Abstract:
A method of starting an auto-ignition gas torch includes increasing a flow of oxygen above zero and increasing a flow of fuel gas to a level lower than the flow of oxygen for improved start reliability. In one form, the flow of oxygen is from about two times to about six times higher than the flow of fuel gas.

Description:
FIELD 
       [0001]    The present disclosure relates generally to oxy-fuel torches and more particularly to oxy-fuel torches having built-in electrical ignition systems, or auto-ignition systems. 
       BACKGROUND 
       [0002]    The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. 
         [0003]    Oxy-fuel torches, or gas torches, generally employ oxygen and a fuel gas, such as acetylene or propane, by way of example, to cut or heat a workpiece. More specifically, preheat oxygen and the fuel gas are mixed and ignited to provide heat to the workpiece, and then additional oxygen, commonly referred to as cutting oxygen, is added to react with the heated workpiece. This reaction of the cutting oxygen with the heated workpiece initiates sufficient heat and momentum of the gases to initiate a cutting process. 
         [0004]    A typical auto-ignition gas cutting torch employs a piezoelectric igniter and spark source near the handle of the torch. To start the gas torch, the operator activates a trigger connected to the piezoelectric igniter to ignite a mixture of the preheat oxygen and the fuel gas. Typically, the mixture of the preheat oxygen and the fuel gas is a fuel-rich mixture. The level of the fuel gas is set to be significantly higher than the level of the preheat oxygen so that the mixture creates a highly carbonizing environment to facilitate ignition of the mixture. Once the mixture of the fuel gas and the preheat gas is ignited, the operator releases the trigger and further adjusts the flow of fuel gas and the cutting oxygen gas to optimize the flame and initiate the cutting process. 
       SUMMARY 
       [0005]    In one form of the present disclosure, a method of starting an auto-ignition gas torch includes increasing a flow of oxygen above zero, and increasing a flow of fuel gas to a level lower than the flow of oxygen. The flow of oxygen is from about two times to about six times higher than the flow of fuel gas. 
         [0006]    In another form, a method of starting an auto-ignition gas torch includes increasing a flow rate of oxygen to level that is an order of magnitude higher than a flow rate of the fuel gas. 
         [0007]    In still another form, a method of starting an auto-ignition gas torch includes providing a flow rate of oxygen that is higher than a flow rate of fuel gas. When the fuel gas is acetylene, the flow of oxygen is from about 10 SCFH to about 22 SCFH and the flow of fuel gas is from about 1.5 SCFH to about 4 SCFH. 
         [0008]    Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       DRAWINGS 
         [0009]    In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which: 
           [0010]      FIG. 1  is a perspective view of a gas cutting torch constructed in accordance with the principles of the present disclosure; 
           [0011]      FIG. 2  is a side hidden line view illustrating various conduit arrays constructed in accordance with the principles of the present disclosure; 
           [0012]      FIG. 3  is a partial perspective view illustrating an ignition trigger and gas control devices construed in accordance with the principles of the present disclosure; 
           [0013]      FIG. 4  is a cross-sectional view through a handle section, the ignition trigger, and a gas control device in accordance with the principles of the present disclosure; 
           [0014]      FIG. 5  is a cross-sectional view of a cutting tip in accordance with the principles of the present disclosure; 
           [0015]      FIG. 6  is a flow diagram of a method of starting an auto-ignition gas torch in accordance with the principles of the present disclosure; and 
           [0016]      FIG. 7  is an exemplary chart showing a relationship among the preheat oxygen flow, the fuel gas, and the start reliability achieved by the method of starting the auto-ignition gas torch, based on the test data of Table 1; 
           [0017]      FIG. 8  another exemplary chart showing a relationship among the preheat oxygen flow, the fuel gas, and the start reliability achieved by the method of starting the auto-ignition gas torch based on the test data of Table 2; 
           [0018]      FIG. 9  is another exemplary chart showing a relationship among the preheat oxygen flow, the fuel gas, and the start reliability achieved by the auto-ignition gas torch based on the test data of Table 3; 
           [0019]      FIG. 10  is a further exemplary chart showing a relationship among the preheat oxygen flow, the fuel gas, and the start reliability achieved by the auto-ignition gas torch based on the test data of Table 4; and 
           [0020]      FIG. 11  is another exemplary chart showing a relationship among the preheat oxygen flow, the fuel gas flow, and the start reliability achieved by the method of starting the auto-ignition gas torch based on the test data of Table 5. 
       
    
    
       [0021]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 
       DETAILED DESCRIPTION 
       [0022]    The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. 
         [0023]    Referring to  FIGS. 1-2 , a gas cutting torch in accordance with the teachings of the present disclosure is illustrated and generally indicated by reference numeral  20 . Although the term “cutting” is used throughout, it should be understood that the present disclosure applies generally to gas torches, such as those that heat and/or cut. Accordingly, the term “cutting” should not be construed to limit the scope of the present disclosure. The gas cutting torch  20  is an auto-ignition gas torch and comprises a handle portion  22 , a trigger system  30  disposed along the handle portion  22 , a gas flow control unit  36 , a tube section  38 , a head portion  44 , and a cutting tip  46 . 
         [0024]    The handle portion  22  defines a proximal end portion  24  and a distal end portion  26 . The gas flow control unit  36  is disposed at the proximal end portion  24  of the handle  22 . The trigger system  30  is disposed along the handle portion  22  and comprises an ignition trigger  32  and a cutting oxygen trigger  34 . The tube section  38  is disposed at the distal end portion  26  of the handle portion  22 . The tube section  38  similarly defines a proximal end portion  40  and a distal end portion  42 . The head portion  44  is disposed proximate the distal end portion  42  of the tube section  38 . The cutting tip  46  is secured to the head portion  44  via a tip seat  48 . The gas flow control unit  36  includes a preheat oxygen metering device  80  and a preheat fuel gas metering device  82  for metering the preheat oxygen and the fuel gas, respectively. 
         [0025]    Referring to  FIG. 2 , the gas cutting torch  20  includes a preheat oxygen conduit array  70 , a fuel gas conduit array  72 , and a cutting oxygen conduit array  74  to direct the flow of preheat oxygen, fuel gas, and cutting oxygen, respectively. The preheat oxygen conduit array  70 , the fuel gas conduit array  72 , and the cutting oxygen conduit array  74  extend from the gas flow control unit  36 , through various components in the gas cutting torch  20 , through the tip seat  48 , to the cutting tip  46 . The gas flow control unit  36  is connected to an external oxygen source (not shown) and an external fuel gas source (not shown). The gas flow control unit  36  controls the flow rate of the preheat oxygen, the fuel gas, and the cutting oxygen from the external oxygen source and the external fuel gas source to the preheat oxygen conduit array  70 , the fuel gas conduit array  72 , and the cutting oxygen conduit array  74 . A first gas control device  146  (shown in  FIG. 3 ), and a second gas control device  148  (shown in  FIG. 3 ) are disposed within the handle portion  22  and connected to the ignition trigger  32  to initiate flow of the preheat oxygen and the flow of fuel gas, respectively. 
         [0026]    Referring to  FIGS. 3 and 4 , an ignition system  60  is disposed within the gas cutting torch  20 , and comprises a piezoelectric igniter  142  in communication with the ignition trigger  32  and an ignition wire  64  that extends from the piezoelectric igniter  142  to the cutting tip  46 . The ignition trigger  32  comprises a trigger body  120 , a latch  126 , and a biasing device  138 . The trigger body  120  includes a forward portion  122  defining a cam surface  124 . The latch  126  is disposed within a groove  128  in the trigger body  120  and slidably engaged within the groove  128  along the direction of arrow A. The latch  126  includes an upper extension  130  defining a ramped surface  134 . The ramped surface  134  cooperates with a corresponding ramped surface  136  of the cavity  132  in the “on” position. In the “off” position, the upper extension  130  abuts an inner surface  140  of the handle body  23  such that the trigger body  120  cannot be moved in the direction of arrow B and thus engage the ignition system  60 . 
         [0027]    The biasing device  138  is a coil spring which biases the ignition trigger  32  in the “off” position. The biasing device  138  abuts the inner surface  140  of the handle body  23  and the trigger body  120  and is biased to move the trigger body  120  downward, or to the “off” position. Therefore, it an operator releases the ignition trigger  32 , the gas cutting torch  20  is turned off, or enters an “auto shut-off” mode, thus improving the safety of operation. 
         [0028]    In operation, an operator slides the latch  126  back and pulls up on the trigger body  120 . The trigger body  120  pivots about the hinge portion  150 , and the internal receptacles  149  engage the gas control devices  146  and  148 , and the flow of preheat oxygen and fuel gas are initiated. The forward portion  122  of the trigger body  120  engages the piezoelectric igniter  142  and an ignition source is generated, which travels down the length of the ignition wire  64  to the cutting tip  46  to start the gas cutting torch  20 . The piezoelectric igniter  142  is further engaged within the ignition trigger  32 , thus permitting operation of the cutting oxygen trigger  34 , and the flow of cutting oxygen. 
         [0029]    The ignition trigger  32  initiates the flow of preheat oxygen and fuel gas from the gas flow control unit  36  to the cutting tip  46 , while also initiating ignition with a single motion by the operator. Therefore, the gas cutting torch  20  can advantageously be started with the use of only one-hand, or in other words, is configured for single-hand operation once the preheat oxygen and preheat fuel are properly set. When an operator releases the latch  126 , the biasing device  138  forces the trigger body  120  back down to its neutral or “off” position. Therefore, the gas cutting torch  20  automatically shuts off when the ignition trigger  32  is released. 
         [0030]    Referring to  FIG. 5 , the tip  46  includes an outer shell  302 , a cap  304 , an inner tube  306 , and an insert  308 . The cutting tip  46  defines a fuel gas passageway  312 , a cutting oxygen gas passageway  314 , and a preheat oxygen gas passageway  316 . The fuel gas passageway  312  is a part of the fuel gas conduit array  72 . The cutting oxygen gas passageway  314  is a part of the cutting oxygen conduit array  74 . The preheat oxygen gas passageway  316  is a part of the preheat oxygen conduit array  70 . 
         [0031]    The ignition wire  64  from the ignition system  60  extends through the central cutting oxygen gas passageway  314  and is in electrical contact with the inner tube  306 , which is conductive and thus generates the spark for ignition of the gas cutting torch  20 . The spark is generated across a gap “G” between the inner tube  306  and the outer shell  302  at the distal end portion  315  of the cutting tip  46 . In operation, the preheat oxygen, fuel gas, and cutting oxygen flow through separate gas conduct arrays are not mixed together until they meet at the distal end portion  315 . Accordingly, the gases are mixed at the distal end portion  315  to provide the post-mix feature, while the spark is generated across the gap “G,” thereby providing a safety feature and a convenience feature to the gas cutting torch  20 . 
         [0032]    Referring to  FIG. 6 , a method of starting an auto-ignition gas torch according to the principles of the present disclosure is described below in more detail. The method  400  of starting an auto-ignition gas torch starts in step  402 . An external oxygen source and an extern fuel gas source are turned on in step  404 . The preheat oxygen gas flow (rate) is adjusted and increased to a first level in step  406 . The preheat gas flow is adjusted by controlling the preheat oxygen metering device  80 . Similarly, the fuel gas flow is adjusted and increased to a second level in step  408 . The fuel gas flow is adjusted by controlling the fuel gas metering device  82 . The first level is set to be higher than the second level so that an oxygen-rich mixture can be created at the distal end of the gas torch  20 . The first level and the second level are determined based on the type of fuel gas used. Generally speaking, the flow of the preheat oxygen is an order of magnitude higher than a flow rate of fuel gas. 
         [0033]    After the flow of the fuel gas and the flow of the preheat oxygen are adjusted according to a predetermined setting, the ignition trigger  32  is activated in step  410 . Activation of the ignition trigger  32  also makes the internal receptacles  149  to engage the gas control devices  146  and  148 . Therefore, the preheat oxygen flow and the fuel gas flow are initiated in step  412 . The preheat oxygen flow and the fuel gas flow are directed from the gas flow control unit  36  to a distal end  315  of the tip  46  in step  414 . The preheat oxygen flow and the fuel gas flow are mixed at the distal end  315  of the tip  46  in step  416 . When the ignition trigger  32  is activated, a spark is generated across the gap G in step  418 . As a result, the mixture of the preheat oxygen flow and the fuel gas flow is ignited to heat the workpiece in step  420 . 
         [0034]    Additionally, when the ignition trigger  32  is activated, the cutting oxygen trigger  34  is also activated to initiate the cutting oxygen flow in step  422 . The cutting oxygen flow is also directed to the distal end  315  of the cutting tip  46  in step  424 . When the cutting oxygen reacts with the heated workpiece, the cutting process is initiated in step  426 . The method  400  ends in step  428 . 
         [0035]    The method  400  of starting an auto-ignition gas torch in accordance with the principles of the present disclosure creates an oxygen-rich mixture at a distal end  315  of the cutting tip  46 . The oxygen-rich mixture results in a more reliable ignition for the auto-ignition gas torch that uses a piezoelectric igniter, as opposed to a prior art method which ignites a mixture of the fuel gas and oxygen is a highly carbonizing environment. 
         [0036]    Referring to  FIGS. 7-11 , sample test data for the method  400  of starting the auto-ignition gas torch in accordance with the principles of the present disclosure and charts showing a relationship among the preheat oxygen flow, the fuel gas, and start reliability are explained in greater detail. It should be understood that the test data illustrated herein is merely exemplary and should not be construed as limiting the scope of the present disclosure. 
         [0037]    All of the tests were conducted under conditions where the oxygen regulator pressure was about 30 psig and the fuel gas pressure was about 12 psig. More specifically, when the fuel gas is acetylene, the preheat oxygen flow is from about two times to about six times higher than the fuel gas flow. For example, the flow of the preheat oxygen may be set to be from about 10 SCFH to about 22 SCFH. The flow of fuel gas is from about 1.5 SCFH to about 4 SCFH. (SCFH is a measurement of fluid flow rate and stands for standard cubic feet per hour). When the fuel gas is propane, the flow of the preheat oxygen is from about 7 SCFH to about 27 SCFH, and the flow of fuel gas is from about 1.5 SCFH to about 9.5 SCFH. 
         [0038]    As shown in  FIG. 7  and Table 1 below, when the fuel gas is acetylene, the oxygen flow can range from approximately 3.2 SCFH or 1.5 standard liters per minute (slm) to 49.4 SCFH (or 24 slm), whereas the fuel gas flow can range from 6.3 SCFH (or 3.0 slm) to 14.7 SCFH (or 7 slm). The pilot reliability or start reliability can range from about 14% to about 100%. Start reliability may be determined, for example, based on the non-occurrence of flame burn back, sustenance of torch flame, whether the gas torch can achieve maximum delivery at 12 psig without adversely affecting the flame, and when oxygen over-powers the fuel gas, among others. For example, the start reliability of about 14% may occur when the fuel flow is about 14.7 SCFH and the oxygen flow is about 22.1 SCFH. To increase start reliability, the fuel flow may be reduced while the same preheat oxygen flow is maintained. When the fuel flow is reduced to be approximately 3.2 SCFH, the start reliability can reach 100%. 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
             
             
               
                   
                 Oxygen Flow 
               
             
          
           
               
                 Pilot Reliability 
                 3.2 
                 5.3 
                 7.4 
                 9.5 
                 11.6 
                 13.7 
                 15.8 
                 17.9 
                 20.0 
               
             
          
           
               
                   
                 scfh 
                 slm 
                 1.5 
                 2.5 
                 3.5 
                 4.5 
                 5.5 
                 6.5 
                 7.5 
                 8.5 
                 9.5 
               
               
                   
               
               
                 Fuel 
                 3.2 
                 1.5 
                   
                   
                     0.14  a   
                 0.35 
                 0.45 
                 0.52 
                 0.65 
                 0.65 
                 0.93 
               
               
                 Flow 
                 4.2 
                 2.0 
                   
                   
                     0.17  a   
                     0.13  a   
                 0.07 
                 0.14 
                 0.22 
                 0.31 
                 0.50 
               
               
                   
                 6.3 
                 3.0 
                 0.23 
                 0.63 
                 0.54 
                 0.31 
                 0.30 
                 0.26 
                 0.35 
                 0.42 
                 0.34 
               
               
                   
                 8.4 
                 4.0 
                   
                 0.17 
                 1.00 
                 0.56 
                 0.47 
                 0.32 
                 0.21 
                 0.25 
                 0.25 
               
               
                   
                 10.5 
                 5.0 
                   
                 0.15 
                 0.83 
                 0.91 
                 0.69 
                 0.67 
                 0.91 
                 0.25 
                 0.22 
               
               
                   
                 12.6 
                 6.0 
                   
                   
                 0.25 
                 0.74 
                 1.00 
                 0.83 
                 0.95 
                 0.77 
                 0.95 
               
               
                   
                 14.7 
                 7.0 
                   
                   
                   
                 0.14 
                 1.00 
                 0.54 
                 0.57 
                 0.59 
                 0.61 
               
               
                   
                 16.8 
                 8.0 
               
               
                   
                 18.9 
                 9.0 
               
               
                   
               
             
          
           
               
                   
                 Oxygen Flow 
               
             
          
           
               
                 Pilot Reliability 
                 22.1 
                 24.2 
                 26.3 
                 28.4 
                 30.5 
                 32.6 
                 34.7 
                 36.8 
                 38.9 
               
             
          
           
               
                   
                 scfh 
                 slm 
                 10.5 
                 11.5 
                 12.5 
                 13.5 
                 14.5 
                 15.5 
                 16.5 
                 17.5 
                 18.5 
               
               
                   
               
               
                 Fuel 
                 3.2 
                 1.5 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                 Flow 
                 4.2 
                 2.0 
                 0.59 
                 0.74 
                 0.80 
                 0.91 
                 1.00 
                 1.00 
                 1.00 
                 0.91 
                 1.00 
               
               
                   
                 6.3 
                 3.0 
                 0.42 
                 0.37 
                 0.50 
                 0.52 
                 0.48 
                 0.50 
                 0.58 
                 0.92 
                 1.00 
               
               
                   
                 8.4 
                 4.0 
                 0.32 
                 0.27 
                 0.38 
                 0.23 
                 0.41 
                 0.65 
                 0.58 
                 0.54 
                 0.45 
               
               
                   
                 10.5 
                 5.0 
                 0.16 
                 0.39 
                 0.19 
                 0.29 
                 0.44 
                 0.38 
                 0.29 
                 0.37 
                 0.53 
               
               
                   
                 12.6 
                 6.0 
                 0.80 
                 0.80 
                 0.83 
                 0.87 
                 0.87 
               
               
                   
                 14.7 
                 7.0 
                 0.14 
               
               
                   
                 16.8 
                 8.0 
               
               
                   
                 18.9 
                 9.0 
               
               
                   
               
             
          
           
               
                   
                 Oxygen Flow 
               
             
          
           
               
                 Pilot Reliability 
                 41.0 
                 43.1 
                 45.2 
                 47.3 
                 49.4 
                 51.5 
                 53.6 
                 55.7 
               
             
          
           
               
                   
                 scfh 
                 slm 
                 19.5 
                 20.5 
                 21.5 
                 22.5 
                 23.5 
                 24.5 
                 25.5 
                 26.5 
               
               
                   
               
               
                 Fuel 
                 3.2 
                 1.5 
                 1.00 
                 1.00 
                 1.00 
                 
                   d 
                 
               
               
                 Flow 
                 4.2 
                 2.0 
                 1.00 
                 1.00 
                 0.91 
                 1.00 
                 0.91 
                 
                   c 
                 
               
               
                   
                 6.3 
                 3.0 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 
                   c 
                 
               
               
                   
                 8.4 
                 4.0 
                 0.63 
                 1.00 
                 1.00 
                 
                   c 
                 
               
               
                   
                 10.5 
                 5.0 
                 0.50 
                 
                   c 
                 
               
               
                   
                 12.6 
                 6.0 
               
               
                   
                 14.7 
                 7.0 
               
               
                   
                 16.8 
                 8.0 
               
               
                   
                 18.9 
                 9.0 
               
               
                   
               
               
                 Superscript “a” indicates a situation where burn-back occurs, superscript “b” indicates a situation where too much oxygen is present to sustain the flame, superscript “c” indicates a situation where the gas torch can achieve maximum delivery at 12 psig without adversely affecting the flame, superscript “d” indicates a situation where oxygen over-powers the fuel gas. 
               
             
          
         
       
     
         [0039]    As shown in  FIG. 8  and Table 2 below, in another test where the fuel gas is acetylene, the preheat oxygen flow can range from about 3.2 SCFH (or 1.5 slm) to about 55.7 (or 26.5 slm) and the fuel gas flow can range from about 3.2 SCFH (or 1.5 slm) to about 34.7 SCFH (or 16.5 slm). The start reliability ranges from about 10% to about 100%. 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 2 
               
               
                   
                   
               
             
             
               
                   
                 Oxygen Flow 
               
             
          
           
               
                 Pilot Reliability 
                 3.2 
                 5.3 
                 7.4 
                 9.5 
                 11.6 
                 13.7 
                 15.8 
                 17.9 
                 20.0 
               
             
          
           
               
                   
                 scfh 
                   
                 1.5 
                 2.5 
                 3.5 
                 4.5 
                 5.5 
                 6.5 
                 7.5 
                 8.5 
                 9.5 
               
               
                   
               
               
                 Fuel 
                 3.2 
                 1.5 
                   
                   
                   
                   
                   
                   
                   
                 0.14 
                 0.24 
               
               
                 Flow 
                 5.3 
                 2.5 
               
               
                   
                 7.4 
                 3.5 
                   
                 0.29 
                 1.00 
                 0.77 
                 0.53 
                 0.30 
                 0.15 
                 0.01 
                 0.01 
               
               
                   
                 9.5 
                 4.5 
                   
                 0.12 
                 0.50 
                 0.71 
                 0.81 
                 0.91 
                 0.75 
                 0.59 
                 0.56 
               
               
                   
                 11.6 
                 5.5 
                 0.26 
                 0.83 
                 0.91 
                 1.00 
                 1.00 
                 1.00 
                 0.78 
                 0.56 
                 0.46 
               
               
                   
                 13.7 
                 6.5 
                 0.17 
                 0.50 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 0.79 
               
               
                   
                 15.8 
                 7.5 
                 0.17 
                 0.38 
                 0.59 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 17.9 
                 8.5 
                 0.61 
                 0.91 
                 1.00 
                 0.91 
                 0.95 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 20.0 
                 9.5 
                   
                 0.12 
                 0.67 
                 0.83 
                 0.92 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 22.1 
                 10.5 
                 0.10 
                 0.23 
                 0.45 
                 0.77 
                 0.88 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 24.2 
                 11.5 
                   
                   
                 0.21 
                 0.50 
                 0.61 
                 0.71 
                 0.86 
                 1.00 
                 1.00 
               
               
                   
                 26.3 
                 12.5 
                   
                   
                 0.29 
                 0.58 
                 0.74 
                 0.91 
                 0.91 
                 0.91 
                 0.95 
               
               
                   
                 28.4 
                 13.5 
                   
                   
                 0.04 
                 0.67 
                 0.83 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 30.5 
                 14.5 
                   
                   
                   
                 0.18 
                 0.38 
                 0.59 
                 0.79 
                 1.00 
                 1.00 
               
               
                   
                 32.6 
                 15.5 
                   
                   
                   
                   
                   
                 0.77 
                 0.88 
                 1.00 
                 0.95 
               
               
                   
                 34.7 
                 16.5 
                   
                   
                   
                   
                   
                   
                   
                 0.91 
                 0.95 
               
               
                   
               
             
          
           
               
                   
                 Oxygen Flow 
               
             
          
           
               
                 Pilot Reliability 
                 22.1 
                 24.2 
                 26.3 
                 28.4 
                 30.5 
                 32.6 
                 34.7 
                 36.8 
               
             
          
           
               
                   
                 scfh 
                   
                 10.5 
                 11.5 
                 12.5 
                 13.5 
                 14.5 
                 15.5 
                 16.5 
                 17.5 
               
               
                   
               
               
                 Fuel 
                 3.2 
                 1.5 
                 0.34 
                 0.40 
                 0.45 
                 0.61 
                 0.77 
                 0.84 
                 0.91 
                 0.87 
               
               
                 Flow 
                 5.3 
                 2.5 
                 0.20 
                 0.32 
                 0.44 
                 0.48 
                 0.52 
                 0.55 
                 0.58 
                 0.66 
               
               
                   
                 7.4 
                 3.5 
                 0.01 
                 0.11 
                 0.21 
                 0.36 
                 0.50 
                 0.63 
                 0.77 
                 0.80 
               
               
                   
                 9.5 
                 4.5 
                 0.53 
                 0.43 
                 0.33 
                 0.48 
                 0.63 
                 0.81 
                 1.00 
                 1.00 
               
               
                   
                 11.6 
                 5.5 
                 0.37 
                 0.54 
                 0.71 
                 0.86 
                 1.00 
                 0.95 
                 0.91 
                 0.91 
               
               
                   
                 13.7 
                 6.5 
                 0.59 
                 0.52 
                 0.45 
                 0.58 
                 0.71 
                 0.74 
                 0.77 
                 0.74 
               
               
                   
                 15.8 
                 7.5 
                 1.00 
                 1.00 
                 1.00 
                 0.83 
                 0.67 
                 0.60 
                 0.53 
                 0.76 
               
               
                   
                 17.9 
                 8.5 
                 1.00 
                 0.81 
                 0.63 
                 0.56 
                 0.50 
                 0.49 
                 0.48 
                 0.62 
               
               
                   
                 20.0 
                 9.5 
                 1.00 
                 1.00 
                 1.00 
                 0.83 
                 0.67 
                 0.53 
                 0.40 
                 0.56 
               
               
                   
                 22.1 
                 10.5 
                 1.00 
                 0.92 
                 0.83 
                 0.77 
                 0.71 
                 0.69 
                 0.67 
                 0.72 
               
               
                   
                 24.2 
                 11.5 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 0.88 
                 0.77 
                 0.88 
               
               
                   
                 26.3 
                 12.5 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 0.95 
                 0.91 
                 0.87 
               
               
                   
                 28.4 
                 13.5 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 30.5 
                 14.5 
                 1.00 
                 1.00 
                 1.00 
                 0.88 
                 0.77 
                 0.84 
                 0.91 
                 0.95 
               
               
                   
                 32.6 
                 15.5 
                 0.91 
                 0.95 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 34.7 
                 16.5 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
               
             
          
           
               
                   
                 Oxygen Flow 
               
             
          
           
               
                 Pilot Reliability 
                 38.9 
                 41.0 
                 43.1 
                 45.2 
                 47.3 
                 49.4 
                 51.5 
                 53.6 
                 55.7 
               
             
          
           
               
                   
                 scfh 
                   
                 18.5 
                 19.5 
                 20.5 
                 21.5 
                 22.5 
                 23.5 
                 24.5 
                 25.5 
                 26.5 
               
               
                   
               
               
                 Fuel 
                 3.2 
                 1.5 
                 0.83 
                 0.92 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                 Flow 
                 5.3 
                 2.5 
                 0.73 
                 0.76 
                 0.79 
                 0.85 
                 0.92 
                 0.96 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 7.4 
                 3.5 
                 0.83 
                 0.80 
                 0.77 
                 0.84 
                 0.91 
                 0.91 
                 0.91 
                 0.95 
                 1.00 
               
               
                   
                 9.5 
                 4.5 
                 1.00 
                 0.88 
                 0.77 
                 0.84 
                 0.91 
                 0.95 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 11.6 
                 5.5 
                 0.91 
                 0.95 
                 1.00 
                 1.00 
                 1.00 
                 0.92 
                 0.83 
                 0.92 
                 1.00 
               
               
                   
                 13.7 
                 6.5 
                 0.71 
                 0.86 
                 1.00 
                 1.00 
                 1.00 
                 0.95 
                 0.91 
                 0.95 
                 1.00 
               
               
                   
                 15.8 
                 7.5 
                 1.00 
                 0.95 
                 0.91 
                 0.95 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 17.9 
                 8.5 
                 0.77 
                 0.88 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 20.0 
                 9.5 
                 0.71 
                 0.77 
                 0.83 
                 0.87 
                 0.91 
                 0.91 
                 0.91 
                 0.95 
                 1.00 
               
               
                   
                 22.1 
                 10.5 
                 0.77 
                 0.84 
                 0.91 
                 0.95 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 24.2 
                 11.5 
                 1.00 
                 0.83 
                 0.67 
                 0.79 
                 0.91 
                 0.91 
                 0.91 
                 0.91 
                 0.91 
               
               
                   
                 26.3 
                 12.5 
                 0.83 
                 0.92 
                 1.00 
                 0.95 
                 0.91 
                 0.68 
                 0.45 
                 0.73 
                 1.00 
               
               
                   
                 28.4 
                 13.5 
                 1.00 
                 0.95 
                 0.91 
                 0.73 
                 0.56 
                 0.56 
                 0.56 
                 0.73 
                 0.91 
               
               
                   
                 30.5 
                 14.5 
                 1.00 
                 0.95 
                 0.91 
                 0.84 
                 0.77 
               
               
                   
                 32.6 
                 15.5 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 34.7 
                 16.5 
                 1.00 
                 0.50 
               
               
                   
               
             
          
         
       
     
         [0040]    As shown in  FIG. 9  and Table 3 below, when the fuel gas is propane, the preheat oxygen flow can range from about 3.0 slm to about 27.0 slm, whereas the fuel flow can range from about 1.5 slm to about 5.0 slm. The start reliability can range from about 14% to about 100%. 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 3 
               
               
                   
                   
               
             
             
               
                   
                 Oxygen Flow (slm) 
               
             
          
           
               
                 Pilot Reliability 
                 2.0 
                 3.0 
                 4.0 
                 5.0 
                 6.0 
                 7.0 
                 8.0 
                 9.0 
                 10.0 
               
               
                   
               
             
          
           
               
                 Fuel 
                 1.5 
                   
                 0.95 
                 0.56 
                 0.71 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                 Flow 
                 2.0 
                   
                   
                   
                 0.83 
                 0.25 
                 0.93 
                 1.00 
                 1.00 
                 0.93 
               
               
                 (slm) 
                 3.0 
                   
                   
                   
                   
                 0.49 
                 0.83 
                 0.77 
                 0.36 
                 0.61 
               
               
                   
                 4.0 
                   
                   
                   
                   
                   
                   
                   
                   
                 0.14 
               
               
                   
                 5.0 
               
               
                   
                 5.5 
               
               
                   
                 6.0 
               
               
                   
                 6.5 
               
               
                   
                 7.0 
               
               
                   
               
             
          
           
               
                   
                 Oxygen Flow (slm) 
               
             
          
           
               
                 Pilot Reliability 
                 11.0 
                 12.0 
                 13.0 
                 14.0 
                 15.0 
                 16.0 
                 17.0 
                 18.0 
               
               
                   
               
             
          
           
               
                 Fuel 
                 1.5 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                 Flow 
                 2.0 
                 1.00 
                 0.93 
                 1.00 
                 1.00 
                 1.00 
                 0.81 
                 1.00 
                 0.87 
               
               
                 (slm) 
                 3.0 
                 0.94 
                 1.00 
                 1.00 
                 0.92 
                 1.00 
                 1.00 
                 1.00 
                 0.88 
               
               
                   
                 4.0 
                 0.38 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 5.0 
                   
                 0.28 
                 0.42 
                 0.80 
                 0.8 
                 0.57 
                 0.8 
                 0.92 
               
               
                   
                 5.5 
               
               
                   
                 6.0 
               
               
                   
                 6.5 
               
               
                   
                 7.0 
               
               
                   
               
             
          
           
               
                   
                 Oxygen Flow (slm) 
               
             
          
           
               
                 Pilot Reliability 
                 19.0 
                 20.0 
                 21.0 
                 22.0 
                 23.0 
                 24.0 
                 25.0 
                 26.0 
                 27.0 
               
               
                   
               
             
          
           
               
                 Fuel 
                 1.5 
                 1.00 
                 0.92 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 0.60 
               
               
                 Flow 
                 2.0 
                 1.00 
                 0.93 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 
                   d 
                 
               
               
                 (slm) 
                 3.0 
                 1.00 
                 1.00 
                 1.00 
                 0.92 
                 0.92 
               
               
                   
                 4.0 
                 1.00 
                 1.00 
                 1.00 
                 0.27 
               
               
                   
                 5.0 
                 0.43 
                 0.71 
               
               
                   
                 5.5 
               
               
                   
                 6.0 
               
               
                   
                 6.5 
               
               
                   
                 7.0 
               
               
                   
               
               
                 Superscript “d” indicates a situation where oxygen over-powers the fuel gas. 
               
             
          
         
       
     
         [0041]    As shown in  FIG. 10  and Table 4 below, in another test where the fuel gas is propane, the oxygen flow can range from about 7.4 SCFH to about 55.7 SCFH, whereas the fuel gas flow can range from about 3.2 SCFH (1.5 slm) to about 22.1 SCFH (10.5 slm). The start reliability is from about 4% to about 100%. For example, when the fuel flow rate is about 7.4 SCFH (3.5 slm) and the oxygen flow is about 11.6 SCFH (5.5), the gas torch achieve a start reliability of about 17%. When the oxygen flow is increased to about 13.7, the start reliability is significantly increased from about 17% to about 100%. When the preheat oxygen flow continues to be increased, the start reliability is maintained at about 100%. The oxygen flow is about two times the fuel gas flow or at least an order of a magnitude higher than the fuel gas flow to achieve about 100% start reliability. 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 4 
               
               
                   
                   
               
             
             
               
                   
                 Oxygen Flow 
               
             
          
           
               
                 Pilot Reliability 
                 3.2 
                 5.3 
                 7.4 
                 9.5 
                 11.6 
                 13.7 
                 15.8 
                 17.9 
                 20.0 
               
             
          
           
               
                   
                 scfh 
                   
                 1.5 
                 2.5 
                 3.5 
                 4.5 
                 5.5 
                 6.5 
                 7.5 
                 8.5 
                 9.5 
               
               
                   
               
               
                 Fuel 
                 3.2 
                 1.5 
                   
                   
                 0.85 
                 0.79 
                 0.72 
                 0.65 
                 0.60 
                 0.55 
                 0.62 
               
               
                 Flow 
                 5.3 
                 2.5 
                   
                   
                   
                 0.04 
                 0.48 
                 1.00 
                 1.00 
                 1.00 
                 0.88 
               
               
                   
                 7.4 
                 3.5 
                   
                   
                   
                   
                 0.17 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 9.5 
                 4.5 
                   
                   
                   
                   
                   
                   
                 0.09 
                 0.83 
                 0.80 
               
               
                   
                 11.6 
                 5.5 
               
               
                   
                 13.7 
                 6.5 
               
               
                   
                 15.8 
                 7.5 
               
               
                   
                 17.9 
                 8.5 
               
               
                   
                 20.0 
                 9.5 
               
               
                   
                 22.1 
                 10.5 
               
               
                   
                 24.2 
                 11.5 
               
               
                   
                 26.3 
                 12.5 
               
               
                   
                 28.4 
                 13.5 
               
               
                   
                 30.5 
                 14.5 
               
               
                   
                 32.6 
                 15.5 
               
               
                   
                 34.7 
                 16.5 
               
               
                   
               
             
          
           
               
                   
                 Oxygen Flow 
               
             
          
           
               
                 Pilot Reliability 
                 22.1 
                 24.2 
                 26.3 
                 28.4 
                 30.5 
                 32.6 
                 34.7 
                 36.8 
               
             
          
           
               
                   
                 scfh 
                   
                 10.5 
                 11.5 
                 12.5 
                 13.5 
                 14.5 
                 15.5 
                 16.5 
                 17.5 
               
               
                   
               
               
                 Fuel 
                 3.2 
                 1.5 
                 0.69 
                 0.58 
                 0.48 
                 0.54 
                 0.61 
                 0.73 
                 0.85 
                 0.88 
               
               
                 Flow 
                 5.3 
                 2.5 
                 0.77 
                 0.80 
                 0.83 
                 0.75 
                 0.67 
                 0.83 
                 1.00 
                 1.00 
               
               
                   
                 7.4 
                 3.5 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 9.5 
                 4.5 
                 0.77 
                 0.80 
                 0.83 
                 0.92 
                 1.00 
                 1.00 
                 1.00 
                 0.95 
               
               
                   
                 11.6 
                 5.5 
                 0.83 
                 0.87 
                 0.91 
                 0.95 
                 1.00 
                 0.88 
                 0.77 
                 0.74 
               
               
                   
                 13.7 
                 6.5 
                   
                 0.24 
                 0.67 
                 0.65 
                 0.63 
                 0.81 
                 1.00 
                 0.86 
               
               
                   
                 15.8 
                 7.5 
                   
                   
                   
                   
                 0.71 
                 0.67 
                 0.63 
                 0.81 
               
               
                   
                 17.9 
                 8.5 
                   
                   
                   
                   
                 0.08 
                 0.17 
                 0.25 
                 0.36 
               
               
                   
                 20.0 
                 9.5 
               
               
                   
                 22.1 
                 10.5 
               
               
                   
                 24.2 
                 11.5 
               
               
                   
                 26.3 
                 12.5 
               
               
                   
                 28.4 
                 13.5 
               
               
                   
                 30.5 
                 14.5 
               
               
                   
                 32.6 
                 15.5 
               
               
                   
                 34.7 
                 16.5 
               
               
                   
               
             
          
           
               
                   
                 Oxygen Flow 
               
             
          
           
               
                 Pilot Reliability 
                 38.9 
                 41.0 
                 43.1 
                 45.2 
                 47.3 
                 49.4 
                 51.5 
                 53.6 
                 55.7 
               
             
          
           
               
                   
                 scfh 
                   
                 18.5 
                 19.5 
                 20.5 
                 21.5 
                 22.5 
                 23.5 
                 24.5 
                 25.5 
                 26.5 
               
               
                   
               
               
                 Fuel 
                 3.2 
                 1.5 
                 0.92 
                 0.96 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 0.69 
                 0.37 
               
               
                 Flow 
                 5.3 
                 2.5 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 7.4 
                 3.5 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 9.5 
                 4.5 
                 0.91 
                 0.95 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 11.6 
                 5.5 
                 0.71 
                 0.77 
                 0.83 
                 0.83 
                 0.83 
                 0.92 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 13.7 
                 6.5 
                 0.71 
                 0.74 
                 0.77 
                 0.80 
                 0.83 
                 0.87 
                 0.91 
                 0.95 
                 1.00 
               
               
                   
                 15.8 
                 7.5 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 17.9 
                 8.5 
                 0.48 
                 0.74 
                 1.00 
                 1.00 
                 1.00 
                 0.95 
                 0.91 
                 0.81 
                 0.71 
               
               
                   
                 20.0 
                 9.5 
                 0.07 
                 0.39 
                 0.71 
                 0.71 
                 0.71 
                 0.81 
                 0.91 
                 0.95 
                 1.00 
               
               
                   
                 22.1 
                 10.5 
                   
                   
                 0.17 
                 0.58 
                 1.00 
                 1.00 
                 1.00 
               
               
                   
                 24.2 
                 11.5 
               
               
                   
                 26.3 
                 12.5 
               
               
                   
                 28.4 
                 13.5 
               
               
                   
                 30.5 
                 14.5 
               
               
                   
                 32.6 
                 15.5 
               
               
                   
                 34.7 
                 16.5 
               
               
                   
               
             
          
         
       
     
         [0042]    As shown in  FIG. 11  and Table 5 below, when the fuel gas is methane, the preheat oxygen flow is from about 3.5 slm to about 26.5 slm, whereas the fuel flow is from about 1.5 slm to about 6.5 slm. The start reliability is from about 21% to about 100%. 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 5 
               
               
                   
                   
               
             
             
               
                   
                 Oxygen Flow (slm) 
               
             
          
           
               
                 Pilot Reliability 
                 1.5 
                 2.5 
                 3.5 
                 4.5 
                 5.5 
                 6.5 
                 7.5 
                 8.5 
                 9.5 
                 10.5 
               
               
                   
               
             
          
           
               
                 Fuel 
                 1.5 
                   
                   
                 0.63 
                 0.63 
                 1.00 
                 0.96  d   
                 0.92 
                 0.83  d   
                 0.74 
                 0.83  d   
               
               
                 Flow 
                 2.5 
                   
                   
                   
                 0.08 
                 0.87 
                 0.86  d   
                 0.86 
                 0.92      
                 1.00 
                 0.96  d   
               
               
                 (slm) 
                 3.5 
                   
                   
                   
                   
                   
                 0.58      
                 0.71 
                 0.71  d   
                 0.71 
                 0.73  d   
               
               
                   
                 4.5 
                   
                   
                   
                   
                   
                   
                 0.21 
                 0.61  d   
                 1.00 
                 0.95  d   
               
               
                   
                 5.5 
                   
                   
                   
                   
                   
                   
                   
                 0.16      
                 0.80 
                 0.90  d   
               
               
                   
                 6.5 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 0.32      
               
               
                   
                 7.0 
               
               
                   
                 7.5 
               
               
                   
                 8.0 
               
               
                   
                 8.5 
               
               
                   
                 9.0 
               
               
                   
                 9.5 
               
               
                   
               
             
          
           
               
                   
                 Oxygen Flow (slm) 
               
             
          
           
               
                 Pilot Reliability 
                 11.5 
                 12.5 
                 13.5 
                 14.5 
                 15.5 
                 16.5 
                 17.5 
                 18.5 
               
               
                   
               
             
          
           
               
                 Fuel 
                 1.5 
                 0.92 
                 0.96  d   
                 1.00 
                 0.96  d   
                 0.92 
                 0.96  d   
                 1.00 
                 1.00  d   
               
               
                 Flow 
                 2.5 
                 0.92 
                 0.96  d   
                 1.00 
                 1.00  d   
                 1.00 
                 1.00  d   
                 1.00 
                 1.00  d   
               
               
                 (slm) 
                 3.5 
                 0.75 
                 0.76  d   
                 0.77 
                 0.80  d   
                 0.83 
                 0.87  d   
                 0.91 
                 0.91  d   
               
               
                   
                 4.5 
                 0.91 
                 0.87  d   
                 0.83 
                 0.83  d   
                 0.83 
                 0.83  d   
                 0.83 
                 0.91      
               
               
                   
                 5.5 
                 1.00 
                 0.93  d   
                 0.86 
                 0.83  d   
                 0.80 
                 0.86  d   
                 0.92 
                 0.92  d   
               
               
                   
                 6.5 
                 1.00 
                 1.00  d   
                 1.00 
                 1.00  d   
                 1.00 
                 1.00  d   
                 1.00 
                 1.00  d   
               
               
                   
                 7.0 
               
               
                   
                 7.5 
               
               
                   
                 8.0 
               
               
                   
                 8.5 
               
               
                   
                 9.0 
               
               
                   
                 9.5 
               
               
                   
               
             
          
           
               
                   
                 Oxygen Flow (slm) 
               
             
          
           
               
                 Pilot Reliability 
                 19.5 
                 20.5 
                 21.5 
                 22.5 
                 23.5 
                 24.5 
                 25.5 
                 26.5 
               
               
                   
               
             
          
           
               
                 Fuel 
                 1.5 
                 1.00 
                 0.77  d   
                 0.55 
                   
                   
                   
                   
                   
               
               
                 Flow 
                 2.5 
                 1.00 
                 1.00  d   
                 1.00 
                 1.00  d   
                 1.00 
                 1.00  d   
                 1.00      
                 0.75 
               
               
                 (slm) 
                 3.5 
                 0.91 
                 0.95  d   
                 1.00 
                 1.00  d   
                 1.00 
                 1.00  d   
                 1.00      
                 1.00 
               
               
                   
                 4.5 
                 1.00 
                 1.00  d   
                 1.00 
                 1.00  d   
                 1.00 
                 1.00  d   
                 1.00  d   
                 1.00 
               
               
                   
                 5.5 
                 0.92 
                 0.92  d   
                 0.92 
                 0.92  d   
                 0.92 
                 0.96  d   
                 1.00  d   
                 1.00 
               
               
                   
                 6.5 
                 1.00 
                 0.93  d   
                 0.86 
                 0.86  d   
                 0.86 
                 0.93  d   
                 1.00  d   
                 1.00 
               
               
                   
                 7.0 
               
               
                   
                 7.5 
               
               
                   
                 8.0 
               
               
                   
                 8.5 
               
               
                   
                 9.0 
               
               
                   
                 9.5 
               
               
                   
               
               
                 Superscript “d” indicates a situation where oxygen over-powers the fuel gas. 
               
             
          
         
       
     
         [0043]    It should be noted that the disclosure is not limited to the embodiment described and illustrated as examples. A large variety of modifications have been described and more are part of the knowledge of the person skilled in the art. These and further modifications as well as any replacement by technical equivalents may be added to the description and figures, without leaving the scope of the protection of the disclosure and of the present patent.