WO2019180788A1

WO2019180788A1 - Salt concentration device and scale detection method for salt concentration device

Info

Publication number: WO2019180788A1
Application number: PCT/JP2018/010871
Authority: WO
Inventors: 嘉晃伊藤; 英正垣上; 英夫鈴木
Original assignee: 三菱重工エンジニアリング株式会社
Priority date: 2018-03-19
Filing date: 2018-03-19
Publication date: 2019-09-26

Abstract

This salt concentration device is provided with: a concentration device main body 14 that comprises a filter membrane 13 in which permeate water 12 is obtained from water to be treated 11 by concentrating the salt in the water to be treated 11 and that discharges concentrated water in which salt is concentrated; a main body pressurization device 15 that pressurizes and supplies the water to be treated 11; a concentration device 23 for detection that is provided to a concentrated water branch line L₂₁ by which part of concentrated water 16 from a concentrated water line L₁₃ for discharging concentrated water 16 from the concentration device main body 14 is made to branch, that further concentrates the salt from the concentrated water 16a made to branch, and that comprises a filter membrane 22 for detection by which permeate water 21 for detection is obtained; and a pressurization device 24 for detection that pressurizes the concentrated water 16a made to branch to the concentration device 23 for detection, then supplies the result. A solution permeation parameter and a pre/post-change solute permeation parameter for the water production amount of the concentration device main body 14 obtained via the permeate water 12 and the permeate water 21 for detection are used to detect whether there is change in the adhesion of scale to the concentration device main body 14.

Description

Salt concentration apparatus and scale detection method for salt concentration apparatus

The present invention relates to a salt concentration device and a scale detection method of the salt concentration device.

Conventionally, as a device for obtaining fresh water from seawater, which is to be treated, seawater is pressurized and passed through a type of filtration membrane called a reverse osmosis membrane (RO membrane: Reverse ＲＯ Osmosis Membrane) to remove and concentrate the salt content of seawater. Accordingly, a desalination apparatus is used that produces fresh water (permeated water) to be used as clean water by desalinating seawater.

In this desalination apparatus, when the seawater is concentrated at the surface portion of the reverse osmosis membrane, the inorganic components contained in the seawater are precipitated and the deposit (scale) adheres to the reverse osmosis membrane, the reverse osmosis membrane is blocked. Therefore, the permeation | transmission performance of raw water in a reverse osmosis membrane falls. Therefore, the desalination apparatus calculates the permeation performance of the reverse osmosis membrane obtained during operation, and determines the presence or absence of scale deposition on the reverse osmosis membrane surface from the degree of decrease in the permeation performance of the reverse osmosis membrane.

In addition, as an example of a method for monitoring the reverse osmosis membrane, for example, organic substances, inorganic substances, fungi, and the like attached to the reverse osmosis membrane are directly monitored visually using a part of each of the supply liquid and the concentrated liquid, and reverse osmosis is also performed. There has been proposed a method of directly monitoring the scale generated in the film visually (see, for example, Patent Document 1).

In addition, for example, mine wastewater other than seawater includes mine wastewater, which contains pyrite (FeS ₂ ), and this pyrite is oxidized to produce SO ₄ ²⁻ . Inexpensive Ca (OH) ₂ is used to neutralize mine wastewater. For this reason, the mine wastewater is rich in Ca ²⁺ and SO ₄ ^2- . It is also known that brine, sewage, and factory wastewater are rich in Ca ²⁺ and SO ₄ ^2- . Further, in the cooling tower, heat exchange is performed between the high-temperature exhaust gas discharged from the boiler or the like and the cooling water. Since a part of the cooling water becomes steam by this heat exchange, ions in the cooling water are concentrated. Therefore, the cooling water (blow-down water) discharged from the cooling tower is in a state in which ion concentrations such as Ca ²⁺ and SO ₄ ^2- are high.

The water containing a large amount of these ions is subjected to desalting treatment. As a concentrating device for performing a desalting treatment, for example, a reverse osmosis membrane device, a nanofiltration membrane device, an ion exchange membrane device and the like are known.

However, when desalinating using these devices, fresh water is removed from water containing high concentrations of cations (eg, calcium ions (Ca ²⁺ )) and anions (eg, sulfate ions (SO ₄ ²⁻ )). When obtained, these ions are concentrated on the membrane surface to produce calcium sulfate, a sparingly soluble mineral salt (gypsum (CaSO ₄ )), but the solubility of the generated calcium sulfate exceeds its solubility limit in water There is a case. As a result, there is a problem that calcium sulfate is deposited as a deposit on the membrane surface and the permeate flux (flux) is lowered.

For this reason, conventionally, as a method for monitoring the reverse osmosis membrane, for example, by using a cell for monitoring the reverse osmosis membrane of the reverse osmosis membrane device, it is possible to detect the formation of concentrated salt crystals by visual judgment. There is a proposal (Patent Document 2).

JP 2008-253953 A Special table 2009-524521

Here, in the method of monitoring the reverse osmosis membrane of Patent Document 1, it is disclosed that coloring is performed by adding a staining agent to a foreign substance (organic matter, inorganic matter, fungi, etc.), and visual monitoring is performed directly. Although specific dyeing agents are exemplified for fungi and fungi, only inorganic dyes and the like that have an adsorptive property to inorganic substances are described. Even if there is an appropriate stain for the inorganic substance, the method of periodically adding and monitoring the stain causes a problem in the processing of the stain. On the other hand, when the method of monitoring by adding a staining agent when an abnormality occurs, the burden of processing the staining agent is reduced, but when the permeation performance of the reverse osmosis membrane is reduced to the extent that the performance deterioration of the reverse osmosis membrane can be discriminated. In some cases, the scale deposition proceeds to a level that is difficult to recover by washing. Therefore, in order to remove the scale deposited on the reverse osmosis membrane and wash the reverse osmosis membrane, there is a problem that the filtration treatment operation of the filtration device must be stopped and the production efficiency of the permeated water is poor.

Further, in the monitoring method proposed by Patent Document 2, the generation mechanism of deposits (for example, mineral salt crystals) is based on the growth of nano-level crystal nuclei. The pore size of the reverse osmosis membrane surface of the reverse osmosis membrane device is at a nano level, and if a deposit of sub-μm or less exists on the membrane surface, the reverse osmosis membrane is blocked. In order to visually confirm the deposits of sub-μm or less, it is substantially difficult to photograph with an optical photographing apparatus (for example, an optical microscope), and a photographing apparatus such as an electron microscope is necessary. There is a problem that observation is not possible. Furthermore, since the concentrated water of the reverse osmosis membrane device flows on the surface of the reverse osmosis membrane that can be visually observed, it is substantially difficult to continuously observe the surface of the reverse osmosis membrane with high accuracy through the flowing liquid. There is a problem.

The present invention provides a salt concentration device and a scale detection method for a salt concentration device that can detect the properties of water to be treated and the presence or absence of scale on the membrane of the concentration device without stopping the operation of the concentration device. The task is to do.

According to the first aspect of the present invention, the main body of the concentration apparatus has a filtration membrane that obtains permeated water by concentrating the salinity of the water to be treated from the water to be treated, and discharges the concentrated water in which the salinity is concentrated. A supply line that supplies the water to be treated to the concentration apparatus body, a pressure device for the body that is interposed in the supply line and that supplies the treatment water to the concentration apparatus body under pressure, and the concentration A concentrated water line for supplying the concentrated water from the apparatus main body, a concentrated water branch line for branching a part of the concentrated water from the concentrated water line, and a salinity of the concentrated water branched and provided in the concentrated water branch line Concentrating the sample, the detection concentrating device having a detection filtration membrane for obtaining permeate for detection, and the concentrated water branched from the concentration line branch, pressurizing the branched concentrated water and supplying it to the detection concentration device Pressure device for detection Using the solute permeation parameter and the solution permeation parameter before and after the change in the water production amount of the concentrator main body obtained from the permeate and the permeate for detection, the presence / absence of scale adhesion fluctuation to the concentrator main body is detected. A salt concentration device comprising: a detection unit;

According to the second aspect of the present invention, the salt concentration for separating the water to be treated into the permeated water and the concentrated water in which the salt content is concentrated by the main body of the concentrating device by concentrating the salt content of the water to be treated by the filtration membrane. And a permeate for detection is obtained from the concentrated water by increasing the water pressure of a part of the concentrated water and supplying the concentrated water to the concentration device for detection, and further concentrating the salt content of the concentrated water while improving the concentration rate. The concentration of scale on the concentration device main body according to the salt concentration step for detection, and the solute permeation parameter and the solution permeation parameter before and after the change in the water production amount of the concentration device main body obtained from the permeate and the permeation water for detection. And a detection step of detecting the presence or absence of fluctuations.

According to the present invention, when supplying a part of the concentrated water from the main body of the concentrating device to the detecting concentrating device, the condensing water is pressurized by the detecting pressurizing device, and the permeated water and the detecting permeated water are obtained. Using the solute permeation parameter and the solution permeation parameter before and after the change in the water production amount of the concentrator main body, whether or not the property of the treated water (for example, TDS, temperature, etc.) fluctuates, or the scale adheres to the filter membrane of the concentrator main body The presence or absence of can be detected. Thereby, the property of to-be-processed water and the adhesion of the scale to the concentration apparatus main body can be detected in advance during the concentration operation of to-be-processed water.

FIG. 1 is a schematic diagram of a salt concentration apparatus according to Example 1. FIG. FIG. 2 is a schematic diagram of the salt concentration apparatus according to the second embodiment. FIG. 3 is a diagram showing a relationship between a solute permeation parameter (SPP: Salt Permeability Parameter) and a solution permeation parameter (WPP: Water Permeability Parameter) when the concentrated water to the concentration device for detection is pressurized. FIG. 4 is a diagram showing a scale adhesion map based on the solute permeation parameter and the solution permeation parameter when the concentrated water to the concentration device for detection is pressurized. FIG. 5 is a diagram showing the relationship between the solute permeation parameter and the solution permeation parameter when the concentration water to the concentration device for detection is not increased.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

FIG. 1 is a schematic diagram of a salt concentration apparatus according to Example 1. FIG. As shown in FIG. 1, a salt concentration device 10A according to the present embodiment has a filtration membrane 13 that obtains permeate 12 by concentrating salt contained in water to be treated 11, and the salt is concentrated. and a concentrator body 14 for discharging concentrated water, a supply line L ₁₁ for supplying water to be treated 11 in the concentrator body 14, is interposed in the supply line L _11, the treated water 11 pressurized to concentrator body 14 Pressurizing device 15 for supplying pressure and supplying, concentrated water line L ₁₃ for supplying concentrated water 16 from concentrating device main body 14, and concentrated water branch line L for branching a part of concentrated water 16 from concentrated water line L ₁₃ _21, provided on the concentrated water branch line L _21, the branched concentrated water 16a, the detection concentrator 23 having a detection filter membrane 22 to obtain the detection permeate 21 by further concentrating the salt contained therein Concentrated water branch Interposed down L _21, branched and sensing pressure device 24 supplies the concentrated water 16a pressurizes detection concentrator 23, the permeate 12 and each of the electric conductivity of the detection permeate 21 (EC The solute permeation parameters before and after the change in the water production amount of the permeated water 12 of the concentrator main body 14 obtained from the above, the permeated water amount (Qp) of the permeating water for detection 21 and the supply water pressure (Pf) of the treated water 11 were obtained. Using the solution permeation parameters before and after the change in the water production amount of the permeate 12 of the concentrator main body 14, whether or not the properties of the treated water 11 (for example, TDS (Total Dissolved Solids), temperature, pH, etc.) have changed, or the concentrator And a detection unit 50 that detects the presence or absence of scale adhesion fluctuation on the main body 14. In this embodiment, a reverse osmosis membrane device will be described as an example of a concentrating device for obtaining fresh water. However, the present invention is not limited to this, and the water to be treated 11 is permeated through the filtration membrane 13. The apparatus is not particularly limited as long as the apparatus obtains water 12 and separates it as concentrated water 16.

The concentrator main body 14 is provided with a filtration membrane 13 for removing permeated water 12 and removing permeated water 12 from the water to be treated 11 pressurized by a main body pressurizing device 15 (for example, a booster pump). Have. The concentrator main body 14 is constituted by a reverse osmosis membrane module in which a reverse osmosis membrane element including a reverse osmosis membrane filtration membrane is loaded in a pressure vessel. The filtration membrane 13 is a liquid separation membrane that applies a pressure higher than the osmotic pressure difference between the solutions through the membrane to the high concentration side to prevent the passage of the solute and permeate the solvent. A pressure higher than the osmotic pressure is applied to the treated water 11 supplied to the concentrator main body 14 on the treated water 11 side of the filtration membrane 13 using the main body pressurizing device 15, and then the water is passed through the filtration membrane 13. As a result, the permeated water 12 and the concentrated water 16 are obtained from the treated water 11.

Permeate 12 is supplied to the external water-using equipment or the like via the permeate line L _12. Concentrated water 16 salt is concentrated in concentrator body 14 is discharged out of the system through the concentrated water line L _13.

For example, examples of the membrane structure when a reverse osmosis membrane (RO membrane: Reverse Osmosis Membrane) is used as a filtration membrane include polymer membranes such as composite membranes and phase separation membranes. Examples of the material for the reverse osmosis membrane include aromatic polyamides, aliphatic polyamides, polyamide materials such as composite materials thereof, and cellulose materials such as cellulose acetate.

As described above, the reverse osmosis membrane may be an RO membrane, but is not particularly limited thereto, and for example, an NF membrane (Nanofiltration Membrane) may be used.

Here, the water to be treated 11 includes scale components such as seawater, mine wastewater, blowdown water of a power plant cooling tower, accompanying water at the time of oil / gas production, brine, and factory wastewater. The water to be treated 11, the main body pressing device 15 provided in the supply line L _11, is pressurized to a predetermined pressure (for example 50-70 bar), reverse osmosis provided with a filtration membrane 13 of the reverse osmosis (RO) membranes It introduce | transduces into the concentration apparatus main body 14 which is a membrane apparatus.

In the concentration device main body 14, as a salt concentration step, the salt in the water to be treated 11 is concentrated, and the water that has passed through the filtration membrane 13 is recovered as permeated water 12 that is fresh water. Further, the concentrated water 16 in which the salinity is concentrated in this salinity concentration step is discharged or used separately for recovering the salinity.

In the present embodiment, a concentrated water branch line L ₂₁ that branches a part from the concentrated water line L ₁₃ that discharges the concentrated water 16 is provided. Then, the concentrated water branch line L ₂₁ is obtained by further concentrating the salt contained in the branched concentrated water 16a to obtain the permeated water 21 for detection and concentrating the salt to obtain the concentrated water for detection. The line L ₂₃ is provided with a detection concentrator 23 having a detection filtration membrane 22 for discharging the detection concentrated water 25. The detection filtration membrane 22 is preferably a reverse osmosis (RO) membrane. In particular, it is more preferable that the concentration is the same as that of the reverse osmosis membrane of the reverse osmosis membrane device which is the main body 14 of the concentrator.

Furthermore, the permeate line L ₁₂ for discharging the permeate 12 from the concentrator body 14, an electric conductivity meter for measuring the electrical conductivity of the permeate 12 (EC (Electric Conductivity) meter) 31A and, permeate 12 A flow meter 32A for measuring the flow rate is provided. Further, in the detection permeate line L ₂₂ , an electric conductivity meter (EC (Electric Conductivity) meter) 31B that measures the electrical conductivity of the detection permeate 21 and a flow rate that measures the flow rate of the detection permeate 21. A total of 32B is provided.

A main body pressure gauge P ₁ for measuring the pressure of the water to be treated 11 is provided between the main body pressure device 15 and the concentration device main body 14 in the supply line L ₁₁ . In addition, a detection pressure gauge P ₂ for measuring the pressure of the branched concentrated water 16 a is provided between the detection pressurizing device 24 and the detection concentrating device 23 in the concentrated water branch line L ₂₁ . The permeate line L ₁₂ may be provided with a pressure gauge that measures the pressure of the permeate 12 near the outlet of the filtration membrane 13, and the concentrated water line L ₁₃ is a pressure that measures the pressure of the concentrated water 16. A total may be provided.

Information measured by the

electric conductivity meters

31A and 31B and the

flow meters

32A and 32B is transmitted to the detection unit 50. The detection unit 50 calculates the amount of permeated water of the filtration membrane 13 from the measurement results of the

flow meters

32A and 32B, calculates the electrical conductivity of the treated water 11 from the measurement results of the

electrical conductivity meters

31A and 31B, and the pressure gauge P _1, the treated water 11 from the measurement result of the P _2, permeate 12, and calculates the pressure of the concentrated water 16.

And in the detection part 50, the presence or absence of the change of the property of to-be-processed water, its trend, or the presence or absence of the adhesion of the scale to the filtration membrane 13 of the concentration apparatus main body 14 can be confirmed.

Changes in the properties of the water to be treated can be confirmed by changes in the amount of water and the quality of the water depending on the temperature of the water and the concentration of salt contained in the water.

Here, the so-called mass balance is constant in the present embodiment as the salt treatment condition of the water to be treated 11 supplied to the concentrator main body 14. The operation with a constant mass balance is a general operation of the reverse osmosis membrane device, and controls the supply water pressure by controlling the permeated water amount of the permeated water 12 and the concentrated water amount of the concentrated water 16 to be constant conditions. The operation mode is not. And when a scale adheres to the filtration membrane 13 of the concentration apparatus main body 14, the operation is an operation mode in which the pressure increase operation of the supply pressure is automatically performed in order to ensure the amount of the permeated water 12.

In the case of such an operation mode in which the mass balance is constant, the concentrated water 16 from the concentrator main body 14 is supplied to the detection concentrator 23 while maintaining the pressure discharged from the concentrator main body 14.

Here, when the property of the to-be-treated water 11 to be supplied changes (for example, the salinity concentration in the to-be-treated water 11 increases), when the scale adheres to the filtration membrane 13 on the concentration device body 14 side, The salt concentration in the concentrated water 16 becomes high, and scale adhesion occurs on the detection filtration membrane 22 of the detection concentration device 23.

When the scale adheres to the detection filtration membrane 22, the permeated water amount of the detection permeate 21 decreases.

Therefore, in the present embodiment, the detection pressurizing device 24 is installed in the concentrated water branch line L ₂₁ on the upstream side of the detection concentrating device 23, and the branched concentrated water 16 a is used by using the detection pressurizing device 24. By increasing the pressure, the water pressure of a part of the branched concentrated water 16 is increased and supplied to the detection concentrating device 23 to eliminate the decrease in the permeation amount of the detection permeate water 21 (the permeation amount of the detection permeate water 21 is reduced). Secure).

For example, when the pressure of the water to be treated 11 in the main body pressurizing device 15 is 70 bar, the pressure increase (α) of the detection pressurizing device 24 is ½ of the pressure of the main body pressurizing device 15. The pressure is preferably about 1/50 (more preferably 1/5 to 1/10). The concentrated water 16a thus branched is supplied to the concentration device for detection 23 at a pressure (Y + α) obtained by adding a pressure increase (α) to the pressure (Y) of the concentrated water 16 discharged from the concentration device main body 14. I have to.

Here, the pressure increase (α) is 1/2 (35 bar) to 1/50 (1.4 bar) of the pressure (70 bar) of the main body pressurizing device 15 (more preferably 1/5 (14 Bar) to about 1/10 (7 bar)). A pressure of around 1/7 (10 bar) is preferred.

When the detection concentrator 23 is in a pressure-increased state, that is, when the concentrated water 16 a branched from a part of the concentrated water 16 from the concentrator main body 14 is supplied to the detection concentrator 23, In the case where the pressure of the concentrated water 16a is increased by the pressure device 24, the solute permeation parameters before and after the change in the water production amount of the permeated water 12 of the concentrating device body 14 obtained from the permeated water 12 and the permeated water for detection 21, and the permeated water for detection. The properties of the water to be treated 11 (for example, TDS, temperature, etc.) using the permeated water amount of 21 and the supply water pressure of the water to be treated 11 and the solution permeation parameters before and after the change in the water production amount of the permeated water 12 of the concentrator main body 14 are obtained. ) And the presence / absence of a change in scale adhesion to the filtration membrane 13 of the concentrator main body 14 can be detected. Thereby, the property of to-be-processed water and the adhesion of the scale to the concentration apparatus main body can be detected in advance during the concentration operation of to-be-processed water.

Here, in the present embodiment, the solute permeation parameter can be obtained from, for example, a measurement result of electrical conductivity (EC). Specifically, before and after the water quality of the treated water 11 changes, the “electric conductivity of the detection permeated water 21 (ECp, sensor)” and “the electric conductivity of the permeated water 12 (ECp, plant)” It can be obtained by division.

For example, in this embodiment, as a change in the amount of water produced in the permeated water 12 of the concentrator main body 14, the ratio before and after the change in the water quality of the water to be treated 11, which is a factor that causes scale adhesion, is taken, and relative [(ECp, sensor) / (ECp, plant)]. Here, before and after the change of the water quality of the water to be treated 11, the confirmation of the water quality change is measured at regular intervals, and when there is no change, it is further measured at regular intervals, and when there is a change, there is no change. Comparing cases. This change comparison may be made by dividing (value after change) by (value before change) ((value after change) / (value before change)), or the difference ((value after change) (Value)-(value before change)) may be obtained.

Further, the behavior of the solution permeation parameter can be obtained from the result of multiplying the amount of permeated water of the detection permeated water 21 and the supply pressure of the water to be treated 11 of the main body pressurizing device 15. Specifically, it is obtained by multiplying “the amount of permeated water of the detection permeated water 21” and “the supply water pressure of the treated water 11 to the concentrator main body 14” before and after the change in the water quality of the treated water 11. it can. Here, the “permeated water amount of the permeating water 21 for detection” and the “supply water pressure of the treated water 11 to the concentrator main body 14” are multiplied by these when the filtration membrane performance changes depending on the scale. This is to increase the result because the rate of change is large, but the present invention is not limited to multiplying these values.

For example, in the present embodiment, as the change in the amount of the permeated water 12 of the concentrator main body 14, the ratio before and after the change in the water quality of the water to be treated 11 is taken, and the relative [(Qp, sensor) × (Pf, plant) ] To ask.

FIG. 3 shows an example of the results using the solute permeation parameter and the solution permeation parameter. In FIG. 3, as water to be treated, test water set so that the A value is 10% reduced (black circle mark), 20% reduced (white circle mark), and 40% reduced (triangular mark) is used. The horizontal axis represents the result of obtaining the relative [(ECp, sensor) / (ECp, plant)]. Similarly, using the test water, the vertical axis represents the result of determining the relative [(Qp, sensor) × (Pf, plant)], which is a solution permeation parameter.

As shown in FIG. 3, it was found that as the scale adhesion degree in the water to be treated increases, it tends to fall to the lower right zone from the reference (0). The reference (0) is a case where the measured values before and after the change of the water quality of the treated water 11 are confirmed and there is no change.

Therefore, as shown in FIG. 4, this change can be mapped as alarm 1 zone, alarm 2 zone, and alarm 3 zone. For example, when it is determined that the detection result belongs to the alarm 2 zone, for example, an alarm 51 is issued on an image (for example, a PC screen) or a voice to predict the scale adhesion to the filtration membrane 13 in advance. Can do.

On the other hand, as shown in FIG. 5, in the case where the branching concentrated water 16 a supplied to the detection concentrating device 23 is not boosted without installing the detection pressurizing device 24 in the concentrated water branching line L _21. The plots gathered around the reference (0), and the zone of change could not be confirmed.

In the present embodiment, when the presence or absence of scale adhesion to the filtration membrane 13 of the concentrator main body 14 is confirmed, before and after the change in the water production amount of the permeated water 12 of the concentrator main body 14 has been described, the present invention is limited to this. Is not to be done. You may make it confirm the presence or absence of scale adhesion by confirming the change of the water production amount of the permeated water 12 itself. In addition, in the state of the water to be treated 11 (for example, temperature, pH value, TDS (for example, copper, zinc, mercury, cadmium and other impurities)), the change rate of the state is confirmed in advance, and the corresponding map, etc. Therefore, it is possible to cope in advance with changes in the water to be treated 11 supplied to the concentration device main body 14 due to these.

As described above, according to this embodiment, when a part of the concentrated water from the main body of the concentration device is supplied to the detection concentration device, the concentration water is pressurized by the detection pressure device, The solute permeation parameters before and after the change in the water production amount of the concentrator main body obtained from the above, the solution permeation parameters before and after the change in the water production amount of the concentrator main body obtained from the permeated water amount of the detection permeated water and the supply water pressure of the treated water, and Can be used to detect the presence or absence of fluctuations in the properties of the water to be treated (eg, salt concentration, TDS, temperature, pH, etc.) and the presence or absence of scale adhesion fluctuations on the filter membrane of the concentrator main body. Thereby, the property of to-be-processed water and the adhesion of the scale to the concentration apparatus main body can be detected in advance during the concentration operation of to-be-processed water.

FIG. 2 is a schematic diagram of the salt concentration apparatus according to the second embodiment. As shown in FIG. 2, the salt concentration device 10B according to the present embodiment further desalinates the first concentrated water 16-1 of the first concentration device main body 14-1 using two concentration device main bodies. For this purpose, a second concentrator main body 14-2 is installed to obtain fresh water of the second permeated water 12-1. Since two sets having the same configuration as the apparatus configuration of the first embodiment are connected, the branch number is assigned “−1” to the preceding apparatus, and the branch number “−2” is assigned to the succeeding apparatus. ”Is attached, and redundant description is omitted.

As shown in FIG. 2, when two concentration device main bodies 14-1 and 14-2 are installed, the salinity concentration in the first concentrated water 16-1 is greater than the salinity concentration of the water to be treated 11-1. Therefore, the frequency of scale adhesion to the second filtration membrane 13-2 of the second concentrator main body 14-2 on the rear stage side is high. Therefore, when the second concentrated water 16a-2 branched from the second concentrated water 16-2 is introduced into the second concentration apparatus 23-2 in the second concentration apparatus main body 14-2 as well, As in the case of 1, the pressure is increased by a predetermined pressure using the second detection pressurizing device 24-2.

According to the present embodiment, when a part of the second concentrated water 16-2 from the second concentrating device main body 14-2 is supplied to the second detecting concentrating device 23-2, the second detection is performed. The pressure of the second concentrated water 16-2 is increased by the pressurizing device 24-2, and the concentration of the concentration device main body 14-2 obtained from the second permeated water 12-2 and the second permeated water for detection 21-2 is obtained. Concentrator main body 14 determined from the solute permeation parameters before and after the change in the water production amount of the permeated water 12-2, the permeated water amount of the second detection permeated water 21-2, and the supply water pressure of the first concentrated water 16-1. -2 permeated water 12-2 using the solution permeation parameters before and after the change in the water production amount, the presence or absence of fluctuations in the properties of the first concentrated water 16-1 (eg, TDS, temperature, pH, etc.), the second concentration It is possible to detect the presence or absence of scale adhesion fluctuation on the second filtration membrane 13-2 of the apparatus main body 14-2. As a result, the properties of the treated water 11-1 or the first concentrated water 16-1 and the first or second concentrated water 16-1 in advance during the concentration operation of the treated water 11-1 or the first concentrated water 16-1. It is possible to detect adhesion of scale to the first or second filtration membranes 13-1 and 13-2 of the concentrator main bodies 14-1 and 14-2.

In the present embodiment, two concentration device main bodies are used. However, the present invention is not limited to this, and the second concentrated water 16-2 of the second concentration device main body 14-2 is further added. In order to desalinate, when the third concentrator body is installed, the third concentrated water is branched in the same manner, and a part of the third concentrated water is supplied to the third detecting concentrator. The pressure of the third concentrated water is increased by the third detection pressurizing device, and before and after the change in the water production amount of the permeated water 12 of the concentration device main body 14 obtained from the third permeated water and the third detected permeated water. Solute permeation parameters, solution permeation parameters before and after the change in the amount of water produced in the permeated water 12 of the concentrator body 14 determined from the permeated water amount of the third permeating water for detection and the supply water pressure of the second concentrated water 16-2 The presence or absence of fluctuations in the properties (eg, TDS, temperature, pH, etc.) of the second concentrated water 16-2, It is possible to detect the presence or absence of scale deposition change on the third filtration membrane concentrator body. Thus, during the concentration operation of the water to be treated 11-1 or the first concentrated water 16-1 / second concentrated water 16-2, the water to be treated 11 or the first concentrated water 16-1 / first 2 of the concentrated water 16-2 and the first filtration membrane 13-1 / second filtration of the first concentration device main body 14-1 / second concentration device main body 14-2 / third concentration device main body. The adhesion of the scale to the membrane 13-2 / third filtration membrane can be detected.

10A, 10B Salt concentration device 11 Water to be treated 12 Permeated water 13 Filtration membrane 14 Concentration device main body 15 Pressure device for main body 16 Concentrated water 16a Branched concentrated water 21 Permeated water for detection 22 Filtration membrane for detection 23 Concentration device for detection 24 Pressure detector for detection 25 Concentrated water for

detection

31A,

31B Conductivity meter

32A, 32B Flow meter 50 Detector 51 Alarm L ₁₁ Supply line L ₁₂ Permeated water line L ₁₃ Concentrated water line L ₂₁ Concentrated water branch line L ₂₂ detected Permeated water line L ₂₃ Concentrated water line for detection

Claims

Having a filtration membrane that obtains permeated water by concentrating the salinity of the water to be treated from the water to be treated, and a concentration device main body for discharging the concentrated water in which the salinity is concentrated;
A supply line for supplying the treated water to the concentrator body;
A pressurizing device for a main body, interposed in the supply line, and pressurizing and supplying the treated water to the main body of the concentrating device;
A concentrated water line for supplying the concentrated water from the concentrator body;
A concentrated water branch line for branching a part of the concentrated water from the concentrated water line;
A concentration device for detection having a detection filtration membrane that is provided in the concentrated water branch line and obtains permeate for detection by further concentrating the salt content of the branched concentrated water;
A detection pressure device interposed in the concentrated water branch line, pressurizing the branched concentrated water and supplying the concentrated water to the detection concentration device;
Detection using the solute permeation parameter and the solution permeation parameter before and after the change in the water production amount of the concentrator main body obtained from the permeate and the permeate for detection, to detect the presence or absence of scale adhesion fluctuation to the concentrator main body A salinity concentrator.
In claim 1,
The salinity concentrator, wherein the solute permeation parameter is obtained from the electric conductivity of permeated water for detection and the electric conductivity of permeated water before and after a change in the amount of water produced by the main body of the concentrator.
In claim 1,
The salinity concentrating device, wherein the solution permeation parameter is obtained from a permeated water amount of the detection permeated water before and after a change in a water production amount of the concentrator main body and a supply water pressure of the treated water to the concentrator main body. .
In any one of Claims 1 thru | or 3,
The salinity concentrating device, wherein the detecting pressurizing device increases the pressure of the concentrated water by 1/2 to 1/50 of the pressure of the main body pressurizing device.
A salt concentration step of separating the water to be treated into a permeated water and a concentrated water in which the salt content is concentrated by a concentration device body by concentrating the salt content of the water to be treated with a filtration membrane;
The pressure of a part of the concentrated water is raised and supplied to a concentration device for detection, and the concentration of the concentrated water is further concentrated while improving the concentration rate, thereby obtaining detection permeate from the concentrated water. A salt concentration step;
A detection step of detecting the presence or absence of scale adhesion fluctuation on the concentration device main body based on the solute permeation parameter and the solution permeation parameter before and after the change in the water production amount of the concentration device main body obtained from the permeated water and the permeation water for detection. And a scale detection method for a salinity concentrator.
In claim 5,
The scale detection method for a salinity concentrator, wherein the solute permeation parameter is obtained from the electric conductivity of the permeated water for detection before and after the change in the water production amount of the main body of the concentrator and the electric conductivity of the permeated water.
In claim 5,
The scale detection of the salinity concentrator characterized in that the solution permeation parameter is obtained from the amount of permeate permeate for detection before and after the change of the amount of water produced in the main body of the concentrator and the supply water pressure of the water to be treated to the main body of the concentrator Method.
In any one of Claims 5 thru | or 7,
The detection pressurizing device that pressurizes the concentrated water branched to the detection concentrating device increases the pressure of the concentrated water by 1/2 to 1/50 of the pressure of the main body pressurizing device. A salinity concentration device scale detection method.