US2384920A

US2384920A - Multiflame heating torch

Info

Publication number: US2384920A
Application number: US382160A
Authority: US
Inventors: Howard G Hughey
Original assignee: Air Reduction Co Inc
Current assignee: Airco Inc
Priority date: 1941-03-07
Filing date: 1941-03-07
Publication date: 1945-09-18
Anticipated expiration: 1962-09-18

Description

Sept. 18, 1945. HUGHEY 2,384,920

MULTIFLAME HEATING TORCH Filed March 7, 1941 F INVENTOR Howard G, Hr/ 7161 I l W l3 E ATTOR EIY Patented Sept. 1945 2 92 orrics MULTIFLAME HEATING TORCH Howard G. Hughes, Bloomfield, N. 1., assignor to Air Reduction Company, Incorporated, New York N. Y., a corporation of New York Application March 7, 1941, Serial No. 382,160

'2 Claims. or. 158-214) The invention relates to torches having a number of separate jet orifices to which gas is supplied from a common header.

It is an object of the invention to obtain a balanced gas ratio in' the diflerent flames of such a torch when oxygen and fuel gas are supplied through the header will each. receive the same ratio of oxygen to fuel gas. For example, a branch passage on one side of the main header passage might receive an excess of oiwgen, whereas the branch passage on the other side of the main passage would receive an excess of fuel, with the result that one jet orifice would produce an oxidizing flame while the other would produce a car-' burizing flame.

With this invention a thorough intermingling of the oxygen and fuel gas is obtained within a short distance after the gas stream leaves the mixer by producing changes in cross-section and turbulence of the gas through the combined ac- Fig. 3 is an end view of the torch shown in Fig. 1, but on the same scale as Fig. 2.

The torch of this invention includes a header iii to which are connected a plurality of separate tips ii The torch shown. in the drawing ha four tips II, but other embodiments of the invention have fewer or more tips depending upon the use for which the torch is intended.

Each of the tips ll comprises a flexible tube, preferably of copper, with a Jet oriflce I! at its lower end from which an .oxy-tuel gas mixture is discharged into a flame. The Jet orifice is somewhat smaller in cross-section than the remainder of the tube and is made to accurate size by swaging in a manner well understood in the art. The length of the tubes depends somewhat upon how much flexibility is desired.

The header i0 comprises a metal body with a circle of recesses H for the tips ii. In the illustion of a restricting port in the main passage of the header, upstream from the branch passages, and a dead-end passage or pocket, just beyond the region wherethe branch Passages lead off from the main passage.

Another object of the invention is to prevent or minimize the disturbance of one flame by another in a multi-jet torch, and more especially in a multi-tip torch where gas is supplied to all of the time jets by a common header. torches a single flame may be disturbed, as by flying slag, ,and this invention provides a header construction which prevents such a disturbance from affecting the other flames Or at least minimizes such effect. This obiect'is attained by restricting each branch conduit through which gas is supplied to a jet orifice to a cross-sectional area that is preferably the same as the crosssectional area of the jet orifice, and in any case not more than 15% larger than the cross-sectional area of the jet orifice.

Other objects, features, and advantages of the invention will appearor be pointed out as the In such trated embodiment of the invention the upper end of each of the tips iits tightly into one of the recesses l4, and is secured to the header by hard .solder IE, but other connections between the tips faces of a gear tooth for a flame hardening operation. Two precautions should be observed when bending the tips. Bends should not be so sharp that they close or greatly restrict the opening through the interior of the tip, and it is advisable to leave a straight run near the discharge end of the tip-because a bend too close to theiet orifice i! sometimes produces an undesirable flame'shape.

The recesses in the upper ends of the tips ll and is provided for by not drilling the passage i8 for the full length of the header.

Above the restricting port 20 there is a recess with threads 2| for connecting the header ll directly to a mixer 22. The mixer is of conventional construction. It is sufllcient to understand that oiwgen and fuel gas are brought together in the mixer in the ratio desired for the heating flames. charge conduit in line with the restricting port 2|. The gases discharged from a mixer are not thor- The mixed gases flow through a disoughly commingled, there being a'stratification of the gases until they have traveled for some distance along a delivery conduit. With this invention. however, the novel construction and relation of the gas'passages cause the gases to commingle thoroughly before the gas stream is divided for distribution to the separate tips H, even though the distance from the mixer to the region of division is very shOrt.

The first means for increasing the rate at which the gases commingle is the restricting port 20. Thorough commingling and elimination of stratifioation is promoted by the change in cross-section of the gas stream while passing into and out of the restricting port 20. This port opens into the main supply pusage l8 with an abrupt change in section and produces a turbulence in the gas stream that promotes more complete intermingling of the oxygen and fuel gas.

Another feature of the header construction that promotes a thorough intermingling of the gases is the location of branch conduits 0r passages 24 so that they lead off from the main passage IB at a region intermediate the ends 01' the passage l8. The lower end of the passage I8 is closed by an end wall. shown. in the illustrated embodiment as a plug 25, but it is a feature of the construction that the end wall or plug 25 does not extend up to the region where the branch passages 24 open into the main passage ll. There is, therefore, a dead-end passage or pocket below the region where the gas stream in the main supply conduit 18 divides into the branch conduits 2. This dead-end passage provides a gas cushion that promotes even distribution and increases the turbulence at the entrances to the branch conduits 24. It is not essential that the branch conduits, or the tips that they supply, be at equal angular spacing.

In the illustrated embodiment of the invention the dead-end passage is shown with a length approximately three times as long as its diameter. This is illustrative. but not critical, it being sufiicient that the main supply passage extend for a substantial distance beyond the region where the conduit. The cross-sectional area of the restricting port 20 must not be too large or the gas velocity will be low and the desired results will not be produced. On the other hand, it is important to avoid making this restricting port too small because too much restriction makes necessary an undesirable increase in the operating pressure for the torch. The cross-sectional area of the restricting port 20 is preferably approximately 85% of the sum of the cross-sectional areas oi the orifices l2 of the separate tips H.

In a single-tip torch having a tip as long as the tips ll shown in the drawing, there would be ample time for the oxygen and fuel gas to thoroughly intermingle before they reached the discharge orifice atthe end of the tip. With a multi-iet or multi-tip torch, however, where the gas stream is divided soon after it leaves the mixer, and the oxygen and fuel gas are not thoroughly intermingled, one branch conduit may receive a higher ratio 0! oxygen to fuel gas than the ratio delivered by the mixer. Another branch conduit would, oi course, receive a correspondingly lower ratio or oxygen to fuel gas. Under such conditions, no matter how thoroughly the gases may intermingle while traveling to the discharge ends of their separate tips, one tip will produce an oxidizing'fiame and the other tip a carburizin: flame.-

With multi-tip torches a disturbance of the flame from one tip, such as may be produced icy flying slag, may aiiect the flames of the other tips through pressure reactions in the header. The dead-end passage reduces the effect on the other flames of such disturbances in one flame, but of even greater effectiveness, in reducing or entirely eliminating the transmission of a disturbance in one flame to the flames of other tips, is the cross-sectional area of the branch passages 24.

The cross-sectional area of each branch passage 24 is preierably substantially equal to the cross-sectional area of the jet orifice IE to which gasis supplied by the branch passage 2a. In no case should the branch passage 24 have an area 1 of cross-section more than 15% greater than that i of the jet orifice. The branch passages 26 di-' verge at acute angles from the main supply pas sage l8. The angle of divergence is oi the order of fifteen degrees in the illustrated embodiment of the invention, but different angles can he used. Various other changes and modifications can bemade and some features of the invention can be used without others without departing from the invention as defined inthe claims.

I claim:

1. An oxy-fuel gas torch including a mixer for the oxygen and fuel gas, a header connected directly to the mixer with a central passage into which gas flows from the mixer, a restricting port at the end of the central passage close to said mixer, there being an abrupt change in crosssection from said restricting port to the portion of said passage on the downstream side of the port for causing. turbulence and more thorough mixing of the oxygen and fuel gas as they flow through said central passage, a circle of recesses in the end face of the header remote from the mixer, flexible copper tubes, each with one end fitting and secured in one of the recemes and with a Jet orifice at its other end, branch conduits in the header connecting each of the tubes 'with the central passage, said branch conduits diverging from the central passage at the same jet passages 24 lead oil from the main supply section, and at equal acute angles to the axis 01' the central passage, at equi-angular points around the circumference of the central passage, and each 01' said branch conduits having a cross-sec- 59 tion substantially equal to the cross-section of the jet orifice at the end of the tube to which the branch passage supplies gas, the restricting port in the central passage having a cross-section the order 01' 01' the sum or the cross-sections of the Jet orifices, the central passage extending beyond the region at which it communicates with the branch conduits and terminating in a dead end that forms a pocket for increasing the turbulence of the gas mixture at the region where it divides into the branch conduits.

2. In a torch comprising a plurality of separate tips having jet orifices and a header to which the tips are connected, a main passage to which a mixture of oxygen and fuel gas is supplied, branch conduits leading from the main passage to the respective tips, and means for causing turbulence'ot the gas mixture in the main passage before said gas mixture divides into the branch passages, said means including a restricting port located in the main passage upstream from the branch conduits and having a crosssectional area of the order or 85% of the sum of the cross-sectional areas of the Jet orifices of the tips.

HOWARD G. HUCimY.