Burner device and industrial furnace

Abstract

To facilitate, in a burner device that mixes air jetted out from an air jet port and fuel jetted out from a fuel jet nozzle and burns the mixture, adjusting a position at which the air jetted out from the air jet port and the fuel jetted out from the fuel jet nozzle are mixed and burned.SOLUTION: In a burner device X in which air Air jetted out from an air jet port 21 and fuel G jetted out from a fuel jet nozzle 30 are mixed and burned, a fuel jet nozzle for short flame 31 that mixes and burns the fuel at a position near the air jetted out from the air jet port, and a fuel jet nozzle for long flame 32 that mixes and burns the fuel at a position separated from the air jetted out from the air jet port are provided in the fuel jet nozzle.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a burner device for mixing and burning air ejected from an air outlet and fuel ejected from a fuel ejection nozzle, and an industrial furnace using such a burner device. In particular, the burner device is characterized in that the position where the air ejected from the air outlet and the fuel ejected from the fuel ejection nozzle are mixed and burned can be easily adjusted, and in an industrial furnace using such a burner device, the position where the air ejected from the air outlet and the fuel ejected from the fuel ejection nozzle are mixed and burned can be changed, making it possible to easily adjust the temperature distribution characteristics in the furnace, and to perform appropriate heat treatment on the material to be treated in the furnace. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in industrial furnaces such as continuous heating furnaces, soaking furnaces, melting furnaces, and heat treatment furnaces, a burner device has generally been used in which air ejected from an air ejection port and fuel ejected from a fuel ejection nozzle are mixed and combusted.

[0003] Furthermore, in order to save energy, a regenerative burner device is used that recovers the heat from the combustion gas burned in the furnace while providing a heat storage section to heat the air used for combustion.

[0004] In an industrial furnace using a burner device such as that described above, when heat treating a material to be treated, it may be necessary to heat the entire material to be treated evenly or to heat one side of the material to be treated more strongly, and in this case it may be necessary to adjust the temperature distribution within the furnace.

[0005] In order to adjust the temperature distribution in the furnace in this manner, Patent Document 1 proposes spraying primary fuel from the combustion air supply port of the regenerative burner and spraying secondary fuel from a secondary fuel nozzle into the furnace, thereby controlling the ratio of the supply amounts of primary fuel and secondary fuel.

[0006] However, the method disclosed in Patent Document 1 adjusts the temperature distribution in the furnace by controlling the ratio of the supply amounts of primary fuel and secondary fuel, so that increasing the amount of primary fuel burned causes the problem that NOx emissions during combustion increase. In addition, because the secondary fuel is ejected parallel to the combustion air, the flame caused by secondary combustion becomes longer, making it very difficult to adjust the temperature distribution at various positions in the furnace while maintaining a constant overall amount of combustion in the furnace.

[0007] Furthermore, Patent Document 2 proposes providing a primary fuel nozzle within the combustion air nozzle so that the fuel can be sprayed from around the flow of the combustion air, providing multiple secondary fuel nozzles, and providing each of these secondary fuel nozzles with a flame-holding mechanism at the nozzle outlet at the tip of its piping, which includes a flow path that can supply flame-holding air from around the secondary fuel being sprayed out, so that the fuel can be sprayed directly into the furnace from a location different from the combustion air and approximately parallel to the combustion air nozzle, and providing each secondary fuel flow control valve to change the flame temperature distribution.

[0008] However, even in the case of the above-mentioned Patent Document 2, when the amount of combustion of the primary fuel ejected from the primary fuel nozzle is increased, the problem of an increase in NOx during combustion occurs. Also, since the secondary fuel is ejected from each secondary fuel nozzle parallel to the combustion air, the ratio between the amount of primary fuel ejected from the primary fuel nozzle and the amount of each secondary fuel ejected from each secondary fuel nozzle is controlled to adjust the temperature distribution in the furnace, so there is a problem that it is very difficult to adjust the temperature distribution at various positions in the furnace while maintaining the overall combustion amount in the furnace constant.

[0009] Furthermore, Patent Document 3 proposes a method for operating a regenerative burner device in which each burner has one air nozzle for spraying air and multiple fuel injection nozzles for spraying fuel, the multiple fuel injection nozzles having two or more injection directions, in which the position of the temperature peak, which is the high temperature range of the combustion gas temperature, is changed by changing the injection amount of each of the multiple fuel injection nozzles.

[0010] However, in the system shown in Patent Document 3, multiple fuel injection nozzles, each with a different injection direction, are provided at different positions in the furnace, so fuel supply ports corresponding to each fuel injection nozzle are required, which places restrictions on the position at which each fuel injection nozzle is attached to the furnace, and it is necessary to provide separate equipment such as piping for supplying fuel to each fuel injection nozzle, which increases equipment costs and makes it difficult to control the fuel supplied to each fuel nozzle injection.

[0011] Moreover, in the scrap melting furnace of Patent Document 4, a main burner is provided that sprays a flame (long flame) toward the piled up scrap, and an auxiliary burner is provided that sprays a short flame to melt the scrap piled up in front of the main burner, and the point where the flame is aimed is changed from a distant location to a nearby location as needed while observing the melting state of the scrap so that the scrap melts evenly.

[0012] However, in the system shown in Patent Document 4, in order to change the point at which the flame hits the piled scrap and heats it between a close location and a far location, a plurality of dedicated burners are required, which results in problems such as high component costs, a complex structure, and the need for space around the device. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Patent Application Publication No. 9-145047 [Patent Document 2] JP 2003-74834 A [Patent Document 3] Patent No. 6764000 [Patent Document 4] Japanese Patent Application Publication No. 11-325734 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0014] The present invention aims to solve the above-mentioned problems in a burner device that mixes and burns air ejected from an air outlet and fuel ejected from a fuel ejection nozzle, and in an industrial furnace using such a burner device.

[0015] In particular, the objective of the present invention is to make it possible to easily adjust the position in the burner device where the air ejected from the air outlet and the fuel ejected from the fuel ejection nozzle are mixed and burned, and to easily change the position in an industrial furnace using such a burner device where the air ejected from the air outlet and the fuel ejected from the fuel ejection nozzle are mixed and burned, thereby changing the length of the flame to change the point to be heated and adjusting the temperature distribution within the furnace, thereby enabling the material to be appropriately heated within the furnace. [Means for solving the problem]

[0016] In the burner device of the present invention, in order to solve the above-mentioned problems, in a burner device in which air ejected from an air outlet and fuel ejected from a fuel ejection nozzle are mixed and burned, a short flame fuel ejection nozzle for mixing and burning fuel at a position close to the air ejected from the air outlet, and a long flame fuel ejection nozzle for mixing and burning fuel at a position away from the air ejected from the air outlet are provided within the fuel ejection nozzle.

[0017] Then, as in the burner device of the present invention, by providing a short flame fuel injection nozzle that mixes fuel with the air injected from the air injection port at a position close to the fuel injection port and burns the fuel, and a long flame fuel injection nozzle that mixes fuel with the air injected from the air injection port at a position distant from the fuel injection port, in one fuel injection nozzle, it becomes unnecessary to provide a plurality of fuel injection nozzles with different injection directions at different positions in the furnace, as shown in the above-mentioned Patent Documents 3 and 4. As a result, it becomes unnecessary to provide fuel supply ports corresponding to the respective fuel injection nozzles in the furnace, and it becomes unnecessary to restrict the positions at which the respective fuel injection nozzles are attached to the furnace, to require the provision of separate equipment such as piping for supplying fuel to the separately provided respective fuel injection nozzles, which increases the equipment costs, and to make the control of the fuel supplied to the injection of each fuel nozzle complicated.

[0018] In the burner device of the present invention, at least one of the angle at which fuel is ejected from the short flame nozzle section at the tip of the short flame fuel ejection nozzle toward the air ejected from the air ejection port and the angle at which fuel is ejected from the long flame nozzle section at the tip of the long flame fuel ejection nozzle toward the air ejected from the air ejection port can be adjusted. In this way, it is possible to easily adjust the position at which the fuel ejected from the short flame fuel ejection nozzle is mixed with the air ejected from the air ejection port and burned, or the position at which the fuel ejected from the long flame fuel ejection nozzle is mixed with the air ejected from the air ejection port and burned. Although not shown in the figure, a method for adjusting the angle may be to mechanically move the short flame nozzle section and the long flame nozzle section that eject the fuel from the outside to change the angle, or to manually replace the parts of the short flame nozzle section and the long flame nozzle section themselves with parts with different ejection angles.

[0019] In addition, in the burner device of the present invention, a switching means can be provided for switching the fuel injection nozzle for injecting fuel between the short flame fuel injection nozzle and the long flame fuel injection nozzle, thereby making it possible to clearly distinguish between a short flame and a long flame.

[0020] Furthermore, the burner device of the present invention can be provided with a short flame adjustment valve for adjusting the amount of fuel led to the short flame fuel injection nozzle, and a long flame adjustment valve for adjusting the amount of fuel led to the long flame fuel injection nozzle. In this way, while keeping the amount of fuel mixed with the air injected from the air injection port constant, it becomes possible to easily adjust the amount of fuel injected from the short flame fuel injection nozzle to be mixed with the air injected from the air injection port at a position close to the air injection port and combusted, and the amount of fuel injected from the long flame fuel injection nozzle to be mixed with the air injected from the air injection port at a position distant from the air injection port and combusted.

[0021] In the burner device of the present invention, fuel injection nozzles provided with the short flame fuel injection nozzle and the long flame fuel injection nozzle can be provided symmetrically on both sides of the air injection port from which air is injected. In this way, when fuel injection nozzles provided with the short flame fuel injection nozzle and the long flame fuel injection nozzle are provided symmetrically on both sides of the air injection port and fuel is injected from the short flame fuel injection nozzles and the long flame fuel injection nozzles on both sides, the fuel injected from the short flame fuel injection nozzles and the long flame fuel injection nozzles on both sides join together at a position where they intersect with the air injected from the air injection port and are combusted, and the fuel can be burned along the injection direction of the air whether the flame is close to the air injection port or away from the air injection port.

[0022] In this way, the flame is not oblique to the air ejection direction as in the above-mentioned Patent Document 3, so that there is no bias in the temperature inside the furnace, and the temperature distribution can be made symmetrical with respect to the air ejection direction.

[0023] In the burner device of the present invention, a heat storage section containing a heat storage material can be provided in the air guide tube that guides air to the air outlet. In this way, air can be heated by the heat storage material stored in the heat storage section, and the heated air can be ejected from the air outlet and mixed with the fuel ejected from the short flame fuel ejection nozzle or the long flame fuel ejection nozzle for efficient combustion. Meanwhile, when combustion is stopped, the combustion exhaust gas after combustion can be guided through the air outlet to the heat storage section provided in the air guide tube, and the heat of the combustion exhaust gas can be stored in the heat storage material accommodated in the heat storage section.

[0024] In this way, the combustion air can be preheated by the heat of the combustion exhaust gas after combustion via the heat storage section, thereby saving fuel.

[0025] In addition, in the industrial furnace of the present invention, a burner device for mixing and burning air ejected from an air outlet and fuel ejected from a fuel ejection nozzle is provided on the furnace wall, and the burner device as described above is provided in the industrial furnace.

[0026] In the industrial furnace of the present invention, a plurality of the burner devices can be provided on both furnace walls.

[0027] Furthermore, in the industrial furnace of the present invention, a burner device is provided on the furnace wall for mixing and burning air ejected from an air outlet and fuel ejected from a fuel ejection nozzle, and the burner device is a burner device in which a heat storage section containing a heat storage material is provided in an air guide tube that guides air to the air outlet, and the combustion exhaust gas after combustion in the furnace is guided through the air outlet to the heat storage section provided in the air guide tube, so that the heat of the combustion exhaust gas is stored in the heat storage material contained in the heat storage section, while the air heated by the heat stored in the heat storage material in the heat storage section is guided by the air guide tube to the air outlet and ejected into the furnace. In this manner, air can be heated by the heat storage material stored in the heat storage section as described above, and the heated air can be ejected from the air outlet and mixed with the fuel ejected from the short flame fuel ejection nozzle and the long flame fuel ejection nozzle for efficient combustion. Meanwhile, when combustion is stopped, the combustion exhaust gas after combustion can be guided through the air outlet to the heat storage section provided in the air guide tube, and the heat of the combustion exhaust gas can be stored in the heat storage material contained in the heat storage section.

[0028] Again, by doing so, the flame will not be oblique to the air ejection direction as in Patent Document 3, so there will be no temperature bias in the furnace, and the temperature distribution can be made symmetrical with respect to the air ejection direction.

[0029] In addition, in the industrial furnace of the present invention, when a burner device in which a heat storage section containing a heat storage material is provided in an air guide tube that guides air to the air outlet is used as the burner device as described above, a plurality of the burner devices are provided on both furnace walls, and in each burner device, the combustion exhaust gas after combustion in the furnace is led to the heat storage section provided in the air guide tube through the air outlet provided in one furnace wall, and the heat of the combustion exhaust gas is stored in the heat storage material stored in the heat storage section, and the air heated by the heat storage material stored in the heat storage section is ejected from the air outlet provided in the other furnace wall into the furnace and combusted. In this way, by installing two burner devices in a pair facing each other on both sides of the furnace wall, the heat storage operation and the combustion operation can be specifically performed alternately, and an optimal temperature distribution can be obtained in the industrial furnace provided with the burner device, continuous operation with fuel saving can be performed, and energy saving is possible. Effect of the Invention

[0030] As in the burner device of the present invention, by providing a short flame fuel injection nozzle within one fuel injection nozzle, which mixes and burns fuel at a position close to the air ejected from the air injection port, and a long flame fuel injection nozzle within one fuel injection nozzle, which mixes and burns fuel at a position away from the air ejected from the air injection port, the position where the air ejected from the air injection port and the fuel ejected from the fuel injection nozzle are mixed and burned can be easily adjusted with simple equipment, and the operating conditions can be changed during operation without stopping the equipment.

[0031] Furthermore, in the industrial furnace of the present invention, since the burner device as described above is used, by changing the position where the air ejected from the air outlet and the fuel ejected from the fuel ejection nozzle are mixed and combusted, it becomes possible to easily adjust the length of the flame to change the point at which the heated object is heated or to adjust the temperature distribution within the furnace.

[0032] In addition, because all of this can be achieved with a single fuel injection nozzle, the structure is not complicated and space around the device can be secured. [Brief description of the drawings]

[0033] [Figure 1] FIG. 1 is a schematic explanatory diagram showing a state in which, in a burner device and industrial furnace in embodiment 1 of the present invention, a fuel ejection nozzle equipped with a short flame fuel ejection nozzle and a long flame fuel ejection nozzle is provided on one side of an air ejection port, and fuel is ejected from the long flame fuel ejection nozzle provided within the fuel ejection nozzle into the furnace, and mixed with air ejected from the air ejection port at a position away from the furnace wall to combust the fuel. [Diagram 2] FIG. 1 is a schematic explanatory diagram showing a state in which fuel is ejected into the furnace from a short-flame fuel ejection nozzle provided in the fuel ejection nozzle, and mixed with air ejected from an air ejection port at a position close to the furnace wall in the burner device and industrial furnace of the first embodiment, to combust the fuel. [Diagram 3] This is a schematic explanatory diagram showing a state in which, in a modified example of the burner device and industrial furnace in the above-mentioned embodiment 1, a short flame adjustment valve is provided in the short flame fuel supply pipe to adjust the amount of fuel supplied to the short flame fuel injection nozzle, and a long flame adjustment valve is provided in the long flame fuel supply pipe to adjust the amount of fuel supplied to the long flame fuel injection nozzle, and the amount of fuel injected from the short flame fuel injection nozzle and the amount of fuel injected from the long flame fuel injection nozzle are adjusted for combustion. [Figure 4] This is a schematic explanatory diagram showing a state in which, in a burner device and industrial furnace in embodiment 2 of the present invention, fuel injection nozzles equipped with a short flame fuel injection nozzle and a long flame fuel injection nozzle are arranged symmetrically on both sides of an air injection port, and fuel is injected into the furnace from the short flame fuel injection nozzles provided in each fuel injection nozzle on both sides of the air injection port, and the fuel is mixed with the air injected from the air injection port at a position close to the furnace wall to be combusted. [Diagram 5]FIG. 1 is a schematic explanatory diagram showing a state in which fuel is ejected into the furnace from long-flame fuel ejection nozzles provided in each fuel ejection nozzle on both sides of the air ejection port in the burner device and industrial furnace of the above-mentioned embodiment 2, and the fuel is mixed with the air ejected from the air ejection port at a position far from the furnace wall to be combusted. [Figure 6] In the burner device and industrial furnace of the above-mentioned embodiment 2, (A) is a schematic explanatory diagram showing a state in which fuel is ejected into the furnace from a short-flame fuel ejection nozzle provided in a fuel ejection nozzle on one side of an air ejection port, and fuel is ejected into the furnace from a long-flame fuel ejection nozzle provided in a fuel ejection nozzle on the opposite side of the air ejection port, and the fuel is mixed with the air ejected from the air ejection port at both positions close to the furnace wall and at positions away from the furnace wall to combust the fuel, and (B) is a schematic explanatory diagram showing a state in which fuel is ejected into the furnace from a short-flame fuel ejection nozzle and a long-flame fuel ejection nozzle provided in a fuel ejection nozzle on both sides of an air ejection port, and the fuel is mixed with the air ejected from the air ejection port at both positions close to the furnace wall and at positions away from the furnace wall to combust the fuel, and the amount of fuel ejected from the short-flame fuel ejection nozzle and the amount of fuel ejected from the long-flame fuel ejection nozzle are adjusted to combust the fuel. [Figure 7] In the burner device and industrial furnace of embodiment 3 of the present invention, fuel ejection nozzles each having a short flame fuel ejection nozzle and a long flame fuel ejection nozzle are provided symmetrically on both sides of an air ejection port, and a heat storage section containing a heat storage material is provided in an air guide tube that guides air to the air ejection port. This is a schematic explanatory diagram showing a state in which the burner device is provided so as to face both furnace walls. [Figure 8]In the burner device and industrial furnace of the third embodiment, (A) is a schematic explanatory diagram showing a state in which, in a pair of opposing burner devices provided on both furnace walls, the combustion exhaust gas after combustion in the furnace is guided through the air outlet to the heat storage section provided in the air guide tube to store the heat of the combustion exhaust gas in the heat storage section, and the air heated by the heat storage material stored in the heat storage section is ejected from the air outlet into the furnace to combust fuel, alternately performing a heat storage operation, in which the air heated by the heat stored in the heat storage section is ejected from the air outlet into the furnace to combust fuel, during the combustion operation, in which fuel is ejected from long flame fuel ejection nozzles provided in each fuel ejection nozzle on both sides of the air outlet and mixed with the heated air ejected from the air outlet at a position away from the furnace wall to combust the fuel, and (B) is a schematic diagram showing the temperature distribution in the furnace. [Figure 9] In the burner device and industrial furnace of the third embodiment, (A) is a schematic explanatory diagram showing a state in which, in a pair of opposing burner devices provided on both furnace walls, the combustion exhaust gas after combustion in the furnace is guided through the air outlet to the heat storage section provided in the air guide tube to store the heat of the combustion exhaust gas in the heat storage section, and the air heated by the heat storage material stored in the heat storage section is ejected from the air outlet into the furnace to combust fuel, alternately performing a heat storage operation, in which the air heated by the heat stored in the heat storage section is ejected from the air outlet into the furnace to combust fuel, during the combustion operation, in which fuel is ejected from short-flame fuel ejection nozzles provided in each fuel ejection nozzle on both sides of the air outlet and mixed with the heated air ejected from the air outlet at a position close to the furnace wall to combust the fuel, and (B) is a schematic diagram showing the temperature distribution in the furnace. [Figure 10]In the burner device and industrial furnace according to the third embodiment, (A) is a pair of opposing burner devices provided on both furnace walls, which alternate between a heat storage operation in which the combustion exhaust gas after combustion in the furnace is guided through the air outlet to the heat storage section provided in the air guide pipe to store the heat of the combustion exhaust gas in the heat storage material accommodated in the heat storage section, and a combustion operation in which the air heated by the heat stored in the heat storage material in the heat storage section is ejected from the air outlet into the furnace to combust fuel, during the combustion operation, FIG. 1 is a schematic diagram showing a state in which fuel is ejected into the furnace from long-flame fuel ejection nozzles provided in each fuel ejection nozzle on both sides of the air ejection port, and the fuel is burned by mixing with the heated air ejected from the air ejection port at a position away from the furnace wall, while in a burner device provided on the opposite furnace wall, fuel is ejected into the furnace from short-flame fuel ejection nozzles provided in each fuel ejection nozzle on both sides of the air ejection port, and the fuel is burned by mixing with the heated air ejected from the air ejection port at a position close to the furnace wall; (A) is a schematic diagram showing the temperature distribution in the furnace. [Figure 11] In the burner device and industrial furnace of the third embodiment, (A) is a schematic explanatory diagram showing a state in which, in a pair of opposing burner devices provided on both furnace walls, a heat storage operation in which the combustion exhaust gas after combustion in the furnace is guided through the air outlet to the heat storage section provided in the air guide tube to store the heat of the combustion exhaust gas in the heat storage section, and a combustion operation in which the air heated by the heat stored in the heat storage section is ejected from the air outlet into the furnace to burn fuel, are alternately performed, in which during the combustion operation, fuel is ejected into the furnace from a long flame fuel ejection nozzle provided in a fuel ejection nozzle on one side of the air outlet, and fuel is ejected into the furnace from a short flame fuel ejection nozzle provided in a fuel ejection nozzle on one side of the air outlet, and the fuel is mixed with the heated air ejected from the air outlet at a position away from the furnace wall and a position close to the furnace wall to burn the fuel, and (B) is a schematic diagram showing the temperature distribution in the furnace. [Figure 12]In the burner device and industrial furnace of the above-mentioned embodiment 3, a pair of opposing burner devices are provided on both furnace walls, and the combustion exhaust gas after combustion in the furnace is guided through the air outlet to the heat storage section provided in the air guide tube to store the heat of the combustion exhaust gas in the heat storage material contained in the heat storage section, and the air heated by the heat stored in the heat storage material in the heat storage section is ejected from the air outlet into the furnace to combust the fuel. This is a schematic explanatory diagram showing a state in which a plurality of consecutive burner devices provided on one furnace wall perform a combustion operation while a plurality of consecutive burner devices provided on the opposite furnace wall perform a heat storage operation in alternating operations. BEST MODE FOR CARRYING OUT THEINVENTION

[0034] The burner device and industrial furnace according to the embodiment of the present invention will be specifically described below with reference to the accompanying drawings. Note that the burner device and industrial furnace according to the present invention are not limited to the embodiment shown below, and can be appropriately modified and implemented within the scope of the invention.

[0035] (Embodiment 1) In the burner device X of the industrial furnace according to the first embodiment, as shown in Figs. 1 and 2, an air outlet 21 is provided in the furnace wall 11 of the furnace 10 to eject air (Air) guided by an air guide tube 20 into the furnace 10, and a fuel ejection nozzle 30 is provided in the vicinity of the air outlet 21 to eject fuel (G) onto the furnace wall 11, inclined in a direction toward the air (Air) ejected from the air outlet 21.

[0036] Within the fuel injection nozzle 30, a short flame fuel injection nozzle 31 is provided at a position on the air outlet 21 side, and a long flame fuel injection nozzle 32 is provided next to the short flame fuel injection nozzle 31 at a position farther from the air outlet 21 than the short flame fuel injection nozzle 31. A short flame nozzle section 31a is provided at the tip of the short flame fuel injection nozzle 31 for spraying fuel G toward a position close to the air Air ejected from the air outlet 21, and a long flame nozzle section 32a is provided at the tip of the long flame fuel injection nozzle 32 for spraying fuel G toward a position away from the air Air ejected from the air outlet 21.

[0037] In this embodiment, the short flame nozzle section 31a and the long flame nozzle section 32a are protruding from the tip of the short flame fuel injection nozzle 31 and the long flame fuel injection nozzle 32, and the respective injection angles are tilted toward the farther side and closer side, so that the difference between the short flame and the long flame is clear. However, although not shown, it is also possible to provide angled holes instead of providing the protruding short flame nozzle section 31a and the long flame nozzle section 32a. Also, although not shown, if it is desired to reduce the difference between the short flame and the long flame, it is not necessary to tilt the short flame nozzle section 31a and the long flame nozzle section 32a.

[0038] In addition, in the fuel injection nozzle 30, when switching between the short flame fuel injection nozzle 31 and the long flame fuel injection nozzle 32 that spray fuel G by a switching means, a short flame on-off valve 33b is provided in the short flame fuel supply pipe 33a that supplies fuel G to the short flame fuel injection nozzle 31, and a long flame on-off valve 34b is provided in the long flame fuel supply pipe 34a that guides fuel G to the long flame fuel injection nozzle 32, and the opening and closing of the short flame on-off valve 33b and the long flame on-off valve 34b is controlled by a control device 36.

[0039] 1, in the burner device X according to the first embodiment, when the short flame on-off valve 33b is closed by the control device 36 while the long flame on-off valve 34b is opened, the fuel G is supplied only to the long flame fuel ejection nozzle 32 through the long flame fuel supply pipe 34a, and the fuel G is ejected from the long flame nozzle part 32a at the tip of the long flame fuel ejection nozzle 32 to a position away from the air ejected from the air ejection port 21, and is mixed with the air and combusted at a position away from the air ejection port 21, so that the temperature in the furnace 10 at a position away from the air ejection port 21 becomes higher than the temperature in the vicinity of the air ejection port 21. In the figure, the short flame on-off valve 33b and the long flame on-off valve 34b are shown in black when closed and in white when open.

[0040] On the other hand, as shown in FIG. 2, when the control device 36 closes the long flame on-off valve 34b while opening the short flame on-off valve 33b, fuel G is supplied only to the short flame fuel injection nozzle 31 through the short flame fuel supply pipe 33a, and the fuel G is injected from the short flame nozzle portion 31a at the tip of the short flame fuel injection nozzle 31 to a position close to the air injected from the air injection port 21, and is mixed with the air at a position close to the air injection port 21 and combusted, so that the temperature inside the furnace 10 at the position close to the air injection port 21 becomes higher than the temperature at a position away from the air injection port 21.

[0041] As a result, the control device 36 controls the opening and closing of the short flame on-off valve 33b and the long flame on-off valve 34b, making it possible to easily control the temperature inside the furnace 10 at a position away from the air outlet 21 and the temperature inside the furnace 10 at a position close to the air outlet 21.

[0042] In addition, in the modified burner device X shown in Figure 3, in addition to the short flame on-off valve 33b, a short flame fuel supply pipe 33a that supplies fuel G to the short flame fuel injection nozzle 31 is provided with a short flame adjustment valve 33c that adjusts the amount of fuel G led to the short flame fuel injection nozzle 31, and in addition to the long flame on-off valve 34b, a long flame fuel supply pipe 34a that supplies fuel G to the long flame fuel injection nozzle 32 is provided with a long flame adjustment valve 34c that adjusts the amount of fuel G led to the long flame fuel injection nozzle 32, and the control device 36 controls the short flame on-off valve 33b and the long flame on-off valve 34b, as well as the short flame adjustment valve 33c and the long flame adjustment valve 34c.

[0043] In the burner apparatus X of this modified example, as shown in FIG. 3, the control device 36 opens the short flame on-off valve 33b and the long flame on-off valve 34b, and controls the short flame adjustment valve 33c and the long flame adjustment valve 34c to adjust the amount of fuel G guided to the short flame fuel injection nozzle 31 through the short flame adjustment valve 33c and the amount of fuel G guided to the long flame fuel injection nozzle 32 through the long flame adjustment valve 34c, thereby adjusting the amount of fuel G sprayed from the short flame nozzle portion 31a to a position close to the air sprayed from the air nozzle 21 and to be combusted, and the amount of fuel G sprayed from the long flame nozzle portion 32a to a position away from the air sprayed from the air nozzle 21 and to be combusted.

[0044] In this way, while keeping the amount of fuel G to be mixed with the air ejected from the air outlet 21 and burned constant, the amount of fuel G to be mixed with the air ejected from the air outlet 21 at a position close to the air outlet 21 and burned and the amount of fuel G to be mixed with the air ejected from the air outlet 21 at a position away from the air outlet 21 and burned can be easily adjusted, making it possible to easily control the temperature at each position within the furnace 10, reduce the temperature change between positions close to and away from the air outlet 21, or to change the temperature as desired.

[0045] In addition, it is easy to change the heating point of the object by adjusting the length of the flame, and to adjust the temperature distribution inside the furnace. Taking advantage of this, it can be used as a burner for a melting furnace.

[0046] (Embodiment 2) In the burner device X of the industrial furnace according to the second embodiment, as shown in Figs. 4 to 6, an air outlet 21 for ejecting the air (Air) guided by an air guide pipe 20 into the furnace 10 is provided on the furnace wall 11 of the furnace 10, and fuel ejection nozzles 30 for ejecting fuel (G) are provided symmetrically on both sides of the furnace wall 11 near the air outlet 21, each inclined in a direction toward the air (Air) ejected from the air outlet 21.

[0047] In each of the fuel injection nozzles 30, similarly to the fuel injection nozzle 30 of embodiment 1, a short flame fuel injection nozzle 31 is provided at a position on the air outlet 21 side within the fuel injection nozzle 30, and a long flame fuel injection nozzle 32 is provided in a row at a position farther from the air outlet 21 than the short flame fuel injection nozzle 31, and a short flame nozzle section 31a is provided at the tip of the short flame fuel injection nozzle 31 for spraying fuel G toward a position close to the air Air ejected from the air outlet 21, and a long flame nozzle section 32a is provided at the tip of the long flame fuel injection nozzle 32 for spraying fuel G toward a position away from the air Air ejected from the air outlet 21.

[0048] When switching between the short flame fuel injection nozzle 31 and the long flame fuel injection nozzle 32 that spray fuel G in each fuel injection nozzle 30 by a switching means, a short flame on-off valve 33b is provided in the short flame fuel supply pipe 33a that supplies fuel G to each short flame fuel injection nozzle 31, and a long flame on-off valve 34b is provided in the long flame fuel supply pipe 34a that supplies fuel G to each long flame fuel injection nozzle 32, and the opening and closing of each of the short flame on-off valves 33b and each long flame on-off valve 34b is controlled by a control device 36.

[0049] In the burner device X according to the second embodiment, as shown in FIG. 4, when the control device 36 closes the long flame on-off valves 34b and opens the short flame on-off valves 33b in the fuel ejection nozzles 30 on both sides of the air ejection port 21, the fuel G is not guided to the long flame fuel supply pipes 34a on both sides but is supplied to the short flame fuel ejection nozzles 31 on both sides through the short flame fuel supply pipes 33a on both sides, and the fuel G is ejected from the short flame nozzle parts 31a at the tips of the short flame fuel ejection nozzles 31 on both sides toward a position close to the air ejected from the air ejection port 21, and is joined at a position close to where it intersects with the air ejected from the air ejection port 21 and combusted, and a flame due to the combustion of the fuel G is formed along the ejection direction of the air Air at a position close to the air ejection port 21.

[0050] In this way, the flame is not oblique to the air ejection direction as in the above-mentioned Patent Document 3, so that there is no bias in the temperature inside the furnace, and the temperature distribution can be made symmetrical with respect to the air ejection direction.

[0051] In the burner device X according to the second embodiment, as shown in FIG. 5, when the control device 36 closes the short flame on-off valves 33b and opens the long flame on-off valves 34b in the fuel ejection nozzles 30 on both sides of the air ejection port 21, the fuel G is not guided to the short flame fuel supply pipes 33a on both sides but is supplied to the long flame fuel ejection nozzles 32 on both sides through the long flame fuel supply pipes 34a on both sides, and the fuel G is ejected from the long flame nozzle portions 32a at the tips of the long flame fuel ejection nozzles 32 on both sides toward a position away from the air ejected from the air ejection port 21, and is joined and combusted at a position away from where it intersects with the air ejected from the air ejection port 21, and a flame due to the combustion of the fuel G is formed along the ejection direction of the air Air at a position away from the air ejection port 21.

[0052] In this way, as in the above case, the flame is not oblique to the air ejection direction, so that there is no temperature bias in the furnace and the temperature distribution can be made symmetrical with respect to the air ejection direction.

[0053] In the burner device X according to the second embodiment, as shown in FIG. 6(A), when the control device 36 closes the long flame on-off valve 34b and opens the short flame on-off valve 33b in the fuel ejection nozzle 30 on one side of the air ejection port 21, and closes the short flame on-off valve 33b and opens the long flame on-off valve 34b in the fuel ejection nozzle 30 on the opposite side of the air ejection port 21, the fuel G is not guided to the long flame fuel supply pipe 34a in the fuel ejection nozzle 30 on the side where the long flame on-off valve 34b is closed, but is guided to the short flame fuel ejection nozzle 30 through the short flame fuel supply pipe 33a. On the other hand, in the fuel injection nozzle 30 on the opposite side where the short flame on-off valve 33b is closed, fuel G is not guided to the short flame fuel supply pipe 33a, but is supplied to the long flame fuel injection nozzle 32 through the long flame fuel supply pipe 34a, and fuel G is ejected from the long flame nozzle section 32a at the tip of the long flame fuel injection nozzle 32 toward a position away from the air Air ejected from the air outlet 21.

[0054] As a result, in the fuel injection nozzle 30 on one side with the short flame on-off valve 33b open and the long flame on-off valve 34b closed as described above, the fuel G injected from the short flame nozzle section 31a is mixed and burned at a position close to the air injected from the air outlet 21, and in the fuel injection nozzle 30 on the other side with the short flame on-off valve 33b closed and the long flame on-off valve 34b open, the fuel G injected from the long flame nozzle section 32a is mixed and burned at a position away from the air outlet 21. Thus, the fuel G can be burned at positions close to and away from the air outlet 21, and the temperature at each position in the furnace 10 can be easily controlled, and the temperature change between the positions close to and away from the air outlet 21 can be reduced or the temperature can be changed as desired.

[0055] It also becomes possible to easily adjust the length of the flame to change the point at which the object is heated, and to adjust the temperature distribution within the furnace.

[0056] Furthermore, as shown in FIG. 6(B), even if both the short flame on-off valve 33b and the long flame on-off valve 34b are opened in the fuel injection nozzles 30 on both sides, the fuel G can be burned at positions close to and away from the air outlet 21. As in the above case, the temperature at each position in the furnace 10 can be easily controlled, and the temperature change between the positions close to and away from the air outlet 21 can be reduced.

[0057] Furthermore, the contents shown in the above-mentioned Figs. 4 to 6(B) do not have to be decided upon as one during the operation of the furnace 10, but a plurality of them may be combined and the operation may be performed while changing the order or time according to the situation.

[0058] (Embodiment 3) In the burner device X of the industrial furnace according to the third embodiment, as shown in FIG. 7, fuel injection nozzles 30 for ejecting fuel G are provided symmetrically on both sides of the furnace wall 11 near the air outlet 21, in the same manner as in the second embodiment, and the fuel injection nozzles 30 are provided on both sides of the furnace wall 11 near the air outlet 21, inclined in the direction toward the air Air ejected from the air outlet 21. In each fuel injection nozzle 30, a short flame fuel injection nozzle 31 is provided at a position on the air outlet 21 side, and a long flame fuel injection nozzle 32 is provided in a position farther from the air outlet 21 than the short flame fuel injection nozzle 31. At the tip of the short flame fuel injection nozzle 31, a short flame nozzle section 31a for ejecting fuel G toward a position close to the air Air ejected from the air outlet 21 is provided, and at the tip of the long flame fuel injection nozzle 32, a long flame nozzle section 32a for ejecting fuel G toward a position far from the air Air ejected from the air outlet 21 is provided.

[0059] In addition, in each fuel injection nozzle 30, when switching between the short flame fuel injection nozzle 31 and the long flame fuel injection nozzle 32 that spray fuel G using a switching means, similar to embodiments 1 and 2, a short flame on-off valve 33b is provided in the short flame fuel supply pipe 33a that supplies fuel G to each short flame fuel injection nozzle 31, and a long flame on-off valve 34b is provided in the long flame fuel supply pipe 34a that supplies fuel G to each long flame fuel injection nozzle 32, and the opening and closing of each short flame on-off valve 33b and each long flame on-off valve 34b is controlled by a control device 36.

[0060] In the burner device X of the industrial furnace according to the third embodiment, a heat storage section 40 containing a heat storage material (not shown) is provided in each air guide pipe 20 that guides air to the air outlet 21, an air on-off valve 41a is provided in an air supply pipe 41 that supplies air Air to the heat storage section 40, and an exhaust gas on-off valve 42a is provided in an exhaust gas pipe 42 that stores heat in the heat storage material in the heat storage section 40 and exhausts the combustion exhaust gas Ga after the fuel G is burned, and opening and closing of the air on-off valve 41a and the exhaust gas on-off valve 42a is controlled by the control device 36. Therefore, the burner can be used for such a heat storage alternating combustion burner (regenerative burner).

[0061] Here, in the industrial furnace according to the third embodiment, as shown in Figs. 8 to 12, the burner devices X are arranged in pairs so as to face each other on both sides of the furnace wall 11 in the furnace width direction of the furnace 10, and a plurality of pairs of such paired burner devices X are arranged at required intervals in the furnace length direction of the furnace 10.

[0062] In the industrial furnace shown in Figs. 8 to 12, in the burner device X in one of the furnace walls 11 provided so as to face the furnace walls 11 on both sides as described above, the exhaust gas on-off valve 42a provided in the exhaust gas pipe 42 is closed, while the air on-off valve 41a provided in the air supply pipe 41 is opened, and the air Air is guided to the heat storage section 40 and heated by the heat stored in the heat storage material, and the heated air Air is ejected from the air ejection port 21 into the furnace 10 through the air guide pipe 20, and fuel G is ejected from each fuel ejection nozzle 30 on both sides of the air ejection port 21, and the heated air Air and fuel G are supplied to the furnace 10. 0, while the burner device X in the furnace wall 11 on the opposite side is prevented from ejecting fuel G from each fuel ejection nozzle 30 on both sides of the air ejection port 21. The air on-off valve 41a provided in the air supply pipe 41 is closed, while the exhaust gas on-off valve 42a provided in the exhaust gas pipe 42 is opened, so that the combustion exhaust gas Ga after the fuel G is burned is guided from within the furnace 10 through the air ejection port 21 into the heat storage section 40, and the heat of the combustion exhaust gas Ga is stored in the heat storage material in the heat storage section 40, and then the combustion exhaust gas Ga is exhausted through the exhaust gas pipe 42, thereby performing a heat storage operation.

[0063] In each of the burner devices X, which are provided in pairs facing the furnace walls 11 on both sides, the combustion operation and the heat storage operation are alternately switched. In this way, the combustion air Air can be preheated by the heat of the combustion exhaust gas Ga after combustion through the heat storage section 40, thereby saving fuel.

[0064] In the industrial furnace shown in Figs. 8 to 11, in each burner device X arranged adjacent to each other in the furnace length direction of the furnace 10, the flow direction of the combustion exhaust gas Ga (see the arrows in the figures) is opposite for every pair in the furnace length direction so that there is no bias in the temperature inside the furnace, and the combustion operation and the heat storage operation are alternately switched between.

[0065] Here, in the industrial furnace shown in FIG. 8(A), in each burner device X that performs combustion operation and is provided on the furnace walls 11 on both sides, the control device 36 closes the short flame on-off valve 33b in each fuel ejection nozzle 30 provided on both sides of the air ejection port 21, while opening the long flame on-off valve 34b, and supplies fuel G to the long flame fuel ejection nozzles 32 on both sides through the long flame fuel supply pipes 34a on both sides, and ejects the fuel G from the long flame nozzle parts 32a at the tips of the long flame fuel ejection nozzles 32 on both sides toward a position away from the air ejected from the air ejection port 21, where it joins with the air ejected from the air ejection port 21 at a position away and is combusted.

[0066] In the industrial furnace shown in FIG. 8(A), in each burner device X that performs combustion operation and is provided on the furnace walls 11 on both sides, fuel G is ejected from the long flame nozzle portion 32a at the tip of the long flame fuel ejection nozzles 32 on both sides toward a position away from the air Air ejected from the air ejection port 21, and is combusted by merging with the air Air ejected from the air ejection port 21 at a distant position where they intersect, so that the temperature in the center of the furnace 10 in the furnace width direction becomes higher than the temperatures on both sides in the furnace width direction, as shown in FIG. 8(B).

[0067] In the industrial furnace shown in FIG. 9(A), in each burner device X that performs combustion operation and is provided on the furnace walls 11 on both sides, the control device 36 closes the long flame on-off valve 34b in each fuel ejection nozzle 30 provided on both sides of the air ejection port 21, while opening the short flame on-off valve 33b, and supplies fuel G to the short flame fuel ejection nozzles 31 on both sides through the short flame fuel supply pipes 33a on both sides, and ejects fuel from the short flame nozzle parts 31a at the tips of the short flame fuel ejection nozzles 31 on both sides toward a position close to the air Air ejected from the air ejection port 21, where the fuel joins with the air Air ejected from the air ejection port 21 at a position close to where they intersect, and is combusted.

[0068] In the industrial furnace shown in FIG. 9(A), in each burner device X that performs combustion operation and is provided on the furnace walls 11 on both sides, fuel is ejected from the short flame nozzle portion 31a at the tip of the short flame fuel ejection nozzle 31 on both sides toward a position close to the air Air ejected from the air ejection port 21, and is combusted by merging with the air Air ejected from the air ejection port 21 at a position close to where they intersect, so that the temperature on both sides in the furnace width direction within the furnace 10 becomes higher than the temperature in the center in the furnace width direction, as shown in FIG. 9(B).

[0069] In the industrial furnace shown in FIG. 10(A), in each burner device X that performs a combustion operation and is provided on one side of the furnace wall 11, the control device 36 closes the short flame on-off valve 33b in each fuel ejection nozzle 30 provided on both sides of the air ejection port 21, while opening the long flame on-off valve 34b, supplies fuel G to the long flame fuel ejection nozzles 32 on both sides through the long flame fuel supply pipes 34a on both sides, ejects fuel from the long flame nozzle parts 32a at the tips of the long flame fuel ejection nozzles 32 on both sides toward a position away from the air ejected from the air ejection port 21, and causes the fuel to join the air ejected from the air ejection port 21 at a position away from the air ejected from the air ejection port 21. Meanwhile, in each burner device X that is provided on the furnace wall 11 on the opposite side and performs combustion operation, the control device 36 closes the long flame on-off valve 34b in each fuel injection nozzle 30 provided on both sides of the air injection port 21, while opening the short flame on-off valve 33b, so that fuel G is supplied to the short flame fuel injection nozzles 31 on both sides through the short flame fuel supply pipes 33a on both sides, and the fuel is injected from the short flame nozzle parts 31a at the tips of the short flame fuel injection nozzles 31 on both sides toward a position close to the air Air injected from the air injection port 21, where it is merged with and combusted at a position close to the air Air injected from the air injection port 21.

[0070] As shown in FIG. 10(A), in each burner device X installed on one side of the furnace wall 11 and performing a combustion operation, fuel is ejected from the long flame nozzle portion 32a at the tip of the long flame fuel ejection nozzle 32 on both sides toward a position away from the air ejected from the air ejection port 21, and the fuel is merged with the air ejected from the air ejection port 21 at a position away from where the fuel intersects with the air ejected from the air ejection port 21 and combusted. Meanwhile, in each burner device X installed on the opposite side of the furnace wall 11 and performing a combustion operation, fuel G is ejected from the short flame nozzle portion 31a at the tip of the short flame fuel ejection nozzle 31 on both sides toward a position away from the air ejection port 21 and combusted. When the fuel G is ejected toward a position close to the air ejected from the air outlet 21 and is combusted at a position close to where it intersects with the air ejected from the air outlet 21, as shown in Figure 10 (B), the temperature inside the furnace 10 near the furnace wall 11 on the opposite side where the fuel G is burned near the air ejected from the air outlet 21 becomes higher than the temperature inside the furnace 10 near the furnace wall 11 on the one side where the fuel G is burned at a position away from the air ejected from the air outlet 21, creating a gradient in the temperature distribution inside the furnace 10.

[0071] This can be utilized when heating a steel slab (not shown) by gradually changing the temperature across the width of the furnace (gradient heating).

[0072] In the industrial furnace shown in FIG. 11(A), in each burner device X that performs a combustion operation and is provided on the furnace walls 11 on both sides, the control device 36 closes the long flame on-off valve 34b in the fuel ejection nozzle 30 provided on one side of the air ejection port 21, while opening the short flame on-off valve 33b to supply fuel G to the short flame fuel ejection nozzle 31 through the short flame fuel supply pipe 33a, and directs the fuel G from the short flame nozzle part 31a at the tip of the short flame fuel ejection nozzle 31 to a position close to the air Air ejected from the air ejection port 21. The short flame on-off valve 33b in the fuel injection nozzle 30 provided on the opposite side of the air injection port 21 is closed while the long flame on-off valve 34b is opened to supply fuel G to the long flame fuel injection nozzle 32 through the long flame fuel supply pipe 34a, and the fuel G is injected from the long flame nozzle portion 32a at the tip of the long flame fuel injection nozzle 32 toward a position away from the air injected from the air injection port 21, so that the fuel G is combusted at a position away from the air injected from the air injection port 21.

[0073] In the industrial furnace shown in FIG. 11(A), in each burner device X installed on the furnace walls 11 on both sides, fuel G is ejected from the short flame nozzle section 31a at the tip of the short flame fuel ejection nozzle 31 in the fuel ejection nozzle 30 on one side of the air ejection port 21, and combusted at a position close to the air Air ejected from the air ejection port 21, and at the same time, fuel G is ejected from the long flame nozzle section 32a at the tip of the long flame fuel ejection nozzle 32 in the fuel ejection nozzle 30 on the opposite side of the air ejection port 21, and combusted at a position away from the air Air ejected from the air ejection port 21. In this way, in each burner device X installed on the furnace walls 11 on both sides where combustion is performed, combustion is performed with a combination of long flames and short flames, and as shown in FIG. 11(B), the change in temperature in the furnace 10 in the furnace width direction is reduced, and the furnace 10 can be heated to a constant temperature. Also, although not shown here, even if both the short flame on-off valve 33b and the long flame on-off valve 34b are opened in the fuel injection nozzles 30 on both sides, the fuel G can be burned at positions close to and away from the air outlet 21, as in the case shown in Figure 6 (B) above.This makes it possible to easily control the temperature at each position in the furnace 10, and makes it possible to reduce the temperature change between the positions close to and away from the air outlet 21, or to change the temperature as desired.

[0074] It also becomes possible to easily adjust the length of the flame to change the point at which the object is heated, and to adjust the temperature distribution within the furnace.

[0075] In an industrial furnace such as the continuous heating furnace shown in Figs. 8 to 11, the combustion operation and the heat storage operation are alternately performed while the flow direction of the combustion exhaust gas Ga (see the arrows in the figures) is opposite every pair in the furnace length direction in each burner device X provided adjacent to each other in the furnace length direction so as to prevent temperature deviation in the furnace. However, as in the industrial furnace shown in Fig. 12, the combustion operation and the heat storage operation may be alternately performed while the flow direction of the combustion exhaust gas Ga (see the arrows in the figures) is opposite every two pairs in the furnace length direction in each burner device X provided adjacent to each other in the furnace length direction in each burner device X provided adjacent to each other in the furnace length direction. For example, the combustion operation and the heat storage operation may be alternately performed according to the situation.

[0076] Therefore, the contents shown in the above-mentioned Figs. 8 to 12 do not have to be decided as one during the operation of the furnace 10, but a plurality of them may be combined and the operation may be performed while changing the order or time according to the situation. [Explanation of symbols]

[0077] 10: Furnace 11: Furnace wall 20: Air guide tube 21: Air outlet 30: Fuel injection nozzle 31: Short flame fuel injection nozzle 31a: Short flame nozzle 32: Long flame fuel injection nozzle 32a: Long flame nozzle 33a: Short flame fuel supply pipe 33b: Short flame on-off valve 33c: Short flame adjusting valve 34a:Long flame fuel supply pipe 34b: Long flame on-off valve 34c: Long flame adjusting valve 36: Control device 40: Heat storage part 41: Air supply pipe 41a: Air on-off valve 42: Exhaust gas pipe 42a: Exhaust gas on-off valve Air: G: fuel Ga: Combustion exhaust gas X: Burner device

Claims

1. A burner device which mixes and burns air ejected from an air outlet and fuel ejected from a fuel ejection nozzle, characterized in that the fuel ejection nozzle is provided with a short flame fuel ejection nozzle which mixes and burns fuel at a position close to the air ejected from the air outlet, and a long flame fuel ejection nozzle which mixes and burns fuel at a position away from the air ejected from the air outlet.

2. 2. The burner device according to claim 1, wherein at least one of an angle at which fuel is ejected from the short flame nozzle portion at the tip of the short flame fuel ejection nozzle toward the air ejected from the air ejection port and an angle at which fuel is ejected from the long flame nozzle portion at the tip of the long flame fuel ejection nozzle toward the air ejected from the air ejection port is adjustable.

3. 2. The burner device according to claim 1, further comprising a switching means for switching said fuel injection nozzle for injecting fuel between said short flame fuel injection nozzle and said long flame fuel injection nozzle.

4. 2. The burner device according to claim 1, further comprising a short flame adjusting valve for adjusting the amount of fuel led to the short flame fuel injection nozzle, and a long flame adjusting valve for adjusting the amount of fuel led to the long flame fuel injection nozzle.

5. 2. The burner device according to claim 1, wherein the fuel injection nozzles having the short flame fuel injection nozzle and the long flame fuel injection nozzle are provided symmetrically on both sides of the air injection port for injecting air.

6. 2. The burner device according to claim 1, wherein an air guide pipe for guiding air to said air outlet is provided with a heat storage section containing a heat storage material.

7. An industrial furnace having a burner device provided on a furnace wall for mixing and burning air ejected from an air outlet and fuel ejected from a fuel ejection nozzle, characterized in that the burner device is the burner device described in any one of claims 1 to 6.

8. 8. The industrial furnace according to claim 7, wherein a plurality of said burner devices are provided on both sides of the furnace wall.

9. 13. An industrial furnace having a burner device provided on a furnace wall for mixing and burning air ejected from an air outlet and fuel ejected from a fuel ejection nozzle, the burner device being as described in claim 6, wherein the combustion exhaust gas after combustion in the furnace is guided through the air outlet to a heat storage section provided in an air guide tube, so that the heat of the combustion exhaust gas is stored in a heat storage material contained in the heat storage section, while the air heated by the heat-storing material in the heat storage section is guided by the air guide tube to the air outlet and ejected into the furnace.

10. 10. The industrial furnace according to claim 9, wherein a plurality of the burner devices are provided on both furnace walls, and each burner device alternately performs a heat storage operation in which the combustion exhaust gas after combustion in the furnace is guided through the air outlet to the heat storage section provided in the air guide pipe to store the heat of the combustion exhaust gas in the heat storage material contained in the heat storage section, and a combustion operation in which air heated by the heat stored in the heat storage material in the heat storage section is ejected from the air outlet into the furnace and combusted.

Images