JP6855552B2 - Wind classifier - Google Patents

Description

The present invention relates to a wind power classifier that extracts a fluidized medium together with an incombustible material from the bottom of a fluidized bed furnace that burns or incinerates waste, separates the fluidized medium and the incombustible material, and then classifies the fluidized bed. ..

In order to reduce the volume of waste such as municipal waste efficiently and hygienically, the waste is incinerated in an incinerator. A fluidized bed furnace is often used as an incinerator. A fluidized bed furnace utilizes the large heat capacity of a fluidized medium to put waste into a fluidized medium heated to a high temperature, and causes the waste to be dried, thermally decomposed, and burned in a short time. Fluidized bed furnaces include an internal circulating fluidized bed boiler (ICFB) with an intra-layer heat transfer tube in the fluidized bed, a swirling flow type fluidized bed incinerator (TIF) without an intra-layer heat transfer tube in the fluidized bed, and gasification and melting. There is a furnace (TIFG) and the like.

In a fluidized bed furnace equipped with an intra-layer heat transfer tube in a fluidized bed such as an internal circulating fluidized bed boiler (ICFB), some chlorine is contained in the waste when it is burned. Moves to the surface of the fluidized bed (hereinafter, also referred to as sand) and adheres to the intralayer heat transfer tube to cause molten salt corrosion of the intralayer heat transfer tube. Since the heat transfer tube in the layer is worn by the vigorous flow of sand, it is subject to the molten salt corrosion in addition to the wear. If the salt concentration in the sand is high, the progress of corrosion of the heat transfer tube in the layer will be accelerated. However, since there is no process other than sand replacement for adjusting the salt concentration in the sand, there is a problem that the utility cost becomes high.

On the other hand, even in a fluidized bed furnace such as a swirling flow type fluidized bed incinerator (TIF) that does not have an intra-layer heat transfer tube in the fluidized bed, if the salt concentration in the sand is high, sand circulation conveyors and air diffuser nozzles will be used. There is a problem that maintenance costs increase due to corrosion and wear.
Further, in any type of fluidized bed furnace, salts adhere to the sand surface, so that the sand particle size gradually increases, which causes poor flow.

Special Table 2007-506927

_{In the present invention, after removing deposits such as CaCl 2} from the fluidized medium (sand) discharged from the fluidized bed furnace, the particles on the small particle size side and the fluidized medium on the large particle size side to which salts are attached are used. It is an object of the present invention to provide a wind-type classification device capable of classifying into.

In order to achieve the above object, the wind power classification device of the present invention extracts a fluid medium together with incombustibles from the bottom of a fluidized layer furnace for burning or incineration of waste, and after separating the fluids and incombustibles. A classification device for classifying a flow medium, which is a container-shaped device body having a flow medium inlet at the top and a flow medium outlet at the bottom, and a stepped floor portion installed in the device body. A classification air ejection portion having a plurality of nozzles arranged from top to bottom on a stepped floor portion and a classification air ejection portion installed in the main body of the device facing the classification air ejection portion, the lower end of which is the classification air. It is located facing the stepped floor portion of the ejection portion, has an inner cylinder whose upper end extends out of the machine through the top plate of the apparatus main body, and the plurality of nozzles of the classification air ejection portion are on the upper side. The hole diameter is increased from the nozzle to the lower nozzle, and the flow medium in the main body of the apparatus is fluidized by ejecting the classification air from a plurality of nozzles of the classification air ejection portion to form the inner cylinder. It is characterized in that a flow medium having a low termination speed is discharged to the outside of the machine by the flow of classified air flowing through the inner cylinder.

According to a preferred embodiment of the present invention, the minimum fluidization rate ratio inside the apparatus main body is 2 to 3.
According to a preferred embodiment of the present invention, the stepped floor portion in the classified air ejection portion is characterized in that the inclination angle is set to be equal to or larger than the angle of repose of the flow medium and the incombustible material.
According to a preferred embodiment of the present invention, a wind box for supplying the classification air to the plurality of nozzles is formed below the stepped floor portion in the classification air ejection portion, and the pressure in the wind box is applied. It is characterized in that it is monitored by a pressure gauge and the level of the flow medium in the main body of the apparatus is monitored.

According to one embodiment, the fluidized bed is extracted together with the incombustible material from the bottom of the fluidized bed furnace for burning or incinerating the waste, the fluidized bed and the incombustible material are separated, and then the fluidized bed medium is returned to the fluidized bed furnace. This is a method for treating a fluidized bed in a fluidized bed furnace, in which the fluidized medium and incombustibles are separated, the fluidized medium is guided to a surface polishing machine for surface polishing, and the fluidized medium after surface polishing is guided to a classifier. The fluidized medium having the predetermined particle size is classified from the other fluidized media, and the fluidized bed having the predetermined particle size is returned to the fluidized bed furnace.

According to another embodiment, the fluidized bed is extracted together with the incombustible from the bottom of the fluidized bed furnace for burning or incinerating the waste, the fluidized bed and the incombustible are separated, and then the fluidized bed is returned to the fluidized bed furnace. This is a method for treating a fluidized bed in a fluidized bed furnace in which the fluidized bed is separated from an incombustible material, the fluidized bed is guided to a surface polishing machine to polish the surface, and the fluidized bed after surface polishing is used as the fluidized bed. Return to the furnace.

According to still another embodiment, the fluidized bed is extracted together with the incombustible from the bottom of the fluidized bed furnace for burning or incinerating the waste, the fluidized bed and the incombustible are separated, and then the fluidized bed is returned to the fluidized bed furnace. A surface polishing machine that surface-polishs the fluidized medium after separating the fluidized medium and the incombustible material, and a fluidized medium that has been surface-polished by the surface polishing machine. Among them, a classifying device for classifying a fluidized medium having a predetermined particle size from another fluidized medium and a fluidized bed returning unit for returning the fluidized medium having a predetermined particle size classified by the classifying device to the fluidized bed furnace were provided.

According to still another embodiment, the fluidized bed is extracted together with the incombustible from the bottom of the fluidized bed furnace for burning or incinerating the waste, the fluidized bed and the incombustible are separated, and then the fluidized bed is returned to the fluidized bed furnace. In the fluidized bed furnace as described above, a surface polishing machine for surface-polishing the fluidized medium after separating the fluidized medium and the incombustible material, and a fluidized medium surface-polished by the surface polishing machine. Was provided with a fluidized bed return unit for returning the fluidized bed to the fluidized bed furnace.

According to a preferred embodiment, the flow medium having the predetermined particle size is a flow medium having an average particle size of 0.4 mm to 0.8 mm.
According to a preferred embodiment, the surface polishing machine accommodates a flow medium and a polishing medium in a container-shaped drum, vibrates the drum, and rubs the flow medium particles against each other or the flow medium particles and the polishing medium. It consists of a vibrating mill that polishes the surface of a fluid medium.
According to a preferred embodiment, the surface polishing machine separates the flow medium and the incombustible material, and then surface-polishs the entire amount of the separated flow medium, or surface-polishs a part of the separated flow medium. To do.
According to a preferred embodiment, the classifying device comprises a wind class classifying device that ejects the classifying air toward a flow medium and classifies the particles by utilizing the difference in the terminal velocities of the particles.

According to a preferred embodiment, the fluidized bed returned to the fluidized bed furnace is classified by the fluidized gas, and the salts removed from the fluidized bed by surface polishing are discharged from the fluidized bed furnace together with fly ash. ..

_{According to the present invention, after removing deposits such as CaCl 2} from the fluidized medium (sand) discharged from the fluidized bed furnace, the particles on the small particle size side and the flow on the large particle size side to which salts are attached. It can be classified into media.
In addition, by returning the classified flow medium on the large particle size side to the fluidized bed furnace, the salt concentration in the sand and the particle size are controlled, and the flow failure due to corrosion / wear of the heat transfer tube in the layer and peripheral equipment and the enlargement of the particle size. Can be suppressed at the same time.

FIG. 1 is a schematic view showing a method for processing a fluidized medium in a fluidized bed furnace to which the wind power classification apparatus according to the present invention is applied and a basic concept of the apparatus. FIG. 2 is a diagram schematically showing a surface polishing process of a fluid medium. FIG. 3 is a schematic view showing a method for treating a fluidized medium in a fluidized bed furnace to which the wind power classification apparatus according to the present invention is applied, and a first embodiment of the apparatus. FIG. 4 is a schematic view showing a method for treating a fluidized medium in a fluidized bed furnace to which the wind power classification apparatus according to the present invention is applied, and a second embodiment of the apparatus. FIG. 5 is a schematic view showing a method for treating a fluidized medium in a fluidized bed furnace to which the wind power classification apparatus according to the present invention is applied, and a third embodiment of the apparatus. FIG. 6 is a schematic view showing a fourth embodiment of a fluidized bed processing method and apparatus in a fluidized bed furnace. FIG. 7 is a schematic cross-sectional view showing a wind power classification device according to the present invention installed in the fluidized bed processing device in the fluidized bed furnace shown in FIGS. 3, 4 and 5.

Hereinafter, a method and an apparatus for treating a fluidized medium in a fluidized bed furnace to which the wind power classification apparatus according to the present invention is applied will be described with reference to FIGS. 1 to 7. In FIGS. 1 to 7, the same or corresponding components are designated by the same reference numerals, and duplicate description will be omitted.
FIG. 1 is a schematic view showing a method for processing a fluidized medium in a fluidized bed furnace to which the wind power classification apparatus according to the present invention is applied and a basic concept of the apparatus. As shown in FIG. 1, the fluidized medium discharged from the fluidized bed incinerator 1 is introduced into the surface polishing machine 2 and surface-polished.

FIG. 2 is a diagram schematically showing a surface polishing process of a fluid medium. As shown in FIG. 2, salts such as _{CaCl 2} are attached to the fluidized medium (sand) discharged from the fluidized bed incinerator 1. _{FIG. 2 shows a state in which salts such as CaCl 2} are attached to a flow medium having a particle size of 0.4 to 0.8 mm, and the flow medium has deposits in the surface polishing step by the surface polishing machine 2. Will be removed.

As shown in FIG. 1, the flow medium after surface polishing is guided to the wind power classification device 3, and the flow medium is classified by the wind power classification device 3. In this classification step, particles having a particle size of less than 0.4 mm and salts having a particle size of 0.4 mm or more are classified into a fluidized medium having a particle size of 0.4 mm or more, that is, a fluidized medium having a large particle size. Is returned to the fluidized bed incinerator 1 via the fluidized bed return unit 4. A flow medium containing a large amount of salts having a particle size of less than 0.4 mm (adherent salt-rich flow medium) is discarded. In this way, by selectively taking out and reusing the fluid medium on the large particle size side from which salts have been removed by classification, the salt concentration and particle size in the sand can be controlled, and the heat transfer tube in the layer and peripheral equipment can be corroded. Simultaneously suppresses flow failure due to wear and particle size enlargement. In the illustrated example, in the classification step, the flow medium having a particle size of less than 0.4 mm and the flow medium having a particle size of 0.4 mm or more were classified. Then, the recovery efficiency of the fluid medium increases.

Next, a specific embodiment based on the basic concept shown in FIGS. 1 and 2 will be described.
FIG. 3 is a schematic view showing a method for treating a fluidized medium in a fluidized bed furnace to which the wind power classification apparatus according to the present invention is applied, and a first embodiment of the apparatus. As shown in FIG. 3, the fluidized bed incinerator 1 includes a fluidized bed 11 formed by accumulating a fluidized medium made of sand such as silica sand inside. The fluidized bed 11 is supported by a mountain-shaped floor plate 12 whose center is high and gradually decreases toward both edges, and fluidized air as a fluidized gas flows from the air diffuser nozzle formed on the floor plate 12. It is supplied in 11 so that the fluidized medium flows. By changing the fluidization speed of the fluidized air ejected from the floor plate 12 at the central portion and both side portions of the floor plate 12, a swirling flow of the fluidized medium is formed in the fluidized bed 11. The fluidized bed incinerator 1 is provided with an input port 13 for supplying waste into the fluidized bed on one side wall, and an exhaust port on the upper part of the other side wall for discharging combustion exhaust gas generated when the waste is incinerated. It is equipped with 14. Further, in the lower part of the fluidized bed incinerator 1, under-fire chutes 15 and 15 for extracting a fluidized medium together with incombustibles are formed between both side walls of the fluidized bed incinerator 1 and both side edges of the floor plate 12. Below the furnace chutes 15 and 15, a flow medium extraction device 16 composed of a screw conveyor is installed.

In the apparatus configured as shown in FIG. 3, waste such as municipal waste is supplied to the fluidized bed 11 from the input port 13 and incinerated in the fluidized bed 11. The combustion exhaust gas generated by the incineration process is discharged from the exhaust port 14 and guided to the exhaust gas duct. The fluidized medium (sand) in the fluidized bed 11 is discharged from the furnace chute 15 together with the incombustible material by operating the fluidized medium extraction device 16 formed of a screw conveyor. A vibrating sieve 17 is installed below the flow medium extraction device 16, and the incombustible material and the fluid medium (sand) are separated by the vibrating sieve 17. When incombustibles (aluminum cans, aluminum foil, etc.) with a small specific gravity and a large outer shape are mixed, the incombustibles are blocked inside and at the outlet of the wind power classification device 3, so it is necessary to roughly remove the incombustibles with a vibrating sieve 17. Become. The incombustible material is discarded outside the system, and the flow medium (sand) is conveyed upward by the flow medium elevator 19 and supplied to the distribution tank 20. A seal conveyor 21 is provided at the bottom of the distribution tank 20, and a discharge chute 22 is connected to the middle stage of the distribution tank 20. A surface polishing machine 2 is installed below the seal conveyor 21. The discharge chute 22 is connected to the side wall of the fluidized bed incinerator 1 via a poppet valve 23. Therefore, of the fluidized media (sand) distributed in the distribution tank 20, some of the fluidized media is supplied to the surface grinding machine 2 via the seal conveyor 21, and some of the fluidized media are the discharge chute 22 and the poppet valve 23. It is returned to the fluidized bed 11 of the fluidized bed incinerator 1 via. The poppet valve 23 may be replaced with a rotary valve. The flow medium (sand) overflowing from the distribution tank 20 is transferred to the bunker.

Because the surface polishing machine 2 is, for example, a machine composed of a vibration mill, which performs an operation of rubbing the flow medium particles or the flow medium particles and a steel ball (polishing medium) to generate a shearing force on the surface of the flow medium particles. , Can be expected to have a surface polishing function more than a ball mill. Since ball mills and rod mills are rather crushed, surface polishing functions cannot be expected. In addition, the surface polishing function cannot be expected because it is only mixed in the mixer. The surface polishing machine 2 may be of any method as long as it is a machine that generates a shearing force on the surface of the flowing medium (sand) particles, but the method using a vibration mill most meets the needs for surface polishing of the flowing medium (sand). Fulfill.

In the vibration mill, which is an example of the surface polishing machine 2, a large number of steel balls as a polishing medium are housed in a drum which is a cylindrical container. The flow medium (sand) is thrown into the drum from the charging port, and the entire drum is vibrated up, down, left, and right to polish the surface of the flow medium by rubbing the flow medium particles against each other or the flow medium particles and the steel ball. I do.

In this way, the surface of the flow medium is polished by the surface polishing machine 2 composed of a vibration mill, and reaction products such as _{CaCl 2 adhering to the flow medium are removed.} As shown in FIG. 3, the flow medium after surface polishing is supplied to the wind power classification device 3, and the flow medium having a particle size of 0.4 mm or more is recovered in the wind power classification device 3. The flow medium having a particle size of 0.4 mm or more recovered by the wind power classification device 3 is returned to the inlet side of the flow medium elevator 19 via the seal conveyor 24.

_{On the other hand, the flow medium (sand) containing a large amount of reaction products such as CaCl 2 having} a particle size of less than 0.4 mm is blown off by the air flow of the wind power classifier 3 and discarded into the exhaust gas duct via the discharge pipe 25. .. If there are heat recovery equipment such as economizers and waste heat boilers, the disposal destination should be downstream of them to prevent ash from adhering to the heat recovery equipment and corrosion. If there is no heat recovery equipment (equipment to be protected) in the subsequent stage of the fluidized bed incinerator as in the gas cooling method, the fluidized medium on the small particle size side is discarded from the fluidized bed incinerator 1 together with fly ash, so wind sorting Is unnecessary (described later).

In the embodiment shown in FIG. 3, the furnace and the sand circulation system are sealed by the distribution tank 20 and the under-fire chute 15, and the sand treatment system for polishing the surface of sand is not affected by the operating state of the furnace. By quantitatively changing the sand supply speed to the surface polishing machine 2, the amount of polishing can be adjusted. By branching the sand polishing line from the main sand circulation line, maintenance of the surface polishing machine 2 can be performed even while the sand circulation line is in operation. The length of the seal conveyor 24 is set so that the angle of the internal sand is 15 to 20 °. The same applies to the seal conveyor 21. By driving the seal conveyors 21 and 24 with an inverter, continuous polishing and continuous classification operation become possible. In this case, continuous operation has a higher removal ability to remove deposits from the sand. This is because unpolished sand flows into the main sand circulation system when the polishing line is stopped.

FIG. 4 is a schematic view showing a method for treating a fluidized medium in a fluidized bed furnace to which the wind power classification apparatus according to the present invention is applied, and a second embodiment of the apparatus. In the second embodiment shown in FIG. 4, the surface polishing machine 2 is installed between the vibrating sieve 17 and the flow medium elevator 19. Therefore, the entire amount of the fluid medium (sand) separated by the vibrating sieve 17 is surface-polished. Further, a part of the flow medium distributed in the distribution tank 20 is directly supplied to the wind power classification device 3. Other configurations in the second embodiment shown in FIG. 4 are the same as those in the first embodiment shown in FIG.

In the apparatus configured as shown in FIG. 4, waste such as municipal waste is supplied to the fluidized bed 11 from the input port 13 and incinerated in the fluidized bed 11. The combustion exhaust gas generated by the incineration process is discharged from the exhaust port 14 and guided to the exhaust gas duct. The fluidized medium (sand) in the fluidized bed 11 is discharged from the furnace chute 15 together with the incombustible material by operating the fluidized medium extraction device 16 formed of a screw conveyor. A vibrating sieve 17 is installed below the flow medium extraction device 16, and the incombustible material and the fluid medium (sand) are separated by the vibrating sieve 17. The incombustible material is discarded outside the system, and the fluid medium (sand) is supplied to the surface polishing machine 2 for surface polishing. The surface of the flow medium is polished by a surface polishing machine 2 composed of a vibration mill to remove reaction products such as _{CaCl 2 adhering to the flow medium.} The flow medium after surface polishing is conveyed upward by the flow medium elevator 19 and supplied to the distribution tank 20. Of the fluidized media (sand) distributed in the distribution tank 20, some of the fluidized media is supplied to the wind power classification device 3 via the seal conveyor 21, and some of the fluidized media has the discharge chute 22 and the poppet valve 23. It is returned to the fluidized bed 11 of the fluidized bed incinerator 1 through the via. The flow medium (sand) overflowing from the distribution tank 20 is transferred to the bunker.

The flow medium supplied to the wind power classification device 3 undergoes the classification action of the wind power classification device 3, and the flow medium having a particle size of 0.4 mm or more is recovered. The flow medium having a particle size of 0.4 mm or more recovered by the wind power classification device 3 is returned to the inlet side of the flow medium elevator 19 at a location on the downstream side of the surface polishing machine 2 by the seal conveyor 24. _{On the other hand, the flow medium (sand) containing a large amount of reaction products such as CaCl 2 having} a particle size of less than 0.4 mm is blown off by the air flow of the wind power classifier 3 and discarded in the exhaust gas duct.

According to the second embodiment shown in FIG. 4, there is an advantage that the fluidized bed discharged from the fluidized bed incinerator 1 can be avoided from being polished twice even if the seal conveyors 21 and 24 are not driven by an inverter.

FIG. 5 is a schematic view showing a method for treating a fluidized medium in a fluidized bed furnace to which the wind power classification apparatus according to the present invention is applied, and a third embodiment of the apparatus. The third embodiment shown in FIG. 5 uses a poppet valve 26 instead of the seal conveyor 21 in the second embodiment shown in FIG. A rotary valve may be used instead of the poppet valve. By using the poppet valve or the rotary valve, the flow medium elevator 19 can be shortened and the initial cost can be reduced because the seal conveyor 21 is not provided. Other configurations are the same as those of the second embodiment shown in FIG.

FIG. 6 is a schematic view showing a fourth embodiment of a fluidized bed processing method and apparatus in a fluidized bed furnace. The fourth embodiment shown in FIG. 6 is applied to a gas cooling system in which the exhaust gas discharged from the fluidized bed incinerator 1 flows in the order of a temperature reducing tower, a bag filter, an attracting blower, and a chimney.

In the apparatus configured as shown in FIG. 6, waste such as municipal waste is supplied to the fluidized bed 11 from the input port 13 and incinerated in the fluidized bed 11. The combustion exhaust gas generated by the incineration process is discharged from the exhaust port 14 and guided to the exhaust gas duct. The fluidized medium (sand) in the fluidized bed 11 is discharged from the furnace chute 15 together with the incombustible material by operating the fluidized medium extraction device 16 formed of a screw conveyor. A vibrating sieve 17 is installed below the flow medium extraction device 16, and the incombustible material and the fluid medium (sand) are separated by the vibrating sieve 17. The incombustible material is discarded outside the system, and the fluid medium (sand) is supplied to the surface polishing machine 2 for surface polishing. The surface of the fluidized medium is polished by the surface polishing machine 2 to remove reaction products such as _{CaCl 2 adhering to the fluidized medium.} The flow medium after surface polishing is conveyed upward by the flow medium elevator 19 and supplied to the distribution tank 20. The fluidized medium in the distribution tank 20 is returned to the fluidized bed 11 of the fluidized bed incinerator 1 via the discharge chute 22 and the poppet valve 23. The flow medium (sand) overflowing from the distribution tank 20 is transferred to the bunker.

In the fourth embodiment shown in FIG. 6, the surface-polished fluidized medium (sand) is returned to the fluidized bed incinerator 1 without going through the classification step by the wind-type classification device 3. Therefore, the salts removed by surface polishing flow into the fluidized bed incinerator 1 together with the fluidized bed, but since the removed salts are fine powders, the salts are removed by the classification action by the fluidized gas in the fluidized bed incinerator 1. Together with the ash, it is discharged from the fluidized bed incinerator 1 to the exhaust gas duct.

FIG. 7 is a schematic cross-sectional view showing the wind power classification device 3 according to the present invention installed in the fluidized bed processing device in the fluidized bed furnace shown in FIGS. 3, 4 and 5.
As shown in FIG. 7, the wind power classification device 3 according to the present invention includes a box-shaped container-shaped device main body 31, a classifying air ejection portion 32 having a stepped floor portion arranged in the device main body 31. It includes a pipe-shaped inner cylinder 33 arranged in the apparatus main body 31. The apparatus main body 31 is composed of a closed container having a rectangular horizontal cross section, and has a sand inlet A at the top and a sand outlet B at the bottom. A plurality of nozzles 32n are formed on the stepped floor portion of the classification air ejection portion 32, and each nozzle 32n is formed on the side wall of each staircase. Wind boxes 34 and 35 are formed below the stepped classification air ejection portion 32. A pressure gauge 36 is installed in the wind box 34. The lower end 33a of the pipe-shaped inner cylinder 33 faces the stepped floor portion of the classification air ejection portion 32 with a position where it does not contact the stepped floor portion of the classification air ejection portion 32 as a limit position in order to improve separation efficiency. The upper end 33b of the inner cylinder 33 penetrates the top plate of the apparatus main body 31 and extends upward.

In the windshield classification device 3 configured as shown in FIG. 7, a flow medium (sand) is introduced into the device main body 31, and the sand inlet A and the sand outlet B of the device main body 31 are sealed with a valve or a conveyor. The classification air is supplied to the wind boxes 34 and 35, and the classification air is ejected diagonally downward from the plurality of nozzles 32n of the stepped classification air ejection portion 32. The sand is fluidized by the ejection of the classification air, and the sand on the large particle size side moves along the inclination of the classification air ejection portion 32 and accumulates on the sand outlet B side. On the other hand, the sand on the small particle size side is conveyed by the air flow of the classified air flowing toward the inner cylinder 33 and flows into the inner cylinder 33. Adhesive salt-rich sand with a low terminal velocity is discharged from the inner cylinder 33 to the outside of the machine together with the classification air.

Since the flow velocity required for classification (small particle size side particle terminal velocity ratio 1.0 to 1.3) exists only inside the inner cylinder 33, the inner cylinder 33 is lengthened to widen the classable level range. ing. Since it has been confirmed from the simulation that when the sand level drops below the inner cylinder 33, the sand does not reach the portion where the flow velocity is high and the classification efficiency drops, the operating range is between the sand level H and the sand level L. In FIG. 7, the state of the sand level L is illustrated. The sand level is monitored by the windbox pressure by the pressure gauge 36 installed in the windbox 34. A normal level meter may be used, but it is desirable to monitor with windbox pressure as it wears out and breaks down.

In the wind power classification device 3 configured as shown in FIG. 7, the hole diameter of each nozzle 32n is set so that the sand is evenly fluidized while the inside of the device main body 31 is filled with sand. , Increase from the upper nozzle to the lower nozzle. Since the air flow is directed toward the inner cylinder 33, the classification efficiency is improved. As shown in the figure, by directing the nozzle 32n diagonally downward, it is possible to prevent sand falling into the windboxes 34 and 35 and nozzle blockage due to residual incombustibles. When the level of sand in the apparatus main body 31 is lowered, air is likely to be discharged from the lower nozzle 32n, so that classification failure is unlikely to occur. By adjusting the air volume ejected from each nozzle 32n, it is possible to change the classification point of sand. Since the staircase plate is blasted by the classification air, the nozzle may be directed upward by about 1 to 3 ° with respect to the staircase plate.

The UMF ratio (minimum fluidization rate ratio) inside the wind power classifier 3 is set to 2 to 3. This is because if the UMF ratio is increased, the inside of the wind power classification device 3 is worn out. The angle of the stairs in the classified air ejection portion 32 is set to be equal to or greater than the angle of repose of sand and incombustibles (30 ° to 45 °) so that sand and incombustibles are completely discharged from the sand outlet B. The classification point is fine, but unlike the vibrating sieve, there is no risk of clogging. Although it is possible to classify with a cyclone or other classification device, since the flow velocity can be suppressed with this device, it is possible to make the structure less likely to be blocked or worn by wires or pebbles that have passed through the vibrating sieve. .. In addition, since the stored sand is classified, the classification time can be long and the classification efficiency can be improved. From the above, the wind type classification device 3 having this structure is the best as a classification device for classifying sand on the large particle size side and salts on the small particle size side.

In the present invention, the sand surface-polished by the surface polishing machine 2 is classified into sand on the large particle size side and salts on the small particle size side by the wind power type classifying device 3. Explain why it cannot be replaced with a vibrating sieve.
When removing salts with a vibrating sieve, the mesh must be the same size (about 0.1 mm) as the attached salt particles after polishing, which exceeds the manufacturing limit of punching metal (the limit hole diameter is up to the plate thickness). , Φ2.5mm is the limit). Even if it can be manufactured by laser processing or the like, it takes a considerable amount of sieving time to allow small particles to pass through small holes, and a large sieving is required. Further, if the hole diameter is small, the sieve mesh is clogged immediately, and there is a problem that cleaning is difficult when the clogged hole is formed. The reason why the wind power classification device is used in the present invention is to solve the above-mentioned problems. It is also effective that the wind classification device of the present invention can freely change the classification point according to the object to be removed.

Although the embodiments of the present invention have been described so far, the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention may be implemented in various different forms within the scope of the technical idea.

1 Fluidized bed incinerator 2 Surface polisher 3 Wind-power classification device 4 Fluidized bed return unit 11 Fluidized bed 12 Floor plate 13 Input port 14 Exhaust port 15 Under-fire chute 16 Fluidized bed extraction device 17 Vibration sieve 19 Fluidized bed elevator 20 Distribution tank 21 Seal conveyor 22 Discharge chute 23,26 Poppet valve 24 Seal conveyor 25 Discharge pipe 31 Equipment body 32 Classification air ejection part 32n Nozzle 33 Inner cylinder 34,35 Windbox A Sand inlet B Sand outlet

Claims (4)

A classification device that extracts a fluidized medium from the bottom of a fluidized bed furnace that burns or incinerates waste together with incombustibles, separates the fluidized medium from the incombustibles, and then classifies the fluidized bed.
A container-shaped device body having a flow medium inlet at the top and a flow medium outlet at the bottom,
A classification air ejection portion installed in the main body of the apparatus and having a stepped floor portion and a plurality of nozzles arranged from top to bottom on the stepped floor portion.
The machine is installed in the main body of the device so as to face the classification air ejection portion, the lower end is located facing the stepped floor portion of the classification air ejection portion, and the upper end penetrates the top plate of the device main body. Equipped with an inner cylinder that extends outward
The plurality of nozzles of the classified air ejection portion increase the hole diameter from the upper nozzle to the lower nozzle.
By ejecting the classification air from a plurality of nozzles of the classification air ejection portion, the flow medium in the main body of the apparatus is fluidized and flows into the inner cylinder, and the flow medium having a small terminal velocity flows through the inner cylinder. A wind power classification device that is characterized by being discharged to the outside of the machine by the air flow of. The wind-type classification device according to claim 1, wherein the minimum fluidization rate ratio inside the device main body is 2 to 3. The wind power classification device according to claim 1 or 2 , wherein the stepped floor portion of the classification air ejection portion has an inclination angle set to be equal to or higher than the angle of repose of the flow medium and the incombustible material. A wind box for supplying the classification air to the plurality of nozzles is formed below the stepped floor portion in the classification air ejection portion, the pressure in the wind box is monitored by a pressure gauge, and the apparatus main body is used. The wind power classification device according to any one of claims 1 to 3 , wherein the level of the flow medium in the wind medium is monitored.

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