JP2011255349A - Water treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water treatment apparatus in which a reverse osmosis membrane is restrained from being clogged.SOLUTION: The water treatment apparatus 1 has: a filter 41 which has the reverse osmosis membrane 41a at the least and is used for generating treated water and draining concentrated water; and a flow velocity changing means 9 for changing the flow velocity of the concentrated water to be drained.

Description

  The present invention relates to a water treatment apparatus.

  Conventionally, as a water treatment device, reverse osmosis membrane module units are arranged in multiple stages, and the concentrated water flow path from the previous reverse osmosis membrane module unit communicates with the supply liquid flow path of the subsequent reverse osmosis membrane module unit Is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-056163

  However, in such conventional technology, the water supplied to the reverse osmosis membrane module unit arranged in the subsequent stage is concentrated water having a high concentration, so that dirt adheres to the reverse osmosis membrane and the reverse osmosis membrane is clogged. There is a problem that it is easy.

  Then, an object of this invention is to obtain the water treatment apparatus which can suppress that a reverse osmosis membrane clogs.

  In this invention, it is a water treatment apparatus which has a reverse osmosis membrane, and is equipped with the filter which drains concentrated water while producing | generating treated water, Comprising: The said water treatment apparatus fluctuates the drainage flow rate of the said concentrated water. The main feature is the provision of a flow velocity variation means.

  According to the present invention, the water treatment apparatus includes the flow rate variation means for varying the drainage flow rate of the concentrated water drained from the filter having the reverse osmosis membrane, and the drainage flow rate of the concentrated water is varied by the flow rate variation unit. Thus, the reverse osmosis membrane can be vibrated. As a result, it becomes difficult for dirt to adhere to the reverse osmosis membrane and the reverse osmosis membrane can be prevented from being clogged.

FIG. 1 is an overall configuration diagram schematically showing a water treatment apparatus according to a first embodiment of the present invention. FIG. 2 is an overall configuration diagram schematically showing a water treatment apparatus according to a second embodiment of the present invention. FIG. 3 is an overall configuration diagram schematically showing a water treatment device according to a third embodiment of the present invention. FIG. 4 is an overall configuration diagram schematically showing a water treatment device according to a fourth embodiment of the present invention. FIG. 5 is an overall configuration diagram schematically showing a water treatment device according to a fifth embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the side opposite to the side where the permeated water of the reverse osmosis membrane is generated (the side where water that does not pass through the reverse osmosis membrane of the nanofilter exists) is defined as the raw water side of the reverse osmosis membrane. Moreover, the following several embodiment and its modification include the same component. Therefore, in the following, common reference numerals are given to those similar components, and redundant description is omitted.

(First embodiment)
As shown in FIG. 1, the water treatment apparatus 1 according to the present embodiment includes a housing 2, a water discharge section 3 attached to the housing 2, and a nanofilter (at least reverse) having an NF membrane (reverse osmosis membrane) 41 a. And a water purification unit 4 that is disposed in the housing 2.

  The water discharger 3 includes an operation / notification unit 31 and a water discharge currant 32 discharged from purified water (treated water).

  The water purification unit 4 is connected to the tap water channel P0 via the branch portion D1, and has a main water channel P1 into which tap water as raw water is introduced, and the nanofilter 41 is arranged in the main water channel P1. Yes. Furthermore, in this embodiment, the pre-processing part 40 is arrange | positioned in the upstream of the nano filter 41, and the water pre-processed in the said pre-processing part 40 is introduced into the nano filter 41.

  Specifically, in the present embodiment, the first prefilter 42, the supply pump 43, the second prefilter 44, the third prefilter 45, and the nanofilter 41 are sequentially arranged from the upstream side to the downstream side of the main water passage P1. Is arranged. Moreover, in this embodiment, the pressure sensor 6 which detects the water pressure of the tap water supplied in the water purification part 4 is provided in the upstream of the 1st pre filter 42 of the main channel P1. Between the filter 42 and the supply pump 43, an on-off valve 7 for controlling start and stop of introduction of tap water into the water treatment apparatus 1 is provided.

  The first pre-filter 42 is composed of, for example, a nonwoven fabric filter having a pore diameter of 5 μm, and captures and removes relatively large foreign matters such as large particles and dust mixed in tap water introduced into the main water passage P1. To do. The pre-filter 42 is provided to prevent the pumping capacity from being lowered due to the mixing of fine particles into the supply pump 43 and to prevent the opening / closing operation of the on-off valve 7 from being hindered. It does not have to be provided. However, in that case, for example, it is preferable to dispose a strainer capable of capturing fine particles upstream of the supply pump 43 and the on-off valve 7.

  The water that has passed through the first pre-filter 42 and the on-off valve 7 and reached the supply pump 43 is pressurized (for example, 0.4 MPa) by the supply pump 43 and is pumped downstream. The supply pump 43 generates reverse osmosis pressure of the nanofilter 41 by increasing the pressure of water from which dust or the like has been removed and pumping the water downstream. The arrangement positions of the supply pump 43 and the on-off valve 7 are not limited to those shown in FIG. 1 and can be arranged at other places. For example, it is possible to arrange on the downstream side of the third pre-filter 45 or on the upstream side of the first pre-filter 42 with the strainer arranged on the upstream side.

  Then, the water pressurized by the supply pump 43 and pumped downstream is introduced into the second pre-filter 44 and the third pre-filter 45 to remove free residual chlorine and the like.

  The second pre-filter 44 contains an activated carbon filter (not shown), and removes components dissolved in water, particularly off-flavors and odors, or halogenated carbon such as trihalomethane.

  In addition, a heavy metal removing agent for removing heavy metals may be mixed in the activated carbon filter so that harmful heavy metals such as lead can be adsorbed and removed by the heavy metal removing agent. Further, by decomposing and removing residual chlorine in water with an activated carbon filter, bacteria can easily propagate on the downstream side. In order to prevent this, the second prefilter 44 contains an antibacterial metal such as silver. An antibacterial agent may be mixed.

  Further, the third prefilter 45 is constituted by, for example, a nonwoven fabric filter having a pore diameter of 1 μm, and captures and removes finer suspended substances that are not captured by the first prefilter 42.

  As described above, in the present embodiment, the water pretreated by the first prefilter 42, the supply pump 43, the second prefilter 44, and the third prefilter 45 is introduced into the nanofilter 41. It has become. That is, in the present embodiment, the first prefilter 42, the supply pump 43, the second prefilter 44, and the third prefilter 45 form the preprocessing unit 40.

  Note that the configuration of the pretreatment unit is not limited to this configuration. For example, a block activated carbon filter or a fibrous activated carbon filter is used, and the pore diameter of the filter is used to combine the function of the nonwoven fabric filter. Good.

  And the water pre-processed in the pre-processing part 40 is introduce | transduced into the nano filter 41, and concentrated water and treated water are produced | generated. In the present embodiment, the two nanofilters 41 and 41 are arranged in parallel, and water is introduced through the water passages P2 and P3, respectively.

  A flow rate sensor 8 that detects the amount of inflow into the nanofilter 41 is provided on the upstream side of the nanofilter 41.

  The nanofilter 41 is made of an organic substance (for example, trihalomethane, musty odor and agricultural chemical), heavy metal ions (for example, lead, chromium, cadmium, mercury, arsenic, etc.), and low molecular weight ions such as sodium and calcium by the NF film 41a. It removes components and the like. And the water which permeate | transmitted the NF film | membrane 41a is supplied to the confluence | merging water channel P9 through the processing water channels P4 and P6, respectively, as processed water from which these substances were removed. Further, the water that does not pass through the NF membrane 41a passes through the concentrated water passages P5 and P7 as concentrated water containing the above-described substances, and is discharged to the outside from the merging drainage channel P8 provided with the drainage adjusting valve 9.

  Note that the NF membrane 41a has larger permeation holes than the RO membrane. Therefore, the nanofilter 41 using the NF film 41a can remove particles, organic substances, and heavy metals at a high removal rate of 90% or more, but low molecular weight ionic components remain in the permeated water by about 10 to 30%. It has the characteristic of In this case, for example, when water having a conductivity of 300 μS / cm is permeated, treated water having a conductivity of about 60 μS / cm is obtained as the treated water in which the low molecular ions remain. However, the membrane used as the reverse osmosis membrane is not limited to this NF membrane, and a reverse osmosis membrane such as an RO membrane can also be used.

  In addition, the water flow path P9 is provided with a flow rate sensor 10 that detects the flow rate of the treated water.

  Then, the treated water introduced into the water passage P <b> 9 is taken out from the water discharge currant 32.

  In this embodiment, the pressure sensor 6, the supply pump 43, the on-off valve 7, the flow rate sensor 8, the drainage adjustment valve 9, the flow rate sensor 10, and the operation / notification unit 31 are respectively connected to the wirings H1, H2, H3, and H4. , H5, H6, and H7 to be connected to the control device 11 and controlled by the control device 11.

  Here, in the present embodiment, the water treatment apparatus 1 is provided with a flow rate fluctuation unit that fluctuates the drainage flow rate of the concentrated water.

  Specifically, the drainage adjustment valve 9 is used as a flow velocity fluctuation means. That is, the drainage flow rate of the concentrated water is varied by changing the opening degree of the drainage adjustment valve 9 by the control device 11. In addition, you may make it use the thing which provided the slit in the electromagnetic on-off valve as a flow-rate fluctuation | variation means, and change a drainage speed by the on / off of the said electromagnetic on-off valve. As described above, when the electromagnetic on-off valve provided with the slit is used, the drainage speed can be changed more rapidly.

  The water treatment apparatus 1 having such a configuration operates as follows.

  First, when the operation / notification unit 31 provided in the water discharge unit 3 is operated and the purified water generation mode is selected, the control device 11 opens the on-off valve 6 of the main water passage P1. Then, the tap water is introduced from the tap water channel P0 into the main water channel P1 through the branch portion D1, and the pretreatment unit 40 in the main water channel P1, that is, the first to third pre-filters 42, 44, 45 is connected. While being purified, the water is purified and the pressure is increased by the supply pump 43.

  Then, the water purified by the pretreatment unit 40 is introduced into the nanofilter 41. When the flow rate sensor 8 detects that the amount of water processed by the pretreatment unit 40 is equal to or less than a predetermined value, the control device 11 determines that an abnormality has occurred in the water supply channel, and the control device 11, the on-off valve 6 is closed and the supply pump 43 is stopped, and an abnormality in the water treatment apparatus 1 is notified to the operation / notification unit 31.

  Then, the treated water (purified water) introduced into the nanofilter 41 and permeated through the NF film 41a and from which organic substances and ions dissolved in the water have been removed by the NF film 41a passes through the treated water channels P4 and P6, and the combined water channel P9. Is supplied to the water discharge currant 32 and discharged to the outside.

  On the other hand, water that is introduced into the nanofilter 41 but does not permeate the NF membrane 41a passes through the concentrated water passages P5 and P7 and the combined drainage channel P8 as concentrated water and is discharged to the outside.

  At this time, when the flow rate of the concentrated water is small, the linear velocity of the water flow on the raw water side surface of the NF membrane 41a decreases, and the concentration polarization of the concentrated water tends to occur. Therefore, there is a problem that organic substances, ions and the like are likely to adhere to the surface of the NF film 41a, the NF film 41a is clogged, and the permeated water amount is reduced. Further, when the amount of concentrated water is increased, the occurrence of concentration polarization can be suppressed, but the amount of permeated water is reduced.

  Therefore, in the present embodiment, the opening degree of the drainage adjustment valve 9 is changed by the control device 11 when the purified water is generated. Specifically, the controller 11 increases the opening degree of the on-off valve 9 for a predetermined time (several seconds to several tens of seconds), and reduces the opening degree of the on-off valve 9 after a predetermined time (several seconds to several tens of seconds). The operation is repeated. Thus, by expanding and reducing the opening degree of the on-off valve 9, it is possible to prevent the concentrated water with high concentration from coming into contact with the NF membrane 41a for a long time. Further, since the linear velocity of the water flow on the raw water side surface of the NF film 41a changes abruptly, it becomes possible to wash away organic substances, ions, etc. attached to the surface of the NF film 41a. In this way, by changing the opening degree of the drainage adjustment valve 9, it is possible to suppress adhesion of components such as organic substances and ions to the surface of the NF film 41a.

  When the water flow is stopped by the operation of the operation / notification unit 31, the control device 11 closes the on-off valve 7 and stops the supply pump 43.

  As described above, according to the present embodiment, the water treatment device 1 has a drainage adjustment valve that fluctuates the drainage flow rate of the concentrated water drained from the nanofilter (filter) 41 having the NF membrane (reverse osmosis membrane) 41a. (Velocity variation means) 9 is provided. Then, the control device 11 performs a series of operations in which the opening degree of the on-off valve 9 is increased for a predetermined time (several seconds to several tens of seconds) and the opening degree of the on-off valve 9 is reduced after a predetermined time (several seconds to several tens of seconds). I try to do it repeatedly. In this way, by changing the drainage flow rate of the concentrated water by the drainage adjustment valve (flow rate fluctuation means) 9, the linear velocity of the water flow on the raw water side surface of the NF membrane 41a can be rapidly changed, and the NF membrane 41a It becomes possible to wash away organic substances and ions adhering to the surface.

  When the linear velocity of the water flow on the raw water side surface of the NF membrane 41a is suddenly changed, the NF membrane (reverse osmosis membrane) 41a vibrates due to the rapid change of the linear velocity of the water flow. As a result, it becomes difficult for dirt to adhere to the NF membrane (reverse osmosis membrane) 41a, and the NF membrane (reverse osmosis membrane) 41a can be prevented from being clogged.

(Second Embodiment)
A water treatment apparatus 1A according to the present embodiment has basically the same configuration as that of the first embodiment. That is, the water treatment apparatus 1A includes a housing 2, a water discharge portion 3 attached to the housing 2, and a nanofilter (a filter having at least a reverse osmosis membrane) 41 having an NF membrane (reverse osmosis membrane) 41a. The water purification part 4 arrange | positioned in the housing | casing 2 is provided.

  Here, 1 A of water treatment apparatuses concerning this embodiment differ from the said 1st Embodiment mainly in the point which provided the gas-liquid mixing means as a flow-rate fluctuation | variation means in 1 A of water treatment apparatuses.

  Specifically, as shown in FIG. 2, a gas-liquid mixing unit 12 is provided on the upstream side of the nanofilter 41 and on the downstream side of the flow sensor 8, and is introduced into the nanofilter 41 by the gas-liquid mixing unit 12. Gas is mixed with the water to be used.

  The gas-liquid mixing unit 12 may be a combination of an electromagnetic on-off valve and an ejector, or may be a unit that mixes air such as an air pump. Further, a combination of a gas cylinder and an electromagnetic on-off valve may be used as long as the start and stop of gas mixing can be controlled. In addition, when the gas-liquid mixing part 12 takes in ambient air, it is preferable to provide a dust removing means for removing dust in the air.

  In addition, when gas is mixed with the water introduced into the nanofilter 41, bubbles are aggregated and expanded, and there is a possibility that the bubbles stay on the surface of the NF film 41a. Thus, when bubbles accumulate on the surface of the NF membrane 41a, there is a problem that the effective filtration area of the NF membrane 41a is reduced and the permeated water amount is reduced. Therefore, in the present embodiment, the nanofilter 41 is arranged so that the concentrated drainage side of the NF membrane 41a faces upward so that bubbles can be suppressed from being accumulated on the surface of the NF membrane 41a.

  1 A of water treatment apparatuses provided with this structure are made to mix gas intermittently with the water introduce | transduced into the nano filter 41 by the control apparatus 11 at the time of water purification production | generation.

  In this way, by intermittently mixing the gas introduced into the water introduced into the nanofilter 41, the apparent amount of water introduced into the nanofilter 41 increases and decreases, and the water flow line on the raw water side surface of the NF membrane 41a. The speed can be changed rapidly.

  Further, by mixing the bubbles, the hydrophobic component can be adsorbed to the bubbles. Furthermore, the NF film 41a vibrates due to the bursting / expansion of bubbles in the vicinity of the surface of the NF film 41a, and the components attached to the surface of the NF film 41a can be peeled off.

  Thus, also by this embodiment, there can exist an effect | action and effect similar to the said 1st Embodiment.

(Third embodiment)
The water treatment apparatus 1B according to the present embodiment has basically the same configuration as that of the first embodiment. That is, the water treatment apparatus 1B includes a housing 2, a water discharge unit 3 attached to the housing 2, and a nanofilter (a filter having at least a reverse osmosis membrane) 41 having an NF membrane (reverse osmosis membrane) 41a. The water purification part 4 arrange | positioned in the housing | casing 2 is provided.

  Here, the water treatment apparatus 1B according to the present embodiment is mainly different from the first embodiment in that the water treatment apparatus 1B is provided with a flow path switching means as a flow rate fluctuation means.

  Specifically, as shown in FIG. 3, the main water passage P1 is branched to the water passages P2 and P3 via the branch portion D2 on the upstream side of the nanofilter 41, and the on-off valves 13 and 14 are provided respectively. It has been.

  And the water paths P10 and P11 are connected to the water path P2 via the branch part D3. The water passages P10 and P11 are connected to the nano filter 41, respectively.

  On the other hand, water passages P12 and P13 are connected to the water passage P3 via a branch portion D4, and the water passage P12 is connected to a position different from the water passage P11 of the nanofilter 41.

  The water passages P14 and P15 are connected to the water passage P13 via the branch portion D5, and the water passage P14 is connected to a position different from the water passage P10 of the nanofilter 41.

  Furthermore, the water flow path P15 is connected to a water flow path P16 and a confluence drainage path P8 via a branch portion D6, and an open / close valve 15 is provided in the water flow path P15.

  Further, the water passage P16 is connected to the water passages P2, P10, P11 via the branch portion D3, and the on-off valve 9 is provided in the water passage P16.

  The on-off valve 13, on-off valve 14, and on-off valve 15 are connected to the control device 11 via the wires H8, H9, and H10, respectively, and are controlled by the control device 11.

  Here, in the present embodiment, the opening / closing valve 9 and the opening / closing valve 14 are opened by the control means 11 and water is introduced into the nanofilter 41 with the opening / closing valve 13 and the opening / closing valve 15 closed by the control means 11. And the on-off valve 9 and the on-off valve 14 are closed by the control means 11 and the on-off valve 13 and on-off valve 15 are controlled. In a state of being opened by the means 11, the second flow path for introducing water into the nanofilter 41 (flow path introduced from the water flow paths P11 and P10 and discharged from the water flow paths P12 and P14) is switched. .

  In this way, by repeatedly switching the flow path of the water (concentrated water) introduced into and discharged from the nanofilter 41 by the control means 11, the direction of the water flow on the raw water side surface of the NF membrane 41a changes (inverts). As a result, the concentration polarization of concentrated water can be prevented from occurring.

  In addition, since a turbulent flow is generated in the nanofilter 41 when the flow path is switched, the components attached to the surface of the NF film 41a can be peeled off.

  Thus, also by this embodiment, there can exist an effect | action and effect similar to the said 1st Embodiment.

(Fourth embodiment)
The water treatment apparatus 1C according to the present embodiment has basically the same configuration as that of the first embodiment. That is, the water treatment apparatus 1C includes a housing 2, a water discharge portion 3 attached to the housing 2, and a nanofilter (a filter having at least a reverse osmosis membrane) 41 having an NF membrane (reverse osmosis membrane) 41a. The water purification part 4 arrange | positioned in the housing | casing 2 is provided.

  Here, the water treatment apparatus 1 </ b> C according to the present embodiment is mainly different from the first embodiment in that the water treatment apparatus 1 </ b> C has a reflux path P <b> 16 for returning the concentrated water discharged to the upstream side of the nanofilter 41. It is in the point which provided.

  Specifically, one end of the reflux passage P16 is connected to the concentrated water passages P5 and P7 and the confluence drainage passage P8, and the other end is connected between the on-off valve 7 of the main water passage P0 and the supply pump 43. ing. The recirculation path P16 is also provided with an on-off valve 16, and the on-off valve 16 is connected to the control device 11 via the wiring H11 and controlled by the control device 11.

  In this manner, the drainage flow rate of the concentrated water can be varied by providing the reflux path P16 for refluxing the concentrated water to be drained to the upstream side of the nanofilter 41 and adjusting the reflux amount of the concentrated water.

  Thus, also by this embodiment, there can exist an effect | action and effect similar to the said 1st Embodiment.

  In addition, by adjusting the flow rate of the concentrated water, the NF membrane (reverse osmosis membrane) 41a is clogged without increasing the drainage amount of the concentrated water by changing the drainage flow rate of the concentrated water. Can be suppressed.

(Fifth embodiment)
The water treatment apparatus 1D according to the present embodiment has basically the same configuration as that of the fourth embodiment. That is, the water treatment apparatus 1D includes a housing 2, a water discharge unit 3 attached to the housing 2, and a nanofilter (a filter having at least a reverse osmosis membrane) 41 having an NF membrane (reverse osmosis membrane) 41a. The water purification part 4 arrange | positioned in the housing | casing 2 is provided.

  The water treatment device 1D is provided with a reflux path P16 for returning the drained concentrated water to the upstream side of the nanofilter 41.

  Here, the water treatment apparatus 1D according to the present embodiment is mainly different from the fourth embodiment in that the water treatment sensor 1D detects the water quality (pH or conductivity) of the concentrated water discharged to the water treatment apparatus 1D. (Water quality detection means) 17 is provided.

  In this embodiment, the water quality sensor (water quality detection means) 17 is provided at the junction of the concentrated water passages P5 and P7 of the junction drainage channel P8. In addition, you may make it provide the water quality sensor (water quality detection means) 17 in another place. At this time, the concentrated water drainage channel (concentrated water channels P5, P7 and the combined drainage channel P8) from the nanofilter 41, the reflux channel P16, or the water introduction channel (water channels P2, P3) to the nanofilter 41. It is preferable to provide it in (1).

  Further, the water quality sensor (water quality detection means) 17 is connected to the control device 11 via the wiring H <b> 12 and is controlled by the control device 11.

  In the present embodiment, the water treatment device 1D is provided with a water quality sensor (water quality detection means) 17 for detecting the quality of the drained concentrated water, so that the concentrated water exceeds a predetermined value stored in the control device 11 in advance. When the electrical conductivity is exceeded (when pH or electrical conductivity of a predetermined value or more is detected by the water quality sensor 17), the on-off valve 16 is closed to stop the concentrated water from flowing back. Further, when the concentrated water becomes equal to or less than a predetermined value stored in advance in the control device 11, the on-off valve 16 is opened to recirculate the concentrated water.

  As described above, the drainage flow rate of the concentrated water can also be changed by opening and closing the on-off valve 16 according to the quality of the concentrated water and starting or stopping the reflux of the concentrated water.

  That is, also by this embodiment, the same operation and effect as the first embodiment can be obtained.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment, and various modifications can be made.

1, 1A, 1B, 1C, 1D Water treatment equipment 4 Water purification section 9 Drainage adjustment valve (flow rate fluctuation means)
12 Gas-liquid mixing part (gas-liquid mixing means)
17 Water quality sensor (water quality detection means)
41 Nanofilter (filter)
41a NF membrane (reverse osmosis membrane)
P16 Return path

Claims (5)

A water treatment apparatus having a reverse osmosis membrane and having a filter that generates treated water and drains concentrated water,
The said water treatment apparatus is provided with the flow-rate fluctuation | variation means which fluctuates the drainage flow speed of the said concentrated water, The water treatment apparatus characterized by the above-mentioned.   The water treatment apparatus according to claim 1, wherein the flow velocity fluctuation unit is a gas-liquid mixing unit.   The water treatment apparatus according to claim 1 or 2, wherein the flow rate fluctuation means is a flow path switching means for switching a flow path of water supplied to the filter.   The water treatment apparatus according to any one of claims 1 to 3, wherein the water treatment apparatus includes a reflux path for returning drained concentrated water to the upstream side of the filter.   The water treatment apparatus according to any one of claims 1 to 4, wherein the water treatment apparatus includes water quality detection means for detecting the quality of drained concentrated water.

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