US2285519A - Apparatus for conditioning metal bodies - Google Patents

Description

n 9,1942. J. H. BUCKNAM HAL 2,285,519

APPARATUS FOR CONDITIONING METAL BODIES Filed Feb. 8, 1941 5 Sheets-Sheet 1 INVENTORS ALFRED J. MILLER ATTORNEY JAMES H. BUCKNAM June 9, 1942. J. H. BUCKNAM ET AL APPARATUS FOR CONDITIONENG METAL BODIES 5 Sheets-Sheet 2 M m NL m m N .E v D mum U MA Filed Feb. 8, 1941 ATTORNEY June 9, 1942. J BUCKNAM ETAL 7 2,285,519

APPARATUS FOR CONDITIONING METAL BODIES Filed Feb. 8, 1941 3 Sheets-Sheet 5 lNvENToRS JAMES H. BUCKNAM ALFRED J. MILLER BY ATTORNEY Patented June 9, 1942 UNITED STATES PATENT OFFICE I v APPARATUS rogiziiiligrioniuc METAL I I "James H. Bucknam,

Miller,

C'ranford, and Alfred J.

Garwood, N. J., assignors to The Linde Air Products Company, a corporation of Ohio Application February a, 1941, Serial No. 378,020

(01. ass-23y 14 Claims.

This invention relates to blowpipe apparatus for thermally conditioning the surface of metal bodies, and more particularly to blowpipe apparatus for thermochemically removing a relatively shallow layer-of metal from one or more longitudinal surfaces of a ferrous metal body such as a steel billet, bloom, slab, or the like, and to apparatus for removing scale from one or more --longitudinalsurfaces of a metal body.

In the casting of steel ingots andduring the hot rolling of steel, defects, such as scale, cracks, seams, slag inclusions, and the like, formon and in the surface of the steel bodies, and in turn cause imperfections in the finished rolled prod-v ucts. In order to reduce the number of rejections of the finished products, these surface defects are generally removed before or during an intermediate stage of the rolling operation.

- Scale is commonly removed by pickling, and

other defects have often been removed by mechanically cutting or chipping away the surface metal containing such defects. Blowpipes producing a high temperature heating flame are now often used for directing such a flame Onto the surface to cause the scale to break loose from the base metal by the difference between the expansion of the opposite sides of the scale. Hand-operated blowpipes, commonly referred to as hand-deseaming blowpipes, are now also used for thermochemically removing the defective surface metal adjacent each defect by eflecting the combustion of the steel with an oxidizing gas such as oxygen.' More recently, machines employing suitable blowpipe means have come into use for thermochemically conditioning the surfaces of slabs, and the like. These machines may be used for conditioning steel shapes either when cold or while they are at a rolling temperature and are passing from one roll stand to another such as is commonly employed in a steel mill. The present invention provides an improved apparatus for thermally conditioning thesurfac of a metal body such as a steel bloom, or slab,

or an apparatus for eliminating scale from such a body. The principles of the invention are particularly applied to a machine for thermochem of surface metal from one or more longitudinal surfaces of such a body,

body is moving along ically removing a layer preferably while the steel moved relatively. along at least one longitudinal surface of the slab to remove a relatively shallow layer of metal therefrom. The blowpipe head supporting mechanism is so constructed and arranged that the head may be maintained in position for desurfacing a slab which is longitudinally moved relatively thereto and maybe lowered to a position below the top of the -roll the roll 'table which ratus which may be readily installed in an e'xisting roll table conveyor, such as is used in a steel vmill, for conditioning a longitudinal surface of a metal body while such body is at a rolling temperature and at apoint between successive rolling operations; to provide such apparatus in which the conditioning device may be raised and maintained above the slab in an operating position and maybe lowered and maintained in a position below the top out of the way of metal conveyor; and to which the slab may of the roll table conveyor bodies moving along such provide such apparatus by be supported by a roller disposed substantially directly below the conditioning device when the device is in'the upward operative position.

These and other objects and novel features of this invention will become apparent from the .{ollowing description, taken in connection with he accompanying drawings, in which:

Fig. 1 is a schematic isometric view of a surface conditioning machine embodying the principles of the presentinvention and installed in a roll table conveyor, such as are commonly used in steel mills;

a roll table from one rolling operation to another and while the steel body is at an elevated rolling temperature. A multiple nozzle blowpipe head producing high temperature preheating flames and a compositesheet-like oxygen stream is Fig. 2' is a fragmentary 2-2 of'Fig. 1, and showing the supporting links and connecting gearing; h

vFig. 3 isa side elevational view, partially. in section, showing the surface conditioning machine in the raised operative position'with the conditioning head viewtaken along line inglsteel bodies, usually at an elevated rolling temperatura'from one rolling operation to another. The rollers 20 are each mounted on axles 2l "supported in suitable bearings and connected through bevel gearing to a longitudinal drive shaft which is driven by a motor in the usual manner, the gearing, the drive shaft and the motor are not shown in the interests of greater clarity in the drawings. The surface conditioning'head, shown generally at H, is preferably substantially equal in width to the widest steel body to be surface conditioned and is attached to and supported by a carrier plate 23 which is in turn supported by a suitable vertically floating linkage L which is suspended from an upper frame member 24 extending across the roll table T. Theblowpipe device or machine, essentially comprising the blowpipe head H, linkage L, and frame member 24, is supported at either end by suitable parallel links for upward or downward arcuate movement. One or more hydraulic cylinders C are preferably provided for raising and maintaining the blowplpe machine or surface conditioning machine in the upward position as shown in Figs. 1 and 3 and for retracting or lowering the surface conditioning machine to a position below the top of the conveyor or roll table T as shown in Fig. 4.

On each side of the roll table T, there is a base member 25 which is rigidly mounted on and supported by a suitable foundation or other similar means. Journalled in each member 25 there is a relatively short, front or forward pivot shaft 21 on which is mounted the normally lower end of a. link 28. A long rear shaft 29 is mounted and Journalled at each end in members 25 and,

carrier plate 23 are a number of multiple nozzle blowpipe units or heads 42 which comprise the composite surface conditioning head H. A shield 40 may be provided to protect the head H from damageby heat, oxidation and slag. Each blowpipe unit 42 is adapted to operatively receive a plurality of nozzles 43 and for supplying a combustible gas mixture, such as oxygen and acetylene to the preheat passages of the nozzles and for supplying an oxidizing gas such as oxygen to the oxidizing gas passage of'each nozzle. Each blowpipe unit is also preferably adapted to circulate a cooling medium therethrough and preferably contains suitable valves whereby the adjacent each end of shaft 23, there is mounted thenormally lower end of link 30. The upper end of each of the links 28 and 30 contains a short pivot shaft or pin 3| whereby a T-shaped ..means at each end to brackets 32.

bracket 32 is mounted upon and supported by the upper ends of each pair of front and rear links 28 and 30. The frame member 24 extends across the roll table and is attached by suitable frame member 24, and its attached apparatus,

is supported at each end by a pair of parallel links 28 and 38 and each pair of these links and the corresponding members'25 and 32 form a parallelogram linkage with member 25 forming frame member 24, and four substantially horizontal links 36 are each pivotally mounted at one end on the plate 35 as shown at 31. carrier plate 23 is pivotally connected to the outer The ends of links 38 as at 39. The links 36 and plates 35 and 23 form a parallelogram linkage so that the carrier plate 23 and the attached head H can float substantially vertically. Attached to flow of gases for the nozzles may be turned off and on to vary the effective width of the head H. The multiple nozzle blowpipe units or heads 42 may be of any suitable type, or may be substantially the same as or similar to the blowpipe units disclosed in the copending United States Application, Serial No. 334,510, filed May 11, 19.40, by A. M. Keller, J. H. Bucknam and A. J. Miller. The head H is adapted for applying a substantially sheet-like gaseous stream against the upper surface of slab S to react thermochemically with the surface material and form a molten slag mixture of metal and oxidized metal. The bottom of the blowpipe head H is preferably adapted to slidingly contact the work surface so that a substantially uniform layer of surface metal is removed from the slab when it is moved relatively to the head.

The links 36 enable the head H tofollow the surface of irregular slabs having a surface of varying height and enable the head H to condition slabs of different thicknesses. A small hydraulic or air cylinder 44 may be pivotally mounted on the under side of frame member 24 and piston rod 44' of cylinder 44 may be pivotally connected to one of the links 38-or to a transverse connection between the links such as a rod 45, extending between and fastened to the lower pair of links 36. When air or fluid under pressure is admitted to the rod end of cylinder 44, the head H and carrier plate 23 are lifted vertically and when this pressure is released, the head H is lowered by gravity. If desirable, air or fluid under a relatively low pressure may be admitted to the rod end of cylinder 44 to coun- Thus, the

terbalance or partially counterbalance the weight of head H to control the pressure or weight of the blowpipe units on the slab S, or air or fluid under pressure may be admitted to the head end of cylinder to increase the, force of the head H against the'slab to insure the bottom of the head remaining in contact with the slab S. By

means of cylinder 44, the head H and carrier plate 23 can be raised and lowered to position the head at the starting edge of a slab or raised to prevent damage to the head by the often irregular trailing end of a slab.

It will be seen that, in the operating position, the vertically floating surface conditioning head H is' suspended by the linkage L from the frame member 24 which is in turn movably supported by two pairs of links 28 and 30. Means is also provided for maintaining the surface conditioning machine in the operative position above the slab S and/or for raising and lowering the machine. or to eachbracket 32, there is pivotally connected the outer end of a piston rod 41 of one of the hydraulic cylinders C. A stop 48 is formed on each member 25 to limit the movement of the links in a clockwise direction. When fluid To each end of the frame member 24 the left-hand member 25 impossible to achieve.

7 of the slab S adjacent the under pressure is admitted at 49 to the head ends of the two cylinders C, the frame member 24 and head H are swung upwardly through an arc to the upper operative position as shown in Figs. 1 and 3. When the pressure in the head ends of cylinders C'is released, and if necessary, when fluid under pressure is admitted at 50 at the rod ends of the cylinders C, the surface conditioning machine is lowered below the top of the roll table T as shown in Fig. 4. When the surface dispensed with if the slab is at a high enough.

conditioning machine is retracted to below the top of the roll table, metal bodies may be moved freely along the roll table without interference or damage to the machine. Additionally, such a surfacce conditioning machine may be readily installed in an existing roll table and requires a relatively small amount of space.

When the head H is raised or lowered, it is desirable that both ends of member 24 be moved in unison so that there is no twisting of or possible damage to the machine. Additionally, it is desirable that the end supporting links move in unison. To this end, on and 29, adjacent the inner side of the left-hand member 25, there is mounted a spur gear 52 and 53, respectively, (Fig. 2). Pivotally mounted in there is a third spur gear 54 which meshes with both of the gears 52 and 53 to cause the gears 52 and 53 to turn in the same direction and to cause these two gears and links 28 and 30 to move in unison. Each link 30 isattached to, and turns with the long rear shaft 29 so that both sides of the desurfac- 1 ing machine are raised and lowered in unison.

If all pivotal connections fitted perfectly, the I need of gears 52 and 53 would be lessened but for practical purposes, this is very difficult if not on a suitable foundation and directly beneath the desurfacing head H there is provided a roller 56. The roller 56 is mounted on suitable trunnions journalled in bearing supports 51 and is connected through gearing in the gear box 58 to a drive shaft 59 which may be connected to a drive motor not shown), for example, the cus-' tomary conveyor drive motor. When the slab S is moved along the roll table beneath the desurfacing head H, the roller 56 supports the slab and aids in longitudinally moving the slab. The roller 56 is disposed substantially directly beneath the head H thus preventing the pressure of the head H from deforming or bending the slab S and the friction between the slab and the head from stopping the movement of the slab.

This surface conditioningapparatus is .preferably controlled by the operator while positioned at a control table away from the zone of hi h temperature heat. By means of admit fluid under pressure to the head end of each of the hydraulic cylinders C to raise the conditioning mechanism to the upper operative position. If desirable or necessary, fluid or air under pressure may be admitted to the rod end of cylinder 44 to raise the head H or to partially counter-balance the head H.- The roll table moeach of shafts 21' suitable switches, the operator opens suitable valves to Gil - timerequired for such preheating depends stantially entirely across the slab surface. The

upon the original temperature of the slab and may be temperature, though usually it is desirable to use some'preheat both for starting the cut and to accompany the oxidizing stream during the desurfacing operation. After the zone of surface metal has been heated to the oxygen ignition temperature, the cutting oxygen is turned on and simultaneously the roll table motor is energized to move the slab past head H. The separate oxygen streams from each nozzle blend with the others to form a substantially sheetlike stream of oxygen which removes a substantially uniform layer of surface metal from the slab S. I v i After-the upper surface has been conditioned, the gases are shut oil. If desirable, the slab may be turned over to present a different upper surface and the previously described procedure repeated. After the slab has been conditioned, the pressure in the head end of each cylinder C is released and the frame member and its at-" tached mechanism may be lowered below the top of the roll table T, so that subsequent metal bodies which are not moved along the roll table without interference and without possible damage to the blowpipe machine.

Figures 5 and 6 show another embodiment of the present invention. Referring more particutor may be energized by means of a suitable "inching" switch to position the starting edge After the slab blow'pipe; nozzles. I is correctly positioned, and if the are mounted on each of larly to Figs. 5 and 6, the desurfacing head H' is supported by a frame member 24' similar to the way the head H is supported by the frame member 24. Member 24' is connected to and supported by a frame F. The entire desurfacing machine is supported by and is moved vertically by a pair of hydraulic cylinders C. The cylinders -C' are fastened to the frameF and the lower end of each of the piston rods 41 is connected to a suitable bracket 60, which brackets are fastened to the supporting foundation beneathv the roll table conveyor T. When'fluid under pressure "is admitted at 6| to the head ends of the cylinders C, the machine is raised to the operative position above the roll table as shown in Fig. 5

inoperative position the roller 63 supports the' slab S or any other bodies which may be moved along the roll table T'. Four grooved rollers 65 the front and rear' sides of the frame F and each pair of upper and lower rollers engages a guide-rail 66 for guidingthe machine when it is raised and lowered and for preventing forward or rearward tilting of the machine. 1

In Figs. 5 and 6 to be conditioned may be mounted a lower slab-I 62 and an ,upper slab-supportmachine is in the raised Y of the top surface; the blowpipe head H could be mounted in the supporting frame for conditioning only the bottom surface; an additional blowpipe head could be mounted on the carrier plate 23 to condition the bottom surface of the slab S when the blowpipe machine is in the retracted or lowered position; an additional blowpipe head or heads could be mounted on the machine to condition one or more longitudinal side surfaces simultaneously with the conditioning of the top and/or bottom surface; different blowpipe units .2 couldbe used and other means could be used for raising and lowering the mechanism; and different means such as a furnace oran electric arc could be used for raising the temperature of either the entire slab or a portion of the slab to the ignition temperature.

It will be understood that some features of this invention may be used without others, and that the principles of this invention may be incorporated in other types of surface conditioning. machines.

What is claimed is: I

1. In apparatus for conditioning a surface of a metal body, the combination of a substantially horizontal conveyor for carrying said body and having sections spaced apart; a device operable to condition said surface and movable vertically between said sections to and away from an operative position relatively to a body on said conveyor; mechanism operable to raise said device to said operative position and to lower said device away from said position; and means movable by said mechanism into the space between said sections to cooperate with said sections to support said body.

2. In apparatus for thermally conditioning longitudinal surfaces of metal bodies such as steel slabs, means for horizontally supporting such a slab; a blowpipe device comprising a frame member, a blowpipe head adapted to project a stream of gas against a longitudinal surface of said slab, and means for supporting said head on said member in a position normally adjacent said surface; means supporting said device for movement upwardly and downwardly; means retractable to a position beneath said slab for raising said device to a position above said slab and for lowering said device to' a position below said slab; and means for effecting relative movement between said head and said slab longitudinally thereof.

3. Apparatus as claimed in claim 2 in which said device supporting means includes a base, and a parallelogram linkage pivotally connected between said base and said device to support said device for movement upwardly and downwardly through an arc from one of said positions to the other of said positions.

4. Apparatus for thermochemically removing metal at the oxygen ignition temperature from the surface of a metal body such as a steel slab, comprising means for horizontally supporting and longitudinally propelling such a slab; a blow- -against a longitudinal surface o'fsaid slab, and

means for supporting said head on said member in a position normally adjacent said surface; pivotal means supporting each transverse end of said device for movement upwardly and downwardly; means for moving said device through an arc to a position above said slab supporting means and to aposition belowthe top of said slab supporting means; and means transversely connecting said pivotal supporting means and adapted to move both ends of said device in unison when raised and lowered.

5. Apparatus as claimed in clairn in which said pivotal supporting means includes two links, one of said links being pivotally connected at one end to eachtransverse end of said device;

and said connecting means includes a rotatable transverse shaft on which the opposite ends of' said links are rigidly mounted whereby said links and both ends of said device move in unlson when said-device is raised or lowered."

said head for movement upwardly and down-' wardly; means for horizontally supporting said slab; and power-actuated means for raising said member and said head to an upper position above said slab and for lowering said member and said head to a lower position below said slab.

'7. Apparatus for thermochemically removing surface metal froma metal body such asa steel slab as claimed in claim 6, including a roller mounted on said frame for engaging the bottom surface of such a body when said frame is in the.

lowered position.

8. Retractable blowpipe apparatus adapted to project a gaseous stream against successive upper surface portions of a' metal body such as a steel slab as said slab progresses horizontally relatively to saidapparatus, said apparatus comprising a frame having spaced arms straddling opposite sides of said slab; a blowpipe head supported by said frame in position to project a gaseous stream downwardly against the upper surface of said slab; and frame-retracting means adapted to lower said frame and said head to an inoperative position below said slab.

9. Apparatus for conditioning atleast one longitudinal surface of a metal body such as a steel slab, comprising a roll table conveyor for. horizontally supporting and moving such a slab; a blowpipe machine disposed in alignment with and between the rollers of said roll table, said machine including a blowpipe head adapted to project a gaseous stream against a longitudinal surface of said slab; and, means for supporting and for vertically raising and lowering said blowmachine including a blowpipe head adapted to project a gaseous stream against a longitudinal surface of said slab; and retracting means including pivotal supporting means disposed at the sides of said slab and power-actuated means for supporting and for raising and lowering said blowpipe machine to raise and maintain said blowpipe machine substantially above said slab and to lower and maintain said blowpipe machine substantially below said slab.

11. Apparatus for thermochemically removing.

adapted to direct a stream of oxygen' against a surface of said body; adjustable means for supporting said head on said frame and normally in position to apply said oxygen stream against an upper longitudinal surfaceof said body;

means supporting said frame for movement from an upper normal operating position downwardly between rollers of said conveyor to a position below the top 'of said conveyor; and a roller movement from an upper normal operating position downwardly between rolls of said conveyor to a position below the top of said rolls; and a roller for engaging the bottom surface of said body disposed substantially directly under said head at least when said head is in the normal operating position.

12. Apparatus for thermochemically removing metal from a metal body such as a steel slab as claimed in claim 11, including means for positively driving said roller.

13. Apparatus for thermochemically removing metal at the oxygen ignition temperature from a surface of a metal body such as a steel slab, comprising a roll table conveyor for horizontally supporting and longitudinally propelling such a body; a supporting frame; a blowpipe head mounted on said frame and disposed substantial- 1y directly beneath said head for normally engagingthe bottom surface of said body.

14. Apparatus for thermochemically removing metal at the oxygen ignition temperature from a longitudinal surface of a metal body such as a steel slab, comprising a roll table conveyor for horizontally supporting and, longitudinally propelling such body; a frame; a blowpipe head adapted to direct a substantial sheet-like stream of oxygen against a longitudinal surface of said body; means adjustably supporting said head on said frame and normally in position to apply said 7 oxygenstream against an upper longitudinal surface of said body; pneumatic means supporting said frame for movement from an upper normally operating position downwardly between rollers of said conveyor to a position below the top of said conveyor; a roller rotatably mounted on said frame and disposed substantially directly beneath said head for normally. engaging the bottom surface of said body when said frame is in said upper position; and, a second roller I mounted on said frame for engaging the bottom surface of such a body when said frame is in said lowered position.

JAMES H. BUCKNAM. ALFRED J. MILLER.

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