JP2000126716A - Apparatus for dioxin decomposition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently decompose dioxins and lower their concentrations by heating a treatment object matter in a low-oxygen atmosphere by a high temperature gas and intermittently rotating or continuously and horizontally moving the object matter below a treatment object matter charge opening. SOLUTION: While a decomposition pot 45 of a rotation section 50 is being rotated, fly ash and solid constituents are fed through a supply opening 34 and residues are fed through a residue supply opening 33, and simultaneously a high temperature circulation gas is fed from a plurality of circulation gas supply opening 35, 35 through a bottom lid 46. The rotation section 50 is rotated in a low-oxygen high temperature atmosphere so as to heat a treatment object matter by the circulation gas. Then, the bottom lid 46 is opened about a hinge 46a, and treatment-completed residues 36 are taken out and guided to a water- sealed tank 23 through a residue discharge passage 22 and quenched or is guided to a cooling chamber 38 through the residue discharge passage 22a and quenched by N2 gas. By this method, the quantity of dioxins contained in the residues, fly ash and solid constituents is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a residue, fly ash,
The present invention relates to a dioxin decomposer for reducing the concentration of dioxin contained in other solids and the like.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram of a spouted bed gasifier conventionally provided as one of the plastic waste gasifiers. In FIG. 6, 1 is a first-stage gasifier,
2 is a raw material supply device to the gasification furnace 1, 6 is a cyclone,
Reference numeral 8 denotes a second-stage gasification furnace, 11 denotes a heat recovery device, 13 denotes a gas cleaning device, 15 denotes a waste liquid treatment device, 18 denotes an ejector, and 23 denotes a water seal tank.

In such a spouted bed type gasifier, the first-stage gasifier 1 is started up by the pre-heating device 5 at the time of starting.
While preheating to 0 ° C., the second-stage gasifier 8 is preheated to about 1000 ° C. by a preheating device 9, and the pretreated plastic waste raw material is supplied from the raw material supply device 2 to the raw material supply pipe 3. To the first-stage gasification furnace 1. When the steam-oxygen mixed gas is supplied to the first-stage gasifier 1 through the steam-oxygen mixed gas pipe 4, the raw material and the oxygen in the steam-oxygen mixed gas are heated in a high-temperature atmosphere by preheating in the first-stage gasifier 1. Reacts with and gasifies to generate a primary gasified gas. In order to perform this reaction,
The inside of the gasification furnace 1 is maintained at a temperature of 700 ° C. or higher by the preheating device 5 to form a spouted bed in which the raw material stays in the reaction zone.

[0004] In the first-stage gasification furnace 1, a secondary gasification gas generated in a second-stage gasification furnace 8, which will be described later, or the first-stage gasification furnace 1 is used for a jet in the interior. The high-temperature circulating gas generated by mixing the high-temperature gas of the primary gasification gas generated in the above and the high-temperature steam generated by the heat recovery device 11 and introduced from the steam pipe 12 by the ejector 18 is used as the circulating gas. It is introduced from the pipe 19 and used. This ensures a sufficient reaction temperature and forms a spouted bed in which the raw material stays in the reaction zone of the first-stage gasification furnace 1 so that the gasification reaction can be smoothly performed. The first stage gasifier 1
The high-temperature residue remaining in the gasification reaction described above is taken out from a residue pipe 20 connected to the lower part of the gasification furnace 1 to a water ring tank 23 and cooled.

[0005] Next, the primary gasification gas generated in the first-stage gasification furnace 1 passes through a primary gas pipe 7 and a cyclone 6.
After the fly ash such as dust in the gas is removed in the cyclone 6, the gas is mixed with the steam / oxygen mixed gas introduced from the steam / oxygen mixed gas pipe 4 and supplied to the second-stage gasification furnace 8. You. The fly ash removed in the cyclone 6 is discharged to the outside from an ash pipe 17 connected to a lower portion of the cyclone 6.

In the second-stage gasification furnace 8, steam-oxygen mixed gas mixed as described above is used to decompose soot, tar and the like generated by the reaction in the first-stage gasification furnace 1. And the primary gasification gas are reacted to raise the temperature of the second-stage gasification furnace 8 to 900 to 1000 ° C.

[0007] The secondary gasified gas at 900 to 1000 ° C is led to the heat recovery unit 11 by the secondary gas pipe 10, and its sensible heat is recovered by the heat recovery unit 11 to generate water vapor to generate a gas of about 200 ° C. The temperature is lowered. Then, the secondary gasified gas that has passed through the heat recovery device 11 is washed with water or an alkaline solution in the gas washing device 13, and harmful substances such as HCl, HCN, H ₂ S, and NH ₃ generated in the gasification process. Is largely removed. The waste liquid generated by the gas cleaning enters a waste liquid treatment device 15 through a waste liquid pipe 14 and is subjected to a cleaning treatment in the treatment device 15.
a is discharged outside.

In addition to the above, Japanese Patent Publication No. 6-38863 is provided as a method for reducing dioxin in plastic waste and fly ash during gasification of the waste.

[0009]

In such a spouted bed type gasifier, as described above, the raw material of the plastic waste is used by using the first-stage gasifier 1, the cyclone 6, and the second-stage gasifier 8. During the gasification, the residue discharged from the first-stage gasification furnace 1 and the fly ash discharged from the cyclone 6 and the waste liquid treatment apparatus 1
The solid separated in 5 contains a large amount of dioxin, which is one of the pollution sources.

However, in such a conventional apparatus, no means has been taken to reduce the dioxin to a specified concentration or less. In the prior art such as Japanese Patent Publication No. 6-38863, it is actually difficult to reliably reduce the dioxin concentration to a specified value or less.

[0011] In view of the problems of the prior art, the present invention includes residues, fly ash, and solids in waste liquid discharged from a gasifier such as a jet gasifier as the plastic waste is gasified. It is an object of the present invention to provide a dioxin decomposer capable of reducing the concentration of dioxin discharged from the gasifier to a specified concentration or less by providing a device for decomposing dioxin.

[0012]

SUMMARY OF THE INVENTION In view of the problems of the prior art, the present invention provides, as an invention according to claim 1, a residue discharged from a gasifier for gasifying plastic waste,
In a dioxin decomposing apparatus that receives an object to be processed such as fly ash or other solid matter and decomposes and removes dioxin contained in the object to be processed, a processing object supply port for receiving the object to be processed and an upper surface of the dioxin decomposer are provided. A case in which a gas discharge port for discharging a purge gas after the operation is provided, and a gas supply port for introducing a high-temperature gas and a residue discharge port for discharging a residue after the dioxin decomposition operation are provided on the lower surface; Is provided movably in the horizontal direction in a portion below the workpiece supply port inside the
An object to be processed from the object to be processed is placed on the upper surface, and an object to be processed receiving portion through which the high-temperature gas is allowed to pass, and the gas provided below the object to be processed receiving portion are provided. A dioxin decomposer characterized by comprising a gas passage through which a supply port is communicated and through which a high-temperature gas flows toward the workpiece receiving portion.

According to a second aspect of the present invention, in the first aspect, the workpiece receiving portion has a disassembly pot defined by a plurality of partition walls along a circumferential direction on a rotating portion driven to rotate. When the decomposition pot comes to a position below the supply port, the processing object is supplied and comes into contact with the high-temperature gas.

According to a third aspect of the present invention, in the second aspect, each of the disassembly pots is provided with a bottom lid having a through hole for the high-temperature gas on its lower surface so as to be openable and closable.

According to a fourth aspect of the present invention, in the first aspect, a plurality of the processing object receiving portions are provided so as to be capable of being opened and closed in a vertical direction along a circumferential direction of a rotating portion driven to rotate. A saucer provided with a gas passage hole is provided.

According to this invention, the processing object provided at the upper part of the case is intermittently rotated while the processing object receiving portion comprising the disassembling pot according to the second and third aspects and the tray according to the fourth aspect is intermittently rotated. An object to be processed such as a residue by gasification, fly ash, and other solid matter is supplied from the material supply port. At this time, a plurality of objects to be processed are provided in the circumferential direction, and are sequentially supplied to the object receiving portion below the object supply port by rotation.

On the other hand, a high-temperature gas is introduced into a gas passage provided below the object-receiving portion, and the high-temperature gas flows through a gas introduction hole of the object-receiving portion to cause the gas to be processed. It comes into contact with the workpiece supplied on the workpiece receiver. Since the object receiving portion is intermittently rotating, the object on the object receiving portion is heated in a constant time high temperature gas and a constant low oxygen concentration atmosphere in which the rotation is stopped. It is heated by the contact, the dioxin contained in the object to be treated is decomposed, and the residue after the decomposition of dioxin,
That is, the discharge residue is discharged from the residue discharge port at the bottom of the case.

As described above, the operation of heating the object to be treated by the high-temperature gas to decompose dioxin is performed by intermittently interposing the plurality of object receiving parts provided along the circumferential direction below the object supply port. By rotating the workpiece, the process can be performed for each of the plurality of workpiece receiving sections, whereby the dioxin in the workpiece can be continuously decomposed and removed, and the dioxin concentration can be reduced to a specified value or less. .

Further, by adjusting the rotation speed of the object receiving portion, it is possible to select an optimal time for dioxin decomposition of the object to be processed, whereby the dioxin can be decomposed with the maximum decomposition efficiency. be able to.

According to a fifth aspect of the present invention, in the first aspect, the object receiving portion is provided with a driving roll that is driven to rotate, and is mounted on the driving roll to be moved in the horizontal direction. A mesh belt provided with a plurality of passage holes through which the high-temperature gas flows while the processing object is placed thereon.

According to this invention, the object to be processed is continuously supplied onto the mesh belt by slowly moving the mesh belt below the workpiece supply port at a low speed. By flowing a high-temperature gas from below the belt through the passage hole of the belt, the object to be processed can be placed in a high-temperature low-oxygen atmosphere for a predetermined time to continuously decompose dioxin.

According to a sixth aspect of the present invention, there is provided means for cooling an object to be processed after decomposition of a dioxin.
5. In any one of the above items 5, further comprising a cooling means connected to the residue discharge port for cooling the discharged residue after the decomposition of dioxin.

The inventions according to claims 7 and 8 relate to a specific structure of the cooling means according to claim 6, and the invention according to claim 7 is the cooling apparatus according to claim 6, wherein the cooling means cools the discharge residue. It consists of a water-sealed tank containing water.

According to an eighth aspect of the present invention, in the sixth aspect, the cooling means comprises a cooling chamber for cooling the discharged residue with N ₂ gas.

According to this invention, the residue of the object to be treated, that is, the dioxin heated and decomposed in the object receiving portion, that is, the discharge residue, is guided into the water seal tank and cooled by the water, or the cooling chamber is used. And cooled by N ₂ gas. The rapid cooling of the discharged residue ensures that dioxin in the discharged residue is removed.

According to a ninth aspect of the present invention, the gas generated in the gasifier is introduced into the gas supply port, and the purge gas discharged from the gas outlet is returned to the gasifier. It has a gas circulation path.

According to this invention, the high-temperature gas for gasification of plastic waste generated in the gasification furnace can be circulated as the high-temperature gas for the thermal decomposition of dioxin, and the heat of the high-temperature gas can be used. Since a high-temperature gas source is not required, the apparatus is simplified and the cost is reduced, and the heat of gasification of the plastic waste is used, so that the effective use of heat energy can be realized.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only.

FIG. 2 is a block diagram of a spouted bed gasifier equipped with the dioxin decomposer 21 according to the present invention.

In FIG. 2, reference numeral 1 denotes a first-stage gasifier, 2 denotes a raw material supply device for supplying raw materials of plastic waste to the gasifier 1 through a raw material supply pipe 3, and 6 denotes the first-stage gasifier. A cyclone for separating fly ash from the primary gasification gas sent from 1, a second-stage gasification furnace, 11 a heat recovery unit, 13 a gas cleaning unit, 15 a waste liquid treatment unit, and 18 an ejector is there.

In the spouted bed type gasifier, the first-stage gasifier 1 is heated by the preheating device 5 for about 70
While preheating to 0 ° C., the second-stage gasification furnace 8 is preheated to about 1000 ° C. by a preheating device 9, and the raw material of the pretreated plastic waste is supplied from the raw material supply device 2 to the raw material supply pipe 3. After that, it is supplied to the first-stage gasification furnace 1. When the steam-oxygen mixed gas is supplied to the first-stage gasifier 1 through the steam-oxygen-mixed gas pipe 4, the raw material and the steam-oxygen mixed gas in the first-stage gasifier 1 are heated in a high-temperature atmosphere by preheating. Oxygen reacts with and gasifies to generate a primary gasified gas. In order to perform this reaction, the inside of the gasification furnace 1 is maintained at a temperature of 700 ° C. or higher by the preheating device 5 as described above, and a spouted bed for retaining the raw materials in the reaction zone is formed.

In the first-stage gasification furnace 1, the secondary gasification gas generated in the second-stage gasification furnace 8 or the first-stage gasification furnace as described later is used for jetting inside the first-stage gasification furnace. The high-temperature circulating gas generated by mixing the high-temperature gas of the primary gasification gas generated in 1 with the high-temperature steam generated by the heat recovery device 11 by the ejector 18 is introduced from the circulating gas pipe 19. And use it. In this manner, a spouted bed for ensuring a sufficient reaction temperature and for retaining the raw material in the reaction zone of the first-stage gasification furnace 1 is formed, and the gasification reaction is smoothly performed. In addition, the high-temperature residue remaining in the gasification reaction in the first-stage gasification furnace 1 is discharged from a residue pipe 20 to a dioxin decomposition device 21 described later.

Next, the primary gasification gas generated in the first-stage gasification furnace 1 passes through a primary gas pipe 7 and a cyclone 6.
After the fly ash such as dust in the gas is removed in the cyclone 6, the gas is mixed with the steam / oxygen mixed gas introduced from the steam / oxygen mixed gas pipe 4 and supplied to the second-stage gasification furnace 8. You. The fly ash removed in the cyclone 6 is discharged from a ash pipe 17 connected to the cyclone 6 to a dioxin decomposer 21 described later.

In the second-stage gasification furnace 8, soot generated by the reaction in the first-stage gasification furnace 1 is used.
In order to decompose tar and the like, the steam-oxygen mixed gas mixed as described above reacts with the primary gasification gas,
The temperature of the second-stage gasification furnace 8 is raised to 900 to 1000 ° C.

The secondary gasified gas at 900 to 1000 ° C. is led to the heat recovery device 11 by the secondary gas pipe 10, and the sensible heat is recovered by the heat recovery device 11 to generate steam to generate a gas of about 200 ° C. The temperature is lowered. And heat recovery device 1
The secondary gasified gas passed through 1 is washed with water or an alkaline solution in a gas washing device 13 to remove most of harmful substances such as HCl, HCN, H ₂ S, and NH ₃ generated in the gasification process. Is done. The waste liquid generated by the gas cleaning enters the waste liquid processing device 15 through the waste liquid pipe 14, is subjected to a cleaning process in the waste liquid processing device 15, and the discharged liquid is discharged to the outside by the drain pipe 14b.

The soot and tar-containing solid collected by the cleaning treatment in the waste liquid treatment device 15, that is, the solid-liquid separation treatment by a solid-liquid separation filter (not shown) provided in the waste liquid treatment device 15. The fraction is supplied to a dioxin decomposer 21 to be described later through a solid discharge pipe 16.

The configuration and gasification operation of the above-described spouted bed type gasifier are substantially the same as those of the prior art shown in FIG. In the embodiment of the present invention, the spouted bed gasifier is equipped with a dioxin decomposer 21 for removing dioxin contained in the solids such as the residue, fly ash, and soot.

FIG. 1 is a partially expanded sectional view showing the structure of the dioxin decomposition apparatus 21 according to the first embodiment of the present invention. The dioxin decomposition apparatus 21 is shown in FIG.
As shown in FIG. 1, the main part is composed of a columnar body that rotates intermittently as shown by the arrow in FIG.

In FIG. 1, reference numeral 41 denotes an upper cover, on the upper surface thereof, a residue supply port 33 connected to the residue pipe 20 from the first-stage gasification furnace 1 and a solids discharge pipe 16 from the waste liquid treatment device 15. And a supply path 34 where the ash pipe 17 from the cyclone 6 joins and a purge gas discharge path 3 described later.
Purge gas outlets 31 and 32 are provided to be connected to 9 and 40, respectively, and constitute a fixed portion 50a on the upper side.

Reference numeral 42 denotes a lower lid, on the lower surface of which are provided two circulating gas supply ports 35 connected to the circulating gas pipe 19 from the ejector 18 (in this example, two circulating gas supply ports 35). And a residue discharge path 22 for discharging a treated residue 36 connected to a water seal tank 23 described later and a residue discharge path for discharging a treated residue 36 connected to a cooling chamber 38 described later. 22a are connected to each other to form a lower fixed portion 50b. The residue discharge paths 22 and 22a need not be provided as in this embodiment, and either one may be provided depending on the dioxin decomposition conditions.

Reference numeral 45 denotes a decomposition pot which receives a mixture of solids and fly ash from the supply path 34 and a residue such as a residue from the residue supply port 33, and is divided by a partition wall 43 at equal intervals in the circumferential direction. (In this example, FIG. 1
2 to 16 as shown by reference numerals 1 to 16 in FIG.
) Are provided and open upward. Each of the disassembly pots 45 is provided with a bottom cover 46 that can be opened and closed around a hinge 46a. The bottom cover 46 is formed in a lattice shape so that gas from below can pass through.

Each of the disassembly pot 45 and the bottom cover 46
The lower space of the above-mentioned disassembly pot 45
And, it is partitioned so as to be at the same position in the circumferential direction as the bottom lid 46, and forms a gas passage 44a. Furthermore, each of the disassembly pots 45 constitutes a rotating unit 50 that is intermittently rotated by a rotating device (not shown) together with the bottom lid 46 and the partition wall 44.

The supply path 34 and the residue supply port 3
3. The purge gas discharge ports 31 and 32 are arranged such that the upper openings of the respective decomposition pots 45 are sequentially positioned below the decomposition pots 45 by rotation of the decomposition pots 45, and the circulating gas supply ports 35, 35 and the residue discharge are provided. Road 22, 22a
Are arranged below the disassembly pot 45 sequentially by the rotation of each of the disassembly pots 45.

According to the spouted bed gasifier provided with the dioxin decomposer 21 having the above-described structure, the residue discharged from the first-stage gasifier 1 of the gasifier via the residue pipe 20 and the cyclone The fly ash discharged from the ash pipe 6 through the ash pipe 17 and the solids including soot, tar and the like which are treated inside the waste liquid treatment apparatus 15 are referred to as the residue supply port 33 and the supply path, respectively, through the solids discharge pipe 16. 34
And is introduced into the dioxin decomposer 21. The high-temperature circulating gas that has passed through the circulating gas pipe 19 connected to the outlet of the ejector 18 is introduced into the dioxin decomposer 21 from the circulating gas supply ports 35, 35, respectively.

That is, while rotating the disassembly pot 45 of the rotating section 50, the fly ash and solids are supplied from the supply path 34 above the residue, and the residue is supplied from the residue supply port 33, respectively. A high-temperature circulating gas of 450 ° C. or more is supplied from a circulating gas supply port 35 provided at a lower portion of the decomposition pot 45 through a lattice-shaped bottom lid 46. Then, each of the decomposition pots 45 has an oxygen concentration of 1
The rotating part 50 including the decomposition pot 45 is gently rotated so as to be maintained in a high-temperature atmosphere of 450 ° C. or more at a low oxygen concentration of not more than% by volume, and the workpiece is heated by the circulating gas.

The heating of the object to be processed by the circulating gas is as follows:
By rotating the disassembly pot 45 intermittently, the
No. The processing is sequentially performed for each of the decomposition pots 45 from 1 to 16, whereby the dioxin contained in the object is decomposed.

Then, the processing object supplied into the distribution pot 45 makes one rotation, and the object No. in FIG. 15 or N
o. At the position 16, the bottom cover 46 is opened around the hinge 46a to take out the treated residue 36, and the cooled residue 36 is led from the residue discharge passage 22 to the water sealing tank 23 to be rapidly cooled, or from the residue discharge passage 22a. It is led to the cooling chamber 38 and rapidly cooled by N ₂ gas. The amount of dioxin contained in the residue, ash, or solid is reduced by the heating with the circulating gas and the subsequent rapid cooling by the water seal tank 23 or the cooling chamber 38.

In this embodiment, the decomposition time of the object to be treated can be arbitrarily selected by adjusting the rotation speed of the rotating unit 50 of the dioxin decomposer 21, whereby the maximum dioxin decomposition efficiency can be obtained.

FIG. 3 shows the experimental results in the above embodiment. In the figure, the residue treatments (1) and (2) show that the residue obtained by gasification is treated at a temperature of 450 ° C. or 800 ° C. and a low oxygen concentration ( 0.5 VOL%) for 1 hour in an atmosphere
_It was quenched with _two gases, and the dioxin concentration was below the analyzable concentration below the German regulation value. The treatment (3) of the solid portion in the waste water in the figure shows the concentration of dioxin contained in the solid content in the waste water of the waste liquid treatment device 15, and this solid content is treated (1) and treatment (1). When processing is performed in the same manner as in 2), processing (4) or processing (5)
As can be seen from the graph, the concentration can be reduced to a level lower than the German regulation value.

As described above, according to this embodiment, the solid content in the residue, fly ash, and wastewater from the spouted bed gasifier is 1 vol% or less, and 45%.
In one hour in a high-temperature, low-oxygen atmosphere at a temperature of 0 ° C. or more, the dioxin concentration of the object to be treated such as the above residue can be reduced to a low concentration equal to or lower than the German regulation value.

FIG. 4 is a view corresponding to FIG. 1 of a dioxin decomposition apparatus 21 according to a second embodiment of the present invention. In this embodiment, the disassembly pot 45 in the first embodiment shown in FIG. 1 is eliminated, and the portion for receiving fly ash, solid content and residue is made flat only with the bottom lid 46.

That is, in FIG. 4, reference numeral 46 denotes a bottom cover, a plurality of which are provided in a plane at equal intervals in the circumferential direction as a whole, and are rotatably intermittently rotated by a rotating device (not shown). 50. The bottom lid 46 is rotatable around a hinge 46a as in the first embodiment.

In the second embodiment, the rotating unit 5
When one of the bottom covers 46 comes below the supply path 34 by the rotation of 0, a mixture of the solid content in the waste liquid and the fly ash is supplied from the supply path 34 onto the bottom cover 46. Is located below the residue supply port 33, the residue is supplied from the residue supply port 33 onto the bottom lid 46 thereof.

On the other hand, a high-temperature circulating gas is supplied from the circulating gas pipe 19 through a gas passage 44a through a lattice-shaped bottom cover 46, and solids, fly ash, residues, and other objects to be processed on the bottom cover 46 are removed. As in the first embodiment, the dioxin is removed by heating the circulating gas for a certain period of time while rotating each of the bottom lids 46.

Other structures and operations are the same as those of the first embodiment, and the same members as those of the first embodiment are denoted by the same reference numerals.

FIG. 5 shows a third embodiment of the present invention.
FIG. In this embodiment, an object to be processed is supplied onto a linearly arranged mesh belt while moving the belt, and a high-temperature circulating gas is brought into contact with the object to be processed from the lower surface of the mesh belt. Is maintained in a high temperature atmosphere of 450 ° C. or more for a certain period of time.

That is, in FIG. 5, reference numeral 21 denotes a dioxin decomposing device, which is configured as follows. Reference numeral 51 denotes a cracking furnace, 52 and 52 denote side covers of the cracking furnace 51, and 33 denotes a workpiece supply port provided on an upper surface of the cracking furnace 51.
Reference numeral 53 denotes a circulating gas supply port provided at a lower portion of the cracking furnace 51, and is connected to the circulating gas pipe 19. 3
Reference numeral 2 denotes a purge gas discharge port provided at an upper portion of the decomposition furnace 51, and is connected to the purge gas discharge path 40. Reference numeral 22 denotes a residue discharge port, which is provided below the decomposition furnace 51 and is connected to the water seal tank 23.

In this embodiment, soot,
An object to be treated such as a solid content including tar and the like, fly ash, and residue is provided at an upper portion of the cracking furnace 51, and a supply port 33 where the solid content discharge pipe 16, the fly ash pipe 17, and the residue pipe 20 join together. Is supplied to a flat mesh belt 55 provided in the decomposition furnace 51. The mesh belt 55 is an endless belt driven by a pair of drive rolls 54, 54, and the belt 55 is formed in a mesh structure so that high-temperature gas can pass therethrough. A hot gas box 56 is provided in engagement with the lower surface of the upper belt of the mesh belt 55, and the circulating gas supply port 53 is connected to the hot gas box 56.

FIG. 5 shows a case in which a residue discharge passage 22 and a water seal tank 23 are provided, and the treated residue is cooled by the water in the water seal tank 23. Instead of the water seal tank 23, a cooling chamber 38 (see FIGS. 1 and 4) for cooling with N ₂ gas may be provided.

In this embodiment, solids and residues including fly ash, soot, tar and the like conveyed from the spouted bed type gasifier are moved from the workpiece supply port 33 by the drive roll 54. Is continuously supplied onto the existing mesh belt 55. At this time, the moving speed of the mesh belt 55 is, for example, gradually moving from the supply port 33 side of the processing object to the residue discharge path 22 side at a moving speed of about one hour, while the processing object is sequentially moved on the mesh belt 55. Supplied to

On the other hand, a circulating gas having a high temperature of 450 ° C. or higher is sent to the gas chamber 56 a of the hot gas box 56 through the circulating gas pipe 19 and the circulating gas supply port 53, and is directed upward from the lower surface of the mesh belt 55. It is gushing. The object to be treated is held in a high-temperature atmosphere of 450 ° C. or higher for about one hour by the high-temperature circulating gas to decompose dioxin. Then, the gas having such a decomposition action is used as a purge gas as a purge gas discharge port 32 and a purge gas discharge path 40.
To the lower part of the first-stage gasification furnace 1 (see FIG. 2).

[0062]

As described above, according to the present invention, the object to be treated is heated in a low-oxygen atmosphere by a high-temperature gas to decompose dioxin. By intermittently rotating or continuously moving the workpiece receiving section below the workpiece supply port or horizontally moving the workpiece receiving section, the processing can be performed continuously for each of the plurality of workpiece receiving sections.

Furthermore, the dioxin decomposition time can be adjusted by adjusting the rotation or horizontal movement speed of the object receiving portion, so that the dioxin can be decomposed with the maximum decomposition efficiency, and The dioxin concentration in the product can be reduced to a specified value or less.

In particular, according to the sixth aspect of the present invention, the dioxin is heated and decomposed at the processing object receiving portion, and the discharge residue of the processing object is guided into a water ring tank and cooled by water. Alternatively, it is guided to a cooling chamber and cooled by N2 gas, and dioxin in the discharged residue is surely removed by rapid cooling of the discharged residue.

Further, according to the ninth aspect, the high-temperature gas for gasification of plastic waste generated in the gasification furnace is circulated as the high-temperature gas for thermal decomposition of dioxin, and the heat of the high-temperature gas is reduced. Since it can be used, no special high-temperature gas source is required, the apparatus is simple and low-cost, and the heat of gasification of the plastic waste is used, so that the effective use of heat energy can be realized.

[Brief description of the drawings]

FIG. 1 is a partially developed cross-sectional view illustrating a configuration of a dioxin decomposing apparatus according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram (system diagram) of a spouted bed gasifier for gasifying plastic waste provided with the dioxin decomposer according to the present invention.

FIG. 3 is a table showing a dioxin reduction effect in the embodiment.

FIG. 4 is a view corresponding to FIG. 1, showing a second embodiment of the present invention.

FIG. 5 is a view corresponding to FIG. 1, showing a third embodiment of the present invention.

FIG. 6 is a view corresponding to FIG. 2 showing a spouted bed type gasifier according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st-stage gasifier 8 2nd-stage gasifier 15 Waste liquid treatment device 16 Solid discharge pipe 17 Ash pipe 19 Circulation gas pipe 20 Residual pipe 21 Dioxin decomposer 22 Residual discharge pipe 31, 32 Purge gas discharge port 33 Residue supply Port 34 Supply path 35, 53 Circulating gas supply port 40 Purge gas discharge path 41 Upper lid 42 Lower lid 43 Partition wall 44 Partition wall 44a Gas passage 45 Decomposition pot 46 Bottom lid 50 Rotating parts 50a, 50b Fixed part 54 Drive roll 55 Mesh belt 56 Heat Gas box

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) F27B 9/24 B01D 53/34 134E (72) Inventor Masato Kaneko 6-22, Kannonshinmachi, Nishi-ku, Hiroshima-shi Mitsubishi Heavy Industries, Ltd. Hiroshima Laboratory F-term (reference) 2E191 BA12 BB00 BD11 4D002 AA21 AA40 AC10 BA05 BA12 CA13 EA05 4F301 AA11 AA21 BE01 BF20 CA42 CA52 CA68 CA72 4K050 AA10 BA05 CA08 CA11 CD16 CG22 DA07

Claims (9)

[Claims] 1. A dioxin that receives an object to be treated such as a residue, fly ash, and other solid matter discharged from a gasifier that gasifies plastic waste and decomposes and removes dioxin contained in the object to be treated. In the decomposition apparatus, a workpiece supply port for receiving the workpiece and a gas discharge port for discharging a purge gas after the dioxin decomposition action are provided on an upper surface, and a gas supply port for introducing a high-temperature gas and a dioxin on a lower surface. A case provided with a residue discharge port for discharging the residue after the decomposition action, and a case provided in the case inside the case below the work supply port so as to be movable in a horizontal direction, and on the upper surface, the work An object to be processed is placed from the supply port, and the object to be processed is allowed to pass therethrough, and the object to be processed is provided below the object to be processed, and A dioxin decomposer, wherein a gas supply port is connected to the gas supply port, and a gas passage through which the high-temperature gas flows toward the workpiece receiving portion. 2. The object receiving portion has a decomposition pot formed by partitioning a plurality of partitions along a circumferential direction on a rotating portion driven to rotate, and the decomposition pot is located below the supply port. 2. The dioxin decomposer according to claim 1, wherein the object is supplied and comes in contact with the high-temperature gas when it comes to the process. 3. The dioxin decomposer according to claim 2, wherein each of said decomposition pots is provided with a bottom lid having a through hole for the high-temperature gas on its lower surface so as to be openable and closable. 4. A receiving tray provided with a plurality of the processing object receiving portions openable and closable in a vertical direction along a circumferential direction of a rotating portion driven to rotate, and provided with a passage hole for the high-temperature gas. The dioxin decomposer according to claim 1, comprising: 5. The workpiece receiving portion is rotatably driven by a driving roll, and is mounted on the driving roll to be moved in a horizontal direction. The workpiece is placed on an upper surface and the high temperature 2. The dioxylysis apparatus according to claim 1, further comprising a mesh belt provided with a plurality of passage holes through which gas flows. 6. The dioxin decomposing apparatus according to claim 1, further comprising cooling means connected to the residue discharge port to cool the discharged residue after the dioxin decomposition. 7. The cooling means comprises a water ring tank containing cooling water for cooling the discharged residue.
The dioxin decomposer according to the above. 8. The dioxin decomposer according to claim 6, wherein said cooling means comprises a cooling chamber for cooling said discharge residue with N ₂ gas. 9. A gas circulation path configured to introduce gas generated in the gasifier into the gas supply port and return purge gas discharged from the gas outlet to the gasifier. The dioxin decomposer according to any one of claims 1, 2, 4, 5, and 6.