JPH04297623A - Dredger - Google Patents

Abstract

PURPOSE:To raise the efficiency of construction work by a method in which a sludge breaker is provided to the lower end intake part of a vertical screw conveyer and a sensor and a shutter gate for limiting the inflow of sea water are also provided. CONSTITUTION:A casing 4 having an inlet cutter 5 is rotatably suspended on the casing 2 of a vertical screw conveyer 1 having a screw blade 3. A sludge- collecting hood 11 covering the cutter 5 is rotatably supported on the casing 4, and an auxiliary cutter 11a on the lower part is set between the cutters 5. For the sludge intake port 11d of the hood 11, a shear paddle 30, a shutter gate 60, and a soft sludge sensor 70 are provided. In dredging work, the intake port 11d is directed to the dredging direction, and sludge cut and agitated by the paddle 30 and the cutters 5 is discharged by the blade 3. Sludge layer is detected by the sensor 70, and the gate 60 is vertically operated to reduce the intake amount of area water. The intrusion of foreign matter and occurrence of clogging can thus be prevented, and the need for treatment of excess water can be eliminated. The cost can thus be greatly cut down.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dredging device used, for example, to dredge soft mud such as sludge deposited in water intakes of power plants, seabeds, lakes, rivers, ports, etc.

0002

2. Description of the Related Art There is a pump type dredging device as a conventional dredging device. This pump-type dredging device installs a large-capacity pump on a barge or the like, and extends a hose from the pump to the bottom of the ocean, such as the bottom of a lake, and sucks up the soft mud along with the water. The soft mud dredged in this way is mainly transported to the landfill by transport vessels. At landfill sites, solidifying agents and flocculants are added to solidify the materials.

0003

[Problems to be Solved by the Invention] However, in the conventional dredging equipment described above, the amount of water that is sucked up at the same time as the soft mud is so large that the solidifying agent cannot be mixed until the surplus water has been treated. The drawback was that water treatment required a large amount of money. Therefore, the present applicant proposed an inlet device equipped with an inlet cutter at the lower end of a vertical screw conveyor, and a dredging device equipped with a mud collection hood (Japanese Patent Application No. 116881/1999, Japanese Patent Application No. 2-14
No. 5303, Japanese Patent Application No. 145304, etc.). These dredging devices are excellent dredging devices whose intake ports are buried in the soft mud layer on the ocean floor, preventing seawater from entering as much as possible and sucking in only soft mud. In the case of a relatively hard material composed of , there was a drawback that sufficient stirring and fluidization could not be achieved using only the inlet cutter of the inlet device.

0004

[Means for Solving the Problems] In order to solve these problems, the dredging device of the present invention includes a vertical screw conveyor, and a dredging device rotatably provided at the lower part of the vertical screw conveyor. an inlet device having a plurality of tomoe-shaped inlet cutters spaced apart from each other by an appropriate distance in the vertical direction on the outer periphery of the device; The dredging device is equipped with a hood, and a auxiliary rib cutter is fixed to the inner circumferential surface of the mud collection hood, and is interposed and protruded in the gap between each inlet and cutter, and the mud intake port of the mud collection hood is A plurality of substantially vertical plate-shaped cutter blades are attached to the horizontal rotating shaft at a predetermined distance in the axial direction, and a rotatable shearing paddle is provided. A shutter gate capable of reciprocating in any direction and means for reciprocating and powering the shutter gate are provided, and a sensor for detecting soft mud is provided at the lower end of the shutter gate.

[0005]

[Operation] In the dredging device of the present invention, the mud intake port is oriented in the dredging direction, the mud collection hood is rotated to the back side in the dredging direction so that they face each other, and then the shear paddle and the inlet device are slowly rotated. By moving forward, the solidified soft mud layer at the dredged area is vertically sheared, stirred, and fluidized by the shear paddle, and then horizontally sheared, stirred, and fluidized by the inlet cutter, and the screw of the vertical screw conveyor is rotated. It is guided inside by the suction force, and is transported upward by the screw. At this time, the solidified soft mud is cut into slices by the shear paddle and inlet cutter, becoming soft and fluidized, but the foreign matter present in the soft mud cannot pass between the inlet and cutter. be excluded.

The soft mud thus transported upward by the vertical screw conveyor is discharged from the discharge port at the upper end and is transported to the next process. If the soft mud is hard or sticky, as the operation continues, the soft mud will adhere to the inlet and cutter itself, and this will develop and clog the spaces between the inlets and cutters at each stage, making it difficult for the soft mud to pass through. Become,
Dredging and transportation capacity will be reduced. As a countermeasure for such cases, in the present invention, an auxiliary cutter, which is provided horizontally protruding from the inner circumferential surface of the mud collecting hood and interposed between the inlet and the cutter, destroys and removes these clogged solids. There is.

[0007] In particular, when dredging a thin soft mud layer, so-called thin layer dredging, the mud collecting hood is The signal from the soft mud sensor installed at the front opening is monitored on the dredger, and the shutter gate is lowered until the soft mud reaches the position of the soft mud detection sensor at the lower end of the shutter gate, so that the inlet cutter is covered with soft mud as much as possible. By doing so, the amount of seawater taken into the inlet device will be reduced.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, details of embodiments of the present invention will be explained based on the drawings. 1 to 3 relate to an embodiment of the present invention, in which FIG. 1 is an overall vertical sectional view of a dredging device, FIG. 2 is a plan view taken from FIG. 1II-II, and FIG. 3 is a lower side view taken from FIG. 1III-III. It is. In the figure, 1 is a vertical screw conveyor, 2 is a casing, 3 is a screw (blade), 3a is a rotating shaft, 3b
is the electric motor for driving the screw, 4 is the casing of the inlet device, 5 is the inlet cutter, 6 is the bearing, 7 is the girth gear, 8 is the pinion gear, 9 is the electric motor, 10 is the protective cover, 11 is the mud collecting hood, 11a is an auxiliary cutter, 12 is a bearing, 13 and 14 are chain wheels, 15 is an electric motor, 16 is a protective cover, 20 is a soft mud sensor, 22 is a support for sensor installation, 30 is a shearing paddle, 30a is a rotating shaft, 30b is a paddle cutter and 40 is a hydraulic motor. Further, 50 is a hydraulic cylinder, 60 is a shutter gate, and 70 is a soft mud sensor provided at the lower end of the shutter gate 60.

As shown in the figure, a vertical screw conveyor 1
The structure includes a cylindrical casing 2, a screw rotating shaft 3a that is housed in the casing 2, and is rotationally driven by an electric motor 3b at the top, and a screw blade 3. Soft mud such as sludge is pumped up and discharged from the upper discharge port 2a.

On the other hand, below the casing 2 of the vertical screw conveyor 1, a casing 4 of an inlet device that rotates concentrically and with the same diameter as the casing 2 is suspended via a bearing 6, and a motor 9 and a pinion gear 8. It can be rotated through the girth gear 7. At the lower end of the casing 4, a plurality of inlet cutters 5 each having a toe-shaped shape as shown in FIG. As shown in FIG. 2, the inlet cutter 5 is formed into a circular saw-shaped toe shape so as to shear the soft mud layer located on the outer periphery by rotation. In the present invention, the casing 4 and the inlet cutter 5 are collectively referred to as an inlet device.

Furthermore, a substantially semicircular mud collecting hood 11 is attached to the casing 4 so as to cover the outer periphery of the inlet cutter 5.
A pair of upper and lower bearings 12 are disposed on the outer periphery of the rotor, and the rotor is rotatably driven by an electric motor 15 via chain wheels 13 and 14. 16 is a protective cover for the chain wheel. A flat plate-shaped auxiliary cutter 11a is arranged on the inner peripheral surface of the mud collecting hood 11 so as to be inserted into the gap between each inlet cutter 5.

[0012] In front of the mud collecting hood 11, there is a
A mud intake port 11d as shown in FIG.
Attached to 0a are paddle cutters 30b spaced apart at appropriate intervals, either vertically or with bent ends, and configured to be rotated by a hydraulic motor 40 via a chain wheel at the center of the shaft. The shearing paddle 30 and the hydraulic motor 40, which are composed of the rotating shaft 30a, the paddle cutter 30b, and the bearing 30c, are arranged at the mud intake port 11d of the mud collecting hood 11.

Further, a shutter gate 60 that can freely reciprocate in the vertical direction is disposed at the mud intake port 11d between the shear paddle 30 and the inlet device, and a lower end of the shutter gate 60 has a gate facing in the dredging direction. A soft mud sensor 70 is attached to detect the presence or absence of soft mud. The model of the soft mud sensor 70 is, for example, a type in which a rotary blade is rotated by a low-torque electric motor, and it rotates in running water and stops rotating in soft mud, and the presence or absence of soft mud can be detected by the rotating or stopped state of the rotary blade. I can judge.

Next, the operation of the dredging device constructed as above will be explained.

[0015] After the dredger equipped with the dredging device of the present invention is transported to the dredging site and stopped, the mud collection hood 1 is installed in the dredging direction.
The electric motor 15 is driven and adjusted so that the mud intake port 11d of No. 1 is located. Thereafter, the vertical screw conveyor 1 is gently lowered until it lands on the seabed. After the inlet device (specifically, the inlet cutter 5) and the mud collection hood 11 have landed and buried in the soft mud layer of the seabed, the electric motor 3b is driven to rotate the screw blade 3, and at the same time, the hydraulic motor 40 and the electric motor 9 are activated. Drive the shear paddle 30 and the inlet
When the cutter 5 is rotated, the solidified soft mud layer on the seabed is sheared,
The mixture is stirred and fluidized, and by the suction force generated by the rotation of the screw blade 3, it passes through the opening of the cylinder 5a one after another and enters the apparatus.
It is transported upward by the screw blades 3, reaches the top of the vertical screw conveyor 1, is discharged from the discharge port 2a, and is transported to the final destination via the pressure pump and discharge pipe provided in the next process.

Unlike a submersible pump, the rotary conveyance using the screw blades 3 of the vertical screw conveyor 1 mainly only vertically transports solid soft mud without accompanying much liquid. During this time, foreign matter mixed in the soft mud layer is blocked by the inlet cutter 5 and prevented from entering the inside.

However, even if there are no foreign substances, solidified soft mud, originally hard soft mud, or highly cohesive soft mud gradually adheres to the outer periphery of the inlet cutter 5 and develops as the operation continues, and ultimately may come into close contact between the upper and lower inlet cutters 5 and cause clogging.
If this condition extends over the entire surface of the inlet cutter 5, it becomes difficult for the soft mud to pass through, and the amount of mud passing through it is extremely reduced, resulting in a significant drop in dredging capacity. In order to avoid this situation, the auxiliary rib cutter 11a is always inserted into the gap between each inlet cutter to prevent the formation of clogging. In particular, when dredging a thin layer of soft mud, so-called thin layer dredging, it is necessary to prevent the seawater layer, which is the upper layer of the soft mud layer, from being taken into the inlet device as much as possible.
Soft mud sensor 70 arranged at the lower end of the shutter gate 60
By monitoring the signal on the dredger, the shutter gate 60
By adjusting the height of the inlet cutter 5 with the hydraulic cylinder 50 so that the inlet cutter 5 is covered with as much soft mud as possible, the amount of seawater taken in will be reduced.

As explained above, according to the present invention, under normal operating conditions, it is possible to transport only soft mud, excluding foreign matter, at a high concentration and without much surplus water, and at the same time, it is possible to prevent clogging of the inlet cutter. A supplementary rib cutter was installed to prevent this from happening, allowing continuous stable operation.

[0019]

[Effects of the Invention] As described above, according to the present invention, even a soft mud layer made of solidified mud can be pre-crushed with a shearing paddle and then taken into a mud collection hood, thereby reducing surplus water. Since the soft mud is introduced into the screw conveyor in a state where it is still wet, there is no need to treat surplus water, making it possible to significantly reduce the cost of soft mud processing. In addition, an inlet cutter and a mud collecting hood are installed at the lower end of the vertical screw conveyor, which improves the efficiency of taking soft mud into the vertical screw conveyor.Furthermore, it prevents foreign matter from entering, so the vertical screw In addition to ensuring smooth conveyor operation, the auxiliary cutter on the mud collecting hood constantly prevents clogging between the inlet and cutter, improving maintainability. Particularly when the soft mud layer is thin, the entry of excess water can be prevented by lowering the shutter gate.

[Brief explanation of drawings]

FIG. 1 is an overall vertical sectional view of a dredging device showing an embodiment of the present invention.

FIG. 2 is a plan view taken along line II-II of FIG.

FIG. 3 is a lower side view of a dredging device showing an embodiment of the present invention (
(View III-III in FIG. 1).

[Explanation of symbols]

1 Vertical screw conveyor 2 Casing 3 Screw blade 3b Electric motor 4 Casing of inlet device 5 Inlet cutter 6 Bearing 7 Garth gear 8 Pinion gear 9 Electric motor 10 Protective cover 11　Mud collection hood 11a Auxiliary cutter 12 Bearing 13 Chain wheel 14 Chain wheel 15 Electric motor 16 Protective cover 30 Shear paddle 30a Rotating axis 30b paddle cutter 30C bearing 40 Hydraulic motor 50 Hydraulic cylinder 60 Shutter gate 70 Soft mud sensor

Claims (1)

[Claims] Claim 1: A vertical screw conveyor, and an inlet cutter rotatably provided at the bottom of the vertical screw conveyor and having a plurality of tomb-shaped inlet cutters spaced apart by an appropriate distance in the vertical direction around the outer periphery of the vertical screw conveyor. a mud collecting hood having a substantially semicircular cross-sectional shape rotatably disposed around the outer periphery of the inlet device, and a gap between each inlet and the cutter is provided on the inner peripheral surface of the mud collecting hood. This dredging device has an auxiliary cutter fixedly protruding from the mud collecting hood, and is equipped with a plurality of approximately vertical plates arranged at the mud intake port of the mud collecting hood and spaced apart from each other by a predetermined distance in the axial direction of the horizontal rotating shaft. A cutter blade of the shape is attached and a rotatable shearing paddle is provided, and a shutter gate capable of reciprocating in the vertical direction is provided at the mud intake port of the mud collection hood, and means for reciprocating and powering the shutter gate are provided. A dredging device equipped with a sensor for detecting soft mud at the bottom of the gate.