Combustion device

Abstract

To suppress damage to a burner.SOLUTION: A combustion apparatus 130 includes an inner cylinder nozzle 173, an outer cylinder nozzle 171 which is provided outside the inner cylinder nozzle 173, a first fuel flow passage 177 which is formed between the inner cylinder nozzle 173 and the outer cylinder nozzle 171 and through which first fuel and conveying air flow, a burner 175 which is provided inside the inner cylinder nozzle 173, and an actuator 180 which moves the burner 175 between a first position intruding into a furnace 110 and a second position closer to an inner cylinder injection port 173a of the inner cylinder nozzle 173 than the first position.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a combustion device.

Background Art

[0002] Conventionally, combustion systems using pulverized coal such as biomass and coal as fuel have been utilized. For example, the combustion system of Patent Document 1 discloses a configuration including a furnace, a wind box provided on the furnace wall of the furnace, and a pulverized coal burner provided in the wind box.

[0003] In the combustion system of Patent Document 1, the wind box adjusts the air volume of the air supplied to the furnace and gives a swirling force to the air. The pulverized coal burner has an outer cylinder nozzle, an inner cylinder nozzle, and an oil burner. The outer cylinder nozzle ejects the pulverized coal conveyed by the conveying air. The inner cylinder nozzle is provided inside the outer cylinder nozzle and ejects the combustion air.

[0004] The pulverized coal ejected from the outer cylinder nozzle and the combustion air ejected from the inner cylinder nozzle are introduced into the wind box. The pulverized coal and the combustion air are promoted to mix by the swirling flow of the air flowing in the wind box and are supplied into the furnace. The oil burner is provided inside the inner cylinder nozzle and burns the pulverized coal supplied to the furnace.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the initial stages of operation of such a combustion system, the temperature inside the furnace may be lower than the temperature suitable for burning pulverized coal, making it difficult to burn the coal efficiently. Therefore, in the initial stages of operation of the combustion system, the tip of the oil burner is introduced into the furnace to heat the inside of the furnace by burning oil from the oil burner, and then the pulverized coal is supplied into the furnace and burned.

[0007] However, after heating the furnace with an oil burner, burning pulverized coal inside the furnace could potentially damage the tip of the oil burner due to the heat.

[0008] The purpose of this disclosure is to provide a combustion device capable of suppressing burner damage. [Means for solving the problem]

[0009] To solve the above problems, the combustion apparatus of this disclosure comprises an inner cylinder nozzle, an outer cylinder nozzle provided outside the inner cylinder nozzle, a first fuel passage formed between the inner cylinder nozzle and the outer cylinder nozzle for circulating fuel and air, a burner provided inside the inner cylinder nozzle, and an actuator for moving the tip of the burner between a first position where it enters the furnace and a second position closer to the injection port of the inner cylinder nozzle than the first position. The burner has an inner cylinder and an outer cylinder, and the actuator includes a first actuator that drives the inner cylinder to move the tip of the burner between a first position and a second position, and a second actuator that drives the outer cylinder to move the tip of the burner between the second position and an initial position inside the inner cylinder nozzle. .

[0010] The second position may be the nozzle opening of the inner cylinder nozzle. [Effects of the Invention]

[0012] According to this disclosure, damage to the burner can be suppressed. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a schematic diagram showing the configuration of the combustion system according to this embodiment. [Figure 2] Figure 2 is a magnified view of a portion of the burner in its initial position before the combustion system is operational. [Figure 3]Figure 3 is a magnified view of a portion of the burner during the initial stages of operation of the combustion system. [Figure 4] Figure 4 is a first magnified view of the burner after the temperature inside the furnace has reached a threshold. [Figure 5] Figure 5 is a second magnified view of the burner after the temperature inside the furnace has reached a threshold. [Figure 6] Figure 6 is a diagram illustrating the internal structure of the inner cylinder of a modified burner. [Modes for carrying out the invention]

[0014] Embodiments of this disclosure will be described below with reference to the attached drawings. The dimensions, materials, and other specific numerical values ​​shown in the embodiments are merely examples for the purpose of facilitating understanding and do not limit this disclosure unless otherwise specified. In this specification and drawings, elements having substantially the same function or configuration are denoted by the same reference numerals to avoid redundant explanations, and elements not directly related to this disclosure are omitted from the illustrations.

[0015] Figure 1 is a schematic diagram showing the configuration of the combustion system 100 according to this embodiment. As shown in Figure 1, the combustion system 100 comprises a furnace 110 and a combustion device 130. The furnace 110 is a furnace body that generates combustion heat by burning fuel in the combustion device 130. The combustion gas generated in the furnace 110 is exchanged with water by a heat exchanger (not shown). In the heat exchanger, steam is generated by the heat exchange between water and combustion gas.

[0016] The combustion apparatus 130 includes a wind box 150 and a burner apparatus 170. The wind box 150 is provided around an opening 111a formed in the furnace wall 111 of the furnace 110. The inside of the wind box 150 communicates with the internal space of the furnace 110 through the opening 111a. The wind box 150 supplies combustion air from the outside to the internal space of the furnace 110 through the opening 111a.

[0017] The wind box 150 includes an air volume adjustment device 151. The air volume adjustment device 151 has an air guide duct 153 and air volume adjustment vanes 155. The air guide duct 153 connects the internal space of the wind box 150 and the opening 111a of the furnace wall 111, and guides the combustion air flowing through the wind box 150 to the opening 111a.

[0018] A plurality of air volume adjustment vanes 155 are provided in the air guide duct 153. The plurality of air volume adjustment vanes 155 are respectively attached to the air guide duct 153 via a rotating shaft 157 and are arranged at equal intervals around the opening 111a. Each air volume adjustment vane 155 is configured to be rotatable about the rotating shaft 157.

[0019] The plurality of rotating shafts 157 are connected by a link mechanism (not shown). The plurality of air volume adjustment vanes 155 rotate synchronously by a drive device (not shown) connected to the link mechanism, and the angles are adjusted.

[0020] The air volume adjustment device 151 can impart a swirling force to the combustion air supplied to the furnace 110 by adjusting the angle of the air volume adjustment vanes 155. Further, the air volume adjustment device 151 can adjust the air volume and the swirling force of the combustion air supplied to the furnace 110 by adjusting the angle of the air volume adjustment vanes 155.

[0021] A burner device 170 is provided in the wind box 150. The burner device 170 has an outer cylinder nozzle 171, an inner cylinder nozzle 173, a burner 175, a first fuel flow path 177, and a fuel supply device 179.

[0022] The tip side of the outer cylinder nozzle 171 is inserted into the wind box 150. An inner cylinder nozzle 173 is provided inside the outer cylinder nozzle 171. In other words, the outer cylinder nozzle 171 is provided outside the inner cylinder nozzle 173. A first fuel flow path 177 is formed between the outer cylinder nozzle 171 and the inner cylinder nozzle 173.

[0023] The first fuel channel 177 receives biomass, pulverized coal (hereinafter referred to as the first fuel), and transport air. The first fuel channel 177 circulates the first fuel and transport air.

[0024] The inner cylinder nozzle 173 is located inside the outer cylinder nozzle 171 and allows combustion air to flow through it. An inner cylinder injection port 173a is formed at the tip of the inner cylinder nozzle 173. The combustion air flowing through the inside of the inner cylinder nozzle 173 is injected outwards from the inner cylinder injection port 173a.

[0025] The tip of the outer nozzle 171 is flush with the tip of the inner nozzle 173. In other words, the axial tip position of the outer nozzle 171 is equal to the axial tip position of the inner nozzle 173. Here, "equal" includes both cases where they are perfectly equal and cases where they deviate from the perfectly equal case within the range of tolerances (machining accuracy, assembly error, etc.). Hereafter, "equal" or "same" includes both cases where they are perfectly equal (same) and cases where they deviate from the perfectly equal (same) case within the range of tolerances (machining accuracy, assembly error, etc.).

[0026] An outer cylinder nozzle 171a is formed between the tip of the outer cylinder nozzle 171 and the tip of the inner cylinder nozzle 173. The first fuel and transport air flowing through the first fuel passage 177 are injected outwards from the outer cylinder nozzle 171a.

[0027] The outer cylinder nozzle 171a and the inner cylinder nozzle 173a face the opening 111a of the furnace wall 111. The outer cylinder nozzle 171a and the inner cylinder nozzle 173a are located on the side of the opening 111a of the furnace wall 111 that is away from the internal space of the furnace 110. In other words, the outer cylinder nozzle 171a and the inner cylinder nozzle 173a are positioned on the side of the opening 111a of the furnace wall 111 that is away from the internal space of the furnace 110.

[0028] The burner 175 is installed inside the inner cylinder nozzle 173. Inside the burner 175, a second fuel passage 175a is formed through which oil (hereinafter referred to as the second fuel) flows. The burner 175 injects the second fuel that has flowed through the second fuel passage 175a from the tip 175d (see Figures 2-5), which will be described later. The burner 175 also ignites and burns the injected second fuel. The burner 175 is used to ignite the first fuel and the second fuel introduced into the furnace 110. The burner 175 is also used to heat the temperature inside the furnace 110 to above a threshold by burning only the second fuel when the temperature inside the furnace 110 is below a threshold.

[0029] The fuel supply device 179 supplies the first fuel to the first fuel passage 177. The fuel supply device 179 also supplies the second fuel to the second fuel passage 175a. The fuel supply device 179 can independently adjust the supply amount and supply pressure of the first and second fuels.

[0030] Next, the operation of the combustion device 130 will be described. First fuel and transport air are supplied to the first fuel passage 177 inside the outer cylinder nozzle 171. The first fuel and transport air flow through the first fuel passage 177 while mixing. The first fuel and transport air that have flowed through the first fuel passage 177 are injected into the air guide duct 153 from the outer cylinder injection port 171a.

[0031] Furthermore, combustion air is supplied into the inner cylinder nozzle 173, and the combustion air circulates within the inner cylinder nozzle 173. The combustion air is injected from the inner cylinder injection port 173a into the air guide duct 153. In addition, combustion air is supplied into the wind box 150, and the combustion air circulates within the wind box 150 and the air guide duct 153. The combustion air is injected from the opening 111a into the furnace 110.

[0032] Outside the laminar flow of combustion air injected from the inner cylinder nozzle 173a, a laminar flow of the first fuel and conveying air injected from the outer cylinder nozzle 171a is formed. Furthermore, outside the laminar flow of the first fuel and conveying air injected from the outer cylinder nozzle 171a, a swirling flow of combustion air, whose airflow and swirling force are adjusted by the airflow adjustment device 151, is formed.

[0033] The swirling force of the combustion air causes a shear force to act on the laminar flow of the first fuel and conveying air formed inside, as well as the laminar flow of the combustion air. This shear force promotes the mixing of the combustion air, the first fuel, and the conveying air. As a result, the combustion of the first fuel inside the furnace 110 is promoted.

[0034] Incidentally, in the initial stages of operation of the combustion system 100, the temperature inside the furnace 110 may be lower than the temperature suitable for the combustion of the first fuel, making it impossible to efficiently burn the first fuel. Therefore, in the initial stages of operation of the combustion system 100, the tip of the burner 175 is introduced into the furnace 110, and the inside of the furnace 110 is heated by the combustion of oil by the burner 175. Subsequently, the first fuel is supplied into the furnace 110 and burned together with the combustion of oil by the burner 175.

[0035] However, if the first fuel is burned in the furnace 110 after heating with the burner 175, the heat may damage the burner 175. Therefore, it may become difficult to continue burning the first fuel.

[0036] Therefore, the burner device 170 of this embodiment has a first actuator 180A, a second actuator 180B, and a burner control unit 190 in order to vary the position of the burner 175 according to the conditions inside the furnace 110. The first actuator 180A and the second actuator 180B are collectively referred to simply as actuator 180.

[0037] Actuator 180 is, for example, an air cylinder. However, it is not limited to this, and actuator 180 may be, for example, a hydraulic cylinder or an electric cylinder. The operation of the first actuator 180A, the second actuator 180B, and the burner control unit 190 will be described below.

[0038] Figure 2 is a partially enlarged view of the burner 175 in its initial position before operation of the combustion system 100. As shown in Figure 2, the burner 175 has an inner cylinder 175b and an outer cylinder 175c. The inner cylinder 175b is located inside the outer cylinder 175c and is configured to be movable in the axial direction relative to the outer cylinder 175c.

[0039] The inner cylinder 175b is located closer to the inner cylinder nozzle 173a of the inner cylinder nozzle 173 than the outer cylinder 175c. The tip of the inner cylinder 175b becomes the tip 175d of the burner 175. The inner cylinder 175b is connected to the first actuator 180A shown in Figure 1. The outer cylinder 175c is connected to the second actuator 180B shown in Figure 1.

[0040] The first actuator 180A moves the inner cylinder 175b axially relative to the outer cylinder 175c of the burner 175. The second actuator 180B moves the outer cylinder 175c of the burner 175 axially inside the inner cylinder nozzle 173. Specifically, the first actuator 180A drives the inner cylinder 175b to move the tip 175d of the burner 175 between a first position and a second position, which will be described later. The second actuator 180B drives the outer cylinder 175c to move the tip 175d of the burner 175 between a second position, which will be described later, and an initial position inside the inner cylinder nozzle 173.

[0041] Thus, in this embodiment, the burner 175 is composed of two components, an outer cylinder 175c and an inner cylinder 175b, and is equipped with a first actuator 180A and a second actuator 180B for driving each component. This makes the configuration of the actuator 180 smaller and simpler compared to the case where the burner 175 is driven to the initial position, first position, and second position described later with a single actuator.

[0042] The burner control unit 190 (see Figure 1) controls the first actuator 180A and the second actuator 180B. Before the furnace 110 is in operation, i.e., when it is shut down, the burner 175 is in the initial position shown in Figure 2.

[0043] The initial position of the burner 175 is when its tip 175d is positioned inside the inner cylinder nozzle 173. By positioning the burner 175 in this initial position, its tip 175d is protected by the inner cylinder nozzle 173, thereby preventing damage to the tip 175d.

[0044] Figure 3 is a magnified view of a portion of the burner 175 during the initial operation of the combustion system 100. During the initial operation of the combustion system 100, the temperature inside the furnace 110 may be below a threshold, making it impossible to efficiently burn the first fuel.

[0045] Therefore, in the state shown in Figure 3, the fuel supply device 179 stops supplying the first fuel to the first fuel passage 177. Meanwhile, the fuel supply device 179 starts supplying the second fuel to the second fuel passage 175a of the burner 175 in order to heat the inside of the furnace 110 with the burner 175.

[0046] At this time, the burner control unit 190 drives the first actuator 180A and the second actuator 180B. The burner control unit 190 moves the tip 175d of the burner 175 from the initial position shown in Figure 2 to a first position that is on the side of the furnace 110's internal space beyond the opening 111a of the furnace 110.

[0047] When the tip 175d of the burner 175 is in the first position, the furnace wall 111 is not located around the tip 175d of the burner 175. Therefore, the second fuel injected from the tip 175d of the burner 175 is injected into the internal space of the furnace 110 without colliding with the furnace wall 111. By igniting the second fuel injected in this way, the burner 175 can efficiently heat the temperature inside the furnace 110 to above the threshold during the initial operation of the combustion system 100.

[0048] Figure 4 is a first partial enlarged view of the burner 175 after the temperature inside the furnace 110 has reached a threshold. In Figure 4, the temperature inside the furnace 110 is suitable for the combustion of the first fuel, and the fuel supply device 179 begins supplying the first fuel to the first fuel passage 177. The fuel supply device 179 also continues supplying the second fuel to the second fuel passage 175a.

[0049] At this time, the burner control unit 190 drives the first actuator 180A. The burner control unit 190 moves the position of the tip 175d of the burner 175 to a second position that is closer to the outer cylinder nozzle 171a and inner cylinder nozzle 173a than the first position shown in Figure 3.

[0050] Here, the second position is, for example, a position on the side of the outer cylinder nozzle 171a and inner cylinder nozzle 173a from the opening 111a of the furnace wall 111. In the example shown in Figure 4, the second position is a position between the opening 111a of the furnace wall 111 and the outer cylinder nozzle 171a and inner cylinder nozzle 173a.

[0051] By moving the tip 175d of the burner 175 to the second position, heat damage inside the furnace 110 can be reduced compared to when the tip 175d is in the first position shown in Figure 3. Furthermore, by moving the tip 175d of the burner 175 to the second position, contact between the first fuel, which is biomass or pulverized coal injected from the outer cylinder nozzle 171a, and the tip 175d of the burner 175 can be reduced compared to when the tip 175d is in the first position. Therefore, damage to the tip 175d of the burner 175 due to contact with the first fuel can be reduced.

[0052] To reduce damage to the tip 175d of the burner 175, the position of the tip 175d is preferably such that it is as far away from the opening 111a as possible toward the outer cylinder nozzle 171a and the inner cylinder nozzle 173a. In other words, the position of the tip 175d is preferably as far away from the internal space of the furnace 110 as possible toward the outer cylinder nozzle 171a and the inner cylinder nozzle 173a.

[0053] Figure 5 is a second enlarged view of the burner 175 after the temperature inside the furnace 110 has reached a threshold. Figure 5 is a diagram illustrating a second position different from the second position shown in Figure 4. In Figure 5, the position of the tip 175d is located further from the opening 111a towards the outer cylinder nozzle 171a and inner cylinder nozzle 173a than the second position shown in Figure 4. In Figure 5, as in Figure 4, the fuel supply device 179 starts supplying the first fuel to the first fuel passage 177. The fuel supply device 179 also continues to supply the second fuel to the second fuel passage 175a.

[0054] The burner control unit 190 drives the first actuator 180A. The burner control unit 190 moves the position of the tip 175d of the burner 175 to a position equal to the outer cylinder nozzle 171a and the inner cylinder nozzle 173a. This position is also a second position, which is closer to the outer cylinder nozzle 171a and the inner cylinder nozzle 173a than the first position shown in Figure 3. At this time, the tip 175d of the burner 175, the inner cylinder nozzle 173a, and the outer cylinder nozzle 171a become flush.

[0055] By moving the tip 175d of the burner 175 to a position equal to the outer cylinder nozzle 171a and the inner cylinder nozzle 173a, contact between the first fuel injected from the outer cylinder nozzle 171a and the tip 175d can be reduced as much as possible.

[0056] In this case, if the tip 175d of the burner 175 is located inside the inner cylinder nozzle 173, a portion of the second fuel injected from the tip 175d is blocked by the inner wall of the inner cylinder nozzle 173. As a result, a portion of the second fuel injected from the tip 175d does not reach the internal space of the furnace 110.

[0057] Therefore, when the first fuel is burned by the burner 175, it is preferable that the tip 175d of the burner 175 be positioned at least in the axial direction at the same position as the outer cylinder nozzle 171a and the inner cylinder nozzle 173a, or at a position that protrudes toward the opening 111a.

[0058] Thus, according to this embodiment, the burner device 170 includes an actuator 180 that moves the tip 175d of the burner 175 between a first position in which it enters the furnace 110 and a second position which is closer to the inner cylinder nozzle 173a of the inner cylinder nozzle 173 than the first position.

[0059] This allows the tip 175d of the burner 175 to be moved to a second position closer to the inner cylinder nozzle 173a than the first position within the furnace 110 when burning the first fuel in the furnace 110. As a result, damage to the burner 175 is suppressed as described above, while facilitating the continuation of the combustion of the first fuel.

[0060] In this embodiment, an example was described in which the burner 175 is an oil burner that burns oil as a second fuel. However, it is not limited to this, and for example, the burner 175 may burn a gaseous fuel instead of a liquid fuel. Specifically, the burner 175 may be a gas burner that burns gas as a second fuel. Below, a modified example in which the burner 175 is configured as a gas burner instead of an oil burner will be described.

[0061] Figure 6 is a diagram illustrating the internal configuration of the inner cylinder 275b of the burner 275 according to a modified example. Components that are substantially the same as those of the burner 175 in the above embodiment are denoted by the same reference numerals and their descriptions are omitted. In this modified example, the components of the burner 275 other than the inner cylinder 275b are the same as those of the burner 175 in the above embodiment. Unlike the oil burner in the above embodiment, the burner 275 in this modified example is a gas burner that burns gas as a second fuel.

[0062] As shown in Figure 6, the inner cylinder 275b has a double-pipe structure consisting of an outer pipe 280 and an inner pipe 290. The outer pipe 280 has a cylindrical shape, and the inner pipe 290 is arranged inside the outer pipe 280. The outer pipe 280 is positioned outside the inner pipe 290 so as to surround the inner pipe 290. As described in the above embodiment, the inner cylinder 275b is configured to be axially movable relative to the outer cylinder 175c (see Figures 2-5). However, the outer pipe 280 and the inner pipe 290 are configured not to be axially movable relative to each other. The ends of the outer pipe 280 and the inner pipe 290 are flush with each other.

[0063] Inside the inner piping 290, a gas, which serves as the second fuel, is supplied from the fuel supply device 179. The gas, which serves as the second fuel, flows through the inside of the inner piping 290 and is injected to the outside through an inner opening 291 provided at the end of the inner piping 290.

[0064] Inside the outer piping 280, a gas, which serves as the third fuel, is supplied from the fuel supply device 179. The gas, which serves as the third fuel, flows through the inside of the outer piping 280 and is injected to the outside through an outer opening 281 provided at the end of the outer piping 280.

[0065] Here, the gas used as the third fuel injected from the outer opening 281 is the same gas as the gas used as the second fuel injected from the inner opening 291. However, the gas used as the third fuel injected from the outer opening 281 may be a different gas from the gas used as the second fuel injected from the inner opening 291.

[0066] The fuel supply device 179 can independently adjust the supply amount and supply pressure of the second fuel supplied to the inner piping 290 and the third fuel supplied to the outer piping 280. In this modified example, the supply amount of the third fuel supplied to the outer piping 280 is greater than the supply amount of the second fuel supplied to the inner piping 290. However, the supply amount of the second fuel supplied to the inner piping 290 may be greater than the supply amount of the third fuel supplied to the outer piping 280. Alternatively, the supply amounts of the second fuel supplied to the inner piping 290 and the third fuel supplied to the outer piping 280 may be the same.

[0067] The burner 275 ignites and burns the gas injected from the inner opening 291 and the outer opening 281. In this modified example, by using a double-pipe structure for the burner 275, it is possible to inject a larger volume and higher pressure of gas than in the case of a single-pipe structure. As a result, the range of applicability of the burner 275 in various atmospheres within the furnace 110 can be expanded.

[0068] While embodiments of this disclosure have been described above with reference to the attached drawings, it goes without saying that this disclosure is not limited to such embodiments. It will be obvious to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of this disclosure.

[0069] In the embodiments and modifications described above, examples were given in which the first fuel injected from the outer cylinder nozzle 171a is biomass or pulverized coal. However, the invention is not limited to this, and, as with the modifications described above, the first fuel may be gas or oil.

[0070] In the embodiments and modifications described above, an example was described in which the actuator 180 includes a first actuator 180A and a second actuator 180B. However, the actuator 180 may be composed of a single actuator, but is not limited thereto.

[0071] This disclosure can contribute, for example, to Sustainable Development Goal (SDG) 7, "Ensure access to affordable, reliable, sustainable and modern energy," and Goal 13, "Take urgent action to combat climate change and its impacts." [Explanation of symbols]

[0072] 100 Combustion Systems 110 Furnace 111 Furnace wall 111a aperture 130 Combustion device 150 Window Box 151 Air volume adjustment device 153 Air guide duct 155 Airflow adjustment blades 157 Rotation axis 170 Burner device 171 Outer cylinder nozzle 171a Outer cylinder nozzle 173 Inner cylinder nozzle 173a Inner cylinder injection port 175 Burner 175a Second fuel passage 175b Inner cylinder 175c outer cylinder 175d tip 177 First Fuel Flow Path 179 Fuel supply system 180A First Actuator 180B Second Actuator 190 Burner Control Unit 275 burner 275b Inner cylinder 280 Outside piping 281 Outer opening 290 Internal piping 291 Inner opening

Claims

1. Inner cylinder nozzle, An outer cylinder nozzle provided on the outside of the inner cylinder nozzle, A first fuel passage is formed between the inner cylinder nozzle and the outer cylinder nozzle, through which fuel and air are circulated. A burner provided inside the inner cylinder nozzle, An actuator moves the tip of the burner between a first position where it enters the furnace and a second position where it is closer to the nozzle opening of the inner cylinder nozzle than the first position. It has, The burner has an inner cylinder and an outer cylinder, The actuator is A first actuator drives the inner cylinder to move the tip of the burner between the first position and the second position, A second actuator drives the outer cylinder to move the tip of the burner between the second position and an initial position inside the inner cylinder nozzle, including, Combustion device.

2. The second position is the nozzle opening of the inner cylinder nozzle. The combustion apparatus according to claim 1.

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