JPH04277227A - Dredging device - Google Patents

Abstract

PURPOSE:To eliminate the need for treating surplus water and improve the efficiency of taking in slime by preliminarily crushing the layer of solidified slime with a shearing paddle followed by horizontally shearing, stirring, and fluidizing it with an inlet cutter. CONSTITUTION:A shearing paddle 30 comprising a plural number of paddle cutters 30b mounted on a horizontal rotary shaft 30a in their state being separated at specified intervals in the axis direction is provided at the slime intake port 11d of a slime collection hood 11. The slime intake port 11d is directed in the dredging direction, the slime collection hood 11 is rotated in the back side direction to face each other, and the shearing paddle 30 and the intake device are advanced forward while being driven in rotation. Solidified slime layer is vertically sheared with the shearing paddle 30, stirred and fluidized. Slime is then horizontally cut by an inlet cuter 5, stirred and fluidized. Slime is introduced inside and sent up by means of a vertical screw conveyor 1. Here, foreign maters present in the slime is removed without passing the space between the inlet cutter 5.

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 is that water treatment requires a lot 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; A dredging device comprising a hood, and an auxiliary cutter fixed to the inner circumferential surface of the mud collecting hood and protruding between the inlets and cutters, the dredging device having a mud intake port of the mud collecting hood. A plurality of substantially vertical plate-shaped cutter blades are attached to a horizontal rotating shaft at a predetermined distance in the axial direction, thereby providing a rotatable shearing paddle.

[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 inlet device are slowly rotated while being driven. 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 then the solidified soft mud layer at the dredged area is sheared, stirred, and fluidized by the rotation of the screw of the vertical screw conveyor. It is guided inside by the suction force and 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]

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 an electric motor for driving the screw, 4 is a casing of an inlet device, 5 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 collection 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.

As shown in the figure, a vertical screw conveyor 1
has a structure including 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 the like 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 shaft 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 collection hood 11.

Further, a support 22 projects downward from the lower surface of the upper end of the mud intake port 11d, and a soft mud sensor 20 is attached to this support 22. Soft mud sensor 20
For example, this model uses a type in which the rotary blades are rotated by a low-torque electric motor, which rotates in running water but stops rotating in soft mud, and the presence or absence of soft mud can be determined by the rotating or stopped state of the rotary blades.

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. Drives the shear paddle 30 and the inlet.
When the cutter 5 is rotated, the solidified soft mud layer on the seabed is sheared,
It 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 to reach the upper part of the vertical screw conveyor 1, discharged from the discharge port 2a, and transported to the final destination via the pressure pump and discharge pipe provided in the next process.

Unlike a submersible pump, transportation by the screw blades 3 of the vertical screw conveyor 1 mainly only vertically transports solid soft mud without much liquid suspension. 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, an auxiliary 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.
By monitoring the signals from the soft mud sensors 20 placed at important points on the mud collecting hood 11 on the dredging vessel and adjusting the height of the entire dredging device so that the inlet cutter 5 is covered with soft mud as much as possible, removal is possible. The amount of seawater introduced will decrease.

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. An auxiliary cutter has been 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.

[Brief explanation of the drawing]

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 20 Soft mud sensor 22 Support 30 Shear paddle 30a Rotating axis 30b paddle cutter 30c bearing 40 Hydraulic motor

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 interposed and 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 dredging device equipped with a freely rotatable shearing paddle with a shaped cutter blade attached.