JP7520583B2 - Measuring device, water purification system and measuring method - Google Patents

Description

FIELD OF THE DISCLOSURE The present invention relates to a measurement device , a water purification system , and a measurement method .

A measuring device that measures the migration speed of particles that move by electrophoresis is known as a method for calculating the zeta potential, which is an index of the charged state (surface potential or surface charge) of particle surfaces in liquids in water treatment, material manufacturing, the environment, medicine, etc. In water purification systems that remove particles (impurities) from liquids, a system has been devised that uses a measuring device that measures the migration speed of particles that move by electrophoresis in order to calculate the zeta potential of particles.

JP 2007-203168 A International Publication No. 2014-103860 JP 2014-54603 A

In electrophoretic speed measurement devices such as those described above, if there is a temperature difference between the liquid and its surrounding environment, thermal convection will occur in the liquid, and the particle movement speed may not be measured accurately.

Therefore, one of the objectives of the embodiment is to provide a measurement device and a water purification system that can measure the migration speed of particles due to electrophoresis with high accuracy.

The measuring device of the embodiment includes a container, an electrode, an imaging unit, a calculation unit, a heat insulating unit , and an air conditioning unit . The container contains a liquid. The electrode applies a voltage to the liquid contained in the container. The imaging unit images the liquid contained in the container. The calculation unit calculates the movement speed of particles contained in the liquid based on the imaging data acquired by the imaging unit. The heat insulating unit is disposed so as to surround the container, and has a lower thermal conductivity than the container. The air conditioning unit adjusts the temperature of the gas in the heat insulating unit so that the temperature difference between the liquid in the container and the gas in the heat insulating unit is small.

FIG. 1 is a block diagram illustrating an example of the configuration of a measurement device according to the first embodiment. FIG. 2 is a diagram showing an example of particle movement due to electrophoresis when there is no effect of thermal convection. FIG. 3 is a diagram showing an example of the direction of movement of particles due to electrophoresis when there is an effect of thermal convection. FIG. 4 is a flowchart showing an example of a process flow in the measurement device according to the first embodiment. FIG. 5 is a block diagram showing an example of the configuration of a measurement device according to the second embodiment. FIG. 6 is a flowchart showing an example of a process flow in the measurement device according to the second embodiment. FIG. 7 is a block diagram showing an example of the configuration of a measurement device according to the third embodiment. FIG. 8 is a flowchart showing an example of a process flow in the measurement device according to the third embodiment. FIG. 9 is a block diagram showing an example of the configuration of a measurement device according to the fourth embodiment. FIG. 10 is a block diagram showing an example of the configuration of a measurement device according to the fifth embodiment. FIG. 11 is a block diagram showing an example of the configuration of a water purification system according to the sixth embodiment.

Below, several embodiments and modifications of the present disclosure will be described with reference to the drawings. The configurations of the embodiments and modifications described below, as well as the actions and effects brought about by said configurations, are merely examples and are not limited to the contents described below.

First Embodiment
1 is a block diagram showing an example of the configuration of a measuring device 1 according to a first embodiment. The measuring device 1 is a device that measures the moving speed of particles contained in a liquid when the particles move due to electrophoresis. Electrophoresis is a phenomenon in which particles move according to the charged state of the particles when a voltage is applied to a liquid containing the particles. The liquid may be, for example, a liquid to be subjected to a purification treatment (raw water taken from a river, underground water, lake, groundwater, etc.).

The measuring device 1 according to this embodiment includes a tank 11, a pump 12, an inflow valve 13, a cell 14 (container), a positive electrode 15A (electrode section), a negative electrode 15B (electrode section), a power source 16, an outflow valve 17, an imaging device 18 (imaging section), a calculation device 19 (calculation section), a heat insulating material 20 (heat insulating section), a water thermometer 21 (first detection section), a room temperature gauge 22, an air conditioner 23, a water supply pipe 24, and a drain pipe 25.

The tank 11 stores the liquid (raw water) to be measured. The cell 14 is connected to the tank 11 via the water distribution pipe 24, and stores the liquid that flows out of the tank 11. The pump 12 generates pressure to send the liquid in the tank 11 to the cell 14. The inlet valve 13 adjusts the flow rate of the water distribution pipe 24, and adjusts the amount of liquid flowing into the cell 14. The drain pipe 25 discharges the liquid in the cell 14. The outlet valve 17 adjusts the flow rate of the drain pipe 25, and adjusts the amount of liquid discharged from the cell 14.

The positive electrode 15A and the negative electrode 15B apply a voltage to the liquid in the cell 14 in response to the power supply from the power source 16. The imaging device 18 is a device configured using a lens, an imaging element, a processor, etc. The imaging device 18 images the liquid in the cell 14 to which a voltage has been applied, and obtains imaging data showing the movement of particles contained in the liquid. The arithmetic device 19 is a computer configured using a processor, a storage device, an ASIC (Application Specific Integrated Circuit), etc. The arithmetic device 19 performs a predetermined image processing on the imaging data obtained by the imaging device 18, and calculates the movement speed of the particles contained in the liquid.

At this time, a flocculant that aggregates particles is injected into the tank 11 to generate flocs in which the particles and the flocculant aggregate, and the liquid containing the flocs is stored in the cell 14, making it possible to calculate the movement speed of the flocs. By conducting tests while changing the conditions related to the flocculant (amount injected, type, environment, etc.), it is possible to generate aggregation information that indicates the relationship between the conditions related to the flocculant and the movement speed of the particles (flocs).

The insulating material 20 is installed so as to surround the cells 14, and has a lower thermal conductivity than the cells 14. The specific material of the insulating material 20 is not particularly limited, but may be, for example, urethane foam, polystyrene foam, glass wool, etc. The action of the insulating material 20 makes the temperature around the cells 14 less susceptible to the effect of the temperature of the air outside the insulating material 20.

The water thermometer 21 detects the temperature of the liquid upstream of the insulation 20 in the flow direction (in the water pipe 24 in this embodiment). The room temperature gauge 22 detects the temperature of the gas inside the insulation 20. The air conditioner 23 adjusts the room temperature Tr based on the water temperature Tw detected by the water thermometer 21 and the room temperature Tr detected by the room temperature gauge 22 so that the difference between the water temperature Tw and the room temperature Tr becomes small. The specific configuration of the air conditioner 23 is not particularly limited, but may be, for example, a device that performs heating/cooling or dehumidification using a vapor compression refrigeration cycle, or a heat exchanger that performs heat exchange between the gas inside the insulation 20 and a medium (cold water, hot water, etc.).

The space within the insulation material 20 may be filled with an inert gas to prevent condensation. Generally, air condenses when it is below the dew point, so temperature control by the air conditioner 23 is required to keep the air temperature from falling below the dew point. In contrast, inert gas does not condense, so there is almost no need to adjust the temperature of the inert gas, which can improve safety and reliability. The type of inert gas is not particularly limited, but may be, for example, argon, nitrogen, etc. When argon gas is used, the density of argon gas is greater than that of air, so the argon gas accumulates at the bottom of the insulation material 20. Therefore, for example, if a structure is used in which a lid is provided on the top of the insulation material 20, air will hardly enter the insulation material 20 even if the lid is opened. And if the cell 14 is placed at the bottom of the insulation material 20, the periphery of the cell 14 can be covered with argon gas, and the condensation prevention and high insulation effect of the cell 14 can be maintained.

The above configuration makes it possible to keep the temperature difference between the liquid in the cell 14 and the periphery of the cell 14 small, and to suppress thermal convection in the liquid in the cell 14. This makes it possible to prevent the movement of particles due to electrophoresis from being hindered by thermal convection in the liquid, and improves the measurement accuracy of the particle movement speed.

In the above, a configuration in which the liquid to be tested is sent to the cell 14 using the pump 12 is exemplified, but the method of sending water to the cell 14 is not limited to this. For example, a configuration in which an operator injects the liquid into the cell 14 using a syringe or the like is also possible.

Figure 2 is a diagram showing an example of particle movement due to electrophoresis when there is no effect of thermal convection. Figure 3 is a diagram showing an example of the direction of particle movement due to electrophoresis when there is an effect of thermal convection. In Figures 2 and 3, an imaging area 30 of the imaging device 18 is illustrated.

When a voltage is applied to the positive electrode 15A and the negative electrode 15B installed on both sides of the cell 14, the particles contained in the liquid move according to their charged state. Figures 2 and 3 show an example in which the particle surface is negatively charged and moves toward the positive electrode 15A installed on the left side of the cell 14.

As shown in Figure 2, when there is no effect of thermal convection, in other words, when there is almost no temperature difference between the liquid in cell 14 and the periphery of cell 14, the particles move horizontally. On the other hand, as shown in Figure 3, when there is an effect of thermal convection, in other words, when there is a relatively large temperature difference between the liquid in cell 14 and the periphery of cell 14, the particles move in a diagonal direction. Note that while Figure 3 shows an example in which the particles move diagonally upward, there are also cases in which the particles move diagonally downward. The direction of particle movement when thermal convection occurs changes depending on the relationship between the temperature of the liquid in cell 14 and the temperature around cell 14, the shape of cell 14, etc.

As shown in FIG. 3, if the particles move in an oblique direction, there is a high possibility that the particle movement speed cannot be measured accurately. As described above, according to this embodiment, the temperature difference between the liquid in the cell 14 and the periphery of the cell 14 can be kept small, and thermal convection of the liquid in the cell 14 can be suppressed, so that the particles can be moved in the horizontal direction, as shown in FIG. 2. This improves the measurement accuracy of the particle movement speed.

Figure 4 is a flow chart showing an example of the process flow in the measurement device 1 according to the first embodiment. When measurement of the particle movement speed is started, the water thermometer 21 detects the water temperature Tw, which is the temperature of the liquid flowing through the water pipe 24 (S101), and the room temperature gauge 22 detects the room temperature Tr, which is the temperature of the gas in the insulation material 20 (S102).

If the temperature difference ΔT1 between the water temperature Tw and the room temperature Tr is equal to or greater than the threshold value Tth1 (S103: Yes), the air conditioner 23 adjusts the room temperature Tr so that the temperature difference ΔT1 is reduced (S104). That is, the air conditioner 23 performs cooling if the room temperature Tr is higher than the water temperature Tw by the threshold value Tth1 or more, and performs heating if the room temperature Tr is lower than the water temperature Tw by the threshold value Tth1 or more.

If the temperature difference ΔT1 is not greater than or equal to the threshold value Tth1 (S103: No), the imaging device 18 acquires imaging data of the liquid (particles) in the cell 14 (S105), and the calculation device 19 calculates the movement speed of the particles based on the imaging data (S106).

According to the above embodiment, the temperature difference ΔT1 between the liquid in the cell 14 and the periphery of the cell 14 can be kept small, and thermal convection in the liquid can be suppressed. This improves the measurement accuracy of the movement speed of particles (including flocs).

In the above, an example was given of a configuration in which the temperature of the gas (room temperature Tr) inside the insulation material 20 is adjusted by the air conditioning device 23, but simply surrounding the cell 14 with insulation material 20 can also suppress an increase in the temperature difference ΔT1, improving the measurement accuracy of the particle movement speed.

Other embodiments will be described below with reference to the drawings, but parts that have the same or similar effects as the first embodiment will be given the same reference numerals and their description may be omitted.

Second Embodiment
5 is a block diagram showing an example of the configuration of a measurement device 51 according to the second embodiment. The measurement device 51 according to this embodiment differs from the first embodiment in that a dew point meter 31 (second detection unit) is used.

The dew point meter 31 is a device that detects the dew point temperature Td of the gas in the insulation material 20. The air conditioner 23 according to this embodiment adjusts the room temperature Tr based on the room temperature Tr detected by the room temperature meter 22 and the dew point temperature Td detected by the dew point meter 31 so that the room temperature Tr does not become equal to or lower than the dew point temperature Td.

Figure 6 is a flow chart showing an example of the process flow in the measurement device 51 according to the second embodiment. When measurement of the particle movement speed is started, the room temperature meter 22 detects the room temperature Tr, which is the temperature of the gas in the insulation material 20 (S201), and the dew point meter 31 detects the dew point temperature Td of the gas in the insulation material 20 (S202).

If the room temperature Tr is equal to or lower than the dew point temperature Td (S203: Yes), the air conditioner 23 raises the room temperature Tr (S204). In other words, the air conditioner 23 performs heating so that the room temperature Tr does not become equal to or lower than the dew point temperature Td.

If the room temperature Tr is not equal to or lower than the dew point temperature Td (S203: No), the imaging device 18 acquires imaging data of the liquid (particles) in the cell 14 (S205), and the calculation device 19 calculates the movement speed of the particles based on the imaging data (S206).

According to the above configuration, the room temperature Tr is maintained higher than the dew point temperature Td, so that condensation on the surface of the cell 14 can be prevented and good imaging data can be obtained. That is, according to this embodiment, not only can the temperature difference between the liquid in the cell 14 and the periphery of the cell 14 be kept small by the action of the insulating material 20, but condensation on the surface of the cell 14 can also be prevented. This improves the measurement accuracy of the particle movement speed.

Third Embodiment
7 is a block diagram showing an example of the configuration of a measuring device 61 according to the third embodiment. The measuring device 61 according to the third embodiment includes a heat transfer material 41 (heat transfer section), a sub-distribution pipe 42, a sub-inlet valve 43, and a circulation flow path 45, and differs from the first embodiment in that it does not include an air conditioning device 23.

The heat transfer material 41 has a higher thermal conductivity than the insulating material 20 and constitutes a part of the circulation flow path 45. The material of the heat transfer material 41 is not particularly limited, but may be, for example, a metal (such as stainless steel) having a relatively high thermal conductivity and corrosion resistance. The circulation flow path 45 is a flow path that circulates liquid (in this embodiment, the liquid in the tank 11) within the insulating material 20. In this embodiment, the circulation flow path 45 is a space formed within the heat transfer material 41 installed on the inner wall surface of the insulating material 20 (a space formed between the inner wall surface of the insulating material 20 and the outer wall surface of the heat transfer material 41).

The auxiliary water pipe 42 connects the tank 11 to the circulation flow path 45. The auxiliary inlet valve 43 adjusts the flow rate of the auxiliary water pipe 42 and adjusts the amount of liquid flowing into the circulation flow path 45. The valve control device 44 controls the auxiliary inlet valve 43 based on the water temperature Tw detected by the water thermometer 21 and the room temperature Tr (the temperature of the gas present in the space inside the heat transfer material 41) detected by the room temperature gauge 22. Specifically, the valve control device 44 controls the auxiliary inlet valve 43 so that liquid flows into the circulation flow path 45 when the temperature difference between the water temperature Tw and the room temperature Tr is equal to or greater than a threshold value.

As the liquid circulates through the circulation flow path 45, heat is exchanged between the liquid in the circulation flow path 45 and the gas in the insulation material 20 via the heat transfer material 41. This makes it possible to reduce the temperature difference between the liquid in the cell 14 and the periphery of the cell 14, and suppress thermal convection of the liquid in the cell 14.

Figure 8 is a flow chart showing an example of the process flow in the measurement device 61 according to the third embodiment. When measurement of the particle movement speed is started, the water thermometer 21 detects the water temperature Tw, which is the temperature of the liquid flowing through the water pipe 24 (S301), and the room temperature gauge 22 detects the room temperature Tr, which is the temperature of the gas within the insulation material 20 (heat transfer material 41) (S302).

If the temperature difference ΔT2 between the water temperature Tw and the room temperature Tr is equal to or greater than the threshold value Tth2 (S303: Yes), the valve control device 44 opens the secondary inlet valve 43 (S304) and allows liquid to flow into the circulation flow path 45.

If the temperature difference ΔT2 is not equal to or greater than the threshold value Tth2 (S303: No), the valve control device 44 closes the sub inlet valve 43 (S305) to stop the inflow of liquid into the circulation flow path 45. The imaging device 18 then acquires imaging data of the liquid (particles) in the cell 14 (S306), and the calculation device 19 calculates the movement speed of the particles based on the imaging data (S307).

According to the above embodiment, when the difference between the temperature of the liquid flowing into the cell 14 and the temperature around the cell 14 becomes equal to or greater than a threshold value, liquid flowing out from the same water source (tank 11 in this embodiment) as the liquid flowing into the cell 14 circulates through the circulation flow path 45. This allows the temperature of the liquid circulating through the circulation flow path 45 to be transferred to the gas around the cell 14 via the heat transfer material 41, making it possible to reduce the temperature difference between the liquid in the cell 14 and the periphery of the cell 14. In this way, according to this embodiment, it is possible to suppress thermal convection of the liquid in the cell 14 and improve the measurement accuracy of the particle movement speed without using an air conditioning device 23.

Fourth Embodiment
9 is a block diagram showing an example of the configuration of a measuring device 71 according to the fourth embodiment. The measuring device 71 according to the present embodiment differs from the third embodiment in that tap water is circulated through the circulation flow path 45.

The circulation flow path 45 in this embodiment is connected to a water pipe 48. The auxiliary inlet valve 49 in this embodiment adjusts the flow rate of the water pipe 48 and adjusts the amount of tap water flowing into the circulation flow path 45. The valve control device 50 in this embodiment controls the auxiliary inlet valve 49 based on the water temperature Tw detected by the water thermometer 21 and the room temperature Tr detected by the room temperature gauge 22. Specifically, when the temperature difference between the water temperature Tw and the room temperature Tr is equal to or greater than a threshold value, the valve control device 50 controls the auxiliary inlet valve 43 so that tap water flows into the circulation flow path 45.

When the temperature difference between the liquid to be measured and tap water is sufficiently small, the temperature inside the insulation material 20 can be made closer to the temperature of the liquid inside the cell 14 by circulating tap water through the circulation flow path 45 as described above. According to this embodiment, it is possible to improve the measurement accuracy with a simpler configuration than the third embodiment.

Fifth Embodiment
10 is a block diagram showing an example of the configuration of a measuring device 81 according to the fifth embodiment. The measuring device 81 according to the fifth embodiment differs from the third embodiment in that the circulation flow path 45 is independently configured by the heat transfer material 41.

The circulation flow path 45 in this embodiment is composed of a tubular member made of a heat transfer material 41, and is connected to a secondary water pipe 42. As in the third embodiment, the valve control device 44 controls the secondary inlet valve 43 based on the water temperature Tw detected by the water thermometer 21 and the room temperature Tr detected by the room temperature gauge 22. As in the fourth embodiment, a configuration in which tap water is circulated through the circulation flow path 45 may be adopted.

As described above, by constructing the circulation flow path 45 independently using the heat transfer material 41, heat exchange between the liquid in the circulation flow path 45 and the gas in the insulation material 20 can be efficiently performed.

Sixth Embodiment
11 is a block diagram showing an example of the configuration of a water purification system 101 according to the sixth embodiment. The water purification system 101 is a system that purifies a liquid by using information on the moving speed of particles measured by any one of the above-mentioned measuring devices 1, 51, 61, 71, and 81. The water purification system 101 includes a receiving well 111, a mixing basin 112, a coagulant injector 113, an injection amount control device 114, a flocculation basin 115, a settling basin 116, a filtration basin 117, and measuring devices 1, 51, 61, 71, and 81.

The receiving well 111 takes in the liquid to be purified (e.g., raw water taken from a river, underground water, lake, groundwater, etc.) and adjusts the water level and volume. The mixing basin 112 is a water tank for mixing a predetermined amount of liquid taken in from the receiving well 111 with a coagulant that coagulates particles contained in the liquid. The coagulant injection device 113 is a device for injecting a coagulant into the mixing basin 112. The injection amount control device 114 is a device for controlling the injection amount of the coagulant. The flocculation basin 115 is a water tank for maintaining the liquid mixed with the coagulant under a predetermined environment to form flocs in which the particles and the coagulant are coagulated. The settling basin 116 is a water tank for settling the flocs dispersed in the liquid. The filtration basin 117 is a water tank for filtering the precipitated flocs from the liquid.

The injection amount control device 114 in this embodiment controls the injection amount of the coagulant based on information related to the moving speed of particles (including flocs) acquired from the above-mentioned measuring devices 1, 51, 61, 71, and 81. The information related to the moving speed may be, for example, the above-mentioned coagulation information (information indicating the relationship between the conditions related to the coagulant and the moving speed of particles (flocs)).

According to this embodiment, the amount of coagulant injected can be optimized based on the movement speed measured with high accuracy by the above-mentioned measuring device, and excessive injection of coagulant can be prevented. This makes it possible to improve the quality and reduce costs in the water purification system 101.

Although the above describes the embodiments and modifications of the present invention, the above-mentioned embodiments and modifications are presented as examples and are not intended to limit the scope of the invention. The above-mentioned novel embodiments and modifications can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. The above-mentioned embodiments and modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

1, 51, 61, 71, 81...Measuring device, 11...Tank, 12...Pump, 13...Inlet valve, 14...Cell (container), 15A...Positive electrode (electrode section), 15B...Negative electrode (electrode section), 16...Power source, 17...Outlet valve, 18...Imaging device (imaging section), 19...Calculating device (calculating section), 20...Insulating material (insulating section), 21...Water thermometer (first detection section), 22...Room temperature gauge, 23...Air conditioning device, 24...Water pipe, 25...Drain pipe, 30...Imaging device Image area, 31...dew point meter (second detection section), 41...heat transfer material (heat transfer section), 42...secondary water distribution pipe, 43, 49...secondary inlet valve, 44, 50...valve control device, 45...circulation flow path, 48...water pipe, 101...water purification system, 111...receiving well, 112...mixing basin, 113...coagulant injection device, 114...injection amount control device, 115...flocculation basin, 116...sedimentation basin, 117...filtration basin, Td...dew point temperature, Tr...room temperature, Tw...water temperature

Claims (13)

A container for containing a liquid;
an electrode unit that applies a voltage to the liquid contained in the container;
an imaging unit that images the liquid contained in the container;
a calculation unit that calculates a moving speed of particles contained in the liquid based on the imaging data acquired by the imaging unit;
A heat insulating section that is disposed so as to surround the storage section and has a thermal conductivity lower than that of the storage section;
an air conditioning unit that adjusts the temperature of the gas in the heat insulating unit so that a temperature difference between the liquid in the container unit and the gas in the heat insulating unit is small;
A measuring device comprising: The heat insulating section is filled with an inert gas.
2. The measuring device of claim 1. The inert gas is argon.
3. The measuring device according to claim 2. The inert gas is nitrogen.
3. The measuring device according to claim 2. a first detection unit that detects a temperature of the liquid upstream of the heat insulating unit in a flow direction;
Further comprising:
The air conditioning unit adjusts the temperature of the gas in the heat insulating unit so that a difference between the temperature detected by the first detection unit and the temperature of the gas in the heat insulating unit becomes small.
5. The measuring device according to claim 4. A second detection unit that detects a dew point temperature of a gas in the thermal insulation unit;
An air conditioning unit that adjusts the temperature of the gas in the heat insulating unit so that the temperature of the gas in the heat insulating unit does not become equal to or lower than the dew point temperature;
The measuring device according to any one of claims 1 to 5, further comprising: a heat transfer section that constitutes at least a part of a circulation flow path that circulates a predetermined liquid within the heat insulating section and has a higher thermal conductivity than the heat insulating section;
The measuring device according to any one of claims 1 to 5, further comprising: The predetermined liquid is a liquid flowing out from the same water source as the liquid contained in the container.
8. The measuring device according to claim 7. The predetermined liquid is tap water.
8. The measuring device according to claim 7. a flow rate control unit that causes the specified liquid to flow into the circulation flow path when a temperature difference between the specified liquid upstream of the circulation flow path in a flow direction and the gas in the heat insulating unit is equal to or greater than a threshold value;
The measuring device according to any one of claims 7 to 9, further comprising: The circulation flow path is a space formed in the heat transfer section installed on the inner wall surface of the heat insulating section.
The measuring device according to any one of claims 7 to 10. an injection amount control unit that controls an injection amount of an aggregating agent that agglomerates the particles into the liquid based on information related to the moving speed calculated by the measurement device according to any one of claims 1 to 11;
A water purification system comprising: storing a liquid in a storage portion;
applying a voltage to the liquid contained in the container;
taking an image of the liquid contained in the container;
calculating a moving speed of particles contained in the liquid based on the acquired imaging data;
adjusting the temperature of the gas in the thermal insulation section so that a temperature difference between the liquid in the container section and the gas in the thermal insulation section is small;
Including,
The accommodation portion is surrounded by the heat insulating portion having a lower thermal conductivity than the accommodation portion.
Measuring method.

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