Abstract:
A combustion burner and a pressurized gasification furnace provided with: a burner main body ( 41 ) capable of blowing a fuel gas in which fuel and air are mixed; and an ignition torch ( 42 ) that is provided inside the burner main body ( 41 ) and propagates a flame from the base end part of the torch, with the flame being discharged from the tip end part. By arranging the tip end part ( 42   a ) of the ignition torch ( 42 ) at the base-end side with respect to the tip end part ( 41   a ) of the burner main body ( 41 ), the thermal load at the tip end part of the ignition torch during ignition is reduced, and thus the durability can be improved.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a combustion burner which is used in a furnace such as a pressurized gasification furnace, and a pressurized gasification furnace including the combustion burner. 
       BACKGROUND ART 
       [0002]    For example, in a gasification furnace such as a coal gasification furnace, a start-up burner is provided with an ignition torch in the vicinity thereof to ignite the start-up burner. 
         [0003]    As the ignition torch of the related art, for example, an ignition torch is described in PTL 1 as follows. The ignition torch of PTL 1 is configured to extend across the inside of a gasification furnace from the outside thereof so as to allow fuel and combustion air to be received from one end of the gasification furnace and allow a flame to be sent out from the other end of the gasification furnace, and an ignition unit is provided on one end side which is positioned outside the gasification furnace. 
       CITATION LIST 
     Patent Literature 
       [0004]    [PTL 1] Japanese Unexamined Patent Application Publication No. 2011-117713 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0005]    In the ignition torch of the related art described above, the ignition unit is provided on the base end portion side which is positioned outside the gasification furnace. Therefore, when the start-up burner is ignited by using the ignition torch, the flame formed by the ignition unit propagates toward the tip end portion through the inside of a pipe and ignites fuel gas which is discharged from the tip end portion of the start-up burner. At this time, since the pipe of the ignition torch has a predetermined length, thermal elongation occurs during the propagation of the flame. In this case, the tip end portion of the ignition torch protrudes forward from the tip end portion of the start-up burner and thus is likely to receive a thermal load during the ignition. A flame stabilization unit is formed in the tip end portion of the ignition torch, and thus there is concern that the flame stabilization unit may be burned out by a thermal load during the ignition. 
         [0006]    In order to solve the above-described problems, an object of the present invention is to provide a combustion burner and a pressurized gasification furnace capable of enhancing durability by reducing a thermal load on a tip end portion of an ignition torch. 
       Solution to Problem 
       [0007]    In order to accomplish the object, a combustion burner of the present invention includes: a burner main body which is able to blow fuel gas which is a mixture of fuel and air; and an ignition torch which is disposed inside the burner main body and allows a flame to propagate from a base end portion of the ignition torch so as to be sent out from a tip end portion of the ignition torch, in which the tip end portion of the ignition torch is disposed on the base end portion side with respect to a tip end portion of the burner main body. 
         [0008]    Accordingly, when the fuel gas which is blown from the burner main body is ignited and forms a flame, the tip end portion of the ignition torch is disposed on the base end portion side with respect to the tip end portion of the burner main body. Therefore, a thermal load on the tip end portion of the ignition torch due to the flame of the burner main body can be reduced, and thus durability can be enhanced and the life span can be extended. 
         [0009]    In the combustion burner of the present invention, during a non-operation of the ignition torch, the tip end portion of the ignition torch is disposed closer to the base end portion side than the tip end portion of the burner main body. 
         [0010]    Accordingly, the tip end portion is positioned at a retreat position during the non-operation of the ignition torch, and thus a thermal load on the tip end portion of the ignition torch due to the flame of the burner main body can be reduced. 
         [0011]    In the combustion burner of the present invention, a time of the non-operation of the ignition torch includes a time before allowing the flame to propagate from the base end portion of the ignition torch to the tip end portion or a time after stopping the propagation of the flame by the ignition torch after an ignition of the fuel gas from the burner main body. 
         [0012]    Accordingly, the tip end portion of the ignition torch is positioned at the retreat position before allowing a flame to propagate from the base end portion of the ignition torch to the tip end portion or after stopping the propagation of the flame by the ignition torch after the ignition of the fuel gas from the burner main body, and thus a thermal load on the tip end portion of the ignition torch due to the flame of the burner main body can be reduced. 
         [0013]    In the combustion burner of the present invention, during an operation of the ignition torch, the tip end portion of the ignition torch is disposed at substantially the same position as that of the tip end portion of the burner main body. 
         [0014]    Accordingly, the tip end portion of the ignition torch is positioned at substantially the same position as that of the tip end portion of the burner main body during the operation. Therefore, at this time, the ignition torch can appropriately ignite the fuel gas which is blown from the burner main body by the flame which propagates from the base end portion and is sent out from the tip end portion. 
         [0015]    In the combustion burner of the present invention, a time of the operation of the ignition torch includes a time when the flame is allowed to propagate from the base end portion of the ignition torch to the tip end portion. 
         [0016]    Accordingly, when the flame propagates from the base end portion of the ignition torch to the tip end portion, the tip end portion of the ignition torch is positioned at substantially the same position as that of the tip end portion of the burner main body, and thus the fuel gas which is blown from the burner main body can be appropriately ignited by the ignition torch. 
         [0017]    In the combustion burner of the present invention, the position of the tip end portion during the non-operation of the ignition torch is set in consideration of a length of a pipe through which the flame propagates. 
         [0018]    Accordingly, the position during the operation and the position during the non-operation in the ignition torch can be appropriately set. 
         [0019]    In the combustion burner of the present invention, an ignition unit is provided in the base end portion of the ignition torch, and an on-off valve is provided on a downstream side in a fuel flow direction of the ignition unit. 
         [0020]    Accordingly, since the ignition unit is provided in the base end portion of the ignition torch, regardless of the state of the tip end portion side, the inspection of the ignition unit can be easily performed. In addition, since the on-off valve is provided on the downstream side in the fuel flow direction of the ignition unit, the base end portion side and the tip end portion side can be separated from each other by closing the on-off valve. Therefore, even in a case where inspection is required, the ignition unit side can be separated from the flame by closing the on-off valve, and thus the inspection can be easily performed. 
         [0021]    A pressurized gasification furnace of the present invention includes: a burner main body which is fixed to a furnace wall and is able to blow fuel gas which is a mixture of fuel and air into a furnace; and an ignition torch which is fixed to the furnace wall to be disposed inside the burner main body and allows a flame to propagate from a base end portion of the ignition torch so as to be sent out from a tip end portion of the ignition torch, in which the tip end portion of the ignition torch is disposed on the base end portion side with respect to a tip end portion of the burner main body. 
         [0022]    Accordingly, the tip end portion of the ignition torch is disposed on the base end portion side with respect to the tip end portion of the burner main body when the fuel gas which is blown from the burner main body is ignited and forms a flame. Therefore, a thermal load on the tip end portion of the ignition torch due to the flame of the burner main body can be reduced, and thus durability can be enhanced and the life span can be extended. 
       Advantageous Effects of Invention 
       [0023]    According to the combustion burner and the pressurized gasification furnace of the present invention, since the tip end portion of the ignition torch is disposed on the base end portion side with respect to the tip end portion of the burner main body, a thermal load on the tip end portion of the ignition torch due to the flame of the burner main body can be reduced, and thus durability can be enhanced and the life span can be extended. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0024]      FIG. 1  is a schematic view illustrating a combustion burner according to an embodiment of the present invention. 
           [0025]      FIG. 2  is a schematic view illustrating an action of the combustion burner of the embodiment. 
           [0026]      FIG. 3  is a longitudinal sectional view of a coal gasification furnace container of the embodiment. 
           [0027]      FIG. 4  is a cross-sectional view taken along line A-A of  FIG. 3 , illustrating a transverse sectional view of the coal gasification furnace container of the embodiment. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0028]    Hereinafter, an exemplary embodiment of a combustion burner according to the present invention will be described with reference to the accompanying drawings. In addition, the present invention is not limited by the embodiment, and in a case where there are a plurality of embodiments, a configuration obtained by combining the embodiments is also included in the present invention. 
       Embodiment 
       [0029]      FIG. 1  is a schematic view illustrating a combustion burner according to an embodiment of the present invention,  FIG. 2  is a schematic view illustrating an action of the combustion burner of the embodiment,  FIG. 3  is a longitudinal sectional view of a coal gasification furnace container of the embodiment, and  FIG. 4  is a cross-sectional view taken along line A-A of  FIG. 3 , illustrating a transverse sectional view of the coal gasification furnace container of the embodiment. 
         [0030]    In the embodiment, as illustrated in  FIGS. 3 and 4 , a gasification furnace (pressurized gasification furnace)  1  includes a light oil combustion chamber  3 , a combustor section  5 , and a reductor section  7  in this order from the bottom. The light oil combustion chamber  3  is provided with start-up burners (combustion burners)  12 . Although described later, the start-up burner  12  is configured such that an ignition torch  42  is disposed inside a burner main body  41 . 
         [0031]    The combustor section  5  is provided with pulverized coal burners  14  and char burners  16 . The reductor section  7  is provided with gasification burners  18 . In the light oil combustion chamber  3 , light oil which is injected and sprayed by the start-up burners  12  is burned, and the generated combustion gas heats the combustor section  5  on the upper side. In addition, in the combustor section  5  which reaches a coal ignition temperature or higher, coal is burned with air which is a gasification agent that is only injected into the combustor section  5  and reaches a high temperature such that ash in the coal is melted and flows downward and high-temperature gas generated by the combustion in the combustor section  5  moves upward. In the reductor section  7 , the high-temperature gas which moves upward from the combustor section  5  and coal which is newly injected react with each other, and thus the coal can be converted into gas with good efficiency. 
         [0032]    In the embodiment, a plurality of start-up burners are arranged to oppose each other so as to form a swirling flow in the gasification furnace  1 . As illustrated in  FIG. 1 , the start-up burner  12  is configured to include the burner main body  41  and the ignition torch  42 . The burner main body  41  can blow fuel gas which is a mixture of fuel and air. The ignition torch  42  is disposed inside the burner main body  41  and allows a flame to propagate from the base end portion so as to be sent out from the tip end portion. In addition, the burner main body  41  is ignited by the flame of the ignition torch  42  and can form a flame as the start-up burner  12 . 
         [0033]    The burner main body  41  is provided with a fuel gas passage  53  which is formed between an outer cylinder  51  and an inner cylinder  52 , and a nozzle  54  which is formed at the tip end portion and can blow the fuel gas into the gasification furnace  1 . The outer cylinder  51  and the inner cylinder  52  have cylindrical shapes and are fixed to a furnace wall  1   a , and the base end portions thereof are provided with a fuel gas supply portion and a combustion air supply portion (not illustrated). 
         [0034]    The ignition torch  42  is disposed inside the burner main body  41 , has a cylindrical shape, and is fixed to the furnace wall  1   a . The ignition torch  42  is provided with a mixing chamber  20  in which fuel and combustion air are mixed with each other, an ignition unit  22 , an on-off valve  24 , a combustion pipe  26 , and a flame stabilization unit  28  as main components in this order from the base end portion outside the gasification furnace  1 . 
         [0035]    The mixing chamber  20  is provided with a fuel supply port  30  and a combustion air supply port  31 . Therefore, the fuel and the combustion air are sufficiently mixed with each other in the mixing chamber  20 , and the mixture is ignited by the ignition unit  22  which is provided on the downstream side of the fuel flow. As the ignition unit  22 , ignition by a glow plug, an igniter, or the like is appropriately used. 
         [0036]    The mixing chamber  20  and the ignition unit  22  are disposed outside the gasification furnace  1 . In addition, the on-off valve  24  is provided between the mixing chamber and the combustion pipe  26  which extends across the inside of the gasification furnace  1 . The on-off valve  24  is provided outside the gasification furnace  1 . The on-off valve  24  can allow a fluid between the ignition unit  22  side and the gasification furnace  1  side to flow or to be blocked by opening or closing the passage. The flame stabilization unit  28  which has a greater inner diameter than that of the combustion pipe  26  is provided in the tip end portion of the combustion pipe  26 , and a flame stabilization plate  28   a  is fixed to the inside of the flame stabilization unit  28 . 
         [0037]    In addition, an assist fuel pipe  32  through which assist fuel flows is inserted into the inside of the furnace from the outside of the furnace, and passes through the side of the combustion pipe  26  to extend to the flame stabilization unit  28 . The assist fuel can be supplied to the flame stabilization unit  28  by the assist fuel pipe  32 . 
         [0038]    The start-up burner  12  of the embodiment described above is operated as follows. 
         [0039]    Before the ignition of the ignition torch  42 , first, only the combustion air is supplied from the combustion air supply port  31  to heat the ignition unit  22  to be red-hot. After the temperature of the ignition unit  22  is increased to an ignition temperature, the fuel is supplied from the fuel supply port  30  to the inside of the mixing chamber  20 , and the fuel and the combustion air are mixed with each other. The air ratio (the amount of air actually injected/the amount of air theoretically needed) at this time is about 0.4 to 0.7. 
         [0040]    The mixed fuel gas is ignited by the ignition unit  22  and forms a flame. The flame passes through the opened on-off valve  24  and propagates through the inside of the combustion pipe  26 . In addition, the flame which reaches the flame stabilization unit  28  from the combustion pipe  26  becomes a main flame in the flame stabilization unit  28  and is burned. At this time, the assist fuel is supplied to the flame stabilization unit  28  from the assist fuel pipe  32 . Accordingly, the main flame which grows in the flame stabilization unit  28  is stabilized and is burned. 
         [0041]    On the other hand, the burner main body  41  blows the fuel gas which is a mixture of air and fuel into the gasification furnace  1  from the nozzle  54 . In the ignition torch  42 , when the main flame of the flame stabilization unit  28  is stabilized, the main flame flows out from the flame stabilization unit  28 , and thus the fuel gas which is blown into the gasification furnace  1  from the burner main body  41  is ignited by the flame from the ignition torch  42 , thereby igniting the start-up burner  12 . 
         [0042]    Next, a method of using the on-off valve  24  will be described. 
         [0043]    The inside of the gasification furnace  1  is always maintained under a high temperature condition in a high pressure state in order to primarily accelerate the combustion gasification reaction of char. Therefore, in a case of inspecting the ignition torch  42 , time for depressurizing all of the facilities of the gasification furnace during an operation under pressure to atmospheric pressure is necessary, and thus there is a burden of significant cost and energy consumption for operations of various types of power units during re-pressurization after the inspection. 
         [0044]    As described above, in the case where the inspection of the ignition torch  42  is required, the on-off valve  24  which is provided on the downstream side of the fuel flow of the ignition unit  22  that is provided outside the gasification furnace  1  is used. That is, in a case where the ignition torch  42  has a problem during torch ignition or during the operation of the start-up burner and thus needs to be inspected, the on-off valve  24  is closed in this state. Accordingly, the inside of the gasification furnace  1  is blocked from the ignition unit  22  side, and thus the ignition unit  22  side is released to the air and the inspection operation is performed. 
         [0045]    In the start-up burner  12  of the embodiment which is configured as described above, a tip end portion  42   a  of the ignition torch  42  is disposed on the base end portion side (outside the furnace) with respect to a tip end portion  41   a  of the burner main body  41 . 
         [0046]    Specifically, during the non-operation of the ignition torch  42 , the tip end portion  42   a  of the ignition torch  42  is disposed closer to the base end portion side than the tip end portion  41   a  of the burner main body  41 . A time of the non-operation of the ignition torch  42  indicates a time before allowing a flame to propagate from the base end portion of the ignition torch  42  to the tip end portion or a time after stopping the propagation of the flame by the ignition torch  42  after the ignition of the fuel gas from the burner main body  41 . 
         [0047]    In addition, during the operation of the ignition torch  42 , the tip end portion  42   a  of the ignition torch  42  is disposed at substantially the same position as that of the tip end portion  41   a  of the burner main body  41 . A time of the operation of the ignition torch  42  indicates a time when a flame is allowed to propagate from the base end portion of the ignition torch  42  to the tip end portion. 
         [0048]    In this case, the position of the tip end portion  42   a  during the non-operation of the ignition torch  42  is set in consideration of the length of a pipe (combustion pipe  26  and the like) through which the flame propagates. That is, since the ignition torch  42  has a predetermined length, when a flame propagates from the base end portion to the tip end portion, the base end portion is thermally elongated with respect to the furnace wall  1   a  as the starting point and the ignition torch  42  is thermally elongated toward the tip end portion. Therefore, a retreat distance L during the non-operation of the ignition torch  42  is set so that the tip end portion  42   a  of the ignition torch  42  is positioned at substantially the same position as that of the tip end portion  41   a  of the burner main body  41  when the ignition torch  42  operates to allow a flame to propagate. 
         [0049]    Hereinafter, the action and the effect of the start-up burner  12  of the embodiment will be described. 
         [0050]    Before the start-up burner  12  is started, the tip end portion  42   a  of the ignition torch  42  is positioned on the base end portion side with respect to the tip end portion  41   a  of the burner main body  41  by the retreat distance L. Here, when the ignition torch  42  is operated, the flame propagates from the base end portion side to the tip end portion side, and thus the combustion pipe  26  is heated and reaches a high temperature, thereby causing thermal elongation toward the tip end portion side in the longitudinal direction. In this case, in the ignition torch  42 , as illustrated in  FIG. 2 , the tip end portion  42   a  is positioned at substantially the same position as that of the tip end portion  41   a  of the burner main body  41 . Therefore, the burner main body  41  ignites the fuel gas which is blown into the gasification furnace  1  by receiving the flame from the ignition torch  42  and thus can form a flame as the start-up burner  12 . 
         [0051]    Thereafter, when the flame of the start-up burner  12  (the burner main body  41 ) is stabilized, the propagation of the flame by the ignition torch  42  is stopped, and only the combustion air is supplied. Therefore, in the ignition torch  42 , the combustion pipe  26  is cooled and the temperature thereof is reduced. In this case, the ignition torch  42  contracts toward the base end portion side in the longitudinal direction, and as illustrated in  FIG. 1 , the tip end portion  42   a  is positioned at a position where the tip end portion  42   a  retreats from the tip end portion  41   a  of the burner main body  41 . Therefore, since the tip end portion  42   a  is held at the position where the tip end portion  42   a  retreats from the tip end portion  41   a  of the burner main body  41  toward the inside, a thermal load due to the flame of the burner main body  41  is reduced, and thus the burnout of the ignition torch  42  is prevented. 
         [0052]    As described above, in the combustion burner of the embodiment, the burner main body  41  which can blow the fuel gas, which is a mixture of fuel and air, and the ignition torch  42  which is disposed inside the burner main body  41  and allows a flame to propagate from the base end portion so as to be sent out from the tip end portion are provided, and the tip end portion  42   a  of the ignition torch  42  is disposed on the base end portion side with respect to the tip end portion  41   a  of the burner main body  41 . 
         [0053]    Accordingly, the tip end portion  42   a  of the ignition torch  42  is disposed on the base end portion side with respect to the tip end portion  41   a  of the burner main body  41  when the fuel gas which is blown from the burner main body  41  is ignited and forms a flame. Therefore, a thermal load on the tip end portion  42   a  of the ignition torch  42  due to the flame of the burner main body  41  can be reduced, and thus durability can be enhanced and the life span can be extended. 
         [0054]    In the combustion burner of the embodiment, during the non-operation of the ignition torch  42 , the tip end portion  42   a  of the ignition torch  42  is disposed closer to the base end portion side than the tip end portion  41   a  of the burner main body  41 . Accordingly, the tip end portion is positioned at the retreat position during the non-operation of the ignition torch  42 , and thus a thermal load on the tip end portion  42   a  of the ignition torch  42  due to the flame of the burner main body  41  can be reduced. 
         [0055]    Specifically, the tip end portion  42   a  of the ignition torch  42  is positioned at the retreat position before allowing a flame to propagate from the base end portion of the ignition torch  42  to the tip end portion or after stopping the propagation of the flame by the ignition torch  42  after the ignition of the fuel gas from the burner main body  41 , and thus a thermal load on the tip end portion  42   a  of the ignition torch  42  due to the flame of the burner main body  41  can be reduced. 
         [0056]    In the combustion burner of the embodiment, during the operation of the ignition torch  42 , the tip end portion  42   a  of the ignition torch  42  is disposed at substantially the same position as that of the tip end portion  41   a  of the burner main body  41 . Accordingly, the tip end portion  42   a  of the ignition torch  42  is positioned at substantially the same position as that of the tip end portion  41   a  of the burner main body  41  during the operation. Therefore, at this time, the ignition torch  42  can appropriately ignite the fuel gas which is blown from the burner main body  41  by the flame which propagates from the base end portion and is sent out from the tip end portion. 
         [0057]    Specifically, when the flame propagates from the base end portion of the ignition torch  42  to the tip end portion, the tip end portion  42   a  of the ignition torch  42  is positioned at substantially the same position as that of the tip end portion  41   a  of the burner main body  41 , and thus the fuel gas which is blown from the burner main body  41  can be appropriately ignited by the ignition torch  42 . 
         [0058]    In the combustion burner of the embodiment, the position of the ignition torch  42  during the non-operation is set in consideration of the length of the combustion pipe  26  through which the flame propagates. Accordingly, the position during the operation and the position during the non-operation in the ignition torch  42  can be appropriately set. 
         [0059]    In addition, in the combustion burner of the embodiment, the ignition unit  22  is provided in the base end portion of the ignition torch  42 , and the on-off valve is provided on the downstream side in the fuel flow direction of the ignition unit  22 . Accordingly, regardless of the state of the inside of the gasification furnace  1 , the inspection of the ignition unit  22  can be easily performed. In addition, the inside of the gasification furnace  1  and the ignition unit  22  side can be separated from each other by closing the on-off valve  24 . As a result, even in a case where inspection is required due to various problems, the ignition unit  22  side can be separated from the gasification furnace  1  by closing the on-off valve  24 , and thus the inspection can be easily performed regardless of the state of the inside of the gasification furnace  1 . 
         [0060]    In addition, in the gasification furnace  1  of the embodiment, the burner main body  41  which is fixed to the furnace wall  1   a  and can blow the fuel gas, which is a mixture of fuel and air, into the inside of the furnace, and the ignition torch  42  which is fixed to the furnace wall  1   a  to be disposed inside the burner main body  41  and allows a flame to propagate from the base end portion so as to be sent out from the tip end portion are provided, and the tip end portion  42   a  of the ignition torch  42  is disposed on the base end portion side with respect to the tip end portion  41   a  of the burner main body  41 . 
         [0061]    Accordingly, a thermal load on the tip end portion  42   a  of the ignition torch  42  due to the flame of the burner main body  41  can be reduced, and thus durability can be enhanced and the life span can be extended. 
         [0062]    In addition, in the above-described embodiment, the combustion burner of the present invention is applied to the gasification furnace  1  but is not limited to the gasification furnace  1 . In addition, the ignition torch  42  is configured to include the ignition unit  22 , the on-off valve  24 , the combustion pipe  26 , and the flame stabilization unit  28 , but is not limited to this configuration and arrangement. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1  GASIFICATION FURNACE 
           1   a  FURNACE WALL 
           12  START-UP BURNER (COMBUSTION BURNER) 
           20  MIXING CHAMBER 
           22  IGNITION UNIT 
           24  ON-OFF VALVE 
           26  COMBUSTION PIPE 
           28  FLAME STABILIZATION UNIT 
           41  BURNER MAIN BODY 
           41   a  TIP END PORTION 
           42  IGNITION TORCH 
           42   a  TIP END PORTION