JP3859412B2 - Reverse osmosis apparatus with automatic reverse osmosis membrane cleaning mechanism, and method for producing pure water using the apparatus - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
In the present invention, impurities such as colloids, sparingly soluble salts and bacteria contained in raw water are concentrated and accumulated on the surface of the reverse osmosis membrane, and the quality of the produced pure water (reverse osmosis water) deteriorates. According to a reverse osmosis device that automatically prevents the water permeation performance of a reverse osmosis membrane from being deteriorated over time as a result of adhesion of impurities to the surface of the osmosis membrane, precipitation, etc., and a reverse osmosis method using the device The present invention relates to a method for producing pure water.
[0002]
[Prior art]
In conventional reverse osmosis equipment, the purity (conductivity and number of fine particles) of pure water (reverse immersion water) produced by condensing or precipitating impurities such as colloids, sparingly soluble salts and bacteria on the reverse osmosis membrane・ Endotoxin concentration etc.) deteriorated and water permeability performance deteriorated over time.
When the water permeability is reduced due to clogging of the membrane, the reverse osmosis membrane module is separated, a chemical circulation line is formed, and the complicated operation of pouring an alkali or acidic detergent into the raw water inflow side of the reverse osmosis membrane is required. did.
In addition, a large amount of water was required after washing with the chemical solution as described above in order to wash away the chemical solution used in the washing remaining on the reverse osmosis membrane.
Furthermore, even if the reverse osmosis membrane is chemically deteriorated by the chemical cleaning itself and the water permeability of the reverse osmosis membrane itself is recovered, the water quality may not be recovered. In such a case, there has been a problem that an expensive reverse osmosis membrane needs to be replaced and maintenance costs increase.
[0003]
Conventionally, reverse osmosis water (RO water, reverse osmosed water, hereinafter also referred to as pure water) has been manufactured by an intermittent operation reverse osmosis water production system as shown in FIG. In this system, the concentrated water is removed from the reverse osmosis device C, and the produced pure water (hereinafter also referred to as reverse osmosis water) is stored in a pure water tank, and the pure water tank is filled with pure water. Then, the operation of the pump that supplies the raw water to the reverse osmosis device by the control system f is stopped by the level switch, and conversely, when the amount of water stored in the pure water tank decreases, the control system f detects that the raw water is supplied. The one that resumed the operation of the pump and produced pure water was proposed.
[0004]
[Problems to be solved by the invention]
At the time of pure water preparation by a reverse osmosis device, it is possible to remarkably improve the recovery rate of pure water by attaching a concentrated water circulation line, but on the other hand, there is a problem that the accumulation of impurities increases in the reverse osmosis membrane.
An object of the present invention is to provide a reverse osmosis device with a reverse osmosis membrane automatic cleaning mechanism (hereinafter also simply referred to as a reverse osmosis device) that solves the above-described problems in the production of raw water and a method for producing pure water using the device. It is in.
That is, the object of the present invention is to prevent the concentration of impurities in the reverse osmosis membrane surface and the formation of deposits by incorporating an automatic pure water washing process during use of the reverse osmosis apparatus, and (1) conductivity. Improve the water quality monitored by the number of fine particles, endotoxin concentration, etc., improve the production efficiency of pure water, (2) maintain the water permeability of the reverse osmosis membrane and extend the service life, (3) cumbersome membrane A reverse osmosis device with a reverse osmosis membrane automatic cleaning mechanism that has solved problems such as insoluble or reduced frequency of chemical cleaning that causes chemical degradation and (4) reduced bacterial growth on the membrane surface, and pure water It is to provide a manufacturing method.
[0005]
[Means for Solving the Problems]
The first of the present invention is a reverse osmosis membrane automatic cleaning provided with a pure water recirculation mechanism for cleaning the reverse osmosis membrane of the reverse osmosis device with pure water during the operation of the device on the raw water load side of the reverse osmosis device. By providing a reverse osmosis apparatus with a mechanism, the above problems or problems are solved.
That is, the reverse osmosis device of the present invention is characterized by a time zone in which the amount of water produced is superior to the amount of pure water used during continuous operation, in other words, the amount of water stored in the pure water tank is large and the liquid level in the tank is high. In the state time zone, excess pure water in the pure water tank is returned to the reverse osmosis membrane module, and the module is cleaned. In other words, the apparatus is configured to insert the cleaning process intermittently during continuous operation. By using excess pure water for cleaning, the pure water tank is prevented from overflowing.
The “time zone in which the amount of water stored in the pure water tank is large and the liquid level in the tank is high” means that even if the amount of pure water stored decreases, the reverse osmosis water to the point of use (where it is used) The amount of storage that does not cause the problem of insufficient supply. This is, for example, a state in which the liquid level is at the position of the level switch α in FIG. 1 (this state is also referred to as a state in which the liquid level in the tank is high). In contrast, for example, the position of the level switch β in FIG. When there is a liquid level in the tank (this state is also referred to as a low liquid level in the tank) or in a state where the liquid level is lower than the level switch β, reverse osmosis to the point of use (where to use) There arises a problem that the supply amount of water is insufficient, and the reverse osmosis membrane module cannot be cleaned using pure water in the pure water tank.
A second aspect of the present invention is a method for producing pure water that uses the reverse osmosis device with a reverse osmosis membrane automatic cleaning mechanism to solve the above problems or problems.
[0006]
Specifically, the reverse osmosis device of the present invention includes a raw water load line (a) having an on-off valve for supplying raw water to the reverse osmosis device, and raw water or pure water provided upstream of the reverse osmosis device of the raw water load line. An apparatus used for increasing the pressure (hereinafter also referred to as liquid pressurizing means) (b), having a reverse osmosis membrane that separates raw water into pure water that has passed through the reverse osmosis membrane and concentrated water that has passed through the reverse osmosis membrane A reverse osmosis device (c), one end connected to the reverse osmosis device and the other end connected to the raw water load line downstream of the open / close valve of the raw water load line to form a recirculation loop line (concentrated water line) ) (D), a drainage line (e) having an on- off valve formed by branching from the passage line (concentrated water line), the raw water load line and the passage line (concentrated water line), and the drainage Downstream from the position where the line branches Recirculation loop line having an on-off valve in the flow-through line (f), the reservoir of pure water produced by the reverse osmosis unit (g), one end of the other end connected to the pure water tank raw load line of the opening and closing valve At least a pure water recirculation line (h) having an on- off valve connected to the raw water load line on the downstream side, and an initial drain line (j) branched from the pure water line, and the passing line (d), drainage The present invention relates to a reverse osmosis device with an automatic cleaning mechanism, characterized in that a plurality of on-off valves provided in line (e) and a pure water reflux line (h) are provided in parallel .
The decrease in the membrane function of the reverse osmosis device is not due to the strength deterioration of the membrane itself but due to the deposition of foreign matter on the membrane surface. In the reverse osmosis device of the present invention, excellent cleaning of the reverse osmosis membrane surface by a simple mechanism is performed. As a result, the production efficiency of pure water is remarkably improved, and the performance of the reverse osmosis membrane is maintained for a long time.
[0007]
Specifically, the pure water production method of the present invention uses the reverse osmosis device described above, and first connects the raw water load line, the initial drainage line, and the drainage line for supplying raw water to the reverse osmosis device. A line (concentrated water line) and a drainage line are opened, a pure water line is optionally opened and closed, a liquid pressurizing means is operated with the other lines closed and a reverse osmosis operation is performed. The pure water is drained from the initial drain line, the concentration of the drained pure water is inspected, and the steps (1) to (3) below are continuously performed when the concentration has become better than a certain level. And at least once, a method for producing pure water.
(1) Pure water production process Raw water load line, passage line (concentrated water line) line connected to drainage line, drainage line and pure water line open state, recirculation loop line can be opened and closed arbitrarily, and other lines are closed Supplying raw water in a state, operating the liquid pressurizing means to increase the pressure of the raw water and sending it to the reverse osmosis device to produce pure water.
(2) Pure water replacement cleaning process (A) when the amount of pure water produced by the pure water production process of (1) reaches the predetermined liquid level of the storage container (A), or When the purity of the produced pure water is detected by the amount of pure water stored at a certain level or higher in the storage container and the purity of the pure water is deteriorated below a certain level (B), (A) or (B) is detected, the supply of raw water is stopped, the pure water line is optionally opened and closed, and the passage line (concentrated water line) connected to the drainage line and the drainage line are reversed. A step of supplying pure water from the pure water reflux line to the permeation device and replacing it with pure water while discharging the concentrated water in the passage (concentrated water) line and the reverse osmosis device.
(3) High-speed washing process In the pure water replacement state in the step (2), liquid pressurization is performed with the raw water supply from the raw water load line stopped, the recirculation loop line opened, and the drain line closed. Under normal operation, pure water is recirculated through the recirculation loop line at a high flow rate and the reverse osmosis membrane of the reverse osmosis unit is washed at high speed, and then the wash water that has washed away these impurities is connected to the drainage line. (Concentrated water line), drainage line and pure water recirculation line only open, pure water line open / close optional, other lines closed and fresh pure water injected under the operation of the liquid pressurizing means The process of discharging from the drainage line.
As raw water as referred to in the present invention, for example, tap water, well water and the like can be used.
[0008]
Hereinafter, a reverse osmosis device of the present invention and a method for producing pure water using the reverse osmosis device will be described in detail with reference to the drawings. However, the present invention is not limited to these embodiments.
FIG. 1 is a diagram showing constituent members of a reverse osmosis device with an automatic cleaning mechanism of the present invention and piping flow in the device.
Raw water is supplied through the raw water load line 6 to the reverse osmosis device C of FIG.
The raw water is separated into pure water that has passed through the reverse osmosis membrane and concentrated water that has passed through the reverse osmosis membrane by reverse osmosis at high pressure. Concentrated water which is repelled by the reverse osmosis membrane and passes through the membrane without passing through the membrane is taken out from the reverse osmosis device C by a passage line (concentrated water line) 7.
The raw water load line 6 is provided with a valve 1 for adjusting the supply amount of raw water, preferably a solenoid valve, on the inlet side, and raw water or pure water is supplied between the valve 1 and the reverse osmosis device C. In order to pressurize, a liquid pressurizing means (the high-pressure pump A in this figure) is provided.
Raw water is introduced from the raw water load line 6, pressurized by the pump A, and introduced into the reverse osmosis device C under high pressure (hereinafter also referred to as water flow pressure).
The amount of pure water produced depends on the water permeability of the membrane, the pressure difference between the membranes (water flow pressure), the osmotic pressure of the raw water, and the ratio of the raw water passage line and the amount of pure water taken out (that is, the recovery rate). To do.
[0009]
In general, the purity of pure water obtained from the reverse osmosis device C varies depending on the water pressure (permeated water amount) of raw water and the recovery rate of pure water. In addition, the purity of pure water changes dynamically according to the water flow pressure (transmembrane pressure difference), and the shaking caused by the pressure change causes the closure failure of the seal part in reverse osmosis, causing the components in the raw water to Since the quality of pure water can deteriorate due to leakage, it is preferable to keep the water flow pressure at a high and constant pressure to avoid fluctuations.
As the water flow pressure, a pressure of about 5 kg / cm 2 to 20 kg / cm 2 is usually employed, but the pressure applied to the reverse osmosis device C is preferably high and constant.
[0010]
In order to make the pressure applied to the reverse osmosis membrane constant, the drainage / concentration circulation / pure water reflux line solenoid valve and injection pump play an important role.
That is, in the figure, the two attached in parallel with the solenoid valve for the drainage and the concentrated water circulation line make the flow rate flowing into the reverse osmosis membrane constant or minimize the fluctuation, and make the pressure entering the high-pressure phone more constant. From the purpose. Further, by making the discharge flow rate constant, the pressure applied to the reverse osmosis membrane is made more constant.
[0011]
The passing line (concentrated water line) 7 is connected to the raw water load line 6 on the upstream side of the high-pressure pump A (point F in FIG. 1) to form a recirculation loop line 8. A drain line 9 is provided in the middle of a passage line (concentrated water line) 7 constituting the recirculation loop line 8. Solenoid valves 4 and 4a for drainage are provided in parallel on the drainage line 9. The electromagnetic valves 4 and 4a may be one, but a plurality of electromagnetic valves 4 and 4a may be used to enable a plurality of washing operations described in the following examples, to facilitate flow rate adjustment, and to keep the flow rate flowing into the reverse osmosis membrane constant. preferable.
In addition to the drain valve, it is preferable to provide a pressure relief safety valve D on the drain line 9 in parallel with the drain valve as a measure against overload of the closed circuit.
When the recirculation loop line 8 is formed, it is preferable that the passing-through line (concentrated water line) 7 is provided with solenoid valves 3 a and 3 b before the point where the line is connected to the raw water load line 6. In addition, the number of these solenoid valves may be one, but the plurality of washing operations described in the following examples can be performed similarly to the drainage valves 4a and 4, and the flow rate can be easily adjusted. A plurality is preferable in order to make the flow rate flowing into the reverse osmosis membrane constant.
[0012]
Pure water is taken out from the reverse osmosis device C and stored in a pure water tank through a pure water line 10 having an electromagnetic valve 2 that controls the removal of pure water from the reverse osmosis device C. The pure water line 10 may be provided with a member for monitoring whether or not the pure water from which the pure water is taken out from the reverse osmosis device C has a certain purity. In addition, a branch is provided upstream of the solenoid valve of the pure water line 10 as an initial drain line for discharging stagnant water at the start (not shown), and an electromagnetic valve for adjusting the opening and closing of the initial drain line is provided.
A pure water recirculation line 11 for recirculating pure water taken out from the raw water tank to the raw water load line 6 is coupled to the upstream side of the high-pressure pump A of the raw water load line 6 (point F in FIG. 1). From the viewpoint of simplifying the piping, it is preferable that the point F where the passage (concentration) line 7 is coupled to the raw water load line 6 and the point F where the pure water reflux line 11 is coupled to the raw water load line 6 are preferable. The position of the latter F point may be different. In this case, it is somewhat superior in the washability of the raw water line 6 that the latter in which clean pure water flows is arranged upstream of the former.
[0013]
The pure water reflux line 11 is supplied with a pressure equal to the pressure of the raw water line in order to prevent back flow and facilitate return to the raw water load line, to shorten the distance of the stagnant portion of the pure water reflux line. It is preferable to provide an infusion pump B. Further, on the upstream side of the injection pump B, a line for returning a part of the pure water that has passed through the pump B to the pure water tank is provided in order to secure an outflow path while the solenoid valves 5 and 5a are closed. Provide.
The pure water reflux line 11 is provided with solenoid valves 5a and 5 between the injection pump B and the point F. The solenoid valve 5a and 5 may be one. Similarly, a plurality of cleaning operations described in the following examples are possible, and a plurality of cleaning operations are preferable in order to easily adjust the flow rate (this manufacturing method is referred to as a first manufacturing method).
[0014]
In the description of the present invention based on the drawings, a solenoid valve arranged in parallel is used as a valve. However, the valve used in the apparatus of the present invention is not limited to the solenoid valve, and the solenoid valve arranged in parallel is used. Instead of the valve, a flow rate adjusting valve may be used, and as described above, one may be used instead of a plurality.
[0015]
In another embodiment of the pure water production method of the present invention, in the first production method, the pure water liquid level of the tank is in a middle state by the pure water production step, the pure water replacement washing step or the high-speed washing step. If it becomes, the raw water load line, pure water reflux line, drain line and a recirculation loop line opened, also claim 5 pure water line, characterized in that the continuously performed reverse osmosis in the open state 7. The method for producing pure water according to any one of 7 is mentioned (this production method corresponds to claim 8 and is hereinafter also referred to as production method 2). In this case, whether the level of the pure water tank rises or falls depends on the magnitude relationship between the amount of drainage discharged from the drainage line and the amount of raw water supplied, and the amount used at the point of use of pure water (where it is used).
[0016]
In another embodiment of the pure water production method of the present invention, after the high-speed cleaning, the draining line, the recirculation loop line, the pure water line and the pure water reflux line are opened, and the membrane cleaning with pure water is performed as follows. The pure water production method according to claim 5 , wherein the part is carried out while draining, and part is recirculated (this production method corresponds to claim 7 , hereinafter the production method). 3). In the manufacturing methods 2 and 3, it is desirable that the solenoid valve 2 is opened in the open state because the contamination may occur if the pure water side of the reverse osmosis membrane module is stagnated.
[0017]
Examples of the present invention will be described below.
【Example】
Example 1
This will be described with reference to the drawings.
(1) Initial drainage process In FIG. 1, the raw water load line 6 for initially supplying raw water to the reverse osmosis device, the initial drainage line (not shown), and the drainage line 9 are opened, and the other lines are closed. The liquid pressurizing means is operated to perform reverse osmosis operation, and initial drainage of pure water produced by the operation is performed (however, in the present invention, this initial drainage step is not absolutely necessary requirement) Absent). After the concentration of pure water obtained by this initial drainage becomes a certain concentration or more, for example, the conductivity is 5% or less of the raw water, the process proceeds to the pure water production process. (2) Pure water production process and pure water replacement washing process After the initial drainage, pure water is produced.
In the production of pure water, first, under the operation of the high pressure pump A, one of the solenoid valves 1, 2, 4 and 4a is opened and the other valve is closed. The produced pure water is stored in a storage tank. When the storage tank is full, the level switch is activated, the electromagnetic valves 4, 4a, 5, 5a are opened as shown in FIG. 2, the other electromagnetic valves are opened, and the reverse osmosis membrane of the reverse osmosis device The concentrated water in the module and in the passage line (concentrated water) line 7 is replaced and washed with pure water. This replacement / washing operation removes colloids, sparingly soluble salts, bacteria, etc. deposited on the surface of the reverse osmosis membrane and improves the filtration efficiency of the membrane.
[0018]
In addition, the pure water replacement operation may be started when the purity of pure water taken out from the reverse osmosis apparatus is equal to or lower than a certain level. However, the start of the pure water replacement operation performed by detecting the purity of the pure water is preferably performed in combination with the detection of the position of the pure water tank liquid level. That is, when the pure water tank liquid level is below a certain level and the pure water replacement operation is started based only on the pure water purity detection result, the amount of pure water used is the supply amount. There is a possibility that the water level of the pure water tank will drop and the drought warning will be activated.
At this stage, the flow rate in the line is
The relationship of p = u = v = q + r = x + y is satisfied.
[0019]
In the step of FIG. 2, the concentrated water in the reverse osmosis membrane module and the passage line (concentrated water) line 7 can be replaced with pure water while the electromagnetic valve 2 is opened and pure water is produced. It is convenient when the amount of pure water used is large and there is no allowance for the stop time of pure water production (corresponding to claim 12). In this case, the flow rate in the line satisfies the relationship of p = q + r = u = v + z and v = x + y.
[0020]
Next, as shown in FIG. 3, under the operation of the high-pressure pump A and the supply pump B (however, whether the supply pump B is installed or not, or how it is operated is optional), the solenoid valves 3 and 3a Is opened and the other solenoid valve is closed, so that pure water circulates at a high flow rate in the recirculation loop line 8 of the reverse osmosis device, and the membrane is washed at high speed. The pure water production may be performed in parallel with the cleaning while the electromagnetic valve 2 is opened. In this case, the solenoid valves 5a to 5 must be opened. The amount of pure water to be refluxed is defined by the open / close state of the solenoid valves 5a and 5, and the amount of reflux is equal to the amount of pure water produced.
At this stage, the flow rate in the line is
The relationships u = q + r + s + t = v + z, v = s + t, and z = p = q + r are satisfied.
Next, after a certain time has passed and sufficient cleaning has been achieved or when the pure water tank level has dropped, as shown in FIG. 2, the solenoid valves 4, 4a, 5, 5a are opened, and the other The solenoid valve is closed, and fresh pure water is injected to recirculate in the flow-through (concentrated water) line 7 and the recirculation loop line 8 to wash and drain the water from which impurities have been washed away in a single bath. The electromagnetic valve 2 may be in an open state. In this step, when the level of the pure water tank is lowered and the level switch is activated, or when the water from which impurities have been washed away is drained with new pure water, the first pure water production state is restored.
Maintaining water quality and membrane performance by performing washing and removal efficiently before impurities accumulate in the reverse osmosis membrane while repeating the above processes, and also in the piping, reverse osmosis membrane and pure water tank Prevent the growth of bacteria.
[0021]
Example 2
After the step of FIG. 3, when the pure water tank liquid level is in an intermediate position, the solenoid valves 3a, 4a, 5a are opened under the operation of the high pressure pump A and the supply pump B in the step of FIG. By controlling the other solenoid valves to be closed, the membrane cleaning with pure water can remove and remove impurities from the membrane by partially draining and recirculating partially.
Further, it can be performed while the solenoid valve 2 is opened and a part of the pure water is produced (corresponding to claim 11). In this control, the flow rate in the line is
The relationship of u = v + z, p = q, u = q + s and v = s + x is satisfied.
[0022]
Example 3
As a variation of a pure water manufacturing process the electromagnetic valve 1 is opened in the embodiment, for example, an electromagnetic valve 4a and 4 open, 3a open, 3 to the flow of the concentrated water to the closed drainage is relatively increased The recovery rate decreases (FIG. 6). Conversely, when 3a and 3 are opened, 4a is opened, and 4 is closed, the recovery rate is improved, which is advantageous for producing pure water (FIG. 7). When 3a and 3 are opened and 4a and 4 are closed, the recovery rate is further improved (FIG. 8). In addition, when the solenoid valve 1 is open and one of the solenoid valves 5a and 5 and the solenoid valves 5a and 5 is opened and one of them is closed or both are closed, the reflux rate of pure water decreases (for example, FIG. 9). Purification of the pure water tank is achieved by increasing the reflux amount of pure water and reverse osmosis of reverse osmosis water in the tank again.
[0023]
In the present invention , pure water production and membrane cleaning can be performed simultaneously by combining the open / close states of a plurality of valves provided in parallel as described above . However, the combination of the open / close states of the solenoid valves is not limited to the above, and any combination may be used as long as the production of pure water and the membrane cleaning with pure water can be performed simultaneously. 1 to 8, the filled valve indicates a closed state, and the unfilled valve indicates an open state .
[0024]
【effect】
According to the reverse osmosis device according to the invention and the method for producing pure water using the device, the performance of the reverse osmosis membrane is maintained for a long time due to the excellent cleaning effect of the pure water on the reverse osmosis membrane, and further the blunt water Water quality is also superior to conventional equipment. In addition, the production efficiency of pure water is greatly improved. Since the frequency of replacement of the reverse osmosis membrane and the frequency of chemical cleaning are reduced, the maintenance cost is remarkably low. It can be applied as a means for supplying dialysis water for hemodialysis treatment that requires a stable supply of a large amount of pure water.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram for explaining each component mounting arrangement and piping flow of a reverse osmosis device with a reverse osmosis membrane automatic manufacturing mechanism.
FIG. 2 is a flowchart for single bath cleaning of a reverse osmosis membrane.
FIG. 3 is a flow chart for recirculating and washing a reverse osmosis membrane with pure water.
FIG. 4 is a flow chart in which a reverse osmosis membrane is recirculated and washed with pure water, a part of the reverse osmosis membrane is drained, and pure water production can be performed in parallel.
FIG. 5 is a flowchart of a conventional intermittent operation type RO system.
[Explanation of symbols]
A High pressure pump B Supply pump C Reverse osmosis device α Level switch β Level switch p Recirculation amount from pure water tank q Flow rate passing through valve q Flow rate passing through valve r Flow rate passing through valve s Flow rate passing through valve t Flow rate through the valve u Flow rate through the pump v Flow rate w Flow rate through the pump x Flow rate through the valve y Flow rate through the valve z Flow rate through the valve 1 Solenoid valve 2 Solenoid valve 3 Solenoid valve 3a Solenoid valve 4 Solenoid valve 4a Solenoid valve 5 Solenoid valve 5a Solenoid valve 6 Raw water load line 7 Through (concentrated water) line 8 Recirculation loop line 9 Drain line 10 Pure water (reverse osmosis water) line 11 Pure water recirculation line 12 Three-way solenoid valve 13 Initial Drainage line

Claims (8)

A raw water load line (a) having an on-off valve for supplying raw water to the reverse osmosis device, and a device (hereinafter referred to as liquid additive) used to increase the pressure of raw water or pure water provided upstream of the reverse osmosis device of the raw water load line. (B), a reverse osmosis device (c) having a reverse osmosis membrane that separates raw water into pure water that has passed through the reverse osmosis membrane and concentrated water that has passed through the reverse osmosis membrane, one end being a reverse osmosis device Connected line (concentrated water line) (d) connecting the other end to the raw water load line on the downstream side of the open / close valve of the raw water load line to form a recirculation loop line (d), the passing line (concentrated water line) A drainage line (e) having an opening / closing valve formed by branching from the drainage line (e), formed by the raw water load line and a passage line (concentrated water line), and opened and closed to a passage line downstream from the position where the drainage line branches. re having a valve Ring loopline (f), connected to the raw water load line downstream of the reverse osmosis reservoir of pure water produced by the apparatus (g), one end of the other end connected to the pure water tank off valve of the raw water load line A pure water return line (h) having an open / close valve and an initial drain line (j) branched from the pure water line, and the passing line (d), the drain line (e), and the pure water return line A reverse osmosis device with an automatic cleaning mechanism, wherein the open / close valve provided in (h) is constituted by a plurality provided in parallel . The reverse osmosis device with an automatic cleaning mechanism according to claim 1, wherein a flow rate adjusting valve is provided in place of the on-off valves of the passage line (d), the drainage line (e) and the pure water recirculation line (h) .   The reverse osmosis device according to claim 1 or 2, wherein a passage line (concentrated water line) and a pure water reflux line are connected to the raw water load line on the upstream side of the high-pressure pump.   The reverse osmosis according to any one of claims 1 to 3, wherein the passage line (concentrated water line) and the pure water return line are connected to the same point of the raw water load line (this point is also referred to as F point). apparatus. Using the reverse osmosis device according to claim 1, 3 or 4, the raw water load line for supplying raw water to the reverse osmosis device, the initial drain line and the drain line open / close valve are opened, and the recirculation loop line The open / close valve is arbitrarily opened and closed, the reverse pressure osmosis operation is performed by operating the liquid pressurizing means with the open / close valves of the other lines closed, and the pure water produced by the operation is drained from the initial drain line. The concentration of the drained pure water is inspected, and the following steps (1) to (3) are continuously performed at least once at a stage when the concentration has become better than a certain level. To produce pure water.
(1) Pure water production process Supply of raw water with the open / close valves of the raw water load line, drainage line and pure water line open, the open / close valve of the recirculation loop line can be arbitrarily opened and closed, and the open / close valves of other lines are closed Then, the liquid pressurizing means is operated to increase the pressure of the raw water and send it to the reverse osmosis device to produce pure water.
(2) Pure water replacement cleaning step When the amount of pure water produced by the pure water production step (1) reaches a predetermined high liquid level in the storage container (A) Or, when the purity of the produced pure water is detected by the amount of pure water stored with a pure water level above a certain level in the storage container, and the purity deteriorates below a certain level (B) Detecting the state of (A) or (B) above, stopping the supply of raw water, making the open / close valve of the pure water line optional, reverse the drainage line open, the recirculation loop line closed A step of supplying pure water from the pure water reflux line to the permeation device and replacing it with pure water while discharging the concentrated water in the passage (concentrated water) line and the reverse osmosis device.
(3) High-speed washing step In the pure water replacement state in the step (2), liquid pressurization is performed with the raw water supply from the raw water load line stopped, the recirculation loop line opened, and the drain line closed. After the pure water is recirculated through the recirculation loop line at a high flow rate under the operation of the purification means, the reverse osmosis membrane of the reverse osmosis unit is washed at high speed, and then the washing water from which the impurities have been washed away is discharged into the drainage line and the pure water reflux line. Only the open state, the pure water line is arbitrarily opened and closed, the other lines are closed, and fresh pure water is injected under the operation of the liquid pressurizing means and discharged from the drain line.   The execution time of the pure water replacement cleaning and the cleaning process is performed for a predetermined time, and if the liquid level in the tank falls below a predetermined lower liquid level even within the predetermined time, the pure water production process is immediately performed. 6. The method for producing pure water according to claim 5, wherein   After high-speed cleaning, open / close valves of the drainage line, recirculation loop line, pure water line and pure water reflux line are opened, and membrane cleaning with pure water is performed while partly draining and partly recirculating. The method for producing pure water according to claim 5 or 6, wherein:   When the pure water level of the tank is between the predetermined low and high levels in the pure water production process, pure water replacement cleaning process or high-speed cleaning process, the raw water load line, pure water reflux line, drainage line and recirculation The method for producing pure water according to any one of claims 5 to 7, wherein reverse osmosis is continuously performed with the loop line open and the pure water line open.

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