US2838431A

US2838431A - Method and apparatus for thermochemical metal scarfing

Info

Publication number: US2838431A
Application number: US357496A
Authority: US
Inventors: Allmang William; Carl E Hartmann; Ivan P Thompson
Original assignee: Union Carbide Corp
Current assignee: Union Carbide Corp
Priority date: 1953-05-26
Filing date: 1953-05-26
Publication date: 1958-06-10
Anticipated expiration: 1975-06-10

Description

une 10, '1958 w'. ALLMANG E'r-AL METHOD AND APPARATUS FOR THERMocx-IEMICAL MEM. SCARFING Filed May 2e. 195s 5 Sheets-Sheet 1 June 10,1958 w. ALLMNG ETAL 2,833,431

I METHOD AND APPARATUS FOR THERMOCHEMICAL METAL SCARFING Filed May 26,'1955 s sheets-Sheena INVENTORS v WILLIAM ALLMANG 34x, 5 CARL E.HARTMANN 9i lvAN P.THoMPsoN ATTORN EY June 10, 1958 w. ALLMANG ETAL 2,838,431

vMETHOD AND APPARATUS FOR THERMocx-IEMICAL METAL scARFING 5 Sheets-Sheet 3 Filed May 26. 1953 N AAO S MS RM Y LTD.. ME m Ln.M N E Hm J@ WML T IA P A UL LMM vWCW l B United METHOD AND APPARATUS FOR THERM- CMMICAL METAL SCARFING Application May 26, 1953, Serial No. 357,496

11 Claims. (Cl. 14S- 9.5)

This invention relates to therrnochemical metal scarfing, more particularly to method and apparatus for post-mixed preheat continuous wide oxygen stream desurfacing.

ln such desurfacing, it has been necessary to provide three systems of gas supply. In addition to the main stream of oxidizing gas, the preheat flames to start and stabilize the reaction have required a large number of fuel gas jets, and a supply of preheat oxidizing gas to support combustion thereof. The development of postmixed preheat flames to eliminate flashbacks vhas required a corresponding number of individual oxidizing gas streams, a separate stream for each fuel gas jet to support combustion thereof. The supply and distribution of these preheat oxidizing gas streams has been expensive as to first cost and maintenance.

It is therefore the main object of the present invention to eliminate the separate supply of preheat oxidizing gas. This We accomplish by utilizing the main stream of oxidizing gas as a source of supply of preheat oxygen for the fuel gas preheat flames. I

It has also been desirable to bring the cutting stream of oxidizing gas and the upper preheat flames close to the zone of reaction, but prior expedients have resulted in damage to the orifices by scabs and slivers projecting from the work.. It is therefore another object -to space the orifices above the worlt to clear such scabs and slivers, while confining the stream of oxidizing gas and directing the preheat flames close to thezone of reaction. This we accomplish by increasing the angle of impingement to about 30 and extending the upper surface of the oxidizing gas slot beyond the lower surface thereof to bring the upper surface closer to the work than the lower surface thereof.

Heretofore the nozzle siotfor the cutting stream of oxidizing gas has been manufactured as an insert, which was difficult and expensive to manufacture and replace. It is therefore another object to facilitate and economize the manufacture of this slot. This we accomplish by a built-in construction. Y

Another object is to provide a ywide slot nozzle unit adapted to produce a flared strearmwhereby a plurality of such units placed side by side for scarng slabs, will have their flared streams merge to prevent a ridge therebetween,

Other objects and features of novelty will be apparent from the following description and the accompanying drawings, in which:

Fig. l is a vertical section through a desurfacing head according to, and for carrying out the method of, the present invention;

Fig. 2 is an exploded view of parts lshown in Fig. 1;

Fig. 3 is a perspective View of the front and bottom of the nozzle blocks;

Fig. 4 is similar view of the rear of the nozzle blocks;

Fig. 5 is a section taken along the line5-5 of Fig. l;

Fig. 6 is a section taken along the line 6-6 of Fig. l;

Fig. 7 is a section taken along the line 7-7 of Fig. l;

rates Fatem O Patented June 10, 1958.

Fig. 8 is a section through the preheat fuel gas ports; and

Fig. 9 is a plan of the water cooled skid plate.

Referring more particularly to the drawings, the desurfacing head comprises a nozzle base block 10, a skid block 12, an upper lip plate 14 and a lower lip plate 15. The nozzle base block 10 is bolted and gasketed to a manifold block 16, which comprises a selector valve assembly as disclosed in the Miller andKolody Patent No. 2,524,920, issued October 10, 1950. The skid block 12 is bolted to the bottom of the base block 10. The

lip plates

14 and 15 are bolted to the front face of the base block' 10. This face is about 60 to the horizontal, so that the lip plates are at about 30.

The

lip plates

14 and 15 are spaced apart by end walls 18 to form the cutting slot 20 for the oxidizing gas. The upper lip plate 14 extends forwardly as at 21 about a third of its length beyond the lower lip plate 15, to confine the stream of oxidizing gas close to the reaction zone. The end walls 18 are tapered outwardly at the forward portions of their inner sides as at 19, to cause the oxidizing `gas stream vto expand laterally and thereby provide good coverage when scarng the four sides of a bloom or billet, or to prevent ridges between adjacent units when placedside by side in a slab scarfing machine.

The opposed surfaces of the

lip plates

14 and 15 are provided with uniformly laterally spaced corresponding grooves 22 extending from Ythe rear forward for about two-thirds of the common extent of the lip plates. These grooves 22 receive partitions 23, dividing the slot 20 into parallel oxidizing gas ways 2.4. v

The oxidizing gas ways 24 register with the outlet ends of corresponding groups of bores 26 yin the base block 10 and aligned with the central plane of the oxidizing gas slot 20. These bores are supplied by a transverse bore 28, which, as shownin Fig. 5, receives a divider comprising a stem 31 Vprovided with end wallsv32 and discs 33 spaced corresponding to the slot partitions 23 and dividing the bore 28 into equal oxidizing gas chambers 35. Each chamber 35 is 4supplied by a bore 36 leading to corresponding passages 38 in the manifold block 16, and receiving oxidizing gas therefrom in the customary manner.

The upper lip plate 14 is provided with a row of closely.

spaced bores 40 for projecting jets `of fuel gas down toward the reaction zone. These bores are supplied by a transverse bore 41 as best shown in Figs. 7 and 8. This bore 41 receives a dividercomprising a stem .42 provided with end walls 43 and discs 4.4 spaced corresponding to the oxidizing gas partitions Ziwuand dividing the bore 41 into separate fuel gas .chambers 45. The chambersv 45 are each supplied by separate fuel gas bores 46 Aregistering ywith corresponding bores 47 in the base block 1),

which in turn receive fuel` gas'from bores 48 registering with fuel gas supply bores49 inthe vmanifold Vblock 16.

For cooling the` upper lip plate 14, atransverse bore 52 is provided,'which receives cooling lluidfrom a longitudinal bore 54'show-n'in Fig. invturn receiving from passages 56 registering-with holes 58 inthe slot end wall 18. From the bore 52 the cooling fluid-passes through longitudinai bore 59 and registeringv boret) in the base block 1t) which has a eommunicatingbore 61`leading to the Y in Figures 7l andv 8 for the lower block. The-chambers'I formed thereby are fed'by longitudinal bores-67vregister-` ing with bores 68 in the base block 10 communicating with the supply bores 48 from the manifold passage 49.

For'cooling the lower lip block 15, a transverse bore 72 is provided, which receives cooling uid from a longitudinal bore 73 supplied by a vertical bore 74. From the transverse bore 72, the cooling fluid passes out through longitudinal bore 75 and passages 76 to the holes 58 in the end wall 18.

The skid block 12 contains a cooling jacket 80 which receives cooling uid from the supply passage 81 in the manifold block 16, and registering vertical passage 82 in the base block 10, joining a transverse passage 83 leading to a vertical passage 84, which registers with the skid block entrance passage 85. The cooling jacket 80 by means of a passage 87 is in parallel relation to a bore 86 in the front of the skid block and having out passage 88. Furthermore, the cooling fiuid passes to outlet 89 which is in register with the lower lip plate inlet 74.

We claim:

l. In a process for thermochemically scarfing metal bodies, discharging a sheet-like stream of oxidizing gas onto a reaction zone extending across the entire transverse extent of the surface of a metal body and at an acute angle of impingement to the work surface of said metal body, confining said sheet-like stream of oxidizing gas between upper and lower spaced apart surfaces laterally continuous for the entire transverse extent of the surface of said body, discharging a row of jets of preheat fuel gas at an acute angle to said oxidizing gas stream onto said reaction zone from a row of orifices ahead of at least one of said surfaces, and supplying preheat oxidizing gas from said sheet-like stream of oxidizing gas to support combustion of said jets of fuel gas and produce post-mixed preheat ames therefrom.

2. In a process for thermochemically scarfing metal bodies, discharging a sheet-like stream of oxidizing gas onto a reaction zone extending across the entire width of a metal body and at an acute dihedral angle of impingement to the work surface of said metal body, confining said sheet-like stream of oxidizing gas between upper and lower spaced apart surfaces laterally continuous for the entire width of said body, discharging a row of jets of preheat fuel gas at an acute angle to said oxidizing gas stream onto said reaction zone from a row of orifices below said lower surface, and supplying preheat oxidizing gas from said sheet-like stream of oxidizing gas to support combustion of said jets of fuel gas and produce postt mixed preheat ames therefrom.

3. In a process for thermochemically scarfing metal bodies, discharging a sheet-like stream of oxidizing gas onto a reaction zone extending across the entire width of a metal body and at an acute dihedral angle of impingement to the work surface of said metal body, confining said sheet-like stream of oxidizing gas between upper and lower uniformly spaced apart surfaces laterally continnous for the entire width of said body, discharging a row of jets of preheat fuel gas at an acute angle to said oxidizing gas stream onto said reaction zone from a row of orifices above said upper surface and impinging said stream of oxidizing gas a substantial distance ahead of the said lower surface and supplying preheat oxidizing gas from said sheet-like stream of oxidizing gas to support combustion of said jets of fuel gas and produce postmixed preheat ames therefrom.

4. In a process for thermochemically scarng metal bodies, discharging a sheet-like stream of oxidizing gas onto a reaction zone extending across the entire width of a metal body and at an acute dihedral angle of irnpingement to the work surface of said metal body, confining said sheet-like stream of oxidizing gas between upper and lower uniformly spaced-apart surfaces laterally continuous for the entire width of said body, said Y upper surface extending smoothly and continuously forwardly beyond said lower surface along said inclined ox- 76 idizing gas streamin overhanging relation to said lower surface for a length measured along said stream greater than the spacing of said surfaces toward the reaction zone to terminate the confinement of the top of said oxidizing gas stream closer to the reaction zone than the termination of confinement of the bottom thereof, and thereby discharge the stream of oxidizing gas directly onto the reaction zone of the work surface, discharging a transversely distributed flow of preheat fuel gas at an acute dihedral angle to said oxidizing gas stream from transversely arranged orifice means ahead of the termination of confinement of at least one of said oxidizing gas stream confining surfaces, and supplying preheat oxidizing gas from said sheet-like stream of oxidizing gas to support combustion of said fuel gas to produce a transversely distributed post-mixed preheat fiame.

5. ln apparatus for thermochemically scarng metal bodies, a desurfacing head comprising a nozzle block, a skid plate secured to said nozzle block and having a work engaging surface, said nozzle block having a front seating surface at an angle of about 60 to said work cngaging surface, upper and lower lip plates having their rear ends abutting and secured to said seating surface of said nozzle block in spaced apart relation, side walls closing the space between said lip plates and forming a cutting oxygen slot, transversely arranged preheat fuel gas orifice means in the front face of at least one of said lip plates, said one of said lip plates being free of any internal oxygen passages, the preheat oxygen for said fuel gas orifice means being supplied by said cutting oxygen slot to form transversely distributed post-mixed preheat ame.

6. In apparatus for thermochemically scarfing metal bodies, a desurfacing head comprising a nozzle block, a skid plate secured to said nozzle block and having a work engaging surface, said nozzle block having a front seating surface at an angle of about 60 to said work en 'gaging surface, upper and lower lip plates having their rear ends abutting and secured to said seating surface of said nozzle block in spaced apart relation, said upper lip plate extending integrally forwardly about a third of its length beyond said lower lip plate to bring the front bottom edge of said upper lip plate below the front top edge of said lower lip plate, side walls closing the space between said lip plates and forming a cutting oxygen slot, and means in said nozzle block including orifice means in said front seating surface for supplying cutting oxygen to said slot.

7. In apparatus for thermochemically scarfing metal bodies, a desurfacing head comprising a nozzle block, a skid plate secured to said nozzle block and having .a work engaging surface, said nozzle block having a plane front surface at an angle of about 60 to said work engaging surface, upper and lower lip plates having their rear ends abutting and secured to said plane front surface of said nozzle block in spaced apart relation, said upper lip plate extending integrally forwardly about a third of its length beyond said lower lip plate to bring the front bottom edge of said upper lip plate below the front top edge of said lower lip plate, side walls closing the space between said lip plates and forming a cutting oxygen slot, means in said nozzle block for supplying cutting oxygen to said slot, transversely arranged preheat fuel gas orifice means in the front face of at least one of said lip plates, fuel gas passage means in said one of said lip plates leading to said orifice means and corresponding fuel gas passage means in said nozzle block leading to registering aperture means in the abutting surface thereof for supplying fuel gas to said orifice means.

8. In apparatus for thermochemically scarfng metal bodies, a desurfacing head comprising a nozzle block,

`a skid plate secured to said nozzle block having a work engaging surface, said nozzle block having a front seating surface at an angle of about 60 to said work engaging surface, upper and lower lipy plates having their rear ends abutting and secured to said seating surface of said nozzle block in spaced apart relation, side walls closing the space between said lip plates and forming a cutting oxygen slot, the inner surfaces of said lip plates having longitudinal grooves, vertical partitions fitted into said grooves and dividing said slot into cutting oxygen ways, said nozzle block having passage therein for supplying cutting oxygen to said Ways.

9. In apparatus for thermochemically scariing metal bodies, a desurfacing head comprising a nozzle block, upper and lower lip plates secured in the front of said nozzle block in spaced apart relation, both of said lip plates extending forward from said nozzle block for a length many times the distance therebetween, and the front edge of said upper lip. plate overhanging that of said lower lip plate for a length greater than the distance therebetween, side walls closing the space between said lip plates and forming a cutting oxygen slot, means in said nozzle block for supplying oxidizing gas to said slot, a row of preheat oritices in the front of at least one of said lip plates, fuel gas passages in said lip plate leading to said row of preheat orifices, corresponding fuel gas passages in said nozzle block leading to registering apertures of said lip plate to form continuous conduits for supplying fuel gas to said row of preheat orifices, said lip plate having a transverse bore nearits front end, said roW of preheat orifices communicating with said bore, and a distributor inserted in said bore and having uniformly spaced annular seals dividing said ports into equal groups.

10. In a desurfacing head for thermochernical metal removal, a nozzle block, upper and lower lip plates secured to said nozzle block in spaced apart relation, both of said lip lplates extending forward from said nozzle block for a length many times the distance therebetween, and the front edge of said upper lip plate overhanging that of said lower lip plate for a length greater than the distance therebetween, side walls closing the space between said lip plates and forming with the inner surface of said lip plates having longitudinal grooves, vertical partitions fitted into said grooves and dividing said slot into cutting oxygen ways, said nozzle block having passages therein for supplying cutting oxygen to said ways, at least one of said lip plates having a transverse bore near its front end, a row of preheat ports in the front of said plate communicating with said bore, and a distributor inserted in said bore and having uniformly spaced annular seals dividing said ports into equal groups.

1l. in a desurfacing head for thermochemical metal removal, a nozzle block, upper and lower lip plates secured to the front of said nozzle block in spaced-apart relation, both of said lip plates extending 'forward from said nozzleblock for a length many times the distance therebetween, and the front edge of said upper lip plate overhanging that of said lower lip plate for a length greater than the distance therebetween, side wallsv closing the space between said lip plates and forminga cutting oxygen slot, said nozzle block having a transverse bore receiving a supply of cutting oxygen, a distributor in said bore having annular seals dividing said bore into cham-v bers, and longitudinal bores in said nozzle block communicating with said chambers and opening into the front face of said nozzle block between said lip plates, for supplying cutting oxygen to said slot.

References Cited in the iile of this patent UNITED STATES PATENTS 1,709,886 Smith et al Apr. 23, 1929 2,266,834 Walker et al. Dec. 23, 1941 2,347,758 Walker' et al. May 2, 1944 2,425,710 Buchnam et al. Aug. 19, 1947 2,483,479 Smith et al Oct. 4, 1949 2,532,103 Kiernan Nov. 28, 1950 2,536,609 Kemp Ian. 2, 1951 2,680,608 Buchnam et al. June 8, 1954 2,745,475 Thompson et al May 15, 1956

Claims

1. IN A PROCESS FOR THERMOCHEMICALLY SCARFING METAL BODIES, DISCHARGING A SHEET-LIKE STREAM OF OXIDIZING GAS ONTO A REACTION ZONE EXTENDING ACROSS THE ENTIRE TRANSVERSE EXTENT OF THE SURFACE OF A METAL BODY AND AT AN ACUTE ANGLE OF INPINGEMENT TO THE WORK SURFACE OF SAID METAL BODY, CONFINNG AND SHEET-LIKE STREAM OF OXIDIZING GAS BETWEEN UPPER AND LOWER SPACED APART SURFACES LATERALLY CONTINUOUS FOR THE ENTIRE TRANSVERSE EXTENT OF THE SURFACE OF SAID BODY, DISCHARGING A ROW OF JETS OF PREHEAT FUEL GAS AT AN ACUTE ANGLE TO SAID OXIDIZING GAS STREAM ONTO SAID REACTION ZONE FROM A ROW OF ORIFICES AHEAD OF AT LEAST ONE OF SAID SURFACES, AND SUPPLYING PREHEAT OXIDIZING GAS FROM SAID SHEET-LIKE STREAM OF OXIDIZING GAS TO SUPPORT COMBUSTION OF SAID JETS OF FUEL GAS AND PRODUCE POST-MIXED PREHEAT FLAMES THEREFROM.