JP2007147135A - Fluidized bed furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluidized bed furnace capable of preventing snagging in a heat transfer tube, and clogging between heat transfer tubes of fluidized sand and incineration objects, and capable of efficiently adjusting temperatures of the fluidized sand and the incineration objects. <P>SOLUTION: In the fluidized bed furnace, a straight tube part 41 with a length direction arranged substantially linearly toward a horizontal direction is provided in the heat transfer tube 41 provided in a furnace body and adjusting a temperature of a bed material. Plural rows of straight tube part rows 42 wherein the straight tube parts 41a are plurally arranged in parallel with each other at the same height, are provided at mutually different heights with gaps in between. Gaps Gx formed between the straight tube parts 41a in each straight tube part row 42 are arranged such that they are mutually in the same position as seen from above. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fluidized bed furnace.

  A fluidized bed furnace is known as one of the facilities that incinerate waste. The fluidized bed furnace is equipped with a fluidized bed in which fluidized sand such as silica sand is deposited on the hearth, and it blows and heats the fluidized sand while blowing gas such as air from the hearth into the fluidized bed. Incinerators such as waste are mixed with high-temperature fluidized sand, stirred, dried, pyrolyzed, and burned.

  A heat transfer tube (cooling tube) for adjusting the temperature of the fluidized sand and the incinerated material is provided in the furnace body of the fluidized bed furnace (see Patent Document 1). A refrigerant such as water flows through the heat transfer tube. That is, the fluidized sand and the incinerated material that are in contact with the refrigerant in the heat transfer tube and the surface of the heat exchanger tube exchange heat through the inner and outer surfaces of the heat exchanger tube, thereby cooling the fluidized sand and the incinerated material.

JP-A-11-82967

  However, in the conventional fluidized bed furnace, there is a problem that the fluidized sand and the incinerated material do not flow smoothly because the fluidized sand and the incinerated material are caught in the heat transfer tube or clogged between the heat transfer tubes. there were. In this case, it was difficult to efficiently dry, pyrolyze, and burn the incinerated product. In addition, if the fluidized sand or incinerated material is difficult to flow, the heat transfer tube is likely to wear, and the cost required for repairing the heat transfer tube increases. In order to solve such problems, it may be possible to reduce the number of heat transfer tubes arranged in the fluidized bed. In this case, however, the area where the fluidized bed and the heat transfer tube are in contact with each other is reduced, and the temperature of the fluidized sand and incinerated materials There is a problem that it becomes impossible to adjust efficiently.

  The present invention has been made in view of the above points, and can prevent fluid sand and incinerated material from being caught in the heat transfer tube or clogging between the heat transfer tubes, and can control the temperature of the fluid sand and incinerated material. An object is to provide a fluidized bed furnace which can be adjusted efficiently.

  In order to solve the above problems, according to the present invention, there is provided a fluidized bed furnace in which a fluidized medium is caused to flow in the furnace body and the incinerated product is incinerated, and the fluidized medium is blown and flowed to the hearth of the furnace body. A fluidizing gas supply port for supplying the fluidizing gas is provided, and a heat transfer tube for adjusting the temperature of the fluidizing medium is provided in the furnace body, and the heat transfer tube has a length direction oriented in a horizontal direction. A plurality of straight pipe portions arranged in parallel at the same height and provided in a plurality of stages with gaps at different heights. In addition, there is provided a fluidized bed furnace characterized in that the gaps formed between the straight pipe portions in each straight pipe portion row are arranged at the same position in plan view. . According to such a configuration, the flow path along the substantially vertical direction and the flow path along the substantially horizontal direction are formed between the straight pipe portions, and the flow medium can smoothly flow in these flow paths. it can.

  The intervals between the straight pipe portions in the straight pipe portion rows may be the same as each other. Furthermore, the interval between the straight pipe part rows may be the same.

  The hearth may be inclined with respect to a substantially horizontal plane. The straight pipe portion may be provided substantially perpendicular to the inclination direction of the hearth. Further, the heat transfer tube may be provided on a low side in the inclination direction of the hearth. Further, the plurality of straight pipe portion rows may include a straight pipe portion row that contacts the fluid medium and a straight tube portion row disposed above the fluid medium.

  ADVANTAGE OF THE INVENTION According to this invention, a fluid medium and incinerated material can be smoothly flowed in the clearance gap formed between the straight pipe parts of a heat exchanger tube. Therefore, incineration can be efficiently dried, pyrolyzed, and burned. In addition, the fluid medium and the incinerated material can be sufficiently brought into contact with the heat transfer tube, and the temperature of the fluid medium and the incinerated material can be adjusted efficiently. Furthermore, it is possible to prevent the fluid medium and the incinerated material from being caught by the heat transfer tube or clogging between the straight tube portions. In addition, wear of the heat transfer tube can be suppressed, and the cost required for repairing the heat transfer tube can be reduced.

  Hereinafter, a preferred embodiment of the present invention will be described based on a fluidized bed furnace that incinerates shredder dust of a scrapped vehicle as an incinerated product (incinerated raw material). A fluidized bed furnace 1 shown in FIG. 1 is an inclined dispersion type fluidized bed combustion furnace, and has a substantially square furnace body 2. The lower part of the internal space of the furnace body 2 is a primary combustion chamber S1 for burning the incinerated product (primary combustion), and the upper part is for burning the exhaust gas (secondary combustion) generated by the primary combustion of the incinerated product. The secondary combustion chamber (free board) S2 is performed.

  The side wall portion 6 of the furnace body 2 has a substantially rectangular tube shape having a substantially rectangular cross section, and has four inner side surfaces erected in a substantially vertical direction, that is, the front inner side shown in FIG. It has a side surface 6a, a rear inner surface 6b, a left inner surface 6c, and a right inner surface 6d. The hearth 7 of the furnace body 2 has a substantially rectangular shape, with the width direction directed in the left-right direction (the direction from the front side to the rear side in FIG. 1), and from the front (left side in FIG. 1) to the rear (figure In FIG. 1, it is provided so as to be gradually lowered toward the right). That is, the hearth 7 is provided to be inclined with respect to a substantially horizontal plane between a pair of front inner side surface 6a and rear inner side surface 6b facing each other.

  As shown in FIG. 1, a fluidized bed in which fluidized sand such as silica sand, which is a particulate fluidized medium, is deposited on the hearth 7, that is, the bottom of the primary combustion chamber S 1, and burns incinerated materials with stirring. 10 is formed.

  The furnace body 2 is provided with an inlet 11 for introducing incinerated materials and fluidized sand into the primary combustion chamber S1. The inlet 11 is opened to the front inner side surface 6 a above the fluidized bed 10. That is, it is provided on the high side (upper side) in the inclination direction of the hearth 7. A passage 12 is connected to the input port 11. The incinerated material and the fluidized sand are put into the hopper 13 and mixed by the blender 14, and then the dust supply device 15 is operated to enter the primary combustion chamber S <b> 1 through the passage 12 and the inlet 11 with a predetermined supply capacity. It is supplied continuously.

  As shown in FIG. 2, the insertion port 11 has a central insertion port 11a disposed substantially at the center of the front inner side surface 6a in plan view, and an insertion port disposed on the left and right sides of the insertion port 11a on the front inner side surface 6a. It consists of mouths 11b and 11b. The dust supply device 15 and the passage 12 are connected to the input port 11a and the input ports 11b and 11b, respectively, and the incineration material supplied from the central input port 11a by controlling the operation of each dust supply device 15. The supply amount of fluidized sand and the supply amount of incinerated material and fluidized sand supplied from the inlets 11b, 11b on both sides can be set arbitrarily.

  As shown in FIG. 1, the hearth 7 has a plurality of fluidizing gas supply ports 20 that supply fluidizing gas for blowing fluidized sand to fluidize the primary combustion chamber S <b> 1. Is provided. A blow part 21 divided into a plurality of parts is formed below the hearth 7. As shown in FIG. 3, in this embodiment, the blow-in portion 21 is divided into four parts along the inclination direction of the hearth 7 and three parts along the width direction of the hearth 7. It is divided and arranged. That is, in total, the blow-in part 21 divided into 4 × width direction and 3 = 12 in the inclination direction is attached to the entire lower part of the hearth 7. Then, the fluidizing gas is blown from each blowing portion 21 through the fluidizing gas supply port 20, and the fluidizing gas is discharged upward to blow up the fluidized sand in the primary combustion chamber S1. The fluidized bed 10 is formed by stirring and fluidizing.

  As shown in FIG. 1, the hearth 7 is provided with a take-out port 30 for taking out incinerated combustibles (non-combustible material) and fluidized sand from the primary combustion chamber S1. The take-out port 30 is provided at the lowermost part (lower side) in the inclination direction of the hearth 7. A passage 31 is connected to the outlet 30. Incinerator debris and fluidized sand that have fallen into the passage 31 from the primary combustion chamber S1 through the take-out port 30 are carried out by operation of the discharge device 32, a conveyor (not shown), and the like. Then, after the combustor and the fluidized sand are selected by a sieve (not shown), the fluidized sand is returned to the hopper 13 again.

  The primary combustion chamber S1 is provided with a heat transfer tube group 40 for adjusting the temperature of the fluidized sand. The heat transfer tube group 40 is provided obliquely upward (upward on the lower side) when viewed from the hearth 7 and includes a plurality of, for example, six heat transfer tubes (cooling tubes) 41. A refrigerant such as water (water vapor) is passed through the flow path inside each heat transfer tube 41. The refrigerant passed through the inside of the heat transfer tube group 40 and the fluidized sand in contact with the surface of the heat transfer tube group 40 exchange heat through the inner and outer surfaces of the heat transfer tube group 40, thereby cooling the fluidized sand. , The temperature is adjusted.

  Each of the heat transfer tubes 41 is, for example, a metal pipe, and has, for example, a substantially circular tubular shape having a substantially constant outer diameter and inner diameter. As shown in FIG. 4, the heat transfer tubes 41 are alternately arranged at a plurality of locations (5 locations in the illustrated example). A plurality of (six in the illustrated example) substantially straight straight pipe portions 41a are bent so as to be folded back to the opposite side, and are arranged so as to be arranged substantially parallel to each other. The six straight pipe portions 41a are arranged in parallel with a predetermined interval h between each of the adjacent straight pipe portions 41a.

  Further, in the state of being disposed in the furnace body 2, the straight pipe portion 41a is substantially perpendicular to the left inner surface 6c and the right inner surface 6d between the left inner surface 6c and the right inner surface 6d. It is arranged in a substantially straight line with its length direction oriented in a substantially horizontal direction. Further, the straight pipe portion 41 a is provided so as to be lined up and down in a substantially vertical direction, and is provided substantially perpendicular to the inclination direction of the hearth 7. The curved portions 41b connecting the straight tube portions 41a in each heat transfer tube 41 are fixed so as to be embedded in the side wall portion 6 on the left inner side surface 6c side and the right inner side surface 6d side. Therefore, the curved portion 41b is disposed outside the primary combustion chamber S1, and only the straight pipe portion 41a is disposed in the primary combustion chamber S1.

  The refrigerant is respectively supplied into the heat transfer pipe 41 from the end of the straight pipe portion 41a provided on the lowermost side of the heat transfer pipe 41, and flows alternately in the straight pipe portion 41a and the curved portion 41b. In 41a, while flowing alternately in the opposite direction, the fluid flows from the bottom to the top and is discharged from the end of the straight pipe portion 41a provided on the uppermost side.

  As shown in FIG. 1, the six heat transfer tubes 41 having substantially the same shape as described above are arranged in the front-rear direction (substantially horizontal direction substantially orthogonal to the length direction of the straight pipe portion 41a) in the furnace body 2. Are arranged substantially parallel to each other at equal intervals. Further, the six straight pipe portions 41a provided in each heat transfer tube 41 correspond to the six straight pipe portions 41a of the other heat transfer tubes 41 adjacent to the heat transfer tube 41 at the front or the rear one by one. Are arranged at the same height. That is, each straight tube portion 41 a provided in each heat transfer tube 41 is provided at the same height as any of the straight tube portions 41 a provided in the heat transfer tube 41 adjacent to the heat transfer tube 41.

Thus, six straight pipe portions 41a are arranged at six different heights in the primary combustion chamber S1, and a total of 36 straight pipe portions 41a are provided. That is, six sets of horizontal straight pipe portion rows 42 in which six straight pipe portions 41a are arranged in parallel with each other at the same height are formed, and the straight pipe portion rows 42 are formed in six different heights. They are arranged with a gap between them. As shown in FIG. 5, in the straight pipe portion row 42, between each other straight pipe portion 41a adjacent to each other a gap G _x of the same interval (width) b are formed. A gap G _y having the same interval (height) h is formed between the straight pipe portion rows 42.

Further, the six straight pipe portions 41a provided in each straight pipe portion row 42 are arranged so as to overlap each other in plan view. That is, the five gaps G _x formed in the straight pipe portion row 42 are arranged to overlap each other the same position in a plan view. Accordingly, six sets of vertical straight pipe portion rows 43 in which six straight pipe portions 41a are arranged in parallel to each other are formed. In the present embodiment, each straight tube section 43 is configured by a single independent heat transfer tube 41.

Further, between the straight pipe portion row 42 to each other, it is formed a flow path C _x penetrating along a substantially horizontal direction includes the gaps G _y, respectively, between each straight pipe portion row 43 to each other is , the flow path C _y penetrating along a substantially vertical direction comprise a respective gap G _x are formed. In the present embodiment, five flow paths _Cx and five flow paths _Cy are formed. In the side view viewed the heat transfer tube group 40 from the left inner surface 6c side or the right inner side surface 6d side, each channel C _x and each channel C _y are substantially perpendicular to each other, substantially lattice-shaped flow path formed It is in the state that was done.

By arranging the straight pipe portions 41a as described above, fluid sand and incinerated materials can be suitably flowed. For example, without mutually the same position a gap G _x of the straight pipe portion row 42 in a plan view, the straight pipe section 41a of the upper straight pipe column 42 just above the gap G _x of the lower straight pipe portion rows 42 When to be placed, the flow of the fluidized sand and the material to be incinerated blown up from below the gap G _x is will been hampered by the upper straight pipe portion 41a, it may become difficult rise in the upper part of the gap G _x, the flow The momentum may be weakened. In this case, the fluidized sand and the incinerated material do not flow smoothly, and the temperature control by the heat transfer tube group 40 cannot be sufficiently performed. In addition, the flow of fluid sand and incineration around the straight pipe portion 41a becomes complicated, and damage to the straight pipe portion 41a is likely to proceed. In contrast, as in this embodiment, aligns the gap G _x of the straight pipe portion row 42 to each other the same position in plan view, if such a gap G _x are aligned in the substantially vertical direction, the straight-tube portion 41a with each other during the straight flow channel C _y toward the upper and lower is formed, as shown in FIG. 5, the fluidized sand and the material to be incinerated is, from the lower gap G _x toward the upper gap G _x, flawlessly blown up. Also, from the top of the gap G _x towards the lower gap G _x, it can be smoothly lowered. Furthermore, by are arranged in a substantially horizontal direction, the flow channel C _y a straight flow path C _x transverse crossing is formed in the gap G _y having different heights, the fluidized sand and the material to be incinerated, the horizontal It can move smoothly in the direction. That is, between between each passage C _y, can flow transversely through the gap G _y. In this way, fluidized sand and incinerated materials can flow smoothly.

When it is desired to increase the heat transfer effect of the heat transfer tubes 41, normally, an arrangement in which the projected area of the heat transfer tubes 41 is increased with respect to the upper surface of the hearth 7, for example, each straight tube section 42 in a plan view. It is preferable that the straight pipe portions 41a of the upper straight pipe portion row 42 be arranged directly above the gap G _x of the lower straight pipe portion row 42 without setting the gaps _Gx to the same position. However, according to experiments of the present inventors, towards the structure aligned to each other the same position a gap G _x of the straight pipe portion row 42 in the plan view as described above, it is confirmed to be able to reliably improve the heat transfer efficiency It was. Fluidized state of the fluidized sand and the material to be incinerated occurring furnace within 2 is a complex as unpredictable, according to the arrangement of the straight tube portion 41a having uniform gap G _x to each other the same position in a plan view as described above For example, it is considered that the flow of the fluidizing gas from the hearth 7 works skillfully, the flow around each straight pipe portion 41a is easily performed, and the fluidity can be maintained under favorable conditions.

  In addition, each heat transfer tube 41 is such that only a part of the lower straight pipe portion 41 a is buried in the fluidized bed 10, and the straight pipe portion 41 a provided at the upper portion is disposed above the fluidized bed 10. Is arranged. That is, among the plurality of straight pipe part rows 42, the lower straight pipe part row 42 is buried in the fluidized bed 10, and the straight pipe part row 42 provided on the upper side is disposed above the fluidized bed 10. It is like that. For example, in a state where the fluidized bed 10 is not flowing, the straight pipe portion rows 42 located in the first and second stages from the bottom, that is, a total of 12 straight pipe parts 41a are buried in the fluidized sand, and the fluidized bed 10 In the flowing state, the straight pipe section row 42 located in the first to third stages from the bottom, that is, a total of 18 straight pipe sections 41a are buried in the fluidized sand. Thus, if only a part of the plurality of straight pipe portions 41a is brought into contact with the fluidized sand, than when all the straight pipe portions 41a are buried in the fluidized bed 10, The fluidized bed 10 can flow smoothly.

  The heat transfer tubes 41 are provided in a range of almost the same height as the opening 11 is opened, for example, but are arranged side by side on the low side in the inclination direction of the hearth 7. That is, it is provided at a position on the rear side closer to the rear inner side surface 6b side than the front inner side surface 6a side, and is provided above the take-out port 30, for example. In this way, a sufficient space is formed between the charging port 11 and the heat transfer tube 41 provided at the foremost side, so that fluid sand and incinerated material dropped from the charging port 11 and dropped into the heat transfer tube 41. On the other hand, it does not collide directly and can be dropped on the hearth 7 with a margin. Therefore, damage to the heat transfer tube 41 can be prevented. In addition, the straight pipe portion 41a at the lowermost part of the hearth 7 and the heat transfer tube 41 is provided rather than the case where the heat transfer tube 41 is provided at the same height on the front side in the furnace body 2 (high side in the inclination direction of the hearth 7). A large height can be secured between the two. Therefore, in the space between the hearth 7 and the heat transfer tube 41, the fluidized sand and the incinerated material can be sufficiently flowed.

  As shown in FIG. 1, the side wall 6 of the furnace body 2 is provided with a burner injection port 45 for injecting a flame into the secondary combustion chamber S2. By injecting flame from the injection port 45, combustion of the exhaust gas rising from the primary combustion chamber S1 is promoted.

  An exhaust port 50 for exhausting the atmosphere in the secondary combustion chamber S2 is opened at the upper end of the rear inner surface 6b. An exhaust passage 51 is connected to the exhaust port 50. This exhaust passage 51 is connected to a bag filter 52. The atmosphere in the primary combustion chamber S1 and the secondary combustion chamber S2 rises in the secondary combustion chamber S2 and is exhausted from the exhaust port 50. Then, after dust is captured by the bag filter 52, it is exhausted to the outside. A part of the exhaust gas in which dust is captured by the bag filter 52 passes through the return path 53 and is mixed with an oxygen-containing gas such as air supplied from the air supply path 54. The return path 53 and the air supply path 54 are connected to the gas blowing unit 21 described above via the supply path 55.

  As shown in FIG. 3, the supply path 55 is connected to each gas blowing part 21. A return path 53 for supplying exhaust gas exhausted from the secondary combustion chamber S2 and an air supply path 54 for supplying an oxygen-containing gas such as air are connected to the two mixing chambers 60a and 60b. The exhaust gas and air are mixed in 60b, and the mixed gas is supplied from each supply path 55 to each gas blowing section 21 as a fluidizing gas. In one mixing chamber 60a, each of the half gas blowing portions 21 arranged at positions higher in the direction in which the hearth 7 inclines (in two rows in the width direction on the higher side of the hearth 7). A fluidized mixed gas to be supplied to each of the six arranged gas blowing portions 21) is produced. Further, in the other mixing chamber 60b, the half gas blowing portions 21 (lined in two rows in the width direction on the lower side of the hearth 7) arranged at the lower side in the direction in which the hearth 7 inclines. The fluidizing gas to be supplied to each of the six gas blowing sections 21) arranged in the above is made.

  An exhaust gas flow rate adjustment valve 61 for adjusting the supply amount of exhaust gas supplied into the mixing chambers 60a and 60b is mounted on the return path 53 for each of the mixing chambers 60a and 60b. The air flow rate adjusting valve 62 for adjusting the supply amount of air supplied into the mixing chambers 60a and 60b is mounted for each of the mixing chambers 60a and 60b. By adjusting the exhaust gas flow rate adjusting valve 61 and the air flow rate adjusting valve 62, the mixing ratio of air and exhaust gas in the fluidizing gas produced in each mixing chamber 60a, 60b is made variable independently. Yes. Since the exhaust gas consumes oxygen by incineration, the oxygen concentration is lower than that of air. Thus, when making the fluidizing gas in each mixing chamber 60a, 60b, the mixing ratio of air and exhaust gas is set. By changing it, it is possible to arbitrarily control the amount of oxygen in the fluidizing gas (that is, the oxygen concentration in the fluidizing gas) in each mixing chamber 60a, 60b.

  Each supply path 55 is also provided with a fluidizing gas flow rate adjustment valve 63 for adjusting the supply amount of the fluidizing gas supplied to each gas blowing section 21. By adjusting the fluidizing gas flow rate adjusting valve 63, the flow rate of the fluidizing gas supplied to each gas blowing section 21 is variable. Accordingly, the height of the fluidized sand can be adjusted by increasing or decreasing the fluidization gas blowing speed from each gas blowing section 21. Further, for example, the amount of fluidizing gas blown from the four gas blowing portions 21 arranged at the center portion in the width direction is relatively reduced, and the gas blowing portions 21 arranged at both left and right end portions thereof. It is configured to be arbitrarily controlled, for example, by relatively increasing the amount of fluidizing gas blown from.

  Next, the incineration process of the incinerated product using the fluidized bed furnace 1 configured as described above will be described. First, the incinerated material and fluidized sand introduced into the hopper 13 are mixed by the blender 14, and continuously in the primary combustion chamber S <b> 1 through the passage 12 and the inlet 11 at a predetermined supply flow rate by the operation of the dust supply device 15. To supply.

  The incinerated material supplied into the primary combustion chamber S1 in this way is, for example, shredder dust (ASR) obtained by pulverizing the remainder obtained by removing recycled equipment from a discarded vehicle. The ASR is generated by being pulverized, for example, at a waste automobile treatment plant. Incinerators such as ASR include metals such as Fe, Cu, Zn, and Pb as inorganic substances, glass, etc., and organic compounds include soft resins such as rubber, fiber scrap and urethane, and hard plastics such as vinyl chloride. . Incinerators such as ASR vary in size and shape, so in order to stabilize the incineration, pretreatment such as crushing with a crusher or roller mill should be performed, and the maximum particle size of the incinerator should be 50 mm or less. Is desirable. In addition, it is desirable to selectively remove finely crushed glass from the incinerated product by classification using a vibration sieve, a wind sorter, etc., and to reduce the variation in the particle size of the incinerated product. In addition, it is desirable to incinerate after removing metal components such as Fe, Cu, and Al from the incinerated material by magnetic sorting, eddy current sorting, specific gravity sorting, and the like.

  In the furnace body 2, the heat transfer tube group 40 is provided at the rear, and there is a sufficient space between the input port 11 and the heat transfer tube 41. Is smoothly supplied onto the hearth 7 without colliding with the heat transfer tube 41. Therefore, damage to the heat transfer tube 41 can be prevented.

  While the fluidized sand and the incinerated material are continuously supplied into the primary combustion chamber S1, the primary combustion chamber uses a mixed gas of air and exhaust gas from the secondary combustion chamber S2 from each gas blowing portion 21 as a fluidizing gas. Blows upward into S1, and fluidized sand is blown up and fluidized. In this way, the incinerated product introduced together with the fluidized sand is heated while being agitated by the fluidized fluidized sand and incinerated. Then, combustibles such as resin and fiber waste in the incinerated product are pyrolyzed or burned, and exhaust gas (primary combustion gas) containing gas components such as pyrolysis gas and oxidizing gas is generated. The exhaust gas rises from the fluidized bed 10 and travels to the secondary combustion chamber S2 provided above the fluidized bed 10.

  In addition, the fluidized bed 10 is in contact with each heat transfer tube 41 of the heat transfer tube group 40 and is cooled by the refrigerant passed through the straight tube portion 41a to adjust the temperature. Thereby, even if the calories of the incinerated product are high, the temperature of the fluidized bed 10 is prevented from becoming excessively high, and a stable combustion process can be performed. An incinerated product such as ASR can also be subjected to a stable combustion treatment, and the amount of burnt can be reduced.

In this heat transfer tube group 40, the substantially horizontal position of the straight tube portion 41a and the height in the substantially vertical direction are aligned, and a substantially lattice-shaped flow path composed of flow paths C _x and C _y is formed. Thus, fluidized sand and incinerated materials can flow smoothly between the straight pipe portions 41a. That is, as shown in FIG. 5, the fluidized sand and the material to be incinerated may be along each flow path C _y toward the substantially vertical direction, smoothly raised or lowered through the gaps G _x. Further, it is possible along each flow path C _x toward the substantially horizontal direction, smoothly moving laterally through the gaps G _y. For example, the fluidized sand and the material to be incinerated blown up from below may rise during any of the channel C _y, it flows transversely through the gap G _y communicating with the flow path C _y, located next to it flows into the flow path C _y, it can again fall down in such a flow path C _y. Thus, the fluidized sand and the incinerated material are smoothly flowed around each straight pipe portion 41a. Therefore, incineration can be efficiently dried, pyrolyzed, and burned.

  Further, each heat transfer tube 41 is provided on the lower side in the inclination direction of the hearth 7, and is sufficient between the inlet 11 and the heat transfer tube 41 and between the hearth 7 and the heat transfer tube 41. As these spaces are formed, fluid sand and incinerated materials can flow freely in these spaces. In this way, by allowing fluidized sand and incinerated materials to flow smoothly, incinerated materials can be efficiently dried, pyrolyzed, and burned. In addition, since the flow is actively performed between the straight pipe portions 41a, the temperature control by the heat transfer tube group 40 can be performed efficiently. The temperature of the fluidized bed 10 is maintained at about 600 to 800 ° C., for example.

  Incinerator debris and fluidized sand remaining after the incineration are discharged from the outlet 30. Then, after the debris is sorted and removed by a sieve or the like, the fluidized sand is returned to the hopper 13.

  On the other hand, the exhaust gas rising from the primary combustion chamber S1 to the secondary combustion chamber S2 is heated by mixing the flame supplied from the injection port 45 at the lower end of the secondary combustion chamber S2. The exhaust gas rises in the secondary combustion chamber S2 while being subjected to secondary combustion, and after being burned with unburned gas and fine incinerated matter, it is discharged from the exhaust port 50. And after the fly ash etc. in exhaust gas are collected by the bag filter 52, it is discharged | emitted outside.

According to the fluidized bed furnace 1, the fluidized sand and the material to be incinerated gap G _x, smoothly raised or lowered in the through channel C _y, can be smoothly moved sideways gap G _y, in the channel C _x. Therefore, fluid sand and incineration can be smoothly flowed around each straight pipe portion 41a. Thereby, incineration can be efficiently dried, pyrolyzed, and burned. In addition, the fluidized sand or incinerated material and the heat transfer tube 41 can be brought into sufficient contact, and the temperature of the fluidized sand or incinerated material can be adjusted efficiently. Furthermore, it is possible to prevent fluid sand and incinerated material from being caught by the heat transfer tube 41 and clogging between the straight pipe portions 41a (gap G _x , G _y and flow paths C _x , C _y ). Moreover, wear of the heat transfer tube 41 can be suppressed, and the cost required for cleaning and repairing the heat transfer tube 41 can be suppressed.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various changes and modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

For example, in the above embodiment, the number of heat transfer tubes 41 in the heat transfer tube group 40 is six, but may be five or less, or seven or more. Further, the total number of straight pipe portions 41a is 36, the number of straight pipe portion rows 42 (the number of stages) is six, and the number of straight pipe portion rows 43 is six. Can be set. That is, the number of the channel C _x is five, the number of the channel C _y are the 5 bracts, these numbers can be arbitrarily changed. Further, the number of straight pipe part rows 42 embedded in the fluidized bed 10 and the number of straight pipe parts 41a are not limited to those exemplified in the embodiment, and can be any number.

  In addition, the straight pipe portion 41a is configured to be a part of the curved heat transfer tube 41, and the refrigerant is allowed to flow upward from below, but the configuration is not limited thereto. For example, a straight tubular heat transfer tube that does not have the curved portion 41b may be used.

  In the above embodiment, ASR is illustrated as an incineration material, but the incineration material is not limited to such an incineration material. For example, various types of waste materials such as municipal waste, industrial waste, sludge, wood waste, etc. There may be. Further, for example, a mixture of different types of waste such as a mixture of ASR and pulverized industrial waste may be used. According to the fluidized bed furnace according to the present invention, it is possible to efficiently incinerate wastes of various properties even if they are, for example, flame retardant wastes.

  Further, in the above embodiment, the fluidized bed furnace 1 is a square inclined dispersion type fluidized bed combustion furnace, but the present invention is not limited to this and can be applied to various types of fluidized bed furnaces. For example, in the fluidized bed furnace 1 shown in the embodiment, the method of taking out the debris and the fluid sand is a one-end extraction method that takes out from the lowest part of the inclined hearth 5, but this removal method is performed at the center of the hearth. A so-called center extraction type or the like may be used for taking out debris and fluidized sand from the part.

  The present invention can also be applied to a fluidized bed furnace 1 provided with a boiler, power generation equipment, and the like. For example, a configuration may be adopted in which a refrigerant pipe is provided in the side wall 6 and the heat of the exhaust gas is recovered by heat exchange between the refrigerant and the exhaust gas passed through the refrigerant pipe via the inner and outer surfaces of the refrigerant pipe. good. Moreover, it is good also as a structure which introduce | transduces the exhaust gas after secondary combustion into a boiler, and collect | recovers the heat | fever of exhaust gas in the heat exchanger of a boiler. In that case, it is preferable that the boiler is provided between the secondary combustion chamber S2 and the bag filter 52, and dust is collected in the bag filter 52 after exhaust gas is cooled by the boiler.

  Further, in the above embodiment, the fluidized bed furnace 1 is used for incineration of waste. However, for example, a power generation facility that uses coal, refuse solidified fuel (RDF), or the like as fuel (incinerated). It can also be applied to other combustion furnaces.

  The present invention can be applied to a fluidized bed furnace for incinerating various incinerated products and a method for incinerating a fluidized bed furnace.

It is a schematic longitudinal cross-sectional view of the fluidized bed furnace concerning this Embodiment. It is a schematic cross-sectional view of a fluidized bed furnace. It is a perspective view of the blowing part of the fluidizing gas. It is sectional drawing by the AA line in FIG. It is the longitudinal cross-sectional view which expanded and showed the structure of the straight pipe part vicinity.

Explanation of symbols

C _{x, C y} passage G _{x, G y} gap S1 primary combustion housing S2 secondary combustion chamber 1 fluidized bed furnace 2 furnace inner surfaces 6c after 6 side wall portion 6a inner front surface 6b left inner side surface 6d right inner side surface 7 furnace Floor 10 Fluidized bed 40 Heat transfer tube group 41 Heat transfer tube 41a Straight tube portion 42 Straight tube portion row

Claims (7)

A fluidized bed furnace in which a fluid medium is flowed in a furnace to incinerate incinerated materials,
A fluidizing gas supply port for supplying a fluidizing gas for blowing and fluidizing the fluidizing medium is provided in the hearth of the furnace body,
A heat transfer tube for adjusting the temperature of the fluidized medium is provided in the furnace body,
The heat transfer tube has a straight tube portion arranged in a substantially straight line with its length direction oriented in the horizontal direction,
A plurality of straight pipe portions arranged in parallel at the same height are provided in a plurality of stages with gaps at different heights, and in each straight pipe portion row, A fluidized bed furnace characterized in that the gaps formed therebetween are arranged at the same position in plan view. The fluidized bed furnace according to claim 1, wherein the distance between the straight pipe portions in the straight pipe portion row is the same. The fluidized bed furnace according to claim 1 or 2, wherein the interval between the straight pipe sections is the same. The fluidized bed furnace according to any one of claims 1 to 3, wherein the hearth is inclined with respect to a substantially horizontal plane. The fluidized bed furnace according to claim 4, wherein the straight pipe portion is provided substantially perpendicular to the inclination direction of the hearth. The fluidized bed furnace according to claim 4 or 5, wherein the heat transfer tube is provided on a lower side in an inclination direction of the hearth. The plurality of straight pipe part rows each include a straight pipe part row that comes into contact with the fluid medium, and a straight pipe part row that is disposed above the fluid medium. Fluidized bed furnace as described.

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