Recovery tank system and method of operation thereof

Abstract

To provide a recovery tank system and an operational method thereof capable of improving efficiency of mud recovery and responding to high capacity suction while avoiding higher costs.SOLUTION: A recovery tank system assembled with a recovery tank for sucking and discharging muddy water involving a deposit soil on a water bottom is assembled with a first tank chamber (BL1) for sucking muddy water by forming negative pressure in the inside of a recovery tank (T) and a second tank chamber (BL2) connected with a bottom of the first tank chamber via a first on-off valve (SV1) and having a second on-off valve (SV2) for discharging muddy water to the bottom. In operation of the recovery tank, a) the first on-off valve is opened and the muddy water sucked by and retained in the first tank chamber is allowed to fall to the second tank chamber and retained in the second tank chamber, b) the first on-off valve is closed and the muddy water is sucked and retained in the first tank chamber, c) the second on-off valve is opened and the muddy water retained in the second tank chamber is discharged, and d) the second on-off valve is closed. By repeating a)-d), continuous running of the recovery tank is performed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an underwater sediment recovery system, and more particularly to a recovery tank system and an operating method thereof. [Background technology]

[0002] Various technologies have been proposed for recovering sediment from underwater. In the sand lifting and transporting device disclosed in Patent Document 1, a vacuum generating device is used to suck up the sediment, and compressed air is used to transport the water and sediment continuously to a sediment recovery section (solid-liquid separation device), where the water and sediment are separated to recover a high concentration of the sediment.

[0003] In addition, the sediment removal equipment disclosed in Patent Document 2 is provided with a pair of recovery tanks for solid-liquid separation, and by alternately switching between suction and discharge of water, continuous operation of the discharge system is made possible. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2018-158277 [Patent Document 2] Patent Publication No. 2011-125865 Summary of the Invention [Problem to be solved by the invention]

[0005] In the discharge system disclosed in the above-mentioned Patent Document 2, when the water level in the first collection tank reaches the upper limit, the tank is switched to the second collection tank, during which time the wastewater containing sediment stored in the first collection tank is discharged, and when the second collection tank reaches the upper limit, the tank is switched to the first collection tank, in an alternating operation. For this reason, if there is a difference between the water absorption process time until the collection tank reaches the upper limit and the water discharge process time until the tank reaches the lower limit, efficient discharge processing cannot be performed. For example, if the water discharge process time is significantly shorter than the water absorption process time, when one collection tank completes drainage, it will be in an idle state until the next water absorption begins.

[0006] If multiple collection tanks are to be operated simultaneously, a vacuum suction device with sufficiently high performance must be prepared, but if a large volume of suction is performed, the collection tank may exceed its upper limit and become punctured, which would hinder continuous construction. In addition, the frequent drainage process causes wear on parts, and the high cost of replacing parts is unavoidable.

[0007] The present invention has been devised in consideration of the above circumstances, and an object of the present invention is to provide a recovery tank system and an operating method thereof that can improve the efficiency of mud recovery and handle large-volume suction while avoiding high costs. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, according to one embodiment of the present invention, there is provided a recovery tank system having a recovery tank that sucks in and discharges muddy water containing sedimentary soil at the bottom of the water, wherein the recovery tank has a first tank chamber that sucks in the muddy water by creating negative pressure inside the recovery tank, and a second tank chamber that is connected to the bottom of the first tank chamber through a first opening / closing valve and has a second opening / closing valve for discharging the muddy water to the bottom, and is characterized in that: a) the first opening / closing valve is opened to cause the muddy water sucked into and stored in the first tank chamber to fall into the second tank chamber and be stored in the second tank chamber, b) the first opening / closing valve is closed to store the muddy water sucked into the first tank chamber, c) the second opening / closing valve is opened to discharge the muddy water stored in the second tank chamber, and d) the second opening / closing valve is closed, and continuous operation of the recovery tank is performed by repeating a)-d). According to one embodiment of the present invention, the first opening / closing valve and the second opening / closing valve are valves that open downward to allow muddy water to fall, and a)-d) can be achieved by changing the air pressure in the first tank chamber and the second tank chamber. According to one embodiment of the present invention, the device further includes a first control valve for connecting or isolating the first tank chamber and the second tank chamber, a second control valve for connecting or isolating the second tank chamber and the outside, and a valve controller for controlling the opening and closing of the first and second control valves, respectively, and the valve controller can change the air pressure in the first tank chamber and the second tank chamber by controlling the opening and closing of the first and second control valves, respectively, thereby performing a) to d). According to one embodiment of the present invention, a configuration is provided in which a plurality of the recovery tanks are arranged in parallel, and the repeating steps a) to d) of each recovery tank can be delayed in time. In order to achieve the above-mentioned object, according to one embodiment of the present invention, there is provided an operating method for a recovery tank system equipped with a recovery tank that sucks in and discharges muddy water containing sedimentary soil at the bottom of the water, wherein the recovery tank comprises a first tank chamber that sucks in the muddy water by creating negative pressure inside, and a second tank chamber that is connected to the bottom of the first tank chamber through a first opening / closing valve and has a second opening / closing valve for discharging the muddy water to the bottom, and a valve controller a) opens the first opening / closing valve downward to cause the muddy water sucked into and stored in the first tank chamber to fall into the second tank chamber and store it in the second tank chamber, b) closes the first opening / closing valve to store the muddy water sucked into the first tank chamber, c) opens the second opening / closing valve downward to discharge the muddy water stored in the second tank chamber, and d) closes the second opening / closing valve, and performs continuous operation of the recovery tank by repeating a)-d). According to one embodiment of the present invention, the first opening / closing valve and the second opening / closing valve are valves that open downward to allow muddy water to fall, and the valve controller can carry out a)-d) by changing the air pressure in the first tank chamber and the second tank chamber. According to one embodiment of the present invention, the recovery tank system further includes a first control valve for connecting or isolating the first tank chamber and the second tank chamber, and a second control valve for connecting or isolating the second tank chamber and the outside, and the valve controller controls the opening and closing of the first and second control valves, respectively, to change the air pressure in the first tank chamber and the second tank chamber, thereby carrying out a)-d). According to one embodiment of the present invention, a configuration is provided in which a plurality of the recovery tanks are arranged in parallel, and the valve controller can delay the repeating steps a) to d) of each recovery tank in time. Effect of the Invention

[0009] According to one embodiment of the present invention, the recovery tank, which is composed of a first tank chamber and a second tank chamber, is operated continuously by repeating the above-mentioned steps a)-d), which makes mud recovery more efficient and enables large-volume suction while avoiding high costs. According to one embodiment of the present invention, a)-d) are achieved by changing the air pressure in the first tank chamber and the second tank chamber using first and second opening / closing valves that open downward to allow muddy water to fall, thereby simplifying the configuration for opening and closing control. According to one embodiment of the present invention, by controlling the opening and closing of the first and second control valves, respectively, to change the air pressure in the first tank chamber and the second tank chamber and execute the above a)-d), the opening and closing control of the first and second opening and closing valves in the tank chamber can be executed by the first and second control valves alone, thereby simplifying the configuration for opening and closing control. According to one embodiment of the present invention, a configuration is provided in which multiple recovery tanks are arranged in parallel, and the repeated steps a)-d) of each recovery tank are delayed in time, so that the suction / discharge steps can be executed in parallel and the discharge steps of each recovery tank can be staggered in time. This reduces the capacity of the high concentration transport pump, improves the efficiency of mud recovery, and enables large-volume suction while avoiding high costs. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a barge-based sediment soil recovery facility equipped with a recovery tank system according to a first embodiment of the present invention. [Diagram 2] 1 is a block diagram showing the configuration of a mud recovery tank in a recovery tank system according to a first embodiment. FIG. [Diagram 3] 4 is a flowchart showing an example of operation control of the mud recovery tank in the recovery tank system according to the first embodiment. [Figure 4] FIG. 2 is a schematic diagram showing an example of operation control of the mud recovery tank in the recovery tank system according to the first embodiment. [Diagram 5]4 is a time chart showing five mud absorption / discharge cycles of the mud recovery tank in the recovery tank system according to the first embodiment. [Figure 6] FIG. 1 is a block diagram showing a configuration of a recovery tank system according to a first embodiment. [Figure 7] 4 is a time chart showing an outline of operation control of the recovery tank system according to the first embodiment. [Figure 8] FIG. 5 is a block diagram showing the configuration of a recovery tank system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] 1. First embodiment As illustrated in Figure 1, the sediment recovery equipment mounted on a barge 10 is equipment that sucks up sediment 20 that has accumulated at the bottom of water in rivers, canals, lakes, dam reservoirs, pump settling basins, etc., and recovers the sediment on the barge 10, and the recovered sediment is transported to a settling basin on land.

[0013] Mounted on the barge 10 are a gate-type facility 11, a recovery tank system 12, a filter 13, a vacuum suction device 14, and a high-concentration transport pump 15. The gate-type facility 11 suspends an agitation high-concentration pump 21 by a wire rope 16 so that it can be raised and lowered, and an auger-equipped suction machine 22 attached to the lower end of the agitation high-concentration pump 21 can be lowered to the sedimentary soil 20 at the bottom of the water with a head h. The sedimentary soil 20 sucked up by the auger-equipped suction machine 22 is agitated by the agitation high-concentration pump 21 and transported to the recovery tank system 12 through a vacuum suction pipe 23, and the absorbed water is transported to the recovery tank system 12 through a pumping transport pipe 24.

[0014] The recovery tank system 12 comprises a plurality of recovery tanks, a system for controlling the operation of each tank, and a water tank W for storing the discharged muddy water, and in this embodiment, a pair of mud recovery tanks T1 and T2 are installed. Each mud recovery tank sucks up muddy water mixed with sedimentary soil and water through a vacuum suction pipe 23 in a cycle described below, and discharges it into the water tank W. The muddy water stored in the water tank W is transported to the grit basin by a high-concentration transport pump 15. The suction and discharge of the sedimentary soil 20 is performed by the vacuum suction device 14 creating negative pressure inside the recovery tank through a filter 13, as described below, and the control unit controlling the valves of the mud recovery tank.

[0015] The barge 10 is provided with a control room (not shown), where an operator can visually or monitor the continuous operation control of the recovery tank system 12, which will be described later, and the operation control of the vacuum suction device 14 and the high concentration transport pump 15. Next, the configuration and continuous operation of the recovery tank system 12 will be described in detail with reference to Figs. 2 to 7.

[0016] 1.1) Mud collection tank 2, each of the mud recovery tanks T1 and T2 (hereinafter referred to as mud recovery tank T) has a two-tiered structure consisting of an upper tank chamber BL1 and a lower tank chamber BL2. An inlet I and an outlet E are provided on the top surface of the upper tank chamber BL1, and a vacuum suction pipe 23 is connected to the inlet I, and a vacuum suction device 14 is connected to the outlet E.

[0017] The bottom surface of the upper tank chamber BL1 has a shape that slopes toward the center, and an opening / closing valve SV1 that opens only downward is provided at the center lower end. The upper tank chamber BL1 can be connected downward to the lower tank chamber BL2 through the opening / closing valve SV1. In this embodiment, the opening / closing valve SV1 functions like a check valve, and as described below, it opens and closes naturally according to the air pressure difference between the upper tank chamber BL1 and the lower tank chamber BL2, allowing the muddy water stored in the upper tank chamber BL1 to fall into the lower tank chamber BL2.

[0018] The bottom surface of the lower tank chamber BL2 has a shape that slopes toward the center, and an opening / closing valve SV2 that opens only downward is provided at the central lower end. In this embodiment, the opening / closing valve SV2 functions like a check valve, and as will be described later, opens and closes naturally in response to the pressure difference between the lower tank chamber BL2 and the atmospheric pressure, allowing the muddy water stored in the lower tank chamber BL2 to be discharged into the water tank W.

[0019] The mud recovery tank T according to this embodiment can perform continuous operation of sucking and discharging mud by controlling the opening and closing of the opening and closing valves SV1 and SV2, but the opening and closing control of the opening and closing valves SV1 and SV2 can be realized by various methods. In this embodiment, as described below, the opening and closing control of the opening and closing valves SV1 and SV2 is performed by utilizing the air pressure difference between the upper tank chamber BL1 and the lower tank chamber BL2, and the air pressure difference between the lower tank chamber BL2 and the outside. In other words, the opening and closing valves SV1 and SV2 can be configured as passive valves that can be opened downwards, and no special actuator is required for opening and closing.

[0020] The communication ports C1 and C2 provided on the respective sides of the upper tank chamber BL1 and the lower tank chamber BL2 are connected to a control valve VL1 that can be electromagnetically controlled to open and close, and the upper tank chamber BL1 and the lower tank chamber BL2 are communicated with each other by opening the control valve VL1 and are isolated from each other by closing it. Furthermore, the communication port C3 provided on the side of the lower tank chamber BL2 is connected to a control valve VL2 that can be electromagnetically controlled to open and close, and the lower tank chamber BL2 is communicated with the outside by opening the control valve VL2 and is isolated from the outside by closing it.

[0021] Furthermore, the upper tank chamber BL1 and the lower tank chamber BL2 are provided with level sensors S1 and S2, respectively, for detecting the muddy water levels therein. As will be described later, the valve controller (control section) 100 opens and closes the control valves VL1 and VL2 while monitoring the water levels detected by the level sensors S1 and S2 and / or a timer, thereby executing suction / discharge control of the mud recovery tank. The suction / discharge control of the mud recovery tank will be described below.

[0022] 1.2) Suction / discharge control The suction / discharge control of the valve controller 100 according to this embodiment will be specifically described with reference to Figures 3 and 4. The functions of the valve controller 100 can be realized by executing a program stored in a memory (not shown) on a computer processor.

[0023] 3, when the vacuum suction device 14 is operated (operation 201), the valve controller 100 opens the control valve VL1 to communicate the upper tank chamber BL1 with the lower tank chamber BL2, and closes the control valve VL2 to isolate the lower tank chamber BL2 from the outside (operation 202). As a result, both the upper tank chamber BL1 and the lower tank chamber BL2 become negative pressure, the opening and closing valve SV2 closes naturally, and the opening and closing valve SV1 opens naturally, causing the muddy water to fall into the lower tank chamber BL2 and accumulate there (FIG. 4(A)).

[0024] Next, the valve controller 100 closes the control valves VL1 and VL2 (operation 203). This creates a negative pressure in the upper tank chamber BL1, causing the opening and closing valve SV1 to close naturally, and the muddy water is sucked into and stored in the upper tank chamber BL1 (FIG. 4(B)).

[0025] The valve controller 100 detects whether the water level in the upper tank chamber BL1 detected by the level sensor S1 exceeds a predetermined threshold value L H It is monitored whether the predetermined threshold L H For example, the water level in the upper tank chamber BL1 corresponds to 80% of the tank chamber capacity. As another monitoring method, the valve controller 100 measures the elapsed time from closing the control valves VL1 and VL2 using a timer, and detects whether the timer reaches a predetermined elapsed time Tsuc and whether the water level in the upper tank chamber BL1 reaches a predetermined threshold value L H The elapsed time Tsuc can be the average of the actual measured time from when the water level in the tank chamber BL1 reaches the upper limit value (for example, 80% of the tank chamber capacity) from zero (0%). HIf either the water level in the upper tank chamber BL1 reaches a predetermined threshold value L H It can be judged that this has been achieved.

[0026] The water level in the upper tank chamber BL1 reaches a predetermined threshold L H When the pressure in the lower tank chamber BL2 reaches 1000V (NO in operation 204), the valve controller 100 closes the control valve VL1 and opens the control valve VL2 (operation 205). Closing the control valve VL1 separates the lower tank chamber BL2 from the upper tank chamber BL1, and opening the control valve VL2 connects the lower tank chamber BL2 to the outside and increases the pressure to atmospheric pressure. This causes the opening / closing valve SV2 to open naturally, and the muddy water stored in the lower tank chamber BL2 is discharged into the water tank W (FIG. 4(C)).

[0027] The valve controller 100 monitors whether the water level in the lower tank chamber BL2 detected by the level sensor S2 has become zero, that is, whether the discharge is complete (operation 206). The determination of the discharge completion may be made in combination with monitoring of the elapsed time by a timer.

[0028] If the drainage is complete (YES in operation 206), the valve controller 100 closes the control valves VL1 and VL2 (FIG. 4(D)). If the control is not complete (NO in operation 208), the above-described operations 202 to 208 can be repeated to repeatedly execute the suction / drain cycle shown in FIGS. 4(A) to (D).

[0029] As shown in Fig. 5, the upper tank chamber BL1 continues the suction operation through Fig. 4(A) to Fig. 4(D), and the lower tank chamber BL2 stores muddy water in Fig. 4(A) to Fig. 4(B) and discharges the muddy water in Fig. 4(C) to Fig. 4(D). In one cycle from time t1 to t3, the discharge process is from time t2 to t3, and the time required for the discharge process (discharge process time) is shorter than the time required for the suction process (suction process time), for example, the suction process time = 50 seconds and the discharge process time = 5 seconds.

[0030] 1.3) Recovery Tank System As illustrated in Figure 6, the recovery tank system 12 of this embodiment consists of mud recovery tanks T1 and T2 arranged in parallel, and each of the mud recovery tanks T1 and T2 has the structure shown in Figure 2 and operates in the suction / discharge cycle shown in Figures 3 to 5.

[0031] In the following, in order to avoid duplication of explanation, the following reference symbols are used in Fig. 6. The upper tank chamber BL1, the lower tank chamber BL2, the opening / closing valve SV1, the opening / closing valve SV2, the control valve VL1 and the control valve VL2 of the mud recovery tank T shown in Fig. 2 correspond to the upper tank chamber BL1x, the lower tank chamber BL2x, the opening / closing valve SV 1x , Opening and closing valve SV 2x , control valve VL 1x and control valve VL 2x For example, the control valve VL1 of the mud recovery tank T in FIG. 2 corresponds to the control valve VL of the mud recovery tank T1 in FIG. 11 and the control valve VL of the mud recovery tank T2 11 Since the configurations and functions of these corresponding members are basically the same, detailed descriptions of the structures are omitted.

[0032] Although the level sensors S1 and S2 are not shown in Fig. 6, they are provided in the same manner as in Fig. 2. Therefore, the valve controller 100 controls the control valve VL of the mud recovery tank T1 while monitoring the water levels of the upper and lower tank chambers of the mud recovery tanks T1 and T2. 11 and VL 21 and the control valve VL of the mud recovery tank T2 12 and VL 22 and performs suction / discharge control of the mud recovery tanks T1 and T2 at the timing described below.

[0033] As shown in Fig. 7, the valve controller 100 independently controls the suction / discharge operations of the mud recovery tanks T1 and T2, and starts a mud suction / discharge cycle similar to that of Fig. 5 from time t1 for the mud recovery tank T1, and starts a mud suction / discharge cycle similar to that of Fig. 5 from time t2, which is a predetermined time td behind time t1, for the mud recovery tank T2. This delay time td is set to a time longer than the discharge process time (t3 to t4 or t5 to t6) of the mud recovery tank. In this way, the valve controller 100 makes it possible to continuously operate the mud recovery tanks T1 and T2 so that the timing of the discharge process differs in time.

[0034] For example, as shown in FIG. 6, a suction / discharge cycle can be set so that when the mud recovery tank T1 is in the suction state shown in FIG. 4(A), the mud recovery tank T2 is in the discharge process shown in FIG. 4(C).

[0035] 1.4) Effects As described above, according to the first embodiment of the present invention, when a pair of mud recovery tanks T1 and T2 are operated continuously, the suction / discharge processes of one recovery tank can be delayed by a predetermined time compared to the other, so that the suction / discharge processes of the mud recovery tanks T1 and T2 can be carried out continuously in parallel, thereby making the recovery of sedimentary soil more efficient.

[0036] 2. Second embodiment The present invention is not limited to the continuous operation of the pair of recovery tanks T1 and T2 described above, but can be similarly applied to the continuous operation using a plurality of (three or more) recovery tanks. As the second embodiment of the present invention, the continuous operation of two pairs of recovery tanks T1 to T4 will be described below. However, the same reference numbers or symbols are used for members having the same functions as those in the first embodiment, and the description will be omitted.

[0037] In order to avoid duplication of explanation, the following reference symbols are used in Fig. 8. In other words, as in Fig. 6, the upper tank chamber BL1, lower tank chamber BL2, on-off valve SV1, on-off valve SV2, control valve VL1 and control valve VL2 of the mud recovery tank T shown in Fig. 2 correspond to the upper tank chamber BL1x, lower tank chamber BL2x, on-off valve SV of the mud recovery tank Tx (x=1, 2, 3 or 4). 1x , Opening and closing valve SV 2x , control valve VL 1x and control valve VL 2x Similarly, level sensors S1 and S2 are provided in each of the mud recovery tanks T1 to T4.

[0038] As shown in FIG. 8, the suction pipe 121 connected to the vacuum suction pipe 23 is branched into four parts, the first of which is connected to the control valve VL 10 The second branch is connected to the suction port I1 of the mud recovery tank T1 via the control valve VL 20 The third branch is connected to the suction port I2 of the mud recovery tank T2 via the control valve VL 30 The fourth branch is connected to the suction port I3 of the mud recovery tank T3 via the control valve VL 40 The exhaust port E1 of the mud recovery tank T1 is connected to an exhaust pipe 122 which is connected to the vacuum suction device 14 side, and similarly, the exhaust ports E2 to E4 of the mud recovery tanks T2 to T4 are also connected to the exhaust pipe 122.

[0039] Although not shown in FIG. 8, the recovery tank system 12a is provided with a valve controller 100 similar to that shown in FIG. 2, which controls the control valves VL of the mud recovery tanks T1 and T2 while monitoring the water levels of the upper and lower tank chambers of each of the mud recovery tanks T1 to T4. 11 , V.L. 21 , V.L. 12 and VL 22 and the control valve VL of the mud recovery tanks T3 and T4 13 , V.L. 23 , V.L. 14 and VL 247. The controller 100 controls the opening and closing of the mud recovery tanks T1 to T4, and executes suction / discharge control of the mud recovery tanks T1 to T4 at the same timing as in FIG.

[0040] For example, the valve controller 100 independently controls the suction / discharge operations of the mud recovery tanks T1-T4, and delays the mud suction / discharge cycles of the mud recovery tanks T1-T4 by a predetermined time td, while continuously operating the mud recovery tanks T1-T4 so that the timing of the discharge process differs over time. Alternatively, as shown in Fig. 6, the suction / discharge cycle may be set so that the mud recovery tanks T2 / T4 are in the discharge process shown in Fig. 4(C) when the mud recovery tanks T1 / T3 are in the suction state shown in Fig. 4(A), and the suction / discharge cycle may be set so that the mud recovery tanks T2 / T4 are in the discharge process shown in Fig. 4(C) when the mud recovery tanks T1 / T3 are in the suction state shown in Fig. 4(A).

[0041] The valve controller 100 also controls the control valve VL 10 , V.L. 20 , V.L. 30 and VL 40 By controlling the opening and closing of each tank independently, it is possible to determine which combination of mud recovery tanks will be operated continuously.

[0042] As described above, according to the second embodiment of the present invention, the suction / discharge processes can be carried out continuously without the discharge processes of multiple recovery tanks overlapping in time, thereby making it possible to efficiently recover sedimentary soil.

[0043] The present invention is not limited to two or four collection tanks as described above, but can be similarly applied to parallel continuous operation of any number of collection tanks. That is, by setting the delay time td in the same manner as the setting of the absorption / discharge timing shown in Fig. 7, any number of collection tanks can be operated in parallel continuous operation. [Explanation of symbols]

[0044] 10 barges 11 Gate type equipment 12 Recovery Tank System 13 Filters 14 Vacuum suction device 15 High concentration transport pump 16 Wire Rope 20 Sediment soil 21 Mixing high concentration pump 22 Auger suction machine 23 Vacuum suction tube 24 Water pumping pipe 121 Suction tube 122 Exhaust pipe 100 Valve Controller T1, T2, T3, T4 Recovery Tanks BL1, BL11-BL14 Upper tank room BL2, BL21―BL24 Lower tank room S1, S2 Level Sensors VL1~VL2, VL 11 ~VL 14 , V.L. 21 ~VL 24 Control valve SV1, SV2, SV 11 -SV 14 , S.V. 21 -SV 24 Opening and closing valve

Claims

1. A recovery tank system having a recovery tank that sucks up and discharges muddy water containing sedimentary soil at the bottom of the water, The recovery tank a first tank chamber that draws in the muddy water by creating a negative pressure therein; a second tank chamber connected to the bottom of the first tank chamber through a first opening / closing valve and having a second opening / closing valve for discharging muddy water to the bottom; a first control valve for connecting or isolating the first tank chamber and the second tank chamber; a second control valve for connecting or isolating the second tank chamber to or from the outside; a valve controller that controls the opening and closing of the first and second control valves, respectively; Equipped with a) opening the first opening / closing valve to allow the muddy water sucked and stored in the first tank chamber to fall into the second tank chamber and be stored in the second tank chamber; b) closing the first opening / closing valve to store the muddy water sucked into the first tank chamber; c) opening the second opening / closing valve to discharge the muddy water stored in the second tank chamber; d) closing the second opening / closing valve; By repeating steps a) to d), continuous operation of the recovery tank is performed; The valve controller controls the opening and closing of the first and second control valves, respectively, to change the air pressure in the first tank chamber and the second tank chamber, thereby carrying out a) to d).

2. The recovery tank system described in claim 1, characterized in that the first opening / closing valve and the second opening / closing valve are valves that open downward to allow muddy water to fall, and a) to d) are carried out by changing the air pressure in the first tank chamber and the second tank chamber.

3. 3. The recovery tank system according to claim 1, wherein the recovery tank is configured to have a plurality of recovery tanks arranged in parallel, and the repeating steps of a) to d) of each recovery tank are delayed in time.

4. A method for operating a recovery tank system having a recovery tank that sucks up and discharges muddy water containing sedimentary soil at the bottom of a body of water, comprising: the recovery tank comprises a first tank chamber which sucks in the muddy water by creating a negative pressure inside the first tank chamber, a second tank chamber which is connected to the bottom of the first tank chamber through a first opening / closing valve and has a second opening / closing valve for discharging the muddy water to the bottom, a first control valve for connecting or separating the first tank chamber and the second tank chamber, and a second control valve for connecting or separating the second tank chamber and the outside, The valve controller a) opening the first opening / closing valve downward to allow the muddy water that has been sucked into and stored in the first tank chamber to fall into the second tank chamber and be stored in the second tank chamber; b) closing the first opening / closing valve to store the muddy water sucked into the first tank chamber; c) opening the second opening / closing valve downward to discharge the muddy water stored in the second tank chamber; d) closing the second opening / closing valve; By repeating steps a) to d), continuous operation of the recovery tank is performed; By controlling the opening and closing of the first and second control valves, respectively, the air pressure in the first tank chamber and the second tank chamber are changed, thereby carrying out the above-mentioned a) to d). A method for operating a recovery tank system.

5. The first opening / closing valve and the second opening / closing valve are valves that open downward to allow muddy water to fall, 5. The method of claim 4, wherein the valve controller performs a) to d) by varying the air pressure in the first tank chamber and the second tank chamber.

6. A configuration in which a plurality of the recovery tanks are arranged in parallel, 6. The method of claim 4 or 5, wherein the valve controller delays the repeating steps a) to d) for each recovery tank in time.

Images