JP5694690B2 - Fluidized bed furnace and waste treatment method - Google Patents

Description

  The present invention relates to a fluidized bed furnace for extracting a combustible gas from the waste by heating the waste in a fluidized bed in which fluidized particles are fluidized, and a waste treatment method.

  Conventionally, the thing of patent document 1 is known as a fluidized bed furnace. In this fluidized bed furnace, as shown in FIG. 11, a furnace body 104 having fluidized sand (fluidized particles) 102 at the bottom of the furnace and fluidization of the fluidized sand 102 to form a fluidized bed to form a fluidized bed. And an air supply unit 106 for supplying air into the sand 102. The furnace main body 104 has a side wall, and an input unit 108 for supplying waste on the fluidized bed is provided on the side wall.

  In the fluidized bed furnace 100, the air supply unit 106 supplies air into the high temperature fluidized sand 102 to fluidize the fluidized sand 102 in a suspended state, thereby forming a fluidized bed. The air supply unit 106 is configured so that the fluidized state of the fluidized sand 102 is substantially constant throughout the fluidized bed so that the waste introduced into the fluidized bed from the input unit 108 can be taken into the bed and burned efficiently. Supply air.

  Each time waste is thrown into the high-temperature fluidized sand from the charging unit 108, the waste is mixed with the high-temperature fluidized sand 102 in the fluidized bed and thermally decomposed (gasified). Thereby, combustible gas is generated. This combustible gas is burned at a high temperature in a subsequent melting furnace, for example.

JP 2006-242454 A

  The waste thrown into the fluidized bed furnace 100 is taken into an active fluidized bed and burned or gasified, but the combustible in the waste burns rapidly each time the waste is thrown intermittently. As a result, rapid fluctuations in the amount and concentration of the generated combustible gas are repeated. Since the change in the gasification reaction greatly depends on the quantitativeness of the waste supply, if there is a change in the waste supply or the waste quality, the combustible gas cannot be generated stably. In particular, when the waste contains a large amount of flammable garbage such as paper or sheet-like plastic, the generated flammable gas fluctuates more and its stabilization is required.

  For example, when power generation is performed using the generated combustible gas in a gas engine, stable energy cannot be obtained if the fluctuation of the combustible gas is large. Is required more.

  Accordingly, it is an object of the present invention to provide a fluidized bed furnace and a waste treatment method that can stably obtain a combustible gas even if the waste contains easily burnable garbage.

  Therefore, in order to solve the above problems, the present invention is a fluidized bed furnace that heats waste and takes out combustible gas from the waste, and includes fluidized particles that constitute a fluidized bed for heating waste. A bottom wall for supporting the fluid particles from below and a side wall rising from the bottom wall, and incombustibles in the waste together with the fluid particles at a position deviated in a specific direction from the center position on the bottom wall. An incombustible discharge port is provided for discharging, and the upper surface of the bottom wall is lowered toward the incombustible discharge port so that the incombustible material descends on the upper surface of the bottom wall toward the incombustible discharge port. An inclining furnace body, a gas supply part for fluidizing the fluidized particles by blowing fluidized gas from the bottom wall of the furnace body toward the fluidized particles, and the center of the bottom wall of the side walls Across the position The waste is supplied from a supply side wall located on the opposite side of the material discharge port to a region adjacent to the supply side wall on the fluidized bed, whereby the waste on the fluidized bed is supplied to the incombustible material discharge port side. A waste supply unit to be moved to the fluidized bed by circulating the fluidized particles discharged from the incombustible discharge port to the fluidized bed from the waste supply unit side, and thereby the incombustible discharge port A sand circulation device that forms a flow of fluidized particles from the side of the supply side wall located on the opposite side to the incombustible discharge port. And the said gas supply part blows in the said fluidization gas from the circumference | surroundings of the said incombustible discharge port, the 1st flow which gasifies the said waste by the convection of the said fluid particle and mixing with the said waste Forming a region and blowing fluidized gas between the first fluidized region and the waste supply unit at a flow rate lower than the fluidized gas blowing rate in the first fluidized region, Forming a second fluidized region in which the degree of fluidization of the fluidized particles is lower than that of the first fluidized region, wherein the waste supply unit retains the waste on the second fluidized region, and The waste is supplied from the supply side wall to the fluidized bed so that the accumulated waste sequentially enters the first fluidized region.

  According to this fluidized bed furnace, the first region around the incombustible discharge port and the second fluidized region having a lower degree of fluidization than the first region are formed in the fluidized bed. Stays on the second fluidized area, and the waste supply part is placed on the supply side wall on the fluidized bed so that the waste staying on the second fluidized area is sequentially sent to the first fluidized area side. By supplying waste to the adjacent area, the gas can be sufficiently gasified while suppressing rapid fluctuations in the combustible gas recovered from the fluidized bed furnace, thereby stabilizing the combustible gas from the waste. Can be generated.

  Specifically, since the flow is suppressed in the second flow region, the flammable waste is slowly gasified while staying on the second flow region without being mixed with the flow particles. Therefore, in the second flow region, the rapid combustion of the waste is suppressed, and the generation of combustible gas due to the rapid gasification of the waste is small. The waste staying on the second fluidized area sequentially enters the first area by supplying new waste into the furnace body by the waste supply section. Then, in this first flow region, since the flow is active and the temperature is high due to the combustion of waste, the waste that has entered from above the second flow region is sufficiently mixed with the flow particles, and thus the waste is disposed of. Goods are fully gasified and combustible gas is generated. As a result, intermittent and rapid generation of combustible gas can be suppressed, and generation of the gas can be stabilized. The temperature of the second fluidized region is maintained by returning the high-temperature fluidized particles discharged from the incombustible discharge port by the sand circulation device to the second fluidized region of the fluidized bed. However, since the temperature of the fluidized particles is lowered until the sand circulation device returns from the incombustible discharge port to the fluidized bed, the temperature of the second fluidized region becomes lower than the temperature of the first fluidized region.

  In addition, since the top surface of the bottom wall of the furnace body is inclined so as to become lower toward the incombustible discharge port, the incombustible matter in the waste that sinks to the bottom wall in the fluidized bed is directed toward the incombustible discharge port. Descent over the top surface of the bottom wall. Thereby, the said incombustible substance can be easily discharged | emitted from a furnace main body by discharging | emitting with a fluid particle from an incombustible discharge port.

  The waste supply unit pushes a new waste sideways from the supply side wall toward the waste staying on the second flow region, and thereby the waste staying on the second flow region. It is preferable to sequentially move objects into the first flow region.

  According to such a configuration, since the new waste is pushed sideways toward the waste that stays on the second fluidized area, the waste that is pushed by the waste and stays on the second fluidized area is reduced. It is possible to reliably enter the first flow region.

In the fluidized bed furnace according to the present invention, U _mf is the minimum fluidization velocity that is the minimum flow velocity of the fluidizing gas for fluidizing the fluidized particles, and U ₀ is the average cross-sectional velocity of the fluidizing gas. Then, the gas supply unit blows the fluidizing gas at a flow rate such that U ₀ / U _mf is 1 or more and less than 2 in the second flow region, and U ₀ / U in the first flow region. _The fluidizing gas is preferably blown at a flow rate at which _mf is 2 or more and less than 5. A preferable first flow region and second flow region can be formed by blowing the fluidizing gas at such a flow rate. As a result, the waste can be suitably gasified while suppressing rapid combustion of the waste, and the combustible gas can be stably obtained from the waste.

  It is preferable that the furnace body has a planar shape in which the dimension in the width direction, which is a direction orthogonal to the pushing direction of the waste by the waste supply unit, is uniform in the pushing direction.

  According to this configuration, when the waste on the second flow region is pushed by the waste newly pushed from the waste supply unit and enters the first flow region, this moving direction of the furnace body Since the dimension in the width direction perpendicular to the direction is uniform, the movement of the waste is stabilized. In addition, since the flow of the flowing particles from the second flow region to the first flow region formed by the sand circulation device is the same as the movement direction of the waste, the flow of the flow particles is also stabilized.

  The waste supply unit includes a pusher having a pushing surface extending in the width direction, and the pusher pushes the pusher so that the pushing surface of the pusher simultaneously pushes waste onto the fluidized bed over the entire width direction of the pushing surface. It is preferable to have a drive unit that reciprocates in a direction parallel to the direction.

  According to such a configuration, since the waste can be uniformly pushed in the width direction, the movement of the waste from the second flow region to the first flow region becomes substantially uniform in the width direction. It is possible to prevent the waste from concentrating on the part.

  Further, in order to solve the above-mentioned problems, the present invention is a waste treatment method for heating waste and taking out combustible gas from the waste, and comprises a fluidized bed for heating the waste. Fluid particles, a bottom wall that supports the fluid particles from below, and a side wall that rises from the bottom wall, and the non-combustible material in the waste is disposed at a position biased in a specific direction from the center position of the bottom wall. An incombustible discharge port for discharging together with the fluidized particles is provided, and the upper surface of the bottom wall is disposed on the upper surface of the bottom wall toward the incombustible discharge port so that the upper surface of the bottom wall is the incombustible discharge port. Preparing a fluidized bed furnace having a furnace body inclined so as to become lower toward the bottom, and the fluidization from the region around the incombustible discharge port of the bottom wall of the furnace body toward the fluidized particles. By blowing gas A first flow region in which moving particles convect, and a supply side wall located on the opposite side of the non-combustible discharge port with the first flow region and the side wall sandwiching the center position of the bottom wall; During this period, the fluidized gas is blown at a flow rate lower than the flow rate of the fluidized gas in the first fluidized region, so that the fluidized particles are less fluidized than the first fluidized region. Forming the fluidized region and circulating the fluidized particles discharged from the incombustible discharge port from the supply side wall side to the fluidized bed, thereby circulating the fluidized particles. Forming a flow of fluidized particles from the supply side wall to the incombustible discharge port, and supplying the waste from the supply side wall to a region adjacent to the supply side wall on the fluidized bed, thereby 2 flow areas The waste is retained, and to a process of gasification by the waste was the residence are sequentially enters the first flow area, characterized in that it comprises a.

  According to this waste treatment method, the first region around the incombustible discharge port and the second fluid region having a lower degree of fluidization than the first region are formed in the fluidized bed. When the waste stays on the second fluidized zone and the waste staying on the second fluidized zone sequentially enters the first fluidized zone, the combustible gas recovered from the fluidized bed furnace The waste can be sufficiently gasified while suppressing rapid fluctuations, and thus, combustible gas can be stably generated from the waste.

  In addition, since the top surface of the bottom wall of the furnace body is inclined so as to become lower toward the incombustible discharge port, the incombustible material in the waste descends on the top surface of the bottom wall toward the incombustible discharge port. Therefore, by discharging together with flowing particles from the incombustible discharge port, the incombustible can be easily discharged from the furnace body.

  In the gasification step, the waste is pushed sideways from the supply side wall, whereby the waste staying on the second flow region is sequentially introduced into the first flow region and gasified. It is preferable to do.

  According to such a configuration, since the new waste is pushed sideways toward the waste that stays on the second fluidized area, the waste that is pushed by the waste and stays on the second fluidized area is reduced. The gas can be reliably gasified by entering the first flow region.

In this waste treatment method, if the minimum fluidization speed, which is the minimum flow velocity of the fluidizing gas for fluidizing the fluidized particles, is U _mf and the average cross-sectional flow velocity of the fluidizing gas is U _0. In the second flow region, the fluidizing gas is blown at a flow rate at which U ₀ / U _mf is 1 or more and less than 2, and in the first flow region, a flow rate at which U ₀ / U _mf is 2 or more and less than 5. It is preferable that the fluidizing gas is blown. A preferable first flow region and second flow region can be formed by blowing the fluidizing gas at such a flow rate. As a result, the waste can be suitably gasified while suppressing rapid combustion of the waste, and the combustible gas can be stably obtained from the waste.

  As described above, according to the present invention, it is possible to provide a fluidized bed furnace and a waste treatment method capable of stably obtaining a combustible gas even if the waste contains easily burnable garbage.

It is a schematic structure figure of a fluidized bed furnace concerning this embodiment. It is a cross-sectional view of the furnace main body for demonstrating the insertion position of the waste in the said fluidized bed furnace, and the insertion position of a fluid particle. It is a figure for demonstrating arrangement | positioning of the nozzle in the bottom wall of the said furnace main body. It is a figure for demonstrating the structure which pushes a fluid particle | grain directly into the fluidized bed in the said furnace main body. It is a figure for demonstrating the furnace main body which has a reflection part in the front wall in the fluidized-bed furnace which concerns on other embodiment. It is a figure for demonstrating the furnace main body which has a guide part in the rear wall in the fluidized-bed furnace which concerns on other embodiment. It is a figure for demonstrating the furnace main body which has a roof part in the front wall and rear wall in the fluidized-bed furnace which concerns on other embodiment. It is a figure for demonstrating the furnace main body which has the bent bottom wall in the fluidized-bed furnace which concerns on other embodiment. It is a figure for demonstrating the furnace main body provided with the thermometer and air supply part in the fluidized-bed furnace which concerns on other embodiment. It is a figure for demonstrating the waste supply part in the fluidized-bed furnace which concerns on other embodiment. It is a schematic block diagram of the conventional fluidized bed furnace.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  The fluidized bed furnace according to the present embodiment is a furnace that extracts combustible gas from waste by heating the waste with high-temperature fluidized particles. As shown in FIG. 1, the fluidized bed furnace includes fluidized particles 12, a furnace body 20, a gas supply unit 30, a waste supply unit 40, and a sand circulation device 50.

  The fluidized particles 12 constitute the fluidized bed 14 inside the furnace body 20 and are particles for heating the waste 18. That is, when the fluidized particles 12 heated to a high temperature by the combustion of a part of the waste are mixed with the waste 18, the waste 18 is gasified and combustible gas is generated. In the present embodiment, silica sand or the like is used as the fluid particles 12.

  The furnace body 20 is a part that has the fluidized particles 12 inside and takes out the combustible gas from the waste 18 by the hot fluidized particles 12. The furnace body 20 includes a bottom wall 21 that supports the fluidized particles 12 from below, a side wall 22 that rises from the bottom wall 21, and a combustible gas discharge part 23 that is provided at the upper end of the side wall 22.

  The side wall 22 has a rectangular tube shape extending vertically. Specifically, as shown in FIG. 2, the side wall 22 includes a front wall (supply side wall) 24 and a rear wall 25 that are opposed to each other with a space in the front and rear (left and right in FIG. 2), and the front wall 24. It has horizontal walls 26 and 26 that connect the ends of the rear wall 25 to each other. The lateral walls 26, 26 are parallel to each other. That is, the furnace body 20 has a planar shape in which the dimension in the width direction, which is the distance between the lateral walls 26, 26, is uniform in the front-rear direction.

  A sand insertion portion for inserting the fluidized particles 12 into the furnace body 20 is provided on a side wall (front wall) 24 located on the opposite side of the incombustible discharge port 29 across the center position of the bottom wall 21. 27 and a waste insertion port 28 for inserting the waste 18 into the furnace body 20 are provided.

  The sand insertion portions 27 are provided at both widthwise end portions of the lower portion of the front wall 24 so that fluid particles can be inserted into both widthwise end portions of the furnace body 20 (see FIG. 2). The sand insertion portion 27 is provided at a height position where the fluidized particles 12 can be introduced from above the fluidized particles 12 (fluidized bed 14) supported by the bottom wall 21 of the furnace body 20 toward the fluidized bed 14. . In addition, the location where the flowing particles 12 are introduced is not limited to both ends in the width direction, but may be one end in the width direction. Further, the place where the fluidized particles 12 are charged may be the upper part of the waste 18 (the central part on the front wall 24 side in FIG. 2). By introducing the fluidized particles 12 onto the waste 18, the fluidized particles 12 can be used as an ignition source, and only combustible waste can be stably burned (gasified) first.

  The waste insertion port 28 is provided in substantially the entire width direction in the lower part of the front wall 24. The waste insertion port 28 is at a height position where the waste 18 can be pushed sideways onto the upper surface of the fluidized particles 12 (fluidized bed 14) supported by the bottom wall 21 of the furnace body 20, that is, the fluidized bed 14. The lower end of the waste insertion port 28 is provided at a position slightly higher than the upper surface.

  The combustible gas discharge part 23 is a part for discharging the combustible gas generated in the furnace body 20. The combustible gas discharge part 23 has an outer diameter smaller than that of the side wall 22 so that a duct or the like for supplying the combustible gas obtained in the furnace body 20 to a gas engine or the like of a subsequent power generation process can be connected. ing.

  The bottom wall 21 is provided with an incombustible discharge port 29 for discharging the incombustible material in the waste 18 together with the fluidized particles 12 at a position deviated from the center position in a specific direction. The incombustible discharge port 29 is open in the entire width direction of the bottom wall 21. The upper surface 21a of the bottom wall 21 is inclined so as to become lower toward the incombustible discharge port 29 so that the incombustible material falls on the upper surface 21a. In the bottom wall 21 of the present embodiment, an incombustible discharge port 29 is provided at a position biased to the rear side, and the upper surface 21a of the bottom wall 21 is constant toward the rear (from left to right in FIG. 1). It is an inclined surface that is a downward slope. Specifically, the upper surface 21a of the bottom wall 21 is an inclined surface of 15 ° to 25 ° with respect to the horizontal plane.

  The gas supply unit 30 is a part that fluidizes the fluidized particles 12 by blowing fluidized gas from the bottom wall 21 toward the fluidized particles 12. The gas supply unit 30 includes a plurality of nozzles 31 for blowing out the fluidizing gas, a wind box 32 that supplies the fluidizing gas to each nozzle 31, a blower unit 33 that blows the fluidizing gas to the wind box 32, Have

  The plurality of nozzles 31 are arranged on the bottom wall 21 in a lattice shape spaced in the width direction and the front-rear direction. Each nozzle 31 is attached to the bottom wall 21 so as to penetrate the bottom wall 21. In this embodiment, as shown in FIG. 3, the bottom wall 21 is divided into a front region 21b and a rear region 21c, and the number of nozzles 31 provided in the front region 21b is provided in the rear region 21c. The nozzles 31 are disposed in the regions 21b and 21c so as to be larger than the number of nozzles 31 formed. The number of nozzles 31 between the regions 21b and 21c is not limited, and the number of nozzles 31 in the front region 21b and the number of nozzles 31 in the rear region 21c may be the same. Further, the number of nozzles 31 in the rear region 21c may be larger than the number of nozzles 31 in the front region 21b.

  The air box 32 has a box shape extending in the width direction, serves as a header for distributing the fluidized gas to the nozzles 31 arranged in the width direction on the bottom wall 21, and is blown out from the nozzles 31 arranged in the width direction. It has a function to make the flow rate of fluidized gas uniform. In the present embodiment, a plurality of wind boxes 32 are arranged in the front-rear direction on the lower surface side of the bottom wall 21. Therefore, it is possible to change the flow rate of the fluidizing gas blown from the nozzle 31 for each nozzle 31 corresponding to each wind box 32. In the present embodiment, five wind boxes 32a, 32b, 32c, 32d, and 32e are arranged in the front-rear direction. Specifically, four wind boxes 32 a, 32 b, 32 c, and 32 d are arranged on the front wall 24 side from the incombustible discharge port 29, and one wind box 32 e is placed on the rear wall 25 side from the non-combustible discharge port 29. Has been placed.

  The air blowing unit 33 is a part for blowing (supplying) the fluidizing gas to each wind box 32 and can blow the fluidizing gas at a different flow rate for each wind box 32. The air blowing unit 33 of the present embodiment is configured so that the flow rate of the fluidized gas blown to the wind box 32 on the rear side of the flow rate of the fluidized gas blown to the wind box 32 on the front side with respect to the wind boxes 32 and 32 adjacent in the front-rear direction. The fluidizing gas is blown so that the flow rate is increased. The air blowing unit 33 blows air as a fluidizing gas to each wind box 32, but in addition to this air, an inert gas such as nitrogen can also be blown.

  Specifically, during normal operation of the fluidized bed furnace 10, that is, when the waste 18 is inserted into the furnace body 20 and flammable gas is generated from the waste 18, the blower unit 33 is provided with an incombustible discharge port. The fluidized gas is blown from around 29, and the fluidized particles 12 are convected and mixed with the waste 18 to form the first fluidized region 15 for gasifying the waste 18 and the first flow. By flowing the fluidizing gas between the region 15 and the front wall 24 at a flow rate lower than the flow rate of the fluidizing gas in the first fluidized region 15, the fluidized particles 12 than in the first fluidized region 15. The second flow region 16 having a low degree of fluidization is formed. That is, as described above, the air blowing unit 33 is located on the rear side of the flow rate of the fluidized gas blown to the front side wind box 32 (for example, 32b) with respect to the wind box 32 adjacent in the front-rear direction (for example, By increasing the flow rate of the fluidizing gas blown to 32c), the first fluidized region 15 is formed in the fluidized bed 14 around the incombustible material outlet 29 and the fluidized state is active. And the front wall 24, the second flow region 16 in which flow is suppressed is formed. For example, the blower 33 increases the flow rate of the fluidizing gas supplied to the wind boxes 32c, 32d, and 32e on the rear wall 25 side rather than the flow rate of the fluidizing gas supplied to the wind boxes 32a and 32b on the front wall 24 side. Thus, in the fluidized bed 14, the second flow region 16 in which the flow is suppressed is formed in the region corresponding to the wind boxes 32a and 32b on the front wall side, and also corresponds to the wind boxes 32c, 32d and 32e on the rear wall side. A first flow region 15 in which flow is active is formed in the region.

Specifically, the blower unit 33, the second flow area _16, thereby blown fluidizing gas at a flow rate U o _{/ U mf} is less than 1 or more 2, in the first flow region _{15, U} o / U Fluidizing gas is blown at a flow rate at which _mf is 2 or more and less than 5. Here, U _mf is the minimum fluidizing velocity is the minimum flow rate of the blowing of the fluidizing gas for fluidizing the fluidized particles 12, U _o is the average cross-sectional velocity of the fluidizing gas.

  On the other hand, when the fluidized bed furnace 10 is stopped, that is, when the insertion of the waste 18 into the furnace body 20 is stopped, the blower unit 33 supplies an inert gas to the air as a fluidizing gas supplied to each wind box 32. Blow the mixture. And the ventilation part 33 suppresses that the waste 18 which remains in the furnace main body 20 burns violently by making the ratio of the air and inert gas in fluidization gas gradually increase the inert gas, The temperature rise in the furnace body 20 is suppressed.

  Specifically, in the furnace body 20, during normal operation, the waste 18 is burned and gasified in a state where the oxygen concentration is lower than a value suitable for the combustion of the waste 18. When the insertion of the waste 18 into the furnace main body 20 is stopped in this state, the amount of combustible material in the furnace main body 20 decreases, but a predetermined amount is maintained in the furnace main body 20 in order to maintain the fluidized bed 14. Since fluidized gas (air) is supplied at a flow rate, the oxygen concentration in the furnace body 20 is increased. When the oxygen concentration in the furnace body 20 becomes a value suitable for the combustion of the waste 18 remaining in the furnace body 20, the waste 18 burns violently and the temperature in the furnace body 20 is higher than that during normal operation. To rise. When the inside of the furnace body 20 reaches such a high temperature state, the fluidized particles 12 forming the fluidized bed 14 are hardened by this heat. When the fluidized particles 12 are thus solidified, the fluidized particles 12 are not fluidized even if the fluidized gas is blown into the fluidized particles 12 to form the fluidized bed 14 next time. Therefore, when the insertion of the waste 18 into the furnace body 20 is stopped, the blower unit 33 mixes an inert gas with the air blown into the furnace body 20 and gradually increases the ratio of the inert gas. Thereby, the oxygen concentration in the furnace main body 20 is kept lower than a value suitable for the combustion of the waste 18, and as a result, the waste 18 remaining in the furnace main body 20 is suppressed from burning violently.

  Further, the blower 33 can adjust the temperature of the fluidizing gas blown to the wind box 32. When the operation of the fluidized bed furnace 10 is started, the blower unit 33 blows a high-temperature fluidized gas from the periphery of the incombustible material discharge port 29 toward the fluidized particles 12 so that the waste 18 can be combusted or gasified. The fluidized particles 12 are heated until a certain temperature is reached. In this case, when the fluidized particles 12 become high temperature and the combustion of the waste 18 starts, the temperature of the fluidized particles 12 is maintained by this combustion, and therefore the blower 33 lowers the temperature of the fluidized gas blown to the wind box 32. May be.

  The waste supply unit 40 is a part that supplies the waste 18 from the front wall 24 to a region adjacent to the front wall 24 on the fluidized bed 14. The waste supply unit 40 of the present embodiment pushes the waste 18 sideways onto the fluidized bed 14 from the front wall 24 (specifically, the waste insertion port 28 of the front wall 24), thereby causing the waste 18 to be nonflammable. This is a part to be moved to the object discharge port 29 side. That is, the waste supply unit 40 has the waste 18 so that the waste 18 stays on the second flow region 16 and the stayed waste 18 sequentially enters the first flow region 15. Push in. The waste supply unit 40 includes a pusher 41 and a drive unit (not shown) for driving the pusher 41. The pusher 41 has a pushing surface 42 extending in the width direction. In this embodiment, the length in the width direction of the pushing surface 42 is the same as the width of the waste insertion port 28 of the front wall 24, and the length in the vertical direction is approximately half of the opening height of the waste insertion port 28. is there. The pusher 41 is installed to be movable in the front-rear direction at the same height as the waste insertion port 28. The drive unit includes a power source such as a motor and a cylinder, and the pusher 41 is reciprocated in the front-rear direction by the power. The specific configuration of the waste supply unit 40 is not limited. For example, in the waste supply unit 40 of the present embodiment, the pusher 41 pushes the waste 18 into the furnace, but the waste 18 may be pushed into the furnace by a screw pusher or the like. By using the pusher 41 and the screw pusher, it is possible to supply litter that is small in bulk specific gravity such as paper or plastic sheet and easily scatters into the furnace body 20 in a lump. Compared with the case where it throws in, it can suppress that these refuse scatter in the furnace main body 20. FIG.

  The sand circulation device 50 is a device that circulates the fluidized particles 12 by returning the fluidized particles 12 discharged from the incombustible discharge port 29 to the fluidized bed 14 from the waste supply unit 40 side. Thus, by circulating the fluidized particles 12 discharged from the incombustible discharge port 29 to the front wall 24 side, the flow of the fluidized particles 12 from the front wall 24 toward the incombustible discharge port 29 is formed in the fluidized bed 14. In addition, the second flow region 16 is kept at a high temperature to some extent. The sand circulation device 50 includes an incombustible discharge unit 51, a separation unit 52, and a transport unit 53.

  The incombustible discharge unit 51 is provided below the incombustible discharge port 29 on the bottom wall 21, and moves the mixture of the noncombustible material and the fluidized particles 12 that have fallen from the incombustible discharge port 29 to the separation unit 52. The incombustible discharge part 51 of this embodiment moves the mixture which has fallen from the incombustible discharge port 29 to the separation part 52 by a screw pusher. The separation unit 52 separates the fluidized particles 12 from the mixture sent from the incombustible material discharge unit 51. The separation unit 52 of the present embodiment separates the fluidized particles 12 from the mixture by sieving. The transport unit 53 transports the fluidized particles 12 separated in the separation unit 52 to the sand insertion unit 27 of the furnace body 20 and inserts the fluid particles 12 into the furnace body 20 from the sand insertion unit 27.

  In addition, the sand circulation device 50 of the present embodiment inputs the fluidized particles 12 from above the fluidized bed 14 toward the upper surface of the fluidized bed 14, and thereby the fluidized particles 12 discharged from the incombustible material outlet 29. Although it has returned to the fluidized bed 14, it is not limited to this. For example, as shown in FIG. 4, the fluidized particles 12 ejected from the incombustible material outlet 29 may be returned directly into the fluidized bed 14. In the example shown in FIG. 4, a sand insertion portion (sand insertion opening) 27 </ b> A is provided in the middle wall of the fluidized bed 14 on the front wall 24. A screw pusher 55 is provided at the end of the transport unit 53 of the sand circulation device 50 on the furnace body 20 side, and the end of the transport unit 53 is inserted into the sand insertion unit 27. Thus, the fluidized particles 12 discharged from the incombustible discharge port 29 may be returned directly to the fluidized bed 14 so as to be pushed directly into the fluidized bed 14. In this case, the sand layer containing portion 27 is not limited to the intermediate height position of the fluidized bed 14, and may be located on the upper side in the height direction or on the lower side. By pushing the fluidized particles 12 into the fluidized bed 14, the lateral movement of the fluidized particles 12 can be performed more forcibly, and the incombustible matter can be prevented from staying in the hearth.

  In the fluidized bed furnace 10 configured as described above, the combustible gas is recovered from the waste 18 as follows.

  The air blowing unit 33 supplies the fluidizing gas to each wind box 32. As a result, fluidized gas is blown from the bottom wall 21 toward the fluidized particles 12, and the fluidized bed 14 is formed in the furnace body 20. At this time, the air blowing unit 33 adjusts the flow rate of the fluidizing gas blown to each wind box 32 to form the first fluidized region 15 in the fluidized bed 14 where the flow is active on the incombustible discharge port 29 side. A second flow region 16 in which flow is suppressed is formed between the first flow region 15 and the front wall 24. In addition, the blower unit 33 supplies the high-temperature fluidized gas to the wind box 32 (in the present embodiment, for example, the wind boxes 32c, 32d, and 32e in the present embodiment) corresponding to the first flow region 15 to provide the first flow region. The fluidized particles 12 in the fluidized region 15 are positively heated.

  On the other hand, the sand circulating device 50 circulates the fluidized particles 12 to form a flow of fluidized particles 12 in the fluidized bed 14. Specifically, the incombustible material discharge unit 51 sends the flowing particles 12 that have fallen from the incombustible material discharge port 29 of the furnace body 20 to the separation unit 52, and the transport unit 53 transfers the flowing particles 12 that have passed through the separation unit 52. It is conveyed to the sand insertion part 27. The conveyed fluidized particles 12 are returned from the sand insertion portion 27 to the front wall 24 side of the fluidized bed 14. As described above, the fluidized particles 12 discharged from the incombustible discharge port 29 on the rear wall 25 side are returned to the front wall 24 side of the fluidized bed 14, so that in the fluidized bed 14 from the front wall 24 to the incombustible discharge port 29. A flow of directed fluid particles 12 is formed. At this time, the high temperature fluidized particles 12 in the first fluidized region 15 are ejected from the incombustible material outlet 29, and the sand circulating device 50 returns the fluidized particles 12 to the front wall 24 side of the fluidized bed 14, thereby The temperature of the flow region 16 is maintained at a predetermined temperature. However, since the temperature of the fluidized particles 12 decreases until the sand circulation device 50 returns from the incombustible discharge port 29 to the fluidized bed 14, the temperature of the second fluidized region 16 is the same as that of the first fluidized region 15. It becomes lower than the temperature. Preferably, the temperature of the first flow region 15 is 600 ° C. to 800 ° C., whereas the temperature of the second flow region 16 is maintained at about 400 ° C. to 600 ° C.

  In this way, when the temperature of each of the regions 15 and 16 of the fluidized bed 14 formed in the furnace body 20 reaches a predetermined temperature, the waste supply unit 40 transfers the waste 18 from the waste insertion port 28 to the furnace body 20. Start pushing in. Specifically, the pusher 41 driven by the driving unit pushes the waste 18 sideways toward the rear wall 25 side. As a result, the waste 18 is pushed into the vicinity of the front wall 24 on the second flow region 16 (see FIG. 2).

  Since the flow of the fluidized particles 12 is suppressed in the second fluidized region 16, the pushed waste 18 is not actively mixed with the fluidized particles 12, and most of the waste is on the second fluidized region 16. The heavy incombustibles settle. Therefore, in the second flow region 16, the rapid combustion of the waste 18 is suppressed, and the gas that is easily gasified by the heat radiation in the furnace body 20 is gasified. That is, the waste 18 that is easily gasified, such as plastic and paper, is gasified while moving on the surface layer of the second flow region 16. On the other hand, some of the wood pieces and the like which are difficult to gasify are partially gasified, but most of them reach the first flow region 15 without being gasified. Before the waste 18 that is easily gasified reaches the intense fluidized bed (first fluidized region 15), the fluctuation of the combustible gas generated by gasifying under mild conditions in the second fluidized region 16 is suppressed. be able to. Although the staying waste 18 is burned by the radiant heat in the furnace body 20 as described above, although the temperature in the furnace is 800 to 900 ° C. and higher than the fluidized particles 12 forming the fluidized bed 14, Since the contact with the air is not good, flammable garbage such as paper and sheet-like plastic mainly contained in the waste 18 is gasified. At this time, since the temperature is low and the amount of air (fluidized gas) supplied to the second flow region 16 is small, even the flammable garbage is gradually gasified. Further, since the fluidized particles 12 are gradually discharged through the incombustible discharge port 29, a part of the retained waste 18 is left in FIG. 1 due to the discharge of the fluidized particles 12 and the flow of the fluidized particles 12 by the fluidizing gas. Move or diffuse little by little from right to left. Therefore, even if there are papers that are put in a lump and easily burned, they can be expected to promote gasification by coming out to the surface side during diffusion. As described above, in the second flow region 16, rapid combustion of the waste 18 is suppressed, and rapid increase of combustible gas when the waste 18 is inserted is prevented.

  Next, the new waste 18 is pushed into the furnace main body 20 from the waste insertion port 28 by the pusher 41. Accordingly, the waste 18 staying on the second flow region 16 is pushed by the pushed new waste 18 and enters the first region 15 side in order. In the first flow region 15, since the flow is active and the temperature of the waste 18 becomes high due to the combustion of the waste 18, the waste 18 that has entered from the second flow region 16 is mixed with the flow particles and the gasification is sufficiently performed. This produces flammable gas. Specifically, in the fluidized bed 14, the fluidized state gradually becomes active from the front wall 24 toward the incombustible discharge port 29, so that the waste 18 is moved from the vicinity of the front wall 24 on the second fluidized region 16 to the second fluidized region 16. As the flow proceeds to one fluidized region 15, the fluidized particles 12 are gradually mixed. Moreover, since the air (fluidized gas) blown in as it proceeds from the second fluidized region 16 to the first fluidized region 15 increases, the waste 18 burns and the temperature of the fluidized particles 12 increases. The waste 18 is sufficiently mixed with the fluidized particles 12 in the region above and around the incombustible discharge port 29 in the high-temperature fluidized bed 14, whereby the second fluidized region in the first fluidized region 15. The waste 18 left unburned at 16 is sufficiently gasified.

  On the other hand, the waste 18 newly pushed onto the second fluidized region 16 by the pusher 41 stays on the second fluidized region 16 without being mixed with the fluidized particles 12 as described above, and vigorously burns. It burns gradually in a restrained state.

  As described above, the waste 18 is pushed in one after another by the pusher 41 in a state where the first fluidized region 15 and the second fluidized region 16 are formed in the fluidized bed 14, so that the combustible gas is intermittently and suddenly pushed. Generation can be suppressed and generation of the gas can be stabilized.

  When the fluidized bed furnace 10 is stopped, first, the pushing of the waste 18 into the furnace body 20 by the pusher 41 is stopped. When the pushing of the waste 18 is stopped, the blower unit 33 blows air in which an inert gas is mixed as a fluidizing gas supplied to each wind box 32. At this time, the air blowing unit 33 suppresses the oxygen concentration in the furnace body 20 by gradually increasing the ratio of the air to the inert gas in the fluidized gas and the inert gas as time passes, so that the fluidized bed It suppresses that the waste 18 which remains in 14 burns violently.

  In the present embodiment, when the fluidized bed furnace 10 is stopped, the combustion of the waste 18 remaining in the fluidized bed 14 is suppressed by increasing the ratio of the inert gas in the fluidized gas. The layer 14 may be sprayed with water to prevent the remaining waste 18 from burning.

  Thus, in the fluidized bed furnace 10, even if the waste contains a lot of flammable garbage, intermittent and rapid generation of the combustible gas can be suppressed and the generation of the gas can be stabilized. Specifically, in a state in which the first region 15 around the incombustible discharge port 29 and the second fluid region 16 having a lower degree of fluidization than the first region 15 are formed in the fluidized bed 14. The new waste 18 is pushed onto the second flow region 16, and the new waste 18 stays in the second flow region 16 in order toward the first flow region 15 side. Repeated entry. As a result, in the fluidized bed furnace 10, the waste 18 can be sufficiently gasified while suppressing rapid fluctuation of the obtained combustible gas, and the combustible gas can be stably generated from the waste 18. . In addition, since it is not exposed to the active fluidized bed 14 (first fluidized region 15) immediately after the waste 18 is put in, a large amount of lightweight waste rises into the furnace body 20 and suppresses rapid combustion in the freeboard section. can do.

  Moreover, since the upper surface 21a of the bottom wall 21 of the furnace body 20 is inclined so as to become lower toward the incombustible discharge port 29, the incombustibles in the waste 18 that sinks to the bottom wall 21 in the fluidized bed 14 are: It descends on the upper surface 21 a of the bottom wall 21 toward the incombustible discharge port 29. Thereby, by discharging together with the flowing particles 12 from the incombustible discharge port 29, the incombustible can be easily discharged from the furnace body 20. The incombustible material discharged together with the fluidized particles 12 from the incombustible material outlet 29 is separated from the fluidized particles 12 and removed by the separation unit 52 of the sand circulation device 50.

  Since the furnace body 20 has a uniform planar shape in the width direction in the pushing direction of the waste 18, the waste 18 on the second flow region 16 is newly pushed from the waste supply unit 40. When the waste 18 is pushed by the waste 18 and enters the first flow region 15, the movement of the waste 18 is stabilized. Moreover, since the flow of the fluid particles 12 from the second fluid region 16 to the first fluid region 15 formed by the sand circulation device 50 is the same as the movement direction of the waste 18, the fluid particles 12 also flow. Stabilize.

  In the waste supply unit 40, the pusher 41 reciprocates in a direction parallel to the pushing direction (front-rear direction) so that the pushing surface 42 simultaneously pushes the waste 18 onto the fluidized bed 14 over the entire width direction of the pushing surface 42. This pushes the waste 18 uniformly in the width direction. Therefore, the movement of the waste 18 from the second flow region 16 toward the first flow region 15 becomes substantially uniform in the width direction, and it is possible to prevent the waste 18 from concentrating on a part of the furnace.

  Note that the fluidized bed furnace and the waste treatment method of the present invention are not limited to the above-described embodiments, and it is needless to say that various modifications can be made without departing from the scope of the present invention.

  Although the side wall 22 of the said embodiment has stood up straight from the bottom wall 21 to the combustible gas discharge part 23, it is not limited to this. For example, as shown in FIG. 5, the front wall 24 </ b> A may include a reflecting portion 224 that extends toward the rear wall 25 so as to cover the second flow region 16 at a predetermined height position. According to the front wall 24 </ b> A, the waste 18 staying on the second flow region 16 is heated by the radiant heat from the reflection part 224, and as a result, the waste 18 staying on the second flow region 16. From the above, combustible gas can be generated. That is, gasification of the waste 18 staying on the second flow region 16 is promoted.

  Further, as shown in FIG. 6, a guide portion 225 that extends toward the front wall 24 so that the rear wall 25 </ b> A covers the upper part of the first flow region 15 at a predetermined height position may be provided. The guide unit 225 guides the combustible gas so that the high-temperature combustible gas generated from the waste in the first flow region 15 contacts the waste 18 that stays on the second flow region 16. Thus, the combustible gas is caused to contribute to the heating of the waste 18 on the second flow region 16. As a result, gasification of the waste 18 staying on the second flow region 16 is promoted without adding a special heating means.

  Further, as shown in FIG. 7, the furnace body 20 may include roof portions 324 and 325 extending in a direction in which the front wall 24B and the rear wall 25B approach each other at the same height position. According to the front wall 24B and the rear wall 25B, the waste 18 staying on the second flow region 16 is heated by the radiant heat from the roof portion 324 of the front wall 24B, and gasification is promoted. Further, the furnace body 20B can be downsized by reducing the size in the front-rear direction of the furnace body 20B at a position lower than the combustible gas discharge part 23 at the upper end of the furnace body 20B.

  In the said embodiment, although the inclination | tilt angle of the upper surface 21a of the bottom wall 21 is uniform from the front wall 24 to the incombustible discharge port 29, it is not restricted to this. For example, as shown in FIG. 8, the inclination angle α of the upper surface 21 d on the second flow region 16 side with respect to the horizontal plane may be larger than the inclination angle β with respect to the horizontal surface of the upper surface 21 e on the first flow region 15 side. In this way, by increasing the inclination angle of the upper surface 21 d that supports the second flow region 16 in which the flow of the flowing particles 12 is suppressed from below, the incombustible material that sinks to the bottom wall 21 </ b> A is more than the incombustible material discharge port 29. It can be lowered reliably. Specifically, the inclination angle β with respect to the horizontal surface of the upper surface 21e on the first flow region 15 side is 15 ° to 25 °, and the inclination angle α with respect to the horizontal surface of the upper surface 21d on the second flow region 16 side is 20 °. It is -75 degrees, Preferably it is 20 degrees-30 degrees.

  Further, the upper surface 21 a of the bottom wall 21 may be curved without being inclined straight from the front wall 24 toward the incombustible discharge port 29.

  As shown in FIG. 9, even if a plurality of thermometers T are arranged above the second flow region 16 and an air supply unit 60 capable of supplying air is provided on the second flow region 16. Good. According to such a configuration, it becomes possible to estimate the staying amount of the waste 18 staying on the second flow region 16 and control this staying amount. Specifically, the retention amount of the waste 18 on the second flow region 16 is estimated using the fact that the indicated value of the thermometer T buried in the waste 18 becomes low. When the amount of residence is large, that is, when the thermometer T buried in the waste 18 is large, air is supplied from the air supply unit 60 to raise the temperature in the furnace body 20. Then, gasification of the waste 18 staying on the second flow region 16 is promoted, and the staying amount of the waste 18 is reduced. As another method, if the temperature of the specified thermometer T is equal to or higher than the threshold value, it is determined that there is no dust at the position of the thermometer T. If the temperature is lower than the threshold value, the position of the thermometer T is dirty. The amount of air may be controlled by determining that it is buried in garbage. Further, instead of controlling the amount of air, the amount of waste supplied may be controlled.

  In the said embodiment, although the ventilation part 33 ventilates air and an inert gas as fluidization gas, according to the combustion state in the furnace main body 20, it is comprised so that water vapor | steam and oxygen may be ventilated as fluidization gas. Also good. Further, the fluidized bed furnace 10 is provided with a gas supply unit on the side wall 22 in addition to the gas supply unit 30, and air or gas is supplied from the gas supply unit into the furnace body 20 according to the combustion state of the fluidized bed 14 or the waste 18. You may be comprised so that oxygen, water vapor | steam, etc. can be supplied.

  Further, a high-temperature fluidizing gas may be supplied as the air (fluidizing gas) supplied to the second fluidizing region 16. Even if the temperature of the second fluidized region 16 cannot be sufficiently maintained only by circulation of the fluidized particles 12 by flowing a high-temperature fluidized gas, the second fluidized gas can be supplied without increasing the supply amount of the fluidized gas. The temperature of the flow region 16 can be kept high.

  In the above embodiment, the waste insertion port 28 is provided at a height position that partially overlaps with the waste 18 staying on the fluidized bed 14 in the vertical direction, and the waste 18 supplied from the waste insertion port 28 is provided. However, the waste staying on the upper surface of the fluidized bed 14 is positively moved in the lateral direction (on the first fluidized region 15 side). However, the present invention is not limited to this. That is, the fluidized bed furnace 10 may be configured to supply the waste 18 to a region adjacent to the front wall (supply side wall) 24 on the fluidized bed 14. For example, as shown in FIGS. 10A and 10B, the waste insertion port 28 is adjacent to the front wall 24 on the upper surface of the fluidized bed 14 at a height position near the upper surface of the fluidized bed 14. The waste 18 newly supplied to the waste 18 staying in the region (on the second flow region 16) may be provided at a height position at which the waste 18 does not contact at the time of supply. In this case, as shown in FIG. 10A, for example, the waste insertion port 28 is provided so that new waste can be supplied laterally from a height position above the waste staying on the fluidized bed 14. As shown in FIG. 10B, new waste may be provided so as to be supplied downward from a height position above the waste staying on the fluidized bed 14. As described above, even if the waste 18 is supplied into the furnace body 20, the new flow 18 is supplied onto the stagnant waste 18, so that the pile of the waste 18 collapses and expands, thereby causing the first flow. The waste 18 enters the region 15 side, and the waste stays on the second fluidized region 16 due to the flow of the fluidized particles 12 from the front wall 24 formed in the fluidized bed 14 toward the incombustible discharge port 29. 18 enters the first flow region 15 side. As a result, the waste 18 is sufficiently gasified while suppressing rapid fluctuations in the combustible gas recovered from the fluidized bed furnace 10, and as a result, the combustible gas can be stably generated from the waste 18. it can.

In the above embodiment, the fluidizing gas supplied to each of the fluidized bed 14, the second flow field 16 as described above, blown fluidizing gas at a flow rate U o _/ U _mf is less than 1 or more 2 In the first flow region 15, the fluidizing gas is blown at a flow rate at which U _o / U _mf is 2 or more and less than 5, but incombustible material stays in the hearth (upper surface 21 a of the bottom wall 21). If not discharged, the fluidizing gas may be blown at a flow rate such that U _o / U _mf is 2 or more and less than 5 in the second flow region 16 only for a certain period in order to discharge it to the outside. In this case, the fluidizing gas is not blown uniformly in the second flow region 16, but sequentially from the front wall 24 side (left side in FIG. 1) to the rear wall 25 side (right side in FIG. 1) of the furnace body 20. The supply amount of fluidized gas is gradually increased for each wind box 32. Specifically, the flow rate of the fluidizing gas supplied to the wind box 32a at a certain time t0 is made larger than the flow rate of the fluidizing gas supplied to the other wind boxes, and at the time t1 several seconds later, While returning the flow rate of the fluidizing gas supplied to the wind box 32a to the flow rate during normal operation, the flow rate of the fluidizing gas supplied to the adjacent wind box 32b is higher than the flow rate of the fluidizing gas supplied to other wind boxes. Enlarge. Then, at time t2 after several seconds, the flow rate of the fluidizing gas supplied to the wind box 32b is returned to the original state, and the flow rate of the fluidizing gas supplied to the adjacent wind box 32c is transferred to another wind box. The flow rate of fluidized gas to be supplied is made larger. By such an operation, even if an incombustible material stays in the hearth during normal operation, the incombustible material can be reliably discharged out of the furnace body 20. Since the above operation is performed for a very short time, the influence on the subsequent equipment can be minimized.

DESCRIPTION OF SYMBOLS 10 Fluidized bed furnace 12 Fluidized particle 14 Fluidized bed 15 1st fluidized area 16 2nd fluidized area 18 Waste 20 Furnace main body 21 Bottom wall 21a Bottom wall upper surface 22 Side wall 24 Front wall 25 Rear wall 29 Incombustible discharge port 30 Gas supply unit 40 Waste supply unit 50 Sand circulation device

Claims (8)

A fluidized bed furnace that heats waste and takes out combustible gas from the waste,
Fluidized particles constituting a fluidized bed for heating waste,
A bottom wall that supports the fluidized particles from below and a side wall that rises from the bottom wall, and discharges incombustible materials in the waste together with the fluidized particles to a position that is biased in a specific direction from the center position of the bottom wall. An incombustible discharge port is provided, and the upper surface of the bottom wall is lowered toward the incombustible discharge port so that the incombustible material descends on the upper surface of the bottom wall toward the incombustible discharge port. A furnace body inclined like
A gas supply unit that fluidizes the fluidized particles by blowing fluidized gas from the bottom wall of the furnace body toward the fluidized particles;
The waste is supplied to a region adjacent to the supply side wall on the fluidized bed from a supply side wall located on the opposite side of the incombustible discharge port across the center position of the bottom wall of the side wall, A waste supply unit that moves waste on the fluidized bed to the incombustible discharge port side,
The fluidized particles discharged from the incombustible discharge port are circulated by returning the fluidized particles from the waste supply unit side to the fluidized bed, and thereby the supply side wall located on the opposite side of the incombustible discharge port. A sand circulation device for forming a flow of fluid particles from the side toward the incombustible discharge port ;
A plurality of thermometers disposed above the fluidized bed;
An air supply unit capable of supplying air onto the fluidized bed ,
The gas supply unit blows the fluidizing gas from the periphery of the incombustible discharge port, and the fluidized particles convect and mix with the waste, thereby gasifying the waste. And forming the fluidizing gas between the first fluidizing region and the waste supply unit at a flow rate lower than the fluidizing gas blowing rate in the first fluidizing region. Forming a second flow region in which the fluidized particles are less fluidized than the one flow region;
The waste supply unit has the waste from the supply side wall so that the waste stays on the second flow region, and the stayed waste sequentially enters the first flow region. There line the supply of waste with respect to the fluidized bed,
The plurality of thermometers are arranged at different positions above the second flow region,
The fluidized bed furnace in which the air supply unit supplies air onto the second fluidized region based on the index values of the plurality of thermometers so that the temperature in the furnace body increases . The fluidized bed furnace according to claim 1,
The waste supply unit pushes a new waste sideways from the supply side wall toward the waste staying on the second flow region, and thereby the waste staying on the second flow region. A fluidized bed furnace in which objects are sequentially entered into the first fluidized zone. In the fluidized bed furnace according to claim 1 or 2,
When the minimum fluidization speed that is the minimum flow velocity of the fluidization gas for fluidizing the fluidized particles is U _mf and the average cross-sectional flow velocity of the fluidization gas is U ₀ , the gas supply unit is The fluidizing gas is blown at a flow rate where U ₀ / U _mf is 1 or more and less than 2 in the flow region of 2, and the flow rate of U ₀ / U _mf is 2 or more and less than 5 in the first flow region. A fluidized bed furnace that injects fluidized gas. The fluidized bed furnace according to any one of claims 1 to 3,
The fluidized bed furnace, wherein the furnace body has a planar shape in which a dimension in a width direction that is a direction orthogonal to a pushing direction of the waste by the waste supply unit is uniform in the pushing direction. The fluidized bed furnace according to claim 4,
The waste supply unit includes a pusher having a pushing surface extending in the width direction, and the pusher pushes the pusher so that the pushing surface of the pusher simultaneously pushes waste onto the fluidized bed over the entire width direction of the pushing surface. A fluidized bed furnace having a drive unit that reciprocates in a direction parallel to the direction. A waste treatment method for heating waste to take out combustible gas from the waste,
There are fluidized particles that constitute a fluidized bed for heating the waste, a bottom wall that supports the fluidized particles from below, and a sidewall that rises from the bottom wall, and the bottom wall has a specific direction from its center position. An incombustible discharge port for discharging the incombustible material in the waste together with the fluidized particles is provided at a biased position, and the incombustible material descends on the upper surface of the bottom wall toward the incombustible material discharge port. Preparing a fluidized bed furnace having a furnace body inclined so that the upper surface of the bottom wall is lowered toward the incombustible discharge port;
A first fluidized region in which the fluidized particles are convected is formed by blowing fluidizing gas from the region around the incombustible discharge port in the bottom wall of the furnace body toward the fluidized particles. Between the flow region and the supply side wall located on the opposite side of the incombustible discharge port across the center position of the bottom wall of the side wall, the flow rate of the fluidized gas blown in the first flow region Forming a second fluidized region in which the fluidized particles are less fluidized than the first fluidized region by blowing fluidized gas at a lower flow rate;
The fluidized particles are circulated by returning the fluidized particles discharged from the incombustible discharge port to the fluidized bed from the supply side wall side, and thereby directed from the supply side wall side to the incombustible material discharge port. Forming a flow of fluid particles;
The waste is supplied from the supply side wall to a region adjacent to the supply side wall on the fluidized bed, whereby the waste is retained on the second fluidized region, and the retained waste things were sequentially entering the first flow area when viewed including the steps of gasification, a,
In the step of preparing the fluidized bed furnace, as the fluidized bed furnace, a plurality of thermometers arranged at different positions above the second fluidized region and air can be supplied onto the second fluidized region. And a further air supply unit,
A waste treatment method further comprising a step of supplying air from the air supply unit so that a temperature in the furnace body is increased based on index values of the plurality of thermometers . The waste treatment method according to claim 6,
In the gasification step, new waste is pushed sideways from the supply side wall toward the waste staying on the second flow region, and thereby the waste staying on the second flow region. A waste treatment method in which an object is sequentially gasified by entering the first flow region. The waste disposal method according to claim 6 or 7,
When the minimum fluidization speed that is the minimum flow velocity of the fluidizing gas for fluidizing the fluidized particles is U _mf , and the average cross-sectional flow velocity of the fluidizing gas is U ₀ , the second fluidized region has U _The fluidizing gas is injected at a flow rate at which ₀ / U _mf is 1 or more and less than 2, and the fluidizing gas is injected at a flow rate at which U ₀ / U _mf is 2 or more and less than 5 in the first flow region. , Waste disposal methods.

Images