Technical field
[0001]
This invention relates to water treatment apparatus and backwash methods.
BACKGROUND
[0002]
Water treatment system seawater processing desalination comprises a desalination treatment apparatus using a reverse osmosis membrane or the like. Water treatment system for suppressing the performance degradation due to contamination of a reverse osmosis membrane desalination apparatus, upstream of the desalination apparatus, particulate matter in seawater biofilm filtration media biofilms for filtering bacteria like the filtration apparatus equipped with a includes a pre-processing unit.
[0003]
While utilizing water treatment system, it decreased filtration performance in the pretreatment section, sometimes quality variation of the treated water after filtration will awake.
　Therefore, for example, Patent Document 1, flow the cleaning water to the upstream side from the downstream side of the filter material layer of the filter, to implement a so-called backwashing, configured to remove discloses contaminants adhered to the biofilm.
　To do backwash of filter media layers of such a filtering device ensures that when the flow of washing water, it is necessary to flow the filter media such as sand which constitutes the filter medium layer.
CITATION
Patent Document
[0004]
Patent Document 1: JP 2015-142885 JP
Non-patent literature
[0005]
Non-Patent Document 1: MH Sharqawy, the outer two, "Thermophysical properties of seawater: a review of existing correlations and data", Desalination and Water Treatment, 2010 years. 4 dated 16 Day, P354-P380
Non-Patent Document 2: NP Fofonoff and RC Millard Jr., "Algorithms for computation of fundamental properties of seawater", Unesco Technical. Papers in Marine Science 44, 1983 Nian, P99-P188
Summary of the Invention
Problems that the Invention is to Solve
[0006]
　The or when water to be treated is seawater, it may properties of the water to be treated varies. For example, sea water, its viscosity and density by the water temperature varies. If the viscosity and density of the water to be treated varies, necessary for the flow to the filter material of the filter occurs, the flow rate of the washing water also changes. For example, the higher the viscosity of the water to be treated, in order to flow the filter material, it is necessary to inject the wash water at a higher flow rate. Therefore, most conditions need to determine the flow rate of the washing water on the assumption that poor, there is a problem that can not be efficiently backwash.
　This invention, even if variations in the properties of the water to be treated, and an object thereof is to provide a water treatment apparatus and backwash method capable of efficiently backwash the filter media.
Means for Solving the Problems
[0007]
　According to a first aspect according to the present invention, water treatment apparatus, a filtration apparatus having a filter medium layer subjected to filtration treatment with respect to the for-treatment water which is supplied from the upstream side, of the filter material layer to the filtration device a cleaning water supply unit capable of supplying washing water from the downstream side, and the cleaning water supply unit the flow rate adjusting unit that adjusts the flow rate of the washing water supplied to the filtering device by the flow rate of the washing water, the washing as water is the filter material layer downstream minimum of backwash flow rate can flow toward the upstream side from and a control device having a flow rate control unit for controlling the flow rate adjusting unit.
　According to such a configuration, the control by controlling the flow rate adjuster at a flow rate control unit of the apparatus, so that the washing water is equal to or greater than the lowest backwash flow rate allows flow toward the upstream side of the filter material layer from the downstream side , it is possible to adjust the flow rate of the washing water. Thus, even if the properties of the water to be treated and the cleaning water in the filtration unit is fluctuated, because the wash water flows toward the upstream side of the filter material layer from the downstream side, it is possible to backwash the filter medium layer efficiently it can.
[0008]
　According to a second aspect according to the present invention, water treatment apparatus, the water treatment apparatus of the first aspect, at least one of the density of the water to be treated in the washing water and in the filtration device in the cleaning water supply unit or further comprising a detection unit for obtaining a value related to viscosity, the control device may have a speed calculator for calculating the minimum backwash flow rate based on the value relating to the density or the viscosity.
　Thus, based on at least one of the density or viscosity of the water to be treated of the washing water and the filtration device, by calculating the minimum backwashing flow rate, washed with a flow rate control unit, the calculated minimum backwash flow rate than as the water flows, it is possible to control the flow rate adjuster. Accordingly, as the washing water is a filter material layer or minimum backwash flow rate allows flow toward the upstream side from the downstream side can be adjusted the flow rate of the washing water.
[0009]
　According to a third aspect according to the present invention, water treatment apparatus, the water treatment apparatus of the second aspect, at least one of the temperature of the water to be treated of values for the density and viscosity of the washing water and in the filtration device may be it.
　When the temperature of washing water and the water to be treated is changed, its viscosity varies. Therefore, by detecting the temperature of the washing water and the water to be treated, at a minimum backwash flow rate or a flow rate corresponding to the viscosity of the washing water or treated water, it is possible to perform backwashing of the filter material layer efficiently.
[0010]
　According to a fourth aspect according to the present invention, water treatment apparatus, the water treatment apparatus of the second aspect, at least one of salinity of the water to be treated of values for the density and viscosity of the washing water and in the filtration device may be is the concentration.
　Seawater, by rain water is fresh water is mixed with rain, there is a case where salinity varies. Further, seawater, fresh water from rivers and lakes in the region of inflow salinity varies relative to the surrounding region. In this manner, when the salt concentration in sea water varies, its viscosity varies. Therefore, by detecting the salt concentration in the wash water or water to be treated, at a minimum backwash flow rate or a flow rate corresponding to the viscosity of the washing water or treated water, it is possible to perform backwash of filter media layers.
[0011]
　According to a fifth aspect according to the present invention, water treatment apparatus, the flow of the filter material layer in the water treatment apparatus of the first aspect, in said filtration apparatus from the downstream side of the filtration device when supplying the wash water further comprising a flow detection unit that detects, the control device, backwash speed determination unit which determines the flow rate of the washing water flowing is detected in the filter material by the flow detecting unit as a flow rate of more than the minimum backwash flow rate it may have a.
　Thus, the flow of the filter medium layer when supplying washing water from the downstream side of the filter detected by the flow detecting unit, the flow rate of the washing water when the flow of the filter material is detected, minimum of backwash flow rate of by determining the flow rate, while checking the flow of filter material, it is possible to perform backwash of filter media layers.
[0012]
　According to a sixth aspect according to the present invention, water treatment apparatus, in any one of the water treatment apparatus of the first fifth aspect, the filter material layer of the filtration apparatus is also provided with a biofilm on the surface good.
　With a biofilm on the surface of the filter material layer, in a so-called biofilm filtration device, the flow rate of the washing water is too high, is destroyed biological membranes. Therefore, with at minimum backwash flow rate or at a flow rate to maintain a biofilm, by circulating the washing water can be reliably backwashing the filter medium layer.
[0013]
　According to a seventh aspect of the invention, the water treatment system includes a filtration apparatus having a filter medium layer subjected to filtration treatment with respect to the for-treatment water which is supplied from the upstream side, downstream of the filter material layer to the filtration device a cleaning water supply unit capable of supplying cleaning water from the side, a detector for detecting a value related to at least one of the density or viscosity of the flowing state and the water to be treated of the filter material layer, based on the value relating to the density or viscosity a display unit for displaying information, and an operator-operable operating unit, based on the operation signal sent by the operation of the operation unit is performed in accordance with the information displayed on the display unit, the washing water and a flow rate adjuster for adjusting the flow rate of the washing water supplied to the filtering device by the supply unit.
　According to such a configuration, the detection unit, for detecting a value regarding at least one of the density or viscosity of the flowing state and the water to be treated filter media layer. Information based on the value relating to the detected density or viscosity is displayed on the display unit. The operator views the information displayed on the display unit, the operator inputs a predetermined operation on the operation unit. Then, the operation unit transmits the operation signal corresponding to operation by the operator. Flow rate adjusting unit based on the operation signal sent by operating the operation unit, the flow rate of the washing water supplied to the filtering device by the cleaning water supply unit, the cleaning water toward the upstream side of the filter material layer from the downstream side flow it can be adjusted so as to be capable to become minimum backwash flow rate or more. Thus, even if the properties of the water to be treated and the cleaning water in the filtration unit is fluctuated, because the wash water flows toward the upstream side of the filter material layer from the downstream side, it is possible to backwash the filter medium layer efficiently it can.
[0014]
　According to an eighth aspect of the present invention, backwash method is a backwash method of filtration apparatus having a filter medium layer subjected to filtration treatment with respect to the for-treatment water which is supplied from the upstream side, the flow of the filter medium layer state and the detected values regarding at least one of the density or viscosity of the water to be treated, based on the value relating to the density or viscosity, the cleaning water is can flow the filter medium layer toward the downstream side to the upstream side flow rate the comprises the step of calculating, the step of initiating the supply of washing water toward the upstream side from the downstream side of the filter material layer, until the calculated the flow velocity, the step of increasing the flow rate of the washing water, the.
　In this way, based on at least one of the density or viscosity of the water to be treated of the washing water and the filtration device, the washing water is calculating the flow rate becomes possible flow toward the upstream side of the filter material layer from the downstream side be able to. Further, after starting the supply of the cleaning water to the filter media layers, wash water filter media layer from the downstream side to a flow rate which allows flow toward the upstream side, by increasing the flow rate of the washing water, in the filtration device even if the properties of the water to be treated and the cleaning water fluctuates, since the wash water flows toward the upstream side of the filter material layer from the downstream side, it is possible to reliably perform backwashing of the filter material layer.
[0015]
　According to a ninth aspect according to the present invention, backwash method, the backwash process of the eighth aspect, at least one of the temperature of the water to be treated of values for the density or viscosity is in the washing water and the filtration device may be it.
　When the temperature of washing water and the water to be treated is changed, its viscosity varies. Therefore, by detecting the temperature of the washing water and the water to be treated, at a flow rate that is set depending on the viscosity of the washing water or treated water, it is possible to perform backwashing of the filter material layer efficiently.
[0016]
　According to a tenth aspect according to the present invention, backwash method, the backwash process of the eighth aspect, at least one of salinity of the water to be treated of values for the density and viscosity of the washing water and in the filtration device may be is the concentration.
　When the salinity of the sea water is changed, the viscosity varies. Therefore, by detecting the salt concentration in the wash water or treated water, at a flow rate corresponding to the viscosity of the washing water or treated water, it is possible to perform backwashing of the filter material layer efficiently.
[0017]
　According to an eleventh aspect according to the present invention, backwash method, the backwash process of the eighth aspect, by supplying the washing water from the downstream side of the filtration device, the flow of the filter material layer within the filtration device and detecting the flow rate of the washing water when the flow of the filter material layer is detected, and determining a flow rate that enables the flow, may include a.
　Thus, to detect the flow of the filter medium layer when supplying washing water from the downstream side of the filter at a flow rate of the washing water when the flow of filter medium is detected by performing a backwashing of the filter material layer, while checking the flow of filter material, it is possible to perform backwashing of the filter material layer efficiently.
Effect of the invention
[0018]
　According to the above-mentioned water treatment apparatus and backwash method, even when fluctuations in the properties of the water to be treated, it is possible to efficiently backwash the filter media.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019]
FIG. 1 is a diagram showing the overall configuration of the water treatment system of this embodiment.
2 is a diagram showing the structure of the preprocessing section of the water treatment system.
3 is a map showing an example of correlation minimum backwash flow rate for the temperature of the sea water.
It is a diagram showing the flow of FIG. 4 backwash method.
5 is a diagram showing a configuration of a pre-processing unit in a second modification of the first embodiment.
6 is a diagram showing a configuration of a pre-processing unit in the third modification of the first embodiment.
7 is a diagram showing the configuration of a pre-processing unit in the second embodiment of the water treatment apparatus and backwash methods.
It is a diagram showing the flow of FIG. 8 backwash method.
DESCRIPTION OF THE INVENTION
[0020]
　It will be described below with reference to water treatment apparatus and backwash method according to an embodiment of the invention with reference to the drawings.
(First Embodiment)
　FIG. 1 is a diagram showing the overall configuration of the water treatment system of this embodiment.
　As shown in FIG. 1, the water treatment system 10 of this embodiment includes a preprocessing unit 20, a cartridge filter 30, a high pressure pump 40, and a desalination unit 50, an energy recovery device 60, the .
[0021]
　Preprocessing section 20, intake seawater (water to be treated) W is fed through the intake pipe P1 by intake pump (not shown). Preprocessing section 20, the fed seawater W, before the desalination unit 50 (in front) and filtration, to remove suspended solids in the seawater W or the like. In this embodiment, as a pre-processing unit 20, the sand filtration device (filtration device) 21 is used.
　And a sand filter device 21 halo material layer 21f. Filter medium layer 21f as filter medium, and a predetermined amount of sand (not shown), and biofilm (not shown) grown and maintained on the surface of the sand, the. Filter medium layer 21f is a biofilm, SDI or stains desalination unit 50 (Silt Dencity Index: dirty index) component, to remove the cause of biofouling BOD (Biological Oxygen Demand) components and the like. Furthermore, filter medium layer 21f is by sand, to remove the particulate component contained in the seawater W.
　In front of feeding the sea water W in the pre-processing unit 20, from the inlet P2 connected to intake pipes P1, it is also possible to introduce an aggregating agent or pH adjusting agent.
[0022]
　Cartridge filter 30, in the subsequent stage of the pre-processing unit 20 are connected via the connecting pipe P3. Cartridge filter 30, were not removed by the pre-processing unit 20, for example, 1 ~ 5 [mu] m about fine foreign matter so as not to enter the high-pressure pump 40, removing foreign matter on a given diameter or.
[0023]
　High-pressure pump 40, in the subsequent stage of the cartridge filter 30, are connected via a connecting pipe P4. High-pressure pump 40, the seawater W which has passed through the cartridge filter 30, and raised to a predetermined pressure is fed into the desalination unit 50 through the connection pipe P5.
[0024]
　Desalination unit 50 is, for example, using a reverse osmosis membrane F, to remove ion components from seawater W. In this embodiment, as desalination unit 50 includes a seawater reverse osmosis membrane (Sea Water Reverse Osmosis Membrane) processor 51, a brackish water for reverse osmosis membrane (Brackish Water Reverse Osmosis Membrane) processor 52, a.
[0025]
　Seawater reverse osmosis membrane treatment apparatus 51 in the subsequent stage of the high-pressure pump 40 are connected via a connecting pipe P5. Seawater reverse osmosis membrane treatment apparatus 51, the seawater W which has been boosted by the high-pressure pump 40, via the connecting pipe P5 is passed through the reverse osmosis membrane F, obtain permeated water W2 salinity (ionic components) have been removed . Permeate W2 obtained is fed into the brackish water for reverse osmosis membrane treatment apparatus 52 through a connecting pipe P6. Concentrated water W3 comprising ionic components removed in the seawater reverse osmosis membrane treatment apparatus 51 is sent to the energy recovery device 60 via the connection pipe P7. Concentrated water W3 passing through the energy recovery device 60 is drained to the outside (sea) via a drain pipe P8.
[0026]
　Brackish water for reverse osmosis membrane treatment apparatus 52 in the subsequent stage of the seawater reverse osmosis membrane treatment apparatus 51 are connected via a connecting pipe P6. Brackish water for reverse osmosis membrane treatment apparatus 52, by passing the permeate W2 passed through the seawater reverse osmosis membrane treatment apparatus 51 to the reverse osmosis membrane F, to further remove the ion components, to obtain a pure water W2 '. The resulting pure water W2 'is via the supply pipe P9, is supplied to the water tank (not shown) or the like. Here, in the case where pure water W2 'obtained a beverage or the like, the addition of minerals turned portion P10 provided in the supply pipe P9. Concentrated water W3 comprising ionic components removed in brackish water for reverse osmosis membrane treatment apparatus 52 'is discharged to the drain pipe P8 via a drain pipe P11, and is discharged to the outside (sea).
[0027]
　Energy recovery device 60 recovers the energy from the concentrated water W3 discharged from the seawater reverse osmosis membrane treatment apparatus 51. Concentrated water W3 discharged from the seawater reverse osmosis membrane treatment apparatus 51 is pressurized by the high pressure pump 40. Energy recovery device 60 is provided with a rotor (hydraulic turbine) 61 that is rotated by water flow concentrated water W3 fed from the connection pipe P7. The rotor 61, with the rotational energy by the concentrated water W3 pressurized to rotate the rotor 62 which is integrally connected to the rotor 61. The subsequent stage of the cartridge filter 30, the branch pipe P12 is provided to branch from the connecting pipe P4. Some of the seawater W which has undergone the cartridge filter 30 is fed into the seawater reverse osmosis membrane treatment apparatus 51 by the rotor 62 through the energy recovery device 60 through the branch pipe P12. In this way, it can be used as part of the energy feeding the seawater W in seawater reverse osmosis membrane treatment apparatus 51, the energy of concentrated water W3 recovered by the energy recovery device 60.
[0028]
　Figure 2 is a diagram showing the configuration of a preprocessing unit of the water treatment system.
　As shown in FIG. 2, the preprocessing unit 20 is provided with a sand filtration device 21.
　In this embodiment, the sand filtration system 21, seawater W is passed through the intake pipe P1, filtered process the seawater W. Sand filtration apparatus 21, the seawater W after filtration treatment, is sent from the connecting pipe P3.
[0029]
　Preprocessing section 20 is provided with a backwash processing unit 80 for backwashing the filter material forming the sand filtration apparatus 21 slag material layer 21f. Backwashing processing unit 80 is provided with a washing water tank 81, a flow rate adjusting unit 82, and the on-off valve 83, a detector 84, a controller 85, a.
[0030]
　Wash water tank 81 in order to backwash the sand filter apparatus 21 slag material layer 21f, the washing water Ws, storing the sea water or fresh water. Wash water tank 81, the downstream side of the sand filtration apparatus 21 are connected via the backwashing pipe P20.
[0031]
　Flow rate adjusting section 82 is provided in the backwash pipe P20, the wash water Ws in the washing water tank 81, pumped from the downstream side of the sand filtration apparatus 21 through backwash pipes P20 to sand filtering apparatus 21. Flow rate adjusting unit 82 adjusts the flow rate of the washing water Ws supplied to the sand filtration apparatus 21. Such a flow rate adjustment unit 82, for example, a pump or the like, by varying its operating speed to adjust the flow rate of the washing water Ws supplied to the sand filtration apparatus 21. Further, the flow rate adjusting unit 82, for example while driving the pump at constant rotational speed, the flow rate control valve can be finely adjusted.
　Off valve 83, to open and close the backwash pipe P20.
[0032]
　Detector 84 acquires a value relating to at least one of the density or viscosity of the washing water Ws and seawater W sand filtration apparatus 21. In this embodiment, as the value relating to the density or viscosity, for detecting the temperature of the washing water Ws. Accordingly, the detection unit 84 may use a temperature sensor, for example, it is possible to detect the temperature of the washing water Ws is provided a temperature sensor in the backwash pipe P20.
　Detector 84, provided in the sand filtration apparatus 21 slag material layer 21f, the backwash process temperature seawater W before the sand filtration apparatus 21, or the washing water Ws is sand filtration apparatus within 21 during backwash process temperature of the injected seawater W may be detected.
[0033]
　Controller 85 includes a speed calculator 87, a flow rate control section 86, the.
　Speed calculation unit 87, based on the value relating to at least one of the density or viscosity of the washing water Ws and seawater W sand filtration apparatus 21 calculates the minimum backwash flow rate. The minimum backwashing flow rate, filter material constituting the filter medium layer 21f is a minimum flow rate flowing through the injection of cleaning water Ws.
[0034]
　Flow rate control unit 86, so that the flow speed of washing water Ws is a filter material layer 21f downstream minimum of backwash flow rate can flow toward the upstream side from the controls the rotation speed of the flow rate adjusting unit 82.
[0035]
　Speed calculating unit 87 (also referred to as fluidization velocity) From backwash flow velocity .mu.f, calculated by the following formula [1].
[Equation 1]

　where, mu: fluid viscosity, [rho F : fluid density, D: average particle diameter of the filter medium, Ga: a Galileo number. The fluid viscosity and fluid density is correlated to the temperature and salinity.
[0036]
　Galileo number Ga is obtained by the following formula [2].
[Equation 2]

　Here, [rho S : filter material Density, g: acceleration of gravity.
[0037]
　Further, the fluid viscosity μ, MH Sharqawy et al "Thermophysical properties of seawater: a review of existing correlations and data", as described in equation (21) of Desalination and Water Treatment 16 (2010) P354-P380, e.g. can be obtained by the following formula [3].
[Equation 3]

　Here, t: is the temperature.
[0038]
　The fluid density [rho F may, MH Sharqawy et al "Thermophysical properties of seawater: a review of existing correlations and data", as described in equation Desalination and Water Treatment 16 (2010) P354-P380 (7), for example, can be obtained by the following equation [4].
[Equation 4]

　where, S: salinity, p: is the pressure.
[0039]
　Incidentally, salinity, salinity meter (e.g., Sarinometa OPS manufactured OPTIMARE Corp.) can also be obtained using.
[0040]
　Figure 3 is a map showing an example of correlation minimum backwash flow rate for the temperature of the sea water.
　Further, as shown in FIG. 3, and the correlation minimum backwash flow rate for the temperature from the simulation or experiments or the like, in advance maps, tables, keep the formula or the like. From this correlation, it is possible to determine the lowest backwash flow rate corresponding to the temperature detection value detected by the detector 84.
[0041]
　As shown in FIG. 2, the backwash process unit 80 includes a display unit 84v for displaying the detected temperature value is detected result of the detection unit 84, an operation section 85c for operating the backwashing process unit 80 from the outside, further be able to.
[0042]
　Operation unit 85c, the operator consists operable various switches and the like. Operator, is displayed on the display section 84v, depending on the detected temperature value of the washing water Ws and seawater W, operating the operation unit 85c. Operation unit 85c is sent to the control unit 85 a predetermined operation signal in response to operation of the operator.
[0043]
　Next, a description will be given backwash process in the pretreatment unit 20 described above.
　Figure 4 is a diagram showing the flow of backwashing method.
　As shown in FIG. 4, in the backwash process unit 80, when performing a backwash process, the detection unit 84, the temperature of the washing water Ws or seawater W is measured to obtain the measurement value (step S1). Measurement of the obtained detection unit 84 is displayed on the display unit 84v.
　Operator, the measurement value of the acquired temperature, and inputs the operation unit 85c. Then, the operation unit 85c sends a predetermined operation signal by the operation of the operation unit 85c to the controller 85.
[0044]
　Controller 85, a speed calculation unit 87, based on the operation signal sent from the operation unit 85c (temperature measured value), the above formula [1] and, from a map or the like based on the correlation shown in FIG. 3 , to determine the minimum backwash flow rate corresponding to the temperature measurement value (step S2).
[0045]
　Controller 85 switches the switch valve 83 actuates the flow rate adjustment part 82 from the closed state to the open state. Accordingly, the washing water Ws is through backwashing pipe P20 from a cleaning water tank 81, washing water Ws toward the upstream side from the downstream side of the filter medium layer 21f is supplied, the backwash process is started (step S3).
　Flow rate control unit 86, after starting the operation of the flow rate adjusting unit 82, the rotational speed, the flow rate of the washing water Ws is, until the lowest backwash flow rate than that calculated by the speed calculating part 87, gradually increased. Accordingly, the washing water Ws Gallo material layer 21f from the downstream side to a flow rate that enables flow toward the upstream side, the flow rate of the washing water Ws is increased.
　Here, the flow rate of the washing water Ws, while not less than minimum backwash flow rate calculated by the speed calculating unit 87, preferably in the lowest possible flow rate. When the flow rate of the washing water Ws is too high, because the biofilm of the filter material layer 21f (not shown) is peeled off or the like.
[0046]
　After the start of the backwash process, and the like to a predetermined time, at the time of satisfying the condition for terminating the backwash process (step S4), and to stop the flow speed adjusting unit 82 closes the on-off valve 83, the backwash process the stops (step S5).
[0047]
　Thus, according to the first embodiment described above, by controlling the flow rate adjustment part 82 at a flow rate control unit 86 of the control device 85, can circulate wash water Ws Gallo material layer 21f from the downstream side toward the upstream side so as to be made minimum backwash flow rate or more, the flow rate of the washing water Ws can be adjusted. Thus, even if the properties of the seawater W and cleaning water Ws sand filtration apparatus 21 varies, since the wash water Ws Gallo material layer 21f flows from the downstream side toward the upstream side, the backwashing of the filter medium layer 21f it can be reliably performed.
　In particular, with a biofilm on filter media layer 21f, in a so-called biological Makusuna filtration device 21, the flow speed of washing water Ws is too high, is destroyed biological membranes. Therefore, with at minimum backwash rate or more, as much as possible to suppress the flow rate, by circulating the washing water Ws at a flow rate to maintain a biofilm, it is possible to appropriately backwash filter media layer 21f.
[0048]
　Further, at a speed calculator 87 of the controller 85, based on the temperature measurement value detected by the detection unit 84, by calculating the minimum backwash rate, toward the upstream side washing water Ws Gallo material layer 21f from the downstream side the minimum backwash rate that enables circulation Te can be determined easily and reliably.
[0049]
　Further, when the temperature of the washing water Ws or seawater W is changed, its viscosity varies. The detection unit 84, by detecting the temperature of the washing water Ws or seawater W, or minimum backwash rate or flow rate corresponding to the viscosity of the washing water Ws or seawater W, surely that the backwashing of the filter medium layer 21f can.
[0050]
　Moreover, in the backwash process of sand filtration apparatus 21 described above, and after starting the supply of flush water Ws to filter material layer 21f, it can flow the washing water Ws Gallo material layer 21f from the downstream side toward the upstream side flow rate until and to enhance the flow rate of the washing water Ws. Thereby, also the properties of the seawater W and cleaning water Ws sand filtration apparatus 21 varies, since the wash water Ws Gallo material layer 21f flows from the downstream side toward the upstream side, the backwashing of the filter medium layer 21f it can be reliably performed.
[0051]
　Incidentally, in the first embodiment, based on the detected temperature measurement value by the detection unit 84 has been adapted to determine by calculating the minimum backwash flow rate corresponding to the temperature measurement value at a speed calculating unit 87, which not limited to. For example, based on the detected temperature measurement value by the detecting unit 84, the operator to see the information in a table such as shown in FIG. 3, may determine the minimum backwash flow rate. In this case, by inputting a minimum backwash flow rate the operator has determined the operation unit 85c, it is possible to operate the flow rate adjustment part 82 at the lowest backwash flow rate.
[0052]
(First modification of the first embodiment)
　In the first embodiment, in determining the lowest backwashing flow rate, the detection unit 84, while the temperature of the washing water Ws or seawater W was to measure, limited to this Absent.
　For example, as a value for at least one of the density or viscosity of the washing water Ws and seawater W sand filtration apparatus 21, detected by the detecting section 84, at least one of the electrical conductivity of the washing water Ws and seawater W sand filtration apparatus 21 it may be.
[0053]
　From the electrical conductivity which is detected by the detection unit 84, the salinity S, for example, due to the NP Fofonoff and RC Millard Jr. "Algorithms for computation of fundamental properties of seawater", Unesco Tech. Pap. In Mar. Sci., 38 ( 1983), as illustrated in formula (1) described in P99- P 188, can be obtained by the following formula [5].
[Number 5]

　here, ΔS is, for example, due to the NP Fofonoff and RC Millard Jr. "Algorithms for computation of fundamental properties of seawater", Unesco Tech. Pap. In Mar. Sci., 38 (1983), P99- P as described by formula (2) to 188, can be obtained by the following equation [6].
[6]

　The ratio R T is, for example, due to the NP Fofonoff and RC Millard Jr. "Algorithms for computation of fundamental properties of seawater", Unesco Tech. Pap. In Mar. Sci., 38 (1983), P99- P 188 as in equation (3) described in, can be obtained by the following equation [7].
[Equation 7]

[0054]
　Here, R t is, R = R p · R t · r t from, R t = R / (R p · r t can be calculated as).
　R is salinity S, temperature t, the electrical conductivity of the pressure p as a molecule, 35% denominator salinity, temperature 15 ° C., can be represented by the electrical conductivity and the ratio of KCl at atmospheric pressure .
　Further, R p can be expressed as the ratio of salinity S, temperature t, the electrical conductivity of the pressure p as a molecule, and the denominator salinity S, temperature t, the electrical conductivity of KCl at atmospheric pressure .
　In addition, R the p- is, for example, due to the NP Fofonoff and RC Millard Jr. "Algorithms for computation of fundamental properties of seawater", Unesco Tech. Pap. In Mar. Sci., 38 (1983), is described in the P99- P 188 like other formula (4), by the following equation [8], if the predetermined temperature range, it can be determined as a function of temperature t, pressure p.
[Equation 8]

[0055]
　In addition, R T is, for example, due to the NP Fofonoff and RC Millard Jr. "Algorithms for computation of fundamental properties of seawater", Unesco Tech. Pap. In Mar. Sci., 38 (1983), is described in the P99- P 188 and as, 35% salinity, temperature t, and the molecular electrical conductivity at atmospheric pressure, 35% denominator salinity, temperature 15 ° C., expressed as the ratio in which the electric conductivity of KCl at atmospheric pressure it is known that it is. Further, r t can also be obtained from equation [6] as described herein.

　Further, from equation [5], the viscosity of the washing water Ws or seawater W mu, density [rho F and the above equation [3] can be obtained in [4].
[0056]
　The viscosity μ of the thus-obtained wash water Ws or seawater W, the density [rho F from the above formula [1] and, on the basis of a map or the like obtained in advance by performing experiments, to determine the minimum backwash flow rate it can.
[0057]
　Seawater W, by the rain water is fresh water is mixed with rain, salinity changes. Further, the seawater W is fresh water from rivers and lakes in the region of inflow salinity varies relative to the surrounding region. In this manner, when the salinity of the seawater W vary, its viscosity varies. Therefore, by detecting the salt concentration in the wash water Ws or seawater W, or minimum backwash rate or flow rate corresponding to the viscosity of the washing water Ws or seawater W, it is possible to reliably perform backwashing of the filter material layer 21f .
[0058]
(Second modification of the first embodiment)
　FIG. 5 is a diagram showing the configuration of a pre-processing unit in a second modification of the first embodiment.
　As shown in FIG. 5, the backwash process unit 80 is provided with a washing water tank 81, a flow rate adjusting unit 82, and the on-off valve 83, a detector 84, a control device 85B, the.
[0059]
　In this modification, in the backwash process unit 80, when performing a backwash process, the detection unit 84 to measure the temperature of the washing water Ws or seawater W.
[0060]
　Controller 85B has a detection result detected by the detection unit 84 receives from the detecting unit 84 by an electrical signal. Speed ​​calculator 87 of the controller 85B, the above formula [1], the like shows a correlation as shown in FIG. 3, in accordance with the temperature of the washing water Ws or seawater W detected by the detector 84, a minimum reverse determining a backwash flow rate of more wash flow rate.
[0061]
　Flow rate control unit 86 of the control unit 85B switches the switch valve 83 actuates the flow rate adjustment part 82 from the closed state to the open state. Accordingly, the washing water Ws is through backwashing pipe P20 from a cleaning water tank 81, washing water Ws toward the upstream side from the downstream side of the filter medium layer 21f is supplied, the backwash process is started.
　Flow rate control unit 86, after starting the operation of the flow rate adjusting unit 82, the rotational speed, the flow rate of the washing water Ws is, until the lowest backwash flow rate or more calculated by the speed calculating section 87, gradually increased. Accordingly, the washing water Ws Gallo material layer 21f from the downstream side to a flow rate that enables flow toward the upstream side, the flow rate of the washing water Ws is increased.
[0062]
　After the start of the backwash process, and the like to a predetermined time, at the time of satisfying the condition for terminating the backwash process, to stop the flow speed adjusting unit 82 closes the on-off valve 83, to stop the backwash process.
[0063]
　In this manner, the control device 85B, to detect the temperature of the washing water Ws or sea water is W, the washing water Ws Gallo material layer 21f calculates the minimum backwash flow rate allows flow from downstream to upstream, by controlling the flow rate adjusting unit 82, the flow speed of washing water Ws can be automatically adjusted. Thus, even if the properties of the seawater W and cleaning water Ws sand filtration apparatus 21 varies, since the wash water Ws Gallo material layer 21f flows from the downstream side toward the upstream side, the backwashing of the filter medium layer 21f it can be reliably performed.
[0064]
(Third modification of the first embodiment)
　FIG 6 is a diagram showing the configuration of a pre-processing unit in the third modification of the first embodiment.
　As shown in FIG. 6, the backwash process unit 80 includes a paper tube P21 feeding concentrated water, the flow rate adjusting unit 82, and the on-off valve 83, a detector 84, a controller 85, a.
[0065]
　In the third modified example, as wash water Ws, using concentrated water W3 comprising ionic components removed in the seawater reverse osmosis membrane treatment apparatus 51. Thus, the sheet tube P21 feeding concentrated water is provided so as to connect the connecting pipe P3 and the connection pipe P7.
　Flow rate adjusting unit 82 and the on-off valve 83 is provided in the sheet tube P21 feed concentrate.
[0066]
　According to such a configuration, by controlling the flow rate adjustment part 82 at a flow rate control unit 86 of the control device 85, the use of concentrated water W3 removed in seawater reverse osmosis membrane treatment apparatus 51 as washing water Ws it can. Wash water Ws is flow rate so that the filter media layer 21f minimum of backwash flow rate allows flow toward the upstream side from the downstream side is adjusted. Thus, even if the properties of the seawater W and cleaning water Ws sand filtration apparatus 21 varies, since the wash water Ws Gallo material layer 21f flows from the downstream side toward the upstream side, the backwashing of the filter medium layer 21f it can be properly carried out.
[0067]
(Second Embodiment)
　Next, description will discuss a second embodiment of the water treatment apparatus and backwash method according to the present invention. In the second embodiment described below, only the configuration of the first embodiment and the pre-processing unit are different, with will be denoted by the same reference numerals in the first embodiment and the same parts, the whole of the water treatment system 10 configuration and the like, the duplicated description thereof is omitted.
　Figure 7 is a diagram showing the configuration of a pre-processing unit in the second embodiment of the water treatment apparatus and backwash methods.
　As shown in FIG. 7, the pre-processing unit 20 of the water treatment system 10 in this embodiment is provided with a backwash processing unit 80C for backwashing the filter material forming the sand filtration apparatus 21 slag material layer 21f. Backwashing processing unit 80C includes a washing water tank 81, a flow rate adjusting unit 82, and the on-off valve 83, a detecting unit 84C, a control unit 85C, a.
[0068]
　In this embodiment, as the detection unit 84C, the flow detecting unit for detecting the flow of the filter material constituting the filter material layer 21f sand filtration device within 21 when supplying cleaning water Ws from the downstream side of the sand filtration apparatus 21 (sand) provided with the 84s. In filter media, the turbidity of the water to be treated W and the cleaning water Ws in the sand filtration apparatus 21 varies by fluttering of sand which constitutes the filter material by injection of washing water Ws. Therefore, the flow detecting unit 84s, for example, can be used turbidimeter.
　Further, as a flow detection unit 84s, the filter material captured by a camera or the like, a change in turbidity, may be monitored by comparing the backwash process before the start of the captured image. Further, it may be performed such as monitoring of turbidity by the transmittance or the like using an optical sensor using laser or the like.
[0069]
　Here, by injecting wash water Ws during backwashing process, filter media layer 21f has an upper surface level rises. Therefore, the flow detecting unit 84s, in order to monitor the turbidity, is provided by spaced above the upper surface of the filter material layer 21f. More specifically, installing the flow detecting unit 84s to filter material height during backwash process. For example, the flow detecting unit 84s, compared height L of the filter medium layer 21f during the filtration, may be disposed above at a 0.05-fold (0.05 × L) or more spacing H.
[0070]
　Flow detecting unit 84s from sand filtration device 21 to extract a portion of the water to be treated W, the extracted water to be treated W may be performed such as monitoring of the turbidity.
[0071]
　Controller 85C, along with operating the flow rate adjusting unit 82, after the washing water Ws open the on-off valve 83 was injected into the sand filter apparatus 21, whether the flow of the filter material is detected by the flow detecting unit 84s monitoring to.
　Controller 85C includes a backwashing speed determination unit 88. Backwashing speed determining section 88, the flow detecting unit 84s, when the flow of the filter medium is confirmed, the flow speed of the cleaning water Ws at that time is determined as above velocity minimum backwash flow rate.
[0072]
　Next, a description will be given backwash process in the pretreatment unit 20 described above.
　Figure 8 is a diagram showing the flow of backwashing method.
(Water Quality acquiring step)
　as shown in FIG. 8, in the backwash processing unit 80, by a predetermined operation of the operator, to open the on-off valve 83 from the closed state actuates the flow rate adjustment part 82 by the control unit 85C switches. Thus, the washing water Ws is through backwashing pipe P20 from a cleaning water tank 81, washing water Ws toward the upstream side from the downstream side of the filter medium layer 21f is supplied, the backwash process is started (step S11).
[0073]
　After the start of the backwashing process, monitoring the flow state of the filter medium by the flow detecting unit 84s (step S12).
[0074]
　After a predetermined time has elapsed, with the flow detecting unit 84s, in the filtration device 21 slag material layer 21f, the injection of cleaning water Ws is flow condition of the filter material layer 21f whether changed, for example, detected by a change in turbidity ( step S13).
　In the flow detection unit 84s, for example, such as turbidity increases above a predetermined threshold value, if the change in the flow state of the filter material layer 21f is observed, the flow rate control unit 86 of the control unit 85C has a rotation speed of the flow rate adjuster 82 , it is increased by the rotation number of predetermined, to continue the control returns to step S12 (step S14).
[0075]
　Further, like in the flow detecting unit 84s, for example, increases in turbidity than a predetermined threshold value, if the change in the flow state of filter media were observed, backwashing speed determining section 88, the flow of the filter medium is detected by the flow detecting unit 84s the flow rate of washing water Ws determined as above velocity minimum backwash flow rate is a flow rate control unit 86 stops the increase of the rotational speed of the flow rate adjustment part 82 (step S15)
[0076]
　Flow rate control unit 86 for the rotational speed increase of the flow rate adjusting unit is stopped in step S15, to maintain a flow rate determined by the backwash speed determination section 88 (rpm), the backwash process.
[0077]
　After the start of the backwash process, and the like to a predetermined time, at the time of satisfying the condition for terminating the backwash process (step S16), and stops the flow rate adjusting unit 82 closes the on-off valve 83, the backwash process the stops (step S17).
[0078]
　Therefore, according to the second embodiment described above, the flow of the filter medium layer 21f when the supplied wash water Ws from the downstream side of the sand filtration apparatus 21 is detected by the flow detecting unit 84s, when the flow of the filter material is detected flow rate of the washing water Ws of, by determining a more velocity minimum backwash flow rate, while checking the flow of filter material, it is possible to perform appropriate backwash of filter media layer 21f.
[0079]
(Other Modifications)
　The present invention is not limited to the embodiments described above, without departing from the scope of the invention include those in which various modifications to the embodiments described above. That is, the specific shapes and configurations such as listed in embodiment merely examples and can be appropriately changed.
[0080]
　For example, the configuration shown in the above embodiments and their modifications may be combined as appropriate.
[0081]
　In the above-described embodiments, a sand filtration device 21 has been exemplified as a filtering device, the specific configuration is not intended to be limiting in any way. Furthermore, sand filtration apparatus 21, the series may be provided by connecting a plurality in parallel.
[0082]
　The desalination process unit 50, a seawater reverse osmosis membrane treatment apparatus 51, a configuration and a brackish water for reverse osmosis membrane treatment apparatus 52 is not limited thereto. Only seawater reverse osmosis membrane treatment apparatus 51 may be provided in desalination unit 50.
[0083]
　Other than this, for example, in the above embodiment and the modification thereof, has been given the water treatment system for desalinating seawater W as an example, even for water treatment systems other purposes, enable the invention it can be applied to.
Industrial Applicability
[0084]
　This invention sea water can be applied to a water treatment apparatus and backwash methods for processing desalination. According to the water treatment apparatus and backwash method, at a flow rate of washing water is a filter material layer or negotiable minimum backwash flow rate toward the upstream side from the downstream side, by the supplying wash water, the water to be treated even if variations in the properties is, it is possible to appropriately backwash the filter medium.
DESCRIPTION OF SYMBOLS
[0085]
10 Water treatment system (water treatment
apparatus) 20 preprocessing section
21 sand filtration device (filtration
device) 21f filtration media layer
30 cartridge filter
40 the high-pressure pump
50 desalination unit
reverse for 51 seawater osmosis membrane treatment apparatus
52 brackish water for reverse osmosis membrane treatment device
60 the energy recovery apparatus
61 and 62 rotor
80,80C backwash processing unit
81 the washing water tank (cleaning water supply
unit) 82 flow rate adjusting unit
83 on-off valve
84,84C detector
84s flow detecting portion
84v display unit
85,85B, 85C controller
85c operating unit
86 flow rate control section
87 speed calculator
88 backwashing speed determination unit
F reverse osmosis membrane
H interval
P1 intake pipe
P2 inlet
P3 ~ P7 connecting pipe
Drain P8
P9 supply pipe
P10 input portion
P11 drainage
P12 branch pipe
P20 backwashing pipe
P21 to the concentrated water pipe
S1 ~ S5 su TECH pu
S11 ~ S17 su TECH pu
W seawater
W2 permeated water
concentrated water W3 of
Ws of washing water

The scope of the claims
[Requested item 1]
A filtration device having a filter medium layer subjected to filtration treatment with respect to the for-treatment water which is supplied from the upstream side,
　and the cleaning water supply unit capable of supplying washing water from the downstream side of the filter material layer to the filtration device,
　wherein a flow rate adjusting unit with cleaning water supply unit for adjusting the flow rate of the washing water supplied to the filtering device,
　the flow rate of the washing water, the washing water can flow to the filter medium layer toward the downstream side to the upstream side minimum backwash flow velocity above and so as, controller and, having a flow rate control unit for controlling the flow rate adjusting unit, such
water treatment device comprising a.
[Requested item 2]
　The washing water and further comprising the detecting unit for acquiring a value relating to at least one of the density or viscosity of the water to be treated in the filtration device in the cleaning water supply unit,
　the controller,
　the values for the density or the viscosity water treatment device according to claim 1 having a speed calculator for calculating the minimum backwash flow rate based.
[Requested item 3]
　Water treatment device according to claim 2, wherein the value relating to the density or viscosity of at least one of the temperature of the water to be treated in the washing water and in the filtration apparatus.
[Requested item 4]
　Water treatment device according to claim 2, wherein the value relating to the density or viscosity of at least one of the salinity of the water to be treated of the washing water and in the filtration apparatus.
[Requested item 5]
　The filtration device further comprises a flow detector for detecting the flow of the filter material layer within the filtration device when supplying the washing water from the downstream side of
　the control device, the flow of the filter medium by the flow detecting unit water treatment device according to claim 1 having a backwash speed determination unit which determines the flow rate of the washing water detected as the minimum backwash flow velocity or flow rate.
[Requested item 6]
　Wherein the filter material layer of the filtration device, the water treatment device according to any one of claims 1 to 5 comprising a biological membrane.
[Requested item 7]
　A filtration device having a filter medium layer subjected to filtration treatment with respect to the for-treatment water which is supplied from the upstream side,
　and the cleaning water supply unit capable of supplying washing water from the downstream side of the filter material layer to the filtration device,
　wherein a detector for detecting a value related to at least one of the density or viscosity of the flowing state and the water to be treated filter medium layer,
　and a display unit for displaying information based on the value relating to the density or viscosity,
　that operator can operate the operation and parts,
　based on the operation signal sent by the operation of the operation unit is performed in accordance with the information displayed on the display unit, the flow rate of the washing water supplied to the filtering device by the cleaning water supply unit a flow rate adjusting unit that adjusts the
water treatment system comprising a.
[Requested item 8]
　A backwash process of the filtering device having a filter medium layer subjected to filtration treatment with respect to the for-treatment water which is supplied from the upstream side,
　at least one of the density, or value on the viscosity of the flowing state and the water to be treated of the filter medium layer detects, based on the value relating to the density or viscosity, the steps of the washing water is calculating the flow rate becomes possible flowing through the filter medium layer toward the downstream side to the upstream side,
　the upstream side from the downstream side of the filter medium layer process and, to start the supply of the washing water towards
　until the calculated the flow rate, the step of increasing the flow rate of the washing water
backwash method comprising.
[Requested item 9]
　Backwash method of claim 8 wherein at least one of the temperature of the water to be treated of values ​​for the density and viscosity of the washing water and in the filtration apparatus.
[Requested item 10]
　Backwash method according to claim 8 values ​​for the density or viscosity of at least one of the salinity of the water to be treated of the washing water and in the filtration apparatus.
[Requested item 11]
　Supplying the washing water from the downstream side of the filtration apparatus, the steps of detecting the flow of the filter material layer within the filtration device,
　the flow rate of the washing water when the flow of the filter material layer is detected, the flow backwash method of claim 8 including the step of determining the flow rate becomes possible, and.