JP3947840B2 - Thermal decomposition equipment for dioxin in ash - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for thermally decomposing ash generated in refuse incineration equipment, for example, dioxin contained in fly ash.
[0002]
[Prior art]
It is known that dioxins contained in the fly ash are thermally decomposed by heating the fly ash to a predetermined temperature, for example, 200 to 500 ° C, preferably 300 to 400 ° C, desirably about 350 ° C.
[0003]
As an apparatus for thermally decomposing dioxins contained in fly ash, the present applicant previously provided a thermal decomposition treatment tank provided with a treatment chamber for receiving dioxin-containing ash inside, and a top wall of the thermal decomposition treatment tank. A penetrating vertical rotary shaft, a rotary shaft drive source arranged outside the pyrolysis treatment tank and rotating the rotary shaft, a suspension means provided on the rotary shaft at the upper end of the processing chamber, and a suspension means The thermal decomposition apparatus of the dioxin in ash provided with the several ash heating medium suspended and the medium heating means to heat an ash heating medium was proposed (refer Unexamined-Japanese-Patent No. 2002-45826).
[0004]
In this thermal decomposition apparatus for dioxins in ash, the medium for heating the ash is heated to a predetermined temperature by the medium heating means, and then the ash containing dioxin is put into the processing chamber of the thermal decomposition treatment tank, and then the drive source for the rotating shaft is used. By rotating the rotating shaft, the ash is heated with the heat of the ash heating medium while stirring the ash with the ash heating medium, whereby the dioxins in the ash are decomposed.
[0005]
[Problems to be solved by the invention]
By the way, recently, it has been required to further improve the thermal decomposition efficiency of dioxins in ash. However, in the above apparatus, the ash is only stirred by the heating medium, so the stirring efficiency is not sufficient, and as a result. The effect of uniformly heating the entire ash is not sufficient, and the effect of improving the thermal decomposition efficiency of dioxin is limited.
[0006]
An object of the present invention is to solve the above problems and provide a thermal decomposition apparatus for dioxins in ash that can thermally decompose dioxins more efficiently than conventional apparatuses.
[0007]
[Means for Solving the Problems and Effects of the Invention]
The thermal decomposition apparatus for dioxins in ash according to the invention of claim 1 includes a thermal decomposition treatment tank provided with a treatment chamber for receiving dioxin-containing ash therein, a vertical rotating shaft penetrating the top wall of the thermal decomposition treatment tank, The dioxin in ash includes suspension means provided on the rotating shaft at the upper end of the processing chamber, a plurality of ash heating media suspended by the suspension means, and medium heating means for heating the ash heating medium. In the thermal decomposition apparatus, the treatment chamber is composed of a vertical cylindrical trough having both ends open, a vertical drive shaft disposed in the cylindrical trough, and a spiral blade fixed to the drive shaft. is lower disposed screw conveyor for conveying the upper end from within the cylindrical trough, the lower end portion of the drive shaft of the screw conveyor protrudes downward from the lower end of the cylindrical trough, cylindrical trough in the drive shaft An ash scraping member that scrapes ash into the cylindrical trough by the rotation of the drive shaft is provided in a portion protruding downward from the lower end so as to protrude radially outward from the drive shaft, and the vertical rotation shaft is hollow And the lower end of the rotating shaft is located at the upper end of the processing chamber, the suspension means is provided at the lower end of the rotating shaft, the upper end of the cylindrical trough is fixed to the suspension means, and the screw conveyor is driven. An upper end portion of the shaft is connected to a vertical shaft arranged to rotate relative to the rotation shaft in the rotation shaft, and the vertical shaft is rotated by a driving source provided outside the thermal decomposition treatment tank. This is what is done .
[0008]
According to the thermal decomposition apparatus for dioxins in ash of the invention of claim 1, after the ash heating medium is heated to a predetermined temperature, for example, 350 to 500 ° C. by the medium heating means, the ash containing dioxin is treated in the thermal decomposition treatment tank. Put it in the room, and then rotate the vertical rotating shaft. Then, the ash is heated by the heat of the ash heating medium while being stirred by the ash heating medium, and thereby dioxins in the ash are thermally decomposed. At this time, when the vertical drive shaft of the screw conveyor is rotated, the ash that has entered the inside from the lower end opening of the cylindrical trough is conveyed above the cylindrical trough by the spiral blade, and from the upper end opening of the cylindrical trough. It is discharged out of the trough. Therefore, the flow of ash is generated in the processing chamber by the screw conveyor, and as a result, the ash is stirred, so that the stirring efficiency is improved as compared with the conventional apparatus. As a result, the effect of uniformly heating the ash is improved as compared with the conventional apparatus, and the thermal decomposition efficiency of the dioxins in the ash is excellent.
[0009]
In addition, the lower end of the drive shaft of the screw conveyor protrudes downward from the lower end of the cylindrical trough, and ash is removed by the rotation of the drive shaft into the portion of the drive shaft that protrudes downward from the lower end of the cylindrical trough. Since the ash scraping member that scrapes inwardly protrudes radially outward from the drive shaft, the ash in the processing chamber is scraped into the cylindrical trough by the ash scraping member when the screw conveyor is operated. As a result, the effect of stirring the ash by the screw conveyor is further improved .
[0010]
According to a second aspect of the present invention, there is provided a thermal decomposition apparatus for dioxins in ash according to the first aspect of the present invention, wherein a gas passage extending in the length direction is formed in the vertical shaft, and the drive shaft is formed in a hollow shape with both upper and lower ends closed. In the drive shaft, one end is connected to the lower end opening of the gas passage of the vertical axis, and the other end passes through the peripheral wall of the drive shaft and faces the processing chamber, so that an inert gas blowing pipe is arranged. An inert gas is fed into the passage from an inert gas supply device. In this case, heating of the ash containing dioxin with the heating medium is performed in an inert gas atmosphere by supplying the inert gas from the inert gas supply device through the gas passage and the inert gas blowing pipe into the processing chamber. And the thermal decomposition of dioxins is further promoted.
[0011]
The thermal decomposition apparatus for dioxins in ash according to the invention of claim 3 is the invention of claim 1 or 2, wherein the peripheral wall of the thermal decomposition treatment tank is formed of a non-conductive material and the ash heating medium is formed of a conductive material. The medium heating means is composed of an electromagnetic induction heating coil disposed on the outer peripheral portion of the peripheral wall of the thermal decomposition treatment tank. In this case, since the ash heating medium is heated by the current induced in the ash heating medium by the electromagnetic induction heating coil, the configuration of the medium heating means becomes relatively simple.
[0012]
The thermal decomposition apparatus for dioxins in ash according to the invention of claim 4 is the invention according to claim 3 , wherein the ash heating medium is made of metal and the surface thereof is coated with SiC. In this case, corrosion of the ash heating medium is prevented.
[0013]
The thermal decomposition apparatus for dioxins in ash according to the invention of claim 5 is the invention according to claim 3 or 4 , wherein the distance between the upper and lower ends of the electromagnetic induction heating coil and the metal parts positioned both above and below the electromagnetic induction heating coil is Each of them is 100 mm or more. In this case, the metal component can be prevented from being heated by the electromagnetic induction heating coil.
[0014]
The thermal decomposition apparatus for dioxins in ash according to the invention of claim 6 is the chain suspension according to any one of claims 1 to 5 , wherein the ash heating medium is a chain, and the chain is attached to the suspension means. It is suspended by a member.
[0015]
The apparatus for thermally decomposing dioxin in ash according to the invention of claim 7 is the apparatus according to claim 6 , wherein one ring is attached to the lower end portion of each chain suspension member, and a plurality of chains are attached to each ring. It is. In this case, the space occupied by the chain in the vicinity of the annular body to which the chain suspension member is attached can be reduced, and the ash is smoothly introduced from the charging port formed in the top wall of the thermal decomposition treatment tank. be able to.
[0016]
The thermal decomposition apparatus for dioxins in ash according to the invention of claim 8 is the invention according to any one of claims 1 to 7 , wherein the treatment ash discharge port is formed at the lower end of the peripheral wall of the thermal decomposition treatment tank, and the treatment ash An open / close lid that can be moved up and down is provided at the discharge port, and a gasket is placed between the periphery of the treated ash discharge port in the thermal decomposition treatment tank and the peripheral edge of the open / close lid, and is more radially outward than the gasket. On the other hand, an annular hanging wall is provided over the entire circumference around the treated ash discharge port in the thermal decomposition treatment tank, and the hanging wall enters when the opening and closing lid is closed. A groove is provided over the entire circumference, and sealing powder is placed in the annular groove. In this case, the sealing performance when the lid is closed is excellent, and ash leakage can be reliably prevented.
[0017]
The thermal decomposition apparatus for dioxins in ash according to the invention of claim 9 is the apparatus according to claim 8 , wherein the open / close lid is made of a non-conductive material. In this case, even if the ash heating medium is made of a conductive material and the medium heating means is an electromagnetic induction heating coil disposed on the outer peripheral portion of the peripheral wall of the thermal decomposition treatment tank, heat generation of the opening / closing lid is prevented. Therefore, it is possible to prevent the processing from being hindered due to overheating.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0019]
FIG. 1 shows the structure of the upper part of the thermal decomposition apparatus for dioxins in ash according to the present invention, and FIG. 2 shows the structure of the lower part. Moreover, FIGS. 3-10 shows the structure of each part of the thermal decomposition apparatus of the dioxin in ash by this invention.
[0020]
1 and 2, the thermal decomposition apparatus for dioxins in ash includes a thermal decomposition treatment tank (1) in which the entire interior is an airtight treatment chamber (2) for receiving ash containing dioxin, and a thermal decomposition treatment tank ( Multiple conductive ash heating chains (3) (ash heating medium) placed in the treatment chamber (2) of 1) and chains (3) for heating outside the pyrolysis treatment tank (1) An electromagnetic induction heating coil (4) (medium heating means) and a cooling device (5) for cooling the treated ash, which is heated by the ash heating chain (3) in the treatment chamber (2) and pyrolyzed dioxin It has.
[0021]
The pyrolysis tank (1) is made of a non-conductive material such as cement, refractory, ceramics, heat-resistant resin, etc., and has a vertical cylindrical peripheral wall with both ends opened and a treated ash discharge port (11). (6), a metal top lid (7) (top wall) fixed to the upper end of the peripheral wall (6) and closing the upper end opening of the peripheral wall (6), and cement, refractories, ceramics, heat-resistant resin, etc. It comprises a bottom lid (8) (open / close lid) that is made of a non-conductive material and that can move up and down to close the treated ash discharge port (11) of the peripheral wall (6).
[0022]
A large-diameter portion (6a) is formed at the lower end portion of the peripheral wall (6) via an inclined step portion (9). Also, a metal outward flange (12) is fixed to the lower end of the peripheral wall (6), and the outer peripheral edge of the outward flange (12) is made of non-cementing material such as cement, refractory, ceramics and heat-resistant resin. A treated ash discharge hopper (14) is attached via a cylindrical body (13) formed of a conductive material, and the lower end of the treated ash discharge hopper (14) is connected to the cooling device (5).
[0023]
An ash inlet (15) is formed in the top cover (7), and the lower end opening of the hopper (16) storing ash containing dioxin is connected to the ash inlet (15) via the rotary valve (17). Connected.
[0024]
The bottom lid (8) is arranged in the treated ash outlet (11). A connecting rod (18) protruding downward is fixed to the center of the lower surface of the bottom cover (8), and the center of the lattice-like body (19) is fixed to the lower end of the connecting rod (18). A plurality of guide rods (21) are fixed to the peripheral edge of the grid-like body (19) so as to protrude upward, and the guide rods (21) are fixed to the outward flange (12) in a penetrating manner. (22) It slidably penetrates inside. A tip end portion of a piston rod of a fluid pressure cylinder (23) for vertically moving the bottom lid (8) is pivotally attached to an upper end portion of one guide rod (21). The fluid pressure cylinder (23) is mounted on a support (24) provided on the outward flange (12) with the piston rod facing downward. Then, by moving the piston rod of the fluid pressure cylinder (23) back and forth, the lattice-like body (19) moves up and down, and thereby the bottom cover (8) moves up and down.
[0025]
As shown in FIG. 3, the peripheral edge of the upper surface of the bottom lid (8) is formed as an inclined surface (8a) inclined downward in the radial direction, and an annular groove (25) is formed on the inclined surface (8a). Is formed over the entire circumference. A gasket (26) made of a heat-resistant material is fitted in the annular groove (25), and when the bottom lid (8) is raised and the treated ash discharge port (11) is closed, this gasket ( 26) is in close contact with the lower surface of the inclined step portion (9) of the peripheral wall (6), so that the portion around the bottom lid (8) and the treated ash discharge port (11), that is, the lower end portion of the peripheral wall (6), The space is sealed. Also, an annular hanging wall (27) is fixed over the entire periphery of the outward flange (12) near the inner peripheral edge, and an annular opening is formed over the entire periphery on the peripheral edge of the bottom surface of the bottom cover (8). An annular body (29) having a groove (28) is fixed. Sealing powder (31) is placed in the annular groove (28). Then, when the bottom lid (8) is raised and the treated ash outlet (11) is closed, the hanging wall (27) enters the annular groove (28) and is inserted into the sealing powder (31). This also provides a seal between the bottom lid (8) and the portion around the treated ash discharge port (11).
[0026]
A cylindrical vertical rotating shaft (32) having both ends opened is passed through the central portion of the top cover (7), and is supported rotatably on the top cover (7) at an intermediate portion thereof. As shown in FIG. 4, an arm (33) is fixed to an upper end portion of the rotation shaft (32) so as to protrude radially outward from the rotation shaft (32). The tip of the piston rod of the lateral fluid pressure cylinder (34) for rotating the rotating shaft (32) is pivotally attached to the tip of the arm (33). The fluid pressure cylinder (34) is swingably mounted around a vertical axis on a support (35) provided on a fixed portion (not shown). Then, by moving the piston rod of the fluid pressure cylinder (34) back and forth, the rotating shaft (32) reciprocates by a predetermined angle around the vertical axis.
[0027]
At the upper end in the processing chamber (2), a plurality of arms (36) are radially fixed to the lower end of the rotating shaft (32) at equiangular intervals in the circumferential direction, and these arms (36) A plurality of annular bodies (37) having different diameters are concentrically fixed to each other, and the arm (36) and the annular body (37) constitute a suspension means (see FIG. 5). An ash heating chain (3) made of a conductive material is suspended from these annular bodies (37) as follows. That is, as shown in FIG. 6, the upper ends of the chain suspension members (39A) (39B) are hooked on the annular body (37), and one ash heating is applied to each suspension member (39A) (39B). The upper end of the chain (3) is attached. The lengths of the suspension members (39A) and (39B) adjacent in the radial direction are different.
[0028]
Moreover, as shown in FIG. 7, the length of all the suspension members (39) is made equal, and the upper end part of a some ash heating chain (3) may be attached to each suspension member (39).
[0029]
Furthermore, as shown in FIG. 8, the lengths of all the suspension members (39) are made equal, and one ring (41) is attached to the lower end of each suspension member (39), and each ring (41) In some cases, upper ends of a plurality of ash heating chains (3) may be attached.
[0030]
The ash heating chain (3) is formed of a conductive material such as iron, stainless steel, or ceramics. When the ash heating chain (3) is formed of metal, it is preferable to coat the surface with ceramics such as SiC for the purpose of corrosion protection.
[0031]
Instead of the ash heating chain (3), a bead-like, pipe-like, wire-like, or plate-like ash heating medium may be used. Also in these cases, the upper end is fixed to the annular body (37). A bead shape is a through-hole formed on one diameter of a sphere (in addition to a perfect sphere, a shape similar to a sphere such as an ellipsoid). The wire is passed through and the sphere is prevented from falling off the wire. In addition, the pipe-shaped one includes not only one long pipe as a whole, but also one in which a wire is passed through a plurality of short pipes and the short pipe is prevented from dropping off from the wires. . Furthermore, the plate-like thing includes the thing in which the some short plate was connected with the wire etc. other than what consists of a elongate strip | belt-shaped plate as a whole. Here, the bead-shaped, pipe-shaped, wire-shaped, and plate-shaped ash heating medium is formed of a conductive material such as iron, stainless steel, or ceramics. When the ash heating medium is formed of metal, it is preferable to coat the surface with a ceramic such as SiC for the purpose of corrosion protection.
[0032]
A screw conveyor (42) for conveying ash from the lower end portion to the upper end portion in the processing chamber (2) is disposed in the processing chamber (2) of the thermal decomposition treatment tank (1). The screw conveyor (42) is arranged coaxially with the rotation shaft (32), the upper end is fixed to the arm (36), and the lower end is a rotation shaft (32) positioned at the lower end in the processing chamber (2). ) Larger diameter cylindrical trough (43), a hollow vertical drive shaft (44) disposed in the center of the cylindrical trough (43) and closed at both upper and lower ends, and a drive shaft (44 ) And a spiral blade (45) fixed to the outer peripheral surface. The lower end of the cylindrical trough (43) is substantially at the same height as the ash heating chain (3) and the lower end. The drive shaft (44) is fixed to the lower end of the small-diameter vertical shaft (46) that is disposed in the rotation shaft (32) and is rotatably supported by the rotation shaft (32). The lower end portion of the small-diameter vertical shaft (46) enters the drive shaft (44). The upper end of the small-diameter vertical shaft (46) protrudes upward from the upper end of the rotary shaft (32) and can be rotated by the motor (48) via the transmission (47). A gas passageway (49) extending in the length direction is formed in the small-diameter vertical shaft (46), and an inert gas such as nitrogen gas supplied from the inert gas supply device (51) is supplied to the rotary joint (52 ) Through the gas passage (49). The lower end portion of the drive shaft (44) projects downward from the lower end of the cylindrical trough (43). An inert gas blowing pipe (53) fixed to the lower end of the small-diameter vertical shaft (46) is arranged in the drive shaft (44) so that the upper end communicates with the gas passage (49). The lower end of the inert gas blowing pipe (53) is bent laterally at a height position below the lower end of the cylindrical trough (43), and its tip penetrates the peripheral wall of the drive shaft (44). Facing the processing chamber (2).
[0033]
A plurality of ash scraping members (54) project radially outward and spaced apart from the lower end of the cylindrical trough (43) at the lower end of the drive shaft (44). To be fixed. As shown in FIG. 9, the ash scraping member (54) is formed of a vertical belt-like plate curved forward in the rotational direction of the drive shaft (44) toward the radially outer side.
[0034]
As shown in FIG. 10, the ash scraping member (54A) may be linearly inclined forward in the rotational direction of the drive shaft (44) toward the radially outer side.
[0035]
The electromagnetic induction heating coil (4) is wound around the peripheral wall (6) of the thermal decomposition treatment tank (1) via a heat insulating material (50). The heat insulating material (50) functions to enhance the heat retaining effect in the processing chamber (2). The intervals between the upper and lower ends of the electromagnetic induction heating coil (4) and the top cover (7) and the outward flange (12) are each 100 mm or more.
[0036]
The cooling device (5) includes a horizontal cooling cylinder (55) whose both ends are closed, and a water jacket (56) disposed around the cooling cylinder (55). A treated ash inlet (57) is formed above the right end of the peripheral wall of the cooling cylinder (55), and is connected to the treated ash discharge hopper (14) via a rotary valve (58). A treated ash discharge port (59) is formed below the left end of the peripheral wall of the cooling cylinder (55). In the cooling cylinder (55), a conveying and mixing device (61) for sending and mixing the treated ash charged from the treated ash inlet (57) to the treated ash outlet (59) is arranged. . The transport / mixing device (61) includes a plurality of pairs of two stirring paddles (63) located 180 degrees apart from each other in the circumferential direction on the horizontal rotating shaft (62). It is fixed to the opposite. Two pairs of agitation paddles (63) adjacent to each other in the length direction of the rotation shaft (62) are shifted by 90 degrees in the circumferential direction of the rotation shaft (62). In addition, each stirring paddle (63) can convey the treated ash from the treated ash input port (57) side to the treated ash discharge port (59) side when the rotating shaft (62) is rotated. It is twisted slightly. Then, the treated ash charged into the cooling cylinder (55) from the charging port (57) is transported while being mixed to the discharge port (59) by the transport and mixing device (61). ) Is cooled to a predetermined temperature or lower by cooling water flowing through the inside.
[0037]
For example, the thermal decomposition of dioxins contained in fly ash is performed as follows using the thermal decomposition apparatus having the above configuration.
[0038]
That is, the bottom lid (8) is raised to close the treated ash outlet (11), and the rotary valves (17) and (58) are kept closed, and the ash heating is performed by the electromagnetic induction heating coil (4). The chain (3) is heated to a high temperature, for example, about 350 to 500 ° C.
[0039]
Next, the rotary valve (17) is opened, and fly ash containing dioxin is introduced into the treatment chamber (2) from the hopper (16) through the ash inlet (15) of the thermal decomposition treatment tank (1). Further, an inert gas is supplied into the processing chamber (2) through the gas passage (49) of the small-diameter vertical shaft (46) and the inert gas blowing pipe (53) by the inert gas supply device (51). (2) The inside is an inert gas atmosphere. Next, the rotary valve (17) is closed, and the rotating shaft (61) is reciprocally rotated in different directions alternately by the fluid pressure cylinder (34), so that the fly ash is removed from the ash heating chain (3) for about 1 to 120 minutes. The mixture is heated to a predetermined temperature, for example, 350 ° C. or higher while mixing, to thermally decompose dioxins in the fly ash. At this time, the drive shaft (44) of the screw conveyor (42) is rotated by rotating the small-diameter vertical shaft (46) by the motor (48). Then, ash is scraped into the cylindrical trough (43) by the ash scraping member (54), and the scraped ash is conveyed upward in the cylindrical trough (43) by the spiral blade (45). The cylindrical trough (43) is discharged from the upper end opening to the outside of the trough (43). Therefore, in the processing chamber (2), a flow of fly ash is generated by the screw conveyor (42), which causes the fly ash to be stirred, resulting in excellent stirring efficiency. As a result, the effect of uniformly heating the ash is improved as compared with the conventional apparatus, and the thermal decomposition efficiency of the dioxins in the ash is excellent.
[0040]
Next, the bottom lid (8) is lowered by the fluid pressure cylinder (23) to open the treated ash discharge port (11) and the rotary valve (58) to open the treated ash through the treated ash discharge hopper (14). The cooling tube (55) is charged from the charging port (57), and then the rotary valve (58) is closed. The treated fly ash charged into the cooling cylinder (55) is cooled by flowing through the water jacket (56) while being sent to the treated ash discharge port (59) while being mixed by the conveying and mixing device (61). The water is rapidly cooled to a predetermined temperature, for example, 60 ° C. or lower, and as a result, the treated fly ash is stabilized and dioxins are prevented from being regenerated. Thereafter, the processed fly ash is discharged from the discharge port (59).
[0041]
On the other hand, after the treated fly ash is put into the cooling cylinder (55), the bottom lid (8) is raised by the fluid pressure cylinder (23) to close the treated ash discharge port (11) and the treated ash During the rapid cooling, the ash heating chain (3) is heated by the electromagnetic induction heating coil (4).
[0042]
By repeating such an operation, dioxins contained in the fly ash are thermally decomposed sequentially.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view showing a configuration of an upper portion of a thermal decomposition apparatus for dioxins in ash according to the present invention.
FIG. 2 is a vertical sectional view showing the configuration of the lower part of the thermal decomposition apparatus for dioxins in ash.
3 is a partially enlarged view of FIG. 1 showing a configuration of a lower end portion of a thermal decomposition treatment tank.
4 is a cross-sectional view taken along line IV-IV in FIG.
FIG. 5 is an enlarged cross-sectional view taken along line VV in FIG. 1;
6 is a partially enlarged view of FIG. 1 showing how to install the ash heating chain.
FIG. 7 is a view corresponding to FIG. 6 showing a modification of how to attach the ash heating chain.
FIG. 8 is a view showing another modification of how to install the ash heating chain.
9 is an enlarged sectional view taken along line IX-IX in FIG.
FIG. 10 is a view corresponding to FIG. 9 showing a modification of the ash scraping member.
[Explanation of symbols]
(1): Pyrolysis tank
(2): Processing chamber
(3): Ash heating chain (ash heating medium)
(4): Electromagnetic induction heating coil
(6): Perimeter wall
(7): Top cover (top wall)
(8): Bottom lid
(11): Treated ash outlet
(12): outward flange
(26): Gasket
(27): Annular hanging wall
(28): Annular groove
(31): Powder for sealing
(32): Vertical rotation axis
(36): Arm
(37): Toroid
(39) (39A) (39B): Suspension member
(41): Ring
(42): Screw conveyor
(43): Cylindrical trough
(44): Vertical drive shaft
(45): Spiral feather
(46): Small-diameter vertical axis
(49): Gas passage
(51): Inert gas supply device
(53): Inert gas blowing pipe
(54) (54A): Ash scraping member

Claims (9)

Pyrolysis treatment tank provided with a treatment chamber for receiving dioxin-containing ash inside, a vertical rotation shaft penetrating the top wall of the pyrolysis treatment tank, and a suspension means provided on the rotation shaft at the upper end of the treatment chamber And a thermal decomposition apparatus for dioxins in ash comprising a plurality of ash heating media suspended by the suspension means, and a medium heating means for heating the ash heating medium,
The processing chamber is composed of a vertical cylindrical trough that is open at both ends, a vertical drive shaft disposed in the cylindrical trough, and a spiral blade fixed to the drive shaft, and ash is removed from the cylindrical trough by the spiral blade. A screw conveyor that conveys from the lower end to the upper end is arranged ,
The lower end of the drive shaft of the screw conveyor protrudes downward from the lower end of the cylindrical trough, and the ash is put into the cylindrical trough by the rotation of the drive shaft at the portion protruding downward from the lower end of the cylindrical trough in the drive shaft. An ash scraping member for scraping is provided to protrude radially outward from the drive shaft,
The vertical rotation shaft is hollow and its lower end is located at the upper end of the processing chamber. A suspension means is provided at the lower end of the rotation shaft, and the upper end of the cylindrical trough is fixed to the suspension means. The upper end portion of the drive shaft of the screw conveyor is connected to a vertical shaft arranged to rotate relative to the rotary shaft in the rotary shaft, and the vertical shaft is provided outside the thermal decomposition treatment tank. A thermal decomposition apparatus for dioxins in ash that is rotated by a drive source . A gas passage extending in the length direction is formed in the vertical shaft, the drive shaft is formed in a hollow shape closed at both upper and lower ends, and one end is connected to the lower end opening of the gas passage of the vertical shaft in the drive shaft, An inert gas blowing pipe having the other end penetrating the peripheral wall of the drive shaft and facing the processing chamber is arranged, and an inert gas is sent from the inert gas supply device to the gas passage of the vertical shaft. The thermal decomposition apparatus for dioxins in ash according to 1. The peripheral wall of the thermal decomposition treatment tank is formed of a non-conductive material, the ash heating medium is formed of a conductive material, and the medium heating means is an electromagnetic induction heating coil disposed on the outer periphery of the peripheral wall of the thermal decomposition treatment tank. The thermal decomposition apparatus for dioxins in ash according to claim 1 or 2. The thermal decomposition apparatus for dioxins in ash according to claim 3, wherein the ash heating medium is made of metal and the surface thereof is coated with SiC . The thermal decomposition apparatus for dioxins in ash according to claim 3 or 4, wherein the distance between the upper and lower ends of the electromagnetic induction heating coil and the metal parts positioned on both the upper and lower sides of the electromagnetic induction heating coil is 100 mm or more . The thermal decomposition apparatus for dioxins in ash according to any one of claims 1 to 5, wherein the ash heating medium comprises a chain, and the chain is suspended by a chain suspension member attached to the suspension means . The thermal decomposition apparatus for dioxins in ash according to claim 6, wherein one ring is attached to a lower end portion of each chain suspension member, and a plurality of chains are attached to each ring . A treatment ash discharge port is formed at the lower end of the peripheral wall of the thermal decomposition treatment tank, and an openable / closable lid is provided at the treatment ash discharge port. A gasket is disposed between the peripheral edge of the opening / closing lid, and an annular hanging wall is provided around the entire periphery of the treatment ash discharge port in the thermal decomposition treatment tank in a radially outward direction from the gasket. An annular groove that opens upward at the peripheral edge and into which the hanging wall enters when the opening / closing lid is closed is provided over the entire circumference, and sealing powder is placed in the annular groove. The thermal decomposition apparatus of the dioxin in ash in any one . The thermal decomposition apparatus for dioxins in ash according to claim 8, wherein the opening / closing lid is formed of a non-conductive material .

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