Method and device for collecting sample water

Abstract

To provide a sample water sampling method and a sampling device with which, when sampling sample water to evaluate cleanliness of steam generated in a steam generator, it is possible to measure accurate water quality without contaminating sample water.SOLUTION: There is provided a sample water sampling method for capturing steam generated in a steam generator 50 from a steam introduction passage 11 into a cooler 12, condensing the steam by cooling, and sampling sample water for inspection. With a sample water sampling method and a sampling device 10, the sample water sampling velocity is 10 to 200 mL / minute, and sample water is, by way of a sample water supply passage 14 connecting the cooler 12 and a water sampling container 13 so as not to bring sample water into contact with an outside atmosphere, dripped into the water sampling container 13, with water thereby sampled.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a water sampling method and water sampling device for sampling sample water for testing steam generated from a steam generating device, and more particularly to a water sampling method and water sampling device for sampling sample water for measuring the water quality of steam produced by vaporizing high-purity water such as purified water or water for injection. [Background technology]

[0002] In fields such as medicine and food manufacturing, medical instruments, equipment, drugs, reagents, raw materials, etc. used may become contaminated by airborne microorganisms or particles that adhere to or become mixed in with them. In such cases, the desired cleanliness cannot be maintained, and the items cannot be used as is.

[0003] Therefore, it is necessary to ensure the cleanliness of these instruments, and appropriate sterilization is performed as necessary. Sterilization using high-temperature, high-pressure saturated steam (high-pressure steam sterilization) is a commonly used sterilization method in these fields, and this sterilization method is one of the most common and versatile methods.

[0004] In order to perform such high-pressure steam sterilization, various steam generators for generating highly clean steam (pure steam) have been investigated and improvements have been made (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-124692 A [Patent Document 2] JP 2014-185904 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in these steam generating devices, the quality (cleanliness) of the generated steam is not often checked. However, recently, there are an increasing number of cases where it is necessary to check the cleanliness of the generated steam. In order to check the quality (cleanliness) of such steam, for example, it is possible to evaluate the cleanliness of the steam by temporarily cooling, condensing, and liquefying the generated steam to produce condensed water, and measuring the quality of the condensed water obtained.

[0007] However, the amount of condensed water obtained by liquefying the steam obtained from such a steam generating device depends on the size and capacity of the cooler, and in general, for this type of application, the amount is quite small. Therefore, the condensed water cannot be obtained continuously, but is obtained drop by drop into the water sampling container, and in order to obtain a sufficient amount of condensed water (sample water) to be used for water quality testing, it is necessary to obtain it over a period of, for example, 30 minutes or more.

[0008] In this case, if the condensed water is collected in an open system in contact with the atmosphere, the long collection time required as described above may result in microorganisms, fine particles, etc. present in the atmosphere becoming mixed into the condensed water.

[0009] Depending on the use of the steam, the contamination of such microorganisms, fine particles, etc. may not be a problem in terms of cleanliness, etc. However, when the water supplied to the steam generator is purified water or water for injection, such as in the case of highly clean steam (pure steam) as described above, there is a problem that it cannot be evaluated as it is.

[0010] In other words, since the steam generated from purified water or water for injection (pure steam) contains extremely few impurities and is highly clean, the contamination of the steam with microorganisms or fine particles during the condensation and liquefaction processes is one of the causes of errors in evaluating its characteristics.

[0011] Therefore, an object of the present invention is to provide a method and device for collecting sample water that can accurately measure the water quality without contaminating the sample water when collecting sample water to evaluate the cleanliness of steam generated by a steam generating device. [Means for solving the problem]

[0012] The method for collecting sample water of the present invention is a method for collecting sample water for testing by condensing steam generated from a steam generator through cooling, characterized in that the sample water is collected at a collection rate of 10 to 200 mL / min and the sample water is collected by dripping into a water collection container so as not to come into contact with the external atmosphere.

[0013] The sample water sampling device of the present invention comprises a steam inlet flow path that takes in steam generated from a steam generator, a cooler that condenses the steam introduced from the steam inlet flow path to produce sample water, a water sampling container that contains the sample water, and a sample water supply flow path that connects the cooler and the water sampling container so that the sample water does not come into contact with the external atmosphere, and is characterized in that the steam inlet flow path has an inner diameter of 1 to 20 mm. Effect of the Invention

[0014] According to the method and apparatus for collecting sample water of the present invention, the sample water can be collected without being contaminated, and the characteristics of the steam can be accurately evaluated.

[0015] Furthermore, according to the sample water sampling method and water sampling device of the present invention, before sampling the sample water, the generated steam can be used directly to sterilize the water sampling device, and the steam can be converted into sample water without causing contamination attributable to the water sampling device. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram showing a schematic configuration of a water sample collection device according to one embodiment of the present invention; [Diagram 2]FIG. 2 is a diagram for explaining a method for collecting sample water using the sample water collecting device of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, a sample water sampling method and a sample water sampling device according to an embodiment of the present invention will be described in detail with reference to FIGS.

[0018] [Water sample collection device] As shown in Figure 1, the sample water sampling device 10 of this embodiment is composed of a steam inlet flow path 11 that takes in steam generated from a steam generator 50, a cooler 12 that condenses the steam introduced from the steam inlet flow path 11 to produce sample water, a water sampling container 13 that contains the sample water, and a sample water supply flow path 14 that connects the cooler 12 and the water sampling container 13 so that the sample water does not come into contact with the external atmosphere.

[0019] The steam introduction flow path 11 is a flow path for introducing the steam generated from the steam generator 50 into the cooler 12. This steam introduction flow path 11 is not particularly limited as long as it can introduce the generated steam directly into the cooler 12 and is made of a heat-resistant material that can withstand the temperature of the heating steam. This steam introduction flow path 11 is usually used to introduce the steam generated from the steam generator 50 into the device instead of a pipe that transports the steam to a place of use, or is branched off from that pipe.

[0020] Examples of heat-resistant materials constituting the steam introduction flow path 11 include heat-resistant resins such as polypropylene (PP), polycarbonate (PC), polyether ether ketone (PEEK), fluororesin, nylon, polyvinylidene chloride, polyphenylene sulfide (PPS), metals such as stainless steel and titanium, and heat-resistant glass such as borosilicate glass and synthetic quartz. Note that the material of the steam introduction flow path 11 is preferably one that is not easily affected by temperature drops due to the outside air with which the flow path is in contact, so that the heated steam can be transferred directly to the cooler 12 as steam, and among these, fluororesin is more preferable. Furthermore, in order to prevent condensation of the steam, the steam introduction flow path 11 etc. may be provided with a heater such as a ribbon heater around it so as to be able to heat it, if necessary.

[0021] The vapor introduction channel 11 preferably has an inner diameter of 20 mm or less, and more preferably has an inner diameter of 1 to 10 mm.

[0022] In such a device with a relatively small inner diameter, the sampling speed of the obtained sample water is also slow, and therefore the sampling time is long. However, in this embodiment, as described below, contamination of the sample water can be effectively prevented.

[0023] The cooler 12 cools the steam introduced from the steam introduction passage 11, condenses and liquefies it to produce sample water, and any known cooler having such a function can be used without any particular limitation. As the cooler 12, for example, a water-cooled or air-cooled cooler can be used, and a water-cooled cooler is preferable.

[0024] 1 shows an example of a water-cooled cooler, and this cooler 12 has a cooling flow path 12a. This cooling flow path 12a is interposed between a steam introduction flow path 11 connected to the cooler 12 and a sample water supply flow path 14 described later, and connects these flow paths.

[0025] The cooling pipe 12 has a double pipe structure in which a cooling water flow path is formed around the outer periphery of the cooling flow path 12a so that cooling water can flow through it. The cooler 12 is provided with a cooling water inlet 12b for introducing the cooling water used here into the cooling water flow path, and a cooling water outlet 12c for discharging the cooling water.

[0026] The water sampling container 13 is a container for storing sample water condensed and liquefied by the cooler 12. There are no particular limitations on the type of water sampling container 13 as long as it can stably store sample water. If the capacity of the water sampling container is larger than necessary, it will take a long time to collect water, or the bottle will not be full even if the amount of water required for analysis is collected, so there is a risk of external atmosphere being mixed in from the gas exhaust flow path after the water is collected. Therefore, specifically, a capacity of 30 to 2000 mL is preferable, and 50 to 1000 mL is more preferable.

[0027] In order to prevent the obtained sample water from coming into contact with the outside atmosphere, it is preferable that the container be sealable, and in addition to the sample water supply flow path 14 described below, it is preferable to provide a gas exhaust flow path 15 so that gas can be exhausted from within the water sampling container 13 when the sample water is supplied. This gas exhaust flow path 15 is preferably 50 cm or more long, more preferably 120 to 150 cm long, so as to prevent the outside atmosphere from entering the water sampling container 13.

[0028] The sample water supply flow path 14 connects the cooler 12 and the water sampling container 13 so that the sample water does not come into contact with the outside atmosphere. This sample water supply flow path 14 allows the sample water obtained in the cooler 12 to be supplied into the water sampling container 13 without being exposed to the outside atmosphere.

[0029] The sample water supply flow path 14 may be any flow path that can directly connect the cooler 12 and the water sampling container 13 and can stably circulate the condensed sample water without contacting the external atmosphere. Such sample water supply flow path 14 may be any known piping without any particular limitation, and may be made of, for example, resin, metal, glass, or other materials. The length is preferably a length that allows easy operation, and specifically, is preferably about 3 to 4 m. The shape may be a straight pipe or a tube that can be bent freely.

[0030] The steam generator 50 used in this embodiment may be any known steam generator that vaporizes water to produce steam. However, it is preferable that the water supplied to produce steam is high-purity water that has been subjected to a purification process, such as purified water or water for injection, and that the steam generator 50 can produce high-purity steam (pure steam).

[0031] When using such highly pure water, the water sampling device of this embodiment can greatly reduce the risk of contamination by microorganisms, particulates, etc. in the external atmosphere, making it possible to accurately evaluate the quality (cleanliness) of the steam generated by the steam generator 50.

[0032] It is also preferable to provide valves such as two-way valves for controlling the flow of sample water or gas through the sample water supply flow path 13 and the gas discharge flow path 15. By providing such valves, the sample water can be sampled with a simple operation without contacting the sample water with the external atmosphere (e.g., air, etc.) by opening both valves when sampling the sample water and closing both valves after sampling the sample water.

[0033] In this specification, purified water means water purified by distillation, ion exchange, reverse osmosis, ultrafiltration or a combination thereof, and water for injection means purified water that has been sterilized and conforms to a pyrogen (endotoxin) test. Examples of such purified water and water for injection include those defined in the Japanese Pharmacopoeia.

[0034] A more specific example of a method for purifying purified water or water for injection is a method produced by a known purification process in which raw water such as tap water is passed through an appropriate combination of water treatment devices such as a reverse osmosis membrane (RO), an ion exchange device such as an ion exchange resin tower or an electrodeionization device (EDI), and an ultrafiltration membrane (UF).

[0035] [How to collect sample water] Next, a method for collecting sample water in this embodiment will be described with reference to FIG.

[0036] The method for collecting sample water in this embodiment involves cooling and condensing steam generated from steam generator 50 inside cooler 12 to collect sample water for testing, and the sample water collection rate is 10 to 200 mL / min, and the sample water is collected by dripping it into water collection container 13 without contacting the outside atmosphere. Each operation will be described in detail below.

[0037] First, in the method for collecting sample water of this embodiment, steam generated from the steam generator 50 is introduced into the cooler 12 through a steam introduction passage 11 that connects the steam generator 50 and the cooler 12. Through this steam introduction passage 11, the steam generated by the steam generator 50 is introduced directly into the cooler 12.

[0038] The steam used here may be any steam obtained by vaporizing purified water or water for injection, and is preferably steam heated to 110°C or higher, and more preferably steam used for sterilization (for example, saturated steam at a temperature of 110 to 140°C and pressurized as necessary). Typical examples of this steam for sterilization include saturated steam at 133°C and 0.2 MPa. The higher the temperature, the shorter the time required for sterilization.

[0039] The steam introduced into the cooler 12 is cooled by the cooler 12, and is condensed and liquefied to become sample water. This cooling is performed by introducing steam into the cooling pipe 12a connected to the steam introduction flow path 11 while cooling water is circulating through the cooler 12. The introduced steam is cooled, condensed, and liquefied in the cooling pipe 12a, and the sample water obtained by the liquefaction is circulated to the sample water supply pipe 14 connected to the cooling pipe 12a.

[0040] In this cooling, cooling water is introduced into the cooling water flow path from the cooling water inlet 12b, and the surroundings of the cooling flow path 12a of the cooler 12 are filled with cooling water. The steam flowing inside the cooling flow path 12a is cooled, condensed, and liquefied in this cooling flow path 12a. As a result, the temperature of the cooling water rises due to heat exchange, but cooling water is constantly supplied from the cooling water inlet 12b, and the heated cooling water is discharged from the cooling water outlet 12b, allowing the steam to be efficiently condensed and liquefied in the cooling flow path 12a.

[0041] The sample water obtained by liquefaction and condensation flows through the sample water supply pipe 14 as described above and is stored in the water sampling container 13. At this time, the sample water supply pipe 14 connects between the cooling pipe 12a and the water sampling container 13 in such a way that the sample water does not come into contact with the external atmosphere, and there is no risk of the sample water being contaminated by microorganisms, fine particles, etc. in the external atmosphere.

[0042] As described above, when the amount of steam generated from the steam generator 50 is about 50 to 360 kg / h and the sample water collection rate is 10 to 200 mL / min, the amount of sample water supplied from the sample water supply pipe 14 to the water collection container 13 is small and is obtained by dripping.

[0043] The water sampling container 13 is provided with a gas exhaust flow path 15, and the gas in the water sampling container 13 is exhausted to the outside atmosphere via the gas exhaust flow path 15 according to the amount of sample water supplied from the sample water supply flow path 14. Therefore, the pressure in the water sampling container 13 does not continue to rise.

[0044] In this method of collecting sample water, since steam is always supplied from the steam generator 50, there is little risk of the outside atmosphere being mixed into the water sampling container 13, but there is still a possibility that the outside atmosphere may be drawn in due to a reduction in volume caused by liquefaction of the steam. However, in this embodiment, since the gas exhaust flow path 15 is provided, it is possible to prevent the outside atmosphere from entering the water sampling container 13 even in such a case.

[0045] To ensure such effects and actions, the length of the gas exhaust flow path 15 is preferably 50 cm or more, and more preferably 120 to 150 cm. To prevent this effect, it is preferable to collect water in the water collection container at 80 to 90% of its capacity.

[0046] In this embodiment, for example, it is expected that it will take approximately 30 to 90 minutes to collect 1 L of sample water, but since there is no risk of the obtained sample water coming into contact with the external atmosphere, there is no contamination from the outside, and this method is suitable as a method for collecting sample water to evaluate steam quality (cleanliness).

[0047] After the water sampling operation is completed, the lid that secures the sample water supply flow path 14 and the gas exhaust flow path 15 in the water sampling container 13 may be replaced with a lid that can seal the water sampling container 13. Although there is a possibility that the sample water may come into contact with the outside atmosphere when replacing the lid, this is for a short period of time and the amount of contact is small, so that the quality of the sample water is not affected and there is no problem.

[0048] Furthermore, by attaching two-way valves to the sample water supply flow path 14 and the gas exhaust flow path 15, respectively, and allowing flow through both (opening the valves) during the sample water sampling operation, and stopping flow through both (closing the valves) when the sample water sampling operation is completed, the water sampling container 13 can be sealed without replacing the lid. In this case, the sample water can be prevented from coming into contact with the outside atmosphere, and contamination can be reliably prevented.

[0049] As described above, in this embodiment, sample water for testing can be obtained while suppressing contamination of highly clean steam, but it is preferable that this sample water does not contain microorganisms. For example, such sample water preferably has a viable cell count of less than 10 CFU in 1000 mL of sample water, and more preferably less than 1 CFU.

[0050] Furthermore, before the method for collecting the sample water, the inside of the apparatus for collecting the sample water may be sterilized using steam generated by the steam generator 50. In this case, before sampling the sample water, the steam generating device 50 and the sample water sampling device 10 are connected, and the cooling by the cooler 12 is stopped. In other words, the supply of cooling water to the cooler 12 is stopped.

[0051] In this state, steam is supplied from the steam generator 50 through the steam introduction flow path 11, the cooling pipe 12a, and the sample water supply flow path 14 into the water sampling bottle 15. Furthermore, steam is released from inside the water sampling bottle 15 into the external atmosphere through the gas exhaust flow path 15. By carrying out such an operation before sampling the sample water, the inside of the water sampling device can be sterilized.

[0052] This sterilization method is preferable because it does not require any other device or means, and the steam from the steam generating means 50 can be used for the sterilization, and the water sampling device can be reliably sterilized with a simple device configuration and simple operation. This sterilization method is also preferable because it can eliminate contamination from external factors.

[0053] When carrying out this sterilization treatment, the flow path, the water sampling container, etc. that come into contact with the steam must be made of heat-resistant materials that can withstand the temperature of the steam. In this case, it is preferable to control the temperature so that the steam does not condense or liquefy, so that the steam can sterilize the inside of the water sampling container as well.

[0054] In the gas exhaust flow path 15, partial liquefaction does not pose any problem. In addition, if partial liquefaction occurs in the water sampling container, the sterilization process is performed on all surfaces in the water sampling container. For example, the liquefied condensed water is prevented from accumulating in the same area, and a discharge mechanism (drain) is provided to discharge the liquefied condensed water, so that all surfaces in the water sampling container come into contact with steam.

[0055] After this sterilization process, cooling water is supplied from the cooling water inlet 12b of the cooler 12 and discharged from the cooling water outlet 12c, and the operation of collecting sample water for testing is performed as described above. EXAMPLES

[0056] The present invention will now be further described with reference to examples.

[0057] Example 1 As the sample water sampling device used in this embodiment, the sample water sampling device 10 shown in FIG. 1 was prepared.

[0058] The specific devices and parts constituting the sample water sampling device used here are as follows: Vapor introduction channel 11: Made of perfluoroalkoxyalkane (PFA), inner diameter 8 mm, length 300 cm Cooler 12: Stainless steel (manufactured by Nomura Micro Science Co., Ltd., product name: Mini Condenser CX-5) Water collection container 13: Heat-resistant glass, capacity 1000mL Sample water supply channel 14: Made of PFA, inner diameter 4 mm, length 300 cm Gas exhaust flow path 15: Made of PFA, inner diameter 4 mm, length 150 cm

[0059] In addition, a pure steam generator for sterilization NK-120 (product name, manufactured by Nomura Micro Science Co., Ltd.) was used as the steam generator 50. The steam generation capacity of this steam generator 50 was 50 kg / h.

[0060] Using this sample water sampling device 10, steam was introduced from the steam generator 50 into the cooler 12, and the steam was condensed and liquefied in the cooler 12 to produce sample water, which was then dropped into the water sampling container 13 to sample 1000 mL of sample water over 20 minutes (water sampling rate 50 mL / min). At this time, tap water at 13°C was used as the cooling water supplied to the cooler 12.

[0061] Comparative Example 1 The basic configuration is the same as the sample water sampling device 10 used in Example 1, but the device is configured so that the water sampling container 13 and the sample water supply flow path 14 are not connected, and sample water is sampled with the water sampling container 13 open to the atmosphere.

[0062] The sampling operation of the sample water was carried out in the same manner as in Example 1, and 1000 mL of the sample water was sampled over 20 minutes.

[0063] In each of Example 1 and Comparative Example 1, the same procedure was carried out four times, and the viable cell count and particle count of the obtained sample water were measured as described below. The results are shown in Tables 1 and 2, respectively.

[0064] [Viable bacteria count] The viable bacterial count of the obtained sample water was determined by the membrane filtration method using R2A agar medium at 30°C for 7 days, and the viable bacterial count (CFU) per 1000 mL of sample water was calculated.

[0065] [Fine particle water] The number of insoluble particles in the obtained sample water was measured using a particle counter (manufactured by Rion Co., Ltd., product name: KL-04A). The number of particles was measured for particle sizes of 10 μm or more and 25 μm or more, and was expressed as the number of particles per mL of sample water.

[0066] [Table 1]

[0067] [Table 2]

[0068] As described above, according to the sample water collection method and water collection device of this embodiment, when steam is collected as sample water, there is no risk of contamination by airborne bacteria or airborne particles contained in the external atmosphere, and the quality (cleanliness) of the steam to be evaluated can be accurately and simply evaluated. [Explanation of symbols]

[0069] 10... Sample water sampling device, 11... Steam introduction flow path, 12... Cooler, 13... Water sampling container, 14... Sample water supply flow path, 15... Gas exhaust flow path

Claims

1. A method for collecting sample water for testing, comprising the steps of: condensing steam generated from a steam generator by a cooler; The sampling rate of the sample water is 10 to 200 mL / min; A method for collecting sample water, comprising supplying the sample water together with a portion of the steam from the cooler to a water collection container so as not to come into contact with the external atmosphere, and dropping the water into the water collection container to collect the water.

2. 2. The method for collecting sample water according to claim 1, wherein the water supplied to the steam generating device is purified water or water for injection.

3. Before the sample water is collected, the cooling by the cooler is stopped; 3. The method for sampling sample water according to claim 1, wherein the steam is supplied from the cooler to the water sampling container to sterilize the water sampling path.

4. The method for collecting sample water according to any one of claims 1 to 3, characterized in that the number of viable bacteria in 1000 mL of the sample water is less than 10 CFU.

5. A steam introduction flow path that takes in steam generated from the steam generator; a cooler for condensing the steam introduced through the steam introduction passage to produce sample water; a water sampling container for accommodating the sample water supplied from the cooler together with a portion of the steam; a sample water supply flow path that connects the cooler and the water sampling container such that the sample water supplied from the cooler to the water sampling container together with a portion of the steam does not come into contact with an external atmosphere; having The apparatus for collecting sample water is characterized in that the steam introduction channel has an inner diameter of 1 to 10 mm.

6. The water sampling container has a gas exhaust flow path, 6. The sample water sampling device according to claim 5, wherein the sample water supply flow path and the gas exhaust flow path each have a two-way valve.

7. 7. The water sample collection device according to claim 6, wherein the length of the gas discharge flow path is 120 to 150 cm.

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