JP4380842B2 - Sand lifting equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sand raising device provided in a sand basin such as a rainwater sand basin in a sewage treatment facility.
[0002]
[Prior art]
Conventionally, for example, in a rainwater settling basin of a sewage treatment facility, a trough extending in the water flow direction is provided at the center of the width direction of the sand basin (perpendicular to the water flow direction), and the troughs are the bottom on both the left and right sides of the trough. A small trough extending in the trough direction is provided at a predetermined interval on the inclined surface, and the trough is also inclined so that the center in the water flow direction is the lowest, and sand collecting is performed at the lowest part of the center. A pit is formed, and sand collecting means including a jet pump or a sand pump is provided in the sand collecting pit.
[0003]
Between each small trough, there is a nozzle that ejects pressure water to flow sand accumulated on the bottom toward the trough, and the trough allows the sand in the trough to flow toward the sand collecting pit. A nozzle is provided for ejecting pressure water to be collected.
[0004]
Therefore, when pressure water is simultaneously ejected from the nozzles provided between the small troughs and the nozzles provided in the troughs, the sand accumulated on the bottom surface of the sand basin is collected in the sand collecting pit. The sand in the collecting sand pits, Agesuna means, i.e., by a jet pump or Agesuna pump Ru is transported to a predetermined place. Incidentally, in order to odor or the like kept draining settling basin (dry) state, the total ejection amount of pressure water from the nozzle is always less set than the total emissions of Agesuna means.
[0005]
[Problems to be solved by the invention]
However, in order to collect the sand accumulated on the bottom surface of the sand settling basin in the sand collecting pit, the conventional sand pumping apparatus simultaneously ejects the nozzles provided between the small troughs and the nozzles provided in the troughs. Therefore, the total supply amount of the pressure water is increased, so that there is a disadvantage that a pump having a large pump capacity for supplying the pressure water is required. Further, since the amount of water flowing into the sand collecting pit increases, the capacity of the sanding means such as a jet pump or a sand pump must be increased, and the subsequent post-treatment device such as a sand separator is also large. There was the inconvenience of becoming. Furthermore, when the total amount of pressure water supplied is small, sand accumulates in front of the sand collection pit, which causes a problem of becoming like a weir and reducing sand collection efficiency. In addition, even if there is a large inflow of sediment during heavy rains, and a large amount of sediment has accumulated on the bottom of the sedimentation basin, the total amount of pressure water ejected from the nozzle is to achieve a dry (drainage) condition. Since it is always kept lower than the total discharge of the jet pump or sand pump, the accumulated sediment cannot be guided into the trough, and even if it can be guided into the trough, it may not be able to guide into the sand collecting pit. .
[0006]
Then, this invention was made | formed in order to solve the said fault, Comprising: The objective is to provide the sand collection apparatus which improved sand collection efficiency.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention extends to the bottom surface of a sand basin having an inlet on one end and an outlet on the other end in a direction connecting the inlet and the outlet, A trough having a pit is provided, and a first nozzle that ejects a pressure fluid for flowing sand accumulated on the bottom surface of the sand basin toward the trough, and the sand collected in the trough to the sand collecting pit A sand pumping device provided with a second nozzle for ejecting a pressure fluid for flowing toward the sand collecting pit, and transporting sand collected in the sand collecting pit by sand pumping means operated intermittently based on a water level gauge , the first nozzle and second nozzle, also used as a multi Kunar than transferring the total amount of said Agesuna means each ejection amount, the by ejection from the first nozzle and second nozzle sand when the water level of the pond has exceeded the Tokoro Teimizu position, the It is characterized by having a jetting amount adjusting means for adjusting the direction to lose weight the total ejection amount of the first nozzle and the second nozzle to be less than the constant water level.
Pressure water is raised as the pressure fluid. The sand lifting means also includes a mechanical pumping equipment such as a jet pump, a sand pump, or a crane.
[0008]
In a preferred example of the present invention, the predetermined water level is set to a water level for returning and maintaining the sand basin in a drained (dry) state. In another preferred example of the present invention, the ejection amount adjusting means includes a water level meter that measures the water level of the sand basin, and an automatic control that opens and closes the valves of the first nozzle and the second nozzle according to the measured value of the water level meter. It consists of a valve controller. Further, the ejection amount adjusting means is characterized by comprising a timer that calculates the opening time by calculating based on the total ejection amount of each of the first nozzle and the second nozzle and the volume of the sand basin. . Further, the ejection amount adjustment means measures the total ejection amount of each of the first nozzle and the second nozzle and the transfer amount of the sand lifting means, and compares and calculates both measurement values to output an ejection amount adjustment signal. It is characterized by that.
In order to achieve the above object, the present invention divides the bottom surface of the sand basin into a plurality of regions in the longitudinal direction of the trough, and installs the first nozzle for each region, the first nozzle and the second nozzle And a drive control means for alternately driving and are added.
In addition, in order to achieve the above object, the present invention is characterized in that drive control means for driving the first nozzle in the order from the area far from the sand collecting pit to the area far from the sand collecting pit is added. Here, the drive control means for driving the first nozzle in the order from the area close to the sand collection pit to the area far from the sand collection pit is driven in order from the nozzle closest to the sand collection pit in units of nozzle groups divided for each of a plurality of nozzles. Drive control means for driving, or drive control means for driving the nozzle groups and nozzles in order from the closest to the pit.
[0009]
Here, to eject the pressure fluid so that the sand accumulated on the bottom of the sand basin flows out toward the sand collecting pit, a trough connected to the sand collecting pit is provided and the sand accumulated on the bottom is poured. This refers to a type in which a pressure fluid such as water is ejected toward the trough and sand is discharged into the sand collecting pit via the trough, or a pressure fluid such as water is directly ejected toward the sand collecting pit. Further , adjusting the total amount of pressure fluid ejected from the first nozzle and the second nozzle so as to be equal to or lower than a predetermined water level includes not ejecting from the nozzle at all . In addition, the transfer Okuryou, when it is transported from a plurality of Agesuna means is its total transfer amount.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a sand pumping apparatus according to the present invention applied to a rainwater settling basin (hereinafter referred to as “sedimentation basin”) of a sewage treatment facility. FIG. 1 is a sectional view thereof, FIG. 2 is a partial plan view thereof, FIG. 3 is a cross-sectional view taken along the line II in FIG. 2, and FIG. 1 corresponds to the cross-sectional view taken along the line in FIG. FIG. 4 is an overall plan view centering on the arrangement of the nozzle group of the sand basin, and FIGS. 5A and 5B are time charts showing the driving state of the nozzle group and the like.
[0011]
In the same manner as the conventional sand basin described above, the sand basin 1 is configured such that rainwater flows from one side of the sand basin 1 and the rainwater settled and separated from the sand flows out from the other side of the sand basin 1. If it demonstrates using the top view of FIG. 2, if rainwater flows in from the upper side of FIG. 2, the rainwater which settled-separated the sand will flow out from the lower side of FIG. Further, using the plan view of FIG. 4, if rainwater flows in from the left side (or right side) of FIG. 4, the rainwater settled and separated from the sand flows out from the right side (or left side) of FIG. 4. It becomes.
[0012]
Returning to FIG. 1, the shape of the bottom surface 1 a of the sand basin 1 is provided with a trough 3 extending in the water flow direction at the center of the width direction (perpendicular to the water flow direction) of the sand basin, as shown in FIG. The bottom surfaces of the left and right sides of the trough are inclined so that the trough 3 is lowest, and the bottom surface of the trough 3 has a flat bottom that is lower than the bottom surface 1a provided at a substantially central position in the longitudinal direction of the trough. It is formed so that sand (not shown) on 1a can be collected. Further, as shown in FIG. 3, the trough 3 is inclined forward and backward in the water flow direction so that the sand collecting pit 2 portion is lowest. Therefore, when the water on the bottom surface 1a having a slip shape flows out of a nozzle to be described later, the sand is collected in the sand collecting pit 2 as indicated by an arrow in FIG.
[0013]
The sand pump 10 is a known submersible pump having spiral blades, and a pump that has been used as a submersible sludge pump in a sewage treatment facility can be used. The sand pump 10 has the suction port 11 facing downward, that is, the suction port 11 faces the bottom surface of the sand collecting pit 2 and is spaced from the bottom surface via a discharge pipe 12 and a support 13. It is provided in the settling basin 1. The sand pump 10 is started when it detects that the water level has risen to the operating water level by a water level meter (not shown) provided in the sand collecting pit 2 and stops when the water has been pumped to the stop water level. Be controlled.
[0014]
FIG. 4 shows the nozzles disposed on the bottom surface 1a of the sand basin 1. A plurality of nozzles n, n... Are connected to one header pipe on both the left and right sides of the sand basin 1 in the water flow direction. A plurality of nozzle groups H1 to H8 are provided. As described above, the bottom surface of the sand basin is appropriately divided into a number of regions depending on the size, and sand collection is performed in units of nozzle groups installed in each region as will be described later. The nozzles n, n... Provided in the header pipes are provided at predetermined intervals, and the injection direction of the nozzles n, n... Is in a direction orthogonal to the longitudinal direction of the trough 3. Is provided. A nozzle group constituted by a plurality of nozzles n, n... Corresponds to the first nozzle of claim 1 of the present invention.
[0015]
4 and FIGS. 1 to 3 are omitted for the sake of simplification, but the bottom surface 1a between the nozzles n, n... In FIG. There is a small trough. When such a small trough is provided on the bottom surface 1a, when pressure water is ejected from the nozzle n, sand on the bottom surface 1a can be efficiently poured into the trough 3 through the small trough. There is.
[0016]
In FIG. 4, N1 and N2 are nozzles, which are provided at both ends of the trough 3, that is, opposite to the sand collecting pit 2, respectively, and when the pressure water is ejected from the nozzles N1 and N2, 3 is configured to be able to flow sand in the sand collecting pit 2. The nozzle N1 and the nozzle N2 correspond to the second nozzle of claim 1 of the present invention, but are not necessarily provided in the trough 3, as shown in the figure. You may provide in a side wall.
[0017]
In FIG. 4, N3 and N4 are also the same nozzles as the nozzles N1 and N2, and the walls on both sides in the direction perpendicular to the water flow direction of the sand basin 1 where the sand collecting pit 2 is located (on the upper side in FIG. 4 (a)). , Lower wall) side. And when pressure water is ejected from these nozzles N3 and N4, the sand located on both sides of the sand collecting pit 2 can be gathered together in the sand collecting pit 2.
[0018]
Although omitted in FIG. 4, each of the nozzle groups H1 to H8 and nozzles N1 to N4 configured by connecting a plurality of nozzles to one header pipe is connected to the sand basin 1 or the like via a pump (not shown). The water of the illustrated pump well is configured to be supplied, and water is arbitrarily supplied to each of the nozzle groups H1 to H8 and the nozzles N1 to N4 via an automatic valve (not shown) driven and controlled by a controller described later. It is configured so that it can be supplied.
[0019]
Next, the control operation time chart Agesuna pump 10 using, Roh nozzle N1 Ru Ah in nozzle group H1 ～H8 and the second nozzle is a first nozzle, N2, N3, N4 in FIGS. 5 (a) Nitsu And explain. Although not shown, the pump and automatic valve for supplying pressure water to the sand pump 10, nozzles N1 to N4 and nozzle groups H1 to H8 are mainly composed of a programmable controller that controls the sand basin 1 in an integrated manner. The drive is controlled by a controller (not shown).
[0020]
Assume that the inflow of rainwater into the sand basin 1 is stopped by a gate or an air dam (not shown), and a process of discharging the sediment deposited on the bottom surface of the sand basin 1 has arrived. Due to this arrival, the sand pump 10 is driven.
[0021]
In addition, when the disturbance means which consists of the nozzle which ejects a pressure water is provided under the suction port 11 of the sand pump 10 which this applicant proposes separately, it is predetermined before the operation of the sand pump 10 starts. The sand around the suction port 11 is disturbed by pressure water for a period of time, for example, 1 minute, so that the suction of the sand can be kept good, and this disturbance is continued for a certain time after the sand pump 10 is driven.
[0022]
From each of the nozzle groups H1 to H8 and the nozzles N1 and N2, pressure water is ejected for a predetermined time in the order shown in FIG. In FIG. 5 (a), "N1" indicates that pressure water is ejected from the nozzle N1, and "H3" is provided in the header pipe when the pressure water is supplied to the header pipe. This indicates that pressure water is being injected from the nozzles n, n... Toward the trough 3, and “→” indicates that the process has been switched. The same applies to N2, H1, H2, and H4 to H8. Also, the dotted Agesuna pump 10, according to the water level gauge (not shown), represent the Turkey have been intermittent operation.
[0023]
In FIG. 4, when the left side (nozzle N1 side) is the rainwater inflow port (hereinafter simply referred to as the inflow port) and the right side (nozzle N2 side) is the rainwater outflow port (hereinafter simply referred to as the outflow port), In the case where the bottom surface of 1 is divided into four regions each of the inlet side and the outlet side from the sand collecting pit, in the time chart of FIG. After starting driving from the nozzle group in the nearest area and ending the injection in that area, if the nozzle group in the area nearest to the inlet is driven among the areas on the inlet side, After driving the nozzle group in the area closest to the sand collecting pit in the area, the nozzle group in the area closest to the outlet is driven in the area on the outlet side (N1 → H3 → N1 → H4 → N1). → H1 → N1 → H2 → N1 → N2 → H5 → N2 → H6 → 2 → H7 → N2 → H8 → N2).
[0024]
If this process is considered based on the sand collection pit, since the amount of sedimentation is larger on the inlet side than on the outlet side, first, one side with a large amount of sediment is collected first. It is an example. As another embodiment, the nozzles may be driven alternately from the nozzle group close to the sand collecting pit in order (N1 → H3 → N1 → N2 → H5 → N2 → H4 → N1 → H6 → N2 → H1 → N1 → H7.fwdarw.N2.fwdarw.N2.fwdarw.N1.fwdarw.H8.fwdarw.N2), it may be driven by a pair of opposed nozzle groups (N1.fwdarw.H3.fwdarw.N1.fwdarw.H4.fwdarw.N1.fwdarw.N2.fwdarw.H5.fwdarw.N2.fwdarw.H6.fwdarw.N2.fwdarw.H1.fwdarw.N1) → H2 → N1 → H7 → N2 → H8 → N2). Furthermore, it is also possible to collect sand first from the outlet side opposite to the embodiment of the time chart of FIG. 5 (a) (N2->H5->N2->H6->N2->H7->N2->H8-> N2). → N1 → H3 → N1 → H4 → N1 → H1 → N1 → H2 → N1).
[0025]
In the above embodiment, a pair of nozzle groups opposed to the pond width direction (direction orthogonal to the trough 3) of the sand basin, that is, the upper nozzle group and the lower nozzle group (H1, H2, H3 in FIG. 4). And H4, H5 and H6, H7 and H8), the upper nozzle group (H1, H3, H5, H7) is driven first with priority over the lower nozzle group (H2, H4, H6, H8). However, there is no problem even if the opposite is true. In addition, if the bottom area of the sand basin is small and the amount of pressure water and sand pumping capacity are sufficient, it is possible to collect sand at the inlet and outlet sides simultaneously (for example, N1 → H3 → N1 → Sand collection of H4, N1, H1, N1, H2, N1 and N2, H5, N2, H6, N2, H7, N2, H8, N2 separately and simultaneously). Further, in the time chart of FIG. 5A, each nozzle group H1 to H8 is driven only once, but may be repeated several times.
[0026]
As described above, the trough 3 is completely clogged with the same amount of pressure water as in the prior art by alternately driving the first nozzle (nozzles H1 to H8) and the second nozzles (N1, N2). It can be eliminated and the sand can be moved reliably. Also, by driving the nozzles (nozzles n of H1 to H8) in order from the side closer to the sand collection pit, the sand collection pit 2 before the sand collection pit that always passes when the sand that has settled at any position is collected is the first. Therefore, it does not hinder the subsequent movement of the sand. In addition, when collecting sand repeatedly several times, since the sand collection pit 2 which is the next lower than the sand collection pit 2 and there is a possibility that the leftover from the previous time may be collected is collected first, Does not hinder the movement of the sand.
[0027]
In each of the inlet side and the outlet side, the first nozzle group, that is, a nozzle group close to the sand collecting pit (one or a pair of H3 and H4 if the inlet side or a pair, H5 if the outlet side) , H6 before driving, the trough 3 is cleaned with the nozzles N1, N2 corresponding to the nozzles farthest from the sand collecting pits provided at both ends of the trough 3. This is the final and main trough that leads to the sand collecting pit, so this is the best way to prevent the trough 3 from being buried due to sand settling at the beginning of the sand settling process. , Not always necessary. On the other hand, the nozzles N3 and N4 are driven after the driving of the nozzles N1 and N2 and the nozzle groups H1 to H8. This is because the sand accumulated in the pond width direction around the sand collecting pit 2 is washed away.
[0028]
In addition, when a large amount of sediment flows in during heavy rain and a large amount of sediment accumulates on the bottom of the sedimentation basin, the amount of pressure water discharged from the nozzle is always greater than the discharge (transfer amount) of the sand pump. The control that has been suppressed to a low level is released, and pressure water is ejected from the nozzle with an ejection amount that can collect sand efficiently and reliably regardless of the discharge amount of the sand pump. In other words, a nozzle that can make the total amount of jetting larger than the transfer amount of the sand lifting means is used. However, if the ejection amount of the nozzle is always larger than the transfer amount of the sand lifting means, water accumulates in the sand settling basin, resulting in sand collection under the water. Sand collection underwater is not only economical because the amount of pumped water pumped by the sand pump increases, but it is also necessary to overcome the water pressure and move the sediment, and it is necessary to eject the pressure water from the nozzle at a high pressure. Arise. High-pressure sand collection not only requires a running cost to generate high pressure, but also increases the number of components. In addition, the generation of sewage mist due to high-pressure water is also a big problem from a hygienic point of view, and there is a drawback that sand collection efficiency is lowered because a part of the sand sinks and floats underwater, and then sinks and accumulates again. .
[0029]
Therefore, in order to solve these problems, it is desired that the sand collection in the drainage (dry) state and further the pressure water from the nozzle be ejected at a low pressure. In addition, the dry (drainage) state as used in the field of the present invention refers to a state in which some stagnation of rainwater is allowed as long as sand collection at a high load or high pressure of the sand pump 10 is not required. In the present embodiment, even if the amount of nozzle ejection is greater than the amount of sand pumping means , the nozzle ejection amount is adjusted by intermittently driving the nozzle. That is, when the water level of the sand basin exceeds a predetermined water level, the driving of the nozzle is stopped, and water is transferred to the outside of the sand basin together with the sand by a sand pump that is continuously driven. And when the water level of a sand basin becomes below a predetermined water level, the drive of a nozzle is restarted.
[0030]
Here, in order to take a timing for stopping the nozzle, a water level gauge is provided in the sand collecting pit or trough 3, more specifically, at the bottom level of the opening end of the trough 3 to the sand collecting pit 2, and the water level is monitored. However, by calculating from the ejection amount of the nozzle and the volume of the sand basin and setting the timer, the time chart as shown in FIG. 5B created in the same manner as FIG. It becomes possible to drive and control the sand pumping device of the sand basin 1 shown in FIG. That is, the sand pump 10 is driven, and all nozzles are stopped at the time of transition from one nozzle group to another nozzle group, and the sand basin is returned to and maintained in a drained (dry) state. In this time chart, N1.fwdarw.H3.fwdarw.N1 and N2.fwdarw.H5.fwdarw.N2 have a larger total ejection amount from the nozzle than the others, so that the driving time of only the sand pump 10 is longer than that of the other. . It should be noted that the other drive control pattern examples described above may be used. In short, the drive time of only the sand pump 10 may be provided when shifting to another nozzle group.
[0031]
As described above, in the above-described embodiment, the nozzle is completely stopped and the driving time of only the sand pump 10 is ensured. However, the present invention is not limited to this, and normal times other than when a large amount of earth and sand flows in due to heavy rain or the like. even if, since the Roh nozzle than transfer amount Agesuna means for increasing the Atsumarisuna efficiency are increasing the ejection amount, without the nozzle to complete stop, the ejection amount and Agesuna means Roh nozzle If the flow rate is monitored by a flow meter, the flow rate of both is compared and calculated, and the ejection amount adjustment means for adjusting the ejection amount of the nozzle is provided, the time during which only a smaller amount than the transfer amount of the sand lifting means is ejected from the nozzle A belt can be realized, and the sand basin can be returned to and maintained in a drained (dry) state.
[0032]
In the above-described example, the sand collecting pit 2 is provided in the center of the sand basin 1. However, the sand collecting pit 2 may be provided on the rainwater outflow side. For example, in FIG. 4, when rainwater flows in from the left side, the sand collecting pit 2 is provided on the right end side of the trough 3. Of course, even in this case, the trough 3 is inclined so that the portion where the sand collecting pit 2 is provided is lowest. Furthermore, although the trough 3 was provided in the center of the sand basin 1, you may make it provide in one side wall side. For example, in FIG. 4, the lower nozzle groups H2, H4, H6, and H8 may be omitted, and the trough 3 may be provided in this portion.
[0033]
Moreover, in the above-mentioned example, although the sand pump 10 was shown as a sand pumping means, it is needless to say that it may be a jet pump.
[0034]
【The invention's effect】
According to invention of Claim 1, it extends in the direction which connects the inflow port and an outflow port in the bottom face of the sand basin which has an inflow port in one end side, and an outflow port in the other end side, and has a sand collection pit. A first nozzle that ejects pressure fluid to flow trough the sand deposited on the bottom of the sand basin toward the trough, and pressure to flow the sand collected in the trough toward the sand collection pit A sand pumping device provided with a second nozzle for ejecting a fluid, wherein the sand collected in the sand collecting pit is transferred by a sand pumping means intermittently operated based on a water level meter; the second to the nozzle, since the sum of the respective ejection amount used as multi Kunar than transfer amount Agesuna means, a large amount of sand in the bottom of the settling basin flows into a large amount of sediment in the heavy rain or the like deposited Even in this case, sand can be collected efficiently and reliably. Further, when the water level of the settling basin by ejection from the first nozzle and second nozzle exceeds Tokoro Teimizu position, each jet of the first nozzle to be equal to or less than the predetermined level and a second nozzle Since the ejection amount adjusting means for adjusting the total amount in the direction of decreasing the amount is provided, it is possible to prevent sand collection underwater by keeping the nozzle ejection amount always larger than the transfer amount of the sand lifting means. Therefore, the sand collection efficiency is not reduced.
[0035]
According to invention of Claim 2, a sand basin can be returned and maintained in a drainage (dry) state.
According to invention of Claim 3 thru | or 5 , various ejection amount adjustment means can be used.
[0036]
According to the invention of claim 6 , since the drive control means for alternately driving the first nozzle and the second nozzle is added, the clogging of the trough can be completely eliminated even with the same amount of pressure water as the conventional one, Sand can be moved reliably, and sand collection efficiency can be improved.
[0037]
According to the seventh aspect of the present invention, since the drive control means for driving the nozzles in the order from the area far from the sand collecting pit to the area far from the sand collecting pit is added, it is possible to eliminate the retention of sand settling before the sand collecting pit, and the sand collecting efficiency Can be improved.
[Brief description of the drawings]
FIG. 1 is a sectional view when a sand raising apparatus according to an embodiment of the present invention is applied to a rainwater settling basin of a sewage treatment facility.
FIG. 2 is a plan view of FIG.
FIG. 3 is a cross-sectional view taken along the line II in FIG. 2;
FIG. 4 is a plan view showing the arrangement of nozzle groups.
FIG. 5A is a time chart showing a control operation, and FIG. 5B is a time chart showing another type of control operation.
[Explanation of symbols]
1 rainwater settling basin (sedimentation basin)
2 Sand collection pit 10 Sand pump 11 Suction port 12 Discharge pipe N1 to N4 nozzle H1 to H8 nozzle group n nozzle

Claims (7)

A trough having a sand collecting pit is provided on the bottom surface of the sand basin having an inlet on one end and an outlet on the other end, extending in a direction connecting the inlet and the outlet, and having a sand collecting pit. A first nozzle for ejecting pressure fluid for flowing sand accumulated on the bottom surface toward the trough; and a second nozzle for ejecting pressure fluid for flowing sand collected in the trough toward the sand collecting pit. In the sand raising device, the sand collected in the sand collecting pit is transferred by a sand raising means that is intermittently operated based on a water level gauge .
The first nozzle and second nozzle, used as multilingual Kunar than transferring the total amount of said Agesuna means each ejection amount, the by ejected from the first nozzle and second nozzle sand when the water level of the pond exceeds Tokoro Teimizu position is ejected amount adjusting means for adjusting the direction to lose weight the sum of each of the ejection amount of the first nozzle and second nozzle so that less than the predetermined water level A sanding device characterized by comprising: The sand raising device according to claim 1, wherein the predetermined water level is set to a water level for returning and maintaining the sand basin in a drained (dry) state . The ejection amount adjusting means comprises a water level meter that measures the water level of the sand basin, and an automatic valve controller that controls opening and closing of the first nozzle and the second nozzle according to the measured value of the water level meter. The sand lifting apparatus according to claim 1 or 2 . The ejection amount adjusting means includes a timer that is calculated based on the total ejection amount of each of the first nozzle and the second nozzle and the volume of the sedimentation basin and sets an open time. The sand raising apparatus according to 1 or 2 . The ejection amount adjusting means measures the total ejection amount of each of the first nozzle and the second nozzle and the transfer amount of the sand lifting means, compares both measured values, and outputs an ejection amount adjustment signal. The sand raising apparatus according to claim 1 or 2 , wherein The bottom surface of the sand basin is divided into a plurality of regions in the longitudinal direction of the trough, the first nozzle is installed for each region, and a drive control means for alternately driving the first nozzle and the second nozzle is added. The sand raising device according to claim 1, 2 , 3 , 4 or 5 . The sand pumping device according to claim 6 , further comprising drive control means for driving the first nozzle in order from a region far from the region near the sand collecting pit.

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