JP2003138598A - Method and device for dredging by use of pipe having opening part in bent part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for efficiently dredging up deposit deposited in a dam and a pond at low cost. SOLUTION: A part of a pipe 1 whose both front and rear ends are opened is bent, an opening part 1a is provided in a bent part, and a pressure in the pipe 1 is reduced below a pressure in the surroundings to absorb the deposit 20 through the opening part 1a and discharge it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dredging method and apparatus using a pipe having an opening in a bent portion.

More specifically, the invention of the present application relates to a tank, a pond for a water purification plant or a sewage treatment plant, a sand basin, a reservoir pond,
Easy to aspirate and dredge sediments such as sediment ponds, reservoirs, dam lakes, lakes, lakes, seas, water transmission tunnels, water passages, etc. -It relates to a new method that can be sent and a device therefor.

[0003]

2. Description of the Related Art Conventionally, in facilities for storing fluids, it has been indispensable to provide and maintain means and facilities for discharging settling deposits. There is. Especially in recent years, the problem of lake bottom sediment has become serious, and efficient dredging of the sediment is absolutely necessary to increase the dam's water storage capacity and extend the useful life of the dam. Has become.

As a conventional method for dredging the sediment deposited on the bottom of the dam, <1> a method of flushing sand to discharge the stored sediment together with a large amount of water, and <2> temporary Method of moving the sediment in the middle stream to the water supply area near the dam by lowering the dam water level and flowing water over the exposed sediment. A method to remove sand by providing a bypass tunnel for discharging the mixed water directly downstream, <4
> There are methods such as excavation by dredging vessels and direct excavation of the exposed sediment due to water level drop.

However, the sand removal method by <1> flushing is limited to the flooding period, and when this method is executed, a large amount of water is consumed, so during the flushing period, city water, agricultural water, There is a problem that the original water such as power generation water cannot be used. <2> Even if the dam water level is lowered for a period of time, it is not possible to select the implementation time, and since a large amount of water is consumed, the quality of the water used for original water use deteriorates. And <
3> With the method of sand removal by bypass tunnel, not only is the discharge range limited to the vicinity of the discharge port, but there is also the problem that the amount of investment in initial equipment becomes extremely large. Furthermore, <4
> The dredging method requires the installation of a large machine for dredging in the dam lake, disassembling and transporting these devices, and the transportation of sediment after dredging and drainage, which increases the processing cost. In addition, there is a problem that turbid water is generated.

Therefore, the invention of this application was made in order to solve such conventional problems, and it is not necessary to disassemble and transport a large machine to a dam lake or the like, and excavation and discharge of a wide range of sediments can be performed. It is possible to realize a heterogeneous flow that is ideal for transporting sediments, reduces wear of tubing, and allows sand removal while adjusting the mixed sludge ratio without using any control device. Moreover, it is an object of the present invention to provide a new technical means capable of reducing the cost while suppressing the generation of muddy flow in the reservoir.

[0007]

In order to solve the above-mentioned problems, the invention of the present application is, firstly, to open the front of a pipe in which both front and rear ends are open and an opening is provided on the outer peripheral surface of the bent portion. Maintaining the end in an underwater position where the hydrostatic pressure is higher than the rear open end, and making the pressure inside the pipe lower than the surroundings, suction the sediment around it from the bend opening to the pipe rear open end. Disclosed is a method of dredging using a pipe having an opening in a bent portion, which is characterized in that it is discharged by flow. That is, the first aspect of the present invention maintains the front open end of the pipe in water as described above and generates the water flow inside the pipe while maintaining the rear open end at a position lower than the water surface. The method is characterized in that the pressure inside the pipe is lower than that of the periphery of the pipe, and the sediment deposited on the water bottom is sucked and discharged from the opening of the bent portion and dredged.

Secondly, the invention of this application provides a dredging method characterized in that in the above method, suction in the pipe or flow in the pipe is generated.

Thirdly, the invention of this application provides a dredging device provided with the above-mentioned pipe, and fourthly, so that the front open end does not come into direct contact with the sediment on the lake bottom.
A suction mechanism and an injection mechanism are provided on the rear side of the opening of the bent portion of the pipe processed in the U, V or L shape, that is, on the discharge side of the sediment, and the valve is provided on the front side of the suction mechanism and on the rear side of the injection mechanism. The present invention provides a device for suctioning, dredging, and transporting deposits from the bent portion opening by reducing the pressure by generating a water flow in the pipe.

According to the pipe in which the opening portion is provided in the bent portion as in the device of the invention of this application, suction / dredging / concentration of the concentration automatically adjusted by simply pressing the opening portion of the bent portion against the deposit.
Streaming is possible, and extremely simple and efficient dredging is possible.

In a fifth aspect of the invention of this application, in the device having the above characteristics, the rear open end of the pipe from which sediment is discharged is a floating tank in which the water level inside the box is maintained below the water level at the lake surface. A connected dredging device is provided. Sixthly, a suction device for generating a flow in the pipe, a dredging device having a blowing means or device for water or air arranged in the pipe, and seventhly, a dredging device for the pipe. In the vicinity of the opening of the bent portion, there is provided a dredging device having means or device for stirring or crushing the sediment, and eighthly, there is provided a dredging device having means or device capable of moving the pipe bent portion at least. provide.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The invention of this application has the characteristics as described above. The details of the embodiment will be described below. First of all, in the invention of this application, a pipe whose both ends are opened is bent into a J, U, V or L shape, and an opening is provided in the formed bent portion. In this case, there is no limitation on the method of forming the bent portion or processing for disposing the opening. And
As will be apparent from the following description with reference to the drawings, the opening is not disposed inside the bent portion of the pipe but on the outer peripheral surface portion that bulges out. The pipe provided with the opening is transported to the sediment area of the dam lake while being suspended by, for example, a crane installed on a water ship or a barge, and the bent opening of the pipe is brought close to the sediment. By sucking this, the precipitate is sucked, dredged and sent.

For example, as described above, according to the method and apparatus of the invention of this application, it is possible for the above-mentioned ship to move to any place and to suck and flow the sediment, so that the sediment on the bottom of the lake Will be able to dredge over a wide area.

Of course, the arrangement of the pipes is not limited to one, and a plurality of pipes may be arranged in parallel, fan-shaped, or branched.

The front and rear ends of the pipe according to the invention of this application are open, and the front open end is located at a position in water where the hydrostatic pressure is higher than the rear open end, which is the side on which the sediment is discharged. The front open end of the pipe is then kept underwater in a position where it will not be filled with sediment.

When a flow is generated in the pipe, water is sucked in from the front open end, and the inside of the pipe has a lower pressure than the static fluid pressure of the surroundings. Will be sucked in and discharged with water.

When the sediment is discharged, the resistance in the pipe increases as the concentration of the sediment increases, the flow velocity decreases, the suction force decreases, and water is sucked from the front open end of the pipe with low suction resistance. Thus, dilution results. On the contrary, when the concentration of the precipitate is low, the flow velocity is high and the suction force is large, so that the concentration of the precipitate to be sucked in is increased accordingly. Therefore, the suction force is automatically adjusted simply by positioning the front open end of the pipe in water without using any control device.

The shape of the pipe is, for example, bent into a J, U, V or L shape, but is not particularly limited and may be any other bent shape.

Further, the shape of the opening of the bent portion may be a continuous opening, or a shape in which a circle, a rectangle, an ellipse, etc. are intermittently continuous, and the number of openings, the size and the position of the openings are generally determined. However, since it is necessary to make the opening face the sedimentary sediment to be discharged, it is necessary to open the pipe on the lower side of the pipe, that is, on the outer peripheral surface of the bend, which faces the bottom of the lake or riverbed. Set up a section.

The pipe material is also not particularly limited, and metals such as steel pipes, lining steel pipes, cast iron pipes, and various polymer materials such as vinyl chloride and high-density polyethylene are selected according to the application site and purpose. Can be used.

It is necessary to generate a flow of water in the pipe, but as the energy for that, the hydrostatic pressure is mainly used, and the head difference between inside and outside the lake can also be used. By installing the rear open end of the pipe in the floating tank and maintaining the water level inside the box of the floating tank below the lake level,
It is possible to perform suction, dredging and transport mainly using hydrostatic pressure.

When it is difficult to use the hydrostatic pressure, a suction device for generating a flow in the pipe by suction as another external energy, or a water or air blowing device such as an ejector or a jet pump is used as the pipe. It can be attached to the device and suction, dredging, and sending can be performed by suction with these devices and external energy by blowing.

Of course, the hydrostatic pressure and the external energy may be used together.

FIG. 1 is a diagram illustrating the outline of the dredging method for deposits according to the present invention.

It is assumed that water (17) is stored at the water level (18) in the dam (16) constructed on the ground (15). The sediment (2) is attached to the original ground line (19) of the ground (15).
0) is accumulated along the present lake bottom line (21). Then, in the deposit (20), a pipe (1) having an opening (1a) on the outer circumferential surface of the J-shaped bent portion is oriented in the portion where the pipe (1) is to be discharged.

The pipe (1) is hung and fixed by a crane (5) installed on the water ship (4). Therefore,
By moving the ship (4), the pipe (1) can be freely moved to a desired place to perform suction, dredging and transport.

As energy for generating the flow of water in the pipe (1), here, a floating tank (6) is floated in the lake, and the water level of the water level in the tank (6) and the water level of the lake surface are set. We are taking advantage of the difference.

On the rear side of the opening (1a) of the pipe (1), a water injection pipe (7), an air vent valve (8), a stop valve (9a) and a stop valve (9b) are connected, and the water injection pipe ( A pump (10) is attached to 7).

A flow rate adjusting valve (11) is attached to the rear side of the opening (1a) of the pipe (1) in order to adjust the discharge amount.

Further, the floating tank (6) is provided with a valve (12) and a pump (13) for adjusting the water level in the tank.

In the case of this example, the dredging method of the sediment (20) by the pipe (1) is performed according to the following procedure, for example.

The stop valve (9a) and the stop valve (9b) are closed.

While injecting water from the water injecting pipe (7), the air in the pipe is evacuated by the air bleeding valve (8). When completed, close the water injection pipe (7) and the air vent valve (8).

Open the stop valve (9a).

At the same time when the stop valve (9b) is opened, the deposit (20) is sucked through the opening (1a) and discharged to the floating tank (6) together with water.

When the deposit (20) begins to be discharged, water begins to be sucked in from the front open end (1b) of the pipe (1). Then, when water begins to flow into the pipe (1), the inside of the pipe (1) has a lower pressure than the surrounding static fluid pressure, so that the sediment (20) is continuously sucked together with water from the opening (1a). Discharge.

The discharge of the deposit (20) occurs sequentially along the opening (1a) of the pipe (1), and the deposit (20) in a range corresponding to the length of the opening (1a) of the pipe (1). ) Is discharged.

The pipe having a J-shaped bent portion may have an outer shape as illustrated in FIGS. 2, 4, 5, and 6, for example. In these examples,
The opening (1a) is arranged in a state in which the lower side of the bent portion of the pipe (1), that is, the outer peripheral surface portion that bulges out is intermittently cut out. The front open end (1b) is
It is located in the water above the opening (1a).

The diameter of the pipe (1) may be the same, but it is preferable to narrow it down a little as illustrated in FIG. Further, as illustrated in FIG. 2 and FIG. 3 showing the AA cross section, the plate (2) is attached to the bent portion of the pipe (1) so as to be held, and the plate (2) is held.
By placing a heavy object (3) such as sand between them, the position balance of the pipe (1) can be maintained. At the opening (1a) and the front open end (1b) of the pipe (1), a shield (14) such as a net or a lattice should be provided to avoid clogging due to inhalation of wood chips, rocks, etc. Is preferred.

In the vicinity of the opening (1a) of the pipe,
As illustrated in FIG. 4, high-pressure water from the pipe (23) introduced into the pipe (1) is jetted as a water jet from the jet outlet (24), and the surrounding water is jetted in the jet stirrer (25). It is possible to remove the blockages or suck the deposits while loosening the hardened sediment due to compaction or the like. It is also conceivable to carry out stirring with a stirrer (26) instead of or in combination with a water jet.

It is also possible to attach a hydraulic or electric drive device separately to the pipe and swing it in water, move it in parallel, or rotate it.

FIG. 5 shows an example in which the action of the ejector (27) arranged in the pipe (1) is used as energy for the shape of the flow in the pipe (1), and FIG. 6 shows a vacuum pump ( 28) shows an example using the suction force of 28).

It is preferable to use a pipe having a diameter in the range of 25 to 3500 mm depending on the dredging capacity, the condition of the place, and the size.

As a matter of course, the embodiment of the present invention is not limited to the above-described example in which the pipe (1) is used alone, but may be used in combination with another existing method. For example,
It is also possible to carry out what was excavated by the conventional construction method (dredging, excavation by a land machine) by this invention, and to transport what was discharged by the method of this invention by the conventional method.

[0045]

As described in detail above, according to the invention of this application, the sediment can be efficiently deposited by utilizing the water head difference between the inside and outside of the lake while freely moving to any position such as inside the lake. , The deposit can be discharged. At this time, the optimum discharge condition is achieved and the discharge can be performed with a small head loss, so that the amount of fluid used for discharge can be reduced, the discharge distance can be lengthened, and the tube wear can be reduced. This allows emissions at a very low cost. In addition, since muddy fluid is not generated at the suction port, at the same time as sucking and discharging, tap water from other intake ports, agricultural water, industrial water, power generation water, etc. can be used in parallel. In the case of a new reservoir, sediment,
This can reduce the deposition allowance of sediments and deposits, as deposits can be discharged at any time. Therefore, it is possible to reduce the capacity of the reservoir and reduce the size such as the height of the dam, and even with this small-scale dam, it is possible to obtain the same effect as the conventional one.

[Brief description of drawings]

FIG. 1 is an overall schematic diagram according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a pipe having an opening in a bent portion.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a view in which a water jet and a stirrer are attached to a pipe.

FIG. 5 is a view in which an ejector is attached to a pipe.

FIG. 6 is a view in which a vacuum pump is attached to the pipe.

[Explanation of symbols]

1 J-shaped pipe with an opening at the bend 1a opening 1b Front open end 2 plates 3 heavy goods 4 ships 5 cranes 6 floating tanks 7 Water injection pipe 8 Air vent valve 9a stop valve 9b stop valve 10 pumps 11 Flow control valve 12 Valve for adjusting water level 13 Pump for adjusting water level 14 Defense 15 ground Storage facilities such as 16 dams and dams 17 Fluids such as water 18 Water level 19 Yuan ground line and riverbed line 20 sediment 21 Current Lake Bottom Line 22 Water level in the tank 23 Piping 24 spout 25 Stirrer 26 Stirrer 27 ejector 28 Vacuum pump

Claims (8)

[Claims] 1. A front open end of a pipe which is open at both front and rear ends and has an opening at an outer peripheral surface of a bent portion is maintained at a water position where hydrostatic pressure is higher than that of a rear open end, and the inside of the pipe is surrounded by surroundings. A dredging method using a pipe having an opening at a bent portion, wherein a precipitate around the bent portion is sucked by lowering the pressure and discharged to the open rear end of the pipe. 2. The dredging method according to claim 1, wherein a flow is generated in the pipe by suction in the pipe or by blowing water or air into the pipe. 3. A water position in which a front open end of the pipe has a higher hydrostatic pressure than a rear open end is provided with a pipe which is open at both front and rear ends and is provided with a bent portion and whose opening is provided on an outer peripheral surface thereof. The inside of the pipe is kept at a lower pressure than that of the surroundings by being maintained at, and the precipitate around the pipe is sucked from the opening of the bent portion and discharged to the rear open end of the pipe. A dredging device using a pipe having an opening. 4. A suction mechanism and a water injection mechanism are provided rearward of the opening of the bent portion, and pipes are provided between the suction mechanism and the opening of the bent portion and between the water injection mechanism and the rear open end. The dredging device according to claim 3, wherein: 5. The dredging device according to claim 3, wherein the rear open end of the pipe is connected to a floating tank in which the water level in the box is maintained below the water level in the lake. 6. The dredging device according to claim 3, further comprising means or device for generating a flow in the pipe by suction in the pipe or blowing of water or air into the pipe. . 7. The dredging device according to claim 3, wherein a means or device for stirring or crushing the precipitate is arranged near the opening of the bent portion of the pipe. 8. A means or device for moving at least a bent portion of a pipe is provided.
The dredging device according to any one of 1 to 7.