High temperature gas generator

Abstract

To provide a high-temperature gas generator capable of efficiently and stably generating high-temperature gas even when a burner is operated with a low load while inhibiting unburned fuel gas and combustion-supporting gas from remaining in preheated gas.SOLUTION: A high-temperature gas generator includes: a burner 10 having a combustion chamber 16 in which a flame F is formed by each fuel gas G11, G12 and each combustion-supporting gas G21, G22 and generating high-temperature combustion gas by the flame F; and a high-temperature gas generation furnace 20 that mixes the high-temperature combustion gas with each preheated gas to generate high-temperature gas by supplying each preheated gas while forming the flame F in a heating chamber 23 with one end connected to the combustion chamber 16 side of the burner 10 and that discharges the high-temperature gas from a discharge port arranged at the other end. The burner 10 forms the flame F by causing a second combustion-supporting gas ejection port 15a to jet out the second combustion-supporting gas G22 so as to obtain a turning flow along a central axis J of the burner 10.SELECTED DRAWING: Figure 1B

Description

[Technical field]

[0001] The present invention relates to a hot gas generating device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a method using a burner that generates a flame using a fuel gas and a combustion-supporting gas has been adopted as a method for generating high-temperature inert gas, reducing gas, and oxidizing gas that are used to form an atmosphere in, for example, the smelting of iron and non-ferrous metals and the firing process of ceramics.

[0003] As a method for generating the above-mentioned high-temperature gas, for example, a method has been proposed in which high-temperature combustion gas is generated by a burner installed in a cylindrical high-temperature gas generating furnace, and this high-temperature combustion gas is mixed with a preheated gas to generate high-temperature gas (see, for example, Patent Document 1). In the method disclosed in Patent Document 1, the preheated gas is divided into a primary preheated gas and a secondary preheated gas, the primary preheated gas is ejected in a tangential direction from the inner wall of the furnace near the burner, and the secondary preheated gas is ejected downstream toward the central axis (see Figures 3 to 5 in Patent Document 1). As a result, the high-temperature combustion flame formed by the burner, which travels along the central axis of the high-temperature gas generating furnace, collides with the secondary preheated gas, causing stagnation in the flow of the combustion gas, which lengthens the reaction time and promotes combustion, while at the same time promoting mixing of the high-temperature combustion gas with each preheated gas.

[0004] Patent Document 1 also describes a method in which primary preheated gas is ejected from the outer periphery of a burner, and secondary preheated gas is ejected from the inner wall of a high-temperature gas generator toward the central axis (see Figures 8 and 9 in Patent Document 1). As a result, as in the above, the high-temperature combustion flame formed by the burner proceeding along the central axis of the high-temperature gas generator collides with the secondary preheated gas, causing stagnation in the flow of the combustion gas, which lengthens the reaction time and promotes combustion, while at the same time promoting mixing of the high-temperature combustion gas and each preheated gas.

[0005] As described above, in all of the methods described in Patent Document 1, the high-temperature combustion flame formed by the burner is collided with the secondary preheated gas to cause stagnation in the flow of the combustion gas and lengthen the reaction time, thereby promoting both combustion and mixing of the high-temperature combustion gas with each preheated gas. According to Patent Document 1, it is said that high-temperature gas can be generated in a furnace that is more compact than conventional furnaces.

[0006] However, when a compact high-temperature gas generator is used to eject secondary preheated gas toward a high-temperature combustion flame, there is a concern that the secondary preheated gas may flow back toward the burner, making the combustion state of the flame formed by the burner unstable or making it impossible to maintain the combustion state. In particular, for example, when the preheat temperature of the secondary preheated gas is low, the burner will burn at a low load, which may make the combustion state unstable and make it impossible to maintain the combustion. In addition, for gases with a low calorific value of 2000 Kcal / Nm, such as BFG (Blast Furnace Gas), 3 When a fuel having a low calorific value, such as that below, is used, the above-mentioned problems associated with the backflow of the secondary preheated gas may occur significantly.

[0007] In addition, when the burner is burning at a low load, the fuel ejection speed becomes slow, so that carbon deposits and adheres to the burner nozzle, and there is a risk that this carbon will break off and mix with the secondary preheated gas. In addition, there are problems such as the carbon deposits that have grown on the nozzle making it impossible to operate.

[0008] In addition, there was a problem that the high-temperature combustion flame that collided with the secondary preheated gas flowed toward the furnace wall, causing the furnace wall to become very hot, causing the refractory material that makes up the high-temperature gas generating furnace to melt and shorten the furnace's lifespan. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 3378891 Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in consideration of the above problems, and aims to provide a high-temperature gas generating device that can adjust the temperature of the preheated gas over a wide range and can generate high-temperature gas efficiently and stably even when the burner is burning at a low load. [Means for solving the problem]

[0011] In order to solve the above problems, we have conducted extensive research. As a result, we have found that by ejecting a first combustion supporting gas from the central axis of the burner at the bottom of the combustion chamber, ejecting a first fuel gas from its periphery, and then ejecting a second fuel gas from its periphery, and then ejecting a second combustion supporting gas from the side wall of the combustion chamber toward the second fuel gas so as to have a swirling flow, a flame for low-load combustion can be formed near the central axis, and a flame for high-load combustion can be formed outside of it. In this way, we have further found that by forming two flames, a stable combustion state can be maintained by the flame for low-load combustion during low-load operation, and a stable combustion state can be maintained by the flame for high-load combustion during high-load operation. As a result, we have found that it is possible to ensure a wide turndown while suppressing the unburned fuel gas and combustion supporting gas from remaining in the preheated gas, and that it is possible to efficiently and stably generate high-temperature gas even when the burner is burning at a low load, and have completed the present invention. That is, the present invention includes the following aspects.

[0012] [1] A burner having a combustion chamber in which a flame is formed by a fuel gas and a combustion supporting gas, and generating high-temperature combustion gas by the flame; and a high-temperature gas generator having one end connected to the combustion chamber side of the burner and a cylindrical shape having an internal heating chamber communicating with the combustion chamber, which supplies a preheated gas while forming the flame into the heating chamber, thereby mixing the high-temperature combustion gas and the preheated gas to generate high-temperature gas, and discharging the high-temperature gas from an exhaust port arranged at the other end opposite the combustion chamber. The burner has a combustion chamber having a bottomed conical shape that opens so that the tip side in the direction of flame formation expands in diameter, and opens on the central axis of the burner at the bottom of the combustion chamber, and a first combustion supporting gas, which is the combustion supporting gas, is discharged in a direction along the central axis. a first fuel gas outlet opening at a bottom of the combustion chamber and arranged to surround the first fuel gas outlet in a plan view, and ejecting a first fuel gas, which is the fuel gas, in a direction parallel to the first combustion supporting gas; a second fuel gas outlet opening at the bottom of the combustion chamber and arranged to surround the first fuel gas outlet in a plan view, and ejecting a second fuel gas, which is the fuel gas, in a direction parallel to the first combustion supporting gas and the first fuel gas; and a second fuel gas outlet arranged in a side wall of the combustion chamber and ejecting the second combustion supporting gas toward the second fuel gas, wherein the second combustion supporting gas outlet ejects the second combustion supporting gas so as to have a swirling flow along the central axis of the burner. [2] The high-temperature gas generating apparatus described in [1] above, characterized in that either or both of the first fuel gas outlet and the second fuel gas outlet eject the first fuel gas or the second fuel gas, which is the fuel gas, in a manner that has a swirling flow along the central axis of the burner. [3] The high-temperature gas generating apparatus described in [2] above, characterized in that swirl vanes for ejecting the first fuel gas or the second fuel gas, which is the fuel gas, as a swirling flow are arranged in either or both of the first fuel gas outlet and the second fuel gas outlet. [4] The high-temperature gas generating apparatus described in [3] above, characterized in that the swirl vanes have a plurality of blade portions arranged at an angle to the central axis of the first fuel gas outlet or the second fuel gas outlet, at either or both of the first fuel gas outlet and the second fuel gas outlet. [5] The high-temperature gas generating apparatus according to any one of the above [2] to [4], characterized in that the burner has a swirl number at the second fuel gas outlet of 0.65 or more. [6] The high-temperature gas generation apparatus according to any one of [1] to [5] above, characterized in that a primary preheated gas supply port for supplying a primary preheated gas as the preheated gas and a secondary preheated gas supply port for supplying a secondary preheated gas as the preheated gas are opened inside the heating chamber, the primary preheated gas supply port is arranged at a position on one end side of the high-temperature gas generator at which the primary preheated gas is ejected from the outer periphery of the burner toward the inside of the heating chamber, and the secondary preheated gas supply ports are arranged on the same cross section at at least three or more points on the inner surface of the heating chamber at positions at which the secondary preheated gas is ejected toward the central axis of the high-temperature gas generator, and the secondary preheated gases are collided with each other near the central axis of the high-temperature gas generator to form an airflow toward the burner connected to the one end and an airflow toward the exhaust port arranged at the other end. [7] The high-temperature gas generation apparatus described in [6] above, characterized in that the ratio [L1 / D] of the furnace inner length L1 in the direction along the flame formation direction to the furnace inner diameter D is in the range of 1 to 3. [8] The high-temperature gas generating apparatus described in [7] above, characterized in that the ratio [L2 / D] of the distance L2 from the one end connected to the burner to the secondary preheated gas supply port and the furnace inner diameter D is in the range of 0.7 to 2.1. [9] The fuel gas has a lower heating value of 2000 kcal / Nm 3 The high-temperature gas generating apparatus according to any one of the above [1] to [8], characterized in that:

[10] The high-temperature gas generator according to any one of the above [1] to [9], further comprising a cooling jacket for cooling the burner from an outer periphery side. Effect of the Invention

[0013] As described above, the high-temperature gas generation apparatus of the present invention is provided with a first combustion supporting gas outlet opening on the central axis of the burner at the bottom of the combustion chamber, a first fuel gas outlet arranged to surround the first combustion supporting gas outlet in a planar view, a second fuel gas outlet arranged to surround the first fuel gas outlet in a planar view, and a second combustion supporting gas outlet arranged on the side wall of the combustion chamber, and is configured so that the second combustion supporting gas outlet ejects the second combustion supporting gas so as to have a swirling flow along the central axis of the burner. In this way, by arranging the first combustion supporting gas outlet, the first fuel gas outlet, the second fuel gas outlet, and the second combustion supporting gas outlet that ejects the second combustion supporting gas in a swirling flow, a flame for low-load combustion can be formed near the central axis of the burner, and a flame for high-load combustion can be formed outside of that. As a result, during low-load operation, a stable combustion state can be maintained by the flame for low-load combustion formed near the central axis, and during high-load operation, a stable combustion state can be maintained by the flame for high-load combustion formed outside the flame for low-load combustion. Therefore, a wide range of turndown can be ensured while suppressing the remaining unburned fuel gas and combustion supporting gas in the preheated gas, and high-temperature gas can be generated efficiently and stably even when the burner is burning at a low load. [Brief description of the drawings]

[0014] [Figure 1A] FIG. 1 is a diagram for explaining the configuration of a high-temperature gas generation apparatus according to a first embodiment of the present invention, and is a cross-sectional view along the axial direction of the high-temperature gas generation apparatus, showing the internal structure of the high-temperature gas generation apparatus and the flows of the first fuel gas, the second fuel gas, the first combustion supporting gas, the second combustion supporting gas, the first preheated gas and the second preheated gas together with the flames that are formed. [Figure 1B]FIG. 1B is a diagram for explaining the configuration of a high-temperature gas generation apparatus according to a first embodiment of the present invention, and is a cross-sectional view showing a main part of a burner provided in the high-temperature gas generation apparatus shown in FIG. 1A. [Diagram 2] FIG. 1B is a diagram for explaining the configuration of a high-temperature gas generation apparatus according to a first embodiment of the present invention, and is a cross-sectional view taken along line AA in FIG. 1A. [Figure 3A] FIG. 1C is a diagram for explaining the configuration of the high-temperature gas generation apparatus according to the first embodiment of the present invention, and is a cross-sectional view showing an enlarged view of a swirl vane provided at the second fuel gas outlet shown in FIGS. 1A and 1B. [Figure 3B] FIG. 1C is a diagram for explaining the configuration of the high-temperature gas generation apparatus according to the first embodiment of the present invention, and is an enlarged side view showing a swirl vane provided at the second fuel gas outlet shown in FIGS. 1A and 1B. [Figure 3C] FIG. 1C is a diagram for explaining the configuration of the high-temperature gas generation apparatus according to the first embodiment of the present invention, and is a plan view showing an enlarged view of swirl vanes provided at the second fuel gas outlet shown in FIGS. 1A and 1B. [Figure 4] FIG. 1 is a diagram for explaining the configuration of a high-temperature gas generation apparatus according to a second embodiment of the present invention, showing the internal structure of the high-temperature gas generation apparatus, and a cross-sectional view along the axial direction of the high-temperature gas generation apparatus, showing the flows of the first fuel gas, the second fuel gas, the first combustion supporting gas, the second combustion supporting gas, the first preheated gas and the second preheated gas together with the flames that are formed. [Diagram 5] FIG. 1 is a diagram for explaining the configuration of a high-temperature gas generation apparatus according to a third embodiment of the present invention, showing the internal structure of the high-temperature gas generation apparatus, and a cross-sectional view along the axial direction of the high-temperature gas generation apparatus, showing the flows of the first fuel gas, the second fuel gas, the first combustion supporting gas, the second combustion supporting gas, the first preheated gas and the second preheated gas together with the flames that are formed. [Figure 6]FIG. 10 is a schematic diagram illustrating the configuration of a high-temperature gas generation apparatus according to a fourth embodiment of the present invention, showing the essential parts of a burner provided in the high-temperature gas generation apparatus, and is a cross-sectional view along the axial direction of the high-temperature gas generation apparatus, showing the flows of the first fuel gas, the second fuel gas, the first combustion supporting gas, the second combustion supporting gas, the third combustion supporting gas, and the first preheated gas together with the flames that are formed. [Figure 7] FIG. 11 is a schematic diagram illustrating the configuration of a high-temperature gas generation apparatus according to a fifth embodiment of the present invention, showing the main parts of a burner provided in the high-temperature gas generation apparatus, and is a cross-sectional view along the axial direction of the high-temperature gas generation apparatus, showing the flows of the first fuel gas, the second fuel gas, the third fuel gas, the first combustion supporting gas, the second combustion supporting gas, the third combustion supporting gas, and the first preheated gas together with the flames that are formed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a high-temperature gas generator according to an embodiment of the present invention will be described with reference to Fig. 1A and Fig. 1B to Fig. 7. The drawings used in the following description may show characteristic parts in an enlarged scale for the sake of clarity, and the dimensional ratios of each component may not be the same as in reality. In addition, the materials exemplified in the following description are merely examples, and the present invention is not limited to them. The present invention may be modified as appropriate within the scope of the present invention.

[0016] First Embodiment The configuration of the high-temperature gas generation apparatus according to the first embodiment of the present invention will be described in detail below. FIG. 1A is a cross-sectional view along the axial direction of the high-temperature gas generator 1, showing the internal structure of the high-temperature gas generator 1 of this embodiment, and showing the flows of the first fuel gas G11 and the second fuel gas G12, which are fuel gases, the first combustion supporting gas G21 and the second combustion supporting gas G22, and the primary preheated gas G41 and the secondary preheated gas G42, which are preheated gases, together with the swirling flow of the flame F that is formed. FIG. 1B is a cross-sectional view showing a main part of a burner 10 provided in the high-temperature gas generator 1 shown in FIG. 1A. FIG. 2 is an AA cross-sectional view of the high-temperature gas generator 1 shown in FIG. 1A. FIG. 3A is a cross-sectional view showing an enlarged swirl vane 40 provided at the second fuel gas outlet 13a of the high-temperature gas generator 1 shown in FIG. 1A, FIG. 3B is a side view showing an enlarged swirl vane 40, and FIG. 3C is a plan view showing an enlarged swirl vane 40.

[0017] As shown in Figures 1A and 1B, the high-temperature gas generation apparatus 1 of this embodiment has a combustion chamber 16 in which a flame F is formed with a first fuel gas G11 and a second fuel gas G12, which are fuel gases, and a first combustion supporting gas G21 and a second combustion supporting gas G22, which are combustion supporting gases, and is equipped with a burner 10 that generates a high-temperature combustion gas G3 by the flame F.

[0018] The high-temperature gas generating device 1 is also equipped with a high-temperature gas generating furnace 20, which has one end 21 connected to the combustion chamber 16 side of the burner 10 and has a cylindrical shape with an internal heating chamber 23 that communicates with the combustion chamber 16, and which supplies primary preheated gas G41 and secondary preheated gas G42 while forming a flame F in the heating chamber 23, thereby mixing the high-temperature combustion gas G3 with the preheated gas to generate high-temperature gas G5, and discharges the high-temperature gas G5 from an exhaust port 25 located at the other end 22 opposite the combustion chamber 16. In the high-temperature gas generating apparatus 1 of this embodiment, the second combustion supporting gas outlet 15a provided in the burner 10 ejects the second combustion supporting gas G22 so as to have a swirling flow along the central axis J of the burner 10, thereby forming a flame F.

[0019] More specifically, in the high-temperature gas generator 1 of the example described in this embodiment, the combustion chamber 16 of the burner 10 is formed in a bottomed cone shape that opens so that the tip 11 side in the direction in which the flame F is formed expands, and a first combustion supporting gas outlet 14a that ejects the first combustion supporting gas G21 in a direction along the central axis J is opened at the bottom 16a of the combustion chamber 16. Also, at the bottom 16a of the combustion chamber 16, a first fuel gas outlet 12a that is arranged to surround the first combustion supporting gas outlet 14a in a plan view and ejects the first fuel gas G11 in a direction parallel to the first combustion supporting gas G21, and a second fuel gas outlet 13a that is arranged to surround the first fuel gas outlet 12a in a plan view and ejects the second fuel gas G12 in a direction parallel to the first combustion supporting gas G21 and the first fuel gas G11 are opened. Further, a second combustion supporting gas outlet 15a for ejecting a second combustion supporting gas G22 toward the second fuel gas G12 is opened and disposed on the side wall 16b of the combustion chamber 16. As shown in Fig. 1A and Fig. 1B, the burner 10 provided in the high temperature gas generator 1 of this embodiment ejects the second combustion supporting gas G22 from the second combustion supporting gas outlet 15a so as to have a swirling flow along the central axis J of the burner 10.

[0020] Moreover, the illustrated high-temperature gas generator 1 further includes a cooling jacket 30 for cooling the burner 10.

[0021] In this specification, the central axis J of the high-temperature gas generating apparatus 1 is explained by giving the same symbol (J) to the central axes of the burner 10 and the high-temperature gas generating furnace 20 that constitute the high-temperature gas generating apparatus 1, as well as the central axes of the swirling flows of each gas.

[0022] The high-temperature gas generation apparatus 1 of this embodiment has the above-mentioned configuration and is an apparatus that generates high-temperature gas G5 of, for example, 200 to 1700°C by directly mixing high-temperature combustion gas G3 and preheated gas in the high-temperature gas generation furnace 20 using a so-called direct combustion method. The high-temperature gas G5 generated by the high-temperature gas generator 1 is used, for example, for forming an atmosphere in the smelting of iron and non-ferrous metals, the ceramic firing process, etc. Specifically, the high-temperature gas G5 is obtained by directly mixing, for example, blast furnace top gas (BFG), coke oven gas (COG), natural gas, hydrogen gas (H2), carbon monoxide gas (CO), reducing gas, and gas mixtures thereof that contain combustible components, or oxygen, oxygen-enriched air, air, or inert gas with the high-temperature combustion gas G3 generated by the burner 10.

[0023] The high-temperature gas generator 1 of this embodiment can use a flammable gas with a low calorific value as the first fuel gas G11 and the second fuel gas G12. For example, 3 The following fuel gases can be used. Examples of such fuel gases include natural gas and gases that satisfy the conditions of being flammable and insoluble in water as a fuel. The high-temperature gas generation apparatus 1 of this embodiment can efficiently and stably generate high-temperature gas G5 even when a fuel gas with a low calorific value is used.

[0024] Here, the "lower heating value" described in the present invention is the higher heating value measured by a calorimeter minus the value obtained by multiplying the latent heat of condensation of water vapor by the amount of water vapor, and can be calculated, for example, by the following formula [(lower heating value) = (higher heating value) - (latent heat of condensation of water vapor) x (amount of water vapor)] (see paragraph 0087 of the republished patent WO2014 / 148536). The method for measuring the calorific value is specified in JIS K2301:2011 "Fuel gas and natural gas - Analysis and test methods", and for example, it can be calculated using the method specified in "8.2 Method for calculating the calorific value (gas chromatography method)".

[0025] Further, examples of the first combustion supporting gas G21 and the second combustion supporting gas G22 described in this embodiment include oxygen-enriched air, oxygen, and the like. Moreover, the primary preheated gas G41 and the secondary preheated gas G42 may be, for example, nitrogen gas (N2).

[0026] The burner 10 includes a combustion chamber 16 for forming a flame F, a first combustion supporting gas outlet 14a, a first fuel gas outlet 12a and a second fuel gas outlet 13a which open into a bottom 16a of the combustion chamber 16, and a second combustion supporting gas outlet 15a which opens into a side wall 16b of the combustion chamber 16.

[0027] In the illustrated example, the combustion chamber 16 is a recess formed in a bottomed cone shape that opens so as to expand in diameter toward the tip 11 side, and has a substantially trapezoidal longitudinal section. As described above, the burner 10 generates a flame F in this combustion chamber 16, thereby generating high-temperature combustion gas G3 toward the downstream side of the burner 10, i.e., toward the high-temperature gas generator 20.

[0028] As described above, the first combustion supporting gas outlet 14a, the first fuel gas outlet 12a, the second fuel gas outlet 13a, and the second combustion supporting gas outlet 15a are opened inside the combustion chamber 16, and a flame F is formed inside the combustion chamber 16 by the first fuel gas G11 ejected from the first fuel gas outlet 12a and the second fuel gas G12 ejected from the second fuel gas outlet 13a, the first combustion supporting gas G21 ejected from the first combustion supporting gas outlet 14a, and the second combustion supporting gas G22 ejected from the second combustion supporting gas outlet 15a.

[0029] 1A and 1B, the first combustion supporting gas supply passage 14 is arranged on the central axis J of the burner 10, and is arranged coaxially with the first fuel gas supply passage 12, the details of which will be described later, so as to be surrounded by the first fuel gas supply passage 12. The first combustion supporting gas supply passage 14 is also provided so as to eject the first combustion supporting gas G21 in the axial direction of the burner 10 from a first combustion supporting gas ejection port 14a opening in a bottom portion 16a of the combustion chamber 16 toward the inside of the combustion chamber 16. As long as the first combustion supporting gas outlet 14a opens into the combustion chamber 16, the shape thereof in plan view and the like are not particularly limited, and the first combustion supporting gas outlet 14a can be designed arbitrarily.

[0030] In the illustrated example, the first fuel gas supply passage 12 ejects the first fuel gas G11 in the axial direction of the burner 10 from a first fuel gas ejection port 12a that opens at a position outside the central axis J in the bottom 16a of the combustion chamber 16. As described above, in the example shown in Figures 1A and 1B, the first fuel gas supply passage 12 is disposed so as to surround the first combustion supporting gas supply passage 14. The first fuel gas supply path 12 is connected to a tank filled with the first fuel gas G11, for example, via a fuel flow path pipe and a fuel control unit (not shown), and the first fuel gas G11 is ejected from the first fuel gas outlet 12a into the combustion chamber 16.

[0031] Detailed illustration of the first fuel gas nozzles 12a is omitted, but for example, multiple first fuel gas nozzles 12a are arranged at equal intervals on a circumference centered on the central axis J at the bottom 16a of the combustion chamber 16, so as to surround the first combustion supporting gas nozzle 14a arranged on the central axis J. As long as the first fuel gas outlets 12a are open to the bottom 16a of the combustion chamber 16, the arrangement intervals, number of holes, shape, and the like are not particularly limited and can be set arbitrarily.

[0032] In the illustrated example, the second fuel gas supply passage 13 ejects the second fuel gas G12 in the axial direction of the burner 10 from a second fuel gas outlet 13a that opens at a position outside the first fuel gas outlet 12a in the bottom 16a of the combustion chamber 16. Like the first fuel gas supply passage 12, the second fuel gas supply passage 13 is connected to a tank filled with the second fuel gas G12 via a fuel flow passage pipe and a fuel control section (not shown), for example, to eject the second fuel gas G12 from the second fuel gas outlet 13a toward the inside of the combustion chamber 16.

[0033] Although detailed illustration is omitted, the second fuel gas nozzles 13a are arranged at multiple equal intervals, for example, on a circumference centered on the central axis J at the bottom 16a of the combustion chamber 16, so as to surround the first fuel gas nozzle 12a. Furthermore, as with the multiple first fuel gas nozzles 12a, the multiple second fuel gas nozzles 13a are not particularly limited in terms of their arrangement spacing, number of holes, shape, etc., as long as they open to the bottom 16a of the combustion chamber 16, and can be set as desired.

[0034] In the illustrated example, the second combustion supporting gas supply passage 15 ejects the second combustion supporting gas G22 from a second combustion supporting gas nozzle 15a opening in a side wall 16b of the combustion chamber 16 in a tangential direction of the side wall of the combustion chamber 16. More specifically, the second combustion supporting gas nozzle 15a ejects the second combustion supporting gas G22 so as to have a swirling flow along the central axis J of the burner 10.

[0035] Detailed illustration of the second combustion supporting gas nozzles 15a is omitted, but for example, multiple second combustion supporting gas nozzles 15a are arranged at equal intervals on a circumference centered on the central axis J on the side wall 16b of the combustion chamber 16 so as to surround the first fuel gas nozzle 12a from the outside in a plan view. Furthermore, as long as the second combustion supporting gas ports 15a are open to the side wall 16b of the combustion chamber 16, there are no particular limitations on the arrangement intervals, number of holes, shape, etc., and they can be set arbitrarily. Although detailed illustration is omitted, the above-mentioned multiple second combustion supporting gas outlets 15a may be arranged in a single row on a circumference centered on the central axis J, but is not limited to this. The multiple second combustion supporting gas outlets 15a may be arranged in two or more rows on a circumference centered on the central axis J, for example, at different positions in a direction perpendicular to the central axis J.

[0036] The burner 10 provided in the high-temperature gas generator 1 of the example shown in Figures 1A and 1B has a swirl vane 41 arranged at the first fuel gas outlet 12a for ejecting the first fuel gas G11 as a swirling flow, and a swirl vane 40 arranged at the second fuel gas outlet 13a for ejecting the second fuel gas G12 as a swirling flow. 1A and 1B, the detailed structure of the swirl vanes 40 is omitted, but as shown in Figures 3A, 3B, and 3C (see also Figures 1A and 1B), inside the second fuel gas outlet 13a and the second fuel gas supply passage 13, the swirl vanes 40 are arranged on the outer circumferential surface of the inner pipe of the second fuel gas supply passage 13 so as to be inclined with respect to the central axis of the second fuel gas outlet 13a, i.e., the central axis J of the burner 10. Note that, for convenience of illustration, a portion of the first fuel gas supply passage 12 in the longitudinal direction is omitted in Figures 3A and 3B. The swirl vanes 41 are disposed on the outer circumferential surface of the inner pipe of the first fuel gas supply passage 12 so as to be inclined with respect to the central axis of the first fuel gas outlet 12a, i.e., the central axis J of the burner 10, inside the first fuel gas outlet 12a and the first fuel gas supply passage 12. Since the swirl vanes 41 have the same structure as the swirl vanes 40 shown in Figures 3A to 3C, except for the position of the supply passage to be installed, detailed illustrations are omitted and the swirl vanes 41 will be described with reference to the swirl vanes 40 shown in Figures 3A, 3B, and 3C (see also Figures 1A and 1B).

[0037] The swirl vanes 40 and 41 may be configured to be fixed to the inner pipe side of the second fuel gas supply passage 13 or the inner pipe side of the first fuel gas supply passage 12 without rotating, for example.

[0038] 3B and 3C, four swirl vanes 40 are arranged at equal intervals in the circumferential direction on the outer circumferential surface of the inner pipe of the second fuel gas supply passage 13, and the radial outermost points of the swirl vanes 40 abut against or are close to the inner surface of the outer pipe of the second fuel gas supply passage 13. Although not shown, similar to the case of the swirl vanes 40, four swirl vanes 41 are also arranged at equal intervals in the circumferential direction on the outer circumferential surface of the inner pipe of the first fuel gas supply passage 12, and the radial outermost points of the swirl vanes 41 abut against or are close to the inner surface of the outer pipe of the first fuel gas supply passage 12.

[0039] The inclination angle of the swirl vanes 40 and 41 with respect to the central axis J is not particularly limited, but from the viewpoint of effectively imparting a swirling flow to the first fuel gas G11 and the second fuel gas G12, it is more preferable to set the angle to, for example, a range of 40 to 60°. Here, the inclination angle of the swirl vanes 40 and 41 with respect to the central axis J can be calculated from the following formula (1) by determining the outer diameter and inner diameter of the first fuel gas supply passage 12 and the second fuel gas supply passage 13 from the flow rates and ejection velocities of the first fuel gas G11 and the second fuel gas G12, and setting the swirl number represented by formula (1) described below. For example, when the swirl number is 0.65, the inclination angle of the swirl vanes 40 and 41 with respect to the central axis J obtained from the following formula (1) is 40°, and when the swirl number is 1.4, the inclination angle of the swirl vanes 40 and 41 with respect to the central axis J is 60°.

[0040] In the illustrated example, the swirl vanes 40 are provided in four locations; however, the number of swirl vanes 40 and 41 to be installed is not particularly limited, and they may be provided in five or more locations within the first fuel gas supply passage 12 or the second fuel gas supply passage 13, or a configuration in which they are provided in less than four locations may be adopted. Furthermore, the inclination angle and number of the swirl vanes 40 and 41 relative to the central axis J may be appropriately changed taking into consideration the size of the burner 10 and the strength of the swirl flow.

[0041] The first fuel gas G11 supplied from the first fuel gas supply passage 12 passes through the swirl vane 41 and is ejected from the first fuel gas outlet 12a, and the second fuel gas G12 supplied from the second fuel gas supply passage 13 passes through the swirl vane 40 and is ejected from the second fuel gas outlet 13a. At this time, the first fuel gas G11 and the second fuel gas G12 flow along the inclination of the swirl vane 41 or the swirl vane 40, and are ejected into the combustion chamber 16 while flowing in a swirling manner around the central axis J of the burner 10. In addition, the swirl vane 40 and the swirl vane 41 generate a swirling flow in the same direction as the swirling flow generated by the second combustion supporting gas outlet 15a.

[0042] In this embodiment, by providing the first fuel gas nozzle 12a with the swirl vane 41 having the above-mentioned configuration and the second fuel gas nozzle 13a with the swirl vane 40 having the above-mentioned configuration, it is more preferable that the swirl number represented by the following formula (1) at the first fuel gas nozzle 12a or the second fuel gas nozzle 13a is 0.65 or more.

[0043]

number

[0044] In the above formula (1), S is the swirl number (-), d2 is the inner diameter of the outer pipe of the first fuel gas nozzle 12a (first fuel gas supply passage 12) or the second fuel gas nozzle 13a (second fuel gas supply passage 13), d5 is the outer diameter of the inner pipe of the first fuel gas nozzle 12a (first fuel gas supply passage 12) or the second fuel gas nozzle 13a (second fuel gas supply passage 13), and α is the inclination angle (°) of the swirl vane 41 or the swirl vane 40 with respect to the central axis J.

[0045] In general, the characteristics of a swirling flow, i.e., the swirling strength, are expressed by the swirl number (S) defined by the above formula (1). The larger the value of this swirl number (S), the stronger the swirling flow. A swirl number of 0.65 or more results in a strong swirling flow (see, for example, paragraphs 0025-0026 of JP 2004-108656 A).

[0046] In the burner 10, when the swirl vane 40 having the above-mentioned configuration is arranged at the second fuel gas outlet 13a and the swirl vane 41 is arranged at the first fuel gas outlet 12a, a swirl flow is generated in the second fuel gas G12 ejected from the second fuel gas outlet 13a, and a swirl flow is also generated in the first fuel gas G11 ejected from the first fuel gas outlet 12a. Furthermore, the second combustion supporting gas G22 ejected from the second combustion supporting gas outlet 15a is ejected toward the second fuel gas G12 and the first fuel gas G11 so as to have a swirl flow along the central axis J of the burner 10, thereby forming a backflow area in the vicinity of the central axis of the swirl flow. As a result, the flame F formed in the combustion chamber 16, specifically the high-load combustion flame FB, has a swirl flow and has a backflow area in the vicinity of the central axis of the swirl flow, i.e., the central axis J of the burner 10.

[0047] Furthermore, the burner 10 generates a swirling flow in the first fuel gas G11 and the second fuel gas G12, and ejects the second combustion supporting gas G22 toward the second fuel gas G12 and the first fuel gas G11 in a tangential direction to the swirling flow of the second fuel gas G12 and the first fuel gas G11, thereby forming a backflow region in the vicinity of the central axis of the swirling flow. As a result, the high-load combustion flame FB formed in the combustion chamber 16 has a swirling flow and a backflow region in the vicinity of the central axis of the swirling flow, as described above.

[0048] As described above, the high-temperature gas generator 20 supplies primary preheated gas G41 and secondary preheated gas G42 while forming a flame F in the heating chamber 23, thereby mixing the high-temperature combustion gas G3 with the preheated gases G41, G42 to generate high-temperature gas G5, and discharges the high-temperature gas G5 from an exhaust outlet 25 located at the other end 22 opposite the combustion chamber 16.

[0049] As described above, the high-temperature gas generator 20 is configured in a roughly cylindrical shape with one end 21 connected to the tip 11 side, which is the downstream side of the burner 10, and with an internal heating chamber 23 communicating with the combustion chamber 16 of the burner 10. That is, in the heating chamber 23, the flame F formed in the combustion chamber 16 of the burner 10 is formed so as to spread toward the other end 22 side, which is the downstream side.

[0050] Opening inside the heating chamber 23 are a primary preheated gas outlet 26a for supplying a primary preheated gas G41 as a preheated gas, and a secondary preheated gas outlet 27a for supplying a secondary preheated gas G42 as a preheated gas.

[0051] The primary preheated gas outlet 26a is disposed at a position on one end 21 side of the high temperature gas generator 20 where the primary preheated gas G41 is ejected from the outer periphery of the burner 10 toward the inside of the heating chamber 23. That is, the primary preheated gas outlet 26a is configured, for example, in an annular slit shape in a plan view, and uniformly ejects and supplies the primary preheated gas G41 into the inside of the heating chamber 23 via the primary preheated gas supply path 26 configured annularly so as to surround the outside of the burner 10. As described above, the primary preheated gas outlets 26a are arranged so as to open from the periphery of the burner 10 into the heating chamber 23, and the arrangement interval, shape, and the like are not particularly limited and can be set arbitrarily. For example, the primary preheated gas outlets 26a may be configured from a plurality of outlets, and these outlets may be arranged in a ring shape so as to surround the outside of the burner 10.

[0052] The secondary preheated gas outlets 27a are arranged concentrically (on the same cross section) at at least three locations on the inner surface of the heating chamber 23 at positions for ejecting the secondary preheated gas G42 toward the central axis J of the high-temperature gas generator 20. That is, as shown in Fig. 1A, the secondary preheated gas outlets 27a collide the secondary preheated gas G42 with each other near the central axis of the high-temperature gas generator 20, thereby forming an airflow from the burner 10 connected to one end 21 toward the exhaust port 25 arranged at the other end 22. Furthermore, as long as the multiple secondary preheated gas outlets 27a are arranged so that they open at three or more locations on the inner surface of the heating chamber 23, as described above, their arrangement spacing, number of holes, shape, etc. are not particularly limited and can be set arbitrarily.

[0053] As described above, the exhaust outlet 25 discharges the high-temperature gas G5 generated in the heating chamber 23 to the outside, and in the illustrated example, it is connected to the heating chamber 23 and is configured to protrude cylindrically from the inner wall of the furnace toward the outside of the high-temperature gas generator 20.

[0054] With the above configuration, in the high-temperature gas generator 20, the flame F, which has a swirling flow formed by the burner 10 and has a backflow region (circulating flow) near the central axis of the swirling flow, collides with the secondary preheated gas G42, causing stagnation in the flow of the high-temperature combustion gas G3. This lengthens the reaction time between the high-temperature combustion gas G3 and the primary preheated gas G41 and secondary preheated gas G42, promoting combustion, and promoting mixing of the high-temperature combustion gas G3 with the primary preheated gas G41 and secondary preheated gas G42.

[0055] In addition, the secondary preheated gas outlets 27a may be provided at least in three locations on the inner surface of the heating chamber 23, but it is more preferable to provide them at four or more locations in order to provide symmetry to the secondary preheated gas G42 ejected into the heating chamber 23.

[0056] In addition, the material constituting the heating chamber 23 is not particularly limited, and examples thereof include refractories such as high alumina castables. From the viewpoint of extending the service life, however, it is preferable to use a refractory material having a fire-resistant temperature of about 1600°C or higher.

[0057] In addition, the dimensions of the heating chamber 23 are not particularly limited, but for example, as shown in FIG. 1A, it is preferable that the ratio [L1 / D] of the furnace inner length L1 in the direction along the formation direction of the flame F to the furnace inner diameter D is in the range of 1 to 3. When the above ratio [L1 / D] is 1 or more, the high-temperature combustion gas G3 and the secondary preheated gas G42 in the heating chamber 23 can be mixed sufficiently, and the high-temperature gas G5 discharged from the exhaust port 25 has a uniform and high temperature. In addition, when the above ratio [L1 / D] is 3 or less, it is possible to prevent the furnace wall of the heating chamber 23 from being melted by the flame F, so that the temperature of the high-temperature gas G5 is stabilized and the life of the high-temperature gas generator 20 can be extended.

[0058] Moreover, it is more preferable that the ratio [L2 / D] of the distance L2 from the one end 21 connected to the burner 10 to the center line of the secondary preheated gas outlet 27a of the heating chamber 23 is in the range of 0.7 to 2.1, to the furnace inner diameter D. When the ratio [L2 / D] is 0.7 or more, the influence of the flow of the secondary preheated gas G42 toward the burner 10 side is suppressed from becoming too large, so that the good combustion state of the burner 10 can be maintained and the residual oxygen concentration can be suppressed low. When the ratio [L2 / D] is 2.1 or less, the mixing of the combustion gas and the secondary preheated gas G42 is sufficiently promoted, so that the furnace temperature and the furnace wall temperature of the heating chamber 23 can be suppressed from becoming too high. For the same reason as above, the ratio of the distance L2 to the inner furnace length L1 is more preferably 0.5 to 0.9.

[0059] The cooling jacket 30 is for cooling the burner 10, and in the illustrated example is configured in a cylindrical shape, with a double pipe structure that covers, via an annular space, the outside of the flow passage pipe that constitutes the second combustion supporting gas supply passage 15. This annular space serves as a cooling water flow passage 30a through which the cooling water W flows, and is configured so that the burner 10 can be cooled by the flow of the cooling water W.

[0060] In the illustrated cooling jacket 30, cooling water W is passed through an inlet 30b, passes through a cooling water passage 30a, and is discharged from an outlet 30c. In the high-temperature gas generator 1 of this embodiment, the cooling water W cools the burner 10 when passing through the cooling water passage 30a. The cooling jacket 30 protects each component of the burner 10 from the high-temperature atmosphere and radiant heat caused by the flame, and also suppresses excessive heating within the combustion chamber 16.

[0061] The actions and effects obtained by the high-temperature gas generation apparatus 1 of this embodiment having the above-mentioned configuration will be described below. According to the high-temperature gas generator 1 of the present embodiment, the above-mentioned configuration first ejects the first combustion supporting gas G21 in a straight flow from the central axis J at the bottom 16a of the combustion chamber 16 having a bottomed cone shape, and ejects the first fuel gas G11 for low-load combustion from its periphery (low-load combustion). Furthermore, ejects the second fuel gas G12 for high-load combustion from its periphery in a swirling flow, and ejects the second combustion supporting gas G22 from the side wall 16b of the combustion chamber 16 so as to have a swirling flow along the central axis J of the burner 10 (high-load combustion). By adopting such an ejection form of each gas, a flame FA (flame F) for low-load combustion can be generated near the central axis J of the burner 10, and a flame FB for high-load combustion can be formed outside of it. That is, the burner 10 provided in the high-temperature gas generation apparatus 1 of this embodiment forms two types of flames by mainly burning the first combustion supporting gas G21 and the first fuel gas G11 to form a low-load combustion flame FA, and by mainly burning the second combustion supporting gas G22 and the second fuel gas G12 to form a high-load combustion flame FB.

[0062] As described above, by forming two types of flames F, the low-load combustion flame FA and the high-load combustion flame FB, a stable combustion state can be maintained by the low-load combustion flame FA during low-load operation, and a stable combustion state can be maintained by the high-load combustion flame FB during high-load operation. This makes it possible to suppress unburned combustion-supporting gases (first combustion-supporting gas G21 and second combustion-supporting gas G22) and unburned fuel gases (first fuel gas G11 and second fuel gas G12) from remaining in the high-temperature combustion gas G3 described below, making it possible to stably generate high-temperature gas G5.

[0063] Furthermore, according to this embodiment, by forming the two types of flame F, the low-load combustion flame FA and the high-load combustion flame FB, as described above, it is possible to set the fuel injection speed during low-load operation in the burner 10 to 40 m / s or more, which is equivalent to that during high-load operation. This makes it possible to prevent carbon derived from the fuel gas from adhering to the first fuel gas outlet 12a and the second fuel gas outlet 13a of the burner 10 and their vicinity, even when the high-temperature gas generator 1 is operated at a low load. Therefore, a stable combustion state in the burner 10 can be maintained even during low-load operation.

[0064] Furthermore, according to this embodiment, by forming the two types of flame F, the low-load combustion flame FA and the high-load combustion flame FB, as described above, the low-load combustion flame FA functions as an ignition source in the burner 10. As a result, even if a fuel with a lower calorific value is used as the first fuel gas G11 or the second fuel gas G12, the flame F can be formed with stable combustion.

[0065] More specifically, the high-temperature gas generator 1 of this embodiment is configured to eject the first combustion-supporting gas G21 from the central axis J of the burner 10, and the combustion is promoted by the circulation of the first fuel gas G11, and a more stable flame FA for low-load combustion is formed. In addition, when the flame F has the above-mentioned reverse flow region, the residence time of the first fuel gas G11 and the second fuel gas G12, and the first combustion-supporting gas G21 and the second combustion-supporting gas G22 in the combustion chamber 16 becomes longer, so that it is possible to suppress the remaining of unburned fuel gas and combustion-supporting gas. As a result, even if a gas with a low calorific value is used as the first fuel gas G11 or the second fuel gas G12, the high-temperature gas G5 can be efficiently and stably generated, and this contributes to the miniaturization and long life of the high-temperature gas generator 20.

[0066] Here, the low-load combustion flame FA formed mainly by burning the first combustion supporting gas G21 and the first fuel gas G11 described in this embodiment refers to a flame having the characteristics described below. That is, in this embodiment, a configuration is adopted in which the fuel gas outlet is divided into the first fuel gas outlet 12a and the second fuel gas outlet 13a. As a result, during low-load combustion, the first fuel gas G11 is mainly ejected from the first fuel gas outlet 12a, so that the ejection speed of the fuel gas is maintained even at low load, and the first combustion supporting gas G21 is entrained by the swirling flow of the first fuel gas G11, which promotes the mixing of the gases, and a stable low-load combustion flame FA is formed. As described above, such a low-load combustion flame FA has the effect of maintaining a stable combustion state when the high-temperature gas generator 1 (burner 10) is operated at low load.

[0067] On the other hand, the high-load combustion flame FB formed mainly by burning the second combustion supporting gas G22 and the second fuel gas G12 described in this embodiment refers to a flame having the characteristics described below. That is, in this embodiment, during high-load combustion, in addition to the first fuel gas G11 ejected from the first fuel gas ejection port 12a, the second fuel gas G12 is ejected from the second fuel gas ejection port 13a, so that the ejection speed of the fuel gas does not become too high and the flame does not blow away, and a stable high-load combustion flame FB is formed. As described above, unlike the low-load combustion flame FA, such a high-load combustion flame FB has the effect of maintaining a stable combustion state when the high-temperature gas generator 1 (burner 10) is operated at a high load.

[0068] Furthermore, according to the high-temperature gas generator 1 of this embodiment, as described above, when the burner 10 forms the flame F as a flame with a swirl flow and a backflow region (circulation flow: a flow that flows back toward the burner 10) in the vicinity of the central axis J of the swirl flow, the combustion is promoted by the circulation of the combustion gas, and a more stable flame F is formed. Also, when the flame F has the above-mentioned backflow region, the flame F and the secondary preheated gas G42 are unlikely to collide on the central axis J, so that the combustion state of the flame F is stable, and therefore, even in a compact high-temperature gas generator 20, the high-temperature combustion gas G3 can be efficiently and stably generated. Furthermore, since the flame F has a backflow region, the residence time of the first fuel gas G11 and the second fuel gas G12, and the first combustion-supporting gas G21 and the second combustion-supporting gas G22 in the combustion chamber 16 becomes longer, so that it is possible to suppress the remaining of unburned fuel gas and combustion-supporting gas. As a result, even if the high-temperature gas generator 20 is compact or the first fuel gas G11 and the second fuel gas G12 have low heat generation, the high-temperature gas G5 can be generated efficiently and stably, and the high-temperature gas generator 20 can be made smaller and have a longer life.

[0069] In addition, by dividing the preheated gas into a primary preheated gas G41 and a secondary preheated gas G42 and ejecting the primary preheated gas G41 from the primary preheated gas ejection port 26a arranged around the burner 10, the primary preheated gas G41 flows between the furnace wall of the heating chamber 23 and the spreading flame F, and the furnace wall can be prevented from becoming hot. In particular, in the case of the burner 10 described in this embodiment, which has a combustion chamber 16 formed as a recessed portion formed in a bottomed cone shape, if a configuration is adopted in which the formed flame F easily spreads in the heating chamber 23 of the high-temperature gas generating furnace 20, the furnace wall temperature can be prevented from rising, and an effect of extending the life can be obtained.

[0070] Moreover, the secondary preheated gas G42 is ejected from the side surface of the heating chamber 23 toward the central axis J and collides with the flame F, forming a flow toward the burner 10 side (reverse flow region) and a flow toward the exhaust port 25 side near the central axis J of the heating chamber 23. Of these, the secondary preheated gas G42 toward the burner 10 side is taken into the high-temperature combustion gas G3 generated by the flame F of the burner 10, and circulates together with this high-temperature combustion gas G3 inside the heating chamber 23, promoting mixing. Also, the secondary preheated gas G42 is taken into the flame F to suppress a temperature rise of the flame F, and a rise in the furnace wall temperature of the heating chamber 23 can be suppressed, so that the high-temperature gas generating furnace 20 made of refractory material can be extended in life without melting.

[0071] In addition, the flame F formed by the burner 10 provided in the high-temperature gas generation apparatus 1 of this embodiment can maintain a stable combustion state because the secondary preheated gas G42 does not obstruct the flow of the flame F.

[0072] Furthermore, in the high-temperature gas generator 1 of this embodiment, when a configuration further including a cooling jacket 30 as in the illustrated example is adopted, the following effects can be obtained. That is, by providing the cooling jacket 30, for example, the burner 10 and the cooling water W come into direct contact with each other, or the burner 10 and the cooling water W come into contact with each other via another structure, so that the burner 10 can be sufficiently cooled and melting damage can be prevented. Also, deformation or damage of the burner 10 or the entire high-temperature gas generator 1 due to thermal stress can be prevented, and fatigue damage caused by repeated application of thermal stress can be minimized, enabling an extended lifespan to be achieved.

[0073] According to the high-temperature gas generator 1 of this embodiment, as described above, the burner 10 has the first combustion supporting gas outlet 14a, the first fuel gas outlet 12a, and the second fuel gas outlet 13a arranged at the bottom 16a of the combustion chamber 16, and the second combustion supporting gas outlet 15a for ejecting the second combustion supporting gas G22 in a swirling flow arranged at the side wall 16b of the combustion chamber 16, so that the low-load combustion flame FA can be formed near the central axis J of the burner 10, and the high-load combustion flame FB can be formed outside of the low-load combustion flame FA. As a result, during low-load operation, a stable combustion state can be maintained by the low-load combustion flame FA formed near the central axis J, and during high-load operation, a stable combustion state can be maintained by the high-load combustion flame FB formed outside the low-load combustion flame FA. Therefore, a wide range of turndown can be ensured while suppressing the unburned fuel gases, the first fuel gas G11 and the second fuel gas G12, and the unburned combustion supporting gases, the first combustion supporting gas G21 and the second combustion supporting gas G22, from remaining in the primary preheated gas G41 and the secondary preheated gas G42, and it becomes possible to efficiently and stably generate high-temperature gas G5 even when the burner 10 is burning at a low load.

[0074] Here, the "turndown" described in this specification refers to the range in which burner combustion can be controlled, and is generally expressed as the ratio of [the rated combustion amount of the burner: the minimum controllable combustion amount]. For example, if the turndown is [4:1], it indicates that continuous combustion is possible within the range from the rated combustion amount of the burner to 1 / 4 of this rated combustion amount.

[0075] 1A and 1B, the first combustion supporting gas supply passage 14 and the second combustion supporting gas supply passage 15 provided in the burner 10 of the high temperature gas generator 1 may be configured to supply the combustion supporting gas (first combustion supporting gas G21 and second combustion supporting gas G22) from the same supply pipe, or may be configured to supply the combustion supporting gas from separate supply sources through different supply pipes. Similarly, the first fuel gas supply passage 12 and the second fuel gas supply passage 13 may be configured to supply the fuel gas (first fuel gas G11 and second fuel gas G12) from the same supply pipe, or may be configured to supply the fuel gas from separate supply sources through different supply pipes.

[0076] <Second embodiment> Hereinafter, the configuration of a high-temperature gas generation apparatus according to a second embodiment of the present invention will be described in detail with reference to FIG. In the following description of the high-temperature gas generator 1A of this embodiment, the same components as those of the high-temperature gas generator 1 of the first embodiment shown in Figures 1A and 1B, 2, and 3A to 3B will be given the same symbols, and detailed descriptions thereof may be omitted.

[0077] Figure 4 is a cross-sectional view along the axial direction of the high-temperature gas generation apparatus 1A, showing the internal structure of the high-temperature gas generation apparatus 1A of this embodiment, and also showing the flows of the first fuel gas G11, the second fuel gas G12, the first combustion supporting gas G21, the second combustion supporting gas G22, the primary preheated gas G41 and the secondary preheated gas G42, together with the flame F that is formed.

[0078] As shown in Figure 4, the high-temperature gas generation apparatus 1A of this embodiment is similar to the high-temperature gas generation apparatus 1 of the first embodiment shown in Figures 1A and 1B in that the burner 10 is composed of a combustion chamber 16, a first combustion supporting gas outlet 14a, a first fuel gas outlet 12a and a second fuel gas outlet 13a opening into the bottom 16a of the combustion chamber 16, and a second combustion supporting gas outlet 15a opening into the side wall 16b of the combustion chamber 16. On the other hand, the high-temperature gas generation apparatus 1A of this embodiment differs from the high-temperature gas generation apparatus 1 of the first embodiment in that the high-temperature gas generator 20A is provided with a secondary preheated gas supply pipe 29 that covers the outer periphery of the heating chamber 23 from the outside, and secondary preheated gas G42 is ejected from the secondary preheated gas outlet 27a toward the inside of the heating chamber 23 via a secondary preheated gas supply passage 27 that is connected to this secondary preheated gas supply pipe 29.

[0079] Like the high-temperature gas generator 1 of the first embodiment, the high-temperature gas generator 1A of this embodiment generates high-temperature combustion gas G3 by a flame F formed in the combustion chamber 16 of the burner 10, and generates high-temperature gas G5 by directly mixing the high-temperature combustion gas G3 with the primary preheated gas G41 and the secondary preheated gas G42 in the high-temperature gas generator 20A.

[0080] 4, the secondary preheated gas supply pipe 29 is configured in an annular shape so as to cover the outer periphery of the heating chamber 23 from the outside, and the secondary preheated gas G42 is introduced from a preheated gas inlet 29a. Then, the secondary preheated gas G42 flows from the secondary preheated gas supply pipe 29 into the secondary preheated gas supply path 27, so that the secondary preheated gas G42 is ejected from the secondary preheated gas outlet 27a toward the inside of the heating chamber 23.

[0081] According to the high temperature gas generator 1A of this embodiment, a configuration is adopted in which a high temperature gas generator 20A having a secondary preheated gas supply pipe 29 so as to cover the outer periphery of the heating chamber 23 from the outside is further provided in addition to the high temperature gas generator 1 of the first embodiment as shown in Fig. 1A. As a result, the secondary preheated gas G42 is preheated by the heat dissipated in the heating chamber 23, and by ejecting this secondary preheated gas G42 into the heating chamber 23, it is possible to suppress the heat loss from the furnace body constituting the heating chamber 23 to be extremely small relative to the amount of heat input. Therefore, the high-temperature combustion gas G3 and the primary preheated gas G41 and secondary preheated gas G42 can be mixed more effectively, so that the high-temperature gas G5 can be generated efficiently and stably.

[0082] <Third embodiment> Hereinafter, the configuration of a high-temperature gas generation apparatus according to a third embodiment of the present invention will be described in detail with reference to FIG. In addition, in the description of the high-temperature gas generator 1B of this embodiment given below, the same symbols will be used for configurations that are the same as those of the high-temperature gas generator 1 of the first embodiment shown in Figures 1A and 1B, 2 and 3A-3B, and the high-temperature gas generator 1A of the second embodiment shown in Figure 4, and detailed descriptions thereof may be omitted.

[0083] Figure 5 is a cross-sectional view along the axial direction of the high-temperature gas generator 1B showing the internal structure of the high-temperature gas generator 1B of this embodiment, and also showing the flows of the first fuel gas G11, the second fuel gas G12, the first combustion supporting gas G21, the second combustion supporting gas G22, the primary preheated gas G41 and the secondary preheated gas G42 together with the flame F that is formed.

[0084] As shown in Figure 5, the high-temperature gas generator 1B of this embodiment is similar to the high-temperature gas generator 1 of the first embodiment shown in Figure 1A and the high-temperature gas generator 1A of the second embodiment shown in Figure 4 in that the burner 10 is composed of a combustion chamber 16, a first combustion supporting gas outlet 14a, a first fuel gas outlet 12a and a second fuel gas outlet 13a opening into the bottom 16a of the combustion chamber 16, and a second combustion supporting gas outlet 15a opening into the side wall 16b of the combustion chamber 16. In addition, the high-temperature gas generation apparatus 1B of this embodiment has a similar configuration to the high-temperature gas generation apparatus 1A of the second embodiment in that the high-temperature gas generator 20B is equipped with a secondary preheated gas supply pipe 29C that covers the outer periphery of the area on the other end 22 side of the heating chamber 23 from the outside, and secondary preheated gas G42 is ejected from the secondary preheated gas outlet 27a toward the inside of the heating chamber 23 via a secondary preheated gas supply passage 27 that is connected to this secondary preheated gas supply pipe 29C.

[0085] On the other hand, the high temperature gas generator 1B of this embodiment further includes a primary preheated gas supply pipe 28 that covers the outer periphery of the region on one end 21 side of the heating chamber 23 from the outside so that the high temperature gas generator 20B is adjacent to the secondary preheated gas supply pipe 29C. Also, a primary preheated gas supply passage 26 arranged at a position on one end 21 side of the high temperature gas generator 20B where the primary preheated gas G41 is ejected from the outer periphery side of the burner 10 toward the inside of the heating chamber 23 is connected to the primary preheated gas supply pipe 28. The high temperature gas generator 1B of this embodiment differs from the high temperature gas generator 1A of the second embodiment in that the secondary preheated gas G42 can be ejected from the primary preheated gas ejection port 26a toward the inside of the heating chamber 23 via the primary preheated gas supply passage 26.

[0086] Like the high-temperature gas generator 1 of the first embodiment and the high-temperature gas generator 1A of the second embodiment, the high-temperature gas generator 1B of this embodiment generates high-temperature combustion gas G3 by a flame F formed in the combustion chamber 16 of the burner 10, and generates high-temperature gas G5 by directly mixing the high-temperature combustion gas G3 with the primary preheated gas G41 and the secondary preheated gas G42 in the high-temperature gas generator 20B.

[0087] 5, the primary preheated gas supply pipe 28 is configured in an annular shape so as to cover from the outside the region on one end 21 side on the outer periphery of the heating chamber 23, and the primary preheated gas G41 is introduced from the preheated gas inlet 28a. Then, the primary preheated gas G41 flows from the primary preheated gas supply pipe 28 into the primary preheated gas supply path 26, so that the primary preheated gas G41 is ejected from the primary preheated gas ejection port 26a toward the inside of the heating chamber 23.

[0088] 5, the secondary preheated gas supply pipe 29C is configured in an annular shape so as to cover the area on the other end 22 side on the outer periphery of the heating chamber 23 from the outside, and is disposed close to the above-mentioned primary preheated gas supply pipe 28 on the outer periphery of the heating chamber 23. Similarly to the high-temperature gas generator 1B of the second embodiment, the secondary preheated gas G42 is introduced into the secondary preheated gas supply pipe 29C in the illustrated example from a preheated gas inlet 29a. The secondary preheated gas G42 flows from the secondary preheated gas supply pipe 29C into the secondary preheated gas supply path 27, and the secondary preheated gas G42 is ejected from the secondary preheated gas outlet 27a toward the inside of the heating chamber 23.

[0089] According to the high-temperature gas generator 1B of this embodiment, a configuration is adopted in which a high-temperature gas generator 20C having a primary preheated gas supply pipe 28 is further provided to cover the area on one end 21 side on the outer periphery of the heating chamber 23 from the outside, in addition to the high-temperature gas generator 1A of the second embodiment as shown in FIG. 4. As a result, not only the secondary preheated gas G42 but also the primary preheated gas G41 is preheated by the heat dissipated in the heating chamber 23. Then, by ejecting the primary preheated gas G41 and the secondary preheated gas G42 into the heating chamber 23, it is possible to suppress the heat loss from the furnace body constituting the heating chamber 23 to be extremely small relative to the input heat amount, as described above. Furthermore, the primary preheated gas G41 is preheated by the primary preheated gas supply pipe 28, and the effect of improving the stability of the flame F formed to spread in the heating chamber 23 is obtained. Therefore, as described above, the high-temperature combustion gas G3 and the primary preheated gas G41 and secondary preheated gas G42 can be mixed more effectively, making it possible to generate the high-temperature gas G5 efficiently and stably.

[0090] <Fourth embodiment> Hereinafter, the configuration of a high-temperature gas generation apparatus according to a fourth embodiment of the present invention will be described in detail with reference to FIG. In addition, in the description of the high-temperature gas generator 1C of this embodiment given below, the same symbols are used for configurations that are the same as those of the first embodiment of the high-temperature gas generator 1 shown in Figures 1A and 1B, 2 and 3A-3B, the second embodiment of the high-temperature gas generator 1A shown in Figure 4, and the third embodiment of the high-temperature gas generator 1B shown in Figure 5, and detailed descriptions thereof may be omitted.

[0091] Figure 6 is a cross-sectional view along the axial direction of the high-temperature gas generator 1C showing the main parts of the burner 10C provided in the high-temperature gas generator 1C of this embodiment, and showing the flows of the first fuel gas G11, the second fuel gas G12, the first combustion supporting gas G21, the second combustion supporting gas G22, the third combustion supporting gas G23, and the primary preheated gas G41 together with the flame F that is formed.

[0092] As shown in Figure 6, the high-temperature gas generation apparatus 1C of this embodiment is similar to the high-temperature gas generation apparatus 1 of the first embodiment shown in Figures 1A and 1B in that the burner 10C is composed of a combustion chamber 16, a first combustion supporting gas outlet 14a, a first fuel gas outlet 12a and a second fuel gas outlet 13a opening into the bottom 16a of the combustion chamber 16, and a second combustion supporting gas outlet 15a opening into the side wall 16b of the combustion chamber 16. On the other hand, the high-temperature gas generator 1C of this embodiment differs from the high-temperature gas generator 1 of the first embodiment in that the burner 10C further includes a third combustion supporting gas supply passage 18 having a third combustion supporting gas outlet 18a opening into the side wall 16b of the combustion chamber 16, and is configured to eject the third combustion supporting gas G23 into the combustion chamber 16.

[0093] Like the high-temperature gas generator 1 of the first embodiment, the high-temperature gas generator 1C of this embodiment generates high-temperature combustion gas G3 by a flame F formed in the combustion chamber 16 of the burner 10C, and generates high-temperature gas G5 by directly mixing the high-temperature combustion gas G3 with the primary preheated gas G41 and secondary preheated gas G42 in the high-temperature gas generator 20 (see also Figure 1A).

[0094] 6, the third combustion supporting gas supply passage 18 is disposed coaxially and annularly outside the second combustion supporting gas supply passage 15, and ejects the third combustion supporting gas G23 from a third combustion supporting gas nozzle 18a opening in a side wall 16b of the combustion chamber 16 in the tangential direction of the side wall of the combustion chamber 16. More specifically, the third combustion supporting gas nozzle 18a ejects the third combustion supporting gas G23 so as to have a swirling flow along the central axis J of the burner 10C.

[0095] Detailed illustration of the third combustion supporting gas nozzles 18a is omitted, but for example, multiple third combustion supporting gas nozzles 18a are arranged at equal intervals on a circumference centered on the central axis J on the side wall 16b of the combustion chamber 16, so as to surround the second combustion supporting gas nozzle 15a from the outside in a plan view. Furthermore, as long as the third combustion supporting gas outlets 18a are open to the side wall 16b of the combustion chamber 16, there are no particular limitations on the arrangement intervals, number of holes, shape, etc., and these can be set arbitrarily. Although detailed illustration is omitted, the above-mentioned multiple third combustion supporting gas outlets 18a are arranged in a row on a circle centered on the central axis J, but are not limited to this. The multiple third combustion supporting gas outlets 18a may be arranged in two or more rows on a circle centered on the central axis J, for example, at different positions in a direction perpendicular to the central axis J.

[0096] In this embodiment, the third combustion supporting gas G23 may be the same as the first combustion supporting gas G21 and the second combustion supporting gas G22.

[0097] According to the high-temperature gas generator 1C of this embodiment, the high-temperature gas generator 1 of the first embodiment as shown in Figures 1A and 1B is further provided with a third combustion supporting gas supply passage 18 having a third combustion supporting gas outlet 18a, so that each combustion supporting gas supply passage (outlet) can be used depending on the load of the burner 10C. As a result, for example, during low-load combustion, the first combustion supporting gas G21 is mainly ejected from the first combustion supporting gas outlet 14a, and the second combustion supporting gas G22 is ejected from the second combustion supporting gas outlet 15a, so that the flow rate of each combustion supporting gas can be prevented from decreasing even at low load. Therefore, a stable swirling flow is formed, and a stable low-load combustion flame FA is formed.

[0098] On the other hand, for example, during high load operation, in addition to ejecting the first combustion supporting gas G21 from the first combustion supporting gas nozzle 14a and the second combustion supporting gas G22 from the second combustion supporting gas nozzle 15a, the third combustion supporting gas G23 is ejected from the third combustion supporting gas nozzle 18a, so that the flow rate of each combustion supporting gas does not become too high, and a stable high load combustion flame FB is formed. Therefore, as described above, the high-temperature combustion gas G3 can be mixed more effectively with the primary preheated gas G41 and the secondary preheated gas G42, making it possible to generate the high-temperature gas G5 efficiently and stably (see also Figure 1A).

[0099] <Fifth embodiment> Hereinafter, the configuration of a high-temperature gas generation apparatus according to a fifth embodiment of the present invention will be described in detail with reference to FIG. In the description of the high-temperature gas generator 1D of this embodiment given below, the same symbols will be used for configurations that are the same as those of the high-temperature gas generator 1 of the first embodiment shown in Figures 1A and 1B, 2 and 3A-3B, the high-temperature gas generator 1A of the second embodiment shown in Figure 4, the high-temperature gas generator 1B of the third embodiment shown in Figure 5, and the high-temperature gas generator 1C of the fourth embodiment shown in Figure 6, and detailed descriptions thereof may be omitted.

[0100] Figure 7 is a cross-sectional view along the axial direction of the high-temperature gas generation apparatus 1D, showing the main parts of the burner 10D provided in the high-temperature gas generation apparatus 1D of this embodiment, and also showing the flows of the first fuel gas G11, the second fuel gas G12, the third fuel gas G13, the first combustion supporting gas G21, the second combustion supporting gas G22, the third combustion supporting gas G23, and the primary preheated gas G41 together with the flame F that is formed.

[0101] As shown in Figure 7, the high-temperature gas generation apparatus 1D of this embodiment is similar to the high-temperature gas generation apparatus 1C of the fourth embodiment shown in Figure 6 in that the burner 10D is composed of a combustion chamber 16, a first combustion supporting gas outlet 14a, a first fuel gas outlet 12a and a second fuel gas outlet 13a opening into the bottom 16a of the combustion chamber 16, a second combustion supporting gas outlet 15a opening into the side wall 16b of the combustion chamber 16, and a third combustion supporting gas outlet 18a opening into the side wall 16b of the combustion chamber 16. On the other hand, the high-temperature gas generation apparatus 1D of this embodiment differs from the high-temperature gas generation apparatus 1C of the fourth embodiment in that the burner 10D further includes a third fuel gas supply passage 17 having a third fuel gas outlet 17a opening into the bottom 16a of the combustion chamber 16, and is configured to eject the third fuel gas G13 into the combustion chamber 16.

[0102] Further, in the burner 10D provided in the illustrated high-temperature gas generator 1D, a swirl vane 42 for ejecting the third fuel gas G13 as a swirling flow is arranged at the third fuel gas outlet 17a as well as at the first fuel gas outlet 12a and the second fuel gas outlet 13a. The swirl vane 42 has a structure generally similar to that of the swirl vanes 40 and 41 described above.

[0103] 7, the third fuel gas supply passage 17 is disposed coaxially and annularly outside the second fuel gas supply passage 13, and ejects the third fuel gas G13 from a third fuel gas outlet 17a opening into the bottom 16a of the combustion chamber 16. More specifically, the third fuel gas outlet 17a ejects the third fuel gas G13 in a direction along the central axis J of the burner 10D.

[0104] Detailed illustration of the third fuel gas nozzles 17a is omitted, but for example, multiple third fuel gas nozzles 17a are arranged at equal intervals on a circumference centered on the central axis J at the bottom 16a of the combustion chamber 16 so as to surround the second fuel gas nozzle 13a from the outside in a plan view. Furthermore, as long as the third fuel gas outlets 17a are open to the bottom 16a of the combustion chamber 16, there are no particular limitations on the arrangement intervals, number of holes, shape, and the like, and these can be set arbitrarily. In this embodiment, the third fuel gas G13 may be the same fuel gas as the first fuel gas G11 and the second fuel gas G12.

[0105] According to the high-temperature gas generator 1D of this embodiment, the high-temperature gas generator 1C of the fourth embodiment as shown in Fig. 6 is further provided with a third fuel gas supply passage 17 having a third fuel gas outlet 17a, so that each fuel gas supply passage (outlet) can be used according to the load of the burner 10D. As a result, for example, during low-load combustion, the first fuel gas G11 is mainly ejected from the first fuel gas outlet 12a, and the second fuel gas G12 is ejected from the second fuel gas outlet 13a, so that the flow rate of each fuel gas can be prevented from decreasing even at low load. Therefore, a stable swirling flow is formed, and a stable flame FA for low-load combustion is formed.

[0106] On the other hand, for example, during high-load operation, in addition to ejecting the first fuel gas G11 from the first fuel gas nozzle 12a and the second fuel gas G12 from the second fuel gas nozzle 13a, the third fuel gas G13 is also ejected from the third fuel gas nozzle 17a, so that the flow speeds of the fuel gases do not become too high, and a stable high-load combustion flame FB is formed. Therefore, as described above, the high-temperature combustion gas G3 can be mixed more effectively with the primary preheated gas G41 and the secondary preheated gas G42, making it possible to generate the high-temperature gas G5 efficiently and stably (see also Figure 1A).

[0107] Furthermore, in this embodiment, by combining the configuration for ejecting the first to third combustion supporting gases G21 to G23, which was described in detail in the fourth embodiment, with the configuration for ejecting the first to third fuel gases G11 to G13, the above-mentioned effects can be obtained more significantly.

[0108] <Action and effect> As described above, according to the high-temperature gas generator 1 (1A, 1B, 1C, 1D) of this embodiment, the first combustion supporting gas nozzle 14a, the first fuel gas nozzle 12a, and the second fuel gas nozzle 13a are arranged in the bottom 16a of the combustion chamber 16 in the burner 10, and the second combustion supporting gas nozzle 15a for ejecting the second combustion supporting gas G22 in a swirling flow is arranged in the side wall 16b of the combustion chamber 16, so that the low-load combustion flame FA can be formed near the central axis J of the burner 10 (10C, 10D) and the high-load combustion flame FB can be formed outside of it. As a result, during low-load operation, a stable combustion state can be maintained by the low-load combustion flame FA formed near the central axis J, and during high-load operation, a stable combustion state can be maintained by the high-load combustion flame FB formed outside the low-load combustion flame FA. Therefore, a wide range of turndown can be ensured while preventing unburned fuel gas and combustion supporting gas from remaining in the preheated gas, and high-temperature gas G5 can be generated efficiently and stably even when the burner 10 is burning at a low load.

[0109] <Other aspects of the present invention> Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments described above, and various modifications and variations are possible within the scope of the gist of the present invention as described in the claims. EXAMPLES

[0110] The high-temperature gas generating apparatus according to the present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. Moreover, the conditions employed in this embodiment are merely examples and, similar to the above, do not limit the present invention.

[0111] <Example 1> In this embodiment, a high-temperature gas generator 1 having the configuration according to the present invention as shown in Fig. 1A and Fig. 1B was used, and tests were carried out to generate high-temperature gas G5 under test conditions for generating high-temperature gas G5 over a wide temperature range as shown in Tables 1 and 2 below. Specifically, the high-temperature gas generator 1 was used to check the combustion state of the burner 10, and the residual oxygen concentration and residual methane gas concentration contained in the high-temperature gas G5 discharged from the high-temperature gas generator 20 were measured. In this embodiment, the amount of high-temperature gas G5 generated was 250 Nm 3 / h, the temperature of the high-temperature gas G5 was changed between 200 and 1700°C by adjusting the combustion amount in the burner 10.

[0112] The residual oxygen concentration and the residual methane gas concentration were measured using a commercially available measuring device (GL Sign-S Corporation; product number: Agilent Micro GC).

[0113] That is, in this embodiment, the high-temperature gas generating device 1 used has a combustion chamber 16 in which a low-load combustion flame FA (flame F) is formed from a first fuel gas G11 and a first combustion supporting gas G21, and a high-load combustion flame FB (flame F) is formed from a second fuel gas G12 and a second combustion supporting gas G22, and is equipped with a burner 10 that generates high-temperature combustion gas G3 by each of the above-mentioned flames F. The high-temperature gas generator 1 is provided with a high-temperature gas generator 20, which is cylindrical in shape with one end 21 connected to the combustion chamber 16 side of the burner 10 and a heating chamber 23 inside that communicates with the combustion chamber 16, and which supplies the primary preheated gas G41 and the secondary preheated gas G42 while forming a flame F in the heating chamber 23, thereby mixing the high-temperature combustion gas G3 with the preheated gas to generate high-temperature gas G5, and discharges the high-temperature gas G5 from an outlet 25 disposed at the other end 22 opposite the combustion chamber 16. The high-temperature gas generator 1 used in this embodiment is such that the burner 10 and the second combustion supporting gas outlet 15a discharge the second combustion supporting gas G22 so as to have a swirling flow along the central axis J of the burner 10.

[0114] In addition, the high-temperature gas generation apparatus 1 used in this embodiment has a ratio [L1 / D] of the furnace inner length L1 in the direction along the flame formation direction of the heating chamber 23 in the high-temperature gas generation furnace 20 to the furnace inner diameter D of 1.4, and a ratio [L2 / D] of the distance L2 from the one end 21 connected to the burner 10 to the secondary preheated gas outlet 27a to the furnace inner diameter D of 1.0.

[0115] The test was performed under test conditions using "natural gas" as the fuel type for the first fuel gas G11 and the second fuel gas G12, as shown in Table 1 below. In this embodiment, the conditions were set so that the swirl number at the second fuel gas nozzle 13a of the burner 10 was 0.65. In addition, tests were conducted by setting the flow rates of the oxidizer (O2) used as the first fuel gas G11 and second fuel gas G12, the first combustion supporting gas G21 and second combustion supporting gas G22, and the nitrogen gas (N2) used as the primary preheated gas G41 and secondary preheated gas G42 under the test conditions shown in Table 1 below.

[0116] [Table 1]

[0117] In addition, Table 2 below shows a list of the temperature of the high-temperature gas G5 discharged from the exhaust outlet 25 of the high-temperature gas generator 20, the concentration of residual oxygen (including unburned first combustion supporting gas G21 and second combustion supporting gas G22) in the high-temperature gas G5, and the concentration of residual methane gas (including first fuel gas G11 and second fuel gas G12) in the high-temperature gas G5.

[0118] [Table 2]

[0119] From the results shown in Table 2, it was confirmed that by generating high-temperature gas G5 using the high-temperature gas generation apparatus 1 of the present invention (see Figures 1A and 1B), high-temperature gas G5 can be stably obtained under any of conditions 1 to 4, including when high-temperature gas G5 is generated at the relatively low temperature of 200°C, or when it is generated at a high temperature of 1700°C, and that the residual oxygen concentration and residual methane gas concentration can be suppressed to extremely low levels.

[0120] Here, it is known that, in a process in which high-temperature gas G5 is used, it is preferable to suppress the residual oxygen concentration and the residual methane gas concentration as low as possible in order to prevent oxidation of raw materials such as iron and non-ferrous raw materials and the resulting products, and to maintain a high temperature in the blast furnace in the process. From this perspective, it is clear that the high-temperature gas generator 1 according to the present invention is very suitable for use in generating high-temperature gas G5.

[0121] <Example 2> In Example 2, a test was also conducted to generate high-temperature gas G5 using a high-temperature gas generation device 1 having the configuration of the present invention as shown in Figures 1A and 1B under conditions using fuel gas with a wide range of low heating values ​​as shown in Tables 1 and 2 above. In this embodiment, by appropriately changing the furnace inner diameter D, furnace inner length L1, and distance L2 from one end 21 to the secondary preheated gas outlet 27a in the high-temperature gas generation apparatus 1 and conducting tests, it was investigated whether the residual oxygen concentration and residual methane gas concentration (unburned gas) in the high-temperature gas G5 discharged from the exhaust port 25 could be further reduced.

[0122] In general, when reducing gases containing hydrogen (H2) or carbon monoxide (CO) are preheated and supplied to a melting furnace or a heat treatment device, if the residual oxygen concentration is too high, it may have adverse effects such as oxidizing raw materials such as iron and non-ferrous metals and products obtained from them. In addition, when oxygen or oxygen-enriched air is preheated and supplied to a burner, residual unburned gas such as methane gas may generate heat inside the burner and damage the burner. Furthermore, when an inert gas used as an atmospheric gas in various processes is preheated, the presence of residual oxygen or unburned gas may have adverse effects on the obtained product. In this embodiment, the following study was carried out to determine the optimum conditions for reliably resolving the above-mentioned problems.

[0123] First, in this embodiment, tests were conducted while appropriately changing the ratio [L2 / D] of the distance L2 from the one end 21 to the secondary preheated gas outlet 27a to the furnace inner diameter D within the range of 0.5 to 3, and the optimal value of the above ratio [L2 / D] was investigated.

[0124] As a result, although detailed explanation using drawings etc. is omitted, when the above ratio [L2 / D] is smaller than 0.7, the influence of the flow of the secondary preheated gas G42 toward the burner 10 increases, the combustion condition of the burner 10 becomes unfavorable, and the residual oxygen concentration tends to become high. On the other hand, when the above ratio [L2 / D] is greater than 1.5, the temperature inside the heating chamber 23 increases as the mixing efficiency of the high-temperature combustion gas G3 and the secondary preheated gas G42 gradually decreases, and when the above ratio [L2 / D] is 2.1 or more, the temperature of the furnace wall tends to rise rapidly. The present invention does not particularly limit the above ratio [L2 / D]. On the other hand, from the above study results, it was confirmed that in the present invention, from the viewpoint of obtaining the effect of reducing the residual oxygen concentration to prevent the raw materials and products from being oxidized, and suppressing the amount of remaining unburned gas (residual methane gas) to prevent damage to the burner and furnace wall, it is more preferable to set the above ratio [L2 / D] in the range of 0.7 to 2.1.

[0125] Next, in this embodiment, tests were conducted while appropriately changing the ratio [L1 / D] of the furnace inner length L1 to the furnace inner diameter D in the range of 0.9 to 3.5, the temperature distribution at the exhaust outlet 25 of the high-temperature gas generator 20 was measured, and the optimal value of the above ratio [L1 / D] was investigated.

[0126] As a result, although detailed explanation using drawings etc. is omitted, when the above ratio [L1 / D] is smaller than 1, the high-temperature combustion gas G3 and the secondary preheated gas G42 are not sufficiently mixed in the heating chamber 23, and the temperature of the high-temperature gas G5 near the center at the exhaust outlet 25 tends to be lower. Furthermore, when the ratio [L1 / D] was greater than 3, the temperature of the high-temperature gas G5 tended to gradually decrease due to the effect of heat loss to the furnace body constituting the heating chamber . The present invention does not particularly limit the above ratio [L1 / D]. On the other hand, from the above study results, it was confirmed that in the present invention, from the viewpoint of sufficiently mixing the high-temperature combustion gas G3 and the secondary preheated gas G42 and increasing the temperature of the high-temperature gas G5, it is more preferable to set the above ratio [L1 / D] in the range of 1 to 3. [Industrial Applicability]

[0127] The high-temperature gas generator of the present invention can ensure a wide range of turndown while suppressing the remaining of unburned fuel gas and combustion supporting gas in the preheated gas, and can efficiently and stably generate high-temperature gas even when the burner is burning at a low load. Therefore, the high-temperature gas generator of the present invention is suitable for heating the inside of various industrial furnaces used in, for example, smelting of iron and non-ferrous metals, ceramic firing processes, etc. [Explanation of symbols]

[0128] 1, 1A, 1B, 1C, 1D...High temperature gas generator 10, 10C, 10D…Burner 11...Tip 12...First fuel gas supply line 12a…First fuel gas outlet 13...Second fuel gas supply line 13a…Second fuel gas outlet 17…Third fuel gas supply line 17a…Third fuel gas nozzle 14...First combustion supporting gas supply passage 14a…First combustion supporting gas outlet 15...Second combustion supporting gas supply passage 15a…Second combustion supporting gas outlet 18...Third combustion supporting gas supply passage 18a…Third combustion supporting gas outlet 16…Combustion chamber 16a...bottom 16b…Side wall 30…Cooling jacket 30a...Cooling water flow path 30b…Entrance 30c…Exit 40, 41, 42...Turning blades 20...High-temperature gas generator 21...one end 22...other end 23…Heating chamber 25…Discharge port 26...Primary preheated gas supply line 26a…Primary preheated gas supply port 27...Secondary preheated gas supply line 27a…Secondary preheated gas supply port 28...Primary preheated gas supply pipe 28a…Preheated gas inlet 29, 29C…Secondary preheated gas supply pipe 29a…Preheated gas inlet J…Center axis W…Cooling water G11…First fuel gas (fuel gas) G12…Second fuel gas (fuel gas) G13…Third fuel gas (fuel gas) G21…First combustion supporting gas (combustion supporting gas) G22: Secondary combustion supporting gas (combustion supporting gas) G23…Third combustion supporting gas (combustion supporting gas) G3: High-temperature combustion gas G41…Primary preheated gas (preheated gas) G42…Secondary preheated gas (preheated gas) G5…Hot gas F...Flame FA: Flame for low load combustion FB: High-load combustion flame

Claims

1. a burner having a combustion chamber in which a flame is formed by a fuel gas and a combustion supporting gas, and generating high-temperature combustion gas by the flame; a high-temperature gas generating furnace, one end of which is connected to the combustion chamber side of the burner and which has a cylindrical shape having an internal heating chamber communicating with the combustion chamber, which supplies a preheated gas while forming the flame in the heating chamber, thereby mixing the high-temperature combustion gas with the preheated gas to generate high-temperature gas, and which discharges the high-temperature gas from an exhaust port disposed at the other end opposite the combustion chamber; The burner has a combustion chamber having a bottomed conical shape that opens so that a tip side in a direction in which the flame is formed expands in diameter, a first combustion supporting gas outlet that opens on a central axis of the burner at the bottom of the combustion chamber and ejects a first combustion supporting gas in a direction along the central axis; a first fuel gas outlet that opens to a bottom portion of the combustion chamber, that is disposed so as to surround the first combustion assisting gas outlet in a plan view, and that ejects a first fuel gas, which is the fuel gas, in a direction parallel to the first combustion assisting gas; a second fuel gas outlet that opens to a bottom portion of the combustion chamber, that is disposed so as to surround the first fuel gas outlet in a plan view, and that ejects a second fuel gas, which is the fuel gas, in a direction parallel to the first combustion assisting gas and the first fuel gas; a second combustion assisting gas outlet that is disposed on a side wall of the combustion chamber and that ejects a second combustion assisting gas toward the second fuel gas, A high-temperature gas generating apparatus, characterized in that the second combustion supporting gas outlet ejects the second combustion supporting gas so as to have a swirling flow along the central axis of the burner.

2. The high-temperature gas generating apparatus according to claim 1, characterized in that either or both of the first fuel gas outlet and the second fuel gas outlet eject the first fuel gas or the second fuel gas, which is the fuel gas, so as to have a swirling flow along the central axis of the burner.

3. The high-temperature gas generating apparatus according to claim 2, characterized in that a swirling vane for ejecting the first fuel gas or the second fuel gas, which is the fuel gas, as a swirling flow is arranged in either or both of the first fuel gas outlet and the second fuel gas outlet.

4. The high-temperature gas generation apparatus according to claim 3, characterized in that the swirl vane has a plurality of blade portions arranged at an angle with respect to a central axis of the first fuel gas outlet or the second fuel gas outlet, at either or both of the first fuel gas outlet and the second fuel gas outlet.

5. 5. The high-temperature gas generating apparatus according to claim 2, wherein the burner has a swirl number at the second fuel gas outlet of 0.65 or more.

6. a primary preheated gas supply port for supplying a primary preheated gas as the preheated gas and a secondary preheated gas supply port for supplying a secondary preheated gas as the preheated gas are open inside the heating chamber; the primary preheated gas supply port is disposed at a position on one end side of the high-temperature gas generating furnace where the primary preheated gas is ejected from an outer periphery side of the burner toward the inside of the heating chamber, the secondary preheated gas supply ports are arranged on the same cross section at at least three locations on the inner surface of the heating chamber at positions for ejecting the secondary preheated gas toward the central axis of the high temperature gas generating furnace, The high-temperature gas generating apparatus according to claim 1 or claim 2, characterized in that the secondary preheated gases are collided with each other near the central axis of the high-temperature gas generating furnace, thereby forming an airflow toward the burner connected to the one end and an airflow toward the exhaust port located at the other end.

7. The high-temperature gas generating apparatus according to claim 6, characterized in that the ratio [L1 / D] of the furnace inner length L1 in the direction along the flame formation direction to the furnace inner diameter D is in the range of 1 to 3.

8. The high-temperature gas generating apparatus according to claim 7, characterized in that the ratio [L2 / D] of the distance L2 from the one end connected to the burner to the secondary preheated gas supply port and the furnace inner diameter D is in the range of 0.7 to 2.

1.

9. The fuel gas has a lower heating value of 2000 kcal / Nm ３ 3. The high-temperature gas generating apparatus according to claim 1, wherein:

10. 3. The high-temperature gas generating apparatus according to claim 1, further comprising a cooling jacket for cooling the burner from an outer periphery side.

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