JP2017089899A - Burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent formation of deposit in a combustion chamber.SOLUTION: A burner 1 has a cylindrical combustion chamber 2 with its one end in an axial direction being closed by an end wall 3 and with the other side being applied as a flame injection port 5. The combustion chamber 2 has air supply nozzles 6 arranged along a tangential line direction of a virtual circle assumed in the combustion chamber 2 at three locations in a peripheral direction at a peripheral wall 4 at position near one end in the axial direction. A central part and an outer peripheral part of the end wall 3 have a fuel supply nozzle 7 and an ignition burner 9. A circulation flow 11 is formed in the combustion chamber 2 by combustion air 10 supplied from the air supply nozzles 6 and powder biomass fuel 8 is supplied from the fuel supply nozzle 7 and blown into inside of it. Fine diameter particles in the powder biomass fuel 8 are rapidly drawn into the circulation flow 11 and ignited. Larger diameter particles are promoted to their pyrolysis gas while being floated inside the circulation flow 11 and when their mass becomes low, they are drawn into the circulation flow 11 and ignited.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a burner used for combustion of powdered biomass fuel.

As one of the CO ₂ reduction measures in the global warming problem, it is considered to promote the use of renewable energy. As for renewable energy, the use of biomass derived from plants, such as wood, as a fuel is attracting attention from the viewpoint of carbon neutrality.

  As one of the biomass fuels, a powder biomass fuel (biomass powder fuel) produced by pulverizing woody biomass such as wood is known.

  Conventionally, a burner that uses this type of powdered biomass fuel as the main fuel has been proposed (see, for example, Patent Document 1). The burner has a bottomed cylindrical burner pipe having an open end, a pulverized fuel supply pipe provided on a peripheral wall near the bottom of the burner pipe, and a peripheral wall near the bottom of the burner pipe. The primary air supply port is provided. The pulverized fuel supply pipe is configured to open at a position shifted laterally from the center of the burner pipe.

  Furthermore, in this burner, the biomass powder fuel supplied in the direction along the circumferential direction of the burner pipe from the powder fuel supply pipe, and the primary delivered in the circumferential direction of the burner pipe from the primary air supply port A swirl flow is formed in the burner tube by the mixture of the biomass powder fuel and the primary air.

  Moreover, the biomass powder fuel which can be used for this burner has an average particle size of 300 μm or less, preferably 100 μm or less, and more preferably an average particle size of 30 to 40 μm.

JP 2011-7478 A

  By the way, since woody biomass contains water, powdered biomass fuel produced from woody biomass also contains water.

  The larger the particle size of powdered biomass fuel, the smaller the specific surface area per unit volume. Therefore, during combustion, it takes time to evaporate the contained water, to pyrolyze combustibles and to burn them. become. Therefore, in general, powder biomass fuel burns quickly if the particle size is 100 μm or less, but powder having an average particle size of about 300 μm requires more time to burn out. .

  In addition, powder (particles) having a large particle size has a large weight.

  In the burner disclosed in Patent Document 1, a swirl flow is formed by primary air sent from the primary air supply port in the circumferential direction of the burner tube, and the swirl flow is formed from the pulverized fuel supply line. The biomass powder fuel is supplied in a direction along the swirling direction. For this reason, almost all of the biomass powder fuel is transported in a swirling flow immediately after being supplied from the powder fuel supply pipe. At this time, as the powder (particles) contained in the biomass powder fuel has a larger particle size, the centrifugal force received in the swirl flow increases.

  Therefore, if the biomass powder fuel contains powder (particles) having a particle size of 300 μm or more, the powder is positioned along the inner surface of the peripheral wall of the burner tube by the centrifugal force received in the swirling flow. Easy to move up to. Moreover, the larger the particle size, the longer the time required for combustion.

  For this reason, in the burner shown by patent document 1, the density | concentration of the powder with a big particle size contained in biomass powder fuel becomes high in the position along the inner surface of the surrounding wall of a burner pipe | tube. Therefore, the actual condition is that an unburned powder having a large particle diameter or a powder in the middle of combustion is easily touched on the inner surface of the peripheral wall of the burner tube, and a part of the powder easily adheres. Furthermore, when such deposits occur, the flow of the swirling flow formed along the inner surface of the peripheral wall around the deposits is disturbed. Furthermore, it becomes easy to adhere. Further, depending on the nature of the deposit, the deposit may be in a partially melted clinker state, which may further inhibit the flow. Therefore, the deposits block the flame and create a local high temperature field inside the burner tube, which not only promotes clinker growth but may also damage the inner wall of the burner tube.

  Therefore, in the burner shown in Patent Document 1, when biomass powder fuel having a particle diameter of about 300 μm is used, deposits are likely to be generated inside the burner pipe.

  Therefore, the present invention intends to provide a burner capable of burning pulverized biomass fuel while suppressing the formation of deposits on the inner surface of the peripheral wall of the combustion chamber.

  In order to solve the above problems, the present invention provides a cylindrical combustion chamber closed at one end, a flame outlet provided at the other end of the combustion chamber, and a peripheral wall at one end of the combustion chamber. An air supply nozzle provided at a plurality of three or more locations in the circumferential direction and arranged along a tangential direction of a virtual circle assumed to have a diameter smaller than the inner diameter of the combustion chamber in the combustion chamber; and one end of the combustion chamber On the side, a burner including a fuel supply nozzle for powdered biomass fuel provided toward the inside of the imaginary circle and ignition means provided in the combustion chamber.

  The air supply nozzle is provided in a tangential direction of a virtual circle having a diameter of 25% to 75% of the inner diameter of the combustion chamber.

  The fuel supply nozzle has a configuration in which the direction of opening to the combustion chamber is parallel to the axial direction of the combustion chamber.

  The jet speed of the combustion air into the combustion chamber by the air supply nozzle is set to 7 m / s to 25 m / s.

  The air supply nozzle is configured to form a swirling flow mainly flowing in a cylindrical region away from the inner surface of the peripheral wall of the combustion chamber by the combustion air jetted into the combustion chamber.

  The ejection speed of the powdered biomass fuel into the combustion chamber by the fuel supply nozzle is set to 2 m / s to 10 m / s.

  According to the burner of the present invention, pulverized biomass fuel can be burned in a state where the formation of deposits on the inner surface of the peripheral wall of the combustion chamber is suppressed.

It is a figure which shows embodiment of a burner. It is an AA direction arrow line view of FIG.

  Hereinafter, the burner of this invention is demonstrated with reference to drawings.

  FIG. 1 is a schematic cut side view showing an embodiment of a burner, and FIG. 2 is a view taken in the direction of arrows AA in FIG.

  The burner of this embodiment is shown by the code | symbol 1 in FIG. 1, FIG. 2, and is provided with the cylindrical combustion chamber 2. As shown in FIG. The combustion chamber 2 is closed at one end side in the axial direction by an end wall 3. The peripheral wall 4 and the end wall 3 of the combustion chamber 2 are configured to include a refractory material on at least the inner surface. In addition, it is also possible to use a refractory metal instead of the refractory material on the peripheral wall 4 and the end wall 3 by confirming the combustion state in a preliminary test.

  The other axial end of the combustion chamber 2 is an opening communicating with the outside, and this opening is the flame outlet 5 of the burner 1 of the present embodiment.

  An air supply nozzle 6 is provided on the peripheral wall 4 at one axial end side position of the combustion chamber 2. A fuel supply nozzle 7 for supplying the pulverized biomass fuel 8 to the combustion chamber 2 is provided at or near the axial center position on one end side in the axial direction from the installation position of the air supply nozzle 6 in the combustion chamber 2. Yes. Further, the combustion chamber 2 is provided with an ignition burner 9 as ignition means for igniting the pulverized biomass fuel 8 supplied from the fuel supply nozzle 7.

  The air supply nozzles 6 are provided at a plurality of three or more places arranged at substantially equal intervals in the circumferential direction of the peripheral wall 4. The intervals between the air supply nozzles 6 adjacent to each other in the circumferential direction may not be the same. At this time, the interval between the air supply nozzles 6 adjacent to each other in the circumferential direction has a maximum value of 140 degrees when defined by the central angle. In this way, when supplying the combustion air 10 from the air supply nozzles 6 into the combustion chamber 2, it is possible to prevent the supply amount of the combustion air 10 from being biased in the circumferential direction of the combustion chamber 2. Can do. Therefore, when the swirl flow 11 is formed in the combustion chamber 2 by the combustion air 10 supplied from the air supply nozzles 6 into the combustion chamber 2 as will be described later, the swirl flow 11 is the axis of the combustion chamber 2. It can suppress becoming the arrangement | positioning eccentric from the position.

  FIG. 2 shows, as an example, a configuration in which the air supply nozzles 6 are provided at three locations at intervals of 120 degrees in the circumferential direction.

  Further, inside the combustion chamber 2, 25% to 75% (50% ± 25%) of the inner diameter D of the combustion chamber 2 as shown by a one-dot chain line in FIG. 2, more preferably 40% to 65%, still more preferably. Assumes a virtual circle 12 having a diameter d of 45% to 60% in a concentric arrangement, and each air supply nozzle 6 is arranged along a tangent to the virtual circle 12. Needless to say, the arrangement of the air supply nozzles 6 along the tangent line of the virtual circle 12 may include an angle error. Although not shown, a supply portion for combustion air 10 is connected to the upstream side of each air supply nozzle 6 via an air supply line.

  As a result, the flow (jet) of the combustion air 10 supplied from one air supply nozzle 6 into the combustion chamber 2 is supplied from another air supply nozzle 6 disposed adjacent to the downstream side in the air supply direction. The flow of the combustion air 10 thus applied comes into contact with the virtual circle 12 from the outer peripheral side. For this reason, the traveling direction of the combustion air 10 is turned closer to the axial center of the combustion chamber 2. This phenomenon is repeatedly performed on the combustion air 10 supplied from each air supply nozzle 6 at a plurality of locations in the circumferential direction where each air supply nozzle 6 is disposed. Accordingly, a swirl flow 11 is formed in the combustion chamber 2, and the swirl flow 11 has a diameter corresponding to the diameter d of the virtual circle 12 shown in FIG. 2, as shown in FIG. It flows mainly in a cylindrical region extending along the direction, that is, a cylindrical region away from the inner surface of the peripheral wall 4 of the combustion chamber 2.

  When the diameter d of the virtual circle 12 used for setting the arrangement of the air supply nozzles 6 is less than 25% of the inner diameter D of the combustion chamber 2 as described above, the air supply nozzle 6 supplies the air into the combustion chamber 2. Thus, the flow of the combustion air 10 is concentrated near the axial center position of the combustion chamber 2. For this reason, in the combustion chamber 2, the axial flow becomes strong, and the swirl flow itself of the combustion air 10 becomes difficult to be formed, or even if the swirl flow is formed, the flow velocity in the swirl direction is high. It is not preferable because it slows down.

  On the other hand, when the diameter d of the imaginary circle 12 exceeds 75% of the inner diameter D of the combustion chamber 2, the flow of the combustion air 10 supplied from each air supply nozzle 6 into the combustion chamber 2 is another air supply. It becomes easy to reach the inner surface of the peripheral wall 4 before being affected by the flow of the combustion air 10 supplied from the nozzle 6. In this case, in the combustion chamber 2, since the flow of the combustion air 10 along the inner surface of the peripheral wall 4 is easily formed, the swirl of the combustion air 10 that mainly flows in a cylindrical region away from the inner surface of the peripheral wall 4 of the combustion chamber 2. Since it becomes difficult to form the flow 11, it is not preferable.

  Further, from the viewpoint of satisfactorily forming the swirl flow 11 at a position away from the inner surface of the peripheral wall 4 of the combustion chamber 2, the combustion air 10 is jetted into the combustion chamber 2 from each air supply nozzle 6. If the jet velocity vj at that time is too slow, the flow velocity in the swirling direction of the swirling flow 11 becomes slow. On the other hand, if it is too fast, the position where the swirling flow 11 is formed approaches the inner surface of the peripheral wall 4. Therefore, the ejection speed vj of the combustion air 10 from each air supply nozzle 6 is preferably set to 7 m / s to 25 m / s, more preferably set to 10 m / s to 20 m / s. More preferably, it is set to -15 m / s.

  Note that the ejection speed vj of the combustion air 10 is preferably set as described above, but in the burner 1 of the present embodiment, the number of air supply nozzles 6, the inner diameter D of the combustion chamber 2, and the diameter of the virtual circle 12. d, and the jet velocity vj of the combustion air 10 required to form the swirl flow 11 in the combustion chamber 2 may change depending on the error in manufacturing the product and the like.

  In such a case, an operation test or the like is performed before using the burner 1 of the present embodiment, and combustion air is ejected from each air supply nozzle 6 so that the swirl flow 11 is formed in the combustion chamber 2. The ejection speed vj of 10 may be adjusted as appropriate. Further, at this time, each air supply nozzle 6 may individually adjust the ejection speed vj of the combustion air 10. Therefore, the ejection speed vj of the combustion air 10 ejected from the air supply nozzle 6 may of course be set to a value outside the above-mentioned range. Of course, the ejection velocity vj may be individually different.

  Further, from the viewpoint of efficiently generating the swirl flow 11 in the combustion chamber 2, each air supply nozzle 6 has a plane perpendicular to the axial direction of the combustion chamber 2 as shown in FIGS. 1 and 2. It is preferable to arrange along. However, if the flows of the combustion air 10 supplied from the air supply nozzles 6 interfere with each other, the air supply nozzles 6 may be arranged so as to be displaced in the axial direction of the combustion chamber 2. Good. In this case, if the dimension of the inner diameter of the air supply nozzle 6 is dn, the amount of positional deviation of the air supply nozzles 6 with respect to the axial direction of the combustion chamber 2 is preferably within dn, (1/2) -More preferably, it is within dn. If the swirl flow 11 can be formed in the combustion chamber 2, each air supply nozzle 6 is inclined from the posture shown in FIGS. 1 and 2 toward the other end side or one end side in the axial direction of the combustion chamber 2. Of course, it may be a posture. In this case, the angle at which each air supply nozzle 6 is inclined from the plane perpendicular to the axial direction of the combustion chamber 2 is preferably within 20 degrees, more preferably within 10 degrees, and more preferably within 5 degrees. Is more preferable. At this time, the inclination angle of each air supply nozzle 6 may include an error.

  The total amount of combustion air 10 supplied from each air supply nozzle 6 into the combustion chamber 2 is the amount of air required for complete combustion of the pulverized biomass fuel supplied from the fuel supply nozzle 7 into the combustion chamber 2 ( It is preferable to set to 0.7 to 1.2 times the theoretical air amount). This is because oxygen required to start combustion of the pulverized biomass fuel 8 well in the combustion chamber 2 when the amount of the combustion air 10 supplied to the combustion chamber 2 falls below the lower limit of the above range. This is because a shortage occurs. On the other hand, it has been found that the powdered biomass fuel 8 does not stabilize combustion when the supply amount of the combustion air 10 exceeds the upper limit of the above range. Therefore, it is effective for stable combustion of the pulverized biomass fuel 8 so that the amount of the combustion air 10 supplied to the combustion chamber 2 does not exceed the upper limit of the above range. In the above range, when the amount of combustion air 10 supplied to the combustion chamber 2 is less than 1.0 times the theoretical air amount, the vicinity of the flame outlet 5 on the peripheral wall 4 of the combustion chamber 2 As a configuration in which a supply means (not shown) of combustion air 10 such as an air supply nozzle is added to the position or the downstream vicinity of the flame outlet 5, the powdered biomass fuel 8 is completely burned. You can do it. In addition, you may equip the supply means of this additional combustion air 10 when the quantity of the combustion air 10 supplied to the combustion chamber 2 becomes 1.0 times or more with respect to the theoretical air quantity.

  The fuel supply nozzle 7 is provided so as to be inside the virtual circle 12. Further, the fuel supply nozzle 7 is formed so that the direction of the tip side that opens to the combustion chamber 2 is oriented in a direction parallel to the axial direction of the combustion chamber 2. In addition, the parallel direction in the above is not limited to strict parallel, and it is needless to say that an error may be included. 1 and 2 show a configuration example in a state in which the fuel supply nozzle 7 is provided in the central portion of the end wall 3 in a posture along the axial direction of the combustion chamber 2.

  Although not shown in the figure, a fuel supply line for air-conveying the pulverized biomass fuel 8 from the fuel supply unit is connected to the upstream side of the fuel supply nozzle 7. Thus, in the fuel supply nozzle 7, the powdery biomass fuel 8 is ejected into the combustion chamber 2 on the flow of the carrier air, so that the powdery biomass fuel 8 is converted into the swirl flow 11 of the combustion air 10. It can be blown inward along the axial direction of the swirl flow 11.

At this time, the ejection speed vjs of the powdered biomass fuel 8 from the fuel supply nozzle 7 is preferably set to 2 m / s to 10 m / s, for example, and preferably set to 3 m / s to 5 m / s. Is more preferable.
According to this configuration, as will be described later, the powder biomass fuel 8 having a particle size distribution can be drawn into the swirl flow 11 in order from a powder having a small mass and a small inertia, and can be burned.

  The fuel supply unit has a function of supplying a pulverized biomass fuel 8 having a particle size distribution and having an average particle size of 300 μm, for example.

  Thereby, when the powder biomass fuel 8 is supplied from the fuel supply nozzle 7 into the combustion chamber 2, the powder biomass fuel 8 is inside the swirl flow 11 of the combustion air 10 formed in the combustion chamber 2. Be blown into.

  At this time, the powdered biomass fuel 8 having an average particle size of 300 μm contains fine powder having a particle size of approximately 100 μm or less. Since the flammable volatile matter generated from the fine particle size powder and the powdered biomass fuel 8 has a small mass and a small inertia, the combustion air 10 is swirled near one end in the axial direction of the combustion chamber 2. It is easily drawn into the stream 11 and quickly dispersed, mixed and burned in the combustion air 10. Along with this combustion, a flame 13 is formed in the combustion chamber 2 along the swirl flow 11 of the combustion air 10 from a position near one end in the axial direction.

  Of the powders contained in the powdered biomass fuel 8, the powder having a larger particle diameter than the fine particle powder has a larger inertia based on the larger mass, and therefore the fuel supply nozzle 7 The inside of the swirling flow 11 moves while floating toward the flame outlet 5 side (the other end side in the axial direction) of the combustion chamber 2 due to the momentum injected from. The powder floating inside the swirling flow 11 is heated by the flame 13 already formed along the swirling flow 11 along with the combustion of the fine particle powder and the like, and is pyrolyzed and gasified. The The powder that has undergone pyrolysis gasification is reduced in mass and inertia is reduced, and therefore is easily drawn into the swirl flow 11 together with combustible volatile components generated by pyrolysis gasification. In this way, the powder and combustible volatile matter drawn into the swirling flow 11 are dispersed and mixed in the combustion air 10 forming the swirling flow 11 and are formed along the swirling flow 11. It is ignited by the flame 13 and burns. This combustion further generates a flame 13 along the swirl flow 11.

  Therefore, in the combustion chamber 2, the powder contained in the pulverized biomass fuel 8 is drawn into the swirl flow 11 of the combustion air 10 from the powder having a small particle size and a small mass, and is drawn into the swirl flow 11. A phenomenon occurs in which the powder is ignited and burned by the flame 13 already formed along the swirl flow 11 by the combustion of the smaller powder. For this reason, in the combustion chamber 2, the powder having a particle size larger than 300 μm contained in the powder biomass fuel 8 having an average particle size of 300 μm is also pyrolyzed and gasified inside the swirling flow 11 to obtain a mass. After being reduced, it can be drawn into the swirling flow 11 and sequentially burned.

  For this reason, in the burner 1 of this embodiment, combustion of the pulverized biomass fuel 8 is performed, a cylindrical flame 13 is formed along the swirl flow 11, and the flame 13 and the high-temperature combustion gas swirl. However, it comes to be ejected from the flame outlet 5 to the outside.

  The ignition burner 9 has a swirl flow in which a fine particle size powder and combustible volatile matter out of the powdered biomass fuel 8 ejected from the fuel supply nozzle 7 toward the combustion chamber 2 in the combustion chamber 2. This is for igniting a seed fire in a region drawn into the region and forming a high temperature region in which the pulverized biomass fuel 8 can be ignited.

  In the present embodiment, the ignition burner 9 is provided, for example, on the outer peripheral portion of the end wall 3 in a posture inclined toward the axial center side of the combustion chamber 2.

  The ignition burner 9 may be one that uses LPG, LNG, kerosene, or the like as fuel. From the viewpoint of running cost, it is preferable to use the ignition burner 9 having a heat amount of about several percent of the heat amount of the burner 1 of the present embodiment. For example, when the heat quantity of the burner 1 of the present embodiment is 100,000 kcal / h, the ignition burner 9 may have a heat quantity of about 5000 kcal / h.

  Thereby, the ignition burner 9 forms a high temperature region in which the pulverized biomass fuel 8 can be ignited in the combustion chamber 2 by burning the fuel when the burner 1 of the present embodiment is started. In addition, the flame 13 when the fine particle size powder or combustible volatile matter of the powdered biomass fuel 8 burns in the swirl flow 11 in the combustion chamber 2 is seeded near one end in the axial direction of the combustion chamber 2. When it can hold | maintain as a fire, you may make it extinguish the ignition burner 9 during the driving | operation of the burner 1 of this embodiment after that.

  Moreover, you may use the ignition burner 9 so that a flame may be always held during the driving | operation of the burner 1 of this embodiment. In this case, the pulverized biomass fuel 8 sequentially supplied from the fuel supply nozzle 7 into the combustion chamber 2 can be actively ignited using a seed flame that is held by the ignition burner 9, and therefore, is used. Even if the combustibility change caused by the change in particle size or the amount of moisture occurs in the powdered biomass fuel 8, the operation of the burner 1 of the present embodiment can be continued stably.

  If the ignition burner 9 can ignite a fine particle size powder or combustible volatile matter of the pulverized biomass fuel 8 mixed in the swirl flow 11 of the combustion air 10 in the combustion chamber 2, it is illustrated. Of course, other arrangements may be used. Further, the ignition means may use an ignition burner 9 of a type for burning any fuel other than fossil fuel as long as it can ignite the powdered biomass fuel 8 mixed with the combustion air 10. May use an ignition means of a type other than that using fuel, such as a type of ignition using an electrical phenomenon such as plasma or spark.

  In the above description, among the powders contained in the powdered biomass fuel 8, those having a particle size of approximately 100 μm or less are expressed as fine particle size powders. This explains the behavior of the powder. It is a convenient expression for Therefore, the particle size of the powder that is easily drawn into the swirl flow 11 of the combustion air 10 at a position near one end in the axial direction of the combustion chamber 2 may exceed 100 μm, and the particle size is 100 μm or less. However, of course, there may be powder that is not easily drawn into the swirl flow 11 of the combustion air 10 at a position near one end in the axial direction of the combustion chamber 2 due to the amount of water contained. It is.

  When the burner 1 of the present embodiment having the above-described configuration is used, the combustion chamber 2 starts to supply the combustion air 10 from the air supply nozzle 6, and the combustion chamber 2 contains the combustion air 10. A swirling flow 11 is formed.

  Subsequently, the ignition burner 9 is ignited to form a high temperature region in the combustion chamber 2 for igniting the pulverized biomass fuel 8.

  In this state, supply of the powdered biomass fuel 8 from the fuel supply nozzle 7 into the combustion chamber 2 is started, and the powdered biomass fuel 8 is blown into the swirl flow 11 along the axial direction.

  In the combustion chamber 2, the pulverized biomass fuel 8 blown inside the swirl flow 11 is drawn into the surrounding swirl flow 11 from the powder having a small particle diameter while traveling to the other end side in the axial direction. Burn. At this time, among the powdered biomass fuel 8, the powder with a small particle size and a small inertia is easily drawn into the swirling flow 11 at a position near one end in the axial direction of the combustion chamber 2 and burns quickly. Because it burns out. The powder having a larger particle size is pyrolyzed and gasified by the flame 13 formed along the swirl flow 11 while moving to the other end in the axial direction while floating inside the swirl flow 11, and its mass is increased. Since it becomes small and is drawn into the swirling flow 11 and burns, it burns out.

  For this reason, in the combustion chamber 2, all of the supplied powdered biomass fuel 8 can be burned with a behavior suitable for each particle size. The flame 13 generated by the combustion can be ejected from the flame outlet 5 to the outside as a cylindrical flame 13 along the swirl flow 11.

  When the operation of the burner 1 according to the present embodiment is stopped, the supply of the combustion biomass 10 can be continued for a while after the supply of the pulverized biomass fuel 8 to the combustion chamber 2 is stopped. The supplied powdered biomass fuel 8 can be burned out.

  Thus, in the burner 1 of the present embodiment, even when the powdered biomass fuel 8 having an average particle size of about 300 μm is used as the fuel, the powder is in a position along the inner surface of the peripheral wall 4 of the combustion chamber 2. The concentration of the powder having a large particle size contained in the biomass fuel 8 does not increase.

  Therefore, the burner 1 of this embodiment can burn the pulverized biomass fuel 8 in a state in which the formation of deposits on the inner surface of the peripheral wall 4 of the combustion chamber 2 is suppressed.

  In addition, it is difficult to use the conventional burner in which deposits may be generated in the combustion chamber in a posture in which the flame outlet is directed downward because there is a concern that the deposit may fall from the flame outlet. On the other hand, the burner 1 of the present embodiment can be used even in a posture in which the flame outlet 5 is directed downward because no deposit is generated in the combustion chamber 2. Therefore, the burner 1 of this embodiment can respond to the request | requirement of the burner installation in various attitude | positions.

  Moreover, the burner 1 of this embodiment can normally use the pulverized biomass fuel 8 with an average particle diameter of about 300 μm.

  In general, the powder biomass fuel 8 having a large average particle diameter can increase the production amount per unit time as compared with that having a small average particle diameter, so that the powder biomass fuel 8 having a large average particle diameter can be used. The manufacturing cost tends to be lower.

  For this reason, the burner 1 of this embodiment can use a cheaper biomass fuel regularly compared with the conventional burner for which it is preferable that the average particle diameter is 100 μm or less, and the fuel cost during operation Can be reduced.

  Therefore, the burner 1 of this embodiment can aim at reduction of running cost compared with the conventional burner used for combustion of powder biomass fuel.

Thereby, the burner 1 of this embodiment is effective in encouraging the expansion of utilization of the powdered biomass fuel 8 manufactured from woody biomass, and further can promote the replacement of the fossil fuel with the biomass fuel. , Effective in reducing CO ₂ .

  The burner 1 of the present invention is not limited to the above embodiment, and the diameter and axial dimension of the combustion chamber 2, the wall thickness of the combustion chamber 2, the size of each component device, and their dimensions The ratio is for convenience of illustration and does not reflect the actual device configuration.

  Further, the swirling direction of the swirling flow 11 formed in the combustion chamber 2 may be a direction opposite to the swirling direction illustrated. In this case, the angle posture of the air supply nozzle 6 attached to the combustion chamber 2 may be changed.

  As long as the swirl flow 11 can be formed in the combustion chamber 2, the air supply nozzles 6 may be provided at a plurality of locations in the axial direction of the combustion chamber 2.

  The powdery biomass fuel 8 is exemplified by those derived from woody biomass. However, if it is a fuel derived from biomass and pulverized to a predetermined particle size, it is derived from plants other than woody or from microorganisms. Alternatively, powder biomass fuel 8 may be used.

  Furthermore, the burner 1 of the present invention may be applied to any demand destination (use) where either one or both of the flame 13 and the high-temperature combustion gas are required.

  In addition, it goes without saying that various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Burner 2 Combustion chamber 3 End wall 4 Perimeter wall 5 Flame outlet 6 Air supply nozzle 7 Fuel supply nozzle 8 Powdered biomass fuel 9 Ignition burner (ignition means)
10 Combustion Air 11 Swirl 12 Virtual Circle 13 Flame

Claims (6)

A cylindrical combustion chamber closed at one end,
A flame outlet provided at the other end of the combustion chamber;
Provided at a plurality of three or more locations in the circumferential direction of the peripheral wall at one end side position of the combustion chamber, and arranged along the tangential direction of a virtual circle assumed to have a diameter smaller than the inner diameter of the combustion chamber in the combustion chamber. An air supply nozzle;
A fuel supply nozzle for powdered biomass fuel provided on one end side of the combustion chamber toward the inside of the virtual circle;
And an ignition means provided in the combustion chamber. The burner according to claim 1, wherein the air supply nozzle is provided in a tangential direction of an imaginary circle having a diameter of 25% to 75% of an inner diameter of the combustion chamber. 3. The burner according to claim 1, wherein the fuel supply nozzle has an opening direction parallel to an axial direction of the combustion chamber. The burner according to any one of claims 1 to 3, wherein a jetting speed of combustion air into the combustion chamber by the air supply nozzle is 7 m / s to 25 m / s. The air supply nozzle is for forming a swirling flow mainly flowing in a cylindrical region separated from the inner surface of the peripheral wall of the combustion chamber by the combustion air jetted into the combustion chamber. Item 5. The burner according to any one of items 4. The burner according to any one of claims 1 to 5, wherein an ejection speed of the powdered biomass fuel into the combustion chamber by the fuel supply nozzle is 2 m / s to 10 m / s.

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