JP2005155154A - Mud treatment device and dredge mud treatment system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mud treatment device capable of producing a uniform lump of mud even for mud with high viscosity. <P>SOLUTION: The mud treatment device 11 includes a mud receiving tank 12 storing mud 5, a slurry tank 23 stirring the mud 5 sent out from the slurry tank 23 and a high pressure filter press 30 dehydrating the mud 5 sent out from the slurry tank 23. A circulating pump 28 vertically circulating the mud 5 in the slurry tank 23 is provided to the slurry tank 23. Since particles with large diameters and precipitated downward are thereby again carried to the upper part to enable the mud 5 to forcedly and vertically circulate, slurry liquid having uniform viscosity distribution can be produced without storing the particles with large diameters in the lower part of the slurry tank 23, and as a result, the lump of mud dehydrated and formed by the high pressure filter press can be also formed of the uniform viscosity distribution and the uniform degree of dehydration. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a mud processing apparatus and a dredged mud processing system for processing dredged soil and mud (hereinafter collectively referred to as mud) in harbors, rivers, lakes and the like.

  In harbors, rivers, lakes, etc., mud is dredged for the purpose of purifying water and improving the environment.

  This dredged mud is often sludge-like, and it is difficult to use such mud as it is as a material for landfill civil engineering or to dump it. For this reason, conventionally, the bottom mud is dredged with a backhoe, etc., and the mud is separated from solids such as dust and gravel with a separator, stirred, and pumped to the destination by a pump. A method is used in which a dewatering aid is mixed into mud using a treatment device, and dewatered and solidified to generate a mud mass.

Such a mud treatment device includes a mud receiving tank for storing the pumped mud, a slurry tank for stirring the mud sent from the mud receiving tank together with a dehydrating aid, and a high pressure filter for filtering and dewatering the mud as a dehydrating device. Some are equipped with a press. Here, the mud is stored in a mud tank and then sent from there. Dehydration aid is injected along the way, and the slurry is poured into the slurry tank and stirred. Is made into a mud (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2002-146827 (FIG. 10)

  In the above prior art, since the high-concentration mud is directly pumped to the destination dewatering device, the mud sediment concentration step as a pre-process of the dewatering device can be omitted, thereby simplifying the treatment process. Since there is little generation of concentrated sewage on the ground, the scale of sewage treatment facilities can be reduced.

  However, when the mud has a high concentration and a high viscosity, dehydration becomes difficult, and many dehydration aids are required for dehydration. In this case, the viscosity of the mud itself is high, and the viscosity is further increased by adding a dehydrating aid. And in the case of such a high viscosity mud, there exists a thing with a different particle size distribution between muds, and a thing with a partially insufficient dewatering part. Such a mud is unsuitable for reuse for civil engineering work and has a problem that it is difficult to dispose of it.

  Accordingly, the present invention provides a uniform mud having a uniform particle size distribution and sufficient dewatering over the whole without causing large-diameter particles to collect in the lower part of the slurry tank, even for a highly viscous mud. It aims at providing the mud processing apparatus which can produce a lump.

  As a result of intensive studies to solve the above problems, the present inventor has found that in the case of mud soil having a high concentration and a high viscosity, stirring in the slurry tank may not be sufficiently performed. In particular, the tendency is remarkable when there is a variation in the particle size of the mud. In the slurry tank, large-diameter particles settle quickly, and the lower part of the slurry tank with many such large-diameter particles tends to be insufficiently mixed even if stirred in the same manner as other parts. It is. As a result, uneven mixing of the dewatering aid and the mud occurs, resulting in a slurry having non-uniform viscosity and particle size distribution, and non-uniform mud. Also, if mud with high viscosity flows, the ability of the slurry pump to send mud from the slurry tank to the high-pressure filter press may be reduced, or the pump may be clogged and uniform pumping may not be possible. Become.

  Therefore, the mud treatment apparatus according to claim 1 includes a mud receiving tank for storing mud, a slurry tank for stirring the mud sent from the mud receiving tank, and a dehydration treatment for dehydrating the mud sent from the slurry tank. In the mud treatment apparatus comprising the apparatus, the slurry tank further includes a circulation pump for circulating the mud in the slurry tank up and down.

  According to this configuration, since the slurry tank is provided with the circulation pump that circulates the mud in the tank up and down, the particles that have settled down are conveyed again to the upper part. That is, since the mud is forcedly circulated up and down, a slurry liquid having a uniform particle size distribution can be generated without collecting large-diameter particles in the lower part of the slurry tank.

  In addition to the structure of claim 1, the mud treatment apparatus of claim 2 connects the mud receiving tank to the slurry tank with a first mud feed pipe having a pipe wall provided with an injection hole. A non-powered mixing device is provided in a portion of one mud pipe downstream of the injection hole.

  According to this configuration, the dewatering aid can be injected from the injection hole, and the mud and the dewatering aid can be mixed in advance by a non-powered device before flowing into the slurry tank. It is possible to promote uniform mixing of mud and dewatering aid in the interior.

  In addition to the structure of Claim 1 or 2, the mud treatment apparatus of Claim 3 connects the said slurry tank to the said dehydration apparatus with a 2nd mud feed pipe, and this 2nd mud feed pipe is provided with the 1st pump. After branching to a first branch path and a second branch path having a second pump having a higher discharge pressure than the first pump, the first branch path joins at a junction and is connected to the dehydrator. The mud soil flows through the second branch when the pressure in the second mud pipe is higher than a predetermined pressure.

  According to this configuration, when the pressure of the mud flowing through the second mud pipe is higher than a predetermined pressure (that is, when the viscosity of the mud is high), the mud can flow through the second pump having a high discharge pressure. Therefore, even in the case of high viscosity, uniform discharge is possible, and blockage of the second mud pipe by mud can be prevented.

  According to a fourth aspect of the present invention, the mud treatment apparatus includes a first pressure sensor upstream of the injection hole of the first mud feeding pipe in addition to the configuration according to the third aspect, and is detected by the first pressure sensor. A second pressure sensor for operating the circulation pump when the pressure is higher than a predetermined pressure and detecting the pressure in the second mud pipe after the merging point of the second mud pipe; Features.

  According to this configuration, when the mud is lower than the predetermined pressure, the circulation pump is not operated, and the second pump having a high discharge pressure is not used.

  The dredging mud treatment system according to claim 5 is provided with a mud treatment device at the destination in addition to the configuration according to claims 1 to 4 and dredging the mud at the bottom with a mud content of 70 to 90%. On the dredger, dredging means for frying, separating means for separating dredged mud provided on the dredger from solids such as miscellaneous matter and gravel, stirring means for stirring the separated mud provided on the dredger And a pump means for pumping the agitated mud soil to the destination.

  According to this configuration, the mud with 70 to 90% mud content is dredged from the bottom of the water, solids such as miscellaneous matters are separated from the mud with a dredger, and the separated mud is agitated before being pumped. It can be pumped through to the destination, and lump and mud with high viscosity can be dehydrated better than the mud treatment equipment.

  According to the mud treatment apparatus according to claim 1 of the present invention, since the mud particle size distribution can be made uniform in the slurry tank, the mud mass generated from the dewatering device is made to have a uniform particle size distribution and a uniform size. A mud having a degree of dehydration can be obtained.

  Further, according to the mud treatment apparatus according to claim 2 of the present invention, since the mud and the dehydration aid can be mixed before flowing into the slurry tank, the mud mass generated from the dehydration apparatus can be further homogenized. Can be planned.

  Further, according to the mud treatment apparatus according to claim 3 of the present invention, even when the viscosity is high, the pressure can be uniformly discharged, so that the mud mass generated from the dewatering apparatus can be further homogenized.

  Further, according to the mud treatment apparatus according to claim 4 of the present invention, the circulation pump is not operated except when necessary, and the second pump with a high discharge pressure that requires a high driving force is not used. Electric power can be reduced.

  According to the dredging mud treatment system according to claim 5 of the present invention, mud clay with high viscosity can be dehydrated by a press as it is to obtain a civil engineering material, and the mud can be used as a civil engineering material.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an outline of an example of a dredger 1 that performs dredging in rivers, lakes or harbors. The dredger 1 is mounted with a known backhoe 4 which is fixed in position by a fixing stopper 2 placed at the bottom of a mud dredging site A, and has a grab bucket 3 installed at the tip. Further, the dredger 1 includes a separation tank 6 that separates wood and vinyl from the mud 5 dredged by the backhoe 4, a hopper 7 that further separates foreign matter, gravel, and the like from the mud 5 that has passed through the separation tank 6, and a hopper A stirring tank 8 serving as a stirring means for storing and stirring the mud 5 from 7 and a Mars pump 10 as a pump for continuously pumping the mud 5 from the stirring tank 8 to the pipe 9 are mounted. The pipe line 9 is laid over the surface of the water and further over land, and extends to the place where the mud treatment apparatus of the present embodiment is installed. Note that the means for dredging is not limited to the backhoe 4, and various types can be used. Various pumps other than the Mars pump 10 can also be used.

  The grab bucket 3 is a sealed hydraulic grab bucket, and dreds mud 5 at the bottom of the water on the dredger 1 with a mud content of 70 to 90%. Further, a stirring claw (not shown) serving as a rotating stirring means is provided in the grab bucket 3 to stir and defloat the lumps and the highly viscous mud 5 without hydrating them, thereby improving the fluidity. Can do. Since it can be processed into mud with high fluidity in this way, the pressure loss at the time of pipe 9 pumping is reduced, and it becomes possible to cope with long-distance transfer. Continuous treatment up to dehydration is possible.

  Here, the mud content in the present invention will be described. As shown in the bar graph of FIG. 4 (A), the bottom mud 5 (raw mud) is composed of soil particles and water, and is based on the total volume V1. The volume Vs of soil particles and the volume Vw of water are V1 = Vs + Vw. And as shown in FIG. 4 (B), since the dredged mud 5 (dred mud) is dripped with excess water together with the original mud, the volume of soil particles Vs remains unchanged in the dredged mud 5. Although there is a volume Vw of water, dredged mud 5 becomes volume V2. And mud content rate P (%) is the volume ratio of raw mud and dredged mud, and is represented by the following mathematical formula.

P = V1 / V2 × 100 (%)
The separation tank 6 has a bottomed shape with an opening at the top, and a primary vibrating screen 6a for separating solids (not shown) such as wood and vinyl from the mud 5 is provided obliquely in the upper opening. The primary vibration screen 6a has a vibration mechanism (not shown), and solids such as wood and vinyl are separated from the mud 5 to the outside by the screen 6a. Further, a secondary vibrating screen 7a is provided on the upper portion of the hopper 7, and the solids such as foreign matter and gravel separated by the secondary vibrating screen 7a are discharged to the outside of the hopper 7, and the foreign matter is removed. Mud 5 from which solids such as sand and gravel are separated is sent to the agitation tank 8. The primary vibrating screen 6a and the secondary vibrating screen 7a are separating means.

  FIG. 2 is a conceptual diagram of the mud treatment apparatus 11 of the first embodiment. The mud processing apparatus 11 is provided with a mud receiving tank 12 for temporarily storing the mud 5 that has been pumped through the pipe 9. The mud receiving tank 12 is a hermetically sealed type and has a function of accommodating the mud 5 and managing the amount and concentration of the mud without missing the odor. Further, the mud receiving tank 12 is provided with a stirring means 13, and the stirring means 13 includes a shaft portion 13a provided vertically and a rotating blade 13b attached to the lower end of the shaft portion 13a. 13b is configured to rotate around a shaft portion 13a by a motor (not shown).

  An opening 15 is provided in the lower part of the mud receiving tank 12, and the opening 15 is connected to the first mud feeding pipe 14. A pump 16 for sending the mud 5 stirred in the mud tank 12 is attached to the first mud pipe 14. A first pressure sensor 17 for detecting the pressure of the mud 5 in the first mud pipe 14 is attached downstream of the pump 16 of the first mud pipe 14, and the output of the first pressure sensor 17 is the operation control room. It is transmitted to the control device 18 provided in. Further, an injection hole 20 to which a dehydration aid tank 19 is connected is provided downstream of the first pressure sensor 17. Here, the dehydration aid tank 19 is filled with dehydration aid such as slaked lime or polyaluminum chloride, which improves the dewaterability of the mud 5.

  A static mixer 21, which is a non-powered mixing device, is provided further downstream from the injection hole 20 of the first mud feeding pipe 14 and extends to the upper part of the slurry tank 23. The static mixer 21 is provided with a plurality of spiral blades 22a and 22b arranged coaxially in the first mud pipe 14 as shown in FIG. Each of the blades 22a and 22b has a twist direction (rotation direction) reversed to a right twist and a left twist every pitch p, and the right twist blade 22a and the left twist blade 22b are adjacent to each other at an angle. Is shifted by 90 °. That is, the spiral formed by the entire blades 22a and 22b is discontinuous at every pitch p.

  The slurry tank 23 is provided with stirring means 24 as in the mud tank 12. The stirring means 24 has a shaft portion 24a provided vertically and a rotating blade 24b attached to the lower end of the shaft portion 24a. The rotating blade 24b is rotated around the shaft portion 24a by a motor (not shown). It is configured as follows. Openings 26 and 27 connected to each other by a pipe 25 are provided in a lower part and an upper part of the side wall of the slurry tank 23, and a circulation pump 28 is attached to the pipe 25. Further, another opening 29 is provided in the lower portion of the slurry tank 23, and a second mud feed pipe 31 connected to the high pressure filter press 30 is connected to the opening 29.

  The second mud pipe 31 branches from a branch point 32 on the way in two directions, a first branch path 33 and a second branch path 34. The first branch path 33 has valves on the upstream side and the downstream side. A general slurry pump 37 having 35 and 36 is installed, and a tube pump 40 having a higher discharge pressure than the slurry pump 37 and having valves 38 and 39 on the upstream and downstream sides is attached to the second branch 34. ing. The first branch path 33 and the second branch path 34 are joined at a junction 41 after passing over the downstream valves 36 and 39, respectively. A second pressure sensor 42 is attached to the junction 41, and the output of the second pressure sensor 42 is sent to the control device 18 provided in the operation management room in the same manner as the output of the first pressure sensor 17 described above. It has come to be communicated. Thereafter, the second mud feeding pipe 31 is connected to the high pressure filter press 30 via a high pressure driving pump 43 which is a dehydrating device. The high-pressure filter press 30 forms a filter chamber by arranging a plurality of filter plates in which a plurality of filter cloths are stretched between two plates, and the mud 5 in the filter chamber is driven by the driving pressure of the high-pressure pump. However, the present invention is not limited to this, and it may have other structures as long as it can dehydrate mud.

  Next, the effect | action is demonstrated about the said structure. The mud 5 deposited on the bottom of the dredge is collected by the club bucket 3 of the backhoe 4 and transferred onto the separation tank 6. In the separation tank 6, solids such as wood and vinyl are separated from the mud 5. In this case, the mud 5 can be dredged with a mud content of approximately 70 to 90% by dredging using the sealed grab bucket 3. After separating solids such as wood and vinyl in the separation tank 6, the mud 5 falls to the hopper 7, where solids such as foreign matters and gravel that have not been separated in the separation tank 6 are separated. Further, it is transferred to the stirring tank 8. The mud 5 is mixed to some extent there and then pumped to the pipe 9 by the pump 10. The pumped mud 5 is sent to the mud receiving tank 12 of the mud processing apparatus 11 through the pipe line 9.

  In the mud receiving tank 12, the stirring blade 13b is rotated around the shaft portion 13a by a motor (not shown), and the mud 5 is mixed to some extent by the stirring blade 13b. Thereafter, the mud 5 is sent to the first mud pipe 14 by the pump 16 from the opening 15 provided in the lower part of the mud tank 12. The pressure of the sent mud 5 is detected by the first pressure sensor 17 while flowing through the first mud pipe 14. In addition, the pressure in the 1st mud pipe | tube 14 and the viscosity of the mud 5 have a correlation, and the viscosity of the mud 5 can be grasped | ascertained by detecting a pressure. The pressure detected by the first pressure sensor 17 is transmitted as an electric signal to the control device 18 of the operation management room, compared with a predetermined value, and if it is larger than the predetermined value, the mud 5 in the slurry tank 23 is passed through. Circulation pump 28 is activated to evenly stir. When the signal is smaller than the predetermined value, the circulation pump 28 is not operated. If the pressure signal detected by the first pressure sensor 17 becomes small after the circulation pump 28 is activated, the circulation pump 28 is stopped.

  After passing through the first pressure sensor 17, the mud 5 further flows through the first mud feeding pipe 14, and a dehydration aid is injected from the dehydration aid tank 19 through the injection hole 20. The mud 5 into which the dewatering aid has been injected passes through a static mixer 21 provided in the first mud pipe 14.

  When the mud 5 passes through the static mixer 21, it hits the spiral blades 22a, 22b, so that the mud 5 is given a rotational motion. And since the twist direction of the blade | wings 22a and 22b is reversed for every pitch p, the mud 5 repeats a forward rotation motion and a reverse motion alternately. That is, when moving from forward rotation to inversion or from inversion to normal rotation, the rotation of the fluid is forced in the reverse direction, thereby generating turbulence. Further, since the adjacent blades 22a and 22b are orthogonal to each other at every pitch p, the mud 5 and the dewatering aid are divided when passing through the blades 22a and 22b and entering the next blade 22b and 22a. This phenomenon is continuously performed in the entire static mixer 21, so that the mud 5 and the dewatering aid are uniformly mixed. As described above, the mud 5 and the dewatering aid can be mixed to some extent before flowing into the slurry tank 23 without providing a separate power source or the like.

  Next, the mixed mud 5 flows into the slurry tank 23. In the slurry tank 23, a stirring blade 24b is rotated around a shaft portion 24a by a motor (not shown), and the mud 5 is mixed by the stirring blade 24. At this time, when the viscosity of the mud 5 is high, sufficient agitation is not ensured over the entire slurry tank 23 only by the rotation of the stirring blade 24, so particles of a large diameter among the particles of the mud 5 are below the slurry tank 23. Settling down. However, when the viscosity is high, the circulation pump 28 is operated by the signal from the control device 18 as described above, and the large-diameter particles settled in the lower part are sucked out from the lower opening 26 and are discharged from the upper opening 27. The slurry is again introduced into the slurry tank 23 and circulated, and a uniform particle size distribution can be obtained in the slurry tank 23. Further, when the viscosity of the mud 5 is low, the circulation pump 28 is not operated, but sufficient stirring is ensured throughout the slurry tank 23 only by the rotation of the stirring blade 24, so the mud 5 has a uniform particle size. Distribution is maintained.

  The mud 5 stirred in the slurry tank 23 is then sent from the opening 29 to the second mud pipe 31. In the second mud pipe 31, the valves 35 and 36 are opened and the valves 38 and 39 are closed in the initial state. At the branch point 32, the mud 5 first passes the first branch path 33 through the slurry pump 37. The second pressure sensor 42 measures the pressure, and the high pressure driving pump 43 drives the high pressure filter press 30.

  Further, the pressure measured by the second pressure sensor 42 is transmitted as an electric signal to the control device. When the pressure is larger than a predetermined value, the valves 35 and 36 are closed and the valves 38 and 39 are opened. Then, the mud 5 sent from the slurry tank 23 after that is sent at the branch point 32 through the second branch 34 by the tube pump 40 having a high discharge pressure and passes through the junction 41 to the high pressure filter press 30. It is driven in. Thereafter, the direction in which the mud 5 flows is determined as either the first branch path 33 or the second branch path 34 based on the value of the output signal of the second pressure sensor 42.

  Then, the mud 5 that has been driven into the high-pressure filter press 30 and filtered and dehydrated is generated into a mud mass. In addition, a mud becomes a civil engineering material and can be used as a lump or can be used after being crushed.

  As described above, according to the present embodiment, the slurry tank 23 is provided with the circulation pump 28 for circulating the mud in the tank up and down correspondingly to the first aspect. . That is, since the mud 5 is forcibly circulated up and down, a slurry liquid having a uniform particle size distribution can be generated without collecting particles having a large diameter in the lower part of the slurry tank 23. And since the particle size distribution of the mud 5 in the slurry tank 23 can be made uniform, the mud produced | generated by the high pressure filter press 30 is produced | generated to the mud with uniform particle size distribution and the degree of uniform dehydration. be able to.

  Moreover, in this embodiment, since the mud 5 and the dehydrating aid can be mixed in advance by a static mixer before flowing into the slurry tank 23 in accordance with the second aspect, The mixing of the mud 5 and the dehydrating aid can be made more uniform, and the generated mud mass can be made more uniform.

  Furthermore, in this embodiment, corresponding to claim 3, when the pressure of the mud 5 flowing through the second mud feeding pipe 31 is higher than a predetermined pressure, the mud 5 is sent out by the tube pump 40 having a high discharge pressure. Therefore, even in the case of the mud 5 having a high viscosity, the uniform discharge can be performed, and the clogging of the second mud feeding pipe 31 by the mud 5 can be prevented. Can be achieved.

  Further, in the present embodiment, corresponding to claim 4, the circulation pump 28 is operated only when the pressure of the mud 5 is equal to or higher than a predetermined value, the tube pump 40 is used, and the pressure of the mud 5 is set to a predetermined value. In the following cases, the circulation pump 28 is not operated, and the tube pump 40 that requires a high driving force is not used, so that power consumption can be reduced and efficient plant operation can be achieved.

  Further, in the present embodiment, in correspondence with claim 5, a grab bucket is provided as a dredging means for providing a mud treatment device at the destination, dripping the mud at the bottom of the water at a mud content of 70 to 90% and raising it on the dredger 1 3 and a vibrating screen 6a as a separating means for separating the dredged mud 5 provided on the dredger 1 from solids such as foreign matter and gravel, and stirring as an agitating means for stirring the separated mud 5 provided on the dredger 1 The tank 8 and the Mars pump 10 which is a pump means for pumping the agitated mud 5 provided on the dredger 1 to the destination are provided, so that sand and mud with a mud content of 70 to 90% are dredged from the bottom of the water. The solid matter such as miscellaneous matter is separated from the mud 5 and the like in the dredger 1, the separated mud 5 is stirred before being pumped, and is pumped to the destination through the pipe 9. Better dehydration treatment Can, such as the separation facility is not required in the destination, it is possible to form a low cost civil engineering material from mud 5. Therefore, sedimentation and concentration treatment is not required, and it is not necessary to provide a facility for this purpose at the destination, and treatment of the supernatant water generated by the treatment is unnecessary, and thus there is no generation of concentrated residual water, The scale of the treatment facility can be reduced.

  Next, a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same part as the said 1st Embodiment, and the detailed description is abbreviate | omitted.

  The second embodiment is different from the first embodiment in that the mud receiving tank 12 is also provided with a circulation pump 44. The circulation pump 44 is attached to a pipe 47 that connects between an opening 45 provided in the lower part of the side wall of the mud tank 12 and an opening 46 provided in the upper part. The circulation pump 44 is activated when the pressure of the mud 5 in the first pressure sensor 17 is larger than a predetermined value, similarly to the circulation pump 28 of the slurry tank 23. According to this configuration, when the viscosity of the mud 5 sent out from the mud receiving tank 12 increases, the circulation pump 44 is actuated by the signal from the control device 18 as described above, and the large diameter that tends to sink to the lower part is increased. The particles are sucked out from the lower opening 45 and are again flowed into the mud receiving tank 46 from the upper opening 46 and circulated. As a result, the particle size can be made uniform even in the mud receiving tank 12, and the quality of the final mud mass can be improved.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above embodiment, the output signals of the pressure sensors 17, 42 are transmitted to the control device 18 and compared with a predetermined value by the control device 18. However, the present invention is not limited to this. For example, each pressure sensor 17 , 42 can be directly viewed by the operator, and the operation of the circulation pumps 28, 44 and the selection of the branch paths 33, 34 can be performed manually. In addition, without using a pressure sensor, the operator may determine the state of the mud 5 being pumped to the mud treatment device 11 and appropriately operate the circulation pumps 28, 44 and select the branch paths 33, 34. it can. Furthermore, the circulation pumps 28 and 44 can always be operated regardless of the pressure of the mud 5 in the first mud pipe. Further, various types of dehydration apparatuses can be used for dehydration. Moreover, air pumping etc. may be used as a means for pumping mud with a pipe, and various types of pumps are applicable. Further, the mud treatment device may be mounted on the treatment vessel, and in this way, it is not necessary to secure a place for installing the mud treatment device on land, and the treatment vessel alone can be moved to a necessary place. Furthermore, the civil engineering material obtained from the mud dredged by the dredger can be used as a backfill material at or near the dredging site.

It is a side view which shows the dredger dredging the mud to the mud processing apparatus of 1st Example of this invention. It is a conceptual diagram which shows the mud processing apparatus of 1st Example of this invention. It is sectional drawing which shows the mixer used with the mud processing apparatus of 1st Example of this invention. It is explanatory drawing explaining a moisture content, FIG. 4 (A) is explanatory drawing of raw mud, FIG.4 (B) is explanatory drawing of dredging mud. It is a conceptual diagram which shows the mud processing apparatus of 2nd Example of this invention.

Explanation of symbols

1 Dredger 5 Mud 6a Primary vibrating screen 7a Secondary vibrating screen 8 Stirrer (stirring means)
9 Pipe
10 Mars pump (pump means)
11 Mud disposal equipment
12 Mud tank
14 First mud pipe
16 pump
17 First pressure sensor
18 Control unit
19 Dehydration aid tank
20 Injection hole
21 Static mixer
23 Slurry tank
28 Circulation pump
30 High pressure filter press (dehydrator)
31 Second mud pipe
37 Slurry pump
40 Tube pump
42 Second pressure sensor
43 High pressure driving pump
44 Circulation pump

Claims (5)

  In a mud treatment apparatus comprising a mud receiving tank for storing mud, a slurry tank for stirring mud sent from the mud receiving tank, and a dewatering device for dehydrating the mud sent from the slurry tank, the slurry A mud treatment apparatus comprising a circulation pump for circulating the mud in the slurry tank.   From the mud receiving tank to the slurry tank is connected by a first mud feeding pipe provided with an injection hole in a pipe wall, and a non-powered mixing is provided in a portion downstream of the injection hole of the first mud feeding pipe. The mud treatment apparatus according to claim 1, further comprising an apparatus.   The slurry tank is connected to the dewatering device by a second mud feed pipe, and the second mud feed pipe has a first branch passage having a first pump and a second pump having a higher discharge pressure than the first pump. The second mud is branched to the second branch path, and then joined at the junction and connected to the dewatering device. When the pressure in the second mud pipe is higher than a predetermined pressure, the mud is The mud treatment apparatus according to claim 1 or 2, wherein the mud treatment apparatus flows through the second branch path.   A first pressure sensor is provided upstream of the injection hole of the first mud pipe, and the circulation pump is operated when the pressure detected by the first pressure sensor is higher than a predetermined pressure, and the second The mud processing apparatus according to claim 3, further comprising a second pressure sensor that detects a pressure in the second mud pipe after the joining point.   A dredging means for providing the mud treatment apparatus according to any one of claims 1 to 4 at a destination, dripping the mud at the bottom of the water at a mud content of 70 to 90%, and raising the dredger on the dredger; Separating means for separating dredged mud provided from solids such as foreign matter and gravel, stirring means for stirring the separated mud provided on the dredger, and agitated mud provided on the dredger for the purpose A dredged mud disposal system comprising pump means for pumping to the ground.

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