JPH07136236A - Ozone-mixed steam sterilizing method and device - Google Patents

Abstract

PURPOSE:To provide the ozone-mixed steam sterilizing method and device capable of extremely safely and rapidly executing sterilization. CONSTITUTION:Ozone is supplied into a sterilizing container 7 of a negative pressure state housing a material to be sterilized and thereafter, the ozone-mixed steam is formed and is supplied into the sterilizing container 7, by which the material to be sterilized is sterilized in the state of increasing the temp. and humidity in the sterilizing container 7. The device has an ozone generator 2 for generating ozone, an ejector 3 for forming the ozone-mixed steam by mixing steam with the generated ozone and a vacuum pump 4 for reducing the pressure in the sterilizing container 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly an ozone mixed steam sterilization method and apparatus used in hospitals, research laboratories, laboratory animal facilities, etc., regardless of whether pathogens or non-pathogens attached to instruments, equipment, etc. Firstly, the present invention relates to an ozone mixed steam sterilization method and apparatus suitable for killing all microorganisms and spores, fungi and viruses.

[0002]

2. Description of the Related Art Conventionally, as a disinfection method using ozone, the disinfection method described in Japanese Patent Laid-Open No. 57-131448 is known. This method is a method of sending air containing ozone into the inside of a vacuum container for sterilization.

Typical sterilization methods that do not use ozone include high-pressure steam sterilization, ethylene oxide gas sterilization, and dry heat sterilization.

[0004]

The conventional sterilization method that does not use ozone requires a robust pressure vessel as in the high-pressure steam sterilization method, and high temperature conditions (for example, 170 in the dry heat sterilization method). Many problems remain, such as the inconvenience of being unable to be used for sterilized materials that are not suitable for sterilization) and the difficulty of treating exhaust gas after sterilization as in the ethylene oxide gas sterilization method.

Further, in the conventional disinfection method using ozone, air containing ozone (ozone concentration 1 ppm
It is thought that long-term treatment is required to obtain a sufficient disinfecting effect.
In addition, sterilization (killing all microorganisms regardless of pathogen or non-pathogen) is difficult. That is, in the conventional disinfection method, ozone molecules contained in the air are extremely unstable. Therefore, in order to delay the decomposition of the ozone molecules, a method of sending the air containing ozone at a temperature as low as possible is adopted. However, when ozone is kept at a low temperature, it is possible that the decomposition of ozone molecules can be suppressed and the ozone concentration can be maintained for a long time, but the bactericidal action due to the decomposition of ozone molecules also requires a long time.

On the other hand, according to the research after the above-mentioned application (Japanese Patent Laid-Open No. 57-131448), it has been found that the sterilizing action of ozone has a higher sterilizing power under high humidity than under low humidity. .
It was also found that a more effective bactericidal action can be obtained by heating the sterilized object after contacting it with ozone. Further, it was also shown that the heat resistance of the spores remaining after the ozone treatment was remarkably reduced, and the heat sterilization conditions could be relaxed.

Therefore, the present invention was created in view of these research results in order to solve the above problems, and is an ozone mixture capable of performing extremely safe and rapid sterilization, which cannot be realized by conventional techniques. It is intended to provide a steam sterilization method and apparatus.

[0008]

In order to achieve the above-mentioned object, the first means of the present invention is to supply ozone gas into a negative pressure sterilization container for accommodating an object to be sterilized, and then to supply ozone mixed vapor. It is generated and supplied to the inside of the sterilization container for sterilization in a state where the temperature and humidity inside the sterilization container are increased.

The device in the second means is an ozone generator 2 for generating ozone, and an ejector 3 for mixing the generated ozone with steam to generate ozone mixed steam.
And a vacuum pump 4 for reducing the pressure inside the sterilization container 7.

[0010]

That is, according to the sterilization method of the present invention,
It is sterilized by ozone and ozone mixed steam.

In the device of the present invention, the ejector 3 mixes ozone and steam to generate ozone mixed steam. Then, ozone and ozone mixed vapor are supplied to the inner can 7A of the sterilization container 7 which has been made negative pressure by the vacuum pump 4. In other words, it utilizes the oxidation and sterilization effects of ozone, the temperature and humidity of the saturated steam that promotes it, and the exposure effect of the saturated steam itself.

[0012]

EXAMPLES Examples of the present invention will be described in detail below.

In the sterilization method of the present invention, first, ozone is mixed with steam to generate ozone mixed steam, and this ozone mixed steam is used. When using the ozone-mixed steam, the inside of the sterilization container for storing the sterilization object is set to a negative pressure, and the ozone-mixed steam is supplied to the sterilization container.

At this time, ozone gas which is not mixed with steam is supplied into the negative pressure sterilization container, and then ozone mixed steam is supplied into the sterilization container to increase the temperature and humidity inside the sterilization container. Sterilization in the state enhances the sterilization effect (see FIG. 2).

[0015]

[Table 1] Table 1 shows changes with time in the pressure inside the sterilization container which is preferable for sterilization. That is, when sequentially showing the internal condition of the sterilization container, the sterilization is completed through the vacuum process A, the ozone supply process B, the ozone mixed vapor supply process C, the sterilization process D, the vacuum drying process E, and the atmospheric reduction process F.

The vacuum step A is a step of reducing the internal pressure of the sterilization container and is a step of facilitating the permeation of ozone into the object to be sterilized in the next ozone supply step B. At this time, at the time of the sign "a" where the most negative pressure is reached, the internal pressure is 700 to 750 mmHg and the internal temperature is 20 to 50 degrees Celsius.

In the ozone supplying step B, ozone before mixing the ozone mixed vapor is supplied to the object to be sterilized under negative pressure. At this time, since the inside of the sterilization container is under negative pressure, the ozone molecules spread to every corner of the sterilized object and are in a state of sufficiently contacting the sterilized object.

In the ozone mixed vapor supply step C, the ozone mixed vapor is filled in the sterilization container so that the ozone molecules previously supplied in the ozone supply step B and the ozone molecules of the ozone mixed vapor are sterilized. It is a process to penetrate into.
At this time, the code b changes the pressure within a range not including the codes a and c in consideration of the quality and quantity of the sterilized object inside the sterilization container.

In the sterilization step D (the period indicated by the symbol C), ozone mixed vapor is circulated to bring the internal pressure to atmospheric pressure and the internal temperature is set to 50 to 100 degrees Celsius. Further promotes the decomposition of ozone molecules supplied by the ozone vapor, and also generates a convection inside the sterilization container by the ozone mixed vapor, increasing the chance of ozone coming into contact with the object to be sterilized, and at the same time, due to the exposure action of the saturated vapor itself. This is the process with the highest bactericidal action. At this time, depending on the quantity and quality of the material to be sterilized, the temperature may be increased or the pressure may be increased to some extent.

The vacuum drying step E is a step of drying and cooling the object to be sterilized under high humidity and high temperature. At the time of the code e when the vacuum drying step E is completed, the internal pressure is reduced to 70
0 to 750mmHg, and internal temperature 20 to 50 degrees Celsius.

The atmospheric reduction step F is a step of returning the inside of the sterilization container to the atmospheric pressure in order to take out the object to be sterilized that has been vacuum dried from the sterilization container. Therefore, at the time point indicated by the code at which this atmospheric reduction step F is completed, the internal pressure becomes atmospheric pressure,
The internal temperature is 30 to 60 degrees Celsius.

FIG. 1 shows a circuit of a device for carrying out the present invention. That is, in the figure, reference symbol R indicates air piping, S indicates steam piping, and W indicates water supply piping.

The air pipe R is connected to an ozone generator 2 having an air pump, and the ozone generated by the ozone generator 2 is supplied to the ejector 3 by the operation of the ozone generator 2.

The ejector 3 is also connected to a steam supply pipe S where steam and ozone are mixed. The steam supplied to the ejector 3 is separated into steam and water by passing through the separator 1 in advance, and water drops generated in the steam supply pipe S and condensed water flowing to the bottom of the pipe are separated and removed to obtain high-quality steam with a constant humidity. Is being supplied. Then, the steam separated by the separator 1 is passed through the ejector 3 by the inner-can-feeding electromagnetic valve 3A via the pressure reducing valve 1A and is supplied to the inner can 7A of the sterilization container 7. Therefore, it is possible to supply ozone without mixing steam by closing the inner can steam supply solenoid valve 3A.

The sterilization container 7 is an inner can 7 for storing an object to be sterilized.
A and an outer can 7B that wraps around the inner can 7A have a double structure. Then, the inner can 7A is depressurized by the operation of the ozone generator 2 and the supply of ozone and ozone mixed vapor by the inner can supply electromagnetic valve 3A, and the operation of the vacuum pump 4 via the vacuum electromagnetic valve 4A. At this time, the vacuum pump 4
Uses a water-sealed vacuum pump 4, and in operation of the vacuum pump 4, a priming solenoid valve 4B connected to a water supply pipe W is provided. Further, an inner can temperature controller 8 is provided and the inner can feeding solenoid valve 3A is controlled so that the temperature of the steam discharged from the inner can 7A is sensed and the temperature of the inner can 7A is kept constant. Furthermore, at the end of sterilization, the filtered air solenoid valve 6
With the check valve 6A, clean air is supplied into the inner can 7A through the filter 5.

On the other hand, the outer can 7B is connected to the steam supply pipe S, and the temperature of the outer can 7B is adjusted via the outer can evacuation electromagnetic valve 1B and the check valve 1C controlled by the outer can temperature switch 9. The condensation of the vapor when the ozone mixed vapor is supplied to the inner can 7A is minimized.

Reference numeral 10 indicates an exhaust steam cooler, which lowers the temperature of the exhaust steam and discharges it together with the water supplied from the water supply pipe W. Reference numeral 10A is a cooling solenoid valve.

[0028]

The present invention achieves the original object by having the above-mentioned configuration. That is, according to the first aspect, the ozone mixed vapor provides a rapid sterilization effect which cannot be obtained by the conventional disinfection method using ozone.

Moreover, according to the first and second aspects, since ozone molecules are naturally decomposed after sterilization, there is no fear of secondary contamination after sterilization as in the conventional gas sterilization method. Further, unlike the high-pressure steam sterilization method, there is no need for a robust pressure vessel, and the inconvenience that it cannot be used for an object to be sterilized which is not suitable for high temperature conditions (for example, 170 ° C. or higher) unlike the dry heat sterilization method is solved. Furthermore, the sterilization time can be shortened compared to the conventional high-pressure steam sterilization method because it utilizes the sterilization effect of ozone, the temperature and humidity of saturated steam that promotes it, and the exposure effect of saturated steam itself. it can.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a sterilizer of the present invention.

FIG. 2 is a block diagram showing an embodiment of the sterilization method of the present invention.

[Explanation of symbols]

 R Air piping S Steam supply piping W Water supply piping Q Emission 1 Separator 1A Pressure reducing valve 1B Outer can steaming solenoid valve 1C Check valve 1D Steam trap 2 Ozone generator 2A Check valve 3 Ejector 3A Inner can steaming Solenoid valve 4 Vacuum pump 4A Vacuum solenoid valve 4B Priming solenoid valve 4C Check valve 5 Filter 6 Filtered air solenoid valve 6A Check valve 7 Sterilization container 7A Inner can 7B Outer can 7C Check valve 7D Check valve 8 Inner can temperature Regulator 9 Outer can temperature switch 10 Exhaust steam cooler 10A Cooling solenoid valve

Claims (2)

[Claims] 1. Ozone is supplied into a negative pressure sterilization container for containing an object to be sterilized, and then ozone mixed vapor is generated and supplied into the sterilization container to increase the temperature and humidity inside the sterilization container. A method for sterilizing ozone mixed steam, characterized in that it is sterilized in an open state. 2. An ozone mixture comprising an ozone generator for generating ozone, an ejector for mixing the generated ozone with vapor to generate ozone mixed vapor, and a vacuum pump for decompressing the inside of the sterilization container. Steam sterilizer.