JPH0263B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a gas sterilizer that performs sterilization using a toxic sterilizing gas such as ethylene oxide, and aims to provide a gas sterilizer that is effective in stabilizing sterilization operations. It is an invention aimed at

The gas sterilizer, as shown in FIG.
An air supply pipe 4 equipped with an air supply pipe 4 communicates with a gas source 5, and an exhaust pipe 8 equipped with an exhaust valve 6 and an exhaust pump 7 connects the inside of the can body 2 to an exhaust treatment device 9 for removing toxic gas and discharging it. This is what made me understand. The structure of the gas sterilizer described above has been used conventionally, but in the device of the present invention, the pressure of the sterilizing gas is adjusted according to the level of pressure inside the can body 2, and the gas concentration inside the can body is adjusted. A computer 10 is attached, which controls the opening/closing, starting, and stopping of the air supply valve 3, the exhaust valve 6 (both are electromagnetic valves or motor valves), and the exhaust pump 7 using conductors 11 and 12. I try to do that. 13 is a pressure sensor that detects the internal pressure of the can body 1. computer 10
The control effect will be described later.

When using a gas sterilizer, first close the air supply valve 3.
is closed, the exhaust valve 6 is opened, and the exhaust pump 7 is operated to reduce the pressure inside the can body 2 to a vacuum state. Next, when the exhaust valve 6 is closed, the exhaust pump 7 is stopped, and the air supply valve 3 is opened, pressurized sterile gas is supplied from the gas source 5 to the pipe 4.
It flows into the can body 2 through. When an appropriate amount of gas has flowed in, the air supply valve 3 is closed, and the objects to be sterilized contained in the can 2 are sterilized by the gas inside the can for a predetermined period of time.

The pressure change inside the can body 2 during this operation is as shown by lines a to c schematically shown in FIG. 2. In other words, regarding the A-line, if the exhaust inside the can is started at time A, the pressure inside the can decreases over time, and when the exhaust is stopped at time B and the air supply valve 3 is opened, sterilizing gas flows into the can 2. The pressure inside the can increases, and when the air supply valve 3 is closed at time C, gas sterilization is performed for a predetermined period of time (for example, 3 hours) while the pressure inside the can remains constant. Conventionally, this sterilization operation was performed on a time basis.

However, if the pressure inside the can body 2 is not sufficiently reduced due to a malfunction of the exhaust pump 7, etc., it becomes difficult for the sterilizing gas to flow into the can body 2, and the amount of gas inside the can body decreases, resulting in a sterilization effect. becomes weaker.

This invention attempts to maintain a constant concentration of sterilizing gas sealed within the can by detecting the internal pressure of the can and adjusting the gas pressure fed into the can depending on the degree of internal pressure. That is, when the pressure inside the vessel decreases small (pressure is high) as shown by line a in Figure 2, the feed gas pressure is increased as shown by line a', and the pressure decreases as shown in line c in Figure 2.
When the internal pressure drop is large, as shown by line c, the feed gas pressure is lowered, as shown by line c, and when the internal pressure decreases, as shown by line b, the feed gas pressure is set midway between the two. As shown in line b', the gas concentration becomes almost constant and sterilization is performed in the same way.

In order to operate the sterilizer in this manner, a signal of the internal pressure detected by the pressure sensor 13 is input to the computer 10 to control the opening and closing of the air supply valve 3.

FIG. 3 is a flowchart illustrating the control state by the computer 10.

First, to start gas sterilization, press the start button 14.
Press to start the device. As a result, in the first process 15, the exhaust pump 7 is activated and the exhaust valve 6 is opened. The air supply valve 3 remains closed. As a result, when the pressure inside the can body 2 decreases, the degree of the decrease is detected by the pressure sensor 13 in the first judgment 16, and the internal pressure is 0.35.
It will be judged whether it is less than Kg/ ^cm2 .

If it is not below 0.35Kg/ ^cm2 , the second judgment 17 determines whether there is something wrong with the vacuum device.
The presence or absence of an abnormality is determined based on the signal from the sensor indicating the operation of the main part of the sterilizer. If there is an abnormality, this is notified to the operator by the alarm 18, and if there is no abnormality, the operation of the exhaust pump is continued.

If it is determined in the first determination 16 that the internal pressure is 0.35 kg/cm ² or less, in the second process 19, a timer is activated to continue this state for a predetermined period of time (for example, 5 minutes).

After this time has elapsed, the exhaust valve 6 is closed and the exhaust pump 7 is stopped in the third process 20. Next, in a fourth process 21, the internal pressure of the canister indicated by the pressure sensor 13 is read, and a third determination 22 determines that the internal pressure of the canister is
Determine whether it is 0.15Kg/ ^cm2 or less.

When the internal pressure of the can becomes 0.15 Kg/cm ² or less, the fifth process 23 is activated to open the air supply valve 3 and pressurized sterilization gas flows into the can. This reduces the pressure inside the can to 1.7Kg/
cm ² , the air supply valve 3 is closed in a sixth process 24, and sterilization is performed for a predetermined time (for example, 3 hours) in a seventh process 25.

In the third judgment 22, the pressure inside the can is 0.15Kg/cm ²
If it is determined that the internal pressure is above 0.25Kg/cm 2 , then in the fourth judgment 26 it is judged whether the internal pressure is below 0.25Kg/cm ² , and if it is below this pressure, the air supply valve 3 is opened in the eighth process 27 and sterilized. Gas flows into the can body 2, and the pressure inside the can increases.
When it reaches 1.8Kg/ ^cm2 , the air supply valve 3 is activated by the ninth process 28.
is closed and sterilized by seventh process 25.

In the fourth judgment 26, the pressure inside the can is 0.25Kg/cm ²
When it is determined that the above is the case, the air supply valve 3 is opened in the tenth process 29, and when the pressure inside the can reaches 1.9 kg/cm ² , the air supply valve is closed in the eleventh process 30, and the seventh process 25 is performed to release the gas. Sterilize by pressure.

As seen in the above embodiments, the present invention is capable of increasing the gas pressure in the eleventh process 30 (line a in FIG. Sterilize the can (line a' in Figure 2), and when the pressure inside the can has dropped sufficiently (line c in Figure 2), perform sterilization at a lower gas pressure (line c' in Figure 2) in the sixth process 24, and then sterilize the can. When the decrease in internal body pressure is intermediate as shown by line b in Figure 2, sterilization is carried out at an intermediate gas pressure (line b' in Figure 2) in the ninth process 28. It is possible to sterilize with a constant gas concentration and sterilization time, so gas sterilization work can be stabilized, a reliable sterilization effect can be obtained, and sterilization work plans can be easily planned. .

[Brief explanation of drawings]

The drawings illustrate embodiments of the present invention; FIG. 1 is a schematic diagram showing the outline of a gas sterilizer, FIG. 2 is a diagram showing changes in pressure inside the can, and FIG. 3 is a flowchart showing control by a computer. be. 1: Airtight lid, 2: Can body, 3: Air supply valve, 4: Air supply pipe, 5: Gas source, 6: Exhaust valve, 7: Exhaust pump,
8: Exhaust pipe, 9: Exhaust treatment device, 10: Computer, 11, 12: Leading wire, 13: Pressure sensor, 1
4: Start button, 15: First process, 16: First judgment, 17: Second judgment, 18: Alarm, 19: Second process, 20: Third process, 21: Fourth process, 22:
Third judgment, 23: Fifth processing, 24: Sixth processing, 2
5: Seventh process, 26: Fourth determination, 27: Eighth process, 28: Ninth process, 29: Tenth process, 30 Eleventh process.

Claims (1)

[Claims] 1. A pressure sensor 13 that communicates with the computer 10 is provided in the can body 2 that communicates with the sterile gas source 5 via the air supply valve 3 and communicates with the exhaust treatment device 9 via the exhaust valve 6 and the exhaust pump 7. , a first process 15 of opening the exhaust valve 6 and operating the exhaust pump 7 with the air supply valve 3 closed; and a first determination 16 of determining whether the pressure inside the can is below a predetermined pressure reduction value;
When the first judgment 16 determines that the pressure inside the can is equal to or higher than a predetermined pressure reduction value, the second judgment 17 determines whether there is an abnormality in the vacuum device based on the output; A second process 19 receives the output when it is determined that the pressure is below the reduced pressure value and outputs the output after a predetermined time has elapsed; and a second process 19 closes the exhaust valve 6 and stops the exhaust pump 7 based on the output of the second process 19. A third process 20, a fourth process 21 in which the pressure inside the can is then read by the pressure sensor 13, and a fourth process 21
A plurality of determinations 22, 26, and 29 each operate according to the level of the measured canister pressure, and a fourth process 21 that opens the air supply valve according to the output of each determination. A plurality of processes 24, 28, and 30 in which the gas pressure inside the can is increased to a respective predetermined value depending on the degree of high sterilization gas pressure in the can, and then the air supply valve is closed, and sterilization is performed when the sterilization gas pressure inside the can reaches the respective predetermined value. A gas sterilizer characterized in that it combines a seventh process 25 for starting.