US2362536A - Apparatus for conditioning the surfaces of metal bodies - Google Patents

Description

Nov. 14, 1944. .1. H. BUCKNAM APPARATUS FOR CONDITIONING THE SURFACES OF METAL BODIES 3 Sheets-Sheet 1 Original Filed May 11, 1940 INVENTOR JAMES H BUCKNAM ATTORNEY Nov. 14, 1944.

J. H: BUCKNAM APPARATUS FOR CONDITIONING TYHE SURFACES OF METAL BODIES Original Filed May 11, 1940 WW I 3' Sheets-Sheet 5 Y INVENTOR JAMES H. BUCKNAM- Patented Nov. 14, 1944 "UNITED STATE mmrus Foa coNnmoNmo 'rns summons or METAL BODIES James H. Bucknam, Cranford; N. 1.. assignor to The Linde Air Products Company. a corporation of Ohio Original mam hlay 11, 1940, Serial No.

334,510. Divided and this application June 30, 1942, Serial No. 44am -14 Claims. (cuss-41.4),

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

This application is a division of the copending United States patent application Serial No. 334,510 filed May 11, 1940, jointly by Arthur M.

.Keller, James H. Bucknam, and Alfred J. Miller,

now Patent No, 2,312,418.

In the casting of steel ingots and during the hot rolling of steel, defects such as scale, cracks, seams, slag-inclusions and the like form on and in the surfaces of the steel bodes and causeimperfections in the finished rolledproducts unless removed. In order to reduce the number of reiections of finished rolled products, the surface defects are generally removed before or during an intermediate stage of the rolling. Scale is commonly removed by pickling and other defects have often, been removed by mechanically cutting or chipping away the defective surface metal. 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 effecting the combustion of the steel wlth'oxygen. Recently, machines employing suitable blowpipe means have come into use for thermochemlcally conditioning the surface of billets, 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. 1

The present invention provides blowpipe or f torch means for thermaliyconditioning or scarfylarly blowpipe means suitable for use in a machine for thermochemically removinga. layer of in uniform contact with the steel body irrespec tive of any warp or twist of the surface of the body; to provide such apparatus which includes an improved, water-cooled shoe for contacting the-surface of the steel body to maintain the blowpipe nozzle oriilcesin operative relation to the surface and for protecting the blowpipe nozzles; to provide such apparatus which includes an improved nozzle block; and to provide an improved blowpipe assembly which can be used in any position for, conditioning either hot or cold bodies.

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

surface metal from the body, preferably while the steeljbody is at an elevated temperature. A multiple nozzle headdischarging high-temperature preheating flames and a composite, substantiail sheet-like oxygen stream is moved relatively along the slab and is maintained in contact with Fig. 1 is a side elevational view of an'exempla'ry blowpipe apparatus embodying the features of the present invention;

Fig. 2 is an elevational view of the rear of the blowpipe apparatus of Fig. 1;

Fig. 3 is an enlarged fragmentary detail view of the front of the blowpipe head of Fig, 1;

Fig. 41s a view on an enlarged scale of a section through the blowpipe head taken along line 4-4 of Fig. 3:

Fig. 5 is a fragmentary view similar to Fig. 4 taken along lineI-i of Fig. 3; Fig. 6 is a fragmentary .view of a section disclosing the means for sealing the passage for the end nozzles of each head which section is taken along line 8-6 of Fig. 3:

Fig. 7 is a fragmentary view of a.v section through the nozzle block disclosing the preheating gas distributing passages and taken along line '|.-'-l of Fig.4;

Fig. 8 is a sectional view through the nozzle block to show the cutting oxygen distributing chambers and taken along line H of Fig. 4;

Fig. 9 is a view of a fragmentary section ermisz I Fig. 10, is a view of a fragmentary section tlfumgl; the nomle=bloclr taken along line il- -lll o through the nozzle block taken along line 9- v Fig. 11 is,a rear eleirationalview of the nozzle shoe? and A.

Fig. 12 is a front elevational view ofthe nozzle 7 the work surfaceduring such movement in order that a substantially uniform depth of metal may be-removed and the gas emciently used. i

Accordingly, the principal objects of this invention' are toprovide improved apparatus for surface conditioning a metal body; to provide such apparatus for maintaining a blowpipe head 55 ported adjacent the body by a desurfacin mablock with the nozzle shoe removed.

The conditioning'head may be supported inan' operative position adjacent thejbody to be conditioned by any suitable mechanism. Especially" when the conditioning head is adapted for-desurfacing a ferrous metal body, it may be sup-.-

chine such as is shown and described in the aforementioned United States Patent 2,312,418, of which this is a divisional application. The desurfacing machine preferably includes means for moving the desurfacing head in a direction toward and away from the body prior to and after a surface removing operation, and means for propelling the. body longitudinally while the head is held in contact with a surface of the body during the surface removing operation. Obviously if desired the body may be stationary and the head may be propelled along the body. In either arrangement, there is provided relative movement between the body and head and in such a direction as to remove successive portions of surface metal from the body.

As shown by the drawings, the composite desurfacing head comprises a .plurality of similar blowpipe heads H which are supported on a carrler plate 28 and are preferably urged into contact with the body at a predetermined pressure.

The heads H are shown as being urged against the bottom surface of a slab S which is supported and propelled in the direction of its length. The number of heads employed depends upon the width of surface to be conditioned.

The blowpipe heads'H are similar and only one will be described in detail. Each head H comprises a nozzle retaining-member or block 2| and a removable nozzle protecting shoe portion 22. The head H is removably attached to the carrier plate 20 by bolts 23 and 24. An elongated strip or perforated clamping bar 28 may be placed between the heads of bolts 23 and the head H as shown and, if only part of the bolts 23 should be tight, the head H will still be retained securely in place. In the block 2|, there are a plurality of similar oxidizing gas passages 21 (Figs. 4 and 7) each of which terminates in an enlarged and partly threaded recess at its forward outlet end to operatively receive the inlet end of a nozzle 28 removably secured, therein by means of an externally threaded nozzle retaining nut 23. The inlet end of the passage 21 communicates with a chamber 33 formed in block 2|, there being a chamber 38 for each two passages 21 (Fig. 8). The inlet end of each chamber 38 is adapted for receiving the threaded end or connection of an oxidizing gas supply tube 3| which in turn communicates with a source of oxidizing gas. The oxidizing gas flows from each supply tube 3|, through distributing chambers 30, the two oxidizing gas passages 21 and through the central oxidizing gas bores of a corresponding pair of nozzles 28 secured in block 2|. A sumcient number of tubes 3|, passages 21 and chambers 30 are provided in each block 2| so that the oxidizin gas orifices 28' of all of the nozzles in each head are supplied with oxidizing gas such as oxygen. Each tube 3| contains a manually operable valve 32 for controlling the flowiof oxidizing gas to the corresponding pair of nozzles 28.

The outlet end of each passage 21 is formed to provide a pair of seats which coact with seating surfaces on. the inlet end of a nozzle 28 to form gas-tight seals at 33 and 34, (see Fig. 6). Between these seating surfaces, the cavity in the "I, a plurality of passages 38 may be drilled in the block 2| each communicating with one of the chambers 34. The passages 38 are so drilled that the inlet ends of each pair of passages intersect at the outlet end of a passage 31. The outer ends of passages 38 may be plugged with silver solder or other suitable means. The inlet end of each passage- 31 is adapted to receive the threaded end I of a blowpipe tube 38 of a blowpipe or gas-mixing device 38. A combustible gas and preheating oxygen is mixed in the blowpipe 33 and flows through tube 38, passage 31, two passages 36, into two chambers 38 and from each chamber 38 to the preheating passages and orifices 28" of the corresponding nozzle 28; For each pair of nozzles 28, there -is provided a separate blowpipe 33, a passage 31 and two passages 38.

' The shoe 22 is attached to the nozzle block 2| leakage of cooling fluid therebetween. The forward end of each nozzle 28 extends through a hole 48 in the front wall of the shoe 22 and the for ward end of the nozzle is substantially flush with the outer wall of the shoe. To prevent cooling fluid from leaking past the nozzle 28 to the out side of the shoe, a packing ring 41 which encircles the central portion of the nozzle is pressed against the inner front wall surface of shoe 22 by a compressed spring 48 surrounding the nozzle. Each nozzle is retained in the head H by similar means,

but because of lack of sufllcient space, the end block 2| is formed larger than the nozzle to pronozzles in each head are provided with slightly.

different packing arrangement as shown in Fig. 6.-

manner as the other nozzles.

With this construction of the blowpipe head, the nozzles of each head H may be readily removed, all or singly, for replacement or inspection. By removing bolts 40 and-4|, the shoe 22 may be readily removed to expose the nozzles, which are individually removable for replacement, repair, or inspection. Therefore, the head, may be readily dismantled, repaired and assembled. By loosening bolts 23 and 24, the head H may be readily removed as a unit for repair or replacement.

The heads H are in contact with the bottom surface of a usually hot slab and are in a zone of high-temperature heat from the slab, the preheating flames, the heat of thereaction and the v hot slag. The heads and nozzles must be adequately cooled to prevent overheating. Each nozzle block 2| is adapted to receive a water inlet connection 88. and has formed therein two transverse chambers 8| and 43 and has also formed therein a forward cavity 82 which coacts wlthga cavity 83 in the shoe 22 to form the relatively large cooling chamber 84. vA passage 88 connects the inlet 88 and chamber 8|. A passage 88 provides communication between chambers 8| and 84 and passage 81 provides communication be- If there is enough space, the end nozzles could be packed in the same contains ribs 53 (Fig. 12) formed in the cavity II that engage similar ribs 33 (Fig. 11) formed in cavity 53 of the nozzle shoe. The ribs 33 and Cl strengthen the parts and aid in correctly positioning the block and shoe when they are belns fastened together. Passages 53 are formed an ribs 58 so that cooling fluid can readily flow to'all portions of the chamber 54.

In the block 2| there is a bore 32 (Fig. 5) adapted to receive the threaded connection 33 having attached thereto a length of overflow tubing 64 which extends from connection 33 through bore 62 to substantially the top of chamber 3. Cooling liquid, such as water, flows from a supply tube BI, which is connected to a suitable source of supply, through connection ill, passag 53, chamber 3|, passage-36, chamber 34, passage 31, into chamber 43 and out the overflow tube 64 and. through connection 83 anda tube 66 to a drain. 1 The cooling fluid chambers and connectoing passages are so arranged that all portions of the head and nozzles are adequately cooled. The central portions of nozzles 28 are completely. surrounded by cooling fluid and the gas passages 31 are well cooled to prevent overheating and possible preignition ofth combustible gas mixture. The forward or front faces. only of the nozzles 23 are exposed to the heat but otherwise are fully enclosed. By having the inlet end of overflow tubefl positioned at the top. of chamber 43, the

, chambers of the head are maintained full of coolzles in each blowpipe head are so-spaced that the sides of the individual scarflng oxygen streamsfrom the nozzles merge so as to'direct a substantially sheet-like stream of oxy en ontothe surface of slab S. The bearing surface of shoe 22 which contacts the slab is subject to damage by abrasion, and to protect the shoe, ridges of a metal which is resistant to abrasion at high temperatures may be deposited, as at 31, on the slab contacting urface of the shoe 22. Each head has at least two ridges 01 which extend forwardly and rearwardly and form supporting bearings for engagement with the work surface. The ridges 31 are spacedalong the head and provide'channels between them that permit passage of gas between the head and the work surface. To in- I a,seb,sso

tween chambers 54 and u. m nozzle block nected to a suitable source of supply and to an oxygen header 12 from which lead four lengths of tubing 13. each of which is connected to one of the four tubes 3|. I' or each head H there is a length of tubing II which is connected through a suitable length of pipeand hose connection to an acetylene header 1! and is also connected to a suitable supply source of acetylene. Four lengths of copper tubing II are connected to,

the preheat oxygen supply line I. communicates with a suitable supply source, not shown, and is connected to a preheat oxygen header 30. Each.

of four lengths of copper tubing 3| communicate through a manually operable valve 32 with the header 30 and with one of the blowpipes 33 to supply preheat oxygen thereto. I

A length of copper tubing 33 is connected to a source of constant temperature cooling liquid such as water and to one of the blowpipes 33. The blowpipes 33 are connected by short lengths of tubing 84 and'cooling water flows from one blowpipe to the next through tubes 34. Cooling water flows from the last blowpipe in-each head through a length of tubing 35 to a drain, not shown. The water for cooling the blowpipes is preferably heated to a low constant temperature so as not to vary with the weather or temperature of the supply main,

By means of the manually operable valves in the preheating acetylene and oxygen lines and in the cutting oxygen line, the nozzles may be shut off in pairs, if for any reason it is desired to reduce the total effective width of the desurfacing flame produced by the heads H. Thus, when conditionlug the-surface of a metal body which is narrower than the width of the heads, the end nozzlesmay be shut oil in pairs by means of valves 32. I3, and 32 so the eflective width of the heads is substantially equal to the width of the surface. Normally, all manually operable valves for the nozzles needed to cover the desired width of surface are open and the flow of gases is controlled by electrically operable stop valves and a switch-means for controlling all such electrically operable stop valves not shown maybe conveniently located at a single point.

Obviously, certain features of this invention may be used independently of others and changes may be made in various parts of the apparatus without departing from the spirit and scope of the invention. vI or example, although as herein dis-- closed, the apparatus is especially adapted for desurfacing semi-finished relatively wide steel slabs while they mat a red heat and in transit .ibetween successive rolling operations, it will be crease additionally the useful life of the head, a

layer of abrasion-resistant'material may be deposited on the shoe- 22 and block 2| as is shown generally at 63 and 63, respectively. As shown in 'Fig. 3, the layer 32 covers substantially completely the front face of the shoe 22 through which the nozzles 28 pass except the openings, 43 for the nozzles. A renewable layer of protective material for the front face is thus provided. As shown in Figs. 4 and 5, the shoe 22 overlaps the forward corner of the block 2|, as indicated at 10, so that any force or shockon shoe 22 is taken by the block 2| and shoe 22 can not shift and damage the nozzles or break or strain the bolts "or II.

. There is an oxygen supp y linev II for each head 11 (Figs. 1 and 2). Each ongenlin'e 1| is consteel bodies in other positions. For instance, thes heads are suitable for desurfacing the top or side surfaces of either hot or cold steel bodies. I I claim: Li A nozzle holding and protecting device com prising a nozzle block adapted to be secured to a support and operatively receive a row of noz ales; and a shoeremovably attached solely to" said block and adapted substantially to enclose said nozzles except the orifice ends thereof, said shoe and said block being constructed and arranged to form a fully,enclosed cooling liquid chamber therebetween through which said nozzles extend and constructed and arranged so that said shoe is removable from said block to expose said nozzles.

2. A desurfacing head comprising a nozzle I block adapted to be secured to a support and operblock being constructed and arranged to form a substantially fully enclosed cooling liquid chamber therebetween through which said nozzles extend and so that said shoe is removable from said block to expose said nozzles; and a deposit of wear-resistant metal on said shoe for engaging the workpiece and positioning said nozzles in a predetermined operative relation to the surface of said workpiece.

3. Blowpipe apparatus comprising a block, said block having therein a series of openings each' adapted operatively to receive a nozzle, gas passages for separately conveying a heating gas and an oxidizing gas to each of said openings: and a substantially fully enclosed cooling liquid chamber; a row of nozzles secured in said openings; a nozzle shoe removably attached solely to said block and substantially completely enclosing all of said nozzles except the orifice ends thereof, said block and 'said shoe being constructed and arranged to form a fully enclosed cooling liquid chamber therebetween; and means for removably securing said block to a surface conditioning apparatus.

4. Blowpipe apparatus comprising a nozzle block adapted operatively to receive a nozzle in each of a series of openings formed in a flat forward face of saidnozzle block and adapted to be removably attached to a supporting means; and a nozzle protecting shoe secured fluid-tightly against said forward face and having a front face through which said nozzles extend and a workengaging portion disposed on one side of said nozzles and obliquely thereto, said work engaging portion overlapping the forward corner of said block on said side of the nozzles, said shoe being secured to the block by screws entering from the front of the shoe into said block on the side of the nozzles opposite said work-engaging portion and by screws extending from the rear of the block into said overlapping portion.

5. Blowpipe apparatus comprising a nozzle block adapted operatively to receive a nozzle in each of a series of openings formed in a flat forward face of said nozzle block and adapted to be removably attached to a supporting means; and a nozzle protecting shoe removably secured solely to said block and fluid-tightlyagainst-said forward face, said shoe having a work-engaging wall with a surface portion adapted to slidingly engage the surface of a workpiece. a portion of said wall overlapping a corner portion of said block.

said shoe and said block being so constructed" surface; and a renewable layer of protective maed to discharge initially parallel Jets of desurfacing oxygen against a work surface at an acute angle; passage means in said head for supplying oxygen to the inlet ends of said oxygen passages; interconnected passages formed in said head for conveying cooling fluid therethrough; a wearresistant surface portion on a side of said head adjacent said front face for engaging said work terial covering said front face substantially com- "pletely except where said passages open therethrough 7. A torch comprising an elongated head having a face in which are a number of orifices at spaced points lengthwise of said face and from which desurfacing jets of oxygen are directed against a workpiece, a supporting shoe on said head, said shoe having a surface portion for supportingthe torch on the workpiece, the width of saidshoe being substantiallyas great as the length of said head, and the length of said shoe being at least one-half as great as the width, and having said surface portion so disposed with respect to said face that the Jet orifices are at a predetermined spacing from, and inclination to, the surface to be scarfed when the supporting shoe is in surface contact with the workpiece.

8. A scarfing torch comprising a block tip with an elongated face and a row of jet orifices in' said face for directing scarfing streams of oxy en against the surface of a metal body, and supporting hearings on a side of the block at spaced' regions along the length of the block for supporting the tip on the metal body'in a definite rela- 1 tion to supply air to the region under the face of the tip when said tip is in working relation to the metal body to be scarfed and the supporting bearing is resting on the surface of said metal body.

10. A scarfing torch comprising an elongated block tip with a face and a row of scarfing jet orifices opening through the face at spaced re.- gions along the length of the face, a bearing surface on the side of the tip at an angle to the 11. A scarfing torch comprising a block tip' having an elongated face and a bearing on one side by which the torch is supported on the surface of the metal body to be scarfed. Jet orifices opening through said face at spaced points along the length of the face for directing scarfing jets of oxygen against the metal body, preheating jet orifices opening through the tip face under the oxygen jet orifices, and air passages through the supporting bearing for the supply of air to the preheating flames under the oxygen jets.

12. Surface conditioning apparatus comprising a head having a front face; a row of gas passages opening .through-lsaid front face and adapted to discharge gas against a work surface; passage means in said head for suppl in I to said row of gas passages: interconnected passages in said head for cooling fluid; bearing means on said head for engagement with said work surface to 1 maintain said gas passages in operative relation to the work surface; and a renewable layer of protective material covering said front face substantially completely except where saidgas passages open therethrough.

13.- Surface conditioning apparatus comprising a head; a row of gas discharging nozzles secured along the front of said head; a shoe secured to said head and adapted substantially to enclose said nozzles except the orifice ends thereof and teriai covering said front face substantiaiiv' completely exceptwhere said nozzles extend therethrough.

14. Surfaceconditioning apparatus comprising a head; a row of gas discharging nozzles'secured along the front of said head; a unitary shoe secured to said head and forming a closed cooling fluid chamber with the front of saidhead, said shoe having 'a front wall with openings into which said nozzles extend, said nozzles extending through said chamber and preventing loss of cooling fluid through said openings; and passages in said head for cooling fluid opening into said chamber for passing the cooling fluid intoan'd out 4 of said chamber. v

' a JAMES H. BUCKNAM.

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