JP7582014B2 - Water Sampling System - Google Patents

Description

This disclosure relates to a water sampling system.

For example, there are known technologies related to sampling water for the purpose of managing the quality of treated water in water treatment infrastructure and testing the water quality of oceans and other bodies of water. For example, Patent Document 1 discloses a filtration device for an automatic water sampler that can increase the filtration speed and enhance the particle capture capacity to prevent deterioration of the sample. For example, the filtration device described in Patent Document 1 is used in combination with an automatic water sampler equipped with a refrigeration device that includes auxiliary equipment such as a freezer.

JP 2005-147820 A

Conventional techniques related to sampling of water samples, including the technique described in Patent Document 1, have not given sufficient consideration to efficiently cooling the sample water and storing it in a water sampling container in order to prevent deterioration of the quality of the sample water.

The present disclosure aims to provide a water sampling system that can efficiently cool sample water and store it in a water sampling container.

In some embodiments, the water sampling system includes a flow path through which sample water flows from a water sampling point, a water sampling container that is disposed at the end of the flow path opposite the water sampling point and that stores the sample water that has flowed through the flow path, a first cooling device that is disposed along the flow path and that cools the sample water flowing through the flow path, and a second cooling device that cools the sample water that has accumulated in the water sampling container.

This allows the water sampling system to efficiently cool the sample water and store it in the water sampling container. For example, the water sampling system has a first cooling device that cools the sample water flowing through the flow path in addition to a second cooling device that cools the sample water stored in the water sampling container. Therefore, the water sampling system can cool the sample water in advance on the flow path before the sample water flows into the water sampling container housed in the second cooling device. The sample water flowing through a thin pipe such as a liquid delivery tube that constitutes the flow path has a small flow rate, and can be efficiently cooled in a short time before flowing into the water sampling container. The water sampling system can suppress deterioration of the water quality of the sample water by rapidly cooling the sample water flowing through the flow path to an appropriate water temperature. In other words, the water sampling system can suppress the activity of microorganisms and enzymes contained in the sample water, and suppress predation, consumption, proliferation, death, and decomposition.

In one embodiment, the second cooling device may maintain the temperature of the sample water stored in the water sampling container within a first range. This allows the water sampling system to minimize deterioration of the quality of the sample water stored in the water sampling container. In other words, the water sampling system can minimize the activity of microorganisms and enzymes contained in the sample water, thereby minimizing predation, consumption, proliferation, death, and decomposition. The water sampling system can store the sample water in the water sampling container at an appropriate water temperature due to the cooling effect of the second cooling device.

In one embodiment, the first cooling device may cool the sample water so that the temperature of the sample water flowing to the end of the flow path is within the first range. This allows the water sampling system to adjust the sample water to the storage water temperature in a short time while it is being sent through the flow path. Therefore, the water sampling system does not need to cool the sample water stored in the water sampling container from a temperature higher than the first range to a temperature within the first range using the second cooling device. The second cooling device only needs to have a cooling capacity sufficient to keep the sample water stored in the water sampling container cool, and the configuration as a cooling device can be simplified.

In one embodiment, the first cooling device may have a cooling pipe arranged along the liquid supply pipe constituting the flow path and through which a fluid with a lower temperature than the sample water flowing through the liquid supply pipe flows. This allows the water sampling system to efficiently cool the sample water flowing through the flow path using the principle of a double-pipe heat exchanger. At this time, the sample water flowing through the liquid supply pipe becomes a high-temperature fluid, and the fluid flowing through the cooling pipe becomes a low-temperature fluid. The water sampling system can improve the heat exchange rate by using a counterflow method in such a double-pipe heat exchanger. Therefore, the water sampling system can efficiently cool the sample water in the flow path in a short time before it flows into the water sampling container.

In one embodiment, the second cooling device may have a cooling chamber that houses the water sampling container in a light-shielded state. This allows the water sampling system to improve the cooling effect on the sample water stored in the water sampling container. In addition, the water sampling system can suppress deterioration of the water sample quality caused by light incident from the outside. As a result, the water sampling system can suppress not only deterioration of the water sample quality caused by temperature, but also deterioration of the water sample quality caused by light.

In one embodiment, the cooling chamber may be configured to allow the water sampling container housed therein to be replaced. This allows the water sampling person to easily replace one water sampling container with another water sampling container when the sample water equivalent to the target water sampling volume has accumulated in the one water sampling container.

In one embodiment, the liquid supply pipe constituting the flow path may have a cold insulation structure. This allows the water sampling system to guide the sample water from the first cooling device to the water sampling container while maintaining the temperature of the sample water cooled by the first cooling device.

In one embodiment, the water sampling container may be configured to have a variable capacity depending on the amount of sample water stored in the water sampling container. This allows the water sampling system to maintain a small amount of free space in the water sampling container and to maintain small changes in the free space. Therefore, the water sampling system can improve the efficiency of cooling the sample water stored in the water sampling container by the second cooling device.

The water sampling system according to one embodiment may include a control device that controls the flow rate of the sample water flowing through the flow path so that the flow rate is maintained within a second range.

This allows the water sampling system to contribute to an appropriate understanding of fluctuations in the quality of the sample water. For example, a control device included in the water sampling system controls the adjustment unit so that the flow rate of the sample water flowing through the flow path is maintained within the second range. Through control by such a control device, the water sampling system can perform water sampling processing over a long period of time while steadily maintaining the flow rate and flow rate of the sample water. The water sampling system can also achieve a target water sampling volume over a long period of time while steadily sampling small amounts of sample water.

The water sampling system can therefore properly collect sample water containing the worst or maximum microbiological load without omission. The above-described water sampling method using the water sampling system also makes it possible to detect sudden changes in the quality of the sample water and to detect worst-case scenarios. The worst-case water quality conditions occurring during water sampling are reflected in the sample water, making it possible to not miss any quality risks caused by the worst-case scenario. The water sampling system can collect sample water as a representative sample and an average sample that reflect the overall contamination status of the target fluid. As a result, it becomes easier to properly grasp the water quality fluctuations of the sample water and the control performance of the water treatment system.

In one embodiment, the control device may control the flow rate so that the sample water flows through the flow path continuously for one day. This allows the water sampling system to collect the sample water obtained through the valve in the water sampling container at a predetermined period, such as one day. For example, the water sampling system can be used to continuously sample the sample water at a predetermined period for 365 days to evaluate fluctuations over the long term, such as hourly, daily, and monthly. Even when the sample water is continuously sampled for a long period, such as 24 hours, the water sampling system can suppress deterioration of the water quality of the sample water until subsequent analysis can be performed due to the cooling and cold storage effects of the first and second cooling devices. Even when the sample water is continuously sampled for a long period, such as 24 hours, the water sampling system can maintain appropriate storage conditions for the sample water accumulated in the water sampling container by the first and second cooling devices.

The present disclosure provides a water sampling system that can efficiently cool sample water and store it in a water sampling container.

FIG. 1 is a schematic diagram of a water sampling system according to one embodiment of the present disclosure. FIG. 2 is a diagram showing the configuration of the area II enclosed by the two-dot chain line in FIG. 1 in more detail. 1 is a graph showing an example of a temperature distribution along a flow path in a double-pipe heat exchanger constituted by a liquid supply pipe and a cooling pipe. FIG. 2 is a functional block diagram showing a schematic configuration of the control device shown in FIG. 1 . 1 is a flowchart for explaining a control method according to an embodiment of the present disclosure. FIG. 3 is a configuration diagram corresponding to FIG. 2 and showing a modified example of the water sampling system of FIG. 1. FIG. 11 is a graph showing another example of temperature distribution along a flow path in a double-pipe heat exchanger constituted by a liquid supply pipe and a cooling pipe.

The background technology and issues are explained in more detail.

For example, in field work related to water quality surveys, it is standard to manually collect water samples in a short time and quickly transport them to a laboratory for subsequent processing such as analysis. Generally, collected water samples are kept cool during transportation using simple items such as ice packs and cooler boxes in order to prevent changes in their properties and state, or deterioration. Possible causes of deterioration of water samples include, for example, the proliferation, death, predation, and consumption of microorganisms. In the literature related to environmental surveys, there are many cases where water samples are reported to be stored in the dark at, for example, 4°C after collection, and then processed within 24 hours.

For example, the United States Environmental Protection Agency (2005) Method 1623: Cryptosporidium and Giardia in Water by Filtration/IMS/FA. specifies that sampling should be performed at 1-10°C. For example, the American Public Health Association (2017) Standard Methods for the Examination of Water and Wastewater, 23rd Edition, Water Environment Federation, Alexandria, VA, 9060 B. specifies that if processing cannot be started within one hour of collection, the sample water should be stored in a cool, dark place at 1-10°C for up to 24 hours to avoid freezing. In other words, the sample water should be processed within 24 hours of collection.

In addition, in order to make the collected sample water easier to transport, a so-called bag-in-box method is sometimes used, in which a disposable bag with a variable volume is packed in an outer shell container. This bag-in-box method is used when the amount of sample water to be collected is not yet determined.

There are also water sampling devices that come with a refrigerator, and the collected water sample is stored in the refrigerator. The temperature inside the refrigerator can be adjusted, for example, within the range of -40°C to 60°C.

In addition, the filtration device for an automatic water sampler described in Patent Document 1 prevents deterioration of a liquid sample containing a high concentration of suspended solids such as microorganisms by filtering the sampler to remove the suspended solids and obtain a supernatant liquid when the liquid sampler is used to sample the liquid. In the case of a liquid sample containing a high concentration of microorganisms and substrates, such as the mixed liquid in a reaction tank at a sewage treatment plant, the deterioration of the sample may progress rapidly even while cooling is being attempted to reduce the activity of the microorganisms. Therefore, the filtration device for an automatic water sampler described in Patent Document 1 filters the liquid sample immediately after sampling to separate the microorganisms and prevent deterioration of the sample. The automatic water sampler is equipped with auxiliary equipment such as a refrigerator, allowing the liquid sample to be preserved more effectively.

In the above-mentioned conventional technology, for example, sample water is stored in a simple water sampling container because it is assumed that the sample water will be promptly processed after collection. Such water sampling containers are limited in size to be portable to a laboratory. For example, the water sampler must prepare disposable containers of multiple sizes and combine these to collect sample water. If the water sampling container is not a disposable container, the water sampler must wash the water sampling container after use.

In the case of water sampling devices with refrigerators, there was a problem that the cooling time required to cool the sample water inside the refrigerator was long. There was also a problem that the cooling time differed depending on the free space in the water sampling container.

Below, we will explain a water sampling system 1 that can solve these problems. One embodiment of the present disclosure will be explained with reference to the drawings.

The water sampling system 1 described below can be applied to a variety of fields and uses. For example, the water sampling system 1 can be used to sample water and store sampled water to understand water quality management and treatment performance in water treatment infrastructure including water purification plants, sewage treatment plants, water reclamation facilities, and seawater desalination facilities. The water sampling system 1 can be applied to sample and store sample water used for testing water quality such as fine particles, colloidal dispersions, and microorganisms to understand the dynamics in environmental surveys of water bodies including rivers, oceans, waterfront areas, pools, and bathing beaches.

The water sampling system 1 can be applied to sampling and storing water samples to be used for testing water quality for particles, colloidal dispersions, microorganisms, etc., for understanding the risk of microbial infection in a city that covers water areas and environmental infrastructure. The water sampling system 1 can be applied to sampling and storing water samples to be used for testing water quality for particles, colloidal dispersions, microorganisms, etc., for quantifying risk and performing comparative verification with a threshold value that can be determined as safe, for the purpose of qualitative risk, safety understanding, and quality control of liquids used in the manufacture of beverages or processed foods.

The water sampling system 1 can be used to sample and store water samples used for testing the quality of industrial water, irrigation water, agricultural water, etc. The water sampling system 1 can be used to sample and store water samples used for testing the quality risks, safety understanding, and quality control of liquids used for temperature and humidity control, such as mist spraying, humidification devices, and sprinkling water. The water sampling system 1 can be used to sample and store water samples used for quality control testing in pharmaceutical manufacturing and artificial dialysis therapy, etc.

In this specification, "microorganisms" include, for example, protozoa, bacteria, and viruses. "Protozoa" include, for example, Cryptosporidium and Giardia. "Bacteria" include, for example, Escherichia coli, Staphylococcus aureus, Vibrio cholerae, Mycobacterium tuberculosis, and Helicobacter pylori. "Viruses" include, for example, norovirus, adenovirus, enteric viruses, and Pepper Mild Mottle Virus (PMMoV).

Figure 1 is a schematic diagram of a water sampling system 1 according to one embodiment of the present disclosure. The configuration and functions of the water sampling system 1 according to one embodiment will be mainly described with reference to Figure 1. In Figure 1, solid lines connecting components indicate paths of fluids, and dashed lines connecting components indicate paths of electrical signals.

The water sampling system 1 is a system used to sample and store treated water, for example, in a water treatment infrastructure. The fluid sampled by the water sampling system 1 flows in one direction through a pipe 2 that constitutes part of the water treatment infrastructure. For example, the water quality of such a fluid changes over time. The pipe 2 may constitute a main flow path in the water treatment infrastructure, or may constitute a bypass flow path branched off from the main flow path.

The water sampling system 1 has a removable valve 3 attached to the side of the pipe 2. A portion of the fluid flowing in one direction through the pipe 2 is sampled from the location of the valve 3 on the pipe 2, which serves as the water sampling point. The water sampling system 1 has a water sampling container 4 and a flow path 5. The flow path 5 is composed of a liquid supply pipe that is arranged continuously from the removable valve 3 to the water sampling container 4. Sample water that flows in from the water sampling point flows through the flow path 5. The water sampling container 4 is arranged at the end 5a of the flow path 5 opposite the water sampling point, and stores the sample water that has flowed through the flow path 5. In the water sampling system 1, sample water is sampled from the flow path formed by the pipe 2 through the removable valve 3 and the flow path 5 into the water sampling container 4.

Figure 2 is a diagram showing the configuration of the area II enclosed by the two-dot chain line in Figure 1 in more detail. The liquid supply pipe 5b constituting the flow path 5 in Figure 2 may have a cold insulation structure. For example, the liquid supply pipe 5b may have a vacuum insulation structure in which a vacuum state is maintained between the double-structured pipe walls. In Figure 2, as an example, the water sampling container 4 is configured with a fixed capacity rather than a variable capacity. For example, the water sampling container 4 may include a disposable plastic container. The water sampling system 1 has a first cooling device 10 and a second cooling device 20 for cooling the sample water collected.

The second cooling device 20, for example, houses the water sampling container 4 inside and cools the sample water stored in the water sampling container 4. The second cooling device 20 may maintain the temperature of the sample water stored in the water sampling container 4 within a first range. In other words, the sample water stored in the water sampling container 4 is stored in the second cooling device 20 while being maintained at a temperature within the first range by the second cooling device 20.

In this specification, the "first range" includes, for example, a temperature range capable of suppressing deterioration of the water quality of the sample water stored in the water sampling container 4. In other words, the first range includes a temperature range capable of suppressing the activity of microorganisms and enzymes contained in the sample water, thereby suppressing predation, consumption, proliferation, death, and decomposition. For example, the first range includes a temperature range from 1°C to 10°C.

The second cooling device 20 may have a cooling chamber that houses the water sampling container 4 in a light-shielded state. In other words, such a cooling chamber may have both a light-shielding function for the sample water stored in the water sampling container 4 and a cold storage function that maintains the temperature of the sample water stored in the water sampling container 4 within a first range. Such a cooling chamber may be configured so that the water sampling container 4 stored therein can be replaced.

The first cooling device 10 is disposed along the flow path 5 and cools the sample water flowing through the flow path 5. The first cooling device 10 adjusts the temperature of the sample water flowing through the flow path 5 to an appropriate temperature before the sample water flows into the water sampling container 4. For example, the first cooling device 10 may cool the sample water so that the temperature of the sample water flowing into the end 5a of the flow path 5 falls within a first range. The first cooling device 10 may be disposed on the flow path 5 at a position as close as possible to the water sampling container 4 and the second cooling device 20. This allows the sample water to flow into the water sampling container 4 while more reliably maintaining the cooling effect of the first cooling device 10.

The first cooling device 10 may include a cooling pipe 11 arranged along the liquid supply pipe 5b constituting the flow path 5 and through which a fluid with a lower temperature than the sample water flowing through the liquid supply pipe 5b flows. The cooling pipe 11 may be attached to the liquid supply pipe 5b so as to surround a part of the liquid supply pipe 5b from the outside. That is, a double-pipe heat exchanger may be formed by the liquid supply pipe 5b and the cooling pipe 11. In this case, the flow direction of the low-temperature fluid flowing through the cooling pipe 11 may be opposite to the flow direction of the sample water as a high-temperature fluid flowing through the liquid supply pipe 5b. That is, a counterflow method may be used in the double-pipe heat exchanger.

Figure 3 is a graph showing an example of temperature distribution along the flow path of a double-pipe heat exchanger consisting of a liquid supply pipe 5b and a cooling pipe 11. The graph shown in Figure 3 shows an example of temperature distribution in a counterflow system as an example. The upper graph in Figure 3 shows the temperature distribution of sample water as a high-temperature fluid along the flow path 5. The sample water flows, for example, from left to right on the graph. The lower graph in Figure 3 shows the temperature distribution of a low-temperature fluid along the flow path consisting of a cooling pipe 11. The low-temperature fluid flows, for example, from right to left on the graph.

For example, heat is transferred from the sample water as a high-temperature fluid to the low-temperature fluid, thereby cooling the sample water on the flow path 5 along the first cooling device 10. The temperature of the sample water decreases, for example, from temperature _T1 to temperature _T2 . Meanwhile, the low-temperature fluid flowing through the cooling pipe 11 along the flow path 5 receives heat from the sample water flowing through the flow path 5 and is heated. The temperature of the low-temperature fluid increases, for example, from temperature _t1 to temperature _t2 . The mass flow rates (kg·s ⁻¹ ) of the high-temperature fluid and the low-temperature fluid are M and m, respectively, and the specific heats (J·kg ⁻¹ ·K ⁻¹ ) of the high-temperature fluid and the low-temperature fluid are C _p and c _p , respectively.

At this time, the heat flow rate (W) Q _H lost by the high temperature fluid, the heat flow rate (W) Q _L gained by the low temperature fluid, and the heat exchange flow rate (W) Q in the double pipe heat exchanger are each calculated by the following formulas.

Here, U is the overall heat transfer coefficient (W·m ⁻² ·K ⁻¹ ), A is the heat transfer area (m ² ), and ΔT _lm is the logarithmic mean temperature difference (K) and is calculated by the following formula:

For example, assuming that the average water temperature _T1 of the sample water before being cooled by the first cooling device 10 is 30° C. and the target water temperature _T2 immediately after being cooled by the first cooling device 10 is 10° C., the water temperature of the low-temperature fluid is considered based on the heat transfer area A calculated from the diameter and length of the liquid supply pipe 5b and the cooling pipe 11. Alternatively, the length of the liquid supply pipe 5b and the cooling pipe 11 may be designed based on the practical temperature range of the low-temperature fluid.

For example, let us consider a case where the target amount of water collected per day is 1000 liters (L) and about 0.7 L of sample water flows through the liquid supply pipe 5b per minute. For example, when attempting to cool the sample water from 30°C to 10°C over one minute using a double-pipe heat exchanger, if the sample water (specific heat 1.0 Cal/g/°C, density 1.0 g/ ^cm3 ) is made to flow down an aluminum cooling section provided in the liquid supply pipe 5b along the cooling pipe 11 over one minute, the following cooling capacity for the sample water can be estimated.
Specific heat heat exchanger load capacity (kW)=volume of sample water 0.0007 (m ³ )×specific heat of sample water 4.2 (kJ/kg/° C.)×density of sample water 1000 (kg/m ³ )×20 (° C.)/60 (sec)=0.98 (kW)

The cooling capacity is estimated as a specific heat exchanger load capacity of approximately 1 kW. Therefore, the first cooling device 10 may have a cooling capacity of 1 kW or, for example, 1.2 kW, taking into account a safety factor of 20%. Alternatively, if the time during which the sample water flows through the liquid supply pipe 5b along the cooling pipe 11 is extended from 60 seconds to 120 seconds, the cooling capacity of the first cooling device 10 can be reduced to about half.

By using the first cooling device 10 as described above, the sample water immediately after passing through the first cooling device 10 on the flow path 5 is reliably cooled to 10°C or less. In addition, since the liquid delivery tube 5b constituting the flow path 5 has a cooling structure, the sample water is reliably kept at 10°C or less even at the end 5a of the flow path 5. Furthermore, since the water sampling container 4 is housed inside the second cooling device 20, the sample water accumulated in the water sampling container 4 is reliably kept at 10°C or less even in the water sampling container 4.

Referring again to FIG. 1, the water sampling system 1 may have a control device 30. The sample water is drawn into the water sampling container 4 by the control device 30, which is disposed on the flow path 5 between the valve 3 and the water sampling container 4. As described below, the control device 30 may control the flow rate of the sample water flowing through the flow path 5 so that the flow rate is maintained within a second range. The control device 30 may control the flow rate so that the sample water flows through the flow path 5 constantly throughout the day.

Figure 4 is a functional block diagram showing the schematic configuration of the control device 30 in Figure 1. The configuration and functions of the control device 30 will be mainly described with reference to Figures 1 and 4. The control device 30 has a measurement unit 31, an adjustment unit 32, an input unit 33, an output unit 34, a memory unit 35, and a control unit 36.

The measuring unit 31 measures at least one of the flow rate and flow velocity of the sample water flowing through the flow path 5. The measuring unit 31 transmits the measured information to the control unit 36. In this specification, the "flow rate" means, for example, the volume of the sample water passing through the liquid supply pipe 5b constituting the flow path 5 per unit time, and is expressed in units of L/sec or ^m3 /sec. The "flow rate" means, for example, the flow rate divided by the cross-sectional area of the liquid supply pipe 5b constituting the flow path 5, and is expressed in units of m/sec. For example, the measuring unit 31 includes a flow meter 31a that is disposed downstream of the adjustment unit 32 in the flow path 5 and measures the flow rate of the sample water. Without being limited thereto, the measuring unit 31 may include a flow rate meter that is disposed on the flow path 5 and measures the flow rate of the sample water.

The adjustment unit 32 adjusts the flow rate of the sample water flowing through the flow path 5 based on a control signal received from the control unit 36. If the liquid delivery tubes 5b that make up the flow path 5 are the same and have a constant inner diameter, the adjustment unit 32 adjusts the flow rate of the sample water by adjusting the flow rate of the sample water flowing through the flow path 5. For example, the adjustment unit 32 includes a liquid delivery pump 32a that is disposed upstream of the flow meter 31a in the flow path 5 and adjusts the flow rate of the sample water.

The liquid delivery pump 32a delivers the sample water flowing through the flow path 5 to the downstream side. The liquid delivery pump 32a may be, for example, a peristaltic pump (registered trademark) that delivers liquid by squeezing a soft tube with a roller, or any other pump capable of delivering a specified sample water. Either pressurization or suction may be selected as the type of liquid delivery pump 32a depending on the properties of the sample water. The adjustment unit 32 may be configured to be reconfigurable to either pressurization or suction type liquid delivery pump 32a depending on the sample water.

The input unit 33 includes one or more input interfaces that receive input operations from a user and acquire input information based on the user's operations. For example, the input unit 33 includes, but is not limited to, physical keys, capacitive keys, a touch screen that is integrated with the display of the output unit 34, and a microphone that receives voice input.

The output unit 34 includes one or more output interfaces that output information to the user. For example, the output unit 34 includes, but is not limited to, a display that outputs information as an image and a speaker that outputs information as sound.

The memory unit 35 includes any memory module including a hard disk drive (HDD), a solid state drive (SSD), an electrically erasable programmable read-only memory (EEPROM), a read-only memory (ROM), and a random access memory (RAM). The memory unit 35 may function, for example, as a main memory device, an auxiliary memory device, or a cache memory. The memory unit 35 stores any information used in the operation of the control device 30. For example, the memory unit 35 stores system programs and application programs. The memory unit 35 is not limited to being built into the control device 30, and may include an external memory module connected by a digital input/output port such as a universal serial bus (USB).

The control unit 36 includes one or more processors. In one embodiment, the "processor" is, but is not limited to, a general-purpose processor or a dedicated processor specialized for a particular process. The control unit 36 is communicatively connected to each component that constitutes the control device 30, and controls the operation of the entire control device 30.

The control unit 36 controls the adjustment unit 32 based on at least one of the flow rate and flow velocity of the sample water measured by the measurement unit 31. More specifically, the control unit 36 receives information related to the measurement transmitted from the measurement unit 31. The control unit 36 transmits a control signal to the adjustment unit 32 based on the received information related to the measurement. The control unit 36 controls the adjustment unit 32 so that the flow velocity of the sample water in the flow path 5 is maintained within the second range.

More specifically, the control unit 36 controls the liquid delivery pump 32a based on the flow rate of the sample water measured by the flow meter 31a. The control unit 36 receives flow rate information transmitted from the flow meter 31a. The control unit 36 transmits a control signal to the liquid delivery pump 32a based on the received flow rate information. The control unit 36 controls the liquid delivery pump 32a so that the flow rate of the sample water in the flow path 5 is maintained within a second range. That is, the control unit 36 adjusts the sampling speed and instantaneous amount of sample water flowing through the flow path 5 while linking the liquid delivery pump 32a and the flow meter 31a to each other.

For example, the control unit 36 may calculate the second range based on piping information and water sampling information acquired in advance. In this specification, "piping information" includes, for example, the inner diameter of the liquid supply pipe 5b that constitutes the flow path 5. "Water sampling information" includes the water sampling period, the target water sampling amount, and the allowable range from the target water sampling amount.

In this specification, the "second range" includes a range of flow rates when the sample water is steadily flowing through the flow path 5 so as to reach a target value for the amount of water collected during a preset water collection period. For example, when it is desired to collect a maximum amount of water of 1000 L in small amounts over a day, the average flow rate required per second can be calculated. In addition, the average flow rate can be calculated based on the inner diameter of the liquid delivery tube 5b that constitutes the flow path 5. For example, the second range may be calculated as a range of error determined based on an allowable range from a preset target value for the amount of water collected for such an average flow rate. For example, the control unit 36 may control the adjustment unit 32 so that the sample water constantly flows through the flow path 5 over a day while maintaining the flow rate of the sample water within the second range.

For example, when the flow rate of the sample water in the flow path 5 is about to fall below the second range, the control unit 36 may increase the power of the liquid delivery pump 32a included in the adjustment unit 32 to increase the force that draws the sample water from the pipe 2 to the water sampling container 4. For example, when the flow rate of the sample water in the flow path 5 is about to exceed the second range, the control unit 36 may decrease the power of the liquid delivery pump 32a included in the adjustment unit 32 to decrease the force that draws the sample water from the pipe 2 to the water sampling container 4.

For example, in FIG. 1, when sample water is collected from the pipe 2 through the flow path 5 to the water sampling container 4 without passing through the first cooling device 10, the liquid supply pipe 5b constituting the flow path 5 may be clogged by turbidity and precipitates contained in the sample water. In order to prevent such clogging of the liquid supply pipe 5b, the liquid supply pipe 5b constituting the flow path 5 and the adjustment unit 32 may be designed so that the flow rate of the sample water flowing through the flow path 5 is 1 m/sec or more. For example, when the inner diameter of the liquid supply pipe 5b constituting the flow path 5 is 15 mm, the flow rate corresponding to a flow rate of 1 m/sec is about 170 mL/sec (about 10 L/min). Therefore, in one embodiment, the second range may be included in the range of 1 m/sec or more.

Figure 5 is a flowchart for explaining a control method according to one embodiment of the present disclosure. With reference to Figure 5, the control method executed using the control device 30 of Figure 1 will be mainly explained.

In step S100, the control unit 36 of the control device 30 acquires piping information. For example, such piping information may be input by a user using the input unit 33 and transmitted from the input unit 33 to the control unit 36.

In step S101, the control unit 36 acquires water sampling information. For example, such water sampling information may be input by a user using the input unit 33 and transmitted from the input unit 33 to the control unit 36.

In step S102, the control unit 36 calculates the second range based on the piping information acquired in step S100 and the water sampling information acquired in step S101.

In step S103, the control unit 36 uses the measurement unit 31 to measure at least one of the flow rate and flow velocity of the sample water flowing through the flow path 5.

In step S104, the control unit 36 controls the flow rate of the sample water flowing through the flow path 5 based on at least one of the flow rate and flow velocity of the sample water measured in step S103. In step S104, the control unit 36 controls the adjustment unit 32 so that the flow rate of the sample water is maintained within the second range calculated in step S102.

According to the water sampling system 1 according to the embodiment described above, the sample water can be efficiently cooled and stored in the water sampling container 4. For example, the water sampling system 1 has a first cooling device 10 that cools the sample water flowing through the flow path 5 in addition to the second cooling device 20 that cools the sample water stored in the water sampling container 4. This allows the water sampling system 1 to cool the sample water in advance on the flow path 5 before the sample water flows into the water sampling container 4 housed in the second cooling device 20. The sample water flowing through a narrow pipe such as the liquid delivery pipe 5b that constitutes the flow path 5 has a small flow rate, and can be efficiently cooled in a short time before flowing into the water sampling container 4. The water sampling system 1 can suppress deterioration of the water quality of the sample water by rapidly cooling the sample water flowing through the flow path 5 to an appropriate water temperature. In other words, the water sampling system 1 can suppress predation, preying, proliferation, death, and decomposition by suppressing the activity of microorganisms and enzymes contained in the sample water.

The water sampling system 1 can shorten the cooling time required to cool the sample water in the cooling chamber of the second cooling device 20 by pre-cooling the sample water using the first cooling device 10. In addition, the water sampling system 1 can also reduce the difference in cooling time caused by the free space in the water sampling container 4 by pre-cooling the sample water using the first cooling device 10.

By the second cooling device 20 maintaining the temperature of the sample water stored in the water sampling container 4 within the first range, the water sampling system 1 can minimize deterioration of the quality of the sample water stored in the water sampling container 4. In other words, the water sampling system 1 can minimize the activity of microorganisms and enzymes contained in the sample water, thereby minimizing predation, consumption, proliferation, death, and decomposition. The water sampling system 1 can store the sample water in the water sampling container 4 at an appropriate water temperature due to the cooling effect of the second cooling device 20.

The first cooling device 10 cools the sample water so that the temperature of the sample water flowing into the end 5a of the flow path 5 falls within the first range, and the water sampling system 1 can adjust the sample water to the storage water temperature in a short time while it is being sent through the flow path 5. This eliminates the need for the water sampling system 1 to cool the sample water stored in the water sampling container 4 from a temperature higher than the first range to a temperature within the first range using the second cooling device 20. The second cooling device 20 only needs to have a cooling capacity sufficient to keep the sample water stored in the water sampling container 4 cool, and the configuration as a cooling device can be simplified.

Since the first cooling device 10 has a cooling pipe 11 arranged along the liquid supply pipe 5b that constitutes the flow path 5, the water sampling system 1 can efficiently cool the sample water flowing through the flow path 5 by the principle of a double-pipe heat exchanger. At this time, the sample water flowing through the liquid supply pipe 5b becomes a high-temperature fluid, and the fluid flowing through the cooling pipe 11 becomes a low-temperature fluid. The water sampling system 1 can improve the heat exchange rate by using a countercurrent method in such a double-pipe heat exchanger. Therefore, the water sampling system 1 can efficiently cool the sample water on the flow path 5 in a short time before it flows into the water sampling container 4.

By having a cooling chamber in which the second cooling device 20 houses the water sampling container 4 in a light-shielding state, the water sampling system 1 can improve the cooling effect on the sample water stored in the water sampling container 4. In addition, the water sampling system 1 can suppress deterioration of the water sample quality caused by light incident from the outside. As a result, the water sampling system 1 can suppress not only deterioration of the water sample quality caused by temperature, but also deterioration of the water sample quality caused by light.

The cooling cabinet is configured so that the water sampling container 4 housed therein can be replaced, so that the water sampling person can easily replace one water sampling container 4 with another water sampling container 4 when the sample water equivalent to the target water sampling amount has accumulated in that water sampling container 4.

Since the liquid supply pipe 5b constituting the flow path 5 has a cold storage structure, the water sampling system 1 can guide the sample water from the first cooling device 10 to the water sampling container 4 while maintaining the temperature of the sample water cooled by the first cooling device 10.

The water sampling system 1 can contribute to an appropriate understanding of fluctuations in the quality of the sample water. For example, the control device 30 included in the water sampling system 1 controls the adjustment unit 32 so that the flow rate of the sample water flowing through the flow path 5 is maintained within the second range. Through such control by the control device 30, the water sampling system 1 can perform water sampling processing over a long period of time while steadily maintaining the flow rate and flow rate of the sample water. The water sampling system 1 can also achieve a target water sampling volume over a long period of time while steadily sampling small amounts of sample water.

Therefore, the water sampling system 1 can properly collect sample water containing the worst or maximum microbiological load without any leakage. The above-mentioned water sampling method using the water sampling system 1 also makes it possible to detect sudden changes in the quality of the sample water and to detect worst-case scenarios. The worst water quality conditions occurring during water sampling are reflected in the sample water, making it possible to not miss any quality risks caused by the worst-case scenario. The water sampling system 1 can collect sample water as a representative sample and an average sample that reflect the overall contamination status of the target fluid. As a result, it becomes easier to properly grasp the water quality changes of the sample water and the control performance of the water treatment system.

For example, the water sampling system 1 can help capture the impact on the water quality of the fluid caused by physical or mechanical shocks associated with membrane filtered water, treatment processes, filtration and backwashing, and changes in the operation of the treatment process. The water sampling system 1 can also be used to detect membrane rupture and manage quality assurance of water quality, such as changes in pore size and rupture caused by membrane expansion.

The water sampling system 1 can collect large amounts of water, such as 1000 L, while performing sample water sampling processing without being limited to protozoa, including Cryptosporidium and Giardia.

By including the flowmeter 31a in the measurement unit 31, the control device 30 can execute the control process while referring to the flow rate measured by the flowmeter 31a when controlling the adjustment unit 32 so that the flow rate is maintained within the second range.

The adjustment unit 32 can also include a liquid delivery pump 32a that adjusts the flow rate of the sample water. This allows the water sampling system 1 to achieve a higher flow rate and flow rate on the flow path 5. This prevents clogging of the liquid delivery tube 5b that constitutes the flow path 5 due to turbidity and sediments contained in the sample water. For example, this effect becomes more pronounced when the specified range is included in a range of 1 m/sec or more. In the water sampling system 1, the use of the liquid delivery pump 32a can also ensure sufficient pressure to send the sample water downstream.

The control device 30 controls the flow rate of the sample water so that the sample water flows through the flow path 5 all day, and the water sampling system 1 can collect the sample water obtained through the valve 3 in the water sampling container 4 at a predetermined period, such as one day. For example, the water sampling system 1 can be used to continuously collect sample water at a predetermined period for 365 days to evaluate hourly, daily, monthly, and other fluctuations over the long term. Even when the sample water is continuously collected for a long period of time, such as 24 hours, the water sampling system 1 can suppress deterioration of the water quality of the sample water until subsequent analysis can be performed due to the cooling and cold storage effects of the first cooling device 10 and the second cooling device 20. Even when the sample water is continuously collected for a long period of time, such as 24 hours, the water sampling system 1 can maintain appropriate storage conditions for the sample water stored in the water sampling container 4 by the first cooling device 10 and the second cooling device 20.

The valve 3 is removable, so it can be removed and cleaned when the water sampling system 1 is not performing water sampling processing.

Although the present disclosure has been described based on the drawings and examples, it should be noted that a person skilled in the art would be able to make various modifications and alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included in the scope of the present disclosure. For example, the functions included in each configuration or step can be rearranged so as not to cause logical inconsistencies, and multiple configurations or steps can be combined into one or divided.

For example, the present disclosure may also be realized as a program describing the processing contents for implementing each function of the control device 30 described above, or a storage medium on which a program is recorded. It should be understood that these are also included within the scope of the present disclosure.

For example, the shape, arrangement, orientation, and number of each of the above-mentioned components are not limited to the above description and the illustrations in the drawings. The shape, arrangement, orientation, and number of each of the components may be configured arbitrarily as long as the function can be realized.

For example, based on the water sampling system 1 according to the embodiment described above, the contamination status and removal status may be understood based on the number of microorganisms present, regardless of whether they are alive or dead.

In the water sampling system 1, the sampling period of the sample water may be variable to enable application to the various fields mentioned above, including water supply, food, and drinking water. The shape of the valve 3 for sampling the water may be variable.

In the above embodiment, the first cooling device 10 is described as cooling the sample water so that the temperature of the sample water flowing into the end 5a of the flow path 5 falls within the first range, but this is not limited to the above. The temperature of the sample water flowing into the end 5a of the flow path 5 does not have to fall within the first range. For example, the first cooling device 10 may cool the sample water so that the temperature of the sample water flowing into the end 5a of the flow path 5 is slightly higher than the first range. At this time, the second cooling device 20 may cool the sample water again so that the temperature of the sample water accumulated in the water sampling container 4 falls to the first range.

In the above embodiment, the first cooling device 10 has a cooling pipe 11, and is described as cooling the sample water flowing through the flow path 5 using the principle of a double-pipe heat exchanger, but is not limited to this. The first cooling device 10 may have any other configuration capable of cooling the sample water flowing through the flow path 5. For example, the first cooling device 10 may have a Peltier element instead of or in addition to the cooling pipe 11.

In the above embodiment, the second cooling device 20 has been described as having a cooling chamber that houses the water sampling container 4 in a light-shielded state, but is not limited to this. The second cooling device 20 may be configured in any manner that can cool the sample water stored in the water sampling container 4. For example, the second cooling device 20 does not need to have a light-shielding function.

In the above embodiment, the liquid supply pipe 5b constituting the flow path 5 has been described as having a cold insulation structure, but this is not limited thereto. The liquid supply pipe 5b does not need to have a cold insulation structure as long as the water sampling system 1 can efficiently cool the sample water and store it in the water sampling container 4.

Figure 6 is a configuration diagram corresponding to Figure 2, showing a modified example of the water sampling system 1 of Figure 1. In the above embodiment, the water sampling container 4 is described as being configured with a fixed capacity rather than a variable capacity, but this is not limited to this. The water sampling container 4 may be configured with a variable capacity depending on the amount of sample water stored in the water sampling container 4. For example, the water sampling container 4 may be configured in a so-called bag-in-box method, in which a disposable bag with a variable capacity is packed in an outer container. The water sampling container 4 may be configured by placing a disposable container such as a sterilized plastic bag inside the outer container.

By configuring the water sampling container 4 to have a variable capacity, the water sampling system 1 can maintain the free space in the water sampling container 4 small and also maintain small changes in the free space. This allows the water sampling system 1 to improve the cooling efficiency of the second cooling device 20 for the sample water stored in the water sampling container 4. In addition, by arranging a disposable container inside the outer shell container, the water sampling system 1 can replace the container with a new one each time water is sampled and use it as the water sampling container 4. This saves the water sampling person the trouble of washing the container to reuse it for water sampling, and does not need to consider the influence of previous sample water remaining in the container. The water sampling system 1 realizes specifications that suppress cross-contamination of sample water before and after processing.

The water sampling container 4 is not limited to a configuration based on a disposable bag as described above, and may be configured as a container that can be reused multiple times. In other words, after the water sampling person has finished sampling the sample water using the water sampling system 1, he or she may wash the water sampling container 4 and use it again for water sampling.

FIG. 7 is a graph showing another example of the temperature distribution along the flow path of the double-pipe heat exchanger composed of the liquid supply pipe 5b and the cooling pipe 11. In the above embodiment, the counterflow method is described with reference to FIG. 3 as being used in the double-pipe heat exchanger, but the present invention is not limited to this. As shown in FIG. 7, the parallel flow method may be used in the double-pipe heat exchanger. The upper graph in FIG. 7 shows the temperature distribution of the sample water as the high-temperature fluid along the flow path 5. The sample water flows, for example, from left to right on the graph. The lower graph in FIG. 7 shows the temperature distribution of the low-temperature fluid along the flow path composed of the cooling pipe 11. The low-temperature fluid flows, for example, from left to right on the graph. At this time, the above-mentioned ΔT ₁ and ΔT ₂ are replaced by the following equations.

二重管式熱交換器に関して上述した他の算出方法については、図７の変形例においても同様に当てはまる。

The other calculation methods described above with respect to the double-pipe heat exchanger also apply to the modified example of FIG.

In the above embodiment, the adjustment unit 32 of the control device 30 is described as including the liquid delivery pump 32a, but is not limited to this. The adjustment unit 32 may include a throttle valve instead of the liquid delivery pump 32a. In this case, the water sampling system 1 assumes a case where the water sampling speed is low and precipitation occurs in the flow path 5. More specifically, it assumes a case where the flow rate of the sample water flowing through the flow path 5 is lower than 1 m/sec. Such a throttle valve may be configured integrally with the flow meter 31a, or may be configured as a separate component from the flow meter 31a.

When the adjustment unit 32 includes a throttle valve, the adjustment unit 32 may include, in addition to the throttle valve, a drainage flow path that drains excess sample water that does not pass through the throttle valve. The control device 30 may also have a cleaning unit in addition to the components shown in FIG. 4. The cleaning unit cleans the flow path 5 upstream of the throttle valve and the drainage flow path with cleaning water. The cleaning unit prevents clogging of the liquid supply tube 5b that constitutes the flow path 5 due to turbidity and sediments contained in the sample water.

REFERENCE SIGNS LIST 1 Water sampling system 2 Piping 3 Valve 4 Water sampling container 5 Flow path 5a End 5b Liquid delivery pipe 10 First cooling device 11 Cooling pipe 20 Second cooling device 30 Control device 31 Measurement section 31a Flowmeter 32 Adjustment section 32a Liquid delivery pump 33 Input section 34 Output section 35 Memory section 36 Control section

Claims (9)

a flow path through which sample water flows from a water sampling point;
a water sampling container disposed at an end of the flow path opposite to the water sampling point, for storing the sample water flowing through the flow path;
a first cooling device disposed along the flow path and configured to cool the sample water flowing through the flow path;
A second cooling device that cools the sample water stored in the water sampling container;
Equipped with
the first cooling device cools the sample water so that a temperature of the sample water flowing into the end of the flow path is included in a first range in which a temperature of the sample water stored in the water sampling container is maintained .
Water collection system. The second cooling device maintains the temperature of the sample water stored in the water sampling container within the first range.
2. The water sampling system of claim 1. the first cooling device is disposed along a liquid feed pipe constituting the flow path, and has a cooling pipe through which a fluid having a lower temperature than the sample water flowing through the liquid feed pipe flows;
3. The water sampling system according to claim 1 or 2 . The second cooling device has a cooling chamber for accommodating the water sampling container therein in a light-shielded state.
4. The water sampling system according to claim 1 . The cooling chamber is configured so that the water sampling container housed therein can be replaced.
5. The water sampling system according to claim 4 . A liquid supply pipe constituting the flow path located between the first cooling device and the second cooling device has a cold insulation structure.
6. A water sampling system according to any one of claims 1 to 5 . The water sampling container is configured to have a variable capacity depending on the amount of the sample water stored in the water sampling container.
7. A water sampling system according to any one of claims 1 to 6 . a control device for controlling the flow rate of the sample water flowing through the flow path so as to maintain the flow rate within a second range;
8. A water sampling system according to any one of claims 1 to 7 . The control device controls the flow rate so that the sample water constantly flows through the flow path over a day.
9. The water sampling system according to claim 8 .

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