JPS63166491A - Pipeline sterilizing system - Google Patents

Abstract

PURPOSE:To efficiently sterilize a water conduit, by providing an electrolytic apparatus in the water conduit and performing electrolysis while an aqueous inorg. halide solution is recirculated in the water conduit. CONSTITUTION:An anode 32 and a cathode 33 are provided to the lower part of a water conduit 1 and a DC current is supplied to both electrodes from a power source 34. An aqueous inorg. halide solution is passed through the water conduit 1 and the available chlorine concn. of the inorg halide is adjusted to about 0.5-500ppm. By this method, the aqueous inorg. halide solution is electrolyzed in the water conduit 1 under recirculation to make it possible to uniformly disinfect the water conduit. As inorg. halide, NaCl, KCl, LiCl, AlCl3 or the like can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pipe sterilization system. More specifically, it is a pipe sterilizer that prevents microorganisms from entering through the discharge ports of various devices used in hospitals and other medical institutions, pharmaceutical manufacturers, medical product manufacturers, food manufacturers, etc., and sterilizes the inside of water pipes. Regarding the system.

[Conventional technology] Aseptic conditions must be maintained in the water pipes of equipment cleaners such as ultrasonic cleaners used in hospitals and other medical institutions, and medical instruments such as bladder cleaners and artificial dialysis machines. However, water pipes can become contaminated by microorganisms such as bacteria floating in the air that enters from the outlet etc.
It is considered extremely difficult to maintain sterile conditions free from invasion by such microorganisms. For this reason, conventional sterilization methods using chemicals such as sodium hypochlorite, formalin, and ozone, boiling water, and steam, and
A sterilizer that sterilizes using chlorine generated by electrolysis as disclosed in Japanese Patent Publication No. 30-19596 and Japanese Patent Publication No. 1987-31489, as disclosed in Japanese Utility Model Publication No. 30-13756 and Japanese Patent Application Laid-open No. 56-31489. As disclosed, a device is employed that sterilizes water by applying electricity to the water to be sterilized or by generating ions.

[Problems to be Solved by the Invention] However, the sterilization methods using chemicals, boiling water, steam, etc. require complicated operations, and
The sterilizers disclosed in Publication No. 30 and Japanese Patent Publication No. 44-19596 have complicated structures and high equipment costs;
In addition, it is not possible to form a back contamination prevention zone (barrier) in the pipe, and when using the device disclosed in Japanese Utility Model Publication No. 30-13756, its sterilization ability is insufficient.
Furthermore, in the device disclosed in JP-A-56-31489, the sterilizing effect is small because inorganic halides are not present, or even if they are present, the amount thereof is small, and there is also a back contamination prevention zone (barrier) in the piping. ) cannot be formed.

Therefore, the structure is simpler than before, and it can be disinfected and sterilized reliably, and it also acts as a barrier to prevent reverse contamination.
There is a strong need for a device that can form

In addition, 1. Plants such as pharmaceutical factories and food manufacturing factories need to be sterilized frequently, and sterilization is usually done with chemicals or heat, but as mentioned above, it is necessary to maintain sterile conditions in the water pipes and at the discharge port. Preventing the invasion of microorganisms from humans is an important issue.

[Means for Solving the Problems] Therefore, as a result of research to solve the problems of the conventional technology as described above, the present inventors developed an electrolytic device and a water inlet for electrolyzing an inorganic halide aqueous solution. A conduit consisting of a water conduit with one water stop valve provided at each outlet and an electrolyzer installed in the water conduit between the two water stop valves provided at the water inlet and outlet. Developed a sterilizer and proposed it in patent application No. 178205-1980.
The inventors of the present invention conducted further research and discovered an improved pipe sterilization system that has a simple structure and can more efficiently and reliably sterilize the inside of water pipes, and thus arrived at the present invention.

That is, in the present invention, one or more electrolyzers for electrolyzing an inorganic halide aqueous solution are installed in a water conduit forming a closed circuit, and the inorganic halide aqueous solution in the water conduit is electrolyzed while being circulated. This is a pipe sterilization system that is characterized by the following.

[Function] The pipe sterilization system of the present invention is comprised of a water conduit forming a closed circuit and one or more electrolysis devices for electrolyzing an aqueous solution of an inorganic halide. A tank may be included in the middle of the water pipe. Usually, the water pipe or tank has a water inlet and a discharge port, and a water stop valve is provided here. It is also equipped with a pump to circulate water within the water conduit.

If the water injected into the water pipe is allowed to stagnate for a long period of time, it will be subject to secondary contamination by microorganisms that have entered through the outlet. The water valve is closed, and the water stored in the water pipe is electrolyzed by an electrolyzer installed in the water pipe. At the same time, the water in the water conduit is circulated by a pump or the like within the water conduit forming a closed circuit.

If the water stored in the water pipe contains enough inorganic halides to generate a sufficient amount of hypohalite to be sterilized by electrolysis, the electrolyzer is energized; Hypohalite is produced by anodic oxidation of the halogen ions contained in the.

When the inorganic halide is, for example, sodium chloride, the reaction formula is as follows.

NaCQ + H2O-NaOH+ % Hz↑++C
ji* ↑CL + 2NaOH' -NaC110
+Na (Jl + H1O Sodium hypochlorite thus produced is effective against most microorganisms such as viruses, general non-spore-forming bacteria, acid-fast bacteria, bacterial spores, filamentous fungi, algae, and protozoa, and usually has a concentration of about 10 ppts. It has the ability to complete sterilization in a short period of time at certain concentrations.

Here, the water conduit consists of a water conduit with one water stop valve provided at each of the water inlet and the discharge port, and the electrolyzer is installed in the water conduit between the two water stop valves provided at the water inlet and the discharge port. In the case of a pipe sterilization device made of a water pipe, the generated sodium hypochlorite does not evenly spread to the water pipe between the two water stop valves, and sterilization within the water pipe may be insufficient.

However, in the case of the system of the present invention, the water pipes form a closed circuit, and the water in the water pipes is circulated through the closed circuit by a pump, so there is no such problem and the pipes are thoroughly sterilized. . Furthermore, the concentration of sodium hypochlorite increases due to the chlorine continuously generated by the electrodes during circulation, and the interior of the water pipes is sufficiently sterilized over a wide area.

In addition, if the water stored in the water pipe does not contain enough inorganic halides to generate hypohalite at a sufficient concentration to sterilize it by electrolysis, do not add inorganic halides to the water pipe. Such electrolysis can be performed by using a device that has a supply function.

[Example] Next, embodiments of the pipe sterilization device of the present invention will be described in more detail based on the drawings, but the present invention is not limited thereto.

In Figure 1, (1) is a water pipe forming a closed circuit (hereinafter referred to as water pipe), (2) (2') is an electrolyzer, (3) is a sodium chloride injection device, (4) is a ° pump, ( 5) is a water inlet, (6) is a water stop valve, and (7) is a discharge port. Figure 2 shows an example where a tank (21) (21'') is included in the water pipe.

The water pipe (1) forms a closed circuit with a water stop valve (6),
Water can be circulated in the closed circuit by driving the pump (4).

As the pump (4), a vortex pump, a diaphragm pump, a Franscher pump, etc. are used, but a vortex pump is usually preferable because it has a simple structure and can circulate at a constant rate, and when the water conduit is made of a flexible material. A tube pump can also be used.

As the electrolysis device (2), for example, a device having a configuration as shown in FIG. 3 can be used.

In FIG. 3, two electrodes, namely an anode (32) and a cathode (33), are provided at the bottom of the water pipe (1), and DC electricity is supplied from a power source (34).

The electrodes used for the anode (32) and cathode (33) are usually platinum electrodes, which do not undergo corrosion or other changes even when immersed in water for a long period of time, but metals such as copper and nickel, synthetic resins, and ceramics are also preferred. Electrodes plated or vapor-deposited with gold or platinum are also used.

Further, in order to easily replace these electrodes, the cap (35) provided with the electrodes may be fixed with screws, as shown in FIG. 3.

The power source (34) is usually household AC electricity (100V
) can be transformed into direct current using a transformer, or batteries such as dry cells can be used. Further, a timer may be installed between the power source (34) and the electrodes to ensure that the power is turned on at a predetermined time.

The electric voltage and current applied to the anode (32) and the cathode (33), as well as the current application time, vary depending on the type, concentration, amount, etc. of the inorganic halide aqueous solution in the water conduit (1), so they cannot be determined in general. However, if the inorganic halide is NaCj, the effective chlorine concentration in the water pipe is usually 0.5 to 500 pp.
In particular, in order to sterilize mold and the like, it is adjusted to about 10 ppm or more. Further, the current application time varies depending on the concentration of the inorganic halide aqueous solution, the amount of supply, the amount of current, etc., but is preferably 10 to 120 minutes.

However, if organic matter is contained in the water stored in the water pipe, the chlorine produced by electrolysis may be consumed by the organic matter. It is preferable to make it large.

In addition, if the water stored in the water conduit (1) does not contain enough inorganic halides to generate a sufficient concentration of hypohalite for sterilization by electrolysis,
It is preferable to use a device having the function of supplying an inorganic halide into the water conduit (1).

As the device having the function of supplying an inorganic halide, for example, a device having the function of supplying an aqueous inorganic halide solution having a structure as shown in FIG. 4 can be used.

That is, a bellows-type inorganic halide aqueous solution container (42), which is stably installed by a container stabilizing rod (41), is installed in the main body of the device that has the function of supplying the inorganic halide aqueous solution. By turning the supply feed handle (43), the press plate (46) is moved by a fixed distance by the feed screw (45). By this operation, a certain amount of the inorganic halide aqueous solution in the inorganic halide aqueous solution container (42) is injected into the water conduit (1). In addition, in order to prevent the solution in the water conduit (1) from flowing back into the inorganic halide aqueous solution container (42) and changing the concentration of the inorganic halide aqueous solution in the inorganic halide aqueous solution container (42), a conduit is provided. A check valve (44) is installed at the boundary between the water pipe (1) and the inorganic halide aqueous solution container (42).
may be provided.

As the inorganic halide aqueous solution container (42), in addition to the bellows shape, plastic containers having various shapes can be used, such as a polyethylene bottle that can be compressed. However, in this case, it is preferable to provide an air valve so that the container shape can be restored to its original shape after supplying the inorganic halide aqueous solution.Also, it is preferable to use a container with a syringe-like mechanism. Alternatively, a method may be adopted in which a fixed amount of the inorganic halide aqueous solution is injected by pushing a piston a fixed length.

The concentration and amount of the inorganic halide aqueous solution injected into the water pipe (1) vary depending on the amount of water stored in the water pipe (1), etc., and therefore cannot be determined generally, but usually the water pipe (1) ) An inorganic halide aqueous solution having a concentration of about 0.1 to 30% is injected at a rate of about 1 to 50 ml to a water storage amount of about 100 to 4 oomz.

The inorganic halides used to obtain the inorganic halide aqueous solution include NaCl1sKCβ, LiC
jl, Al1C12, NHa Cjl.

Inorganic chlorides, such as CaCl, which generate chlorine ions by electrolysis of their aqueous solutions; inorganic iodides, such as NaI and Kl; and NaBr.

Examples include inorganic oxalides such as KBr, but among these, Na is particularly preferred due to its ease of availability.
Cl1 (sodium chloride) can be preferably used.

In addition, in the invention, in addition to the method of injecting an inorganic halide into the water conduit (1) as described above, for example, an inorganic halide that exhibits sustained release properties such as tablets or capsules formed into pellets in a predetermined amount can be used. It is also possible to adopt a method of supplying water to the water conduit (1) using a water pipe (1).

The above-mentioned tablets may be sustained-release tablets whose components are coated with a hydrogel or the like in order to gradually dissolve the components.The hydrogel may be cross-linked 2-hydroxyethyl methacrylate. Polymers or copolymers are preferably used.

Alternatively, a system may be used in which sustained-release tablets are set near the electrodes and the tablets are replaced periodically depending on the lifespan of the tablets.

For the water stop valves (6) provided at the water inlet and outlet, it is recommended to use various manual valves or solenoid valves, especially in order to prevent the invasion of microorganisms from the outside.
An electromagnetic valve using an elastic pinch valve as described in Japanese Patent No. 7-9366 may also be used.

If the container of the water conduit circuit is large, a plurality of electrolyzers may be provided as shown in FIG.

In this case, a plurality of sets of electrodes may be used and a single electric circuit may be used, or the electrodes may be installed within the tank.

In this way, by circulating the water containing hypohalite in the water pipe, the entire water pipe can be disinfected evenly.

Example 1 An electrolytic device as shown in FIG. 3 was connected to a silicon tube having an inner diameter of 5 u to form a closed circuit.

A water inlet and outlet were provided in the circuit, and tap water and 20% sodium chloride water were injected to fill the circuit. The content in the circuit was approximately 100 ml.

Next, a current of 20 mA was applied directly to the electrode, and the liquid was circulated at a rate of 20 ml/ml by a tube pump. When electrolysis was performed while circulating for 60 minutes, the effective chlorine concentration of the circulating fluid was 40 ppm.

Examples 2 to 6 Culture solutions of various microorganisms were inoculated into the closed circuit of Example 1 at concentrations shown in Table 1. Next, the same aqueous sodium chloride solution as in Example 1 was injected, and electrolysis was carried out for 60 minutes while circulating the solution. Next, the liquid in the circuit was sampled and a sterility test was conducted based on the 10th revised Japanese Pharmacopoeia, "General Test Methods 37. Sterility Test Methods." The results are shown in Table 1.

[Effects of the Invention] As described above, the pipe sterilization system of the present invention is simple in structure and operation, can completely disinfect every corner of the water pipe by circulating the liquid, and can easily increase the disinfectant concentration. Therefore, it is extremely useful for preventing microbial contamination of various types of piping, such as dialysate piping of artificial dialysis machines, automatic biochemical analyzers, and food and pharmaceutical manufacturing plants.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams of the pipe sterilization system of the present invention,
FIG. 3 is a schematic explanatory diagram of an electrolytic device, and FIG. 4 is a schematic explanatory diagram of an inorganic halide supply device. (Main symbols on the drawing) (1): Water pipe (2) (2”): Electrolyzer (4): Pump (6); Water stop valve Figure 1 Figure 2

Claims (2)

[Claims] (1) One or more electrolyzers for electrolyzing an inorganic halide aqueous solution are installed in a water conduit forming a closed circuit, and electrolysis is performed while circulating the inorganic halide aqueous solution in the water conduit. Pipe sterilization system characterized by (2) The pipe sterilization system according to claim 1, which includes a device for supplying an inorganic halide into the water pipe.