US2218827A - Flame hardening - Google Patents

Description

Oct. 22, 1940.

C. MOTT ET AL FLAME HARDENING Filed April 7. 1938 2 Sheets-Sheet l is I I .E. Q

Z 2 F C a INVENTOR Chesier Mail? Malc ZmLJV/Zakj ATTO RN EYS Oct. 22, 1940. Q -r AL 2,218,827

NNNNNN O R Chester Mott Malcolm L. Windy Patented Oct. 22, 1940 UNITED STATES,

FLAME HARDENING Chester Mott, Evanston, Chicago, 111., assignors Company, Chicago, 111., ware and Malcolm L. Whitley, to National Cylinder Gas a corporation" of Dela- Appiication April'l, 1938, Serial No. 200,64 Claims. (Q1. 299-141) This invention relates to torches or burners utilizing a mixture of a combustible gas and a combustion supporting gas such as, for instance, a mixture of acetylene and oxygen to produce a high temperature flame particularly suitable for the heat treatment of metal.

An object of this invention is to produce a sheet-like flame which may be directed against the surface of a metal member and progressively moved over said surface in such a manner that the surface covered is heated uniformly.

It has been proposed to form the sheet-like flame by providing the burner with a.row or several rows of circular apertures spaced apart and collectively'forming the burner outlet. The temperature of a flame e 'tted from a small orifice varies from a high point of relatively small area close to the outlet, known as the cone, to a low point at the tip of the flame. The cone temperature, when oxygen and acetylene aroused, may be approximately 6300 F., and the temperature at the tip of the envelope only 2300'F., with an intermediate point about half way between the two of about 3800 F. In order to obtain the maximum heating effect with a minimum amount of fuel, it is necessary to hold the burner outlet very close to the metal to be treated so that the metal lies in the cone area where the highest temperature exists. With a series of small outlet openings and with the necessary distance of, for instance, one-quarter inch between drilled holes, there is a temperature differential between the center of one cone and the point half way between the centers of adjacent cones. The cones from small outlet openings are so small that they do not overlap and blend together to produce an even temperature across the curtain or sheet of flame. To get uniform flame temperature across the sheet of flame, it is necessary to hold the burner spaced away from the work to such a distance that the flames issuing from the several holescan have an opportunity to blend with adjacent flames. Thus, it is necessary that work be held at some intermediate point in the length of the flame, which intermediate point may have a temperature of approximately 3800 F. which is considerably lower than the maximum temperature of the center of the cone immediately in front of the burner outlets.

An object of the present invention is to produce a burner or torch tip which will form a long even curtain of flame having substantially the same temperature along its length at any given distance from the burner outlet, and further to so position the small outlets that the separate cones produced in front of the several small outlets blend to form a continuous line across the. burner outlets and at substantially the maximum temperature.

A still further object is to produce a device 5 which may be made from standard parts and wherein the burner openings may be adjusted as to size to compensate for wear or to vary the size of the jets and the quantity of gas used in accordance with the particular work for which the device is to be used.

The device of the present invention maybe economically and accurately manufactured by the use of ordinary good shop practice despite the fact that the nozzle orifices are very small, and without drilling or spacing lengthwise of the sheet of flame.

A further object is to produce a burner of this general character which can be readily cleaned and kept clean.

A further object is to provide a torch having very small closely spaced outlet openings, but so designed that the resistance to flow of the gases through said openings is the minimum.

In the accompanying drawings are illustrated certain embodiments of the invention, but it will be understood that various changes may be made within the scope of the invention as deflned in the appended claims.

In the drawings- Fig. 1 is a side view of a torc having the improved burner or torch tip construction;

Fig. 2 is an end view of the burner;

Fig. 3 is a face view of the outlet side of the burner;

Fig. 4 is a side view of the burner, a portion being removed to show the passages;

Fig. 5 is a face view of a torch for simultaneously heating and quenching the material being treated, and having a pair of nozzles such as those described herein;

Fig. 6 is an end view of the apparatus shown in Fig. 5;

Fig. 7 is an end view of parts of a burner, on an enlarged scale, showing how the grooves providing the gas passages may be formed;

Figs. 8 and 9 are sections on the lines 8-8 and 9-9, respectively, of Fig. '7;

Fig. 10 is a view similar to Fig. '7, but showing an alternative arrangement;

Fig. 11 is a sectionalview showing an alternative arrangement of parts for forming the passages; and Y Fig. 12 is a view of an annular burners for heating a tube or rod.

arrangement of Our improved torch tip, burner or nozzle may be used with any common form of torch and gas mixing device to which the combustible and combustion supporting gases are delivered through suitable pipes or conduits. Pipe I may be used to convey a combustible gas, such as acetylene, and pipe 2 may beused to convey a combustion supporting gas, such as oxygen, the flow of gas being controlled by valves 3 and 4. From these valves the gases are admitted into any suitable mixing chamber which may be disposed in the handle 6 and then flow to the shank or body 1 of the tip, burner or nozzle 8.

The shank 1 at its terminal portion has a pair of grooved or slotted interengaging plates 9 and I0. Each plate has a series of parallel grooves or slots separated by ribs or ridges. The grooves H in plate I0 are of such size as to receive the ribs ll of the plate 9 and the grooves [6 of the plate 9 receive the ribs i 5 of the plate ID, the side faces of all of the grooves and ridges lying in parallel planes. When the plates are placed together with the grooved sides facing each other, the ribs or ridges of one plate fit snugly into the grooves of the other plate, as seen in Fig. 3, but do not extend to the bottoms of said grooves so that there are formed two closely spaced rows of closely spaced passages II for the exit of the gas. The passages of one row are arranged alternately with those of the other row, and are approximately equal in width to the spaces so that the gas issues along the entire length of the burner outlet. The passages all communicate with the manifold section 1 of the shank I. The area of these apertures or passages may be varied by spacing between the plates 9 and ID to any desired distance. This may be done in various ways,

' for example, by suitable shims 20. By varying the number of shims that are inserted between the edges of the plates, the cross-sectional area of the openings in the nozzle can be varied within the desired limits but due to the parallelism of the sides of all of the grooves and ridges, such adjustment of the plates toward or from each other does not result in any interconnection of the passages along their lengths, and leaves the passages separate and independent.

With this type of construction the grooves may be made as narrow as .025 of an inch or even smaller and with an equal width of ribs so that the cones of the flame issuing from the several closely juxtaposed but separate orifices will overlap and blend, thus producing a substantially continuous sheet or curtain of flame along the length of the nozzle and of the flame cone temperature. Thus the burner may be held close to the metal being treated so that the cone temperature may be utilized to heat the metal and there will not be any areas of the work in the path of the flame which are not substantially uniformly heated. The work may be heated up in very much less time than if the burner be held further away and an intermediate point of the flame engaged the work. Thus there is obtained more rapid and more uniform heating, and the flame may be advanced over the work much more rapidly, for instance, twelve to fifteen inches per minute, instead of only four to eight.

The gas passages in the grooves are preferably of larger size at their inlet end than at the delivery end. This may be accomplished by inserting the ridges or ribs l5 of the members 9 and Ill further into the grooves l6 at the outlet ends of the passages ll than at the inlet end, as

shown in Figs. '7, 8 and 9. The same effect may be accomplished by making the grooves li deeper at the gas inlet end, as shown in the members 9 and l in Fig. 10.

In Fig. 11 the members 9 and i have the grooves concave on their inner sides so that the ribs cannot seat at the bottom of the grooves and the passages are thus plane-convex in cross section, and 1 Fig. 12 is a plan view of an apparatus embodying a plurality of the nozzles for heat treating the surface of a cylindrical body.

In any of these forms the two members may be detachably secured together by screws, bolts or an encirclingband, or the parts after being adjusted to the desired position may be welded together.

In Figs. 5 and 6 is shownan apparatus for both heating and quenching in one operation. A torch I the heating nozzle 8 to the quenching nozzle 28 so they may be operated as a unit.

As will be seen in Fig. 6, the nozzle 8 is positicned in a somewhat lower plane than the nozzle 28, and a partition plate 34 extending below the outlet of the nozzle 8 serves to separate the two nozzles and the fluids discharged therefrom so that the quenching fluid will not interfere with the action of the flame issuing from nozzle 8.

In operation, the heating nozzle maybe held close to the work because the temperature is uniform across the line of the openings even close thereto. In this way, full advantage of the high temperature of the cone area may be had, and the metal can be heated in considerably less time than if some point of the flame further from the nozzle were used. Reducing the time of heating reduces the heat penetration so that a more desirable result of mere surface heating may be obtained than with prior art devices where the lower temperature of the fiameis utilized and the heat penetration is deeper.

Flame hardening is done by moving the nozzle slowly over the work and'following the flame with the quenching medium. In practice it has been found that applicants nozzle may advance faster thanthe prior art nozzles, thus reducing the cost of the operation materially.

In the construction illustrated in Figs. 5 and 6, the quenching nozzle is attached to the heating nozzle and follows over the work directly behind the latter. This arrangement provides for an easily handled unitary structure to accomplish both the heating and quenching in one operation.

employed informing the fluid passages of the burner or of the quenching device, or both.

The construction shown in Figs. 1 to 6, inclusive, is primarily for flame hardening flat surfaces. If it is desired to flame harden a curved surface the members defining the fluid passages may have curved edges. In Fig. 12 there is shown somewhat diagrammatically four burners 40, each of which may be formed substantially as above described except that they have curved edges. The burners may be connected by brackets, lugs, clamps or the like M so as to deliver an annular flame, indicated by the letter F and against the periphery of a cylindrical rod, bar, tube or other element. The four burners may have separate gas delivery pipes 42, 42', 42 and 42 leading from a single handle or support 43. With each burner there will be a corresponding quenching device with its water delivery pipe.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A nozzle having a pair of parallel rigidly connected plates, each having the face thereof toward the other plate provided with narrow alternate grooves and ridges each having parallel side faces, the ridges of each plate snugly fitting into but not extending to the bottoms of the grooves of the other plate, whereby there are formed a row of separate passages, the spacing between the bottoms of the grooves and the tops of the ridges being greater at the inlet ends of said passages than at the outlet ends.

2. A nozzle having a parallel plates, each having the face thereof toward the other plate provided with narrow alternate grooves andridges extending across the entire width of the face each having parallel side walls, the ridges of each plate extending into but not completely filling the grooves of the other plate, whereby there are formed two closely juxtaposed rows of separate passages, the bottom surfaces of the grooves of one member being in a plane parallel to the plane of the tops of the ridges along a portion of the length of the grooves, and in a plane diverging therefrom along another portion of said-length, whereby the passages are of gradually decreasing crosssectional area for a portion of the length, and of uniform cross-sectional area along another portion of the length.

3. A nozzle having a pair of plates in face to face relationship,

rigidly connected each having the face thereof toward-the other plate provided pair of rigidly connected with narrow alternate grooves and ridges each having parallel side walls, the ridges of each plate extending into but not completely filling the grooves of the other plate, whereby there are formed a row of separate passages, the ridges extending nearer to the bottoms of the grooves at one end than at the-other.

4. A nozzle for a flame hardening apparatus, including a pair, of rigidly connected parallel plates in face-to-face relationship each having a series of transverse grooves with intervening ridges across the face thereof toward the other plate, the side faces of all of the ridges and grooves lying in parallel planes and the ridges of each plate being of substantially the same width as the grooves of the opposite plate and snugly fitting therein but with the terminal surfaces of the ridges spaced to any desired distance from the bottoms of the grooves, to form two closely juxtaposed rows of relatively'long passages of relatively small but adjustable crosssection, and each passage being independent of the other passages in all-normal relative adjustmerits of the plates toward and from each other, the passages of one row alternating with those of the other row and the spacing between the rows being so small that the several jets of fluid delivered under pressure through said passages form a substantially continuous sheet along the length of the series of outlets.

5. A nozzle having a pair of rigidly connected parallel plateseach having a series of transverse grooves with intervening ridges across the face thereof, the side faces of all of the ridges and grooves lying in parallel planes and the ridges of each plate snugly fitting within the grooves of the other but spaced from the bottoms of said grooves to form two closely juxtaposed rows of relatively long passages of relatively small crosssection, and each passage being independent of the others. irrespective of the distance to which the ridges extend into the giooves, the passages of one groove alternating with those of the other and the spacing between the grooves being so small that the several jets of fluid delivered under pressure through said passages form a substantially continuous sheet along the length of the series of outlets, and a manifold of gradually reducing cross-sectionalarea permanently secured to both plates along the edges thereof at one end of such passages for delivering fluid to the latter.

CHESTER MO'I'I. MALCOLM L. WHALEY.

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