CN113039007A

CN113039007A - Water purifier and household water purifier

Info

Publication number: CN113039007A
Application number: CN201980074224.8A
Authority: CN
Inventors: 熊谷宗乡; 门马哲也
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2018-11-27
Filing date: 2019-11-20
Publication date: 2021-06-25
Also published as: WO2020110853A1; JPWO2020110853A1; JP7346447B2

Abstract

A water purifying apparatus is provided which can reduce the consumption of adsorption and removal members and suppress the decrease in function. A water purifier (1) purifies water by using an RO membrane (18) and a DI filter (19), and an opening/closing mechanism (32) for blocking the flow of water in a water passage from the RO membrane (18) to the DI filter (19) is provided in the water passage.

Description

Water purifier and household water purifier

Technical Field

The present invention relates to a water purifier and a household water purifier.

Background

In recent years, water purifying apparatuses using reverse osmosis membranes (RO membranes) have been proposed.

In the case where further purification is required because it is very difficult to completely separate water molecules from impurities by the RO membrane, patent document 1, for example, discloses a technique of improving purity by repeating purification by providing a plurality of purification mechanisms using RO membranes.

As a new method for improving the purity of purified water, a method using an ion exchange resin has been adopted in recent years. Specifically, a filter (hereinafter, DI filter) in which an ion exchange resin is filled in a water passage casing is disposed at the rear stage of an RO membrane, and purified water having passed through the RO membrane is passed through the DI filter to remove further residual impurities, thereby obtaining high purification performance (for example, patent document 2).

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2006-263542 patent document 2: japanese laid-open patent publication No. 2013-107031 "

Disclosure of Invention

Problems to be solved by the invention

However, the purified water using the above-described DI filter has an advantage of a simple structure as compared with a method of repeatedly purifying water using an RO membrane, and on the other hand, the DI filter has a limited purification function, and has a problem that the function is lost when a certain amount of impurities are removed. Therefore, in the purification of water using a DI filter, it is required to maintain the function thereof longer, and efforts are required to suppress the consumption of the performance thereof. In general, this can be said not only for the DI filter but also for the adsorption and removal member that performs adsorption and removal of impurities with limited purification function.

An object of one aspect of the present invention is to realize a water purification apparatus that can reduce consumption of an adsorption-removal member and suppress a decrease in function, when the RO membrane and the adsorption-removal member that adsorbs and removes impurities are used in combination.

Means for solving the problems

In order to solve the above-described problems, a water purification apparatus according to an aspect of the present invention is a water purification apparatus for purifying water using a reverse osmosis membrane and an adsorption removal member for adsorbing and removing impurities, wherein the adsorption removal member is disposed on a path from the reverse osmosis membrane to a water intake of purified water purified by the reverse osmosis membrane; a first blocking means for blocking the flow of water in the water passage from the reverse osmosis membrane to the adsorption and removal member is provided in the water passage.

Advantageous effects

According to one aspect of the present invention, a water purification apparatus can be realized in which the consumption of the adsorption and removal member is reduced and the decrease in function can be suppressed.

Drawings

Fig. 1 is a schematic diagram showing a schematic configuration of a water purification apparatus according to embodiment 1 of the present invention.

Fig. 2 is a schematic diagram showing a schematic configuration of a water purification apparatus according to embodiment 2 of the present invention.

Fig. 3 is a schematic view showing a modification of the water purifying apparatus shown in fig. 2.

Fig. 4 is a schematic diagram showing a schematic configuration of a water purification apparatus according to embodiment 3 of the present invention.

Fig. 5 is a schematic view showing a modification of the water purifying apparatus shown in fig. 4.

Fig. 6 is a schematic diagram showing a schematic configuration of a water purification apparatus according to embodiment 4 of the present invention.

Fig. 7 is a schematic view showing a modification of the water purifying apparatus shown in fig. 6.

Fig. 8 is a schematic view showing another modification of the water purifying apparatus shown in fig. 6.

Detailed Description

[ embodiment 1]

Hereinafter, one embodiment of the present invention will be described in detail.

(Structure of Water purification device)

As shown in fig. 1, the water purifier 1 is a domestic water purifier using a filter (DI filter) filled with a reverse osmosis membrane (RO membrane) and an ion exchange resin. The water purifying apparatus 1 includes a main path (flow path) 50 that takes in raw water from an intake port 50a on one end side and discharges purified water from an output port 50b on the other end side. When the water purifying apparatus 1 is a household water purifier, the inlet 50a is connected to a tap water pipe (raw water), and the outlet 50b is connected to an outlet opening/closing mechanism such as a faucet. The first drain path (waste path) 51 described later is connected to, for example, a drain pipe under the water tank.

A pressure switch 10, a solenoid valve 31, a pressure reducing valve 11, a PP (polypropylene) filter 12, a front TDS13, a water temperature meter 14, a front flow meter 15, an AC (activated carbon) filter 16, a Pump17, an RO membrane (reverse osmosis membrane) 18, an opening/closing mechanism (first blocking mechanism) 32, a DI filter (impurity adsorption and removal means) 19, a rear flow meter 20, and a rear TDS21 are arranged in this order from the most upstream side of the main path 50.

The pressure switch 10 is a switch that is turned on at a constant pressure or more, and is turned on when the pressure of raw water (tap water pressure) can be detected by supplying raw water to the main path 50. The pressure reducing valve 11 makes the water pressure of the tap water flowing through the main path 50 constant.

The PP (polypropylene) filter 12 is a nonwoven fabric made of polypropylene (PP) and having relatively thin meshes, and removes relatively large impurities such as rust contained in raw water. The material is not limited, and may be Polyethylene (PE). By removing relatively large impurities in advance before arrival, deterioration of a reverse osmosis membrane (hereinafter referred to as RO membrane) described later can be suppressed.

The front TDS13 and the rear TDS21 are water quality sensors that measure indicators indicating water quality, and measure the conductivity of water to detect the concentration of impurities in the water. The front TDS13 measures the quality of raw water introduced from the introduction port 50a, and the rear TDS21 measures the quality of purified water taken out from the take-out port 50 b. These measurement results are sent to a control section, not shown, which calculates the purge rate from the measurement value of the front side TDS13 and the measurement value of the rear side TDS 21.

The water temperature gauge 14 is used to calibrate the front TDS13 and the rear TDS 21. This is due to the temperature dependence of the conductivity measured by the front side TDS13 and the rear side TDS 21. The detection result is output to the control unit.

The AC filter 16 removes free substances such as free chlorine compounds contained in the raw water with activated carbon. In addition, the RO membrane 18 is deteriorated by free chlorine compounds (so-called chlorine) contained in the raw water, tap water. Therefore, by removing the free chlorine compounds by the AC filter 16 before reaching, the deterioration of the RO membrane 18 can be suppressed.

The Pump17 is used to supply water to the RO membrane 18 at the subsequent stage while applying a predetermined pressure, and to realize a cross flow system by the RO membrane 18 described later.

The front-side flowmeter 15 and the rear-side flowmeter 20 are sensors that measure the flow rate of water flowing through the main path 50. The measurement result is output to the control section, which calculates the recovery rate based on the introduced amount (usage amount) of raw water as a measurement value of the front-side flow meter 15 and the generated amount of purified water as a measurement value of the rear-side flow meter 20.

As the arrangement position of the front-side flow meter 15, as shown in fig. 1, it is preferable to provide the front-side flow meter 15 between the PP filter 12 and the AC filter 16. This is because, by being disposed at the rear stage (downstream side) of the PP filter 12, it is possible to prevent dirt from adhering to the front-side flow meter 15.

Further, the pressure reducing valve 11, the PP filter 12, the front TDS13, the water thermometer 14, the AC filter 16, the rear flow meter 20, and the rear TDS21 may be provided as needed.

The RO membrane 18 separates water molecules and impurities. Here, the water pressure is applied by the Pump17 and the water to be purified is caused to flow to the surface of the RO membrane 18, thereby separating the water into treated water that has passed through the RO membrane 18 and non-passed drain water. The RO membrane 18 is separated into treated water (purified water) and drain water (concentrated water) by a so-called cross flow system.

The treated water flows through the main path (50), flows to the DI filter 19 at the subsequent stage of the RO membrane 18, and is discharged from the waste port of the first drain path 51. As described above, the waste port is connected to, for example, a drain pipe under the sink.

The first drain path 51 is provided with a flush solenoid valve 22. The flush solenoid valve 22 is a flow rate limiting valve that limits the flow rate of drain water flowing in the first drain path 51. For example, the flush solenoid valve 22 functions as follows: the flow rate is restricted in a closed state (power-off state (non-energized state)), and the flow path is opened as much as possible in an open state (power-on state (energized state)) to allow water to flow.

(purification based on RO Membrane 18)

According to the RO membrane 18, almost all impurities dissolved in water are removed regardless of whether it is harmful or harmless, and pure water of high purity can be obtained. The RO membrane 18 is formed of a mesh-like polymer film formed by crosslinking, and since only water molecules substantially permeate through the polymer film depending on the size of the mesh, the RO membrane is separated from impurities, and the above-described purification performance can be obtained.

The cross flow system is a system in which water to be purified is passed over the surface of the RO membrane 18 while a constant water pressure is applied, and at this time, water that has passed through the RO membrane 18 by the water pressure is taken out as purified water, and water that has not passed through the RO membrane 18 and remains is discarded as drain water. Therefore, the cross flow method always separates impurities from water molecules by passing the surface of the RO membrane 18 through a liquid. In the process of flowing the water on the drain side on the surface of the RO membrane 18, only water molecules permeate the RO membrane 18 and disappear, so that the impurities are relatively concentrated and are discarded in a state of an increased concentration as compared with before the water passes on the surface of the RO membrane 18. Thus, the purified water using the RO membrane 18 is accompanied by a certain amount of drain water (concentrated water).

Here, in order to pass water on the surface of the RO membrane 18 while applying a water pressure, a Pump17 (electric Pump) disposed at the front stage of the RO membrane 18 and a flush solenoid valve 22 as a flow rate regulating means disposed on the first drain path 51 as the rear stage of the RO membrane 18 are used. By flow restricting the amount of water delivered by the Pump17 at the rear section of the RO membrane 18, the path from the Pump17 across the surface of the RO membrane 18 to the flush solenoid valve 22 is pressurized by the force of the Pump 17. Since the higher the pressure is, the more the amount of purified water that permeates the RO membrane 18 increases, in practice, the liquid feeding performance and the flow rate limiting amount of Pump17 are determined in consideration of these balances so as to obtain the target pressure and purified water.

As described above, the flush solenoid valve 22 has a function of restricting the flow rate in the closed state as described above and opening the flow path as much as possible in the open state to allow water to flow. This makes it possible to electrically switch between a function of generating purified water by applying pressure to the surface of the RO membrane 18 and a function of flushing the surface of the RO membrane 18 with a large amount of water as needed.

In addition, since the RO membrane 18 has a fine structure as described above, pretreatment of water to be purified is generally performed to maintain the performance. For example, the removal of deposits, particles, and adhesive substances by a filter (referred to as a fine filter or the like: PP filter 12) mainly made of fibers such as PP (polypropylene) and PE (polyethylene), and the adsorption removal of chlorine, organic substances, and the like used for sterilization treatment of a water pipe by a filter (AC filter 16) mainly made of activated carbon correspond to the removal.

(decontamination based on DI Filter 19)

The DI filter 19 is a filter in which a water passage casing is filled with ion exchange resin. As the ion exchange resin, an ion exchange resin having a function of removing both cations and anions as impurity components is preferably used for purification of water. That is, the DI filter 19 purifies water by converting cations into hydrogen ions and anions into hydroxide ions, and neutralizing the released hydrogen ions and hydroxide ions in water and returning them to the water. Therefore, the DI filter 19 can be said to be an impurity adsorption and removal member that adsorbs and removes impurities contained in the water purified by the RO membrane 18.

(function and Effect of opening/closing mechanism 32)

The opening/closing mechanism 32 is provided in the middle of the path (main path 50) connecting the RO membrane 18 and the DI filter 19, and is a mechanism for blocking diffusion of impurities dissolved in water. In this case, the opening/closing mechanism 32 opens the main path 50 during the cleaning operation to allow water to pass therethrough, and blocks the main path 50 during the stop of the cleaning operation to block the water passing through the opening/closing mechanism 32.

Thus, while the purge operation is stopped, the total amount of impurities removed by the DI filter 19 is suppressed, unnecessary consumption of the purge performance is prevented, and the purge function of the DI filter 19 can be used for a longer period.

Normally, when the water purification operation is continued, the purified water and the drain water in which the impurities are concentrated are separated with the RO membrane 18 interposed therebetween, and only the purified water produced by the RO membrane 18 in which the impurities are small is supplied to the DI filter 19. However, when the purification operation is stopped and the water is not passed through the water purifier 1, impurities contained in the water that has passed through the region before the RO membrane 18 permeate through the RO membrane 18 and diffuse with time in the water on the purified water side after passing through the RO membrane 18. Therefore, when the path blocking mechanism (the opening/closing mechanism 32) is not provided as described above, the impurities having passed through the RO membrane 18 are gradually diffused to the DI filter 19 and purified by the ion exchange resin in the DI filter 19. This phenomenon continues until the impurity concentration in the water across the RO membrane 18 becomes equal, and therefore, this phenomenon continues until the impurities of the water finally remaining in all the regions on the front side of the RO membrane 18 are purified by the DI filter 19. Therefore, impurities that should be discarded as concentrated water generated by the RO membrane 18 are also purified by the DI filter 19, and the purification performance of the DI filter 19 is consumed in large amounts, resulting in waste. Therefore, by providing the opening/closing mechanism 32 for blocking diffusion of the impurities dissolved in the water on the path connecting the RO membrane 18 and the DI filter 19 as described above, the impurities accompanying the diffusion of the substances as described above can be prevented from reaching the DI filter 19.

As described above, the opening/closing mechanism 32 is preferably provided as close as possible to the RO membrane 18 in order to narrow the diffusion range of the impurities sandwiching the RO membrane 18 and reduce the amount of impurities purified by the DI filter 19 when the purification operation is restarted.

(Effect)

According to the above configuration, when the purging operation is stopped, the opening/closing mechanism 32 can suppress diffusion of the impurities that have oozed out from the RO membrane 18. Thus, impurities reaching the DI filter (19) are reduced, and unnecessary impurities do not need to be removed when the purge operation is stopped, so that deterioration of the DI filter (19), that is, the service life can be prolonged. That is, according to the water purifier 1, the unnecessary consumption of the purification performance of the DI filter 19 can be prevented in the purification mechanism in which the purification is performed by the DI filter 19 after the purification by the RO membrane 18, and the functional life can be maintained for a long time.

Further, if the opening/closing mechanism 32 is provided at a position as close as possible to the RO membrane 18 (position immediately after the RO membrane), the concentrated water floating near the RO membrane 18 when the purification operation is stopped can be prevented from diffusing to the DI filter 19 as much as possible. This can further extend the functional life of the DI filter 19.

In the present embodiment, the opening/closing mechanism 32 provided in the middle of the connection between the RO membrane 18 and the DI filter 19 may be a mechanism that opens and closes without electric power (for example, a manual opening/closing mechanism (valve) or a check valve), or may be a mechanism that opens and closes with electric power (for example, a solenoid valve).

[ embodiment 2]

Another embodiment of the present invention will be described below. Note that, for convenience of description, members having the same functions as those described in the above embodiments are given the same reference numerals, and description thereof will not be repeated.

(Structure of Water purification device)

As shown in fig. 2, a water purification apparatus 1A according to the present embodiment is different from the water purification apparatus 1 according to embodiment 1 in that a check valve 33 capable of passing water only in the forward flow direction (here, the outlet 50b side) is used instead of the opening/closing mechanism 32 between the RO membrane 18 and the DI filter 19. The water purification apparatus 1A has the same configuration as the water purification apparatus 1 of embodiment 1 described above, except that the one-way valve 33 is used instead of the opening/closing mechanism 32.

(Effect)

When the check valve 33 is used as the opening/closing mechanism 32, the valve is opened by the water pressure in the downstream direction thereof during the purge operation, and water is passed through the valve. However, since the water pressure disappears and the valve closes during the operation stop, diffusion of the impurities through the valve can be blocked, and convenience is provided in that the operation of the opening/closing mechanism and the purge operation can be automatically interlocked.

Further, the check valve 33 operates without electric power, and therefore operates even in the event of a power failure. Further, since the water purifying apparatus 1A is not expensive like the solenoid valve, it can be manufactured at low cost.

[ modified examples ]

As shown in fig. 3, a water purification apparatus 1B according to the present modification example shows an example in which an electromagnetic valve (second shut-off means) 31 disposed between a pressure switch 10 and a pressure reducing valve 11 in the water purification apparatus 1A shown in fig. 2 is disposed downstream of a flushing electromagnetic valve 22. In the water purifying apparatus 1B, a tap is provided as one of opening and closing mechanisms for opening and closing the outlet 50B in the main path 50 at the outlet 50B. In this case, the power supply of the water purifier 1 is turned on by the operation of turning on the faucet, and the power supply of the water purifier 1 is turned off by the operation of turning off the faucet.

Therefore, the purge operation can be stopped by turning off the faucet. Thus, when the purge operation is stopped, the solenoid valve 31 can be turned off to close the first drain path 51, and therefore the concentrated water flowing from the flush solenoid valve 22 is not discarded. When the purge operation is stopped, the pressure in the vicinity of the R0 film 18 is maintained by the check valve 33 and the solenoid valve 31 in the off state because the tap provided at the outlet 50b of the main path 50 is closed. This allows the purified water to be taken out without a delay when the purification operation is resumed. That is, a faucet as a kind of the outlet opening/closing mechanism is provided in the outlet 50b in addition to the check valve 33, and the opening/closing of the faucet is interlocked with the purge operation. This has the effect of not only allowing the purified water to be taken out without a delay when the purification operation is resumed, but also allowing the purified water to be immediately stopped from being discharged in response to the stop of the purification operation.

In addition, the solenoid valve 31 may be disposed between the RO membrane 18 and the flush solenoid valve 22. In this case, the same effect as that obtained when the solenoid valve 31 is disposed downstream of the flush solenoid valve 22 can be obtained.

Further, the check valve 33 of the water purifying apparatus 1A shown in fig. 2 may be an electromagnetic valve as an opening/closing mechanism that is interlocked with the cleaning operation. For example, as shown in the water purifying apparatus 1C shown in fig. 4, an electromagnetic valve 34 may be provided between the RO membrane 18 and the DI filter 19.

Similarly, as shown in the water purifying apparatus 1D shown in fig. 5, the check valve 33 of the water purifying apparatus 1B shown in fig. 3 may be replaced with an electromagnetic valve 34.

The electromagnetic valve (34) is in an ON state when the cleaning operation is performed, opens the main path (50) to allow water to flow from the RO membrane (18) to the DI filter (19), and is in an OFF state when the cleaning operation is stopped, and closes the main path (50) to prevent water from flowing from the RO membrane (18) to the DI filter (19). That is, the electromagnetic valve 34 blocks the water passage in conjunction with the stop of the purge operation, and opens the water passage in conjunction with the restart of the purge operation.

In the water purification apparatus 1D shown in fig. 5, the electromagnetic valve 34 is in the off state in response to the actuation thereof when the purification operation is stopped, and therefore, the pressure can be maintained when the purification operation is stopped, unlike the water purification apparatus 1B shown in fig. 3, even if a faucet is not provided at the outlet 50B.

That is, in the case of the check valve 33, since the water passing in the forward direction continues until the water pressure in the path disappears, it is necessary to provide a tap or the like at the intake port so as to interlock the opening mechanism with the purge operation in order to stop the discharge of the purified water without a time lag while the purge operation is stopped.

As shown in the water purifying apparatus 1B shown in fig. 3 or the water purifying apparatus 1D shown in fig. 5, the electromagnetic valve 31 as a new opening/closing mechanism which is interlocked with the purging operation may be provided in the first drain path 51 which is the rear stage of the R0 membrane 18, and the first drain path 51 may be opened during the purging operation and the first drain path 51 may be blocked during the stopping of the purging operation. In addition to the above-described effects, for example, when water, such as tap water, to which a water pressure is constantly applied is used as raw water, the purified water can be immediately discharged when the operation is restarted while preventing the water from being constantly discarded through the first water discharge path 51 when the purification operation is stopped. This is because the water pressure in the first drain path 51 is maintained by closing the electromagnetic valve 31 when the purge operation is stopped.

In addition, although the examples of using the check valve and the electromagnetic valve as the opening/closing mechanism provided between the R0 film 18 and the DI filter 19 have been described in the

above embodiments

1 and 2, the example of using the flow path switching mechanism for switching the flow path will be described in the following embodiment 3.

[ embodiment 3]

(Structure of Water purification device)

As shown in fig. 6, a water purification apparatus 1E according to the present embodiment is different from the water purification apparatus 1 according to embodiment 1 in that a flow path switching mechanism 35 is used instead of the opening/closing mechanism 32 between the RO membrane 18 and the DI filter 19. The water purification apparatus 1E has the same configuration as the water purification apparatus 1 of embodiment 1 described above, except that the flow path switching mechanism 35 is used instead of the opening/closing mechanism 32.

The flow path switching mechanism 35 switches between a first flow path (1) from the RO membrane 18 to the DI filter 19 and a second flow path (2) from the RO membrane 18 to the second drain path 52. Here, the flow path switching mechanism 35 is switched to the first flow path (1) during the cleaning operation so that the water having passed through the RO membrane 18 flows into the DI filter 19; when the cleaning operation is stopped, the flow path is switched to the second flow path (2) so that the water having passed through the RO membrane (18) does not flow into the DI filter (19). Thus, the flow path switching mechanism 35 functions similarly to a check valve and an electromagnetic valve.

Therefore, the water purification apparatus 1E according to the present embodiment can obtain the same effects as the water purification apparatus 1 according to embodiment 1 and the water purification apparatuses 1A and 1C according to embodiment 2.

The flow path switching mechanism 35 can also discharge the concentrated water having permeated the RO membrane 18 from the second drainage path 52 by switching to the second flow path (2) when the purification operation is stopped so that the water having permeated the RO membrane 18 does not flow into the DI filter 19. Accordingly, since the concentrated water is not accumulated between the RO membrane 18 and the DI filter 19 when the purging operation is stopped, the initial water flowing from the RO membrane 18 to the DI filter 19 contains less impurities when the purging operation is restarted, and the load on the DI filter 19 can be reduced.

Further, when the purge operation is started again, it is preferable that the second channel (2) be switched to the first channel (1) without directly switching from the second channel (2) to the first channel (1) by the channel switching mechanism 35, and that the second channel (2) be switched to the first channel (1) after a predetermined time has elapsed. In this case, when the cleaning operation is resumed, water that has accumulated in the vicinity of the RO membrane 18, particularly water that has permeated the rear stage side of the RO membrane 18 (water that has increased in impurity concentration during the stop of the operation) is discarded from the second flow channel (2) without passing water through the DI filter 19. Thereafter, by switching to the first flow path (1), the water appropriately purified by the RO membrane 18 can be sent to the DI filter 19. This can further extend the life of the DI filter 19.

The concentrate may be directly discarded from the second drain path 52, but the second drain path 52 may be connected to a stage subsequent to the flush solenoid valve 22 of the first drain path 51, as in the water purification apparatus 1F shown in fig. 7, for example. In this case, the concentrated water to be discarded can be made to flow together in one path.

Further, as in the water purifier IG shown in fig. 8, the second drain path is connected to the first drain path 51 at a position downstream of the flushing solenoid valve 22, and the solenoid valve 31 as a new opening/closing mechanism interlocked with the cleaning operation is provided at a position downstream of the junction of the first drain path 51 and the second drain path. The electromagnetic valve 31 may be configured such that: the first drain path 51 is opened during the purge operation, and the first drain path 51 is blocked during the stop of the purge operation. In this case, the same effects as those of the

water purifying apparatuses

1B and 1D of embodiment 2 can be obtained. That is, for example, when water to which a water pressure is constantly applied, such as tap water, is used as raw water, it is possible to prevent the water from being constantly discarded through the first drainage path 51 when the purification operation is stopped, and to immediately discharge the purified water when the operation is restarted without any time difference.

In the water purification apparatus described in each embodiment, the DI filter 19 is disposed at the rear stage of the RO membrane 18. However, the filter is not limited to the DI filter 19, and may be an AC (activated carbon) filter, or any filter as long as it can adsorb and remove other impurities. The present invention is particularly effective as an adsorption removal filter having a limited purification function.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention. Further, by combining the technical means disclosed in the respective embodiments, new technical features can be formed.

Description of the reference numerals

1. 1A, 1B, 1C, 1D, 1E, 1F and 1G water purifying device

10 pressure switch

11 pressure reducing valve

12 PP filter

13 front side TDS

14 water temperature meter

15 front-side flow meter

16 AC filter

17 Pump

18 RO membrane

19 DI Filter (adsorption removal component)

20 rear flow meter

21 rear side TDS

22 flushing solenoid valve

31. 34 solenoid valve

32 opening and closing mechanism

33 one-way valve

35 flow path switching mechanism

50 main path

50a inlet

50b, 51b take-out port

51 first drainage route (waste route)

52 second drainage path

Claims

1. A water purification apparatus for purifying water using a reverse osmosis membrane and an adsorption removal member for adsorbing and removing impurities,

the adsorption and removal member is disposed on a path from the reverse osmosis membrane to an outlet for purified water purified by the reverse osmosis membrane,

a first blocking means for blocking the flow of water in the water passage from the reverse osmosis membrane to the adsorption and removal member is provided in the water passage.

2. The water purifying apparatus as claimed in claim 1, wherein the first blocking mechanism is provided at a position closer to the reverse osmosis membrane than the adsorption removing member.

3. The water purification apparatus of claim 1 or 2, wherein the first blocking mechanism is a one-way valve that allows water to flow only in a downstream direction.

4. The water purifying apparatus as claimed in any one of claims 1 to 3,

a flow rate limiting valve for reducing the flow rate in a power-off state compared with the flow rate in a power-on state is provided in a waste path from the reverse osmosis membrane to a waste port of concentrated water generated by purification treatment of the reverse osmosis membrane,

the waste path is provided with a second blocking mechanism for blocking the water in the waste path from flowing in and out.

5. The water purifying apparatus as claimed in claim 4, wherein the first blocking means and the second blocking means block the water passage path in conjunction with stopping the purifying operation and open the water passage path in conjunction with restarting the purifying operation.

6. The water purifying apparatus as claimed in any one of claims 1 to 5, wherein the adsorption removing member is a filter filled with an ion exchange resin.

7. The water purifying apparatus as claimed in any one of claims 1 to 6, wherein a water discharge path for discharging water on a path from the reverse osmosis membrane to the first blocking mechanism is provided.

8. The water purifying apparatus according to claim 7, wherein the first blocking mechanism is a flow path switching mechanism that switches a first flow path from the reverse osmosis membrane to the adsorption and removal member and a second flow path from the reverse osmosis membrane to the drain path.

9. A household water purifier comprising the water purifying apparatus according to any one of claims 1 to 8.