US2425710A - Blowpipe nozzle - Google Patents

Description

Aug 19, 1947 J. H. BucKNAM TAL 2,425,710

BLOWPIPE NOZZLE Filed Nov. 1, 1944 (EIM y/70 55 55 @43g f Patented Aug. 19, 1947 BLOWPIPE NOZZLE James H. Bucknam, Cranford, and Ivan P. Thompson, Elizabeth, N. J.,-a.ssignors to The gillide Air Products Company, a corporation of Application November 1, 1944, Serial No. 561,358

, 1o claims. (o1. 15s-27.4)

This application is a continuation-impart of application Serial No. 478,202, filed March 6,1943, for Blowpipe nozzle, and application Serial No. 517,472 filed January 7, 1944, for Process of thermochemically conditioning metal bodies. In the drawings: Y

The invention relates to post-mixed Oxy-fuel Figure 1 is a view in side elevation of; a nozzle gas scarfing nozzles, and more particularly to exemplifying the invention; two-piece slotted nozzles in which oxygen and Figure 241s an enlarged fragmentary longitudiacetylene or other fuel gas mix and .burn at the nal sectional view of the nozzle shown in Fig. point of exit from the nozzle. The acetylene is ure 1 A directed into an outer fringe of a cutting oxygen Figure 3 is a fragmentary longitudinal secstream, which supplies the oxygen for supporting tional view taken on line 3-3 of Figure 2; combustion of the acetylene. During initial pre- Figure 4 is a view in front end elevation of the heating, the oxygen is supplied at low velocity nozzle, a portion of the end wall of the cap being and during cutting at high velocity. l5 broken away;

The main objects of the invention are to pro Figure 5 is a view in rear end elevation of the vide an improved postmixed Oxy-fuel gas scarng nozzle; nozzle; post-mixed nozzles that are effective and Figure 6 is a view similar to Figure 4 of a mod.. efficient in operation, and relatively easy to keep ification; clean and maintain in proper operating condi- 2o lFigure 7 is a fragmentary sectional view taken tion; and nozzles of this type that are capable .online 1-1 of Figure 6; and of being manufactured in production. p Figures 8 and 9 are views similar to Figures 4 In accordance with the invention, there is proand 7, respectively, of another modication. vided a blowpipe nozzle including a body, and The two-piece post-mixed oxy-fuel gas scarilng an end cap which is removably secured to the nozzle N, shown inFigures 1-5, consists of abody body. The rear end portion of the nozzle body B and a cap C, each being Composed of a. highly and cutting oxygen passage are similar to con.. heat-conductive metal such as copper. The body ventional Oxy-acetylene scarf-lng nozzles of the B has an oxygen supply passage O and a plu premixed type. .-The front end portion of the rality of acetylene supply passages A. The oxy. nozzle body and the preheat gas passages, howgen supply passage O includes an inlet portion ever, are different. The outside diameter of the I0 of substantially constant diameter, a. :dared front end portion of the body is reduced to permit portion l 2. a Short medial DOIOI! (not Shown) slipping the cap over the end portion of the body. of Constant diameter, and an outlet portion I4 The end wall of thiscap acts as a baille to direct Which gradually Changes from circular to at the acetylene, issuing from the preheat holes, cross-section, the discharge orce I6 of the oxyinto the cutting oxygen stream. The cap is progen passage O being oblong and having broached vided with a transverse slot extending across the lateral Walls I1. This causes the central oxygen face that is slightly wider than the small dimenpassage O to discharge a characteristic desursion of a slot in the nozzle body. The cap slot is facing or scaring oxygen stream, generally alined with the body slot when the cap is installed known as the cutting Oxygen Stream. on the body to provide an outlet passage for the The front end portion I8 of the body B is prostream of cutting oxygen. In a preferred modivided with a transverse slot 20 which is in alinefication, acetylene chambers are provided across ment with and wider than the oxygen discharge the end face of the nozzle body .by continuous orice I6 to provide a recess or step 22 which acts grooves, one on each side, milled in at right to divert a lateral portion of the Otherwise Solid angles to the slot. The bottoms of such grooves cutting Oxygen stream, surrounding the latter by are sloped at an angle to facilitate cleaning an oxygen skirt in the nature of an eddy current through the slots. As the cutting oxygen stream fringe. The CBP C iS 21150 provided With a transis ordinarily at too high a velocity during scarring verse slot 24 extending across ,its relatively thick to hold a llame, a step is provided in the cutting wall 26 in alinement with the body slot 20. The oxygen passage by milling the slot across the end cap slot 24 is only slightly Wider than the body of the nozzle. Such step acts, thru the edge slot 20 to insure an aspirating eiect upon the effect of the sharp corner, to divert a lateral acetylene. Acetylene passages or chambers are portion of the oxygen .stream to mix with the provided across the end face of the nozzle body acetylene. The external'dimensions of the nozzle are the same as those of standard premixed nozchangeable with such premixed nozzles, as far as the nozzle shoes ,and head are concerned. v-

-by continuous grooves 28, one on each side of the nozzle, which are milled in at right angles to the slot 20. Such grooves are approximately .020 inch deep at the point of exit into the slot 20 and have bottoms that are sloped at an angle of the order of 30 to a plane which is perpendicular to the rlongitudinal axis of the oxygen passage, to facilitate cleaning.

Thus, when the cap C is secured in place on the front end portion in the body B, enlarged distribution acetylene chambers 3D are provided between the cap and the body, acetylene being supplied to such chambers through the acetylene supply passages or holes A, and discharged from the chambers through narrow slots or ports 32 located in the walls of the slot 20, and covered by half portions 34 of the end wall 26 of the cap. Such half portions 34 of the end wall of the cap are supported by four end face segments or portions 36 of the nozzle body. The cap is removably securedl in place on the front end portion i8 of the nozzle body by any suitable means, such as a fillet weld 38 which may be melted, when desired, to remove the cap from the nozzle body. The opposed walls of the cap slot 24 are bevelled at 29 so that a cleaning tool may be inserted through slot'24 into the acetylene ports 32.

The gas inlet end portion of the body B is provided with a pair of radially and longitudinally spaced frustoconical annular seats 40 and 42 which are adapted to mate in gas-tight relation with corresponding seats in a conventional head (not shown) of a desurfacing unit or blowpipe. The body B is also provided with an annular flange 44 having longitudinal slots 4B for receiving tongues (not shown) for locating the nozzle in proper position with respect to the head. The nozzle is coupled tothe head in the usual Way so that acetylene is delivered to the acetylene passages A, and oxygen is delivered to the oxygen passage O.

In operation, oxygen is rst supplied to the oxygen supply passage O only in suficient quantities to mix with the acetylene discharged by the opposed ports 32 in the walls of the oxygen slot 20 to produce an elongated externally mixed Oxy-acetylene flame for initially heating work to start the scaring or desurfacing operation. After the work has thus been initially heated, the velocity of the oxygen stream discharged by the supply passage O is increased to a desired value, depending upon the nature of the operation to be performed, in this case scarfing, without altering the quantity of acetylene supplied to the nozzle. The otherwise solid desurfacing oxygen stream thereupon is provided at its opposite lateral surfaces with elongated preheating flames composed of a mixture of oxygen and acetylene, mixed externally of the nozzle. Such flames are concentrated in the scarng zone, and are quite satisfactory for desurfacing hot steel. Such nozzle, under ideal conditions is more efficient than a standard nozzle of the premixed type.

In order to avoid gouges or ruts between cuts when attempting to obtain deep cuts, the angle of diversion of the broached-out side walls |'l of the outlet portion I4 of the oxygen supply passage O, is preferably of the order of This causes a slight ridge between grooves or cuts under most conditions, but the quality of the cuts is superior to that obtained with standard premixed desurfacing nozzles. The main reason for this is that'the cutting streams do not spread as much and consequently do not interfere with each other as much on multiple nozzle set-ups.

Cuts having a depth in excess of 1/8 inch have been obtained that are relatively flat, with the exception of a slight ridge approximately l/c.l inch to nl; inch high between the individual cuts.

The surface of the oxygen supply passage O is preferably chromium plated to inhibit erosion. The nozzle is constructed so that the cap C can be replaced, in case the cap becomes damaged or burned in use. Maintenance of the nozzle N when installed in a desurfacing machine is quite simple. It consists merely of cleaning the loose carbon and slag off the face of the nozzle, out of the acetylene ports, and out of the step in the cutting oxygen passage. Usually this is much easier to do than it is to drill out the preheat holes on standard premixed nozzles.

In the modification shown in Figs. 6 and 7, a blowpipe nozzle 50 is provided which comprises a tubular body or member 5| having a central oxygen supply passage 52 extending longitudinally therethrough and also having a plurality of acetylene supply passages 53 arranged in spaced relation to the oxygen passage 52; the discharge ends of all of such passages terminating in the front end face of the member 5|. The nozzle 50 also includes an end cap 54 having a cylindrical skirt 55 fitting a reduced annular end portion 56 of the tubular body member 5|, the bottom panel 51 of the cap 54 being seated on the end face of the body so that such bottom panel is supported by such end face. The cap 54 is secured in place on the member 5| by any suitable means.

The body member 5| and the end cap 54 are provided 'with enlarged acetylene distributing chambers 58, 58 there-between into which the acetylene supply passages 53 discharge, the chambers 58 being formed by removing sections of the end portion'56 from opposite sides thereof. The end portion 56 of the member 5| is also provided with a plurality of inclined acetylene discharge holes 59 connecting the acetylene distributing chambers 58 to the enlarged orifice or slot 60 in line with the oxygen supply passage 52 for discharging the acetylene inwardly and forwardly against opposite sides of the single stream of oxygen as the latter leaves the discharge orice 6| of the oxygen supply passage 52. The oxygen orifice 6|, the slot 6.0 and the panel slot opening 62 are oblong in cross section, so that a flat but solid stream of cutting oxygen is discharged by the nozzle 50, the acetylene distributing chambers 58 being located parallel to the long sides of the panel opening. I'he acetylene discharge holes 59 are arranged in parallel relation to each other, there being a hole 59 corresponding to each acetylene passage 53, and the holes 59 are shown round, but may be flat so as to provide slots the wide sides of which are parallel to the Wide sides of the oblong oxygen orifice.

It has been found that it is probably -better to use flat acetylene slots than round holes for discharging the acetylene against the oxygen stream, perhaps because a certain amount of oxygen is taken from the side of the oxygen stream by each jet of acetylene in its combustion and this lack of oxygen in line with the pure acetylene holes leaves a ridge in the surface of the Work when such holes are round. Such ridge in some cases is undesirable in that it is somewhat higher than the balance of the work. If ve acetylene preheat holes that are round are used, for example, five ridges may be formed on the work surface. By using several flat holes or flat slots for the'acetylene such undesirable ridge condition is minimized; although, of course, with a long acetylene slot I2, as shown in Figs. l to 5, no ridges are formed in the work surface. An advantage of the post-mixed nozzle with flat acetylene holes is that the acetylene outlet passages are easier to keep clean. The operation of the nozzle shown in Figs. 6 and 'l is substantially similar to that described above in connection with the nozzle shown in Figs. l to 5.

Referring to Figs. 8 and 9, the illustrated blowpipe nozzle 10 comprises a generally tubular body 1| having a central oxygen supply passage 12 extending longitudinally therethrough and also having a plurality of acetylene supply passages 13 in spaced relation to such oxygen passage. Th discharge ends of the passages 12 and 13 terminate in an end face 14 of the member 1I, which end face is provided with a plurality of transverse grooves 16 forming separate enlarged acetylene chambers the bottoms of which are inclined inwardly and forwardly toward the discharge end 16 of the oxygen passage 12. .An end cap 11 fits the end portion of the body 1| and is provided with a bottom panel 18 which engages the end face 14 so as to be supported thereby. The bottom panel 16 is provided with an opening 19 the inner edges of which are laterally offset with respect to the edges of the discharge orifice 16 of the oxygen passage 12. Such discharge orifice 16 of the oxygen passage is provided with a peripheral recess or slot 80 and is entirely open for discharging only a single stream of oxygen through the slot or opening 19 of the cap. The grooves 15 are disposed so that the acetylene ports direct the acetylene discharged by the acetylene supply passages 13 inwardly toward` the single stream of oxygen as the latter leaves the discharge end 16 of the oxygen passage 12. The opening 19, the slot 80 and the discharge orifice 16 of the oxygen passage 12 are all oblong in cross section, and the grooves or slots 15 are disposed in parallel relation to each other and at opposite sides of the stream of oxygen so that the formation of ridges in the work may be inhibited. The operation of the nozzle 10 is substantially similar to that of nozzle N.

What is claimed is:

1. A two-piece post-mixed oxy-fuel gas scarfing nozzle including a Ibody having an oxygen supply passage provided fwith a single oblong oxygen discharge orifice which is axially in line with such oxygen supply passage, the front end portion of said body having a transverse slot which is in alinement with and wider than such orifice, fuel gas outlet ports located in opposite walls of said slot, fuel gas supply passage means communicating with such fuel gas ports, andra cap removably secured to the frontend portion of said body, said cap having an end wall provided with a transverse slot which is in alinement with and only slightly wider than the slot vrin the front end portion of said body, said fuel gas passage means comprising enlarged fuel gas chambers located between the cap and body, the fuel gas passage means directly upstream of said fuel. gas ports having inclined bottom surfaces.

2. A two-piece post-mixed oxy-rfuel gas scarfing nozzle, as defined by claim 1, in which the fuel gas outlet ports are located between the end wall oi' said cap and the front end of said body.

3. A two-piece post-mixed oxy-fuel gas scarfing nozzle, as defined by claim 1, in which the fuel gas outlet ports are connected' to the fuelgas chambers by inclined fuel gas discharge holes in the front end portion of the body.

4. A blowpipe nozzle comprising a member having an oxygen supply passage extending therethrough and also having acetylene supply passage means arranged in spaced relation to said oxygen supply passage, the discharge ends of all of said passages terminatingin an end face of said member, an end cap having a skirt fitting an end portion of said member, the bottom panel of said cap engaging said end face so as to be supported thereby, said bottom panel being provided with an opening the inner edge of which is laterally offset with respect to the edge of the discharge orifice of said oxygen supply passage, said discharge orifice of the oxygen supply passage being provided with a peripheral recess and being entirely open for discharging only a single stream of oxygen, and said end face having grooves the bottoms of which are inclined inwardly and outwardly, said grooves being disposed so as to direct the acetylene discharged by said acetylene passage means inwardly toward said single stream of oxygen as the latter leaves the discharge end of said oxygen passage.

5. A blowpipe nozzle as claimed by claim 4, in which said opening and the discharge orifice of said oxygen supply passage are oblong in cross section, and said grooves are disposed in parallel relation to each other and at opposite sides of the long edges of said discharge orifice of said oxygen supply passage.

6. In a blowpipe nozzle for flame heating and removing metal thermochemically from a metal body with fuel gas and oxygen, the combination comprising, means including an orifice fol` dis- I charging a stream of oxygen from the nozzle,

means including a step in said orifice for creating an eddy current fringe of oxygen adjacent the main part of such stream, and means for discharging fuel gas from the nozzle to mix with such eddy current fringe, forming a combustible mixture which, when ignited, produces a flame extending alongside the main part of such stream of oxygen, said last named means comprising a lateral fuel gas outlet in the side wall of said step for directing fuel gas laterally toward the stream of oxygen, said fuel gas outlet having a bottom wall which is inclined with respect to such side wall.

7. A post-mixed desurfacing blowpipe nozzle having a first single oblong discharge orifice for discharging a stream 0i' oxygen, said nozzle having an oxygen supply passage upstream of and axially in line with said orifice, said oxygen supply passage having an outlet portion upstream of said orifice which gradually changes from circular to oblong cross-section and merges with said first orifice, each longer side of said passage being pro vided with a lateral step portion for creating an eddy current fringe of oxygen downstream of said orifice, the step portions forming an enlarged passage, said enlarged vpassage terminating in a second discharge orice, means forming enlarged fuel gas chambers adjacent opposite longer sides of the enlarged passage, fuel gas supply passages in said nozzle discharging into said chambers, and restricted passage means providing communication between said chambers and said enlarged portion.

8. A post-mixed desurfacing blowpipe nozzle as defined by claim 7, in which the restricted passage means, providing communication between said chambers and said enlarged portion, consist of narrow elongated slots extending parallel to the longer axis of the first oblong oxygen discharge Orifice.

9. A post-mixed desurfacing blowpipe nozzle as defined by claim 7, in which the restricted passage means, providing communication between said chambers and said enlarged Portion, consist of inclined holes.

10. A post-mixed desurfacing blowpipe nozzle as defined by claim 7. in which the restricted passage means, providing communication between said chambers and said enlarged portion, consist of transverse grooves.

l JAMES H. BUCKNAM.

IVAN P. THOMPSON.

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

Number A Number 8 Name Date Egger et al Sept. l, 1942 Kehl Nov. 28, 1939 Harris July 29, 1919 Miller Oct. 1, 1929 Scheller July 21, 1942 Hendricks May 8, 1934 Harrison Aug. 23, 1910 Oldham May 1, '1934 Bucknam Sept. 24, 1940 Menne July 1, 1902 Jones Dec. 23, 1941 Harris Dec. 16, 1924 Cartwright Apr. 2, 1889 FOREIGN PATENTS Country Date France Nov. 19, 1926 Germany June 4, 1918 France May 3, 1937 Switzerland Feb. 17, 1936 Germany May 31, 1919 Germany Aug. 25, 1920 Great Britain July 22, 1915 Great Britain of 1922

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