steel is being poured. Blocks are normally disposed between the shoulder 16 and the top of the ingot mold during pouring and when the ingot mold has been filled, the blocks are removed and the bottom of the hot top then rides on the solidifying steel in the ingot mold. In order to protect the bottom end of the hot top casing 12 from the heat of the steel, a bottom refractory ring 18 is normally disposed adjacent to the bottom end of the hot top so that it is between the ledge 14 at the bottom end of the casing 12 and the steel in the ingot mold. Wiper strips 19, shown in FIG. 2, are conventionally provided to prevent molten steel from escaping between the hot top and the ingot mold. A conventional bottom refractory ring is held in place by spring clips such as the spring clip 20 shown in FIG. 2.

In the type of hot top shown in FIGS. 1 and 2, the brick lining is comprised of hard fireclay brick and is conventionally coated with a slurry before the lining is used to facilitate the stripping of the hot top from the sinkhead of the ingot. Even though the refractory lining 13 is comprised of hard fireclay brick, the lining may be damaged each time the hot top is used and if so, this damage is repaired before the hot top is use again. The refractory lining 13 is repaired by patching the places of the lining which have deteriorated or been damaged with a fictile or plastic material. rials are conventional and well known to those skilled in the art. After the brick lining 13 is patched, it has heretofore been the custom to assemble a preformed ring onto the bottom of the hot top. According to one feature of the present invention, the bottom ring is formed in situ on the hot top, preferably at the same time that the brick lining 13 is patched and is preferably formed of the same material as is used for patching the lining. To facilitate the molding or forming of the ring 18, a removable form 25 is provided. In the illustrated embodiment the removable form 25 comprises an annular rim-like member which is adapted to telescope over the bottom end portion of the casing 12. provided with a plurality of movable pins 26 which project from the inner side of the member 25 and which engage the bottom end wall of the casing 12 to limit the telescoping movement of the form 25. The position of the retractable pins 26 determines the extent of telescoping movement and also the thickness of the ring 18.

When the form 25 is in position on the inverted hot top,

the upper portion of the form member 25 extends upwardly from the end wall of the hot top and forms a prolongation of the exterior side wall of the hot top.

With the form 25 in place, the refractory ring 18 may be formed in situ by applying fictile refractory material within the form 25 to cover the exposed portion of the metal casing within the form 25. The form 25 deter mines the outer peripheral face of the ring and the height of the form is utilized as a guide for the thickness of the ring, the fictile material preferably being applied to the height of the form above the ledge 14. Preferably, the ring is formed at the same time that the brick lining 13 is patched. However, the ring may be formed simultaneously with the application of the conventional slurry to the fireclay brick lining and may be of the same material as conventionally used for the slurry. After the fictile material has been applied to patch the firebrick lining 13 and to form the ring 18, the material and ring are dried.

If the ring is formed when the lining is patched, the portions of the brick lining 13 adjacent the ring 18 are filled with patching material which will be integral with the material forming the ring 18, as indicated by the reference numeral 27. If the ring is formed when the conventional slurry is applied the ring will be integral with the coating formed by the dried slurry on the exposed face of the fireclay brick. V

The form 25 may be removed as soon as the fictile material forming the ring has suflicient body to maintain Such patching mate- The form member 25 is a 4 its shape. Preferably, the fictile material should have suflicient body to permit the removal of the form immediately after the ring is molded. Before the material forming the ring 18 loses its fictileness, conventional wiper strips 19 may be inserted between the ring 18 and the bottom end wall of the hot top casing as is shown in FIG. 2. The wiper strip 19 includes an edge portion 28 which is disposed between the ring 18 and the ledge 14 and a portion 29 which extends outwardly from the adjacent side wall of the hot top casing 12.

The conventional spring clips 20 may be applied to secure the ring and wiper strips in position. Conventional patching material and slurry material will, however have sufficient adherence when dried to the parts to which they are applied making it unnecessary to use spring clips under normal conditions.

The bottom ring may also be formed in situ when the hot top casing 12 is of the type having a lining 32 of soft insulating fire brick as is shown in FIGS. 3 and 4. In such a hot top, the insulating fire brick lining 32 is protected during use by a veneer 33 of protective material applied to the face of the lining. In FIG. 3, an apparatus is shown for applying the veneer to the face of the fire brick lining 32, the apparatus also being constructed to mold, in situ, a bottom refractory ring 18 simultaneously with the forming of the veneer 33. The apparatus for forming the veneer 33 and the ring 18 is comprised of a mandrel 36 including a body portion 36a adapted to telescope within the hot top from the lower end thereof, the hot top being shown in an inverted position in FIGS. 3 and 4. As shown in FIG. 3, the hot top to be treated is supported on a roller table 37 which forms a part of a conveyor for handling the hot top. The mandrel 36 is supported above the table 37 and a hot top supported on the table is moved into telescoped relationship with the mandrel 36 by the operation of a ram 38 connected to the table 37 to raise and lower the same. When the mandrel 36 is in telescoped relation with the hot top, the lower end of the body portion 36a of the mandrel closely fits the opening in what is normally the top of the hot top to close the same. The outer side 40 of the mandrel body, disposed opposite the fire brick lining 32 when the mandrel and hot top are telescoped, is spaced from the fire brick lining to define with the face of the fire brick lining a mold cavity for forming the protective veneer 33. A mold cavity for the ring 18 is formed in part by a flange 42 which extends radially outwardly at the upper end of the mandrel body 36a so as to overlie the ledge 14 of the casing 12. 'When the mandrel is telescoped within the hot top, the radial flange 42 is spaced from the ledge 14 of the hot top a distance equal to the desired thickness of the bottom refractory ring 18.

The mandrel 36 further includes a flange 44 that extends axially from the radial flange 42 and which is adapted to telescope over the reduced portion 15 of the hot top casing. It can now be seen that the flanges 42-, 44 cooperate with the adjacent ledge 14 of the hot top casing to form a mold cavity for the ring 18.

The mandrel 36 is constructed so that there is clearance between the ledge 14 of the casing 12 and the mandrel body 36a when it is telescoped within the hot top, and the portion of the mandrel body 36:: opposite the inner side of the ledge 14 may be shaped, as indicated at 46, so that the inner side of the ring 18 tapers inwardly to the exposed face of the veneer 33.

The mandrel body 36:: is provided with a central axially extending bore which opens into the upper end of the mandrel 36 and with radially extending ports 50 which communicate with the interior of the bore 48 and open into the veneer mold cavity when the hot top is telescoped over the mandrel. The fictile material for forming the veneer 33 and the ring 18 is supplied to the veneer and ring cavities defined by the mandrel and hot top through the bore 48 and the ports 50. In the illustrated apparatus, a conduit member 51 is positioned within the bore 48 and extends upwardly therefrom and has a plunger member 52 disposed in the upper end thereof. The plunger member 52 is reciprocable by a cylinder and piston unit 53 disposed in the upper end of the conduit member 51 and connected to the plunger. When the material is to be supplied to form the veneer and ring, the piston and cylinder unit 53 is actuated to move the plunger member 52 downwardly in the conduit member 51.

Fictile material is supplied to the conduit member 51 through an opening 55' therein disposed immediately under the plunger member 52 when the latter is in its uppermost position. The opening 55 is connected to a storage container 56 by a conduit 57 which opens into the bottom of the storage container. The fictile material stored in the container 56 is moved into the conduits 57 and through the opening 55 by the operation of a piston and cylinder unit 58 associated with the container '56 and having piston rod 60 connected to a plunger 61 in the container 56. The plunger 61 is positioned adjacent the bottom of the container 56 and is reciprocated along the bottom toward and away from the conduit 5-7 by operation of the piston cylinder unit 58. When the plunger 61 moves toward the conduit 57, fictile material is forced out of the container 56 into the conduit 57 and then into the conduit member 51.

It will be noted that the bottom refractory ring 18 formed as disclosed herein also provides protection for the inner inclined face of the ledge 14 and for the exposed part of the underside of fire brick lining 32, the underside being the uppermost side of the hot top as viewed in FIGS. 3 and 4 since the hot top is shown in an inverted position. Furthermore, it will be noted that in accordance with one feature of the present invention, the hot top is provided with a protective veneer for the fire brick lining and a bottom refractory ring which are formed integrally with each other.

The embodiment shown in FIG. 4 is substantially the same as that of FIG. 3 and the parts thereof have been given the same reference numerals as the corresponding parts of FIG. 3. The embodiment of FIG. 4 differs from that of FIG. 3 in that the mandrel is formed to provide a longer taper at 46 for the inside face of the ring. In the embodiment of FIGS. 3 and 4, wiper strips may be inserted 'as in the embodiment of FIGS. 1 and 2.

It should be further noted that a reinforcement 63 may be molded into the bottom ring as is shown in FIGS. 1 and 4.

It can now be seen that a new and approved method and apparatus has been provided for providing a hot top with a bottom ring, as well as with a bottom ring and a protective layer of fictile material, in one case the protective layer being a repair of a damaged lining, and in another case the layer being a veneer applied to the face of the brick lining of the hot top. While the apparatus of FIGS. 3 and 4 has been described as applying veneer to the face of a relatively soft insulating fire brick lining, it will be appreciated that the same apparatus could be used to apply a protective veneer and to form the ring 18, even though the fire brick lining is of relatively hard material, such as fireclay brick. It is to be further understood that the veneer 33 and ring 18 of FIGS. 3 and 4 could be formed by hand as the ring in FIGS. 1 and 2.

While the term ring has been used to describe the bottom refractory member applied to the hot top casing, it is to be understood that hot top casings are often polygonal in configuration and the term ring is used as a word of art and is intended to cover configurations other than round.

While certain embodiments of the present invention have been described in considerable detail, it is hereby our intention to cover those modifications, constructions and arrangements thereof which fall within the ability of those skilled in the art and the scope and the spirit of the present invention.

What we claim is:

1. An apparatus for applying a veneer to the exposed face of a brick lining of a hot top comprised of a bricklined, open-ended, metal casing and for providing the hot top with a ring which covers the outer end wall at one end of the casing, the apparatus comprising a mandrel adapted to be telescoped into said casing from one end, said mandrel when in telescoped relationship being spaced from the exposed face of the brick lining to provide with the face the side walls of a veneer mold cavity and having a portion overlying said one end in spaced relationship thereto, said portion having a substantially continuous member extending axially therefrom to engage said casing at said one end adjacent the outer periphery of said outer end wall to define, with said portion and end wall, the side walls of a ring cavity, means associated with said mandrel for supplying fictile heat-protective material to the cavities defined by said mandrel and including the cavity defined by said portion and said means in cooperation with said one end of said hot top.

2. In an apparatus as defined in claim 1 wherein said mandrel is shaped to provide clearance between the mandrel and the hot top to place said veneer cavity in substantially continuous communication with said ring cavity at the end thereof adjacent the ring cavity.

3. An apparatus for forming a ring on the outer face of one end of a hot top, said hot top comprising an open ended tubular metal casing and said apparatus comprising a member supported for movement axially of said opening to and from a position adjacent said outer face to form with said outer face a mold cavity for said ring, said member including a first part adapted to be received in said opening and a second part extending transversely of the axis of said opening to overlie said end face in spaced relationship thereto when said first part is received in said opening, said second part being continuous to provide a substantially imperforate wall for the mold cavity, said member further comprising a continuous portion extending axially from said second part at the outer periphery thereof in the direction of the hot top to engage the latter when said first part is disposed in the hot top opening to provide the wall of the mold cavity for forming the outer peripheral, axially extending surface of the ring, said portion providing a substantially imperforate cavity Wall, said second part together with said continuous portion defining with said hot top the ring cavity.

References Cited in the file of this patent UNITED STATES PATENTS 1,695,855 Moore Dec. 18, 1928 1,769,529 Miller July 1, 1930 1,777,660 Dahl Oct. 7, 1930 1,921,729 Charman Aug. 8, 1933 2,572,452 Daley Oct. 23, 1951 2,741,816 White Apr. 17, 1956 2,896,266 Anthony July 28, 1959 FOREIGN PATENTS 1,111,594 France November 1955 562,330 Canada Aug. 26, 1958

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