JP2005334816A - Filter pond system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter pond system in the filter pond of which pretreated raw water can be treated effectively. <P>SOLUTION: This filter pond system is constituted so that the raw water which is gathered by a water intake pump 1 and pretreated is received in the filter pond 4 through an inflow valve 3 and filtered and the obtained filtrate is discharged through a filtration valve 5. An operation control means C is arranged for stopping the operation of the water intake pump 1, then closing the filtration valve 5 and subsequently closing the inflow valve 3 when the operation of the filter pond 4 is stopped. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a filter basin system in which raw water collected by a water intake pump and pretreated is received into a filter basin through an inflow valve, and filtered to flow out from the filter valve.

  In such a filtration pond system, the raw water collected by a water intake pump is usually added with other processes such as agglomeration treatment, precipitation treatment, biological contact treatment, activated carbon treatment, etc. according to water quality requirements. Or after pre-treatment in various forms such as replacement with a membrane separation device, it is introduced into the filtration basin by an inflow valve. In the filtration pond, the introduced raw water is filtered and discharged to the filtration valve. Through the pretreatment, the raw water is naturally advected to the filtration basin by the gradient of the water level, and can be continuously filtered without power.

  The amount of water to be supplied by such a filter basin system often varies depending on the time zone. In particular, in filtered pond systems in areas where there is little water consumption during the daytime and late at night, and there is much water consumption from evening to night, such as satellite urban areas, the amount of filtered water supply varies greatly throughout the day. In such a case, the operation | movement which stops operation of a filtration basin is performed in the time zone with few filtrate water supply amounts. Conventionally, in such a case, when the operation of the filtration pond is stopped, the intake pump is stopped and the filtration valve is stopped (for example, see Patent Document 1).

JP-A-5-288161

  However, if the method of flowing the raw water into the individual treatment tanks is performed by a head difference, even if the water intake pump is stopped, the water used for the pretreatment process will remain in the downstream treatment tank for a while. Continue to flow, such as overflow. It will be in the situation which continues flowing for a while toward the inflow valve side of the filtration pond system. However, the water flowing in this way (hereinafter referred to as surplus raw water) is not allowed to flow into the filter basin, and is usually discarded after passing through the pretreatment process, and is wasted.

  Then, in view of the said actual condition, this invention aims at provision of the filter basin system which can process the raw | natural water provided for the pre-treatment with a filter basin effectively.

  The characteristic configuration of the filter basin system of the present invention is a filter pond system that receives raw water collected and pretreated by a water intake pump into a filter basin from an inflow valve, and filters it out of the filter valve. In stopping, after the operation of the intake pump is stopped, the filtration valve is closed, and then the operation control means for closing the inflow valve is provided.

  The filtration pond can perform raw water filtration operation in the filtration pond by operating a water intake pump and keeping the inflow valve and the filtration valve open. Usually, the supply amount of raw water and the amount of filtered water discharged from the filtration valve are set to be balanced.

When the operation of the water intake pump is stopped when the operation is stopped, the supply of raw water to the pretreatment is stopped. In this filtration basin system, since the said inflow valve is maintained in an open state at this time, the said filtration basin can receive the surplus raw | natural water produced by the said pretreatment. At this time, since the filtration valve is in an open state, the raw water in the filtration pond is filtered and discharged from the filtration valve while the filtration pond receives excess raw water.
In this state, the supply of raw water to the pretreatment process is stopped and the supply water to the filtration basin is only surplus raw water, so the amount of water flowing into the filtration basin is less than the amount of water flowing into the filtration basin during normal operation. . At this time, since the opening degree of the inflow valve and the filtration valve is not changed, the filtration basin can accept the surplus raw water so that it can be effectively used while gradually lowering the water level.

Thereafter, when the filtration valve is closed, the filtration of the raw water in the filtration pond is stopped. At this time, the timing of closing the filtration valve is appropriately delayed from the stop of the intake pump so that the amount of water in the filtration basin is not too small and a sufficient amount of excess raw water can be received.
In this state, the filtration basin does not perform filtration, and the excess raw water is received in the filtration basin, so that the water level of the filtration basin once lowered can be recovered.

Furthermore, if the said inflow valve is closed after closing the said filtration valve, reception of the surplus raw water to the said filtration pond will be stopped. The timing of closing the inflow valve is appropriately delayed from the closing operation of the filtration valve so that the amount of water in the filtration pond does not become excessive and a sufficient amount of surplus raw water can be received.
Thereby, surplus raw water can fully be received in the filtration pond, and surplus raw water can be stored effectively.

  Therefore, according to the said structure, the capacity | capacitance of a filtration basin can be used effectively and surplus raw | natural water can be used effectively. In addition, since most of the excess raw water generated in the pretreatment is accepted by the filtration pond, even if the excess raw water remains in the pretreatment process and is discarded as it is, the amount of waste is reduced.

  In addition, the operation of the inflow valve and the filtration valve can be minimized in order to effectively use the surplus raw water, and the increase in turbidity of the filtered water based on the operation of the inflow valve and the filtration valve can be suppressed.

  In addition, after the operation of the intake pump is stopped, until the operation is resumed, the filtration pond will wait for a state in which the surplus raw water is received and the water level is sufficiently secured. The water can be supplied with good responsiveness.

  The operation control means in the filtration pond system of the present invention preferably includes a timer mechanism that closes at least one of the filtration valve and the inflow valve based on a set time after the operation of the intake pump is stopped.

  As described above, in order to close the filtration valve, it is desirable to delay the intake pump from being stopped to such an extent that the amount of water in the filtration pond is not too small and a sufficient amount of excess raw water can be received. . On the other hand, in order to close the inflow valve, it is desirable to delay the filtration valve from stopping so that the amount of water in the filtration basin is not excessive and a sufficient amount of surplus raw water can be received.

  Here, the amount of the surplus raw water generated in the pretreatment is substantially determined by the configuration of the pretreatment process, and the time required for the surplus raw water to flow into the filter basin can be obtained almost accurately. Furthermore, since the capacity of the filter basin, the rate of decrease in the filter basin water level, etc. are also known, the timer mechanism determines when to close the filtration valve and the inflow valve, and the capacity in the filter basin is used sufficiently effectively. Therefore, effective use of surplus raw water can be achieved. Further, when the timing for closing the filtration valve and the inflow valve is controlled by time, the process management of the filtration basin is facilitated and reliable operation can be performed. In addition, operation control can be performed with a simple design change by simply monitoring the existing filtration basin system with a timer mechanism without adding special equipment to the filtration basin.

  The operation control means in the filtration basin system of the present invention includes a water level control mechanism that closes at least one of the filtration valve and the inflow valve based on the water level of the filtration basin after the operation of the intake pump is stopped. Is preferred.

  When the filtration valve is closed based on the water level of the filtration basin, the water level in the filtration basin can be detected directly and reliably, and the water level in which the amount of water in the filtration basin is not excessive can be maintained. Moreover, if the said inflow valve is closed based on the water level of the said filter basin, the water level in the said filter basin can be detected directly and reliably, and the water level which does not have the excessive amount of water in the said filter basin can be maintained.

  The filtration pond water level control mechanism preferably closes the filtration valve based on a lower limit water level lower than the normal operation water level of the filter basin and closes the inflow valve based on an upper limit water level higher than the normal operation water level. .

  If the said filtration valve and an inflow valve are opened after stopping a water intake pump, the said filtration pond will continue flowing out filtered water, receiving the excess raw water. At this time, in general, the amount of filtered water does not change much while the inflow of surplus raw water gradually decreases, so the water level of the filtration pond decreases. In other words, after the intake pump is stopped, the surplus raw water can be accepted and reliably used until the water level in the filtration basin reaches the lower limit water level. Next, if the filtration valve is closed when the lower limit water level is reached, excess raw water flows into the filtration pond but does not flow out, and the water level in the filtration basin begins to rise and flows in until the inflow valve is closed. Excess raw water can be stored in the filtration pond. At this time, since the excess raw water is stored from the lower limit water level to the upper limit water level, a large amount of excess raw water is stored by setting the lower limit water level sufficiently lower than the normal operation water level and the upper limit water level sufficiently higher than the normal operation water level. can do.

  Moreover, the filtration pond system of the present invention is provided with a water purification pond that stores the purified water after being filtered by the filtration pond, and the operation control unit is configured to stop the operation of the intake pump and then from the filtration pond to the water purification pond. It is preferable to provide a water purification tank water level control mechanism that closes the filtration valve based on the flow rate of filtered water.

As described above, when the filtration valve is closed, the amount of excess raw water that can be received in the filtration basin can be secured by sufficiently lowering the water level of the filtration basin. It is desirable that raw water be filtered out as much as possible before flowing out to the water purification pond.
Such an outflow amount can be determined by the amount of water discharged from the filtration valve per unit time, the amount of water supplied to the inflow valve per unit time, and the amount of water stored in the filter basin. That is, the amount of decrease in the amount of filtered pond water per unit time is known from the difference between the amount of discharged water and the amount of supplied water. By comparing this reduced amount with the amount of water until the water level in the filter basin reaches the lower limit, the amount of water that can be transferred after the intake pump is stopped can be calculated.

  Therefore, after the operation of the intake pump is stopped according to the amount of raw water that can flow out, the filtration valve is closed based on the flow rate of filtrate from the filtration basin to the water purification basin. It is possible to receive as much surplus raw water as possible and effectively use the surplus raw water while staying inside.

In addition, when the above-mentioned operation control means is provided, it is not necessary to close the filtration valve and the inflow valve based on the same factor. For example, it is possible to control the operation based on different factors, such as closing the filtration valve by a timer mechanism and closing the inflow valve based on a water level control mechanism.
Moreover, the said operation control means can close the said filtration valve and the said inflow valve based on a some factor. For example, both the timer mechanism and the water level control mechanism can be monitored, and the filtration valve can be closed based on one of the factors established earlier. In this way, the water level in the filtration basin can be monitored more reliably.

  Furthermore, in addition to the above-described configuration, a water purification pond that stores the purified water after filtering in the filtration pond is provided, and the operation control means is set so that the water level of the water purification pond that receives the purified water from the filtration valve is lower than the full water level. When the high water level is reached, the operation of the intake pump can be stopped.

  That is, according to this configuration, when the filtration pond is stopped, a predetermined amount of filtered water flows into the water purification pond after the intake pump is stopped. Therefore, in the water purification pond, the intake water pump is stopped at a set high water level that is lower than the full water level of the water purification pond so that the filtered water discharged from the filtration basin can be received and stored after the water intake pump is stopped. It will be done at. Further, if the stop of the intake pump is controlled by the water level of the water purification pond, the amount of filtered water flowing into the filtration basin after the water intake pump is stopped can be managed by the water level of the water purification pond, and the filtration pond is further increased. It is possible to reliably manage the operation.

  Hereinafter, an embodiment of a filtration pond system of the present invention will be described with reference to the drawings.

<First embodiment>
As shown in FIGS. 1 and 2, the filtration pond system of the present invention is used in, for example, a water purification facility, and raw water collected by a water intake pump 1 is used as a chemical mixing treatment unit 22, a coagulation treatment unit 23, and a precipitation treatment unit 24. The pretreatment unit 2 provided in this order is pretreated so that water with less turbidity components and the like can be obtained by pretreatment that aggregates, precipitates and separates turbidity components and the like in the raw water.

  The raw water that has passed through the pretreatment unit 2 is received by the filtration basin 4 from the inflow valve 3. In the filtration basin 4, raw water is filtered with a filter medium, and the filtered filtrate is configured to flow out from the filtration valve 5 to the water purification basin 6.

  The filtration basin 4 is provided with a water level sensor 41, and provided with valve opening / closing means 42 for opening and closing the inflow valve 3 and the filtration valve 5 when the intake pump 1 is operated based on the detected water level of the water level sensor 41, A water level control mechanism 43 that maintains the water level of the filtration basin 4 within the set range is configured. The water level control mechanism 43 is realized by providing a computer provided as the operation control means C with a program that receives an input of the detected water level from the water level sensor 41 and outputs an operation signal for operating the valve opening / closing means 42. Is done.

  Further, when the operation of the filtration basin 4 is stopped, the valve opening / closing means 42 closes the filtration valve 5 after the first set time T1 has elapsed after the operation of the intake pump 1 is stopped, and further the second set time T2 A timer mechanism 44 that closes the inflow valve 3 after the passage is provided. The timer mechanism 44 is realized by providing a computer provided as the operation control means C with a program that outputs an operation signal for operating the inflow valve 3 with reference to the timer.

  Further, the water purification tank 6 is provided with a water level gauge 61, and when the water level of the water purification tank 6 that receives the purified water from the filtration valve 5 reaches a set high water level HL lower than the full water level HH, the operation of the intake pump 1 A water level detection mechanism 62 for stopping is provided. Further, the timer mechanism 44 has a function of stopping the operation of the water intake pump 1 at a regular time every day. The water level detection mechanism 62 is realized by providing a computer provided as the operation control means C with a program that receives an input from the water level gauge 61 and outputs an operation signal for operating the water intake pump 1.

With such a configuration, the filter basin system is operated as shown in FIG.
When the set high water level HL of the clean water reservoir 6 is detected (point A) or at regular times, the intake pump 1 is first stopped (point B) when the filtration basin 4 is stopped.

  At this time, inflow of raw water is stopped in the pretreatment unit 2, but surplus raw water flows for a while after that. This surplus raw water flows into the filtration basin 4 because the inflow valve 3 of the filtration basin 4 is open. At this time, since the filtration valve 5 is also in the open state, the filtration operation is continued in the filtration basin 4, and the filtered water continues to flow out into the water purification basin 6, and the water level in the filtration basin 4 is reduced according to the decrease in the inflow of surplus raw water. Will decline. Moreover, the filtered water which flows out from the filtration basin 4 is received, but the water level of the said water purification pond 6 rises, but since the said setting high water level HL is set lower than the full water level HH, in the said water purification pond 6 the said filtration Water can be received and stored, and the filtered water is not wasted.

  The lowering of the water level in the filtration basin 4 is determined by the difference between the amount of inflow of the excess raw water into the filtration basin 4 and the outflow amount of the filtered water. Therefore, the water level in the filtration basin 4 sufficiently decreases empirically after the intake pump 1 is stopped. The timer mechanism 44 measures this time as a first set time T1, and closes the filtration valve 5 (point C).

  Since the water level control mechanism 43 controls the water level in the filtration basin 4 between the normal high water level H1 and the normal low water level L1, the filtration basin 1 is stopped when the intake pump 1 is stopped. The water level 4 is maintained higher than the normal low water level L1 (point D). Therefore, after the intake pump 1 is stopped by setting the time for the water level to fall from the normal low water level L1 to the lower limit water level L in the filtration basin 4 as the first set time T1, the filtration valve Control is performed so that the water level of the filtration basin 4 does not drop too much below the lower limit water level L (point E) before 5 is closed.

  When the filtration valve 5 is closed, the outflow of filtered water from the filtration basin 4 to the clean water basin 6 is stopped. In this state, since the inflow valve 3 is open, when the filtration basin 4 receives the inflow of the excess raw water, the water level in the filtration basin 4 rises. Moreover, since filtered water does not flow in the water purification tank 6, a water level begins to fall according to consumption of purified water (after the F point). In general, since the time when the filtration basin 4 is stopped is set in accordance with the time when the consumption of purified water is low, the water level of the clarification pond 6 is maintained at a high level for a while after the normal filtration valve 5 is stopped.

  Since the rise in the water level of the filtration basin 4 is determined by the inflow of the excess raw water, if the filtration basin 4 receives the surplus raw water, the surplus raw water that has flowed into the filtration basin 4 by that time is stored in the filtration basin 4; It will be effectively used during the next filtration basin 4 operation. Therefore, if the period during which the filtration basin 4 can receive the surplus raw water is empirically found as the second set time T2, the timer mechanism 44 measures the second set time T2, and the inflow valve 3 By closing (G point), sufficient surplus raw water can be stored in the filtration basin 4. Thereafter, the surplus raw water flowing through the pretreatment unit 2 does not flow into the filtration basin 4 and is discarded.

  Next, when the operation of the filtration basin 4 is resumed, the intake water is taken at a fixed time every day (point I) or when the water level gauge 61 detects the set low water level L0 of the water purification basin 6 (point J). The pump 1 is started and simultaneously the filtration valve 5 and the inflow valve 3 are opened. At this time, since there is no surplus raw water in the pretreatment unit 2, the raw water inflow from the inflow valve 3 gradually increases after the raw water supply by the intake pump 1 is started. Moreover, since the said filtration basin 4 stores the said surplus raw | natural water and starts a driving | running from the state (K point) with a high water level, the supply of the filtered water with respect to the water purification tank 6 is started immediately. Therefore, the water level of the filtration basin 4 is gradually lowered and converges between the normal high water level H1 and the normal low water level L1, thereby enabling stable operation.

<Second embodiment>
The filtration pond system of the present invention can control the filtration valve 5 and the inflow valve 3 based only on the water level of the filtration valve. The basic configuration is the same as that of the first embodiment.

  The valve opening / closing means 42 closes the filtration valve 5 when the water level of the filtration basin 4 reaches the lower limit water level L after the operation of the intake pump 1 is stopped when the operation of the filtration basin 4 is stopped. Thereafter, the water level detection mechanism 62 closes the inflow valve 3 when the water level of the filtration basin 4 reaches the upper limit water level H. Further, the lower limit water level L is set to a low water level at which the surface of the filter medium built in the filtration basin 4 is not exposed, and the upper limit water level H can sufficiently store the surplus raw water in the filtration basin 4. Set to high water level.

  Even when the intake pump 1 is stopped, the water level control mechanism 43 can perform water level control using the normal low water level L1 as the lower limit water level L and the normal high water level H1 as the upper limit water level H. In this case, the water level control can be performed using the configuration of the existing filtration basin system as it is.

The filter basin system of this embodiment is operated as shown in FIG.
When the set high water level HL of the clean water reservoir 6 is detected, the water intake pump 1 is first stopped when the filtration basin 4 is stopped.

  Since the water level of the filtration basin 4 is determined by the difference between the amount of inflow of the surplus raw water into the filtration basin 4 and the amount of filtered water, the amount of filtered water does not change so much and decreases continuously when the amount of inflow decreases. Therefore, when the water level sensor 41 detects the lower limit water level L, the water level control mechanism 43 closes the filtration valve 5.

  Since the inflow valve 3 is in an open state, the water level of the filtration basin 4 rises upon receiving the surplus raw water.

  Since the rise in the water level of the filtration basin 4 is determined by the inflow of the excess raw water, if the filtration basin 4 receives the surplus raw water, the surplus raw water that has flowed into the filtration basin 4 until that time is stored in the filtration basin 4. It will be used effectively during the next operation of the filter basin 4. Therefore, when the upper limit water level H at which the filtration basin 4 can receive the surplus raw water is detected by the water level sensor 41 and the inflow valve 3 is closed by the water level control mechanism 43, sufficient surplus raw water is stored in the filtration basin 4. be able to. Thereafter, the surplus raw water flowing through the pretreatment unit 2 does not flow into the filtration basin 4 and is discarded.

<Other embodiments>
In the previous embodiment, the example in which the closing operation of the filtration valve 5 is performed based on the first set time T1 or the water level of the filtration basin 4 has been shown. It can be performed based on various factors such as water level.

As shown in FIG. 4, after the intake pump 1 is stopped, the filtered water inflow amount flowing out to the water purification basin 6 is discharged until the normal low water level L <b> 1 in the filtration basin 4 is displaced to the lower limit water level L. By closing the filtration valve 5 when the total amount of water is reached, the same operation as in the second embodiment can be performed regardless of the water supply from the water purification tank 6. In addition, when operating the filtration valve 5 by the water level detection mechanism 62 using the water level gauge 61 of the water purification tank 6, if water supply from the water purification tank 6 is expected after the intake pump 1 is stopped, The set high water level HL may be set in consideration of the water supply amount.
For example, the water storage amount within the water level difference between the set high water level HL and the full water level HH in the water purification pond 6 and the water storage amount within the water level difference between the normal low water level L1 and the lower limit water level L in the filtration pond 4 Keep them consistent. Under this condition, if the filtration valve 5 is closed based on the detection of the full water level HH of the water purification tank 6, the second operation described above is performed unless water is supplied from the water purification tank 6 after the filtration valve 5 is closed. Water level fluctuations similar to the morphology will be observed.

  Further, when the intake pump 1 is started and stopped, and the filtration valve 5 and the inflow valve 3 are opened and closed based on the set time, the set time can be measured based on various criteria. For example, in the previous first embodiment, the second set time T2 for closing the inflow valve 3 is set based on the time point when the filtration valve 5 is closed, but it may be set based on the stop time of the intake pump 1. Good. Also, instead of setting the intake pump 1 to start and stop at a fixed time every day, the intake pump 1 can be started and stopped based on the stop time of the intake pump 1 and the elapsed time after startup, and various settings are possible. It is.

  Furthermore, even if the operation of closing the filtration valve 5 is performed based on any factor such as the set time, the water level of the filtration basin 4, the water level of the water purification basin 6, the operation of closing the inflow valve 3, It can be performed based on any factor of the set time and the water level of the filtration basin 4. These factors may be the same as in the previous embodiment, or may be different. For example, the filtration valve 5 may be closed based on a set time, the inflow valve 3 may be closed based on the water level of the filtration basin 4, the filtration valve 5 may be closed based on the water level of the water purification basin 6, The inflow valve 3 may be closed based on the set time. If the operations of the filtration valve 5 and the inflow valve 3 are performed based on the same factor, the above-described operation can be performed with only a small design change to the existing filtration pond system. This is preferable.

  In addition, the operation of the filtration valve 5 and the inflow valve 3 can be performed based on any one factor such as the set time, the water level of the filtration basin 4, etc., but may be performed based on a plurality of factors. . For example, the filtration valve 5 is stopped based on the earlier one of the first set time T1 after the intake pump 1 stops and the water level of the water purification basin 6 reaching the full water level HH. Or the stop of the inflow valve 3 is either when the second set time T2 has elapsed since the stop of the filtration valve 5 or when the upper limit water level H of the filtration basin 4 is detected. Can be done based on the earlier one. If it does in this way, while the operation of the filtration basin 4 is controlled more reliably and stably, surplus raw water can be used effectively and the water recovery rate can be increased.

  The form of the filtration basin 4 is arbitrary, and the filtration valve 5 and the inflow valve 3 are not limited to so-called valves, and other inflow / outflow devices such as siphons and air traps can be used as appropriate.

Schematic diagram of filtration basin system Operation control explanatory diagram of the filtration pond system in the first embodiment Operation control explanatory diagram of the filtration pond system in the second embodiment Operation control explanatory drawing of the filtration pond system in other embodiments Operation control explanatory drawing of the filtration pond system in other embodiments

Explanation of symbols

1 Intake pump 3 Inflow valve 4 Filtration basin 5 Filtration valve C Operation control means

Claims (6)

A filter basin system that receives raw water collected and pretreated by a water intake pump into a filter basin from an inflow valve, and filters it out of the filter valve,
A filtration basin system provided with operation control means for closing the filtration valve and then closing the inflow valve after the operation of the intake pump is stopped when the operation of the filtration pond is stopped. The operation control means includes
The filtration pond system of Claim 1 provided with the timer mechanism which closes at least any one of the said filtration valve and the said inflow valve based on setting time after the operation | movement stop of the said intake pump. The operation control means includes
The filtration basin system of Claim 1 provided with the water level control mechanism which closes at least any one of the said filtration valve and the said inflow valve based on the water level of the said filtration basin after the operation stop of the said intake pump.   The filtration basin system according to claim 3, wherein the filtration basin water level control mechanism closes the filtration valve based on a lower limit water level lower than a normal operation water level of the filtration basin and closes an inflow valve based on an upper limit water level higher than the normal operation water level. . Provided with a water purification pond for storing purified water after filtration in the filtration pond,
The operation control means includes
The filtration pond system of Claim 1 provided with the purified water level control mechanism which closes the said filtration valve based on the filtered water transfer flow volume from the said filtration pond to the said purified pond after the operation stop of the said intake pump. Provided with a water purification pond for storing purified water after filtration in the filtration pond,
The said operation control means stops the operation | movement of the said intake pump when the water level of the water purification tank which receives the purified water from the said filtration valve reaches the setting high water level lower than a full water level. The described filtration pond system.

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