JP2014153153A - Contaminated soil processing system and contaminated soil processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decontaminate contaminated soil and reduce the volume of the contaminated soil more safely at low cost.SOLUTION: A contaminated soil processing system 1, which classifies contaminated soil into soil for incineration and soil for dehydration via a first classification mechanism 16, incinerates the soil for incineration in a burner reactor 18 to reduce the volume of the soil and dehydrates the soil for dehydration in a dehydration reactor 20 to reduce the volume of the soil. An exhaust heat supply mechanism 22 supplies exhaust heat generated in the burner reactor 18 to the dehydration reactor 20, so that the exhaust heat generated in the burner reactor 18 is used for dehydration processing in the dehydration reactor 20. A bagging device 8 having a vacuum deaeration function deaerates the soil classified as fine particles by a classification device 6 in vacuum and packs the soil into a bag-like container, which process prevents the generation of dust containing pollutants. Furthermore, the bagging device 8 has the bag-like container attached and detached automatically and a worker does not have to do the attachment/detachment job. This configuration can decontaminate contaminated soil and reduce the volume of the contaminated soil more safely at low cost.

Description

  The present invention relates to a contaminated soil treatment system and a contaminated soil treatment method.

  Conventionally, inventions related to decontamination treatment of soil contaminated with pollutants such as radioactive substances have been proposed, and an apparatus for selecting a treatment method in accordance with the soil contamination concentration has been proposed (for example, patent document). 1). It is necessary to store the contaminated soil thus decontaminated in a state where it is packed in a flexible container or the like in a predetermined location according to the remaining contamination concentration. However, it is difficult to secure a storage place for such contaminated soil due to consideration of the surrounding environment. For this reason, in order to effectively use the secured storage location, volume reduction of the contaminated soil is required, and various techniques for this requirement have been proposed. For example, a method of reducing the volume of contaminated soil containing organic substances such as sludge and dead leaves by incineration, or a method of reducing the volume using a dry decontamination apparatus previously filed by the present inventors (Japanese Patent Application No. 2013-17146). ) Etc.

JP 2010-269275 A

However, in the volume reduction method by incineration, although the contaminated soil is reduced in volume by incineration, there is a case where the concentration of contamination becomes high due to volume reduction, which makes storage difficult. Furthermore, depending on the type of contaminated soil, it may not be possible to reduce the volume by incineration. Further, in the method using a dry decontamination apparatus, it is necessary to use a hot air generating furnace or the like, so that when a large amount of contaminated soil is treated, the fuel cost becomes high.
In addition, when contaminated soil that has been reduced in volume by the above-described methods is packed in a flexible container or the like, there is a possibility that dust containing pollutants may be generated, and workers have to work with great care. .
This invention is made | formed in view of the said subject, The place made into the objective is in decontamination and volume reduction of a contaminated soil more safely, suppressing cost.

(Aspect of the Invention)
The following aspects of the present invention exemplify the configuration of the present invention, and will be described separately for easy understanding of various configurations of the present invention. Each section does not limit the technical scope of the present invention, and some of the components of each section are replaced, deleted, or further while referring to the best mode for carrying out the invention. Those to which the above components are added can also be included in the technical scope of the present invention.

  (1) A contaminated soil treatment system for decontaminating and reducing the volume of contaminated soil, a volume reduction unit for reducing the volume of the soil, and crushing and pulverizing the soil reduced in volume by the volume reduction unit A crushing device for crushing, a classification device for classifying the soil pulverized and finely pulverized by the crushing device, and filling the bag-shaped container with finely sized soil out of the soil classified by the classification device And a plurality of transfer mechanisms for transferring the soil between the components constituting the system, and a control device for controlling the entire system, wherein the volume reduction unit is configured to incinerate the soil. A first separation mechanism that separates soil into soil to be dried, a combustion furnace that reduces the volume of the soil that has been separated into incinerators by incineration, and a soil that has been separated into objects to be dried by drying Reduced drying oven and generated in the combustion furnace Heat contaminated soil treatment system including a waste heat supply mechanism for supplying to said drying furnace (claim 1).

  The contaminated soil treatment system described in this section consists of a volume reduction unit that reduces the volume of soil collected at a contaminated soil collection site, a pulverizer that crushes and pulverizes the reduced volume, A classification device that classifies the pulverized soil according to the particle size, and a bagging device that fills the bag-shaped container with the fine-grained soil among the classified soils are included. Examples of contaminated soil to be treated by this system include soil contaminated with radioactive substances.

  The volume reduction unit includes a first separation mechanism, a combustion furnace, a drying furnace, and an exhaust heat supply mechanism. The first separation mechanism separates the soil into the soil to be incinerated and the soil to be dried. To do. The combustion furnace incinerates the soil separated as an incineration target by the first separation mechanism, thereby reducing the volume of the soil, and the drying furnace is the soil separated as the drying target by the first separation mechanism. The soil is reduced in volume by drying with hot air. At this time, the exhaust heat supply mechanism supplies exhaust heat generated in the combustion furnace by incineration of the soil to the drying furnace. Thereby, a drying furnace will utilize the waste heat which generate | occur | produced in the combustion furnace supplied by the waste heat supply mechanism for the drying process of soil. Further, for example, when the exhaust heat supply mechanism is constituted by a suction fan and piping, the suction fan and piping are not only installed at a position for sucking hot air in the combustion furnace into the drying furnace, but also air in the drying furnace. If it is also installed at a position where it is discharged to the outside, the air flow becomes lubricated, and hot air in the combustion furnace is efficiently taken into the drying furnace.

In addition, the pulverizer disintegrates and finely pulverizes the soil, thereby eliminating soil aggregation and making the soil fine. The classifier is a volume-reduced unit that is reduced in volume by incineration or drying, and further crushed and pulverized in the pulverizer. And classified into coarse-grained soil. For this reason, generation | occurrence | production of the variation in the classification accuracy resulting from the state of the soil used as a process target, such as the moisture content of the extract | collected soil, and agglomeration of a soil, is avoided, and classification accuracy will be improved.
In addition, the bagging device fills finely sized soil among the soil classified by the classification device into a bag-like container such as a flexible container. At this time, in order to ensure safety, the soil may be filled in a bag smaller than the flexible container, and this bag may be put into the flexible container to form a double container. In this case, a plurality of bags may be put into the flexible container according to the difference in size between the bag and the flexible container.

  In addition, the contaminated soil treatment system described in this section includes a plurality of transfer mechanisms that transfer soil between components constituting the system, and a control device that controls the entire system. For each of the plurality of transfer mechanisms, an appropriate transfer means, such as a conveyor or a crane, is used according to the state of the soil transferred between the components. The control device controls each component constituting the system so that soil treatment and soil transfer can be performed smoothly, and may be configured as a single unit that controls the entire system. It may be composed of a plurality of units including one or a plurality of components installed. In this way, the entire system, including the transfer of soil, except for personnel required for system monitoring, is operated without direct human intervention. Decontamination and volume reduction of soil.

(2) In the above item (1), the bag filling device has a vacuum deaeration function for vacuum deaeration of the soil when filling the bag-like container with a soil, and an automatic desorption function for the bag-like container. Contaminated soil treatment system (Claim 2).
In the contaminated soil treatment system described in this section, the bagging device has a vacuum deaeration function and an automatic desorption function of the bag-like container. As a result, when the bag-shaped container is filled with finely sized soil among the soil classified by the classifying device, that is, with a small particle size containing most of the pollutant, the soil is filled while vacuum degassing. By doing so, scattering of dust containing pollutants is prevented. Further, since the bag-like container is attached to and detached from the bagging device automatically, it is not necessary for an operator to approach the bagging device and perform the removal operation. Therefore, the safety of workers is further increased. Moreover, when filling a bag-like container with soil or after filling, the bag-like container may be vibrated up and down to improve the bulk density.

(3) In the above (1) and (2), the first separation mechanism includes a first radiation dose measuring device that measures the radiation dose of the soil, and the soil type and / or the first radiation dose. A contaminated soil treatment system that separates soil into incineration-target soil and dry-treatment target soil based on the radiation dose measured by the measuring device (claim 3).
In the contaminated soil treatment system described in this section, the first separation mechanism of the volume reduction unit includes the first radiation dose measuring device that measures the radiation dose of the soil. Based on one or both of the soil type and the radiation dose measured by the first radiation dose measuring device, the soil is classified into the soil subject to incineration and the soil subject to dry treatment. Examples of the soil type include whether or not the soil contains organic matter and has flammability. In this case, the type is determined visually.

  Moreover, as a radiation dose used as the reference | standard at the time of fractionating soil, for example, whether a radioactivity density | concentration is 240 Bq / kg or less or 480 Bq / kg or less is mentioned. These figures are 8000 Bq / kg or less (the Tohoku-Pacific Ocean Earthquake that occurred on March 11, 2003), which is said to be able to safely treat the radioactive concentration of the soil even when the soil is incinerated. This is a guideline that is calculated according to the type of combustion furnace in order to comply with Article 14 of the Special Measures Law concerning the handling of environmental pollution caused by radioactive substances released by nuclear power plant accidents. That is, if both the example of the above-mentioned soil type and the example of the radiation dose of 240 Bq / kg or less are used as the criteria for classification, it contains organic substances and has flammability, and the radioactivity concentration is 240 Bq / kg or less. The soil that is incinerated is classified into soil that is subject to incineration, and soil that does not contain organic matter and is not flammable, or soil that has a radioactivity concentration exceeding 240 Bq / kg, is classified into soil that is subject to drying. As a result, only the soil that has been reduced in volume by incineration and whose radioactive concentration does not exceed the concentration that can be safely processed even if incinerated is classified as the target for incineration, so the volume can be reduced by an appropriate method according to the soil. It will become.

  (4) In the above items (1) to (3), a weight measuring device for measuring the weight of the soil in the bag-shaped container, a volume measuring device for measuring the volume of the soil in the bag-shaped container, and the bag Based on the second radiation dose measuring device for measuring the radiation dose of the soil in the container, the measurement result of the weight measuring device and the volume measuring device, and the measurement result of the second radiation dose measuring device, A contaminated soil treatment system including a sorting mechanism for sorting bag-like containers (claim 4).

  The contaminated soil treatment system described in this section includes a weight measuring device, a volume measuring device, and a second radiation dose measuring device for measuring each of the weight, volume, and radiation dose of the soil in the bag-like container, Furthermore, based on these measurement results, a sorting mechanism for sorting the soil into bag-like containers is included. As this sorting mechanism, a mechanism using an unmanned forklift controlled by a control device or the like can be exemplified. In this case, for example, the control device grasps the radiation dose of the soil in the bag-like container, and controls so that the soil is transferred together with the bag-like container to a sorting place according to a preset value of the radiation dose. The device controls an unmanned forklift. As a result, the soil is efficiently sorted without direct human intervention. Furthermore, by sorting the soil according to the radiation dose, appropriate storage and management according to the radioactivity concentration can be performed.

(5) In the above item (4), a contaminated soil treatment system including a void elimination mechanism that eliminates voids in the upper portion of the bag-shaped container before the volume measuring instrument measures the volume of the soil in the bag-shaped container. (Claim 5).
The contaminated soil treatment system described in this section includes a void elimination mechanism that eliminates voids in the upper portion of the bag-like container before the volume measuring instrument measures the volume of the soil in the bag-like container. Since the volume of the soil is measured in a state in which the voids are eliminated, the volume of the soil is measured more accurately.

(6) In the above items (1) to (5), including a third radiation dose measuring device for measuring the radiation dose of coarse soil among the soil classified by the classification device, the third radiation A contaminated soil treatment system including a second sorting mechanism that sorts soil whose radiation dose measured by a quantity measuring device exceeds a predetermined value so as to be transferred to the pulverizer (Claim 6).
The contaminated soil treatment system described in this section includes a second classification mechanism having a third radiation dose measuring device, and the second classification mechanism has a particle size of the soil classified by the classification device. The radiation dose of the rough soil is measured with a third radiation dose meter, and the soil whose measurement result exceeds a predetermined value is sorted so as to be transferred to the pulverizer. This ensures the isolation and storage of soil containing pollutants. In addition, about the soil whose measurement result with the 3rd radiation dose measuring instrument is below a predetermined value, for example, processing according to the regulation which the country sets in the future, such as returning to a collection place or reusing. Become.

  (7) A contaminated soil treatment method for decontaminating and reducing the volume of contaminated soil, the contaminated soil collection step, the volume reduction step of reducing the volume of soil collected in the contaminated soil collection step, and the volume reduction A pulverization and fine pulverization step for finely pulverizing the soil reduced in the pulverization step, a classification step for classifying the finely divided soil according to the pulverization and pulverization step, and the classification step And a bagging step of filling a bag-shaped container with a fine-grained soil, and the soil collected in the contaminated soil collection step in the volume reduction step is a soil to be incinerated. Separated into soil subject to drying treatment, the volume of soil separated into incineration target is reduced by incineration treatment, and the volume of soil separated into drying treatment subject is reduced by drying treatment, which is generated by incineration treatment. Contaminated soil treatment method using waste heat for drying treatment (claim 7) .

(8) The contaminated soil treatment method according to (7), wherein in the bagging step, the bag-like container is filled while the soil is vacuum degassed (Claim 8).
(9) In the above paragraphs (7) and (8), in the volume reduction step, the soil collected in the contaminated soil collection step is subjected to the incineration target soil and the drying treatment based on the soil type and / or radiation dose. A contaminated soil treatment method wherein the soil is separated from the target soil (claim 9).
(10) In the above items (7) to (9), the weight and volume of the soil in the bag-like container are measured and the radiation dose is measured. Based on the measurement result of the weight and volume and the measurement result of the radiation dose. A contaminated soil treatment method including a sorting step of sorting the bag-like containers (claim 10).

(11) In the above paragraph (10), in the sorting step, before measuring the volume of the soil in the bag-like container, the contaminated soil treatment method for eliminating the void in the upper part in the bag-like container (claim 11). .
(12) In the above items (7) to (11), the radiation dose of coarse soil is measured among the soils classified in the classification step, and when the radiation dose exceeds a predetermined value, the pulverization is performed. And a method for treating contaminated soil to be returned to the pulverization step (claim 12).
And the contaminated soil processing method as described in (7) to (12) term is performed using the contaminated soil processing system as described in said (1) to (6) term, respectively, (1) To (6), the equivalent effect is exhibited.

  Since this invention was comprised in this way, it becomes possible to decontaminate and reduce the volume of contaminated soil more safely, suppressing cost.

It is the schematic which shows the flow of a soil process with the structure of the contaminated soil processing system which concerns on embodiment of this invention. It is a schematic cross section which shows an example of the grinding | pulverization apparatus which comprises the contaminated soil processing system which concerns on embodiment of this invention. It is a schematic cross section which shows an example of the classification apparatus which comprises the contaminated soil processing system which concerns on embodiment of this invention. 1 shows an example of a weight measuring instrument, a void elimination mechanism, a volume measuring instrument, a second radiation dose measuring instrument, and the like that constitute a contaminated soil treatment system according to an embodiment of the present invention. Schematic, (b) is a schematic view from the front direction near the volume measuring device. It is the schematic which shows an example of the sorting mechanism which comprises the contaminated soil processing system which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, parts that are the same as or correspond to those in the prior art are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 1 is a schematic diagram showing a configuration of a contaminated soil treatment system 1 according to an embodiment of the present invention, together with a soil treatment flow. First, the configuration of the contaminated soil treatment system 1 will be described. As shown in the figure, the contaminated soil treatment system 1 includes a volume reduction unit 2 for reducing the volume of soil collected from a collection site of the contaminated soil, and a volume reduction. Pulverizing device 4 for pulverizing and pulverizing the soil, classifying device 6 for classifying the pulverized and pulverized soil into fine particles and coarse particles, and the soil classified as fine particles in a bag-like container And a bagging device 8 for filling.

  The volume reduction unit 2 includes a first sorting mechanism 16 having a first radiation dose measuring device 14, a combustion furnace 18 for incinerating soil, a drying furnace 20 for drying soil, and an exhaust of the combustion furnace 18. And an exhaust heat supply mechanism 22 for supplying heat to the drying furnace 20. In the example of FIG. 1, the exhaust heat supply mechanism 22 includes a pipe 28 a in which the suction fan 24 is disposed and a pipe 28 b in which the suction fan 26 is disposed. The piping 28a is provided at a position connecting the inside of the combustion furnace 18 and the inside of the drying furnace 20, and the suction fan 24 is arranged such that the blowing direction is the direction in which hot air inside the combustion furnace 18 is supplied to the inside of the drying furnace 20. Is installed. The pipe 28b is provided at a position connecting the inside of the drying furnace 20 and the outside of the drying furnace 20, and the suction fan 26 has a blowing direction in which the air inside the drying furnace 20 is discharged to the outside of the drying furnace 20. It is installed to become.

  The contaminated soil treatment system 1 includes a weight measuring device 30 that measures the weight of the soil in the bag-like container, a void elimination mechanism 38 that eliminates the void in the upper portion of the bag-like container, and the volume of the soil in the bag-like container. A volume measuring device 32 that measures the amount of radiation, a second radiation dose measuring device 34 that measures the radiation dose of the soil in the bag-like container, and a sorting mechanism 36 that sorts the soil for each bag-like vessel. Further, the contaminated soil treatment system 1 includes a second classification mechanism 42 that classifies the soil classified as coarse particles by the classification device 6 based on the radiation dose measured by the third radiation dose measuring device 40, and FIG. And a plurality of transfer mechanisms 10 (10a to 10d) for transferring soil between the components and a control device 12 for controlling the entire system. For each of the plurality of transfer mechanisms 10, various transfer means corresponding to the state of the soil to be transferred can be used. For example, in addition to a mechanical type such as a conveyor or a crane, a duct or a shooter is used. Also good.

Next, the contaminated soil processing method by the contaminated soil processing system 1 which concerns on embodiment of this invention is demonstrated, referring FIG. For convenience of explanation, explanation will be made for each step performed by the contaminated soil treatment method.
(Contaminated soil sampling process): Collects contaminated soil. Depending on the soil, soil from the ground surface to an appropriate depth using an appropriate civil engineering machine such as a backhoe or manually if necessary This is a process of collecting.

  (Volume reduction step): This is a step of reducing the volume of the soil collected in the contaminated soil collection step by the volume reduction unit 2. Specifically, first, the type of soil is determined by visual observation or the like, and for example, it is determined whether or not the soil contains organic matter and has flammability. This determination result is input to the first sorting mechanism 16, the control device 12, etc., and the first sorting mechanism 16 obtains soil type information directly or indirectly via the control device 12 or the like. And the 1st classification mechanism 16 measures the radiation dose of the soil with the 1st radiation dose measuring device 14, and soil is incinerated with the soil based on this measurement result and the kind of soil, and the drying process object Sort into soil. In this case, for example, soil containing organic matter and flammable and having a radioactivity concentration of 240 Bq / kg or less is classified as soil to be incinerated, and soil that does not satisfy this condition is treated as soil to be dried. Sort.

  The soil sorted into the incineration target by the first sorting mechanism 16 is transferred to the combustion furnace 18 by the transfer means 10 and then incinerated in the combustion furnace 18 to reduce the volume. At this time, hot air inside the combustion furnace 18 is supplied to the inside of the drying furnace 20 by the suction fan 24 via the pipe 28a. On the other hand, the soil separated into the objects to be dried by the first separation mechanism 16 is transferred to the drying furnace 20 by the transfer means 10 and then dried by hot air in the drying furnace 20 to reduce the volume. At this time, hot air inside the combustion furnace 18 supplied by the suction fan 24 via the pipe 28a is used for at least part of the hot air for drying the soil. Further, the air inside the drying furnace 20 is released to the outside of the drying furnace 20 by the suction fan 26 via the pipe 28b.

(Crushing and fine pulverization step) In this step, the agglomeration of the soil reduced in the volume reduction step is loosened using the pulverizer 4 and finely pulverized. In this step, it is preferable to gradually pulverize the surface from the surface in such a manner that the soil is not pulverized all at once with a strong force. This is because the fine particles of the soil put into the pulverizer 4 have a lot of contaminants attached to the surface portion. This is because if the surface portion is separated and separated as fine particles by the subsequent classification step, the fine particles to which the contaminants are attached can be separated and isolated very efficiently. For the pulverization apparatus 4, for example, a centrifugal fluid pulverization apparatus 4 shown in FIG. 2 is used.
In the embodiment shown in FIG. 1, an example in which the centrifugal fluid pulverizer 4 is used as an example of a preferable form in which crushing and pulverization are performed simultaneously will be described. However, the embodiment of the present invention is not limited to this. For example, crushing and fine pulverization may be performed by separate apparatuses.

The centrifugal fluid crusher 4 will be described in detail. As illustrated in FIG. 2, the centrifugal fluid crusher 4 has an outer peripheral ring 407 attached to the inside of a casing 408 covering the main body portion via a connecting member 409. . Reference numeral 410 denotes a pedestal, which pivotally supports the rotating dish 406 via a bearing 411. The rotating shaft 402 is driven by a power source such as an electric motor via a speed reduction mechanism or the like. In the center of the ceiling of the casing 408, a soil introduction pipe 412 is installed. An opening 413 is provided so as to surround the introduction pipe 412, and a duct 414 is connected to the opening 413. In this embodiment, the duct 414 is connected to the airflow classifier 6 shown in FIG. 3 used in the next classification step.
In this embodiment, the outer ring 407 is lined with a liner, and a large number of slits or small holes 415 are formed so as to penetrate the wall surface. A side cover 416 is annularly provided between the bottom of the outer surface of the outer peripheral ring 407 and the inner surface of the casing 408, and an air introduction chamber 417 is defined between the side cover 416, the casing 408 and the outer surface of the outer peripheral ring 407. Thus, air can be introduced from the air introduction pipe 418. Note that the upper end of the side cover 416 is tightly fixed to the outer side surface of the outer peripheral ring 407.

A clearance 419 of 10 to 30% of the minimum ball diameter of the ball 423 such as a steel ball is secured between the outer peripheral edge of the rotating dish 406 and the bottom inner peripheral surface of the outer peripheral ring 407, and the bottom cover 420 has a clearance 419. It is arranged in an annular shape so as to cover the lower side of. In the present embodiment, air can be introduced into the bottom cover 420 by perforating the side cover 416 or connecting an air introduction tube.
The bottom cover 420 and the air introduction chamber 417 are connected to a pipe line 421 for extraction and transfer, and the pipe line 421 can return fine particles to the input pipe 412. Further, a scraper 422 is installed on the lower side of the outer peripheral edge of the rotating dish 406 so that fine particles dropped in the bottom cover 420 are gathered toward the connecting portion of the extraction conduit 421.
In addition, as a centrifugal fluid grinding type grinding device that pulverizes the raw material by putting a ball such as a steel ball in the rotating dish and the outer ring, for example, CFMILL (registered trademark) is known as a centrifugal fluid grinding device type. There are a continuous type for continuously treating raw materials and a batch type for treating batches, both of which are within the applicable range of the present invention.

When the reduced volume of the soil in the volume reduction process is input from the input pipe 412 of the centrifugal fluid crusher 4 having the above-described configuration, the ball 423 and the inner wall surface of the outer ring 407 are moved along with the rotation of the rotating dish 406. Fine particles are pulverized by generating a spiral motion such as a rope tying by synthesizing a circular motion that circulates through the plate surface and a rotational motion around the central axis of the rotating plate 406.
The air introduced into the air introduction chamber 417 and the bottom cover 420 from the air introduction pipe 418 flows into the pulverization chamber through the clearance 419, the slit or the small hole 415, and the duct 414 is accompanied by the powder generated by the pulverization. It enters the inside and is sent to the airflow classifier 6.

(Classifying step) This is a step of classifying the soil that has been loosened and refined in the crushing and pulverizing step using the classifying device 6 according to the particle size. For example, an airflow classifier (see, for example, Japanese Patent No. 2645615) or the like can be used as the classifier 6, and in this embodiment, the airflow classifier 6 shown in FIG. 3 is used. . The airflow classifier 6 sorts the collected soil pulverized by the centrifugal fluid pulverizer 4 (see FIG. 2) into powder of a required particle size by the airflow, and the classification principle is gravity classification, inertia. Broadly divided into force classification and centrifugal classification. Centrifugal force classification suitable for mass classification of powders includes a free vortex type that swirls the air flow by making the shape of the classification chamber spiral, and the air flow is forced by rotating blades provided in the classification chamber There is a forced vortex to be swirled and a combination of these two, a free vortex and a forced vortex.
An example illustrated in FIG. 3 is configured inside a cylindrical classification chamber 601 and a dispersion chamber 602 having a reduced diameter, and a vertical drive shaft 607 rotatably supported at the center of the classification chamber 601. And a rotating impeller 608A having a large number of classification blades 608 rotating integrally therewith, and a fine powder discharge port 609 communicating with the inside of the rotating impeller 608A is disposed above the rotating impeller 608A. Yes. On the outer periphery of the rotary impeller 608A, fixed wings 606 having a large number of slit-shaped openings for swirling the classification air are fixed concentrically at appropriate intervals and connected to the fixed wings 606. A guide cone 610 having a reduced diameter is provided.

  In the dispersion chamber 602, a dispersion plate 604 is provided on the drive shaft 607 in the lower part of the rotary impeller 608A, and the soil crushed and finely pulverized by the centrifugal fluid crusher 4 supplied from the supply port 603 is classified. Classification is performed in the chamber 601. A structure in which particles falling along the inner walls of the fixed wing 606 and the guide cone 610 are introduced and dispersed into the classification air entering from the classification air intake port 605 via the slit 605A. It is what.

On the other hand, the rotary impeller 608A is a conical disk having a step on the outside at a position of an intermediate diameter, and a plurality of through holes 608B are arranged at equal pitches on the circumference of the step. Coarse powder or coarse particles that have fallen to the conical disk inside the hole 608B can be dropped downward. The diameter of the through hole 608B is about 5 to 10 mm, but is made as small as possible so as not to be blocked. The reason why the rotary impeller 608A is a conical disk having a step is that the coarse powder falling on the conical disk is surely discharged from the through hole 608B and passes through the through hole 608B from the inside between the rotary blades. This is to prevent passing through to the outside.
The classification is first performed with the primary swirl airflow, and further with the balance between the centrifugal force and the drag force of the air flowing inward in the secondary swirl airflow, and the fine particles having a required particle size pass through the fine powder outlet 609. It is taken out of the system as fine powder. On the other hand, coarse particles larger than the required particle size are subjected to centrifugal force due to the secondary swirling airflow, are spun off in the outer peripheral direction of the rotary impeller 608A, and descend along the inside of the fixed blade 606, via the fixed blade 606. Although exposed to the classification air entering the inside and subjected to a dispersing action, the coarse particles further continue to fall toward the coarse powder outlet 611. The dispersed fine particles are again carried together with the classification air into the secondary swirling airflow and classified.

(Bag filling step) This is a step of filling the bag-shaped container with finely sized soil out of the soil classified in the classification step while vacuum degassing with the bag filling device 8. The bagging device 8 has a vacuum deaeration function for vacuum deaeration of the soil and an automatic desorption function for the bag-like container. For example, the vacuum deaeration function is provided with a screw type deaeration device. Realized.
The finely classified soil classified by the classification device 6 is transferred to the bagging device 8 by the transfer means 10, and in the bagging device 8, the bag-like container is vacuum degassed by the vacuum degassing function of the bagging device 8. Filled. When filling the soil, or after filling, the bulk density is improved by vibrating the bag-like container up and down. Further, the bag-like container is attached to the bagging device 8 with the opening being opened by the automatic detaching function of the bagging device 8, and after the soil is filled, the opening is closed and the bagging device 8 is closed. Removed from. In this embodiment, it is assumed that a flexible container and a bag smaller than the flexible container are used as the bag-like container, and a plurality of bags filled with soil by the bag filling device 8 are put into the flexible container.

  (Sorting process) This is a process of sorting the soil in a bag-like container unit based on the radiation dose of the soil in the bag-like container. Specifically, as shown in FIG. 4A, a bag-like container (Flecon) F filled with soil by the bagging device 8 is transferred onto the transfer means 10b (conveyor) by the transfer means 10a (crane). The A weight measuring device 30 configured using a load cell or the like is incorporated in the transfer means 10b. When the bag-like container F is placed on the transfer means 10b, the weight measuring device 30 has a bag-like container F. Measure the weight of the soil inside. The soil weight measurement value is sent to the control device 12 or the like. And the transfer means 10b moves the bag-shaped container F to the transfer means 10c (conveyor) direction (left direction in a figure), when the weight measurement by the weight measuring device 30 is complete | finished.

  The bag-like container F that has been transferred to the transfer means 10c is slowly moved to the left in FIG. 4A on the transfer means 10c, and the gap in the bag-like container F is eliminated by the gap elimination mechanism 38. The The gap elimination mechanism 38 eliminates the gap in the upper part of the bag-like container F by pressing the pressing plate 38a against the upper part of the bag-like container F, for example, for about 3 seconds. The gap elimination mechanism 38 is configured such that the presser plate 38a can move in a predetermined range in the vertical and horizontal directions in FIG. 4A so as to correspond to the bag-like container F that moves on the transfer means 10c.

The bag-like container F from which the internal gap has been eliminated reaches the installation positions of the volume measuring device 32 and the second radiation dose measuring device 34 while being moved leftward by the transfer means 10c, and the inside of the bag-like container F The soil volume and radiation dose are measured. 4 (a) and 4 (b), the volume measuring device 32 includes an upper sensor 32a for measuring the size of the bag-like container F from above and a side sensor for measuring the size of the bag-like container F from the lateral direction. 32b, and the volume of the soil in the bag-like container F is calculated from the dimension data measured by both sensors 32a and 32b. Further, the second radiation dose measuring device 34 is incorporated in the transfer means 10c, and measures the radiation dose of the soil in the bag-like container F passing over the second radiation dose measuring device 34 of the transfer means 10c. To do. The volume measurement value and the radiation dose measurement value of the soil are sent to the control device 12 or the like.
Then, as shown in FIG. 4A, the bag-like container F in which the volume of the soil and the radiation dose are measured is moved leftward in the figure by the transfer means 10c, and the transfer means 10d (the sorting preparation position ap). It is moved onto the conveyor) and enters a temporary standby state. The transfer means 10d sequentially moves the bag-like container F on the transfer means 10d to the left in the drawing in accordance with the pace moved from the transfer means 10c and the pace taken out by the sorting mechanism 36 described later.

  Subsequently, as shown in FIG. 5, the sorting mechanism 36 sorts the soil in units of bag-like containers F. In the example of FIG. 5, the sorting mechanism 36 includes unmanned forklifts 50a and 50b controlled by the control device 12 (see FIG. 1). The control device 12 includes the weight measurement value, the volume measurement value of the soil in the bag-like container F obtained from each of the weight measurement device 30, the volume measurement device 32, and the second radiation dose measurement device 34 shown in FIG. While grasping which bag-like container F the radiation dose measurement value corresponds to, the position management of the bag-like container F is performed. Then, for example, the radiation dose per unit weight of the soil filled in each bag-like container F is calculated, and the bag-like containers F are sorted based on this calculated value.

  More specifically, the sorting mechanism 36 carries out the bag-like container F from the sorting preparation position ap by a clamp-type unmanned forklift 50 a and places it on the pallet 52. Then, the bag-like container F placed on the pallet 52 is divided by the load-type unmanned forklift 50b according to the radiation dose value per unit weight, and any of a plurality of predetermined sorting positions spA to spD. Carry to that position. At this time, the control device 12 selects the bag-like container F from among the plurality of sorting positions spA to spD according to the radiation dose per unit weight of the soil in the bag-like container F carried by the unmanned forklift 50b. The sorting position for transporting the vehicle is selected, and the unmanned forklift 50b is guided to the selected sorting position. Thus, according to the radiation dose per unit weight of the soil, the soil is sorted by the bag-like container F unit. The pallet 52 is collected by the unmanned forklift 50b that has finished carrying the bag-like container F.

  (Coarse particle management step) Of the soil classified in the classification step, this is a step of managing the coarse soil. In the example of FIG. 1, the radiation dose of the soil classified into the coarse particles by the classification device 6 is measured by the third radiation dose measuring device 40, and the second classification mechanism 42 is used based on the measured radiation dose. Sort the soil. For example, if the radiation dose is below a predetermined value and the soil is so low that the soil can be returned to the collection site or reused, it is separated for use and the radiation dose is the predetermined value. About the remaining soil exceeding this, it shall return to the grinding | pulverization apparatus 4 by the transfer means 10, and shall further decontaminate.

  Now, according to the embodiment of the present invention configured as described above, the following operational effects can be obtained. That is, as shown in FIG. 1, a contaminated soil treatment system 1 according to an embodiment of the present invention includes a volume reduction unit 2 that reduces the volume of soil collected at a contaminated soil collection site, and a volume of reduced soil. Pulverizing device 4 for pulverizing and pulverizing the soil, classifying device 6 for classifying the pulverized and pulverized soil according to the particle size, and bagging that fills the bag-shaped container with the finely divided soil among the classified soils A device 8 is included. In the example of FIG. 1, soil contaminated with a radioactive substance is a processing target of the system 1.

  The volume reduction unit 2 includes a first separation mechanism 16, a combustion furnace 18, a drying furnace 20, and an exhaust heat supply mechanism 22, and the first separation mechanism 16 performs a drying process on the soil to be incinerated. Sort into target soil. And the combustion furnace 18 reduces the volume of the soil by incinerating the soil separated as the incineration target by the first separation mechanism 16, and the drying furnace 20 is the target of the drying process by the first separation mechanism 16. The sorted soil is dried with hot air to reduce the volume of the soil. At this time, the exhaust heat supply mechanism 22 supplies exhaust heat generated in the combustion furnace 18 to the drying furnace 20 by soil incineration processing. Thereby, since the drying furnace 20 can use the exhaust heat generated in the combustion furnace 18 supplied by the exhaust heat supply mechanism 22 for the drying treatment of the soil, the fuel cost for generating hot air or the like can be reduced. It becomes possible to reduce significantly. Further, when the exhaust heat supply mechanism 22 is configured by a suction fan and piping, the suction fan 24 and the piping 28a are placed at a position where hot air in the combustion furnace 18 is sucked into the drying furnace 20 as in the example of FIG. If the suction fan 26 and the pipe 28b are installed not only at the position but also at the position where the air in the drying furnace 20 is discharged to the outside, the air flow becomes lubricated and the hot air in the combustion furnace 18 is heated. Can be efficiently taken into the drying furnace 20.

  Moreover, the crushing device 4 in which the centrifugal fluid crushing device etc. shown in FIG. 2 is used crushes and pulverizes the soil, thereby eliminating soil agglomeration and making the soil fine. And the classifier 6 in which the airflow classifier shown in FIG. 3 is used is the soil reduced in volume by the incineration process and the drying process in the volume reduction unit 2, and further crushed and finely pulverized in the pulverizer 4 Are classified into fine-grained soil containing most of the pollutants and coarse-grained soil. For this reason, generation | occurrence | production of the variation in classification accuracy resulting from the state of the soil used as a process target, such as moisture content of the extract | collected soil, and soil aggregation, can be avoided, and it becomes possible to raise classification accuracy.

Further, the bagging device 8 has a vacuum deaeration function and an automatic desorption function of the bag-like container. Thereby, when filling the bag-shaped container with finely sized soil, that is, soil having a small particle size including most of the pollutant among the soil classified by the classifying device 6, the soil is vacuum deaerated. By filling, scattering of dust containing pollutants can be prevented. Furthermore, since the detachment of the bag-like container to the bagging device 8 is automatically performed, it is not necessary for the worker to approach the bagging device 8 and perform the detaching operation. Therefore, it is possible to further improve the safety of the worker. In addition, when the soil is filled in the bag-like container or after the filling, if the bag-like container is vibrated up and down, the bulk density can be improved.
In addition, as a bag-like container filled with soil, for example, a flexible container as indicated by a symbol F in FIGS. Moreover, if soil is filled in a bag smaller than the FIBC, and this bag is put into the FIBC to form a double container, the contaminated soil can be sealed more safely. In this case, a plurality of bags may be put into the flexible container according to the difference in size between the bag and the flexible container.

  In addition, as shown in FIG. 1, the contaminated soil treatment system 1 according to the embodiment of the present invention controls a plurality of transfer mechanisms 10 that transfer soil between components constituting the system, and the entire system. And a control device 12. In each of the plurality of transfer mechanisms 10, appropriate transfer means corresponding to the state of the soil transferred between the components, for example, conveyors (reference numerals 10b, 10c, 10d in FIG. 4) and cranes (in FIG. 4). Reference numerals 10a) and the like are used. The control device 12 controls each component constituting the system so that soil treatment and soil transfer can be performed smoothly, and may be configured as a single unit that controls the entire system, A single system or a plurality of systems including those installed for each of a plurality of components may be used. Thus, in the contaminated soil treatment system 1 according to the embodiment of the present invention, the entire system including the transfer of soil is operated without direct human intervention, except for personnel required for system monitoring. Therefore, it is possible to further improve safety and decontaminate and reduce the volume of contaminated soil.

  Furthermore, in the contaminated soil treatment system 1 according to the embodiment of the present invention, the first separation mechanism 16 of the volume reduction unit includes the first radiation dose measuring device 14 that measures the radiation dose of the soil. When separating the soil, the soil is classified into the soil to be incinerated and the soil to be dried based on one or both of the soil type and the radiation dose measured by the first radiation dose measuring device 14. It is. As the type of soil here, in the contaminated soil treatment method according to the embodiment of the present invention, whether or not the soil contains organic matter and has flammability is determined by visual observation or the like.

  Moreover, in the contaminated soil processing method which concerns on embodiment of this invention as a radiation dose used as the reference | standard at the time of classifying soil, it is determined whether a radioactivity density | concentration is 240 Bq / kg or less. This numerical value is an example of a standard that is calculated according to the type of the combustion furnace 18 in order to reduce the radioactive concentration of the soil to 8000 Bq / kg or less, which can be safely treated even when the soil is incinerated. is there. That is, in the contaminated soil treatment method according to the embodiment of the present invention, soil containing organic matter and flammable and having a radioactivity concentration of 240 Bq / kg or less is separated into soil to be incinerated and contains organic matter. First, soil that does not have flammability and soil whose radioactivity concentration exceeds 240 Bq / kg are classified into soil to be dried. As a result, only the soil that has been reduced in volume by incineration and whose radioactive concentration does not exceed the concentration that can be safely processed even if incinerated is classified as the target for incineration, so the volume can be reduced by an appropriate method according to the soil. Can be realized.

  Moreover, the contaminated soil processing system 1 which concerns on embodiment of this invention is a weight measuring device which measures each of the weight of the soil in a bag-like container F, a volume, and a radiation dose, as shown in FIG.1 and FIG.4. 30, a volume measuring device 32, and a second radiation dose measuring device 34 are included. Furthermore, as shown in FIG.1 and FIG.5, based on these measurement results, the sorting mechanism 36 which sorts soil by the bag-like container F unit is included. In the example of FIG. 5, unmanned forklifts 50a and 50b controlled by the control device 12 and the like are used for the sorting mechanism 36. And the control apparatus 12 grasps | ascertains the radiation dose etc. of the soil in the bag-like container F, and the bag-like container F is placed in any of the sorting places spA, spB, spC, spD according to the preset radiation dose value. The unmanned forklift 50b is controlled so as to transfer the whole soil. Thereby, the soil can be sorted efficiently without direct human intervention. Further, by sorting the soil according to the radiation dose, it is possible to appropriately store and manage the soil according to the radioactivity concentration.

In addition, the contaminated soil treatment system 1 according to the embodiment of the present invention eliminates the void in the upper portion of the bag-like container F before the volume measuring device 32 measures the volume of the soil in the bag-like container F. By including the mechanism 38, the volume of the soil is measured in a state where the voids in the bag-like container F are eliminated, so that the volume of the soil can be measured more accurately.
Furthermore, as shown in FIG. 1, the contaminated soil treatment system 1 according to the embodiment of the present invention includes a second sorting mechanism 42 having a third radiation dose measuring device 40, and the second sorting mechanism 42. The mechanism 42 measures the radiation dose of the coarse-grained soil out of the soil classified by the classification device 6 with the third radiation dose measuring device 40, and the soil whose measurement result exceeds a predetermined value to the grinding device 4. To be transported. Thereby, isolation and storage of soil containing pollutants can be ensured. In addition, about the soil whose measurement result in the 3rd radiation dose measuring device 40 is below a predetermined value, in the contaminated soil processing method which concerns on embodiment of this invention, returning to a collection place, reusing, etc., In the future, processing will be performed based on the provisions established by the country.

  1: Contaminated soil treatment system, 2: Volume reduction unit, 4: Crusher (centrifugal fluid crusher), 6: Classifier (airflow type classifier), 8: Bagging device, 10: Transfer mechanism, 12: Control Apparatus: 14: first radiation dose measuring device, 16: first separation mechanism, 18: combustion furnace, 20: drying furnace, 22: exhaust heat supply mechanism, 30: weight measuring device, 32: volume measuring device, 34 : Second radiation dose measuring device, 36: sorting mechanism, 38: void elimination mechanism, 40: third radiation dose measuring device, 42: second sorting mechanism, F: bag-like container

Claims (12)

A contaminated soil treatment system for decontaminating and reducing the volume of contaminated soil,
A volume reduction unit for reducing the volume of the soil, a pulverizer for pulverizing and pulverizing the soil reduced in volume by the volume reduction unit, and a size of the pulverized and pulverized soil by the pulverizer A classifying device that classifies according to the classification, a bagging device that fills a bag-shaped container with fine-grained soil among the soil classified by the classifying device, and a plurality of units that transfer soil between each component constituting the system And a control device for controlling the entire system,
The volume reduction unit includes a first separation mechanism that separates soil into soil to be incinerated and soil to be dried, and a combustion furnace that reduces the volume of soil separated into objects to be incinerated by incineration. A pollution characterized by including a drying furnace for reducing the volume of the soil separated into objects to be dried by a drying process, and an exhaust heat supply mechanism for supplying exhaust heat generated in the combustion furnace to the drying furnace. Soil treatment system.   The said bagging apparatus has a vacuum deaeration function which vacuum-deaerates the soil when filling the bag-like container with soil, and an automatic desorption function of the bag-like container. Contaminated soil treatment system.   The first fractionation mechanism includes a first radiation dose measuring device that measures the radiation dose of the soil, and based on the type of soil and / or the radiation dose measured by the first radiation dose measuring device, The contaminated soil treatment system according to claim 1 or 2, wherein the soil is classified into a soil to be incinerated and a soil to be dried.   A weight measuring device for measuring the weight of the soil in the bag-shaped container, a volume measuring device for measuring the volume of the soil in the bag-shaped container, and a second measuring the radiation dose of the soil in the bag-shaped container. A radiation dose measuring device; and a sorting mechanism for sorting the bag-like containers based on the measurement results of the weight measuring device and the volume measuring device and the measurement results of the second radiation dose measuring device. The contaminated soil treatment system according to any one of claims 1 to 3.   5. The contaminated soil treatment system according to claim 4, further comprising a void elimination mechanism that eliminates voids in the upper portion of the bag-like container before the volume measuring instrument measures the volume of the soil in the bag-like container. .   Among the soil classified by the classifier, a soil that includes a third radiation dose measuring device that measures the radiation dose of coarse-grained soil, and the radiation dose measured by the third radiation dose measuring device exceeds a predetermined value The contaminated soil treatment system according to any one of claims 1 to 5, further comprising a second sorting mechanism that sorts the soil so as to be transferred to the pulverizer. A contaminated soil treatment method for decontaminating and reducing the volume of contaminated soil,
A contaminated soil collecting step, a volume reducing step for reducing the volume of the soil collected in the contaminated soil collecting step, and a crushing and pulverizing step for refining the soil reduced in the volume reducing step. , A classification step of classifying the soil finely divided in the pulverization and fine pulverization step according to the particle size, and the bagging that fills the bag-shaped container with the fine particle size of the soil classified in the classification step Including a process,
In the volume reduction step, the soil collected in the contaminated soil collection step is separated into a soil subject to incineration and a soil subject to dry treatment, and the soil separated into the subject to incineration is reduced in volume by incineration. A method for treating contaminated soil, comprising reducing the volume of the soil separated into objects to be dried by a drying process, and using the exhaust heat generated by the incineration process for the drying process.   8. The contaminated soil treatment method according to claim 7, wherein in the bagging step, the bag-like container is filled while the soil is vacuum degassed.   In the volume reduction step, the soil collected in the contaminated soil collection step is classified into a soil to be incinerated and a soil to be dried based on the type and / or radiation dose of the soil. Item 9. The contaminated soil treatment method according to Item 7 or 8.   Including a sorting step of measuring the weight and volume of the soil in the bag-shaped container and measuring the radiation dose, and sorting the bag-shaped container based on the measurement result of the weight and volume and the measurement result of the radiation dose. The method for treating contaminated soil according to any one of claims 7 to 9, characterized in that:   The contaminated soil treatment method according to claim 10, wherein, in the sorting step, the void in the upper part of the bag-like container is eliminated before measuring the volume of the soil in the bag-like container.   The soil dose classified in the classification step, the radiation dose of the coarse soil is measured, and when the radiation dose exceeds a predetermined value, returning to the pulverization and pulverization step. The contaminated soil treatment method according to any one of 7 to 11.

Images