JP3311139B2 - Membrane module system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a membrane module system used, for example, in seawater desalination equipment.

[0002]

2. Description of the Related Art Conventionally, there is known a membrane module system which obtains drinking water or other water by filtering a liquid to be treated containing impurities, for example, seawater, with a membrane module. In this membrane module system, the membrane module 11 shown in FIG. 7 is used.

[0003] The membrane module 11 is divided into a primary side and a secondary side by a filtration membrane (for example, a reverse osmosis membrane, an ultrafiltration membrane, a hollow fiber membrane, etc.) 12 inside the main body.
A supply line 13 and a return line 14 are connected to the primary side, respectively, and a delivery line 15 is connected to the secondary side. To the membrane module 11, seawater as a liquid to be treated is supplied from a supply line 13 connected to the primary side thereof, and the permeated liquid permeating the membrane 12 is transmitted to the membrane module 11 by a delivery line 15 connected to the secondary side. Sent to the process.
The liquid that does not pass through the membrane 12 is connected to the primary side and discharged from the membrane module 11 through the return line 14.

Here, since the membrane module system is used as an industrial plant, it is necessary to keep the flow rate of the permeate almost constant. Further, the recovery rate of the membrane module 11, that is, the ratio of the permeate flow rate to the supply liquid flow rate (= permeate flow rate / supply liquid flow rate) also needs to be maintained at a substantially constant target value. This is because if the recovery rate exceeds a certain value, component precipitation in the supply liquid occurs on the surface of the membrane 12, resulting in a decrease in the quality of the permeate and a deterioration in the performance of the membrane 12. Conversely, if the recovery rate is equal to or less than a certain value, it means that the supply liquid is excessively supplied with respect to the flow rate of the permeate, which is not preferable because it lowers economic efficiency.

[0005]

As described above, the membrane module system is required to maintain the permeate flow rate and the recovery rate within a certain range. However, the membrane 12 is gradually clogged with the elapse of the filtration time. Therefore, it is difficult to keep the flow rate of the permeated liquid constant, and the recovery rate changes accordingly.

An object of the present invention is to provide a membrane module system capable of maintaining a permeate flow rate and a recovery rate within a certain range even if the filtration membrane is clogged.

[0007]

SUMMARY OF THE INVENTION A membrane module system according to the present invention is used for filtration which separates a liquid to be treated, which is divided into a primary side and a secondary side by a membrane and which is supplied to the primary side, through the membrane to a secondary side. A supply line for the liquid to be treated and a return line for discharging a liquid that does not pass through the membrane from the membrane module are connected to the primary side of the membrane module, and a delivery line for sending the permeate to the secondary side. Lines are connected, and flow meters respectively provided on the primary side line and the sending line composed of the supply line and the return line, and provided on the primary side line, and of the liquid to be treated in the primary side line. A pressure adjuster capable of adjusting pressure and a flow rate of the permeate are input, and the pressure adjuster controls the pressure of the liquid to be treated so that the permeate flow rate becomes a set value. A pressure control unit, a flow control unit provided in the primary line, and capable of adjusting the flow rate of the liquid to be treated in the primary line, and inputting the flow rate measured in the primary line and the permeate flow rate And a recovery rate control means for controlling a flow rate of the liquid to be treated by the flow rate adjusting unit so as to obtain a recovery rate of a permeate flow rate with respect to a supply flow rate to the membrane module, and to maintain the recovery rate at a set value. It is characterized by the following.

The membrane module system according to the present invention is characterized in that an adjustment valve is provided in a return line as a pressure adjustment unit, and a variable speed pump for supplying a liquid to be treated is provided in a supply line as a flow adjustment unit.

The membrane module system according to the present invention is characterized in that a pressure regulating valve is provided in a supply line as a pressure regulating unit, and a flow regulating valve is provided in a return line as a flow regulating unit.

In the membrane module system according to the present invention, a pressure sensor is provided in the supply line, and an abnormality detecting device is provided for judging that the membrane module has degraded above a standard when an input value from the pressure sensor exceeds a preset value. It is characterized by having.

The membrane module system according to the present invention is provided with a sensor for measuring the rotation speed of the variable bundle pump, and when the rotation speed input from the sensor exceeds a preset value, it is determined that the membrane module has deteriorated beyond the reference. An abnormality detection device is provided.

In the membrane module system according to the present invention, the respective flow rates from the supply line, the return line, and the delivery line are input to calculate the flow balance of these, and when the flow balance is unbalanced, the flow rate ratio between the respective lines is calculated. A damaged line detection device for identifying a damaged line is provided.

[0013] The membrane module system according to the present invention is characterized in that a valve for adjusting the permeate flow rate is provided in the delivery line.

[0014] A membrane module system according to the present invention comprises a pump for supplying a liquid to be treated, which is connected to a supply line via a discharge valve and supplies the liquid to be treated stored in the liquid tank to be treated to the supply line during operation; A connection line connecting the inlet side of the membrane module and the liquid tank to be processed via a connection valve, and the discharge valve and the connection valve which are in a closed state when the pump is stopped. Cavitation preventing means for controlling the connection valve to a fully open state prior to the opening operation of the valve, and opening the discharge valve at a speed at which cavitation does not occur until the opening degree at which cavitation does not occur under the condition that the connection valve is fully opened. It is characterized by having.

[0015]

In the membrane module system according to the present invention, the pressure of the liquid to be treated in the primary side line is increased in accordance with the decrease in the flow rate of the permeate due to clogging of the membrane, and the flow rate of the permeate is increased. With respect to the accompanying change in the supply flow rate of the liquid to be treated, the flow rate adjustment unit maintains the flow rate and the recovery rate of the permeate in a certain range.

In the membrane module system according to the present invention,
The pressure of the liquid to be treated in the primary line is adjusted by opening and closing an adjustment valve provided in the return line. The problem is dealt with by adjusting the rotation speed.

In the membrane module system according to the present invention,
Pressure adjustment of the processing target in the primary line is performed by opening and closing a pressure adjusting valve provided in the supply line, and in response to a change in the supply flow rate of the liquid to be processed, the opening degree of the flow control valve provided in the return line is adjusted. We deal with it by changing it.

In the membrane module system according to the present invention,
When the pressure of the processing liquid in the supply line exceeds a preset value, it is determined that the membrane module has deteriorated beyond the standard.

In the membrane module system according to the present invention,
When the rotation speed of the variable speed pump for supplying the liquid to be processed exceeds a preset value, it is determined that the film has deteriorated beyond the membrane module standard.

In the membrane module system according to the present invention,
The balance of each flow rate for the supply line, the return line, and the delivery line is also determined, and it is determined whether the flow balance is unbalanced. If the balance is unbalanced, the damaged line is identified from the flow rate ratio between each line. .

In the membrane module system according to the present invention,
The permeate flow rate can be finely adjusted by a permeate flow rate control valve provided in the delivery line.

In the membrane module system according to the present invention,
When the liquid supply pump connected to the supply line via the discharge valve is started, the connection valve provided on the connection line between the inlet side of the membrane module and the liquid tank to be processed opens the discharge valve. Prior to this, cavitation is prevented by opening the discharge valve at a speed that does not cause cavitation up to an opening degree that does not cause cavitation under the condition that the connection valve is fully opened.

[0023]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of a membrane module system according to the present invention, and uses the membrane module 11 described in FIG. A supply line 13 for supplying a non-treatment liquid (hereinafter, referred to as raw water) to the membrane module 11 has a pump 17 for supplying raw water, and a discharge valve 1 for the pump 17.
8 and a flow meter 19 are sequentially provided. The pump 17 has a variable speed, and a sensor 20 for detecting a rotational speed.
Having. Further, a delivery line 15 for delivering a permeated liquid (hereinafter referred to as permeated water) that has passed through the membrane 12 to the next step.
, A flow meter 21 and a flow control valve 22 are sequentially provided. Further, a flow meter 23 and a pressure adjusting valve 24 are sequentially provided in a return line 14 from which a concentrated liquid that does not pass through the membrane 12 (hereinafter, referred to as return water) is discharged from the membrane module 11. .

Reference numeral 26 denotes a control device which is constituted by, for example, a microcomputer or the like, and has each function realizing means described below.

Reference numeral 27 denotes a pressure control means,
Detecting a change in the flow rate of the permeated water obtained in by order to maintain the flow rate Q _F at a constant value, the supply line 13 and return line 1
The raw water pressure P _i in the primary line of the membrane module 11 made up of 4 is controlled. Therefore, enter the permeate flow rate Q _F from the flow meter 21 provided in the delivery line 15, and outputs a pressure control signal corresponding to the flow rate change. In this embodiment, since the valve 24 provided on the return line 14 is used as a pressure adjusting section of the primary line, an opening signal for the valve 24 is output as the pressure control signal.

Reference numeral 28 denotes a recovery rate control means.
Recovery of permeate flow rate Q _F for the raw water supply flow rate Q _P to _{1 φ (= Q F / Q} P) controls the supply flow rate of raw water to be constant. For that purpose, first, the flow rates Q _P and Q _F are inputted from the flow meter 19 of the supply line 13 and the flow meter 21 of the delivery line 15 constituting the primary line, and the recovery rate φ is obtained by the recovery rate calculating means 29. Next, the supply flow rate of the raw water is controlled by the flow rate control means 30 in order to keep the recovery rate φ constant. In this embodiment, the variable speed pump 17 is used as a flow rate adjusting unit for adjusting the supply flow rate, and a deviation signal from the current rotation speed N of the variable speed pump 17 is output as a flow rate control signal.

In addition, an abnormality detecting means 31 and a broken line detecting means 32 are shown, which will be described later.

In the above configuration, the raw water is supplied from the supply line 13 into the membrane module 12 by the supply pump 17, filtered by the membrane 12, and then sent out as the permeated water from the delivery line 15 to the next step. The concentrated water that does not pass through the membrane 12 is discharged from the membrane module 11 through the return line 14.

[0030] In such a membrane module system, film 12 gradually clogging occurs with the lapse of filtration time, the flow rate Q _F of permeate decreases, also decreases recovery phi.
For this permeate flow amount of reduction, it is possible to restore the transmission rate by raising the primary pressure P _i of the membrane module 11.

FIG. 4 shows the above relationship. That is,
Initial filtration properties of the membrane module 11 is _{a 0,} the permeate flow rate _Q primary pressure to obtain the target value _{Q F0} of _{F P i0}
Suppose it was necessary. When the filtration characteristics of the membrane module 11 deteriorate as a ₁ and a ₂ due to clogging with the passage of the filtration time, the primary pressure p _i of the membrane module 11 is increased to increase the initial permeate flow rate target value. Q _F0 can be obtained.

[0032] Incidentally, P _IS is the threshold for abnormality determination, the primary pressure P _i is exceeds this value, it is determined that the film module 11 does not perform its normal filtration function.

[0033] From the above relationships, the pressure control means 27 from the measured value of the flow meter 21, when the passing water flow rate Q _F is reduced, adjustment valve provided to the return line 14 to compensate for the decrease 2
The opening of 4 is reduced to increase the primary pressure of the module 11. That is, by reducing the opening of the regulating valve 24,
The line resistance of the entire primary line increases, and the membrane module 1
Primary pressure of 1 rises, the permeate flow rate Q _F is increased.
However, since the supply flow rate Q _P of the raw water by pipeline resistance increases decreasing recovery rate φ increases. The recovery control means 28 controls the supply flow rate Q _P which caused the recovery rate φ to increase.
In order to compensate for the decrease, the rotation speed increase command is output to the variable speed pump 17. The supply flow rate Q _P of the raw water by the control increases, also returns to the original value recovery phi.

FIG. 5 shows the above relationship. The pressure-flow rate characteristic according to the current rotation speed of the variable speed pump 17 is b ₀ , the current line resistance characteristic of the primary line is r ₀ ,
The current raw water supply flow rate based on these intersections A is Q _P0 ,
The primary pressure is P ₀ (corresponding to P _i0 in FIG. 4). Pipeline resistance characteristics squeeze the opening of the control valve 24 of the return line 14 in this state is changed to r _1, the intersection moves to A '. Therefore, the primary pressure increases and the supply flow rate decreases as shown. Therefore, to increase the rotational speed of the variable speed pump 17, the pressure - Varying the flow rate characteristics b ₁ intersection B
And the raw water supply flow rate returns to the original value Q _P0 , and the primary side pressure further increases to P ₁ (corresponding to P _i0 in FIG. 4). Therefore, the target permeate flow rate Q _F0 is obtained,
In addition, the recovery rate φ can be maintained within a certain range.

[0035] in the figure _{P s} is abnormal judgment threshold (corresponding to _{P is} shown in FIG. 4). That is, the pressure when the line resistance characteristic of the primary line is increased to r ₂ , the rotational speed of the variable speed pump 17 is increased until the characteristic b ₂ is obtained, and the intersection of these moves to C. At the above pressure, it is determined that the membrane module 11 cannot perform a normal filtration function.

The abnormality detecting means 31 is for judging the above-mentioned abnormality of the membrane module 11.
Of the pressure-flow rate characteristic b ₂
When the rotation speed is equal to or higher than the rotation speed that causes the above, it is determined that the membrane module 11 is abnormal. Therefore, by providing the detection means 31 above, an abnormality due to clogging of the membrane module 11 can be detected, and measures such as cleaning can be taken at an early stage.

The broken line detecting means 32 includes a supply line 13 connected to the membrane module 11, a return line 1
4. For detecting a rupture occurring in any of the delivery lines 15, the values of the flow rates Q _P , Q _B , and Q _F are input from the flow meters 19, 21, and 23 provided in the lines 13, 14, and 15, respectively. The rupture point is determined from these values. That is, if the burst to the each line 13, 14 and 15 is not, the respective flow rate _{Q P, Q B, Q F,} although keeping the balance relationship of _{Q P = Q F + Q B} , somewhere lines If a rupture occurs, this balance will be lost. Therefore, as shown in FIG. 6, first, the presence or absence of rupture is determined by monitoring the balance of the balance (step 101). When a rupture is detected due to the imbalance of the balance, the rupture portion is specified by sequentially judging the flow ratio of each line (steps 102, 103, 104).

As described above, if the broken line detecting means 32 is provided, the broken state of each of the lines 13, 14, and 15 connected to the membrane module 11 can be properly grasped during the operation of the membrane module system. It can be identified and dealt with early and prevent the spread of rupture.

The delivery line 15 has a flow control valve 22.
Since is provided, it is also possible to fine-tune the permeate flow rate Q _F that this valve 22 is sent to the next step.

Next, the embodiment of FIG. 2 will be described. Raw water supply line 13 and return line 1 for membrane module 11
4. The provision of the transmission line 15 is the same as in the embodiment of FIG. In this embodiment, a pressure adjusting valve 35 provided on the discharge side of the raw water supply pump 34 is used as a pressure adjusting unit for adjusting the primary pressure of the membrane module 11.
A pressure sensor 36 for measuring the side pressure is provided on an output side line of the pressure regulating valve 35. In this embodiment, a flow control valve 37 provided on the return line 14 is used as a raw water supply flow control unit for adjusting the recovery rate φ. Since the transmission line 15 has the same configuration as that of the embodiment of FIG. 1, the corresponding reference numerals are assigned and the description is omitted.

Pressure control means 27 in control device 26
, Like the foregoing embodiment, the permeate flow rate Q _F of the membrane module 11, when reduced by clogging of the membrane 12, the permeate flow rate Q _F by increasing the pressure of the primary side line of the membrane module 11 It measures the increase. However, having a conversion unit 39 for converting due to the use of pressure regulating valve 35 as a pressure adjusting portion of the primary line, the permeate flow rate Q _F to be measured by the flow meter 21 to the permeate pressure value P _F. Converted pressure value P _F is supplied to the pressure control unit 40, wherein the predetermined target value (pressure value corresponding to the permeate flow that the target) deviation between the P _F0 is obtained. Pressure control signal from the pressure controller 40 and the obtained difference between the current value P _P of the supply line pressure, i.e., outputs an opening signal for the regulating valve 35.

The recovery rate control means 28 is, similarly to the above embodiment, provided with the flow meter 1 of the supply line 13 constituting the primary line.
9 and the flow rate _Q P from the flow meter 21 of the delivery line 15, Q
A recovery rate calculating means 41 for inputting _F and obtaining a recovery rate φ is provided. The flow rate control means 42 controls the return line 14 to control the recovery rate φ calculated by the recovery rate calculation means 29 to a target value.
Controls regulating valve 37 provided in, for adjusting the return water flow rate Q _B.

Here, the recovery rate can be obtained by φ = Q _F / Q _P , where Q _P = Q _F + Q _B , and therefore φ = Q _F
/ Q _F + Q _B , but since the permeated water flow rate Q _F is constant, it is possible to control the recovery rate φ to a target value by adjusting the return water flow rate Q _B.

The abnormality detecting means 31 detects an abnormality due to clogging of the membrane module 11 as in the embodiment shown in FIG. 1. In this embodiment, the raw water supply line 13 is used.
Is provided with a pressure sensor 36, and the measured value is used for abnormality determination. That is, the pressure sensor 36
Primary pressure P _P of in the detected film module 11 _(FIG. 4
The type corresponding) to P _i, which was compared with the abnormality determination threshold value (corresponding to the threshold P _{i s} in FIG. 4), the detected primary pressure P _P is the threshold If it exceeds, it is determined that the membrane module 11 is abnormal.

In the above configuration, the raw water is supplied to the supply pump 34.
The pressure is adjusted to a predetermined primary pressure by a pressure regulating valve 35, supplied to the inside of the membrane module 11 from the supply line 13, filtered by the membrane 12, and then sent out from the delivery line 15 as permeated water to the next step. The concentrated water that does not pass through the membrane 12 is discharged from the membrane module 11 through the return line 14.

[0046] In such a membrane module system, the clogging occurs in the film 12, the flow rate of permeate Q _F
And the recovery rate φ also decreases. When reduction of the permeate flow rate Q _F occurs, the pressure control means 27 produces a pressure control signal to compensate for the flow rate decrease increases the primary pressure P _P by changing the degree of opening of the pressure regulating valve 35 . By this operation, the flow rate Q _F that passes through the membrane 12 rises, the flow rate also varies flowing through the primary line at the same time also varies recovery phi. Recovery control means 28 captures the change in flow rate, to maintain the recovery of φ to the target value by controlling the opening degree of the flow rate adjusting valve 23 provided in the return line 14, to control the water flow rate Q _B back.

[0047] With the above operation, it is possible to maintain permeate flow rate Q _F and the recovery rate φ a constant preset range, respectively.

If the primary pressure of the membrane module 11 rises abnormally due to an increase in clogging of the membrane 12, etc., the output of the pressure sensor 36 is compared with a threshold value by the abnormality detecting means 31. This abnormal state can be detected.

Although not shown, a broken line detecting means 32 similar to that of the embodiment shown in FIG. 1 is provided to detect a rupture portion of each line. fine adjustment of the flow rate Q _F may be carried out.

Next, the embodiment shown in FIG. 3 will be described. Raw water in a raw water tank (liquid tank to be treated) 46 is supplied to the membrane module 11 by a supply line 13 having a supply pump 44 and a discharge valve 45. The configuration of this part is basically the same as that shown in FIG. This is the same as the embodiment of FIG. When the supply pump 44 is started in such a configuration, the discharge valve 45 is closed as is well known, and after the discharge pressure of the supply pump 44 reaches a predetermined value, the discharge valve 45 is opened, and the film is supplied from the supply line 13 to the membrane. Raw water is supplied to the module 11.

Here, in opening the discharge valve 45, when the discharge valve 45 is opened at a stretch, a high pressure on the inlet side of the discharge valve 45 is suddenly applied to the membrane module 11 side.
2 may be damaged by a strong impact. Therefore, the discharge valve 45 is gradually opened to operate the membrane module 11.
It was considered that the pressure applied to the side was gradually increased.

However, it is known that cavitation occurs in the valve when the valve is slowly opened in a state where the pressure difference between the inlet side and the outlet side is large. When cavitation occurs, a strong impact is applied to the valve, which may damage the valve and related parts. For this reason, it is not preferable to gradually open the discharge valve 42 as described above, and it has been difficult to operate the discharge pump 42 when starting the supply pump 41.

Therefore, in the embodiment shown in FIG.
A connection line 48 having a connection valve 47 is installed between the inlet side of the raw water tank 1 and the inside of the raw water tank 46, and a cavitation preventing means 49 is provided as a function realizing means of the control device 26. The connection valve 47 and the supply pump 44 and the discharge valve 45 are controlled in cooperation with each other so that cavitation does not occur.

Here, when the supply pump 44 is stopped, both the discharge valve 45 and the connection valve 47 are closed. Supply pump 4
When the discharge valve 45 is started, the discharge valve 45 is opened when its discharge pressure reaches a predetermined value. However, the cavitation preventing means 49 performs the opening operation of the discharge valve 45 (e.g. The connection valve 47 is opened (at the same time as the start), and the discharge valve 45 is opened after the connection valve 47 is fully opened. In this case, the discharge valve 45 is opened at a relatively high speed at which cavitation does not occur, up to a relatively large opening at which cavitation does not occur.

As described above, when the discharge valve 45 is opened at a relatively high speed to a relatively large opening, the pressure on the outlet side of the discharge valve rapidly increases, so that cavitation does not occur. Further, since the connection line 48 is connected to the inlet side of the membrane module 11 and the connection valve 47 is fully open, most of the high-pressure water discharged from the discharge valve 45 passes through the connection line 48 and passes through the raw water tank 46. Is returned to. Therefore, the pressure on the membrane module 11 does not rise rapidly,
Gradually rise. Therefore, no impact pressure is applied to the membrane module 11 and no cavitation occurs, so that the damage thereof can be prevented.

After the opening operation of the discharge valve 45 is completed in this way, the connecting valve 47 is gradually closed to finally bring it to the fully closed state. After this, such as by controlling the primary side pressure of the membrane module 11 by the means described in the embodiments of FIGS. 1 and 2, to maintain the permeate flow rate Q _F and the recovery rate φ a constant preset range, respectively.

[0057]

As described above, according to the present invention, the permeate flow rate from the membrane module and the recovery rate of the permeate flow rate with respect to the supply liquid flow rate can be maintained within a certain range, respectively. A permeate can be obtained.

In addition, if the abnormality detecting means and the damage preventing means are provided, it is possible to detect the abnormality of the membrane module or the broken part of each line at an early stage in the operation state.

Further, if a connecting line is provided between the inlet side of the membrane module and the liquid tank to be treated, it is possible to prevent cavitation and the occurrence of impact pressure on the membrane module, thereby preventing damage to the equipment.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a membrane module system according to the present invention.

FIG. 2 is a block diagram showing an embodiment of the present invention.

FIG. 3 is a block diagram showing an embodiment of the present invention.

FIG. 4 is a characteristic diagram illustrating the relationship between the primary pressure and the permeate flow rate of the membrane module used in the present invention.

FIG. 5 is a characteristic diagram illustrating a pressure-flow rate characteristic of a primary line with respect to a rotation speed of a variable speed pump used in the embodiment of FIG. 1;

FIG. 6 is a flowchart showing processing contents of a damaged line detection unit shown in FIG. 1;

FIG. 7 is a diagram showing a configuration of a membrane module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Membrane module 12 Membrane 13 Supply line 14 Return line 15 Permeate liquid line 17, 37 Flow control part 19, 21, 23 Flow meter 22 Valve for permeate flow control 24, 35 Pressure control part 27 Pressure control means 28 Recovery rate control Means 31 Abnormality detecting means 32 Damaged line detecting means 41 Pump for supplying liquid to be treated 42 Discharge valve 43 Liquid tank to be treated 44 Connecting valve 45 Connecting line 46 Cavitation preventing means

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hirokazu Kondo 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu Plant, Toshiba Corporation (72) Inventor Shoji Uchida 1-1-1, Shibaura, Minato-ku, Tokyo Shares (72) Inventor Mayumi Kurata 1 Toshiba-cho, Fuchu-shi, Tokyo Toshiba Fuchu Plant (56) References JP-A-64-67204 (JP, A) JP-A-63-270592 ( JP, A) JP-A-59-189911 (JP, A) JP-A-62-191097 (JP, A) JP-A 64-11610 (JP, A) JP-A-57-48303 (JP, A) (58) ) Surveyed field (Int.Cl. ⁷ , DB name) B01D 61/12 B01D 61/22 B01D 65/10 C02F 1/44

Claims (3)

(57) [Claims] 1. A filtration membrane module, which is separated into a primary side and a secondary side by a membrane and allows a liquid to be treated supplied to the primary side to pass through the membrane to the secondary side, and has a primary side of the membrane module. Is connected to a supply line for the liquid to be treated and a return line for discharging a liquid that does not pass through the membrane from the membrane module,
A delivery line for sending a permeate is connected to the secondary side, and in the membrane module system, a flow meter provided on each of the primary side line and the delivery line including the supply line and the return line; Provided, a pressure adjusting unit capable of adjusting the pressure of the liquid to be treated in this primary line, and inputting the flow rate of the permeate, and the pressure adjuster so that the permeate flow rate becomes a set value. Pressure control means for controlling the pressure of the processing, provided in the primary line, a flow rate adjustment unit capable of adjusting the flow rate of the liquid to be processed in the primary line, and the flow rate measured in the primary line The permeate flow rate is input and the recovery rate of the permeate flow rate with respect to the supply flow rate to the membrane module is determined, and the flow rate adjustment is performed so that the recovery rate maintains a set value. A recovery rate control means for controlling the flow rate of the liquid to be treated by the control means, a regulating valve is provided in the return line as a pressure regulating section, and a variable speed pump for supplying the liquid to be treated is provided in the supply line as a flow rate regulating section. A membrane for measuring a rotational speed of the pump, and an abnormality detecting device for judging that the membrane module has deteriorated beyond a reference when a rotational speed inputted from the sensor exceeds a preset value. Module system. 2. A membrane module for filtration, which is separated into a primary side and a secondary side by a membrane and allows the liquid to be treated supplied to the primary side to pass through the membrane to the secondary side, and the primary side of the membrane module is provided. Is connected to a supply line for the liquid to be treated and a return line for discharging a liquid that does not pass through the membrane from the membrane module,
A delivery line for sending a permeate is connected to the secondary side, and in the membrane module system, a flow meter provided on each of the primary side line and the delivery line including the supply line and the return line; Provided, a pressure adjusting unit capable of adjusting the pressure of the liquid to be treated in this primary line, and inputting the flow rate of the permeate, and the pressure adjuster so that the permeate flow rate becomes a set value. Pressure control means for controlling the pressure of the treatment, provided in the primary line, a flow rate adjustment unit capable of adjusting the flow rate of the liquid to be treated in this primary line, and the flow rate measured in the primary line The permeate flow rate is input and the recovery rate of the permeate flow rate with respect to the supply flow rate to the membrane module is determined. And a recovery rate control means for controlling the flow rate of the liquid to be treated by the control unit.The flow rates from the supply line, the return line, and the delivery line are input to obtain flow rate balances thereof, and when the flow rate balance is unbalanced, A membrane module system provided with a broken line detecting device for specifying a broken line from a flow rate ratio between lines. 3. A membrane module for filtration, wherein the membrane is separated into a primary side and a secondary side by a membrane and a liquid to be treated supplied to the primary side is transmitted through the membrane to the secondary side. Is connected to a supply line for the liquid to be treated and a return line for discharging a liquid that does not pass through the membrane from the membrane module,
Further, in a membrane module system in which a delivery line for delivering a permeate is connected to the secondary side, the processing liquid connected to the supply line via a discharge valve and stored in the processing target liquid tank during operation is supplied to the supply line. A pump for supplying the liquid to be processed, a connection line connecting the inlet side of the membrane module and the liquid tank to be processed via a connection valve, and the discharge valve which is in a closed state when the pump is stopped. When the pump is started, the connection valve is controlled to a fully opened state prior to the opening operation of the discharge valve, and the discharge valve is opened at a speed that does not cause cavitation on condition that the connection valve is fully opened. And a cavitation preventing means.