JP2011194288A - Bottom mud purification apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bottom mud purification apparatus which agitates organic matter and the like in water to float them, can recovery the floated matter by a recovery pump to perform purification treatment, and can purify the organic matter efficiently and at a low cost in comparison with the conventional apparatus which pumps bottom mud up together with sand.SOLUTION: The bottom mud purification apparatus includes a support 2, a shroud 3, and the recovery pump 4. First nozzles 15 and second nozzles 16 are installed in the peripheral wall of the cylindrical shroud 3 so that their jet central axes P1, P2 are directed to fixed directions to rotate the agitated bottom mud to one direction along the shroud 3. The organic matter-containing fine grained soil, sand and gravel are separated by the agitation action of both nozzles 15, 16, and the separated organic matter and fine grained soil are floated together with air from an upper surface opening of the shroud 3 along the support 2 and recovered by the recovery pump 4. The upper opening surface of the shroud 3 is provided with a plurality of restricting wings 32 for restricting the overflow of a rotating agitation flow.

Description

  The present invention relates to a bottom mud purification apparatus for separating and removing organic matter such as sludge and pollutants in closed water areas such as harbors, lakes, rivers, and ponds.

  Regarding this kind of bottom mud purification apparatus, the method for treating dredged bottom mud disclosed in Patent Document 1 is known. There, the bottom mud is pumped together with sand and gravel by a mud pump, ozone is brought into contact with the pumped mud, and a flocculant is added to decompose humic substances (organic substances). Next, the bottom mud treated with ozone is subjected to solid-liquid separation, the separated floc (solid phase) is returned to the water bottom, and ozone is again brought into contact with the separated liquid to re-decompose the humic substance.

  In the bottom mud purification apparatus of the present invention, pressurized water or air is jetted toward the bottom mud, the bottom mud is stirred to levitate the organic matter, and the buoyed organic matter is pumped to the stern or the like with a recovery pump. A seed purification device is disclosed in US Pat. There, high-pressure water is ejected from a nozzle submerged in water to separate the contaminants adhering to gravel, etc., and the separated contaminants are received by a bucket disposed downstream from the nozzle and collected by a recovery pump. Store in a collection container and drain.

  In the bottom quality improvement method of Patent Document 3, the sludge-like bottom mud is pumped up with seawater, and the pumped mud is separated into sand and anaerobic bottom mud with a hydrocyclone separator, Only sand is returned to the bottom. Anaerobic bottom mud is composed of clay, silt, organic matter, etc., and is accommodated in each of the first and second bottom mud improvement tanks and subjected to aerobic treatment (intermittent aeration). The modified anaerobic bottom mud can be reused for paddy field soil, raw materials for inorganic baked products, etc., and returned to the original water area if necessary.

  In the underwater sediment processing apparatus of Patent Document 4, a rectangular box-shaped casing that opens downward is submerged on the sea floor, and high-pressure water is ejected while the nozzles provided at six locations in the casing swing around the vertical axis. The shells and oyster shells deposited on the sea floor surrounded by the casing are crushed. Seawater ejected from the nozzle is pressurized to a high pressure (150 kgf per square centimeter).

Japanese Patent Laying-Open No. 2009-18223 (paragraph number 0019, FIG. 1) JP 2002-28526 A (paragraph number 0015, FIG. 2) JP 2007-98253 A (paragraph number 0022, FIG. 1) Japanese Patent No. 2746868 (paragraph number 0016, FIG. 3)

  In the method for treating dredged bottom mud in Patent Document 1, the bottom mud is pumped up with sand and gravel by a pump, and ozone is brought into contact with the pumped mud, and a flocculant is added to remove organic matter. . As described above, according to the purification method in which the bottom mud is sanded together with the sand, the purification treatment can be surely performed, but the entire apparatus becomes large and the processing cost increases. In addition, it takes a lot of labor and cost to return the treated sand, gravel, or floc (solid phase) to the bottom of the water.

  In the purification device of Patent Document 2, high-pressure water ejected from a nozzle is sprayed onto gravel and the like, and the separated contaminants are received by a downstream bucket and collected by a collection pump. For this reason, most of the separated contaminants are easily diffused downstream of the purification site, and the contaminants cannot be effectively recovered.

  In the bottom quality improvement method of Patent Document 3, sludge-shaped bottom mud is pumped up, and the pumped mud is separated into sand and anaerobic bottom mud using a liquid cyclone separator, To the bottom. Therefore, although more reliable purification processing can be performed, like the purification method of Patent Document 1, the entire apparatus becomes large and processing costs increase. It takes considerable effort and cost to return the sand and gravel after treatment to the bottom of the water. The underwater sediment processing apparatus of Patent Document 4 only crushes shells and oyster shells deposited on the seabed surrounded by a casing, and cannot process organic substances typified by sludge.

The object of the present invention is to stir and float organic matter and the like in water, and this floated matter can be recovered by a recovery pump and purified, and therefore more efficient than conventional devices that lift mud with sand, And it is providing the bottom mud purification apparatus which can purify | clean organic substance at lower cost.
The object of the present invention is to efficiently separate and recover organic matter and fine-grained soil, despite the fact that the overall structure is simple and the introduction cost is low, thus greatly reducing the labor and cost required to purify the bottom mud. An object of the present invention is to provide an economical bottom mud purification device that can be used.

  The bottom mud purification apparatus according to the present invention is disposed on the peripheral surface of the support column 2 suspended by the suspension device 1, the shroud 3 fixed to the lower end of the support column 2, and the support column 2 above the shroud 3. A recovery pump 4 that recovers organic matter and fine-grained soil that floats along the support 2 is provided. On the peripheral wall of the cylindrical shroud 3 whose upper and lower surfaces are open, a plurality of first nozzles 15 for jetting pressurized water toward the bottom mud in the shroud 3 and pressurized air are pressurized. A plurality of second nozzles 16 that are jetted into the shroud 3 together with the water thus formed are provided at predetermined intervals. In the first nozzle 15 and the second nozzle 16, the respective ejection center axes P 1 and P 2 are directed in the same direction along the circumferential direction of the support column 2, and the stirred bottom mud is unidirectional along the shroud 3. You can turn. The fine soil containing organic matter, sand and gravel collide with each other in the shroud 3 by the stirring action of both nozzles 15 and 16 to separate the organic matter, and the separated organic matter and fine particulate soil are supported from the upper surface opening of the shroud 3 It is levitated along with air along the line 2 and collected by the collection pump 4. In addition, the rotation direction of the support | pillar 2 means the rotation direction around the support | pillar 2 when seeing the shroud 3 from a plane like FIG. 4, and when it is a clockwise rotation direction and a counterclockwise rotation direction It means that either. Accordingly, the fact that the ejection center axes P1 and P2 are oriented in the same direction along the circumferential direction of the column 2 means that the ejection center axes P1 and P2 when viewed from the plane are in the clockwise direction as shown in FIG. It means that it is directed along one of the counterclockwise rotation directions.

  A plurality of regulating blades 32 are provided on the upper opening surface of the shroud 3 to restrict the swirling stirring flow from overflowing. The cross section of the regulating blade 32 is inclined downward from the upper turning side of the stirring flow toward the lower turning side.

  The first nozzle 15 is disposed on the peripheral wall near the lower edge of the shroud 3, and the second nozzle 16 is disposed on the peripheral wall of the shroud 3 above the first nozzle 15. The ejection center axis P1 of the first nozzle 15 and the ejection center axis P2 of the second nozzle 16 are set obliquely downward from the position where the nozzles 15 and 16 are fixed to the shroud 3, respectively. The inclination angle θ2 of the ejection center axis P2 of the second nozzle 16 is set larger than the inclination angle θ1 of the ejection center axis P1 of the first nozzle 15.

  A stirring blade 33 for stirring the swirling flow is provided on at least one of the inner surface of the shroud 3, the outer surface of the support column 2 surrounded by the shroud 3, and the lower surface of the regulating blade 32.

  The shroud 3 is fixedly supported by a plurality of brackets 10 arranged radially on the peripheral surface of the support column 2. A regulating blade 32 is disposed in the overlapping region of the shroud 3 and the bracket 10.

  In the bottom mud purification apparatus according to the present invention, the first nozzle 15 and the second nozzle 16 are provided on the peripheral wall of the cylindrical shroud 3, and the bottom mud is dug up with high-pressure water ejected from both nozzles 15 and 16. The mixture was stirred and swirled along the shroud 3. Sand, gravel, fine-grained soil and organic matter constituting the bottom mud are separated while being stirred while swirling in the shroud 3. The agitated sand, gravel, fine-grained soil, and organic matter are eventually spouted up the shroud 3 along the support column 2, but the mass of the fine-grained soil containing organic matter and organic matter is lighter than sand and gravel. Therefore, it is spouted upwards together with the air. However, sand and gravel that are large and have a large mass have a limit in the distance that can be spouted, and sink to the bottom by their own weight. As a result, sand and gravel and fine-grained soil and organic matter can be classified in water, and the organic matter and fine-grained soil that have been levitated with air can be collected and purified by the collection pump 4.

  As described above, according to the bottom mud purification apparatus of the present invention, only the fine-grained soil containing the organic part and organic matter to be purified can be collected by the collection pump 4, so that the conventional apparatus for lifting the bottom mud together with sand and the like Compared to the above, organic substances and the like can be collected efficiently, and the operating cost of the purification apparatus can be greatly reduced. In addition, since the purification device is constituted by the column 2, the shroud 3, the recovery pump 4, the first and second nozzles 15 and 16, etc., the overall structure is simplified and purification is performed as compared with the conventional device of this type. Equipment introduction costs can be reduced. In addition, since organic matter and fine-grained soil are classified from sand and gravel in water, organic matter and fine-grained soil can be separated and recovered efficiently, thus greatly reducing the labor and cost required for bottom mud purification. As a result, it is possible to provide an economical bottom mud purification device. In the process in which the bottom mud is stirred and swirled in the shroud 3, the sand and gravel in the purification target zone can be aerated and aerobicized by contacting with the air supplied from the second nozzle 16, and thus settled on the bottom of the water after stirring. Sand and gravel also help to purify the water quality of the target area.

  When the regulating blade 32 is provided on the upper opening surface of the shroud 3, the regulating blade 32 regulates the swirling stirring flow from overflowing from the upper surface of the shroud 3, and the organic matter and fine-grained soil are sufficiently stirred together with sand and gravel. Thus, separation of organic substances can be promoted. In addition, in the process of stirring, sand, gravel, fine-grained soil, and organic matter can be sufficiently brought into contact with air to aerobize sand and gravel, or promote the levitation of fine-grained soil and organic matter. Therefore, it is possible to further reliably separate fine soil and organic matter from sand and gravel, and to promote purification of water quality by the sand and gravel after purification.

  If the cross section of the regulating blade 32 is inclined downward from the upper turning side of the stirring flow toward the lower turning side, sand or gravel having a mass larger than that of the organic matter can collide with the regulating blade 32 to reduce kinetic energy. Further, it is possible to guide the sand and gravel in a direction crossing the turning direction and eject the sand and gravel from between the regulating blades 32. Therefore, it is possible to more reliably classify organic matter and fine-grained soil from sand and gravel by sufficiently suppressing the height of the sand and gravel.

  The first nozzle 15 arranged near the lower edge of the shroud 3 digs up and suspends the bottom mud while the shroud 3 is sunk in the bottom mud. The second nozzle 16 arranged above the first nozzle 15 agitates the bottom mud dug up and supplies air while swirling along the shroud 3. In this way, the first nozzle 15 and the second nozzle 16 having different functions excavate, stir, and swirl the bottom mud, thereby effectively stirring sand, gravel, fine-grained soil, organic matter, and aeration. Can be done.

  When the inclination angle θ2 of the ejection center axis P2 of the second nozzle 16 set obliquely downward is set larger than the inclination angle θ1 of the ejection center axis P1 of the first nozzle 15, both ejection center axes P1 and P2 intersect in the vertical direction. Therefore, the contact opportunity between the suspended bottom mud and the air ejected from the second nozzle 16 can be increased. Accordingly, sand and gravel can be effectively aerated by bringing a sufficient amount of air into contact with the bottom mud dug up by the first nozzle 15.

  When the stirring blade 33 is provided on the shroud 3, the support column 2, and the regulating blade 32, the flow of the stirring flow swirling along the shroud 3 is obstructed by the stirring blade 33, and a vortex is generated downstream from the stirring blade 33. Can do. Since the water, sand, gravel, fine-grained soil, and organic matter flowing through the vortex are vigorously mixed, the stirring effect can be further improved.

  When the regulating blade 32 is disposed in the overlapping region of the shroud 3 and the bracket 10, the stirring flow swirling along the upper portion of the shroud is stopped at the lower edge portion of the bracket 10, and the stirring flow that tries to overflow from the upper surface of the shroud 3 is generated. It can be regulated by the regulating blade 32. Therefore, the kinetic energy of sand and gravel with a large mass can be more reliably reduced by the bracket 10 and the regulating blade 32, and the sand and gravel blast can be effectively suppressed.

It is a vertical front view of the principal part of the bottom mud purification apparatus which concerns on this invention. It is a schematic explanatory drawing which shows the whole thing of a bottom mud purification apparatus. It is a cross-sectional top view of a shroud. It is a cross-sectional top view which shows the arrangement | positioning form of a 1st nozzle and a 2nd nozzle. It is a longitudinal cross-sectional view of a 1st nozzle. It is the sectional view on the AA line in FIG. It is a longitudinal cross-sectional view of a 2nd nozzle. It is the BB sectional view taken on the line in FIG. It is a longitudinal cross-sectional view which shows the modification of a bottom mud purification apparatus. It is a longitudinal cross-sectional view which shows another modification of a bottom mud purification apparatus.

(Example) FIGS. 1-8 has shown the Example of the bottom mud purification apparatus which concerns on this invention. In this embodiment, the case of purifying sludge-like bottom mud that sinks to the seabed such as a harbor will be described. In FIG. 2, the purification device is disposed on the peripheral surface of the support column 2 suspended by the suspension device 1 such as a crane or a backhoe, the shroud 3 fixed to the lower end of the support column 2, and the support column 2 above the shroud 3. The recovery pump 4 is configured. When the suspension device 1 is constituted by a construction machine such as a backhoe, it is possible to prevent the purification device from rotating by receiving a jet reaction force of nozzles 15 and 16 described later by the construction machine. The suspension device 1 is provided on a stern together with a pump, a compressor, and the like, and in the vicinity thereof, a filtration device 5 for filtering organic matter and fine-grained soil recovered by the recovery pump 4 is installed. In order to prevent the bottom mud agitated by the purification device from dispersing or flowing out of the purification target area, the periphery of the purification target area is divided by a silt curtain 6.

  The support column 2 is formed in a hollow tubular shape, and a lower end 7 of the support column 2 is tapered and tapered. A metal pipe or a branch pipe for feeding seawater or air pressurized by a pump or a compressor to nozzles 15 and 16 to be described later is fixed to the peripheral surface of the support column 2. These pipes, the pump and the compressor are connected via a high-pressure rubber hose (not shown) provided between the suspension device 1 and the support column 2. The power supply line for the recovery pump 4 and the recovery pipe are arranged along the peripheral surface of the support column 2 in the same manner as the previous pipe.

  As shown in FIG. 1, the shroud 3 is made of a steel plate cylindrical body whose upper and lower surfaces are open, and is fixed to an upper bracket (bracket) 10 and a lower bracket (bracket) 11 provided at the lower portion of the previous support column 2. It is supported concentrically with the column 2. The upper bracket 10 is arranged in a cross shape on the peripheral surface of the support column 2, and a lower portion thereof is inserted into a slit in the peripheral wall of the shroud 3, and each of the inner and outer intersecting portions with the slit is welded. Thus, the lower part of the upper bracket 10 is intentionally positioned inside the upper opening of the shroud 3, and the overlapping dimension of the shroud 3 and the upper bracket 10, that is, from the upper opening surface of the shroud 3 to the lower edge of the upper bracket 10. The distance is 200 mm. The lower bracket 11 is composed of a cross-shaped frame and is welded to the lower end 7 of the support column 2 and the inner wall of the shroud 3. The arrangement positions of the upper bracket 10 and the lower bracket 11 are shifted by 45 degrees in the circumferential direction (see FIG. 3).

  Near the lower edge of the peripheral wall of the shroud 3, four first nozzles 15 that eject pressurized seawater toward the bottom mud in the shroud 3 are provided at equal intervals. Further, four second nozzles 16 for ejecting pressurized air into the shroud 3 together with the pressurized seawater are provided at equal intervals on the peripheral wall of the shroud 3 above the first nozzle 15. As shown in FIG. 4, the first nozzle 15 and the second nozzle 16 are arranged such that their positions when viewed from the plane are shifted in the circumferential direction.

  The ejection center axis P1 of the first nozzle 15 and the ejection center axis P2 of the second nozzle 16 intersect with each other in a square shape when viewed from the inside of the shroud 3, and each ejection center axis P1 and P2 is the support column 2. Are oriented in the same direction along the circumferential direction. In this embodiment, the ejection center axes P1 and P2 are directed along the counterclockwise rotation direction. Each of the ejection center axes P1 and P2 is set so as to be directed obliquely downward from a position where the nozzles 15 and 16 are fixed to the shroud 3. Specifically, as shown in FIG. 5, the inclination angle θ1 of the ejection center axis P1 is 10 degrees with respect to the horizontal plane, whereas the inclination angle θ2 of the latter ejection center axis P2 is in the horizontal plane as shown in FIG. The angle is set to 20 degrees. As shown in FIG. 4, when the shroud 3 is viewed from the plane, the angle α between the center line connecting the center of the support column 2 and the mounting center of the nozzles 15 and 16 and the ejection center axes P1 and P2 is respectively In this embodiment, the angle is set to 35 degrees.

  The 1st nozzle 15 spouts the seawater pressurized to 120Kgf or more per square centimeter toward the bottom mud in the shroud 3, digs up the bottom mud, sand, and gravel, and stirs. The second nozzle 16 mixes air pressurized to 7 Kgf per square centimeter with seawater pressurized to 30 Kgf per square centimeter and jets it into the shroud 3 to cooperate with the first nozzle 15. Agitate the bottom mud, sand and gravel. When the purification device is viewed as a whole, the ejection directions of all the nozzles 15 and 16 are set in the same direction along the peripheral wall of the shroud 3. Therefore, the bottom mud, sand, and gravel stirred by the water flow ejected from both nozzles 15 and 16 swirl counterclockwise in the shroud 3 toward FIG.

  As shown in FIGS. 5 and 6, the first nozzle 15 includes a columnar nozzle block 18 and a nozzle piece 20 that is fixed so as to face the nozzle opening 19 at the tip of the nozzle block 18. Suction openings 21 are formed at two locations on the peripheral wall of the cylindrical nozzle port 19 along the opening center lines parallel to each other. When high-pressure seawater is ejected from the nozzle piece 20, seawater, sand, gravel, fine-grained soil, and organic matter existing around the nozzle opening 19 are sucked from the suction opening 21 and ejected together with the high-pressure seawater. As shown in FIG. 6, since the suction openings 21 are arranged in a staggered manner, the accompanying jet flow jetted from the nozzle port 19 becomes a water flow twisted in one direction. Therefore, the stirring effect by the first nozzle 15 can be improved. A pump for supplying high-pressure seawater to the first nozzle 15 is denoted by reference numeral 36 in FIG.

  As shown in FIG. 7, the second nozzle 16 includes a rectangular parallelepiped nozzle main body 24, an air introduction block 25 fixed to the nozzle main body 24, and a nozzle piece 26 fixed between both of them. I have. A liquid inlet 27 is formed in the nozzle body 24, and an air inlet 28 and a mixing chamber 29 are provided in the air introduction block 25. Reference numeral 30 denotes a nozzle port. The flow of seawater ejected from the nozzle piece 26 to the mixing chamber 29 allows air supplied from the air inlet 28 to be mixed into seawater in the mixing chamber 29 and ejected from the nozzle port 30. In this way, when air is mixed and ejected into pressurized seawater, the bottom mud is formed by penetrating the pressurized water containing air farther than when the pressurized air is ejected alone. Aerobic can be achieved by effectively bringing air into contact with fine-grained soil, sand and gravel. A pump for supplying high-pressure seawater to the second nozzle 16 is indicated by reference numeral 36 in FIG. 2, and a compressor for supplying pressurized air to the second nozzle 16 is indicated by reference numeral 38 in FIG. Note that the pump 36 for the first nozzle 15 and the pump 37 for the second nozzle 16 pressurize the seawater stored in the tank 39 provided on the stern and feed the seawater to the nozzles 15 and 16. The tank 39 stores clean seawater that has been filtered by the filtration device 5.

  By ejecting a large amount of seawater from both the nozzles 15 and 16, a stirring flow swirling in one direction is formed inside the shroud 3, but the stirring flow in the shroud 3 overflows freely from the upper opening surface. In order to limit this, twelve regulating blades 32 are provided radially. The regulating blade 32 is disposed in the overlapping region of the shroud 3 and the upper bracket 10 and is welded to each of the outer peripheral surface of the support column 2 and the inner peripheral surface of the shroud 3. The blade width of the regulating blade 32 is narrow on the side of the support column 2, and is formed wider as it approaches the shroud 3. The cross section of the regulating blade 32 is inclined so as to incline downward from the upper turning side of the turning water flow toward the lower turning side. As shown in FIG. 3, gaps serving as seawater, sand, gravel, fine-grained soil, and organic matter outlets 35 are radially formed between the regulating blades 32 adjacent in the circumferential direction. When the opening of the shroud 3 is viewed from above, the ratio of the projected area occupied by the regulating blade 32 to the opening area of the shroud 3 is about half.

  As described above, when the regulating blade 32 is inclined downward from the upper turning side toward the lower turning side, fine soil, sand, gravel, etc. flowing along with the turning water flow are restricted from overflowing from the upper opening of the shroud 3. Thus, the bottom mud in the shroud 3 can be effectively stirred. In particular, sand or gravel with a mass larger than that of organic matter collides with the regulating blade 32 to reduce the kinetic energy, and further changes the direction in a direction crossing the turning direction and ejects from the outlet 35 between the regulating blades 32. Therefore, it is possible to more reliably classify organic matter and fine-grained soil from sand and gravel by sufficiently suppressing the height of the sand and gravel.

  A stirring blade 33 is fixed to one lower surface of the regulating blade 32. The stirring blade 33 is made of a strip-shaped steel plate, and is fixed in a state of projecting downward at a midway portion in the radial direction of the regulating blade 32. When the stirring blade 33 is provided in this way, the swirling operation of the fine-grained soil, sand, and gravel swirling in the shroud 3 is disturbed by the stirring blade 33, and a vortex is generated downstream from the stirring blade 33. Can be further improved. The lower wall of the upper bracket 10 located on the inner surface of the shroud 3 also serves to improve the stirring effect by receiving the swirling water flow.

  In order to effectively recover seawater with a high concentration of organic matter by the recovery pump 4, the recovery pump 4 is suspended so that the suction port 4 a is located above (the sea level side) above the shroud 3. The hanging height of the recovery pump 4 is changed according to the change of the tide level and the situation of the bottom mud, and the concentration is the highest while measuring or visually checking the concentration of the organic matter contained in the seawater discharged from the recovery pump 4. The organic matter is collected in the dark position. The organic matter and seawater sucked into the recovery pump 4 are supplied to the filtration device 5 and subjected to filtration processing.

  As shown in FIG. 2, the purification apparatus configured as described above is configured to place the shroud 3 at the bottom while spouting seawater including pressurized air and pressurized air from the first and second nozzles 15 and 16. Sedimented in mud, the recovery pump 4 is operated, the organic matter is pumped up together with the seawater, and is sent to the filtration device 5. The lower edge of the shroud 3 sunk in the bottom mud is submerged in the bottom mud by about 50 cm from the bottom mud surface. However, as the purification process proceeds, the bottom mud is gradually eroded by the high-pressure seawater ejected from both nozzles 15 and 16, so that the strut 2 and the shroud 3 are further moved following the erosion action of the bottom mud. It can sink and sink to the seabed. When the shroud 3 is sunk in the bottom mud, or when the column 2 and the shroud 3 are further submerged as described above, the lower end 7 of the column 2 serves to dig up the bottom mud while pushing it along the tapered surface.

  By the way, the bottom mud is composed of fine-grained soil mainly composed of settled organic matter and coarse particles such as sand and gravel that are larger than fine-grained soil, and is attached to or adsorbed on the surface of coarse particles. The amount of organic matter contained is much less than the amount of organic matter adhering to or adsorbed on the fine-grained soil. The difference in the amount of adsorbed and adsorbed organic matter is due to the fact that the specific surface area (surface area per unit weight) of fine-grained soil is much larger than the specific surface area of coarse particles, and the specific surface area is large. The amount of organic matter adsorbed becomes larger by that amount.

  In addition, when the total mass and the total surface area of the average bottom mud are 100%, the proportion of the mass occupied by the fine-grained soil is only 10 to 15%, but the specific surface area of the fine-grained soil is 80 to 90%. is occupying. Therefore, when it is assumed that the adsorption and adhesion of organic matter depends on the surface area, 80 to 90% of the organic matter contained in the bottom mud can be removed by purifying the fine-grained soil constituting the bottom mud. The purification apparatus of the present invention performs the purification process by utilizing this fact, and makes it possible to more effectively remove the organic matter and fine-grained soil containing the organic matter while performing the minimum amount of mud.

  In the process of purifying the bottom mud, a large amount of seawater is ejected from the nozzles 15 and 16 into the shroud 3. Therefore, the agitated fine-grained soil, sand, and gravel spout along the support column 2 from the outlet 35 of the shroud 3 together with the swirling water flow. At this time, organic matter and fine-grained soil having a lighter specific gravity than sand and gravel blast up to the far side (sea surface side) from the shroud 3 together with the air blown into the shroud 3. The sprayed organic matter and fine-grained soil are recovered together with seawater by the recovery pump 4 as described above, and fed to the filtration device 5.

  On the other hand, sand and gravel have a large mass and thus have a limited distance to be spouted, and most of them sink by their own weight before reaching the suction port 4a of the recovery pump 4. Thus, in the purification apparatus of the present invention, sand and gravel with large mass can be classified in seawater, and fine particles containing organic matter and organic matter can be effectively recovered by the recovery pump 4. Therefore, compared with the conventional purification apparatus which pumps up all of the bottom mud, organic matter and fine-grained soil containing organic matter can be effectively recovered at a lower cost. Since sand and gravel settled on the seabed are aerobic in contact with air while being stirred in the shroud 3, it helps to purify the quality of the bottom water in the state of being deposited on the seabed after stirring. .

  When a certain period of time has elapsed or when the shroud 3 has reached the bottom of the seabed, the sinking positions of the support column 2 and the shroud 3 are changed, and the organic matter that spouts from the shroud 3 The fine-grained soil is recovered by the recovery pump 4 and fed to the filtration device 5. Thereafter, by repeatedly performing the same purification operation, the bottom mud in the entire region surrounded by the silt curtain 6 can be removed. Although the filtered organic substance and the fine-grained soil containing the organic part remain in the filtering device 5, these filtration residues are taken out from the filtering device 5 and packed in bags, and are separately detoxified on land.

  As described above, according to the purification apparatus of the present invention, organic matter and fine-grained soil containing organic matter are stirred inside the shroud 3 to be separated from sand and gravel, spouted along the support column 2, And we could classify gravel. In addition, organic matter that floats with air and fine-grained soil containing organic matter are collected and purified by the collection pump 4, so that the bottom is more efficient and less expensive than conventional equipment that pumps all the bottom mud. The mud can be purified. In addition, since the overall structure is simple, it is possible to efficiently separate and recover the bottom mud even though the introduction cost of the purification device can be reduced. Therefore, the cost required for the purification of the bottom mud as a whole can be greatly reduced. . Since separation of organic substances and the like is performed in water, generation of vibration and noise can be suppressed, and bottom mud can be purified in a quieter state.

  FIG. 9 shows a modification of the purification device. There, the inclination angle of the regulating blade 32 can be changed according to the physical characteristics of the bottom mud to be purified and the difference in the ratio of sand and gravel contained in the bottom mud. Specifically, the shafts 40 fixed to the inner and outer ends of each regulating blade 32 are rotatably supported by the support column 2 and the shroud 3, and the bevel gear 41 is fixed to the shaft 40 supported by the support column 2. Further, in order to simultaneously rotate the group of bevel gears 40, a rotatable ring gear 42 is provided inside the column 2 so that it can be rotationally driven by the rotational power of the motor 43 via a gear mechanism. The rotational power of the motor 43 is converted into rotational power about the horizontal axis through the worm 44 and the worm gear 45, and further converted into rotational power about the vertical axis by the pair of bevel gears 46 and 47, and then the bevel gear 47 and It is transmitted to the internal gear 49 of the ring gear 42 via the drive gear 48 that rotates together. According to this drive mechanism, by driving the motor 43 in the normal direction or in the reverse direction, the regulating blade 32 can be tilted up and down around the shaft 40 and the tilt angle can be freely changed. The regulating blade 32 that is pivotally supported can be freely selected such as half of all regulating blades, one third, one quarter, and the like.

  FIG. 10 shows still another modification of the purification device. In this case, the lower end 7 of the support 2 formed in a tapered shape with a downward slope is protruded downward from the lower opening surface of the shroud 3. According to this purification device, the bottom mud can be pushed away by the lower end 7 of the support column 2 prior to the shroud 3 sinking into the bottom mud. Can be done automatically. Further, it is possible to smoothly sink the support column 2 and the shroud 3 toward the seabed base while pushing the bottom mud at the lower end 7 of the support column 2.

  In the above embodiment, four first nozzles 15 and four second nozzles 15 are provided on the peripheral wall of the shroud 3, but this is not necessary, and the number of the nozzles 15, 16 is not limited by the size of the shroud 3. The necessary number of arrangements may be selected according to the cross-sectional shape. If necessary, the second nozzle 16 can be disposed on the peripheral wall near the lower edge of the shroud 3, and the first nozzle 15 can be disposed on the peripheral wall of the shroud 3 above the second nozzle 16.

  The regulating blades 32 do not need to be arranged radially, and each regulating blade 32 can be arranged in a spiral shape. The stirring blade 33 can be provided on the inner surface of the shroud 3, the outer surface of the support column 2 surrounded by the shroud 3, or the like. Under the suction port 4a of the recovery pump 4, a hood for guiding the sprayed organic matter and fine-grained soil toward the suction port 4a can be provided. The angle α between the center line connecting the attachment centers of the nozzles 15 and 16 and the ejection center axes P1 and P2 does not have to be the same. Further, the angle α of the ejection center axis P1 of the four first nozzles 15 may be individually different. Similarly, the angle α of the ejection center axis P2 of the four second nozzles 16 may be individually different.

DESCRIPTION OF SYMBOLS 1 Suspension apparatus 2 Support | pillar 3 Shroud 4 Recovery pump 5 Filtration apparatus 15 1st nozzle 16 2nd nozzle 32 Control blade

Claims (5)

The support column (2) suspended by the suspension device (1), the shroud (3) fixed to the lower end of the support column (2), and the peripheral surface of the support column (2) above the shroud (3). And a recovery pump (4) for recovering organic matter and fine-grained soil levitated along the strut (2),
On the peripheral wall of the cylindrical shroud (3) whose upper and lower surfaces are open, a plurality of first nozzles (15) for jetting pressurized water toward the bottom mud in the shroud (3), and pressurization And a plurality of second nozzles (16) for ejecting the compressed air together with the pressurized water into the shroud (3), are provided at predetermined intervals,
In the first nozzle (15) and the second nozzle (16), the central axis (P1, P2) of each jet is directed in the same direction along the circumferential direction of the support column (2). Can turn in one direction along the shroud (3)
The fine-grained soil, sand and gravel containing organic matter collide with each other in the shroud (3) by the stirring action of both nozzles (15, 16) to separate the organic matter, and the separated organic matter and fine-grained soil are separated from the shroud (3 The bottom mud purification device is levitated with air along the support column (2) from the upper surface opening and is recovered by the recovery pump (4). On the upper opening surface of the shroud (3), a plurality of regulating blades (32) for regulating the swirling stirring flow from overflowing are provided.
The bottom mud purification apparatus according to claim 1, wherein a cross section of the regulating blade (32) is inclined downward from the upper turning side of the stirring flow toward the lower turning side. The first nozzle (15) is disposed on the peripheral wall near the lower edge of the shroud (3), and the second nozzle (16) is disposed on the peripheral wall of the shroud (3) above the first nozzle (15),
Each of the ejection center axis (P1) of the first nozzle (15) and the ejection center axis (P2) of the second nozzle (16) is oblique from the position where each nozzle (15, 16) is fixed to the shroud (3). Set to face down,
The inclination angle (θ2) of the ejection center axis (P2) of the second nozzle (16) is set larger than the inclination angle (θ1) of the ejection center axis (P1) of the first nozzle (15). The bottom mud purification device described.   A stirring blade (33) for stirring the swirling flow is provided on at least one of the inner surface of the shroud (3), the outer surface of the support (2) surrounded by the shroud (3), and the lower surface of the regulating blade (32). Item 4. The bottom mud purification apparatus according to Item 2 or 3. The shroud (3) is fixedly supported by a plurality of brackets (10) arranged radially on the peripheral surface of the support column (2),
The bottom mud purification apparatus according to claim 2, 3 or 4, wherein a regulating blade (32) is disposed in the overlapping region of the shroud (3) and the bracket (10).

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