Method for controlling combustion of a combustion burner and combustion burner

Abstract

In a combustion burner that burns combustible gases generated by the gasification of waste, the aim is to stabilize ignition and the flame after ignition, and to reduce the amount of fossil fuels used. [Solution] This is a combustion control method for a combustion burner in which combustible gas generated by the gasification of waste and combustion air are mixed and burned in a first premixing region in the combustion chamber and in a second premixing region in the combustion chamber located downstream of the first premixing region in the flow direction of the combustible gas. In the first mixing step, the combustible gas and combustion air are mixed in the first premixing region to form a first mixture; in the second mixing step, the combustible gas and combustion air are mixed in the second premixing region to form a second mixture; in the ignition step, the first mixture formed in the first mixing step is ignited; and in the propagation step, the flame of the first mixture in the combustion chamber ignited in the ignition step is propagated within the combustion chamber to the second mixture formed in the second mixing step.

Description

Technical Field

[0001] The present invention relates to a combustion burner that burns combustible gas generated by gasification of waste.

Background Art

[0002] Waste treatment furnaces such as waste gasification melting furnaces are used for treating waste such as general waste and industrial waste. The combustible gas generated in the waste treatment furnace is burned by a combustion burner in a combustion chamber to recover heat. As a combustion burner that burns combustible gas generated by gasification of waste, a premixed combustion burner with a simple structure and capable of improving combustibility is known (for example, Patent Document 1).

[0003] In the combustion burner of Patent Document 1, in order to enable stable flame formation even when the calorific value of the combustible gas generated by gasification of waste is low, one of the plurality of burner ports is extended with a burner tile to expand the premixed region as a ignition burner port, and a pilot burner is installed near the outlet of this ignition burner port. With this combustion burner, a certain effect has been obtained in stabilizing the flame during combustion of the combustible gas generated by gasification of waste.

[0004] However, in this combustion burner, the pilot burner is installed so as to supply a kindling flame from the side near the outlet of the ignition burner port. Therefore, regarding the flame stabilization during combustion of the combustible gas generated by gasification of waste, there are still the following problems. (1) Flame propagation from the ignition burner port to other burner ports may be difficult to occur, and there is room for further improvement in the ignition property for combustible gas. (2) In order to bring the kindling flame of the pilot burner into contact with the mixture in other burner ports, it is necessary to extend the kindling flame, and as a result, the amount of fossil fuel (normal fuel) used increases. Especially in a large combustion burner, the distance to other burner ports becomes longer, and the amount of fossil fuel used increases.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2012-17897 [Overview of the project] [Problems that the invention aims to solve]

[0006] The problem that this invention aims to solve is to stabilize ignition and the flame after ignition in a combustion burner that burns combustible gas generated by the gasification of waste, and to reduce the amount of fossil fuels used. [Means for solving the problem]

[0007] To solve the above problems, the inventors conducted numerous tests and studies and found that it is effective to divide the process of forming the air-fuel mixture in the premixing region into two stages. Specifically, they found that it is effective to form the air-fuel mixture in a central premixing region located in the center of the premixing region as the first stage, and to form the air-fuel mixture in a peripheral premixing region located downstream of the central premixing region as the second stage, and to ignite the air-fuel mixture in the central premixing region with an ignition means.

[0008] The present invention was conceived based on the above findings, and in one view thereof, provides a combustion control method for a combustion burner and a combustion burner. <Method for controlling combustion in a combustion burner> A combustion control method for a combustion burner, wherein a combustible gas generated by the gasification of waste and combustion air are mixed and burned in a first premixing region within the combustion chamber and in a second premixing region within the combustion chamber located downstream of the first premixing region in the flow direction of the combustible gas, The first mixing step, The second mixed step, Ignition step, The propagation step includes, In the first mixing step, the combustible gas and the combustion air are mixed in the first premixed region to form a first mixture. In the second mixing step, the combustible gas and the combustion air are mixed in the second premixing region to form a second mixture. In the ignition step, the first mixture formed in the first mixing step is ignited. In the propagation step, the flame of the first mixture in the combustion chamber, which is ignited in the ignition step, is propagated within the combustion chamber to the second mixture formed in the second mixing step. A method for controlling the combustion of the combustion burner, characterized by the above. <Combustion Burner> A combustion burner that mixes and burns a combustible gas generated by the gasification of waste and combustion air in a first premixing region within the combustion chamber and in a second premixing region within the combustion chamber located downstream of the first premixing region in the flow direction of the combustible gas, In the first premixing region, a first mixing means mixes the combustible gas and the combustion air to form a first mixture, In the aforementioned second premixing region, a second mixing means mixes the combustible gas and the combustion air to form a second mixture, An ignition means for igniting the first mixture formed by the first mixing means, A propagation means propagates the flame of the first mixture in the combustion chamber, which is ignited by the ignition means, to the second mixture formed by the second mixing means within the combustion chamber. A combustion burner characterized by having the following features. [Effects of the Invention]

[0009] According to the present invention, in a combustion burner that burns combustible gas generated by the gasification of waste, it is possible to stabilize ignition and the flame after ignition, and to reduce the amount of fossil fuels used. [Brief explanation of the drawing]

[0010] [Figure 1]Conceptual diagram of a waste gasification and melting system to which a combustion burner according to an embodiment of the present invention is applied. [Figure 2] Schematic longitudinal sectional view of a combustion burner according to an embodiment of the present invention. [Figure 3] Cross-sectional view taken along line I-I of FIG. 2. [Figure 4] Cross-sectional view taken along line II-II of FIG. 3. [Figure 5A] Schematic perspective view of a combustion burner according to an embodiment of the present invention as viewed from the downstream side at an angle different from that of FIG. 5B. [Figure 5B] Schematic perspective view of a combustion burner according to an embodiment of the present invention as viewed from the downstream side at an angle different from that of FIG. 5A. [Figure 6] Schematic perspective view of a combustion burner according to an embodiment of the present invention as viewed from the upstream side. [Figure 7] Plan perspective view of FIG. 6. [Figure 8] A combustion burner according to another embodiment of the present invention is schematically shown, where (a) is a schematic view as seen from the downstream side and (b) is a schematic view as seen from the side. [Figure 9] A combustion burner according to still another embodiment of the present invention is schematically shown, where (a) is a schematic view as seen from the downstream side and (b) is a schematic view as seen from the side.

MODE FOR CARRYING OUT THE INVENTION

[0011] <Embodiment 1> FIG. 1 conceptually shows a waste gasification and melting system to which a combustion burner according to an embodiment of the present invention is applied. In waste treatment furnace A, waste is fed in from the top of the furnace via the input device A1 along with auxiliary materials such as coke and limestone. After going through the processes of drying, thermal decomposition, combustion, and melting, the molten material is discharged from the slag outlet A2 at the bottom of the furnace. Meanwhile, the combustible components are discharged from the gas pipe A3 at the top of the furnace as combustible gas containing combustible dust and thermal decomposition gases (CO, H2, CH4, CO2, N2, etc.). The combustible gas is introduced into the secondary combustion chamber C via the combustion burner B and combusted, and heat is recovered by heat exchange in boiler D. The steam generated in boiler D is sent to the steam turbine / power generation device E. The exhaust gas from boiler D is separated into solid and gas by the dust collector F and discharged from the chimney H by the blower G.

[0012] Next, the configuration of combustion burner B will be described. Figure 2 schematically shows a longitudinal section of combustion burner B, which is one embodiment of the present invention. Figure 3 shows section II of Figure 2, and Figure 4 shows section II-II of Figure 3. Furthermore, Figures 5A and 5B show schematic perspective views of combustion burner B from the downstream side (secondary combustion chamber C side) at different angles, respectively, and Figure 6 shows a schematic perspective view of combustion burner B from the upstream side (gas pipe A3 side). Finally, Figure 7 shows a plan perspective view of Figure 6. In this specification, "upstream" and "downstream" refer to the direction of flow of the flammable gas.

[0013] As shown in Figure 2, the combustion burner B comprises a burner body B1 connected to the downstream end of the gas pipe A3, a burner port B2 connecting the downstream end of the burner body B1 to the gas inlet C1 of the secondary combustion chamber C, and a pilot burner B3 installed in the burner port B2 as an ignition means. Combustible gas generated in the waste treatment furnace A is introduced into the burner body B1 via gas pipe A3, and air from an air source (not shown) is introduced as combustion air via air duct B4. The combustible gas and combustion air introduced into the burner body B1 are mixed in a premixing region, which will be described later, to form a mixture. A perforated metal plate B5 is placed inside the air duct B4 as a flow straightening plate.

[0014] Next, we will explain the specific configuration of the burner unit B1. As shown in Figures 5A, 5B, and 6, the burner body B1 has a roughly rectangular inner cylinder 1, a roughly rectangular outer cylinder 2 arranged at intervals surrounding the inner cylinder 1, and a partition plate 3 that defines the distance between the inner cylinder 1 and the outer cylinder 2. The partition plate 3 has multiple openings 3a at intervals, and this partition plate 3 also functions as a rectifier plate for combustion air. Note that in Figures 5A, 5B, and 6, the outer cylinder 2 is partially omitted as appropriate in order to show the internal structure of the burner body B1. The inner cylinder 1 has its upstream end connected to the downstream end of the gas pipe A3. This allows combustible gas generated in the waste treatment furnace A to be introduced into the inner cylinder 1. Meanwhile, combustion air is introduced into the outer cylinder 2 via the air duct B4 described above. Specifically, as shown in Figures 6 and 7, a combustion air inlet 21a is provided on the bottom plate 21 of the outer cylinder 2, and the air duct B4 is connected to this combustion air inlet 21a. In other words, combustion air is introduced into the outer cylinder 2 via the air duct B4 and the combustion air inlet 21a.

[0015] As clearly shown in Figures 6 and 7, four branch posts 4 are arranged in parallel and spaced apart within the inner cylinder 1 in a direction perpendicular to the flow direction of the combustible gas (hereinafter also referred to as the "width direction"). In plan view, the branch posts 4 are formed so that the upstream side is pointed. Specifically, the shape of the upstream portion 41 of the branch post 4 is such that, in plan view, the upstream end is the apex and it widens on both sides as it moves downstream. The downstream portion 42, which is continuous with this upstream portion 41, is formed by a pair of side plates 42A and 42B that extend parallel to the downstream side. Here, as shown in Figure 7, in the two branch posts 4B located on the periphery side of the four branch posts 4, the length of the side plates 42A and 42B along the flow direction of the combustible gas (hereinafter simply referred to as "length") is the same. On the other hand, in the two branch posts 4A located on the central side of the four branch posts 4, the length of the central side plate 42A is shorter than the length of the peripheral side plate 42B. In the following explanation, when it is not necessary to distinguish between the central branch post 4A and the peripheral branch post 4B, they will be collectively referred to as "branch post 4".

[0016] As shown in Figure 6, the branch post 4 is a plate member that extends vertically and is provided vertically between the bottom plate 11 and the top plate 12 of the inner cylinder 1. That is, the lower end of the branch post 4 is connected to the bottom plate 11, and the upper end of the branch post 4 is connected to the top plate 12.

[0017] As shown in Figures 3, 4, 5A, 5B, and 7, a burner tile 5 is positioned at the downstream end of the branching post 4. Specifically, as clearly shown in Figure 7, the entire upstream portion 51 and part of the downstream portion 52 of the burner tile 5 are inserted between the side plates 42A and 42B that constitute the downstream portion 42 of the branching post 4, with a gap in the width direction. That is, the remaining portion of the downstream portion 52 of the burner tile 5 protrudes downstream from the downstream portion 42 of the branching post 4. On the other hand, a partition plate 6 is provided between the downstream end of side plate 42A and the side surface of burner tile 5, and another partition plate 6 is provided between the downstream end of side plate 42B and the side surface of burner tile 5. Furthermore, partition plates 6 are provided between the downstream ends of the two side plates 13 of the inner cylinder 1 and the downstream ends of the two side plates 23 of the outer cylinder 2. Each partition plate 6 is provided with multiple discharge holes 6a for discharging combustion air, spaced vertically apart, as shown in Figures 4, 5A, and 5B.

[0018] As shown in Figure 6, the top plate 12 of the inner cylinder 1 has eight openings 12a to h. Also, as shown in Figure 7, the bottom plate 11 of the inner cylinder 1 also has eight openings 11a to h. These eight openings 11a to h of the bottom plate 11 and the eight openings 12a to h of the top plate 12 are arranged to overlap in a plan view. That is, for example, the opening 11a of the bottom plate 11 and the opening 12a of the top plate 12 are the same shape and are located in positions that overlap in a plan view. The same applies to the openings 11b to h of the bottom plate 11 and the openings 12b to h of the top plate 12. Furthermore, all eight openings 11a to h of the bottom plate 11 and the eight openings 12a to h of the top plate 12 are arranged to communicate with the internal space of the branch post 4. In other words, the internal space of the branch post 4 is connected to the space (gap) between the bottom plate 11 of the inner cylinder 1 and the bottom plate 21 of the outer cylinder 2 via the eight openings 11a to h of the bottom plate 11, and also to the space (gap) between the top plate 12 of the inner cylinder 1 and the top plate 22 of the outer cylinder 2 via the eight openings 12a to h of the top plate 12.

[0019] Next, we will explain the operation of combustion burner B. The combustible gas generated in the waste treatment furnace A is introduced to the upstream side of the inner cylinder 1 via gas pipe A3. This combustible gas is then branched into five flows 7A to E by four branching posts 4 inside the inner cylinder 1, as shown by the white arrows in Figure 3, and each flows downstream. The central flow 7A is defined by the two central side plates 42A of the two branching posts 4A located on the central side, as can be seen in Figure 7. The combustible gas along this central flow 7A is discharged from between the downstream ends of the two side plates 42A to the central premixing region 8A, which is located in the center of the premixing region 8. In other words, in this embodiment, the area between the downstream ends of the two central side plates 42A of the two branching posts 4A located on the central side forms the central gas discharge section 81A that discharges the combustible gas to the central premixing region 8A.

[0020] Furthermore, the two peripheral flows 7B and 7C adjacent to the central flow 7A are defined, respectively, by the two peripheral side plates 42B of the two branch posts 4A located on the central side and the two central side plates 42A of the two branch posts 4B located on the peripheral side. The flammable gas along these peripheral flows 7B and 7C is discharged from between the downstream ends of the two side plates 42B and 42A to the peripheral premixing region 8B, which is located on the peripheral side of the premixing region 8. In other words, in this embodiment, the area between the downstream ends of the two side plates 42B and 42A serves as a peripheral gas discharge section 81B that discharges flammable gas to the peripheral premixing region 8B.

[0021] Furthermore, the two peripheral flows 7D and 7E adjacent to the two peripheral flows 7B and 7C described above are defined by the two peripheral side plates 42B of the two branch posts 4B located on the peripheral side and the two side plates 13 of the inner cylinder 1, respectively. The flammable gas along these peripheral flows 7D and 7E is discharged from between the downstream ends of the two side plates 42B and the two side plates 13 to the peripheral premixing region 8C, which is located on the peripheral side of the premixing region 8. In other words, in this embodiment, the area between the downstream ends of the two side plates 42B and the two side plates 13 serves as a peripheral gas discharge section 81C that discharges flammable gas to the peripheral premixing region 8C.

[0022] Meanwhile, combustion air is introduced into the space (gap) between the inner cylinder 1 and the outer cylinder 2 via the air duct B4 and the combustion air inlet 21a. A portion of this combustion air is then introduced into the internal space of the four branching posts 4 through the eight openings 11a to h in the bottom plate 11 and the eight openings 12a to h in the top plate 12. The combustion air introduced into the internal space of the four branching posts 4 is then branched into two flows by the burner tile 5, as shown by the short black arrows in Figure 3, and discharged from the discharge holes 6a provided in the partition plate 6. Furthermore, a portion of the combustion air introduced into the space (gap) between the inner cylinder 1 and the outer cylinder 2 via the air duct B4 and the combustion air inlet 21a flows downstream through the two slit-shaped spaces (gaps) between the two side plates 13 of the inner cylinder 1 and the two side plates 23 of the outer cylinder 2, as shown by the long black arrows in Figure 3, and is discharged from the discharge holes 6a provided in the partition plate 6 between the downstream ends of the two side plates 13 of the inner cylinder 1 and the downstream ends of the two side plates 23 of the outer cylinder 2.

[0023] As described above, in the two central branch posts 4A of the four branch posts 4, the length of the central side plate 42A is shorter than the length of the peripheral side plate 42B. Therefore, the two partition plates 6 (hereinafter referred to as "central partition plates 6A") provided between the downstream end of the central side plate 42A and the side of the burner tile 5 in the two central branch posts 4A are located upstream of the six peripheral partition plates 6 (hereinafter referred to as "peripheral partition plates 6B"). Also, the two partition plates 6 provided between the downstream ends of the two side plates 13 of the inner cylinder 1 and the downstream ends of the two side plates 23 of the outer cylinder 2 are located downstream of the central partition plates 6A (hereinafter, these two partition plates 6 are referred to as "peripheral partition plates 6C").

[0024] The two central partition plates 6A are positioned to sandwich the central gas discharge section 81A described above, and combustion air is discharged into the central premixing region 8A from the discharge holes 6a provided in each of the two central partition plates 6A. In other words, in this embodiment, each of the two central partition plates 6A serves as a central air discharge section 82A that discharges combustion air into the central premixing region 8A. Furthermore, the six peripheral partition plates 6B and the two peripheral partition plates 6C are arranged to sandwich the aforementioned peripheral gas discharge section 81B or peripheral gas discharge section 81C, and combustion air is discharged into the peripheral premixing regions 8B and 8C from the discharge holes 6a provided in each of the six peripheral partition plates 6B and the two peripheral partition plates 6C. In other words, in this embodiment, the six peripheral partition plates 6B and the two peripheral partition plates 6C each serve as peripheral air discharge sections 82B and 82C that discharge combustion air into the peripheral premixing regions 8B and 8C.

[0025] To summarize, as conceptually shown in Figure 3, combustion burner B includes a premixing region 8 for mixing combustible gas and combustion air, and this premixing region 8 includes a central premixing region 8A and peripheral premixing regions 8B and 8C. Specifically, the central premixing region 8A is located in the center of the premixing region 8, and the peripheral premixing regions 8B and 8C are located downstream of the central premixing region 8A. Furthermore, the pilot burner B3, which is the ignition means, is positioned to ignite the air-fuel mixture in the central premixing region 8A, as conceptually shown in Figure 3, along with the aforementioned premixing region 8 (central premixing region 8A and peripheral premixing regions 8B, 8C). Therefore, in combustion burner B, the process of forming the air-fuel mixture in the premixing region 8 is divided into two stages. Specifically, in the first stage, the air-fuel mixture is formed in the central premixing region 8A located in the center of the premixing region 8, and in the second stage, the air-fuel mixture is formed in the peripheral premixing region located downstream of the central premixing region 8A, and the air-fuel mixture in the central premixing region 8A is ignited by pilot burner B3. This allows for ignition and flame stabilization in the combustion burner B, which burns the combustible gas generated by the gasification of waste, and also reduces the amount of fossil fuels used. Specifically, in combustion burner B, the central premixing region 8A is located upstream of the surrounding premixing regions 8B and 8C in the premixing region 8, so that a sufficient run-up distance for mixing can be secured in a limited space, and a sufficient mixture can be formed. By igniting the mixture in the central premixing region 8A, flame propagation to the surrounding premixing regions 8B and 8C, which are located downstream of the central premixing region 8A and are positioned on either side of it, proceeds smoothly, and ignition can be quickly induced throughout the entire premixing region 8 within a limited time. Furthermore, in this embodiment, the pilot burner B3, which is the ignition means, is used to ignite the mixture in the central premixing region 8A, and the pilot flame of the pilot burner B3 can be brought into direct contact with the mixture in the central premixing region 8A. Therefore, ignition and the flame after ignition can be stably maintained in the central premixing region 8A. Furthermore, as conceptually shown in Figure 2, the pilot flame length of the pilot burner B3 can be the minimum necessary length L1, which is sufficient to allow direct contact with the mixture in the central premixing region 8A. Therefore, the amount of fossil fuels used can also be reduced. In summary, according to this embodiment, in the combustion burner B that burns the combustible gas generated by the gasification of waste, it is possible to stabilize the ignition and the flame after ignition, and to reduce the amount of fossil fuels used. In Figure 3, the symbol C2 indicates the inner circumferential wall of the secondary combustion chamber C.

[0026] Furthermore, in this embodiment, the pilot burner B3, which is the ignition means, is positioned vertically downward toward the central premixing region 8A. That is, in this embodiment, the pilot burner B3, which is the ignition means, is positioned on the top plate portion of the burner port B2, as shown in Figure 2. There is less dust accumulation on the top plate portion of the burner port B2, and the pilot flame of the pilot burner B3 is formed vertically downward toward gravity. Therefore, the pilot flame of the pilot burner B3 is easier to maintain, and the amount of fossil fuels used can be further reduced.

[0027] Furthermore, as can be seen from Figure 3 in this embodiment, the central premixing region 8A and the peripheral premixing regions 8B and 8C have a plane-symmetric relationship with respect to a vertical plane passing through the central axis 8D of the premixing region 8. This allows flame propagation from the central premixing region 8A to the peripheral premixing regions 8B and 8C to proceed more smoothly, and the ignition and the flame after ignition are further stabilized. In addition, in this embodiment, the pilot burner B3, which is the ignition means, is positioned such that its central axis B31 aligns with the vertical plane passing through the central axis 8D of the premixing region 8. That is, in this embodiment, the central premixing region 8A and the peripheral premixing regions 8B and 8C have a plane-symmetric relationship with respect to the central axis B31 of the pilot burner B3 and the vertical plane passing through the central axis 8D of the premixing region 8. Therefore, the ignition and the flame after ignition are further stabilized. Note that Figure 3 conceptually shows the premixing region 8, which includes the central premixing region 8A and the peripheral premixing regions 8B and 8C. While the actual premixing region 8 is not necessarily formed in layers as shown in Figure 3, the symmetry and other aspects described above are as shown in Figure 3.

[0028] Furthermore, as shown in Figure 3 of this embodiment, the base region of the central premixing region 8A is sandwiched between the two central burner tiles 5. In other words, the two central burner tiles 5 serve as flame stabilizers for the base region of the central premixing region 8A. As a result, ignition and the flame after ignition are further stabilized.

[0029] Furthermore, in this embodiment, as shown in Figure 4 for example, the central gas discharge section 81A, the central air discharge section 82A, the peripheral gas discharge sections 81B, 81C, and the peripheral air discharge sections 82B, 82C are all provided to extend in the vertical direction, and are also provided to be symmetrical with respect to the vertical plane passing through the central axis 8D of the premixing region 8. As a result, the central premixing region 8A and the peripheral premixing regions 8B, 8C are appropriately provided in a symmetrical relationship as described above. Therefore, flame propagation from the central premixing region 8A to the peripheral air discharge sections 82B, 82C proceeds more smoothly, and ignition and the flame after ignition are further stabilized.

[0030] Furthermore, in this embodiment, the distance L(m) (see Figure 3) from the central gas discharge section 81A to the ignition point of the mixture in the central premixing region 8A by the pilot burner B3 is configured to satisfy the following equation (1). L < T×S (1) In this embodiment, T is the ignition delay time (s) of the mixture in the central premixing region 8A, and S is the flow velocity (m / s) of the mixture in the central premixing region 8A. Here, if "L ≥ (T×S)", that is, if the distance L from the pilot burner B3 to the ignition point of the air-fuel mixture in the central premixing region 8A is greater than or equal to (T×S), there is a possibility that the air-fuel mixture will self-ignite before forced ignition by the pilot burner B3, causing a flashback. Therefore, it is preferable to configure the system so that this distance L satisfies the above equation (1).

[0031] Furthermore, in this embodiment, the flammable gas concentration of the mixture in the central premixing region 8A (hereinafter referred to as the "central flammable gas concentration") is set to be equal to or greater than the flammable gas concentration of the mixture in the surrounding premixing regions 8B and 8C (hereinafter referred to as the "surrounding flammable gas concentration"). Here, if the combustible gas generated by the gasification of waste is high in calories, the central combustible gas concentration and the surrounding combustible gas concentration may be the same. However, if the combustible gas is low in calories or contains a lot of dust, it is preferable to increase the central combustible gas concentration from the viewpoint of ignition stability. Furthermore, the central and surrounding flammable gas concentrations can be adjusted, for example, by adjusting the size of the central gas discharge section 81A, the central air discharge section 82A, the surrounding gas discharge sections 81B and 81C, and the surrounding air discharge sections 82B and 82C.

[0032] <Embodiment 2> Figure 8 schematically shows a combustion burner, which is another embodiment of the present invention. In Figure 8, components corresponding to the previous embodiment (Embodiment 1) are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0033] In the previous embodiment 1, the inner cylinder 1 and outer cylinder 2 constituting the burner body B1 were each made into roughly rectangular tubes, but in this embodiment 2, the inner cylinder 1 and outer cylinder 2 are each made into roughly cylindrical shapes. As conceptually shown in Figure 8, in this second embodiment as well, the central premixing region 8A is located in the center of the premixing region 8, and the peripheral premixing region 8B is located downstream of the central premixing region 8A. Furthermore, the peripheral premixing region 8B is arranged to surround the central premixing region 8. In addition, the pilot burner B3, which is the ignition means, is positioned to ignite the mixture in the central premixing region 8A. Therefore, in this second embodiment as well, similar to the first embodiment, it is possible to stabilize the flame after ignition and reduce the amount of fossil fuels used in the combustion burner B that burns the combustible gas generated by the gasification of waste.

[0034] <Embodiment 3> Figure 9 schematically shows a combustion burner, which is yet another embodiment of the present invention. In Figure 9, components corresponding to the previous embodiment 1 are denoted by the same reference numerals, and their detailed descriptions are omitted.

[0035] In the previous embodiment 1, the central gas discharge section 81A, the central air discharge section 82A, the peripheral gas discharge sections 81B, 81C, and the peripheral air discharge sections 82B, 82C were all provided in the shape of slits extending in the vertical direction. However, in this embodiment 3, the central gas discharge section 81A, the central air discharge section 82A, the peripheral gas discharge section 81B, and the peripheral air discharge section 82B are all provided in the shape of slits extending in the horizontal direction. As conceptually shown in Figure 9, in this embodiment 3, the central premixing region 8A is located in the center of the premixing region 8, and the peripheral premixing region 8B is located downstream of the central premixing region 8A. Furthermore, the peripheral premixing region 8B is located so as to sandwich the central premixing region 8. In addition, the pilot burner B3, which is the ignition means, is positioned to ignite the mixture in the central premixing region 8A. Therefore, in this embodiment 3, as in the previous embodiments 1 and 2, it is possible to stabilize the ignition and the flame after ignition in the combustion burner B that burns the combustible gas generated by the gasification of waste, and to reduce the amount of fossil fuel used. In the above embodiment 1 and embodiment 3, the inner cylinder 1 and outer cylinder 2 are each approximately rectangular in shape, but the inner cylinder 1 and outer cylinder 2 can also be approximately cylindrical in shape.

[0036] In embodiments 1 to 3 described above, a pilot burner was used as the ignition means, but other ignition means such as a spark plug can also be used. Furthermore, when a spark plug is used as the ignition means, it may be positioned vertically upward toward the central premixing region. In addition, in addition to the pilot burner, which is the ignition means for igniting the air-fuel mixture in the central premixing region, a spark plug or the like can also be provided as an auxiliary ignition means for igniting the air-fuel mixture in the surrounding premixing region. [Examples]

[0037] As an embodiment of the present invention, a combustion test was conducted using the combustion burner of Embodiment 1 described above. As a comparative example, a combustion test was similarly conducted using a combustion burner that supplies a pilot light from the side, as described in Patent Document 1 described above. As a result, it was confirmed that the combustion temperature of the combustion burner was higher in the example compared to the comparative example. This confirmed that the ignition and the flame after ignition were more stable in the example compared to the comparative example. Furthermore, when comparing the amount of fossil fuel (city gas) used in the pilot burner between the example and the comparative example, it was possible to reduce the amount used in the example to less than 1 / 6 of that used in the comparative example. [Explanation of Symbols]

[0038] A waste treatment furnace A1 Loading device A2 Slag outlet A3 gas pipe B Combustion Burner B1 Burner Body B2 Burnerport B3 Pilot burner (ignition method) B31 Pilot burner (ignition mechanism) central axis B4 Air Duct B5 Perforated Metal (Rectifier Plate) C Secondary combustion chamber C1 Gas Inlet C2 Inner wall D Boiler E. Steam Turbine / Power Generation Equipment F Dust collector G Blower H Chimney L1 Pilot burner pilot flame length 1. Inner cylinder 11 Bottom plate 11a~h opening 12 Top plate 12a~h opening 13 Side panel 2. Outer cylinder 21 Bottom plate 21a Gas inlet 22 Top plate 23 Side panel 3. Partition plate (flow straightening plate) 3a aperture 4 branch post 4A Central branch post Branch post on the periphery side of 4B 41 Upstream of the branching post 42 Downstream section of the branching post 42A Central side panel 42B Peripheral side panel 5 Burner Tiles 51 Upstream of the burner tile 52 Downstream section of the Vernatile 6 partition plates 6a Discharge hole 6A Central partition plate (central air discharge section) 6B, 6C Peripheral partition plate (peripheral air discharge section) 7A Flow of flammable gas (central flow) 7B~E Flow of flammable gas (flow in the surrounding area) 8 Premix region 8A Central premix area 81A Central gas discharge section 82A Central air discharge section 8B,8C Peripheral premix area 81B, 81C Peripheral gas discharge section 82B, 82C Peripheral air discharge section 8D Central axis of the premixing region

Claims

1. A combustion control method for a combustion burner, wherein a combustible gas generated by the gasification of waste and combustion air are mixed and burned in a first premixing region within the combustion chamber and in a second premixing region within the combustion chamber located downstream of the first premixing region in the flow direction of the combustible gas, The first mixing step, The second mixing step, Ignition step, The propagation step includes, In the first mixing step, the combustible gas and the combustion air are mixed in the first premixed region to form a first mixture. In the second mixing step, the combustible gas and the combustion air are mixed in the second premixed region to form a second mixture. In the ignition step, the first mixture formed in the first mixing step is ignited. In the propagation step, the flame of the first mixture in the combustion chamber, which is ignited in the ignition step, is propagated within the combustion chamber to the second mixture formed in the second mixing step. A method for controlling the combustion of a combustion burner, characterized by the features described above.

2. A combustion burner that mixes and burns a combustible gas generated by the gasification of waste and combustion air in a first premixing region within the combustion chamber and in a second premixing region within the combustion chamber located downstream of the first premixing region in the flow direction of the combustible gas, A first mixing means for mixing the combustible gas and the combustion air in the first premixing region to form a first mixture, In the second premixing region, a second mixing means mixes the combustible gas and the combustion air to form a second mixture, An ignition means for igniting the first mixture formed by the first mixing means, A propagation means propagates the flame of the first mixture in the combustion chamber, which is ignited by the ignition means, to the second mixture formed by the second mixing means within the combustion chamber. A combustion burner characterized by having the following features.

3. The combustion chamber further comprises a plurality of branching posts arranged in a direction perpendicular to the flow direction of the combustible gas within the combustion chamber, The multiple branch posts include a first branch post and a second branch post, The combustion burner according to feature 2.

4. The first branch post is located upstream of the first premixing region in the flow direction of the combustible gas, The combustion burner according to feature 3.

5. The second branch post is located upstream of the second premixing region in the flow direction of the combustible gas, The combustion burner according to feature 3.

6. The first branch post includes a pair of side plates extending in the direction of the flow of the combustible gas, Of the pair of side plates, the length of one side plate and the length of the other side plate are different. The combustion burner according to feature 4.

7. The second branch post includes a pair of side plates extending in the direction of the flow of the combustible gas, Of the pair of side plates, the length of one side plate is the same as the length of the other side plate. The combustion burner according to feature 5.

8. The ignition means is provided facing vertically downward toward the first premixing region. A combustion burner according to any one of claims 2 to 7, characterized by the following:

9. The combustion burner according to claim 8, characterized in that the ignition means includes a pilot burner or a spark plug.

10. The aforementioned combustion burner is for use in a melting furnace. A combustion burner according to any one of claims 2 to 7, characterized by the following:

Images