JPH0880340A - Method for detecting clogging of disinfection filter for gas sterilizer - Google Patents

Abstract

(57) [Summary] [Purpose] To detect easily the clogging condition of the sterilization filter used in the gas sterilizer with high accuracy. [Structure] The object to be sterilized in the sterilization container is processed in the order of a sterilization process, a pulsing cleaning process, and a blow cleaning process. After reducing the pressure P in the sterilization container to a predetermined pressure P ₁ , clean air is sucked into the sterilization container through the sterilization filter while the vacuum pump is operating. Set pressure P in the sterilization container
The pressure P in the sterilization container after the elapse of a time up to ₂ or after a predetermined time is measured to detect the presence or absence of clogging of the sterilization filter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The method for detecting clogging of a sterilization filter for a gas sterilizer according to the present invention is for determining the clogging state of a sterilization filter used in a gas sterilizer and knowing when to replace the filter. To use.

[0002]

2. Description of the Related Art Sterilizers are installed in hospitals and various laboratories to sterilize used surgical tools and experimental instruments before reusing them. In particular, a gas sterilizer that performs a sterilization process with a sterilizing gas such as ethylene oxide gas is used for the sterilization process of the sterilization object having low heat resistance.

First, the construction of such a gas sterilizer and the steps of the sterilization process will be described with reference to FIGS. Inside the sterilization container 1 having an airtight lid (not shown) that can be opened and closed freely and containing the object to be sterilized, in the middle of the exhaust pipe 8 through which the upstream end is passed, the sterilization container 1 is opened and closed in order. A valve 6 and a vacuum pump 7 of an ejector type or a water seal type are provided. The downstream end of the exhaust pipe 8 is open to the outside.
In addition, a sterilization filter 4 and an on-off valve 5 are provided in series in order from the upstream side in the middle of an intake pipe 3 having the downstream end passed through the sterilization container 1 and the upstream end opened to the atmosphere, and the sterilization is performed. Clean air can be sucked into the container 1. Further, the storage unit 2 can store a small-sized cylinder filled with a sterilizing gas such as ethylene oxide gas, which is used up in one sterilization process. The ethylene oxide gas for sterilization may be supplied from such a small cylinder as well as a desired amount from a large cylinder.

In order to perform sterilization work using the gas sterilization apparatus configured as described above, first, the object to be sterilized is put in the sterilization container 1, the on-off valve 5 is closed, and then the on-off valve 6 is opened. . Then, the vacuum pump 7 is operated to suck the air in the sterilization container 1 through the exhaust pipe 8 from the intake port of the vacuum pump 7. During operation of the vacuum pump 7, compressed air is sent from an air compressor or the like through an air supply pipe 9 to an air supply port of the vacuum pump 7, and the compressed air is jetted from a nozzle in the vacuum pump 7. The pressure inside the vacuum pump 7 is reduced. In this way, first, the pressure inside the sterilization container 1 is lowered (made into a vacuum state) by discharging the air contained in the object to be sterilized and infiltrating the sterilizing gas into the inside of the object to be sterilized. This is to make it easier.

Next, a predetermined amount of water is supplied into the sterilization container 1 from a water supply means (not shown) such as a water storage tank, and a humidification process for humidifying the object to be sterilized is performed. At this time, by operating a metering pump (not shown) for a predetermined time, a predetermined amount of water is injected into the sterilized container 1 whose pressure has dropped, and this water is evaporated in the sterilized container 1.

In this way, after the air contained in the object to be sterilized has been exhausted and the humidifying step as described above has been carried out, a sterilization step for sterilizing the object to be sterilized is then carried out. This sterilization step is performed by filling the sterilization container 1 with sterilization gas. That is, with the on-off valve 6 closed, the storage section 2
The sealing plate of the small cylinder in the storage unit 2 is broken by a solenoid or the like provided in the portion, and the sterilizing gas is introduced into the sterilization container 1. As a result, the object to be sterilized in the sterilization container 1 is sterilized by the sterilizing gas. After the sterilization process for a predetermined time is completed, the on-off valve 6 is opened again and the vacuum pump 7 is operated to discharge the sterilization gas in the sterilization container 1 used in the sterilization process to the outside through the exhaust pipe 8.

As described above, even after the sterilizing gas in the sterilization container 1 is discharged, when the sterilized object is a fibrous material such as clothes for a patient or a futon, the sterilized gas is deep inside the sterilized object. There is a possibility that it has penetrated to and remains in this sterilized object. Therefore, a cleaning step is performed to remove the sterilizing gas remaining on the object to be sterilized. In this cleaning process, as shown in FIG. 1, a pulsing cleaning process and a blowing process are sequentially performed. In the pulsing cleaning process, first, the opening / closing valve 6 is opened with the opening / closing valve 5 closed, and the vacuum pump 7 is operated to evacuate the sterilization container 1. When the inside of the sterilization container 1 becomes a vacuum, the vacuum pump 7 is stopped and the opening / closing valve 5 which has been closed until then is opened, and the clean air that has passed through the sterilization filter 4 is sucked into the sterilization container 1. As a result, if the pressure in the sterilization container 1 rises,
The vacuum pump 7 is operated again with the on-off valve 5 closed, and the operation of evacuating the sterilization container 1 is repeated. That is, in the pulsing cleaning process, the sterilization gas adhering to the object to be sterilized is separated by repeating such feeding and discharging of clean air in the sterilization container 1 several times.

After performing the pulsing cleaning step, the opening / closing valve 5 is opened while the operation of the vacuum pump 7 is continued. Then, the sterilizing gas separated from the object to be sterilized is removed from the sterilization container 1 by a blow cleaning process in which the clean air that has passed through the sterilization filter 4 is circulated in the sterilization container 1. By the pulsing cleaning process and the blow cleaning process as described above, the sterilizing gas remaining in the sterilization container 1 is replaced with clean air, and the sterilizing gas adhering to the object to be sterilized is also removed. In the process diagram of FIG. 1, the pressure in the sterilization container 1 is controlled by appropriately controlling the opening / closing of the opening / closing valve 5, the operation / stop of the vacuum pump 7 and the opening / closing of the opening / closing valve 6 after the blow cleaning. Fluctuate. Due to this pressure fluctuation, the sterilization gas adhering to the object to be sterilized can be more reliably separated and removed. The blow cleaning process and the pressure fluctuation process are combined to form an aeration process in which the sterilization container 1 is filled with clean air instead of discharging the sterilization gas separated from the object to be sterilized.

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The sterilization filter used in the gas sterilization apparatus as described above passes air in the atmosphere and collects dust and bacteria contained in the air to clean it. Since air is used, clogging occurs due to long-term use, and the suction efficiency of clean air decreases. If the disinfection filter is clogged, not only the efficiency of the sterilization process as a whole is deteriorated, but also if the clogging progresses beyond a certain level, the operation of the gas sterilizer cannot be continued.

For this reason, the replacement cycle of the sterilization filter is set roughly, for example, once a year, and when the replacement time is reached, replacement is performed regardless of the actual clogging state. . However, depending on the frequency of use of the gas sterilizer, there is a change in the time when the sterilization filter is clogged.Therefore, the clogging condition of this sterilization filter can be accurately determined and notified to the user, so that the clogging will be blocked. It has become necessary to urge replacement of the sterilization filter that has not been performed, and to avoid a situation where the gas sterilizer cannot be operated suddenly. The clogging detection method of the disinfection filter for gas sterilizer of the present invention is invented in view of the above-mentioned circumstances.

[0011]

The present inventor conducted the following test as a preliminary test for inventing a method for detecting clogging of a disinfection filter for a gas sterilizer. First, a sterilization filter with advanced clogging and a sterilization filter without clogging (hereinafter referred to as “normal sterilization filter”) were prepared. Then, each sterilization filter is attached to the gas sterilizer, and the pressure P in the sterilization container 1 (FIG. 2) which is lowered by the operation of the vacuum pump 7 (FIG. 2) is the vacuum pump 7
The time T ₁ required to rise to a predetermined pressure was measured in the state where the pressure was stopped. According to this measurement work, the vacuum pump 7
In the state in which the sterilization container 1 is stopped, the time T ₁ required for the pressure P in the sterilization container 1 to rise from, for example, −600 mmHg to −150 mmHg is about 30 seconds in the sterilization filter with the progress of clogging. It took about 11 seconds with the bacteria filter.
From this measurement result, it was found that the time T ₁ required to increase the pressure P in the sterilization container ₁ becomes longer and the efficiency is remarkably reduced when the sterilization filter with the increased clogging is used.

Next, the pressure P in the sterilization container 1 which has been reduced by the operation of the vacuum pump 7 in the gas sterilizer equipped with the respective sterilization filters rises up to a predetermined pressure while the vacuum pump 7 is in operation. The time T ₂ required for the measurement was measured.
The time T ₂ required for the pressure P in the sterilization container 1 to rise from, for example, -600 mmHg to -150 mmHg while the vacuum pump 7 is operating is about 55 seconds in the disinfected filter with the clogging. With a normal sterilization filter, it took about 11 seconds. As described above, the required time T ₂ when the vacuum pump 7 is operated is longer than the required time T ₁ when the vacuum pump 7 is stopped as compared with the time required for the normal filter and the disinfected filter with advanced clogging. It was found that the ratio of time was large and the detection sensitivity for clogging was improved.

[0013]

In any of the methods for detecting clogging of a sterilization filter for a gas sterilizer according to the present invention, the sterilization gas is filled in a sterilized container which is closed while the object to be sterilized is stored therein. The sterilization process of sterilizing the sterilized product, the discharge of gas from the sterilization container by operating the vacuum pump, and the intake of clean air into the sterilization container through the sterilization filter are alternately repeated several times, thereby A pulsing cleaning step for removing the sterilizing gas adhering to the object to be sterilized while changing the pressure of, and a blow cleaning step for sucking clean air into the sterilization container through the sterilization filter while operating the vacuum pump, This is a method for detecting clogging of the sterilization filter with a gas sterilizer that performs a sterilization process, a pulsing cleaning process, and a blow cleaning process in this order.

Particularly, in the detection method described in claim 1, after the inside of the sterilization container is reduced to a predetermined pressure by the vacuum pump, the inside of the sterilization container is passed through the sterilization filter with the vacuum pump being operated. Inhale clean air into. Then, the time required for the inside of the sterilization container to rise to the set pressure is measured, and when this time is longer than the preset time, it is determined that the sterilization filter is clogged. The set time is experimentally obtained from the relationship between the predetermined pressure and the set pressure, and is input in advance to a controller such as a microcomputer that determines clogging.

Further, in the detection method according to the second aspect, after the inside of the sterilization container is reduced to a predetermined pressure by the vacuum pump, the sterilization container is passed through the sterilization filter while the vacuum pump is operating. Aspirate clean air into it. Then, the pressure inside the sterilization container is measured after the set time has elapsed, and when the pressure is lower than a preset set pressure, it is determined that the sterilization filter is clogged. The above set pressure is also obtained experimentally and is input in advance to a controller for judging clogging.

[0016]

According to the method for detecting clogging of the disinfection filter for a gas sterilizer configured and operating as described above, the pressure display and the monitoring timer in the sterilization container provided in the current gas sterilizer are used. The clogging state of the sterilization filter can be easily detected with high accuracy. That is, the sterilization work of the object to be sterilized in the sterilization container is performed in the order of a sterilization process, a pulsing cleaning process, and a blowing process, and clean air is sucked into the sterilization container whose pressure has been reduced to a predetermined pressure through a sterilization filter. Then, while the vacuum pump is in operation, the time required for the inside of the sterilization container to rise to the set pressure is measured (in the case of claim 1), or the pressure inside the sterilization container after the set time is measured ( In the case of claim 2), the clogging state of the sterilization filter is determined.
Therefore, the efficiency of the sterilization work will not be lowered by accurately replacing the sterilization filter and continuing to use the clogged sterilization filter.

[0017]

EXAMPLE A method for detecting clogging of a sterilization filter for a gas sterilizer according to the present invention uses a conventionally known gas sterilizer almost as it is, a pressure sensor for measuring the pressure in a sterilization container, and a sterilizer. The clogging state of the sterilization filter is accurately detected by using the signal with the monitoring timer for watching the progress of the process.

First, a first embodiment corresponding to claim 1 of the present invention will be described. As explained in the above-mentioned conventional example,
In the gas sterilizer, even after the sterilization gas is discharged from the sterilization container 1 (FIG. 2) after the sterilization process of the object to be sterilized, the sterilized gas adheres to the object to be sterilized. The pulsing cleaning process for repeatedly vacuuming the container 1 and the blow cleaning process for circulating clean air in the sterilized container 1 for cleaning are performed in order.

In the present invention, the pressure P in the sterilization container 1 is set to the predetermined pressure P by the vacuum pump 7 (FIG. 2) at the final time of the pulsing cleaning step after the sterilization (after the sterilization step) thus performed. After reducing the pressure to ₁ , the open / close valve 5 is opened while the vacuum pump 7 is in operation, and clean air is sucked into the sterilization container 1 through the sterilization filter 4 (FIG. 2). Then, a time T required for a predetermined pressure P ₁ of the sterilization vessel 1 rises to the setting pressure P ₂ is measured, when the time T is longer than the set time t set in advance,
It is determined that the sterilization filter 4 is clogged to the extent that it needs to be replaced. The set time t is a part of the time zone for supplying air that is continuous with the blow cleaning process that is performed after the pulsing cleaning process is completed. Therefore, no special time is required for determining the clogging of the sterilization filter 4.

More specifically, as is clear from the above-mentioned preliminary test, it is necessary to increase the pressure P in the sterilization container by using the sterilized filter which is clogged as compared with the ordinary sterilized filter. The time T becomes longer. When a normal sterilization filter is used in a gas sterilizer and the vacuum pump 7 is operated with the on-off valve 5 opened, the pressure P of the sterilization container 1 is maintained at, for example, 0 to -60 mmHg. Therefore, if the pressure P in the sterilization container 1 rises to -100 mmHg or more after at least the set time t obtained by an appropriate experiment, the sterilization filter in use is not clogged enough to require replacement. Can be determined. In this embodiment, FIG.
As shown in, the set pressure P ₂ is set to -100 mmHg, and the pressure P in the sterilization container 1 is set to the set pressure P from the predetermined pressure P ₁ -600 mmHg in which the pressure is the lowest in the pulsing cleaning process.
_The time T required to rise to 2-100 mmHg is measured, and when this time T is longer than the set time t, it is determined that the sterilization filter in use is clogged enough to require replacement. .

[0021] That is, in the diagram indicated by the solid line in FIG. 1, for example a pressure P of the sterilization vessel 1 is the predetermined pressure P ₁ -6
When the time T required to rise from 00 mmHg to the set pressure P ₂ -100 mmHg is the set time t or less (T ≦ t), the sterilization used in the gas sterilizer showing the operating condition of this diagram The filter determines that it is not clogged enough to require replacement.

On the other hand, as shown by the chain line in FIG. 1, the time T required to rise from the predetermined pressure P ₁ to the set pressure P ₂ is longer than the set time t (T = t + α> t). In this case, it can be determined that the sterilization filter is clogged enough to require replacement.

Further, the set time t is, for example, a time t ₁ for notifying the replacement time of the sterilization filter 4 and a time t _{2 for} which the operation of the gas sterilizer is finally disabled due to further progress of clogging. It is also possible to perform a two-step warning operation by classifying into two.

Next, a second embodiment corresponding to claim 2 will be described. In the above-described first embodiment, the time until the pressure P in the sterilization container reaches the set pressure is compared with the set time t to make a determination, but in the present embodiment, the time for making the determination is set in advance. .

That is, again, at the final time of the pulsing cleaning process, the inside of the sterilization container 1 is pressurized to a predetermined pressure P by the vacuum pump 7 (FIG. 2).
After the pressure is reduced to ₁ , the open / close valve 5 is opened while the vacuum pump 7 is operating, and clean air is sucked into the sterilization container 1 through the sterilization filter 4. Then, the set time t
After the lapse of time, the pressure P in the sterilization container 1 is measured, and when this pressure P is lower than a preset pressure P ₂ , the sterilization filter 4 used in this gas sterilizer needs to be replaced. Judge as clogged. With reference to FIG.
In the diagram indicated by the chain line, since the pressure P (point P _{3 in the} figure) in the sterilization container 1 is lower than the set pressure P ₂ even after the time t has passed, the sterilization filter 4 needs to be replaced. Judge as clogged. Also in this embodiment, the set pressure P ₂ is set to 2
As a stage, it is possible to notify the replacement time of the sterilization filter 4 and prevent the operation of the gas sterilizer from being suddenly stopped.

[0026]

Since the method for detecting clogging of a disinfection filter for a gas sterilizer according to the present invention is configured and operates as described above, the present gas sterilizer can be used almost without adding any other device. It can be used as it is to accurately determine the clogging state of the sterilization filter. Therefore, it is possible to replace the sterilization filter before it is clogged, and prevent the efficiency of the sterilization processing work from being reduced due to the clogging and the unexpected interruption. Moreover, since it is not necessary to take special time to detect clogging, the efficiency of sterilization work is not deteriorated.

[Brief description of drawings]

FIG. 1 is a diagram showing an operating condition of a gas sterilizer.

FIG. 2 is a circuit diagram of a general gas sterilizer.

[Explanation of symbols]

 1 Sterilization container 2 Storage part 3 Intake pipe 4 Sterilization filter 5, 6 Open / close valve 7 Vacuum pump 8 Exhaust pipe 9 Air supply pipe

Claims (2)

[Claims] 1. A sterilization process in which a sterilizing gas is filled in a sterilization container which is closed in a state in which the sterilization object is stored, and a gas is discharged from the sterilization container by operating a vacuum pump. By alternately repeating clean air suction into the sterilization container through the sterilization filter a plurality of times, the pulsing cleaning process for removing the sterilization gas adhering to the object to be sterilized while changing the pressure in the sterilization container, and the above A gas sterilizer that performs a blow cleaning step of sucking clean air into the sterilization container through the sterilization filter while operating a vacuum pump in the order of a sterilization step, a pulsing cleaning step, and a blow cleaning step. The method for detecting the clogging of the sterilization container is as follows. Suction clean air into the sterilization container through the sterilization filter, measure the time required to rise to a set pressure in the sterilization container, if this time is longer than the preset time set, A method for detecting clogging of a sterilization filter for a gas sterilizer, which determines that the sterilization filter is clogged. 2. A sterilization process in which a sterilizing gas is filled in a sterilized container which is closed in a state where the object to be sterilized is stored, and a gas is discharged from the sterilized container by operating a vacuum pump. By alternately repeating clean air suction into the sterilization container through the sterilization filter a plurality of times, the pulsing cleaning process for removing the sterilization gas adhering to the object to be sterilized while changing the pressure in the sterilization container, and the above A gas sterilizer that performs a blow cleaning step of sucking clean air into the sterilization container through the sterilization filter while operating a vacuum pump in the order of a sterilization step, a pulsing cleaning step, and a blow cleaning step. The method for detecting the clogging of the sterilization container is as follows. The clean air is sucked into the sterilization container through the sterilization filter, the pressure in the sterilization container after a set time has elapsed is measured, and if the pressure is lower than a preset set pressure, the sterilization is performed. A method for detecting clogging of a disinfection filter for a gas sterilizer, which determines that the filter is clogged.