JP2017064600A - Washing method of reverse osmosis membrane module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a washing method of a reverse osmosis membrane module which can efficiently wash a membrane surface of the reverse osmosis membrane module during flushing operation.SOLUTION: In a washing method of a reverse osmosis membrane module 5 of a reverse osmosis membrane separation apparatus 4, which separates a permeated water W2 and a concentrated water W3 by introducing a supply water W1 to the reverse osmosis membrane module 5, washing gas is introduced to a primary side washing water in executing flushing operation of washing the primary side of the reverse osmosis membrane module 5 with the primary side washing water.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for cleaning a reverse osmosis membrane module.

  High-purity pure water that does not contain impurities is used in the manufacture of pharmaceuticals and cosmetics, the cleaning of electronic parts and precision equipment, and the like. This type of pure water is generally produced by treating feed water such as ground water and tap water with a reverse osmosis membrane separator and purifying the obtained permeate. The reverse osmosis membrane separation device includes a reverse osmosis membrane module, and can separate supply water into permeate and concentrated water. In the following description, the reverse osmosis membrane module is also referred to as “RO membrane module”, and the reverse osmosis membrane is also referred to as “RO membrane”.

  The water permeability coefficient of the RO membrane used in the RO membrane module varies depending on the temperature of the supplied water and the state of the membrane (clogging of pores and oxidative deterioration of the material). That is, the flow rate of the permeate varies depending on the temperature of the feed water and the state of the membrane. Therefore, a reverse osmosis membrane separation device that performs a flushing operation for periodically cleaning the surface of the primary side of the RO membrane module has been proposed in order to maintain the water permeability of the RO membrane module (see Patent Document 1).

JP 2005-279461 A

  However, only the flushing operation for cleaning the surface on the primary side of the RO membrane module may not sufficiently remove the deposits attached to the membrane surface of the reverse osmosis membrane module. In a reverse osmosis membrane separation apparatus that performs a flushing operation, it is desired to effectively wash the membrane surface of a reverse osmosis membrane module.

  An object of this invention is to provide the washing | cleaning method of the reverse osmosis membrane module which can wash | clean the membrane surface of a reverse osmosis membrane module effectively in flushing operation | movement.

  The present invention relates to a method for cleaning the reverse osmosis membrane module in a reverse osmosis membrane separation device that separates permeate and concentrated water by introducing feed water into the reverse osmosis membrane module, the primary osmosis membrane module primary The present invention relates to a method for cleaning a reverse osmosis membrane module in which a cleaning gas is introduced into the primary side cleaning water when performing a flushing operation for cleaning the side with the primary side cleaning water.

  Moreover, it is preferable to introduce the cleaning gas into the primary side cleaning water through a filter that removes foreign matters.

  Further, on the upstream side or the downstream side of the reverse osmosis membrane module, there is a decarbonation membrane module that produces decarbonated water by removing carbon dioxide contained in the supply water or permeated water in the reverse osmosis membrane module with a sweep gas. In the upstream of the reverse osmosis membrane module, the primary side wash water is introduced as a driving fluid, and a sweep gas discharged from the decarbonation membrane module is sucked as an aspiration fluid, and the sweep An ejector for sending the primary side cleaning water mixed with gas as a mixed fluid is disposed, and when the flushing operation is performed, the sweep gas as the cleaning gas is discharged from the primary side cleaning water by the ejector. It is preferable to introduce into.

  Moreover, when performing the flushing operation, it is preferable that the chemical is introduced into the primary side cleaning water in association with the cleaning gas introduced into the primary side cleaning water.

  ADVANTAGE OF THE INVENTION According to this invention, the washing | cleaning method of the reverse osmosis membrane module which can wash | clean the membrane surface of a reverse osmosis membrane module effectively in flushing operation can be provided.

1 is an overall configuration diagram of a water treatment system 100 according to a first embodiment. It is a whole block diagram of water treatment system 100A concerning a 2nd embodiment. It is a whole block diagram of the water treatment system 100B which concerns on 3rd Embodiment.

(First embodiment)
A water treatment system 100 according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of a water treatment system 100 according to the first embodiment.

As shown in FIG. 1, the water treatment system 100 according to the first embodiment includes a decarbonation membrane device 1, a reverse osmosis membrane separation device 4 provided on the upstream side of the decarbonation membrane device 1, and an ejector component 7. .
More specifically, the water treatment system 100 includes a pressurizing pump 2, a pressurizing side inverter 3, an RO membrane module 5 as a reverse osmosis membrane module, a proportional control drain valve 6, a decarbonation membrane module 10, and a safety valve 31. A treated water valve 32, a concentrated water circulation valve 33, a check valve 11, a vacuum pump 12 as a sweep pump, a vacuum side inverter 13, an air on / off valve 14, an air filter 15, an ejector 8, An ejector valve 9 serving as an on-off valve, a medicine supply device 34, a medicine supply valve 35, and a control unit 20 are provided. The pressurizing pump 2, the pressurizing side inverter 3, and the control unit 20 are used in common in the decarbonation membrane device 1 and the reverse osmosis membrane separation device 4.

Further, the water treatment system 100 includes a pressure sensor S1, a first electrical conductivity sensor S2, a water temperature sensor S4, a first flow rate sensor S5, a second flow rate sensor S6, and a second electrical conductivity sensor S7. Is provided. In FIG. 1, the path of electrical connection is indicated by a broken line (the same applies to FIG. 2 described later).
The control unit 20 includes a pressurizing side inverter 3, a proportional control drain valve 6, a vacuum side inverter 13, an air on / off valve 14, an ejector valve 9, a medicine supply device 34, a pressure sensor S1, a first electrical conductivity sensor S2, and a water temperature sensor. S4, 1st flow sensor S5, 2nd flow sensor S6, and 2nd electric conductivity sensor S7 are electrically connected.

  In addition, the water treatment system 100 includes a supply water line L1, a permeate water line L2, a concentrated water line L3, a circulating water line L4, a drainage line L5, a decarbonated water line L6, and air as a sweep gas line. A suction line L7, an air discharge line L8 as a gas discharge line, a permeate return line L9, an ejector line L10, a suction fluid introduction line L11, and a medicine supply line L12 are provided. The “line” in the present specification is a general term for lines capable of flowing a fluid such as a flow path, a path, and a pipeline.

In the present embodiment, the decarbonation apparatus 1 includes a pressurization pump 2, a pressurization side inverter 3, a decarboxylation film module 10, a check valve 11, a vacuum pump 12, and a vacuum side inverter 13. , Air on / off valve 14, air filter 15, control unit 20, supply water line L1, decarbonated water line L6, air suction line L7 as a sweep gas line, and air discharge line L8 as a discharge line , And is configured.
The reverse osmosis membrane separation device 4 includes an RO membrane module 5, a pressurizing pump 2, a pressurizing side inverter 3, a proportional control drain valve 6, a safety valve 31, a treated water valve 32, and a concentrated water circulation valve 33. The control unit 20, the supply water line L1, the permeate water line L2, the concentrated water line L3, the circulating water line L4, the drainage line L5, the permeate return line L9, the pressure sensor S1, and the first electric A conductivity sensor S2, a water temperature sensor S4, a first flow rate sensor S5, a second flow rate sensor S6, and a second electrical conductivity sensor S7 are provided.
Further, the ejector component 7 includes an ejector 8, an ejector valve 9, a medicine supply device 34, a medicine supply valve 35, an ejector line L10, a suction fluid introduction line L11, and a medicine supply line L12. Composed.

  The supply water line L1 is a line for supplying the supply water W1 to the RO membrane module 5. The upstream end of the supply water line L1 is connected to a supply source (not shown) of the supply water W1. The downstream end of the supply water line L <b> 1 is connected to the primary inlet port of the RO membrane module 5. In the supply water line L1, in order from the upstream side to the downstream side, the connection part J2, the connection part J4, the pressure pump 2, the pressure sensor S1, the connection part J6, the connection part J7, the first electrical conductivity sensor S2, An RO membrane module 5 is provided.

  The pressurizing pump 2 is a device that sucks in the supply water W <b> 1 flowing through the supply water line L <b> 1 and pumps (discharges) it toward the RO membrane module 5. The pressurizing pump 2 is supplied with driving power whose frequency is converted from the pressurizing side inverter 3. The pressurizing pump 2 is driven at a rotational speed corresponding to the frequency (hereinafter also referred to as “driving frequency”) of the driving power supplied (input).

  The pressurizing side inverter 3 is an electric circuit (or a device having the circuit) that supplies driving power having a frequency converted to the pressurizing pump 2. A command signal is input from the control unit 20 to the pressure side inverter 3. The pressurizing side inverter 3 outputs driving power having a driving frequency corresponding to the command signal (current value signal or voltage value signal) input by the control unit 20 to the pressurizing pump 2.

  The pressure sensor S1 is a device that detects the discharge pressure (operating pressure) of the pressure pump 2. The pressure sensor S <b> 1 is disposed in the vicinity of the discharge side of the pressure pump 2. The vicinity of the discharge side of the pressurizing pump 2 means a position where a pressure that can be regarded as the discharge pressure of the pressurizing pump 2 can be detected. The pressure of the supply water W1 detected by the pressure sensor S1 (hereinafter also referred to as “detected pressure value”) is transmitted to the control unit 20 as a detection signal.

  The first electrical conductivity sensor S2 is a device that detects the electrical conductivity of the supply water W1 on the primary side of the RO membrane module 5. The electrical conductivity of the supply water W1 detected by the first electrical conductivity sensor S2 is transmitted to the control unit 20 as a detection signal. The electrical conductivity of the supply water W1 detected by the first electrical conductivity sensor S2 is converted into an osmotic pressure in the control unit 20 based on a conversion formula, a conversion table, and the like.

  The ejector line L10 is a line that branches from the supply water line L1 and joins the supply water line L1, and a portion W1a of the supply water W1 that flows through the supply water line L1 flows through the ejector line L10. The upstream end of the ejector line L10 is connected to the supply water line L1 at the connection J6. The downstream end of the ejector line L10 is connected to the supply water line L1 at the connection J7. An ejector 8 is provided in the ejector line L10. The connecting part J6 and the connecting part J7 are disposed between the pressurizing pump 2 and the RO membrane module 5 in the supply water line L1. The connection part J6 is arrange | positioned in the supply water line L1 upstream from the connection part J7.

The ejector 8 is disposed on the upstream side of the RO membrane module 5. The ejector 8 includes a first suction part 8c for sucking the first suction fluid, a second suction part 8d for sucking the second suction fluid, a driving fluid introduction part 8a for introducing the driving fluid, and a mixed fluid being sent out. The mixed fluid delivery section 8b is provided.
The ejector 8 introduces the supply water W1a (primary washing water) flowing through the ejector line L10 from the drive fluid introduction section 8a as a drive fluid. The ejector 8 sucks the mixed air G2a (sweep gas) (described later) discharged from the decarbonation membrane module 10 flowing through the suction fluid introduction line L11 (described later) from the first suction portion 8c as a suction fluid and supplies the medicine. The chemical | medical solution W5 which distribute | circulates the line L12 is attracted | sucked from the 2nd suction part 8d as a suction fluid. The ejector 8 sends the supply water W1b (primary side wash water) mixed with the mixed air G2a and the chemical liquid W5 from the mixed fluid delivery unit 8b to the ejector line L10 as a mixed fluid. In addition, when making the ejector 8 suck | inhale the mixed air G2a, the vacuum pump 12 mentioned later is stopped.

The drug supply device 34 is a device that distributes the drug solution W5 (drug) sucked by the second suction unit 8d of the ejector 8 to the drug supply line L12. When the medicine supply device 34 performs the flushing operation, the medicine liquid W5 sucked into the second suction part 8d of the ejector 8 is supplied to the medicine supply line L12 so as to be accompanied by the mixed air G2a introduced into the supply water W1. Supply.
Examples of the drug contained in the chemical solution W5 supplied to the drug supply line L12 by the drug supply device 34 include salts such as sodium chloride, alkalis such as sodium hydroxide and potassium hydroxide, and organic acids (eg, oxalic acid, citric acid). Acid) or inorganic acids (eg hydrochloric acid, sulfuric acid, nitric acid). In addition, you may add a dispersing agent, a disinfectant, etc. mainly on salt, an alkali, an acid, etc.

  The medicine supply line L12 is a line that connects the medicine supply device 34 and the second suction part 8d of the ejector 8. The drug solution W5 supplied from the drug supply device 34 is circulated through the drug supply line L12. A drug supply valve 35 is disposed in the drug supply line L12.

  The medicine supply valve 35 is a valve that opens and closes the medicine supply line L12. By opening the medicine supply valve 35, the medicine supply line L12 is opened, and the ejector 8 sucks the liquid medicine W5 flowing through the medicine supply line L12 as a suction fluid via the second suction part 8d.

The RO membrane module 5 is a facility that performs membrane separation processing of the supply water W1 discharged from the pressurizing pump 2 into permeate water W2 from which dissolved salts have been removed and concentrated water W3 from which dissolved salts have been concentrated. The RO membrane module 5 includes a single or a plurality of RO membrane elements (not shown). The RO membrane module 5 membrane-separates the supply water W1 with these RO membrane elements to produce permeated water W2 and concentrated water W3. The reverse osmosis membrane separation device 4 separates the permeated water W2 and the concentrated water W3 by introducing the supply water W1 into the RO membrane module 5.
In the present embodiment, the reverse osmosis membrane separation device 4 supplies the permeated water W2 separated by the RO membrane module 5 to the decarbonation membrane device 1 as treated water.

  The permeated water line L2 is a line for sending the permeated water W2 separated by the RO membrane module 5. The upstream end of the permeate line L2 is connected to the secondary port of the RO membrane module 5. The permeated water line L <b> 2 is a line that supplies permeated water W <b> 2 as treated water to the decarbonation membrane module 10. The downstream end of the permeate line L <b> 2 is connected to the water inlet 10 a of the decarbonation membrane module 10. The permeated water line L2 is provided with a water temperature sensor S4, a first flow rate sensor S5, an electrical conductivity sensor S7, and a connecting portion J3 in order from the upstream side to the downstream side.

  The water temperature sensor S4 is a device that detects the temperature of the permeated water W2. The temperature of the permeated water W2 detected by the water temperature sensor S4 (hereinafter also referred to as “detected water temperature value”) is transmitted to the control unit 20 as a detection signal.

  In the present embodiment, the water temperature sensor S4 is arranged on the downstream side of the RO membrane module 5 so that the water temperature sensor S4 detects the temperature of the permeated water W2. However, the present invention is not limited to this. The water temperature sensor S4 may be arranged on the upstream side of the RO membrane module 5, and the water temperature sensor S4 may be configured to detect the temperature of the supply water W1. This is because the temperature of water can be regarded as substantially the same water temperature value on the upstream side and the downstream side of the RO membrane module 5.

  The first flow rate sensor S5 is a device that detects the flow rate of the permeated water W2 flowing through the permeated water line L2. The flow rate of the permeated water W2 detected by the first flow rate sensor S5 (hereinafter also referred to as “detected flow rate value”) is transmitted to the control unit 20 as a pulse signal.

  The second electrical conductivity sensor S7 is a device that detects the electrical conductivity of the permeated water W2 flowing through the permeated water line L2. The electrical conductivity of the permeated water W2 detected by the second electrical conductivity sensor S7 is transmitted to the control unit 20 as a detection signal.

  The concentrated water line L3 is a line for sending the concentrated water W3 separated by the RO membrane module 5. The upstream end of the concentrated water line L3 is connected to the primary outlet port of the RO membrane module 5. Further, the downstream side of the concentrated water line L3 is connected to the circulating water line L4 and the drainage line L5 at the connection portion J1.

  The circulating water line L4 returns a part W31 of the concentrated water W3 separated by the RO membrane module 5 and flowing through the concentrated water line L3 to the upstream side of the RO membrane module 5 and the pressure pump 2 in the supply water line L1. It is a line to do. The upstream end of the circulating water line L4 is connected to the concentrated water line L3 at the connecting portion J1. The downstream end of the circulating water line L4 is connected to the upstream side of the pressurizing pump 2 in the supply water line L1 at the connecting portion J2. A concentrated water circulation valve 33 is provided in the circulating water line L4.

  The concentrated water circulation valve 33 is a valve that opens and closes the circulating water line L4. The concentrated water circulation valve 33 is controlled to be in an open state when the permeated water W2 is produced by the RO membrane module 5. The concentrated water circulation valve 33 is controlled to be closed when the flushing operation control is executed in the cleaning process.

  The drainage line L5 is a line for discharging the remaining portion W32 of the concentrated water W3 separated by the RO membrane module 5 and flowing through the concentrated water line L3 to the outside of the apparatus (outside the system). The drain line L5 is provided with a proportional control drain valve 6 and a second flow rate sensor S6.

  The proportional control drain valve 6 is a valve that adjusts the drainage flow rate of the remaining portion W32 of the concentrated water W3 discharged out of the apparatus from the drain line L5. The valve opening degree of the proportional control drain valve 6 is controlled by a drive signal transmitted from the control unit 20. By sending a current value signal (for example, 4 to 20 mA) from the control unit 20 to the proportional control drain valve 6 to control the valve opening, the drainage flow rate of the remaining portion W32 of the concentrated water W3 can be adjusted.

  The permeate return line L9 is a line that returns permeate water W2 sent to the permeate water line L2 to the upstream side of the pressurizing pump 2 in the supply water line L1 in the flushing operation control (described later). The upstream end of the permeate return line L9 is connected to the permeate line L2 at the connection J3. The connecting portion J3 is disposed between the secondary port of the RO membrane module 5 and a water inlet 10a (described later) of the decarbonation membrane module 10. Further, the downstream end of the permeate return line L9 is connected to the supply water line L1 at the connection J4. The connecting portion J4 is disposed on the upstream side of the pressurizing pump 2. A safety valve 31 is provided on the permeate return line L9.

  The safety valve 31 is a valve that opens when the in-pipe pressure of the permeate line L2 becomes equal to or higher than a set pressure in the flushing operation control (described later), and causes the permeate W2 to flow through the permeate return line L9. . That is, the safety valve 31 returns the permeated water W2 that is equal to or higher than the set pressure to the supply water line L1 via the permeate return line L9, thereby generating excessive back pressure on the secondary side of the RO membrane module 5. To prevent.

  The decarbonation membrane device 1 produces decarbonated water W4 from the permeated water W2 supplied as the water to be treated. The decarbonation membrane module 10 is disposed on the downstream side of the RO membrane module 5. The decarbonation membrane module 10 deaerates (removes) the carbon dioxide gas contained in the permeated water W2 as the water to be treated with the air G1 (sweep gas) that flows in, and produces decarbonated water W4. The decarbonation membrane module 10 includes an air inlet 10c through which air G1 flows, an air outlet 10d through which air G2 containing carbon dioxide (hereinafter also referred to as “mixed air”) is discharged, and permeated water W2 containing carbon dioxide. An inflow water inlet 10a and a decarbonated water outlet 10b from which decarbonated water W4 from which carbon dioxide gas has been removed are discharged are provided. In the case of an external perfusion type gas separation membrane module, the air inlet 10c and the air outlet 10d communicate with the inside of the hollow fiber membrane. On the other hand, the water inlet 10a and the decarbonated water outlet 10b communicate with the outside of the hollow fiber membrane. The downstream end of the permeate line L2 is connected to the water inlet 10a of the decarbonation membrane module 10, and the upstream side of the decarbonated water line L6 is connected to the decarbonated water outlet 10b of the decarbonation membrane module 10. The ends are connected.

  The air suction line L7 is a line through which air G1 (sweep gas) flowing into the decarbonation membrane module 10 flows. The upstream end of the air suction line L7 is released to the atmosphere via the air filter 15. The downstream end of the air suction line L7 is connected to the air inlet 10c of the decarbonation membrane module 10. The air suction line L7 is provided with an air filter 15 and an air on / off valve 14 in order from the upstream side. The air filter 15 is a component for removing foreign substances from the introduced air G1. The air on / off valve 14 opens and closes the air suction line L7. The air on / off valve 14 is controlled to be opened and closed by a control unit 20 described later.

  The air discharge line L8 is a line through which the mixed air G2 containing carbon dioxide gas discharged from the decarbonation membrane module 10 flows. The upstream end of the air discharge line L8 is connected to the air discharge port 10d of the decarbonation membrane module 10. The mixed air G2 is discharged from the downstream side of the air discharge line L8. In the air discharge line L8, a check valve V11 and a vacuum pump 12 are provided in order from the upstream side.

The vacuum pump 12 causes the air G1 to flow into the decarbonized membrane module 10 via the air suction line L7 and the carbonic acid from the decarbonized membrane module 10 via the air discharge line L8 when the air on-off valve 14 is open. It is a device that discharges mixed air G2 containing gas.
Further, the vacuum pump 12 decarboxylates from the inside of the decarbonation membrane module 10 so that the inside of the decarbonation membrane module 10 is in a vacuum state via the air discharge line L8 when the air on-off valve 14 is closed. It is a device that evacuates the outside of the membrane module 10.
The vacuum pump 12 is supplied with driving power whose frequency is converted from the vacuum-side inverter 13. The vacuum pump 12 is driven at a rotational speed corresponding to the frequency of drive power supplied from the vacuum-side inverter 13 (hereinafter also referred to as “drive frequency”).

  The vacuum-side inverter 13 is an electric circuit (or a device having the circuit) that supplies driving power whose frequency is converted to the vacuum pump 12. A command signal is input from the control unit 20 to the vacuum-side inverter 13. The vacuum-side inverter 13 outputs drive power having a drive frequency corresponding to the command signal (current value signal or voltage value signal) input by the control unit 20 to the vacuum pump 12.

In the decarbonation apparatus 1, when the air on / off valve 14 is opened and the vacuum pump 12 is driven, the air G1 sucked from the air suction line L7 passes through the air filter 15 and the air on / off valve 14 and then the decarbonation film module. 10 is introduced. The air G1 flows inside the hollow fiber membrane inside the decarbonation membrane module 10, and the mixed air G2 is discharged from the air discharge port 10d to the air discharge line L8. Thereby, in the decarbonation membrane module 10, air circulates continuously.
In the present embodiment, the air suction line L7, the air on-off valve 14, the vacuum pump 12, the vacuum side inverter 13, and the air discharge line L8 constitute gas sweeping means. In order to remove the carbon dioxide gas contained in the permeated water W2 by the decarbonation membrane module 10, the gas sweeping means causes the air G1 flowing through the air suction line L7 to flow into the decarbonation membrane module 10, and the decarbonation membrane module 10 The mixed air G2 containing carbon dioxide gas is discharged to the outside.

On the other hand, in the decarbonation membrane device 1, when the air on-off valve 14 is closed and the vacuum pump 12 is driven, the inside of the hollow fiber membrane of the decarbonation membrane module 10 is evacuated via the air discharge line L8. As described above, vacuuming is performed from the inside of the decarbonation membrane module 10 toward the outside of the decarbonation membrane module 10.
In the present embodiment, the air suction line L7, the air on-off valve 14, the vacuum pump 12, the vacuum side inverter 13, and the air discharge line L8 constitute a vacuuming means. In order to remove the carbon dioxide gas contained in the permeated water W2 by the decarbonation membrane module 10, the evacuation means decarboxylates from the inside of the decarbonation membrane module 10 so that the inside of the decarbonation membrane module 10 is in a vacuum state. A vacuum is drawn toward the outside of the membrane module 10 to discharge carbon dioxide gas to the outside of the decarbonation membrane module 10.

  In the suction fluid introduction line L11, a part G2a of the mixed air G2 that flows through the air discharge line L8 flows toward the first suction portion 8c of the ejector 8. The upstream end portion of the suction fluid introduction line L11 is connected between the decarbonation membrane module 10 and the check valve 11 in the air discharge line L8 at the connection portion J5. The downstream end of the suction fluid introduction line L11 is connected to the first suction portion 8c of the ejector 8. An ejector valve 9 is disposed in the suction fluid introduction line L11.

  The ejector valve 9 is a valve that opens and closes the suction fluid introduction line L11. By opening the ejector valve 9, the suction fluid introduction line L11 is opened, and the ejector 8 sucks the mixed air G2a flowing through the suction fluid introduction line L11 through the first suction portion 8c as suction fluid. To do.

  The decarbonated water line L6 is a line through which the decarbonated water W4 produced by the decarboxylated membrane module 10 is sent out. The upstream end of the decarbonated water line L6 is connected to the decarbonated water discharge port 10b of the decarbonated membrane module 10. The downstream end of the decarbonated water line L6 is connected to a demand destination device (not shown), a treated water tank (not shown), and the like. A treated water valve 32 is provided in the decarbonated water line L6.

  The control unit 20 is configured by a microprocessor (not shown) including a CPU and a memory. The control unit 20 controls the decarbonation membrane device 1 and the reverse osmosis membrane separation device 4.

The control unit 20 can execute a normal operation and a deterioration suppression operation in the decarbonation film device 1.
The normal operation in the decarbonation membrane device 1 by the control unit 20 is to operate the pressurizing pump 2 with air G1 (sweep gas) flowing into the decarbonation membrane module 10 in order to produce decarbonated water. In this operation, the decarbonized water W4 is produced by passing the permeated water W2 through the decarbonized membrane module 10.

  On the other hand, the deterioration suppression operation in the decarbonation membrane device 1 by the control unit 20 is a state in which a vacuum is drawn from the inside of the decarbonation membrane module 10 to the outside so that the inside of the decarbonation membrane module 10 is in a vacuum state. In this operation, the pressurizing pump 3 is operated by controlling the pressurizing-side inverter 3 to pass the permeated water W2 through the decarbonation membrane module 10. When the concentration of chlorine in the permeated water W2 is high, if the permeated water W2 is passed through the decarbonation membrane module 10 in a state where the gas sweep operation is performed during normal operation, the decarbonation membrane module 10 may be deteriorated. There is sex. Therefore, the deterioration suppression operation in the decarbonation film device 1 is executed to suppress the deterioration of the decarbonation film module 10.

  In the reverse osmosis membrane separation device 4, the control unit 20 is configured to perform the manufacturing process and the cleaning process, the pressurization side inverter 3 (pressure pump 2), the treated water valve 32, the concentrated water circulation valve 33, and the proportional control drain valve 6. To control.

[Manufacturing process]
First, the manufacturing process will be described. The manufacturing process is a process of manufacturing the permeated water W2 in the reverse osmosis membrane separation device 4. The control unit 20 executes the water amount control of the permeated water W2 and the recovery rate control of the permeated water W2 as a manufacturing process.
Hereinafter, the water amount control of the permeated water W2 and the recovery rate control of the permeated water W2 will be described.

<Water volume control of permeated water W2>
The control unit 20 can select and execute, for example, flow rate feedback water amount control, pressure feedback water amount control, or temperature feedforward water amount control as the water amount control of the permeated water W2. The outline of each water quantity control is as follows.

(Flow rate feedback water volume control)
The control unit 20 calculates a driving frequency for driving the pressurizing pump 2 using the detected flow rate value of the first flow rate sensor S5 as a feedback value so that the flow rate of the permeated water W2 becomes a preset target flow rate value. To do. Then, the control unit 20 outputs a command signal (current value signal or voltage value signal) corresponding to the calculated value of the drive frequency to the pressurizing side inverter 3 (hereinafter also referred to as “flow rate feedback water amount control”). For example, a speed type digital PID algorithm can be used for calculation of the drive frequency in the main water amount control.

(Pressure feedback water volume control)
The control unit 20 uses the detected pressure value of the pressurizing pump 2 (the detected pressure value of the pressure sensor S1) as a feedback value so that the flow rate of the permeated water W2 becomes a preset target flow rate value. Calculate the drive frequency. Then, the control unit 20 outputs a command signal (current value signal or voltage value signal) corresponding to the calculated value of the drive frequency to the pressurizing side inverter 3 (hereinafter also referred to as “pressure feedback water amount control”). For example, a speed type digital PID algorithm can be used for calculation of the drive frequency in the main water amount control.

(Temperature feedforward water volume control)
The control unit 20 calculates the drive frequency of the pressurizing pump 2 using the detected temperature value of the water temperature sensor S4 as a feedforward value so that the flow rate of the permeated water W2 becomes a preset target flow rate value. Then, the control unit 20 outputs a command signal (current value signal or voltage value signal) corresponding to the calculated value of the drive frequency to the pressurizing side inverter 3 (hereinafter also referred to as “temperature feedforward water amount control”).

<Recovery rate control of permeate W2>
The recovery rate of the permeated water W2 is the ratio of the flow rate of the permeated water W2 to the flow rate of the supplied water W1 supplied to the RO membrane module 5 (the flow rate of the permeated water W2 / the flow rate of the supplied water W1).
The control unit 20 can select and execute, for example, temperature feedforward recovery rate control, water quality feedforward, or water quality feedback recovery rate control as the recovery rate control of the permeated water W2. The outline of each recovery rate control is as follows.

(Temperature feedforward recovery rate control)
The control unit 20 calculates the allowable concentration rate of silica in the concentrated water W3 based on the silica concentration determined in advance from the silica concentration of the supply water W1 and the detected temperature value of the water temperature sensor S4. Then, the control unit 20 calculates the drainage flow rate from the calculated value of the allowable concentration magnification and the target flow rate value of the permeate W2, and the actual drainage amount of the concentrate W3 (the detected flow rate value of the second flow rate sensor S6) is the drainage flow rate. The valve opening degree of the proportional control drain valve 6 is controlled so as to be a calculated value (target drainage flow rate) (hereinafter also referred to as “temperature feedforward recovery rate control”).

(Water quality feedforward recovery rate control)
The control unit 20 calculates an allowable concentration rate of calcium carbonate in the concentrated water W3 based on the solubility of calcium carbonate acquired in advance and the measured hardness value of the hardness sensor. Then, the control unit 20 calculates the drainage flow rate from the calculated value of the allowable concentration magnification and the target flow rate value of the permeate W2, and the actual drainage amount of the concentrate W3 (the detected flow rate value of the second flow rate sensor S6) is the drainage flow rate. The valve opening degree of the proportional control drain valve 6 is controlled so as to be a calculated value (target drainage flow rate) (hereinafter also referred to as “water quality feedforward recovery rate control”).

(Water quality feedback recovery rate control)
The control unit 20 directly controls the valve opening degree of the proportional control drain valve 6 so that the measured electric conductivity value of the second electric conductivity sensor S7 becomes a preset target electric conductivity (hereinafter, “ Water quality feedback recovery rate control ”). For example, a speed type digital PID algorithm can be used to determine the valve opening in this control.

<Control example of water amount control and recovery rate control of permeate W2>
In the water amount control and recovery rate control of the permeated water W2, a pattern that is executed by combining “flow rate feedback water amount control” and “temperature feed forward recovery rate control”, “pressure feedback water amount control”, and “water quality feed forward”. Examples include a pattern executed by combining “recovery control” and a pattern executed by combining “temperature feedforward water amount control” and “water quality feedback recovery rate control”. It should be noted that this combination is not excluded.

[Washing process]
Next, the cleaning process will be described.
The cleaning process is a process of cleaning the RO membrane module 5.
The control unit 20 performs flushing operation control in the cleaning process.
<Flushing operation control>
In the cleaning process, the control unit 20 performs flushing operation control when a predetermined condition is satisfied. Examples of the predetermined conditions include the following [a] to [d].
[A] When production of the permeated water W2 is finished (when operation of the device is finished)
[B] When the continuation time during which the permeated water W2 is not manufactured after the end of the previous flushing operation is a set time (eg, 1 hour) [c] Integrated manufacturing time of the permeated water W2 after the end of the previous flushing operation Reaches the set time (e.g., 30 minutes) [d] When the membrane contamination level of the RO membrane module 5 exceeds an allowable value, the RO membrane contamination level is, for example, the primary side inlet port of the RO membrane module 5 And the pressure difference between the primary side outlet port and the primary side outlet port is obtained by measuring with a differential pressure gauge (not shown).
For example, the flushing operation control is executed for 120 seconds under the conditions [a] and [d]. For example, under the conditions [b] and [c], the process is executed for 60 seconds.

  In the flushing operation control, the control unit 20 performs cleaning of the primary side of the RO membrane module 5. In the flushing operation control, the supply water W <b> 1 is supplied to the primary side of the RO membrane module 5. In the flushing operation control, the pressurizing pump 2 is fixed at a driving frequency (for example, 30 Hz) lower than the maximum driving frequency (50 Hz or 60 Hz). At this time, most of the supply water W1 flows through the surface of the RO membrane without passing through the RO membrane, and is discharged to the outside through the concentrated water line L3 as flushing washing wastewater. By this flushing operation control, scale nuclei and deposited suspended substances deposited on the surface of the RO membrane are removed.

In the flushing operation control in the cleaning process, the control unit 20 performs the flushing operation for cleaning the primary side of the RO membrane module 5 with the supply water W1 (primary side wash water). The mixed air G2a (cleaning gas) flowing through the suction fluid introduction line L11 is introduced. The control unit 20 introduces the mixed air G2a (cleaning gas) into the supply water W1 (primary cleaning water) through the air filter 15 that removes foreign matter.
In addition, when performing the flushing operation, the control unit 20 causes the mixed liquid G2a (cleaning gas) to be introduced to the supply water W1 (primary cleaning water) to accompany the chemical liquid W5 (chemical) to the primary cleaning water. Introduce.

Next, a method for cleaning the RO membrane module 5 according to this embodiment will be described.
In the cleaning process, the control unit 20 performs flushing operation control when a predetermined condition is satisfied. Examples of the predetermined condition include the above-described [a] to [d].

In the flushing control operation, the control unit 20 stops the vacuum pump 12 and opens the ejector valve 9. In addition, the control unit 20 operates the medicine supply device 34 and controls the medicine supply valve 35 to be in an open state.
In addition, the control unit 20 controls the treated water valve 32 to be in a closed state and controls the concentrated water circulation valve 33 to be in a closed state.

In this state, by driving the pressurizing pump 2, a flushing operation for cleaning the primary side of the RO membrane module 5 with the supply water W1 flowing through the supply water line L1 is executed.
Thus, when performing the flushing operation, the ejector 8 can be used to introduce the mixed air G2a (cleaning gas) flowing through the suction fluid introduction line L11 into the supply water W1 (primary side cleaning water).
Further, when performing the flushing operation, the chemical liquid W5 (chemical) is supplied to the supply water W1 (primary side wash water) by being accompanied by the mixed air G2a (cleaning gas) introduced into the supply water W1 (primary side wash water). Can be introduced.

  In addition, the permeated water W2 separated by the RO membrane module 5 by executing the flushing operation control in a state where the treated water valve 32 is in the closed state is passed through the permeated water return line L9. Returned to the primary side. Thereby, since the permeated water W2 on the secondary side of the RO membrane module 5 is returned to the primary side of the RO membrane module 5, when the first flushing step is being performed, It can suppress that a pressure becomes high.

According to the cleaning method of the RO membrane module 5 according to the present embodiment described above, for example, the following effects are exhibited.
In the RO membrane module 5 cleaning method according to the first embodiment, the RO membrane module 5 in the reverse osmosis membrane separation device 4 that separates the permeated water W2 and the concentrated water W3 by introducing the supply water W1 into the RO membrane module 5. When the flushing operation of cleaning the primary side of the RO membrane module 5 with the supply water W1 (primary side cleaning water) is performed, the mixed air G2a (cleaning) is supplied to the supply water W1 (primary side cleaning water). Gas).

  Therefore, when the flushing operation is executed, the mixed air G2a (cleaning gas) introduced into the supply water W1 by the ejector 8 becomes bubbles (air bubbles), and the supply water W1 including the bubbles (air bubbles) of the mixed air G2a becomes the RO membrane. It flows on the membrane surface of the module 5. Thereby, the deposit | attachment adhering to the membrane surface of RO membrane module 5 can be removed effectively. Therefore, the membrane surface of the RO membrane module 5 can be effectively cleaned in the flushing operation.

  In the present embodiment, the mixed air G2a (cleaning gas) is introduced into the supply water W1 (primary cleaning water) through the air filter 15 that removes foreign matters. Therefore, the membrane surface of the RO membrane module 5 can be washed with the supply water W1 containing the bubbles of the mixed air G2a from which foreign matters have been removed. Thereby, the flushing operation can be performed without adhering foreign matter in the air to the membrane surface of the RO membrane module 5.

Further, in the present embodiment, when the flushing operation is performed, the mixed air G2a as the cleaning gas is introduced into the supply water W1 (primary side cleaning water) by the ejector 8. For this reason, the mixed air G2a discharged from the decarbonation membrane module 10 is introduced into the supply water W1 by using the ejector 8 without preparing another facility for introducing the cleaning gas into the supply water W1. The membrane surface of the RO membrane module 5 can be washed with bubbles of the mixed air G2a.
Therefore, in the water treatment system 100 including the RO membrane module 5 and the decarbonation membrane module 10, the flushing operation can be executed with the simple configuration using the supply water W1 into which the cleaning gas is introduced.

  Further, the mixed air G2 contains carbon dioxide gas removed by the decarbonation membrane module 10. Therefore, since the mixed air G2a containing carbon dioxide gas is introduced into the supply water W1, the pH value of the supply water W1 decreases, the supply water W1 becomes acidic, and the supply water W1 easily dissolves the scale. Therefore, by washing the RO membrane module 5 with the supply water W1 into which the mixed air G2a containing carbon dioxide gas is introduced, the scale is easily dissolved, and the deposits attached to the membrane surface of the RO membrane module 5 are more effective. Can be removed.

In the present embodiment, when the flushing operation is performed, the medicine is supplied with the mixed air G2a (cleaning gas) to be introduced into the supply water W1 (primary side wash water) to supply the medicine to the supply water W1 (primary side wash water). ).
As a result, the concentration of the supply water W1 on the primary side of the RO membrane module 5 is increased by supplying the chemical to the supply water W1 on the primary side of the RO membrane module 5, and the primary side from the secondary side of the RO membrane module 5 The osmotic pressure of the supply water W1 on the primary side of the RO membrane module 5 is adjusted so that the permeated water W2 moves toward the side. In this embodiment, the primary side of the RO membrane module 5 means the upstream side of the RO membrane module 5 when reverse osmosis occurs in the RO membrane module 5, and the forward osmosis occurs in the RO membrane module 5. Is on the downstream side of the RO membrane module 5. The secondary side of the RO membrane module 5 means the downstream side of the RO membrane module 5 when reverse osmosis occurs in the RO membrane module 5, and when forward osmosis occurs in the RO membrane module 5, the RO membrane Upstream of module 5

  The osmotic pressure of the supply water W1 on the primary side of the RO membrane module 5 is obtained by converting the electrical conductivity of the supply water W1 on the primary side of the RO membrane module 5 detected by the first electrical conductivity sensor S2 into an osmotic pressure. Desired. For example, when the chemical | medical agent added to the supply water W1 is sodium chloride, the control part 20 has memorize | stored the conversion type | formula, a conversion table, etc. about the osmotic pressure with respect to the electrical conductivity in sodium chloride, and the stored conversion type | formula Based on the conversion table or the like, the electrical conductivity of the supply water W1 detected by the first electrical conductivity sensor S2 is converted into an osmotic pressure. Since the osmotic pressure of the permeated water W2 on the secondary side of the RO membrane module 5 can be regarded as constant, if the osmotic pressure of the supply water W1 on the primary side of the RO membrane module 5 is measured, the RO membrane module 5 An outline of the osmotic pressure difference between the osmotic pressure on the primary side and the osmotic pressure on the secondary side can be obtained.

By increasing the concentration of the supply water W <b> 1 on the primary side of the RO membrane module 5, permeation from the secondary side of the RO membrane module 5 having a low water concentration toward the primary side of the RO membrane module 5 having a high water concentration. A forward osmosis effect in which the water W2 moves can be generated.
For this reason, the permeated water W2 moves from the secondary side of the RO membrane module 5 to the primary side by the forward osmosis action, so that the deposits easily float on the surface of the membrane from the pores of the membrane of the RO membrane module 5. . Then, by performing the flushing operation after adjusting the osmotic pressure, the shearing force of water (the force to peel off the deposits attached to the membrane surface of the RO membrane module 5) increases on the primary side of the RO membrane module 5. The deposits can be effectively removed from the membrane surface and the pores of the RO membrane module 5. Therefore, the membrane surface of the RO membrane module 5 can be effectively washed in the flushing operation.

(Second Embodiment)
Next, the configuration of a water treatment system 100A according to the second embodiment of the present invention will be described with reference to FIG. FIG. 2 is an overall configuration diagram of a water treatment system 100A according to the second embodiment.
As shown in FIG. 2, in the first embodiment, the reverse osmosis membrane separation device 4 is disposed on the upstream side of the decarbonation membrane device 1, whereas in the second embodiment, the reverse osmosis membrane separation device 4 is arranged as a decarbonation membrane. The water treatment system 100A according to the second embodiment is different from the water treatment system 100 according to the first embodiment in that it is disposed on the downstream side of the device 1. The decarbonation membrane module 10 is disposed on the upstream side of the RO membrane module 5.
In the second embodiment, differences from the first embodiment will be mainly described. In the second embodiment, the same or equivalent components as those in the first embodiment will be described with the same reference numerals. In the second embodiment, the description overlapping with the first embodiment is omitted as appropriate.

  As shown in FIG. 2, in the water treatment system 100A according to the second embodiment, in the water treatment system 100 according to the first embodiment, the supply water line L1, the RO membrane module 5, the permeate water line L2, and the decarbonation membrane module. 10 and the decarbonated water line L6 are arranged in this order from the upstream side to the downstream side (see FIG. 1), whereas the supply water line L1, the decarbonated membrane module 10, the decarbonated water line L6, and the RO membrane The module 5 and the permeate water line L2 are arranged in this order from the upstream side to the downstream side. Moreover, in the water treatment system 100A according to the second embodiment, the supply pump 2a is provided in the supply water line L1.

The supply water line L <b> 1 is a line that supplies supply water W <b> 1 as water to be treated to the decarbonation membrane module 10. The upstream end of the supply water line L1 is connected to a supply source (not shown) of the supply water W1. The downstream end of the supply water line L <b> 1 is connected to the water inlet 10 a of the decarbonation membrane module 10. The supply water line L1 is provided with a supply pump 2a and a decarbonation membrane module 10 in order from the upstream side to the downstream side.
In the present embodiment, the decarbonation membrane device 1 supplies decarbonated water W4 produced by the decarbonation membrane module 10 to the reverse osmosis membrane separation device 4 as supply water.

  The supply pump 2a is a device that sucks the supply water W1 flowing through the supply water line L1 and pumps (discharges) the supply water W1 toward the decarbonation membrane module 10. The drive power whose frequency is converted is supplied from the supply-side inverter 3a to the supply pump 2a. The supply pump 2a is driven at a rotational speed corresponding to the frequency (hereinafter also referred to as “drive frequency”) of the supplied (input) drive power.

  The supply-side inverter 3a is an electric circuit (or a device having the circuit) that supplies drive power whose frequency is converted to the supply pump 2a. The supply side inverter 3 a is electrically connected to the control unit 20. A command signal is input from the control unit 20 to the supply-side inverter 3a. The supply-side inverter 3a outputs drive power having a drive frequency corresponding to the command signal (current value signal or voltage value signal) input by the control unit 20 to the supply pump 2a.

  The decarbonated water line L6 is a line for supplying decarbonated water W4 to the RO membrane module 5. The upstream end of the decarbonated water line L6 is connected to the decarbonated water discharge port 10b of the decarbonated membrane module 10. The downstream end of the decarbonated water line L6 is connected to the primary inlet port of the RO membrane module 5. In the decarbonated water line L6, in order from the upstream side to the downstream side, the connecting portion J2, the connecting portion J4, the pressurizing pump 2, the pressure sensor S1, the connecting portion J6, the connecting portion J7, and the first electric conductivity sensor S2. The RO membrane module 5 is provided.

  The pressurizing pump 2 is a device that sucks decarbonated water W4 flowing through the decarbonated water line L6 and pumps (discharges) it to the RO membrane module 5. The pressurizing pump 2 is supplied with driving power whose frequency is converted from the pressurizing side inverter 3. The pressurizing pump 2 is driven at a rotational speed corresponding to the frequency (hereinafter also referred to as “driving frequency”) of the driving power supplied (input).

  The pressurizing side inverter 3 is an electric circuit (or a device having the circuit) that supplies driving power having a frequency converted to the pressurizing pump 2. A command signal is input from the control unit 20 to the pressure side inverter 3. The pressurizing side inverter 3 outputs driving power having a driving frequency corresponding to the command signal (current value signal or voltage value signal) input by the control unit 20 to the pressurizing pump 2.

  The RO membrane module 5 is a facility for subjecting the decarbonated water W4 discharged from the pressurizing pump 2 to membrane separation treatment into permeated water W2 from which dissolved salts are removed and concentrated water W3 from which dissolved salts are concentrated. The RO membrane module 5 includes a single or a plurality of RO membrane elements (not shown). The RO membrane module 5 performs membrane separation treatment of the decarbonated water W4 with these RO membrane elements to produce the permeated water W2 and the concentrated water W3.

  The pressure sensor S1 is a device that detects the discharge pressure (operating pressure) of the pressure pump 2. The pressure sensor S <b> 1 is disposed in the vicinity of the discharge side of the pressure pump 2. The vicinity of the discharge side of the pressurizing pump 2 means a position where a pressure that can be regarded as the discharge pressure of the pressurizing pump 2 can be detected. The pressure of the decarbonated water W4 detected by the pressure sensor S1 (hereinafter also referred to as “detected pressure value”) is transmitted to the control unit 20 as a detection signal.

  The first electrical conductivity sensor S2 is a device that detects the electrical conductivity of the decarbonated water W4 on the primary side of the RO membrane module 5. The electrical conductivity of the decarbonated water W4 detected by the first electrical conductivity sensor S2 is transmitted to the control unit 20 as a detection signal. The electrical conductivity of the decarbonated water W4 detected by the first electrical conductivity sensor S2 is converted into an osmotic pressure in the control unit 20 based on a conversion formula, a conversion table, and the like.

  The ejector line L10 is a line that branches from the decarbonated water line L6, joins the decarbonated water line L6, and a portion W4a of the decarbonated water W4 that circulates through the decarbonated water line L6. The upstream end of the ejector line L10 is connected to the decarbonated water line L6 at the connection J6. The downstream end of the ejector line L10 is connected to the decarbonated water line L6 at the connection J7. An ejector 8 is provided in the ejector line L10. The connecting part J6 and the connecting part J7 are arranged between the pressurizing pump 2 and the RO membrane module 5 in the decarbonated water line L6. The connection portion J6 is disposed on the upstream side of the connection portion J7 in the decarbonated water line L6.

The ejector 8 includes a first suction part 8c for sucking the first suction fluid, a second suction part 8d for sucking the second suction fluid, a driving fluid introduction part 8a for introducing the driving fluid, and a mixed fluid being sent out. The mixed fluid delivery section 8b is provided.
The ejector 8 introduces decarbonated water W4a flowing through the ejector line L10 from the drive fluid introduction portion 8a as a drive fluid. The ejector 8 sucks the mixed air G2a (described later) flowing through the suction fluid introduction line L11 (described later) from the first suction portion 8c as a suction fluid and performs second suction using the chemical liquid W5 flowing through the drug supply line L12 as the suction fluid. Aspirate from part 8d. The ejector 8 sends the supply water W1b mixed with the mixed air G2a and the chemical liquid W5 from the mixed fluid delivery unit 8b to the ejector line L10 as a mixed fluid. Note that the vacuum pump 12 is stopped when the ejector 8 sucks the mixed air G2a.

  The permeated water line L2 is a line for sending the permeated water W2 separated by the RO membrane module 5. The upstream end of the permeate line L2 is connected to the secondary port of the RO membrane module 5. The downstream end of the permeate line L2 is connected to a demand destination device (not shown), a treated water tank (not shown), and the like. In the permeated water line L2, a water temperature sensor S4, a first flow rate sensor S5, a second electrical conductivity sensor S7, a connecting portion J3, and a treated water valve 32 are provided in order from the upstream side to the downstream side.

Since the concentrated water line L3 and the drainage line L5 are the same structures as the water treatment system 100 of 1st Embodiment, description of 1st Embodiment is used and the description is abbreviate | omitted.
The circulating water line L4 is separated by the RO membrane module 5 and passes a part W31 of the concentrated water W3 flowing through the concentrated water line L3 between the decarbonized membrane module 10 and the pressure pump 2 in the decarbonated water line L6. This is the line to return. The upstream end of the circulating water line L4 is connected to the concentrated water line L3 at the connecting portion J1. Further, the downstream end of the circulating water line L4 is connected between the decarbonation membrane module 10 and the pressure pump 2 in the decarbonated water line L6 at the connection portion J2.

In the second embodiment, the decarbonation membrane device 1 supplies decarbonated water W4 produced by the decarbonation membrane module 10 to the reverse osmosis membrane separation device 4 as supply water.
Moreover, the control part 20 controls the decarbonation membrane apparatus 1, the reverse osmosis membrane separation apparatus 4, and the ejector valve 9 similarly to 1st Embodiment.

  According to the water treatment system 100A of the second embodiment, the same effects as those of the first embodiment described above are exhibited.

(Third embodiment)
Next, the configuration of the water treatment system 100B according to the third embodiment of the present invention will be described with reference to FIG. FIG. 3 is an overall configuration diagram of a water treatment system 100B according to the third embodiment.

  The third embodiment is a modification of the first embodiment. The third embodiment is mainly different from the first embodiment in that the configuration of the ejector configuration unit 7B is different from the configuration of the ejector configuration unit 7 of the first embodiment, and the medicine supply ejector configuration unit 17 is provided. In the third embodiment, differences from the first embodiment will be mainly described. In the third embodiment, the same or equivalent components as those in the first embodiment will be described with the same reference numerals. In the third embodiment, the description overlapping with that of the first embodiment is omitted as appropriate.

  As shown in FIG. 3, the water treatment system 100B according to the third embodiment includes a decarbonation membrane device 1, a reverse osmosis membrane separation device 4 provided on the upstream side of the decarbonation membrane device 1, and an ejector component 7B. And an ejector component 17 for supplying a medicine.

  The ejector component 7B is provided in the supply water line L1. The ejector component 7B includes an ejector 80, an ejector valve 9, an ejector line L10, and a suction fluid introduction line L11. The ejector 80 of the third embodiment is configured without including the second suction portion 8d of the ejector 8 of the first embodiment. Therefore, the ejector 80 of the third embodiment does not suck the chemical liquid as a suction fluid. Since the other structure of the ejector 80, the ejector valve 9, the ejector line L10, and the suction fluid introduction line L11 are the same as those in the first embodiment, the description thereof is omitted.

  The medicine supply ejector component 17 is provided in the circulating water line L4. The medicine supply ejector component 17 includes a medicine supply ejector 18, a medicine supply device 34, a medicine supply valve 35, a medicine supply line L 12, and a medicine supply ejector line L 13.

  The medicine supply ejector line L13 is a line branched from the circulating water line L4 and joined to the circulating water line L4, and a portion W31a of the concentrated water W31 flowing through the circulating water line L4 flows therethrough. The upstream end of the medicine supply ejector line L13 is connected to the circulating water line L4 at the connection J8. The downstream end of the medicine supply ejector line L13 is connected to the circulating water line L4 at the connection J9. A medicine supply ejector 18 is provided in the medicine supply ejector line L13. The connecting part J8 and the connecting part J9 are arranged on the upstream side and the downstream side of the concentrated water circulation valve 33 in the circulating water line L4. The connection part J8 is arrange | positioned in the circulating water line L4 upstream from the connection part J9.

In the circulating water line L4, the medicine supply ejector 18 is disposed on the upstream side of the connection portion J2 where the circulating water line L4 joins the supply water line L1. The medicine supply ejector 18 includes a suction part 18c through which suction fluid is sucked, a drive fluid introduction part 18a through which drive fluid is introduced, and a mixed fluid delivery part 18b through which mixed fluid is delivered.
The medicine supply ejector 18 introduces the concentrated water W31a flowing through the medicine supply ejector line L13 from the driving fluid introduction portion 18a as a driving fluid. The medicine supply ejector 18 sucks the chemical liquid W5 flowing through the medicine supply line L12 from the suction portion 18c as a suction fluid. The medicine supply ejector 18 sends the concentrated water W31b mixed with the medicine liquid W5 from the mixed fluid delivery section 18b to the medicine supply ejector line L13 as a mixed fluid.

The drug supply device 34 is a device that distributes the drug solution W5 (drug) sucked by the suction portion 18c of the drug supply ejector 18 to the drug supply line L12. When the medicine supply device 34 performs the flushing operation, the medicine liquid W5 sucked into the suction portion 18c of the medicine supply ejector 18 is supplied to the medicine supply line L12.
Examples of the drug contained in the chemical solution W5 supplied to the drug supply line L12 by the drug supply device 34 include salts such as sodium chloride, alkalis such as sodium hydroxide and potassium hydroxide, and organic acids (eg, oxalic acid, citric acid). Acid) or inorganic acids (eg hydrochloric acid, sulfuric acid, nitric acid). In addition, you may add a dispersing agent, a disinfectant, etc. mainly on salt, an alkali, an acid, etc.

  The medicine supply line L12 is a line connecting the medicine supply device 34 and the suction part 18c of the medicine supply ejector 18. The drug solution W5 supplied from the drug supply device 34 is circulated through the drug supply line L12. A drug supply valve 35 is disposed in the drug supply line L12.

  The medicine supply valve 35 is a valve that opens and closes the medicine supply line L12. By opening the medicine supply valve 35, the medicine supply line L12 is opened, and the medicine supply ejector 18 sucks the medicine liquid W5 flowing through the medicine supply line L12 as a suction fluid via the suction portion 8c. .

When performing the cleaning method of the RO membrane module 5 according to the third embodiment, in the flushing control operation, similarly to the cleaning method of the RO membrane module 5 according to the present embodiment of the first embodiment, the control unit 20 Then, the vacuum pump 12 is stopped and the ejector valve 9 is opened. In addition, the control unit 20 operates the medicine supply device 34 and controls the medicine supply valve 35 to be in an open state.
In addition, the control unit 20 controls the treated water valve 32 to be in a closed state and controls the concentrated water circulation valve 33 to be in a closed state.

In this state, by driving the pressurizing pump 2, a flushing operation for cleaning the primary side of the RO membrane module 5 with the supply water W1 flowing through the supply water line L1 is executed.
Thereby, when performing the flushing operation, the ejector 80 can be used to introduce the mixed air G2a (cleaning gas) flowing through the suction fluid introduction line L11 into the supply water W1 (primary side cleaning water).
Further, when the flushing operation is performed, the drug solution W5 flowing through the drug supply line L12 can be introduced into the concentrated water W31 flowing through the circulating water line L4 using the drug supply ejector 18. Thus, when performing the flushing operation, the chemical is introduced into the supply water W1 via the circulating water line L4, thereby being accompanied by the mixed air G2a (cleaning gas) introduced into the supply water W1 (primary side wash water). Thus, the chemical liquid W5 (medicine) can be introduced into the supply water W1 (primary side wash water).

  According to the water treatment system 100B of the third embodiment, the same effects as those of the first embodiment described above are exhibited.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and can be implemented in various forms.
For example, in the above-described embodiment, the ejector 8 is used to introduce the mixed air G2a (cleaning gas) into the supply water W1 (primary cleaning water), but the present invention is not limited thereto. As a method for introducing the cleaning gas into the supply water W1 (primary side cleaning water), the ejector 8 may not be used. For example, when a flushing operation is performed by providing another pressurizing pump for introducing air. The air may be introduced into the supply water W1 by a pressurizing pump.

  In the first embodiment, the reverse osmosis membrane separation device 4 is disposed on the upstream side of the decarbonation membrane device 1, and the reverse osmosis membrane separation device 4 is treated with the permeated water W2 separated by the reverse osmosis membrane module 5. The decarbonation apparatus 1 was supplied as water. Further, in the second embodiment, the reverse osmosis membrane separation device 4 is disposed on the downstream side of the decarbonation membrane device 1, and the decarbonation membrane device 1 is supplied with decarbonated water W4 produced by the decarbonation membrane module 10. As shown in FIG. However, the configuration is not limited to this, and the decarbonation apparatus 1 may not be provided.

  In the first embodiment and the second embodiment, one reverse osmosis membrane separation device 4 and one decarbonation membrane device 1 are provided in series. However, the present invention is not limited to this. For example, two reverse osmosis membrane separations The device 4 may be provided in series. For example, when two reverse osmosis membrane separation devices 4 are provided in series, an upstream reverse osmosis membrane separation device, a decarboxylation membrane device, and a downstream reverse osmosis membrane separation device are arranged from the upstream side toward the downstream side. They can be arranged in series. This configuration can be realized by further providing a reverse osmosis membrane separation device on the downstream side of the reverse osmosis membrane separation device 4 and the decarbonation membrane device 1 in the first embodiment. The configuration of the reverse osmosis membrane separation device arranged on the downstream side can be the same as that of the reverse osmosis membrane separation device of the first embodiment.

  Moreover, in the said embodiment, although the sweep gas which flows in into a decarbonation membrane module was comprised with the air G1, it is not restrict | limited to this. For example, the sweep gas may be composed of an inert gas such as nitrogen.

4 Reverse osmosis membrane separator 5 RO membrane module (reverse osmosis membrane module)
8 Ejector 10 Decarbonation module 15 Air filter (filter)
G2a mixed air (cleaning gas, sweep gas)
W1 supply water (primary side wash water)
W2 Permeated water W3 Concentrated water

Claims (4)

A method for cleaning the reverse osmosis membrane module in a reverse osmosis membrane separation device that separates permeated water and concentrated water by introducing feed water into the reverse osmosis membrane module,
A method for cleaning a reverse osmosis membrane module, wherein a cleaning gas is introduced into the primary side cleaning water when performing a flushing operation for cleaning the primary side of the reverse osmosis membrane module with a primary side cleaning water. The method for cleaning a reverse osmosis membrane module according to claim 1, wherein the cleaning gas is introduced into the primary cleaning water through a filter that removes foreign matters. On the upstream side or downstream side of the reverse osmosis membrane module, a decarbonation membrane module for producing decarbonated water by removing carbon dioxide contained in supply water or permeated water in the reverse osmosis membrane module with a sweep gas is disposed. And
On the upstream side of the reverse osmosis membrane module, the primary side wash water is introduced as a driving fluid, the sweep gas discharged from the decarbonation membrane module is sucked as a suction fluid, and the sweep gas is mixed. An ejector for delivering the primary side wash water as a mixed fluid is disposed;
The method for cleaning a reverse osmosis membrane module according to claim 1 or 2, wherein when performing the flushing operation, the sweep gas as the cleaning gas is introduced into the primary-side cleaning water by the ejector. The reverse osmosis membrane module according to any one of claims 1 to 3, wherein when performing the flushing operation, the chemical is introduced into the primary side cleaning water in association with the cleaning gas introduced into the primary side cleaning water. Cleaning method.

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