JP5270048B1 - Soil decontamination equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To move soil in a region contaminated with a radioactive substance to the region and decontaminate it without using a chemical substance such as a leaching agent, and to perform all the processes in a continuous process.
SOLUTION: A soil decontamination apparatus installed on a loading platform of an automobile A, slurry preparing means 2 for suspending soil to be decontaminated, soil particles having a size larger than a certain size and receiving the suspension. 1st solid-liquid separation means 4 which isolate | separates into lower soil particulates, and makes soil soil flow down to the receiving tank 3 with the water which disperse | distributes this, The surface layer of the soil particle received from this is grind | polished, and the soil slightly reduced The surface polishing means 5 for forming the particles and the detached soil particles, and the received soil particles and the soil particles are separated, and the soil particles are caused to flow down to the receiving tank 3 in a suspended state in purified water. The particles comprise a second solid-liquid separation means 7 for discharging as decontaminated soil, a solid-liquid separation device 10 for processing a suspension of soil fine particles, and a filter means 13.
[Selection] Figure 1

Description

  The present invention relates to a soil decontamination apparatus that decontaminates soil contaminated with radioactive substances such as cesium 137 and cesium 134, and more particularly to a soil decontamination apparatus that can move to a contaminated area and perform decontamination treatment of contaminated soil. .

Soil contaminated with radioactive material should be decontaminated to a level that does not harm human health, especially if it is in an area for human use.
For example, radioactive materials released in the March 2011 nuclear accident were scattered over a wide area, for example, by riding in the wind, and contaminated a wide range of soils with radioactive materials. A lot of radioactive material was released, but the amount of cesium 137 with a particularly large amount and a long half-life seems to be large. Cesium 134 appears to have been released in the same amount as cesium 137, but it appears to be decreasing significantly due to its short half-life of about 2 years. At present, the cesium contamination seems to dominate the nuclear accident. The soil may be contaminated with radioactive substances for various reasons other than this, and in that case, it is not necessarily contaminated with cesium. In any case, these contaminated soils should be properly decontaminated.

  With regard to decontamination of soil contaminated with such radioactive substances, a decontamination method has been proposed and reported only by stripping the soil in the contaminated area with a certain thickness. In this decontamination method, there is a particularly excellent method for treating soil that has been peeled off, such as changing the top and bottom of the soil and returning it to the same place, or simply carrying it to another place for storage. Not proposed or implemented. That is, in such a decontamination method, the surface soil containing a large amount of radioactive material is simply peeled off, so the amount of soil removed is extremely large, and it is not easy to find a place to isolate and store it. Is normal. Therefore, it should be said that it is completely unsuitable for a wide range of decontamination.

  Patent Document 1 is a method for decontamination of a soil surface layer part, which is a soil surface layer part that fixes a surface layer part of soil contaminated with a pollutant and peels the soil of the fixed surface layer part from the underlying soil. This is a decontamination method. Only the example in which the surface layer of the soil is fixed by cultivating plants such as turfgrass on the soil is shown, and other methods are not assumed.

  According to the contamination removal method of the soil surface layer part of this Patent Document 1, it is possible to reliably peel off the surface soil of a predetermined thickness, or to reduce the scattering of dried soil particles at the time of peeling, It is claimed that there is an advantage that it can suppress the diffusion of pollutants deep into the ground, but in any case, like the previous example of stripping of topsoil of a certain thickness, the surface layer of the target area The only problem is the removal of soil, and the treatment of soil entangled with the stripped plants is the next problem. It is necessary to keep this in isolation, but it is clear that such a place is not easily obtained. There is a problem similar to the example of stripping off the topsoil having a certain thickness.

  Patent Document 2 is a processing method and apparatus for contaminated particulate matter. This method involves treating particulate matter contaminated in one or a combination of heavy metal, radioactive material, and organic matter with a leaching solution, a surfactant, and these. In a method for treating particulate matter comprising the step of washing with a fluidizing fluid of a contaminant selected from the group consisting of: and thereby fluidizing soluble and dispersible contaminants in the liquid phase of the fluidizing solution of contaminant A step of mechanically separating large particles of the same size with substantially no residual contamination from medium size particles, fine particles and a fluidizing solution of pollutants, and the separated large particles are mainly composed of water. A step of obtaining a particulate material to be recovered by washing with a cleaning solution of the above, and separating the fine particles from the medium-sized particles according to the size difference by countercurrent of the pollutant fluidization solution And attrition polishing of medium-sized particles from which fine particles have been removed by countercurrent of the fluidizing solution of the contaminant, thereby removing the attached fine particles from the medium-sized particles, and dropping Separating the fine particles from medium-sized particles according to the size difference by countercurrent of the wash water, and additionally generating a waste slurry and an effluent consisting of medium-sized particles and wash water, and a medium size A method for treating contaminated particulate matter, comprising: dehydrating an effluent composed of particles and washing water to obtain particulate matter to be recovered.

  In addition, this apparatus is an apparatus for treating a particulate material contaminated with one or a combination of heavy metals, radioactive materials, and organic materials, and the particulate material is selected from the group consisting of a leaching solution, a surfactant, and a mixture thereof. Large particles of the same size with substantially no residual contamination are mechanically separated from the medium size particles, particulates and contaminant fluidization solution and separated into large A size separator for washing particulates with water to obtain a particulate material to be recovered, and a waste slurry by separating fine particles from medium sized particles according to the size difference by countercurrent of the fluidizing fluid of the pollutant The first mineral jig to be generated and the medium sized particles with the fine particles removed by counter-current of the fluidizing fluid of the pollutant are polished so that the attached fine particles are of medium size. Attrition scrubber that drops off particles and separated fine particles from medium-sized particles by countercurrent of washing water according to the size difference, effluent consisting of waste slurry, medium-sized particles and washing water It is a contaminated particulate matter processing apparatus having a clarifier that dehydrates an effluent composed of a second mineral jig to be additionally generated, medium-sized particles and washing water to obtain particulate matter to be recovered.

  Therefore, according to the processing method and apparatus for contaminated particulate matter of Patent Document 2, the soil is classified with a size separator such as a rotating drum or a vibrating screen, and then washed with a fluidizing solution of the contaminant. Rinse with separately supplied water and inspect for residual contamination, and if not, return to the site where the soil was excavated, while soil particles smaller than this would be It is sent out to the next stage in a fluidized state. When the target soil is contaminated with radioactive substances, the above-mentioned pollutant fluidizing solution is a leaching agent that leaches out the soil, and as the leaching agent, potassium carbonate, Sodium carbonate, acetic acid, sodium hypochlorite or the like is used. These leaching agents are used for the treatment of such a large amount of soil, and are required in large amounts. Therefore, the processing cost is increased. Further, these leaching agents need to be removed from moisture, and those that have achieved leaching action and those that do not need to be removed later.

  The soil particles of 5 mm or less are treated with the first mineral jig in the next stage to separate the soil particles of 60 microns or less and the larger soil particles of 5 mm to 60 microns, the latter large soil particles. Is ground with an attrition scrubber, and fine particles on the surface are removed, and further treated with a second mineral jig, and separated into soil particles of 60 microns or less and soil particles of a larger size. The above 60 micron or less soil particles are slurries dispersed in the pollutant fluidizing solution, all of which are fed into a precipitation facility and precipitated by adding a precipitant. These soil particles are strongly contaminated with organic matter and heavy metals, and they are supposed to settle. The process using the first and second mineral jigs is a process for removing these contaminants. It is clear that

  Large soil particles are treated with a third mineral jig that operates in cross flow mode, and waste solid particles containing heavy metals with high density are removed. Other soil particles are dewatered by clarifier, a dehydrator. And dried with a drying pad. The separated solid waste particles are disposed of, and the dried soil particles are subjected to a cleanliness test and returned to the dig site if there are no problems.

  According to the processing method and apparatus for polluted particulate matter of Patent Document 2, the purpose is to remove pollutants from soil contaminated with radioactive materials and heavy metals, and so on. In the first stage of the process, the radioactive substance is removed by leaching and removing the radioactive substance contained in the soil with the leaching agent constituting the pollutant fluidizing solution in the size separator. In the subsequent stage, it can be said that mineral jigs and the like are carried out exactly for the purpose of removing heavy metals and the like. As described above, the leaching agent for leaching radioactive materials leads to an increase in decontamination cost due to its use, and further requires its removal.

  Moreover, the processing method and apparatus of the pollutant particulate matter of patent document 2 are installed and used in any place, and are not movable. Therefore, the soil to be decontaminated requires a troublesome work such as bringing it to a place where it is installed by a transportation means such as a truck, and processing it again.

  Patent Document 3 is a method for removing metals, radioactive contaminants, and the like from particulates, which includes metal, metal compounds, and / or radioactive contaminants, including debris, fine particle fractions, and large particle fractions. In the method of removing from the granular material, a step of supplying the granular material (a), a step of sieving the granular material (b), and combining the granular material and the liquid from step (b) to form a slurry, The step (c) of washing off the slurry and removing the fine particles from the surface of the large-sized particles, and the fine particles of step (c) from the large-sized particles of the step (c) in the slurry are divided by a countercurrent liquid, (D) carrying the fine particles as a part of the waste slurry by the counter-current liquid, and removing the plant fragments or debris from the fine particles obtained in step (d) to generate a contaminated fine particle flow (e) A density separator, a paramagnetic separator or a combination of these Combined with a method having the steps (f) the fine particles and the metal compound of step (e), and / or a radioactive contaminants separated.

  The removal method of the metal, radioactive contamination factor, etc. of this patent document 3 is the same as the treatment method and apparatus of the pollutant particulate material of patent document 2, and it is not only the removal of the radioactive material but also the particulate matter related to the complex contamination by heavy metals and others. It is a dyeing method. The large-sized particles supplied in the step (a) and screened in the step (b) are inspected and discharged out of the process. Smaller size particulates remaining in step (b) are added with a fouling agent fluidizing solution to wash away particulates adhering to them from medium particles. As this contamination factor fluidizing solution, an elution solution such as potassium carbonate is used in the same manner as in Patent Document 2 in order to leach soluble radioactive compounds. At this stage, radioactive contaminants are leached and separated and removed in a later process. The subsequent process is a process of removing contaminants such as heavy metals or plant pieces using the difference in specific gravity.

  The removal method of the metal, radioactive contamination factor, etc. of this patent document 3 is a method of removing a radioactive substance using a leaching agent similarly to patent document 2, and it is necessary to perform the removal later, There is also a problem of increased costs for using such chemical substances. Furthermore, since the equipment that implements this method does not have moving means, it is necessary to transport the soil from the contaminated area to the place where the equipment is installed in order to decontaminate the soil. There is also.

JP 2012-223698 A Japanese Patent Laid-Open No. 06-343948 Japanese Patent Laid-Open No. 07-185513

  The present invention moves the soil in the area contaminated with radioactive substances to the area, decontaminates it at a high level, returns the decontaminated soil to the area, and removes only a small amount of high-concentration radiation contaminants removed. It is a problem to be solved to provide a soil decontamination apparatus that performs isolation disposal. In addition, the removal of radioactive materials from the soil is efficient without the use of chemicals such as leaching agents, economically and without increasing the amount of contaminants that must be sequestered, and all processing steps can be performed continuously. It is an object of the present invention to provide a soil decontamination apparatus that can be executed automatically.

1 of this invention is the soil decontamination apparatus installed in the loading platform of a motor vehicle,
Slurry preparing means for preparing a dispersed suspension of contaminated soil contaminated with radioactive substances by adding purified water to the soil to be decontaminated;
While receiving the suspension from the slurry preparation means and spraying and adding purified water to the suspension, soil particles of a certain size or more exceeding the size containing the radioactive substance above the decontamination level to the center and below it First solid-liquid separation means for separating soil fine particles having a size, and causing the soil fine particles and water dispersed therein to flow down to a receiving tank below;
The soil particles of a certain size or more are received from the first solid-liquid separation means, and the surface of the soil particles is rubbed so that the surfaces of the soil particles rub against each other by adding purified water to the soil particles and moving and moving the soil particles. Surface layer polishing means for polishing,
The soil particles whose surface layer has been polished from the surface layer polishing means, the soil particles generated by polishing and the water in which they are dispersed are received, and the water particles are dispersed and suspended in the purified water while further adding purified water thereto, and the A second solid-liquid separation means for separating the soil particles, causing only the suspension in which the soil fine particles are dispersed to flow down to the receiving tank below, and discharging the soil particles to the outside as decontaminated soil;
Below the first solid-liquid separation means and the second solid-liquid separation means, which receives a suspension in which soil fine particles separated and flowed down from the first solid-liquid separation means and the second solid-liquid separation means are dispersed. The receiving tank to be disposed on;
A solid-liquid separation device that receives a suspension of soil fine particles received by the receiving tank and separates water and soil fine particles dispersed therein from the suspension;
Contaminated soil discharging means for discharging the soil fine particles separated and removed from the suspension water by the solid-liquid separator to the outside,
Filter means for removing the component derived from the soil to be decontaminated remaining from the water that is separated and discharged from the soil fine particles of the suspension by the solid-liquid separator;
The water from which the soil-derived components remaining in the filter means have been removed is received and stored as purified water, and a purified water tank that supplies the purified water to each part that requires purified water,
Consisting of
In addition, with respect to the slurry preparation means, the first solid-liquid separation means, the surface layer polishing means, the second solid-liquid separation means, the solid-liquid separation device, the contaminated soil discharge means, and the filter means, each of those processes is performed in a continuous process. It is the soil decontamination apparatus comprised in.

In the soil decontamination apparatus of 1 of the present invention described above, the slurry preparation means is
A hopper for continuously receiving the soil to be decontaminated, and having a water introduction means for allowing purified water to accompany the receiving soil at the receiving port;
A tubular body having the rear peripheral side communicated with the lower end of the hopper in a direction orthogonal to the axial direction;
A nozzle arranged at the rear end of the tubular body to inject pressure water from the rear end toward the front end along the axis thereof;
A collision plate arranged at a front end of the tubular body with a certain gap so as to form a discharge port that opens in a circumferential direction between the front end, and is arranged in a plane perpendicular to the axial direction of the tubular body. The collision plate
Can be configured.

2 of the present invention is the soil decontamination apparatus of 1 of the present invention,
The first solid-liquid separation means or the second solid-liquid separation means,
A net inclined downward from the inlet end toward the outlet end that receives the dispersed water of the soil at the inlet end and discharges soil particles having a size larger than the mesh opening at the outlet end opposite to the inlet end. A cylindrical body;
A support means for rotatably supporting the mesh cylindrical body about its axis;
Rotation drive means for rotating the mesh cylinder about its axis;
A tubular supply means body arranged in parallel to the length direction of the mesh cylinder and a plurality of nozzles arranged in the supply means body, and for supplying purified water through the mesh into the mesh cylinder Purified water supply means for supplying purified water by spraying from the nozzle toward the mesh cylinder;
It is composed of

3 of the present invention is the soil decontamination apparatus of 1 or 2 of the present invention,
The surface polishing means,
The soil particles separated by the first solid-liquid separation means are received together with purified water at the inlet end, and ground soil particles and soil fine particles are discharged at the outlet end opposite to the inlet end, from the inlet end to the outlet end. A cylindrical body that is inclined downwardly;
Supporting means for rotatably supporting the cylindrical body about its axis;
Rotation drive means for rotating the cylindrical body about its axis;
An agitating member for polishing which is arranged in parallel to the inside of the cylindrical body so that the axial center of the cylindrical body does not coincide with the axial center and rotates in the opposite direction to the cylindrical body, and descends the inner periphery of the cylindrical body An agitating member for polishing arranged to agitate the flowing soil particles so that the soil particles rub against each other and polish each other.
It is composed of

  Therefore, according to the soil decontamination apparatus of the present invention, the soil is moved to an area contaminated with radioactive substances, and the contaminated soil in the area is received and decontaminated. It can be returned to its original location. The radiation dose of the decontaminated soil is separated and removed by the first solid-liquid separation means, the size of the soil particles to be flowed down to the receiving tank in a suspension state, and the soil particle surface layer by the surface polishing means The degree of decontamination can be increased by increasing the degree of polishing. That is, if necessary, the decontamination rate of a desired radiation dose can be adjusted by appropriately setting the above size and the degree of polishing. After completion of decontamination, in addition to decontaminated soil, agglomeration flocs containing radioactive substances separated from the soil by decontamination are produced, and this amount is a standard for separation by the first solid-liquid separation means. It depends on the size of the soil particles and the degree of the surface layer of the soil particles polished by the surface polishing means. The larger the former and the greater the latter, that is, the higher the decontamination rate, the greater the amount of aggregated floc. Conversely, it will decrease. However, after securing a sufficient decontamination rate, in most cases, it is a small amount compared to decontaminated soil that can be returned to its original location. The purified water used for decontamination can be recycled. Therefore, the device can be operated anywhere with or without water at the decontamination site.

  Moreover, according to the soil decontamination apparatus of 1 of this invention, since it can move to the area contaminated with the radioactive substance and can perform the decontamination work of the soil of the area, it is necessary to transport the contaminated soil. There is no. Therefore, it is possible to eliminate the possibility that the uncontaminated area is contaminated with the contaminated soil, and the cost is excellent.

  The present invention is based on the knowledge that the radioactive substance contained in the soil, which is obtained as a result of the investigation and research by the present inventors, is mostly present on the surface layer including the surface of the soil particles, and on the other hand, the small size. Based on the fact that the surface area of soil particles is larger than the volume of the soil, the soil is divided by the size of the soil particles, and soil fine particles below a certain size with a high proportion of radioactive substances are removed from the soil. Even for large-sized soil particles, the removal of radioactive material with a high removal rate can be achieved by polishing and removing the surface layer containing a high proportion of radioactive material.

  Therefore, in this invention, it moves to the area | region where the soil of a process target exists with the motor vehicle which installed this, and decontamination operation | movement of the soil of the area is performed. After moving to a predetermined area, first, the soil to be decontaminated in the area is introduced into the slurry creating means. Here, the purified water supplied from the water purification tank is sprayed and added to the soil, and the soil particles are dispersed in the purified water to create a suspension of the soil particles. This suspension is transferred to the first solid-liquid separation means in the next stage, where soil fine particles of a certain size or less are separated and removed from soil particles of a larger size. This separation and removal can be performed by various means, but fine particles passing therethrough can be caused to flow down to a receiving tank below together with water to disperse the particles using a mesh having a corresponding size. Since the soil is dispersed in purified water as a suspension, small soil particles can be well separated from larger soil particles.

  The remaining large-sized soil particles are transferred to the surface polishing means, and the surface layer is polished. In the surface polishing means, the soil particles are added with purified water supplied from the water purification tank and stirred while flowing to ensure fluidity. By this stirring, the soil particles rub against each other. They will be polished together. The soil particles thus slightly reduced and the soil fine particles generated by polishing are delivered to the next second solid-liquid separation means while maintaining fluidity by purified water.

  In the second solid-liquid separation means, the soil particles and the soil fine particles generated by the polishing are further added with purified water supplied from the water purification tank to form a suspension, where the size of the suspension is large. The soil particles are left, and the suspension in which the small-sized soil fine particles are dispersed is separated and flows down to the receiving tank below. This separation can be performed by various means as in the case of the first solid-liquid separation means, but can be performed using an appropriate mesh of openings.

  The larger size soil particles remaining in the second solid-liquid separation means are discharged to the outside as decontaminated soil. As described above, a large amount of radioactive material is contained in the surface layer of soil particles. Therefore, when the surface layer is polished and removed, most of the radioactive material contained in the soil particles is removed. In addition, the soil fine particles, which were smaller than the initial size, have a large surface area compared to the volume and a small size in the central direction, so it can be seen that most of the sites contain a lot of radioactive substances. By removing small soil particles, the amount of radioactive material remaining in the soil can be extremely reduced.

  Thus, as described above, the large-sized soil particles remaining in the second solid-liquid separation means can extremely reduce the amount of residual radioactive material, and can be returned to the original location. . As described above, the amount of the remaining radioactive substance is determined by the size of the soil particles that are used as a reference for separation by the first solid-liquid separation unit and the degree of the surface layer of the soil particles that are polished by the surface layer polishing unit. However, it is easy to make the level sufficiently lower than 8000 Bq / kg.

  On the other hand, the suspension of the soil fine particles flowing down to the receiving tank is fed to the solid-liquid separation device where the solid-liquid separation is performed. This can be done using various separation means including known techniques. For example, the flocculant can be added to the suspension, thereby causing the soil fine particles to aggregate, and the resulting aggregated floc can be separated and removed from the water containing it. Thus, for example, the soil fine particles separated and removed as agglomerated flocs are discharged out of the apparatus by the contaminated soil discharging means. Such agglomerated flocs are composed of soil fine particles containing a large amount of radioactive material and a flocculant, and therefore are subjected to isolation treatment. It is preferable to enable automatic processing without touching human hands.

  Further, the water separated and discharged from the soil fine particles of the suspension by the solid-liquid separation device may pass through the filter means and remain without being removed in the above process. Various components such as a small amount of aggregated floc and color and odorous components derived from the soil to be treated are removed, and the obtained water is transferred to the water purification tank as purified water. Known means can be employed as the filter means. The effect can be enhanced by combining a plurality of types of filters. For example, a paper filter or a zeolite filter.

  Thus, according to the soil decontamination apparatus of 1 of the present invention, the above-described effects can be obtained.

  Moreover, in the soil decontamination apparatus of 1 of this invention, it is possible to comprise the said slurry preparation means as mentioned above, and when comprised in that way, the soil of the decontamination object which this apparatus received is said slurry. It can be set as the suspension disperse | distributed to clean water favorably with a preparation means. Therefore, the small-sized soil fine particles can be reliably separated from the larger-sized soil particles by the first solid-liquid separation means and allowed to flow down to the receiving tank below in a suspension state. That is, when the soil to be decontaminated put into the hopper flows down to the rear part of the pipe body with purified water added, the aggregated state or the like is crushed by the pressure water ejected from the nozzle at the rear end, Dispersed in purified water and pressure water accompanying the addition. The soil dispersed in such pressure water collides with the collision plate at the rear end together with the pressure water and scatters to form a better dispersed suspension, which is discharged from the outlet around the rear. Will be.

  Therefore, in the soil decontamination apparatus according to 1 of the present invention, when the slurry means is configured as described above, it is possible to satisfactorily separate small-sized soil fine particles containing a large amount of radioactive substances from large-sized soil particles. It is possible to perform the decontamination operation on the soil at a high level.

  According to the soil decontamination apparatus of 2 of the present invention, when water in which soil particles and soil fine particles are dispersed is received in the mesh cylinder, purified water is injected into the mesh cylinder from the outside, Soil particles, etc. are further dispersed and suspended appropriately with the clean water being injected, and flow down according to the inclination while stirring in the rotating mesh cylinder and pass through the mesh of the mesh cylinder. Only small-sized soil fine particles to flow will flow down into the receiving tank below through the mesh in a suspended state in water.

  As described above, soil particles and the like are introduced into the mesh cylinder in a suspended state in the purified water or in a fluidized state by the purified water, and are further stirred from inside the rotating mesh cylinder. Since purified water is injected and introduced, the suspension is well dispersed in the purified water. According to the soil decontamination apparatus of 3 of the present invention, therefore, the soil fine particles are reliably separated from the larger-sized soil particles in the water, and can surely flow down with moisture through the mesh of the mesh cylindrical body. Thus, soil fine particles having a high content of radioactive substance can be reliably separated from other large-sized soil particles and allowed to flow down into the receiving tank below.

  According to the soil decontamination apparatus of 3 of the present invention, when the soil particles separated by the first solid-liquid separation means are introduced into the cylindrical body together with the purified water, the soil particles containing the purified water descend in the cylindrical body. Rotating the cylindrical body while flowing down according to the inclination, and agitating satisfactorily by receiving a rotating operation in the opposite direction to the cylindrical body of the agitating member for polishing disposed along the length direction in the cylindrical body. Particles rub against each other on the surface, and the surface layer of soil particles is polished appropriately. Thus, the surface layer containing the radioactive material of the soil particles in a high proportion is separated as fine particles, and thereby the radioactive material is removed from the soil particles.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic top view which shows the soil decontamination apparatus of one Example. BRIEF DESCRIPTION OF THE DRAWINGS Schematic side explanatory drawing which shows the soil decontamination apparatus of one Example. (a) is the side view which shows the slurry preparation means and 1st solid-liquid separation means of the soil decontamination apparatus of one Example (The 1st solid-liquid separation means should be right-down, but for convenience of drawing, it is horizontal. (B) is a rear view. (a) is a partially cutaway side view of the slurry preparation means of the soil decontamination apparatus of one embodiment, (b) is a front view with the collision plate removed, (c) is a partially cutaway enlarged sectional view of (a). . (a) is a side view of the surface polishing means of the soil decontamination apparatus of one embodiment (should be lowered to the right, but is drawn horizontally for convenience of drawing), and (b) is a side sectional view (lower right) (It should be horizontal for convenience of drawing). The front view of the surface layer grinding | polishing means of the soil decontamination apparatus of one Example. (a) is a side view showing the second solid-liquid separation means of the soil decontamination apparatus of one embodiment (should be right-down, but is drawn horizontally for convenience of drawing), (b) is the front Figure. (a) is a side explanatory view showing the solid-liquid separation part of the solid-liquid separation device in the soil decontamination device of one embodiment (should be right-down, but is drawn horizontally for convenience of drawing), ( b) is a partially cutaway side view showing the inlet end of the separation target water, and (c) is a front view.

  A mode for carrying out the invention will be described in detail based on an embodiment with reference to the drawings.

  As shown in FIGS. 1 and 2, the soil decontamination apparatus of this embodiment is a soil decontamination apparatus installed on the loading platform of the automobile A, and a folding belt conveyor 1 that is a means for receiving soil to be decontaminated. Slurry preparation means 2 that receives the soil from the belt conveyor 1 and suspends the soil, and receives the suspension of the soil prepared by the slurry preparation means 2, and mainly concentrates radioactive substances at a decontamination level. The size is larger than a certain size, and in this embodiment, the soil particles having a size of 25 μm or more are separated from the smaller soil particles, and the soil particles are received in the suspended state in the purified water. A first solid-liquid separation means 4 flowing down to the tank 3; a transfer conveyor 6 for transferring soil particles of a certain size or more separated by the first solid-liquid separation means 4 to the surface polishing means 5 of the next stage; First The surface layer polishing for polishing the surface layer of the soil particles received from the solid-liquid separation means 4 via the transfer conveyor 6 to form slightly smaller soil particles and finely sized soil particles separated from the surface layer. Means 5, a transfer conveyor 8 for transferring the soil particles polished by the surface layer polishing means 5 and fine soil particles to the second solid-liquid separation means 7 in the next stage, and the transfer conveyor 8 through the transfer conveyor 8. The second is to separate the soil particles received from the surface polishing means 5 and the fine-sized soil particulates, flow the soil particulates down to the receiving tank 3 in a suspended state in purified water, and discharge the soil particles. Solid-liquid separation means 7, discharge conveyor 18 for discharging soil particles separated by the second solid-liquid separation means 7 as decontaminated soil, the first solid-liquid separation means 4, and the second solid-liquid separation With separation means 7 The receiving tank 3 positioned below the first solid-liquid separating means 4 and the second solid-liquid separating means 7 for receiving a suspension in which soil fine particles dispersed and flowed are dispersed, and the receiving tank The solid-liquid separator 10 which receives the suspension of the soil fine particles 3 received through the transfer pump device 9 and the pipe and separates the water and the soil fine particles dispersed therein from the suspension, and the solid-liquid separation Contaminated soil discharge conveyor 11 which is a contaminated soil discharging means for discharging soil fine particles separated and removed from the suspension water by apparatus 10 to the outside, and soil fine particles of suspension by solid-liquid separator 10 The filter means 13 that receives the water separated and discharged through the pump device 12a and the pipe 12b and removes components such as soil-derived color and odor remaining in the water and other components, and the filter means 13 The water from which the fine particles are removed is received and stored as purified water through the pump device 14a and the pipe 14b, and the slurry preparation means 2, the surface layer polishing means 5, the first solid-liquid separation means 4, the second solid-liquid separation means 7 and And a water purification tank 15 that supplies the purified water to the solid-liquid separator 10.

  This soil decontamination apparatus is installed on the loading platform of the automobile A as shown in FIGS.

  As shown in FIGS. 1 and 2, the foldable belt conveyor 1 is configured to be extended from the front right side of the loading platform of the automobile A to the outside, and is a publicly known configuration. It is a foldable type and can be deployed as shown in FIGS. 1 and 2 before moving to a predetermined location in the area where the soil to be decontaminated and starting the decontamination operation. . The inner end of the foldable belt conveyor 1 is arranged so as to be located immediately above the soil receiving hopper 2a of the slurry creating means 2. The length is such a dimension that the outer end is gently inclined in a state where the outer end reaches the ground on the side of the loading platform of the automobile A.

  As shown in FIGS. 1 and 2, the slurry creating means 2 is disposed on the upper right side of the loading platform of the automobile A. In particular, as shown in FIGS. 4 (a) to 4 (c), a hopper 2a for continuously receiving the soil to be decontaminated, and a tubular body 2b in which the rear portion is connected to the lower end of the hopper 2a. And a nozzle 2c for jetting pressure water disposed at the rear end of the tube body 2b, and a collision plate 2d attached to the front end of the tube body 2b at a predetermined interval.

  As shown in FIGS. 4 (a) to (c), the hopper 2a is provided with two purified water introduction pipes (purified water introduction means) 2a1, 2a1 180 along the inner surface of the upper open soil receiving port. Arrange at angular intervals of degrees. These purified water introduction pipes 2a1 and 2a1 are connected via a pipe corresponding to the purified water tank 15 and a pump device 16 for sending purified water, and the pump device 16 constantly feeds purified water during operation of the device. It is like that.

  As shown in FIGS. 4A to 4C, the lower end of the hopper 2a is connected to the rear peripheral side of the tubular body 2b. The lower end of the hopper 2a and the rear part of the pipe body 2b are connected in a state in which their axial centers are orthogonal to each other, and the soil introduced into the hopper 2a is accompanied by the purified water introduced through the purified water introduction pipes 2a1 and 2a1. Then, it flows down to the rear part of the tube body 2b.

  As shown in FIGS. 4 (b) and 4 (c), the nozzle 2c is disposed at the rear end of the tube 2b, and extends from the rear end to the front end along the axis of the tube 2b. The pressure water is jetted toward it. As shown in FIGS. 4A and 4C, the nozzle 2c is connected to the water purification tank 15 via a predetermined pipe and a pump device 17 for generating pressure water disposed in the middle thereof. . Accordingly, during operation of this apparatus, the purified water stored in the water purification tank 15 is pressurized from the nozzle 2c by the pump apparatus 17 and injected as pressure water, and flows into the pipe body b together with the purified water through the hopper 2a. The soil to be dyed is dispersed by the pressure water, and dispersed in the pressure water and the purified water that has flowed along with the pressure water to form a suspension of soil particles.

  As shown in FIGS. 4 (a) and 4 (c), the collision plate 2d is disposed in a plane perpendicular to the axial center with a predetermined gap at the front end of the tube body 2b, and The tube 2b is connected to the front end of the tube 2b by connecting shafts arranged at an angular interval of 90 degrees in the circumferential direction at the front end of the tube 2b. Accordingly, a discharge port that opens in the circumferential direction is opened between the collision plate 2d and the front end of the tube body 2b. Therefore, as described above, when the suspension formed by the pressure water in the pipe body 2b reaches the front end of the pipe body 2b, it collides with the collision plate 2d, further increasing the degree of dispersion, It becomes a suspension that is even better dispersed in the purified water and is then discharged from a discharge port that opens in the circumferential direction.

  As shown in FIGS. 1 and 2, the first solid-liquid separation means 4 is arranged at the frontmost part of the loading platform of the automobile A and at the uppermost part in a direction orthogonal to the length direction. In particular, a later-described net-made cylindrical body 4a is arranged at that position in that direction. As shown in FIGS. 3 (a) and 3 (b), the first solid-liquid separation means 4 includes a mesh cylinder 4a inclined downward from the inlet end toward the exit end, and the mesh cylinder 4a. A support means 4b for rotatably supporting the shaft center, a rotation driving means 4c for rotating the mesh cylinder 4a around the axis, and an obliquely upper portion of the mesh cylinder 4a on the outside of the mesh cylinder 4a. It is comprised with the purified water supply means 4d distribute | arranged in parallel with the length direction.

  As shown in FIGS. 3 (a) and 3 (b), the mesh cylindrical body 4a has a plurality of, for example, six shaft-like members at an angle of 60 degrees in the circumferential direction along the temporary cylinder. These are arranged at intervals, and a plurality of ring-shaped members are sheathed at regular intervals, and are joined together to form a cylindrical skeleton, and a net is lined inside the skeleton. As shown in Fig. 3 (a), the lining material is lined from the outermost end on the outlet side to the inner ring member on the outlet end side, and the outermost end on the outlet side and one inner side from it. Between the ring members, the netting material is not lined, and serves as a soil particle discharge port. Of course, the mesh cylinder 4a may have other configurations, but the suspension or fluidized soil can move smoothly on the inner surface of the mesh cylinder 4a. It is necessary to have a smooth structure with few irregularities. Note that the mesh material has a mesh size that allows particles smaller than a certain size of soil particles to pass through, that is, in this example, a mesh material with a mesh size of 100 mesh that allows particles smaller than 25 μm to pass through. .

  The support means 4b has annular flange-like rail members 4b1 and 4b1 arranged at two locations near the inlet end and the outlet end of the outer periphery of the mesh cylinder 4a, and each of the support means 4b is supported to freely roll these members. The support wheels 4b2, 4b2, and 4b2 are arranged at an angular interval of 120 degrees in the direction, and a support frame (not shown) that rotatably supports the support wheels 4b2, 4b2, and 4b2. The saddle-like rail members 4b1 and 4b1 are fixed to six shaft-like members constituting the skeleton of the mesh cylinder 4a.

  As shown in FIGS. 3 (a) and 3 (b), the rotation drive means 4c includes a belt wheel 4c1 disposed near the inlet end of the outer periphery of the mesh cylinder 4a, a motor 4c2 for rotation drive, A belt wheel 4c3 fixed to the output shaft of the electric motor 4c2 and a belt 4c4 hung on the belt wheel 4c1 disposed on the outer periphery of the mesh cylinder 4a. The belt wheel 4c1 disposed on the outer periphery of the mesh cylinder 4a is fixed to six shaft-like members constituting the skeleton of the mesh cylinder 4a. In this embodiment, the belt is used as the transmission means of the driving force of the rotation driving means 4c. However, it is possible to adopt a chain and a chain wheel, or a gear train, and those Alternatively, it is free to adopt other appropriate means.

  As shown in FIGS. 3 (a) and 3 (b), the purified water supply means 4d includes a pipe body 4d1 which is a supply means main body arranged in parallel with and obliquely above the outside of the mesh cylinder 4a, and the pipe. The body 4d1 is composed of a plurality of nozzles 4d2, 4d2,... Arranged at regular intervals toward the mesh cylinder 4a, and the pipe body 4d1 has piping for supplying purified water from the water purification tank 15. A pump device 16 for feeding purified water is connected to the pipe. Thus, during operation of this decontamination apparatus, the purified water sent out by the pump device 16 is supplied to the pipe body 4d1 of the purified water supply means 4d, and the mesh cylinder 4a from the nozzles 4d2, 4d2,. And is supplied into the inside through the mesh.

  As shown in FIG. 3 (a), a discharge port at the front end of the tube body 2b of the slurry creating means 2 is arranged in an inserted state at the inlet end of the mesh cylinder 4a. Thus, the suspension of the soil to be decontaminated created by the slurry creating means 2 is discharged to the inlet end of the net cylindrical body 4a of the first solid-liquid separating means 4.

  As shown in FIGS. 1 and 2, the surface layer polishing means 5 is disposed behind the hopper 2 a of the first solid-liquid separation means 4 and the slurry preparation means 2 in the loading platform of the automobile A. It is arranged below and parallel to the means 4.

  As shown in FIGS. 5 (a), 5 (b) and 6, the surface layer polishing means 5 removes the soil particles separated by the first solid-liquid separation means 4 from the transfer conveyor 6, the introduction hopper 5a and the extension. Downward from the inlet end toward the outlet end, which is received together with purified water at the inlet end via the pipe 5b and discharges ground soil particles and soil fine particles generated by polishing at the outlet end opposite to the inlet end. An inclined cylinder 5c, support means 5d for supporting the cylinder 5c so as to be rotatable about its axis, rotation drive means 5e for rotating the cylinder 5c about its axis, and the cylinder It comprises a stirring member 5f for polishing disposed in the body 5c.

  As shown in FIGS. 5 (a), 5 (b) and 6, the introduction hopper 5a is an upwardly-spreading member disposed slightly above the inlet end of the cylindrical body 5c, and along the inner surface thereof. A purified water introduction pipe 5a1 is arranged. The purified water introduction pipe 5a1 is connected via a pipe corresponding to the purified water tank 15 and a pump device 16 for sending purified water, and the pump device 16 constantly feeds purified water during operation of the device. ing. The extension pipe 5b is connected to the lower end of the introduction hopper 5a, and the extension pipe 5b extends obliquely and the lower end is located in the inlet end of the cylindrical body 5c, as shown in FIG. The soil particles received by the introduction hopper 5a and the accompanying clean water can be introduced into the cylindrical body 5c.

  The cylindrical body 5c is a cylindrical member made of metal (stainless steel) as shown in FIGS. 5 (a), 5 (b), and 6, and a certain distance is provided between the outlet ends thereof. Two frame rings 5c1 and 5c1 are arranged. A frame ring 5c1 on the side in contact with the outlet end is fixed to the outlet end, and the other frame ring 5c1 is a connecting shaft arranged at an angular interval of 60 degrees in the circumferential direction on the frame ring 5c1 fixed to the outlet end. It is connected. The gaps between the frame rings 5c1 and 5c1 serve as soil particles after polishing, soil fine particles generated by polishing, and an outlet for water in which they are dispersed.

  As shown in FIGS. 5 (a), 5 (b), and 6, the support means 5d is an annular bowl-shaped rail member 5d1 disposed at two locations near the inlet end and the outlet end of the outer periphery of the cylindrical body 5c. 5d1, and support wheels 5d2, 5d2, 5d2 arranged at an angular interval of 120 degrees in the circumferential direction so as to support them rotatably, and a support (not shown) that rotatably supports the support wheels 5d2, 5d2, 5d2 It consists of a frame. The saddle-like rail members 5d1, 5d1 are fixed to the outer periphery of the cylindrical body 5c.

As shown in FIGS. 5 (a) and 6, the rotation driving means 5e includes a belt wheel 5e1 arranged near the inlet end of the outer periphery of the cylindrical body 5c, a motor 5e2 for rotation driving, and an electric motor 5e2. A belt wheel 5e3 fixed to the output shaft and a belt 5e4 stretched over the belt wheel 5e1 disposed on the outer periphery of the cylindrical body 5c. The belt wheel 5e1 disposed on the outer periphery of the cylindrical body 5c is fixed to the outer periphery of the cylindrical body 5c. In this embodiment, a belt wheel and a belt are used as means for transmitting the rotational driving force of the electric motor 5e2. However, instead of this, it is also possible to adopt a chain, a chain wheel, a gear train, or the like. . Other transmission means may be employed.

  As shown in FIGS. 5 (a), 5 (b) and 6, the polishing stirring member 5f has a rotating shaft 5f1 parallel to the shaft center at a position lower than the shaft center of the cylindrical body 5c, and a shaft A plurality of stirring members 5f2, 5f2,... Fixed with a heart. The stirring members 5f2, 5f2,... Are square plate-like members as viewed from the front, respectively, and are alternately shifted in phase by 45 degrees in the circumferential direction so that the rotating shaft 5f1 has its axis. It is connected and fixed by the heart. The plurality of stirring members 5f2, 5f2,... Further, in this embodiment, the configuration is as described above, but it is not inconvenient to have a configuration in which a quadrangular prism in which the stirring members 5f2, 5f2,... Are coupled without shifting the phase is coupled to the rotating shaft 5f1. Moreover, it is also possible to employ | adopt the stirring member of another structure, if it has an appropriate stirring function.

  As shown in FIGS. 5 (a) and 5 (b), the rotary shaft 5f1 has a gear 5f3 fixed to the end protruding from the inlet end of the cylindrical body 5c, and the rotary shaft 5f1 The motor 5f5 is driven to rotate through the gear 5f3, the gear 5f4 with which the gear 5f3 is engaged, and the output shaft of the electric motor 5f5 to which the gear 5f3 is fixed. The direction of this rotation is opposite to the direction of rotation of the cylindrical body 5c.

  As shown in FIGS. 1 and 2, the transfer conveyor 6 has a receiving end positioned immediately below the discharge port formed at the outlet end of the net cylindrical body 4a of the first solid-liquid separating means 4, This is a belt conveyor in which the supply end is positioned immediately above the introduction hopper 5a disposed just before the entrance end of the cylindrical body 5c of the surface polishing means 5. This is a member having a known configuration.

  Thus, the soil particles separated by the first solid-liquid separation means 4 are transferred through the transfer conveyor 6 described above, supplied to the introduction hopper 5a, and extended together with the purified water supplied from the purified water introduction pipe 5a1 arranged here. It is introduced into the inlet end of the cylindrical body 5c through the pipe 5b. The cylindrical body 5c is inclined downward toward the outlet end side, and the soil particles are given fluidity by the added purified water, and thus flow down in the cylindrical body 5c toward the outlet end side. However, at the same time, the cylindrical body 5c rotates about its axis, so that it is agitated by this, and the stirring members 5f2, 5f2,... Of the polishing stirring member 5f disposed in the cylindrical body 5c. Rotates in the opposite direction to the cylindrical body 5c, whereby a stirring operation is applied at a higher level. In this way, the soil particles are in a relationship in which the particles rub against each other on the surface and the surface layer of each other is polished. The soil particles flow and move to the outlet end of the cylindrical body 5c while repeating this, and the ground particles are ground together with the water particles accompanied by the slightly-sized soil particles and the newly generated soil fine particles. It is discharged from the outlet at the outlet end.

  As shown in FIGS. 1 and 2, the second solid-liquid separation means 7 is arranged in the height direction between the first solid-liquid separation means 4 and the surface polishing means 5 in the front-rear direction of the loading platform of the automobile A. Then, the members are located slightly below the surface layer polishing means 5 and arranged in parallel with each other.

  As shown in FIGS. 7A and 7B, the second solid-liquid separation means 7 has the same configuration as the first solid-liquid separation means 4 and is inclined downward from the inlet end toward the outlet end. A mesh cylinder 7a, a support means 7b for rotatably supporting the mesh cylinder 7a around its axis, and a rotation drive means 7c for rotationally driving the mesh cylinder 7a around its axis And a purified water supply means 7d arranged obliquely above the outside in parallel to the length direction of the net-made cylindrical body 7a. The mesh cylinder 7a differs from the mesh cylinder 4a of the first solid-liquid separation means 4 only in the mesh openings used. The mesh cylinder 7a of the second solid-liquid separation means 7 has a mesh opening of 125 mesh, and soil particles of approximately 20 μm or more cannot pass therethrough. Other than this, that is, the support means 7b, the rotation drive means 7c and the purified water supply means 7d have the same configuration as the support means 4b, the rotation drive means 4c and the purified water supply means 4d of the first solid-liquid separation means, respectively. is there.

  As shown in FIGS. 1 and 2, the moving conveyor 8 has an introduction end located immediately below a discharge port formed at an exit end of the cylindrical body 5 c of the surface polishing means 5, and a supply end at the second end. The front branch conveyor 8a located slightly above the inlet end of the net cylinder 7a of the solid-liquid separation means 7 and the introduction end is located immediately below the supply end of the front branch conveyor 8a, and the supply end is The two-solid-liquid separating means 7 is constituted by a rear branch conveyor 8b located at a position slightly inside the inlet end of the net cylinder 7a. The front branch conveyor 8a and the rear branch conveyor 8b are each a known belt conveyor.

  As shown in FIGS. 1 and 2, the discharge conveyor 18 has an introduction end located immediately below the discharge opening at the outlet end of the mesh cylinder 7a of the second solid-liquid separation means 7, and the discharge end is an automobile. It is a conveyor apparatus extended to the side part of A. When not in use, it can be rotated back to the loading platform of the car A. This is a belt conveyor having a known configuration.

  Therefore, during the operation of the decontamination apparatus, the purified water sent out by the pump device 16 is jetted into the mesh cylinder 7a from the nozzle arranged in the pipe body of the purified water supply means 7d, and enters the inside through the mesh. Will be supplied. Polished soil particles sent to the inlet end of the net cylinder 7a from the cylinder 5c of the surface polishing means 5 through the front branch conveyor 8a and the rear branch conveyor 8b of the transfer conveyor 8 by polishing The generated soil fine particles and the water in which they are fluidized flow down in the mesh cylinder 7a according to the inclination. At this time, as described above, the purified water is supplied from the purified water supply means 7d into the mesh cylinder 7a, and the soil particles and the soil fine particles are added with the purified water, stirred by the rotation of the mesh cylinder 7a, and suspended. The suspension of the soil fine particles generated as a turbid liquid flows down through the mesh and flows down to the receiving tank 3. On the other hand, soil particles that have become slightly smaller due to polishing cannot pass through the mesh (125 mesh), so they move to the outlet end, discharge and fall from the outlet, and decontaminate through the discharge conveyor 18. Waste soil will be discharged to the outside.

  As shown in FIGS. 1 and 2, the receiving tank 3 includes the slurry creating means 2, the first solid / liquid separating means 4, the surface polishing means 5, and the second solid / liquid at the front of the loading platform of the automobile A. It is the lower part of the section where the separating means 7 is arranged, and passes through the mesh of the mesh cylinder 4a of the first solid-liquid separation means 4 and the mesh of the mesh cylinder 7a of the second solid-liquid separation means 7. It is a container member that receives a suspension of soil particulates flowing down and temporarily stores it.

  The transfer pump device 9 is a pump device for pumping out a suspension of soil particulates that has flowed down into the receiving tank 3, and is arranged in the receiving tank 3 as shown in FIG. The transfer pump device 9 is configured to send a suspension of soil fine particles therein to the solid-liquid separation device 10 through a pipe (not shown).

  The solid-liquid separation device 10 is divided into a flocculant charging unit 10a and a flocculant mixing tank 10b, and a solid-liquid separation promoting unit 10c and a solid-liquid separation unit 10d. As shown in FIG. 4, the former flocculant charging part 10a and the flocculant mixing tank 10b are configured in a section immediately after the section constituting the receiving tank 3 of the loading platform of the automobile A, and the latter solid-liquid separation promoting part 10c. The solid-liquid separation unit 10d is configured in a section immediately after the section where the water purification tank 15 is disposed immediately after the section where the flocculant charging section 10a and the flocculant mixing tank 10b are disposed.

  The flocculant charging unit 10a is a means for charging an appropriate amount of flocculant into the flocculant mixing tank 10b, and is a known means. The flocculant mixing tank 10b is supplied with a suspension of fine soil particles through a pipe (not shown) from the receiving tank 3 by the transfer pump device 9, and the flocculant charged therein is uniformly formed into the suspension. It is a container member to be mixed, and is a known means. The stirring and mixing of the flocculant and the suspension in the flocculant mixing tank 10b is performed by adding a suspension to which the flocculant is added by a submersible pump (not shown) to the solid-liquid separation promoting unit 10c. The flow moves by the pumping operation to be sent out, and the inflow operation of the suspension of the soil fine particles flowing into the pumping operation.

  The solid-liquid separation promoting unit 10c is a known device that constitutes a spiral flow channel, and agglomerates of the soil particles in the suspension received from the flocculant mixing tank 10b by the flocculant by taking a long residence time. The action is sufficiently advanced to grow agglomerated floc in which soil fine particles are aggregated and supply the solid-liquid separation unit 10d.

  As shown in FIGS. 8A to 8C, the solid-liquid separation unit 10d includes a mesh cylinder 10d1 that is inclined downward, a support means 10d2 that rotatably supports the mesh cylinder 10d1, and the mesh cylinder 10d1. A rotational drive means 10d3 for rotationally driving the water, a purified water supply means 10d4 for injecting purified water into the mesh cylinder 10d1, and a box-shaped member 10d5 surrounding all the above components, the mesh cylinder in the vicinity of the bottom. The box-shaped member 10d5 that receives the water that has passed through the body 10d1 and the configuration excluding the mesh openings of the box-shaped member 10d5 and the net-shaped cylindrical body 10d1 are each of the first solid-liquid separation means 4 It is exactly the same as the component. The mesh cylindrical body 10d1 has a mesh opening that does not allow the passage of soil fine particles that are agglomerated flocs, but substantially allows water and soil-derived colors and odor-causing components to pass. In this embodiment, 125 mesh.

  That is, the mesh cylinder 10d1 is the same as the mesh cylinder 4a except for the mesh openings, the support means 10d2 is the support means 4b, the rotation drive means 10d3 is the rotation drive means 4c, and the purified water supply means. 10d4 is the completely same structure as the purified water supply means 4d.

  As shown in FIG. 8 (a), the net cylinder 10d1 of the solid-liquid separation part 10d has water at its inlet end that contains agglomerated flocs aggregated with soil fine particles extending from the solid-liquid separation promoting part 10c. The end of the transfer pipe 10d6 is entered. At the end of the transfer pipe 10d6, as shown in FIG. 8 (b) in particular, a collision plate 10d7 having a conical configuration with a constant interval from the end is arranged. 10d7 is connected to the transfer pipe 10d6 by a connecting shaft disposed at an angular interval of 90 degrees in the circumferential direction, and the gap between the end of the transfer pipe 10d6 and the collision plate 10d7 is the solid-liquid separation promoting portion. It becomes the discharge port of the water containing the aggregation floc supplied from 10c.

  Therefore, when the water containing the aggregated flocs of the soil fine particles supplied from the solid-liquid separation promoting unit 10c is supplied to the solid-liquid separation unit 10d through the transfer pipe 10d6 and flows out from the end thereof, It collides with the collision plate 10d7, and flows in while being widely dispersed in the mesh cylinder 10d1. The water containing the aggregated floc flowing into the mesh cylinder 10d1 moves to the outlet end side in accordance with the inclination of the mesh cylinder 10d1, and at this time, the purified water supply means 10d4 supplies the purified water while being stirred by the rotation. The coagulated floc that is supplied and spread in the mesh cylinder 10d1 and stirred is washed away by soil-purified color and odor-causing components adhering thereto. Thus, the aggregated flocs descend to the outlet end side while removing the soil-derived components and the like, and the water flowing together with the aggregated flocs together with the soil-derived components and the like is the bottom of the box-shaped member 10d5 through the mesh of the mesh cylinder 10d1. Will flow down to the side. The water supplied and supplied from the purified water supply means 10d4 also plays a role of eliminating clogging of the mesh of the mesh cylinder 10d1.

  The aggregated flocs of the soil particles that have moved to the outlet end of the mesh cylinder 10d1 are discharged from the outlet at the outlet end, fall to the receiving end of the contaminated soil discharge conveyor 11, and are discharged to the outside. On the other hand, the water flowing down to the bottom of the box-shaped member 10d5 is sent to the filter means 13 in the next stage. The solid-liquid separation promoting unit 10c and the solid-liquid separation unit 10d employ the above-described configuration, but any other known configuration can be employed. 1 and 2, the contaminated soil discharge conveyor 11 is a belt conveyor extending from the exit side lower part of the net cylindrical body 10d1 of the solid-liquid separation part 10d to the side part of the loading platform of the automobile A, This is a known configuration.

The coagulation floc discharged from the contaminated soil discharge conveyor 11 is composed of soil fine particles containing a large amount of radioactive material and an aggregating agent, and is therefore isolated.
Further, the aggregated floc in which the soil fine particles discharged from the pollution level discharge conveyor 11 are aggregated is configured to automatically perform dehydration and packaging processing without human intervention.

  As shown in FIG. 1, the filter means 13 is a component arranged in the last section of the loading platform of the automobile A, and is composed of three types of filters: a paper filter 13a, a zeolite filter 13b, and a finishing filter 13c. . The paper filter 13a is a filter filled with paper as a filter material, the zeolite filter 13b is a filter filled with zeolite as a filter material, and the finishing filter 13c is a filter filled with activated carbon as a filter material. Both are known filter means.

  As shown in FIGS. 1 and 2, the paper filter 13a of the filter means 13 is connected to the pipe 12b connected to the outlet of the bottom of the box-shaped member of the solid-liquid separator 10d of the solid-liquid separator 10. Yes, the pump device 12a is inserted in the middle of the pipe 12b. In the pumping operation of the pump device 12 a, water from which the aggregated floc has been removed is pumped out from the outlet of the bottom of the box-shaped member of the solid-liquid separation unit 10 d of the solid-liquid separation device 10. Then, the resultant is filtered, then filtered through the zeolite filter 13b, and finally, the final filter is performed through the finishing filter 13c. Various components such as aggregated floc that may remain in this way and color and odor components contained in the soil to be decontaminated, which were not removed in the process of removing radioactive substances, Recycle to clean water.

  As shown in FIG. 1, the finishing filter 13c of the filter means 13 is connected to the pipe 14b connected to the receiving port of the water purification tank 15, and the pump device 14a is inserted in the middle of the pipe 14b. It is. The filter means 13 removes various soil-derived residual components other than radioactive substances, and the water regenerated into purified water is pumped out from the outlet of the finishing filter 13c by the pump device 14a, and the purified water tank 15 is passed through the pipe 14b. To supply.

  As shown in FIGS. 1 and 2, the water purification tank 15 includes a section in which the flocculant charging unit 10 a and the flocculant mixing tank 10 b of the solid-liquid separator 10 are arranged, and a solid-liquid separation promoting unit of the solid-liquid separator 10. 10c and a box-shaped container-like member disposed in a section between the section where the solid-liquid separation unit 10d is disposed, and a container that receives water removed from soil-derived components and the like by the filter means 13 and stores it as purified water It is a member. In addition, as described above, the water purification tank 15 is provided in the solid-liquid separation unit 10d of the slurry preparation unit 2, the first solid-liquid separation unit 4, the surface layer polishing unit 5, the second solid-liquid separation unit 7, and the solid-liquid separation device 10. It is also a means for supplying purified water, and is a container member for storing water to be circulated and used in this apparatus.

  Incidentally, in the section where the flocculant charging unit 10a and the flocculant mixing tank 10b of the solid-liquid separation apparatus 10 are arranged, as shown in FIGS. 1 and 2, diesel power generation for supplying electric power used in this apparatus is provided. Machine 19 is installed and necessary wiring is performed. Thus, with this device, it is possible to carry out soil decontamination activities in an area where power cannot be easily obtained without inconvenience. As described above, since water is circulated, it can be executed without any inconvenience even when decontamination activities are performed in an area where water cannot be easily obtained.

  Therefore, according to the soil decontamination apparatus of this embodiment, the soil can be freely moved to the area contaminated with the radioactive material, and the contaminated soil in the area is accepted and decontaminated. Can be returned to its original position. The radiation dose of the decontaminated soil is moved to the disposal side by the first solid-liquid separation means 4, that is, the size of the soil particles to be flowed down to the receiving tank 3 as a suspension in water should be set appropriately. And by appropriately setting the size of the amount to be polished by the surface layer polishing means 5, it can be adjusted according to the desired one. Usually, it is appropriate if decontamination can be performed at a decontamination rate of about 80 to 95% with respect to that before decontamination.

  After completion of decontamination, in addition to decontaminated soil, agglomeration flocs containing radioactive materials separated from the soil by decontamination are generated, but this varies depending on how the decontamination rate is set as described above. Come. When the decontamination rate is increased, the above-mentioned aggregation flocs increase, and when the decontamination rate is decreased, it decreases. Unless decontamination of soil in extremely high radiation dose areas, such decontamination flocs are as described above when decontamination is performed at a decontamination rate of about 80 to 95%. Compared to decontaminated soil that can be returned to its original location.

  Further, as described above, the purified water used in the soil decontamination apparatus of this embodiment is to be circulated, and therefore the apparatus of this embodiment operates everywhere regardless of the presence or absence of water at the decontamination site. be able to. As described above, since the diesel generator 19 is mounted, even if electric power cannot be easily obtained at the decontamination site, it can be operated without any problem.

  Further, according to the soil decontamination apparatus of this embodiment, since it is possible to move to the area contaminated with the radioactive material and perform decontamination work of the soil in the area, it is necessary to transport the contaminated soil. No. Therefore, it is possible to eliminate the possibility that the uncontaminated area is contaminated with contaminated soil, and the cost is excellent.

  As described above, the soil decontamination apparatus according to this embodiment is a vehicle in which the soil decontamination apparatus is installed, and moves to an area where soil contaminated with a radioactive material to be treated exists and performs a treatment operation. After moving to a predetermined area, first, expand the folding belt conveyor 1 that is a receiving means for the soil to be decontaminated in the area, and extend it to the lower side of the loading platform of the car A. Then, the soil to be decontaminated is introduced into the slurry creating means 2.

  The soil fed by the belt conveyor 1 is continuously fed into the hopper 2a of the slurry creating means 2 from its tip, and is accompanied by the purified water supplied from the purified water introduction pipes 2a1 and 2a1 arranged in the hopper 2a. However, it falls into the lower pipe body 2b. Pressure water is jetted from the nozzle 2c at the rear end of the pipe body 2b, which collides with the falling soil, crushes the lump of soil, and in this process, the accompanying water and pressure water, The soil particles will be dispersed. The soil particles dispersed in the pressure water or the like move further forward in the tube body 2b together with them, and collide with the front collision plate 2d, where the dispersibility in the purified water further increases, and thus the generated soil particles The suspension is discharged from the discharge port at the tip of the tube body 2b and introduced into the inlet end of the net cylinder 4a of the first solid-liquid separation means 4.

  The suspension of the soil particles flows toward the outlet end according to the inclination while being stirred in the rotating mesh cylinder 4a by the rotation. In this process, the soil fine particles having a smaller size than the mesh of the mesh cylinder 4a and the water in which the particles are suspended gradually flow down to the receiving tank 3 below. Purified water is jetted from the nozzle of the purified water supply means 4d, thereby eliminating clogging caused by soil particles that may occur in the mesh, and at the same time, flowing into the interior of the mesh cylinder 4a through the mesh. With water purification, the suspension of soil particles is always diluted, in which the soil particles are widely dispersed, and small and larger particles are present in a separated state. Through the mesh of the reticulated cylindrical body 4a, the separation and flow of the smaller-sized soil fine particles to the receiving tank 3 is surely performed. That is, in the mesh-made cylindrical body 4a, soil fine particles less than 250 μm that can surely pass through a 100-mesh mesh can be almost surely flowed down to the receiving tank 3.

  Thus, only the soil particles exceeding the size are discharged at the outlet of the outlet end of the mesh cylinder 4a. The soil particles are carried by the transfer conveyor 6 and are put into the introduction hopper 5a of the surface layer polishing means 5. The soil particles introduced here flow down while being accompanied by the purified water introduced through the purified water introduction pipe 5a1, and are introduced into the inlet end of the cylindrical body 5c through the extension pipe 5b. In this cylindrical body 5c, the soil particles given fluidity with purified water are stirred while being stirred by the action of the polishing stirring member 5f that rotates in the opposite direction to the rotation of the cylindrical body 5c. It moves to the exit end side according to the inclination of the cylindrical body 5c.

  The soil particles are agitated as described above by the rotation of the cylindrical body 5c and the reverse rotation of the polishing stirring member 5f, and the surfaces of adjacent soil particles rub against each other. Will fit. In this way, the surface layer of the individual soil particles is polished and removed, and on the other hand, soil fine particles detached from the surface layer of the soil particles are generated. As described above, these soil particles and fine particles flow and move to the outlet end of the cylindrical body 5c and are discharged from the outlet at the outlet end.

  The soil particles whose surface layer discharged from the discharge port at the outlet end of the cylindrical body 5c is polished and removed to a slightly smaller size and the soil fine particles generated by the polishing are the front branch conveyor 8a and the rear branch of the transfer conveyor 8. It is conveyed by the minute conveyor 8b and is put into the inlet end of the net-made cylindrical body 7a of the second solid-liquid separation means 7. The soil particles and the like thrown into the mesh cylinder 7a are stirred by the rotation, but at the same time, purified water is jetted from the outside purified water supply means 7d and flows into the interior, and the soil particles Then, a fine particle suspension is formed, and soil fine particles having a size smaller than the mesh of the mesh cylinder 7a and purified water flow down to the receiving tank 3 below the mesh. Suspension of soil particles and the like is rotated and stirred while flowing toward the outlet end according to the inclination of the mesh cylinder 7a, and receives the supply of purified water sprayed from the external purified water supply means 7d, thereby releasing the clogging of the mesh On the other hand, the small-sized soil fine particles and water flowing below the mesh are satisfactorily subjected to dilution. Thus, only the soil particles having a size exceeding the size of the mesh and some purified water reach the discharge port at the outlet end of the mesh cylinder 7a, and are discharged from the discharge port. That is, only the soil particles exceeding the mesh size of 125 mesh and some purified water accompanying this are discharged.

  Soil particles and the like discharged from the discharge port are discharged out of the side of the automobile A by the discharge conveyor 18 disposed below. This soil particle removes the surface layer containing the radioactive material at the level to be removed, and soil fine particles containing a high level of radioactive material are also removed and sufficiently decontaminated. Can be returned to. Usually, each part is set with the goal of decontamination to a level well below 8000 Bq / kg, and this can be easily realized. That is, as described above, a large amount of radioactive material is contained in the surface layer of soil particles, and therefore, most of the radioactive material contained in soil particles is removed by polishing and removing the surface layer. It becomes. Small-sized soil particles have a large surface area compared to the volume and a small size in the central direction, so it can be seen that most of the parts contain a large amount of radioactive material. This is because the amount of radioactive substances remaining in the soil can be extremely reduced by removing small soil particles.

  On the other hand, the suspension of the soil fine particles flowing down to the receiving tank 3 is sequentially sent to the solid-liquid separator 10. In the solid-liquid separator 10, the flocculant is first introduced into the flocculant mixing unit 10b, and the flocculant is charged from the flocculant charging unit 10a into the introduced suspension of soil fine particles. In the flocculant mixing unit 10b, the movement of the suspension introduced therein, and the movement of the suspension in the flocculant mixing section 10b sent to the next solid-liquid separation promoting unit 10c by the pump device disposed therein, A stirring action occurs, and the added flocculant is mixed into the suspension.

  From the flocculant mixing unit 10b, as described above, the suspension of the soil fine particles mixed with the flocculant is sent out to the solid-liquid separation promoting unit 10c by the pump device to constitute the solid-liquid separation promoting unit 10c. While moving through the spiral flow channel, the soil flocs in which the soil particles are aggregated are bonded to each other and grow while moving through the spiral flow channel. This spiral flow channel is intended to extend the flow channel as much as possible to bond the generated flocculent flocs of the soil fine particles and grow them.

  Thus, the water containing the flocs of soil particles grown in the solid-liquid separation promoting unit 10c moves to the next solid-liquid separation unit 10d through the transfer pipe 10d6 and is distributed here at the end of the transfer pipe 10d6. It collides with the colliding plate 10d7 and is widely dispersed and discharged to the inlet end of the mesh cylinder 10d1. The coagulated floc introduced together with water and widely spread at the inlet end of the net-made cylindrical body 10d1 has its surface washed with purified water sprayed from the external purified water supply means 10d4 and is attached to the soil. The odor and color-causing components will be washed away. The water containing the coagulated flocs flows and moves toward the outlet end side according to the inclination of the mesh cylinder 10d1 while being agitated by the rotating operation and receiving the cleaning action by the purified water as described above. The water introduced with the coagulation floc and the water supplied by the purified water supply means 10d4 flow down to the bottom of the box-shaped member 10d5 through the mesh while flowing in the mesh cylinder 10d1 according to the inclination. The soil-derived color and odor-causing components washed away from the aggregated floc flow down to the bottom of the box-shaped member 10d5 together with these waters. Since the flocs of soil fine particles cannot pass through the mesh, they move to the outlet at the outlet end and are discharged from here.

  The agglomerated flock discharged from the discharge port is received by the contaminated soil discharge conveyor 11 and carried outside the side of the loading platform of the automobile A. In addition, since this aggregation floc consists of soil fine particles and a flocculant containing many radioactive substances, it isolates. In addition, the aggregated floc in which the soil fine particles discharged from the pollution level discharge conveyor 11 are aggregated is configured to automatically perform dehydration processing, packaging operation, and the like without human intervention.

  Further, the water that has flowed down to the bottom of the box-shaped member 10d5 in the solid-liquid separation unit 10d of the solid-liquid separation apparatus 10 has removed aggregated flocs of soil fine particles containing radioactive substances. However, various components derived from soil remain, and these various components should be removed from the viewpoint of recycling this water as purified water.

  The water that has flowed down to the bottom of the box-shaped member 10d5 of the solid-liquid separation unit 10d is introduced into the filter means 13, and sequentially passes through the paper filter 13a, the zeolite filter 13b, and the finishing filter 13c, and a trace amount that may remain. Various components such as agglomerated floc and soil-derived color and odor components that were not removed in the process of removing radioactive substances are removed and regenerated into purified water. The regenerated water is sent to the water purification tank 15 and can be used as purified water.

<Results of soil decontamination>
The measurement results of the radiation dose after decontamination of the five types of soil decontaminated with the soil decontamination apparatus of the above examples are shown in Table 1 below. Table 2 below shows the measurement results of the radiation dose of the aggregated floc produced by decontamination and the water returned to the water purification tank.
The target soils are: (1) Gutter collected soil in Koriyama City, Fukushima Prefecture, (2) Mixed garden soil in Koriyama City, Fukushima Prefecture (1: 3), (3) Mixed garden soil in Koriyama City, Fukushima Prefecture (1: 5) (4) Mixed garden soil in Koriyama City, Fukushima Prefecture (1: 7) and (5) Field soil in Koriyama City, Fukushima Prefecture.
The "mixed garden soil" is a mixture of sand that is not contaminated with radioactive substances in the weight ratio shown in parentheses in the garden soil of Koriyama, Fukushima Prefecture, respectively, to create a plurality of soils with different radiation doses It was done in.
Further, the agglomerated floc is a mixture of the agglomerated flocs produced by the decontamination of the mixed garden soil of (2), (3) and (4) at the same ratio.
In addition, the water is also used when decontaminating the mixed garden soils of (2), (3) and (4), respectively, and mixed at the same ratio with those filtered by the filter means and returned to the water purification tank. .
EG & G ORTEC, GEM-15180-P High-purity germanium gamma-ray spectrometer is used to measure the radiation dose for the soil (1) to (5) above before decontamination and after decontamination. Used. A U-8 container was used for the measurement. Each measurement time excluding water is 7200 seconds. The measurement time for water is 86400 seconds. In any case, iodine 131 is not detected.

  As shown in Table 1, it is considered that the decontamination rate of the radioactive material to the soil according to this example is sufficient. Both are decontaminated to a level that can be returned to the original location. In addition, although the tendency for the decontamination rate to become higher in the soil with a high radioactivity concentration is recognized, as described above, the decontamination rate is a sufficiently high decontamination rate even in the low soil. As shown in Table 2, agglomerated floc is high in radiation dose, but this is natural because it concentrates what was dispersed in the soil. To do. As shown in Table 2, radioactive water is completely removed from the treated water, and there is no problem in repeated use.

  The soil decontamination apparatus of the present invention can be used in the fields of machinery manufacturing and soil decontamination.

DESCRIPTION OF SYMBOLS 1 Belt conveyor 2 Slurry preparation means 2a Hopper 2a1 Purified water introduction pipe 2b Pipe body 2c Nozzle 2d Collision plate 3 Receiving tank 4 First solid-liquid separation means 4a Net-made cylindrical body 4b Support means 4b1 Cascade rail member 4b2 Support wheel 4c Rotation Driving means 4c1 Belt wheel 4c2 Electric motor 4c3 Belt wheel (fixed to the output shaft of the motor)
4c4 belt 4d purified water supply means 4d1 pipe body 4d2 nozzle 5 surface polishing means 5a introduction hopper 5a1 purified water introduction pipe 5b extension pipe 5c cylindrical body 5c1 frame ring 5d support means 5d1 saddle-like rail member 5d2 support wheel 5e rotation wheel 5e 1 support wheel 5e 5e2 Motor 5e3 Motor output shaft belt wheel 5e4 Belt 5f Polishing stirring member 5f1 Rotating shaft 5f2 Stirring member 5f3 Gear 5f4 Motor output shaft gear 5f5 Motor 6 Transfer conveyor (from first solid-liquid separating means to surface layer polishing means transfer)
7 Second solid-liquid separation means 7a Net cylinder 7b Support means 7c Rotation drive means 7d Purified water supply means 8 Transfer conveyor (transfer from surface layer polishing means to second solid-liquid separation means)
8a Front branch conveyor 8b Rear branch conveyor 9 Transfer pump device (supplied from the receiving tank to the solid-liquid separator)
DESCRIPTION OF SYMBOLS 10 Solid-liquid separation apparatus 10a Coagulant inlet 10b Coagulant mixing tank 10c Solid-liquid separation promotion part 10d Solid-liquid separation part 10d1 Net-made cylindrical body 10d2 Support means 10d3 Rotation drive means 10d4 Purified water supply means 10d5 Box-shaped member 10d6 Transfer piping 10d7 Collision plate 11 Contamination degree discharge conveyor 12a Pump device 12b Pipe 13 Filter means 13a Paper filter 13b Zeolite filter 13c Finishing filter 14a Pump device (from finishing filter to purified water tank)
14b Piping 15 Water purification tank 16 Pump device (for sending purified water from the water purification tank)
17 Pump device (for sending pressure water to slurry making means)
18 Discharge conveyor (for discharging soil particles separated by the second solid-liquid separation means)
19 Diesel Generator A Automobile

Claims (3)

A soil decontamination device installed on the platform of an automobile,
Slurry preparing means for preparing a dispersed suspension of contaminated soil contaminated with radioactive substances by adding purified water to the soil to be decontaminated;
While receiving the suspension from the slurry preparation means and spraying and adding purified water to the suspension, soil particles of a certain size or more exceeding the size containing the radioactive substance above the decontamination level to the center and below it First solid-liquid separation means for separating soil fine particles having a size, and causing the soil fine particles and water dispersed therein to flow down to a receiving tank below;
The soil particles of a certain size or more are received from the first solid-liquid separation means, and the surface of the soil particles is rubbed so that the surfaces of the soil particles rub against each other by adding purified water to the soil particles and moving and moving the soil particles. Surface layer polishing means for polishing,
The soil particles whose surface layer has been polished from the surface layer polishing means, the soil particles generated by polishing and the water in which they are dispersed are received, and the water particles are dispersed and suspended in the purified water while further adding purified water thereto, and the A second solid-liquid separation means for separating the soil particles, causing only the suspension in which the soil fine particles are dispersed to flow down to the receiving tank below, and discharging the soil particles to the outside as decontaminated soil;
Below the first solid-liquid separation means and the second solid-liquid separation means, which receives a suspension in which soil fine particles separated and flowed down from the first solid-liquid separation means and the second solid-liquid separation means are dispersed. The receiving tank to be disposed on;
A solid-liquid separation device that receives a suspension of soil fine particles received by the receiving tank and separates water and soil fine particles dispersed therein from the suspension;
Contaminated soil discharging means for discharging the soil fine particles separated and removed from the suspension water by the solid-liquid separator to the outside,
Filter means for removing the component derived from the soil to be decontaminated remaining from the water that is separated and discharged from the soil fine particles of the suspension by the solid-liquid separator;
The water from which the soil-derived components remaining in the filter means have been removed is received and stored as purified water, and a purified water tank that supplies the purified water to each part that requires purified water,
Consisting of
In addition, with respect to the slurry preparation means, the first solid-liquid separation means, the surface layer polishing means, the second solid-liquid separation means, the solid-liquid separation device, the contaminated soil discharge means, and the filter means, each of those processes is performed in a continuous process. Soil decontamination equipment configured in The first solid-liquid separation means or the second solid-liquid separation means,
A net inclined downward from the inlet end toward the outlet end that receives the dispersed water of the soil at the inlet end and discharges soil particles having a size larger than the mesh opening at the outlet end opposite to the inlet end. A cylindrical body;
A support means for rotatably supporting the mesh cylindrical body about its axis;
Rotation drive means for rotating the mesh cylinder about its axis;
A tubular supply means body arranged in parallel to the length direction of the mesh cylinder and a plurality of nozzles arranged in the supply means body, and for supplying purified water through the mesh into the mesh cylinder Purified water supply means for supplying purified water by spraying from the nozzle toward the mesh cylinder;
The soil decontamination apparatus of Claim 1 comprised by these. The surface polishing means,
The soil particles separated by the first solid-liquid separation means are received together with purified water at the inlet end, and ground soil particles and soil fine particles are discharged at the outlet end opposite to the inlet end, from the inlet end to the outlet end. A cylindrical body that is inclined downwardly;
Supporting means for rotatably supporting the cylindrical body about its axis;
Rotation drive means for rotating the cylindrical body about its axis;
An agitating member for polishing which is arranged in parallel to the inside of the cylindrical body so that the axial center of the cylindrical body does not coincide with the axial center and rotates in the opposite direction to the cylindrical body, and descends the inner periphery of the cylindrical body An agitating member for polishing arranged to agitate the flowing soil particles so that the soil particles rub against each other and polish each other.
The soil decontamination apparatus of Claim 1 or 2 comprised by these.

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