JP6879099B2 - Water treatment system controller - Google Patents

Description

The present invention relates to a control device for a water treatment system including a filtration membrane device.

High-purity pure water containing no impurities is used in cleaning processes of food factories, machine factories, chemical factories, etc. In order to produce this type of pure water, a filtration membrane such as a reverse osmosis membrane (hereinafter, also referred to as “RO membrane”) is used in the water treatment system to obtain salt, heavy metal ions, dissolved silica, and nitrate from the supplied water. It can remove sex nitrogen, bacteria, mutagenic substances, organic chlorine compounds and the like.

In such a water treatment system, when supplying the supplied water to the filtration membrane, the supplied water is pretreated with a chlorine-based disinfectant, and residual chlorine is removed using a chemical such as SBS (sodium bisulfite). May be removed. There is a peculiar pattern of residual chlorine leakage in the removal of the residual chlorine concentration by this chemical.

FIG. 5 shows a water treatment system 20 including an SBS chemical injection device 21, a residual chlorine meter 22 as a chlorine concentration measuring device, an RO device 23, and a storage tank 25, in which a reducing agent is injected from the SBS chemical injection device 5. , The leakage pattern of the residual chlorine when removing the residual chlorine remaining in the raw water is shown. In the graph in FIG. 5, the hump-shaped curve shows the SBS input amount, and the straight line with the thorn-shaped protrusions shows the residual chlorine spike-like leakage, that is, relatively short. A pattern of duration leaks.

Since a diaphragm pump is normally used to input chemicals such as SBS, as shown in FIG. 5, there is pulsation in the input amount of the chemical solution (note that the degree of pulsation depends on the input amount of the chemical solution and the water treatment system. Affected by the construction of). Therefore, if the amount of the chemical solution added is insufficient with respect to the residual chlorine concentration to be removed, the timing at which the residual chlorine concentration increases due to pulsation occurs at predetermined intervals in a spike shape. When the spike-shaped residual chlorine leakage at the monitoring point is small, the supplied water is agitated in the circulation line of the RO device 23, so that the residual chlorine concentration on the RO membrane surface becomes zero, but SBS If the input amount is insufficient and the spike-like residual chlorine leakage exceeds a certain level, the residual chlorine remains even after stirring, which causes deterioration of the RO film.

FIG. 6 is a graph showing how the residual chlorine concentration on the RO film surface and the peak value of spike-shaped residual chlorine leakage change as the amount of SBS input is increased. The residual chlorine concentration on the RO film surface shows two patterns, a pattern (A) and a pattern (B).

In the region where SBS is completely deficient, both the peak value of spike-shaped residual chlorine leakage and the residual chlorine concentration on the RO membrane surface are high, but as the amount of SBS input increases, both values increase. It will decrease. Eventually, as in pattern (A), the pace of decrease in the residual chlorine concentration on the RO film surface slows down, or as in pattern (B), the residual chlorine on the RO film surface becomes zero, and the SBS becomes Although it is not completely deficient, it is an area where spike-shaped residual chlorine leaks occur.

In the conventional monitoring method, the residual chlorine concentration is monitored in the SBS completely deficient region. Even with this method, it is possible to monitor the residual chlorine concentration on the RO film surface, but when it is discovered that the residual chlorine concentration is above a predetermined value, the RO film has already been damaged by chlorine deterioration. , It was often too late.

Filtration membranes containing RO membranes deteriorate in proportion to the product of the exposure concentration of residual chlorine and the exposure time. Therefore, even if the residual chlorine leaks at a low concentration and for a short time, the deterioration of the filtration membrane progresses by being repeated. More specifically, when the degree of leakage of spike-shaped residual chlorine at the monitoring point is small, the supplied water is agitated in the circulation line of the filtration membrane device, so that the residual chlorine on the filtration membrane surface is agitated. The concentration becomes zero, but if the spike-like leakage exceeds a certain limit, residual chlorine remains even if the supplied water is agitated in the circulation line, which causes deterioration of the filtration membrane. From the viewpoint of filtration membrane protection, it is desirable to monitor using an alarm even if the residual chlorine leaks at a low concentration for a short time, but if the judgment conditions are strict, erroneous judgments due to disturbance factors occur frequently, which is not practical.

Conversely, by monitoring this spike-like leakage of residual chlorine, it is possible to detect chlorine leakage due to a malfunction of the chemical injection pump or an increase in the residual chlorine concentration in the raw water before damaging the filtration membrane with chlorine deterioration. It becomes possible.

In this respect, Patent Document 1 is different from the residual chlorine concentration, but when the ORP (oxidation-reduction potential) of the supply water and the integrated value of the ORP measured by the measuring means are each equal to or more than the reference value, the film is deteriorated. Since there is a risk, the operation control device of the water production plant having the ORP diagnostic means for operating the abnormality notification means is disclosed.

Japanese Unexamined Patent Publication No. 8-126882

As described above, it can be said that detecting spike-shaped residual chlorine leakage is useful for the monitored system, but there remains a problem regarding the specific monitoring method. In the following, this problem will be specifically described with reference to FIGS. 7 and 8.

As shown in FIG. 7, a leak that lasts for a certain period of time can be monitored by alarm monitoring of a threshold value × time, but a spike-shaped leak is difficult to distinguish from a false positive and is difficult to monitor by an alarm. ..

FIG. 8 is a graph showing the timing of alarm determination in the conventional monitoring method. Immediately after the start of water supply, the water quality becomes unstable due to factors such as the discharge of stagnant water. Therefore, T1 is not monitored above the water quality for a certain period of time after the start of water supply. Then, when the delay time T2 elapses after the residual chlorine concentration exceeds the threshold value, an alarm is determined. As described above, in the normal monitoring of the residual chlorine concentration, it is common to perform an alarm determination when the residual chlorine concentration continuously exceeds the threshold value.

However, spike-shaped residual chlorine leaks occur intermittently, and the concentration changes drastically. Therefore, it is difficult to monitor spike-shaped leaks by conventional detection and determination methods.

Spike-like residual chlorine leaks occur in sync with the shot of the drug injection pump. The number of shots is usually 300 spm (5 Hz in frequency conversion) for the selected pump, and 360 spm (6 Hz in frequency conversion) depending on the type of pump. As shown in FIG. 9, the leakage interval is about 200 msec at the minimum. When calculating the integrated value of the residual chlorine concentration for use in an alarm, for example, it is necessary to sample the concentration value that fluctuates in a 200 msec cycle at a timing sufficiently finer than the fluctuation cycle and perform the integrated calculation, so 200 msec. An arithmetic circuit that can accurately integrate the sections of is required. If the integration at 20 msec, which is 10 times the cycle, is used, a dedicated microcomputer circuit or a sequencer capable of high-speed processing to some extent is required, and the control panel itself becomes expensive.

In addition, the electrode-type water quality meter cannot respond very quickly, including the replacement speed of the sample water in the cell holder, and has the ability to output an output that accurately traces the true value for spike-like residual chlorine leakage. I can't expect it. Therefore, if the spike-shaped leakage pattern is integrated only by numerical processing, a large error will occur in the integrated value as shown in FIG.

Therefore, an object of the present invention is to accurately monitor chlorine leakage to the filtration membrane device with a relatively simple circuit.

The present invention includes a filter membrane device, a water supply line for supplying supply water to the filter membrane device, a chemical injection device for injecting a drug for removing chlorine into the supply water flowing through the water supply line, and the chemical injection device. A control device for a water treatment system including a chlorine concentration measuring device for measuring the chlorine concentration of the supplied water between the filter membrane device and the filter membrane device, wherein the chlorine concentration measured by the chlorine concentration measuring device is the first. When the number-of-times measuring unit that measures the number of times the threshold is exceeded in a spike shape and the number of times that the number-of-times measuring unit measures within a predetermined time exceeds the first set number of times, an abnormality of the water treatment system is determined. The present invention relates to a control device including an abnormality determination unit.

Further, the drug injection device control unit for controlling the drug injection device is further provided, and when the abnormality determination unit determines an abnormality because the number of times exceeds the first set number of times, the drug injection device control unit is provided. Preferably control the grout so as to increase the amount of drug injected by the grout.

Further, the drug injection device control unit for controlling the drug injection device is further provided, and when the abnormality determination unit determines an abnormality because the number of times exceeds the first set number of times, the drug injection device control unit is provided. It is preferable to control the drug injecting device so as to increase the number of times the drug injecting device injects a predetermined amount of the drug within a predetermined time.

Further, the abnormality determination unit determines an abnormality when the number of times is less than the second set number of times, which is less than the first set number of times, and the number of times is lower than the second set number of times. Therefore, when the abnormality determination unit determines an abnormality, it is preferable that the drug injection device control unit controls the drug injection device so as to reduce the amount of the drug injected by the drug injection device.

Further, the abnormality determination unit determines an abnormality when the number of times is less than the second set number of times, which is less than the first set number of times, and the number of times is lower than the second set number of times. Therefore, when the abnormality determination unit determines an abnormality, the drug injection device control unit reduces the number of times the drug injection device injects a predetermined amount of the drug within a predetermined time. It is preferable to control.

Further, it is preferable to further include an alarm unit that issues an alarm when the number of times exceeds the third set number of times, which is larger than the first set number of times.

Further, it is preferable that the number-of-times measuring unit stops the measurement of the number of times for a predetermined time from the start of supplying water to the water treatment system and / or the change of the operating conditions of the water treatment system.

According to the present invention, it is possible to provide a control device that accurately monitors chlorine leakage to the filtration membrane device with a relatively simple circuit.

It is an overall block diagram of the water treatment system provided with the control device which concerns on embodiment of this invention. It is a functional block diagram of the control device which concerns on embodiment of this invention. It is a figure which shows the outline of this invention. It is a figure which shows the operation flow of the control device which concerns on embodiment of this invention. It is explanatory drawing about the problem of the prior art. It is explanatory drawing about the problem of the prior art. It is explanatory drawing about the problem of the prior art. It is explanatory drawing about the problem of the prior art. It is explanatory drawing about the problem of the prior art. It is explanatory drawing about the problem of the prior art.

[Construction of the invention]
First, the overall configuration of the water treatment system including the control device according to the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is an overall configuration diagram of a water treatment system 1 including a control device 100 according to the present invention.

As shown in FIG. 1, the water treatment system 1 includes a chemical injection device 5, a chlorine concentration measuring device 6, a pressurizing pump 8, an inverter 9, an RO module 11 as a filtration membrane device, and a constant flow valve 12. A drain valve 17, a flow sensor FM, and a control device 100 are provided. The illustration of the electrical connection line between the control device 100 and the device to be controlled is omitted.

The water treatment system 1 includes a supply water line L1, a permeated water line L2, a concentrated water line L3, a circulating water line L4, and a concentrated drainage line L5 as lines. "Line" is a general term for lines through which fluid can flow, such as channels, paths, and pipelines. Further, regardless of the origin (source) and the water quality thereof, the water circulating in the supply water line L1, the concentrated water line L3 or the circulating water line L4 is also referred to as "supply water", and the concentrated water line L3 and the circulating water line L4. Alternatively, the water flowing through the concentrated drainage line L5 is also referred to as "concentrated water".

The supply water line L1 is a line for supplying supply waters W11 to W12 toward the RO module 11. The supply water line L1 has a first supply water line L11 and a second supply water line L12 from the upstream side to the downstream side.

The upstream end of the first supply water line L11 is connected to the water source 2 of the supply water W11. The downstream end of the first supply water line L11 is connected to the second supply water line L12 and the circulating water line L4 at the connection portion J1. The first supply water line L11 is provided with a chemical injection device 5 and a chlorine concentration measuring device in this order from the upstream side to the downstream side.

The chemical injection device 5 is a device that injects a reducing agent into a line through which one or more supply water of the supply water line L1, the concentrated water line L3, and the circulating water line L4 flows. In the present embodiment, the chemical injection device 5 is a device for injecting a reducing agent into the supply water W11 flowing through the supply water line L1 (first supply water line L11). The chemical injection device 5 is electrically connected to the control device 100.

In the present embodiment, the chemical injection device 5 intermittently injects a reducing agent in order to remove residual chlorine in the supply water W11. Examples of the reducing agent include SBS and the like.

The chlorine concentration measuring device 6 measures the concentration of residual chlorine remaining in the supply water W11 flowing through the supply water line L1. The chlorine concentration measuring device 6 is electrically connected to the control device 100, and the measured residual chlorine concentration is transmitted to the control device 100.

The upstream end of the second supply water line L12 is connected to the connecting portion J1. The downstream end of the second supply water line L12 is connected to the primary inlet port of the RO module 11. A pressurizing pump 8 is provided in the second supply water line L12.

The pressurizing pump 8 is a device that sucks the supply water W12 and pumps (discharges) it toward the RO module 11. The pressurizing pump 8 is supplied with driving power whose frequency has been converted from the inverter 9. The pressurizing pump 8 is driven at a rotation speed corresponding to the frequency of the supplied (input) driving power (hereinafter, also referred to as “driving frequency”).

The inverter 9 is an electric circuit (or a device having the circuit) that supplies the pressurizing pump 8 with driving power whose frequency has been converted. The inverter 9 is electrically connected to the control device 100. A command signal is input to the inverter 9 from the control device 100. The inverter 9 outputs the drive power of the drive frequency corresponding to the command signal (current value signal or voltage value signal) input by the control device 100 to the pressurizing pump 8.

The supply water W12 is supplied to the RO module 11 via the pressurizing pump 8. Further, the supply water W12 includes supply water W11 and circulating water W40 (described later).

The RO module 11 is a facility that separates the supply water W12 into the permeated water W20 and the concentrated water W30. Specifically, the RO module 11 is a facility that separates the supply water W12 discharged from the pressurizing pump 8 into permeated water W20 from which dissolved salts have been removed and concentrated water W30 from which dissolved salts have been concentrated. is there. The RO module 11 includes a single or multiple reverse osmosis membrane elements (not shown). The RO module 11 membrane-separates the supply water W12 by these reverse osmosis membrane elements to produce the permeated water W20 and the concentrated water W30.

The permeated water line L2 is a line that sends out the permeated water W20 separated by the RO module 11. The upstream end of the permeated water line L2 is connected to the secondary port of the RO module 11. The downstream end of the permeated water line L2 is connected to a storage tank (not shown). A flow rate sensor FM is provided on the permeated water line L2.

The flow rate sensor FM is a device that detects the flow rate of the permeated water W20 flowing through the permeated water line L2. The flow rate sensor FM is electrically connected to the control device 100. The flow rate of the permeated water W20 detected by the flow rate sensor FM (hereinafter, also referred to as “detected flow rate value”) is transmitted to the control device 100 as a pulse signal.

The concentrated water line L3 is a line through which the concentrated water W30 separated by the RO module 11 flows. The upstream end of the concentrated water line L3 is connected to the primary exit port of the RO module 11. Further, the downstream side of the concentrated water line L3 is branched into a circulating water line L4 and a concentrated drainage line L5 at the connection portion J2.

The circulating water line L4 is a line connected to the concentrated water line L3 and returns the concentrated water (circulating water W40) as the supply water to the supply water line L1. In the present embodiment, the circulating water line L4 uses the concentrated water W30 flowing through the concentrated water line L3 as the circulating water W40 on the upstream side of the pressurizing pump 8 in the supply water line L1 and more than the chlorine concentration measuring device 6. It is a line that returns (circulates) to the downstream side. The upstream end of the circulating water line L4 is connected to the concentrated water line L3 at the connecting portion J2. Further, the downstream end of the circulating water line L4 is connected to the supply water line L1 at the connecting portion J1. The circulating water line L4 is provided with a constant flow valve 12.

The constant flow valve 12 adjusts the flow rate of the circulating water W40 flowing through the circulating water line L4 so as to be maintained at a predetermined constant flow rate value. The "constant flow rate value" held by the constant flow rate valve 12 is a concept in which the constant flow rate value has a range, and is not limited to only the target flow rate value of the constant flow rate valve 12. For example, in consideration of the characteristics of the constant flow rate mechanism (for example, temperature characteristics due to the material and structure), those having an adjustment error of about ± 10% with respect to the target flow rate value in the constant flow rate valve 12 are included. The constant flow rate valve 12 maintains a constant flow rate value without requiring auxiliary power or external operation, and examples thereof include those called by the name of water governor. The constant flow rate valve 12 may be operated by auxiliary power or an external operation to maintain a constant flow rate value.

The concentrated drainage line L5 is a line connected to the concentrated water line L3 and discharges the concentrated water as the concentrated drainage W50 to the outside of the system. In the present embodiment, the concentrated drainage line L5 is connected to the concentrated water line L3 at the connection portion J2, and the concentrated water W30 separated by the RO module 11 is discharged to the outside of the device (outside the system) as the concentrated drainage W50. Is.

The drain valve 17 is a valve that regulates the flow rate of the concentrated drainage W50 discharged from the concentrated drainage line L5 to the outside of the device. The drain valve 17 is electrically connected to the control device 100. The valve opening degree of the drain valve 17 is controlled by a drive signal transmitted from the control device 100. The drainage flow rate of the concentrated drainage W50 can be adjusted by transmitting a current value signal (for example, 4 to 20 mA) from the control device 100 to the drainage valve 17 and controlling the valve opening degree.

The control device 100 includes a CPU, a ROM, a RAM, a CMOS memory, and the like, and these are known to those skilled in the art, which are configured to be able to communicate with each other via a bus.

The CPU is a processor that controls the water treatment system 1 as a whole. The CPU reads various programs stored in the ROM via a bus and controls the entire water treatment system 1 according to the various programs, so that the control device 100 counts the number of times as shown in the functional block diagram of FIG. It is configured to realize the functions of the measurement unit 101, the abnormality determination unit 102, the drug injection device control unit 103, and the alarm unit 104. Various data such as temporary calculation data and display data are stored in the RAM. The CMOS memory is backed up by a battery (not shown), and is configured as a non-volatile memory whose storage state is maintained even when the power of the water treatment system 1 is turned off.

The number-of-times measuring unit 101 measures the number of times that the chlorine concentration measured by the chlorine concentration measuring device 6 exceeds a predetermined threshold value in a spike shape in a predetermined period. Specifically, as shown in FIG. 3, during the operation of the RO module 11, the chlorine concentration measured by the chlorine concentration measuring device 6 exceeds the threshold value in a spike shape, that is, the duration is shorter than a predetermined time. In time, measure the number of times the threshold is exceeded. It should be noted that the water quality becomes unstable due to factors such as the discharge of stagnant water for a predetermined time from the start of supply of the water supplied to the water treatment system 1 and / or the change of the operating conditions of the water treatment system 1, and the water treatment system 1 operates normally. Even if it is made, residual chlorine leakage may occur. Therefore, the number-of-times measuring unit 101 does not have to count the number of times the threshold value is exceeded in a spike shape in this predetermined time.

The abnormality determination unit 102 compares the number of times measured by the number measurement unit 101 with a preset number of times, and determines an abnormality of the water treatment system 1 based on the comparison result. More specifically, the abnormality determination unit 102 determines the abnormality of the water treatment system 1 when the number of times measured by the number measurement unit 101 exceeds the first set number of times. On the other hand, even when the number of times measured by the number-of-times measuring unit 101 is lower than the second set number of times, which is lower than the first set number of times, the abnormality of the water treatment system 1 is determined.

The drug injection device control unit 103 controls the drug injection device 5 to increase or decrease the amount of the reducing agent injected by the drug injection device 5.
More specifically, when the number of times measured by the abnormality determination unit 102 exceeds the first set number of times described above, the number of times the chemical injection device 5 injects the drug into the supply water W11 is a predetermined number of times. The drug injection device control unit 103 controls the drug injection device 5 so as to increase the amount of the drug to be injected. Alternatively, the drug injection device control unit 103 may control the drug injection device 5 so that the drug injection device 5 increases the number of times a predetermined amount of the drug is injected into the supply water W11.
On the other hand, when the number of times measured by the abnormality determination unit 102 is less than the above-mentioned second set number of times, the drug injection device 5 injects the drug into the supply water W11 with the predetermined number of times. The drug injection device control unit 103 controls the drug injection device 5 so as to reduce the amount of the drug. Alternatively, the drug injection device control unit 103 may control the drug injection device 5 so that the number of times the drug injection device 5 injects a predetermined amount of the drug into the supply water W11 is reduced.

The alarm unit 104 issues an alarm when the number of times measured by the number-of-times measuring unit 101 exceeds the third set number of times, which is higher than the first set number of times.

Subsequently, the operation of the control device 100 according to the embodiment of the present invention will be described with reference to the flowchart of FIG. FIG. 4 is a flowchart showing an operation example of the control device 100 according to the embodiment of the present invention. Although the above is repeated, in the following description, the magnitude relationship between the first setting number, the second setting number, and the third setting number is "second setting number <first setting number <first. It becomes "the number of times of setting of 3."

In step S1, the number of times measuring unit 101 measures the number of times that the residual chlorine concentration of the supplied water W11 exceeds the first threshold value in a spike shape in a predetermined period.

In step S2, when the number of measurements is equal to or less than the first set number (S2: YES), the process proceeds to step S3. When the number of measurements exceeds the first set number (S2: NO), the process proceeds to step S4.

In step S3, when the number of measurements is equal to or greater than the second set number (S3: YES), the process returns to step S1 (return). If the number of measurements is less than the second set number (S3: NO), the process proceeds to step S5.

In step S4, when the number of measurements is equal to or less than the third set number (S4: YES), the process proceeds to step S6. When the number of measurements exceeds the third set number (S4: NO), the process proceeds to step S7.

In step S5, the drug injection device control unit 103 controls the drug injection device 5 so that the number of times the drug injection device 5 injects the drug into the supplied water W11 remains a predetermined number and the amount of the drug to be injected is reduced. .. Alternatively, the drug injection device control unit 103 may control the drug injection device 5 so that the number of times the drug injection device 5 injects a predetermined amount of the drug into the supply water W11 is reduced. After that, the process returns to step S1 (return).

In step S6, the drug injection device control unit 103 controls the drug injection device 5 so that the number of times the drug injection device 5 injects the drug into the supplied water W11 remains a predetermined number and the amount of the injected drug is increased. .. Alternatively, the drug injection device control unit 103 may control the drug injection device 5 so that the drug injection device 5 increases the number of times a predetermined amount of the drug is injected into the supply water W11. After that, the process returns to step S1 (return).

In step S7 as well, similarly to step S6, the drug injection device control unit 103 controls the drug injection device 5 so that the drug injection device 5 increases the amount of the drug to be injected into the supply water W11. Alternatively, the drug injection device control unit 103 may control the drug injection device 5 so that the drug injection device 5 increases the number of times a predetermined amount of the drug is injected into the supply water W11.

In step S8, the alarm unit 104 issues an alarm. After that, the process returns to step S1 (return).

[Effect of Embodiment]
According to the control device 100 described above, for example, the following effects are achieved.
The control device 100 of the present invention measures the number of times the chlorine concentration measured by the chlorine concentration measuring device 6 exceeds the first threshold value in a spike shape, and the number of times measuring unit 101 measures within a predetermined time. It is provided with an abnormality determination unit 102 that determines an abnormality of the water treatment system 1 when the number of times exceeds the first set number of times.

Therefore, instead of calculating the integrated value at which the chlorine concentration exceeds the threshold value, by measuring the number of times the chlorine concentration exceeds the threshold value, chlorine leakage to the filtration membrane device is reliably monitored more easily than the normal integration method. be able to.

Further, when the abnormality determination unit 102 determines an abnormality because the number of measurements by the number measurement unit 101 exceeds the first set number, the drug injection device control unit 103 determines the amount of the drug to be injected by the drug injection device 5. The drug injection device 5 is controlled so as to increase.

Therefore, when the amount of residual chlorine in the water supplied to the RO module 11 is large, the RO membrane can be protected by increasing the amount of the drug injected by the chemical injection device 5 and reducing the amount of residual chlorine. Become.

Further, when the abnormality determination unit 102 determines an abnormality because the number of measurements by the number measurement unit 101 exceeds the first set number of times, the drug injection device control unit 103 has the drug injection device 5 in place within a predetermined time. The infusion device 5 is controlled to increase the number of infusions of a fixed amount of drug.

Therefore, when the amount of residual chlorine in the water supply W11 to the RO module 11 is large, the RO membrane is protected by increasing the number of times the chemical injection device 5 injects a predetermined amount of the drug and reducing the amount of residual chlorine. Is possible.

Further, since the number of times of measurement by the number-of-times measuring unit 101 is lower than the second set number of times, when the abnormality determination unit 102 determines an abnormality, the drug injection device control unit 103 uses the drug injection device 5 to inject the drug. The infusion device 5 is controlled to reduce the amount.

Further, since the number of measurements by the number-of-times measuring unit 101 is lower than the second set number of times, when the abnormality determination unit 102 determines an abnormality, the drug-injection device control unit 103 causes the drug-injection device 5 to perform the drug-injection device 5 within a predetermined time. The drug injection device 5 is controlled so as to reduce the number of times a predetermined amount of the drug is injected.

Therefore, when the drug is excessively injected into the supply water W11 supplied to the RO module 11, the injection amount of the drug can be reduced.

Further, when the number of times measured by the number-of-times measuring unit 101 exceeds the third set number of times, which is larger than the first set number of times, the alarm unit 104 issues an alarm.

Therefore, when the residual chlorine in the water supplied to the RO module 11 is considerably large, issuing an alarm to the administrator of the water treatment system 1 may cause a malfunction of the chemical injection pump or deterioration of the chemical solution. Can be informed about.

Further, the number-of-times measuring unit 101 stops the measurement of the number of times for a predetermined time from the start of supplying the water supplied to the water treatment system 1 and / or the change of the operating conditions of the water treatment system 1.

During a predetermined time from the start of operation of the water treatment system 1 and / or the change of operating conditions, the chemical injection is unstable, and even if the water treatment system 1 can be operated normally, residual chlorine leakage may occur. is there. By masking that period, it becomes possible to monitor the leakage of residual chlorine only during steady operation.

[Modification example]
Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be implemented in various forms.

For example, in the above embodiment, the embodiment in which the RO module 11 is used as the filter device for the supplied water in the water treatment system 1 has been described, but the present invention is not limited thereto. For example, the above control device 100 is applied to a water treatment system including a filtration device using a membrane other than the RO membrane such as a UF membrane, and further a filtration device using a filter medium such as an ion exchange resin. It is also possible to do.

1 Water treatment system 2 Water source 5 Chemical injection device 6 Chlorine concentration measuring device 8 Pressurized pump 9 Inverter 11 RO module 12 Constant flow valve 17 Drain valve 20 Water treatment system 21 SBS chemical injection device 22 Residual chlorine meter 23 RO device 25 Storage tank 100 Control device 101 Counting unit 102 Abnormality determination unit 103 Drug injection device control unit 104 Alarm unit

Claims (7)

A filtration membrane device, a water supply line for supplying supply water to the filtration membrane device, a chemical injection device for injecting a drug for removing chlorine into the supply water flowing through the water supply line, the chemical injection device and the filtration membrane. A control device for a water treatment system including a chlorine concentration measuring device for measuring the chlorine concentration of the supplied water between the device and the device.
A number measurement unit that measures the number of times the chlorine concentration measured by the chlorine concentration measuring device exceeds the first threshold value in a spike shape, and
An abnormality determination unit that determines an abnormality in the water treatment system when the number of times measured by the number measurement unit within a predetermined time exceeds the first set number of times.
A control device comprising. Further provided with a drug injection device control unit for controlling the drug injection device,
When the abnormality determination unit determines an abnormality because the number of times exceeds the first set number of times, the drug injection device control unit increases the amount of the drug injected by the drug injection device. The control device according to claim 1, which controls the drug injection device. Further provided with a drug injection device control unit for controlling the drug injection device,
When the abnormality determination unit determines an abnormality because the number of times exceeds the first set number of times, the drug injection device control unit injects a predetermined amount of the drug within a predetermined time. The control device according to claim 1, wherein the drug injection device is controlled so as to increase the number of times. The abnormality determination unit determines an abnormality when the number of times is less than the second set number of times, which is less than the first set number of times.
Since the number of times is lower than the second set number of times, when the abnormality determination unit determines an abnormality, the drug injection device control unit reduces the amount of the drug injected by the drug injection device. The control device according to claim 2 or 3, which controls the drug injection device. The abnormality determination unit determines an abnormality when the number of times is less than the second set number of times, which is less than the first set number of times.
Since the number of times is lower than the second set number of times, when the abnormality determination unit determines an abnormality, the drug injection device control unit injects a predetermined amount of the drug within a predetermined time. The control device according to claim 2 or 3, which controls the drug injection device so as to reduce the number of times of squeezing. The control device according to any one of claims 1 to 5, further comprising an alarm unit that issues an alarm when the number of times exceeds the third set number of times, which is larger than the first set number of times. .. Any one of claims 1 to 6, wherein the number-of-times measuring unit stops the measurement of the number of times for a predetermined time from the start of supplying water to the water treatment system and / or the change of the operating conditions of the water treatment system. The control device according to item 1.

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