US2416161A

US2416161A - Heating flame regulation

Info

Publication number: US2416161A
Authority: US
Inventors: Eibe W Deck
Original assignee: Union Carbide and Carbon Corp
Current assignee: Union Carbide Corp
Priority date: 1942-06-12
Filing date: 1942-06-12
Publication date: 1947-02-18
Anticipated expiration: 1964-02-18

Description

Feb. 18, 1947.

l'hoio Cell E. W. DECK HEATING FLAME REGULATION Flled June 12,

AMPLI HER REACTOR ATTO RN EY Patented Feb. 18, 1947 HEATING FLAME REGULATION Elbe W. Deck, Plainfleld, N. 1., alslgnor to Union Carbide and Carbon Corporation, a corporation of New York Application June 12, 1942, Serial No. 446,810

24 Claims.

This invention relates to the regulation of desired characteristics or heating flames, particularly flames produced by the combustion of a mixture of fuel gas and oxidizing gas, such as oxygen and acetylene, and used in seam weldin operations or stationary welding operations, such as bronze welding and pressure welding, wherein the metal is brought up to the desired temperature quickly and then held at substantially that temperature for a heat soaking period. This invention also relates to apparatus for effecting such regulation. This invention particularly rclates to the regulation of such flames wherein desired characteristics-as the flame temperature, available heat, velocity of the flame Jet, and rate of flame propagation. all of which aifect the heating eflect of the flame or rate of transfer of heat from the flame to a workpiece-are varied. Other characteristics-as the relative length of the inner cone, distance between the end of the inner cone and the surface of the work or contact area of the inner cone, and the ratio between oxygen and fuel gas in the combustible mixture (which afl'ects the chemical activity between the flame and the material being heatedi-are maintained substantially constant.

The amount of heat transferred, or B. t. u. absorbed by the workpiece, is dependent on the total available B. t. u. and the efliciency of heat transfer. The total available 13. t. u. may be altered by varying the quantity or type of constituents of the flame. The efliciency of heat transfer may be altered by varying the temperature of the flame, the velocity of the flame Jet, and the rate of flame propagation. To maintain the maximum effectiveness of the heating operation, it is desirable that the spacing between the blowpipe and the surface of the workpiece shall be maintained substantially constant. that the length of the inner cone of the flame shall be maintained substantially constant, that the character of the flame, i. e., neutral, oxidizing, or carburizing shall be maintained substantially constant or varied only as necessary, and, in some instances, that a blowpipe or equivalent flame producing means shall be moved across a workpiece at a substan. tially constant speed. Thus, an object of this invention is to provide a novel method oi and apparatus for heating flame regulation. whereby the heating eflect of the flame, or the amount of heat transferred to the workpiece, may be varied as desired without substantially impairing the effectiveness, or facility with which the heating operatlon can be carried out, i. e., without changing the length of the inner cone or the separation of 2 the blow-pipe and the work or the rate of relative travel of the work.

Among other objects of this invention are to provide a novel method of controlling the rate of heat transfer from a flame to a workpiece; to provide a novel method of varying the temperature or other desired characteristics of a heating flame without varying the length of the inner cone of the flame, and without altering a desired carburizing or oxidizing effect of the flame, or without altering the chemical character of the flame from neutral, when the same is to be maintained; to provide such a method wherein the tendency for flashbacks is minimized; to provide such a method by which a surface area may be heated relatively quickly to a desired temperature and that temperature maintained without the danger of overheating the surface of the work; to provide apparatus for carrying out the above method; and to provide such apparatus which may be made substantially automatic in operation, and also may be made to respond to variations in heating conditions at the surface of the workpiece. Other objects and novel features of this invention will become apparent from the followin r ption and accompanying drawing, in which:

Fig. 1 is a schematic illustration, partly in section, of an city-acetylene blowpipe, and apparatus constructed in accordance with this invention, for regulating the flame produced by the blowpipe;

Fig. 2 is a cross-section of an oxygen-air-seetylene regulator and proportioner constructed in accordance with this invention; and

Fig. 3 is a. schematic illustration of constant speed strip welding apparatus, including a multiflame oxv-acetylene blowpipe, and apparatus by which the flames produced by the blowpipe are regulated in accordance with the method of this invention.

In accordance with the method of this invention, in order to vary the heating eflect of a flame, the combustible mixture formin the flamewhich combustible mixture is normally formed by mixing fuel gas and an oxidizing gas having a relatively high oxygen content, preferably substantially pure oxygen-is instead formed by mixing fuel gas and an oxidizing gas mixture consisting of oxygen and oxidizing gas having a relatively low oxygen content, preferably air. The relative proportion of oxygen to air (oxygen to nitrogen) in the oxidizing gas mixture is increased when a greater heating eflect is desired. At the same time. the pressure and flow of the oxidizing gas mixture is increased proportionally. and the pressure and flow of the fuel gas is varied in accordance with the variation in oxidizing gas pressure and flow.

Also in accordance with this invention, fuel gases such as acetylene and hydrogen may be mixed with oxygen, and the pressure and flow of acetylene regulated to vary the heating effect of the flame. the pressure and flow of oxygen bein regulated in accordance with that of the sect?- lene. It will be evident that other fuel gases. or mixtures thereof, may be utilized, in carrying out this invention.

By the above method, the heating eifect of the flame may be varied as desired, since the available heat and the temperature of the flame will vary in accordance with the relative proportion of oxygen in the oxidizing gas or in accordance with the relative amount of acetylene in the fuel gas mixture. and the velocity of the flame Jet will vary in accordance with the pressure of fuel gas and oxidizing gas. Not only will the length of the inner cone remain substantially constant, but also the chemical character of the flame will remain unchanged. The latter feature is particularly important when the nature of the work requires a constant character of flame, such as carburizing for certain types of welding, oxidizing for rapid heating, or neutral for other heatin operations.

Apparatus for carrying out the above method and constructed in accordance with this invention, as illustrated in Fig. 1, may comprise a proportioner P for controlling the relative proportions of oxygen and air in an oxidizing gas mixture formed in a regulator R. Regulator R controls the pressure or amount of fuel gas or acetylene passing to a blowpipe B, along with the airoxygen mixture. Regulating valves V on blowpipe 3 are adjusted to provide the desired initial mixture of oxygen and acetylene, or oxidizing gas and fuel gas, passing to a tip T. The initial setting of valves V is preferably maintained, since variations in temperature and heating effect of the flame are readily achieved by adjustment of proportioner P. Regulator R and proportioner P may be combined in a single casing. as in Fig. 2. in which a combined proportioner and regulator RP is illustrated.

The strip welding apparatus illustrated in Fig. 3 comprises, in general, a machine welding blowpipe M provided with a head H adapted to di rect a plurality of high temperature heatin flames along a welding seam on a workpiece W. The relative proportions of oxygen, acetylene, and air in the combustible mixture, forming the heating flames discharged from head H, are determined by a combined regulator and proportioner RP, which is controlled by a solenoid S. In turn, solenoid S is controlled by a photo-cell control unit C, which is responsive to variations in a thermal condition of the welding seam.

The above apparatus may also be utilized in carryi g out the method of this invention wherein the proportions of a fuel gas mixture are varied. and the pressure of oxygen is varied in accordance with the pressure of a. fuel gas such as acetylene, as explained previously. Thus, the proportioner P of Fig. 1 may control the relative proportions of acetylene and hydrogen, for instance, while the regulator B may control the pressure and flow of oxygen in accordance with the pressure and flow of acetylene. Similarly, the combined proportioner and regulator of Fig. 2 may be supplied with acetylene, hydrogen, and

oxygen; and the regulator and proportioner RP of Fig. 3 may control the relative proportions of acetylene, hydrogen, and oxygen, to welding blowpipe M. Thus, it will be understood that oxygen and air may be replaced by acetylene and hydrogen or the like. respectively, and that acetylene or fuel gas may be replaced by oxygen, in the various passages, chambers, hoses, etc.. of the apparatus described below.

Referring again to Fig. 1, for a more detailed description of the apparatus illustrated therein. oxygen and air are supplied through hoses II and II, respectively, to casing l2 of the proportioner P; The oxygen flows from an inlet chamber ll to an outlet chamber 14, such flow being controlled by a valve II, Valve II is controlled by a. diaphragm l8, actuated by a compression spring l1 and the differential between the pressure in oxygen outlet chamber l4 and the pressure in an air inlet chamber ll. oxy en pressure being exerted against the valve side of the diaphragm and air pressure being exerted against the opposite side of the diaphragm. The force exerted by spring I1 is adjusted by a screw l8, which may be turned down to cause spring II to exert a greater force against diaphragm ii and thereby produce a higher oxygen pressure in chamber l4. This produces a correspondingly increased flow of oxygen through hose 2|, from chamber l4 to oxygen inlet chamber 22 of regulator R. The air pressure is normally maintained substantially constant, though, if desired, an increase or decrease in the oxygen pressure can be produced by increasing or decreasing the air pressure, due to the effect upon diaphragm is and consequent opening or closing of valve It.

The air is led from chamber II through a hose 23 to an air-oxygen mixing chamber 24 of regulator R. Oxygen from hose 2| passes into oxygen inlet chamber 22 and flows through a restricting orifice 25 into mixing chamber 24. From chamber 24, the oxidizing gas or air-oxygen mixture flows through a hose 26 to blowpipe B,

When the oxygen pressure in chamber l4 increases as regulated by screw It. the oxygen pressure in chamber 22 of regulator R increases, and flow through orifice 25 proportionally increases. The resultant increased flow of oxygen into chamber 24 causes the relative amount of oxygen therein to increase, and the proportion (and partial pressure) of oxygen in the air-oxygen mixture to increase. As the oxygen pressure (and the flow of oxygen through the orifice 25) increases the pressure difference between the air supply line H and the chamber 24 decreases, reducing the flow of the air. so that a point will be reached at which very little air will be present in the chamber 24, and substantially pure oxygen will be delivered through hose 28 to blowpipe B. When this point is reached, oxygen will back up through hose 2! into chamber it. As long as the oxygen pressure for passage 2| is well above the air pressure in passage 28, there will be no danger of the air pressure in the mixing chamber 24 stepping the flow of oxygen because there will still be an oxygen pressure drop across the orifice 2!. This will also be the case when no air is supplied, as when the heating flame of blowpipe B is being adjusted to the desired oxy-acetylene or oxyfuel gas ratio by valves V at the beginning of the heating operation.

The pressure of fuel gas or acetylene flowing to the blowpipe-from an inlet hose 28 through an inlet chamber 28 in regulator R, to an outlet chamber II and through a hose II to blowpipe B-ls regulated in accordance with the pressure 01' oxygen in chamber 22. The reason the gas from the hose 28 is regulated in accordance with oxygen pressure is because in practice the fuel gas usually passes through a pressure regulator so that the fuel gas pressure is fairly constant in the supply line 28. For this purpose, a valve 32, which at all times automatically controls the flow of acetylene from chamber 2! to chamber II, is attached to and actuated by a double diaphragm arrangement, comprising an upper diaphragm l3 and a lower diaphragm II, the two diaphragms being connected together to move in unison, The force produced by the pressure oxygen in chamber 22, exerted against diaphragm 38 which forms the lower wall of chamber 22, acts to open valve 32, while the force produced by the pressure of acetylene in chamber ll, exerted against diaphragm II which forms the upper wall of chamber ll. acts to close valve 32. Thus, the pressure and flow of acetylene is determined by the pressure and flow oi ongen, which in turn determines the pressure and flow of oxidizing gas and the proportion of oxygen in the oxidizing gas mixture.

The double diaphragm arrangement is a safety feature which assists in preventing the formation of a combustible or explosive mixture in either the oxygen or acetylene supp y line, due to leakage from the other line. Vent 35 in casing 36 of the regulator provides communication between the atmosphere and the space between the diaphragms, so that ii either diaphragm is ruptured, the fuel gas or oxygen, as the case may be, will escape to the atmosphere. It will be understood that the eflective areas of the two diaphragms may be difl'erent, so that a change in the oxygen pressure in chamber 22 will produce a fractional proportional change in the acetylene pressure in chamber 80.

The acetylene or fuel gas and oxidizing gas mixture are mixed in the blowpipe B to form a combustible mixture, which is discharged from tip T to produce a heating flame. Changes in temperature and heating effect of this flame are readily effected. Assuming that screw I! is set for the lowest flame temperature obtainable with the setting of valves V, and it is desired to increase the heating effect of the flame, the screw II is merely turned down so that spring I! will exert a greater force against diaphragm l8. This causes valve II to open to a greater extent, causes the pressure of oxygen in chamber II to increase, and also causes a greater amount of oxygen to flow to regulator R and the pressure in chamber 22 to increase. This results in a greater flow of oxygen through orifice 2!, a displacement of air in chamber 2|, an increase in the proportion of oxygen in the oxidizing gas mixture, and an increase in the pressure of the oxidizing gas mixture. At the same time, the increase in the pressure of oxygen in chamber 22 causes an increase in the pressure and flow oi acetylene, with a resultant increase in the total amount of omen and acetylene in the combustible mixture. The resultant increased rate oi flame propagation is compensated by the increased velocity 0 the jet, due to the increased pressure of oxidizing gas and fuel gas. However, the ratio of oxygen to acetylene in the combustible mixture remains the same, and neither the character '01 the flame nor the length of the inner cone of the flame will be changed. Thus, the heating eflect and temperature of the flame may be varied over a wide range while maintaining the eflectiveness or the heat- 6 ing operation. It is estimated that, by this invention, the temperature of a substantially neutral oxyacetylene heating flame can be varied over a range extending from approximately 4000 F. to 5500 1''.

Similarly, when the heating eii'ect oi the time isregulatedbyvaryingtheconstimentsoiatuel gas mixture, acetylene may be supplied through hose ll, hydrogen or the like through hose II, and men through hose 2|. Turning down screw ll will cause the pressure of acetylene to increase, the relative proportion of acetylene in the fuel gas mixture to increase, and the pressure and flow of oxygen to increase. Thus, the heating eflect oi the flame may be increased without changing substantially the character of the flame or length of the inner cone.

The combined regulator and proportioner RP illustrated in Fig. 2. comprises a casing II to which an ongen inlet pipe II is connected; an upper cap II, to which an air inlet pipe I! is connected; and a double lower cap, consisting oi an intermediate section 48 and a lower section II, to which an acetylene inlet pipe II is connected. Oxygen 'i;;' from pipe ll through an inlet passage 40 to a valve chamber 41, formed in casing IS. The flow of oxygen from valve chamber 41 to an oxygen chamber 48 is controlled by a valve 49, which seats against the tapered underside oi an oriflce id in a valve bushing II. The stem of valve Ill extends through oriflce 50, while bushing ll threadedly engages casing 30, to close the upper end oi valve chamber 41 and hold a sealing gasket it against a suitable shoulder in the casing. The upper end or the stem of valve is is attached to a diaphragm 53, the periphery of which is clamped securely between casing II and cap Ii for sealing purposes. The central portion of diaphragm 93 is clamped between a pair of bearing plates 54, attached to the stem of valve 49 and provided with upturned edges to prevent rupture oi the diaphragm upon flexing. Diaphragm ill may comprise a rubber disc, as shown. or may comprise several layers of rubber or other suitable material, such as metal, synthetic rubber substitute. or canvas impregnated with rubber or the equivalent. Diaphragm It forms a partition between oxygen chamber 48 and an air-oxygen mixing chamber 56, formed principally in cap ll, oxygen passing from chamber It to mixing chamber ii through an oriflce S8 in the diaphragm. Air passes into chamber II from inlet 42, the mixture of air and omen being led from chamber 55 by an outlet pipe 51, to a blowpipe or similar apparatus.

The pressure of oxygen in chamber 48 and the consequent flow of oxygen through oriflce which in turn determines the proportion of oxygen to air in the oxidizing gas mixture, as explained in connection with orifice 25 of the apparatus of Fig. l-is determined by the force exerted by a relatively heavy coil spring I! disposed in chamber 55 and bearing at its lower end against the upper diaphr zm plate M. The force exerted by spring 58 may be adjusted by a screw 58, extending through cap II and engaging a bearing disc 6| interposed between screw 5! and spring Bl. Screw 59 is provided with a packing gland 6| to prevent leakage from chamber I. The force exerted by spring 58 is opposed. in part, by a coil spring I! which bears at its lower end against a suitable recess in bushing i0 and :51: its upper end against lower diaphragm plate The pressure and flow of acetylene, as before,

are proportional to the pressure and flow 01' oxygen. The flow of acetylene from inlet II to an outlet pipe Gl-through an inlet passage II and a valve chamber 86 to a diaphragm chamber 81 and an outlet passage 68-is controlled by a valve 89, in turn connected to a double diaphragm assembly including a diaphragm 10. Oxygen pressure is exerted against diaphragm 10 in a chamber ll, formed between housing 38 and the diaph'ragm, the periphery of which is clamped between housing and intermediate cap II, for sealing purposes. Oxygen is led from chamber 48 to chamber II by a connecting passage 12, so that variations of oxygen pressure in chamber II will be communicated to chamber H, and the pressure exerted against diaphragm ID will cause the flow oi acetylene to be correspondingly regulated. Acetylene valve 89 is similar to oxygen valve 49, seating against the tapered lower portion of an orifice I3 in a bushing 14 which threadedly engages lower cap 44 and clamps a gasket 15 against a shoulder formed in the cap, for sealing purposes.

Utilized principally for safety purposes, the double diaphragm arrangement includes a lower acetylene diaphragm 16, while a chamber 11, formed in intermediate cap 43 between upper oxygen diaphragm Ill and lower acetylene diaphragm 16, is vented to the atmosphere by holes 19 extending through cap I. Should rupture of either diaphragm occur, the oxygen or acetylene, as the case may be, will be vented to the atmosphere through holes 19, instead of passing into the other line. As before, the possibility of a combustible or explosive mixture being formed in either supply line is avoided.

The upper end of chamber 81 is closed by diaphragm 16, which is clamped between intermediate cap I! and lower cap 44. The central portions of diaphragms l and 18, are clamped between pairs of discs 80 and 8|, respectively. The upper end of the stem of valve 89 is attached to diaphragm l6 and dies Bl, while diaphragms l0 and I6 are secured together, to move in'unlson, by a stud 82. Also, the lower end of a spring 83 extends into a recess in bushing 14 while the upper end of the spring engages lower disc III at diaphragm 15.

Spring 83 compensates in part for the higher pressure at which oxygen normally is passed through the device, and for the diflerence in area between diaphragms and 16, which difference in area is such that a change in oxygen pressure will produce a proportional but unequal change in the acetylene pressure. If desired, the area of diaphragm 16 may be made equal to or greater than the area of diaphragm ll. Also, a spring may be provided to bear against the lower end of valve 69, so that any desired relation between the oxygen pressure and the acetylene pressure may be obtained. The relative areas of diaphragm Ill and I6 and the strength of spring 83 may be varied as desired, particularly for is the same. Also, when acetylene, hydrogen or the like, and oxygen are supplied through pipes 40, I2, and II, respectively, the operation of the apparatus again corresponds to the operation of the apparatus of Fig. 1 when corresponding gases are utilized.

In the constant speed strip' welding apparatus illustrated in Fig. 3, the combined proportioner and regulator RP is similar in construction to the combined proportioner and regulator RP of Fig. 2. Thus, oxygen, air, and acetylene are supplied thereto by

hoses

85, 86, an 81, respectively. Acetylene flows to the blowpipe M through a, hose 88, while the oxidizing gas mixture of oxygen and air flows to blowpipe M through a hose B9. During the welding operation, the head H and control unit C are moved at a substantially constant speed along the seam to be welded, or the work W is moved between the two at a substantially constant speed. The spacing of the head above the work and the control unit below the work are maintained substantially constant. The operation of the combined proportioner and regulator RP is controlled by solenoid S, the core of which is operatlvely connected with a spring, similar to spring 58 of the regulator and proportioner RP of Fig. 2. The amount of current passing through the solenoid S determines the pull exerted upon the core, which in turn determines the pressure of the spring and thereby causes the proportions of oxygen and air in the oxidizing gas mixture and the pressure of acetylene to vary as desired. As solenoid S is controlled by a photo-cell control unit C, responsive to thermal conditions of the welding operation, the heating eflect oi the flame will be varied as necessary, to maintain substantially the same thermal condition at all points of the welding operation and thereby produce a uniform weld.

Photo-cell unit C comprises a photo-electric cell 80, disposed at the lower end of a tube 9| which protects the cell and also excludes thermal radiations other than those emanating rrom the underside of the welding seam. Photo-cell is of a type responsive to variations in the radiations which reflect the thermal condition of the welding seam, and causes proportional variations in the electrical impulses passing through the photo-cell and to an amplifier 92 through wires 93. In the amplifier 92, the impulse variations are amplified to provide more sensitive control, the amplifier being connected with a reactor 94 by wires 95. In the reactor, the variations in impulse are imposed upon electricity passing to solenoid S through wires 96, the reactor being supplied by wires 91 from an A. C. supply line 98. Thus, in response to a decrease or increase in the radiations reflecting the thermal condition of the welding operation, the control unit 0 will cause the force exerted by solenoid S on the control spring of the combined regulator and proportioner RP to increase or decrease, so that the heating efl'ect of the flames discharged from head H will increase or decrease, as the case may be, to maintain substantially uniform welding conditions along the seam.

At the beginning of the welding operation, the combustible mixture preferably consists of oxygen and acetylene, valves V being adjusted to provide heating flames having the highest temperature and greatest heating effect. After the initial portion of the seam has been heated to the desired temperature, and the welding operation thus started, the relative motion between the head H and control unit C and the workpiece W is begun, so that the heating flames will be applied to successive portions of the seam. As the welding operation progresses, variations in the temperature and thermal condition of the weld at the point of application of the flames will be compensated for and corrected by variations in the heating eflect of the flames.

Similarly, when a mixture of fuel gases rather than oxidizing gases is utilized, the combustible mixture at the beginning of the operation preferably consists of acetylene and oxygen. After the welding operation is started, and welding along the seam progresses, reductions in the heat necessary to maintain the desired thermal condition will be effected by the introduction of hydrogen into the fuel gas mixture and a decrease in the pressure and flow of acetylene and in the pressure and flow of oxygen, as controlled by solenoid S and the combined regulator and proportioner RP, in turn controlled by photo-cell unit C.

From the foregoing, it will be apparent that this invention provides an efficacious and highly desirable method of and apparatus for controlling or varying characteristics of a heating flame. The method of this invention has advantages not possessed by other methods of changing the heating effect by varying the constituents of the combustible mixture. In the case of an oxy-acetylene flame, for instance, if the amount of oxygen in the combustible mixture should be decreased without varying other constituents, a neutral flame would become carburizing or an oxidizing flame would become neutral. Similarly, if the amount of acetylene is reduced sufllciently to lower the temperature and heating eifect of the flame, then a neutral flame would become oxidizing or a carburizing flame would become neutral. Furthermore, if the supply of both oxygen and acetylene were reduced simultaneously without any other change in the combustible mixture, not only would the length of the inner cone be changed, but also the danger of flashbacks would be increased due to the jet velocity becoming less than the velocity of flame propagation. Flashbacks and resultant backfires sometimes result in expensive work being damaged or ruined.

Furthermore, while oxy-acetylene heating flames, and acetylene and hydrogen fuel gases. have been given as specific examples in explaining this invention, it will be understood that these are only representative of many other types of heating flames and fuel gases to which this invention is applicable. Thus, the method of this invention includes regulatin predetermined characteristics of a heating flame while maintaining other predetermined characteristics substantially constant, the flame being produced by a combustible mixture of fuel and oxidizing gases and at least a portion of the oxidizing gas being substantially pure oxygen. Broadly, the method comprises varying the pressure and flow of at least one of the constituent gases in accordance with the pressure and flow of another of the constituent gases to increase or decrease the heating effect of the flame, the regulation of the pressure and flow of the constituent gases bein such that an increase in the pressure and flow of substantially pure oxygen occurs substantially simultaneously with an increase in the pressure and flow of a fuel gas of which a greater amount tends to increase the heating effect of the flame.

It will also be understood that the method and apparatus of this invention are useful in heating operations other than strip welding, and heating operations combined with other operations. For

instance, the principles of this invention are applicable to the normalizing or softening of a relatively hard surface layer along the kerf produced by an oxygen cutting let; the principles of this invention are applicable to flame hardening. i. e., local heating followed by a suitable cooling or quenching step to harden the heated surface; the principles of this invention are applicable to preheating for welding, or both preheating and. heating during actual fusion; the principles of this invention are applicable to preheating for oxygen cutting; and the principles of this invention are applicable to many other operations involving heating, which will readily suggest themselves to those skilled in the art.

An advantage of the present invention resides in the simplicity of construction and ease of operation in being able to vary the heating eflect of the blowpipe flame as desired without the mechanisms heretofore required for increasing the separation between the work and the blowpipe, or changing the rate of relative travel between the work and blowpipe. This has been possible because applicant has retained the length of the inner cone of the blowpipe flame substantially constant.

What is claimed is: g

1. Apparatus for regulating the heating effect of a flame produced by the combustion of fuel gas, comprising means for mixing oxidizing gas having a. relatively high oxygen content and a stream of oxidizing gas having a relatively low oxygen content to form an initial mixture; means for varying the proportion of oxidizing sas having a relatively high oxygen content and varying the pressure of said oxidizing gas of high oxygen content; means in addition to the other means for throttling the flow of said initial mixture; means for simultaneously varying the pressure of fuel gas; means for throttling the flow of said fuel gas; and means for mixing said initial mixture gases with such fuel gas to form a combustible mixture, whereby the proportion of oxidizing gas having a relatively high oxygen content may be increased, the pressure of oxidizing gases may be increased, and the pressure of fuel gas may be increased simultaneously, to produce an increase in the heating effect of said flame.

2. Apparatus for regulating a heating flame produced by the combustion of a fuel gas, comprising means for mixing fuel gas and an oxidizing gas mixture to form a combustible mixture; means for controlling the flow of fuel gas supplied to said mixing means in accordance with the pressure of oxidizing gas; walls forming a chamber for mixing oxidizing gas having a relatively high oxygen content and a stream of oxidizing gas having a relatively low oxygen content: one of the chamber walls having an orifice through which said oxidizing gas having a high oxygen content passes into said chamber; and means for passing oxidizing gas mixture from said chamber to said means for mixing fuel gas and oxidizing gas mixture at reduced pressure.

3. Flame heating apparatus comprising a blowpipe for mixing fuel gas and oxidizing gas to provide a combustible mixture which will produce a high temperature heating flame; oxidizing gas richness regulating means having a chamber provided with walls within which air and oxygen are adapted to be mixed; a valve in said regulating means for controlling the flow of fuel gas from a fuel gas inlet to a fuel gas outlet; a wall of said chamber having an orifice through which oxygen is conducted to said mixing chamber; said regulating means including diaphragm means for controlling said fuel gas valve and subject on one 'side to the outlet pressure of fuel gas and on the other side to the pressure of oxygen on the inlet side of said orifice; and conduit means connecting said blow-pipe with said fuel gas outlet and with said mixing chamber; said regulating means including means for controlling the pressure of oxygen supplied to said oriiice.

4. Apparatus as deflned in claim 3, in which said oxygen pressure control means comprises a valve and a diaphragm controlling said valve, movement of said diaphragm being controlled by oxygen pressure exerted against one side of said diaphragm.

5. Apparatus as deflned in claim 3, wherein said diaphragm means comprises a pair of spaced diaphragms connected together to move in unison. one 01' said diaphragms being subiect on one side to fuel gas pressure and the other of said diaphragms being of larger eflective area and subject on its opposite side to ongen pressure with the space between said diaphragms being vented to the atmosphere.

6. In a flame heating apparatus, including a blowpipe for mixing fuel gas and oxidizing gas to provide a combustible mixture. a combined oxidizing gas pressure regulator and oxygen richness proportioner having a chamber in which air and oxygen are mixed; said regulator and proportioner having a fuel gas inlet passage. a fuel gas outlet passage. an oxygen inlet passage to said mixing chamber; a valve for controlling the flow of fuel gas from the fuel gas inlet passage to the fuel gas outlet passage; a valve controlling the flow of oxygen from the oxygen inlet passage to the mixing chamber; said mixing chamber having a, wall in which is an orifice leading from said oxygen inlet passage to said mixing chamber: a connection between said mixing chamber and said blowpipe; an air supply passage leading to said mixing chamber: and means for controlling said fuel gas valve and responsive to variations in pressure in said oxygen inlet 7. In flame heating apparatus as defined in claim 6, means for controlling said oxygen valve including a diaphragm subiect on one side to the pressure in said oxygen inlet passage and on the other side to the pressure in said mixing chamher.

8. In flame heating apparatus as defined in claim 8, wherein means for controlling said oxygen valve comprises a, diaphragm 'and an adjustable spring acting against one side of said dinphragm, said diaphragm forming a wall between said oxygen inlet passage and said air supply passage, and said orifice leading from said oxygen inlet passage to said mixing chamber through said diaphragm.

9. A method of regulating characteristics of a flame produced principally by the combustion of acetylene, which comprises mixing acetylene and hydrogen to form a fuel gas mixture; supplying ongen to support the combustion of such mixture; and increasing the proportion of acetylene in said fuel gas mixture and simultaneously increasing the pressure and flow of oxygen, to produce an increase in the heating eifect of said flame.

10. A method of regulating the heating eil'ect of a flame produced by the combustion of a mixture of acetylene, hydrogen, and oxygen, such method comprising varying the pressure and rate of flow effected by said pressure 0! a 110W stream of acetylene; regulating the pressure and flow of a stream of oxygen directly in accordance with the varied pressure oi acetylene; simultaneously proportioning the flow of a stream of hydrogen inversely to and with the flow of acetylene; and mixing the acetylene with the gierogen and with the owgen to form said mix- 11. A method of producing a flame having an adjustable heating eifect which comprises providing a supply of diluent gas at desired supply pressure; providing supplies of combustible mixture forming gases comprising acetylene and oxygen -at least one of which is under higher pressure; reducing the pressure of said one of said combustible mixture forming gases and maintaining such initially reduced pressure above said diluent supply pressure; further reducing the pressure of said one combustible mixture forming gas to a value equal to said diluent supply pressure while admixing said one gas with said diluent which is inert with respect to the said one gas to form an initial mixture having a desired composition; regulating the pressure of the other oi said combustible mixture forming gases in accordance with said initially reduced pressure of said one combustion mixture forming gas; and admixing said other combustible mixture forming gas under the head of its regulated pressure with said initial mixture to form. when ignited, said flame.

12. A. method of varying the heating eifect of a flame which comprises providing a supply oi diluent gas at desired supply pressure; providing supplies of combustible mixture forming gases at least one of which is under higher pressure: reducing the pressure of said one of said combustible mixture forming gases and maintaining such initially reduced pressure above said diluent supply pressure; further reducing the pressure of said one combustible mixture forming gas to a value equal to said diluent supply pressure while admixing said one gas with said diluent which is inert with respect to the said one gas to form an initial mixture having desired adiustable proportions; regulating the pressure of the other of said combustible mixture forming gases in accordance with said initially reduced pressure of said one gas; and flnally admixing said other combustible mixture forming gas under the head of its regulated pressure with said initial mixture to form, when ignited, said flame.

13. A method of varying the heating effect of a flame which comprises supplying air at a desired pressure; supplying oxygen at a higher pressure; reducing the pressure of said oxygen and maintaining such initially reduced pressure above the air supply pressure: further reducing the pressure of said oxygen to a value equal to said air supply pressure while admixing said oxygen with said air to form a mixtur of air and oxygen having desired proportions; regulating the pressure of a supply of fuel gas in accordance with said initially reduced pressure of oxygen alone; admixing proportioned amounts of said fuel gas under the head of said regulated pressure with proportioned amounts of said mixture of air and oxygen to form, when ignited, said flame; and adjusting the degree by which said initially reduced pressure or owgen exceeds the air supply pressure to vary the heating eifect or said flame without substantially changing the proportionality between oxygen and fuel in said flame.

A met f va yin the heating eflect of a flame which comprises providing a supply of diluent gas at a desired supply pressure; providing a supply of acetylene at a higher pressure; automatically reducing the pressure of said acetylene and maintaining such initially reduced pressure above the diluent supply pressure; further reducing the pressure of said acetylene to a value equal to said diluent supply pressure while admixing said acetylene and diluent to form an initial mixture of acetylene and diluent of desired proportions; regulating the pressure oi a supply of oxygen in accordance with said initially reduced pressure of acetylene; mixing proportioned amounts of said oxygen under the head of said regulated pressure with proportioned amounts of said initial mixture to form, when ignited, said flame; and adjusting the degree by which said initially reduced pressure of acetylene exceeds said diluent pressure to vary the heating effect of said flame without substantially changing the proportionality between oxygen and acetylene in the flame.

15. The method of adjusting the heating effect of a flame supplied by a mixture of fuel gas and oxidizing gas which comprises flowing a diluent gas into one of the components of said mixture which is inert with respect to the diluent, controlling the flow of the mixture component to be diluted in response to a difference between the diluent pressure and the pressurepf said one mixture component before being diluted and when the pressure of said one compo-l nent is above a predetermined value, controlling the flow of the other mixture component in response to the pressure difference between it and the pressure of the mixture component to be diluted, and mixing said fuel gas with said 0111- dizing gas.

16. The method of adjusting the heating effect of a flame supplied by a mixture of fuel gas and oxidizing gas which comprises flowing a diluent gas into one of the components of said mixture which is inert with respect to the diluent, controlling the flow of the mixture component to be diluted in response to the difference between the diluent pressure and the pressure of said one mixture component before being diluted and when the pressure of said one component is above a predetermined value, and mixing said fuel gas with said oxidizing gas.

17. The method of changing the velocity and heating effect of a gas flame supplied by a fuel gas, a gas rich in oxygen, and ages having a relatively low oxygen content which comprises initially adjusting the flow of the gas rich in oxygen, further controlling the flow of said gas rich in oxygen in response to the difference in pressure between it alone and the gas having a relatively low oxygen content and adjusting the flow of fuel gas in response to the pressure difference between it and said gas rich in oxygen to retain the length of the inner cone of said flame constant and the ratio of oxygen to fuel constant for one kind of fuel.

18. An apparatus for changing the velocity and heat of a gas flame nozzle while maintaining the ratio of available oxygen to fuel gas substantially constant which comprises, a line for supplying a gas having a low oxygen content, a line for supplying a gas rich in oxygen, a line for supplying fuel gas, a valve in the line rich in oxygen, means for automatically adjusting said valve in response to pressure difference between the line with relatively low oxygen content and the portion of the line rich in oxygen between the valve and the nozzle when said line rich in oxygen is above a given pressure, a valve in the fuel gas line, and means for automatically controlling said last mentioned valve in response to the pressure diiference between the fuel gas line and said portion of the line rich in oxygen between the nozzle and first mentioned valve.

19. Apparatus for controlling the relative supply of a gas rich in oxygen content to a gas having a lower oxygen content, comprising a fuel supply line, a supply line for each oxidizing gas, a valve in the line rich in oxygen, a device responsive to pressure difierence between said line hav-- ing a low oxygen content and the portion of the line rich in oxygen adjacent but beyond the said valve when above a predetermined pressure for controlling the supply of gas rich in oxygen, and

means beyond said valve for mixing the gas low in oxygen with the gas rich in oxygen prior to contact with the fuel and its supply line.

20. Apparatus for controlling the heat of a flame supplied by fuel and oxidizing gases and comprising a pair of passages for combustible mixture forming gases, a third passage for a diluent gas, a valve in one passage of said pair, a device for controlling said valve in response to the pressure diil'erence between said one passage beyond said valve when the pressure is above a given amount and said third passage; means for mixing the gas from said one passage and said diluent to form a gaseous mixture which is nonexplosive, a valve in the other passage of said pair, a device for controlling said other valve in response to the difference between the pressure in said other passage after its valve and the pressure in said one passage after its valve and before said mixing means, and blowpipe means for mixing the gases from said other passage and the mixture from said mixing means.

21. The method of operating a blowpipe to change the heating effect of the flame without substantially changing the length of the inner cone of the flame which comprises supplyin two components of a fuel gas mixture to said blowpipe, diluting one of said components with a compatible diluent to form a non-explosive preliminary mixture, varying the flow of said one component, further adjusting the flow of the varied component in response to the pressure of the diluent gas flowing to the formation of said preliminary mixture, and adjusting the dew of the other component in response to pressure of the adjusted first mentioned component to maintain the ratio of oxygen to fuel gas substantially constant.

' 22. The method of operating a blowpipe to change the heating effect or the flame without substantially changing the length of the inner cone of the flame which comprises supplying two components of a fuel gas mixture to said blowpipe, diluting one of said components with a compatible diluent to form a non-explosive preliminary mixture, varying the flow of said one component, further adjusting the flow of the varied component in response to the pressure of the diluent gas flowing to the formation of said preliminary mixture, adjusting the flow of the other component in response to pressure of the adjusted first mentioned component to maintain the ratio of oxygen to fuel gas substantially constant, and reducing the pressure of the first mentioned component subsequent to its control of said other or second mentioned component, said diluting including mixing said diluent and first mentioned component after the pressure or the first component has been reduced.

23. The method of operating a blowpipe to change the heating efi'ect or the fiame without substantially changing the length or the inner cone oi the flame, which. comprises supplying two unmixed components 01' a fuel gas mixture to said hlowpipe, flowing a diluent into one or said components which is non-explosive with the diluent, controlling the now 01' said diluent in response to a reduced pressure or said one of said components, controlling the flowing 01' said one of the components with which the diliuent is mixed, and controlling the now of the other component in response to the pressure 0! the flowing firstmentioned component with which the diluent is mixed.

24. Apparatus for changing the heating eflect or the flame from a blowpipe which comprises means for supplying two components of a fuel ga mixture to a blowpipe, means for supplying a diluent gas for one of said components, a manually adjusted valve for said one of said components which valve is also automatically adjustable in response to pressure of said diluent gas being supplied, a valve for controlling the fiow oi the other component in response to pressure of the first mentioned component being supplied, a pressure reducing orifice through which the first mentioned component passes after it so has controlled the supply of the second component, a mixing chamber with which said diluent 16 gas supply means is connected and into which said first component also passes alter being reduced in pressure by its passage through said orifice. and means for conducting the controlled mixture or diluent gas and first component as well as the controlled second component to said blowpipe.

ElIBE W. DECK.

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

UNITED STATES PATENTS Number Name Date 985,896 Hopkins Mar. 7, 1911 1,213,159 Dalen Jan. 23, 1917 1,325,116 Bebille Dec. 16, 1919 1,539,630 Beaird May 26, 1925 2,089,014 Bucknam et al. Aug. 3, 1937 2,089,015 Bucknam et ai Aug. 3, 1937 2,099,029 Jones Aug. 3, 1937 1,719,898 McNeil July 14, 1932 2,193,240 Schmidt Mar. 12, 1940 2,280,029 Crowe Apr. 14, 1942 2,196,902 Jones Apr. 9, 1940 2,364,645 Mott Dec. 12, 1944 FOREIGN PATENTS Number Country Date 554,664 German July 14, 1932 825,890

British Feb. 20, 1930 Certificate of Correction Patent No. 2,416,161.

February 18, 1947.

EIBE W. DECK It is hereby certified that errors appear in the rinted specification of the above numbered patent requiring correction as follows: discs; column 10, line 64, claim 2, strike out the words olumn 7, line 43, for dies read at reduced pressure and insert the same after the word chamber and before the semi-colon, line 61, same claim; and that the said Letters Patent should be read with these corrections therein that the same may co nform to the record of the case in the Patent Office.

Signed and sealed this 13th day of May, A. D. 1947.

LESLIE FRAZER,

First Assistant Commissioner of Patents.