JPH0633481A - Dredging device - Google Patents

Abstract

PURPOSE:To prevent the incursion of foreign matters to the inside of a dredging device by providing a sludge collecting board to a gap between inlet cutters, exceeding set value in consumptive current value of a motor to release a brake of the sludge collecting board, and making common rotation with the inlet cutters. CONSTITUTION:A position of a sludge collecting board 11 is adjusted to the rear side of a dredging direction, and a vertical screw conveyer 2 is lowered to bury an inlet device 5 and the sludge collecting board 11 into a sludge layer. After that, motors 3b and 9 are driven to rotate screw blades 3 and inlet cutters 5b, and the sludge layer is fluidified to introduce it to the inside of a dredging device 1 with suction force. Then, it is conveyed to the last position from a discharge port 2a through a discharge pipe 26, etc. At that time, conveyance by the screw blades 3 is mainly made only for vertical conveyance of solid sludge. When foreign matters are mixed, the motor is overloaded, set current value is exceeded to release a brake 15A of the sludge collecting board 11, and common rotation is made with the inlet cutters 5b to eliminate foreign matters. Loading is suppressed by auxiliary cutters 11a. According to the constitution, controllability and dredging efficiency can be improved.

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 dredging soft mud such as sludge accumulated in a water intake, a seabed, a lake, a river, a port, etc. of a power plant.

[0002]

2. Description of the Related Art Dredging of sludge such as sludge deposited on the seabed may cause a submersible pump to plunge into the sludge layer and suck it up.
Alternatively, it was done by scooping up the soft mud from the seabed with a grab bucket. However, this method cannot dredge a high-concentration soft mud, and because it sucks a large amount of seawater together with the soft mud, it has a poor pumping efficiency. In addition, the grab bucket method causes turbidity in seawater, There was a problem of causing secondary pollution.
Therefore, in order to solve these problems, a dredging device consisting of a vertical screw conveyor and an inlet device rotatably arranged at the lower end of this vertical screw conveyor was put into practical use, and it was placed near the upper end of the vertical screw conveyor. The soft mud discharged from the discharge port is pressurized by a pressure pump and pressure-fed to the discharge pipe via the check valve. Further, compressed air is pressure-injected from an air nozzle (ejector) provided in the middle of the discharge pipe for a long distance. A method of transportation has been proposed by the applicant.

FIG. 5 shows a conventional dredging device of this type, which is a dredging device 1 provided with a rotatable semi-circular mud collecting plate 11 on the outer periphery of an inlet device 5, in which the mud collecting plate 11 is dredged. After being rotated and opposed to the rear side in the direction, the inlet cutter 5 is slowly moved forward while the inlet cutter 5b is used to horizontally shear, stir, and fluidize the solidified mud layer at the dredging point to vertically move it. It is guided to the inside by the suction force due to the rotation of the screw blades 3 of the mold screw conveyor 2 and is moved upward by the screw blades 3. At this time, the solidified soft mud is cut into slices by the inlet / cutter 5b and becomes soft and fluidized, but the foreign matter present in the soft mud cannot pass between the inlet / cutter 5b and is eliminated. To be done. The soft mud that has been lifted and transferred by the vertical screw conveyor 2 in this way is discharged from the discharge port 2a at the upper end and is conveyed to the next step.

When the soft mud is hard or has a strong adhesiveness, the soft mud adheres to the inlet cutter 5b itself as the operation continues, and this develops to clog the space between the inlet cutter 5b. The passage of the soft mud deteriorates,
Dredging and transportation capacity will be reduced. As a countermeasure in such a case, the inner surface of the mud collector 11 is projected horizontally and the inlet
The auxiliary cutters 11a sandwiched between the cutters 5b are designed to destroy and remove these clogged solid matters.

[0005]

However, when rocks or other foreign substances larger than the gap between the inlet and the cutter are mixed in the soft mud to be dredged, these foreign substances are scraped together with the inlet and cutter, It comes into contact with the auxiliary cutter on the back side in the traveling direction, the electric motor that is the rotation driving means of the inlet device is overloaded, and the rotation of the inlet cutter of the inlet device stops,
Unnecessary force may be applied to the structural parts, resulting in damage.

[0006]

In order to solve the above-mentioned problems, in the dredging device of the present invention, a vertical screw conveyor and an outer peripheral surface rotatably provided at the lower part of the vertical screw conveyor are provided. And an inlet device in which a plurality of stages of inlet cutters are vertically spaced from each other,
Dredging provided with a mud collecting plate having a substantially semicircular shape rotatably arranged on the outer periphery of the inlet device and having an auxiliary cutter provided on the inner peripheral surface so as to project in the gap between the inlet and the cutter. A device for rotating and driving the mud collecting plate is provided with a brake mechanism, and the inlet of the inlet device is
The control device transmits a command signal for releasing the brake holding force to the brake mechanism when the current value of the electric motor for rotating the cutter exceeds the set value.

[0007]

In the dredging device of the present invention, foreign matter such as rocks is caught in the inlet / cutter of the inlet device during operation and is rotated as it is, and is contacted with the auxiliary cutter of the mud collecting plate on the back side to prevent the motor of the inlet device from passing. When it becomes a load, the actual current value exceeds the preset current value in the control device, and the control device issues a release command to the brake mechanism of the mud plate, and the gripping force of the brake is released. The mud plate rotates in the same direction as the inlet cutter. Therefore, the electric motor of the inlet device and each device forming the power transmission mechanism are not subjected to an unreasonable force, and can be protected from damage.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 4 relate to an embodiment of the present invention,
1 is an overall vertical cross-sectional view of the dredging device, and FIG. 2 is I of FIG.
FIG. 3 is a plan view seen from I-II, FIG. 3 is a bottom side view of the dredging device, and FIG. 4 is a block diagram of the control device. In the figure, 1 is a dredging device, 2 is a vertical screw conveyor, 2A is a casing, 3 is a screw (blade), 3a is a rotating shaft, 3b is a screw driving electric motor, 4 is an inlet device casing, and 5 is an inlet device. , 5a is an inlet cylinder, 5b is an inlet cutter, 6 is a bearing, 7 is a girth gear, 8 is a pinion gear, 9 is an electric motor, 10 is a protective cover, 11 is a mud collecting plate, 11a is an auxiliary cutter, 12 is a bearing, 13 Reference numerals 14 and 14 are chain wheels, 15 is an electric motor, 15A is a brake, and 16 is a protective cover.

As shown in the figure, the vertical screw conveyor 2
Has a cylindrical casing 2A, a screw rotating shaft 3a housed in the casing 2A and driven to rotate by a top electric motor 3b, and a screw blade 3, and the screw blade 3 causes sludge and the like. The soft mud is lifted and discharged from the upper discharge port 2a.

On the other hand, below the casing 2A of the vertical screw conveyor 2, a casing 4 of an inlet device 5 which rotates concentrically and with the same diameter as the casing 2A is suspended via a bearing 6, and an electric motor 9 and a pinion are provided. It can be rotationally driven via the gear 8 and the girth gear 7. At the lower end of the casing 4, inlet-cutters 5b having a toe-shaped plan view as shown in FIG. 2 are mounted in a plurality of stages on an inlet cylinder 5a having a large side opening. As shown in FIG. 2, the inlet cutter 5b is formed in a circular saw shape so as to shear the soft mud layer located on the outer circumference by rotation.

Further, a substantially semi-circular mud collecting plate 11 is disposed on the outer circumference of the casing 4 so as to cover the outer circumference of the inlet cutter 5b and is supported by bearings 12, and the electric motor 15 is provided via chain wheels 13 and 14. It is driven to rotate by. Reference numeral 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 plate 11 so as to be inserted into the gap between the inlet cutters 5b. Reference numeral 11b is a through hole for passing water.

At the discharge port 2a of the vertical screw conveyor 2, a straight pipe 20, an elbow pipe 21, an electromagnetic flow meter 22, a straight pipe 23,
Check valve 24, pressure pump 25, discharge pipe 26 are connected,
An air pipe 27 is provided at a position near the pressure pump 25 of the discharge pipe 26.
Air nozzle 2 for injecting compressed air supplied by a
7 are provided. As shown in FIG. 1, it is preferable that the pressure feed pump 25 is provided at a position lower than the discharge port 2a, and the air nozzle 27 is provided as close as possible to the discharge port of the pressure feed pump 25. Therefore, the check valve 24 is arranged not on the discharge side of the pressure pump 25 but on the suction side. The electromagnetic flow meter 22 measures the flow rate by detecting the velocity of a transported object that crosses the magnetic field applied to the flow meter.

Further, the dredging device 1 of the present invention is provided with a control device 30 which is connected to the electric motor 9 and the brake 15A by electric wiring for control. The control device 30 is shown in FIG.
As shown in Fig. 3, a setter, a comparator, a controller (regulator, operator), an amplifier, a converter, etc. are built-in, and the motor 9
The current value measured by the ammeter 9a is input, and conversely, the output signal from the controller 30 is the brake 15A of the mud collector 11.
Be sent to.

The operation of the dredging device 1 of the present invention constructed as above will be described. After the dredger equipped with the dredging device 1 of the present invention is transferred to the dredging site and stopped, the electric motor 15 is adjusted so that the mud collecting plate 11 comes to the back side in the dredging direction, and the brake 15A is gripped. After that, the vertical screw conveyor 2 is gently lowered until it reaches the bottom of the sea. After the inlet device 5 (specifically, the inlet cutter 5b) and the mud collecting plate 11 are landed and buried in the seabed soft mud layer, the electric motor 3b is driven to rotate the screw blades 3,
At the same time, when the electric motor 9 is driven to rotate the inlet cutter 5b, the seabed soft mud layer is sheared, stirred, and fluidized, and the suction force generated by the rotation of the screw blades 3 passes through the openings of the inlet cylinder 5a one after another into the apparatus. After entering, it is transported upward by the screw blades 3, reaches the upper part of the vertical screw conveyor 2, is discharged from the discharge port 2a, and finally passes through the electromagnetic flow meter 22, the check valve 24, the pressure pump 25, and the discharge pipe 26. Transported to the ground.

Unlike the submersible pump, the transportation by the screw blades 3 of the vertical screw conveyor 2 mainly carries out the vertical transportation of the solid soft mud without much liquid. During this time, foreign matter mixed in the soft mud layer is blocked by the inlet cutter 5b and prevented from entering the inside.

However, even if there is no foreign matter, the hardened mud, the originally hard mud, or the strongly softened mud gradually adheres to and develops on the outer periphery of the inlet cutter 5b as the operation continues, and finally, Is the upper and lower inlet cutters 5b
It may be clogged due to close contact with each other across the space, and if this state covers the entire surface of the inlet / cutter 5b, it will be difficult for the soft mud to pass, and the amount of passage will be extremely reduced, drastically reducing the dredging capacity. To do. In order to avoid this condition, the auxiliary cutter 1 is always installed in the space between the inlets and cutters 5b.
1a enters to prevent the formation of clogging.

As described above, according to the present invention, in normal operation, only the soft mud excluding foreign matter can be transported at a high concentration and with little excess water, and the inlet cutter 5b can be clogged. Since the auxiliary cutter 11a is provided so as to prevent the occurrence of the above, continuous stable operation can be continued.

When a rock or a large amount of foreign matter larger than the vertical pitch distance of the inlet cutter 5b is taken in, a gap between the inlet cutter 5b and the stationary auxiliary cutter 11a on the back side in the traveling direction is provided. The foreign matter is caught and interferes with the smooth rotation of the inlet cutter 5b. At this time, as a matter of course, the electric motor 9 for rotationally driving the inlet cutter 5b is overloaded, and the consumed current becomes a value much higher than the rated current. Therefore, the measured current value sent to the control device 30 is compared with the preset value of the current input in advance by the comparator, and when the preset value is exceeded, a release command is sent to the brake 15A via the controller to collect the mud. The plate 11 is rotated together with the inlet cutter 5b. The controller is composed of a controller and an actuator.The controller indicates the degree of the operation command according to how the measured value exceeds the set value, and the controller brakes based on the instruction from the controller. The operation command is transmitted to 15A. The lines with arrows in the figure show the flow of signals. After the operation has been changed and a certain time has passed by the timer, the mud collecting plate 11 does not co-rotate and foreign matter falls off, and then the mud collecting plate 11 is held in a proper position by the brake. With the above operation, even if foreign matter is caught between the inlet cutter and the auxiliary cutter, the overload condition can be detected quickly and the damage to the equipment and rotary drive part can be dealt with. A method of using a clutch instead of the brake 15A and releasing the clutch when overloaded can also be adopted. When a hydraulic motor is used instead of the electric motor 9, a pressure control valve (relief valve) is used in the hydraulic circuit.
A system may be provided in which the hydraulic fluid is released to the oil tank when the pressure exceeds a certain level in the case of overload, and the mud collecting plate rotates together with the inlet cutter.

[0019]

As described above, in the dredging device of the present invention, even if an overload condition occurs due to the intake of foreign matter such as rocks, the brake holding force of the mud collecting plate is automatically released and co-rotates. As a result, foreign matter is eliminated, so that the motor can be protected and damage to the equipment can be prevented. Therefore, continuous stable operation is achieved, and maintainability and dredging efficiency are improved.

[Brief description of drawings]

FIG. 1 is an overall vertical cross-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 bottom side view of the dredging device according to the embodiment of the present invention.

FIG. 4 is a block diagram of a control device according to an embodiment of the present invention.

FIG. 5 is an overall vertical cross-sectional view of a conventional dredging device.

[Explanation of symbols]

 1 Dredging Device 2 Vertical Screw Conveyor 2A Casing 2a Discharge Port 3 Screw Blade 3a Rotating Shaft 3b Electric Motor 4 Casing 5 Inlet Device 5a Inlet Tube 5b Inlet / Cutter 6 Bearing 7 Garth Gear 8 Pinion Gear 9 Electric Motor 9a Protective Current Meter 11 Mud board 11a Auxiliary cutter 12 Bearing 13 Chain wheel 14 Chain wheel 15 Electric motor 15A Brake 20 Straight pipe 21 Elbow pipe 22 Electromagnetic flow meter 23 Direct pipe 24 Check valve 25 Pressure feed pump 26 Discharge pipe 27 Air nozzle 27a Air pipe 30 Control device

Claims (1)

[Claims] 1. A vertical screw conveyor, an inlet device provided rotatably at a lower portion of the vertical screw conveyor and provided with a plurality of stages of inlet cutters on an outer peripheral surface thereof and vertically spaced apart at appropriate intervals, and the inlet. A dredging device provided with a mud collecting plate having a substantially semicircular shape rotatably arranged on the outer periphery of the device and having an auxiliary cutter provided on the inner peripheral surface so as to project in the gap between the inlet and the cutter. Therefore, a command for releasing the brake holding force when the electric current value of the electric motor for rotating the inlet cutter of the inlet device exceeds a set value is provided with a brake mechanism for the electric motor for rotating the mud collecting plate. A dredging device comprising a control device for transmitting a signal to the brake mechanism.