JPS6267418A - Method for inspecting leakage of gas sterilizer - Google Patents

Abstract

PURPOSE:To make it possible to detect leakage without leaking a large amount of sterilizing gas to the outside in any state, by detecting the presence of the difference between the pressure rising speeds in a sterilizing container immediately before and after reaching atmospheric pressure. CONSTITUTION:When sterilizing work is performed, an airtight lid 1 is opened to receive an article to be sterilized in a sterilizing container 2 and, after the airtight lid 1 has been closed, a vacuum pump 11 is operated to evacuate the sterilizing container 2. Next, an opening/closing valve 4 is opened to supply sterilizing gas into the sterilizing container 2 until the pressure in said container 2 comes positive and, thereafter, the pressure in the sterilizing container 2 is kept constant for a definite time. At this time, a microcomputer 15, to which the signal from a pressure sensor 13 measuring the pressure in the sterilizing container immediately before reaching atmospheric pressure with that immediately after reaching the atmospheric pressure and, when difference is generated between the pressure rising speeds in the sterilizing container immediately before and after reaching the atmospheric pressure, the generation of leakage is judged.

Description

Detailed Description of the Invention 8. Elements of the Invention (Industrial Application Field) The method for detecting leakage in a gas sterilizer according to the first aspect of the invention is applicable to hospitals and hospitals for sterilizing medical instruments, laboratory instruments, etc. Quickly detects leaks in gas sterilizers installed in laboratories, etc.
This minimizes the amount of sterilization gas leaking to the outside.

(Prior Art) Medical instruments, laboratory instruments, etc. used in hospitals, research institutes, etc. must be sterilized after use to prevent infection by attached bacteria.

For this reason, conventional steam sterilizers have been used to sterilize objects to be sterilized stored in a sterilization container by pumping air into a high-temperature, high-pressure wood I, and steam sterilizers have been used to sterilize objects stored in the sterilization container by pumping air into a high-temperature, high-pressure wood I. Gas sterilizers are used that supply sterilizing gas such as ethylene oxide or formalin. Among these, gas sterilizers are used when the object to be sterilized is sensitive to heat, or when the bacteria attached to it are fFtM bacteria.

FIG. 3 is a schematic diagram showing a gas sterilizer used in such a case. First, the structure and operation of this gas sterilizer will be explained to @mushi. It feels like it can be opened and closed freely! e The sterilization container 2 equipped with a lid T is connected to one end of a gas supply pipe 5 having a vaporizer 3 and an on-off valve 4 in the middle, and the other end of this gas supply pipe 5 is connected to a gas pump 6. has been done. The sterilization container 2 also has a sterilization filter 7 at one end, an intake pipe 9 at the other end with an on-off valve 8 in the middle, and an exhaust pipe 12 in which an on-off valve 10 and a vacuum pump 11 are provided in the middle. are connected to the respective ends.

When performing sterilization using the gas sterilizer configured in this manner, the airtight lid 1 is opened, the object to be sterilized is placed in the sterilization container 2, and the airtight lid 1 is then closed.

The on-off valve 4.8 is closed, and the vacuum pump 11 is operated with the on-off valve 10 opened to create a vacuum inside the sterilization container z, making it easier for the sterilization gas to penetrate into the object to be sterilized. Sterile container 2
After maintaining the inside in a vacuum state for a certain period of time, open/close valve 8.1
0 is closed, the on-off valve 4 is opened, and sterilization gas is introduced into the sterilization container 2. After the sterilizing gas is supplied until the pressure inside the sterilizing container z reaches a positive pressure as shown by the solid line a in the fourth factor, the on-off valve 4 is closed to keep the pressure inside the sterilizing container 2 constant for a predetermined period of time. . When sterilization for a predetermined period of time is completed, the on-off valve 8.10 is opened while the on-off valve 4 remains closed, the vacuum pump 11t is operated, the sterilization gas in the sterilization container 2 is discharged, and the sterilization gas in the sterilization container 2 is discharged. Sending sterile air into the sterile container 2,
By continuously operating the vacuum pump 11 for a predetermined period of time, the sterile gas in the container body 1 is replaced with sterile air, and the
Since the sterilization gas adhering to the IV4 object is also removed, the operation of the vacuum pump 11 is stopped, the airtight Ml is opened, and the sterilization container 2 is removed.
Take out the items to be sterilized inside.

The dregs sterilizer is configured and used as described above, but during sterilization work, the sterilization gas inside the M sterilization container leaks, and the gas pH,
If a room containing bacteria is filled with bacteria, it will endanger the health of people working in the room.

For this reason, the presence or absence of leakage of the M<empty container 2 has been conventionally inspected by various methods. Figure 5 shows the first example of the conventional leakage inspection method. In this method, when the inside of the sterile container z is evacuated, if there is a leak, the pressure inside the sterilized container 2 will be the same. The presence or absence of leakage is inspected by utilizing the gradual rise as shown by the chain line in the figure. Also, in the second example shown in Figure 56, if the inside of the sterilization container 2 is under positive pressure due to the sterilization gas, if there is a leak, the sterilization container 2
The pressure inside is chained to the same figure! The presence or absence of leakage is tested using the gradual decline as shown by ac.

(Problem that issue 1 attempts to solve) However, as described in 1-1, the leakage of sterile container 2 is
When inspecting for nothing, the following inconvenience occurs.

That is, when the airtight lid 1 provided on the sterile container 2 is of the outward-opening type,
When the inside of this sterilization container z is evacuated, the airtight 41 is pressed toward the sterilization container 2 by atmospheric pressure. For this reason,
air'! F: Air does not enter into the sterilization container 2 even if the lid is improperly tightened.

Although the pressure inside this sterilization container 2 does not change as shown by the chain line in FIG. 5, when the inside of this sterilization container 2 becomes positive pressure due to the supply of sterilization gas, this sterilization gas leaks to the outside. Put it away.

As shown in Figure 6, if the inside of the sterilization container 2 is under positive pressure, there is no problem like this if you check for leakage. Quite a lot in between! The sterilization gas from step 5 will leak to the outside.

The leak testing method for a gas sterilizer of the present invention eliminates all of the above-mentioned inconveniences.

b9 Structure of the Invention A gas sterilizer that tests for leaks using the leakage testing method for a gas sterilizer of the present invention uses a vacuum pump to exhaust the air inside a sterilization container that stores objects to be sterilized to create a negative pressure inside the sterilization container. After that, sterilizing gas is supplied into the sterilizing container at a constant rate to bring the inside of the sterilizing container to atmospheric pressure and then to positive pressure, which acts to sterilize the object to be sterilized.

In the present invention, in order to check for leakage of sterilizing gas from a gas sterilizer that operates in this way, the pressure inside the sterilization container is checked immediately before it reaches atmospheric pressure.

j? Compare the speed with the rate of pressure rise in the sterilizer immediately after reaching atmospheric pressure, and if there is a difference in the rate of pressure rise in the sterilizer immediately before and after reaching atmospheric pressure, there is a leak. I judge that.

The reason why the presence or absence of leakage in the sterilization container is determined based on the presence or absence of a difference in the rate of pressure rise within the sterilization container immediately before and after reaching atmospheric pressure is as follows.

In other words, if there is a leak in the sterilization container and the pressure inside the sterilization container is negative, the pressure inside the sterilization container due to the inflow of air will increase the needle speed to the original pressure 1-
If the pressure inside the sterilization container is positive, the pressure inside the sterilization container will increase at the original rate of pressure increase due to the outflow of sterilization gas into the atmosphere. This is because even if there are few leaking stars, the difference in pressure rise speed becomes large, and leakage can be easily detected.

For example, as shown in Figure 2, a sterile container? The pressure inside is -p
The time from (negative pressure) to atmospheric pressure (θ atmospheric pressure) is t,
, if t2 is the time it takes for the pressure to rise from atmospheric pressure to +P (positive pressure), it will be 1.=12 if there is no leakage, but 1.=12 if there is a leakage. <12.

Furthermore, in the leak testing method for a gas sterilizer of the present invention, if necessary, even if the needle speed is equal to the pressure immediately before and after the pressure inside the sterilization container reaches atmospheric pressure, the pressure inside the sterilization container may be reduced to atmospheric pressure. In this case, the rate of pressure increase in this sterilized container is measured and recorded at small intervals, and if this rate of pressure increase is slower than the rate of pressure increase that was measured and recorded immediately before, it is determined that there is a leak. Do it like this.

The reason for inspecting for leakage even after the pressure inside the sterilization container becomes positive is as follows.

In other words, if the leak occurs due to a cause other than improper tightening of the airtight lid, or if the airtight lid opens inward, leakage can be completely detected by changing the needle speed at pressures around atmospheric pressure as described above.
Air in the sterilization container: If the container is an outward-opening type, leakage due to improper tightening of the airtight lid will not occur if the pressure inside the sterilization container is negative, and the above pressure is positive pressure. It occurs only after. If a leak due to poor tightening occurs immediately after the pressure inside the sterile container exceeds atmospheric pressure, it can be determined that the pressure inside the sterile container is around atmospheric pressure; just by comparing needle speeds, leaks can be detected. However, leakage due to such causes does not necessarily occur immediately after positive pressure has been established inside the sterile container; i.e., if the inside of the sterile container is under negative pressure, the airtight lid of the sterile container must be directed toward this sterile container. The par 2 is used to maintain airtightness between the two, as they are pressed strongly by atmospheric pressure.
The king is also strongly compressed and tightly adheres to the surface that is to be kept airtight. In this way, if the backing is brought into close contact with the surface that should be airtight with strong force, even if the inside of the sterilized container becomes positive pressure, if the pressure is small, no leakage will occur, and the inside of the sterilized container will not leak. The sterilization gas inside the sterilization container begins to leak outside after the pressure reaches a certain level and the backing peels off from the surface that is to be kept airtight. In this case, the L needle speed of the pressure inside the sterilization container becomes slow after the inside of the sterilization container becomes positive pressure, as shown by the chain line e in Figure 3, so the pressure increases at small intervals. The speed is measured, and if the speed drops midway through, it is determined that there is a leak.

In addition, when measuring the pressure inside a sterile container and the needle speed, it is also possible to calculate the pressure change per constant surface, or to calculate the time required for the pressure to rise by a constant pressure difference, but atmospheric pressure When determining the presence or absence of a difference in pressure 1 - rising speed between immediately before and after, it is more convenient to find the time required to increase I-'yl by a constant pressure difference.

The gas M bacteria leakage testing method of the present invention includes the first step.
As shown in the figure, a signal from a pressure sensor 13 that measures the pressure inside the sterile container 2 and a signal from a clock element 14 such as a clock pulse generator are sent to a microcomputer 15.
This can be easily done by comparing. When this microcomputer 15 determines that there is a leak, it closes the on-off valve 4 in the middle of the gas supply pipe 5, and also closes the alarm 16.
sends a signal to warn that there is a leak.

C1 Effects of the Invention The method for inspecting leaks in gas sterilizers of the present invention is structured and operates as described above, so that no matter what the situation, it is possible to prevent leakage without causing a large amount of sterilizing gas to leak to the outside. It can be detected and the gas sterilizer can be operated safely.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a gas sterilizer for carrying out the leak detection method for detecting leaks. Figure 4 is a schematic diagram showing the basic configuration of the gas sterilizer, Figures 5-6
The figure is a diagram showing pressure changes inside a sterilization container used when inspecting for leakage using a conventional method. l: airtight lid, 2: sterile container, 3: vaporizer, 4: on-off valve,
5: gas supply pipe, 6: gas cylinder, 7: sterilization filter,
8: Open/close valve, 9: Intake pipe, 10: Open/close valve, 11: Vacuum pump, 12: Exhaust pipe, 13: Pressure sensor, 14: Clock element, 15: Microcomputer, 16: Alarm.

Claims (1)

[Claims] 1) After the air in the sterilization container containing the object to be sterilized is exhausted by a vacuum pump to create a negative pressure in the sterilization container, a fixed amount of sterilization gas is supplied into the sterilization container. A method of inspecting for leakage of sterilizing gas from a gas sterilizer that sterilizes objects to be sterilized by raising the inside of the sterilization container to atmospheric pressure and then further positive pressure, and sterilization immediately before atmospheric pressure is reached. Comparing the rate of pressure increase inside the container and the rate of pressure increase inside the sterilizer immediately after reaching atmospheric pressure, it was found that there was a difference in the rate of pressure increase inside the sterilization container immediately before and after reaching atmospheric pressure. In case,
Leak inspection method for gas sterilizers to determine if there is a leak. 2) After the air inside the sterilization container containing the items to be sterilized is exhausted using a vacuum pump to create a negative pressure inside the sterilization container, a fixed amount of sterilization gas is supplied into the sterilization container to greatly expand the inside of the sterilization container. A method of testing whether there is a leak of sterilizing gas from a gas sterilizer that sterilizes the object by increasing the atmospheric pressure to positive pressure, and measuring the rate of pressure rise in the sterilization container just before reaching atmospheric pressure. and the rate of pressure rise in the sterilizer immediately after reaching atmospheric pressure, and if there is a difference in the rate of pressure rise in the sterilizer immediately before and after reaching atmospheric pressure,
If it is determined that there is a leak and there is no difference in the rate of pressure rise above, and if the pressure inside the sterilization container exceeds atmospheric pressure,
A leak inspection method for gas sterilizers that measures and records the rate of pressure increase in the sterilization container at small intervals, and determines that there is a leak if the rate of pressure increase is slower than the rate of pressure increase that was measured and recorded immediately before. .