JPH0335452B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thin layer dredging device for dredging a wide range of surface soil at the bottom of water with a high water content.

Generally, in closed bays, organic substances and harmful substances contained in industrial wastewater flowing in from rivers etc. are deposited over a wide area on the water bottom, becoming a major cause of environmental pollution.According to various surveys, It is said that simply removing a thin layer of surface sediment from the bottom of the water over a wide area can have a significant effect on environmental purification. In addition, dredged surface soil is generally disposed of in a landfill, but in recent years it has become increasingly difficult to secure land for landfill due to environmental problems caused by the creation of a landfill and a decrease in demand for reclaimed land. It is necessary to keep the amount of surface layer dredging to the minimum necessary.

By the way, the dredging device of the drag suction dredger that has been commonly used uses a pump to lift surface soil from the water bottom by dragging a tiltable drag arm that is lowered to the water bottom from the center or both sides of the hull. As a result, the dredging trajectory is linear and the trench cross section is jagged, which not only makes it impossible to efficiently dredge the surface sediment on the water bottom, but also causes the surface sediment on the water bottom to be stirred up by the drag arm dragging the water bottom. The drawback was that the surrounding area became polluted, which could impede underwater monitoring using underwater cameras, echo sounders, etc.

The present invention was proposed in view of the above-mentioned circumstances and the conventional drawbacks, and proposes a thin-layer dredging device that can efficiently dredge the surface soil of a wide range of water bottoms to the minimum extent necessary, and does not pollute the surrounding area. This is what I am trying to do.

In order to solve the above-mentioned problems, the thin layer dredging device of the present invention collects surface layer sediment from the water bottom at the lower end of a tiltable suction pipe that lifts surface layer sediment from the center or side of the ship. A mud collecting device that scrapes mud in a direction perpendicular to the direction of movement of the ship is installed, and the mud collecting device is covered with a pollution prevention cover having a garbage screen on the side in the direction of movement of the ship, and the lower end of the mud suction pipe is collected by the mud collecting device. It is characterized by an opening facing the muddy surface soil.

Since the thin-layer dredging device of the present invention is configured as described above, the surface soil on the water bottom is cleaned of foreign matter such as garbage by the garbage screen, and then the mud collecting device is used to move the sediment in the direction of movement of the ship. It will be scraped together in the perpendicular direction. In this way, the surface layer soil that has been raked up without polluting the surrounding area is lifted up by a suction pipe that opens towards the collected surface layer soil, and the surface layer soil can deviate during underwater transportation, causing secondary pollution. There isn't.

Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings.

In the figure, 1 is the hull, and mud suction pipes 2 for lifting surface soil are installed on both sides of the ship so as to be tiltable.
The upper end of the tank is in communication with a mud pump 3 installed inside the hull 1. 4 is a winch, and the tip of a wire 5 wound around the winch 4 is locked to a reinforcing member 6 at the lowest stage that horizontally connects and reinforces the mud suction pipes 2 that are lowered in parallel, and the winch 4 is By operating it, the tilting angle of the suction pipe 2 lowered to the water bottom 7 can be arbitrarily adjusted. Reference numeral 8 denotes a mud collection device attached to the lower end of the mud suction pipe 2, which is constructed by planting scraping boards 10 at predetermined intervals on the belt 9 of a belt conveyor, and is installed in a direction perpendicular to the traveling direction of the hull 1. It is stretched by pulleys 11. Reference numeral 12 denotes a pollution prevention cover that covers the mud collection device 8 having the above-mentioned structure, and a dirt screen 13 for removing foreign matter such as dirt is provided on the pollution prevention cover 12 on the side in the direction of movement of the hull 1. Further, 14 is a support plate that supports the pulley 11. And mud suction pipe 2
The lower end is gently bent into a hook shape,
An opening is opened toward the surface soil collected by the mud collecting device 8 inside the pollution prevention cover 12 . Reference numeral 15 is an acoustic sounder that detects the thickness of the surface soil on the water bottom 7 and remotely controls the winch 4 to automatically adjust the dredging depth. Note that an underwater camera may be attached to the lower reinforcing member 6 that reinforces the mud suction pipe 2, so that the winch 4 can be manually operated while monitoring the water bottom 7 at the front of the mud collection device 8.

According to the thin layer dredging device of the present invention having the above configuration, the suction pipes 2 are lowered from both sides of the hull 1 to the water bottom 7.
After setting the tilting angle of the winch 4 to an optimal value according to the thickness of the layer to be dredged, the hull 1 is moved, and the surface soil is removed by the garbage screen 13 after foreign matter such as garbage is removed. The mud is collected at the lower end of the mud suction pipe 2 by the mud collecting device 8. At this time, the surface soil is stirred by the scraping plate 10 of the mud collecting device 8, but since the mud collecting device 8 is covered with the pollution prevention cover 12, the surrounding area will not become polluted. The surface soil collected by the mud collecting device 8 is lifted by a suction pipe 2 that opens toward the collected surface soil, and is pumped from the upper end of the suction pipe 2 via a pump 3 as shown in the figure. If not, they will fall one after another into a basket and be collected. Therefore,
If the hull 1 is moved slowly, the surface earth and sand on the water bottom 7 will be dredged uniformly and efficiently over a wide area in a plane by the width of movement of the mud collecting device 8.

In this embodiment, the mud suction pipes 2 are lowered to the water bottom 7 from both sides of the hull 1, but the mud suction pipes 2
Alternatively, only one line may be lowered from the center of the hull 1 to the bottom of the water. In this case, the mud collecting device 8 may be arranged in an inverted T-shape with respect to the mud suction pipe 2. Also,
In this embodiment, a reinforcing material 6 is attached to the mud suction pipe 2 to function as a ladder, but if the water is deep and strength is required, a highly rigid and tiltable ladder may be provided. The mud suction pipe 2 may be attached to the ladder.

As specifically explained above, according to the present invention, surface sediment on the water bottom is widely scraped up in a direction perpendicular to the direction of movement of the ship, and the collected surface sediment is intensively pumped up using a suction pipe. This makes it possible to efficiently and uniformly dredge surface sediment on the water bottom that has accumulated over a wide area in a short period of time. In addition, since the mud collecting device is surrounded by a pollution prevention cover, the surrounding area will not become polluted during mud collection, and since the pollution prevention cover is equipped with a dust screen, foreign substances such as rubber can be removed. It will not get mixed into the mud collection equipment or suction pipes and cause malfunction of the equipment. Since the surface layer soil to be pumped is conveyed underwater while being confined in the suction pipe, the surface layer soil will not deviate during underwater conveyance and cause secondary pollution. It is possible to provide a thin layer dredging device that has many advantages such as, is easy to operate, and is extremely effective in practice.

[Brief explanation of the drawing]

FIG. 1 is a side view of a dredger equipped with the thin-layer dredging device of the present invention, FIG. 2 is a partial front view seen from the direction of arrow A in FIG. 1, and FIG. FIG. 3 is a cross-sectional view taken along line B. FIG. 1...hull, 2...sludge pipe, 7...bottom, 8...
...Sludge collecting device, 12...Pollution prevention cover, 13...
garbage screen.

Claims (1)

[Claims] 1. A belt conveyor with a scraping board installed at the lower end of a tiltable suction pipe that lifts surface sediment that has been lowered to the water bottom from the center or side of the ship, removes surface sediment from the water bottom in a direction perpendicular to the direction of travel of the ship. A mud collecting device is installed, and the mud collecting device is covered with a pollution prevention cover that has a garbage screen on the side in the direction of movement of the ship, and the lower end of the mud suction pipe is directed toward the surface soil collected by the mud collecting device. A thin layer dredging device characterized by having an opening.