JP2022102428A - Dredge pump - Google Patents

Abstract

To eliminate lock or blockage when an impeller is locked or blocked, and also prevent or suppress blockage of sediment in a mud feeding pipeline.SOLUTION: A dredge pump 10 includes: blockage detection means 40A and 40B for detecting a drive state of an impeller 2; a branched pipeline 14 branched from a mud feeding pipeline 13 of a casing 1; a first check valve 11 mounted on the branched pipeline 14; a second check valve 12 mounted on the downstream of a branched part in the mud feeding pipeline 13; and a controller 30 for executing blockage elimination processing. The controller 30 executes blockage elimination control for reversely driving the impeller 2 in a state in which the first check valve 11 is opened and the second check valve 12 is closed when blockage information from the blockage detection means 40A and 40B is acquired, and executes normal control of normally driving the impeller 2 in a state in which the first check valve 11 is closed and the second check valve 12 is opened when the blockage information is not acquired.SELECTED DRAWING: Figure 2

Description

The present invention relates to a dredging technique for dredging sediments deposited on the bottom of a dam lake or the like, and particularly relates to a dredging pump suitable for this type of application.

In a general dam, dredging work is required to maintain the dam's water storage capacity in order to discharge sediments such as mud, earth and sand, pebbles, gravel, and sunken trees that have accumulated on the bottom of the dam lake.
On the other hand, for example, Patent Document 1 discloses a pump dredging device that sucks and sends mud from the bottom of the water by a dredging pump. The dredging device described in the same document includes a dredging pump and a crusher provided at a position facing the suction side of the dredging pump.

In particular, in the dredging device described in the same document, two twin-screw crushers are arranged in two upper and lower stages as crushers. As a result, according to the dredging device described in the same document, even if the sediment contains jade stones or sunken trees, the sediment can be more reliably sucked and discharged by the dredging pump by the two-stage crushing process. Can be crushed. Therefore, it is possible to prevent or suppress the clogging of the dredging pump.

Japanese Unexamined Patent Publication No. 2019-178566

As described above, the technique described in Patent Document 1 prevents or suppresses blockage in the dredging pump in the subsequent process by devising the process before the suction / discharge process in the dredging pump, that is, the crushing process. It is a technique to do.

Therefore, since the dredging pump itself and the blockage in the mud feed line are the same as those in the past, it is necessary to provide a dredging technique capable of preventing or suppressing the blockage in the pump itself and the mud feed line in the pump dredging method. So, there is still room for consideration.

Here, in the pump dredging, the sand content in the mud feed liquid is suppressed to a predetermined ratio or less in order to avoid blockage due to sediment sedimentation in the mud feed pipe line piped on the discharge side of the dredging pump. Measures to operate the dredging pump are generally taken.

On the other hand, even when a crusher is used as in the technique described in Patent Document 1, if boulders or sunken trees are sucked into the casing, the impeller rotating in the casing may be locked or blocked. .. Normally, when the operator determines that the impeller is in the locked or blocked state, a measure is taken to reverse the impeller to release the locked or blocked state.

However, in pump dredging, simply reverse driving the impeller causes backflow of earth and sand being discharged in the mud pipe line, which causes the sand content in the vicinity of the discharge side in the mud pipe line to exceed a predetermined ratio. If the amount increases, the sediment may be blocked in the mud pipe and it may be difficult to restart.

Therefore, the present invention has been made by paying attention to such a problem, and in the pump dredging method, when the impeller is locked or blocked in the casing, the impeller is reversed in the casing. It is an object of the present invention to provide a dredging pump capable of releasing the lock or blockage of the impeller and also preventing or suppressing the blockage of earth and sand in the mud feeding pipeline.

In order to solve the above problems, the dredging pump according to one aspect of the present invention is a dredging pump including a casing and an impeller rotatably arranged in the casing, and the impeller is locked or closed. A blockage detecting means for detecting a blockage, a branch pipeline branched from a mud feeding pipeline connected to the discharge side of the casing and opened into water, and a first valve attached to the opening of the branch pipeline. And, it is obtained from the blockage detecting means and the second valve which is interposed downstream of the branch portion in the middle of the mud feeding pipeline and operates in the opposite direction to the first valve. The controller includes a controller that executes a blockage clearing process based on the blockage information, and when the blockage information is acquired, the controller is in a state where the first valve is open and the second valve is closed. When the blockage elimination control for reversely driving the impeller is executed in the closed state and the blockage information is not acquired, the first valve is closed and the second valve is open. It is characterized in that normal control for driving the impeller in the forward direction is executed.

According to the dredging pump according to one aspect of the present invention, when the locked or closed state of the impeller is detected in the casing, the impeller can be reversed to release the locked or closed state of the impeller.
Further, according to the dredging pump according to one aspect of the present invention, when the impeller is reversely driven, the first valve is opened while the second valve is closed. As a result, during the reverse drive of the impeller, the water taken in from the opening of the branch pipeline is introduced from the middle part of the mud pipe, while the earth and sand in the mud pipe stays at the position before the reverse drive. It is maintained as it is.

Therefore, the backflow of the earth and sand that was in the discharged state in the mud feeding pipe is prevented, and the impeller can be quickly and surely released from the locked or blocked state by the smooth reverse control.
Therefore, according to the dredging pump according to one aspect of the present invention, when the impeller is locked or blocked in the casing, the impeller is reversed to release the lock or blockage of the impeller in the casing, and the mud is fed. It is also possible to prevent or suppress the blockage of earth and sand in the pipeline.

As described above, according to the present invention, when the impeller is locked or blocked in the casing, the impeller is reversed to release the lock or blockage of the impeller in the casing, and in the mud pipe. It is also possible to prevent or suppress the blockage of earth and sand.

It is a schematic diagram explaining one Embodiment of the dredging system using the dredging pump which concerns on one aspect of this invention. It is explanatory drawing of one Embodiment of the dredging pump which concerns on one aspect of this invention. It is shown as a schematic addition. It is a flowchart of the blockage clearing process executed by the management computer (controller) in the embodiment shown in FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate. The drawings are schematic. Therefore, it should be noted that the relationship, ratio, etc. between the thickness and the plane dimension are different from the actual ones, and there are parts where the relationship and ratio of the dimensions are different between the drawings.
Further, the embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention describes the material, shape, structure, and arrangement of constituent parts. Etc. are not specified in the following embodiments.

FIG. 1 shows a dredging system including the dredging pump 10 of the present embodiment.
As shown in the figure, this dredging system includes a water base 50 arranged on a water SL such as a dam lake, and a dredging device 100 suspended from the water base 50 by a wire 57 and deployed on the bottom of the water. It is composed.

The water base 50 is equipped with a generator 51, a working machine 54 including a winch, a variable capacity type hydraulic pump 55 driven by an internal combustion engine as a hydraulic source, and a management computer 30 constituting a controller. Ru. The management computer 30, the generator 51, and the hydraulic pump 55 are connected to the dredging device 100 arranged at the bottom SB of the dam lake via the umbilical cable 56.

The dredging device 100 is capable of supplying electric power and control signals necessary for operating the dredging device 100 and supplying pressure oil from the surface base 50 side via an umbilical cable 56. The dredging device 100 of the present embodiment includes a dredging yakura 53 that can be erected on the bottom SB of a dam lake, and a dredging pump 10 installed in the center of the dredging yakura 53. The dredging pump 10 of the present embodiment employs a submersible sand pump, which enables pump dredging to send excavated sediment together with mud water to a mud feeding hose 7.

Specifically, the dredging pump 10 of the present embodiment includes a pump drive unit 3 and a casing 1 provided at the lower part of the pump drive unit 3, as shown in FIG. The casing 1 is provided with a suction port 1s on the bottom surface, and a suction hopper (not shown) is attached to the suction port 1s. When configured as a dredging device using the dredging pump 10 of the present embodiment, a crusher can be provided at a portion of the suction hopper on the suction port 1s side of the dredging pump 10. In the example of the figure, a perforated pipe type strainer 15 is attached.

The submersible motor 5 is built in the pump drive unit 3. A captire cable 52 is connected from the control unit 6 to the upper part of the pump drive unit 3, and the electric power supplied from the generator 51 provided at the water base 50 on the lake is submerged from the captire cable 52 via the control unit 6. It is supplied to the motor 5. The captire cable 52 is provided inside the umbilical cable 56 in FIG. 1.

In the drive shaft 8 of the submersible motor 5, the upper and lower parts of the drive shaft 8 are rotatably supported by bearings 9A and 9B, and the lower end of the drive shaft 8 is projected downward from the center of the upper part of the casing 1. In the casing 1, the impeller 2 is coaxially mounted on the tip of the drive shaft 8. Between the pump drive unit 3 and the casing 1, a shaft seal portion 4 such as a mechanical seal or an oil seal is provided at a position around the drive shaft 8 of the submersible motor 5.

A discharge port 1t is provided on the side surface of the casing 1, and the mud feed pipe line 13 is connected to the discharge port 1t. The mud pipe line 13 is connected to a flexible mud hose 7 extending along the bottom of the lake. As a result, in the dredging pump 10 of the present embodiment, when the submersible motor 5 is driven, the impeller 2 is driven in the forward direction in a predetermined direction to generate a vortex in the casing 1, and the amount of pump drainage from the suction hopper facing the lake bottom side. The mud water is sucked together with the crushed dredged material, and can be discharged from the suction port 1s to the mud feeding hose 7 via the mud feeding pipe line 13.

Here, in the dredging pump 10 of the present embodiment, an elbow is interposed at a connecting portion between the mud feeding pipe line 13 and the mud feeding hose 7, and a branch pipe line 14 is provided. As a result, the branch pipe 14 is branched from the mud pipe 13 connected to the discharge side of the casing 1 and opened in the water.
Further, in the dredging pump 10 of the present embodiment, the first check valve 11 as the first valve is attached to the opening of the branch pipeline 14. In the figure, a strainer 16 made of round steel in a mesh pattern is attached to the opening on the suction side of the first check valve 11. Further, a second check valve 12 as a second valve is mounted in the middle of the mud feed pipe 13 at a position downstream of the branch portion of the branch pipe 14.

The first check valve 11 of the present embodiment has a forward direction in which the fluid flows from the opening side of the branch pipeline 14 toward the casing 1, and automatically closes when the fluid tries to flow in the opposite direction. It is a check valve. On the other hand, the second check valve 12 of the present embodiment has a forward direction in which the fluid flows from the casing 1 side toward the mud pipe line 13 side, and automatically closes when the fluid tries to flow in the opposite direction. It is a check valve that valves.

Further, in the dredging pump 10 of the present embodiment, pressure detection sensors 40A and 40B are attached to the suction port 1s and the discharge port 1t of the casing 1 as blockage detecting means for detecting the locked or blocked state of the impeller, respectively. Then, the management computer 30 monitors the transfer state of the dredged object and executes the blockage clearing process to prevent or suppress the blockage, and when it is determined to be the blockage state, the impeller 2 is reversely driven to perform reverse drainage. It is designed to perform control.

Specifically, the management computer 30 is a central processing unit (CPU), a storage unit such as a RAM (random access memory) and a ROM (read-only memory) connected to the central processing unit (CPU), and an input / output device (not shown below). And so on. The storage unit stores a plurality of drive patterns in which torque information and the like required for drainage by the dredging pump 10 according to the type of dredging object (for example, boulders, sunken trees) are stored in advance.

The management computer 30 drives the dredging pump 10 according to the condition of the dredged object based on the pressure detection sensors 40A and 40B and the current information acquired from the circuit for controlling the constant horsepower of the submersible motor 5. Appropriate control is possible by selecting a pattern and using a regulator, for example.

The blockage clearing process is a timer interrupt process for the normal control process that drives the impeller 2 in the forward rotation. When the blockage clearing process is executed, the management computer 30 shifts to step S10 as shown in FIG. Then, it monitors whether or not the blockage information has been acquired.

In the present embodiment, the blockage information is acquired by comparing the pressure information from the pressure detection sensors 40A and 40B, the current information from the submersible motor 5, and the preset thresholds. Then, under the monitoring of the management computer 30, if the blockage information is acquired, the process proceeds to step S20, and if not, the process proceeds to step S30.

Here, as the blockage information acquired from the blockage detection means, in the present embodiment, each measured value by the pressure detection sensors 40A and 40B is used as pressure information, and an arbitrary threshold value is set for each measured value and is virtual. The current value of the submersible motor 5 at the operating point is monitored, and an arbitrary threshold value is set for this current value as well. Then, the management computer 30 is configured to assume that the blockage information has been acquired when these values exceed the preset lower limit value or upper limit value, and to determine that the dredging pump 10 has been blocked. ..

More specifically, for example, when the water depth of the bottom SB of the dam lake is 5 m and the total pump lift of the dredging pump 10 is 15 m (the liquid specific gravity is 1), at this time, if it is during normal operation. , 5 m as the pressure information of the pressure detection sensor 40A of the suction port 1s, 20 m as the pressure information of the pressure detection sensor 40B of the discharge port 1t, and 50A as the current value of the submersible motor 5 at the virtual operation point. (However, the unit of pressure is the water column m).

On the other hand, as the threshold value, for example, 2 m as the pressure information at the suction port 1s, for example 10 m as the pressure information at the discharge port 1t, and for example 30A as the current value of the submersible motor 5 at the virtual operation point are preset. It is assumed that it has been done. Therefore, since it is determined that all of the above measured values are within the range of the normal values, the management computer 30 determines that the operating state is normal and continues the normal operation.

On the other hand, as an example at the time of closure, the pressure information of the pressure detection sensor 40A of the suction port 1s is 1 m, the pressure information of the pressure detection sensor 40B of the discharge port 1t is 5 m, and the current value of the underwater motor 5 at the virtual operation point. It is assumed that 20A is sent to the management computer 30 as each measured value.

The management computer 30 compares the above threshold value with the acquired measured value, and in this example, the pressure information 1 m at the suction port 1s, the pressure information 5 m at the suction port 1s, and the underwater at the virtual operation point. Since all of the current values 20A of the motor 5 are smaller than the predetermined threshold value, it is determined that the pressure drop occurs at the same time and the blockage information is acquired. As a result, in step S20, the management computer 30 executes the blockage elimination control that reversely drives the impeller, and then returns the process to step S10. In step S30, the normal control for driving the impeller in the forward direction is continued and the processing is returned.

As a result, when the blockage information is acquired, the management computer 30 reversely drives the impeller 2 with the first check valve 11 open and the second check valve 12 closed. It is possible to execute blockage resolution control.
Further, when the blockage information is not acquired, the management computer 30 drives the impeller 2 in a forward rotation state with the first check valve 11 closed and the second check valve 12 open. It is possible to execute normal control.

Next, the procedure for dredging the sediment from the bottom of the dam lake by the dredging device 100 provided with the above-mentioned dredging pump 10 and the operation / effect of the dredging pump 10 will be described.
First, as shown in FIG. 1, the water base 50 in which the dredging device 100 is hung is anchored at a target position on the lake. Next, the wire 57 is unwound using the working machine 54 installed at the water base 50, the dredging device 100 is lowered into water, and the dredging device 100 is placed at an appropriate position on the bottom of the dam lake so as to have a desired arrangement. Dredging Yakura 53 is installed.

After the dredging device 100 is installed, a crusher and a dredging pump 10 (not shown) are driven. When the dredging device 100 is driven, the crusher crushes the dredging material and sends out the dredging material toward the upper dredging pump 10.
The dredging pump 10 sucks the excavated sediment together with the muddy water, and for example, in FIG. 1, from the arrangement position S of the dredging device 100 to the transfer position M on the water via the mud feeding hose 7 arranged in the water. Moving. The dredging device 100 can be moved to the hanging water base 50 to continue dredging of sediments at the bottom of the dam lake.

Here, in the pump dredging based on the performance of the dredging pump 10, if the dredging pump 10 is not properly controlled, the ratio (sand content) of the earth and sand containing the crushed dredged material increases, and the pump is fed. If the pumping distance of the mud hose 7 becomes long, the mud feeding pipe line 13 and the mud feeding hose 7 may be blocked, and the crushed dredged material may not be stably transported.

In pump dredging, in order to avoid sedimentation in the piping, a method of operating the dredging pump 10 such as a submersible pump while suppressing the sand content of the slurry liquid to a predetermined ratio or less is generally adopted.
On the other hand, in the dredging device 100 of the present embodiment, the management computer 30 is based on the pressure detection sensors 40A and 40B and the current information acquired from the circuit for controlling the constant horsepower of the submersible motor 5. When the blockage information is not acquired, the normal control for driving the impeller 2 in the forward direction is executed with the first check valve 11 closed and the second check valve 12 open. ..

In normal control, the management computer 30 selects the drive pattern of the dredging pump 10 according to the condition of the dredged object, and uses, for example, a regulator to suppress the sand content of the pumping liquid to a predetermined value or less. Increase or decrease the suction flow rate of 10.

As a result, the dredging device 100 of the present embodiment can continue the normal control of driving the impeller in the forward direction while more preferably preventing or suppressing the blockage of the dredging pump 10. Therefore, the dredging device 100 of the present embodiment suppresses the sand content in the slurry liquid pressure-fed by the dredging pump 10 to a predetermined value or less, thereby preventing sedimentation in the mud feeding pipe line 13 and the mud feeding hose 7. It is suitable for avoiding it.

Here, depending on the properties of the dredging material containing boulders and sunken trees in the sediment, the dredging pump 10 may be clogged. On the other hand, in the dredging pump 10 of the present embodiment, when the management computer 30 executes the blockage clearing process, monitors the transfer state of the dredged material, and determines that the blockage state is determined, the check valves 11 and 12 have two check valves. Since the blockage release control that reversely drives the impeller is executed in cooperation with the opening / closing operation, when the impeller is locked or blocked, the impeller lock or blockage is quickly released and in the mud feeding pipeline. It is also possible to prevent or suppress the blockage of earth and sand.

In other words, where a dredging pump is used to remove sediment accumulated on the bottom of a dam or lake, driftwood is sunk on the bottom of the lake. Therefore, if this is sucked into the impeller 2, the impeller 2 will lock or the casing 1 will be blocked. Conventionally, when a lock or blockage occurs in the impeller portion, the impeller is made to flow backward to solve the problem.

However, as described above, in the pump dredging, if the impeller is simply driven in the reverse direction, a backflow of earth and sand being discharged occurs in the mud feeding hose 7 and the mud feeding pipe line 13, which causes the mud feeding. If the sand content in the vicinity of the discharge side in the pipeline 13 increases more than a predetermined ratio, sediment may be blocked in the mud feeding pipeline 13 and restarting may be difficult.

On the other hand, in the dredging pump 10 of the present embodiment, the management computer 30 monitors the pressure detection sensor 40A provided in the suction portion, the pressure detection sensor 40B provided in the sweep portion, and the drive current value of the submersible motor 5. Since the management computer 30 executes the blockage release control when it is determined that the lock or blockage state is set, the lock can be released quickly and surely by the smooth reverse control. Therefore, it is possible to prevent or suppress the blockage of the dredging pump 10.

In particular, in the dredging pump 10 of the present embodiment, as described above, the first check valve 11 is interposed in the mud feed pipe line 13 on the discharge side, and the dredging sediment from the discharge port side at the time of reverse rotation control. Can prevent backflow. Then, the return flow path at the time of reverse rotation control is branched from the mud feeding pipe line 13 by the branch pipe line 14, and the branch pipe line 14 operates in the opposite direction to the first check valve 11. The check valve 12 is equipped.

Therefore, at the time of the blockage elimination control, the blockage elimination control for reversely driving the impeller 2 can be executed with the first check valve 11 open and the second check valve 12 closed. As a result, according to the dredging pump 10 of the present embodiment, when the impeller 2 is reversely driven, the water taken in from the opening of the branch pipe 14 is introduced from the middle part of the mud pipe 13 while the mud is fed. The earth and sand in the hose 7 and the mud pipe line 13 are maintained in the position before the reverse rotation drive.

Therefore, according to the dredging pump 10 of the present embodiment, the impeller 2 is reversed to release the lock or blockage of the impeller 2 in the casing 1, and the blockage of earth and sand in the mud feed pipe 13 is also performed. It can be prevented or suppressed.
The dredging pump according to the present invention is not limited to the above embodiment, and of course, various modifications can be made without departing from the gist of the present invention.

For example, in the above embodiment, an example in which the check valves 11 and 12 are provided in the mud transmission line 13 and the branch line 14 respectively is shown, but the present invention is not limited to this, and instead of the check valve, for example, electromagnetic waves are shown. An opening / closing valve may be provided in each pipeline, and the electromagnetic opening / closing valve may be configured to be controlled by the management computer 30 (controller).

1 Casing 2 Impeller 3 Pump drive part 4 Shaft seal part 5 Submersible motor 6 Control unit 7 Mud feed hose 8 Drive shaft 9A, 9B Bearing 10 Dredging pump 11 First check valve (first valve)
12 Second check valve (second valve)
13 Mud transmission line 14 Branch line line 15 Strainer 16 Strainer 30 Management computer (controller)
40A, 40B pressure sensor (blockage detection means)
50 Water base 51 Generator 52 Captire cable 53 Dredging Yakura 54 Working machine 55 Hydraulic pump 56 Umbilical cable 57 Wire 100 Dredging device

Claims (2)

A dredging pump comprising a casing and an impeller rotatably arranged within the casing.
A blockage detecting means for detecting the locked or blocked state of the impeller, and
A branch pipeline that is branched from the mud transmission pipeline connected to the discharge side of the casing and is opened into the water.
The first valve attached to the opening of the branch pipeline,
A second valve that is located in the middle of the mud feed pipe line and is interposed downstream of the branch portion and that opens and closes in the opposite direction to the first check valve.
A controller that executes a blockage clearing process based on the blockage information acquired from the blockage detection means is provided.
The controller
When the blockage information is acquired, the blockage cancellation control for reversely driving the impeller is executed with the first valve open and the second valve closed.
When the blockage information is not acquired, the normal control for driving the impeller in the forward direction is executed with the first valve closed and the second valve open.
A dredging pump characterized by that. The dredging pump according to claim 1, wherein the first valve and the second valve are check valves.

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