Technical field
[0001]
　The present invention, water treatment apparatus, and its operation method.
Background technique
[0002]
　Desalination and seawater, as a technique for performing purification of industrial water, water treatment apparatus using a reverse osmosis membrane has been put to practical use. As a specific example, there is known a technique described in Patent Document 1. The film processing apparatus disclosed in Patent Document 1, each upstream stage side of the membrane module bank with a plurality of membrane modules, and a membrane module bank downstream stage, the raw water to the upstream stage side of the membrane module bank (the It has a pump for pumping the treated water), and.
[0003]
　However, in such devices, with respect to the proportion of fresh water that is recovered from the treatment water such as seawater (fresh water recovery ratio), in advance the target value is defined. When freshwater recovery is too high, the salt concentration in the concentrated water is a component of the fresh water is separated residual resulting in excessively increased. If the concentrated water of high salt concentrations were discharged into the environment, there is concern that environmental load increases. Therefore, if desalinate example seawater, freshwater recovery rate is set to about 25 to 40%.
[0004]
　Meanwhile, with the continuous operation of the device, if the performance of the reverse osmosis membrane is decreased, fresh water recovery ratio is relatively decreased. In this case, by increasing the supply pressure of the water to be treated for the reverse osmosis membrane, it is necessary to compensate for the decrease of the fresh water recovery. To increase the fresh water recovery ratio, by increasing the output of the pump, the supply pressure of the water to be treated for the reverse osmosis membrane is enhanced. By the pressure of the water to be treated is increased, the amount of fresh water that is separated in the reverse osmosis membrane is increased, fresh water recovery starts to rise.
CITATION
Patent Literature
[0005]
Patent Document 1: JP 2013-22544 JP
Summary of the Invention
Problems that the Invention is to Solve
[0006]
　However, with the fresh water recovery as described above is increased, the amount of concentrated water to be separated from the treated water is reduced. That is, in the apparatus described in Patent Document 1, the amount of concentrated water from the upstream stage side of the membrane module bank is supplied to the membrane module banks of the downstream stage is decreased. Furthermore, in the device using a reverse osmosis membrane, the lower limit value is set to the amount of concentrated water discharged from the one per element (flow rate). When the amount of the concentrated water is below the lower limit, problems such as scale deposits is caused by an increase in membrane surface concentration by concentration polarization at the membrane module, there is sufficient separation may not be performed enrichment. Accordingly, in the apparatus described in Patent Document 1, fresh water recovery becomes limited.
[0007]
　The present invention has been made in view of the above circumstances and aims to improve the fresh water recovery and utilization of the water treatment apparatus.
Means for Solving the Problems
[0008]
　The present invention employs the following means to solve the above problems.
　According to a first aspect of the present invention, the water treatment device is disposed in parallel with each other, the treated water supplied from the upstream side more as reverse osmosis unit for separating the primary concentrated water and freshwater a primary unit having a primary element, by pumping the water to be treated from an upstream side of the primary unit, a pump for supplying該被treated water to the primary unit, with small number are provided than said primary element , they are arranged in parallel with each other, and a secondary unit having a secondary element of a reverse osmosis unit for separating the primary concentrated water to the secondary concentrated water and fresh water, all of the water to be treated and the primary concentrated water one or, to use a sub-element of a reverse osmosis unit for separating the concentrated water and fresh water, the sub-elements, as the primary element in the primary unit- Comprising mode and, and a mode switching unit to switch to one of the secondary mode to use as the secondary element in the secondary unit.
[0009]
　According to the above configuration, by increasing the output of the pump, fresh water is recovered from the secondary unit ratio relative to the deposition of the water to be treated (freshwater recovery) increases. When fresh water recovery ratio increases, the amount of the primary concentrated water flowing into per secondary element is reduced in the secondary unit.
　Here, the primary element, and a reverse osmosis membrane device, such as a secondary element, the lower limit value is set to the amount of concentrated water discharged. In the water treatment apparatus, if the amount of the secondary concentrate as described above is reduced to switch to the primary mode sub-element from the secondary mode by the mode switching unit. This makes it possible to use a sub-element as a primary element. Treatment water guided to the sub-elements in the primary mode is separated into a primary concentrated water and fresh water.
　Therefore, by switching the sub-elements in the primary mode, the number of primary elements in the primary unit is substantially increased, so that the number of the secondary element in the secondary unit is reduced. Thus, for each secondary element one per secondary units, it can lead to a sufficient amount of the secondary concentrate.
[0010]
　According to a second aspect of the present invention, the water treatment apparatus according to the first embodiment, the sub-element is 1 Tsuonashi of the secondary element in the secondary unit, the mode switching unit, the a sub dispensing line from between the pump and the primary unit leads to treatment water toward the sub-element, a first valve provided in the sub-distribution on line, the concentrated water that has been separated by the sub-element, a sub catchment line leading to the second unit as the primary concentrated water, and a second valve provided in the sub-water collecting line on a first switching valve capable of stopping the discharge of fresh water from the sub-element, It includes a second switching valve that can stop the discharge of concentrated water from the sub-element, and a third switching valve capable of stopping the supply of the primary concentrated water to the sub-elements from the secondary unit Good.
[0011]
　According to the arrangement, the first switching valve, the second switching valve, by closing the third switching valve, respectively, the secondary elements as sub-elements can be separated from the secondary unit. After disconnecting the sub-elements, by opening the first valve described above, and a second valve respectively, the sub-distribution lines, and the sub-catchment line to open. Thus, after the treatment water is introduced from the upstream side of the primary unit in the sub-elements, a primary concentrated water and fresh water through the reverse osmosis in said subelements are generated. The primary concentrated water is recovered by the sub catchment line. In particular, these first valve, the second valve can be opened and closed in the valve during operation of the device. Thus, without stopping the water treatment device can be passed water against subelements. In other words, without lowering the operating rate of the water treatment apparatus, it is possible to switch between modes.
[0012]
　According to a third aspect of the present invention, the water treatment apparatus according to the second aspect, a reflux line for recirculating part of the fresh water that the separated secondary unit on the upstream side of the pump, the provided on the reflux line, and a reflux pump for pumping said fresh water is provided on the return line, a recirculation valve for adjusting the flow state of the fresh water, may be provided.
[0013]
　According to the arrangement, a portion of the fresh water that is separated by the secondary unit, after removing the reflux line, it is possible to recirculate the water to be treated upstream of the pump. Accordingly, even when the concentration water treated water is reduced to the primary unit, by reflux of the freshwater it can compensate for the reduction of the water to be treated.
[0014]
　According to a fourth aspect of the present invention, the water treatment apparatus according to any one the above aspects, the water to be treated, the primary concentrated water, the secondary concentrated water, at least in one characteristic value of the fresh water a measuring unit for measuring the Langelier saturation index obtained from the characteristic value, based on a comparison of the predetermined reference value, controls the switching of the primary mode and secondary mode of the sub-elements according to the mode switching unit a control unit for, may be provided.
[0015]
　Furthermore, according to a fifth aspect of the present invention, the water treatment apparatus according to the fourth embodiment, the characteristic value, the water to be treated, the primary concentrated water, the secondary concentrated water, at least of the fresh water in one temperature, or electrical conductivity, wherein the control unit, the temperature, or may comprise a calculation unit for calculating the Langelier saturation index based on the electric conductivity.
[0016]
　According to the above-described configuration, water to be treated, the primary concentrated water, secondary concentrated water, depending on in at least one quality of fresh water, it is possible to maximize the fresh water recovery ratio by the water treatment device. In particular, by providing the control unit and the measurement unit, by autonomously adjusting the performance of the water treatment device to changes in the water quality due to seasonal variations, it is possible to flexibly cope with the change.
[0017]
　According to a sixth aspect of the present invention, a method of operating a water treatment apparatus, the operation of the water treatment device when switching the water treatment apparatus according to the second or third aspect from the secondary mode to the primary mode step a method, closing the first switching valve, and a step of stopping the discharge of fresh water from the sub-element, which closes said second switching valve to stop the discharge of concentrated water from the subelements When, by closing the third switching valve, and a step of stopping the supply of the primary concentrated water to the sub-elements from the secondary unit, by opening the first valve, the sub-element through the sub-distribution lines wherein the step of directing the water to be treated, the at first valve to open the second valve in a state that is open, said the separated concentrated water primarily concentrated in the sub-element through the sub water collecting line As comprising the steps of: directing said secondary unit.
[0018]
　According to the above method, the first switching valve in first mode switching unit, the second switching valve, by closing the third switching valve, respectively, the discharge of fresh water for the sub-elements, the discharge of concentrated water, and the primary from the upstream side supplying concentrated water is stopped. Thus, substantially sub-element is in a state of being separated from the secondary unit. In this state, by opening the first valve described above, and a second valve in this order, the sub-distribution lines, and the sub-water collecting line is opened, the sub-element treatment water is introduced. That is, sub-element, and functions as one of the primary elements. Thereafter, the water to be treated is guided to the sub-element is separated into a primary concentrated water and fresh water.
　In particular, these first valve, the second valve can be opened and closed in the valve during operation of the device. Thus, without stopping the water treatment device can be passed water against subelements. In other words, without lowering the operating rate of the water treatment apparatus, it is possible to switch between modes.
Effect of the invention
[0019]
　Water treatment apparatus of the present invention, and according to the method of operating a water treatment apparatus, it is possible to improve the fresh water recovery and utilization.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020]
Is a system diagram showing a water treatment apparatus according to the first embodiment of FIG. 1 the present invention.
FIG. 2 is a process diagram illustrating a method of operating the water treatment apparatus according to a first embodiment of the present invention.
Is a system diagram showing a water treatment apparatus according to the second embodiment of FIG. 3 the invention.
4 is a process diagram illustrating a method of operating the water treatment apparatus according to a second embodiment of the present invention.
5 is a system diagram showing a water treatment apparatus according to a modification of the present invention.
DESCRIPTION OF THE INVENTION
[0021]
First Embodiment
　For the first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the water treatment device 1 according to this embodiment, the intake line L1 treatment water SW flows, a pump P for pumping the downstream water to be treated SW from an upstream water intake line L1, a plurality reverse osmosis unit (primary element E1, the secondary element E2) in preparation primary unit U1 having, and a secondary unit U2, a connecting line Lc connecting these primary unit U1 and a secondary unit U2 to each other, the there. Furthermore, the water treatment apparatus 1 switches between subelements E2s as reverse osmosis unit either one of the above treated water SW and primary concentrated water CW1 is introduced, the use state (mode) of this sub-element E2s a mode switching unit 2, and a.
[0022]
　Intake line L1 is a flow path for guiding the treated water SW supplied from the outside to the water treatment device 1. On the upstream side of the intake line L1, for example, pre-processing unit (not shown) is provided. In the pretreatment device, it or oxidizing agent for suppressing the organisms contained in the sea water is attached to the apparatus, fine particles, addition of the agent for aggregating the colloid, and adjustment of pH is carried out. More specifically, such hypochlorite is preferably used as the oxidizing agent. Further, as the coagulant and an inorganic coagulant such as ferric chloride, polymer flocculants such as PAC are used. Suspension are agglomerated by these coagulants are removed by sand filter.
[0023]
　Thus, treated water SW that has been subjected to pretreatment, by a pump P provided on intake line L1, is pumped from the upstream side to the downstream side in said mounting water line L1.
[0024]
　Primary unit U1, and the secondary unit U2 is a device for separating and concentrating by reverse osmosis treated water SW guided by the intake line L1. Primary unit U1 includes a plurality of primary elements E1 arranged in parallel with each other, a primary distribution line Ld1 for distributing the water to be treated SW in intake line L1 relative to the plurality of primary elements E1, emissions from the primary element E1 is primary concentrated water CW1, and freshwater (primary freshwater FW1) has primary catchment line Lg1 flowing respectively, and the primary freshwater line Lf1, the.
[0025]
　Primary Element E1 is a reverse osmosis membrane (RO membrane: Reverse Osmosis Membrane) such as a hollow fiber membrane or a spiral membrane is the reverse osmosis unit provided inside the. Each primary element E1 includes an exterior member called a vessel is provided with a reverse osmosis membrane arranged inside the vessel, mainly. Furthermore, the vessel, the primary inlet E11 connected to the distribution line, a primary catchment line Lg1, and primary freshwater line Lf1 primary condensing Mizuguchi respectively connected to E12, and primary freshwater collecting Mizuguchi E13, is provided It is.
[0026]
　Primary unit U1 is constituted by the primary element E1 is arranged in parallel with each other. In the present embodiment as an example, five primary elements E1 are arranged in parallel. More specifically, the downstream end of the intake line L1, a primary inlet E11 of each primary element E1 are connected to one another by the distribution lines. Furthermore, the primary condensing water line Lg1 includes a primary condensing Mizuguchi E12 of each of the primary elements E1, are connected to each other and the upstream end of the connecting line Lc (described later). Primary freshwater line Lf1 is a flow path for discharging and recovering separated fresh water to the outside in each primary element E1. Downstream of the primary freshwater line Lf1 is and tanks for storing the recovered fresh water, equipment is connected for applying a further filtration (both not shown). By being configured as described above, five primary elements E1 is at an parallel.
　The number of primary element E1 is not limited to five, as long as more than the number of later-described secondary element E2 may be a four or less, or may be six or more.
[0027]
　The secondary unit U2 is a configuration similar to that the primary unit U1, a device for further separation and concentration of the primary concentrated water CW1 generated by the primary unit U1. More specifically, the secondary unit U2 is partitioned with a plurality of secondary elements E2 arranged in parallel with one another, these for a plurality of secondary element E2, a primary concentrated water CW1 generated by the primary unit U1 a secondary distribution lines Ld2, secondary concentrated water CW2 discharged from the secondary element E2, and freshwater (secondary freshwater FW2) flows respectively secondary catchment line Lg2, and a secondary freshwater line Lf2, the It has.
[0028]
　Although the secondary element E2 is reverse osmosis membrane apparatus having the same structure as performance and Primary Element E1 above, distinguish these in the following description. The vessel of the secondary element E2, secondary and secondary inlet E21 connected to the dispensing line Ld2, secondary catchment line Lg2, and secondary freshwater line secondary convex respectively connected to Lf2 Mizuguchi E22 and, a secondary fresh water collection Mizuguchi E23, is provided.
[0029]
　Similar to the primary unit U1, the secondary unit U2 is composed of a plurality of secondary element E2 is arranged in parallel with each other. The number of secondary element E2 in the secondary unit U2 is set smaller than the number of primary element E1 in the primary unit U1. In the present embodiment, three secondary element E2 is provided in the secondary unit U2. However, the number of secondary element E2 is not limited to three, as long as less than the number of primary elements E1, may be two or may be four or more.
[0030]
　In the present embodiment, among these three secondary element E2, 1 single secondary element E2 has been with the subelements E2s. As system for supplying discharge of concentrated water and fresh water with respect to the sub-element E2s, sub-line system S is provided. More specifically, as sub-line system S, the sub-element E2s, a sub dispensing line Ls1 for introducing the treatment water SW from above intake line L1, for collecting concentrated water produced in the subelement E2s a sub catchment line Ls2, but are connected.
[0031]
　Sub dispensing line Ls1 is the between the pump P and the primary unit U1 on intake line L1, a flow passage connecting the secondary distribution lines Ld2, a in the secondary element E2 as subelements E2s.
　Sub catchment line Ls2, as well as the secondary catchment line Lg2 in the secondary element E2 as subelements E2s, the flow path between the primary unit U1 and a secondary unit U2 (link line Lc which will be described later), the a flow passage connecting.
[0032]
　Sub dispensing line Ls1, and on the sub-catchment line Ls2, the valve device for adjusting the flow state of the flow paths are provided. Sub valve device provided on the distribution line Ls1 is a first valve V1. On the other hand, a valve device provided on the sub catchment line Ls2 is a second valve V2.
　The sub-line system S having such a structure, are part of the mode switching unit 2 to be described later.
[0033]
　Connection lines Lc are connected with the downstream side of the primary unit U1, and (including sub-elements E2s) upstream of the secondary unit U2. More specifically, the connection line Lc connects the downstream end of the respective primary catchment line Lg1 in the primary unit U1, the upstream end of each secondary distribution lines Ld2 in the secondary unit U2 to each other ing.
　Thus, the primary unit primary concentrated water CW1 generated by U1, the primary catchment line Lg1, connection lines Lc, and by distribution in the order of the secondary distribution lines Ld2, secondary unit U2 comprising the subelements E2s It is distributed to each of the secondary element E2. In the secondary element E2, by the primary concentrated water CW1 is further separation and concentration, fresh water and (secondary freshwater FW2), and the secondary concentrated water CW2 as a component of the residual except the secondary freshwater FW2 is generated It is. Fresh water is recovered through the secondary fresh water line Lf2. After secondary concentrated water CW2 is recovered through secondary catchment line Lg2, and is discharged to the outside via the post-processing by an external equipment (not shown).
[0034]
　Further, the sub-element E2s described above are capable to switch modes between a first mode which is used as one of the primary elements E1, a secondary mode which is used as one of the secondary element E2 . Such switching of mode is performed by the mode switching unit 2. Mode switching unit 2 includes a sub-line system S described above, the divided portion 4, a. Dividing unit 4 has a three valve device. These valve devices are respectively first switching valve Vc1, the second switching valve Vc2, and a third switching valve Vc3.
[0035]
　The first switching valve Vc1 is provided on the secondary freshwater line Lf2 leading to secondary element E2 as subelements E2s. By opening and closing the first switching valve Vc1, it is switched distribution state of freshwater (secondary freshwater FW2) in the secondary freshwater line Lf2. For example, by closing the first switching valve Vc1, and it is capable of stopping the flow of secondary freshwater FW2.
　Second switching valve Vc2 is provided on the secondary catchment line Lg2 leading to secondary element E2 as subelements E2s. By opening and closing the second switching valve Vc2, it is switched distribution state of CW2 secondary concentrated water in the secondary catchment line Lg2. For example, by closing the second switching valve Vc2, distribution of the secondary concentrated water CW2 is capable stopped.
　Third switching valve Vc3 is provided on the secondary distribution lines Ld2 connected to the secondary element E2 as subelements E2s. By opening and closing the third switching valve Vc3, it is switched distribution state of the primary concentrated water CW1 in the secondary distribution lines Ld2. For example, by closing the third switching valve Vc3, distribution of primary concentrated water CW1 is capable stopped.
[0036]
　These first switching valve Vc1, the second switching valve Vc2, above the line by closing the third switching valve Vc3, respectively (secondary freshwater line Lf2, secondary catchment line Lg2, secondary distribution lines Ld2) is closed that. Thus, the supply of the primary concentrated water CW1 for subelements E2s, and secondary freshwater FW2 and the discharge of the secondary concentrate CW2 becomes impossible process is stopped. That is, the sub element E2s is in a state of being separated from the system.
[0037]
　Will now be described with reference to FIGS. 1 and 2 a description is given of a method of operating the water treatment device 1 as described above.
　First, a description will be given state (secondary mode) using sub-element E2s above as one of the secondary element E2. When in the secondary mode, in the mode switching unit 2, the valve device in the segmented portion 4 (the first switching valve Vc1, the second switching valve Vc2, third switching valve Vc3) is open both. On the other hand, the valve device provided in the sub-line system S (first valve V1, the second valve V2) is in a state where both are closed. In the water treatment apparatus 1, the secondary mode is a normal operating condition.
[0038]
　By driving the pump P under the more secondary modes, the treatment water SW is led to the primary unit U1 via the intake line L1. Treatment water SW pressurized by the pump P is passed through a high pressure state with respect to the reverse osmosis membrane of each primary element E1.
[0039]
　In the primary unit U1, reverse osmosis is carried out with respect to the treatment water SW in each primary element E1. Thus, in the primary element E1 includes a primary concentrated water CW1 salinity and the like in the treatment water SW is concentrated primary freshwater FW1 and a residual component excluding the primary concentrated water CW1 (fresh water) is generated . More specifically, among the water to be treated SW, the primary fresh water FW1 by fresh water component reaches the downstream through the reverse osmosis membrane. By primary freshwater FW1 is transmitted to the downstream side, the upstream side of the reverse osmosis membrane, salts contained in the treated water SW is concentrated. Thus, the primary concentrated water CW1 are generated at the upstream side of the reverse osmosis membrane. In the downstream side of the reverse osmosis membrane, a pressure of the primary freshwater FW1 is smaller than the pressure of the treated water SW.
[0040]
　Primary freshwater FW1 is recovered to the outside through the above-mentioned primary freshwater line Lf1. The primary concentrated water CW1, after collected in the primary catchment line Lg1, and flows into the secondary unit U2 on the downstream side via the connection line Lc. In the secondary unit U2, connecting line Lc menstrual primary concentrated water CW1 which has flowed in is, the secondary distribution lines Ld2, each of which is distributed to each of the secondary element E2. Incidentally, as described above, since the third switching valve Vc3 in the mode switching unit 2 is opened, the primary concentrated water CW1 even subelement E2s as a secondary element E2 is dispensed.
[0041]
　Among the secondary element E2, similarly to the primary element E1, and concentrated freshwater isolation and salts from the primary concentrated water CW1 is performed. That is, as the fresh ingredients in the primary concentrated water CW1 secondary freshwater FW2, and a component of the residual secondary concentrated water CW2 except the secondary freshwater FW2 are generated.
[0042]
　Secondary freshwater FW2 is recovered to the outside by the secondary freshwater FW2 collecting water line. Secondary concentrated water CW2, after collected in the secondary catchment line Lg2, and is discharged into the outside environment. By the above operation is continuously performed, the water to be treated SW (seawater) is desalinated.
[0043]
　Incidentally, the water treatment device 1 as described above, the volume ratio of fresh water that is recovered from the treated water SW (freshwater recovery) in advance the target value is defined. For example, to desalinate seawater, freshwater recovery rate is set to about 25 to 40%. However, with the continuous operation of the device, if the performance of the reverse osmosis membrane is decreased, fresh water recovery is relatively lowered, which may fall below the target value of the. In this case, by increasing the output of the pump P, the supply pressure of the water to be treated SW for reverse osmosis membrane is enhanced. By the pressure of the water to be treated SW increases, the amount of fresh water that is separated in the reverse osmosis membrane is increased, fresh water recovery starts to rise.
[0044]
　However, with the fresh water recovery as described above is increased, the amount of secondary concentrated water CW2 is separated from treated water SW is reduced. Here, in the apparatus using a reverse osmosis membrane, the lower limit value is set to the amount of concentrated water discharged (flow rate). When the amount of the concentrated water is below the lower limit, problems such as scale deposits is caused by an increase in membrane surface concentration by concentration polarization at the membrane module, there is sufficient separation may not be performed enrichment.
[0045]
　Therefore, the water treatment apparatus 1 according to this embodiment, by the above-described mode switching unit 2, the secondary element E2 as subelements E2s, used as a primary element E1 (switch to primary mode) that is, the secondary element it is possible to reduce substantially the number of E2.
　For operation at the time of such mode switching, described in detail below. When switching the sub-elements E2s in secondary mode to the primary mode, first the sub-element E2s are separated by separation section 4 of the from in the secondary unit U2.
[0046]
　As more specifically shown in FIG. 2, as a method for operating the water treatment device 1 for switching the mode for the sub-element E2s, a step of closing the first switching valve Vc1, a step of closing the second switching valve Vc2, a step of closing the third switching valve Vc3 is performed in the above order.
　By closing the first switch valve Vc1, distribution of secondary freshwater FW2 stops during secondary freshwater line Lf2 (freshwater line). Subsequently, in a second switching valve Vc2 closed after closing the first switching valve Vc1, circulation of CW2 is stopped secondary concentrated water in the secondary catchment line Lg2 (secondary concentrated water CW2 line). Next, by closing the third switching valve Vc3 after closing the second switching valve Vc2, secondary water collecting line Lg2 is closed. Thus, the supply of the primary concentrated water CW1 by secondary catchment line Lg2 is stopped.
　Thereby, the secondary element E2 as subelements E2s is disconnected from the other secondary elements E2 in the secondary unit U2 (is divided). Incidentally, inside the sub-element E2s this time, a state of primary concentrated water CW1 stagnates.
[0047]
　Then, opening the first valve V1 on the sub-distribution lines Ls1. Thus, a portion of the water to be treated SW flowing medium intake line L1 is guided to the sub-element E2s through sub distribution lines Ls1. That is, by the treatment water SW as well as other primary element E1 is guided subelement E2s begin functions as the primary element E1. Thus, treatment water SW is in subelements E2s, and concentrated water as the primary concentrated water CW1, is separated into fresh water as a primary fresh water FW1.
[0048]
　Moreover, opening the second valve V2 on the sub catchment line Ls2 in this state. Thus, the primary concentrated water CW1 generated by sub-elements E2s is recovered by a sub catchment line Ls2. Sub catchment line Ls2, since it is connected to the connecting line Lc as described above, the primary concentrated water CW1 generated by sub-elements E2s is guided to the secondary unit U2 via the connection line Lc. In the secondary unit U2 is by other secondary element E2 except subelements E2s, after separation of the primary concentrated water CW1 is performed, the secondary concentrate CW2, are respectively collected as a secondary freshwater FW2.
[0049]
　Then, again opening the first switching valve Vc1 above. Thus, fresh water produced in subelement E2s is recovered by the secondary freshwater line Lf2.
[0050]
　As described above, the water treatment apparatus 1 according to this embodiment, by increasing the output of the pump P, the proportion of fresh water that is recovered from the secondary unit U2 occupied against the deposition of the water to be treated SW (freshwater recovery rate) increases. When fresh water recovery ratio increases, the amount of the secondary concentrate CW2 discharged from per one E21 secondary elements in secondary unit U2 is reduced.
[0051]
　On the other hand, the reverse osmosis unit, a lower limit value is set to the amount of concentrated water discharged from per single element. Therefore, the water treatment apparatus 1 according to this embodiment, when the amount of the secondary concentrate CW2 as described above is reduced, by the mode switching unit 2 by switching the mode of the sub-elements E2s, the subelements E2s It adopts a configuration to be used as one of the primary elements E1.
[0052]
　More specifically, in the water treatment device 1 described above, in the state of being operated in the original secondary mode, the number of primary element E1 in the primary unit U1 5 Tsutosare secondary elements in the secondary unit U2 E2 the number is 3 Tsutosa.
[0053]
　On the other hand, when it is switched to the primary mode, secondary element E2 as subelements E2s is incorporated into apparently primary unit U1, and functions as one of the primary elements E1. That is, the primary unit U1 in this state, has six primary elements E1, secondary unit U2 has two secondary element E2.
[0054]
　Thus, the primary unit U1, can generate more freshwater than the secondary mode. In other words, it is possible to improve the maximum value of the fresh water recovery. On the other hand, the amount of primary concentrated water CW1 in accordance with this fresh water recovery increases is reduced. Here, in the primary mode, the number of secondary element E2 in the secondary unit U2 has decreased in comparison with the case in the secondary mode. Thus, fresh water recovery ratio is increased, even when the concentration water is lowered, it is possible to increase the amount of secondary concentrated water CW2 discharged from around one of the remaining secondary element E2.
[0055]
　Moreover, switching of the mode as described above, the valve device in the mode switching unit 2 (the first switching valve Vc1, the second switching valve Vc2, third switching valve Vc3, the first valve V1, the second valve V2), respectively it can be easily performed only by operation. In addition, these valve devices can be opened and closed in the water treatment apparatus 1 of the passing water (in operation). Therefore, the water treatment apparatus 1 according to this embodiment, without stopping the operation, it is possible to switch the state of use of subelements E2s. Thus, without lowering the operating rate of the water treatment apparatus 1, it is possible to improve the maximum value of the fresh water recovery.
[0056]
　Here, for example, to increase the flow rate of the concentrated water per secondary element E2, when the inflow of concentrated water to some of the secondary element E2 prevents (plug) is water treatment in order to carry out the arrangement of the plug to stop water flow to the apparatus 1 (stopping the operation) need arises. However, according to the above configuration, since during operation of the water treatment apparatus 1 is capable of operation, the water treatment device 1 of the operating rate by the operation can be reduced the possibility of reduction.
[0057]
　It has been described with reference to the drawings for the first embodiment of the present invention. However, the above-described configuration is only an example and can be subjected to various modifications.
[0058]
[Second Embodiment]
　Next, a second embodiment of the present invention will be described with reference to FIG. Incidentally, the same reference numerals are given to configurations similar to the first embodiment described above, a detailed description thereof will be omitted. As shown in FIG. 3, the water treatment apparatus 1 according to the present embodiment, the pump P, in addition to the primary unit U1, connecting line Lc, the secondary unit U2, and a mode switching section 2, is provided recirculation section 3 It is.
[0059]
　Recirculation section 3 includes a reflux line Lc1 recirculating fresh water as a secondary freshwater FW2 the upstream side of the primary unit U1, a reflux pump Pc for pumping the secondary freshwater FW2 on the reflux line Lc1 in one direction, like a recirculation valve V3 provided on the reflux line Lc1, and a.
[0060]
　In this embodiment, the reflux line Lc1 are connected to each other and a downstream region than the first switching valve Vc1 on the secondary freshwater line Lf2, the upstream region from the pump P on the intake line L1 . By refluxing pump Pc is driven, the secondary freshwater FW2 taken out by the reflux line Lc1, pumped toward the intake line L1 side. Reflux valve V3 is a valve device for switching the flow state of the secondary freshwater FW2 in the return line Lc1.
[0061]
　To describe the configuration methods of operating the water treatment device 1 as described above. In operating the water treatment apparatus 1 comprises the steps of first opening the recirculation valve V3 described above, performing the step of driving a reflux pump Pc, and in order. Thus, a portion of the secondary freshwater FW2 flowing medium secondary freshwater line Lf2 is then taken out by reflux line, is fed into the intake line L1. By thus fresh water is supplied to the intake line L1, the amount of the water to be treated SW in intake line L1 increases. In other words, each primary element E1 in the primary unit U1, so that the more concentrated water is introduced.
[0062]
　Therefore, to decrease the supply amount of concentrated water (water to be treated SW) to the primary unit U1, even when the lower limit of concentration water to the primary elements E1, secondary freshwater by recirculation section 3 of the FW2 by refluxing, it can compensate for the reduction of the concentration water.
[0063]
　Further, the mode switching unit 2 in the embodiments described above, and the operation of the reflux section 3 may be performed by an operator, or may be performed by the control unit 5 shown in FIG. When using a control unit 5, on the intake line L1 described above, and on the connection line Lc, water (water to be treated SW in each line by providing a measuring unit 6, the primary concentrated water CW1, secondary concentrated water CW2, primary freshwater FW1, characteristic value of the secondary freshwater FW2) is measured. Based on these characteristic values, the control unit 5 controls the opening and closing of the valve device of the mode switching unit 2.
[0064]
　Control unit 5, the measuring unit and the calculation unit 51 for calculating, based on various characteristic values ​​obtained by 6, the arithmetic unit 51 determination unit 52 operation necessity of mode switching unit 2 on the basis of the calculation result of When the mode switching unit 2 based on the determination of the determination unit 52, and the valve arrangement recirculation section 3 (first switching valve Vc1, the second switching valve Vc2, third switching valve Vc3, the first valve V1, the second valve V2, has a signal generator 53 for instructing the opening of the recirculation valve V3) as an electrical signal.
[0065]
　When employing the above configuration, the measuring unit 6, the electric conductivity of the water, temperature, LSI (Langelier Saturation Index: Langeliar Saturation Index) continuously measuring the characteristic values ​​such as. Determining unit 52 in the control unit 5 performs with these characteristic values, the comparison with the reference value or reference range determined in advance. If it meets the reference value or reference range, the determination unit 52 determines that it is possible to raise the fresh water recovery ratio, from the mode-switching (secondary mode subelements E2s by the mode switching unit 2 to the primary mode switching) or the reflux reflux portion 3 by secondary freshwater FW2 performed.
[0066]
　Incidentally, definitive when using LSI as an index, the "if they meet the reference value or reference range", when LSI is smaller than the reference value (e.g., less than zero) it corresponds. Moreover, the determination of the increase in availability of fresh water recovery is usually performed to confirm the scale deposition presence of the element by LSI, but electrical conductivity, may be the same determination based on the temperature.
[0067]
　Values generally LSI, the electrical conductivity of the measured water, and on the values of the temperature. Furthermore, the electrical conductivity is determined by the dissolved salt concentration in the water (i.e., the concentration of salt dissolved in the ionic state as the electrolyte). Further, as the temperature of the water rises 1 ° C., the value of the LSI is generally 1.5 × 10 -2 increases.
[0068]
　Thus, the electrical conductivity by measuring unit 6, and after the temperature measured, the arithmetic unit 51 in the control unit 5, by carrying out calculation based on these characteristic values, it is also possible to adopt a configuration that calculates the LSI converted value is there. Even in this case, the determination unit 52 of the controller 5 based on the LSI converted value, determines an increase availability of fresh water recovery.
[0069]
　That is, when the LSI to be electrical conductivity or temperature of the reference range corresponding to the smaller than the reference value, it is determined that the determination unit 52 can increase the fresh water recovery ratio, according to the mode switching unit 2 a mode switching subelements E2s, is refluxed by the reflux section 3 is performed.
[0070]
　According to such a configuration, depending on the quality of the water to be treated SW, the autonomously can be maximized freshwater recovery rates. In particular, the performance of the water treatment device 1 can correspond flexibly to changes in the water quality due to seasonal fluctuations.
Industrial Applicability
[0071]
　Water treatment device 1 described above, and according to the method of operating the water treatment apparatus 1, it is possible to improve the freshwater recovery and utilization.
DESCRIPTION OF SYMBOLS
[0072]
1 ... water treatment device 2 ... holds one then cut for the portion 3 ... also flows portion 4 ... breaking portion 5 ... imperial system portion 51 ... arithmetic unit 52 ... determination section 53 ... signal generating section 6 ... measurement unit CWl ... a concentrated water CW2 is ... secondary concentrated water E1 ... a Ester Rayon me nn Suites E11 ... primary flow inlet E12 ... a collector nozzle E13 ... a fresh water collecting port E2 of ... secondary Ester Rayon me nn Suites E21 ... secondary flow inlet E22 ... secondary collecting port E23, ... secondary freshwater collecting port E2s ... sa bu Ester Ritz me nn Suites FWl ... a freshwater FW2 ... secondary freshwater Ll ... intake LITE nn Lc of ... contact zoku LITE nn Lc1 and ... also flows LITE nn LdI ... primary distribution LITE nn Ld2 and ... secondary distribution LITE nn Lf1 ... a fresh LITE nn Lf2 are ... secondary freshwater LITE nn Lg1 ... a sump LITE nn Lg2, ... two secondary sump LITE nn LsI ... sa STAB assigned LITE nn Ls2 ... sa STAB sump LITE nn P ... Polyster nn pu Pc ... also flows Polyster nn pu S ... sa STAB LITE nn system SW ... treatment water Ul ... once yu ni ッ Suites U2 ... two Yu ... ni ッ Suites first Bian Vl V2 V3 ... ... second Bian Bian also flows ... Vc1 of the first cut for the second cut Bian Vc2 is ... ... for the third cut for Vc3 of Bian Bian

The scope of the claims
[Claim 1]
　Are arranged in parallel with each other, a primary unit having a plurality of primary elements of the treated water supplied from the upstream side as a reverse osmosis unit for separating the primary concentrated water and fresh water,
　the water to be treated the primary unit upstream by pumping from a pump that supplies該被treated water to said primary unit,
　said with a small number are provided than the primary elements, are arranged in parallel with each other, the primary concentrated water secondary concentrated and a secondary unit having a secondary element of a reverse osmosis unit for separating water and fresh water,
　the one of the water to be treated and the primary concentrated water, reverse osmosis unit for separating the concentrated water and fresh water and sub-elements as,
　the in the sub-elements, a primary modes used as the primary element in the primary unit, the secondary unit two A mode switching unit to switch to one of the secondary mode to use as an element
a water treatment apparatus comprising a.
[Claim 2]
　The sub-element, 1 Tsuonashi of the secondary element in the secondary unit,
　the mode switching unit,
　the sub-distribution lines to direct the treated water toward the sub-element from between the primary unit and the pump When,
　a first valve provided in the sub-distribution on line,
　the concentrated water that has been separated by the sub-elements, and the sub-water collecting line leading to the secondary unit as the primary concentrated water,
　the sub-water collecting line on a second valve provided on,
　the a first switching valve capable of stopping the discharge of fresh water from the sub-element,
　a second switching valve that can stop the discharge of concentrated water from the sub-elements,
　the secondary unit a third switching valve capable of stopping the supply of the primary concentrated water to the sub-elements from the
water treatment apparatus according to claim 1 comprising a.
[Claim 3]
　A reflux line for recirculating part of the fresh water separated by the secondary unit on the upstream side of the pump,
　provided on the reflux line, and a reflux pump for pumping said fresh water,
　provided on the reflux line , a recirculation valve for adjusting the flow state of the freshwater
water treatment apparatus according to claim 2 comprising a.
[Claim 4]
　The water to be treated, the primary concentrated water, the secondary concentrated water, and a measuring unit for measuring at least in one characteristic value of the fresh water,
　the Langelier saturation index obtained from the characteristic value, the reference value set in advance based on a comparison of a control unit for controlling the switching of the primary mode and the secondary mode, the sub-elements according to the mode switching unit
water treatment device according to claim 1, further comprising a any one of 3.
[Claim 5]
　The characteristic value, the water to be treated, the primary concentrated water, the secondary concentrated water, at least in one temperature, or electrical conductivity of the fresh water,
　the control unit, the temperature or the electrical conductivity water treatment device according to claim 4 comprising a calculation unit for calculating the Langelier saturation index based on.
[Claim 6]
　A method of operating a water treatment apparatus when switching the water treatment device according to claim 2 or 3 from the secondary mode to the primary mode,
　by closing the first switching valve, the fresh water from the subelements a step of stopping the discharge,
　and closing the second switching valve, and a step of stopping the discharge of concentrated water from the sub-elements,
　by closing the third switching valve, from the secondary unit to the sub-elements and stopping the supply of the primary concentrated water,
　by opening the first valve, and directing the water to be treated the subelements through the sub-distribution line,
　the first in a state in which the first valve is opened by opening the second valve, the steps leading to the secondary unit the concentrated water the separated in the sub-element through the sub water collecting line as the primary concentrated water
water treatment apparatus comprising Operation method.