US2476456A - Wide deseaming process and nozzle - Google Patents

Description

y 1949. A. P. SCHELLER' 2,476,456

. WIDE DESEAMING PROCESS-AND .NOZZLE Filed June 7, 1946 INVENTOR 3 ARTHUR P.SCH ELLER ATTORNEY Patented July 19, ,1949

UNITED- STATES PATENT OFFICE winnifiesiiriivmirgi g iiss AND NOZZLE. I 1

.etali Patent No. 2,266,834, dated December 23; I941, "when metal containing surface fissures for other surface defeots is rolled, the defeots-arelnbt ieliminated and they are sometimes rolled "into thee-body of the metal in the dorm :of concealed firib oriiiedhezirhs or' cracks. A1so, When thesufiace ctfntarnaving steep proj ections thereon orgroove's the'rein with steep sides is rolled out, the sides of these irregular surfaces fold'iover arid include oxide-s within the folds and causeeoneealed c'racksiin' the body of themetalin thesame way. a

In order "to eliminate the-defectsandthe formation ofseams-withinthe body of the metalit is necessary-to remove the defectivehmetal portions so that only sound-hondedmetal-remains and so that the slopes of i theadepression and elevations that may be left on the surface of the billet will be so gradual that-these slopes will not befolded over and-rolled into-the body of the metalwhen itisrolled. g I H Much time andlabor tare sa v'ed by removing the defective surface portionsm-ofvthe steelor- .iron thermochemically with theluse-tof an hxidizi'ng stream ofcg-as. The desiredcontounof the-groove cut by the -oxidizing gas is obtained with a deseaming -blowpipe nozzle .iconstructed to ,permit the passagewof a -suitalolevo1ume .of gas. eta-re atively low orifice velocity, he efor examme, about 585 feet-per second. -lhecozitoiir of the cut is controlled by'theishane of 'the orifice and the velocity o'fthe oxidizingstrieamissuingitherefrom. Velocitiesv d ffthezigas stream'commbmy used for oxygen c "tting" rs'evermg .ofmetals are equal to or higher-than thevelo'clty' that :lsjprocluced by gas flowing tnrcugnatpassage ofuniform cross-sectional area. Therefore, th'e'relatively low orifice 'veiocity uesirea ifor'removmg Surface metal is onevvliiiihfis'bfdw' thatoommon'ly'usedfor cuttirrg' lgeffs. V s

in "conjunction with deseaniing blovviiipes of the" type disclosed in Jacobson et al} Patent rjyfinie 7, ,fSerial'Nn. 674,913 *Q h (01. 148.

-Ne. 2,2 84,574, dated May 26, 'I94'2,=lnvolv 1ng the use-"of a starting rod.

Such blow-pipe is "provided with a mechanism for feeding metal wire or rod "into the flame adjacent the end of the rro2z'le. A control lever pivotally mounted on-'the blowpipe "adjacent the rear part of the handle "is =operativ1y -asseciated with both the rod feeding :Jmechanism and the means f or controlling the supply-of *outting' oiiygen. With the preheating flames lighted, the control lever maybe swung through-a '-'part of-its stroke to feed ashort-length'of starting rlod'into the preheating flames;

During such first part of .the'stroke onlythe rod feed mechanism is :acttiatedand"thecuttirlg oxygen valve remains closed. The fl'ever is "held 7 infthispositi on'untiltherod'is heated 'aitleast' lto its ignition temperature, WhereupQnT'thefIeYr fis swung further to open the cutting miy'g'en ',.va'1ve.

During this latter part o'fthe stroke of thellever no additional feeding ;of the-rod is caused by the rod feeding mechanism. Practically-simultaneously with the opening of T the cutting oxygen valve the blowpipe is moved or swung in the direction of the discharge cutting-:oxygen stream to deseam a ferrous metal ."bodylina,-manner*we1l known to those skillediinlthe-art.

..Prior to the"inventionideseamingccuts fupto=;1% inches Wide having fairly-uniformdepthsha've been made. Howeventherezex'is'ts a demand for wider outs in'a=singlelpassgsotthat the number iof jpass'es oan Tbe ireducedz'and the entire edge- Of --a slab, for example? can be skimscar fed by-a single nozzle.

This is accomplished aocbrding to the present invention by providing 'a no'zzlehaving the same seat construction andoverall length asthe "standard "deseaming nozzle, so as' to' make -theapp'aratus as lightiin-weight-as=possible*and al's'o'capable of use with blowpipes-already'inuse. .H'owever, theexitor outlet portion ofthe cuttingoxygen passage in the nozzle is -'swaged to about double the diameter "of-the "lrilefipoition.

'To defiect the cutting 'oxygenuniformly against the wall of theoutlet portionandfillsueh'portion, thereby ensuring a uniform "'fa'ce' velocity of the cutting oxygen with a "minimum turbulence a divergently drilled baffle is inserted insuchoutl'et portion from the face 'endofthe-muzzle, and held in place "at "the inner 'endof'suchl With "the improved nozzle Heseaming cuts substan'tially Wider than those aobtainable ,prior to l-"the' invention are "possible; In Tact, cuts more the inlet end of passage H.

3 than twice as wide have been made with excellent efficiency,

Referring to the drawing;

Fig. 1 is a longitudinal view in cross section of a deseaming blowpipe nozzle exemplifying the invention.

Figs. 2 and 3 are front and rear views, respectively, of such nozzle.

The blank from which nozzle N is formed comprises an elongated body In of heat conductive metal, such as copper, provided with a relatively large central passage I I which extends axially throughout the length of the nozzle, for conveying cutting oxygen therethrough. The rear end of the tubular body Ill is provided with a seat l2 surrounding the entrance end of the passage The seat I2 is adapted to form ahermetical seal with a complementary seat in a socket in the blowpipe head to which the nozzle is adapted to be connected. Oxygen gas is adapted to flow from the blowpipe head into the passage II from which it discharges onto the workpiece being treated.

A series of preheat or combustible gas passages |3 are arranged in generally parallel relation about the central passage II. The rear ends or inlets of these passages terminate in an annular groove M which is spaced forwardly of 7 The groove l4 forms a gas-distributing chamber with a portion of the'blowpipe head; A seat l6 surrounds the preheat passages I 3 and forms a hermetical seal with a complementary seat in the socket of the blowpipe head. A'combustible gas, such as a mixture of oxygen and acetylene, is fed to said gas-distributing 'chainber, thence through the preheatpassages l3, and finally the gas mixture discharges "from the outlets of said passages, in the front end face F of the nozzle N, to provide an annular row of preheating flames.

An annular collar IT is provided close to and forwardly of the seat' It, and is of such outer diameter that it cooperates with an integral shoulder |8 located at the extreme rear end of the nozzle N to provide an abutment for a hollow coupling nut l9.

A protective collar C is secured to the forward end of the nozzle N by an annular fillet weld 3|, as disclosed and claimed in Egger et al. Patent No. 2,294,392, dated September 1, 1942. The hollow coupling nut is has screw threads 20 adapted to cooperate with complementary threads in the socket of the blowpipe head to which the nozzle is to be secured. The nut is rotatable and slidable axially relatively to and upon the outside surface of the nozzle N when coupling the nozzle to the blowpipe head, thus permitting any circumferential portion of the collar C to be located in work-contacting position and thereby affording a longer life for the nozzle, since the wearresistant collar may then be adjusted so that it wears on evenly throughout its circumference.

While coupling the nozzle to a blowpipe head, an end of the nut bears against the collar l1. Furthermore, the abutments provided by flared portion 22' and collar ll, being of greater outside diameters than the inside diameter of the nut, prevent removal of the nut is from the nozzle, but permit sliding and rotation of the nut relatively to the nozzle.

The axially, extending passage ll of the elongated nozzle 'N is composed of an inlet portion 2| of constant diameter, a central flaredportion 22 of frusto conical shape, and an outlet portion 23 of constant diameter; the diameter of the outlet portion 23 being about twice that of the inlet portion 2|. A baflie 24 is fitted in the passage II at the juncture of the frusto-conical portion 22 and outlet portion 23. The baflie 24 is provided with a central axially extending orifice 25, and an annularly arranged series of orifices 26 the axes of which diverge downstream with respect to the longitudinal axis of the nozzle N.

The frusto-conical portion 22 controls the expansion of the confined stream of cutting oxygen as it leaves the inlet portion 2|, to about four times the cross-section thereof, the expanded stream being broken up immediately after such expansion into a plurality of jets by the orifices 25, 26. The cutting oxygen jets, however, are recombined in the outlet portion 23 of the nozzle into a composite oxygen stream of uniform crosssectional area. The composite stream of cutting oxygen is discharged from the outlet portion 23 into the atmosphere, and thereupon applied at an acute angle against the surface to be des'eamed. .Such surface is heated by the oxy-fuel gas flames discharged by thepreheating gas passages l3, and thermochemical skin-scarring is accomplished by advancing the composite stream of oxygen with respect to the heated surface, in themanner well known to those skilled in the art.

The nozzle and processof the invention have proved to be very effective for making exceptionally wide deseaming cuts which are more than twice as wide as the deseaming cuts possible according to the prior art. This is accomplished mainly because a relatively large flow of cutting oxygen is discharged from the nozzle N with a minimum of turbulence and at a substantially uniform 'face velocity. This is due to the fact that the major turbulence-producing pressureshock of the oxygen stream directly upstream of the bafile 24, due to rapid expansion of the gas in the conical portion 22, is prevented by the baffle 24, while the minor turbulence-producing pressure-shocks, due to expansion of the smaller jets in the outlet portion 23, are neutralized by one another in such outlet portion as the jets recombine to form the composite oxygen stream which is discharged to the atmosphere from the portion'23.

, What is claimed is r a 1. An elongated nozzle having an axially extending fluid passage comprising'an inlet portion of constant diameter, a central portion of frustoconical shape, and an outlet portion of constant diameter, the diameter of the outlet portion be- 'ingabout' twice that of the inlet portion, and a elongated cutting oxygen passage provided with an .inlet portion, a flared central portion, and an outlet portion, said inlet and outlet portions being about equal injlength, thecross-sectional areaof 'ea'ch substantially constant throughout the length thereof, and the cross-sectional area of-theoutlet portion being about four times that of'th inlet pcrtmmja cl means located in such passage, at the juncture of said outlet portion and the flared central portion, consisting of a baflle having a central axially extending orifice and an annularly arranged series of orifices the axes of which diverge downstream with respect to the longitudinal axis of the nozzle for directing portions of the cutting oxygen stream outwardly against the wall of the outlet portion to reduce turbulence and produce a discharged stream of substantially uniform face velocity.

3. Process of wide deseaming which comprises heating the surface of a ferrous metal body to the ignition temperature with oxygen, expanding a confined stream of cutting oxygen to about four times the cross-sectional area thereof, breaking up the stream immediately after such expansion into a plurality of jets one of which jets is axially in line with such stream and the remainder of which jets are arranged annularly about such axial jet and are divergent with respect thereto, recombining such jets into a composite stream of uniform cross-sectional area equal in size and shape to that following the first expansion, discharging such composite stream into the atmosphere with a minimum of turbulence and at a substantially uniform face velocity, applying the discharged stream at an acute angle against the heated surface of such ferrous metal body, and thermochemically skin-scarfing the body by advancing the composite stream of oxygen with respect to the surface thereof.

4. In the art of deseaming ferrous metal bodies by applying a stream of oxygen at an acute angle against the surface to be deseamed while heating the adjacent metal, the method of increasing the width of the out which comprises ex-. panding the cutting oxygen stream while it is still confined, separating and deflecting portions of the expanded stream outwardly immediately after expansion, and confining the resulting composite stream to an unobstructed path of uniform crosssectional area prior to discharge into the atmosphere, which area is equal to that of such expanded stream, to provide a cutting oxygen stream of substantially uniform face velocity with a minimum of turbulence.

ARTHUR P. SCHELLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,840,196 Hasse Jan. 5, 1932 1,860,347 Crowe May 31, 1932 ,957,351 Oldham May 1, 1934 2,148,936 Geibig et al Feb. 28, 1939 2,238,360 Forster Apr. 15, 1941 2,266,834 Walker et a1. Dec. 23, 1941 2,347,758 Walker et a1 May 2, 1944 2,365,411 Jacobsson Dec. 19, 1944 2,396,765 Walker Mar. 19, 1946

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