Mobile water channel and wet soil transfer method using the same

Abstract

To provide a mobile water channel through which wet soil containing much water can be efficiently transferred and a wet soil transfer method using the same.SOLUTION: A mobile water channel 30 comprises a movable water channel 31 through which wet soil M stored in the water channel formed into a recessed shape by a flexible belt can be conveyed in a conveying direction. The movable water channel 31 conveys the wet soil M of a water content rate of 30%-90%.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a technique for transporting wet soil and sand. [Background technology]

[0002] As an application example of the wet sediment transport technology, for example, wet sediment is transported from a dredged area such as an offshore shipping channel to a landfill site such as an offshore sediment disposal site. Since the water-containing sediment dredged from offshore dredging sites is treated as industrial waste, the seawater cannot be separated and disposed of at the dredging site. Therefore, it is necessary to transport the entire wet soil containing a large amount of seawater (for example, a water content of about 70%, the same applies below) to a landfill site (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-200925 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the problem with transporting wet sediment using large dredgers is that their draft is too shallow to transport the wet sediment close to the inland area of ​​the reclaimed land. Furthermore, although small dredgers can transport materials in shallower drafts, there is a problem that batch processing of small-volume transports using small dredgers results in poor work efficiency.

[0005] Therefore, one possible measure would be to transfer the wet sediment from the large dredger to a transport device at a receiving site near the offshore disposal site so that large dredgers can enter, and then transport the wet sediment to a transfer site near the inland area of ​​the offshore disposal site.

[0006] However, when transporting the wet sediment to the offshore sediment disposal site, if the transporting equipment is, for example, a general belt conveyor, although it is suitable for long-distance transport, it is difficult to transport the entire wet sediment, which contains a large amount of seawater.

[0007] On the other hand, if the transporting equipment is a slurry pump, it can transport the entire wet sediment containing a large amount of seawater, but depending on the water content, it may be necessary to add water. Furthermore, a single slurry pump is not suitable for long-distance transport; a large multi-stage pump is required, and the power required to operate the multi-stage pump is also large.

[0008] Furthermore, for example, the technology described in Patent Document 1 claims to transport the entire wet soil and sand by the air lift effect, but the power required to operate the air lift-related equipment is also large, so there is still room for improvement in terms of improving the transport efficiency.

[0009] Therefore, the present invention has been made with a focus on these problems, and its objective is to provide a moving waterway that can efficiently transport wet soil containing a large amount of water without adding water to adjust the moisture content, and a method for transporting wet soil using the same. [Means for solving the problem]

[0010] In order to solve the above problem, one embodiment of the moving waterway of the present invention comprises a movable waterway that can transport wet sediment contained in a waterway formed by a flexible belt along a transport direction, and is characterized in that the movable waterway transports wet sediment with a moisture content of 30% or more and 90% or less.

[0011] In addition, in order to solve the above-mentioned problems, a method for transporting wet soil according to one embodiment of the present invention is characterized in that the wet soil is dredged material transported by ship from a dredging site, and a moving waterway according to one embodiment of the present invention is used to receive the wet soil dredged at the dredging site from a transporting ship, and transport the dredged material and the like to a landfill site where the landfill will be carried out. [Effects of the Invention]

[0012] According to the present invention, it is possible to efficiently transport wet soil containing a large amount of water without adding water for the purpose of adjusting the moisture content. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic overall diagram illustrating one embodiment of a waterway according to one aspect of the present invention, showing a plan view of the area from a dredged area such as an offshore waterway to an offshore sediment disposal site. [Figure 2] 2A and 2B are schematic diagrams illustrating the main parts of FIG. 1, in which FIG. 2A is an enlarged view of the side portion of the moving water channel according to this embodiment, and FIG. 2B is a view from the direction of arrow A in FIG. 2A. [Figure 3] 3 is an explanatory diagram of a movable waterway in the moving waterway shown in FIG. 2, where FIG. 3(a) is an enlarged schematic diagram of part B in FIG. 2, and FIG. 3(b) is a schematic diagram of the ZZ cross section in FIG. [Figure 4] This is a graph explaining the applicable range of conveying devices for high-moisture soil. The figure shows the applicable range of a slurry pump, a belt conveyor, and the moving water channel of the present invention, based on the relationship between the particle size and moisture content of gravel in high-moisture soil. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present invention will be described below with reference to the accompanying drawings. The waterway of this embodiment is an example of a configuration for transporting wet sediment dredged from an offshore dredging site from a large dredger to a landfill site at a receiving site near the offshore sediment disposal site. It should be noted that the drawings are schematic, and therefore the relationships and ratios between thicknesses and planar dimensions may differ from those in reality, and the drawings may also contain parts where the relationships and ratios between dimensions differ from one another. Furthermore, the embodiments described below are intended to exemplify devices and methods for embodying the technical ideas of the present invention, and the technical ideas of the present invention do not limit the materials, shapes, structures, arrangements, etc. of the components to the embodiments described below.

[0015] As shown in Figure 1, in the wet soil transport system 100 of this embodiment, wet soil M dredged at a dredging area D of a nearby offshore waterway is used as soil for landfill work at offshore S in an offshore soil disposal site U, which is a reclaimed land. The receiving area H is set up so that a large dredger F that transports the wet soil M can enter up to the seawall K.

[0016] Here, the wet sediment transport system 100 of this embodiment includes a waterway 30 along the seawall K of the offshore sediment disposal site U. The waterway 30 of this embodiment has a movable waterway 31 formed by an endless, circular flexible belt. In the wet sediment transport system 100 of this embodiment, a transfer pipe 18 for transporting wet sediment M is laid along the seawall K from the large dredger F to the receiving section 16 of the waterway 30.

[0017] In detail, in the moving water channel 30 of this embodiment, as shown in an enlarged view in Figure 2, multiple frame support legs 36 are cast onto the revetment K along the extension direction of the revetment K, and a moving water channel frame 37 is stretched approximately horizontally along the revetment K so as to connect the upper parts of the multiple frame support legs 36 to each other.

[0018] The movable waterway 31 is stretched between the inlet roller 32 and the outlet roller 33 so that the wet soil M received at the receiving section 16 can be transported to a remote location T of the offshore soil disposal site U shown in Figure 1 (for example, a location 1,400 m away).

[0019] As shown in Figure 2, the movable waterway 31 is supported at its inlet side by inlet rollers 32 relative to the moving waterway frame 37, and at its outlet side by outlet rollers 33 relative to the moving waterway frame 37. The shaft end of the inlet roller 32 is connected to the output shaft of a drive motor (not shown), and by driving the drive motor, the upper waterway of the movable waterway 31 can be smoothly driven from the inlet roller 32 side toward the outlet roller 33.

[0020] Furthermore, the tension of the flexible belt of the movable waterway 31 can be adjusted by an adjustment mechanism including a take-up roller (not shown). Also, a return roller (not shown) is disposed at an appropriate position on the return side of the flexible belt so that the return portion of the flexible belt on the lower side of the waterway can be smoothly returned toward the inlet side of the waterway.

[0021] In the moving water channel 30 of this embodiment, as shown in Fig. 1(b), a plurality of bottom rollers 34 are arranged horizontally and spaced apart in the conveying direction with their axes perpendicular to the conveying direction on the underside of the flexible belt that constitutes the movable water channel 31. Furthermore, a pair of water channel side rollers 35 are provided at both ends of each bottom roller 34 and are arranged diagonally so as to bend both ends of the flexible belt upward, thereby forming a water channel with a concave interior.

[0022] In particular, in the moving waterway 30 of this embodiment, the receiving section 16 is located at the upper inlet side of the moving waterway 30 and is equipped with a skirt structure 10 configured to be able to receive wet soil M dredged in the dredging area D.

[0023] As shown in Figure 2, the skirt structure 10 has a skirt frame 12 that is disposed above the moving water channel frame 37 at a distance, and that has a rectangular weir shape and is open at the top and bottom. The skirt frame 12 is supported above the moving water channel frame 37 by left and right skirt supports 13 along the movable water channel 31 on the left and right sides in the width direction of the movable water channel 31.

[0024] Seal plates 11 are provided at the bottom of the left and right skirt frames 12 so as to protrude opposite the inner surface of the lower movable waterway 31. The seal plates 11 are connected to the skirt frames 12 by a plurality of seal fixing parts 14, including a fastening structure using bolts and nuts, allowing the smooth introduction of wet sediment M into the inlet side of the moving waterway 30.

[0025] In the moving waterway 30 of this embodiment, as shown in the image of Figure 3(a), the belt tension of the movable waterway 31 is adjusted (relaxed) so as to create a twill pattern on the water surface Wh of the wet sediment M in the movable waterway 31. The tension of the flexible belt is adjusted (relaxed) by adjusting the take-up roller. In this example of this embodiment, the take-up roller is moved an appropriate amount toward the slack side relative to the normal set tension.

[0026] 3(b), a pair of waterway side rollers 35 are arranged diagonally on both ends of each bottom roller 34, and maintain the flexible belt that constitutes the movable waterway 31 in a conveying position in which it forms a concave waterway. In a conveying position in which it forms a concave waterway, it is preferable that the water depth of the movable waterway 31 is shallow in order to ensure internal friction in the viscous fluid being conveyed, and in the moving waterway 30 of this embodiment, the arrangement shape (cross-sectional shape in the conveying direction) of the waterway bottom rollers 34 and waterway side rollers 35 that maintain the conveying position is flat.

[0027] Specifically, in the moving water channel 30 of this embodiment, the cross section of the water channel formed by the bottom rollers 34 and the water channel side rollers 35 in the conveying direction, as shown in Figure 3(b), has a higher horizontal ratio than the vertical ratio. This is advantageous because it ensures higher internal friction in the viscous fluid in the direction of gravity and can further improve the conveying speed efficiency. The water channel 30 of this embodiment can be configured to transport wet soil with a moisture content of 30% to 90% (see area A1 in FIG. 5), and can also be configured to transport wet soil with a moisture content of 60% to 80% (see area A2 in FIG. 5).

[0028] Furthermore, in the moving water channel 30 of this embodiment, the seal plate 11 is arranged along the conveying direction so as to protrude downward from the upper frame 37 at a position facing each water channel side roller 35 from the inside of the movable water channel 31, and the lower end 11s of the seal plate 11 is abutted against the inner surface of the flexible belt that constitutes the movable water channel 31, thereby forming a seal against the wet sediment M in the movable water channel 31.

[0029] Next, a method for transporting wet soil M using the wet soil transport system 100 of this embodiment, as well as the effects of the wet soil transport system 100 of this embodiment and the method for transporting wet soil M using the system will be described.

[0030] In this embodiment, as shown in Figure 1, wet sediment M is transferred to the receiving section 16 of the wet sediment transport system 100 at a receiving site H near the offshore of the offshore sediment disposal site U so that a large dredger F can enter, and the wet sediment M received at the receiving section 16 is transported to a remote location T, which is the transfer site of the offshore sediment disposal site U, via the waterway 30 of the wet sediment transport system 100. In particular, in this embodiment, a waterway 30 capable of upstream transport is used to transport high-moisture water-containing soil M transported from a dredging site D offshore S to a receiving site H by a large dredger F to a remote location T at an offshore soil disposal site U.

[0031] Here, the water content W of the water-containing soil M containing seawater dredged at a dredging area D such as an offshore waterway is approximately 200% to 65%. Moisture content W = weight of water / weight of dry soil x 100 Moisture content W' = weight of water / total weight x 100 =W / (100+W)×100 Therefore, the moisture content W' of this type of water-containing soil M can be estimated to be approximately 67 to 39%.

[0032] For such a water content W' of the water-containing soil M, if the transport equipment is a normal belt conveyor, as shown in Figure 4, it requires little power and is suitable for long-distance transport, but it is difficult to transport the entire water-containing soil M, which contains a large amount of seawater, to a remote location T. That is, when using a belt conveyor, for example in earth pressure shield construction, the optimum moisture content W' is set to about 20% or less, as shown in the figure, so it is necessary to dehydrate the entire wet soil M. In addition, there is also the problem that the size of the equipment becomes large when using a belt conveyor.

[0033] On the other hand, if the transporting equipment is a slurry pump, it can transport the entire wet sediment containing a large amount of seawater with a compact configuration, but as shown in the same figure, the transportable moisture content W' is 50% or more, and the preferable moisture content W' is 80% or more. Therefore, depending on the moisture content W', it may be necessary to add water to the entire wet soil M. Also, a slurry pump alone is not suitable for transporting the soil over long distances such as remote locations T; a large, multi-stage pump is required, and the power required to operate the multi-stage pump is also large.

[0034] In contrast, in the wet soil transport system 100 of this embodiment, as shown in Figure 2, the moving water channel 30 is provided with a movable water channel 31 that can transport wet soil M contained in a water channel formed by a flexible belt along the transport direction, and the movable water channel 31 can transport wet soil M with a moisture content of 30% or more and 90% or less. As a result, with the water channel 30 of this embodiment and the method for transporting wet soil M using it, when wet soil M is received in the receiving section 16, it is possible to simultaneously transport low-moisture content soil Ml and high-moisture content soil or water Mh, as shown in Figure 3 [Invention 1].

[0035] In particular, the waterway 30 of this embodiment and the method for transporting wet sediment M using it can transport wet sediment M containing high water content or water Mh along with low water content sediment Ml, as shown in Figure 3.Therefore, as shown in Figures 1 and 2, wet sediment M containing a large amount of seawater can be efficiently transported from the receiving site H to a remote location T of the offshore sediment disposal site (landfill) U without adding water to adjust the water content. Therefore, it is possible to reduce the transport energy of the entire wet soil transport system 100, and also to significantly reduce the problem of wear on components during pump transport. Therefore, wear on components is reduced and the life of the equipment can be extended [Invention 7].

[0036] [Transportation test] A transportation test of high water content soil (fresh water transportation) was carried out under various test conditions for the flow channel 30 having the configuration of the above embodiment. The outline of the test conditions (A to F) that were changed and compared is as follows. Among the following test conditions (A to F), the conditions aimed at improving the transport speed are accelerated release in <Condition D> and tension relaxation in <Condition F>, and the addition of crushed stone in <Condition E> is positioned as a condition intended for the transport of dredged soil as in this embodiment.

[0037] Condition A: Change in the inclination angle of the moving channel frame 37 of the movable channel 31: horizontal (upward gradient 3°, -0.2° with tension relaxation) <Condition B> Change in belt speed (m / min) of the flexible belt of the movable waterway 31: 90, 120, 150 <Condition C> Change of conveyor drive state of movable waterway 31: Start from stopped state. <Condition D> Change in the method of supplying water (corresponding to high-moisture content sediment or water Mh) to the movable waterway 31: The water is stored in a weir and then released into the movable waterway 31. Furthermore, the water is accelerated and released from the outlet of the transfer pipe 18 into the movable waterway 31 from the downstream side to the upstream side. Condition E: Change in whether or not crushed stone (equivalent to 1 ml of low-moisture soil) is added simultaneously: Yes, No Condition F: Change in tension of the flexible belt that constitutes the movable waterway 31: normal, relaxed (movement of take-up roller)

[0038] As a result of carrying out the above-mentioned transport test, it was confirmed that transport, including upstream transport, was possible under all of the test conditions (A to F) that were compared using the configuration of the moving water channel 30 of this embodiment. It was also confirmed that the transport speed was further improved by adding crushed stone under <Condition E> and by relaxing the tension under <Condition F>.

[0039] That is, according to the moving water channel 30 of this embodiment, it is possible to transport, including upstream transport, wet sediment with a moisture content of 30% to 90%, as shown in area A1 of Fig. 4 [Invention 1]. Also, according to the moving water channel 30 of this embodiment, it is possible to transport, including upstream transport, wet sediment with a moisture content of 60% to 80%, as shown in area A2 of Fig. 4 [Invention 2].

[0040] In particular, it was confirmed that tension relaxation under Condition F shown in Figure 3(a) is effective in improving the conveying speed. Here, in the results of the above conveying test, although the detailed mechanism of the relationship between the appearance of the twill pattern on the water surface Wh, which was seen along with the rising waves when the tension was relaxed, and the improvement in conveying speed, it was confirmed that when the tension was relaxed within the desired range, the twill pattern appeared more clearly on the water surface Wh during conveying [Invention 3], [Invention 6].

[0041] From this, it is thought that relaxation of the tension of the movable waterway (flexible belt) 31 can generate waves in the wet sediment M in the waterway, thereby increasing the rocking effect that reaches the surface of the water. However, if the tension relaxation is too great, the energy with which the gravel in the wet sediment M collides with the surface of the movable waterway (flexible belt) 31 and the supporting bottom roller 34 and waterway side roller 35 in the direction of travel will become stronger, which may reduce the durability of the movable waterway (flexible belt) 31, bottom roller 34 and waterway side roller 35.

[0042] Furthermore, in the wet soil transport system 100 of this embodiment, as shown in Figure 2, the receiving section 16 is provided with a skirt structure 10 that forms a seal on both sides of the width of the waterway, and wet soil M can be introduced from the skirt structure 10 provided in the receiving section 16 to the inlet side of the moving waterway 30, which is suitable for smoothly introducing wet soil M into the movable waterway 31 from the inlet side of the moving waterway 30 [Invention 4].

[0043] In particular, the wet soil transport system 100 of this embodiment employs the above-mentioned moving water channel 30, and as shown in the results of the above-mentioned transport test, with the moving water channel 30 and the method of transporting wet soil M using it, when wet soil M is received in the receiving section 16, the moving water channel 30, which has an upward gradient of more than horizontal, can transport high-water content soil Mh upstream together with low-water content soil Ml [Invention 5].

[0044] Furthermore, in the moving water channel 30 of this embodiment, as shown in Figure 3(b), the cross section in the conveying direction has a higher proportion of horizontal than vertical, which is preferable because it ensures higher internal friction in the viscous fluid in the direction of gravity and can further improve the efficiency of the conveying speed.

[0045] As described above, the present invention is an innovative transport technology that is distinct from belt conveyors and enables upstream transport using the concept of a ``moving water channel.'' The moving water channel 30 equipped in the wet soil transport system 100 of this embodiment and the method for transporting wet soil M using it enable efficient transport of wet soil M without adding water for the purpose of adjusting the moisture content. The waterway and the wet soil using it according to the present invention are not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention.

[0046] For example, in the above embodiment, as an application example of the waterway of the present invention and the method for transporting wet sediment using the same, wet sediment M is dredged material transported by a large dredger F from a dredging site D of an offshore waterway, the receiving site H is set up so that the wet sediment M can be received in the receiving section 16 from the large dredger F that transports the wet sediment M dredged at the dredging site, and the transfer site T is an offshore sediment disposal site (landfill) U where the dredged material is filled in, but the scope of application of the present invention is not limited to this.

[0047] For example, the waterway and the method for transporting wet soil using the same according to the present invention can also be applied to the slurry shield method used in tunnel construction. In other words, even in the muddy water shield method, wet soil (slurry) containing a large amount of water is transported, but since the water content of the slurry discharged from the face is low in order to be pumped, water is added to the discharged slurry before it is pumped. Therefore, by applying the water channel of the present invention to the mud shield construction method, the slurry discharged from the tunnel face, which is wet soil containing a large amount of water, can be transported efficiently without adding water to adjust the water content. [Explanation of symbols]

[0048] 10 Skirt structure 11 Seal plate 12 Skirt Frame 13 Skirt support 14 Seal fixing part 16 Reception Department 18 Transfer pipe 30 Waterway 31 Movable waterway 32 Inlet roller 33 Exit roller 34 Underwater Roller 35 Waterway side roller 36 Frame support leg 37 Waterway Frame 38 Drive motor 100 Wet soil transport system F Large Dredger (ship) D (Ocean Route) Dredging Area H Reception location K. Seawall T Remote location (transportation location) U Offshore soil disposal site (landfill) S Offshore M Water-containing sediment Ml Low moisture content soil Mh High moisture content soil or water Wh Water surface of hydrated sediment

Claims

1. a movable waterway formed by a flexible belt that can transport wet soil and sand contained in the waterway along a transport direction; The movable waterway is characterized in that it transports wet sediment with a moisture content of 30% or more and 90% or less.

2. 2. The waterway according to claim 1, wherein the water-containing soil has a moisture content of 60% or more and 80% or less.

3. 2. The moving waterway according to claim 1, wherein the movable waterway generates a surge in the water-containing sediment in the waterway to transport the sediment.

4. 2. The moving waterway according to claim 1, wherein the movable waterway has a skirt structure that forms a seal on both sides of the waterway in the width direction at the receiving portion for the wet sediment.

5. 2. The moving waterway according to claim 1, wherein the movable waterway transports the wet sediment upstream along the waterway having an upward gradient of at least horizontal.

6. 2. The moving waterway according to claim 1, wherein the tension of the flexible belt is adjusted so as to create a twill pattern on the water surface of the wet sediment in the waterway.

7. The wet sediment is dredged material transported by ship from the dredging site, Using the waterway according to any one of claims 1 to 6, A method for transporting wet soil and sand, characterized in that the movable waterway receives wet soil and sand dredged at the dredging site from a transporting ship and transports the dredged material, including the material, to a landfill site where it will be filled in.

Images