JP2007260214A - Method for sterilizing purified water outlet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for reliably sterilizing a purified water outlet communicating with a purified water treating device in a short time. <P>SOLUTION: Steam at the temperature of 100-400°C is blown to the purified water outlet which communicates with the purified water treating device, especially, to the purified water outlet including the distal end of the outlet and an opening/closing valve. Water with high quality corresponding to the water to be used for steam generation is used in the case of the purified water where electrolyte, the dissolution amount of organic matters, and the number of particulates, etc., are simultaneously managed. The outlet can be a mounting port of a filter to catch bacteria living in the purified water. The filter for catching the bacteria is mounted after sterilizing the outlet by the method of the present invention. A fixed amount of purified water is made to flow, so as to allow the bacteria to be stuck onto the filter. Thus, the number of bacteria is measured after culturing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is a pure water outlet sterilization method communicating with a pure water treatment apparatus.

  In pure water used in the electronics industry, pharmaceutical manufacturing, food industry, hospitals, research facilities, etc., together with various ion concentrations and the number of fine particles in pure water, the number of bacteria [hereinafter simply referred to as “the number of bacteria”. ] Is also required to be below the reference value. Particularly in the use of pharmaceutical manufacturing, food industry, hospitals, etc., the management of the number of bacteria is the most important item. When bacteria enter somewhere in the pure water treatment equipment, such as in the production, storage, and supply of pure water, they multiply in the system over time, so the number of bacteria is always below the reference value in the pure water treatment equipment. That must be monitored. However, in bacteria, it is difficult to automatically measure and display the number of bacteria with a measuring instrument, so it is common to collect a part of water and measure the number of bacteria separately by culturing.

  Sample water used for measuring the number of bacteria in pure water when taking out pure water from a pure water treatment device is collected from an outlet installed in a part of the pipe through which pure water flows. Even if the apparatus and the pure water pipe are kept sterile, if the pure water outlet is contaminated by surrounding bacteria, the extracted pure water will also be contaminated by bacteria. Therefore, before taking out pure water, it is important that the outlet including the outlet tip and the open / close valve is free of living bacteria. In particular, the measurement of the number of bacteria in pure water is a problem related to the accuracy of the measured value. Therefore, in order to kill bacteria in and around the outlet, a method of heating the outlet with a heater, a method of immersing the outlet in hot water (see FIG. 1), a method of applying hot water to the outlet [ FIG. 2] is performed. However, if the temperature of the heater is set sufficiently high, the purpose of sterilization can be achieved, but there is another problem such as the troublesomeness of installing the heater and the cause of generating dust at the outlet, which increases the solid content in pure water. Problems arise. The method of immersing the outlet in hot water is limited to the shape of the outlet, such as the outlet protruding below the pipe, and the method of applying hot water to the outlet is sufficient for contact with hot water. Insufficient sterilization may occur, it may be difficult to ensure sufficient heating to kill the attached bacteria, and there is a risk of burns from hot water splashing.

  Therefore, a method of sterilizing the inner and outer surfaces of the faucet using ultraviolet light to completely sterilize the vicinity of the outlet, and attaching a cover that does not allow outside air to freely enter the vicinity of the faucet (see Patent Document 1), A double pipe is made of a material with good UV transmittance such as quartz or fluororesin near the outlet, a flow path is formed between the outer pipe and the inner pipe, and an ultraviolet lamp is inserted inside the inner pipe to flow. Proposals have been made on a method of ultraviolet sterilization on both the inside and outside of the outlet (see Patent Document 2).

Japanese Patent Laid-Open No. 06-320153 JP-A-08-066677

  In view of the above problems, an object of the present invention is to provide a method for surely sterilizing a pure water outlet communicating with a pure water treatment apparatus in a short time.

  In order to achieve the above object, the pure water outlet sterilization method according to the present invention provides a pure water outlet communicating with a pure water treatment apparatus, particularly a pure water outlet including an outlet tip and an open / close valve. To spray steam at ℃. This outlet can also be an attachment port for a filter for collecting bacteria that live in pure water.

  According to the method of the present invention, the bacteria attached to the outlet of the pure water treatment apparatus are completely killed in a short time, and the pure water can be collected without being contaminated by external bacteria. This is particularly effective when measuring the number of bacteria in pure water. Furthermore, compared to handling hot water, steam is less likely to cause accidents such as burns, and no special device is required at the outlet.

  The present invention is a sterilization method at the outlet of pure water communicating with a pure water treatment apparatus, and a conceptual diagram of the embodiment is shown in FIG. Here, the pure water treatment device includes all devices that handle pure water, such as a device for producing, storing, and supplying pure water, and piping around these devices. The outflow port is a port for taking out pure water from the pure water treatment apparatus, and is a portion including at least the outflow port front end portion, the open / close valve and the surrounding piping. The material of the outlet end portion, the open / close valve and the surrounding piping is not particularly limited in the present invention, but can withstand the temperature of the steam used in consideration of the spraying of steam in the present invention. It is usually a ferrous metal such as stainless steel, or plastic.

  The sterilization method of the present invention can be used for any water regardless of the bacterial count level, but the pure water with a bacterial count of 1 / L or less is usually the target. Water quality other than the number of bacteria is not particularly limited.

  The sterilization method of this invention exists in spraying 100-400 degreeC steam on the outflow port from a pure water processing apparatus. 100 ° C is the saturated vapor boiling point of water under atmospheric pressure, and steam of 100 ° C or higher can be heated at high temperature or high pressure steam by heating water in a closed vessel such as a boiler, Normal pressure steam. Although the steam temperature may exceed 400 ° C., there is a complicated handling of high-temperature steam, and the temperature is higher than necessary for the purpose of sterilization. When only the number of bacteria is controlled, it is sterilized by the generation of steam, so the raw water that generates pure water may be any water, but when the electrolyte, the dissolved amount of organic matter, the number of fine particles, etc. are also controlled at the same time It is necessary to use water of high quality corresponding to steam generation. The time for spraying steam is not uniformly determined depending on the temperature and amount of steam, but is usually 1 minute or longer, preferably 2 to 10 minutes, more preferably 3 to 5 minutes. The steam discharge pressure is not limited as long as the outlet of the pure water treatment apparatus is not destroyed and can be handled. Bacteria attached to the on-off valve and the surrounding piping can be completely killed by contact with steam.

  The sterilization method of the present invention is useful when sampling a sample in measuring the number of bacteria living in pure water, and the outlet sterilized by the method of the present invention is attached to a filter for collecting bacteria for measuring the number of bacteria. By using the mouth, the number of bacteria in pure water can be accurately measured.

Hereinafter, the measurement of the number of bacteria performed by sterilizing the outlet of pure water communicating with the pure water treatment apparatus by the method of the present invention and attaching a filter for collecting bacteria here will be described.
Since pure water originally has very few bacteria, it is not possible to simply collect pure water and measure the number of bacteria. Therefore, a filter for measuring the number of bacteria is installed at the outlet, and a certain amount of pure water as a target is allowed to flow through the filter to allow bacteria to adhere to the filter. The filter is for collecting bacteria, and usually has a pore size of 0.45 μm or less, and is fixed with a filter holder. Next, the number of bacteria on the filter is measured by culturing, and the number of bacteria relative to the amount of pure water passed through the filter is determined. [Refer to JIS K0550]

  The bacterial culture method is, for example, a standard liquid medium or an M-TGE liquid medium, and a filter through which pure water has passed is placed on the medium, and the temperature is 30 ° C. to 40 ° C., preferably 30 ° C. to 35 ° C. for 24 hours or more. Culture and count the number of colonies formed on the filter.

  It goes without saying that the culture and counting of bacteria are not contaminated with external bacteria, and are usually carried out on a sterile bench dedicated to measuring the number of bacteria in a clean room.

[Test equipment]
An outlet having an open / close valve was provided in a pipe branched horizontally from the pure water pipe as shown in FIG. 3, and a filter was installed at the tip of the outlet.

〔Test method〕
Example: in a clean room, the number of bacteria was intentionally contaminated off valve and outlet tip with water of about 10 ³ / mL. Sterilize by spraying steam at 140 ° C and discharge pressure of 0.25 MPa from the boiler directly into the valve from the open / close valve, outlet, and outlet, then attach a filter to the tip of the outlet, 10 L of water was flowed. The filter was taken out, placed on M-TGE medium, cultured at 30 ° C. for 48 hours, and the number of bacteria in pure water was measured from the bacterial colonies.
Comparative example: The open / close valve and the outlet tip were intentionally contaminated in the same manner as in the above example, and 90 ° C. water was poured from above the open / close valve and the outlet tip to sterilize the filter. After attaching and flowing 10 L of pure water, the filter was taken out and cultured, and the number of bacteria was measured from the bacterial colonies.

この結果から、スチームにより短時間にて確実に殺菌できることがわかる。 〔result〕
The results are shown in Table 1.

From this result, it can be seen that steam can surely sterilize in a short time.

  According to the method of the present invention, pure water is collected from a pure water treatment apparatus without being contaminated by external bacteria by a simple operation, and a sample free from bacterial contamination can be obtained when measuring the number of bacteria in pure water. . Furthermore, it is a handling that is unlikely to cause an unexpected accident such as a burn, and it is not necessary to incorporate a large special device.

It is an image figure of the method of immersing the conventional outflow port in hot water. It is an image figure of the method of applying a hot water to the conventional outflow port. It is a figure explaining the state which provided the outflow port which has an on-off valve in the piping branched in the horizontal direction from the pure water piping.

Explanation of symbols

1: Pure water outlet 2: Outlet tip 3: Open / close valve 4: (Branch) piping 5: Flow of pure water (in the main pipe) 10: Boiler 11: Steam injection nozzle 12: Steam 13: Beaker 14: Thermal purity water

Claims (3)

  A pure water outlet sterilization method, wherein steam at 100 to 400 ° C. is sprayed on a pure water outlet communicating with a pure water treatment apparatus.   The method for sterilizing a pure water outlet according to claim 1, wherein the outlet includes an outlet tip and an opening / closing valve.   The method for sterilizing a pure water outlet according to claim 1, wherein the outlet is an attachment port of a filter for collecting bacteria for measuring the number of bacteria living in the pure water.

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