JP2007307484A - Facility and method for sand collection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a facility for sand collection suppressing floating up of grit. <P>SOLUTION: This facility for sand collection 22A collects sediment g settled on the bottom 16 of a grit pit 12 retaining raw water, and is provided with jetting nozzles 24a-24c, a high pressure pump P2, a pressurized water supply line 30 and a return line 38. The high pressure pump P2 is disposed in the pressurized water supply line 30, and pressurizes and sends water of a clean water source 32 to respective jetting nozzles 24a-24c as pressurized water. The respective jetting nozzles 24a-24c are disposed on the bottom 16 of the grit pit 12, and jet the pressurized water toward a sand collection pit 14. The return line 38 is branched from a main line 30a of the pressurized water supply line 30, and returns at least part of the pressurized water sent from the high pressure pump P2 to the clean water source 32. Thus, the flow rate of the pressurized water jetted from the respective jetting nozzles 24a-24c is reduced, to reduce a flow speed of the pressurized water. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sand collection facility and a sand collection method.

  A sand settling tank provided in a water purification plant, a sewage treatment plant, etc. is for removing sedimentary substances (for example, sand), cans, vinyl, etc. contained in raw water from the raw water. Below, the sedimentary substance deposited on the bottom of the sand settling tank is referred to as sand settling. Conventionally, a sand settling facility that effectively removes sand settling at the bottom of a sand settling tank is known (see, for example, Patent Document 1).

In this sand settling facility, pressure water is jetted from a jet nozzle provided at the bottom, and the sand settling in front of the jet nozzle is swept away to collect sand settling in a sand collecting pit. Then, the settling sand collected in the sand collecting pit is discharged out of the settling tank by a jet pump.
Japanese Patent Laid-Open No. 2004-122042

  By the way, in the conventional sand settling equipment, the injection valve is provided in the pressure water supply line connecting the clarified water source and the injection nozzle, and the injection of the pressure water from the injection nozzle is started by opening or closing this injection valve. Or it has stopped. Therefore, when the opening of the injection valve is opened or closed, the opening of the injection valve gradually increases or decreases, so that the flow rate of the pressure water injected from the injection nozzle increases, and the sedimentation rises. There was a problem.

  An object of the present invention is to provide a sand collecting facility capable of suppressing the occurrence of sand soaking.

  A sand collection facility according to the present invention is a sand collection facility for collecting deposits accumulated at the bottom of a sand settling tank in which raw water is retained in a sand collection pit, and is disposed at the bottom of the sand settling tank and is disposed on the sand collection pit side. An injection nozzle that injects pressure water toward the water, a pressure water pump that compresses the water of the clarified water source and sends it as pressure water to the injection nozzle, and the clarified water source and the injection nozzle are connected via the pressure water pump to inject A pressure water supply line for supplying pressure water to the nozzle, and at least a part of the pressure water branched from the pressure water supply line between the pressure water pump and the injection nozzle of the pressure water supply line and sent from the pressure water pump. And a return line for returning to the source of clarified water.

  In the sand collecting facility according to the present invention, at least a part of the pressure water is returned to the clarified water source by the return line. Therefore, the flow rate of the pressure water ejected from the ejection nozzle is reduced, and the flow rate of the pressure water ejected from the ejection nozzle is reduced. As a result, it is possible to suppress the rising of the sand. Moreover, since the water returned to the clarified water source by the return line can be used again as the pressure water, the amount of water used as the clarified water source can be reduced.

  The return line is preferably provided with a throttle means for restricting the flow path of the return line. If it does in this way, according to the opening degree of a throttle means, the flow volume of the pressure water which returns to a clarified water source through a return line will be adjusted. Therefore, it is possible to further suppress the rising of the sand by adjusting the opening of the throttle means so that the flow rate of the pressure water ejected from the ejection nozzle is constant.

  Moreover, it is preferable to provide a control means for controlling the opening degree of the throttle means. In this way, the opening degree of the throttle means can be adjusted by the control means.

  Also, a measuring means for measuring the thickness of the deposit between the sand collecting pit and the injection nozzle is provided, and the control means controls the opening degree of the throttle means according to the thickness of the deposit measured by the measuring means. It is preferable to do. As described above, the control unit adjusts the opening degree of the throttle unit according to the thickness of the deposit, whereby the injection amount of the pressure water from the injection nozzle is controlled. As a result, when the deposit is thin, the amount of pressure water returned to the clear water source is increased by increasing the opening of the throttle means, and the deposit is made into a sand collection pit while suppressing the rising of the sedimentation. It becomes possible to collect. On the other hand, when the deposit is thick, it is possible to effectively collect the deposit in the sand collection pit by reducing the amount of pressure water returned to the clarified water source by reducing the opening of the throttle means. It becomes.

  The measuring means includes a sensor unit that detects the thickness of the deposit, and a lifting unit that raises and lowers the sensor unit in the depth direction of the sand basin, and the sensor unit projects light, and In order to receive the light projected from the light projecting unit, the light projecting unit includes a plurality of sensors configured to face the light projecting unit, and the plurality of sensors are sand sink tanks in the sensor unit. It is preferable that they are arranged in an array in the depth direction. In this way, when the sensor unit is lowered, the light emitted from the light projecting unit is received by the light receiving unit in the sensor located above the deposit, while the sensor buried in the deposit is The light projected from the light projecting unit is blocked by the deposits and hardly reaches the light receiving unit. As a result, it is possible to determine whether or not the thickness of the deposit is a predetermined thickness corresponding to a preset threshold value depending on the number of sensors having an input signal.

  By the way, when the opening of the flow path of the pressure water supply line gradually increases when the pressure water is injected from the injection nozzle, or when the injection of the pressure water by the injection nozzle is terminated, the flow path of the pressure water supply line is opened. When the degree gradually decreases, the pressure water pressure in the pressure water supply line and the return line increases, and the flow rate of the pressure water ejected from the ejection nozzle increases, and the deposit g tends to rise. .

  Therefore, it is preferable that the control means controls the opening degree of the throttling means in accordance with information relating to the pressure level of the pressure water returned to the clear water source by the return line. In this way, the control means adjusts the opening of the throttle means in accordance with the information regarding the magnitude of the pressure water pressure returned to the clear water source by the return line, thereby controlling the injection amount of the pressure water from the injection nozzle. The As a result, when the pressure water pressure in the return line increases, the throttle means is controlled by the control means so as to increase the opening of the throttle means, and the pressure water returned to the clarified water source through the return line. By increasing this amount, it is possible to adjust the opening of the throttle means so that the flow rate of the pressure water injected from the injection nozzle is constant while suppressing the soaking of the deposit.

  On the other hand, in the sand collecting method according to the present invention, the spray nozzle disposed at the bottom of the sand settling tank and the clarified water source are connected by a pressure water supply line, and the compressed clarified water source water is sprayed from the spray nozzle as pressure water. A sand collecting method for collecting sediment deposited at the bottom in a sand collecting pit, and a throttling means provided in a return line that branches from the pressure water supply line and returns at least part of the pressure water to the clarified water source The flow of the return line, the step of injecting the pressure water from the injection nozzle after opening the flow path of the return line, and the end of the injection of the pressure water by the injection nozzle And a step of opening the flow path.

  In the sand collecting method according to the present invention, before the step of injecting the pressure water from the injection nozzle, the throttle means is controlled to open the flow path of the return line, and when the injection of the pressure water by the injection nozzle is finished, The flow path is open. Therefore, when the pressure water is injected from the injection nozzle, the opening degree of the flow path of the pressure water supply line gradually increases, or when the injection of the pressure water by the injection nozzle is finished, the opening degree of the flow path of the pressure water supply line Even if the pressure gradually decreases, the pressure water is returned to the clarified water source by the return line, so the flow rate of the pressure water injected from the injection nozzle decreases and the flow rate of the pressure water injected from the injection nozzle decreases. . As a result, it is possible to suppress the rising of the sand. Moreover, since the water returned to the clarified water source by the return line can be used again as the pressure water, the amount of water used as the clarified water source can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the sand collection equipment which can suppress generation | occurrence | production of the rising of a sedimentation can be provided.

  Preferred embodiments of the present invention will be described with reference to the drawings. Note that in the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

(First embodiment)
With reference to FIG.1 and FIG.2, the structure of 22 A of sand collection facilities provided in the sand basin equipment 10 and the sand basin equipment 10 is demonstrated. FIG. 1 is a side cross-sectional view illustrating a sand basin facility including a sand collection facility according to the first embodiment. FIG. 2 is a top view showing a sand basin facility including the sand collecting facility according to the first embodiment.

  The settling basin facility 10 is a facility for removing sedimentary substances such as sand contained in the raw water to be treated and introducing the water from which sedimentary substances have been removed into the subsequent process as pretreatment water. For example, a water purification plant Applicable to sewage treatment plants. The settling basin facility 10 includes a settling basin (sand settling tank) 12 for retaining raw water. In the settling basin facility 10, raw water (for example, sewage or mixed water of sewage and rainwater) flowing in from a water intake facility or the like (not shown) disposed on the upstream side of the settling basin 12 passes through the raw water inflow line L1. It flows continuously into the sand basin 12 through it. Hereinafter, the inflow direction of raw water into the sand basin 12 in the raw water inflow line L1 (direction of arrow A shown in FIGS. 1 and 2) is referred to as the longitudinal direction of the sand basin 12, and is orthogonal to the longitudinal direction of the sand basin 12. This direction is referred to as the width direction of the sand basin 12, and the depth direction of the sand basin 12 is referred to as the vertical direction of the sand basin 12.

  A screen S is attached to the raw water inflow line L1 side of the sand basin 12. The screen S removes relatively large suspended matters such as cans, vinyl, and cloth contained in the raw water from the raw water.

  A sand collection pit 14 is formed in the sand basin 12 and is arranged on the inflow side (upstream side) of the raw water. The sand collecting pit 14 has a concave shape that is recessed from the bottom 16 of the sand basin 12. On the downstream side of the sand collecting pit 14, a deposition region 18 is provided for depositing a sedimentary substance having a relatively large particle size such as sand contained in the incoming raw water.

  A plurality (three in the first embodiment) of stepped steps 18a to 18c are formed in the deposition region 18, and the height of these steps 18a to 18c increases toward the downstream side. Are getting higher. Therefore, the flow rate of the raw water flowing in from the raw water inflow line L1 gradually decreases as it goes downstream, and the sedimentary substance contained in the raw water settles as the flow rate of the raw water decreases. Accordingly, the sedimentary substance is deposited as a deposit g on each step 18 a to 18 c of the deposition region 18 that is the bottom 16 of the sand basin 12.

  Further, in the sand basin 12, a pump well 20 is formed on the downstream side of the sedimentation region 18 for retaining treated water after passing through the sedimentation region 18 and settling of the sedimentary substance as pretreatment water. The pump well 20 has a concave shape that is recessed from the bottom 16. The pretreated water staying in the pump well 20 is discharged by the pretreated water discharge pump P1 and the pretreated water discharge line L2, and is introduced into a post facility (not shown) disposed on the downstream side of the sand basin 12. .

  Further, the sand basin facility 10 includes a sand collection facility 22 </ b> A that collects the deposit g accumulated in the step portions 18 a to 18 c of the deposition region 18 in the sand collection pit 14. The sand collecting facility 22A includes first to third injection nozzle groups 24A to 24C, a jet pump 26, and a control device (control means) 28.

  Each injection nozzle group 24A-24C is each arrange | positioned at each step part 18a-18c along the inflow direction of raw | natural water. Each of the injection nozzle groups 24 </ b> A to 24 </ b> C has a plurality of injection nozzles 24 a to 24 c arranged in parallel in the width direction of the sand basin 12. Each of the injection nozzles 24 a to 24 c is arranged so that the injection port faces the sand collecting pit 14.

  Each of the injection nozzle groups 24 </ b> A to 24 </ b> C is connected to a clarified water source 32 by a pressure water supply line 30. As the clarified water source 32, for example, clarified water stored in a water tank or pretreated water of the pump well 20 can be used. The pressure water supply line 30 includes a main line 30a and branch lines 30b to 30d branched from the main line 30a and connected to the injection nozzle groups 24A to 24C, respectively.

  The main line 30a is provided with a high-pressure pump (pressure water pump) P2 on the clarified water source 32 side that compresses the water (clarified water) of the clarified water source 32 and sends it as pressure water to each of the injection nozzle groups 24A to 24C. . The branch lines 30b to 30c are provided with first to third motor-operated valves 34A to 34C on the main line 30a side, respectively. Therefore, by opening each of the first to third motor operated valves 34A to 34C, the pressure water is jetted toward the sand collecting pit 14 from the jet ports of the jet nozzles 24a to 24c in the jet nozzle groups 24A to 24C. The sediment g is collected in the sand collecting pit 14 by the pressure water.

  Here, a return line 38 branched from the main line 30 a of the pressure water supply line 30 is connected to the pressure water supply line 30. The return line 38 is connected to the clarified water source 32, and returns the pressure water flowing through the main line 30a sent from the high-pressure pump P2 to the clarified water source 32. The return line 38 is provided with a return valve (throttle means) 40 that is an electric valve. Therefore, a part of the pressure water flowing through the main line 30a is returned to the clarified water source 32 by opening the return valve 40, and the flow path of the return line 38 is blocked by closing the return valve 40. .

  The jet pump 26 is arranged so that the suction port 26 a is located in the sand collecting pit 14. The jet pump 26 is connected to the main line 30a of the pressure water supply line 30, and sucks the deposit g in the sand collection pit 14 using the pressure water flowing through the main line 30a sent from the high pressure pump P2. Can be done. The deposit g sucked by the jet pump 26 is discharged out of the sand basin facility 10 through the deposit discharge line L3. If the sediment g can be discharged from the sand collection pit 14, a sand pumping device other than the jet pump 26 can be used.

  The control device 28 is connected to the high-pressure pump P2, the jet pump 26, the electric valves 34A to 34C, and the return valve 40, and drives the high-pressure pump P2 and the jet pump 26 and the electric valves 34A to 34C and the return valve 40. Controls opening and closing.

  Then, with reference to FIG. 3, operation | movement of the sand collection equipment 22A which has the structure mentioned above is demonstrated. FIG. 3 is a flowchart showing an operation procedure from the start of operation to the end of operation of the sand collecting facility according to the first embodiment. Note that step is abbreviated as S in FIG. 3 and FIGS.

  First, in the initial state in which the high-pressure pump P2 and the jet pump 26 are stopped and the motor-operated valves 34A to 34C and the return valve 40 are closed, the sand collecting facility 22 provided in the sand settling basin facility for collecting sand. Start driving. When the operation of the sand collecting facility 22A is started, the process proceeds to step 100, where the control device 28 instructs the return valve 40 to open the return valve 40. Then, it progresses to step 102, the control apparatus 28 instructs | commands the high pressure pump P2, starts the drive of the high pressure pump P2, compresses the water of the clarified water source 32, and sends it out to the pressure water supply line 30 as pressure water. At this time, since all the motor-operated valves 34A to 34C are closed and the return valve 40 is opened, the pressure water sent from the high-pressure pump P2 is returned to the clarified water source 32 through the return line 38. It becomes.

  Subsequently, when the control device 28 determines that the return valve 40 has been opened to a preset opening degree, the process proceeds to step 104, where the control device 28 instructs the jet pump 26 to drive the jet pump 26, and collects sand. The deposit g in the pit 14 is discharged. Subsequently, the routine proceeds to step 106 where the control device 28 instructs the third motor operated valve 34C to open the third motor operated valve 34C. At this time, when the third electric valve 34C is opened, the pressure water sent from the high pressure pump P2 passes through the pressure water supply line 30 (the main line 30a and the branch line 30d), and each injection nozzle in the injection nozzle group 24C. It will be injected from 24c. When the control device 28 determines that a predetermined time (for example, 30 seconds) has elapsed since the opening of the third motor operated valve 34C, the process proceeds to step 108, and the control device 28 instructs the third motor operated valve 34C. The third motor operated valve 34C is closed. As a result, the deposit g on the step portion 18c is washed away toward the sand collecting pit 14, and the deposit g is hardly deposited on the step portion 18c.

  Subsequently, the routine proceeds to step 110, where the control device 28 instructs the second motor operated valve 34B to open the second motor operated valve 34B. At this time, when the second motor-operated valve 34B is opened, the pressure water sent from the high-pressure pump P2 passes through the pressure water supply line 30 (the main line 30a and the branch line 30c), and each injection nozzle in the injection nozzle group 24B. It will be injected from 24b. When the control device 28 determines that a predetermined time (for example, 30 seconds) has elapsed since the opening of the second motor operated valve 34B, the process proceeds to step 112, and the control device 28 instructs the second motor operated valve 34B. The second motor operated valve 34B is closed. As a result, the deposit g on the step portion 18b is pushed toward the sand collecting pit 14 and the deposit g is hardly deposited on the step portion 18b. In order to keep the pressure water pressure in the pressure water supply line 30 constant, it is preferable to open the second motor-operated valve 34B simultaneously with the closing of the third motor-operated valve 34C in step 108.

  Subsequently, the routine proceeds to step 114 where the control device 28 instructs the first motor operated valve 34A to open the first motor operated valve 34A. At this time, when the first electric valve 34A is opened, the pressure water sent from the high pressure pump P2 passes through the pressure water supply line 30 (the main line 30a and the branch line 30b), and each injection nozzle in the injection nozzle group 24A. It will be injected from 24a. When the control device 28 determines that a predetermined time (for example, 30 seconds) has elapsed since the opening of the first motor operated valve 34A, the process proceeds to step 116, and the control device 28 instructs the first motor operated valve 34A. The first electric valve 34A is closed. As a result, the deposit g on the step portion 18a is washed away toward the sand collecting pit 14, and the deposit g is hardly deposited on the step portion 18a. In order to keep the pressure water pressure in the pressure water supply line 30 constant, it is preferable to open the first electric valve 34A simultaneously with the closing of the second electric valve 34B in step 112.

  Then, it progresses to step 118, the control apparatus 28 drives the jet pump 26, and discharges the deposit g collected in the sand collection pit 14 by operation | movement of steps 106-116. Subsequently, the process proceeds to step 120, where the control device 28 instructs the high pressure pump P2 to stop driving the high pressure pump P2. Subsequently, the process proceeds to step 122, where the control device 28 instructs the return valve 40 to close the return valve 40, whereby the operation of the sand collecting facility 22A is completed. In order to collect the deposit g in the sand collecting pit 14 more reliably, it is preferable to repeat the operations of steps 106 to 118 three to six times.

  As described above, in the first embodiment, the sand collecting facility 22A includes the return line 38 that returns at least part of the pressure water sent from the high-pressure pump P2 to the clarified water source 32. Therefore, by returning the pressure water to the clarified water source 32 by the return line 38, the flow rate of the pressure water injected from each of the injection nozzles 24a to 24c in each of the injection nozzle groups 24A to 24C decreases, and each of the injection nozzles 24a to 24a. The flow rate of the pressure water injected from 24c becomes small. As a result, it is possible to suppress the rising of the sand. Moreover, since the water returned to the clarified water source 32 by the return line 38 can be used again as pressure water, the amount of water used by the clarified water source 32 can be reduced. Furthermore, even if all the motor-operated valves 34 </ b> A to 34 </ b> C are closed, the pressure water is returned to the clarified water source 32 by the return line 38, thereby reducing the pressure fluctuation range of the pressure water in the pressure water supply line 30. Become. Therefore, it becomes possible to reduce the operation load of the high-pressure pump P2.

  In the first embodiment, the return valve 40 is opened before the motor-operated valves 34A to 34C are opened, and the return valve 40 is opened when the motor-operated valves 34A to 34C are closed. Therefore, when the motor-operated valves 34A to 34C are opened, the opening degree of the motor-operated valves 34A to 34C is gradually increased, or when the motor-operated valves 34A to 34C are closed, the motor-operated valves 34A to 34C are gradually opened. Even in this case, since the pressure water is returned to the clarified water source 32 by the return line 38, the flow rate of the pressure water injected from each of the injection nozzles 24a to 24c decreases, and the pressure water injected from each of the injection nozzles 24a to 24c. The flow rate is reduced. As a result, it is possible to suppress the rising of the sand.

(Second Embodiment)
Then, with reference to FIGS. 4-8, the structure of the sand collection equipment 22B with which the sand basin equipment 10 was equipped is demonstrated. FIG. 4 is a side sectional view showing a sand basin facility equipped with a sand collecting facility according to the second embodiment, and FIG. 5 is a top view showing a sand basin facility equipped with a sand collecting facility according to the second embodiment. 6 is a longitudinal sectional view showing a measuring device for sand collecting equipment according to the second embodiment, FIG. 7 is a perspective view of a sensor unit, and FIG. 8 is a sectional view taken along line VIII-VIII in FIG. The sand collecting facility 22B according to the second embodiment is different from the sand collecting facility 22A according to the first embodiment in that a measuring device (measuring unit) 100 is provided. Below, it demonstrates centering on difference with the sand collection equipment 22A which concerns on 1st Embodiment, and the overlapping description is abbreviate | omitted.

  The measuring device 100 measures the thickness of the deposit g in the step portion 18a. Therefore, the measuring device 100 is the most upstream (FIG. 4) among the injection nozzles 24a to 24c respectively disposed in the step portions 18a to 18c along the inflow direction of raw water (the direction of arrow A in FIGS. 4 and 5). In addition, it is provided in front of the injection nozzle 24a located on the leftmost side in FIG.

  As illustrated in FIG. 6, the measuring device 100 includes a protective tube 102, a housing tube 104, a driving unit 106, and a measuring unit 108. The protective tube 102 is a tubular member that is shorter than the length of the sand basin 12 in the vertical direction, and the accommodating tube 104 is disposed therein. The protective tube 102 is attached to the side wall portion 12a of the sand basin 12 via the supports s1 and s2 so that the upper end portion is higher than the water surface in order to prevent the raw water from flowing into the protective tube 102 from the upper end portion. It has been. Therefore, the housing tube 104 is protected from the raw water flow and the like by the protective tube 102.

  The storage tube 104 is a tubular member that extends in the vertical direction of the sand basin 12, and holds a measurement unit 108 therein.

  The drive unit 106 is connected to the upper end portion of the storage tube 104 via a shaft 106 a, and is driven by the control device 28 to serve as a lifting unit that moves the storage tube 104 in the vertical direction of the sand basin 12. . The drive part 106 is attached to the upper part of the side wall part 12a in the sand basin 12 via the support s3.

  The measuring unit 108 includes a connecting part 110 that extends in the vertical direction of the sand basin 12 and a sensor part 112 that is connected to the storage tube 104 via the connecting part 110.

  As shown in FIGS. 7 and 8, the sensor unit 112 includes a bar-like member 114 extending in the vertical direction and a sensor control unit 116 provided on the upper part of the bar-like member 114. The rod-shaped member 114 is formed with a recess 118 that is recessed inward of the one side surface (surface) 114a along the vertical direction. The recess 118 has side surfaces 118a and 118b facing each other, and a plurality of light projectors (light projecting units) 120 are arranged in the vertical direction at regular intervals inside the one side surface 118a. In the interior of 118b, light receivers (light receiving portions) 122 are arranged in the vertical direction at regular intervals so as to face the projectors 120, respectively. One sensor 124 is configured by the projector 120 and the light receiving unit 122 disposed at a position facing the projector 120 in order to receive the light L projected from the projector 120. Therefore, the sensor unit 112 has a plurality of sensors 124 arranged in parallel (in an array) along the vertical direction. As the projector 120, a semiconductor laser or a light emitting diode that emits light L of visible light, infrared light, or ultraviolet light can be used. As the light receiver 122, a photodiode or the like can be used.

  The sensor control unit 116 controls the operation of each sensor 124 and drives each projector 120 and each light receiver 122. The light receiving state (the magnitude of the signal intensity obtained by receiving light) in each light receiver 122 is converted into an electric signal, and the electric signal is transmitted from the sensor control unit 116 to the control device via a wiring line provided in the cable 126. 28 is output.

  In the measuring apparatus 100 configured as described above, when the storage tube 104 is lowered, a part of the sensor unit 112 (rod-like member 114) is inserted into the deposit g as shown in FIG. It becomes. Therefore, when the sensor 124 is buried in the deposit g, the light L projected from the projector 120 that constitutes the sensor 124 is blocked or absorbed by the deposit g, and the light receiver that constitutes the sensor 124. It becomes difficult to reach 122. Since more sensors are embedded in the deposit g when the deposit g is thick as shown in FIG. 10 than when the deposit g is thin as shown in FIG. The thickness of the deposit g can be measured by the number of sensors that no longer receive the light L. Here, the state in which the light receiver 122 no longer receives the light L from the projector 120 includes a state in which the magnitude of the signal intensity obtained by the light receiver 122 receiving the light L is smaller than a predetermined threshold value. It is.

  Then, when the control device 28 determines that the thickness of the deposit g measured by the measuring device 100 is thicker than the thickness of the deposit g set in advance, the motor-operated valves 34A to 34C and the jet pump 26 are driven. To control.

  Then, with reference to FIGS. 11-13, operation | movement of the sand collection equipment 22B which has the structure mentioned above is demonstrated. FIG. 11 is a flowchart showing an operation procedure from the start of operation to the end of operation of the sand collecting facility according to the second embodiment, FIG. 12 is a flowchart showing a procedure of the deposit discharge first process, and FIG. 13 is a deposit. It is a flowchart which shows the process sequence of discharge 2nd process.

  When the operation of the sand collecting facility 22B is started, the process proceeds to step 130, where the control device 28 instructs the drive unit 106 of the measuring device 100 to lower the storage tube 104 storing the measuring unit 108 to the bottom 11. Subsequently, the process proceeds to step 132, where the control device 28 instructs the sensor control unit 116 to drive all the sensors 124 of the sensor unit 112, and projects the light L from each light projector 120 toward each light receiver 122. . Subsequently, when proceeding to step 134, it is determined whether or not the number of sensors 124 having an input signal indicating that the light receiver 122 has received the light L from the projector 120 is equal to or smaller than a preset threshold value, that is, the deposit g. The control device 28 determines whether or not the thickness is larger than a preset thickness of the deposit g.

  When the controller 28 determines in step 134 that the number of sensors 124 having an input signal is greater than the threshold value (the thickness of the deposit g is greater than the thickness of the deposit g set in advance), the control device 28 determines in step 136. Then, the deposit discharge first process is started. When the first deposit discharge process is started, the process proceeds to step 140 shown in FIG. 12, and the control device 28 instructs the drive unit 106 of the measurement device 100 to protect the storage tube 104 in which the measurement unit 108 is stored. Raise to accommodate within tube 102. Subsequently, the routine proceeds to step 142 where the control device 28 instructs the return valve 40 to open the return valve 40. Then, it progresses to step 144, the control apparatus 28 instructs | commands the high pressure pump P2, starts the drive of the high pressure pump P2, compresses the water of the clarified water source 32, and sends it out to the pressure water supply line 30 as pressure water.

  Subsequently, the process proceeds to step 146, where the control device 28 instructs the jet pump 26 to drive the jet pump 26 and discharges the deposit g in the sand collecting pit 14. Subsequently, the process proceeds to step 148, where the control device 28 instructs the first motor operated valve 34A to open the first motor operated valve 34A and injects the pressure water from each of the injection nozzles 24a in the injection nozzle group 24A. The deposit g on the portion 18a is pushed away to the sand collecting pit 14 side. When the controller 28 determines that a predetermined time (for example, 30 seconds) has elapsed since the opening of the first motor operated valve 34A, the process proceeds to step 150, and the controller 28 instructs the first motor operated valve 34A. The first electric valve 34A is closed. Subsequently, the process proceeds to Steps 152 and 154, and the second motor-operated valve 34B is opened and closed in the same manner as Steps 148 and 152, and pressure water is injected from each of the injection nozzles 24b in the injection nozzle group 24B. The upper deposit g is pushed away to the sand collecting pit 14 side. Then, it progresses to step 156,158, the 3rd motor operated valve 34C is opened and closed similarly to step 148,152 and step 154,156, and pressure water is injected from each injection nozzle 24c in the injection nozzle group 24C. As a result, the deposit g on the stepped portion 18c is washed away to the sand collecting pit 14 side. As a result, the deposit g on the step portion 18c is washed away toward the sand collecting pit 14, and the deposit g is hardly deposited on the step portion 18c.

  Subsequently, the process proceeds to step 160, where the control device 28 instructs the jet pump 26 to drive the jet pump 26, and the deposit g in the sand collecting pit 14 is discharged. Subsequently, the routine proceeds to step 162, where the control device 28 instructs the first motor operated valve 34A to open the first motor operated valve 34A and injects the pressure water from each injection nozzle 24a in the injection nozzle group 24A. The deposit g on the portion 18a is pushed away to the sand collecting pit 14 side. When the control device 28 determines that a predetermined time (for example, 30 seconds) has elapsed since the opening of the first motor operated valve 34A, the process proceeds to step 164, and the control device 28 instructs the first motor operated valve 34A. The first electric valve 34A is closed. Subsequently, the process proceeds to Steps 166 and 168, and the second motor-operated valve 34B is opened and closed in the same manner as Steps 162 and 164, and pressure water is injected from each of the injection nozzles 24b in the injection nozzle group 24B, thereby causing the step portion 18b. The upper deposit g is pushed away to the sand collecting pit 14 side. As a result, the deposit g on the step portion 18b is pushed toward the sand collecting pit 14 and the deposit g is hardly deposited on the step portion 18b.

  Subsequently, the process proceeds to step 170, where the control device 28 instructs the jet pump 26 to drive the jet pump 26, and the deposit g in the sand collecting pit 14 is discharged. Subsequently, the process proceeds to step 172, where the control device 28 instructs the first motor operated valve 34A to open the first motor operated valve 34A and injects the pressure water from each injection nozzle 24a in the injection nozzle group 24A. The deposit g on the portion 18a is pushed away to the sand collecting pit 14 side. When the control device 28 determines that a predetermined time (for example, 30 seconds) has elapsed since the opening of the first motor operated valve 34A, the process proceeds to step 174, and the control device 28 instructs the first motor operated valve 34A. The first electric valve 34A is closed. As a result, the deposit g on the step portion 18a is washed away toward the sand collecting pit 14, and the deposit g is hardly deposited on the step portion 18a.

  Subsequently, the process proceeds to step 176, where the control device 28 drives the jet pump 26 to discharge the deposit g in the sand collecting pit 14. Subsequently, the routine proceeds to step 178, where the control device 28 instructs the high pressure pump P2 to stop driving the high pressure pump P2. Subsequently, the process proceeds to step 180 where the control device 28 instructs the return valve 40 to close the return valve 40, whereby the first sediment discharge process is completed, and the operation of the sand collecting facility 22B is completed. In order to collect the deposit g in the sand collecting pit 14 more reliably, it is preferable to repeat the operations of steps 148 to 176 3 to 6 times.

  On the other hand, when the control device 28 determines that the number of sensors 124 having an input signal is equal to or less than a threshold value (the thickness of the deposit g is equal to or less than a preset thickness of the deposit g), FIG. Then, the process proceeds to step 138 where the deposit discharge second process is performed. When the first deposit discharge process is started, the process proceeds to step 182 shown in FIG. 13, and the control device 28 instructs the drive unit 106 of the measurement device 100 to protect the storage tube 104 in which the measurement unit 108 is stored. Raise to accommodate within tube 102. Then, after performing the operation | movement of the same steps 100-122 as 22 A of sand collection facilities which concern on 1st Embodiment, the sediment discharge | emission 2nd process is complete | finished and the driving | operation of the sand collection facility 22B is complete | finished. As a result, the deposit g is collected in the sand collection pit 14, and the deposit g collected in the sand collection pit 14 is discharged out of the sand basin facility 10 by the jet pump 26.

  As mentioned above, in 2nd Embodiment, there exists an effect similar to 22 A of sand collection equipment which concerns on 1st Embodiment.

  Moreover, in 2nd Embodiment, the thickness of the deposit g is measured by the sensor part 112 of the measuring device 100, and the injection of the pressure water from each injection nozzle 24a-24c is carried out by the control apparatus 28 according to the measurement result. The deposit g is discharged while being controlled. Therefore, the rising of the deposit g can be suppressed regardless of the thickness of the deposit g, and the deposit can be collected in the sand collecting pit 14 more reliably. As a result, the deposit g can be discharged from the sand basin 12 efficiently.

  If the control device 28 controls the motor-operated valves 34A to 34C according to the number of sensors 124 buried in the deposit g so as to inject the pressure water from the injection nozzles 24a to 24c, the deposit g This is preferable because it is possible to more effectively suppress the soaring.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments. For example, in the first and second embodiments, the return valve 40 is opened to a preset opening degree before the motor-operated valves 34A to 34C are opened, and the return valve 40 is closed when the motor-operated valves 34A to 34C are closed. Although it is in an open state, it is not limited to this. That is, the opening degree of the return valve 40 may be controlled according to the opening degree of each of the motor operated valves 34A to 34C so that the flow rate of the pressure water injected from each of the injection nozzles 24a to 24c is constant. In this way, it is possible to further suppress the rising of the sand.

  In the first and second embodiments, the flow path of the return line 38 is narrowed by opening and closing the return valve 40 as being particularly suitable. However, such a return valve 40 is not provided and the return line is not provided. An orifice with a constant throttling amount of 38 may be provided, or only the return line 38 may be provided. Further, a constant flow valve or the like may be used as the return valve 40 instead of the electric valve.

  Moreover, in 2nd Embodiment, although the injection of the pressure water from each injection nozzle 24a-24c was controlled by the control apparatus 28 according to the thickness of the deposit g measured by the sensor part 112 of the measuring apparatus 100, it was controlled. The opening degree of the return valve 40 may be controlled by the control device 28 according to the thickness of the deposit g measured by the sensor unit 112 of the measuring device 100. Specifically, when the deposit g is thick, the opening of the return valve 40 is reduced to increase the amount of pressure water injected from each of the injection nozzles 24a to 24c. If it is thin, the return valve 40 may be controlled so that the opening of the return valve 40 is increased to reduce the amount of pressure water injected from each of the injection nozzles 24a to 24c. In this way, when the deposit g is thin, the opening of the return valve 40 is increased and the amount of pressure water returned to the clarified water source 32 is increased, thereby suppressing the soaking of the sediment. g can be collected in the sand collecting pit 14. On the other hand, when the deposit g is thick, the opening of the return valve 40 is reduced to reduce the amount of pressure water returned to the clarified water source 32, thereby effectively depositing the deposit g into the sand collecting pit 14. It becomes possible to collect.

  In the second embodiment, the thickness of the deposit g in the step portion 18a is measured by the measuring device 100. However, the measuring device 100 is also provided in front of the injection nozzle 24c, and the deposit g in the step portion 18c is provided. You may make it measure the thickness of. Further, the measuring device 100 may be provided in front of the injection nozzles 24b and 24c, respectively, and the thickness of the deposit g in the step portions 18b and 18c may be measured. When the flow rate and flow rate of raw water is high due to heavy rain or the like, sedimentary substances such as sand contained in the raw water are likely to accumulate on the downstream side, and the thickness of the deposit g is reduced at the step portion 18a, and the step portion 18c. Then, there exists a possibility that the thickness of the deposit g may become thick. If the thickness of the deposit g becomes too thick as described above, the deposit g may not move even if the pressure water is jetted from the jet nozzle 24c. However, as described above, the measuring device 100 is moved in front of the jet nozzle 24c. However, by arranging the thickness of the deposit g between the sand collection pits 14 at a position where the thickness can be measured, the deposits g of the steps 18a to 18c can be collected in the sand collection pit 14 more reliably. It becomes like this.

  In the second embodiment, the deposit discharge second process is performed when the thickness of the deposit g is equal to or less than the preset thickness of the deposit g. It is not necessary to perform processing. If it does in this way, it will be possible to reduce the amount of water required for collection of the deposit g compared with the case where pressure water is periodically injected from each injection nozzle 24a-24c irrespective of the thickness of the deposit g. Become.

  By the way, when injecting pressure water from each injection nozzle 24a-24c, when the opening degree of the flow path of the pressure water supply line 30 (opening degree of each motor-operated valve 34A-34C) gradually increases, or each injection nozzle 24a. When the opening of the flow path of the pressure water supply line 30 (opening of each motor operated valve 34A to 34C) is gradually reduced when the injection of the pressure water by ˜24c is finished, the pressure water supply line 30 and the return line The pressure water pressure at 38 is increased, the flow rate of the pressure water ejected from each of the ejection nozzles 24a to 24c is increased, and the deposit g is likely to rise.

  Therefore, in the sand collecting facility 22C according to the third embodiment, as shown in FIG. 14, a pressure gauge 200 is provided in the return line 38 of the sand collecting facility 22A according to the first embodiment, and the return measured by the pressure gauge 200 is obtained. The opening degree of the return valve 40 is controlled by the control device 28 in accordance with information on the magnitude of the pressure in the line 38 (for example, the flow rate in the return line 38). As described above, the control device 28 adjusts the opening degree of the return valve 40 according to the information on the pressure level of the pressure water returned to the clarified water source 32 by the return line 38, so that each of the injection nozzles 24a to 24c The injection amount of pressure water is controlled. As a result, when the pressure water pressure in the return line 38 becomes high, the return valve 40 is controlled by the control device 28 so as to increase the opening degree of the return valve 40, and the clarified water source passes through the return line 38. By increasing the amount of pressure water returned to 32, the opening degree of the return valve 40 is adjusted so that the flow rate of the pressure water injected from each of the injection nozzles 24a to 24c is constant while suppressing the rise of the deposit g. It becomes possible to do.

  Any device other than the pressure gauge 200 may be used as long as it can acquire information on the magnitude of the pressure in the return line 38. Further, the measuring device 100 in the sand collecting facility 22B according to the second embodiment is provided in the sand collecting facility 22C, and measurement is performed by the measuring device 100 in addition to the control of the return valve 40 according to the information regarding the magnitude of the pressure of the return line 38. The return valve 40 may be controlled in accordance with the thickness of the deposited g.

It is side surface sectional drawing which shows the sand basin equipment provided with the sand collection equipment which concerns on 1st Embodiment. It is a top view which shows the sand basin equipment provided with the sand collection equipment which concerns on 1st Embodiment. It is a flowchart which shows the operation | movement procedure from the driving | operation start of the sand collection equipment which concerns on 1st Embodiment to the completion | finish of driving | operation. It is side surface sectional drawing which shows the sand basin equipment provided with the sand collection equipment which concerns on 2nd Embodiment. It is a top view which shows the sand basin equipment provided with the sand collection equipment which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows the measuring apparatus of the sand collection equipment which concerns on 2nd Embodiment. It is a perspective view of a sensor part. It is the VIII-VIII sectional view taken on the line of FIG. It is a figure which shows a mode that the thickness of a deposit is measured with a measuring device. It is a figure which shows a mode that the thickness of a deposit is measured with a measuring device. It is a flowchart which shows the operation | movement procedure from the driving | running start of the sand collection equipment which concerns on 2nd Embodiment to an operation completion. It is a flowchart which shows the process sequence of a deposit discharge 1st process. It is a flowchart which shows the process sequence of a deposit discharge 2nd process. It is side surface sectional drawing which shows the sand basin equipment provided with the sand collection equipment which concerns on 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Sand basin equipment, 12 ... Sand basin (sand basin), 14 ... Sand collection pit, 16 ... Bottom part, 22A, 22B, 22C ... Sand collection equipment, 24a-24c ... Injection nozzle, 28 ... Control apparatus (control means) , 30 ... Pressure water supply line, 32 ... Clear water source, 38 ... Return line, 40 ... Return valve (throttle means), 100 ... Measuring device (measuring means), 106 ... Drive part (lifting / lowering means), 112 ... Sensor part, DESCRIPTION OF SYMBOLS 120 ... Light-projection part, 122 ... Light-receiving part, 124 ... Sensor, 200 ... Pressure gauge, g ... Deposit, P2 ... High pressure pump (pressure water pump).

Claims (7)

A sand collection facility that collects sediment deposited at the bottom of a sand settling tank that retains raw water in a sand collection pit,
An injection nozzle that is arranged at the bottom of the sand basin and injects pressure water toward the sand collecting pit side;
A pressure water pump that compresses the water of the clarified water source and sends it as pressure water to the jet nozzle;
A pressure water supply line for connecting the clarified water source and the injection nozzle via the pressure water pump, and supplying pressure water to the injection nozzle;
A return line that branches from the pressure water supply line between the pressure water pump of the pressure water supply line and the injection nozzle and returns at least a part of the pressure water sent from the pressure water pump to the clarified water source; A sand collection facility characterized by comprising.   2. The sand collecting facility according to claim 1, wherein the return line is provided with a throttle means for restricting a flow path of the return line.   The sand collecting facility according to claim 2, further comprising a control unit that controls an opening degree of the throttling unit. Comprising measuring means for measuring the thickness of the deposit between the sand collecting pit and the injection nozzle,
The sand collecting facility according to claim 3, wherein the control means controls the opening degree of the throttling means according to the thickness of the deposit measured by the measuring means. The measuring means includes
A sensor unit for detecting the thickness of the deposit;
Elevating means for elevating the sensor unit in the depth direction of the sand basin,
The sensor unit includes a light projecting unit that projects light, and a light receiving unit disposed to face the light projecting unit in order to receive light projected from the light projecting unit. Have multiple sensors,
The sand collecting facility according to claim 4, wherein the plurality of sensors are arranged in an array in the depth direction of the sand basin in the sensor unit.   The said control means controls the opening degree of the said throttle means according to the information regarding the magnitude | size of the pressure water pressure returned by the said return line to the said clarified water source. The sand collection facility described in the section. The deposit deposited on the bottom by connecting the spray nozzle disposed at the bottom of the sand settling tank and the clarified water source by a pressure water supply line and spraying the compressed water from the clarified water source as pressure water from the spray nozzle. A sand collection method for collecting objects in a sand collection pit,
Controlling the throttle means provided in the return line branched from the pressure water supply line and returning at least part of the pressure water to the clarified water source, and opening the flow path of the return line;
Injecting pressure water from the injection nozzle after opening the flow path of the return line;
And a step of opening the flow path of the return line when the injection of the pressure water by the spray nozzle is finished.

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