JPH08117510A - Liquid property measuring apparatus - Google Patents

Abstract

PURPOSE: To properly carry out surface cleaning of a hot film sensor element within a short time and improve the measurement precision. CONSTITUTION: A liquid property measuring apparatus is provided with a tubular detection part 33 having an inlet of raw water such as a dehydrated filtered liquid in one end and an outlet of the raw water in the other end, a hot film sensor 34 so installed in the detection part as to be brought into contact with the raw water, and a light-transmissive type cleaning evaluating sensor unit 35 installed slightly above the hot film sensor. Based on the output value of the cleaning evaluating sensor unit, a control computing unit 40 carries out cleaning evaluation of the hot film sensor and controls the liquid property measurement to be the optimum state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid property measuring device, and in particular, it is obtained by dehydrating a suspension of sludge or the like containing a large amount of a viscous substance or a fibrous suspension substance or the sludge with a dehydrator. The present invention relates to a liquid property measuring device that measures the properties of a dehydrated filtrate or the like (hereinafter referred to as “suspension”) as raw water.

[0002]

2. Description of the Related Art Conventionally, a measuring device of this type has been incorporated in a water treatment device such as a coagulation treatment device for wastewater treatment and a sludge dewatering device, and has been used to measure a suspension or the like sent using a pump. The liquid property was measured, and the amount of the coagulant added to the water treatment device was controlled based on the measured value. As a specific example of such a measuring device, for example, Japanese Patent Application No. 2-4009.
There is one used in the aggregating apparatus shown in No. 8.
In the agglomeration processing device, as shown in FIG.
Sludge is fed from the raw mud pit 11 to the flocculation tank 13, the flocculating agent from the chemical liquid storage tank 14 is added by the chemical injection pump 15, and the flocculation treatment is performed. Separated. In the above device, the filtrate separated from the filtrate storage tank 17 is sent by the pump 18,
The liquid property was detected by using the heat transfer detector 19, and the control calculator 20 performed optimum chemical injection control based on the detected liquid property. The heat transfer detector is composed of, for example, a hot film sensor, and controls the chemical injection amount according to the detection value of the hot film sensor, but the element surface of the hot film sensor is a liquid for measurement. Since it is easy to get dirty due to its properties, it was washed with water to prevent deterioration of measurement accuracy.

[0003]

However, in the above device, when measuring raw water containing a large amount of viscous substances or suspended substances, slime or scale adheres to the element surface of the hot film sensor, With water washing, it becomes difficult to sufficiently remove the above-mentioned deposits, and there is a problem that the deterioration of the hot film sensor with time is accelerated. Further, in this case, since the time spent for cleaning becomes long, it is necessary to change the process such as extending the measurement time or shortening the cleaning interval, which causes a problem that the measurement cycle becomes unstable. It was

The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid property measuring apparatus capable of accurately cleaning the element surface of a hot film sensor in a short time and improving the measurement accuracy. To do.

[0005]

In order to achieve the above object, in the present invention, a tubular detector having an inlet of raw water at one end and an outlet of the raw water at the other end is contacted with the raw water flowing in the detector. As described above, a liquid-state measuring device including a heat transfer detector including a hot film sensor provided in the detection unit and a tubular supply pipe connected to the detection unit and supplying wash water and wash air is provided. Provided.

In the measuring device according to the second aspect of the present invention, a tubular detector having an inlet for raw water at one end and an outlet for the raw water at the other end is provided in the detector so as to come into contact with the raw water flowing in the detector. And a cleaning unit for cleaning the heat transfer detector, and a transmitted light type cleaning property evaluation sensor for evaluating the cleaning property of the heat transfer detector.

[0007]

Since the hot film sensor is cleaned with the cleaning water, the air mixed solution, etc. supplied from the supply pipe, the accuracy of cleaning the element surface of the hot film sensor can be improved. In the measuring device according to the second aspect, since the transmitted light type cleaning property evaluation sensor is provided to evaluate the cleaning property of the element surface of the hot film sensor, the cleaning property can be evaluated with high sensitivity. It is possible to easily correct the measurement system and replace the sensor.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A measuring device according to the present invention will be described with reference to the drawings of FIGS. FIG. 1 is a configuration diagram showing an example of a measuring device according to the present invention. In the figure, the measuring device includes a pit 11, a pump 12, a coagulation tank 13, a chemical solution storage tank 14, a chemical injection pump 15, and a dehydrator 1 of the conventional example shown in FIG. 7.
6 and the agitation motor 10 are applied to the agglomeration processing apparatus, and the pipes 21 to 28, the receiving tank 30, the liquid level gauges 32 and 37, the liquid property detection unit 33, and the hot film sensor 34. It is composed of a transmitted light type cleaning property evaluation sensor unit 35, a measurement auxiliary tank 36, a water receiving tank 38, an exhaust pump 39, a control arithmetic unit 40 and the like.
The pipes 21 to 28 form a pipe system passage.

The receiving tank 30 is located at the upper position of the tank.
The dehydrator 1 is connected to the pipe 21 and is connected via the pipe 21.
Suspension and the like are introduced from 6. An automatic valve V0 is arranged in the middle of the pipe 21. In addition, the pipe 21 is
It is also connected to the storage tank 42 via the flow rate adjusting valve V10.
The capacity of the receiving tank 30 is configured so that the above-mentioned suspension liquid or the like can always be stored at a constant level so that the hot film sensor 34 can continuously measure the liquid property for a predetermined time. Further, the receiving tank 30 is connected to the automatic valve V1 via the pipe 22 at the lowest position of the bottom of the receiving tank 30 so that the suspension or the like can flow out to the pipe 24. Further, the receiving tank 30 is connected to the flow rate adjusting valve V9 through the pipe 22 so that the suspension liquid or the like can flow into the storage tank 41. Furthermore, the receiving tank 30 has an overflow opening (not shown) and an overflow tank 43.
The tank bottom of the overflow tank 43 is connected to the storage tank 41 through the pipe 23, and the overflow of the liquid is possible.

The mesh screen 31 is for preventing coarse dust, fibrous substances, etc. contained in the suspension flowing into the receiving tank 30 from being mixed into the pipe passage, and is incorporated in the receiving tank 30. The mesh size is arbitrarily set according to the target liquid type. The liquid level meter 32 is arranged above the receiving tank 30 and is provided with three electrodes.
The liquid level inside is detected by two levels of levels H1 and M1 (H1> M1), and the detection signal of each level is output to the control arithmetic unit 40 which controls the drive of the exhaust pump 39. The level L1 electrode is a common electrode.

The measurement auxiliary tank 36 is a water tank having a closed structure, and the pipe 26 connected to the M2 level position below the tank.
It is connected to the liquid state detection unit 33 via the liquid storage device and stores the suspension or the like flowing in from the liquid state detection unit 33 at a constant level H2. The positional relationship between the receiving tank 30 and the measurement auxiliary tank 36 is such that the H1 level of the receiving tank 30 is H2 of the measurement auxiliary tank 36.
It is arranged to be higher than the level. Further, the pipe 26 is arranged such that the highest portion of the pipe 26 is higher than the liquid level H1 of the receiving tank 30 by Δh, and a water head difference (head difference) of Δh is generated. For this reason, when the automatic valves V1 and V2 are in the open state, the suspension liquid and the like remain in the pipe 26 and do not flow into the measurement auxiliary tank 36. Therefore, the liquid level in the measurement auxiliary tank 36 remains empty. Become.

The measurement auxiliary tank 36 is connected to the water receiving tank 38 via the pipe 27 and the automatic valve V3 at the bottommost position of the tank bottom, and when the automatic valve V3 is opened, the suspension or the like is received in the water receiving tank 38. It is supposed to be leaked to. In addition, the measurement auxiliary tank 36
Is connected to the exhaust pump 39 via the pipe 28 at the tank upper position. An automatic valve V8 is provided in the middle of the pipe 28. When the exhaust pump 39 is driven while the automatic valve V2 is closed and the automatic valve V8 is open,
The suspensions and the like in the receiving tank 30 are provided in the pipes 22, 24 and 26.
Through the measurement auxiliary tank 36. Further, the measurement auxiliary tank 36 is connected to the water receiving tank 38 via the pipe 29 and the pipe 27 connected to a position slightly higher than the H2 level, so that the liquid level in the measurement auxiliary tank 36 does not exceed the H2 level. As described above, the liquid can overflow.

The liquid level meter 37 is arranged above the measurement auxiliary tank 35 and detects the liquid level in the measurement auxiliary tank 36 at two levels H2 and M2 (H2> M2) by three electrodes. , And outputs the detection signal of each level to the control arithmetic unit 40 that controls the drive of the exhaust pump 39. The level L2 electrode is a common electrode. Further, in this embodiment, the liquid level M1 of the liquid level meter 32 and the liquid level H2 of the liquid level meter 37 are set to the same height.

The water receiving tank 38 is connected to the measuring auxiliary tank 36 via the pipe 27 and the automatic valve V3, and the measuring auxiliary tank 36 is connected to the measuring auxiliary tank 36.
It is possible to inflow the suspension etc. Further, the water receiving tank 38 is connected to the pipe 24 via an automatic valve V7 so that the suspension and the like in the pipe system passage and the cleaning drainage can flow in. The exhaust pump 39 is started by the drive control of the control calculation unit 40, and exhausts the measurement auxiliary tank 36 having a closed structure.

As shown in FIG. 2, the liquid state detection unit 33 is made of a tubular hard glass and comprises a hot film sensor 34 for detecting the liquid state and a transmitted light type cleaning property evaluation sensor unit 35 slightly above it. And are provided. The detection unit 33 is connected to the receiving tank 30 via the pipe 22, the automatic valve V1, and the pipe 24, and the suspension or the like can flow from the receiving tank 30. Further, the pipe 24 has an automatic valve V
The wash water supply pipe is connected via 4. The cleaning water from the cleaning water supply pipe cleans the detection element 34a of the hot film sensor 34 and the flat hard glass 35a, 35b of the cleaning property evaluation sensor unit 35.

Further, in the liquid state detecting portion 33, a washing water or washing air supply pipe 33a is provided near the center thereof so as to face the detecting element 34a of the hot film sensor 34. The supply pipe 33a is connected to the automatic valve V5 and the automatic valve V6 via the pipe 25. When the automatic valve V5 is opened, high-pressure washing water from the outside is removed from the automatic valves V5 and V6.
When they are simultaneously opened, the air-mixed liquid can flow into each of the detection units 33, and the high-pressure water flow causes the detection elements 34 to flow.
A and the flat hard glass 35a, 35b are forcibly washed. In addition, in the detection unit 33, in order to obtain a stable laminar flow at the time of measurement and prevent the generation of bubbles, the inner diameter near the inlet is gradually reduced with respect to the liquid flow direction as shown in FIG. It has a tapered diaphragm structure.

Detection element 34 of hot film sensor 34
As shown in FIG. 2, a is provided so as to be in contact with the liquid flowing in the detection unit 33, and the liquid property of the suspension or the like flowing from the receiving tank 30 is continuously maintained for a predetermined time (for example, 3 minutes). The measurement is performed and the measured value is output to the control calculation unit 40 that performs the optimum chemical injection control. As shown in FIG. 2, the transmitted light type cleaning property evaluation sensor unit 35 includes flat hard glasses 35 a and 35 b provided on the upper side wall of the hot film sensor 34 so as to face each other, and a laser beam in the detection unit 33. , A light emitting section 35c for outputting a laser beam, a light receiving section 35d for receiving a laser beam, a light emitting section 35c and a light receiving section 35d
Of the laser beam transmitted through the detection unit 33, and the detection signal corresponding to the transmitted light amount of the laser beam is transmitted to the control arithmetic unit 4
It is composed of a controller unit 35e for outputting 0. In the cleaning property evaluation sensor unit 35, the flat hard glass 35a, 35b is cleaned with cleaning water supplied through the pipe 24, high-pressure cleaning water supplied through the supply pipe 33a, an air mixed liquid, or the like.

The control arithmetic unit 40 includes automatic valves V0 to V
8. The stirring motor 10, the chemical injection pump 15, the liquid level gauges 32 and 37, the hot film sensor 34, and the controller unit 35e of the cleaning property evaluation sensor unit 35 are electrically connected to each other. In addition to controlling the chemical injection amount according to the detection signal, the valve opening / closing operation and the drive control of the exhaust pump 39 are controlled by a preset operation control program, detection signals from the liquid level meters 32 and 37, and the controller unit 35e. To do. That is,
The control calculation unit 40 of the present embodiment calculates the cleanliness of the hot film sensor 34 based on the detection signal from the controller 35e according to the amount of transmitted light of the laser beam, and executes the forced cleaning according to the cleanliness. Decide whether to do it.

Next, the operation of the liquid property measuring device shown in FIG. 1 will be described with reference to the flowchart of FIG. In addition,
In the flocculation processing device, the suspension or the like is fed from the pit 11 to the flocculation tank 1.
3, the stirring motor 10 and the chemical injection pump 1
5, the coagulant is injected into the coagulation tank 13, the coagulation process is performed, the dehydrated cake and the dehydrated filtrate are separated by the dehydrator 16, and the suspension and the like are supplied to the measuring device. . Further, in the initial state of the measuring device, the receiving tank 30, the auxiliary measurement tank 36, the piping system, and the like are empty and clean so that liquid passing and measurement can be performed. In addition, automatic valve V0
All of V8 to V8 are controlled to be in the closed state, and in this state, the suspension liquid or the like from the dehydrator 16 is discharged to the storage tank 42 via the pipe 21 and the flow rate adjusting valve V10.

First, in the liquid flow measuring step of step 101, the control arithmetic unit 40 controls the closed automatic valve V0.
Among V8, the automatic valves V1 and V2 are controlled to be in the open state, the automatic valve V0 is further opened, and the suspension or the like is supplied from the pipe 21 to the receiving tank 30 and the pipe 24. Next, when a detection signal indicating that the suspension or the like in the receiving tank 30 has reached the H1 level is input from the liquid level meter 32, the operation of the liquid passing and measuring process is started, and the automatic valve is operated. V2 is closed, the automatic valve V8 is opened, the exhaust pump 39 is driven and controlled, and the exhaust pump 39 is started. As a result, the suspension or the like in the receiving tank 30 overcomes the head difference Δh with the pipe 26.

Once the head difference Δh is overcome, the suctioned suspension liquid and the like are added to the receiving tank 3 with a siphon effect.
The liquid flows from 0 into the measurement auxiliary tank 36, and the liquid level in the measurement auxiliary tank 36 rises. At this time, the liquid in the water receiving tank 38 is also sucked from the pipe 29 and rises to some extent, but by setting the distance between the auxiliary measurement tank 36 and the water receiving tank 38 to be sufficiently longer than the head difference Δh, The liquid in 38 stops in the pipe 29, and the reverse flow of the liquid to the auxiliary measurement tank 36 is prevented.

Then, when a detection signal indicating that the suspension or the like in the measurement auxiliary tank 36 has reached the H 2 level is input from the liquid level meter 37, the control arithmetic unit 40 shifts to the measurement operation, The exhaust pump 39 is stopped, the automatic valve V3 is opened, the power of the hot film sensor 34 is turned on, and the measurement is started. The openings of the automatic valves V0 and V3 are set so that the liquid level of the receiving tank 30 is maintained at the liquid level H1 and the liquid level of the measurement auxiliary tank 36 is maintained at the liquid level H2. The liquid level difference of 36 is kept constant.

As a result, the suspension or the like in the receiving tank 30 is
Due to the siphon effect, the liquid is fed into the measurement auxiliary tank 36 at a constant speed after a predetermined time through the pipes 22, 24 and 26, and the liquid flow is pulsated to pass in a stable laminar flow state. It is possible to measure the liquid property with high accuracy by the 34. In the measuring device of the present invention, instead of stopping the exhaust pump 39 at the level H2 and opening the automatic valve V3, the exhaust pump 39 is not stopped even when the above H2 is reached, and the suspension or the like is piped 29. You may make it overflow through. In this case, the siphon effect may or may not be used. Also in this case, since the suspension or the like is temporarily stored in the measurement auxiliary tank 36 and then drained, the influence of the pulsation of the exhaust pump 39 is eliminated and a stable measurement result can be obtained. Further, the exhaust pump 39 is stopped at the level M2 and the liquid is received from the receiving tank 30 by the siphon effect and the measurement auxiliary tank 3 is used.
6 may be made to flow into. In this case, the driving time of the exhaust pump 39 is shortened, so that the power consumption can be reduced.

In the hot film sensor 34, the liquid level meter 32 detects the liquid level between the liquid levels H1 and M1, the liquid level meter 37 detects the liquid level between H2 and M2, and Only when the automatic valve V1 is open, that is, when the suspension or the like is flowing through the liquid state detection unit 33, power is supplied and measurement is performed during this period. Then, when the liquid level of the receiving tank 30 or the measurement auxiliary tank 36 is lowered and the above-described power-on condition is no longer satisfied, the power supply is stopped and the hot film sensor 34 is protected.

When a suspension or the like is flown to the hot film sensor 34, the sensor is soiled and the measurement performance deteriorates. Therefore, the drainage and cleaning steps are executed every time the measurement time reaches a predetermined time. First, in the drainage process, the control arithmetic unit 40 controls the automatic valve V1 to be in the closed state and the automatic valves V2, V3, and V7 to be in the open state, so that the measurement auxiliary tank 36, the suspension of the piping system path, etc. Is drained to the water receiving tank 38 (step 102).

Then, the control operation unit 40 has a timer function provided in its own device, and after a predetermined time has passed from the control of the automatic valve, that is, the measurement auxiliary tank 36, the suspension in the piping system passage, etc. are completely removed. After the liquid is drained, the cleaning process is started and only the automatic valves V3 and V4 are controlled to be in the open state. As a result, the wash water is drained to the water receiving tank 38 through the pipe 24, the detecting unit 33, the pipe 26, the measurement auxiliary tank 36, and the pipe 27.
In the meantime, the piping 24, 26, the surface of the detection element 34a of the hot film sensor 34, and the cleaning performance evaluation sensor unit 35
The flat hard glasses 35a and 35b are cleaned (step 103). When the automatic valve V3 is continuously controlled to be closed, the cleaning water is stored in the measurement auxiliary tank 36.

At this time, instead of opening the automatic valve V3, by flushing the washing water into the pipe 29,
The measurement auxiliary tank 36 and the pipe 29 can be washed. Next, in the control calculation unit 40, the cleaning water is measured in the measurement auxiliary tank 36.
When reaching the level H2 of, the automatic drain valve V4 is closed and the automatic valves V2, V3 and V7 are controlled to be in the open state,
The cleaning water in the piping system, the detection unit 33, and the measurement auxiliary tank 36 is drained into the water receiving tank 38 at once (step 104).

When it is desired to wash the inside of the receiving tank 30, in the washing process, the automatic valve V1 is opened to store the washing water in the receiving tank 30, and when the level H1 is reached, the process goes to the draining process, The automatic valve V7 is controlled to be in the open state, and the cleaning water in the receiving tank 30 is immediately drained to the water receiving tank 38 to wash the receiving tank 30. Next, the cleaning water in the measurement auxiliary tank 36 has a level M.
When it reaches 2, move to the water flow process. In the water passing step, the control arithmetic unit 40 uses the automatic valves V1 to V3, V
By controlling 7 to be closed and the automatic valve V4 to be open, water is supplied to the piping system (step 105). As a result, the cleaning water flows into the measurement auxiliary tank 36 through the pipe 24, the detection unit 33, and the pipe 26, raises the liquid level in the measurement auxiliary tank 36, and the hot film by the cleaning property evaluation sensor unit 35. It is possible to measure the contamination of the sensor 34.

The control calculation unit 40 measures the contamination of the hot film sensor 34 (step 107) while performing the water amount confirmation step (step 106). Step 1
In the water amount confirmation step of 06, the control operation unit 40 confirms the water amount in the measurement auxiliary tank 36, and indicates from the liquid level meter 37 that the cleaning water in the measurement auxiliary tank 36 has reached the H2 level. When the detection signal is input, automatic valves V3, V7
To the open state and the automatic valve V4 to the closed state to control the piping 2
6. The cleaning water in the measurement auxiliary tank 36 is drained to the water receiving tank 38. The above-mentioned amount of water may be confirmed, for example, by a timer function provided in the device itself, after a predetermined time has passed from the time of water passage, and this time may be recognized as a constant amount of water capable of measuring dirt, or It is also possible to dispose a flow meter in the piping system and recognize a constant amount of water by the measured value of the flow meter.

In the cleaning performance evaluation detection by measuring the sensor contamination in step 107, for example, as shown in FIG. 5, the detection unit 33 is cleaned for 60 seconds, and the control calculation unit 40
During this time, the detection signal from the controller unit 35e is taken in at a predetermined interval, and the cleanliness of the hot film sensor 34 is calculated based on the detection signal. And
When the cleanliness does not exceed 50% even after the lapse of 60 seconds, the control calculation unit 40 executes the forced cleaning (step 108).

In this forced cleaning step, for example, as shown in FIG. 4, high-pressure cleaning water is sprayed on the hot film sensor 34 for cleaning, and cleaning water is mixed with air to clean the hot film sensor 34. And the like exist, and the forced cleaning is performed for 60 seconds, respectively, as in the cleaning process of step 103. In the case of cleaning with the above high pressure cleaning water, the control arithmetic unit 40 controls the automatic valves V5 and V7 to the open state and causes the high pressure cleaning water to flow into the detection unit 33 through the pipe 25, and the hot film sensor. The detection element 34a of 34 and the flat hard glass 35a, 35b of the cleaning property evaluation sensor unit 35 are cleaned. In the case of cleaning with the air mixed liquid, the control arithmetic unit 40 uses the automatic valve V5 ...
V7 is controlled to be in an open state, and an air mixed liquid of cleaning water and air is caused to flow into the detection unit 33 through the pipe 25 to clean the detection element 34a and the flat hard glasses 35a and 35b. When the forced cleaning is completed, step 1
Returning to 04, the above-mentioned steps of draining water, passing water, confirming the amount of water, measuring sensor contamination, etc. are repeated.

Further, in step 107, based on the detection signal from the cleaning property evaluation sensor unit 35, when the cleanliness exceeds 50% after 60 seconds from the cleaning,
The control calculation unit 40 shifts to the drainage process, and the automatic valve V
2, V3, V7 are controlled to open state, and wash water is received in the water tank 38
(Step 109). Then, after a lapse of a predetermined time from the drainage, the process returns to step 101, the liquid passing and measuring steps are executed, and the measurement of the liquid property of the suspension or the like is restarted.

The above-mentioned forced cleaning is performed, and step 10
Even if the cleaning property is evaluated to be good by the sensor dirt measurement of 7 and the cleaning property is evaluated as good,
The measurement accuracy of the hot film sensor 34 may not return to the optimum state. In this case, it is assumed that the hot film sensor 34 has deteriorated with time, and the base value of the hot film sensor 34 is corrected (automatic calibration), overhauled, or replaced with a new one. Can be applied.

Further, in the measurement of the sensor dirt in this embodiment, the detection signal is fetched at a predetermined interval to perform the cleaning evaluation. However, the present invention is not limited to this, and the cleanliness of the sensor 34 has reached a predetermined value, for example. If not, step 104-
It is also possible to cyclically repeat 107 and set to perform the forced cleaning when the predetermined value is not reached even after the predetermined number of times.

In the forced cleaning step, in addition to this embodiment,
For example, when the automatic valves V4 and V6 are opened and cleaning is performed by blowing compressed air to the sensor in cleaning water, when cleaning is performed using chemicals for cleaning, air mixed liquid, high pressure cleaning water or chemical cleaning, etc. It is conceivable that cleaning is performed by combining the above. Further, without performing the forced cleaning, for example, in the cleaning process of step 103, air mixture cleaning, high-pressure cleaning water or chemical cleaning is performed, and when the cleanliness is low, the cleaning process is cyclically repeated. It is also possible to set to.

Therefore, in this embodiment, a hard glass detector is used to evaluate the washability of the hot film sensor according to the light transmittance of the detector during water washing. If it is bad, the cleaning property is enhanced by performing forced cleaning, so that the element surface of the hot film sensor can be accurately cleaned in a short time, and the measurement accuracy can be improved. Therefore, in this embodiment, the cleaning degree is improved, the temperature of the hot film sensor can be prevented from being raised, and the deterioration degree of the sensor over time can be reduced, and the hot film sensor can be maintained in an optimum state to improve the reliability of the entire system. Can be improved.

Further, in this embodiment, since the cleanliness is detected by using the transmitted light type cleaning property evaluation sensor unit for the cleaning property evaluation, it is possible to evaluate the cleaning property of the hot film sensor with high sensitivity. . Therefore, in this embodiment, since the cleaning property of the hot film sensor can be accurately evaluated,
It is possible to easily clean the sensor, correct the measurement system, replace the sensor, and the like.

Further, in this embodiment, the sensor cleaning pattern can be arbitrarily changed, so that it is possible to set the optimum cleaning pattern according to the degree of difficulty of contamination and the type of raw water to be measured. In the above examples, the washability evaluation of the hot film sensor was performed using the transmitted light type washability evaluation sensor unit, but the present invention is not limited to this, and the washability evaluation sensor unit is not used for washing. It is also possible to perform sex evaluation. In this case, in the sensor dirt measurement shown in step 107 of FIG. 4, a change in the temperature of the wash water (hereinafter, referred to as “sensor temperature”) when the flow velocity is constant is detected by the hot film sensor 34, and The control calculation unit 40 is set to calculate the cleanliness of the hot film sensor 34 based on the detected temperature change.

That is, as shown in Table 1 below, for example, the sensor temperature of the hot film sensor changes depending on the flow rate of the washing water flowing on the surface of the element which is the detecting portion of the sensor, and when the flow rate is constant, the element temperature is constant. When a dirt film is formed on the surface, it also changes depending on the thickness of the dirt film.

[0040]

[Table 1] Here, the water temperature is 20 ° C and the sensor surface area is 16.1 mm.
² , constant current supply value is 500mA, dirt film thermal conductivity is 1
It is set to 0 Kcal / Hv / ° C / m.

This embodiment utilizes the latter change, and detects stains on the element surface of the sensor by detecting the change in sensor temperature when the liquid quality and flow velocity of the wash water are constant. is there. In the water supply and measurement process of FIG. 4, in the control operation unit of the present embodiment, when the degree of contamination is less than or equal to the diagnostic boundary line B shown in FIG. 6, the base value of the sensor (the detected value of the hot film sensor and The base value of the U-shaped characteristic according to the chemical injection amount) is calibrated, and when the degree of contamination exceeds the diagnostic boundary line B shown in FIG. 6, the process moves to the forced cleaning step to force the hot film sensor to be cleaned. I do.

When the stain measurement value due to the sensor temperature is extremely bad, for example, the thickness of the stain film at which the detected sensor temperature is about 5 ° C. higher than the sensor temperature when the thickness of the stain film is 0 mm. In the case of 0.6 mm or more, the hot film sensor is visually inspected and overhauled, or the hot film sensor is replaced.

Therefore, also in this embodiment, since the cleaning property of the hot film sensor can be evaluated accurately, the same effects as those of the first embodiment can be obtained, and the cleaning of the sensor, the correction of the measuring system, the replacement of the sensor, etc. Can be performed easily, and the number of parts of the equipment used for the cleaning property evaluation can be reduced, so that the manufacturing cost can be reduced. Further, in this embodiment, the hot film sensor 34 can be set to be washed when necessary. In this case,
For example, in the liquid passing and measuring process of step 101 in FIG. 4, it is determined whether the measurement accuracy of the hot film sensor 34 is in the optimum state. That is, in this case, the sensor 34
The measurement accuracy of the sensor 34 is judged by detecting whether or not aggregation failure or excessive addition occurs in accordance with the optimal chemical injection control of the aggregating agent according to the detection value of. Then, in this determination, when the measurement accuracy of the sensor 34 is in the optimum state, the liquid passing and measuring steps are continuously executed, and the sensor 3
When the measurement accuracy of 4 is not optimum, step 102
Then, the operation is performed so as to execute processes such as drainage, cleaning of the hot film sensor 34, and sensor dirt measurement. As a result, in the above-described measuring device, continuous measurement for a long time is possible, and sensor cleaning can be performed as necessary.

In the above embodiment, the case of the continuous type measuring device has been described, but the present invention is not limited to this.
It can also be applied as a batch type measuring device. In the case of this batch measurement, the liquid level of the receiving tank 30 is H1.
When the liquid level of the measurement auxiliary tank 36 reaches the overflow level H2, the automatic valve V0 is closed and the liquid property is measured while the suspension or the like flows from the receiving tank 30 to the measurement auxiliary tank 36 by the siphon effect. Done. In this case, the receiving tank 30 and the measurement auxiliary tank 36 have the same inner diameter, or the liquid drop from the receiving tank 30 to the measurement auxiliary tank 36 is
If the liquid level level H1 to M1 of the receiving tank 30 is small, the liquid level difference between the tanks can be regarded as substantially constant, the speed of the liquid flowing to the hot film sensor 34 becomes constant, and stable measurement is possible during that time. Become. Then, when this measurement is completed, the suspension or the like is drained, and steps such as washing of the hot film sensor 34, measurement of sensor dirt, forced washing and the like are performed for the next liquid property measurement.

Thus, in the case of the batch type measuring device, the cleaning property of the hot film sensor can be regularly evaluated every time a certain amount of liquid property is measured, so that the temperature of the hot film sensor is prevented from increasing. In addition, the degree of deterioration of the sensor over time can be reduced, the hot film sensor can be maintained in an optimum state, and the reliability of the entire system can be improved.

[0046]

As described above, according to the present invention, the detector having the inlet of raw water at one end and the outlet of the raw water at the other end and the detector so as to come into contact with the raw water flowing in the detector. Since the heat transfer detector provided and the supply pipe connected to the detection unit and supplying the cleaning water and the cleaning air are provided, the element surface of the hot film sensor is accurately cleaned in a short time, and the measurement accuracy is improved. Can be improved.

According to a second aspect of the present invention, the heat transfer detector provided in the detection unit so as to come into contact with the detection unit having the raw water inlet at one end and the raw water outlet at the other end and the raw water flowing in the detection unit. And a cleaning pipe connected to the detection unit for supplying cleaning water and cleaning air, and a cleaning property evaluation sensor provided in the detection unit for evaluating the cleaning property of the heat transfer detector. The cleaning property can be well evaluated, and cleaning of the sensor, correction of the measurement system, replacement of the sensor, and the like can be easily performed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a measuring device according to the present invention.

FIG. 2 is a configuration diagram of a detection unit shown in FIG.

FIG. 3 is a partial cross-sectional view of a detection unit A portion shown in FIG.

4 is a flowchart for explaining the operation of the measuring device shown in FIG.

5 is a diagram showing cleaning characteristics of the element surface of the hot film sensor shown in FIG.

FIG. 6 is a diagram showing the influence of element surface contamination of the hot film sensor on the sensor temperature.

FIG. 7 is a configuration diagram showing an example of a conventional measuring device.

[Explanation of symbols]

 30 acceptance tank 32, 37 liquid level meter 33 detection unit 34 hot film sensor 35 transmitted light type cleaning property evaluation sensor unit 36 measurement auxiliary tank 38 water reception tank 39 exhaust pump 40 control calculation unit V0-V8 automatic valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihisa Kishine 3-4-7 Nishishinjuku, Shinjuku-ku, Tokyo Kurita Industry Co., Ltd.

Claims (2)

[Claims] 1. A detector having an inlet of raw water at one end and an outlet of the raw water at the other end, and a heat transfer detector provided in the detector so as to come into contact with the raw water flowing in the detector, A liquid property measuring device, comprising: a supply pipe connected to a detection unit and supplying cleaning water and cleaning air. 2. A detection unit having an inlet of raw water at one end and an outlet of the raw water at the other end, and a heat transfer detector provided in the detection unit so as to come into contact with the raw water flowing in the detection unit, A liquid property measuring device comprising: a cleaning unit for cleaning the heat transfer detector; and a cleaning property evaluation sensor for evaluating the cleaning property of the heat transfer detector.