JP6424107B2 - Volume reduction treatment apparatus and volume reduction treatment method for persistent degradable waste - Google Patents

Description

  The technology disclosed in this specification relates to a technology for volume reduction treatment of hardly decomposable waste.

  Patent Document 1 discloses a volume reduction treatment apparatus for hardly decomposable waste. Volume reduction treatment equipment reduces wastes with relatively high levels of radioactivity among the hard-to-decompose wastes (including used ion exchange resins) generated at nuclear power plants and facilities that handle hard-to-decompose substances. Used to hold and stabilize. The volume reduction processing apparatus of Patent Document 1 includes a dry distillation section and a residue storage section connected to the bottom of the dry distillation section. In the dry distillation section, the input hardly decomposeable waste is thermally decomposed. The residue generated by the thermal decomposition is discharged and stored in the residue storage unit. The residue stored in the residue storage part contains combustible components (organic matter). For this reason, the process which further thermally decomposes the combustible part in a residue is performed by providing a superheated steam supply means in a residue storage part, and supplying superheated steam to a residue storage part. Thus, in the technology of Patent Document 1, the volume reduction rate of the hardly decomposable waste is improved by thermally decomposing the hardly decomposable waste in two stages in the dry distillation part and the residue storage part.

JP2013-248580A

  Although the volume reduction rate of the hardly decomposable waste can be improved by the technique of Patent Document 1, further improvement in volume reduction rate is required. This specification discloses the technique which can further improve the volume reduction rate of a hardly decomposable waste.

  A volume reduction treatment device for a hardly decomposable waste disclosed in the present specification includes a dry distillation unit, an external heating unit, a waste supply unit, a residue storage unit, a first superheated steam supply unit, a transfer unit, A second superheated steam supply means. The external superheating means heats the dry distillation section from the outside. The waste supply means supplies the hardly decomposable waste from one end of the dry distillation section. One end of the residue storage unit is connected to the other end of the dry distillation unit, and stores residue generated by pyrolyzing the hardly decomposable waste in the dry distillation unit. The first superheated steam supply means supplies superheated steam to the residue reservoir. The transfer unit is connected to the other end of the residue storage unit and transfers the residue stored in the residue storage unit while stirring. The second superheated steam supply means supplies superheated steam to the transfer unit.

  In said volume reduction processing apparatus, the transfer part is connected to the other end of the residue storage part, and a transfer part transfers the residue stored in the residue storage part, stirring. Superheated steam is supplied to the transfer section by the second superheated steam supply means. According to this configuration, since the superheated steam is supplied to the residue transferred by the transfer unit while being stirred, the superheated steam easily comes into contact with the surface of the residue. For this reason, in a transfer part, the combustible part which could not be thermally decomposed in the residue storage part can be thermally decomposed appropriately. That is, in the volume reduction processing apparatus described above, the hardly decomposable waste is thermally decomposed in three stages in the dry distillation section, the residue storage section, and the transfer section. Thereby, the volume reduction rate of a hardly decomposable waste can further be improved compared with the structure which thermally decomposes in two steps in a dry distillation part and a residue storage part.

  In addition, the present specification discloses a novel volume-reducing treatment method for hardly-decomposable waste that can solve the above-described problems. This volume reduction processing method includes a first pyrolysis step and a second pyrolysis step. In the first pyrolysis step, the hardly decomposable waste is pyrolyzed by pyrolysis. In the second pyrolysis step, the residue generated in the first pyrolysis step is pyrolyzed with superheated steam while stirring. According to this volume reduction treatment method, the volume reduction rate of hardly decomposable waste can be improved.

  Details of the technology disclosed in this specification and further improvements will be described in detail in the detailed description and examples.

1 is a schematic cross-sectional view of a ball-type carbonization furnace of Example 1. FIG. Sectional drawing in the II-II line of FIG.

  The main features of the embodiments described below are listed. The technical elements described below are independent technical elements and exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Absent.

(Characteristic 1) In the volumetric treatment device of the hardly decomposable waste disclosed in the present specification, the transfer unit may continuously transfer the residue stored in the residue storage unit. According to this configuration, even when the waste supply means continuously inputs the hardly decomposable waste into the dry distillation section, it is possible to avoid a large amount of residue from being accumulated in the residue storage section. For this reason, it can suppress that the volume reduction rate in a residue storage part falls resulting from a large amount of residue accumulating in a residue storage part. That is, the waste supply means can continuously input the hardly decomposable waste into the dry distillation part while suppressing the decrease in the volume reduction rate in the residue storage part. Can be processed.

(Characteristic 2) In the volumetric treatment apparatus for hardly decomposable waste disclosed in the present specification, the amount of water vapor per unit time supplied by the second superheated steam supply means is supplied by the first superheated steam supply means. It may be less than the amount of water vapor per unit time. Since the residue is transferred while being stirred in the transfer unit, the surface of the residue can be efficiently contacted with superheated steam. Therefore, even if the unit flow rate of water vapor supplied by the second superheated steam supply unit is smaller than the unit flow rate of water vapor supplied by the first superheated steam supply unit, the combustible component in the residue is appropriately pyrolyzed in the transfer unit. can do. According to this configuration, it is possible to reduce the amount of superheated steam necessary for pyrolyzing the hardly decomposable waste per unit amount while improving the volume reduction rate.

(Characteristic 3) In the volume-reducing treatment apparatus for hardly decomposable waste disclosed in the present specification, the dry distillation section includes a metal reaction vessel, and a plurality of ceramic or metal balls filled in the reaction vessel. And a stirring means for stirring the plurality of balls. By using a ball-type dry distillation section, it is possible to efficiently perform thermal decomposition of the input of the hardly decomposable waste.

(Characteristic 4) In the volumetric treatment device for persistent decomposition waste disclosed in this specification, the persistent decomposition waste is ion exchange resin, activated carbon, sludge, waste oil / water-containing waste oil, laundry waste liquid / drain, and concentrated waste liquid thereof. , At least one of organic waste liquid and rubber may be included.

  With reference to FIGS. 1 and 2, the ball type dry distillation furnace 10 and the volume reduction method using the ball type dry distillation furnace 10 according to the first embodiment will be described. The ball-type carbonization furnace 10 reduces the volume of used ion exchange resin having a relatively high level of radioactivity generated in a nuclear facility. As shown in FIG. 1, the ball-type carbonization furnace 10 includes a carbonization unit 20, a residue storage unit 36 connected to the lower surface of the carbonization unit 20, a filter unit 44 disposed on the upper surface of the residue storage unit 36, and a residue A screw conveyor 50 connected to the lower end of the reservoir 36. The dry distillation unit 20 includes an external electric heater 28 that heats the dry distillation unit 20 from the outside, an ion exchange resin supply nozzle 30 that supplies an ion exchange resin from the upper surface of the dry distillation unit 20, and a side surface above the dry distillation unit 20. A superheated steam supply nozzle 32 for supplying superheated steam is provided. The residue storage unit 36 is provided with a superheated steam supply nozzle 38 that supplies superheated steam to the residue storage unit 36. The filter unit 44 is provided with an exhaust gas outlet 48 for discharging the exhaust gas filtered by the filter unit 44. The screw conveyor 50 has a supply port 53 for supplying the residue discharged from the residue storage unit 36 to the screw conveyor 50, a discharge port 54 for discharging the residue transferred by the screw conveyor 50, and superheated steam to the screw conveyor 50. A superheated steam supply nozzle 62 for supplying is provided. The ball-type carbonization furnace 10 corresponds to an example of a “volume reduction treatment apparatus”.

  The dry distillation section 20 includes a cylindrical sealed reaction vessel 21, a plurality of ceramic balls 24 filled in the reaction vessel 21, a stirring blade 26 that stirs the balls 24, and a rotation that rotates the stirring blade 26. It has a shaft 22. The reaction vessel 21 has a cylindrical shape made of metal, and includes a pressure control mechanism (not shown) that maintains the pressure in the reaction vessel 21 at −0.5 to −10 kPa. On the outer peripheral surface of the reaction vessel 21, heaters 28 are arranged at substantially equal intervals in the z direction. The heater 28 can control the temperature in the reaction vessel 21 to a desired temperature (about 400 to 700 ° C.). The length in the z direction of the reaction vessel 21 is appropriately determined according to the type of the hardly decomposable waste to be treated. The stirring blade 26 and the rotating shaft 22 correspond to an example of “stirring means”, and the heater 28 corresponds to an example of “external heating means”.

  A rotation shaft 22 is provided at the axial center of the reaction vessel 21. The rotating shaft 22 is rotated at a predetermined speed (about 0.1 to 2.0 rpm, preferably 0.5 rpm or more) by a drive motor (not shown). A spiral stirring blade 26 is attached to the periphery of the rotating shaft 22. The stirring blade 26 has a spiral outer frame portion (not shown) extending so as to surround the rotary shaft 22 and a plurality of plate-like blade portions (not shown) that connect the outer frame portion and the rotary shaft 22. . The outer frame portion is located in the vicinity of the inner peripheral surface of the reaction vessel 21. The plurality of wing portions are arranged in a distributed manner at intervals from the upper end to the lower end of the outer frame portion. For this reason, a space is formed between two adjacent wings. In addition, the shape of the wing portion may be a flat plate shape or a plate shape having a curved surface.

  As the ball 24 in the reaction vessel 21, a ceramic ball having a diameter of 10 to 25 mm and having corrosion resistance is used. However, the material of the ball 24 is not limited to this, and may be made of Hastelloy or Inconel, which is a high nickel alloy. By being agitated by the agitating blade 26, the ball 24 repeatedly descends and rises in the reaction vessel 21.

  An ion exchange resin supply nozzle 30 is installed on the upper surface of the reaction vessel 21. From the ion exchange resin supply nozzle 30, ion exchange resin generated in the nuclear facility is supplied into the reaction vessel 21. The ion exchange resin is continuously supplied from the ion exchange resin supply nozzle 30 at a predetermined speed. The ion exchange resin supplied into the reaction vessel 21 adheres to the surface of the ball 24 and moves inside the reaction vessel 21. For this reason, the residence time of the ion exchange resin in the reaction vessel 21 is the same as the descent time of the ball 24. The ion exchange resin supplied into the reaction vessel 21 may be a slurry in which a resin and moisture are mixed at a predetermined ratio (for example, moisture of 85 to 95% with respect to resin of 5 to 15%). The ion exchange resin supply nozzle 30 corresponds to an example of “waste supply means”.

  A superheated steam supply nozzle 32 is installed on the side surface above the reaction vessel 21. Superheated steam is supplied from the superheated steam supply nozzle 32 to the ion exchange resin attached to the surface of the ball 24. As a result, the ion exchange resin and superheated steam react in the reaction vessel 21 to thermally decompose the ion exchange resin, and a residue and exhaust gas are generated. In the reaction vessel 21, the volume of the ion exchange resin is reduced to about 1/4. Note that whether or not superheated steam is supplied from the superheated steam supply nozzle 32 is arbitrary, and can be appropriately determined according to the moisture content of the ion exchange resin supplied from the ion exchange resin supply nozzle 30. For example, when the moisture content of the ion exchange resin is high, the supply of superheated steam from the superheated steam supply nozzle 32 may be stopped. On the other hand, when the moisture content of the ion exchange resin is low, superheated steam may be supplied from the superheated steam supply nozzle 32.

  A holding plate 34 for holding the ball 24 in the reaction vessel 21 is disposed at the lower end of the reaction vessel 21. The residue storage part 36 is provided below the holding plate 34. The holding plate 34 prohibits the passage of the ball 24 while allowing the residue and the exhaust gas to pass therethrough. Thereby, the ball 24 filled in the reaction vessel 21 is prevented from falling into the residue storage unit 36, while the residue and exhaust gas generated in the reaction vessel 21 can move to the residue storage unit 36.

  The residue storage part 36 has a cylindrical shape at the upper part and a truncated cone shape whose diameter decreases as it goes downward. The angle formed by the wall surface of the truncated cone portion and the xy plane is equal to or greater than the repose angle of the residue. For this reason, the residue discharged from the lower end of the reaction vessel 21 slides down on the wall surface of the truncated cone part toward the lower part of the residue storage part 36 or falls as it is. On the other hand, the exhaust gas discharged from the reaction vessel 21 moves to the filter unit 44 (described later). The lower end of the residue storage part 36 is opened, and the supply port 53 of the screw conveyor 50 is connected to the lower end (described later). Therefore, strictly speaking, the residue falls to a space immediately below the supply port 53, and when the space is filled with the residue, the residue is stored in a lower portion of the residue storage portion 36 that is a space above the space.

  A superheated steam supply nozzle 38 is provided on the wall surface of the residue reservoir 36. The superheated steam supply nozzle 38 supplies superheated steam to the residue stored in the residue storage unit 36 (including residues that are falling in the residue storage unit 36). When the residue is in sufficient contact with the superheated steam, the combustible component in the residue reacts with the superheated steam and thermally decomposes, so that the residue is further reduced in volume. On the other hand, when the residue does not sufficiently contact with the superheated steam, the combustible component in the residue is not thermally decomposed, and the residue is not reduced in volume. Hereinafter, a residue (that is, a residue that is sufficiently in contact with superheated steam) whose combustible component has been thermally decomposed in the residue storage unit 36 is particularly referred to as a “decomposed residue”, and a residue ( That is, a residue that has not been in sufficient contact with superheated steam) is particularly referred to as an “undecomposed residue”. In the residue storage part 36, it is stored in a state where the decomposed residue and the undecomposed residue are mixed. The superheated steam supply nozzle 38 corresponds to an example of “first superheated steam supply means”.

  External electric heaters 40 are provided on the outer peripheral surface of the residue reservoir 36 at substantially equal intervals in the z direction. The temperature in the residue reservoir 36 is controlled by the heater 40 to a temperature (about 400 to 700 ° C.) at which the combustible component in the residue can be thermally decomposed.

  A filter unit 44 is disposed on the upper surface of the residue storage unit 36. The residue storage part 36 and the filter part 44 are connected. The filter unit 44 includes a cylindrical filter container 45 and a sintered metal filter 46 installed in the filter container 45. In addition, although the sintered metal filter was used in the present Example, it is not restricted to this, For example, you may use a ceramic filter.

  An exhaust gas outlet 48 is installed on the upper side surface of the filter container 45. The exhaust gas outlet 48 is connected to an exhaust gas treatment device (not shown). The exhaust gas treatment device includes an exhaust gas blower. For this reason, the pressure in the filter container 45 (particularly the pressure in the vicinity of the exhaust gas outlet 48) is lower than the pressure in the residue reservoir 36. Therefore, among the residue and exhaust gas discharged from the reaction container 21 to the residue storage unit 36, the exhaust gas moves to the filter container 45 side and rises in the filter container 45. The exhaust gas is filtered by the sintered metal filter 46 in the process of rising in the filter container 45. The filtered exhaust gas is discharged from the exhaust gas outlet 48 and sent to an exhaust gas treatment device (not shown).

  The screw conveyor 50 is connected to the lower end of the residue storage unit 36. The screw conveyor 50 includes a casing 52, a rotating shaft 56, screw blades 58, and a drive motor 60. The screw conveyor 50 corresponds to an example of a “transfer section”.

  The casing 52 has a cylindrical shape with a bottom and a lid, and its central axis extends in the x direction. As shown in FIG. 2, as for the cross section in the yz plane direction of the casing 52, the substantially lower half is a semicircle shape, and the substantially upper half is a rectangular shape. In FIG. 2, the screw blades 58 are indicated by broken lines. As shown in FIG. 1, a supply port 53 is provided on the upper surface of the end portion of the casing 52 on the −x direction side. The supply port 53 is connected to the lower end of the residue storage unit 36 in an airtight and liquid tight manner. The residue discharged from the reaction vessel 21 to the residue storage unit 36 is supplied into the casing 52 through the supply port 53. A discharge port 54 is provided on the lower surface of the end portion on the x direction side of the casing 52. The residue transferred by the screw conveyor 50 is discharged from the discharge port 54 and sent to a solidification facility (not shown).

The rotating shaft 56 is provided in the axial center part of the casing 52 (refer FIG. 2). The rotating shaft 56 is rotated at a predetermined speed by the drive motor 60. A spiral screw blade 58 is attached to the periphery of the rotating shaft 56. The screw blade 58 rotates integrally with the rotating shaft 56. The outer edge of the screw blade 58 is located in the vicinity of the inner peripheral surface of the lower half of the casing 52 (that is, the portion having a semicircular cross section), while the upper surface 52a (see FIG. 2) of the casing 52 is predetermined. It is located at a position with an interval of. When the rotating shaft 56 is rotated by the drive motor 60, the residue supplied from the supply port 53 (that is, the residue obtained by mixing the decomposed residue and the undecomposed residue) is stirred inside the casing 52 with the rotation of the screw blade 58. Move in the x direction.
As described above, the lower half of the casing 52 is formed to have a semicircular cross section, and the outer edge of the screw blade 58 is positioned in the vicinity of the inner peripheral surface of the lower half of the casing 52, thereby It can suppress that a residue accumulates in the lower part of 52, without being transferred by the screw blade | wing 58. FIG. The screw blade 58 can appropriately transfer the residue supplied from the supply port 53. The residence time of the residue in the screw conveyor 50 is preferably about 1 hour or longer. Thereby, the combustible part in an undecomposed residue can be thermally decomposed suitably. The drive motor 60 continues until the residue is stored at a predetermined height in the residue storage unit 36 (that is, until a predetermined time elapses after the supply of the ion exchange resin from the ion exchange resin supply nozzle 30 is started). It is controlled not to start driving. Thereby, it is possible to prevent the residue from being transferred by the screw conveyor 50 while the thermal decomposition of the residue in the residue storage unit 36 is insufficient. A time for thermally decomposing the residue in the residue storage unit 36 can be secured.

The superheated steam supply nozzle 62 is provided adjacent to the supply port 53 on the upper surface 52 a (see FIG. 2) of the casing 52. The superheated steam supply nozzle 62 supplies superheated steam to the residue transferred while being stirred in the casing 52. The amount of superheated steam per unit time supplied from the superheated steam supply nozzle 62 is smaller than the amount of superheated steam per unit time supplied from the superheated steam supply nozzle 38, and the ratio is about 1:10. The superheated steam is supplied at a flow rate of about 1 to 10 [m / s]. When the flow rate of the superheated steam is less than about 1 [m / s], the undecomposed residue does not sufficiently contact with the superheated steam, and the combustible component in the undecomposed residue is difficult to be thermally decomposed. On the other hand, if the flow rate of superheated steam is greater than about 10 [m / s], the residue may rise by the injection pressure of superheated steam, and the residue may not be properly transferred by the screw blades 58. By supplying the superheated steam within the range of the above flow rate, the undecomposed residue is sufficiently in contact with the superheated steam in the casing 52. Therefore, the combustible component in the undecomposed residue reacts with the superheated steam and is thermally decomposed. The volume of undecomposed residue is reduced.
As described above, the upper half of the casing 52 is formed to have a rectangular cross section, and the outer edge of the screw blade 58 is positioned at a predetermined distance from the upper surface 52a of the casing 52. A space extending in the xy plane direction can be formed in the upper part of the casing 52. For this reason, by providing the superheated steam supply nozzle 62 on the upper surface 52a of the casing 52, the superheated steam can be suitably moved through the upper space in the casing 52 without hindering the transfer of the residue being transferred by the screw blades 58. can do. Specifically, the superheated steam supplied from the superheated steam supply nozzle 62 passes through the upper space in the casing 52 and moves to the relatively low pressure filter unit 44 side. Thereby, the undecomposed residue in the casing 52 comes into contact with the superheated steam in the space from the supply port 53 to the superheated steam supply nozzle 62. For this reason, an undecomposed residue can contact superheated steam over a long period of time, and as a result, the volume reduction rate can be further improved. The residue discharged from the discharge port 54 is reduced to about 1/20 of the ion exchange resin charged into the reaction vessel 21. The superheated steam supply nozzle 62 corresponds to an example of “second superheated steam supply means”.

  Next, a method for reducing the volume of the ion exchange resin by the ball-type carbonization furnace 10 of this embodiment will be described. In the following, the flow of the ion exchange resin volume reduction process will be mainly described, and the detailed description of the same contents as those described above will be omitted.

(Ion exchange resin supply process, superheated steam supply process for dry distillation section, first pyrolysis process)
First, the ion exchange resin is supplied from the ion exchange resin supply nozzle 30 to the reaction vessel 21 of the dry distillation section 20 (ion exchange resin supply step), and superheated steam is supplied from the superheated steam supply nozzle 32 (superheated steam supply for dry distillation section). Process). The supply amount per unit time of the ion exchange resin and superheated steam is controlled by a control device (not shown). In the reaction vessel 21, the ion exchange resin is thermally decomposed by superheated steam and reduced in volume (first pyrolysis step). When the ion exchange resin is thermally decomposed, residue and exhaust gas are generated. In addition, the superheated steam supply process for dry distillation parts does not need to be implemented.

(Storage process, filtration process)
From the lower end of the reaction vessel 21, the residue and exhaust gas are discharged to the residue storage portion 36 through the opening of the holding plate 34. Among these, the residue falls with its own weight and is stored in the lower part of the residue storage unit 36 (including the space immediately below the supply port 53 of the screw conveyor 50) (storage process). On the other hand, the exhaust gas moves to the filter container 45 side and is filtered by the sintered metal filter 46 (filtering step). The exhaust gas filtered in the filtration step is sent from the exhaust gas outlet 48 to the exhaust gas treatment device.

(First superheated steam supply step, reservoir pyrolysis step)
Superheated steam is supplied from the superheated steam supply nozzle 38 to the residue storage unit 36 (first superheated steam supply process). The supply amount of superheated steam per unit time is controlled by a control device. Part of the residue stored in the residue storage part 36 in the storage process (including the residue falling in the residue storage part 36) is sufficiently in contact with this superheated steam, so that the combustible part is pyrolyzed, The volume is reduced (reservoir pyrolysis step). When the residue is thermally decomposed by the storage portion pyrolysis step, a decomposed residue is generated. On the other hand, since the remainder of the residue stored in the residue storage part 36 in a storage process cannot fully contact with the superheated steam supplied from the superheated steam supply nozzle 38, it is not thermally decomposed in the storage part pyrolysis process. As a result, an undecomposed residue is generated in the residue storage unit 36.

(Transfer process)
When the residue (mixed residue of decomposed residue and undecomposed residue) stored in the residue storage unit 36 exceeds a predetermined amount, the drive motor 60 drives the rotating shaft 56 to rotate the screw blade 58. The drive motor 60 is controlled by a control device (not shown). Thereby, the residue (mixed residue of the decomposed residue and the undecomposed residue) stored in the space immediately below the supply port 53 of the screw conveyor 50 is transferred in the x direction while being stirred by the rotation of the screw blade 58 ( Transfer process). The control device performs control so that the amount of residue transferred per unit time in the transfer step is substantially equal to the amount of residue stored per unit time in the storage step. Thereby, a fixed amount of residue is always stored in the residue storage unit 36 except when the ball-type carbonization furnace 10 starts operation and when the operation ends. For this reason, the volume reduction rate of the residue in the residue storage part 36 is stabilized, and as a result, the volume reduction rate of the residue discharged | emitted from the discharge port 54 of the screw conveyor 50 is stabilized. The ball-type dry distillation furnace 10 can be continuously operated appropriately for 24 hours.

(Second superheated steam supply step, second pyrolysis step)
Superheated steam is supplied from the superheated steam supply nozzle 62 into the casing 52 (second superheated steam supply process). The supply amount of superheated steam per unit time is controlled by a control device (not shown). Among the residues that are transferred while being stirred in the transfer step, the undecomposed residue is sufficiently brought into contact with the superheated steam, whereby the combustible component is thermally decomposed and reduced in volume (second thermal decomposition step). The residue thermally decomposed in the second pyrolysis step is discharged from the discharge port 54 together with the decomposed residue and sent to the solidification facility.

  In the ball type dry distillation furnace 10 of the present embodiment, the screw conveyor 50 is connected to the lower end of the residue storage unit 36, and the screw conveyor 50 transfers the residue stored in the residue storage unit 36 while stirring. Superheated steam is supplied from the superheated steam supply nozzle 62 to the screw conveyor 50. Thus, by supplying superheated steam while stirring the residue, the superheated steam easily comes into contact with the surface of the residue. For this reason, in the screw conveyor 50, the combustible part in the undecomposed residue which could not be thermally decomposed by the residue storage part 36 can be thermally decomposed, and the volume reduction rate of the ion exchange resin can be further improved. Moreover, according to the structure of the ball-type dry distillation furnace 10, the residue can be thermally decomposed during the transfer of the residue. For this reason, the transfer time of a residue can be effectively utilized by forming the screw conveyor 50 toward solidification equipment.

Here, the advantages of the ball type carbonization furnace 10 of the present embodiment compared to the conventional ball type carbonization furnace will be described in detail. First, since the conventional ball-type dry distillation furnace does not include a screw conveyor for transferring the residue in the residue storage unit, a large amount of residue accumulates in the residue storage unit with a long time operation. For this reason, superheated steam cannot be sufficiently brought into contact with the residue, the combustible component in the residue cannot be sufficiently pyrolyzed, and the volume reduction rate is not sufficiently improved.
In addition, since the ion exchange resin is a hardly decomposable waste, it takes time to thermally decompose the combustible content in the residue. For this reason, conventionally, when a certain amount of residue is stored in the residue storage part, the time for approximately 10 to 4 hours for thermally decomposing combustible components in the residue by temporarily stopping the introduction of the ion exchange resin ) Had to be secured (so-called post-processing). Although the combustible content in the residue is thermally decomposed to some extent by performing the post-treatment, there is a problem that the treatment efficiency is lowered because the ion-exchange resin cannot be input during that time. In addition, there was a limit to improving the volume reduction rate of the residue by post-treatment.
Furthermore, the conventional ball-type carbonization furnace does not include a screw conveyor, and has a configuration in which pyrolysis is performed in two stages in the carbonization section and the residue storage section. That is, in the conventional ball-type dry distillation furnace, a damper that can be opened and closed is provided at the lower end of the residue reservoir, and the residue is discharged from the residue reservoir 36 by opening and closing the damper. For this reason, the damper is closed while the residue is thermally decomposed in the residue storage unit 36, and the damper is opened after the thermal decomposition is completed. When the damper is opened, the treated residue is discharged from the damper and sent to the solidification facility. While the damper is opened and the residue is discharged to the outside, it is necessary to prevent the residue from being discharged from the reaction vessel to the residue storage part. That is, the ion exchange resin could not be continuously charged into the reaction vessel.

In the ball type dry distillation furnace 10 of the present embodiment, a screw conveyor 50 is connected to the lower end of the residue storage unit instead of the damper. Since the rotating shaft 56 rotates at a predetermined speed, the residue stored in the residue storage unit 36 is continuously transferred by the screw blades 58. For this reason, even if ion-exchange resin is continuously charged into the reaction vessel 21, it is possible to avoid a large amount of residue from being accumulated in the residue reservoir 36. Therefore, it can suppress that the volume reduction rate in the residue storage part 36 falls because a large amount of residue accumulates in the residue storage part 36. FIG. That is, it is possible to continuously treat the ion exchange resin for 24 hours in the ball-type dry distillation furnace 10 while suppressing a decrease in the volume reduction rate in the residue storage unit 36.
Moreover, the residue (undecomposed residue) that could not be thermally decomposed in the residue storage unit 36 is appropriately thermally decomposed in the screw conveyor 50. This eliminates the need for post-processing that was conventionally required. Moreover, the contact efficiency of the residue and superheated steam in the screw conveyor 50 is very high as compared with the contact efficiency of the residue and superheated steam in the post-treatment. For this reason, combustible components in the undecomposed residue can be processed in a shorter time (that is, with a smaller amount of superheated steam) at a higher thermal decomposition rate as compared with the conventional post-treatment. That is, both the volume reduction rate and the processing efficiency can be improved at the same time.

  Moreover, in the ball-type dry distillation furnace 10 of the present embodiment, since the residue is transferred while being stirred in the screw conveyor 50, the surface of the undecomposed residue can be efficiently contacted with superheated steam. For this reason, even if the unit flow rate of the superheated steam supplied from the superheated steam supply nozzle 62 is smaller than the unit flow rate of the superheated steam supplied from the superheated steam supply nozzle 38, and the ratio is about 1:10, the screw In the conveyor 50, combustible components in the undecomposed residue can be efficiently decomposed. For this reason, the amount of superheated steam required for pyrolyzing the ion exchange resin per unit amount while improving the volume reduction rate compared to the conventional configuration in which the post-treatment is performed for a long time in the residue reservoir Can be reduced. Since the amount of superheated steam can be reduced, the exhaust gas treatment device can be downsized.

  In addition, in a conventional ball-type carbonization furnace, if a large amount of residue accumulates in the residue storage part, the reason why the thermal decomposition rate of the combustible content in the residue decreases is considered as follows. That is, the residue generated by pyrolyzing the ion exchange resin is usually powdery and lightweight. However, as a result of investigations by the inventors, some of these residues are separated from each other by sintering or the like. It turned out to be an aggregate that was assembled and hardened. In general, it is considered that in the residue storage unit, the residue is lifted by the superheated steam injection pressure so that the residue is thermally decomposed by contacting the residue with the superheated steam. However, since the aggregate of residues is relatively heavy, it does not rise due to the superheated steam injection pressure, and it is difficult to make sufficient contact with the superheated steam. For this reason, thermal decomposition of the combustible part in the aggregate becomes insufficient, and as a result, if a large amount of residue accumulates in the residue storage part, it is considered that the thermal decomposition rate of the combustible part in the residue decreases. On the other hand, in the ball-type dry distillation furnace 10 of the present embodiment, the residue aggregate is agitated by the screw conveyor 50 so that the residue aggregate is finely granulated and is in good contact with superheated steam, thereby improving the volume reduction rate. It is thought that is planned.

  As mentioned above, although the Example of the technique which this specification discloses was described in detail, these are only illustrations, and the volume reduction processing apparatus and volume reduction processing method of the hardly decomposable waste which this specification discloses are the above-mentioned. Various modifications and changes of the embodiment are included. For example, although the ball type carbonization furnace is used in Example 1, the type of the carbonization furnace is not limited to this, and for example, an induction heating type carbonization furnace may be used.

  In Example 1, an example in which an ion exchange resin is treated has been described. However, the technique disclosed in the present specification can be applied to other hardly decomposable wastes (for example, activated carbon, sludge, waste oil / water-containing waste oil, laundry waste liquid / Drainage and its concentrated waste liquid, organic waste liquid, rubber, etc.).

  Further, the screw conveyor 50 may be in any direction as long as the residue can ensure a certain residence time in the screw conveyor 50. For example, the screw conveyor 50 may be inclined or may extend in the vertical direction. An axisless screw conveyor may be used. Moreover, the screw conveyor 50 does not need to transfer a residue continuously. For example, when a certain amount of residue is accumulated in the residue storage unit 36, the residue is transferred, and when the predetermined amount of residue is transferred, the residue transfer is stopped until a certain amount of residue is accumulated in the residue storage unit 36 again. Also good. Moreover, it is not restricted to a screw conveyor to transfer the residue discharged | emitted from the residue storage part 36, For example, you may transfer, stirring a residue with a rotary conveyor. Further, the superheated steam supply nozzle 62 may be provided on the side peripheral surface of the casing 52, for example, may be provided at an end portion of the casing 52 on the −x direction side. Moreover, you may install the heater which heats the screw conveyor 50 from the outside. A plurality of superheated steam supply nozzles 62 may be installed.

  The ratio of the unit flow rate of water vapor supplied from the superheated steam supply nozzle 62 and the unit flow rate of water vapor supplied from the superheated steam supply nozzle 38 is not limited to 1:10. For example, when the volume ratio of the screw conveyor 50 to the residue storage unit 36 is smaller than that of the ball-type carbonization furnace 10 of the first embodiment, the above ratio may be 0.8: 10, for example. On the contrary, when the volume ratio with respect to the residue storage part 36 of the screw conveyor 50 becomes large, said ratio may be 1.3: 10, for example.

  In addition, an open / close door may be provided at the lower end of the residue storage unit 36. When the continuous operation starts, the door may be closed and the door may be opened when a certain amount of residue is stored in the residue storage unit 36. According to this structure, it can suppress more reliably that the residue thrown in at the time of a driving | operation start being supplied to the screw conveyor 50 through the supply port 53, without fully thermally decomposing in the residue storage part 36. FIG.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

10: Ball-type carbonization furnace 20: Carbonization unit 21: Reaction vessel 22: Rotating shaft 24: Ball 26: Stirring blade 28: Heater 30: Ion exchange resin supply nozzle 32: Superheated steam supply nozzle 36: Residue storage unit 38: Superheated steam Supply nozzle 44: Filter unit 50: Screw conveyor 52: Casing 53: Supply port 54: Discharge port 56: Rotating shaft 58: Screw blade 60: Drive motor 62: Superheated steam supply nozzle

Claims (6)

It is a device that reduces the volume of persistent waste,
A dry distillation section;
An external heating means for heating the dry distillation section from the outside;
Waste supply means for supplying hardly decomposable waste from one end of the dry distillation section;
One end of which is connected to the other end of the carbonization unit, and a residue storage unit in which residues generated by pyrolyzing the hardly decomposable waste in the carbonization unit are stored,
First superheated steam supply means for supplying superheated steam to the residue reservoir,
A transfer unit connected to the other end of the residue storage unit and transferring the residue stored in the residue storage unit while stirring;
And a second superheated steam supply means for supplying superheated steam to the transfer section.   The volume reduction processing apparatus according to claim 1, wherein the transfer unit continuously transfers the residue stored in the residue storage unit.   The volume reduction according to claim 1 or 2, wherein the amount of water vapor per unit time supplied by the second superheated steam supply unit is smaller than the amount of water vapor per unit time supplied by the first superheated steam supply unit. Processing equipment.   The said carbonization part has a metal reaction container, a plurality of ceramic or metal balls filled in the reaction container, and a stirring means for stirring the plurality of balls. The volume reduction processing apparatus according to any one of the above. The hard-to-decompose waste comprises at least one of ion exchange resin, activated carbon, sludge, waste oil , hydrous waste oil, laundry waste liquid , drain , laundry waste concentrated waste liquid, drain concentrated waste liquid , organic waste liquid and rubber. Item 5. The volume reduction processing device according to any one of Items 1 to 4. It is a method to reduce the volume of refractory waste,
A first pyrolysis step of pyrolyzing a hardly decomposable waste by dry distillation with superheated steam in a dry distillation furnace ;
In the transfer unit that transfers the residue generated by the first pyrolysis step from the dry distillation furnace, the second pyrolysis step of thermally decomposing with superheated steam supplied to the transfer unit while stirring the residue , Volume reduction processing method.

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