US2967790A

US2967790A - Method and apparatus for cleaning a hot top

Info

Publication number: US2967790A
Application number: US703024A
Authority: US
Inventors: Robert C Beason; Benjamin F Anthony
Original assignee: Oglebay Norton Co
Current assignee: Oglebay Norton Co
Priority date: 1957-12-16
Filing date: 1957-12-16
Publication date: 1961-01-10
Anticipated expiration: 1978-01-10

Description

Jan. 10,1961 R. c. BEASON ET AL 2,967,790

METHOD AND APPARATUS FOR CLEANING A HOT TOP- Filed Dec. 16, 1957 J2 I INVENTORS ROBERT C. 854.50 6 1 BEMMM/N fi'A/vmo/vv Arm/avers United States PatentU NIETHOD AND APPARATUS FOR CLEANING A HOT TOP Robert C. Beason, Lyndhurst, and Benjamin F. Anthony, Cleveland Heights, Ohio, assignors to Oglebay Norton Company, Cleveland, Ohio, a corporation of Delaware Filed Dec. 16, 1957, Ser. No. 703,024

5 Claims. (Cl. 1348) The present invention relates to'a method and appara- 'tus for cleaning a hot top and has as an object thereof the provision of a method and apparatus for removing a spent refractory veneer from the interior walls of the hot top.

In the conventional method of casting ingots, a melt of the material to be cast is poured into the upper end of a mold. As the material cools it shrinks and an axial cavity will be present in the cast ingot unless positive steps are taken to prevent the formation of the same.

. 'A conventional manner of preventing the formation of an axial cavity is to provide the ingot mold with a hot top which provides a reservoir of molten metal that feeds into the ingot mold as the metal therein freezes thereby preventing the formation of the axial cavity. Conventionally, such a hot top comprises a casing having the internal walls thereof lined with a firebrick lining and 'an end portion which is adapted to be received within the ingot mold and to ride upon the molten metal therein. The end of the hot top opposite the ingot mold has casing portions defining an end wall with a central opening therein through which the ingot mold and hot top are filled with molten metal. Because of the firebrick lining, the metal within the hot top is maintained in a molten state as the metal in the mold freezes, and the molten metal in the hot top will feed into the ingot mold 'as the metal therein freezes to prevent the formation of 'the axial cavity.

One type of hot top which may be utilized is that 'described in Anthony application Serial No. 203,666, filed December 30, 195 0, and now Patent No. 2,833,008. In the type of hot top disclosed in the aforementioned application the firebrick lining is made of a soft brick and is protected during each casting operation by a veneer of refractory material applied to the exterior face of the firebrick lining. The protective veneer is spent with each casting and must be replaced. Before a new veneer can be applied to the firebrick lining, the spent veneer .remaining on the lining from the previous operation must be removed therefrom.

An object of the present invention is to provide a method and apparatus for quickly, efficiently and accurately removing spent veneer from the interior of the .hot top to provide a clean face for receiving anew veneer of protective refractory material.

Another object of the present invention is to provide a new and improved apparatus and method for removing spent veneer from a hot top in which a cleaning broach or member is moved through the hot top opening to remove the spent veneer and which is such that the hot top and cleaning member need not be precisely aligned prior to the cleaning operation with little or no danger of the cleaning member damaging the fragile refractory brick lining of the hot top as the cleaning member moves into the hot top opening or during the cleaning operation. Another object is to provide a method and apparatus .Las in the preceding object wherein the hot top is centered Irelative to the cleaning member by pilot means carried Patented Jan. 10,1961

operation.

It is also an object to provide a new and improved apparatus of the type described in which the hot tops are moved into cleaning position by a power operated member adjacent the underside of the hot top and in which the guide means carried by the member for removing the spent veneer passes through the hot top, the apparatus being so constructed that the guide means and power operated member do not interfere with each other.

In the preferred embodiment of the invention suitable means is provided for supporting a hot top having a spent veneer on the faces of the interior walls thereof in approximate alignment with a cleaning member having a cross section corresponding in shape and size to the central opening of the hot top defined by the exterior faces of the firebrick lining in the hot top and adapted to remove or breach the spent veneer from the firebrick lining upon a relative telescoping movement between the hot top and cleaning member which effects a relative movement of the cleaning member from one end of the firebrick lining to the other. The apparatus of the present invention has means for effecting the telescoping movement or work stroke and the cleaning member carries pilot means which lead the cleaning member into the hot top and which pass through the end of the hot top opposite to the entrance end. The pilot means engages the casing at the end thereof opposite to the entrance end to effect a centering of the hot top with respect to the cleaning member. The supporting means for the hot top is constructed to permit the passage of the pilot means with out interference therewith.

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 all matter shown therein, whether or not expressly described, and in which:

Fig. 1 is an elevational view with parts cut away,- of an apparatus embodying the present invention and showing a hot top in position to have a spent veneer thereon removed by operation of the apparatus;

Fig. 2 is a view taken approximately along the line 2-4 of Fig. l but showing the parts of the apparatus :in

their relative positions immediately after completion of the cleaning stroke, and 1 Fig. 3 is a view looking in the direction of the arrows approximately from line 3--3 of Fig. 1.

Referring to the drawings, the apparatus shown therein comprises a roller conveyor 10, including a table section.

awaiting movement to the treating position after the spent veneer has been removed from the hot top in the treating position. v v

The conveyor 10 comprises horizontally spaced

horizontal rows

13, 14 of stub. rollers 15 which engage opposite edge portions of the hot tops to support the latter for movement along the conveyor.

The table section 11 below the cleaning member 12 also includes spaced

rows

16, 17 of stub rollers 15 which are respectively aligned with the spaced

rows

13, 14 of the conveyor 10 and form extensions thereof so that the hot tops on the conveyor 10 can be moved onto the table section 11. For purposes which will be apparent as the description proceeds, the

rows

16, 17 of rollers 15 are respectively supported by

angle irons

20, 21 of a framework 22 supported on a stand 23 for horizontal movement transversely of the conveyor against the action of springs biasing the framework to a central position on the stand 23. The

angle irons

20, 21 each have a vertical leg 24 that mount the respective row of rollers 15 and a horizontally extending portion that mounts wheels which ride on a horizontal portion 25 of an adjacent angle iron 26 which is part of the stand 23. The angle irons 26 each have a vertical portion 27 that extend along the adjacent one of the

angle irons

20, 21. The framework 22 is biased to a central position on the stand 23 by springs 28 interposed between the vertical portions 24 of the

angle irons

20, 21 and the adjacent vertical portions 27 of the angle irons 26, the springs 28 being disposed about pins which extend between the

vertical por tions

24, 27.

An indexing bar 30 extends along the length of the conveyor including the table section 11 and is reciprocable to index the hot tops A along the conveyor 10 to sequentially position the hot tops onto the table section 11 and to remove them therefrom. The bar 30 is disposed between the rows of rollers and is spaced therefrom and has a plurality of indexing members 31 pivotally mounted thereon by pivot pins 31a and extending above the top of the conveyor 10. The indexing members 31 are adapted to engage the hot tops on the conveyor when the bar is moved to the left, as the bar is viewed in Fig. 1, to cause the hot tops to move with the bar. A stop pin 32 adjacent each indexing member 31 prevents rotational movement of the corresponding indexing member when it is engaged with the hot top and while the bar is moving to the left. When the bar is returned in its reciprocating stroke, the indexing members 31 are free to rotate about their pivot pins and will so rotate to a position below the top of the conveyor 10 and table section 11 when they engage a hot top in their return movement. It can now be seen that the bar 30 is reciprocable to step the hot tops along the conveyor 10 and the indexing members are positioned so that a hot top moving along the conveyor 10 will center on the table section 11 as one of the indexing steps and will be moved from the table section on the next indexing movement of the bar. Any suitable power means, such as a hydraulic cylinder, controlled in a conventional manner may be utilized to reciprocate the bar 30.

The hot tops shown in the drawing each comprises an outer, open-ended hollow casing 33, which is conventionally a metal casing, having a lining of firebrick 34 on the interior wall thereof. As may be seen by reference to the drawings, the firebrick lining 34 is disposed between inwardly turned

casing portions

35, 36 at the opposite ends, respectively, of the casing 33 and the exterior faces of firebrick lining constitute the side wall of the hot top cavity designated by the reference numeral 37. The illusrated firebrick lining is formed of side shapes which lie along respective lines defining a rectangle and corner shapes which join the side shapes to provide a lining polygonal in cross section with the exterior faces thereof defining a hot top opening having a polygonal cross section uniform in size through the length of the lining. In the illustrated hot top, the casing portions 35 terminate short of the central opening while the casing portions 36 extend beyond the firebrick lining and define an opening 38 aligned with the central opening defined by the firebrick lining but of smaller crosssectional area.

The end portion 33a of the casing 33 adjacent the inwardly turned portions 35 has a reduced outer dimension as compared to the other end portion and is adapted to be received within the ingot mold when the hot top is in use during the casting operation. The end portion 33a is, therefore, during the casting operation, the bottom portion of the hot top while the lower portion of the hot top as viewed in the drawings is actually the top 4 of the hot top. In other words, the hot tops are shown in the drawings in inverted positions.

The hot top A shown in the treating position on the table section 11 is illustrated as having a spent veneer 39 of protective refractory material on the face of the firebrick lining 34. This veneer is removed from the hot top by the action of cleaning member 12. The cleaning member 12 has a cross section corresponding in size and shape to the cross section of the cavity 37 and is adapted to remove or broach the veneer 39 from the firebrick lining 34 when moved from one end of the firebrick lining to the other. The cleaning member 12 is fixed to the lower end of a piston rod 40 of a vertical hydraulic cylinder 41 dependingly supported in a position above the table section from crosshead 42. The crosshead 42 extends between and is supported by a pair of horizontal members 43 fixed to the upper ends of a pair of stanchions 44. The cylinder 41 is a double acting cylinder and has

pressure fiuid conduits

45, 46 connected to its upper and lower ends respectively and pressure fluid is supplied through the conduit 46 to elevate the cleaning member to the position shown in the drawings. The cleaning member may be moved downwardly to telescope it within the hot top A positioned therebeneath and to actuate it from one end of the firebrick lining 34 to the other by connecting the conduit 46 to drain and supplying pressure fluid through the conduit 45. It will be noted that gravity would cause the falling of the cleaning member 12as long as the

conduits

45, 46 were connected to drain or atmosphere but the apparatus is preferably so constructed that it is possible to supply pressure fluid through the conduit 45 to actuate the cleaning member 12 after it engages the spent veneer on the firebrick lining 34.

According to the present invention the cleaning member 12 includes pilot means 50 welded, or otherwise secured, to the lower side, in the illustrated embodiment, of the cleaning member 12 and leads the cleaning mem her into the hot top when the cylinder 41 is operated to move the cleaning member in a work stroke to remove the spent veneer from a hot top positioned on table section 11. The pilot means 50 comprises a pair of spaced

vertical plates

51, 52, depending from the underside of the cleaning member 12 and lying in planes substantially parallel to the vertical center-line plane of the conveyor 10. The

plates

51, 52 are adapted to pass through the opening 38 in the hot top casing and are spaced a distance which permits them to pass between the rows of rollers 15 and to straddle the reciprocating indexing bar 30.

The

plates

51, 52 pass through the opening 38 in the hot top casing with clearance between the sides and edges thereof and the casing of the hot top and each of the plates carry a plurality of guide members 54 which engage the side wall of the opening 38 to center the hot top with respect to the cleaning member 12. A guide member 54 is mounted adjacent each vertical edge of the

plates

51, 52 and extends outwardly from the plate member to engage with the adjacent end wall of the opening 38 and a guide member 54 is also mounted intermediate the vertical side edges of each plate and extends laterally therefrom at approximately the center line thereof to engage with the adjacent longitudinal side wall of the opening 38. The guide members 54 along the side edges ofthe

plates

51, 52 are each connected to the plates by bolts which thread into the plate and which pass through respective elongated openings 56 in the guide member. The openings 56 permit adjustment of the guide member toward and away from the adjacent sidewall of the opening 38. Vertical backing strips 57 are carried by

plates

51, 52 adjacent each of the guide members 54 extending outwardly from the vertical edges thereof and adjusting screws 58 are threaded therethrough to engage the adjacent guide member and adjust the innermost position of the guide member with respect to supporting plate. The guide members 54 extending ber to be adjusted toward and away from the adjacent longitudinal side wall of the opening 38.

In the illustrated pilot means, the guide members engage the casing of the hot top at six points to center the hot top with respect to the cleaning member 12 as the cleaning member is actuated through its work stroke.

The lengths of the guide members 54 are such that they engage the side walls of the opening 38 to efiect a centering ofthe hot top with respect to the cleaning member 12 before the latter engages the spent veneer on the firebrick lining of the hot top. It will be noted that the hot top is free to move longitudinally or transversely of the conveyor to provide the necessary centering movement by reason of rollers and of the spring mounting for the table section 11. While in the illustrated embodiment the hot top is supported so that it may move relative to the cleaning member when being centered by the pilot means, it will be understood by those skilled in the art that the cleaning member 12 could be movably supported to effect the centering movement of the hot top and cleaning member or both could be supported for movement to eifect centering. As can be seen by reference to Fig. 2, after the cleaning member 12 has completed a work stroke, the

plates

51, 52 on pilot means 30 extend downwardly through the opening 38 and straddle the reciprocating indexing bar 30.

It can now be seen that the present invention provides a novel apparatus for removing spent veneer from the firebrick lining of a hot top, which apparatus is capable of performing the operation quickly and efficiently and does not require the hot top and cleaning tool to be precisely positioned before the apparatus is operated t remove the veneer.

While the preferred embodiment of the present invention has been described in considerable detail, it is to be understood that it is our intention to cover all modifications, constructions and arrangements which fall within the ability of those skilled in the art and within the scope and spirit of the present invention.

Having thus described the invention, we claim:

1. The method of removing spent veneer from a hot top comprising a casing having a first opening of uniform cross section communicating with one end thereof and a frangible brick lining providing the side walls of said opening, said veneer being on said side walls and said casing having inturned portions at its other end opposite to said one end extending inwardly of said side walls and defining a second opening, the steps comprising effecting relative movement between a cleaning member configured to clean the veneer from said side walls and said hot top to cause the cleaning member to move into said first opening from said one end and throughout the extent of said side walls, and centering said cleaning member with respect to said first opening in response to said relative movement and holding said cleaning member centered during the movement of the latter through said opening by piloting on said portions with a part carried by said cleaning member and moved by said relative movement through said first opening and into said second opening and into engagement with said portions in advance of the entrance of said cleaning member into said first opening.

2. An apparatus for removing a spent veneer from the side walls of an axially extending opening in a casing of a hot top, the opening having a uniform cross section throughout the length of the walls from which the veneer is to be removed and a frangible lining providing the side walls to be cleaned and said casing including portions extending inwardly of the side walls of :said opening at one end thereof; a cleaning member ha iing a configuration corresponding to the configuration of the uniform cross section of the opening and receivable in said opening from the end thereof opposite to said one end and adapted to remove veneer from the side walls upon movement within said opening from one end of said side walls to the other end thereof, the outer periphery of said cleaning member being disposed about an axis aligned with the axis of said opening during the cleaning operation, support means for supporting said cleaning member and said hot top in an approximately axially aligned relationship, means for effecting relative reciprocatory movement of said cleaning member and hot top to efiect work and return strokes of said cleaning member, and pilot means on said member extending from the lead side of said cleaning member a distance greater than the length of theside walls to be cleaned and having outer sides parallel to the axis of the cleaning member and engageable with the inner ends of said casing portions to align said axes in advance of said cleaning member engaging said walls to hold said casing and cleaning member in an aligned position and against relative movement transversely of said axis, said pilot means being disposed within the outer periphery of said cleaning member and said support means supporting said hot top and cleaning member for relative centering movement to align said axes in response to the engagement of said pilot means with said portions and relative movement between said cleaning member and casing, said support means including means supporting said casing and cleaning member for limited relative movement from an aligned position in any direction in a plane perpendicular to the axis of said opening, and said pilot means comprising a plurality of guide members extending from said cleaning member parallel to the axis thereof and means supporting said members on said cleaning member for lateral adjustment in a direction perpendicular to the axis of said cleaning member.

3. An apparatus as defined in claim 2 wherein said support means includes a horizontal roller table for supporting said hot top and providing for relative movement of said hot top with respect to said cleaning member in either of two opposite directions perpendicular to the axis of the hot top from an aligned position with said cleaning member and means supporting said table and cleaning member for relative movement in opposite di rections perpendicular to the first said directions.

4. An apparatus as defined in claim 2 wherein said support means include a table for supporting said hot top in position to be cleaned, said table having an opening therein extending in the direction of movement of said hot top to and from its cleaning position, and further comprising a reciprocable index rod disposed adjacent the opening in said table and reciprocable to move a hot top to and from a position to be cleaned, said guide members being spaced from each other and being received by the opening in said table during the cleaning stroke of said cleaning member and straddling said index rod.

5. An apparatus for removing a spent veneer from the side walls of an axially extending opening in a casing of a hot top, the opening having a uniform cross section throughout the length of the walls from which the veneer is to be removed and a frangible brick lining providing the side walls to be cleaned, a cleaning member having a configuration corresponding to the configuration of the uniform cross section of the opening and conceivable in said opening from one end thereof and adapted to remove veneer from the side walls upon movement within said opening from said one end of said side walls to the other end thereof, the outer periphery of said cleaning member being disposed about an axis aligned with the axis of said opening during the cleaning operation, support means for supporting said cleaning member and said hot top in an approximately axially aligned 7 relationship'and for efiecting reciprocatory-movement to effect work and return strokes of said cleaning member, and pilot means on said member engaging said casing during said work stroke to hold said "casing and cleaning member in an aligned position and against relative movement transversely of the axis of said opening, said pilot means being disposed on said cleaning member to engage said casing in advance of said cleaning member being received in said opening, said support means supporting said hot top and cleaning member for relative centering movement to align said axes in response to relative movement between said cleaning member and casing to dispose the former in said opening comprising a horizontal roller table for supporting said hot top for relative movement of said hot top with respect to said cleaning member in either of two opposite directions from analigned positionwithsaid cleaning member and means supporting said tableand cleaning member for movement in opposite directions perpendicular to the first said directions.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent No 2,967,790 January 10, 1961 Robert C. Beason et al It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 6, lines 67 and 68, for "conceivable" read receivable Signed and sealed this 30th day of Mayl96l (SEAL) Attest:

ERNEST W. SWIDER v I DAVID L. LADD Attesting Officer Commissioner of Patents

Claims

5. AN APPARATUS FOR REMOVING A SPENT VENEER FROM THE SIDE WALLS OF AN AXIALLY EXTENDING OPENING IN A CASING OF A HOT TOP, THE OPENING HAVING A UNIFORM CROSS SECTION THROUGHOUT THE LENGTH OF THE WALLS FROM WHICH THE VENEER IS TO BE REMOVED AND A FRANGIBLE BRICK LINING PROVIDING THE SIDE WALLS TO BE CLEANED, A CLEANING MEMBER HAVING A CONFIGURATION CORRESPONDING TO THE CONFIGURATION OF THE UNIFORM CROSS SECTION OF THE OPENING AND CONCEIVABLE IN SAID OPENING FROM ONE END THEREOF AND ADAPTED TO REMOVE VENEER FROM THE SAID WALLS UPON MOVEMENT WITHIN SAID OPENING FROM SID ONE END OF SAID SIDE WALLS TO THE OTHER END THEREOF, THE OUTER PERIPHERY OF SAID CLEANING MEMBER BEING DISPOSED ABOUT AN AXIS ALIGNED WITH THE AXIS OF SAID OPENING DURING THE CLEANING OPERATION, SUPPER MEANS FOR SUPPORTING SAID CLEANING MEMBER AND SAID HOT TOP IN AN APPROXIMATELY AXIALLY ALIGNED RELATIONSHIP AND FOR EFFECTING RECIPROCATORY MOVEMENT TO EFFECT WORK AND RETURN STROKES OF SAID CLEANING MEMBER, AND PILOT MEANS ON SAID MEMBER ENGAGING SAID CASING DURING SAID WORK STROKE TO HOLD SAID CASING AND CLEANING MEMBER IN AN ALIGNED POSITION AND AGAINST RELATIVE MOVEMENT TRANSVERSELY OF THE AXIS OF SAID OPENING, SAID PILOT MEANS BEING DISPOSED ON SAID CLEANING MEMBER TO ENGAGE SAID CASING IN ADVANCE OF SAID CLEANING MEMBER BEING RECEIVED IN SAID OPENING, SAID SUPPORT MEANS SUPPORTING SAID HOT TOP AND CLEANING MEMBER FOR RELATIVE CENTERING MOVEMENT TO ALIGN SAID AXES IN RESPONSE TO RELATIVE MOVEMENT BETWEEN SAID CLEANING MEMBER AND CASING TO DISPOSE THE FORMER IN SAID OPENING COMPRISING A HORIZONTAL ROLLER TABLE FOR SUPPORTING SAID HOT TOP FOR RELATIVE MOVEMENT OF SAID HOT TOP WITH RESPECT TO SAID CLEANING MEMBER IN EITHER OF TWO OPPOSITE DIRECTIONS FROM AN ALIGNED POSITION WITH SAID CLEANING MEMBER AND MEANS SUPPORTING SAID TABLE AND CLEANING MEMBER FOR MOVEMENT IN OPPOSITE DIRECTIONS PERPENDICULAR TO THE FIRST SAID DIRECTIONS.