WO2011161948A1

WO2011161948A1 - Fluidized bed furnace and waste processing method

Info

Publication number: WO2011161948A1
Application number: PCT/JP2011/003528
Authority: WO
Inventors: 卓也松村; 博之細田; 伊藤　正
Original assignee: 株式会社神鋼環境ソリューション
Priority date: 2010-06-22
Filing date: 2011-06-21
Publication date: 2011-12-29
Also published as: EP2587147A4; PL2587147T3; CN102947647A; EP2587147B1; US20130098277A1; EP2587147A1

Abstract

The disclosed fluidized bed furnace is characterized by: forming a first fluid region (15), which is fluidized to a degree that waste (18) at the top of fluid particles (12) can be retained, by means of blowing fluidization gas in from the periphery of a mixture discharge port (29); forming a second fluid region (16) that has a higher degree of fluidization of fluid particles (12) than the first fluid region (15) does by means of blowing fluidization gas in between the first fluid region (15) and a reverse-side wall (25) at a high flow rate, and as a result the fluid particles (12) mix with the waste (18) and cause said waste (18) to be gasified; and supplying the waste (18) from a supply-side wall (24) to the fluidized bed (14) in a manner such that the waste (18) is retained over the first fluid region (15) and the retained waste (18) progressively advances into the second fluid region (16).

Description

Fluidized bed furnace and waste treatment method

The present invention relates to a fluidized bed furnace for extracting 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, a fluidized bed furnace described in Patent Document 1 is known. As shown in FIG. 9, this fluidized bed furnace has a furnace body 104 having fluidized sand (fluidized particles) 102 at the bottom of the furnace, and fluidized sand at the bottom of the furnace for fluidizing the fluidized sand 102 to form a fluidized bed. An air supply unit 106 for supplying air into the air supply 102. The furnace body 104 has side walls. The side wall is provided with a charging unit 108 for charging waste onto the fluidized bed.

In the fluidized bed furnace 100, the air supply unit 106 supplies air into the high-temperature fluidized sand 102. As a result, the fluidized sand 102 is floated and fluidized to form a fluidized bed. At this time, in the air supply unit 106, the fluidized state of the fluidized sand 102 is substantially the entire fluidized bed so that the waste introduced into the fluidized bed from the input unit 108 is taken into the bed and burned efficiently. Supply air so that it is constant.

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

The waste thrown into the fluidized bed furnace 100 is taken into an active fluidized bed and burned or gasified. At this time, every time the waste is intermittently added, the combustible in the waste burns rapidly, so that sudden fluctuations in the amount and concentration of the generated combustible gas are repeated. This change in gasification reaction is highly dependent on the quantitative nature of the waste supply. For this reason, combustible gas cannot be generated stably when there is a change in waste supply or change in waste quality. 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. For this reason, stabilization of the combustible gas obtained in a fluidized bed furnace is calculated | required more.

Japanese Unexamined Patent Publication No. 2006-242454

An object of the present invention is 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.

According to one aspect of the present invention, there is provided a fluidized bed furnace for heating the waste and taking out the combustible gas from the waste, the fluidized particles constituting the fluidized bed for heating the waste, A bottom wall that supports fluid particles from below and a side wall that rises from the bottom wall, and the bottom wall is heated in a non-combustible manner in the waste and the waste at a position biased in a specific direction from the center position thereof. A mixture discharge port for discharging the generated carbide together with the fluidized particles is provided, and the top surface of the bottom wall is disposed on the top surface of the bottom wall so as to descend the fluidized particles toward the mixture discharge port. A furnace body that is inclined so as to become lower toward the outlet; a gas supply section that fluidizes the fluidized particles by blowing fluidized gas from the bottom wall of the furnace body toward the fluidized particles; and the side wall 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 same side as the mixture discharge port with respect to the center position of the bottom wall. A waste supply unit that moves the waste to the side of the opposite side wall that is located on the opposite side of the mixture discharge port across the center position of the bottom wall of the side wall. The gas supply section has a first fluidization region having a fluidization degree such that waste can be retained on the upper side of the fluidized particles by blowing the fluidizing gas from the periphery of the mixture discharge port. And the fluidized gas is blown between the first fluidized region and the opposite side wall at a flow rate higher than the fluidized gas blown velocity in the first fluidized region. The fluidized particles have a higher degree of fluidization than the one fluidized region, thereby forming a second fluidized region in which the fluidized particles are convected and mixed with the waste to gasify the waste, The waste supply unit has the waste from the supply side wall so that the waste stays on the first flow region and the stayed waste sequentially enters the second flow region. Waste for fluidized bed To supply the goods.

FIG. 1 is a schematic configuration diagram of a fluidized bed furnace according to the present embodiment. FIG. 2 is a cross-sectional view of the furnace main body for explaining the waste insertion position, the fluid particle insertion position, and the carbide insertion position in the fluidized bed furnace. FIG. 3 is a view for explaining the arrangement of nozzles on the bottom wall of the furnace body. FIG. 4 is a view for explaining a furnace main body in a fluidized bed furnace according to another embodiment and having a reflection portion on a front wall. FIG. 5 is a view for explaining a furnace main body in a fluidized bed furnace according to another embodiment and having a guide portion on a rear wall. FIG. 6 is a diagram for explaining a furnace main body in a fluidized bed furnace according to another embodiment having a roof portion on a front wall and a rear wall. FIG. 7 is a view for explaining a furnace body including a thermometer and an air supply unit in a fluidized bed furnace according to another embodiment. FIG. 8 is a diagram for explaining a waste supply unit in a fluidized bed furnace according to another embodiment. FIG. 9 is a schematic configuration diagram of a 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 takes out 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, a sand circulation device 50, and a carbide insertion device 60. .

The fluidized particles 12 constitute a fluidized bed 14 inside the furnace body 20 and heat the waste 18. That is, when the fluidized particles 12 heated to a high temperature by the combustion of a part of the waste 18 are mixed with the waste 18, the waste 18 is gasified to generate a combustible gas. The fluidized particles 12 of this embodiment are silica sand or the like.

The furnace body 20 has fluid particles 12 inside, and takes out combustible gas from the waste 18 by the high temperature fluid 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 (opposite side wall) 25 that are opposed to each other at the front and rear (left and right in FIG. 2). It has

horizontal walls

26 and 26 that connect the end portions of the front wall 24 and the rear wall 25, respectively. 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.

The side wall (front wall) 24 located on the same side as the mixture discharge port 29 with respect to the center position of the bottom wall 21 of the side wall 22 has a sand insertion portion 27 and a waste insertion port 28. The sand insertion portion 27 inserts the fluidized particles 12 into the furnace body 20, and the waste insertion port 28 inserts the waste 18 into the furnace body 20. Further, the side wall (rear wall) 25 located on the side opposite to the mixture discharge port 29 across the center position of the bottom wall 21 of the side wall 22 has a carbide insertion portion 63. The carbide insertion portion 63 inserts carbide (for example, char) generated by heating the waste 18 into the furnace body 20.

Specifically, the sand insertion portion 27 is located on the front wall 24 side in the furnace body 20 and in the width direction center portion so that the flowing particles can be inserted (see FIG. 2). Provided. The sand insertion portion 27 is provided from the upper side of the fluidized particles 12 (fluidized bed 14) supported by the bottom wall 21 of the furnace body 20 to the fluidized bed 14 (specifically, the waste 18 that is supplied and retained on the fluidized bed 14). ) Is provided at a height position where the flowing particles 12 can be introduced. By providing the sand insertion portion 27 at such a position, the fluidized particles 12 can be put on the waste 18 staying on the fluidized bed 14. Thereby, only the flammable garbage in the waste 18 is stably burned (gasified) first with the fluidized particles 12 as an ignition source. The place where the flowing particles 12 are introduced is not limited to the front wall 24 but may be provided on the rear wall 25 or the lateral wall 26.

The carbide insertion portion 63 is provided in the center portion in the width direction at the lower portion of the rear wall 25 so that the carbide can be inserted into the center portion in the width direction on the rear wall 25 side in the furnace body 20 (see FIG. 2). The carbide insertion portion 63 is provided at a height where the carbide can be charged from above the fluidized bed 14 in the furnace body 20 toward the fluidized bed 14. In addition, the carbide | carbonized_material insertion part 63 may be provided in the intermediate | middle height position of the fluidized bed 14 in an up-down direction. If the carbide insertion portion 63 is provided at such a position, the carbide is directly inserted into the fluidized bed 14. For this reason, even if a light carbide that stays on the fluidized bed 14 and is not easily mixed with the fluidized particles 12 when the carbide is introduced from above the fluidized bed 14, it is reliably inserted into the fluidized bed 14. Ensure gasification.

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

The combustible gas discharge unit 23 discharges the combustible gas generated in the furnace body 20. This combustible gas discharge part 23 has an outer diameter narrower 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, for example, a gas engine of a power generation process in the subsequent stage can be connected. Yes.

The bottom wall 21 has a mixture discharge port 29 for discharging incombustibles in the waste 18 and carbides generated by heating the waste 18 together with the fluidized particles 12 at a position deviated from the center position in a specific direction. The mixture discharge port 29 opens over the entire width direction in the bottom wall 21. The upper surface 21a of the bottom wall 21 is inclined so as to become lower toward the mixture outlet 29 so that the fluidized particles 12 descend on the upper surface 21a. The bottom wall 21 of the present embodiment has a mixture discharge port 29 at a position biased to the front side, and the upper surface 21a of the bottom wall 21 moves downward (from left to right in FIG. 1) at a certain level. It is a 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. By providing the mixture discharge port 29 at such a position, the mixture settles from the waste 18 inserted in the region adjacent to the front wall 24 on the fluidized bed 14 from the waste insertion port 28 provided in the front wall 24. Incombustibles and carbides are efficiently discharged out of the furnace body 20. Incombustible materials and carbides that settle in the fluidized bed 14 from the waste 18 that has diffused toward the rear wall 25 on the fluidized bed 14 also descend to the mixture discharge port 29 along the inclination of the upper surface 21 a of the bottom wall 21. For this reason, incombustibles and carbides settled on the rear wall 25 side are also easily discharged out of the furnace body 20.

Also, the top wall 21a of the bottom wall 21 is inclined so as to become lower toward the mixture discharge port 29. For this reason, during the operation of the fluidized bed furnace 10, the fluidized particles 12 move from the rear wall 25 toward the front wall 24 in a region adjacent to the upper surface 21 a of the fluidized bed 14.

The gas supply unit 30 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 grid pattern 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 the present embodiment, as shown in FIG. 3, the bottom wall 21 is divided into a rear region 21b and a front region 21c. And each nozzle 31 is arrange | positioned in each area | region 21b, 21c so that the number of the nozzles 31 provided in the back side area | region 21b may be larger than the number of the nozzles 31 provided in the front side area | region 21c. In addition, the magnitude | size of the number of the nozzles 31 between the area | regions 21b and 21c is not limited. For example, the number of nozzles 31 in the front region 21c and the number of nozzles 31 in the rear region 21b may be the same. Further, the number of nozzles 31 in the front region 21c may be larger than the number of nozzles 31 in the rear region 21b.

The wind box 32 has a box shape extending in the width direction and serves as a header for distributing the fluidized gas to the nozzles 31 arranged in the width direction on the bottom wall 21. The air box 32 has a function of making the flow rate of the fluidized gas blown out from the nozzles 31 arranged in the width direction 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, for each nozzle 31 corresponding to each wind box 32, the flow rate of the fluidized gas blown from the nozzle 31 can be changed. In the present embodiment, five

wind boxes

32a, 32b, 32c, 32d, and 32e are arranged in the front-rear direction. Specifically, four

wind boxes

32a, 32b, 32c, and 32d are arranged on the rear wall 25 side of the mixture discharge port 29, and one wind box 32e is arranged on the front wall 24 side of the mixture discharge port 29. ing.

The blower 33 blows (supplies) fluidized gas to each wind box 32. The blower 33 can blow the fluidizing gas at different flow rates 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 blower 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 33 is connected to the mixture outlet 29. The fluidizing gas is blown from the surroundings. At this time, the air blowing unit 33 forms the first flow region 15 having a fluidization degree to the extent that the waste 18 can stay above the fluidized particles 12. At the same time, the blower 33 blows fluidized gas between the first fluidized region 15 and the rear wall 25 at a flow rate higher than the fluidized gas blown velocity in the first fluidized region 15. The second fluidized region 16 having a higher degree of fluidization of the fluidized particles 12 than the first fluidized region 15 is formed. That is, as described above, the air blowing unit 33 has a rear air box (for example, a flow rate of fluidized gas blown to the front air box (for example, 32c) with respect to the air box 32 adjacent in the front-rear direction (for example, The flow rate of the fluidizing gas blown to 32b) is increased. As a result, the blower 33 forms the first fluidized region 15 in which the fluidized state is suppressed around the mixture discharge port 29 in the fluidized bed 14, and between the first fluidized region 15 and the rear wall 25. A second flow region 16 in which flow is active is formed. Further, the air blowing unit 33 makes the flow rate of the fluidizing gas supplied to the

wind boxes

32c, 32d, 32e on the front wall 24 side constant, and fluidizes the flow rate supplied to the

wind boxes

32a, 32b on the rear wall 25 side from this flow rate. The gas flow rate may be increased. As a result, the air blowing section 33 forms the first flow region 15 in which flow is suppressed in the region corresponding to the

wind boxes

32c, 32d, and 32e on the front wall 24 side in the fluidized bed 14, and the wind on the rear wall 25 side. A second flow region 16 in which flow is active is formed in a region corresponding to the

boxes

32a and 32b.

Specifically, in the first flow region 15, the blower unit 33 blows the fluidizing gas at a flow rate at which U _o / U _mf is 1 or more and less than 2, and in the second flow region 16, 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 fluidization speed that is the minimum flow velocity of the fluidization gas blowing for fluidizing the fluidized particles 12. _Uo is the average cross-sectional flow velocity of the fluidized 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 main body 20 is stopped, the blower 33 is an inert gas to the air as a fluidizing gas supplied to each wind box 32. Blow the mixture. And the ventilation part 33 makes an inert gas gradually increase the ratio of the air and inert gas in fluidization gas. Thereby, the blower 33 suppresses the waste 18 remaining in the furnace body 20 from burning violently, and suppresses the temperature rise in the furnace body 20.

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 body 20 is stopped in this state, the amount of combustible material in the furnace body 20 decreases. At this time, since the fluidizing gas (air) is supplied at a predetermined flow rate in order to maintain the fluidized bed 14 in the furnace body 20, the oxygen concentration in the furnace body 20 becomes high. 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 body 20 is kept lower than a value suitable for the combustion of the waste 18. As a result, the waste 18 remaining in the furnace body 20 can be prevented from burning violently.

Furthermore, 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 high-temperature fluidized gas from the portion corresponding to the second fluidized region 16 toward the fluidized particles 12. In this way, the blower 33 heats the fluidized particles 12 until the temperature reaches a temperature at which the waste 18 can be combusted and gasified. 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. For this reason, the air blower 33 may lower the temperature of the fluidized gas blown to the wind box 32 when the combustion starts.

The waste supply unit 40 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 2 to the flow region 16 side. That is, the waste supply unit 40 pushes the waste 18 so that the waste 18 stays on the first flow region 15 and the stayed waste 18 sequentially enters the second flow region 16. I do. 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 the present 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. Further, the length of the pushing surface 42 in the vertical direction is substantially half of the opening height of the waste insertion port 28. The pusher 41 is installed to be movable in the front-rear direction at the same height position 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. However, the waste supply unit may be configured to push the waste 18 into the furnace by a screw pusher or the like (see FIG. 8A). By using the pusher 41 and the screw pusher, dust having a small bulk specific gravity such as paper or plastic sheet and easily scattered is supplied into the furnace body 20 as a lump. Thereby, compared with the case where garbage is thrown in from the upper part of the conventional furnace, scattering of the garbage in the furnace main body 20 is suppressed.

The sand circulating device 50 circulates the fluidized particles 12 by separating the fluidized particles 12 from the mixture of incombustibles, carbides, and fluidized particles 12 discharged from the mixture outlet 29 and returning them to the furnace body 20. In this manner, the sand circulating device 50 separates the high temperature fluidized particles 12 from the mixture and returns them to the furnace body 20, thereby maintaining the amount of fluidized particles 12 constituting the fluidized bed 14 in the furnace body 20. It becomes easy to maintain the temperature of the fluidized bed 14. The sand circulation device 50 includes a mixture discharge unit 51, a fluid particle separation unit 52, and a fluid particle transport unit 53.

The mixture discharge unit 51 is provided below the mixture discharge port 29 of the bottom wall 21, and moves the mixture of the incombustible material, the carbide, and the fluidized particles 12 that have dropped from the mixture discharge port 29 to the fluidized particle separation unit 52. The mixture discharge part 51 of this embodiment moves the mixture which has fallen from the mixture discharge port 29 to the fluid particle separation part 52 with a screw pushing machine. The fluid particle separation unit 52 separates the fluid particles 12 from the mixture sent from the mixture discharge unit 51. The fluid particle separator 52 of this embodiment separates the fluid particles 12 from the mixture using a sieve. The fluidized particle separation unit 52 sends the mixture after separating the fluidized particles 12 to the carbide separation unit 61. The fluidized particle transport unit 53 transports the fluidized particles 12 separated in the fluidized particle separation unit 52 to the sand insertion unit 27 of the furnace body 20 and inserts the fluidized particle 12 into the furnace body 20 from the sand insertion unit 27.

In addition, although the sand circulation apparatus 50 of this embodiment has thrown the fluid particle | grains 12 toward the upper surface of the said fluidized bed 14 from the upper direction of the fluidized bed 14, it is not limited to this. The sand circulation device may return the fluidized particles 12 to the fluidized bed 14 by pushing directly into the fluidized bed 14.

The carbide insertion device 60 separates carbide from the mixture discharged from the mixture discharge port 29, and returns the separated carbide into the furnace body 20 from the rear wall 25 side. In this way, the carbide layer insertion device 60 returns the carbide discharged from the mixture discharge port 29 to the second flow region 16, thereby obtaining a combustible gas from the carbide discharged together with the incombustible material outside the furnace body 20. Is possible. As a result, combustible gas can be efficiently obtained from the waste 18 supplied to the fluidized bed furnace 10. Further, the temperature of the second flow region 16 is maintained at a high temperature by heat generated when the carbide is gasified. The carbide insertion device 60 includes a carbide separation unit 61 and a carbide conveyance unit 62.

The carbide separator 61 separates the carbide from the mixture sent from the fluidized particle separator 52. The carbide separation unit 61 of the present embodiment separates carbides from the mixture after the fluidized particles 12 are separated in the fluidized particle separation unit 52. The carbide separator 61 is, for example, a specific gravity separator that separates carbides from the mixture by vibration. The carbide conveying unit 62 conveys the carbide separated in the carbide separating unit 61 to the carbide inserting unit 63 of the furnace body 20, and inserts the conveyed carbide into the furnace main body 20 from the carbide inserting unit 63.

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

Blower 33 supplies 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 blower 33 adjusts the flow rate of the fluidizing gas blown to each wind box 32. Thereby, in the fluidized bed 14, the first fluidized region 15 in which the fluid is suppressed is formed on the mixture discharge port 29 side, and the fluid is actively flowed between the first fluidized region 15 and the rear wall 25. A flow region 16 is formed. Further, the blower unit 33 supplies a high-temperature fluidizing gas to the wind box 32 (in this embodiment, for example, the

wind boxes

32a and 32b) corresponding to the second flow region 16, and The fluidized particles 12 are actively heated. At this time, movement of the fluidized particles 12 from the second region 16 to the first region 15 in the region near the upper surface 21a of the fluidized bed 14 caused by the inclination of the upper surface 21a of the bottom wall 21 causes the first fluidized region 15 to move to the first fluidized region 15. Heat is supplied.

In this way, the temperature of each of the

regions

15 and 16 of the fluidized bed 14 formed in the furnace body 20 is a predetermined temperature (in this embodiment, the temperature of the second fluidized region 16 is about 600 ° C. to 800 ° C. When the temperature of the first flow region 15 reaches about 400 ° C. to 600 ° C.), the waste supply unit 40 starts to push the waste 18 into the furnace body 20 from the waste insertion port 28. Specifically, the pusher 41 driven by the driving unit pushes the waste 18 sideways toward the rear wall 25 side. Thereby, the waste 18 is pushed into the area adjacent to the front wall 24 on the first flow area 15 (see FIG. 2).

The flow of the fluidized particles 12 in the first fluidized region 15 is suppressed. For this reason, the pushed waste 18 is not positively mixed with the fluidized particles 12, and most of the waste 18 stays on the first fluidized region 15, and a part of heavy incombustibles and carbides settle. Therefore, in the first flow region 15, the rapid combustion of the waste 18 is suppressed, and what is easily gasified in the waste 18 is gasified by thermal radiation in the furnace body 20. That is, the waste 18 that is easily gasified, such as plastic or paper, is gasified while moving on the surface layer of the first flow region 15. That is, the waste 18 that is easily gasified, such as plastic or 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 second flow region 16 without being gasified. In this way, the waste 18 that is easily gasified is gasified in a gentle condition in the first fluidized region 15 before reaching the intense fluidized bed (second fluidized region 16). Thereby, the fluctuation | variation of the combustible gas to generate | occur | produce is suppressed. Further, the heavy incombustible material settles in the first flow region 15 and is discharged from the mixture discharge port 29 as it is. For this reason, incombustibles do not easily stay in the hearth. On the other hand, some of the waste that is difficult to gasify, such as a piece of wood, may be carbonized by passing through the first flow region 15 and discharged from the mixture discharge port 29. The staying waste 18 is burned by the temperature in the furnace body 20 (heat of the free board portion) as described above. However, although the temperature in the furnace body 20 is 800 ° C. to 900 ° C. and higher than the fluidized particles 12 forming the fluidized bed 14, the contact between the waste 18 and the air is not good. For this reason, 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 first flow region 15 is small, even the flammable garbage is gradually gasified. Further, due to the flow of the fluidized particles 12 by the fluidizing gas, a part of the staying waste 18 moves little by little from the first fluidized region 15 to the second fluidized region 16 (from the right side to the left side in FIG. 1) or Spread. For this reason, even when the waste 18 is put in a lump and there is a flammable paper inside, the paper is gasified by coming out to the surface side of the lump at the time of diffusion. In this way, in the first flow region 15, the rapid combustion of the waste 18 is suppressed, and a rapid increase in combustible gas when the waste 18 is inserted is prevented.

Next, new waste 18 is pushed into the furnace body 20 from the waste insertion port 28 by the pusher 41. As a result, the waste 18 staying on the first flow region 15 is pushed by the pushed new waste 18 and sequentially enters the second region 16 side. In the second flow region 16, since the flow is active and the temperature of the waste 18 is increased due to the combustion of the waste 18, the waste 18 that has entered from the first flow region 15 is mixed with the fluidized particles 12 and is sufficiently gasified. To be done. Thereby, combustible gas is generated. Specifically, in the fluidized bed 14, the fluidized state gradually becomes active from the front wall 24 toward the rear wall 25. For this reason, the waste 18 is gradually mixed with the fluidized particles 12 as it proceeds from the region adjacent to the front wall 24 on the first fluidized region 15 to the second fluidized region 16. Further, the amount of air (fluidized gas) blown into the fluidized bed 14 from the front wall 24 toward the rear wall 25 increases. For this reason, as the waste 18 advances from the first fluidized region 15 to the second fluidized region 16, it burns and the temperature of the fluidized particles 12 increases. The waste 18 is sufficiently mixed with the fluidized particles 12 in the high-temperature second fluidized region 16. Thereby, the gasification of the waste 18 left unburned in the first flow region 15 is sufficiently performed in the second flow region 16.

On the other hand, the waste 18 newly pushed onto the first fluidized area 15 by the pusher 41 stays on the first fluidized area 15 without being mixed with the fluidized particles 12 as described above. The waste 18 gradually burns in a state where intense combustion is suppressed.

As described above, the waste 18 is pushed in one after another by the pusher 41 in the 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.

The incombustibles and carbides that have settled in the first fluidized zone 15 are discharged together with the fluidized particles 12 from a mixture outlet 29 provided on the lower side of the first fluidized zone 15. Incombustible materials and carbides that have settled in the second flow region 16 are inclined so that the upper surface 21a of the bottom wall 21 has a downward slope toward the mixture discharge port 29, and thus descend along this. Move to the mixture outlet 29. The moved incombustibles and carbides are discharged together with the fluidized particles 12. The sand circulation device 50 separates the fluidized particles 12 from the mixture discharged from the mixture discharge port 29 and inserts the separated fluidized particles 12 into the furnace body 20. At the same time, the carbide insertion device 60 separates carbide from the mixture discharged from the mixture discharge port 29 and inserts the separated carbide into the furnace body 20. Specifically, the mixture discharge unit 51 sends the mixture that has dropped from the mixture discharge port 29 of the furnace body 20 to the fluidized particle separation unit 52. The fluidized particle separation unit 52 separates the fluidized particles 12 from the mixture, and the fluidized particle conveyance unit 53 conveys the fluidized particles separated by the fluidized particle separation unit 52 to the sand insertion unit 27 of the furnace body 20. Thereby, the amount of the fluidized particles 12 forming the fluidized bed 14 is maintained in the furnace body 20. On the other hand, the fluid particle separator 52 sends the mixture from which the fluid particles 12 are separated to the carbide separator 61, and the carbide separator 61 separates the carbide from the mixture. The carbide conveying unit 62 conveys the carbide separated by the carbide separating unit 61 to the carbide inserting unit 63 of the furnace body 20. Thereby, the carbide | carbonized_material discharged | emitted from the furnace main body 20 with the incombustible substance can be returned in the furnace main body 20, and can be gasified. As a result, according to the fluidized bed furnace 10, combustible gas can be efficiently obtained from the waste 18.

When the fluidized bed furnace 10 stops, 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 causes the inert gas to gradually increase the ratio of the air and the inert gas in the fluidized gas with the passage of time. In this way, the air blowing unit 33 suppresses the oxygen concentration in the furnace body 20 and suppresses the waste 18 remaining in the fluidized bed 14 from burning violently.

In the present embodiment, when the fluidized bed furnace 10 is stopped, the ratio of the inert gas in the fluidized gas is gradually increased so that intense combustion of the waste 18 remaining in the fluidized bed 14 is suppressed. . However, when the fluidized bed furnace 10 is stopped, the remaining waste 18 may be prevented from burning by spraying water on the fluidized bed 14.

According to the fluidized bed furnace 10 described above, even if the waste 18 contains a lot of flammable garbage, intermittent and rapid generation of combustible gas is suppressed, and generation of the gas is stabilized. Specifically, in the fluidized bed 14, a first region 15 around the mixture outlet 29 and a second fluidized region 16 having a higher degree of fluidization than the first region 15 are formed. In this state, new waste 18 is pushed onto the first flow region 15. The waste 18 in which the new waste 18 stays on the first fluidized area 15 is made to enter the second fluidized area 16 in order. The above operation is repeated. Thereby, in the fluidized-bed furnace 10, the waste 18 is fully gasified while suppressing a rapid fluctuation of the obtained combustible gas. As a result, combustible gas can be stably generated from the waste 18. In addition, since the waste 18 is not exposed to the active fluidized bed 14 (second fluidized region 16) immediately after being introduced into the furnace body 20, a large amount of light waste rises into the furnace body 20 and suddenly rises in the free board section. Combustion can be suppressed.

Further, the first flow region 15 is formed above the mixture discharge port 29 and the waste 18 is supplied to the upper side thereof, so that the waste 18 is retained on the first flow region 15 and the waste is discharged. The flammable garbage in 18 is slowly gasified. Even if incombustibles and carbides sink to the furnace bottom while the flammable garbage is gasified, the incombustibles and carbides can be easily discharged from the furnace body 20. Moreover, even if incombustibles and carbides sink to the bottom wall 21 after the waste 18 enters the second flow region 16 from the first flow region 15, the waste 18 is inclined toward the mixture discharge port 29. Incombustible materials and carbides descend along the bottom wall upper surface 21a. For this reason, these incombustibles and carbides can be easily discharged. Further, since the fluidizing gas is actively supplied in the second flow region 16, this also promotes the descent toward the mixture outlet 29 of incombustibles and carbides.

The furnace body 20 has a planar shape in which the dimension in the width direction is uniform in the pushing direction of the waste 18. For this reason, when the waste 18 on the first flow region 15 is pushed by the waste 18 newly pushed from the waste supply unit 40 and enters the second flow region 16 side, the waste 18 The movement is stable.

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. . Thereby, the pushing surface 42 pushes the waste 18 onto the fluidized bed 14 uniformly in the width direction. Therefore, the movement of the waste 18 from the first flow region 15 to the second flow region 16 becomes substantially uniform in the width direction, and it is possible to prevent the waste 18 from concentrating on a part of the furnace.

It should be noted that the fluidized bed furnace and the waste treatment method of the present invention are not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the gist of the present invention.

The side wall 22 of the above embodiment rises straight from the bottom wall 21 to the combustible gas discharge part 23, but is not limited to this. For example, as shown in FIG. 4, the front wall 24 </ b> A may include a reflecting portion 224 that extends toward the rear wall 25 so as to cover the upper part of the first flow region 15 at a predetermined height position. According to the front wall 24 </ b> A, the waste 18 staying on the first flow region 15 is heated by the radiant heat from the reflecting portion 224. As a result, combustible gas can be generated from the waste 18 staying on the first flow region 15. That is, the gasification of the waste 18 staying on the first flow region 15 is promoted. In this case, the sand insertion portion 27 may be provided in a portion of the front wall 24A that stands vertically from the bottom wall 21 or may be provided in the reflection portion 224.

Further, as shown in FIG. 5, the rear wall 25 </ b> A may include a guide portion 225 that extends toward the front wall 24 so as to cover the upper part of the second flow region 16 at a predetermined height position. The guide unit 225 guides the combustible gas so that the high-temperature combustible gas generated from the waste 18 in the second flow region 16 contacts the waste 18 staying on the first flow region 15. Thereby, the guide part 225 makes combustible gas contribute to the heating of the waste 18 on the said 1st flow area | region 15. FIG. As a result, gasification of the waste 18 staying on the first flow region 15 is promoted without adding any special heating means to the furnace body 20. In this case, the carbide insertion portion 63 may be provided at a portion of the rear wall 25 that stands vertically from the bottom wall 21 or may be provided at the guide portion 225.

Further, as shown in FIG. 6, the front wall 24B and the rear wall 25B may include

roof portions

324 and 325 extending in directions approaching each other at the same height position. According to the front wall 24B and the rear wall 25B, the waste 18 staying on the first flow region 15 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 this case, the sand insertion portion 27 may be provided in a portion of the front wall 24B that stands vertically from the bottom wall 21 or may be provided in the roof portion 324. Further, the carbide insertion portion 63 may be provided in a portion of the rear wall 25B that is vertically rising from the bottom wall 21 or may be provided in the roof portion 325.

In the above embodiment, only the carbide is inserted from the carbide insertion portion 63 into the furnace main body 20, but the carbide may be inserted together with the fluidized particles 12 from the carbide insertion portion 63 into the furnace main body 20.

Moreover, although the carbide | carbonized_material insertion apparatus 60 of the said embodiment inserts the carbide | carbonized_material isolate | separated from the mixture into the furnace main body 20 as it is from the carbide | carbonized_material insertion part 63, you may insert into the furnace main body 20 after crushing the isolate | separated carbide | carbonized_material. . Thereby, even if the carbide | carbonized_material discharged | emitted from the mixture discharge port 29 is a big lump, it can be made into the predetermined magnitude | size which is easy to gasify by heating, and can be returned in the furnace main body 20. FIG.

Further, the upper surface 21 a of the bottom wall 21 may be curved without being inclined straight from the rear wall 25 toward the mixture discharge port 29.

As shown in FIG. 7, a plurality of thermometers T may be disposed above the first flow region 15, and an air supply unit 65 capable of supplying air may be provided on the first flow region 15. . According to such a configuration, it is possible to estimate the staying amount of the waste 18 staying on the first flow region 15, and to control this staying amount. Specifically, the retention value of the waste 18 on the first flow region 15 is estimated by utilizing 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, the air supply unit 65 supplies air to raise the temperature in the furnace body 20. Then, gasification of the waste 18 staying on the first flow region 15 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, dust is detected at the position of the thermometer T. The amount of air may be controlled by determining that it is present (buried in garbage). Moreover, instead of controlling the amount of air, the amount of waste supplied may be controlled.

In the above embodiment, the air blowing unit 33 blows air or inert gas as fluidized gas, but is not limited thereto. For example, the blower 33 may blow steam or oxygen as fluidized gas according to the combustion state in the furnace body 20. 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, the fluidizing gas supplied to the first fluidizing region 15 may be a high temperature fluidizing gas. Even when the first fluidized region 15 cannot be maintained at a necessary temperature only by the heat transmitted from the second fluidized region 16 by supplying the high-temperature fluidized gas, the supply amount of the fluidized gas is reduced. The temperature of the first flow region 15 can be kept high without increasing it.

In the above-described embodiment, the waste insertion port 28 is provided at a height position that partially overlaps the waste 18 staying on the fluidized bed 14 in the vertical direction, and is supplied from the waste insertion port 28. Although the waste 18 stays on the upper surface of the fluidized bed 14 is positively moved in the lateral direction (first fluidized region 15 side), the present invention is not limited to this. That is, the fluidized bed furnace 10 may be configured so that the waste 18 can be supplied to a region adjacent to the front wall (supply side wall) 24 on the fluidized bed 14. For example, as shown in FIGS. 8 (A) and 8 (B), the waste insertion port 28 is located at a height near the upper surface of the fluidized bed 14 and above the waste 18 staying on the fluidized bed 14. It may be provided at a height position where the new waste 18 is inserted so as to be placed thereon. In this case, as shown in FIG. 8A, for example, the waste insertion port 28 is provided so that new waste 18 can be supplied laterally from a height position above the waste staying on the fluidized bed 14. May be. Further, as shown in FIG. 8B, the waste insertion port 28 may be provided so that new waste 18 can be supplied downward from above the waste 18 staying on the fluidized bed 14. Even if the waste 18 is supplied into the furnace main body 20 as described above, a new waste 18 is supplied onto the staying waste 18, so that the pile of the waste 18 collapses and expands, and the second flow. Waste 18 enters the region 16 side. For this reason, the waste 18 is sufficiently gasified while the rapid fluctuation of the combustible gas recovered from the fluidized bed furnace 10 is suppressed. As a result, combustible gas is stably generated from the waste 18.

Moreover, in the said embodiment, when an incombustible substance stays in the vicinity of the mixture discharge port 29 of the hearth (upper surface 21a of the bottom wall 21) and is not discharged | emitted outside, in order to discharge | emit this outside, it is only a fixed period. Also in one flow region 15, 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 this case, the fluidizing gas is not uniformly blown in the first flow region 15, but from the rear wall 25 side (left side in FIG. 1) to the front wall 24 side (right side in FIG. 1). It is preferable that the wind box 32 in which the supply amount of the fluidizing gas is larger than the flow rate during normal operation is sequentially changed. By such an operation, even if an incombustible material stays in the vicinity of the mixture outlet 29 of the hearth during normal operation, the incombustible material is 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.

[Outline of the embodiment]
The above embodiment is summarized as follows.

That is, the fluidized bed furnace according to the above embodiment 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 that supports the fluidized particles from below and a side wall that rises from the bottom wall, the non-combustible material in the waste and the waste in the waste A mixture discharge port is provided for discharging carbide generated by heating together with the fluidized particles, and the upper surface of the bottom wall is disposed on the top surface of the bottom wall so as to lower the fluidized particles toward the mixture discharge port. A furnace body inclined to become lower toward the mixture discharge port, a gas supply section for fluidizing the fluidized particles by blowing fluidized gas from the bottom wall of the furnace body toward the fluidized particles, and The waste is supplied from the supply side wall located on the same side as the mixture outlet to the center position of the bottom wall of the wall to the region adjacent to the supply side wall on the fluidized bed, thereby A waste supply unit that moves waste on a fluidized bed to the side of the opposite side wall that is located on the opposite side of the mixture discharge port across the center position of the bottom wall of the side wall, and the gas supply The part forms a first fluidized region having a fluidization degree such that waste can be retained on the upper side of the fluidized particles by blowing the fluidized gas from the periphery of the mixture discharge port. By blowing fluidizing gas between the first fluidized region and the opposite side wall at a flow rate higher than the fluidizing gas blowing rate in the first fluidized region, Also said fluid particles The degree of fluidization is high, whereby the fluidized particles convect and mix with the waste to form a second fluidized region that gasifies the waste, and the waste supply unit The waste is retained on the fluidized zone, and the waste is supplied from the supply side wall to the fluidized bed so that the retained waste sequentially enters the second fluidized region. It is characterized by performing.

According to this fluidized bed furnace, a first region around the mixture outlet and a second fluidized region having a higher degree of fluidization than the first region are formed in the fluidized bed. Then, the waste supply section is on the fluidized bed so that the waste stays on the first fluidized area, and the waste accumulated on the first fluidized area is sequentially sent to the second fluidized area side. Waste is supplied to an area adjacent to the supply side wall. As a result, the waste is sufficiently gasified while suppressing rapid fluctuations in the combustible gas recovered from the fluidized bed furnace, thereby stably generating the combustible gas from the waste.

Specifically, in the first flow region, since the flow is suppressed so that the waste can stay on the upper surface of the first flow region, the first flow is not mixed with the flow particles. The flammable garbage in the waste gasifies slowly while staying on the area. Therefore, in the first flow region, rapid combustion of waste is suppressed, and thereby generation of combustible gas due to rapid gasification of waste is suppressed. The waste staying on the first fluidized area sequentially enters the second area by supplying new waste into the furnace body by the waste supply section. Then, in this second flow region, since the flow is active and the temperature is high due to the combustion of the waste, the waste that has entered from the first 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 the combustible gas is suppressed, and the generation of the gas is stabilized.

Also, a first flow region is formed above the mixture discharge port, and waste is supplied above the first flow region. For this reason, while the flammable garbage in the waste staying on the first flow region is slowly gasified, the non-combustible material in the waste and the carbide generated by the heating of the waste reach the furnace bottom. Even if it sinks, these incombustibles and carbides are easily discharged from the furnace body. In addition, even if incombustibles and carbides sink to the bottom wall after the waste enters the second flow region from the first flow region, along the top surface of the bottom wall inclined so as to become lower toward the mixture discharge port. Incombustibles and carbides fall. For this reason, these incombustibles and carbides are easily discharged from the furnace body.

In addition, since the upper surface of the bottom wall is inclined so as to be lowered toward the mixture discharge port (that is, inclined so as to be lowered from the second region toward the first region), The hot fluid particles descend on the top surface of the bottom wall toward the first fluid region. Thereby, heat is supplied to the first flow region.

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

According to such a configuration, new waste is pushed sideways toward the waste staying on the first flow region. For this reason, the waste which is pushed by the waste and stays on the first flow region surely enters the second flow region.

The fluidized bed furnace includes a carbide insertion device that separates the carbide from the mixture of the incombustible material, the carbide, and the fluidized particles discharged from the mixture discharge port and returns the carbide to the fluidized bed from the opposite side wall side. Are preferred.

According to such a configuration, the carbide insertion device returns the carbide discharged together with the flowing particles and the incombustible material from the mixture discharge port to the second flow region where the flow is active and high temperature. Thereby, combustible gas is obtained from the carbide. As a result, combustible gas can be efficiently obtained from the waste. In addition, the temperature of the second flow region is maintained at a high temperature by heat generated when the carbide is gasified.

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 air 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 first flow region, and U ₀ / U in the second flow region. It is preferable to blow the fluidizing gas at a flow rate at which _mf is 2 or more and less than 5. When the fluidizing gas is blown at such a flow rate, the first fluidized region and the second fluidized region that are preferable in the fluidized bed are formed. As a result, gasification of the waste is suitably performed while suppressing rapid combustion of the waste, and combustible gas can be stably obtained from the waste.

It is preferable to provide a sand circulation device that separates the flowing particles from the mixture discharged from the mixture discharge port and returns the separated flowing particles into the furnace body.

According to such a configuration, the sand circulating device separates the high-temperature fluidized particles from the mixture discharged from the mixture discharge port and returns it to the furnace body. As a result, the amount of fluidized particles constituting the fluidized bed is maintained and the temperature of the fluidized bed is easily maintained.

In this case, it is preferable that the sand circulation device returns the fluidized particles separated from the mixture onto the waste that remains on the first fluidized region.

According to such a configuration, the sand circulating device returns the high-temperature fluidized particles discharged from the mixture discharge port onto the waste staying on the first flow region. Thereby, flammable garbage in the waste is stably combusted (gasified) using the high-temperature fluidized particles as an ignition source.

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 first flow region is pushed by the waste newly supplied from the waste supply unit and enters the second flow region, the waste of the furnace main body Since the dimension in the width direction orthogonal to the moving direction is uniform, the movement of the waste is 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, the waste can be uniformly pushed in the width direction. For this reason, the movement of the waste from the first flow region to the second flow region becomes substantially uniform in the width direction. As a result, it is possible to prevent the waste from being concentrated in a part of the furnace.

In addition, the waste treatment method according to the above embodiment is a waste treatment method for heating waste to take out combustible gas from the waste, and includes a fluidized bed for heating the waste. A non-combustible material in the waste having a fluidized particle, a bottom wall supporting the fluidized particle from below, and a side wall rising from the bottom wall at a position deviated in a specific direction from the center of the bottom wall; And a mixture outlet for discharging carbide generated by heating the waste together with the fluidized particles, and the bottom of the fluidized particles descends on the upper surface of the bottom wall toward the mixture outlet. Providing a fluidized bed furnace having a furnace body inclined such that the upper surface of the wall is lowered toward the mixture outlet, and the flow from the region around the mixture outlet of the bottom wall of the furnace body particle A fluidizing gas is blown toward the fluidized particles to form a first fluidized region having a fluidization degree that allows waste to stay above the fluidized particles, and the first fluidized region and the side wall. Fluidized at a flow rate higher than the flow rate of the fluidized gas blown in the first flow region between the mixture discharge port and the opposite side wall on the opposite side across the center position of the bottom wall Forming a second fluidized region having a higher degree of fluidization of the fluidized particles than the first fluidized region by blowing gas, and discharging the mixture with respect to a center position of the bottom wall among the side walls. Supplying the waste to a region adjacent to the supply side wall on the fluidized bed from a supply side wall located on the same side as the outlet, thereby retaining the waste on the first fluidized region; And the stay And waste are sequentially entered in the second flow region, characterized in that it comprises the steps of gasification, the by.

According to this waste treatment method, in the fluidized bed, a first region around the mixture discharge port and a second fluidized region having a higher degree of fluidization than the first region are formed. Then, the waste stays on the first flow region, and the waste staying on the first flow region sequentially enters the second flow region. Thereby, the gasification of the waste is sufficiently performed while the rapid fluctuation of the combustible gas recovered from the fluidized bed furnace is suppressed. As a result, combustible gas is stably generated from the waste.

Also, a first flow region is formed above the mixture discharge port, and waste is supplied to the upper surface thereof. Thereby, while the waste stays on the first flow region and the flammable garbage in the waste is slowly gasified, the non-combustible material in the waste and the carbide generated by heating the waste are generated. Even if it sinks to the furnace bottom, these incombustibles and carbides are easily and reliably discharged from the furnace body. In addition, even if incombustibles and carbides sink to the bottom wall after the waste enters the second flow region from the first flow region, along the top surface of the bottom wall inclined so as to become lower toward the mixture discharge port. Incombustibles and carbides fall. For this reason, these incombustibles and carbides are easily discharged from the furnace body.

In the gasification step, new waste is pushed laterally from the supply side wall toward the waste staying on the first flow region, and thereby the waste staying on the first flow region. It is preferable to sequentially gasify the object by entering the second flow region.

According to such a configuration, new waste is pushed sideways toward the waste staying on the first flow region. For this reason, the waste that is pushed by the waste and stays on the first flow region can surely enter the second flow region and be gasified.

The waste treatment method includes a step of separating carbide from a mixture of the incombustible material, the carbide, and the fluidized particles discharged from the mixture discharge port and returning the separated carbide to the fluidized bed from the opposite side wall side. Are preferred.

According to such a configuration, the carbide discharged together with the flowing particles and the incombustible material is separated from the mixture discharge port, and the flow is active and returned to the high temperature second flow region. Thereby, this carbide | carbonized_material is gasified reliably. Moreover, it becomes easy to maintain the temperature of the second fluidized region at a high temperature by heat generated when the carbide is gasified.

In the 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 first flow region, the fluidizing gas is blown at a flow rate such that U ₀ / U _mf is 1 or more and less than 2, and in the second flow region, the flow rate is such that U ₀ / U _mf is 2 or more and less than 5. It is preferred that the fluidizing gas is blown.

When the fluidizing gas is blown at such a flow rate, the first fluidized region and the second fluidized region that are preferable in the fluidized bed are formed. As a result, gasification of the waste is suitably performed while suppressing rapid combustion of the waste, and combustible gas can be stably obtained from the waste.

As described above, the fluidized bed furnace and the waste treatment method according to the present invention are useful for extracting the combustible gas from the waste by heating the waste in the fluidized bed in which the fluidized particles are fluidized. Yes, it is suitable for stably obtaining flammable gas even if it is waste containing flammable garbage.

Claims

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, the non-combustible material in the waste and the heating of the waste at a position deviated in a specific direction from the center position on the bottom wall A mixture outlet is provided for discharging the carbide generated by the above together with the fluidized particles, and the upper surface of the bottom wall is placed on the mixture so as to lower the fluidized particles on the upper surface of the bottom wall toward the mixture outlet. A furnace body that inclines so as to become lower toward the discharge port;
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 same side as the mixture discharge port with respect to the center position of the bottom wall among the side walls, thereby A waste supply unit that moves waste on the fluidized bed to the side of the opposite side wall located on the opposite side of the mixture discharge port across the center position of the bottom wall of the side wall, and
The gas supply unit forms a first fluidized region having a fluidization degree such that waste can be retained above the fluidized particles by blowing the fluidized gas from around the mixture discharge port. In addition, the fluidizing gas is blown between the first fluidizing region and the opposite side wall at a flow rate higher than the fluidizing gas blowing velocity in the first fluidizing region. The fluidized particles have a higher degree of fluidization than the fluidized region, whereby the fluidized particles convect and mix with the waste to form a second fluidized region that gasifies the waste,
The waste supply unit has the waste from the supply side wall so that the waste stays on the first flow region and the stayed waste sequentially enters the second flow region. A fluidized bed furnace that supplies waste to a fluidized bed.
The fluidized bed furnace according to claim 1,
The waste supply unit pushes a new waste laterally from the supply side wall toward the waste staying on the first flow region, and thereby the waste staying on the first flow region. A fluidized bed furnace in which things sequentially enter the second fluidized zone.
In the fluidized bed furnace according to claim 1 or 2,
A fluidized bed furnace comprising a carbide insertion device that separates carbide from the mixture of the incombustible material, the carbide, and the fluidized particles discharged from the mixture discharge port and returns the mixture to the fluidized bed from the opposite side wall.
The fluidized bed furnace according to any one of claims 1 to 3,
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 air 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 1, and the flow rate of U 0 / U mf is 2 or more and less than 5 in the second flow region. A fluidized bed furnace that injects fluidized gas.
The fluidized bed furnace according to any one of claims 1 to 4,
A fluidized bed furnace comprising a sand circulation device that separates the fluidized particles from the mixture discharged from the mixture discharge port and returns the separated fluidized particles into the furnace body.
The fluidized bed furnace according to claim 5,
The sand circulation device is a fluidized bed furnace in which the fluidized particles separated from the mixture are returned onto the waste staying on the first fluidized zone.
In a fluidized bed furnace given in any 1 paragraph of Claims 1 thru / or 6,
The fluidized bed furnace, wherein the furnace body has a planar shape in which a dimension in a width direction which 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 7,
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. A mixture discharge port for discharging the non-combustible material in the waste and the carbide generated by heating the waste together with the fluidized particles is provided at a biased position on the upper surface of the bottom wall toward the mixture discharge port. Providing a fluidized bed furnace having a furnace body inclined so that the upper surface of the bottom wall is lowered toward the mixture discharge port so that the fluidized particles fall;
The degree of fluidization that allows waste to stay above the fluidized particles by blowing fluidized gas toward the fluidized particles from the region around the mixture outlet in the bottom wall of the furnace body. Between the first flow region and the opposite side wall located on the opposite side of the mixture outlet from the side wall with the center position of the bottom wall interposed therebetween. A second fluidized region having a higher degree of fluidization of the fluidized particles than the first fluidized region by blowing fluidized gas at a flow rate higher than the flow rate of fluidizing gas blown in the first fluidized region. Forming, and
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 same side as the mixture discharge port with respect to the center position of the bottom wall among the side walls, thereby A waste treatment method comprising: stagnating the waste on the first fluidized area and gasifying the retained waste sequentially into the second fluidized area.
The waste disposal method according to claim 9, wherein
In the gasification step, new waste is pushed laterally from the supply side wall toward the waste staying on the first flow region, and thereby the waste staying on the first flow region. A waste treatment method in which an object is sequentially gasified by entering the second flow region.
The waste disposal method according to claim 9 or 10,
A waste treatment method comprising: separating carbide from a mixture of the non-combustible material, the carbide, and the fluidized particles discharged from the mixture discharge port and returning the carbide to the fluidized bed from the opposite side wall.
The waste treatment method according to any one of claims 9 to 11,
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 , U 1 in the first fluidized region 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 second flow region. , Waste disposal methods.