JPS63305907A - Monitor for clogging of filter medium of filter - Google Patents

Abstract

PURPOSE:To wash a filter medium at a proper starting point of washing by alarming the start of washing of the filter medium on the basis of the degree of clogging thereof which is calculated from turbidity and the flow rate of waste liquid in the inlet side of a filter. CONSTITUTION:The differential pressure of waste liquid in an outlet pipe 6 and an inlet pipe 5 is detected with a differential pressure detector 20 and turbidity of waste liquid passed through the inlet pipe 5 is detected with a turbidity detector 21 and its flow rate is detected with a rate detector 22 and furthermore the degree of clogging of a filter medium 4 is calculated with an arithmetic unit 23 on the basis of the detection signal of turbidity and the detection signal of the flow rate. The start of washing of the filter medium 4 is alarmed so that the filter medium 4 can be washing at the proper starting point of washing by utilizing a decision device 24, an alarm device 25 for starting washing, an alarming buzzer 25a, a memory 27, a counter 28 and the differential pressure detector 20, etc., on the basis of this degree of clogging. As a result, the number of washing and the effluent amount of waste water of washing in the case of washing the filter medium 4 are reduced and also the operating efficiency of a filter 1 can be enhanced.

Description

Detailed Description of the Invention (Objective of the Invention) (Industrial Application Field) The present invention relates to a filter clogging monitoring device for a filtration device that filters waste liquid such as radioactive waste liquid, and in particular, to The present invention relates to a filter clogging monitoring device for a filtration device that detects cleaning time.

(Prior Art) Conventionally, a filter clogging monitoring device for this type of filtration device is configured as shown in FIG. A filter 4 made of a thread membrane or the like is suspended in a substantially U-shape, and the waste liquid flowing in the direction of the solid arrow in the figure is filtered by the filter 4.

An inlet pipe 5 is connected to the waste liquid inlet in the lower part of the filter case 2, and an outlet pipe 6 is connected to the waste liquid outlet in the upper part of the filter case 2. A differential pressure detector 9 is interposed in the middle of the instrumentation pipe 7 .

The differential pressure detector 9 detects the differential pressure of the waste liquid flowing through the inlet pipe 5 and the outlet pipe 6 of the filtration device 1, and sends the differential pressure detection signal to the indicator 10 and the alarm determiner 11. They are designed to give each.

The indicator 10 is configured to compare the differential pressure detection signal from the differential pressure detector 9 with the differential pressure upper limit set value of the filter 4 and indicate the deviation.

On the other hand, the alarm judgment device 11 compares the differential pressure detection signal from the differential pressure detector 9 with the cleaning start setting value, and when the difference j■ detection signal exceeds the cleaning start setting value, sounds the buzzer 12 and starts cleaning. Alert start request.

Upon hearing this cleaning start alarm, the operator closes the large mouth valve 8 to backwash the filter 4 of the filtration device 1, stops the flow of waste liquid into the filter case 2, listens to the drain valve 13, and closes the large mouth valve 8 to backwash the filter 4 of the filtration device 1. Washing water shown by the broken line in the figure is supplied from the pipe 6 into the filter case 2, and the filter 4 is backwashed to remove foreign matter 14 such as dust attached to the filter 4.
The washing wastewater containing 4 is received by the receiving tank 15 and stored.

Figure 4 shows the filter case 2 before and after cleaning the filter 4.
2 is a graph showing fluctuations in the differential pressure ΔP of waste liquid between the inlet side and the outlet side, with the vertical axis representing the differential pressure ΔP and the horizontal axis representing the time t.

As shown in FIG. 4, immediately after the differential pressure ΔP reaches the cleaning start set value 16 and the filter 4 is cleaned, the differential pressure ΔP reaches the point 17.
However, the cleaning is not complete and some clogging remains, so the differential pressure ΔP does not decrease to the initial level before cleaning, and from then on, the differential pressure ΔP immediately after cleaning increases as the number of cleaning increases. Then, the pressure difference ΔP gradually becomes higher than the pressure difference ΔP before cleaning.

For this reason, the time from immediately after cleaning the filter 4 until the differential pressure ΔP reaches the cleaning start set value 16 again becomes shorter as the number of cleanings increases, and the cleaning interval also gradually becomes shorter. Eventually, the life of the filter 4 will come to an end.

Therefore, in the latter half of the life of the filter 4, the number of times the filter 4 is washed increases compared to the first half of its life, but the time required for waste liquid filtration by the filter 4 is shortened, and the amount of cleaning waste water discharged after cleaning the filter 4 increases. .

(Problems to be solved by the invention) As mentioned above, conventional filtration'! The filter clogging monitoring device between i1 detects the cleaning start point of the filter 4 based on the differential pressure ΔP before and after the filter 4, and the cleaning start point is fixed. In the later stages of the life of the filter 4, the number of times of washing increases, the amount of washing waste water used to wash the filter 4 increases, the operating time of the filter 1 becomes shorter, and the operating efficiency of the filter 1 decreases.

In addition, in the filter clogging monitoring device of a conventional filtration device, although cleaning of the filter 4 is not originally necessary, due to a change in the flow rate of waste liquid introduced into the filter case 2, the differential pressure Δ
There is a problem in that P increases transiently and an alarm is issued to request the start of cleaning.

The present invention has been made in consideration of such circumstances, and its purpose is to provide a filter clogging monitoring device for a filtration device that can reduce cleaning wastewater and detect and issue an alarm on cleaning effectiveness.

[Structure of the invention]

(Means for Solving the Problems) That is, the present invention provides a differential pressure detector that detects the pressure difference of the waste liquid flowing between the waste liquid inlet side and the waste liquid outlet side of a filtration device equipped with a filter for filtering the waste liquid, and the above-mentioned A turbidity detector detects the turbidity of the waste liquid on the waste liquid inlet side, a flow rate detector detects the waste liquid flow rate on the waste liquid inlet side, and each detection signal from this flow rate detector and the turbidity detector is used to detect the filter. A magnifier that calculates the degree of clogging and a p-signal from this magnifier is compared with a cleaning start set value, and when this calculated signal exceeds the cleaning start set value, a determination is made to output a cleaning start command signal. a memory for reading and storing the differential pressure detection signal from the differential pressure detector upon receiving the cleaning start command signal from the determination device, and a memory for reading and storing the differential pressure detection signal from the differential pressure detector after cleaning the filter. At the same time, the differential pressure detection signal before filter cleaning is read from the memory, and when the rate of decrease in the differential pressure after cleaning the filter calculated from both read values falls below the differential pressure decrease rate setting value, a cleaning failure signal is generated. a differential pressure reduction rate determiner that outputs, and a counter that outputs a cleaning failure signal when it is detected that the output interval of the cleaning start command signal from the determiner is shorter than the output-to-output M setting value;
A cleaning start alarm device that alerts you to a request to start cleaning the filter when it receives a cleaning start command signal from the above determination device, and a cleaning start alarm device that alerts you to a request to start cleaning the filter when it receives a cleaning start command signal from the above judgment device, and a cleaning start alarm device that starts cleaning the filter when each of the cleaning failure signals is received from the differential pressure drop judgment device and the counter. It is characterized in that it has respective cleaning failure alarm devices that each warn of failures.

(Function) During operation of the filtration device, the turbidity of the waste liquid flowing through the waste liquid inlet side is detected by the turbidity detector, the flow rate of the waste liquid is detected by the flow rate detector, and the differential pressure of the waste liquid before and after the filter is detected by the turbidity detector. Detected by a pressure detector.

The turbidity detection signal from the turbidity detector and the flow rate detection value from the flow rate detector are given to a calculator, where the degree of clogging of the filter is calculated.

This degree of clogging is determined by calculating a required coefficient by multiplying the turbidity detection signal of the waste liquid by the flow rate detection signal of the waste liquid, and this coefficient corresponds to the degree of clogging of the filter obtained from experimental data. It is calculated by comparing the coefficient of waste liquid turbidity and flow rate.Furthermore, this degree of clogging is compared with the cleaning start setting value in a judgment device, and when this degree of clogging exceeds the set value, A cleaning start command signal is output.

This cleaning start command signal is given to the cleaning start alarm,
A cleaning start request is notified.

Upon hearing this cleaning start request alarm, the operator stops the filtration operation of the filtration device and performs a filter cleaning operation.

After the filter cleaning operation is completed, the filtration device restarts the filtration operation.

For this purpose, a pressure difference is generated between the waste liquid before and after the filter, this pressure difference is detected by a pressure difference detector, and the detected value of the pressure difference detector is read into a differential pressure reduction rate determiner.

In addition, the differential pressure reduction rate determiner reads the detected differential pressure value before cleaning from the memory, calculates the differential pressure decrease rate after cleaning with respect to the detected differential pressure value after cleaning, and this rate of decrease is lower than the set value. In some cases, a cleaning failure signal is output, and one of the cleaning failure alarms is activated to warn that cleaning is insufficient.

Furthermore, when the output interval of the cleaning start command signal outputted from the judgment device is shorter than the set value, a cleaning failure signal is output from the counter = 8-, and the cleaning failure alarm is activated to activate the cleaning failure alarm. Alerts you that cleaning is insufficient.

Therefore, according to the present invention, it is possible to wash the filter at an appropriate washing starting point, and it is possible to reduce the number of times of washing and to reduce the washing waste water used to wash the filter.
It is possible to improve the operating efficiency of the filtration device.

(Example) Hereinafter, an example of the present invention will be described based on FIGS. 1 and 2.

FIG. 1 is an overall configuration diagram of an embodiment of the present invention. In the figure, the filtration device 1 is constructed in the same manner as the conventional example shown in FIG. The same reference numerals are given to the corresponding parts.

A differential pressure detector 20 that detects the differential pressure between the inlet side and the outlet side of the filter case 2 is interposed in the middle of the instrumentation piping 7 of the filtration device 1, and a differential pressure detector 20 is interposed in the inlet pipe 5 on the upstream side of the large mouth valve 8. A turbidity detector 21 that detects the turbidity of waste liquid and a flow rate detector 22 that detects the flow rate of waste liquid are connected in parallel, and these turbidity detector 21 and flow rate detector 22 are connected in parallel. It is connected to a determining device 24 via a device 23 .

The calculator 23 calculates a required coefficient by, for example, multiplying the detected turbidity value of the waste liquid received from the turbidity detector 21 and the detected flow rate value of the waste liquid received from the flow rate detector 22, and calculates the required coefficient. , the degree of clogging of the filter 4 is calculated by comparing the coefficient between the waste liquid turbidity and the flow rate corresponding to the degree of clogging of the filter 4 obtained from the experimental data, and this degree of clogging is further determined by a determination device. 24, the degree of clogging is compared with the cleaning start setting value, and when the degree of clogging exceeds the cleaning start setting value, the judgment device 24
A cleaning start command signal S24 is output from.

The output side of the determiner 24 is connected to an inlet end of an external output processing circuit 26 to which a cleaning start alarm 25 is connected, a memory 27, and a counter 28, respectively.

The input side of the memory 27 is also connected to the output side of the differential pressure detector 20, and when it receives the cleaning start command signal 324 from the determiner 24, it starts cleaning based on the differential pressure detection value detected by the differential pressure detector 20. The output side of this memory 27 is connected to a differential pressure reduction rate detection circuit 29. The differential pressure is read and stored as the previous differential pressure.

The differential pressure reduction rate determiner 29 uses the differential pressure detector 2 to determine the differential pressure across the filter 4 that occurs when the filtration device 1 restarts operation after cleaning the filter 4 as a detected differential pressure value after cleaning the filter 4.
At the same time, the differential pressure detection value accumulated in the memory 27 is read as the differential pressure before cleaning, and these two read values, that is, the differential pressure before cleaning and the differential pressure after cleaning, are compared to determine the differential pressure before cleaning. The rate of decrease in differential pressure after cleaning is calculated with respect to the differential pressure of The signal is supplied to a poor cleaning lamp circuit 30, and the poor cleaning lamp 30a is turned on to warn of a poor cleaning of the filter 4.

In other words, if the filter 4 is cleaned, the differential pressure before and after the filter 4 will be lower than before cleaning, so the fact that the rate of decrease in the differential pressure before cleaning the filter 4 is lower than the differential pressure decrease rate setting value is due to the fact that the filter 4 is Indicates insufficient cleaning.

Further, the counter 28 receives all the cleaning start command signals S24 from the determiner 24 and counts the output interval of these plural cleaning start command signals S24, and this output interval is shorter than the output interval of the set value. When the cleaning failure signal S28 is amplified by the external output processing circuit 26, it is applied to the second cleaning failure lamp circuit 31, and the cleaning failure lamp 31a is turned on to issue an alarm.

That is, if the cleaning of the filter 4 is insufficient, the determination device 2
Since the output interval of the cleaning start command signal S24 outputted from 4 becomes gradually shorter, when the output interval becomes lower than the set value, a warning of poor cleaning is output.

Next, the operation of this embodiment will be explained.

When the inlet valve 8 of the filtration device 1 is closed and the waste liquid is introduced into the filter case 2 through the inlet pipe 5, the waste liquid passes through the filter 4.
It is filtered by the filter and flows out from the outlet pipe 6.

The differential pressure of the waste liquid between the outlet pipe 6 and the inlet pipe 5 is determined by the differential pressure detector 2.
0, the turbidity of the waste liquid passing through the inlet pipe 5 is detected by the turbidity detector 21, and the flow rate is detected by the flow rate detector 2.
2, and these turbidity detection signal and flow rate detection signal are given to a computing unit 23.

The calculator 23 calculates the 1 mark of clogging of the filter 4 based on the turbidity detection signal and the flow rate detection signal. This degree of clogging is compared with a cleaning start set value by the determiner 24, and when the set value is exceeded, a cleaning start command signal S24 is outputted from the determiner 24.

After the cleaning start command signal S24 is amplified by the external output processing circuit 26, it is given to the cleaning start alarm 25, which causes the alarm buzzer 25a to sound, thereby warning that the cleaning of the filter 4 is requested to start.

Further, the cleaning start command signal S24 is given to the memory 27 and the counter 28, and upon receiving the cleaning start command signal S24, the memory 27 receives the differential pressure detection value at that time from the differential pressure detector 20. Read and accumulate as differential pressure.

On the other hand, the counter 28 receives all the cleaning start command signals and counts the output interval of each cleaning start command signal.

Then, the operator hears the sound of the alarm buzzer 25a of the cleaning start alarm 25, and in order to clean the filter 4,
At the same time as closing the inlet valve 8, the drain valve 13 is opened, the cleaning water is introduced into the filter case 2 through the outlet pipe 6, the cleaning water is caused to flow back through the filter 4 for backwashing, and the cleaning waste water after cleaning is opened. The water is drained into the tank 15 by being guided by the drain valve 13 located in the tank 15.

After the cleaning of the filter 4 is completed, the drain valve 13 is closed, the large mouth valve 8 is opened, the supply of cleaning water to the filter case 2 is stopped, and the waste liquid is introduced into the filter case 2 again.
Restart operation of filtration device 1.

For this reason, a differential pressure is generated again in the waste liquid flowing between the inlet pipe 5 and the outlet pipe 6, and this differential pressure is detected by the differential pressure detector 20, and the differential pressure decrease rate is detected as the differential pressure immediately after cleaning. It is given to the determiner 29.

For this purpose, the differential pressure reduction rate determiner 29 reads -1, that is, the detected differential pressure value before cleaning, from the memory 27 when the cleaning start command signal S24 is output, and compares this with the detected differential pressure value after cleaning. However, when the differential pressure decrease rate is calculated and the calculated value is lower than the differential pressure decrease rate set value, a cleaning failure signal S29 is generated.
is applied to the first failed cleaning lamp circuit 30 via the external output processing circuit 30 to light up the failed cleaning lamp 30a,
Alerts about poor cleaning.

In addition, the counter 28 that receives all the cleaning start command signals S24 from the determiner 24 is configured to receive all of the cleaning start command signals S24.
, and when the output interval becomes shorter than a required setting value, the cleaning failure signal S28 is sent to the second cleaning failure lamp circuit 31 via the external output processing circuit 30.
to turn on the poor cleaning lamp 31a to warn of poor cleaning.

In this embodiment, as described above, the cleaning start alarm ¥3S24 is output based on the degree of clogging of the filter 4, so as shown in FIG. Cleaning starting point A1゜A2. A3. A4 is the differential pressure point B1 immediately after cleaning. B2° increases as B3 increases, and varies compared to the conventional cleaning starting point 16 (see FIG. 4) which is constant.

Therefore, it is possible to prevent the number of washings from increasing with the passage of time t as in the conventional example, and it is also possible to reduce washing waste water.

In addition, in this embodiment, when the rate of decrease in the differential pressure before and after cleaning the filter 4 is lower than the differential pressure decrease rate setting, or when the cleaning interval becomes shorter than the set value, the poor cleaning lamps 30a and 31a are turned on, respectively. Since the cleaning failure is alarmed, the operation Q can recognize the cleaning failure of the filter 4.

〔Effect of the invention〕

As explained above, the present invention calculates the degree of filter clogging from the turbidity and flow rate at the waste liquid inlet side of the filtration device, and issues an alarm to start filter cleaning based on this degree of clogging, so that appropriate cleaning can be started. The number of cleaning ports can be reduced, and the amount of waste water discharged from cleaning the filter can be reduced, improving the operating efficiency of the filtration device. I can do it.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of an embodiment of a filter clogging monitoring device for a filtration device according to the present invention, and Fig. 2 is a difference in waste liquid between the inlet side and the outlet side of the filter case in the embodiment shown in Fig. 1. A graph showing pressure fluctuations, Figure 3 is a diagram showing the overall configuration of the filter [1 clogging monitoring device] of a conventional filtration device, and Figure 4 is a diagram showing
It is a dimensional graph showing the differential pressure fluctuation of the waste liquid in the conventional example shown in the figure. DESCRIPTION OF SYMBOLS 1...filtration device, 4...) r filter, 5...inlet pipe, 6...outlet pipe, 20...differential pressure detector, 21...
Turbidity detector, 22... Flow detector, 23... Performance device, 24... Judgment device, 25... Cleaning start alarm, 27
...Memory, 2B...Counter, 29...Differential pressure reduction rate judge, 30°31...Poor cleaning lamp circuit. @Figure 1

Claims (1)

[Claims] A differential pressure detector that detects the pressure difference of the waste liquid flowing between the waste liquid inlet side and the waste liquid outlet side of a filtration device equipped with a filter for filtering the waste liquid, and a turbidity detector that detects the turbidity of the waste liquid on the waste liquid inlet side. , a flow rate detector for detecting the flow rate of the waste liquid on the waste liquid inlet side, a computing unit for calculating the degree of clogging of the filter from each detection signal from the flow rate detector and the turbidity detector, and A judgment device that compares the calculated signal with the cleaning start setting value and outputs a cleaning start command signal when the calculated signal exceeds the cleaning start setting value, and a judgment device that outputs a cleaning start command signal when the calculation signal exceeds the cleaning start setting value. A memory that reads and stores the differential pressure detection signal from the differential pressure detector, and a memory that reads the differential pressure detection signal from the differential pressure detector after cleaning the filter, and reads the differential pressure detection signal before filter cleaning from the memory; A differential pressure decrease rate determiner that outputs a cleaning failure signal when the rate of decrease in the differential pressure after cleaning the filter calculated from both read values is lower than the differential pressure decrease rate set value, and a cleaning start command from the determiner. A counter that outputs a cleaning failure signal when it detects that the signal output interval is shorter than the output interval setting value, and a cleaning device that alerts you to a filter cleaning start request when it receives a cleaning start command signal from the above-mentioned judger. A filter of a filtration device, comprising a start alarm, and a cleaning failure alarm that warns of cleaning failure of the filter when receiving each of the cleaning failure signals from the differential pressure drop determination device and the counter, respectively. Clogging monitoring device.