JP5961044B2 - Volume reduction treatment method and volume reduction treatment apparatus 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. In particular, the present invention relates to a technique that can be suitably used for volume reduction treatment of ion exchange resins used in nuclear power plants.

  As the hardly decomposable waste, for example, an ion exchange resin used in a nuclear power plant is known. That is, in a nuclear power plant, a large amount of ion exchange resin is used for purification of system water and purification of water injected into the system in order to prevent corrosion of equipment. Since these ion-exchange resins deteriorate in performance over time, they become waste after being used for a predetermined period. Conventionally, used ion exchange resins generated at nuclear power plants are sorted by radioactivity level and stored together with water in storage tanks. The ion exchange resin has a characteristic that it is stable and hardly decomposable in a natural state, but since it is an organic substance, it may be deteriorated in the long term. Therefore, when disposing of the used ion exchange resin as waste, it is necessary to make it mineralized and stabilized.

  Various mineralization volume reduction technologies such as incineration treatment, thermal decomposition treatment, and oxidative decomposition treatment have been developed as methods for treating used ion exchange resins generated at nuclear power plants. Currently, some nuclear power plants are subjected to high-temperature incineration at 800 ° C. or higher for those with low radioactivity levels. On the other hand, those with relatively high levels of radioactivity have problems with the treatment of refractories that constitute the processing furnace used during high-temperature incineration, and the problem of Cs scattering associated with high-temperature incineration. Is difficult and is currently stored in a storage tank together with water. In order to solve these problems, a technique for mineralizing and reducing the spent ion exchange resin using a carbonization apparatus has been developed (for example, Patent Document 1).

JP 63-171400 A

  As described above, the used ion exchange resin generated in the nuclear power plant is stored in the storage tank together with water. For this reason, when processing a used ion exchange resin in a carbonization apparatus, a slurry of a high moisture content ion exchange resin transferred from a storage tank (a moisture content of 70% or more (solid content of 30% or less, usually a solid content of 5 ~ 15%)) can be put into the carbonization apparatus as it is. However, if a slurry of an ion exchange resin having a high moisture content is put into a dry distillation apparatus as it is, a large amount of water evaporates from the slurry of the ion exchange resin, so that it is necessary to enlarge the dry distillation apparatus. Therefore, it is also conceivable that the slurry of the ion exchange resin transferred from the storage tank is dehydrated by a dehydrator, and the ion exchange resin whose moisture content has been reduced by dehydration is put into the dry distillation apparatus. Although this method can suppress the enlargement of the carbonization apparatus, a dehydrator is required, and there is a problem that a facility for treating water separated from the slurry by dehydration is also required.

  The present specification discloses a technique capable of suppressing an increase in size of a processing apparatus while adopting a method in which a slurry of a hardly decomposable waste having a high moisture content is introduced as it is into the processing apparatus.

The method of reducing the volume of the hardly decomposable waste disclosed in the present specification includes a step of thermally decomposing the hardly decomposable waste by supplying a slurry of the hardly decomposable waste and superheated steam to the dry distillation section. Yes. The slurry of the hardly decomposable waste is supplied from one end of the dry distillation part in a state where the moisture content exceeds 70%, and the gas generated by thermally decomposing the hardly decomposable waste is discharged from the other end of the dry distillation part. . And the temperature in the other end of a dry distillation part is 460-700 degreeC, It is characterized by the above-mentioned.

  In this volume reduction processing method, a slurry of highly degradable waste having a high moisture content is supplied to one end of the dry distillation section, and gas generated by pyrolyzing the hardly decomposable waste from the other end of the dry distillation section is discharged. . At this time, the temperature of the other end of the dry distillation section (position where the dry distillation process is completed) is adjusted to 460 to 700 ° C. That is, the amount of superheated steam supplied to the dry distillation unit and the heating amount for heating the dry distillation unit are adjusted so that the temperature at the other end of the dry distillation unit is 460 to 700 ° C. As a result, the amount of superheated steam is adjusted according to the moisture content of the slurry of the hardly decomposable waste put into the dry distillation section, the amount of steam generated in the dry distillation section is suppressed, and the processing apparatus is enlarged. This can be suppressed. Further, as shown in the experimental results to be described later conducted by the present inventors, by adjusting the temperature at the other end of the dry distillation section to be 460 to 700 ° C., a slurry of highly decomposable waste with a high moisture content. Even if it is put into the dry distillation section as it is, the hardly decomposable waste can be sufficiently reduced. Therefore, according to this volume reduction processing method, it is possible to suppress an increase in the size of the processing apparatus while reducing the volume of the hard-decomposable waste slurry having a high moisture content by directly putting it into the processing apparatus.

In addition, the present specification discloses an apparatus for reducing the volume of a novel hardly decomposable waste that can solve the above problems. The volume reduction treatment apparatus includes a carbonization unit, an external heating unit that heats the carbonization unit from the outside, a slurry supply unit that supplies a slurry of hardly decomposable waste having a moisture content exceeding 70% to one end of the carbonization unit, Superheated steam supply means for supplying superheated steam to the dry distillation section, temperature detection means for detecting the temperature at the other end of the dry distillation section, and based on the temperature detected by the temperature detection means, external heating means, slurry supply means, and superheat Control means for controlling the water vapor supply means. The carbonization unit thermally decomposes the hardly decomposable waste supplied from the slurry supply unit and discharges gas generated by thermally decomposing the hardly decomposable waste from the other end. The control means controls the external heating means, the slurry supply means, and the superheated steam supply means so that the temperature detected by the temperature detection means is 460 to 700 ° C. According to this volume reduction processing apparatus, the volume reduction processing method disclosed in the present specification can be suitably implemented.

It is a figure for demonstrating the whole structure of the volume reduction processing system which concerns on a present Example. It is a figure for demonstrating the ball-type dry distillation furnace which concerns on a present Example.

  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.

(Feature 1) In the volume reduction treatment method disclosed in the present specification, the temperature at the other end of the dry distillation section may be 500 ° C. or higher. According to such a configuration, the hardly decomposable waste can be sufficiently decomposed in the dry distillation section, and the weight loss rate can be improved.

(Characteristic 2) In the volume reduction processing method disclosed in the present specification, the other end of the dry distillation section is connected to a powder storage section for storing residues generated by pyrolyzing the hardly decomposable waste. Also good. The dry distillation section may include an external electric heater for controlling the temperature in the dry distillation section, and the powder storage section may include an external electric heater provided on the wall surface . In this case, the superheated steam is supplied to the powder storage unit, and the superheated steam supplied to the powder storage unit may be supplied to the dry distillation unit through the powder storage unit. And when the moisture content of the slurry of the hardly decomposable waste put into the dry distillation unit per unit time is a, and the moisture content of the superheated steam put into the powder storage unit per unit time is b, The ratio (a / b) may be 1.0 or less. And by adjusting the temperature of the superheated steam supplied to the powder storage unit, the output of the external electric heater provided in the dry distillation unit, and the output of the external electric heater provided in the powder storage unit , The temperature at the other end of the dry distillation section may be 460 to 700 ° C. According to such a configuration, since the superheated steam is supplied to the powder storage part, even if a part of the input difficult-to-decompose waste is not decomposed in the dry distillation part, the undegraded difficult-to-decompose waste Can be decomposed in the powder reservoir. Moreover, the temperature of the other end of a dry distillation part can be suitably maintained at 460 degreeC or more because ratio (a / b) shall be 1.0 or less.

(Characteristic 3) In the volume reduction processing method disclosed in the present specification, the dry distillation section includes a metal reaction vessel, a plurality of ceramic or metal balls filled in the reaction vessel, and the plurality of balls. You may have a stirring means to stir. 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 volume reduction treatment method disclosed in the present specification, the hardly decomposable waste may contain at least one of an ion exchange resin, activated carbon, sludge , and rubber.

  Hereinafter, the volume reduction processing system according to the embodiment will be described. The volume reduction processing system of the present embodiment is a system for volume reduction processing of used ion exchange resin generated at a nuclear power plant. As shown in FIG. 1, the volume reduction treatment system includes a resin receiving tank 1, a superheated steam supply device 4, a ball-type dry distillation furnace 3, an exhaust gas treatment device 5, and a control device 2.

  The resin receiving tank 1 stores a used ion exchange resin generated at a nuclear power plant as a 5-15% slurry (resin 5-15%, moisture 85-95%). A supply pump 6 is connected to the resin supply port of the resin receiving tank 1. When the supply pump 6 operates, the slurry in the resin receiving tank 1 is supplied to the ball-type dry distillation furnace 3 through the supply path.

  The superheated steam supply device 4 includes a water tank 7, a supply pump 8, a steam generator 9, and a steam superheater 10. A supply pump 8 is connected to the supply port of the water tank 7. When the supply pump 8 is activated, the water in the water tank 7 is supplied to the steam generator 9. The steam generator 9 uses water supplied from the water tank 7 as water vapor. A steam superheater 10 is connected to the steam generator 9, and water vapor generated by the steam generator 9 is supplied to the steam superheater 10. The steam superheater 10 superheats the steam supplied from the steam generator 9 to form superheated steam. The superheated steam generated by the steam superheater 10 is supplied to the ball-type dry distillation furnace 3.

  The ball-type dry distillation furnace 3 brings the ion-exchange resin slurry stored in the resin receiving tank 1 into contact with the superheated steam supplied from the superheated steam supply device 4 to thermally decompose the ion-exchange resin. . The gas generated by the thermal decomposition is sent to the exhaust gas treatment device 5, and the residue after the thermal decomposition of the ion exchange resin is sent to the solidification facility. The detailed configuration of the ball-type dry distillation furnace 3 will be described in detail later.

  The exhaust gas treatment device 5 treats the exhaust gas supplied from the ball-type dry distillation furnace 3, renders it harmless and exhausts it to the atmosphere. The exhaust gas treatment device 5 includes a secondary combustor that burns combustible components in the exhaust gas supplied from the ball-type dry distillation furnace 3, and a plurality of HEPA filters that remove particulates in the exhaust gas exhausted from the secondary combustor. have. By discharging the gas after passing through the HEPA filter to the atmosphere, it is possible to prevent the fine particles contained in the exhaust gas from diffusing into the atmosphere.

  The control device 2 is a control device that controls each device constituting the volume reduction processing system. For example, the control device 2 supplies the ion exchange resin supplied to the ball-type dry distillation furnace 3 (supply amount per hour) and the supply amount of superheated steam supplied to the ball-type dry distillation furnace 3 (supply per hour). Amount) and the atmospheric temperature in the ball-type carbonization furnace 3 are controlled. That is, the control device 2 controls the supply amount of the ion exchange resin by controlling the supply pump 6, and controls the supply amount of the superheated steam by controlling the superheated steam supply device 4. The ambient temperature is controlled by controlling the heater output. The operation of the control device 2 will be described in detail later.

  Next, the detailed configuration of the ball-type carbonization furnace 3 will be described with reference to FIG. As shown in FIG. 2, the ball-type dry distillation furnace 3 includes a metal sealed reaction vessel 11 as a ball filling unit, and an external heater 14 (illustrated in FIG. 1) for heating the inside of the reaction vessel 11 from the outside of the vessel. The ceramic or metal ball 12 filled in the reaction vessel 11, the stirring blade 13 that can mechanically agitate the ball 12, and the ions that supply the ion exchange resin from above the reaction vessel 11 onto the ball 12 An exchange resin supply nozzle 16 and a superheated steam supply nozzle 15 for supplying superheated steam from the upper part of the reaction vessel 11 onto the balls 12 are configured.

  Note that whether or not superheated steam is supplied from the superheated steam supply nozzle 15 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 16. For example, when the moisture content of the ion exchange resin is high, the supply of superheated steam from the superheated steam supply nozzle 15 may be stopped, whereas when the moisture content of the ion exchange resin is low, the superheated steam supply nozzle 15 Superheated steam may be supplied.

  The sealed reaction vessel 11 is constituted by a metal cylinder having a diameter of, for example, 400 mm and a length of 500 mm, a pressure control mechanism for maintaining the pressure in the reaction vessel 11 at −0.5 to −10 kPa, and a reaction An external electric heater 14 for controlling the inside of the container 11 to a desired temperature is provided. The length of the reaction vessel 11 is not limited to 500 mm, and can be appropriately determined according to the type of ion exchange resin to be processed. In addition, when the slurry of the ion exchange resin having a high moisture content is directly charged into the reaction vessel 11, the length of the reaction vessel 11 is preferably 500 mm or more because the temperature of the ion exchange resin is difficult to increase. By setting the length of the reaction vessel 11 to 500 mm or more, the reaction time can be made sufficiently long, and the charged ion exchange resin can be suitably pyrolyzed.

  The shaft of the reaction vessel 11 is provided with a rotating shaft that is rotated at a low speed (about 0.1 to 2.0 rpm, preferably 0.5 rpm or more) by a drive motor installed at the top of the reaction vessel 11. Yes. A stirring blade 13 that is a spiral blade is formed around the periphery of the rotating shaft such that the outer edge is positioned close to the inner peripheral surface of the reaction vessel 11 and the inner edge forms a space between the rotating shaft and the inner periphery. It is attached.

The balls 12 in the reaction vessel 11 are made of corrosion-resistant ceramic balls or Hastelloy (registered trademark) or Inconel (registered trademark) , which is a high nickel alloy, and have a particle size of 10 to 25 mm. . The ball 12 ascends the peripheral portion in the reaction vessel 11 while being stirred by the stirring blade 13, and the balls located at the upper portion in the reaction vessel 11 are sequentially lowered into the space formed accordingly. Go.

  A holding plate 23 for holding the ball 12 in the reaction vessel 11 is disposed at the lower end of the reaction vessel 11 (shown in FIG. 1). The holding plate 23 prohibits the passage of the ball 12 while allowing the passage of the gas and the ion exchange resin residue. As a result, the balls 12 filled in the reaction vessel 11 are prevented from falling into the powder reservoir 19, while the residue that has not been pyrolyzed in the reaction vessel 11 and the gas generated by the pyrolysis are powdered. The storage unit 19 can be moved.

  A temperature sensor 22 (shown in FIG. 1) is disposed at the approximate center of the lower surface of the holding plate 23. The temperature sensor 22 detects the temperature of the lower end of the reaction vessel 11 (that is, the lower end of the dry distillation section). The temperature sensor 22 is connected to the control device 2. The temperature detected by the temperature sensor 22 is input to the control device 2.

  A powder reservoir 19 is provided below the reaction vessel 11. The powder storage unit 19 separates solid (powder such as ion exchange resin residue) from the gas discharged from the reaction vessel 11 and stores the separated powder. A superheated steam supply nozzle 21 is provided at the lower end of the powder storage unit 19. The superheated steam supply nozzle 21 is supplied with superheated steam from the superheated steam supply device 4. The superheated steam supplied from the superheated steam supply nozzle 21 into the powder reservoir 19 is used to decompose combustible components contained in the residue of the ion exchange resin. Further, a part of the superheated steam supplied into the powder reservoir 19 flows into the reaction vessel 11 and contacts the ion exchange resin in the reaction vessel 11 and is used for thermal decomposition of the ion exchange resin. The temperature of the superheated steam supplied from the superheated steam supply nozzle 21 is adjusted to 500 to 700 ° C, preferably 550 ° C or less. By setting the temperature of the superheated steam to 500 ° C. or higher, thermal decomposition of the ion exchange resin can be promoted. Moreover, durability of the metal housing which comprises the outline of the ball-type dry distillation furnace 3 can be improved because the temperature of superheated steam shall be 700 degrees C or less.

  An external electric heater 20 is provided on the wall surface of the powder storage unit 19. The heater 20 controls the atmosphere temperature in the powder reservoir 19 to a temperature at which the residue of the ion exchange resin can be thermally decomposed.

  A sintered metal filter 17 is disposed on the upper surface of the powder storage unit 19. The gas in the powder reservoir 19 is filtered by the sintered metal filter 17. The exhaust gas filtered by the sintered metal filter 17 is sent to the exhaust gas treatment device 5 from the exhaust gas outlet 18.

  Next, a method for reducing the volume of the ion exchange resin by the volume reduction processing system according to the present embodiment will be described. First, the control device 2 drives the supply pump 6 to supply the ion exchange resin slurry to the reaction vessel 11 of the ball-type dry distillation furnace 3, and also drives the superheated steam supply device 4 to supply the superheated steam to the ball-type dry distillation furnace 3. To the powder storage unit 19. At this time, when the water content of the ion exchange resin supplied to the reaction vessel 11 per unit time is a and the water content of superheated steam supplied to the powder reservoir 19 per unit time is b, the ratio ( a / b) is adjusted to 1.0 or less. By adjusting the moisture ratio (a / b) to an appropriate value, the atmospheric temperature in the ball-type dry distillation furnace 3 is suitably maintained at a temperature necessary for thermally decomposing the ion exchange resin.

  The ion exchange resin slurry supplied to the reaction vessel 11 is supplied from the ion exchange resin supply nozzle 16 into the reaction vessel 11. The ion exchange resin supplied into the reaction vessel 11 is initially in a water-containing state of 5 to 15% slurry, and basically adheres to the surface of the ball 13 and moves in the furnace. For this reason, the residence time of the ion exchange resin in the reaction vessel 11 is the same as the ball descent time. The ball descent time can be freely adjusted by the size of the stirring blade, the rotation speed, the ball size, and the height of the packed bed, but the ball descent time (that is, the residence time of the ion exchange resin in the reaction vessel 11). ) Is preferable for improving the weight loss rate. Specifically, a method of reducing the diameter of the ball, reducing the rotation speed of the rotating shaft, or increasing the length of the packed bed filled with the ball can be employed.

  The superheated steam supplied into the powder storage unit 19 is supplied from the superheated steam supply nozzle 21 into the powder storage unit 19. A part of the water vapor supplied into the powder reservoir 19 enters the reaction vessel 11 and is supplied to the ion exchange resin attached to the surface of the ball 13. The temperature of the superheated steam supplied into the powder storage unit 19 is set to 500 to 700 ° C., while the ion exchange resin supplied into the reaction vessel 11 is set to room temperature. For this reason, the upper layer part of reaction container 11 is lower than the temperature of the lower layer part of reaction container 11, and the temperature of the position of the lower end of reaction container 11 becomes the highest. Therefore, the temperature of the ion exchange resin charged into the reaction vessel 11 gradually increases as it moves from the upper layer portion to the lower layer portion.

  Therefore, the ion exchange resin charged into the reaction vessel 11 is divided into a first stage (around 100 ° C.) in which water contained in the ion exchange resin evaporates and a second stage (200 to 300 ° C.) in which ion exchange groups are separated. ) And the third stage (300 to 600 ° C.) in which carbonization of the substrate by dehydrogenation occurs. Here, since the ball 13 is agitated when the ball 13 having the ion exchange resin attached passes through the second stage (200 to 300 ° C.) where the ion exchange group is separated, the ion exchange resin and the superheated steam are efficient. Contact well. Thereby, the sulfonyl bridge | crosslinking of an ion exchange resin (more specifically, cation exchange resin) is suppressed, and the weight loss rate improvement of an ion exchange resin is attained.

  Further, in this embodiment, the control device 2 determines the amount of ion-exchange resin slurry supplied to the reaction vessel 11 and the powder reservoir so that the temperature detected by the temperature sensor 22 is 460 to 700 ° C. The amount of superheated steam supplied to 19 and the output of various heaters 14 and 20 are controlled. As a result, even when the ion exchange resin is charged into the reaction vessel 11 in a water content state of 5 to 15% slurry, the temperature at the lower end of the reaction vessel 11 is maintained at a sufficient temperature necessary for the decomposition of the ion exchange resin. The volume of the ion exchange resin can be sufficiently reduced in the container 11. Further, by controlling the temperature of the lower end of the reaction vessel 11 to be 460 to 700 ° C., as a result, the supply amount of the ion exchange resin slurry into the reaction vessel 11 and the superheated steam to the powder reservoir 19 The supply amount is optimized. As a result, the ball-type dry distillation furnace 3 is prevented from being enlarged, and the exhaust gas treatment device 5 is prevented from being enlarged.

  Residue (mainly iron oxide) generated by the decomposition in the reaction vessel 11 is discharged to the powder reservoir 19. Since it is difficult for the residue to accumulate in the reaction vessel 11, various problems associated with the residue processing in the reaction vessel 11 can be effectively avoided. In this embodiment, superheated steam is supplied to the lower part of the powder storage unit 19 and the powder storage unit 19 is heated by the heater 20. Thereby, the temperature of the powder storage unit 16 is controlled to 460 ° C. or higher, preferably 500 ° C. or higher, which is higher than the decomposition temperature of polystyrene. Therefore, the undecomposed portion in the residue discharged to the powder storage unit 19 is decomposed, and the weight reduction rate of the ion exchange resin can be further improved.

  Decomposed gases (CO, CxHy), sulfuric acid gas, sulfurous acid gas and the like generated by the decomposition in the reaction vessel 11 are discharged from the exhaust gas outlet 18 through the sintered metal filter 17 and processed by the exhaust gas treatment device 5. For this reason, it is possible to safely reduce the volume of used ion exchange resin generated at a nuclear power plant without risk of environmental pollution due to radioactivity. The sintered metal filter 17 can be a ceramic filter.

  In the volume reduction processing system of the present embodiment, the temperature of the lower end of the reaction vessel 11 is detected by the temperature sensor 22, and the ion exchange resin supplied to the reaction vessel 11 is adjusted so that the detected temperature becomes 460 to 700 ° C. The amount of slurry, the amount of superheated steam supplied to the powder reservoir 19, and the outputs of the various heaters 14 and 20 are controlled. Thereby, volume reduction of the ion exchange resin having a high moisture content can be realized while suppressing an increase in the size of the ball-type dry distillation furnace 3 and an increase in the size of the exhaust gas treatment device 5. In an experiment conducted by the present inventors, the output temperature of the heater of the reaction vessel 11 was 550 ° C., the temperature of superheated steam supplied to the powder reservoir 19 was 550 ° C., and the ion exchange resin was 0.8 dry · kg / By supplying the reaction vessel 11 with h (moisture is 10 liters / h), the temperature detected by the temperature sensor 22 is stabilized at 500 ° C., and the weight reduction rate is 97% (dry weight basis). I was able to.

  As mentioned above, although one Example of the technique disclosed by this specification was described in detail, this is only an illustration and does not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

In the embodiment described above, the ion exchange resin was processed using a ball-type dry distillation furnace, but various types of dry distillation apparatuses can be used. For example, using the dry distillation device, for a screw feeder type, supplying ion exchange resin to one end of the screw feeder may be configured so as to discharge the decomposition gas and residue from the other end of the screw feeder.

  Moreover, although the example which processes an ion exchange resin was demonstrated in the Example mentioned above, the technique disclosed by this specification is other hard-to-decompose wastes (For example, activated carbon, sludge, waste oil / water-containing waste oil, washing waste liquid) -It can be used for volume reduction treatment of drain and its concentrated waste liquid, organic waste liquid, rubber, etc.

  In the above-described embodiment, the room temperature ion exchange resin slurry is supplied to the reaction vessel 11. However, a heater is provided in an apparatus for supplying the ion exchange resin slurry and the ion exchange resin supplied to the reaction vessel 11 is supplied. The slurry may be heated. As a result, the temperature of the upper layer portion of the reaction vessel 11 is suppressed from decreasing, and the reaction vessel 11 can be downsized.

  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.

DESCRIPTION OF SYMBOLS 1 Resin receiving tank 2 Control apparatus 3 Ball-type carbonization furnace 4 Superheated steam supply apparatus 5 Exhaust gas treatment means 6 Supply pump 7 Water tank 8 Supply pump 9 Steam generator 10 Steam superheater 11 Sealed reaction vessel 14 External electric heater 12 Ball 13 Stirring blade 16 Ion exchange resin supply nozzle 15 Superheated steam supply nozzle 17 Sintered metal filter 18 Exhaust gas outlet 19 Powder reservoir 20 External electric heater 21 Superheated steam nozzle 22 Temperature sensor 23 Holding plate

Claims (5)

It is a method to reduce the volume of refractory waste,
It has a step of thermally decomposing the hardly decomposable waste by supplying the slurry of the hardly decomposable waste and superheated steam to the dry distillation section,
The slurry of the hardly decomposable waste is supplied from one end of the dry distillation part in a state where the moisture content exceeds 70%, and the gas generated by thermally decomposing the hardly decomposable waste is discharged from the other end of the dry distillation part,
The other end of the dry distillation section is connected to a powder storage section for storing residues generated by pyrolyzing the hardly decomposable waste,
The dry distillation section has an external electric heater for controlling the temperature in the dry distillation section,
The powder reservoir is equipped with an external electric heater provided on its wall surface ,
Superheated steam is supplied to the powder reservoir,
The superheated steam supplied to the powder storage part is supplied to the dry distillation part through the powder storage part,
When the moisture content of the slurry of the hardly decomposable waste introduced into the dry distillation unit per unit time is a and the moisture content of the superheated steam introduced into the powder storage unit per unit time is b, the ratio ( a / b) is 1.0 or less,
By adjusting the temperature of the superheated steam supplied to the powder storage unit, the output of the external electric heater provided in the dry distillation unit, and the output of the external electric heater provided in the powder storage unit , the dry distillation unit The volume reduction processing method in which the temperature in the other end is 460-700 degreeC.   The volume reduction processing method according to claim 1, wherein the temperature at the other end of the dry distillation section is 500 ° C. or higher.   The dry distillation section has a metal reaction vessel, a plurality of ceramic or metal balls filled in the reaction vessel, and a stirring means for stirring the plurality of balls. The volume reduction processing method described.   The volume reduction treatment method according to any one of claims 1 to 3, wherein the hardly decomposable waste contains at least one of an ion exchange resin, activated carbon, sludge, and rubber. It is a device that reduces the volume of persistent waste,
A dry distillation section;
An external electric heater for heating the dry distillation section from the outside ;
A slurry supplying means for supplying a slurry of hardly decomposable waste having a moisture content of more than 70% to one end of the dry distillation section;
Superheated steam supply means for supplying superheated steam to the dry distillation section;
Temperature detecting means for detecting the temperature of the other end of the dry distillation section;
Based on the temperature detected by the temperature detection means, it has an external electric heater , a slurry supply means, and a control means for controlling the superheated steam supply means,
The carbonization section thermally decomposes the hardly decomposable waste supplied from the slurry supply means, and discharges gas generated by thermally decomposing the hardly decomposable waste from the other end.
The control means is a volume reduction processing apparatus that controls the external electric heater , the slurry supply means, and the superheated steam supply means so that the temperature detected by the temperature detection means is 460 to 700 ° C.

Images