JP2013174057A - Device and method for removing contaminated soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a peeling device and a contaminated soil removing device and method which efficiently and effectively perform decontamination of a soil surface layer, removal of sludge, and removal of other contaminants, and reduce secondary health damage as much as possible.SOLUTION: A peeling device which peels the surface layer of contaminated soil while moving and transfers the peeled soil comprises: rotor blades which rotate to scrape and roll up the surface layer of the contaminated soil; a hood which is located above the rotor blades and prevents scattering of the rolled-up contaminated soil; and transfer means which mounts the contaminated soil falling down in the hood thereon and transfers it.

Description

  The present invention relates to a contaminated soil removing apparatus and a decontamination method for efficiently and effectively removing contaminants such as radioactive substances that contaminate a soil surface layer and the like, sludge accumulated on a soil surface layer, and the like.

  As a result of the Great East Japan Earthquake on March 11, 2011, radioactive materials were released from the Fukushima nuclear power plant, and the radioactive materials diffused over a wide area to remove or reduce the radioactive materials (hereinafter simply referred to as “decontamination”). It is peeling off.

  On the other hand, the decontamination methods differ depending on the house (roof, wall, fence), residential land, schoolyard, cultivated land, etc., and there are various types depending on the structure, shape, range, and the like.

  In particular, decontamination work for a wide range of soil surface layers is generally carried out in schoolyards by topsoil cutting and recovery by human power, and topsoil cutting and recovery work by known heavy machinery such as excavators (Non-Patent Documents 1 and 2).

  However, manual decontamination over a wide area is not efficient. In addition, decontamination work using known heavy machinery collects more soil than necessary, and the treatment of the collected soil becomes a problem. Furthermore, any soil surface decontamination means is costly and involves a soil scraping operation, so there is a problem of re-diffusion of radioactive substances, and the radiation concentration cannot be effectively reduced. Furthermore, there is a problem of internal exposure when the worker sucks the floating radioactive material. Therefore, these decontamination methods are not efficient and effective decontamination methods.

  Even far away from the Fukushima nuclear power plant, the radiation dose caused by cesium 134 and 137 in a region called a hot spot is high, and is regarded as a problem. Since the influence of radiation on children is considered to be high, decontamination of public facilities such as schoolyards, parks, and playgrounds is an urgent task, and the probability of an efficient and effective decontamination method is desired.

  In addition, in the earthquake, tsunami caused extensive accumulation of underwater sediments, garbage, and unnecessary and unsuitable earth and sand (hereinafter simply referred to as “sludge”) on cultivated land. Removal is also an important issue.

  If sludge is present, crops cannot be planted and cultivated on cultivated land, and a rotting odor is generated, which is not a good environment for health. However, in the removal of the sludge, there is no current method for dealing with slack, except for handling by manpower and known heavy machinery work.

  At present, there is no efficient and effective decontamination method, sludge removal method, and other contaminant removal means in a wide range of soil surface layers.

http://www.city.yoshikawa.saitama.jp/11,30190,115,636.html http://josen.env.go.jp/photo.html

  Accordingly, the present invention provides a delamination device that removes soil surface decontamination, sludge removal, and other contaminants efficiently and effectively, at a lower cost, and reduces secondary health damage as much as possible. It is an object of the present invention to provide a contaminated soil removal apparatus and a method for removing the same.

In order to solve the above problems, the present invention provides:
(1)
A stripping device for polluting soil that peels the surface layer of contaminated soil while moving, and transports the stripped soil, and is positioned above the rotor blade, and a rotor blade that rotates and scrapes the surface layer of the contaminated soil. The peeling apparatus is characterized by comprising a hood that prevents the scattered contaminated soil from being scattered, and a transfer means for transferring and transferring the contaminated soil dropped in the hood.
(2)
The transfer means is a substantially horizontal first belt conveyor, is fixed to the side surface of the first belt conveyor, has a length to a position where the rotor blade reaches a lower position, and the rotor blade; The peeling device according to (1) is provided with a cover disposed with a slight clearance therebetween.
(3)
The rotor blade includes a rotation shaft, a fixed portion that is connected and fixed to the rotation shaft, and a blade that includes a flat portion that is bent and connected to the fixed portion in an L shape, and the blade is in the longitudinal direction of the rotation shaft. The flat portion that is arranged in a plurality of rows and is not fixed to the rotating shaft draws a cylindrical side surface locus by rotating the rotating shaft, and the configuration of the peeling apparatus according to (1) or (2), did.
(4)
The blades arranged in a plurality of rows in front are arranged in a plurality of rows in a spiral manner on the rotating shaft.
(5)
The configuration of the peeling apparatus according to any one of (1) to (4), wherein a tip of the blade is tapered in a rotation direction.
(6)
The rotary device, the hood, and the cover are integrated and can be moved up and down, and the peeling device according to any one of (1) to (5) is configured.
(7)
(1)-(6) WHEREIN: It was set as the structure of the contaminated soil removal apparatus characterized by making the accompanying vehicle which loads the said contaminated soil peeled along with the peeling apparatus in any one of (6).
(8)
(7) According to (7), the detaching apparatus according to any one of (1) to (6) is moved, and a towing vehicle is provided to supply the rotational power of the rotor blade and the rotational power of the conveyor. It was set as the structure of the contaminated soil removal apparatus.
(9)
(7) or (8) by using the contaminated soil removal device, 2-5 cm of the contaminated lawn surface layer is peeled from the surface layer and collected to decontaminate the lawn land, did.
(10)
The contaminated soil removal apparatus according to (7) or (8) is used to decontaminate the contaminated soil.
(11)
The contaminated soil is soil contaminated with a radioactive substance or tsunami sludge. The method for removing contaminated soil according to (10) is provided.

  Since this invention is the said structure, even if it is a wide range contaminated soil, the contaminated soil surface layer part can be peeled off efficiently and at low cost, and it becomes possible to reduce a contaminant concentration.

  Moreover, even if the pollutant is a radioactive substance, since the peeled off contaminated soil is small, the degree of secondary damage to health such as internal exposure can be greatly reduced, and the radiation dose can be effectively reduced.

  When the decontamination target is lawn, the radiation dose can be reduced even with minimal exfoliation, leaving an underground stalk and root system. Therefore, since the turf can be regenerated without changing the turf, the turf is decontaminated at a low cost. In addition, it is also effective for decontamination of contaminated soil, land where a wide range of soils such as the ground are exposed, farm fields with tsunami sludge, and paddy fields.

It is the photograph which image | photographed the mode of decontamination of the lawn ground using the contaminated soil removal apparatus which is this invention. It is a perspective view of the peeling apparatus which is this invention. It is a disassembled perspective view of a peeling apparatus. It is a perspective view of an example of a rotor blade. It is a partial exploded perspective view of a transfer unit. It is a cross-sectional schematic diagram which shows the mode of peeling of the soil surface layer part by a peeling apparatus. It is explanatory drawing of the decontamination process of a golf course. It is the photograph which image | photographed the mode of the decontamination work of the schoolyard using the contaminated soil removal apparatus which is this invention.

    Hereinafter, the present invention will be described in detail with reference to the drawings.

・ Removal of radioactive material from grassland Figure 1 shows a photograph of the lawn decontamination test. In the decontamination test, the contaminated soil removal apparatus 1 according to the present invention was used.

  The contaminated soil removal apparatus 1 is a peeling apparatus 2 that peels and transports a soil surface layer part that is contaminated with a contaminant while moving, here, a lawn surface layer part 8 that contains a radioactive substance that is adsorbed and stays on the lawn. A towing vehicle 6 that pulls 2 and supplies power to the peeling device 2, and an accompanying vehicle 7 that loads and collects the separated soil 8 a that has run along and separated from the peeling device 2.

  The decontamination work is a peeling device 2 that is connected to a tractor that is a tow vehicle 6 and moves, and the lawn surface layer 8 that is contaminated with radioactive material is peeled by about 2 cm, and the truck bed that is the accompanying vehicle 7 is contaminated soil. It is transferred to the exfoliated soil 8a and collected by the truck. In addition, since the peeling soil 8a is transported vigorously from the belt conveyor of the peeling device 2 on the side of the truck bed 1, the plate 7a is set up to prevent the peeling soil 8a from scattering.

  As can be seen from FIG. 1, the peeling device 2 peels the lawn surface layer 8 contaminated with the radioactive substance, but no scattering of the peeled soil 8a is observed in the vicinity thereof. In addition, the radiation dose before decontamination of the test turf was 0.520 μsievert per hour (5 cm from the surface layer), but the delamination part 8b after the decontamination test using the delamination device 2 and the contaminated soil removal device 1 The radiation dose was 0.178 μSv per hour, which is less than the 0.23 μSh per hour of the decontamination standard value shown by the Ministry of the Environment. As a result, an effective decontamination effect on the lawn was recognized. In addition, an average of 50% or more of the decontamination effect was exhibited in tests at a plurality of locations.

  Therefore, the peeling device 2 and the contaminated soil removal device 1 solve the problems of radioactive material re-scattering and internal exposure, and are effective for decontamination of a wide range of contaminated grassland, that is, the surface layer of a wide range of contaminated soil. You can say that.

  Hereinafter, the configuration of the contaminated soil removal apparatus 1 will be described in more detail with reference to FIGS. FIG. 2 is a perspective view of the peeling device 2, FIG. 3 is a partially exploded perspective view of the peeling device 2, and FIG. 6 is a schematic cross-sectional view taken along the line AA in FIG.

  The peeling device 2 pulled by the towing vehicle 6 includes a rotor blade 3, a drive unit 4, and a transfer unit 5. In addition, the peeling apparatus 2 may be provided with a self-propelled mechanism.

  As shown in FIGS. 2, 3, and 6, the drive unit 4 is connected to the towing vehicle 6 by a connecting portion 4a, and stores therein a rotor blade 2a that rotates and peels off the surface layer portion of the contaminated soil. Is connected to the transfer unit 5.

  Here, as shown in FIG. 2, the rotary drive input part 4d which inputs motive power from the outside (the towing vehicle 6) is provided, and the rotor blade 3, the transfer means of the transfer unit 5 (first and second belt conveyors 5b, 5e) is transmitted (the dashed line arrow (power transmission system 4e)). Dashed arrows indicate the direction of rotation.

  If the tow vehicle 6 is a tractor, generally a power take-out 6a (FIG. 3) is provided, from which rotational drive can be obtained by the rotational drive input unit 4d. The rotation of the rotor blade 3 and the transfer unit 5 is not limited to the input from the power takeout 6a but may be obtained from a battery, a self-propelled driving force, or the like.

  As shown in FIG. 6 and the like, the drive unit 4 includes a front hood 4b and an upper hood 4c connected to the front hood. The lower end of the front hood 4b is close to the soil surface layer portion, and prevents the separated soil 8a from scattering.

  Furthermore, the drive unit 4 includes a front support 4h. A front roller 4g is provided at the lower end of the front strut 4h, and a handle 4f is provided at the upper end. By rotating the handle 4f, the length of the front strut 4h is variable, and the position of the rotor blade 3 can be moved up and down. At that time, the front hood 4b moves up and down in the same manner.

  As shown in FIGS. 3, 4, and 6, the rotor blade 3 receives a rotational power (broken line in FIG. 3) from the drive unit 4 and rotates toward the traveling direction side (broken arrow direction), and a rotational shaft It consists of a plurality of plates 3f having a plurality of projections 3g (here, four locations) fixed perpendicularly to the longitudinal direction of 3a, and a substantially L-shaped blade 3b fixed to the projection 3g. In FIG. 6, the black blade 3b is the back side, and the gray blade 3b is the front side.

  The shape of the plate 3f is not particularly limited, but the position of the protrusion 3g is arranged at a different angle from the position of the protrusion 3g of the adjacent plate 3f. As a result, four rows of blades 3b are arranged in a spiral (broken line).

  The blade 3b may be substantially L-shaped that is fixed to the plate 3f with screws or the like. In other words, the fixed portion 3c is fixed to the rotary shaft 3a via the plate 3f, and the flat portion 3d is bent and connected to the fixed portion 3c at approximately 90 °. Further, the rotation direction side of the flat portion 3d has a taper 3e shape that becomes narrower toward the tip, so that the peeling effect is high.

  The blades 3b are arranged in a plurality of rows in the longitudinal direction of the rotating shaft 3a, and the flat portion 3d not fixed to the rotating shaft 3a draws a cylinder side surface trajectory by rotating the rotating shaft 3a and scrapes the contaminated soil surface layer portion. Roll up.

  As shown in FIGS. 3, 5, and 6, the transfer unit 5 is connected to the drive unit 4 by a frame 5 n. The first belt conveyor 5b, the rear hood 5a, the left and right hoods 5p, 5p 'and 5q are connected to the frame 5n.

  The rear hood 5 a overlaps the upper hood 4 c of the drive unit 4. And the hood is formed by the front hood 4b of the drive unit 4, the upper hood 4c, the rear hood 5a of the transfer unit 5, and the left and right hoods 5p, 5p ', 5q, and scattering of contaminated soil to the outside of the hood is prevented.

  Further, as shown in FIG. 6, the side surface of the substantially horizontal first belt conveyor 5 b has a length up to the position where the rotor blade 3 reaches the lower position, and has a slight clearance 5 s between the rotor blade 3 and the rotor blade 3. A cover 5k is provided. If the lower end of the cover 5k has a length close to the peeled soil surface, the falling of the peeled soil 8a onto the peeled portion is reduced, and the contaminants can be further reduced. The upper end (guide portion 5t) of the cover 5k is located above the first belt conveyor 5b, which is effective for preventing the peeling soil 8a from scattering.

  Moreover, the 2nd belt conveyor 5e which can adjust an angle with the hydraulic pressure 5f is provided in the vicinity of the 1st belt conveyor 5b. This facilitates the transfer of the accompanying vehicle 7 to the loading platform. Side guides 5g are erected on both sides of the second belt conveyor 5e to prevent spillage of the peeled soil 8a being transferred. As shown in FIG. 2, you may fix the stopper 5i which applies peeling soil on the extension line of the 2nd belt conveyor 5e. It prevents the exfoliated soil 8a from being blown up beyond the intended loading platform.

  Furthermore, the transfer unit 5 includes a rear support 5r as seen in FIG. A rear roller 5d is provided at the lower end of the rear post 5r, and a handle 5c is provided at the upper end. By rotating the handle 5c, the length of the rear post 5r is variable, and the position of the rotor blade 3 can be moved up and down. At that time, the cover 5k moves up and down in the same manner.

  Decontamination of the lawn ground (lawn surface layer 8) shown in FIG. 1 will be described in detail with reference to FIG. The left column of FIG. 7 is a schematic cross-sectional view of the decontamination mechanism while maintaining the regeneration power of the lawn. The right column is a photograph corresponding to the left column in which an actual decontamination test and a reproduction situation are photographed.

  As shown in FIG. 7 (A), the radioactive substance adsorbing layer 9 in the lawn, that is, the lawn surface layer 8 is an upper layer in which the root system 8e and the underground stalk 8d are partially left as a result of intensive research. It turned out that it did not reach deeply.

  Therefore, decontamination of the lawn can be performed by removing a part of the lawn leaf portion 8c and the underground cheek stalk 8d (peeling depth (within a broken line)). That is, as shown in FIG. 7B, the radioactive dose can be sufficiently reduced by peeling off the lawn surface layer 8 while leaving a part of the basement 8d with the blade 3b. The actual work is shown in FIG.

  Moreover, by leaving 8d of the underground corn stalk and applying fertilizer if necessary, the lawn can be regenerated (D) without being replaced, which is extremely economical. The state after the test is shown in FIG. The grass regenerates 58 days after peeling with the peeling device 2 of the present invention (rectangular dark portion), and 39 days after peeling, the grass is regenerated (partially dark portion).

  In addition, when decontaminating turf land without refurbishing the lawn, measurement of radioactive concentration, investigation of the accumulation of underground cheek stalks, root systems, and cuttings, as well as estimation of the adsorbed part of radioactive substances, peeling depth, etc. It is desirable to adjust appropriately.

  And it is efficient and effective when the decontamination work of one section is performed, the peeling depth is determined, and the decontamination work is performed. Finally, it is confirmed that the radiation concentration is not more than 0.23 μsieval per hour, and the decontamination action is finished.

  Conventionally, in the case of decontamination of lawn and ground, the peeling depth is about 5 cm. However, as a result of earnest research, when the contaminated soil removing device 1 according to the present invention, particularly the peeling device 2 is used, the peeling depth is It has been found that about 2 cm to 3 and preferably about 2 cm is sufficient. As a result, the treatment of the exfoliated soil can be minimized, and it can be regenerated without changing the lawn and economically decontaminated.

[Removal of radioactive materials in the ground (application to schoolyard decontamination)]
In FIG. 8, the photograph of the decontamination test of the school yard 10 of the school using the contaminated soil removal apparatus 1 was shown. Public facilities, especially infants and school children, are highly sensitive to radiation, and decontamination of gardens, schoolyards, playgrounds, and parks is urgently needed.

  As shown in FIG. 8, by using the contaminated soil removal apparatus 1 according to the present invention for decontamination of schoolyards, the decontamination of a site, garden, schoolyard, playground, and park where a wide range of soil is exposed can be efficiently performed. Can be done effectively. The peeling depth (peeling part 10a) at that time is 2 to 5 cm, and further, scattering and diffusion of the peeled soil are small, and it can be well below 0.23 microsieves per hour.

  Therefore, the treatment amount of the exfoliated soil 10b can be extremely small as compared with the conventional work. Further, there is no scattering of the exfoliated soil 10b, that is, there is no re-diffusion of radioactive substances, and secondary damage to human health such as internal exposure of workers can be suppressed to a minimum.

[Application to removal of sludge from tsunami damage]
By using the contaminated soil removing apparatus 1 according to the present invention, it can be efficiently used to remove sludge such as marine sediment deposited on cultivated land (field, paddy field) or the like. In addition to the contamination caused by the diffusion of radioactive materials, the removal of sludge deposited on cultivated land in the coastal area of the Tohoku region is an urgent issue. The application of the soil removal apparatus 1 is extremely effective.

DESCRIPTION OF SYMBOLS 1 Contaminated soil removal apparatus 2 Separation apparatus 3 Rotor blade 3a Rotating shaft 3b Blade 3c Fixed part 3d Flat part 3e Taper 3f Plate 3g Projection 4 Drive unit 4a Connection part 4b Front hood 4c Upper hood 4d Rotation drive input part 4e Power transmission system 4f Handle 4g Front roller 4h Front strut 5 Transfer unit 5a Rear hood 5b First belt conveyor 5c Handle 5d Rear roller 5e Second belt conveyor 5f Hydraulic pressure 5g Side guide 5h Rotating shaft 5i Stopper 5k Cover 5m Rotating shaft 5p Left cover 5p 'Left cover 5q Right cover 5r Rear support 5s Clearance 5t Guide part 6 Towing vehicle 6a Power take-out 7 Accompaniment car 7a Plate 8 Lawn surface layer part 8a Peeling soil 8b Peeling part 8c Leaf part 8d Underground stalk 8e Root system 8f Underground part 8g Joint soil 9 Radioactive substance Adsorption layer 10 Schoolyard 10a Peeling part 10b Away soil

Claims (11)

A stripping device for contaminated soil that peels off the surface layer of contaminated soil while moving and transports the stripped soil,
A rotor blade that rotates and scrapes and rolls up the surface layer of the contaminated soil, a hood that is positioned above the rotor blade and prevents the contaminated soil from being scattered, and a transfer means that carries and transports the contaminated soil dropped in the hood And a peeling device characterized by comprising: The transfer means is a substantially horizontal first belt conveyor, is fixed to the side surface of the first belt conveyor, has a length to a position where the rotor blade reaches a lower position, and the rotor blade; The peeling apparatus according to claim 1, further comprising a cover disposed with a slight clearance therebetween. The rotor blade includes a rotation shaft, a fixed portion that is connected and fixed to the rotation shaft, and a blade that includes a flat portion that is bent and connected to the fixed portion in an L shape, and the blade is in the longitudinal direction of the rotation shaft. 3. The peeling device according to claim 1, wherein the flat portion that is arranged in a plurality of rows and is not fixed to the rotation shaft draws a cylindrical side surface locus by the rotation of the rotation shaft. The peeling device according to claim 3, wherein the plurality of blades arranged in front of the plurality of rows are arranged in a plurality of rows spirally on the rotation shaft. The peeling device according to any one of claims 1 to 4, wherein a tip of the blade is tapered in a rotation direction. The peeling device according to any one of claims 1 to 5, wherein the rotary blade, the hood, and the cover are integrally movable. A contaminated soil removing apparatus, wherein the accompanying device carrying the separated contaminated soil is caused to run in parallel with the peeling device according to any one of claims 1 to 6. The detaching apparatus according to any one of claims 1 to 6, further comprising a towing vehicle that supplies rotational power of the rotor blade and rotational power of the conveyor. The contaminated soil removal apparatus described. A decontamination method for lawn lands, wherein the contaminated turf surface layer is peeled and collected 2 to 5 cm from the surface layer by the contaminated soil removal apparatus according to claim 7 or 8, and the turf lands are decontaminated. A method for removing contaminated soil, wherein the contaminated soil is decontaminated by the contaminated soil removing apparatus according to claim 7 or 8. The method for removing contaminated soil according to claim 10, wherein the contaminated soil is soil contaminated with radioactive substances or tsunami sludge.