JP2005188057A - Dredging device and dredging method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dredging device and a dredging method capable of dredging a thin layer portion including surface layer floated sludge with high concentration without increasing pressure in a casing. <P>SOLUTION: This dredging device 1 comprises a scraping means 4 scraping bottom sludge to the inside of the casing 3 and a bottom sludge storage tank part 5 storing the scraped bottom sludge. The bottom sludge storage tank part 5 further comprises an agitator 7 agitating the bottom sludge in the tank for fluidization and a sludge discharge pump 8 communicating with the bottom sludge storage tank part 5 and sucking the fluidized bottom sludge to the surface of water. Since the pump can fluidize the the bottom sludge, namely, scraped cake-like mud and muddy water by agitating and easily suck the fluidized bottom sludge to the surface of water by the sludge discharge pump 8, the thin layer portion including the surface layer floated sludge can be dredged with high concentration without increasing the pressure in the casing 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a dredging apparatus and dredging method for dredging bottom mud of a water bottom.

  Generally, the bottom mud is dredged by a suction system using a pump provided in a dredger device suspended from a dredger. In this method, a large amount of water is sucked together with the bottom mud, so that the dredging efficiency is poor, and the wastewater treatment requires a troublesome procedure and the economic burden increases.

  Therefore, as a conventional technique for solving the above-described problem, for example, in Patent Document 1, a chain that rotates endlessly is disposed in a casing having an opening on one side of the lower side, and mud mud is opened through this opening. A plurality of scraping plates are supported, and are extended upward along the lower running surface of the chain from the opening edge at the bottom of the casing, forming a slight gap with the scraping plate. A slope is arranged, and an air supply pipe for supplying compressed air into the casing and a storage tank for storing mud falling from the slope are attached to the casing, and the mud in the storage tank is discharged to the outside. A dredge device configured to connect the sludge discharging means is disclosed, and the scraper plate is energized by operating the chain while supplying compressed air into the casing. Rotates the less, the increase the take along a slope of the mud, and draining the meantime the mud, it has been possible to improve the dredging efficiency by reducing the water content of the mud.

Japanese Patent No. 2847342

  However, in the above-described invention of Patent Document 1, nitrogen, phosphorus, etc., which are eutrophication substances of the bottom mud surface layer to be dredged, are contained by supplying compressed air into the casing and pressurizing the inside of the casing. Incorporation of floating mud into the casing is hindered.

  On the other hand, when sucked with a mud pump without the pressure inside the casing, moisture and floating mud are sucked first, so a water channel is formed in the casing and the bottom mud and the like swept up into a cake is sucked. It becomes difficult, the mud content decreases, and dredging at high concentration becomes difficult.

  The present invention has been made in view of such points, and an object thereof is to provide a dredging device and a dredging method that enables high-concentration dredging of a thin layer portion including surface layer mud without air pressure inside the casing. And

As a means for solving the above-mentioned problems, the present invention provides a dredge apparatus according to claim 1 in which the mud is raked up through the opening in a casing provided with an opening on the bottom surface in the dredge direction front side. And a bottom mud storage tank that stores the bottom mud that has been lifted by the lifting means, and a stirrer that stirs and fluidizes the bottom mud stored in the bottom mud storage tank. It is provided with a drainage pump that is disposed and communicates with the bottom mud storage tank part through a pipe and sucks the bottom mud fluidized in the bottom mud storage tank part onto the water.
By configuring in this way, the bottom mud is raked up by the lifting means from the opening provided in the casing and stored in the bottom mud storage tank part, and the bottom mud in the bottom mud storage tank part, i.e. in the form of cake. Since the mud and muddy water to be pumped up are uniformly stirred and fluidized by a stirrer, the fluidized bottom mud can be easily sucked up to the water through a pipe by a mud pump without pressure inside the casing. In addition, high-concentration dredging of the thin layer portion including the surface layer mud becomes possible.

Further, the invention of the dredge device according to claim 2 is the invention according to claim 1, wherein the stirrer extends in the bottom mud storage tank portion in a direction perpendicular to the dredging direction, A drive shaft that is rotated by a motor; and a blade portion that is spirally wound around the drive shaft in a predetermined range on the left and right sides of the drive shaft, wherein the one blade portion is counterclockwise and the other blade portion Is configured in a right-handed manner, and further, the pipe communicating with the mud pump is connected to the bottom mud storage tank portion where the substantially central portion of the drive shaft is located.
By configuring in this way, the bottom mud stored in the bottom mud storage tank portion is substantially stirred in and fluidized by the left and right blade portions while being substantially the same as the bottom mud storage tank portion along the left and right blade portions. A pipe connected to the drainage pump is connected to the central part of the bottom mud storage tank. Can be easily sucked on the water without the need for

The invention of the dredging method according to claim 3 is a method of dripping bottom mud, which is stirred and fluidized before the bottom mud is lifted and sucked up onto the water by a mud pump. It is characterized by doing.
By adopting such a method, the scraped mud, that is, the cake-like mud and mud water are stirred and fluidized, and the formation of a water channel is prevented. It can be easily sucked up onto the water by a mud pump, and high-concentration dredging of the thin layer portion including the surface layer floating mud becomes possible.

  According to the dredging apparatus and dredging method of the present invention, the surface layer mud to be dredged is reliably taken into the casing while suppressing the generation and diffusion of turbidity, and high concentration dredging is possible in the thin layer portion, which is optimal in the environment. . Also, as before, moisture and floating mud are sucked first to prevent the formation of a water channel, and the cake-like bottom mud that has been fried up is fluidized and easily put on the water by a mud pump. Can suck up.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to FIGS.
As shown in FIG. 1, the dredge device 1 according to the embodiment of the present invention is provided in a casing 3 provided with an opening 2 on the bottom surface on the front side in the dredging direction, and the lifting means for raking the bottom mud through the opening 2 4 and the bottom mud storage tank part 5 which is provided in the casing 3 and stores the scraped bottom mud, and is provided in the bottom mud storage tank part 5 and agitates and fluidizes the bottom mud therein. The agitator 7 and the bottom mud storage tank 5 are communicated with each other via pipes 6a and 6 and are roughly constituted by a drainage pump 8 for sucking the fluidized bottom mud in the bottom mud storage tank 5 into the water. The thin layer portion including the surface layer mud about 30 cm from the bottom of the water is dredged at a high concentration.

  The casing 3 includes a casing body 3a having a slope 3c that is an inclined slope on the bottom surface, and a cover 3b having a bent portion in a side view on the front side. The opening 2 is provided so as to straddle the casing body 3a and the cover 3b, and in a state where the casing 3 is horizontally placed so that the upper surface of the casing 3 is horizontal, the opening 2 is positioned higher than the rear edge 2b. The direction is set.

  The rake means 4 includes a plurality of excavating blades 11 attached to a chain 10 that rotates endlessly at a predetermined pitch, and side plates 12 disposed on both sides of the excavating blades 11. The chain 10 is composed of two left and right strips, and is wound around a pair of left and right drive sprockets 15 arranged on the casing body 3a side and a pair of left and right free wheels 17 arranged facing the opening 2 on the cover 3b side. Yes. The drive sprocket 15 has a rotation shaft 16 to which rotation from a motor (not shown) is transmitted fixed at the center thereof, and is rotatably supported by the casing body 3 a via the rotation shaft 16. The rotation of the drive sprocket 15 is transmitted to the free wheel 17 through the chain 10, and the excavation blade 11 and the side plate 12 rotate counterclockwise integrally with the chain 10 as indicated by an arrow C. Therefore, the free wheel 17 has a rotating shaft 18 fixed at the center thereof, and is supported by the casing body 3a via the rotating shaft 18 so as to be rotatable. Further, the free wheel 17 is formed to have a larger diameter than the drive sprocket 15, and the rotation center thereof is set at a position below the rotation center of the drive sprocket 15. 3 is inclined upward from the opening 2 side toward the rear side in the saddle direction.

  A slope 3c is formed on the bottom surface of the casing body 3a so as to be parallel to the lower running surface of the chain 10 from the rear edge 2b of the opening 2. The rear end of the slope 3c is set to be at a position substantially below the rotating shaft 16 of the drive sprocket 15.

  The bottom mud storage tank unit 5 is provided with a step from the rear end of the slope 3c and is formed in a substantially box shape, and the step is set to a predetermined depth at which bottom mud can be stored. As shown in FIGS. 1 and 3, a pipe 6 a is extended to the rear wall 5 a forming the bottom mud storage tank portion 5 from the approximate center in the width direction (direction perpendicular to the dredging direction). A pipe 6 communicating with the mud pump 8 is connected to 6a. As shown in FIG. 1, the mud pump 8 is mounted on an upper wall 5 b that closes the upper portion of the bottom mud storage tank 5, and a pipe 20 extending from the mud pump 8 reaches the ship.

Further, as shown in FIGS. 1 and 2, a stirrer 7 for stirring and fluidizing the bottom mud in the bottom mud storage tank 5 is provided in the bottom mud storage tank 5. It extends in the direction (direction orthogonal to the heel direction) and is supported on both side surfaces of the casing body 3a.
As shown in FIG. 2, the stirrer 7 includes a drive shaft 25 rotated by a motor 21, and blade portions 27 and 27 ′ spirally wound around the drive shaft 25 in a predetermined range on the left and right sides of the drive shaft 25. It is configured.

  As shown in FIG. 2, the drive shaft 25 is connected to the output shaft of the motor 21 at a connecting portion 22, and bearing portions 23 and 23 are provided at both ends thereof. The drive shaft 25 is spaced from the circumferential surface by 90 ° in the circumferential direction in the axial sectional view (see FIG. 2B) and at a predetermined interval in the axial direction in the plan view (see FIG. 2A). A plurality of shafts 26 are protruded. Further, on the drive shaft 25, plate-like blade portions 27 wound in a left-handed spiral around the drive shaft 25 are supported on the side surfaces of the plurality of shafts 26 in a predetermined range on the motor 21 side. On the other hand, in a predetermined range opposite to the motor 21 side, plate-like blade portions 27 ′ wound in a right-handed spiral around the drive shaft 25 are supported on the side surfaces of the plurality of shafts 26. With this configuration, when the drive shaft 25 is rotated in the direction of the arrow B, the bottom mud moves toward the center of the drive shaft 25 while being stirred and fluidized by the left and right blade portions 27 and 27 ′. become.

Therefore, when the stirrer 7 is mounted in the bottom mud storage tank 5, the bottom mud storage tank 5 is located behind the substantially central portion where the blades 27, 27 ′ and the shaft 26 are not formed on the drive shaft 25. The pipe 6a provided on the rear wall 5a is located.
In addition, in order to increase the stirring effect of the bottom mud between the plurality of shafts 26 provided on the drive shaft 25, as shown by a one-dot chain line in FIG. Sometimes it is provided.

Next, the operation of the scissor device 1 according to the embodiment of the present invention will be described.
The dredging device 1 of the present invention is suspended and supported by a ladder (not shown) extending from a dredger (not shown). The dredging device 1 is settled on the bottom mud by operating the ladder, and the drive sprocket 15 is installed. While starting the rotating motor (not shown), the mud pump 8 and the stirrer 7, the dredging device 1 is moved in the dredging direction at a predetermined speed, and the thin layer portion including the surface floating mud about 30 cm from the bottom of the water is raised. Hesitate with concentration.
Then, the bottom mud is lifted up by the excavating blade 11 and the side plate 12 which are the lifting means 4, and the raised bottom mud is moved to the slope 3 c together with the excavating blade 11 in the rotation direction of the chain 10 (counterclockwise direction). Then, it is dropped from the rear end of the slope 3c and stored in the bottom mud storage tank 5. The bottom mud stored in the bottom mud storage tank 5 is uniformly agitated and fluidized as the blade portions 27 and 27 ′ constituting the stirrer 7 rotate in the B direction, and the bottom mud is stored. The bottom mud collected at the substantially central portion in the width direction of the tank portion 5 and collected at the substantially central portion is provided at the substantially central portion of the rear wall 5a of the bottom mud storage tank portion 5 by the suction force of the mud pump 8. It is pumped from 6a to the water via pipes 6 and 20.

As described above, according to the dredging apparatus and dredging method of the present invention, the bottom mud that has been lifted up by the lifting means 4 is moved along the slope 3c by the excavating blade 11 that rotates together with the chain 10 to the bottom mud storage tank section. It is transferred to 5. And the bottom mud stored in the bottom mud storage tank 5, that is, the cake-like mud and mud are uniformly stirred and fluidized by the stirrer 7, and at the substantially central portion of the bottom mud storage tank 5. Collected and sucked up onto the water through the pipes 6 and 20 from the pipe 6 a provided at the substantially central portion of the bottom mud storage tank 5 by the suction force of the mud pump 8.
In this way, the crushed bottom mud is fluidized without being pressurized in the casing 3, and is collected in the vicinity of the pipe 6 a provided in the substantially central portion of the bottom mud storage tank 5, and is larger by the mud pump 8. Since it can be sucked up easily without the need for suction, the mud containing the most eutrophication substances such as nitrogen and phosphorus is reliably taken into the casing 3 while suppressing the generation and diffusion of turbidity. High concentration of soot (partial mud content of 50% or more) is possible, which is optimal in the environment.

FIG. 1 is a diagram showing a scissor device according to an embodiment of the present invention. (A) of FIG. 2 is a figure which shows the stirrer which is a structure of the dredge apparatus which concerns on embodiment of this invention, (b) is sectional drawing which shows the blade | wing part of a stirrer. FIG. 3 is a view as seen from the AA direction of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dredge apparatus 2 Opening 3 Casing 3a Casing main body 3c Slope 4 Lifting means 5 Bottom mud storage tank part 7 Stirrer 8 Mud pump 10 Chain 11 Excavation blade 12 Side plate 25 Drive shaft 21 Motor 27, 27 'Blade | wing part

Claims (3)

In the casing provided with an opening on the bottom surface on the front side in the dredging direction, there is provided a lifting means that lifts the bottom mud through the opening, and a bottom mud storage tank portion that stores the bottom mud that has been lifted by the lifting means, A stirrer that stirs and fluidizes the bottom mud stored therein is disposed in the bottom mud storage tank, and communicates with the bottom mud storage tank through a pipe and flows in the bottom mud storage tank. A dredging device equipped with a mud pump that sucks the bottom mud into water. The stirrer extends in the bottom mud storage tank portion in a direction perpendicular to the dredging direction, and the stirrer has a drive shaft that is rotated by a motor and a predetermined range on the left and right sides of the drive shaft around the drive shaft. A blade portion wound spirally, the one blade portion is configured to be left-handed, the other blade portion is configured to be right-handed, and the pipe communicating with the mud pump is connected to the drive shaft. The dredging device according to claim 1, wherein the dredging device is connected to the bottom mud storage tank portion where the substantially central portion is located. A method for dredging bottom mud, wherein the bottom mud is stirred and fluidized before the bottom mud is raked up and sucked onto the water by a drainage pump.

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