US3409233A

US3409233A - Slotted scarfing burner

Info

Publication number: US3409233A
Application number: US561199A
Authority: US
Inventors: Joseph F Kiernan
Original assignee: Air Reduction Co Inc
Current assignee: Airco Inc
Priority date: 1966-06-28
Filing date: 1966-06-28
Publication date: 1968-11-05
Anticipated expiration: 1985-11-05
Also published as: GB1154945A

Description

c 3,409,233 SLOTTED SCARFING BURNER Joseph F. Kiernan,` Dun ellen, NJ., assignor, to'A Re- [ductionCompany,v Incorporated, New Yorlr, 'N fa to vdistribute more, evenly across the; length of ,theburner ,and thetransversewidth o f the workpiece. v .1 Another object ofthe inventionistov providefascarfng burner of the character indicated with the burner con,- structed of separate parts assembledin such awayas to simplify the'rnanufacture and reducethe cost'of the Cutting oxygen is supplied-through several' passages through the back face of the burner yinto a header that extends thewidth of the bl,1r ner.On. bo th` s idesof the .points of entry of, the supplypassages into therheader thevheader .opens -forwardly into .jetpassages elongated in the direction t of the width-of` the 3 burner, the jet lp asf sagesy jointlyforminga nearly continuous but nsubdivided jet. The jet passagesopen into arectangular slot cut into the frontwface of the burner, the height of the slot be# ing a little greater than theheight of the jet passage.

Beginning a short distancev from the forwardopening of the jet passages :and extending substantially tothe front face4 of the burner, are upper4 and lower inserts extending the-entire width of the burner vand restricting the, oxygen to a relatively thin vsheetebetween them. The faces, ofI the inserts toward the jets are shaped to promote turbulence in the sheetof oxygen. Thecorn-bination of features promotes =a uniform distribution of oxygen flow across the entire width of the burner. 'Preheat orifices in the face `Vof the burner extend in a row above and a row below the y cuofaenslot..l f

V"This invention Vr'elates'to scarfing burnerswhich are used fordire'cting oxygen against a surface'of a billet,

slab; or other workpiece for the-purpose of removing de- 'Y fectivesurface metal before the workpieceV is *rolled to finalfform.' y f f fr f n "'In order-to remove cracksyand other surface perfe'c tions whilefthezsteel is on the rolling mill line, it is a practice to remove the entiresurface from theworkpiece `by means of oxygen jetsdirected against theheated` sur# face'at a `low angle of attack.'When a row .of individual jets isdisposed transversely of` the' work-piece, there is more metal removed alongv thecenter axis of-each jet than along the sides, yandthe jetsmust be of sufficient size and close enough together to remove the necessary:y depth of metal'at the vregion wherethe jets are least effective. This results the removal of more, metal'than necessary at the regions where the jets are'moreieifectivq `and the scar'fed 'surface has'a waveytransverse contour whereas 1 workpiece with less variation',transverselyt'bf the `workpiece,l in the depth of metal removedand Awith a resulting smoother surface after the scarng operation. j vAnother object isfto provide la'scarfing burner with a pluralityof oxygen outlets in the face of a'bur'ner which is constructed so as to produce turbulence of the oxygen anda4 resultingmore even distribution u of the oxygen supply transversely ofthe direction ofrelative'movernent of the burner and theworkpiece.

The preferred `embodiment of the invention has a row of oxygen jet passages, each of which is elongated in the direction in which the row extends, and with the outlets of the jet passages closely Vspaced from one another. Thel face of the burner is recessed so that there is a substantial distance from the discharge face of the oxygen jets to the workpiece and this gives 'the oxygentime burner.v One feature relates-to, the ,use of inserts in the recessed. face of the .burner with the, inserts extending part :Way into the pathof the oxygen streams andawith faces ofthe inserts that are at an acuteangle .to the direction of `flow of the oxygen streams for producing a uniform, sheet-like streaml ofl oxygenw, Y v f Other objects,.features and advantages of the invention will vappear vor be pointed out as the description, proceeds. VIn the drawing, forming a part hereof, in-A whichlike reference characters indicate corresponding parts in all the views: f l -z .v n.

FIGURE l is a fragmentary --front view of a scarting burner-v made in accordance with this invention;

FIGURE 2 is a sectional view taken on the,li ne 2-2 ofFIGURE 1; t

FIGURES 3 and 4 are sectional views taken on the lines 3-3 and 4-4, respectively, of FIGURE 2;

' FIGURE 5 is a view similar to FIGURE 1 but showing theback of the burner; -FIGURE 6 is an enlarged, fragmentary, sectional view of a portion of the construction shown in FIGURE 2; and

. FIGURE 7 is 4a diagrammatic view showing the way in which the burner of this invention is used for removing surface metal from a workpiece.

-.;FIGURES 1 and 2 show a scarfing burner 10 having a body portion 11 with .an upstanding llug 12 for connecting the burner to a supporting manifold block. The lug 12 has openings 14 through which -fastening means, such as bolts, extend for securing the burner to the support.

VThe burner has a front face 18 which includes a forwardly-extended upper face portion 20 with an undercut shoulder 22 at its lower end, anda lower face portion 24.

Through upper and `lowerfaces pre-heat

orifices

26 and 28 are drilled.

The upper pre-heat orifices 26 are located in a row extending lengthwise of the -burner face 18, and these orifices 26 open into a header passage 30 in the body portion 11. Fuel gas is supplied to the header passage 30 through a passage 32, shown in FIGURE 2; and there are a plurality of such passages 32 atspaced locations along the length 'of the header passage 30 so as to obtain more uniform pressure and dw distribution lengthwise of the passage 30.

In the construction illustrated in the drawing, there are two passages 32, as shown in FIGURE 5, but it will be understood that there can be more than two passages and that by providing more supply passages-32, the cross section of the header passage 30 can be made smaller, without having objectionable pressure drops in the portion of the passage 30 between the supply passages 32.

The lower pre-heat orifices 28 open into a header passage 38 whichis supplied with fuel gas through a plurality of supply passages 40, in the same manner as the passages 32 supplythe header passage 30, already described. I

The front -face 18 is recessed between the rows of pre'-

v heat orifices

26 and 28 by a continuous channel 44 run ning lengthwise of the burner face and extending for substantially the full length of the burner. The portion of the burner body through which the channel 44 extends, is of composite construction, as will be explained in connection with FIGURE 6, but for thepresent, a description of the composite construction is not necessary to'aYV description of the operation of the burner.

A bottom or inner wall46 of the channel 44 has a plurality of oxygen jets 48 opening through it and these oxygen jets communicate with Ian oxygen header passage 50. Each of the oxygen jet orifices 48 is elongated inthe direction of the length of the burner 10. These orifices 48 may be of oval shape, but they are preferably constructed with semi-circular ends and parallel top and bottom walls, as best shown in FIGURE'4. Thepor'ific'es 48 are spaced closely together;' the spacing Shown' in the drawing being approximately equal to, or slightly greater than, the height of each orifice. The term height is used end face 66, at the end of the insert which vconfronts the discharge ends of the orifices 48. These end faces 64 'and 66 are at an angle to the-direction of the oxygen flow. This angle can be a right angle, but it is preferable to have it an acute angle;hthatvyis, to have the ends of the inserts 6Qland 62 etapered atasteepangl. The angle is not'criticalfbut bestresults aregobtained by having it approximatelyflS or more `Awhen theangllegs measured between the sloping face of the 'insert-'60 or .62 and. the longitudinal axis of the oxygen jet orifice 48.

'It"is not essential but preferable that the open space between the

inserts

60 and 62 be off-less height than the herein to designate the dimension of the elongated orifice In order to obtain the highly uniform oxygen tiow from the different oxygen jet orifices 48, it is important to maintainthe oxygen pressure in the header passage 50 as uniform as possible. To attain this result without making the header passage 50 excessively large in cross section, a plurality of oxygen supply passages 54 are provided through the back of the burner, communicating with the 'header passage S0. FIGURE 5 shows four oxygen supply passages 54. These passages are of large cross section and preferably of a cross section substantially approaching that of the header passage 50.

In the preferred construction, one of the oxygen supply passages 54 opens into the header passage 50 between every two oxygen jet passages 48. This is advantageous because the tendency is for gas velocities to reach a maximum at the center of a jet discharged from an orifice; and by bringing the oxygen into the header passage 50, at the sides of the jet orifices 48, lsuch pressure drop as does occur'in the header passage 50 compensates the tendency of jet streams to have a higher velocity midway between the sides of the stream. The oxygen supply passages 54 are drilled into the body portion 11 of the burner at an angle, as shown in FIGURE 2, so that the flow of the oxygen has to change its direction before reaching any part of the jet orifices 48, and this also tends to obtain more uniform flow of oxygen through the oxygen jet orifices.

An important feature of this invention is the production of turbulence of the oxygen as it fiows from the jet orifices 48 through the channel 44 for final discharge from the channel 44 and into contact with the surface of a workpiece. This turbulence is produced by having inserts `60 and 62 located in the channel 44. Each of the

inserts

60 and 62 extends for the full length of the channel; that is, from one side of the burner to the other. The insert v60 is against the upper wall of the channel 44 and the insert 62 is against the lower wall of the channel. The open area of the channel 44, between the

inserts

60 and 62, is of course, much less than the original area of the channel, and the height of this open 4area is preferably somewhat less than the height of the oxygen jet orifices 48. Thus, the

inserts

60 and 62 extend part way into and interfere with the path of the oxygen streams as they discharge from the orifices 48. The disturbance caused by this extension of the inserts into the path of the oxygen streams produces the turbulence of the oxygen which tends to distribute the oxygen and oxygen pressure more uniformly across the full length of the burner as the oxygen flows from the jet orifices 48 to the discharge end of the channel 44.

In the construction illustrated in FIGURE 2, the insert 60 has an end face 64, and the insert 62 has an oxygen jet orifices 48. Because of the fact that the parts of the faces 64 and 66 which contact w'ith the oxygen streams to produce the turbulence are spaced some distance from "the'wall 46 throughwhich Ithe jet orifi'c'es"48 o'pen, there is'some expansion of the cross sectio of the oxygen jets before they strike the corners of 'the inserts where the walls 64 and 66 meet the parallel'confronting faces of the inserts. It will be evident, therefore,l that even though the spacing between thelinserts 6'0 and 62 is as great as the height of the orifices 48, or slightly greater, the abutment surfaces providedby the end walls 64 and 66 are still in the path of the oxygen jets which have somewhat greater height than the outlets of the orifices 48 by the time they contact -withthese abutment surfaces of the inserts, as already explained. v

In order to be most effective in producing turbulence and resulting mixing of the oxygen from the different jet orifices 48, the abutment faces 64 and 66 should make a sharp corner where they merge with the confronting faces of the

inserts

60 and 62; that is, the merger should not be along a fair curve such as is used in nozzles for the purpose of preventing turbulent liow.

FIGURE 6 shows a detail of the construction of the burner. For more convenient manufacture, the channel 44 is made substantially greater in height than are the oxygen jet orifices 48, and the

inserts

60 and 62 are then placed in the channel 44 as a convenient way of provid ing abutment. faces extending part way into the path of theoxygen streams for producing turbulence. This is .a practical and economical construction, but within the broaderaspects of the invention, it is sufiicient that the face of the burner be recessed, as is provided yby I`the channel 44; that the oxygen jet orifices open through the recessed portion of the face; and that some abutment surfaces b e provided in the recess, near the end ofthe recess into which the oxygen jet orifices open, regardless of whether these abutment surfaces are end faces of an insert or are part of a one-piece shoulder in the recess.

In the construction shown in the drawing, and especially in FIGURE 6, the

inserts

60 and 62 are held in the channel 44 by

lips

72 and 74 attached to an upper forward portion 76 and a lower forward portion 78, respectively, of the body portion 11 of the burner. These

forward portions

76 and 78 are secured to the rearward part of the body portion by any suitable fastening means, such as silver brazingv or screws 92. The upper and lower faces 20, 24 and inserts 60, 62 being removable are easily replaced when worn or eroded. Thus the entire burner need not be discarded when these parts become worn.

Further to facilitate the manufacture of the body portion 11, the header passage 30 is made withv a continuous slot 94 extending through the front surface of the rearward part 90. The upper pre-heat jet orifices 26 are drilled through the upper forward portion 76 in position to communicate with the slot 94. Insimilar manner, the header passage 38 is constructed with'a slot 96 extending for its full length and opening through the front face of the rearward part 90 of the burner body and the lower pre-heat jet orifices 28 are drilled through the lower forward portion 78 in position to communicate with the slot 96.

FIGURE 6 also shows a feature of the preferred conamazes struction in which a median plane 98, of the channel 44, extends at an angle to the plane of the face of the mid portion 24 of the burner. This angle is indicated by the intersection of the median plane 98 with a normal 100 to the plane of the mid portion 24 of the burner face.

The overhang construction, which is indicated by 'reference numbers and 22 is only required to mechanically anchorA pre-heat flames such as natural gas, propane etc. The overhang could be eliminated when acetylene is used as the fuel gas. No anchoring means is required on the lower face -for any type of fuel.

The face of the burner has a lower portion 102 extending rearwardly at a sharp angle for facilitating the inclining of the burner to direct the oxygen and preheat jets downward at an acute angle to a work piece 104, as shown in FIGURE 7.

The preferred embodiment of the invention has been illustrated and described, but changes and modifications can be made and some Ifeatures can ybe used in different combinations without departing from the invention as defined in the claims.

What is claimed is:

1. A scarfing burner comprising a body having a face with a row or orifices, said orifices being elongated in the direction in which the row extends, means for supplying oxygen to said orifices, the face of the burner being recessed in front of the row of oxygen orifices by a continuous slot extending in the same direction as said row of oxygen orifices, and the height of the open area at the downstream end of the slot being less than the corresponding height of the elongated oxygen orifices.

2. The scarfing burner described in claim 1 characterized by at least one other row of orifices, said other row of orifies extending in a direction generally parallel to the direction of extent of the row of oxygen orifices and at a location close to the downstream end of the recess in the face for supplying pre-heating flames for a scarfing operation.

3. The scarfing burner described in claim 1 characterized by the slot having a height substantially greater than the height of the oxygen orifices in a direction normal to the direction of the elongated extent of the oxygen orifices, lbut the open area of the slot being reduced along at least one inside surface thereof by an insert which obstructs part of the cross section of the slot and which leaves an open area of the slot with its height less than said corresponding height of the elongated oxygen orifices.

4. The scarfing burner described in claim 3 characterized by the end of the insert nearest to the oxygen orifices having a corner extending into the path of oxygen streams discharged from`the orifices for producing turbulence and mixing of the oxygen streams from the different orifices as said streams are discharged through the slot.

' 5. The scarfing burner described in claim 4 characterized -by inserts in both the top and bottom of the slot reducing the height of the open area of said slot.

l6. The scarfing burner described in claim 5 characterized by each of the inserts having a corner at its end which is nearest to the oxygen orifices, the corner being spaced from said orifices and extending into the path of oxygen streams discharged lfrom the orifices for producing turbulence and increasing mixing of the oxygen streams from the different orifices as said streams are discharged through the slot. y

7. A slotted scarfing burner comprising a burner body with a series of elongated oxygen supply passageways separate from one another, a continuous slot in the burner Vbody and into which the oxygen supply passageways discharge, and inserts in the slot tapered for a short length at the upstream ends thereof for compressing and unig formly distributing the flow of oxygen across the slot.

8. The scarfing burner described in claim 7 characterized by the vpassageways being in a row lengthwise of the slot, and the elongation of each passageway being in the direction in which the row extends.

9. The scarfing burner described in claim 8 characterized by a header passage in the burner body for supplying oxygen to a plurality of the oxygen passageways.

10. The scarfing burner described in claim 9 characterized by a plurality of oxygen inlet passages opening into the header passage at locations spaced lengthwise of the header passage, means for supplying oxygen at substantially the same pressure to the different oxygen inlet passages to maintain substantially equal pressure of oxygen at all of the oxygen supply passageways.

11. The scarfing vburner described in claim 10 characterized by the oxygen inlet passages opening into the header passage at locations between the successive oxygen supply passageways.

12. The scarfing burner described in claim 7 characterized by other jet orifices located in a row extending generally parallel to the slot and opening through a face of the burner near the discharge end of the slot lfor directing pre-heating jets against a surface to be scarfed and against the scarfing oxygen stream during operation.

13. The scarfing burner described in claim7 characterized by the burner body being a composite construction and having -face portions secured thereto with lips that extend across the downstream ends of the inserts to retain the inserts in the slot. v Y

14. vThe scarfing burner described in claim 13 characterizedrby a header passage in the burner -body above the slot, another header passage inthe burner body below Athe s'1ot,-the header passages above and below the slot opening through a portion of the burner body with continuous openings that are covered by said face porti/ons of the -burner,'and each of the face portions having a row of orifices extendingv therethrough land communicating with said continuous openings for supplying pre- -heating jets to a work piece during a scarfing operation.

References Cited Thompson et al. 239-556 X M. HENSQN WOOD, JR., Primary Examiner. H. NATTER, Assistant Examiner.