JP5589481B2 - Filtration system - Google Patents

Description

  The present invention relates to a filtration system equipped with a filtration device that produces suspended water by capturing suspended substances contained in raw water with a filter medium.

Conventionally, a filtration apparatus equipped with a filtration treatment device for producing treated water by capturing suspended substances (for example, fine particles, organic matter, oxidized precipitates of dissolved iron, etc.) contained in raw water such as groundwater with a filter medium (filter medium layer). A system is provided (see, for example, Patent Documents 1 and 2).
In such a filtration system, a flocculant is often added to the raw water prior to the filtration treatment in order to easily remove suspended substances contained in the raw water by coagulation (flocculation).

  The filter medium of the filtration apparatus gradually decreases in trapping capacity (filtering capacity) as the trapped suspended matter increases. Therefore, the trapping ability of the filter medium is recovered by periodically cleaning (backwashing and washing with water) the filter medium using cleaning water (raw water or treated water).

Japanese Patent Laid-Open No. 62-191014 JP 2003-190973 A

  Generally, the flocculant has viscosity (adsorption force). Moreover, the addition amount of the flocculant is increased or decreased depending on the quality of the raw water. Therefore, in the filtration system described in the above-mentioned patent document, when a large amount of flocculant is added to the filter medium in which the amount of suspended substances trapped is increased, the flocculant is added to the filter medium and the suspended substance trapped in the filter medium. Easy to adhere (fix). Therefore, the filter medium is likely to be clogged, and it is difficult to recover the capturing ability even if the filter medium is washed.

  An object of this invention is to provide the filtration system which can recover | recover easily the capture | acquisition capability of a filter medium.

The present invention includes a filtering means for producing treated water by capturing suspended substances contained in raw water with a filter medium, a cleaning means for performing a cleaning operation comprising a reverse cleaning process and a water washing process on the filter medium, and the filtration Before the filtration treatment by the means is performed, the flocculant addition means for adding the flocculant to the raw water, the pollution degree detection means for detecting the degree of pollution that is the degree of pollution of the filter medium, and the pollution degree detection means are detected. The turbidity trapping amount calculating means for calculating the turbidity trapping amount that is the amount of suspended matter trapped by the filter medium based on the turbidity, and the flocculant added to the raw water by the flocculant adding means Flocculant addition ratio calculating means for calculating the addition ratio, cleaning operation execution request determining means for determining whether or not the filtering means is requested to perform the cleaning operation of the filter medium, and the cleaning operation execution request determining means Further, when it is determined that the washing device is requested to perform the cleaning operation, the turbidity trapping amount calculated by the turbidity trapping amount calculation unit and the flocculant calculated by the flocculant addition ratio calculation unit A cleaning time setting means for setting the cleaning time of the filter medium based on the addition ratio of the filter medium, and a cleaning operation for controlling the cleaning means to perform the cleaning operation based on the cleaning time set by the cleaning time setting means The cleaning time setting means sets the cleaning time longer as the turbid trapping amount calculated by the turbid trapping amount calculation means increases, and is calculated by the flocculant addition ratio calculation means. was about filtration systems added proportion you enough washing time set longer large flocculant.

  Further, the back washing time for carrying out the back washing step and the water washing time for carrying out the water washing step were calculated by the turbid trapping amount calculated by the turbid trapping amount calculating unit and the flocculant addition ratio calculating unit. It is preferable to set individually based on the addition ratio of the flocculant.

Further, the present invention is a filtration means for producing treated water by capturing suspended substances contained in raw water with a filter medium, and a cleaning means for performing a washing operation comprising a reverse washing process and a water washing process on the filter medium, Before the filtration treatment by the filtration means is performed, the flocculant addition means for adding the flocculant to the raw water, the pollution degree detection means for detecting the degree of pollution that is the degree of pollution of the filter medium, and the pollution degree detection means Based on the detected turbidity, added to the raw water by the turbidity trapping amount calculating means for calculating the amount of suspended matter trapped by the filter medium and the flocculant adding means. A flocculant addition ratio calculating means for calculating an addition ratio of the flocculant; a cleaning operation execution request determining means for determining whether or not a request for executing the cleaning operation of the filter medium is made in the filtering means; and the cleaning operation execution request. Size When it is determined by the means that the washing means is requested to perform the cleaning operation, the turbidity trapping amount calculated by the turbidity trapping amount calculation means and the flocculation calculated by the flocculant addition ratio calculation means Cleaning water amount setting means for setting the cleaning water amount of the filter medium based on the addition ratio of the agent, and cleaning for controlling the cleaning means to perform a cleaning operation based on the cleaning water amount set by the cleaning water amount setting means An operation execution control means , wherein the washing water amount setting means sets the washing water amount as the turbidity trapping amount calculated by the turbidity trapping amount calculation means increases, and is calculated by the flocculant addition ratio calculation means. about filtration systems that many sets the amount of wash water larger the proportion of the added flocculant is.

  Further, the amount of washing water used in the reverse washing step and the amount of rinsing water used in the washing step are calculated as the turbidity trapping amount calculated by the turbidity trapping amount calculating means and the flocculant addition ratio calculation. It is preferably set individually based on the addition ratio of the flocculant calculated by the means.

  ADVANTAGE OF THE INVENTION According to this invention, the filtration system which can recover | recover the trapping ability of a filter medium easily can be provided.

It is a lineblock diagram showing filtration system 1 of a 1st embodiment. It is a functional block diagram concerning control of filtration system 1 of a 1st embodiment. It is a figure which shows the example of a setting of the washing | cleaning time set based on the suspended solid capture amount and the addition ratio of a flocculant. It is a figure which shows the relationship between the amount of turbidity trapping in the case of making the addition ratio of a flocculant into a parameter, and washing | cleaning time. It is a flowchart which shows control of the filtration system 1 of 1st Embodiment. It is a block diagram which shows 1 A of filtration systems of 2nd Embodiment. It is a functional block diagram concerning control of filtration system 1A of a 2nd embodiment. It is a flowchart which shows control of the filtration system 1A of 2nd Embodiment.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram illustrating a filtration system 1 according to a first embodiment of the present invention.

As shown in FIG. 1, the filtration system 1 according to the first embodiment of the present invention includes a raw water line L1 through which raw water W1 such as ground water flows, a raw water pump 2, a raw water valve 3, and a suspension contained in the raw water W1. A filtration device 4 that captures a substance by a filter medium (not shown) to produce treated water W2, a treated water line L2 through which treated water W2 circulates, a water supply valve 7, and a treated water tank that stores treated water W2. 8, treated water distribution line L3, treated water distribution pump 9, backwash water supply line L5, backwash water supply pump 15, backwash valve 16, drain line L4, backup water supply line Lb, The raw water turbidity meter 10, the flocculant addition device 11, the treated water turbidity meter 18, the flow meter 19, and the control device 30 are mainly configured.
In addition, the “line” in this specification is a general term for a line capable of flowing a fluid such as a flow path, a path, and a pipeline.

  The upstream end of the raw water line L1 is connected to a supply source (not shown) of the raw water W1. The downstream end of the raw water line L1 is connected to the filtration device 4 (a control valve 6 described later). The raw water pump 2 is provided in the raw water line L1. The raw water pump 2 sends raw water W1 such as groundwater to the filtration device 4. The raw water pump 2 is electrically connected to a control device 30 (described later). Operation (drive and stop) of the raw water pump 2 is controlled by a control device 30 (described later). The raw water valve 3 is provided in the raw water line L1. The raw water valve 3 is electrically connected to a control device 30 (described later). The raw water valve 3 opens and closes the raw water line L1. Opening and closing of the raw water valve 3 is controlled by a control device 30 (described later).

  The raw water line L1, the raw water pump 2 and the raw water valve 3 also function as a cleaning means for rinsing the backwashed filter medium 4 of the filtration apparatus 4 with the raw water W1 and discharging the raw water W1 rinsed with the filter medium out of the system.

  The raw water turbidity meter 10 measures the turbidity of the raw water W1 at the measurement point J1 of the raw water line L1. That is, the raw water turbidity meter 10 functions as a turbidity detecting means for measuring the turbidity of the raw water W1 on the inlet side of the filtration device 4. The raw water turbidimeter 10 is electrically connected to a control device 30 (described later). The signal measured by the raw water turbidimeter 10 is input to the control device 30.

  The flocculant addition device 11 adds a predetermined flocculant at the addition point J2 of the raw water line L1 in order to remove suspended substances in the downstream filtration processing device 4 (described later). That is, the flocculant addition device 11 functions as a flocculant addition means. The flocculant is appropriately selected according to the type of suspended substance and the pH value of the raw water W1.

  The flocculant addition device 11 includes a flocculant reservoir 11a and a flocculant addition pump 11b. The flocculant storage part 11a stores the flocculant. The flocculant addition pump 11b sends and adds the flocculant stored in the flocculant reservoir 11a to the raw water W1 at the addition point J2 of the raw water line L1. The flocculant addition pump 11b is electrically connected to a control device 30 (described later). The operation (drive and stop) of the flocculant addition pump 11b is controlled by a control device 30 (described later).

  The filtration apparatus 4 is provided at the downstream end of the raw water line L1, and produces treated water W2 by capturing suspended substances contained in the raw water W1 with a filter medium (not shown). The filtration processing device 4 includes a filtration tower 5 having a filter medium, a control valve 6 as a back cleaning means, and a drain line L4. The filtration apparatus 4 is configured to be able to wash the filter medium (implement a back washing process and a water washing process).

  That is, at the time of the back washing process, the washing water is supplied to the filter medium via the back washing water supply line L5 (described later) (in this embodiment, it is treated water W2. Hereinafter, it may be referred to as “back washing water” as appropriate). Is supplied, and the suspended substance trapped by the filter medium is discharged out of the system together with the washing water. In the water washing step, in order to rinse the back-washed filter medium, rinse water (raw water W1 in this embodiment) is supplied to the filter medium, and the rinse water rinsed with the filter medium is configured to be discharged out of the system. .

  The filter tower 5 has a filter medium (not shown) for filtering suspended substances. The control valve 6 switches the flow path of water (raw water W1, treated water W2, backwash water or rinsing water at the time of cleaning the filter medium) flowing into or out of the filter tower 5. The control valve 6 is electrically connected to a control device 30 (described later). The control valve 6 is controlled to switch the flow path by a control device 30 (described later). The control valve 6 functions as a cleaning unit.

  The drainage line L4 is connected to the control valve 6 and discharges backwash water (treated water W2) at the time of washing the filter medium, which will be described later, rinse water (raw water W1) at the time of washing the filter medium, and the like. The drain line L4 functions as a cleaning means.

  The filtration processing device 4 is configured to be backwashable by the treated water W2 (backwash water) supplied from the treated water tank 8 via the backwash water supply line L5. The upstream end of the backwash water supply line L5 is connected to the treated water tank 8. The downstream end of the backwash water supply line L5 joins the raw water line L1 at the junction J3.

  The backwash water supply pump 15 is provided on the upstream side of the backwash water supply line L5. The backwash water supply pump 15 sends the treated water W2 as backwash water toward the downstream junction J3. The backwash water supply pump 15 is electrically connected to a control device 30 (described later). The operation (drive and stop) of the backwash water supply pump 15 is controlled by the control device 30. The backwash water supply pump 15 functions as a cleaning means.

  The backwash valve 16 is provided on the downstream side of the backwash water supply line L5. The backwash valve 16 opens and closes the backwash water supply line L5. The backwash valve 16 is electrically connected to a control device 30 (described later). The backwash valve 16 is controlled to be opened and closed by the control device 30. The backwash valve 16 functions as a cleaning means.

  The filtration device 4 is variously selected according to the substance to be removed in the raw water W1. Examples of the filtration processing device 4 include the following sand filtration device, iron removal manganese removal device, and activated carbon filtration device. All of these apparatuses can capture and remove suspended substances contained in the raw water W1 by the sieving effect of the filter medium.

  The sand filtration device captures and removes suspended substances such as fine particles contained in the raw water W1 with a filter medium (not shown). Examples of the sand filtration device include a tower type having a filter medium layer (not shown) formed from a coarse filter medium such as meteorite and a fine filter medium such as anthracite and filter sand. When a sand filtration device is used as the filtration processing device 4, it is necessary to make the suspended substances contained in the raw water W1 coagulate (floc) and easily remove them. Therefore, the flocculant is added by the flocculant adding device 11 arranged on the upstream side of the filtration tower 5. As the flocculant, for example, an inorganic flocculant can be used, and specifically, aluminum flocculants such as polyaluminum chloride (PAC) and aluminum sulfate, and iron flocculants ferric chloride and sulfuric acid. Examples thereof include ferric iron and polysilica iron (PSI).

  The iron removal manganese removal apparatus captures and removes dissolved iron and dissolved manganese together with suspended substances such as fine particles contained in the raw water W1 with a filter medium (not shown), and a filtration tower packed with the filter medium. It has. Usually, particulate manganese chamotte or manganese zeolite is used for the filter medium. Moreover, when an iron removal manganese removal apparatus is used as the filtration processing apparatus 4, it removes, after oxidizing the dissolved iron and dissolved manganese contained in raw | natural water W1. Therefore, the flocculant addition device 11 disposed on the upstream side of the filtration tower 5 adds the flocculant to aggregate the suspended substances such as fine particles, and the oxidant addition device disposed on the upstream side of the filtration tower 5. (Not shown), an oxidizing agent (for example, sodium hypochlorite) is added to oxidize dissolved iron and dissolved manganese.

  Specifically, the dissolved iron contained in the raw water W1 is oxidized by the action of the oxidant, and is converted into ferric hydroxide through insoluble ferrous hydroxide (that is, suspended into a substance). Filtered by the filter medium. When the dissolved manganese contained in the raw water W1 comes into contact with the filter medium by the action of the oxidizing agent, the oxidation proceeds and is adsorbed and removed by the filter medium.

The activated carbon filter removes impurities such as organic substances, chromaticity components, and odor components together with suspended substances contained in the raw water W1 with a filter medium made of an adsorbent, and includes a filter tower filled with the adsorbent. ing. Usually, particulate or fibrous activated carbon is used as the adsorbent. Then, in order to agglomerate the suspended substance, the aggregating agent is added by the aggregating agent adding device 11 arranged on the upstream side of the filtration tower 5.
The activated carbon filtration device may be used in combination with the sand filtration device and / or the iron removal manganese removal device. In that case, it is preferable to arrange the activated carbon filtration device on the downstream side of the sand filtration device and / or the iron removal manganese removal device. This is because, for example, residual chlorine derived from the oxidizing agent that has passed through the iron removal manganese removal apparatus can be decomposed by the activated carbon filtration apparatus by arranging in this way.

A treated water line L2 is connected to the filtration device 4 configured as described above.
Next, components related to the treated water line L2 and the treated water line L2 will be described. The upstream end of the treated water line L2 is connected to the filtration device 4 (control valve 6). The downstream end of the treated water line L2 is connected to the treated water tank 8. In the treated water line L2, treated water W2 produced by the filtration device 4 flows.
A water supply valve 7 is provided in the treated water line L2. The water supply valve 7 opens and closes the treated water line L2. The water supply valve 7 is electrically connected to a control device 30 (described later). Opening and closing of the water supply valve 7 is controlled by the control device 30.

  The turbidimeter for treated water 18 is connected to the treated water line L2 at a measurement point J4. The turbidity meter for treated water 18 measures the turbidity of the treated water W2 flowing through the treated water line L2. That is, the turbidity meter for treated water 18 functions as a turbidity detecting means for measuring the turbidity of the treated water W2 on the outlet side of the filtration device 4. The treated water turbidimeter 18 is electrically connected to a control device 30 (described later). The signal measured by the treated water turbidimeter 18 is input to the control device 30.

  Moreover, the flowmeter 19 is connected to the treated water line L2 at the measurement point J5. The flow meter 19 measures the integrated flow rate of the treated water W2 flowing through the treated water line L2. That is, the flow meter 19 detects the accumulated usage amount per unit time of the treated water W2 by the system maintenance manager. The flow meter 19 is electrically connected to a control device 30 (described later). A signal measured by the flow meter 19 is input to the control device 30. In the control device 30, the integrated flow rate per unit time of the treated water W2 is calculated based on the signal measured by the flow meter 19. The history of the integrated flow rate is stored in the memory unit 40 described later. In addition, the flow meter 19 can also be provided in the treated water distribution line L3 mentioned later.

The treated water tank 8 is connected to the downstream end of the treated water line L2. The treated water tank 8 stores treated water W2.
The treated water tank 8 includes a water level gauge 8a. The water level meter 8a measures the water level of the treated water W2 stored in the treated water tank 8. The water level gauge 8a is electrically connected to a control device 30 (described later). The signal measured by the water level gauge 8a is input to the control device 30. The water level of the treated water tank 8 is calculated by the control device 30.

  In the filtration apparatus 4 of this embodiment, when the distribution of the treated water W2 is requested, the treated water distribution pump 9 described later is operated, and the treated water W2 in the treated water tank 8 is distributed to the demand location. For this reason, the water level gauge 8a detects a decrease in water and full water in the treated water tank 8 to determine the feed start timing and feed stop timing of the treated water W2 (that is, drive and stop timing of the raw water pump 2) during the filtration process. be able to.

  Further, a backup water supply line Lb is connected to the treated water tank 8. In the case where the storage amount of the treated water W2 in the treated water tank 8 is insufficient with respect to the demand amount of the treated water W2, the backup water supply line Lb is treated water or clean water produced by a separate filtration system or the like. Is supplied to the treated water tank 8.

  A backup water supply valve 26 is provided in the backup water supply line Lb. The backup water supply valve 26 opens and closes the backup water supply line Lb. The backup water supply valve 26 is electrically connected to a control device 30 (described later). The backup water supply valve 26 is controlled to be opened and closed by the control device 30.

The treated water distribution line L3 distributes the treated water W2 downstream. The upstream end of the treated water distribution line L3 is connected to the treated water tank 8. The downstream end of the treated water distribution line L3 is connected to a demand point (not shown) of the treated water W2. As described above, the flow meter 19 can be provided in the treated water distribution line L3 instead of the treated water line L2.
A treated water distribution pump 9 is provided in the treated water distribution line L3. The treated water distribution pump 9 sends treated water W2 from the treated water tank 8 to a downstream demand point (not shown). The treated water distribution pump 9 is electrically connected to a control device 30 (described later). Operation (drive and stop) of the treated water distribution pump 9 is controlled by the control device 30.

  Next, functions related to control of the filtration system 1 of the first embodiment will be described with reference to FIGS. FIG. 2 is a functional block diagram relating to the control of the filtration system 1 of the first embodiment. FIG. 3 is a diagram illustrating a setting example of the cleaning time set based on the turbid trapping amount and the addition ratio of the flocculant. FIG. 4 is a diagram showing the relationship between the amount of trapped turbidity and the cleaning time when the addition ratio of the flocculant is used as a parameter.

  The control apparatus 30 controls each part in the filtration system 1 of 1st Embodiment. As shown in FIG. 2, the control device 30 includes, for example, the raw water pump 2, the treated water distribution pump 9, the flocculant addition pump 11b, the backwash water supply pump 15, the raw water valve 3, the control valve 6, the water supply valve 7, The wash valve 16 and the backup water supply valve 26 are electrically connected.

  In addition, the control device 30 is electrically connected to each measurement device in the filtration system 1, and information on the addition amount of the flocculant set and input from a predetermined keyboard (described later) and measurement information measured by each measurement device. Receive. The measuring devices are, for example, a flow meter 19, a water level meter 8a, a raw water turbidity meter 10, and a treated water turbidity meter 18. The control device 30 is electrically connected to a keyboard (not shown) for inputting the amount of flocculant and various settings.

  The control device 30 includes a control unit 31 and a memory unit 40. The control unit 31 includes a time information measurement unit 32, a turbid trapping amount calculation unit 33 as a turbid trapping amount calculation unit, a flocculant addition ratio calculation unit 34 as a flocculant addition rate calculation unit, and a cleaning operation execution request. A cleaning operation execution request determination unit 35 as a determination unit, a cleaning time setting unit 36 as a cleaning time setting unit, and a cleaning operation execution control unit 37 as a cleaning operation execution control unit are provided.

  The time information measuring unit 32 measures the accumulated water passing time (filtering continuation time) of the raw water W1 to the filtration device 4. Further, the time information measuring unit 32 measures the elapsed back washing time and the elapsed water washing time. The time information measurement unit 32 measures time information such as the current time.

  The turbidity trapping amount calculation unit 33 calculates the turbidity trapping amount (the turbidity trapping amount per unit filter medium amount) of the filtration apparatus 4 by the following equation (1).

Turbid trapping amount = instantaneous flow rate of treated water x passing time x {(turbidity of raw water at the inlet side of the filtration apparatus-turbidity of treated water at the outlet side of the filtration apparatus) + coagulant addition amount} / filter medium Amount of ... (1)
Here, the “instantaneous flow rate of treated water” in Equation (1) is the instantaneous flow rate of treated water W2 measured by the flow meter 19. The “water passage time” is an accumulated water passage time from the previous cleaning operation to the present time in the filtration apparatus 4. The “water passing time” is measured by the time information measuring unit 32 of the control device 30.

  The “turbidity of raw water on the inlet side of the filtration apparatus” is the turbidity of the raw water W1 on the inlet side of the filtration apparatus 4 (the amount of suspended matter contained in a unit amount of raw water). The turbidity of the raw water W1 is measured by the turbidimeter 10 for raw water.

  “Turbidity of treated water on the outlet side of the filtration apparatus” is the turbidity of the treated water W2 on the outlet side of the filtration apparatus 4 (amount of suspended matter contained in a unit amount of treated water). That is, the turbidity (hereinafter referred to as “treated water turbidity”) leaked into the treated water W2 due to a decrease in the filtration capacity of the filtered material due to an increase in the amount of trapped turbidity in the filtration device 4. The treated water turbidity is measured by the treated water turbidimeter 18.

  The “coagulant addition amount” is the amount of the coagulant added to the raw water W1 by the coagulant addition device 11 (the amount of the coagulant contained in the unit amount of raw water). The addition amount of the flocculant is set and input by a system maintenance manager from an input means (not shown). The “amount of filter medium” is the amount (usually volume) of the filter medium of the filtration apparatus 4 and is a known value.

  The flocculant addition ratio calculation unit 34 calculates the addition ratio of the flocculant added to the raw water W1 by the flocculant addition apparatus 11. The addition ratio of the flocculant is appropriately changed according to the addition amount of the flocculant or the dilution amount of the flocculant.

  The cleaning operation execution request determination unit 35 determines whether or not the filtration processing device 4 has requested execution of the filter medium cleaning operation. The execution request for the cleaning operation is output when the turbidity of the treated water W2 exceeds a predetermined value.

  The cleaning time setting unit 36 determines the cleaning time (reverse cleaning) of the filter medium based on the turbid trapping amount calculated by the turbid trapping amount calculation unit 33 and the flocculant addition ratio calculated by the flocculant addition ratio calculation unit 34. Time and washing time). The back washing time and the water washing time are individually set as will be described later.

  Specifically, the cleaning time setting unit 36, as shown separately in (a), (b), and (c) in FIG. Set the washing time (back washing time and water washing time). Here, (A) shows a case where the amount of trapped turbidity is large and the addition ratio of the flocculant is small. In this case (a), the cleaning time is set to, for example, 25 minutes (reverse cleaning time of 15 minutes, water cleaning time of 10 minutes).

  (B) shows a case where the trapped amount of turbidity is as small as about 70% in the case of (A), but the addition ratio of the flocculant is about 300% in the case of (A). Therefore, in the case of (b), it is necessary to carry out the cleaning operation in consideration of the viscosity (adsorption force) of the flocculant as compared with the case of (b). Therefore, in the case of (b), the cleaning time setting unit 36 sets the cleaning time longer than the cleaning time in the case of (a), for example, the cleaning time is 35 minutes (reverse cleaning time is 20 minutes). The washing time is set to 15 minutes).

  (C) shows the case where the trapped amount of turbidity is about 30% of the case (B), and the addition ratio of the flocculant is zero. Therefore, in the case of (C), the cleaning operation can be performed without considering the viscosity (adsorption force) of the flocculant as compared with the case (A). Therefore, in the case of (C), the cleaning time setting unit 36 sets the cleaning time to be shorter than the cleaning time in the case of (A). For example, the cleaning time is set to 10 minutes (reverse cleaning time is 5 minutes). Set the washing time to 5 minutes.

  Next, the relationship between the amount of trapped turbidity and the cleaning time when the addition ratio of the flocculant is used as a parameter will be described with reference to FIG. In FIG. 4, a straight line 41 shows the relationship between the amount of trapped turbidity and the cleaning time when the addition ratio a of the flocculant is, for example, zero. In the straight line 41, when the trapped amount of turbidity is a constant value S, the cleaning time is set to T1.

  The straight line 42 shows the relationship between the amount of trapped turbidity and the cleaning time when the addition ratio a of the flocculant is, for example, 0.01. In the straight line 42, when the trapped amount of turbidity is a constant value S, the cleaning time is set to T2 (> T1). Moreover, the straight line 43 shows the relationship between the amount of trapped turbidity and the cleaning time when the addition ratio a of the flocculant is, for example, 0.02. In the straight line 43, when the trapped amount of turbidity is a constant value S, the cleaning time is set to T3 (> T2).

  As described above, when the trapped amount of turbidity is constant, the cleaning time setting unit 36 sets the cleaning time longer as the addition ratio of the flocculant increases in consideration of the viscosity (adsorption force) of the flocculant. Moreover, when the filtration tower 5 of the filtration apparatus 4 is large and the amount of the filter medium is large, the amount of trapped turbidity is also increased. Therefore, the cleaning time setting unit 36 sets the cleaning time longer as the amount of trapped turbidity increases.

Further, the cleaning time setting unit 36 can also calculate the cleaning time by the following equation (2).
Washing time = (1 + a) × (turbidity trapping amount) + b (2)
In the formula (2), a is the addition ratio of the flocculant. b is an aging deterioration coefficient set according to the degree of aging of the filter medium.

  As described above, the cleaning time setting unit 36 sets the cleaning time longer as the turbid trapping amount calculated by the turbid trapping amount calculation unit 33 increases, and is calculated by the flocculant addition ratio calculation unit 34. The larger the addition ratio of the flocculant, the longer the cleaning time is set. Accordingly, when the trapped amount of turbidity is small, the cleaning time can be shortened and the cleaning water can be saved. Moreover, when there is much turbidity capture | acquisition amount, a filter medium can be wash | cleaned reliably and the capture | acquisition capability of a filter medium can be recovered at an early stage.

  The cleaning time setting unit 36 sets a cleaning time in consideration of the viscosity (adsorption force) of the flocculant. Therefore, the life of the filter medium can be extended. The washing time setting unit 36 individually sets the back washing time and the water washing time based on the amount of trapped turbidity and the addition ratio of the flocculant. Thereby, the filter medium is finely washed according to the pollution situation. Therefore, the filter medium can be washed quickly and reliably while saving washing water.

  Next, the cleaning operation execution control unit 37 will be described with reference to FIG. When it is determined that the cleaning operation execution request determined by the cleaning operation execution request determination unit 35 is made, the cleaning operation execution control unit 37 performs the reverse cleaning time and the water cleaning time set by the cleaning time setting unit 36. The back washing process and the water washing process are carried out based on

  Specifically, when performing the reverse cleaning process, the cleaning operation execution control unit 37 switches the control valve 6 to the flow path setting for the reverse cleaning process and closes the raw water valve 3 and the water supply valve 7. Then, the backwash valve 16 is opened. Then, the backwash water supply pump 15 is operated for the set backwash time and then stopped.

  When performing the washing process, the washing operation execution control unit 37 switches the control valve 6 to the flow setting for the washing process, closes the backwash valve 16 while the water supply valve 7 is closed, The raw water valve 3 is opened. Then, the raw water pump 2 is operated for the set washing time and then stopped.

  Further, the cleaning operation execution control unit 37 determines whether or not the cleaning operation is finished. Specifically, the cleaning operation execution control unit 37 determines whether or not the cleaning time (reverse cleaning time and water cleaning time) measured by the time information measuring unit 32 has reached the cleaning time set by the cleaning time setting unit 36. Determine whether.

  The memory unit 40 stores a control program and various data necessary for controlling the filtration system 1. Specifically, the memory unit 40 is a control program for operating various functions necessary for controlling the filtration system 1, various measurement data measured by the measurement devices, and input input from an input unit (not shown). Data (for example, the turbidity data measured by the raw water turbidimeter 10 and the treated water turbidimeter 18, the flow data measured by the flow meter 19, the accumulated water passing time measured by the time information measuring unit 32, and Washing time, set amount of flocculant added and filter medium amount), various calculated values (for example, turbid trapping amount, flocculant addition ratio), various threshold values (for example, turbid trapping amount threshold, raw water turbidity) Threshold and treated water turbidity threshold).

  Next, the basic operation of the filtration system 1 of the first embodiment will be described with reference to FIG. In the case of a filtration process during normal operation, the control valve 6 of the filtration apparatus 4 is set as a flow path for the filtration process. When there is a distribution request for the treated water W2, the treated water distribution pump 9 is operated by the control device 30, whereby the treated water W2 stored in the treated water tank 8 is sent to the downstream demand point (distribution start). ). When the water level gauge 8a detects a decrease in the treated water tank 8, the control device 30 operates the raw water pump 2 and the flocculant addition pump 11b in the raw water line L1, and opens the raw water valve 3. . Further, the control device 30 opens the water supply valve 7 of the treated water line L2. In this case, the backwash water supply pump 15 in the backwash water supply line L5 is not operated, and the backwash valve 16 remains closed.

The raw water W1 is supplied to the raw water line L1 by the raw water pump 2. A predetermined flocculant is added by the flocculant adding device 11 at the addition point J2.
The raw water W <b> 1 to which the flocculant is added is introduced into the filtration tower 5 through the control valve 6 of the filtration processing device 4. In the filtration tower 5, the raw water W1 is caused to flow so as to descend with respect to the filter medium layer. Thereby, the suspended substance contained in the raw water W1 is captured by the filter medium, and the treated water W2 is produced. The manufactured treated water W2 is circulated to the treated water line L2 via the control valve 6 and stored in the treated water tank 8.

In the treated water line L2, the turbidity of the treated water W2 is measured by the treated water turbidimeter 18, and the integrated flow rate of the treated water W2 is measured by the flow meter 19. These pieces of measurement information are received by the control device 30.
When the distribution request for the treated water W2 disappears, the treated water distribution pump 9 is stopped by the control device 30 (distribution stop). Subsequently, when the water level gauge 8a detects that the treated water tank 8 is full, the control device 30 stops the raw water pump 2 and the flocculant addition pump 11b in the raw water line L1, and closes the raw water valve 3. The Further, the control device 30 closes the water supply valve 7 of the treated water line L2.

  When the control device 30 determines that the water level of the treated water W2 in the treated water tank 8 has reached a predetermined lower limit value, the control device 30 opens the backup water supply valve 26 of the backup water supply line Lb. Is done. Thereby, the backup water Wb is supplied to the treated water tank 8.

  Next, the washing operation (back washing process and water washing process) of the filtration apparatus 4 will be described. During the reverse cleaning process, the control device 30 (cleaning operation execution control unit 37) stops the raw water pump 2 in the raw water line L1, closes the raw water valve 3, and controls the control valve 6 of the filtration device 4. , The flow path for the reverse cleaning process is set. Further, the control device 30 closes the water supply valve 7 of the treated water line L2, operates the backwash water supply pump 15 in the backwash water supply line L5, and opens the backwash valve 16. Thereby, in the filtration tower 5, the treated water W2 is flowed so as to rise with respect to the filter medium layer, and the filter medium is developed. The backwash water after washing is discharged out of the system through the drain line L4. This reverse cleaning process is performed based on the reverse cleaning time (described later) set by the cleaning time setting unit 36.

  Further, during the water washing process, the control device 30 (cleaning operation execution control unit 37) operates the raw water pump 2 in the raw water line L1, opens the raw water valve 3, and controls the control valve 6 of the filtration device 4. Is set in the flow path for the water washing step. Further, the control device 30 maintains the water supply valve 7 of the treated water line L2 in the closed state, the backwash water supply pump 15 in the backwash water supply line L5 is stopped, and the backwash valve 16 is closed. The Thereby, in the filtration tower 5, the raw water W1 as rinsing water is caused to flow downward with respect to the filter medium layer, and the filter medium is rinsed. The rinsing water after the water washing is discharged out of the system through the drain line L4. This water washing step is performed based on the water washing time (described later) set by the washing time setting unit 36.

  After the cleaning operation by the control device 30 (cleaning operation execution control unit 37) is completed, the normal operation mode is restored. That is, the process returns to the filtration step to produce the treated water W2, the raw water valve 3 and the water supply valve 7 are opened, and the raw water pump 2 and the like are operated.

Next, characteristic control of the filtration system 1 of the first embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing the control of the filtration system 1 of the first embodiment.
As shown in FIG. 5, in step ST <b> 1, the system maintenance manager inputs the addition amount of the flocculant to the control device 30 using a keyboard (not shown). The control device 30 receives the data of the addition amount of the flocculant and stores it in the memory unit 40.

  In step ST2, the turbidity of the raw water W1 is detected by the turbidimeter 10 for raw water. Moreover, the turbidity of the treated water W2 is detected by the turbidimeter 18 for treated water. Furthermore, the instantaneous flow rate of the treated water W2 is detected by the flow meter 19. Further, the time information measuring unit 32 detects the accumulated water passage time from the previous cleaning operation in the filtration apparatus 4 to the present.

  In step ST3, the turbidity trapping amount calculation unit 33 calculates the turbidity trapping amount according to the above-described equation (1) based on the turbidity detected in step ST2.

  In step ST4, the flocculant addition ratio calculation unit 34 calculates the addition ratio of the flocculant added to the raw water W1.

In step ST <b> 5, the cleaning operation execution request determination unit 35 determines whether or not the filtration processing device 4 has requested execution of the filter medium cleaning operation. When the execution request | requirement of washing | cleaning operation is made in the filtration processing apparatus 4, it progresses to step ST6.
On the other hand, when the execution request | requirement of washing | cleaning operation is not made in the filtration processing apparatus 4, it returns to step ST1.

  In step ST6, the washing time setting unit 36 determines the washing time (back washing time and water washing time) of the filter medium based on the turbid trapping amount calculated in step ST3 and the addition ratio of the flocculant calculated in step ST4. Set. Specifically, as described above, the cleaning time is set longer as the amount of trapped turbidity is larger, and the cleaning time is set longer as the addition ratio of the flocculant is larger. Further, the back washing time and the water washing time are individually set based on the amount of trapped turbidity and the addition ratio of the flocculant.

  In step ST7, the cleaning operation execution control unit 37 prepares for the transition to the cleaning operation (back cleaning process). Specifically, the cleaning operation execution control unit 37 switches the control valve 6 to the flow path setting for the reverse cleaning process, closes the raw water valve 3 and the water supply valve 7, and opens the backwash valve 16.

  In step ST8, the cleaning operation execution control unit 37 performs the cleaning operation of the filter medium of the filtration device 4 based on the cleaning time set in step ST6. That is, the cleaning operation execution control unit 37 operates the backwash water supply pump 15 based on the backwash time individually set in step ST6, and performs the backwash process.

  Subsequently, the cleaning operation execution control unit 37 prepares for the transition to the water washing step. Specifically, the cleaning operation execution control unit 37 switches the control valve 6 to the flow path setting for the water washing process, closes the backwash valve 16 with the water supply valve 7 closed, and opens the raw water valve 3. To do. And based on the water washing time set in step ST6, the raw | natural water pump 2 is drive | operated and a water washing process is implemented.

  As described above, the cleaning operation execution control unit 37 cleans the filter medium with a longer cleaning time as the turbidity trapping amount calculated by the turbidity trapping amount calculation unit 33 increases, and calculates by the flocculant addition ratio calculation unit 34. As the added ratio of the flocculant added is larger, the filter medium is washed with a longer washing time. As a result, when the amount of trapped turbidity is small, the cleaning time is shortened and the amount of cleaning water (treated water W2 and raw water W1) used can be reduced. Moreover, the water stop time (distribution stop time) of the treated water W2 can be shortened (reduced). Further, since the back washing time and the water washing time can be set individually, a fine washing operation can be performed according to the degree of decrease in the trapping ability of the filter medium.

  In step ST <b> 9, the cleaning operation execution control unit 37 determines whether the set cleaning time (reverse cleaning time and water cleaning time) has elapsed based on the time information measured by the time information measuring unit 32. That is, it is determined whether or not the cleaning time set by the cleaning time setting unit 36 has elapsed and the cleaning operation (reverse cleaning process and water cleaning process) by the cleaning operation execution control unit 37 has ended.

  In step ST9, when the cleaning operation is finished (YES), this control is finished, and the operation mode returns to the normal filtration process. That is, the process returns to the filtration step to produce the treated water W2.

  On the other hand, if the cleaning operation by the cleaning operation execution control unit 37 is not completed (NO), the process returns to step ST8 and the cleaning operation is performed until the set cleaning time has elapsed.

According to the filtration system 1 of 1st Embodiment demonstrated above, each effect shown below is show | played.
The filtration system 1 of the first embodiment includes a turbidity trapping amount calculation unit 33 that calculates a turbidity trapping amount, a flocculant addition rate calculation unit 34 that calculates a flocculant addition rate, and a filtration processing device 4 that uses a filter medium. When it is determined that the cleaning operation execution request determination unit 35 determines whether or not the cleaning operation execution request is made, and the cleaning operation execution request is made, the turbidity trapping amount calculation unit 33 calculates Based on the turbidity trapping amount and the addition rate of the flocculant calculated by the flocculant addition rate calculation unit 34, the cleaning time setting unit 36 that sets the cleaning time of the filter medium based on the addition rate of the flocculant, and the cleaning time set by the cleaning time setting unit 36 Based on this, the control valve 6, the backwash water supply pump 15, the backwash valve 16, the raw water pump 2, the raw water valve 3, and the like are provided so as to perform the cleaning operation.

  Therefore, according to the filtration system 1 of 1st Embodiment, the washing | cleaning time which considered the contamination condition of the filter medium by a suspended solid and the viscosity (adsorption force) of the coagulant | flocculant adsorbed on the filter medium can be set. Thereby, it is possible to quickly and surely wash the filter medium while saving washing water (treated water W2 and raw water W1), and it is possible to easily recover the filter medium capturing ability.

Moreover, in the filtration system 1 of 1st Embodiment, the washing | cleaning time setting part 36 sets washing | cleaning time long, so that there is much turbidity trapping amount calculated by the turbidity trapping amount calculation part 33, and calculates a flocculant addition ratio. The larger the flocculant addition ratio calculated by the section 34, the longer the cleaning time.
Therefore, when the amount of trapped turbidity is small, the washing time can be shortened and washing water can be saved. Moreover, when there is much turbidity capture | acquisition amount, a filter medium can be wash | cleaned reliably and the capture | acquisition capability of a filter medium can be recovered at an early stage.

  In addition, the cleaning time can be set in consideration of the viscosity (adsorption force) of the flocculant. Therefore, when the addition ratio of the flocculant is small, the cleaning time can be shortened and the cleaning water can be saved. Moreover, when the addition ratio of a flocculant is large, a filter medium can be wash | cleaned reliably and the capture | acquisition capability of a filter medium can be recovered early. Moreover, the lifetime of a filter medium can be extended by washing | cleaning a filter medium reliably.

In the filtration system 1 of the first embodiment, the backwash time and the water wash time are calculated by the turbid trapping amount and the flocculant addition ratio calculating unit 34 calculated by the turbid trapping amount calculating unit 33. It is set individually based on the addition ratio of.
Therefore, it is possible to finely clean the filter medium according to the state of contamination of the filter medium, and it is possible to clean the filter medium quickly and reliably while saving washing water.

  Next, another embodiment of the present invention will be described. The other embodiments will be described mainly with respect to points different from the control method of the first embodiment. The same reference numerals are given to the same configurations as those of the first embodiment, and detailed descriptions thereof will be omitted. For the points not specifically described in other embodiments, the description of the first embodiment is appropriately applied or incorporated.

[Second Embodiment]
Next, the configuration of a filtration system 1A according to the second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a configuration diagram illustrating a filtration system 1A according to the second embodiment.

  In the filtration system 1 (see FIG. 1) of the first embodiment, the washing operation (back washing process and water washing process) is controlled based on the washing time, whereas in the filtration system 1A of the second embodiment of the present invention. Controls the cleaning operation based on the amount of cleaning water. Here, the “amount of washing water” includes the amount of washing water used in the reverse washing step and the amount of rinsing water used in the washing step, and is an integrated flow of washing water and an integrated flow of rinsing water.

  As shown in FIG. 6, the filtration system 1 </ b> A of the second embodiment of the present invention includes a flush water flow meter 27 in addition to the configuration of the filtration system 1 (see FIG. 1) of the first embodiment. Since the other configuration of the filtration system 1A of the second embodiment is the same as the configuration of the filtration system 1 of the first embodiment, a duplicate description is omitted.

  The washing water flow meter 27 is connected to the raw water line L1 at a measurement point J6. The measurement point J6 is located on the downstream side of the junction point J3 in the raw water line L1. The washing water flow meter 27 measures the integrated flow rate of the washing water (raw water W1 and treated water W2). The washing water flow meter 27 is electrically connected to a control device 30A (described later). The signal measured by the washing water flow meter 27 is input to the control device 30A.

Next, with reference to FIG. 7, the function which concerns on control of 1 A of filtration systems of 2nd Embodiment is demonstrated. FIG. 7 is a functional block diagram relating to the control of the filtration system 1A of the second embodiment.
The control device 30A controls each part in the filtration system 1A of the second embodiment. As shown in FIG. 7, the control device 30A includes, for example, the raw water pump 2, the treated water distribution pump 9, the flocculant addition pump 11b, the backwash water supply pump 15, the raw water valve 3, the control valve 6, the water supply valve 7, and the reverse The wash valve 16 and the backup water supply valve 26 are electrically connected.

  Further, the control device 30A is electrically connected to each measuring device in the filtration system 1A, and the information on the addition amount of the flocculant set and inputted from a predetermined keyboard (described later) and the measurement information measured by each measuring device. Receive. The measuring device is obtained by adding a washing water flow meter 27 to the measuring device of the first embodiment (see FIG. 2). Further, a keyboard (not shown) for inputting the amount of the flocculant and various settings is electrically connected to the control device 30A.

  The control device 30A includes a control unit 31A and a memory unit 40A. The control unit 31A includes a time information measuring unit 32, a turbid trapping amount calculating unit 33 serving as a turbid trapping amount calculating unit, a flocculant addition rate calculating unit 34 serving as a flocculant addition rate calculating unit, and a cleaning operation execution request. A cleaning operation execution request determination unit 35 as a determination unit, a cleaning water amount setting unit 38 as a cleaning water amount setting unit, and a cleaning operation execution control unit 37 as a cleaning operation execution control unit are provided.

  The time information measurement unit 32, the turbid trapping amount calculation unit 33, the flocculant addition ratio calculation unit 34, the cleaning operation execution request determination unit 35, and the cleaning operation execution control unit 37 are configured in the filtration system 1 of the first embodiment. Because of this, duplicate explanation is omitted.

  The cleaning water amount setting unit 38 sets the cleaning water amount based on the turbidity trapping amount calculated by the turbidity trapping amount calculation unit 33 and the flocculant addition ratio calculated by the flocculant addition ratio calculation unit 34. Specifically, according to the case where the washing time setting unit 36 of the first embodiment sets the washing time (back washing time and water washing time) of the filter medium based on the turbid trapping amount and the addition ratio of the flocculant. The cleaning water amount setting unit 38 sets the cleaning water amount.

  That is, the washing water amount setting unit 38 sets the washing water amount as the turbidity trapping amount calculated by the turbidity trapping amount calculating unit 33 increases, and the flocculant addition ratio calculated by the flocculant addition ratio calculating unit 34 is set. The larger the is, the larger the amount of washing water is set. The cleaning water amount setting unit 38 individually sets the amount of cleaning water (treated water W2) used in the reverse cleaning step and the amount of rinsing water (raw water W1) used in the washing step.

  Next, the cleaning operation execution control unit 37 will be described with reference to FIG. When it is determined that the cleaning operation execution request determined by the cleaning operation execution request determination unit 35 has been made, the cleaning operation execution control unit 37 reverses based on the cleaning water amount set by the cleaning water amount setting unit 38. A washing process and a water washing process are performed.

  Specifically, when performing the reverse cleaning process, the cleaning operation execution control unit 37 switches the control valve 6 to the flow path setting for the reverse cleaning process and closes the raw water valve 3 and the water supply valve 7. Then, the backwash valve 16 is opened. Then, the backwash water supply pump 15 is operated, and the operation of the backwash water supply pump 15 is stopped when the integrated flow rate of the backwash water reaches a set value.

  When performing the washing process, the washing operation execution control unit 37 switches the control valve 6 to the flow setting for the washing process, closes the backwash valve 16 while the water supply valve 7 is closed, The raw water valve 3 is opened. And the raw | natural water pump 2 is drive | operated, and the operation | movement of the raw | natural water pump 2 is stopped when the integrated flow volume of the rinse water becomes a set value so that it may mention later.

  Further, the cleaning operation execution control unit 37 determines whether or not the cleaning operation is finished. Specifically, the cleaning operation execution control unit 37 determines whether or not the integrated flow rate of backwashing water and the integrated flow rate of rinsing water have reached respective set values.

  The memory unit 40A stores a control program and various data necessary for controlling the filtration system 1A. Specifically, the memory unit 40A has a control program for operating various functions necessary for controlling the filtration system 1A, various measurement data measured by the measurement devices, and input input from an input unit (not shown). Data (for example, turbidity data measured by the raw water turbidity meter 10 and the treated water turbidity meter 18, integrated flow rate data measured by the flow meter 19 and the wash water flow meter 27, and the setting input flocculant Added amount and amount of filter medium), various calculated values (for example, turbidity trapping amount, flocculant addition ratio), various threshold values (for example, turbidity trapping amount threshold value, raw water turbidity threshold value and treated water turbidity value) Threshold).

Next, characteristic control of the filtration system 1A of the second embodiment will be described with reference to FIG. FIG. 8 is a flowchart showing control of the filtration system 1A of the second embodiment.
As shown in FIG. 8, steps ST11 to ST15 in the control of the filtration system 1A of the second embodiment are the same as steps ST1 to ST5 in the control of the filtration system 1 of the first embodiment (see FIG. 5). Therefore, a duplicate description is omitted and the description will be made from step ST16.

  In step ST16, the cleaning water amount setting unit 38 sets the cleaning water amount based on the turbidity trapping amount calculated in step ST13 and the flocculant addition ratio calculated in step ST14. Specifically, the washing water amount setting unit 38 sets the washing water amount as the turbidity trapping amount increases, and sets the washing water amount as the flocculant addition ratio increases. The cleaning water amount setting unit 38 individually sets the amount of cleaning water (treated water W2) used in the reverse cleaning step and the amount of rinsing water (raw water W1) used in the washing step.

  In step ST <b> 17, the cleaning operation execution control unit 37 prepares to shift to the cleaning operation (back cleaning process). Specifically, the cleaning operation execution control unit 37 switches the control valve 6 to the flow path setting for the reverse cleaning process, closes the raw water valve 3 and the water supply valve 7, and opens the backwash valve 16.

  In step ST18, the cleaning operation execution control unit 37 performs the cleaning operation of the filter medium of the filtration apparatus 4 based on the amount of cleaning water set in step ST16. That is, the cleaning operation execution control unit 37 first operates the backwashing water supply pump 15 and performs the backwashing process by the amount of cleaning water set in step ST16.

  Subsequently, the cleaning operation execution control unit 37 prepares for the transition to the water washing step. Specifically, the cleaning operation execution control unit 37 switches the control valve 6 to the flow path setting for the water washing process, closes the backwash valve 16 with the water supply valve 7 closed, and opens the raw water valve 3. To do. And the raw | natural water pump 2 is drive | operated and the water washing process is implemented only for the amount of water of the rinse water set in step ST16.

  As described above, the washing operation execution control unit 37 cleans the filter medium with a larger amount of washing water as the turbidity trapping amount calculated by the turbidity trapping amount calculation unit 33 increases, and calculates by the flocculant addition ratio calculation unit 34. As the added ratio of the flocculant is increased, the filter medium is washed with a larger amount of washing water. As a result, when the amount of trapped turbidity is small, the cleaning time is shortened and the amount of cleaning water (treated water W2 and raw water W1) used can be reduced. Moreover, the water stop time (distribution stop time) of the treated water W2 can be shortened (reduced). In addition, since the amount of backwash water (treated water W2) and the amount of rinse water (raw water W1) can be set individually, a fine washing operation is carried out according to the degree of reduction in the trapping ability of the filter medium. be able to.

In step ST19, the cleaning operation execution control unit 37 determines whether or not the cleaning operation has been completed. Specifically, the cleaning operation execution control unit 37 determines whether or not the amount of cleaning water (the integrated flow rate of backwashing water and the integrated flow rate of rinsing water) has reached the set value set in step ST16. When the cleaning operation is completed (YES), this control is completed and the operation mode of the normal filtration process is restored. That is, the process returns to the filtration step to produce the treated water W2.
On the other hand, if the cleaning operation by the cleaning operation execution control unit 37 is not completed (NO), the process returns to step ST18 and the cleaning operation is performed until the set amount of cleaning water is used.

According to 1 A of filtration systems of 2nd Embodiment demonstrated above, in addition to the effect similar to the case of filtration system 1 of 1st Embodiment, each effect shown below is show | played.
The filtration system 1A according to the second embodiment includes a turbid trapping amount calculating unit 33 that calculates a turbid trapping amount, a flocculant addition rate calculating unit 34 that calculates a flocculant addition rate, and a filtration processing device 4 that uses a filter medium. When it is determined that the cleaning operation execution request determination unit 35 determines whether or not the cleaning operation execution request is made, and the cleaning operation execution request is made, the turbidity trapping amount calculation unit 33 calculates The amount of washing water set by the washing water amount setting unit 38 and the washing water amount setting unit 38 for setting the washing water amount of the filter medium based on the addition rate of the flocculant calculated by the turbidity trapping amount and the flocculant addition ratio calculating unit 34 Based on this, the control valve 6, the backwash water supply pump 15, the backwash valve 16, the raw water pump 2, the raw water valve 3, and the like are provided so as to perform the cleaning operation.

  Therefore, according to the filtration system 1A of the second embodiment, it is possible to set the amount of washing water in consideration of the state of contamination of the filter medium due to the suspended substance and the viscosity (adsorption force) of the flocculant adsorbed on the filter medium. Thereby, while further saving the washing water (treated water W2 and raw water W1), the filter medium can be quickly and reliably washed, and the trapping ability of the filter medium can be easily recovered.

Next, the effect produced by the filtration system 1A of the second embodiment will be described in detail in comparison with the case of the filtration system 1 of the first embodiment.
In the filtration system 1 of the first embodiment, as described above, the back washing process and the water washing process are controlled by the washing time (the time during which the back washing valve 16 and the raw water valve 3 are opened). In this case, if the instantaneous flow rate of the treated water W2 or the raw water W1 varies in the reverse washing process or the water washing process, the amount of the treated water W2 used for the reverse washing or the amount of the raw water W1 used for the washing varies.

  That is, even if it is going to send the treated water W2 or raw water W1 water at a constant flow rate from the backwash water supply pump 15 or the raw water pump 2, if the pressure loss generated in the filtration tower 5 fluctuates, The flow rate fluctuates. In particular, as the suspended substance remains in the filter medium, the pressure loss generated in the filter tower 5 increases. This pressure loss also varies depending on the progress of the cleaning operation.

  If the instantaneous flow rate of the treated water W2 or the raw water W1 is reduced during the cleaning operation of the filter medium, the amount of water necessary for cleaning becomes insufficient. Therefore, there is a possibility that the suspended matter is discharged and rinsed incompletely and the quality of the treated water W2 is deteriorated. Therefore, in the control of the filtration system 1 of the first embodiment, it is necessary to take a longer washing time (back washing time and water washing time) in consideration of fluctuations in the instantaneous flow rates of the treated water W2 and the raw water W1.

  On the other hand, in the filtration system 1A of the second embodiment, the cleaning operation (back cleaning process and water cleaning process) is controlled based on a preset cleaning water amount (integrated flow rate). Therefore, the suspended matter can be completely discharged and rinsed. Therefore, in the filtration system 1A of the second embodiment, unlike the filtration system 1 of the first embodiment, it is not necessary to expect fluctuations in the instantaneous flow rates of the treated water W2 and the raw water W1. Therefore, in the filtration system 1A of the second embodiment, the back washing process and the water washing process can be completed in a short time, and the water stop time (distribution stop time) of the treated water W2 can be shortened.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be modified as appropriate.
For example, in the said 1st Embodiment and the said 2nd Embodiment, it demonstrated as what uses the treated water W2 for the backwashing water (washing water) at the time of a backwashing process, and uses raw | natural water W1 for the rinsing water at the time of a waterwashing process. However, it is not limited to this. For example, the treated water W2 may be used for backwashing water and rinsing water, or raw water W1 may be used for backwashing water and rinsing water.

  Moreover, in the said 2nd Embodiment, although the flowmeter 27 for washing water was demonstrated as what is connected to the raw | natural water line L1 in the measurement point J6, it is not restrict | limited to this. For example, the washing water flow meter 27 may be connected to the drain line L4. Further, when the treated water W <b> 2 is used for the backwash water and the rinse water, the flush water flow meter 27 may be connected to the backwash water supply line L <b> 5 on the downstream side of the backwash water supply pump 15.

  Moreover, in the water washing process of the said 1st Embodiment and the said 2nd Embodiment, when aiming at the further time shortening, you may control a required apparatus so that the instantaneous flow rate of rinsing water may be increased. For example, in the water washing step, it is only necessary that the retained water inside the filtration tower 5 can be discharged to the outside of the filtration tower 5. Therefore, for example, by increasing the instantaneous flow rate of the rinsing water (raw water W1) by the following means, the time required for the water washing step can be shortened.

  For example, as a first means, the operating frequency of the raw water pump 2 is controlled using an inverter, and the rotational speed of the raw water pump 2 during the water washing process is increased more than the rotational speed of the raw water pump 2 during the filtration process.

  Further, as a second means, a flow rate control valve (not shown) is provided in the raw water line L1 downstream of the raw water pump 2, and the valve opening degree of the flow rate control valve during the rinsing process is determined from the valve opening degree during the filtration process. Also make it bigger.

  Furthermore, as the third means, the first means and the second means may be used in combination. That is, the operating frequency of the raw water pump 2 is controlled using an inverter, and the number of revolutions of the raw water pump 2 during the rinsing process is increased more than the number of revolutions of the raw water pump 2 during the filtration process. The raw water line L1 is provided with a flow rate control valve (not shown), and the valve opening degree of the flow rate control valve during the water washing process is made larger than the valve opening degree during the filtration process.

1,1A Filtration system 2 Raw water pump (cleaning means)
3 Raw water valve (cleaning means)
4 Filtration processing equipment (filtration means)
6 Control valve (cleaning means)
10 Raw water turbidity meter (turbidity detection means)
11 Flocculant addition device (Flocculant addition means)
15 Backwash water supply pump (cleaning means)
16 Backwash valve (cleaning means)
18 Turbidimeter for treated water (turbidity detection means)
33 Turbidity trapping amount calculation unit (turbidity trapping amount calculation means)
34 Flocculant addition ratio calculation section (Flocculant addition ratio calculation means)
35 Cleaning operation execution request determination unit (cleaning operation execution request determination means)
36 Cleaning time setting section (cleaning time setting means)
37 Cleaning operation execution control unit (cleaning operation execution control means)
38 Washing water amount setting section (washing water amount setting means)
L1 Raw water line (cleaning means)
L4 Drainage line (cleaning means)
L5 Backwash water supply line (cleaning means)
W1 Raw water W2 Treated water

Claims (4)

Filtration means for producing suspended water by capturing suspended substances contained in raw water with a filter medium;
Cleaning means for performing a cleaning operation consisting of a reverse cleaning process and a water cleaning process on the filter medium,
A flocculant adding means for adding a flocculant to the raw water before the filtration treatment by the filtering means;
Pollution degree detection means for detecting the degree of pollution of the filter medium,
Based on the turbidity detected by the turbidity detection means, a turbidity trapping amount calculating means for calculating a turbidity trapping amount that is the amount of suspended matter trapped by the filter medium;
A flocculant addition ratio calculating means for calculating an addition ratio of the flocculant added to the raw water by the flocculant adding means;
A cleaning operation execution request determination unit that determines whether or not an execution request for the cleaning operation of the filter medium is made in the filtering unit;
When it is determined by the cleaning operation execution request determining means that a request for performing the cleaning operation is made in the filtering means, the turbid trapping amount calculated by the turbid trapping amount calculating means and the flocculant addition ratio calculation are calculated. Cleaning time setting means for setting the cleaning time of the filter medium based on the addition ratio of the flocculant calculated by the means;
Based on the cleaning time set by the cleaning time setting means, a cleaning operation execution control means for controlling the cleaning means to perform a cleaning operation;
Equipped with a,
The washing time setting means sets the washing time longer as the turbidity trapping amount calculated by the turbidity trapping amount calculating means is larger, and the flocculant addition ratio calculated by the flocculant addition ratio calculating means is larger. filtration system that set longer cleaning time about. The back washing time for performing the back washing step and the water washing time for carrying out the water washing step are the turbid trapping amount calculated by the turbid trapping amount calculating means and the flocculant calculated by the flocculant addition ratio calculating means. The filtration system according to claim 1, wherein the filtration system is individually set on the basis of the addition ratio. Filtration means for producing suspended water by capturing suspended substances contained in raw water with a filter medium;
Cleaning means for performing a cleaning operation consisting of a reverse cleaning process and a water cleaning process on the filter medium,
A flocculant adding means for adding a flocculant to the raw water before the filtration treatment by the filtering means;
Pollution degree detection means for detecting the degree of pollution of the filter medium,
Based on the turbidity detected by the turbidity detection means, a turbidity trapping amount calculating means for calculating a turbidity trapping amount that is the amount of suspended matter trapped by the filter medium;
A flocculant addition ratio calculating means for calculating an addition ratio of the flocculant added to the raw water by the flocculant adding means;
A cleaning operation execution request determination unit that determines whether or not an execution request for the cleaning operation of the filter medium is made in the filtering unit;
When it is determined by the cleaning operation execution request determining means that a request for performing the cleaning operation is made in the filtering means, the turbid trapping amount calculated by the turbid trapping amount calculating means and the flocculant addition ratio calculation are calculated. A washing water amount setting means for setting the washing water amount of the filter medium based on the addition ratio of the flocculant calculated by the means;
A cleaning operation execution control unit for controlling the cleaning unit to perform a cleaning operation based on the amount of cleaning water set by the cleaning water amount setting unit;
Equipped with a,
The washing water amount setting means sets the washing water amount as the turbidity trapping amount calculated by the turbidity trapping amount calculation unit increases, and the addition rate of the flocculant calculated by the flocculant addition rate calculation unit is large. filtration system that many set the amount of wash water about. The amount of washing water used in the back washing step and the amount of rinsing water used in the washing step are determined by the turbid trapping amount calculated by the turbid trapping amount calculating unit and the flocculant addition ratio calculating unit. The filtration system according to claim 3 , which is set individually based on the calculated addition ratio of the flocculant.

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