JP6526499B2 - Burner - Google Patents

Description

  The present invention relates to a burner using biomass as a fuel.

As one of the measures to reduce CO ₂ in the global warming problem, it is considered to promote the use of renewable energy. With regard to renewable energy, from the viewpoint of carbon neutrality, the use of plant-derived biomass such as wood as a fuel has attracted attention.

  Biomass fuels are often used in the form of straw, chips and pellets. These biomass fuels require time to burn. Therefore, when using these biomass fuels, combustion is performed in a combustion chamber provided with a fuel support such as a large grate in the hearth (see, for example, Patent Document 1).

JP, 2010-107165, A

  However, in the case shown in Patent Document 1, air is supplied to the biomass fuel layer (solid fuel layer) formed on the upper side of the fuel support from a large number of air supply ports provided in the hearth. As the biomass fuel layer does not have the function of stirring the biomass fuel, the biomass fuel which is accidentally in contact with the air only burns sequentially. Therefore, since what is shown by patent documents 1 takes time to burn an individual particle of biomass fuel, there is a problem that responsiveness to combustion control is low.

  Moreover, what was shown by patent document 1 is supposed to be equipped with the function to reduce the dispersion | variation in the characteristic by a shape (dimension) and a water | moisture content, etc. for biomass fuel like a chip, but all biomass fuels Since the fuel is supplied from the same supply port into the furnace, efficient combustion can not be performed according to the fuel properties, and biomass fuel supplied from the same supply port can only be leveled to some extent.

  Therefore, the present invention is intended to provide a burner capable of using biomass fuel of various properties and shapes, and capable of improving the response to combustion control.

In order to solve the above problems, the present invention provides a combustion chamber, a fluidized bed provided at the bottom of the combustion chamber, and a powder fuel nozzle provided in the combustion chamber and blowing powder biomass fuel into the combustion chamber. When the ignition means for igniting the powder biomass fuel blown into the combustion chamber from the pulverized fuel nozzle, of the fluidized bed is provided in an upper position than the installation position of the powder fuel nozzles in the combustion chamber A biomass fuel supply unit for supplying biomass fuel into the combustion chamber from above, the combustion chamber having a gas outlet, and a gas passage having a main combustion air supply nozzle for supplying main combustion air at the gas outlet One end side is connected, and it is set as the burner which has the flame spout equipped with the other end side of this gas passage .

  Among the biomass fuel supplied from the biomass fuel supply unit, one having a large particle diameter falls into the fluidized bed.

  The inside of the combustion chamber and the fluidized bed are configured to be heated by the combustion of the powdery biomass fuel blown into the combustion chamber from the powder fuel nozzle.

  The combustion chamber has a combustion air supply nozzle for supplying combustion air, and the combustion air supplied from the combustion air supply nozzle is configured to form a swirl flow inside the combustion chamber.

  The combustion chamber has a longitudinal shape, the gas outlet is provided at the top of the combustion chamber, the powder fuel nozzle is provided on the side wall of the combustion chamber, and the biomass fuel supply unit is the powder in the combustion chamber. The combustion air supply nozzle is provided at a position higher than the body fuel nozzle, and is provided at a position lower than the biomass fuel supply portion on the side wall of the combustion chamber and at a position not interfering with the powder fuel nozzle. is there.

  The combustion chamber is horizontally elongated, the fluidized bed is provided at the bottom of one end of the combustion chamber, the biomass fuel supply unit is provided above the fluidized bed, and the gas outlet is provided in the combustion chamber. It is set as the structure provided in the other end side.

  According to the burner of the present invention, it is possible to use biomass fuel of various properties and shapes, and to improve the response to combustion control.

It is a schematic sectional side view which shows 1st Embodiment of a burner. It is an AA arrow direction view of FIG. The usage example of a burner is shown, (a) is a general | schematic cutting | disconnection side view, (b) is a BB arrow direction view of (a). It is a schematic sectional side view which shows 2nd Embodiment of a burner. FIG. 5 is a view in the direction of arrows CC in FIG. 4.

  The burner of the present invention will be described with reference to the drawings.

First Embodiment
FIG. 1 is a cutaway side view showing a first embodiment of the burner, and FIG. 2 is a view taken in the direction of arrows AA in FIG.

  The burner of the present embodiment is shown by reference numeral 1 in FIG. 1 and FIG. 2, and is provided with a combustion chamber 2 having a gas outlet 3 at the top and a fluid bed 4 at the bottom as a cylindrical shape extending vertically. . The combustion chamber 2 is provided with a powder fuel nozzle 5, a biomass fuel supply unit 6, and a combustion air supply nozzle 7. Furthermore, in the burner 1 of the present embodiment, one end side of the gas passage 8 provided with the main combustion air supply nozzle 9 is connected to the gas outlet 3, and the other end side of the gas passage 8 is the flame jet port 10. Have.

  The fluidized bed 4 is filled with a heat medium (fluid medium) 11 of solid particles such as sand. Below the fluidized bed 4, a heat medium support member 12 such as a porous plate or a porous plate through which air can pass while blocking the passage of the heat medium 11, an air diffuser 13, and an air box 14 are provided. It is done. Connected to the air box 14 is an air supply line 16 a for leading fluidizing air 17 a which also serves as combustion air from the blower 15. Thereby, in the fluidized bed 4, the heat medium 11 is fluidized by the fluidizing air 17 a which is introduced from below through the air box 14, the air diffuser 13, and the heat medium support member 12 and is jetted upward.

  Therefore, while the fluidized bed 4 supports and stirs the biomass fuel 18 supplied to the combustion chamber 2 from the biomass fuel supply unit 6 and falling to the fluidized bed 4 as described later, with the fluidized heat medium 11, The fluidization air 17a can be used for combustion. At this time, in the fluidized bed 4, the supplied amount of the fluidizing air 17 a and the supplied amount of the biomass fuel 18 dropped and supplied to the fluidized bed 4 from the biomass fuel supply unit 6 cause partial combustion of the biomass fuel 18 ( The complete combustion of the biomass fuel 18 is adjusted to be insufficient in oxygen). Therefore, in the fluidized bed 4, the biomass fuel 18 is partially burned, and the heat of combustion generated by the partial combustion is used to perform pyrolysis gasification of the remaining portion of the biomass fuel 18. In the fluidized bed 4, by partially burning the biomass fuel 18, the biomass fuel 18 slowly burns while leaving the effect of stirring the solid fuel specific to the fluidized bed, so the shape and property of the biomass fuel 18 fluctuates Fluctuating combustion can be suppressed.

  The combustible gas generated by the pyrolysis and gasification of the biomass fuel 18 in the fluidized bed 4 together with the combustion gas generated by the partial combustion of the biomass fuel 18 and the air after being used as the fluidizing air 17 a in the fluidized bed 4 The combustion chamber 2 is raised to the gas outlet 3.

  In the combustion chamber 2, a region close to the lower portion of the combustion chamber 2 immediately above the fluidized bed 4 is a combustion portion 19 in which the biomass fuel 18 supported by the fluidized bed 4 is partially burned and pyrolyzed and gasified as described above It has become. A region above the combustion unit 19 in the combustion chamber 2 is a gasification combustion space 20.

  The powder fuel nozzle 5 is provided at a position near the lower portion of the gasification combustion space 20 on the side wall 21 of the combustion chamber 2.

  The powder fuel nozzle 5 is a nozzle for supplying and burning wood flour 22 as powder biomass fuel so as to be blown into the combustion chamber 2 together with the transfer air 17b which also serves as the combustion air.

  For this reason, the powder fuel nozzle 5 guides the transport air 17 b from the wood powder supply unit 23 as the powder biomass fuel supply unit and the blower 15 to the end (proximal end) side located outside the side wall 21. The air supply line 16b is connected.

  The wood powder 22 is a powdered fuel of woody biomass prepared to be able to be ignited and burned by the pilot burner 24 by blowing it into the combustion chamber 2 together with the transfer air 17 b from the powder fuel nozzle 5, for example, The water content is 20% or less, and the particle size is 500 μm or less.

  For example, a fixed amount feeder such as a screw feeder is used as the wood flour supply unit 23.

  As a result, when the wood powder 22 is quantitatively supplied from the wood powder supply unit 23 in the powder fuel nozzle 5, the wood powder 22 is transported by the transport air 17b supplied from the air supply line 16b (air flow transport) ) To be blown into the combustion chamber 2. Under the present circumstances, in order to prevent retention of the wood powder 22 inside the powder fuel nozzle 5, the flow velocity of the wood powder 22 and the transport air 17b which are blown into the combustion chamber 2 from the front end side of the powder fuel nozzle 5 is 5 m. It is preferable to set to / s or more.

  A pilot burner 24 as an ignition means is provided near the tip end side of the powder fuel nozzle 5 in the side wall 21.

  The pilot burner 24 is supplied with fuel 25 such as LPG, city gas, kerosene and the like from a fuel supply unit (not shown), and is also supplied with pilot air 17c from the blower 15 through the air supply line 16c. Furthermore, the pilot burner 24 is configured to include an ignition device (not shown), and in the state where the fuel 25 and the pilot air 17c are supplied, the ignition device can be used to ignite a pilot fire, and this pilot can be held. It has become.

  The pilot burner 24 is provided in the flow path (not shown) of the wood powder 22 and the transport air 17b inside the powder fuel nozzle 5 instead of the position near the tip end side of the powder fuel nozzle 5 of the side wall 21. It may be done.

  As a result, in the combustion chamber 2, the wood powder 22 blown into the combustion chamber 2 together with the transfer air 17 b from the powder fuel nozzle 5 is ignited by the pilot burner 24 and burned using the transfer air 17 b. The heat of combustion of the powder 22 heats the inside of the combustion chamber 2 and the fluidized bed 4. At this time, since the wood powder 22 is a powder having a small particle diameter as described above, it is burned quickly in the combustion chamber 2.

  Therefore, the burner 1 of the present embodiment can control the temperature of the combustion chamber 2 by adjusting the amount of wood powder 22 to be blown into the combustion chamber 2 from the powder fuel nozzle 5 and burned. .

  It should be noted that if the supply amount of the transfer air 17b is set to an amount that is increased or decreased by a certain width based on the amount of air required to completely burn the wood powder 22 blown into the combustion chamber 2 Good. At this time, in the case where the amount of supply of the transfer air 17 b is excessive with respect to the amount of air required for complete combustion of the wood powder 22, the excess is used for partial combustion of the biomass fuel 18. On the other hand, when the transport air 17b is insufficient relative to the amount of air required for the complete combustion of the wood flour 22, the wood flour 22 has an unburned residue, but the unburned wood flour 22 falls into the fluidized bed 4 It is used together with the biomass fuel 18 for partial combustion and pyrolysis gasification. Furthermore, among the wood flour 22, the wood flour 22 having a relatively large particle size may not be able to burn when suspended in space when blown into the combustion chamber 2 from the powder fuel nozzle 5, The flaming wood powder 22 produced in this case falls into the fluidized bed 4 and is used for partial combustion and pyrolysis gasification together with the biomass fuel 18 as described above.

  Further, it is preferable that the powder fuel nozzle 5 has a flame holder (not shown) or a flame holding structure (hereinafter referred to as a flame holder or the like) by a step or the like (not shown). Thus, according to the configuration provided with the flame holder etc., the wood powder 22 newly blown into the combustion chamber 2 from the powder fuel nozzle 5 can be sequentially ignited by the flame held by the flame holder etc. . For this reason, since the pilot burner 24 can be extinguished once it is ignited by the wood powder 22 blown into the combustion chamber 2 from the powder fuel nozzle 5 except at the time of cold start, it is used in the pilot burner 24 Consumption of the fuel 25 can be reduced.

  The biomass fuel supply unit 6 is preferably provided at a position above the installation position of the powder fuel nozzle 5 on the side wall 21. This is because the biomass fuel 18 supplied from the biomass fuel supply unit 6 passes through the area where the burning of the wood powder 22 by the powder fuel nozzle 5 is performed when it falls to the fluidized bed 4 as described later. In order to promote the combustion of the biomass fuel 18.

  The biomass fuel supply unit 6 is, for example, a device for supplying biomass fuel 18 which is wood biomass having a particle diameter of 500 μm to 25 mm to the combustion chamber 2. From the viewpoint of efficiently advancing partial combustion and pyrolysis gasification, it is preferable that the particle size of the biomass fuel 18 be as uniform as possible within the range of 500 μm to 25 mm, but the particle size is less than 500 μm. And those beyond 25 mm may be included.

  The biomass fuel 18 uses, for example, crushed materials (chips) produced by crushing with a crusher (not shown) such as lumber, lumber scraps, pruning branches, construction waste materials, etc. be able to. Furthermore, as the biomass fuel 18, pellets produced from woody biomass may be used.

  The biomass fuel 18 is not particularly limited to the moisture content, but in order to increase the lower calorific value, it is preferable that the moisture content be as low as possible.

  The biomass fuel supply unit 6 used to supply this kind of biomass fuel 18 uses, for example, a fixed amount feeder such as a screw feeder. Thereby, the biomass fuel supply unit 6 can supply the biomass fuel 18 to the combustion chamber 2 quantitatively.

  The combustion air supply nozzle 7 is provided at a position below the biomass fuel supply unit 6 on the side wall 21 and at a position not to interfere with the powder fuel nozzle 5. FIGS. 1 and 2 show an example in which two combustion air supply nozzles 7 are provided on the side wall 21. The combustion air supply nozzle 7 is disposed in the horizontal direction, and is attached to the side wall 21 in a posture along the tangential direction of the outer periphery of the combustion chamber 2 as shown in FIG. Furthermore, an air supply line 16 d is connected to the combustion air supply nozzle 7 in order to lead the combustion air 17 d from the blower 15.

  Thereby, in the combustion chamber 2, when the combustion air 17d is supplied from the combustion air supply nozzle 7, it swirls to the combustion chamber 2 as shown by the arrow in FIG. An upward flow of the flowing combustion air 17d is formed.

  The amount of the combustion air 17 d supplied from the combustion air supply nozzle 7 is the sum of the amount of the combustion air 17 a supplied to the fluidized bed 4 and the amount supplied of the biomass fuel 18 supplied from the biomass fuel supply unit 6. The total amount is adjusted so that partial combustion occurs (so that the complete combustion of the entire biomass fuel 18 is insufficient in oxygen).

  When the biomass fuel 18 is supplied from the biomass fuel supply unit 6 to the combustion chamber 2, the biomass fuel 18 contacts the upward flow of the combustion air 17 d. For this reason, among the biomass fuels 18, those with small particle sizes are suspended by the upward flow of the combustion air 17d, and those with larger particle sizes gradually descend in the upward flow, The same partial combustion and pyrolysis gasification as described above are performed. Among the biomass fuels 18, those with large particle sizes in which partial combustion and pyrolysis gasification have not progressed completely in the upflow fall to the fluidized bed 4 as shown by the two-dot chain line in FIG. The partial combustion and pyrolysis gasification described above take place in layer 4.

  Therefore, partial combustion and pyrolysis gasification are performed in the combustion chamber 2 for all the supplied biomass fuels 18. The combustible gas generated by the pyrolysis and gasification of the biomass fuel 18 in the combustion chamber 2 is combined with the combustion gas by the partial combustion of the biomass fuel 18 and the air after being used as the fluidizing air 17a and the combustion air 17d. To the gas outlet 3.

  The gas passage 8 is, for example, a cylinder extending in the lateral direction, and is connected to the gas outlet 3 at one end side in the longitudinal direction, and the opening at the other end side in the longitudinal direction is a flame jet port 10.

  For example, as shown in FIG. 1, a main combustion air supply nozzle 9 is provided in the gas passage 8 in a posture facing the flame jet port 10 side. Connected to the main combustion air supply nozzle 9 is an air supply line 16 e for guiding the main combustion air 17 e from the blower 15. As a result, in the gas passage 8, the main combustion air 17 e is supplied from the main combustion air supply nozzle 9 to the gas containing the combustible gas led to the gas passage 8 from the gas outlet 3 of the combustion chamber 2. The main combustion is further performed by the main combustion air 17e of the flammable gas. The high temperature combustion gas 26 generated by the main combustion is ejected from the flame jet nozzle 10 together with the flame 27.

  Although not shown, the main combustion air supply nozzle 9 may be attached tangentially to the outer periphery of the gas passage 8 so that the main combustion air 17 e is supplied to the gas passage 8 while swirling.

  In order to start the burner 1 of the present embodiment having the above configuration, first, the wood powder 22 and the transfer air 17b are blown into the combustion chamber 2 from the powder fuel nozzle 5 while the pilot burner 24 is ignited. Thereby, in the combustion chamber 2, the wood powder 22 is burned using the transport air 17 b, so the temperature of the combustion chamber 2 and the fluidized bed 4 is raised to the ignition temperature of the biomass fuel 18 or more by the combustion heat. Let it warm. At this time, the fluidized bed 4 causes the heat medium 11 to flow by the fluidizing air 17a, and the supply of the combustion air 17d from the combustion air supply nozzle 7 to the combustion chamber 2 and the main combustion air supply nozzle The supply of the main combustion air 17e from 9 to the gas passage 8 is started.

  Next, the burner 1 of the present embodiment starts supplying the biomass fuel 18 from the biomass fuel supply unit 6 to the combustion chamber 2 after the temperatures of the combustion chamber 2 and the fluidized bed 4 rise to the ignition temperature of the biomass fuel 18 Do. As a result, in the combustion chamber 2, partial combustion and pyrolysis gasification are performed in a floating state by the combustion air 17 d of the biomass fuel 18. Furthermore, biomass fuel 18 having a relatively large particle size, in which partial combustion or pyrolysis gasification can not completely proceed in the floating state, falls to fluidized bed 4 and is fluidized in fluidized bed 4 using fluidized air 17a. Partial combustion and pyrolysis gasification are performed. The gas including the combustible gas generated by the pyrolysis and gasification of the biomass fuel 18 in the combustion chamber 2 is then continuously led from the gas outlet 3 to the gas passage 8.

  In the gas passage 8, the main combustion air supply nozzle 9 supplies the main combustion air 17e to the gas containing combustible gas continuously introduced from the combustion chamber 2, so that the main combustion of the combustible gas is performed. . Thereby, the burner 1 of the present embodiment can eject the high temperature combustion gas 26 generated by the main combustion together with the flame 27 from the flame spout 10.

  As described above, the burner 1 of the present embodiment can be started from cold using wood powder 22 which is a powdery biomass fuel, and the biomass fuel 18 is used as a fuel to operate at high temperatures. 26 and the flame 27 can be supplied to the outside from the flame spout 10.

  Furthermore, since the burner 1 of this embodiment can control the temperature of the combustion chamber 2 by controlling the amount of wood powder 22 supplied from the powder fuel nozzle 5, the response to combustion control can be improved. be able to.

  The burner 1 of the present embodiment can make all fuel other than the fuel 25 for the pilot burner 24 derived from biomass, and can be a device in consideration of carbon neutrality.

  Moreover, since the biomass fuel 18 having a relatively small particle size can be consumed by partial combustion and pyrolysis gasification in a floating state in the gasification combustion space 20, the fluidized bed 4 can be used in the combustion chamber 2. It does not accept the entire amount of biomass fuel 18 supplied. Therefore, the burner 1 of the present embodiment can reduce the size of the fluidized bed 4 and can make the bed height of the fluidized bed 4 shallow, so the blower 15 is required for supplying the fluidizing air 17 a. It is possible to reduce the required power.

  The burner 1 of this embodiment uses wood flour 22 for start-up and combustion control, but other biomass-derived fuels use biomass fuel 18 with a relatively large particle size of about 500 μm to 25 mm. Can. Therefore, the burner 1 according to the present embodiment does not have to use the whole amount of fuel used as the wood powder 22 produced by the pulverization process, and furthermore, the limitation of the moisture content of the biomass fuel 18 is loose compared to the wood powder 22. Therefore, the fuel productivity can be improved and the fuel production cost can be reduced.

  Furthermore, in the burner 1 of the present embodiment, the wood flour 22 which is a powder biomass fuel is blown into the combustion chamber 2 together with the transfer air 17b from the powder fuel nozzle 5 for combustion, and the biomass fuel having a larger particle diameter The reference numeral 18 is supplied from the biomass fuel supply unit 6 to the combustion chamber 2 to be used for partial combustion and pyrolysis gasification in the gasification combustion space 20 and the fluidized bed 4. Therefore, the burner 1 of the present embodiment can efficiently burn the fuel having different particle sizes derived from biomass by supplying it to the combustion chamber 2 by the feeding method suitable for the fuel property.

[Use Example of First Embodiment]
FIG. 3 shows an example of use of the burner of the first embodiment, and FIG. 3 (a) is a schematic cut side view, and FIG. 3 (b) is a view taken in the direction of arrows B-B in FIG. .

  In FIGS. 3A and 3B, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals and the description thereof will be omitted.

  The burner 1 of the first embodiment can be used, for example, as a heating source of a smoke tube boiler.

  By the way, when burning the fuel derived from biomass, it may be contained in the state which ash floated in combustion gas. In addition, the ashes may contain (adhere) unburned components of combustibles.

  In view of this point, the burner 1 of the first embodiment is preferably applied as a heating source to, for example, the smoke tube boiler 100 configured as shown in FIGS. 3 (a) and 3 (b).

  The smoke tube boiler 100 includes a can 102 for storing water 101, a plurality of smoke tubes 103 disposed in the can 102 and having an axial direction in the vertical direction, one end side connected to the burner 1, and the burner 1 A flue pipe 104 for introducing combustion gas into the lower side of the can 102 from the other end side, a lower end side of the flue pipe 103 and a lower end side of the flue pipe 104 for introducing combustion gas provided at the lower part of the can 102 And an ash receiving portion 105 that communicates with each other.

  Specifically, the can body 102 has a cylindrical shape disposed in the vertical direction, and an upper end plate (a header) 107 and a lower end plate (a header) at the upper end side and the lower end edge inside the body 106, respectively. The space between the upper and lower mirror plates 107 and 108 is used as a storage space 109 for the water 101.

  A space above the upper mirror plate 107 in the can body 102 is a gas collecting portion 110.

  The pipe diameter of the smoke pipe 103 is set smaller than the pipe diameter of the combustion gas introduction smoke pipe 104. The smoke pipe 103 is disposed in the can 102 so as to surround the combustion gas introduction smoke pipe 104 in a posture parallel to the axial direction of the can 102. The upper end side of the smoke pipe 103 is fixed to the upper mirror plate 107 in a penetrating state, and the upper end opening portion communicates with the gas collecting portion 110. The lower end side of the smoke pipe 103 is fixed to the lower mirror plate 108 in a penetrating state, and the lower end opening portion communicates with the ash receiving portion 105.

  The upper end side of the combustion gas introducing smoke pipe 104 is attached to the body portion 106 of the can 102 so as to penetrate from the inside of the can 102 and protrude outward, and the opening of the projecting end is an inlet 111 ing. The inlet 111 is connected to the flame jet nozzle 10 of the burner 1.

  As shown in FIG. 3A, the combustion gas introduction smoke pipe 104 extends horizontally from the inlet 111 side in the can 102 and is bent downward at the central portion of the can 102 and has a lower end. The side is attached to the central portion of the lower end plate 108 so as to penetrate from above. The lower end opening of the combustion gas introduction smoke pipe 104 is an outlet 112 communicating with the central portion of the ash receiver 105.

  As a result, the combustion gas 26 ejected together with the flame 27 (see FIG. 1) from the flame outlet 10 of the burner 1 flows from the upper side to the lower side after being introduced from the inlet 111 side into the combustion gas introduction smoke pipe 104 It is introduced into the ash receiving unit 105. At this time, the pipe diameter of the combustion gas introduction smoke pipe 104 is equal to the diameter of the flame jet outlet 10, so the flow velocity of the combustion gas 26 is maintained at the flow velocity jetted from the flame jet outlet 10. Therefore, even if the ash 113 floats in the combustion gas 26 and is accompanied by the ash 113, the ash 113 is received together with the combustion gas 26 in a state in which adhesion to the inner surface of the combustion gas introduction smoke pipe 104 is suppressed. It is introduced into section 105.

  The ash receiving portion 105 is a cylindrical container provided on the lower side of the can body 102 with the same diameter as the diameter of the can body 102, and the upper end side thereof is airtightly attached to the lower end side of the can body 102 There is.

  The ash receiving unit 105 decelerates (decreases) the flow velocity of the combustion gas 26 introduced from the outlet 112 side of the combustion gas introduction smoke pipe 104 to a flow velocity that does not reach the terminal velocity of the ash 113 in the ash receiving unit 105. The flow passage cross-sectional area is made larger than the flow passage cross-sectional area of the combustion gas introduction smoke pipe 104.

  Specifically, since the ash receiving portion 105 has the same diameter as the can 102, the above-described flow passage cross-sectional area is obtained by adjusting the height dimension of the ash receiving portion 105.

  Thereby, when the combustion gas 26 is introduced into the ash receiving portion 105 from the outlet 112 of the combustion gas introduction smoke pipe 104, the combustion gas 26 once flows downward as shown by an arrow in FIG. Then, it diffuses to the surroundings, and then it is turned upward and then flows into each smoke pipe 103.

  For this reason, the ash 113 carried along with the combustion gas 26 and flowing into the ash receiving portion 105 is led to the inner bottom side of the ash receiving portion 105 by the flow of the combustion gas 26. At that time, most of the ash 113 is left unentrained in the flow of the combustion gas 26 due to the flow velocity of the combustion gas 26 becoming less than the terminal velocity of the ash 113. Therefore, even if the ash 113 is contained in the combustion gas 26, the ash receiver 105 can separate most of the ash 113 and settle it in the inner bottom of the ash receiver 105.

  Further, in the ash receiving portion 105, the side wall portion 105a and the bottom wall portion 105b are constructed of a refractory material, and the temperature inside the combustion gas 26 can be maintained at the temperature at which unburned matter in the ash 113 burns. It is made up of As a result, the unburned component in the ash 113 in the process of settling and the unburned component in the ash 113 deposited on the inner bottom of the ash receiving portion 105 are burned by the oxygen (surplus oxygen) remaining in the combustion gas 26.

  Further, in the ash receiver 105, an air supply line 114 for supplying the air 115 into the ash receiver 105 is connected to the side wall 105a. Thereby, in the ash receiving unit 105, the combustion of the unburned portion in the ash 113 settled in the ash receiving unit 105 is further promoted by the air 115 supplied from the air supply line 114.

  The side wall portion 105a of the ash receiving portion 105 has an ash discharge port 116 for discharging ash, and the ash 113 can be scraped from the ash receiving portion 105 periodically (for example, once a month). . Although not shown, the ash discharge port 116 is provided with a lid for opening and closing.

  A combustion gas outlet 117 is provided on the side wall portion of the gas collecting portion 110. The combustion gas outlet 117 is connected to the cyclone 118 via a combustion gas discharge line 119. Thereby, after the ash is removed by the cyclone 118, the combustion gas 26 discharged from the combustion gas outlet 117 is discharged to the atmosphere through a chimney not shown, an exhaust gas processing device, and the like.

  In FIG. 3A, the combustion gas outlet 117 is provided on the side wall of the gas collecting portion 110 as an example, but the combustion gas outlet 117 is provided on the top of the can 102, and the can can be The combustion gas 26 may be discharged from the top of the 102.

  The combustion gas introduction smoke pipe 104 has a configuration in which the inlet 111 is opened to the body portion 106 of the can 102. However, the inlet 111 side is penetrated to the upper mirror plate 107, and The combustion gas 26 may be introduced from the upper side of the upper mirror plate 107 by opening the side wall portion of the collecting portion 110.

  In FIGS. 3A and 3B, although the plurality of smoke pipes 103 in the can body 102 are installed at substantially constant intervals in the can body 102, the combustion of the gas collecting portion 110 in the circumferential direction of the can body 102 is performed. The arrangement interval of the smoke tubes 103 in the area closer to the side where the gas outlet 117 is arranged is made sparse, and the arrangement interval of the smoke pipes 103 in the area far from the side where the combustion gas outlet 117 is arranged is made denser It is also good. In this way, it is possible to make the diffusion of the flow of the combustion gas 26 in the circumferential direction in the ash receiving portion 105 more uniform, and to make the flow rate of the combustion gas 26 of each smoke pipe 103 more uniform.

  Although not shown, a water supply line for supplying water 101 to be heated from the outside of the can 102 is connected to the storage space 109, and the water 101 is stored in the storage space 109 when the smoke tube boiler 100 is used. Is stored at the set level.

  In the case where the smoke tube boiler 100 is used as a hot water boiler, a line for circulating the hot water with the external heat utilization unit (heat demand unit) (not shown) is connected to the storage space 109. When the smoke tube boiler 100 is used as a steam boiler, a steam takeout line for taking out steam may be connected to the storage space 109.

  In FIG. 3A, reference numeral 120 denotes an expansion portion provided at an intermediate position to absorb the thermal expansion of the combustion gas introduction smoke pipe 104.

  According to this use example, the burner 1 is operated using the wood powder 22 and the biomass fuel 18 as described above, and the combustion gas 26 ejected from the flame outlet 10 is used to introduce the combustion gas of the smoke tube boiler 100. The gas is supplied to the inlet 111 of the smoke pipe 104.

  Thereby, in the combustion gas introduction smoke pipe 104, the combustion gas 26 flows from the upper side to the lower side where the outlet 112 is located. Since the tube diameter of the combustion gas introduction smoke pipe 104 is equal to the diameter of the flame outlet 10, the flow velocity of the combustion gas 26 flowing through the combustion gas introduction smoke pipe 104 is maintained, and the flow does not stagnate. Therefore, adhesion of the ash 113 to the inner surface of the combustion gas introduction smoke pipe 104 is suppressed. Thus, the combustion gas introduction smoke pipe 104 can reduce the frequency of cleaning.

  The combustion gas 26 that has reached the outlet 112 of the combustion gas introduction smoke pipe 104 flows downward into the ash receiving portion 105, diffuses to the surroundings, and then is inverted upward and flows into each smoke pipe 103.

  The flow velocity of the combustion gas 26 that has flowed into the ash receiving portion 105 is significantly reduced, and the flow velocity does not reach the terminal velocity of the ash 113. As a result, the ash 113 settles in the ash receiving portion 105.

  Furthermore, in the ash receiving portion 105, the flow direction of the combustion gas 26 when introduced from the outlet 112 of the combustion gas introduction smoke pipe 104 is directed downward, so the ash 113 contained in the combustion gas 26 A force (inertial force) directed to the inner bottom portion of the ash receiving portion 105 acts. As a result, the ash 113 is less likely to be entrained by the flow of the combustion gas 26 which is upward after the flow velocity is reduced in the ash receiving portion 105, and sedimentation in the ash receiving portion 105 is further promoted. Separation is promoted.

  The ash 113 which settles in the ash receiver 105 and the unburned matter contained in the ash 113 which settles on the inner bottom are burned by the excess oxygen in the combustion gas 26, and furthermore, the ash receiver 105 from the air supply line 114. It burns also by the air 115 supplied inside.

  Moreover, the area of the inner bottom surface of the ash receiving portion 105 is the same as the cross-sectional area of the can body 102. Therefore, the ashes 113 settled by the ashes receiving portion 105 can be efficiently contacted with the excess oxygen in the combustion gas 26 and the air 115 in a dispersed state on the inner bottom surface, and the unburned components in the ashes 113 are burned. It can prompt you.

  As the amount of ash 113 itself decreases when the unburned matter in the ash 113 burns, this also reduces the amount of ash 113 entrained in the combustion gas 26.

  Therefore, in the smoke tube boiler 100, the amount of the ash 113 which accompanies the combustion gas 26 and flows into the smoke tube 103 is reduced, so adhesion of the ash 113 to the smoke tube 103 can be suppressed. Thereby, since it is not necessary to consider securing of the flow-path cross-sectional area in the state to which the ash 113 adhered, the smoke pipe 103 can make a pipe diameter small. Therefore, in the smoke tube boiler 100, the density of the arrangement of the smoke tubes 103 can be improved, and the advantage that the entire size of the smoke tube boiler 100 can be reduced can be obtained. Moreover, since it can suppress that the ash 113 adheres to the smoke pipe 103, the smoke pipe boiler 100 can suppress the fall of boiler efficiency.

  In addition, since the amount of ash 113 carried by the combustion gas 26 is reduced, the dust collection load of the dust collector such as the cyclone 118 installed downstream of the smoke pipe boiler 100 can be reduced, and the frequency of cleaning the dust collector is reduced. There is also the advantage that the operating period can be extended by reducing it.

  Furthermore, since the smoke tube boiler 100 burns the unburned component in the ash 113 in the ash receiver 105, the heat generated during the combustion is given to the combustion gas 26 passing through the ash receiver 105. The heat held by the combustion gas 26 is recovered by heat exchange in the water 101 around the smoke pipe 103 while the combustion gas 26 flows through the smoke pipe 103. Therefore, in the present use example, the amount of heat possessed by the unburned component in the ash 113 contained in the combustion gas 26 can also be effectively used for the generation of hot water or steam.

  Further, in the smoke tube boiler 100, since the plurality of smoke tubes 103 are distributed around the combustion gas introduction smoke pipe 104 within a range not interfering with the combustion gas introduction smoke pipe 104, the waste space in the can 102 is eliminated. Is being reduced.

Second Embodiment
FIG. 4 is a cutaway side view showing a second embodiment of the burner, and FIG. 5 is a view taken in the direction of arrows CC in FIG.

  In FIGS. 4 and 5, the same components as those shown in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

  The burner 1a of the present embodiment is provided with a fluidized bed 4 in which the cylindrical combustion chamber 2a is formed to be horizontally long, an opening 28 is provided at the bottom of one end of the combustion chamber 2a. The configuration of the fluidized bed 4 is the same as that of the first embodiment.

  A powder fuel nozzle 5 is provided on the side wall 29 on one end side of the combustion chamber 2a, and a pilot burner 24 is provided in the vicinity thereof. The configurations of the powder fuel nozzle 5 and the pilot burner 24 are the same as those in the first embodiment. Therefore, in the powder fuel nozzle 5, the interior of the combustion chamber 2a and the fluidized bed 4 can be heated by burning the wood powder 22 blown into the combustion chamber 2a using the transfer air 17b.

  Furthermore, a biomass fuel supply unit 6 is provided at the top of one end side of the combustion chamber 2 a so as to be directly above the fluidized bed 4.

  In the combustion chamber 2a, a region immediately above the fluidized bed 4 at one end side thereof is a combustion unit 19 indicated by an alternate long and short dash line in FIG. 4 and a region excluding the combustion unit 19 is a gasification combustion space 20. In FIG. 4, a region close to the other end from the upper portion on one end side of the combustion chamber 2 a is a gasification combustion space 20.

  The biomass fuel supply unit 6 is openly connected to the gasification combustion space 20 at the top of one end side of the combustion chamber 2a. Thereby, the biomass fuel 18 supplied from the biomass fuel supply unit 6 is supplied to the gasification combustion space 20, and of the biomass fuel 18, partial combustion or pyrolysis gasification proceeds in a floating state in the gasification combustion space 20. Those having a relatively large particle size which can not be restricted are dropped and supplied to the fluidized bed 4 through the gasification combustion space 20.

  Further, a combustion air supply nozzle 7 opened in the combustion chamber 2a is provided on the cylindrical outer periphery of the combustion chamber 2a in a posture along the tangential direction. In FIG. 4, the combustion air supply nozzles 7 are provided, for example, at two locations in the axial direction of the combustion chamber 2a. Thus, the combustion air 17d supplied from the combustion air supply nozzle 7 to the combustion chamber 2a flows toward the gas outlet 3 on the other end side of the combustion chamber 2a while turning as shown by the arrow in FIG. Be

  One end side of the gas passage 8 is connected to the gas outlet 3, and the other end side opening of the gas passage 8 is a flame jet port 10.

  The main combustion air supply nozzle 9 is provided on the peripheral wall of the gas passage 8 at a position close to the flame spout 10 in an inclined posture toward the flame spout 10 side, and the main combustion air 17e is a flame spout It is supplied in the direction of 10.

  The other configuration is the same as that of the first embodiment.

  When the burner 1a according to the present embodiment is activated, wood powder 22 is blown into the combustion chamber 2a from the powder fuel nozzle 5 together with the transfer air 17b and burned, and the combustion chamber 2a and the fluidized bed 4 are ignited at the biomass fuel 18 temperature. Raise the temperature above. At this time, the fluidized bed 4 causes the heat medium 11 to flow by the fluidizing air 17a, and the supply of the combustion air 17d from the combustion air supply nozzle 7 to the combustion chamber 2 and the main combustion air supply nozzle The supply of the main combustion air 17e from 9 to the gas passage 8 is started.

  Next, the burner 1 of the present embodiment starts supplying the biomass fuel 18 from the biomass fuel supply unit 6 to the combustion chamber 2 after the temperatures of the combustion chamber 2 and the fluidized bed 4 rise to the ignition temperature of the biomass fuel 18 Do. In the combustion chamber 2, partial combustion and thermal decomposition gasification are performed in a floating state by the combustion air 17 d of the biomass fuel 18. Furthermore, biomass fuel 18 having a relatively large particle size, in which partial combustion or pyrolysis gasification can not completely proceed in the floating state, falls to fluidized bed 4 and is fluidized in fluidized bed 4 using fluidized air 17a. Partial combustion and pyrolysis gasification are performed. In the combustion chamber 2, the gas including the combustible gas generated by the pyrolysis and gasification of the biomass fuel 18 is continuously introduced from the gas outlet 3 to the gas passage 8.

  In the gas passage 8, main combustion air 17e is supplied from the main combustion air supply nozzle 9 to the gas containing combustible gas continuously introduced from the combustion chamber 2, and the main combustion of the combustible gas is performed. Thus, the burner 1 of the present embodiment can eject the high temperature combustion gas 26 generated by the main combustion from the flame jet nozzle 10 together with the flame 27.

  Therefore, also by the burner 1a of this embodiment, the same effect as that of the first embodiment can be obtained.

  The present invention is not limited to the embodiments described above, and the sizes and dimensional ratios of the combustion chambers 2 and 2a, the fluidized bed 4 and the parts of the gas passage 8 and the respective constituent devices are for convenience of illustration. It does not reflect the actual device configuration.

  Further, the arrangement of the powder fuel nozzle 5 in the combustion chamber 2, 2a is based on the combustion of the powder biomass fuel such as wood powder 22 blown into the combustion chamber from the powder fuel nozzle 5, the inside of the combustion chamber 2, 2a and the fluidized bed As long as 4 can be heated, it is good also as arrangement except showing in figure.

  The arrangement and the number of the combustion air supply nozzles 7 in the combustion chambers 2 and 2a may be the arrangement and the number other than illustrated. Further, although it is desirable that the combustion air supply nozzle 7 is arranged and oriented such that a swirling flow of the combustion air 17d can be formed in the combustion chamber 2, 2a, the combustion air supply nozzle 7 is used for combustion in the combustion chamber 2, 2a. As long as the air 17 d can be supplied to burn the biomass fuel 18 supplied from the biomass fuel supply unit 6, any arrangement and orientation may be used.

  The direction (angular attitude) of the gas passage 8 may be changed as appropriate according to the direction of the flame jet nozzle 10. Further, the arrangement and the number of the main combustion air supply nozzles 9 in the gas passage 8 may be the arrangement and the number other than illustrated.

  The fuel blown into the combustion chamber 2, 2a from the powder fuel nozzle 5 is exemplified by wood flour 22. However, any fuel other than wood flour 22 may be used if it is a biomass-derived fuel and it is a pulverized fuel. Powdered biomass fuel may be used.

  The particle diameter of the wood powder 22 may be ignited using the pilot burner 24 when supplying together with the transport air 17b from the powder fuel nozzle 5 at the time of cold start according to the combustion ease of the biomass as the raw material If possible, it may exceed 500 μm. Although the moisture content of the wood powder 22 has been described as 20% or less, if it can be ignited using the pilot burner 24 when it is supplied together with the transport air 17b from the powder fuel nozzle 5 at cold start, it exceeds 20% It may be Of course, during normal operation or hot start other than cold start, if it is possible to ignite in the gasification combustion space 20 or the combustion part 19 regardless of the presence or absence of the pilot burner 24, the particle size and moisture content of the wood powder 22 May be changed as appropriate. In addition, the particle size of the biomass fuel 18 may be appropriately changed in accordance with the ease of combustion of the biomass as the raw material.

  Although the raw material of the wood flour 22 and the biomass fuel 18 has been described as woody biomass, biomass derived from plants other than wood, or biomass derived from microorganisms may be used as the raw material.

  Although the fluidizing air 17a, the transfer air 17b, the pilot air 17c, the combustion air 17d, and the main combustion air 17e are supplied from the single blower 15, the plurality of blowers 15 may be used. Good.

  The burners 1 and 1a of the present invention may be applied as a heating source of any type of boiler other than the smoke tube boiler 100 shown in FIGS. 3 (a) and 3 (b). Furthermore, the burners 1 and 1a of the present invention may be applied to any demand (use) where either or both of the high temperature combustion gas 26 and the flame 27 are required.

  It goes without saying that various modifications can be made without departing from the scope of the present invention.

1, 1a burner 2, 2a combustion chamber 3 gas outlet 4 fluidized bed 5 powder fuel nozzle 6 biomass fuel supply unit 7 combustion air supply nozzle 8 gas passage 9 main combustion air supply nozzle 10 flame outlet 17d combustion air 17e main combustion For air 18 Biomass fuel 21 Side wall 22 Wood powder (Powder biomass fuel)
24 Pilot burner (ignition means)

Claims (6)

With the combustion chamber,
A fluidized bed provided at the bottom of the combustion chamber;
A pulverized fuel nozzle for blowing a powder biomass fuel to the combustion chamber provided in the combustion chamber,
An ignition means for igniting the powder biomass fuel blown into the combustion chamber from the powder fuel nozzle;
A biomass fuel supply unit provided at a position above the installation position of the powder fuel nozzle in the combustion chamber to supply biomass fuel from the upper side of the fluidized bed into the combustion chamber ;
The combustion chamber has a gas outlet, and the gas outlet is connected to one end of a gas passage provided with a main combustion air supply nozzle to which main combustion air is supplied, and provided at the other end of the gas passage A burner characterized by having a flame spout. The burner according to claim 1, wherein among the biomass fuel supplied from the biomass fuel supply unit, one having a large particle diameter falls into the fluidized bed. The burner according to claim 1 or 2, wherein the inside of the combustion chamber and the fluidized bed are heated by the combustion of the powdered biomass fuel blown into the combustion chamber from the powdered fuel nozzle. The combustion chamber includes a combustion air supply nozzle for supplying combustion air,
The burner according to any one of claims 1 to 3, wherein the combustion air supplied from the combustion air supply nozzle forms a swirling flow inside the combustion chamber. The combustion chamber has an elongated shape,
The gas outlet is provided at the top of the combustion chamber,
The powder fuel nozzle is provided on a side wall of the combustion chamber,
The biomass fuel supply unit is provided at a position higher than the powder fuel nozzle in the combustion chamber,
The combustion air supply nozzle is provided at a position lower than the biomass fuel supply portion on the side wall of the combustion chamber and at a position not interfering with the powder fuel nozzle.
The burner according to any one of claims 1 to 4 . The combustion chamber has a horizontally long shape,
The fluidized bed is provided at the bottom of one end of the combustion chamber,
The biomass fuel supply unit is provided above the fluid bed,
The gas outlet is provided at the other end of the combustion chamber.
The burner according to any one of claims 1 to 4 .

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