JP6869487B2 - Gas sterilizer - Google Patents

Description

The present invention is a gas sterilizer capable of detecting leakage of sterilized gas in the gas supply path from the gas container to the sterilized can body when filling the sterilized can body containing the sterilized object with sterilized gas from the gas container. Regarding.

Conventionally, for example, the following Patent Document 1 describes a technique related to such a gas sterilizer.

The invention described in Patent Document 1 is a gas sterilizer that uses ethylene oxide gas or formalin gas to sterilize used surgical tools, patient clothes, laboratory instruments, etc., and uses a high-pressure sterilized gas. A filled cylinder 1, a main valve 2 provided at the mouth of the cylinder 1, a sterilization container 3 that can be sealed while storing an object to be sterilized, and a gas supply that connects the sterilization container 3 and the cylinder 1. It has a passage 4, and in the middle of the gas supply passage 4, a second on-off valve 11, a pressure detecting element 6, and a first on-off valve 10 are provided in order and in series from the side of the cylinder 1.

In Patent Document 1, in order to detect leakage of sterilized gas at a connection point of the pressure detecting element 6, a first on-off valve 10 and a second on-off valve 11 are arranged on both sides of the pressure detecting element 6, and these are opened and closed. The valve is configured to be controlled by the controller 12. That is, the controller 12 closes the first on-off valve 10, opens the main valve 2 and the second on-off valve 11, and sends high-pressure sterilized gas into the gas supply path 4. After closing the second on-off valve 11, the controller 12 determines that the sterilized gas has leaked from the connection portion of the pressure detecting element 6 when the pressure drop inside the gas supply path 4 exceeds a certain range. Issue an alarm according to the degree of leakage.

As described above, Patent Document 1 accurately determines the presence or absence of leakage of sterilizing gas at the installation portion of the pressure detecting element 6, issues an alarm depending on the degree of shallow leakage, and attempts to stop the supply of sterilizing gas. is there.

Jikkenhei No. 3-13147

The gas sterilizer of Patent Document 1 is provided with a first on-off valve 10 and a second on-off valve 11 on both sides of the pressure detecting element 6 to detect a change in pressure in the gas supply path 4. In this case, even if a drop in pressure is detected, the leak location cannot be identified. That is, in addition to the pressure detection element 6, the first on-off valve 10 and the second on-off valve 11 are connected to the gas supply path 4, and sterilized gas leaks at the connection points of these on-off valves. Even if it is, the detection pressure drops. Therefore, in order to identify the leaked part of the sterilized gas, it is necessary to further inspect each connection part, which makes the repair work complicated.

For this reason, there has been a demand for a gas sterilizer that can easily identify the leakage point of the sterilized gas in the gas supply path.

(Characteristic composition)
The characteristic configuration of the gas sterilizer according to the present invention is
A sterilized can that houses the sterilized object and
A pressure gauge for measuring the internal pressure of the sterilized can body and
A gas supply path for supplying a sterilizing gas having a pressure higher than the internal pressure of the sterilizing can body from a gas container filled with the sterilizing gas to the sterilizing can body.
An upstream first solenoid valve and a downstream second solenoid valve provided in series with the gas supply path ,
To perform an alternative inspection operation of valve opening operating as before Symbol first solenoid valve and said second solenoid valve, the pressure change in the sterilized can body when the sterilizing gas to flow into the case, the pressure A control unit that measures using a meter and
A failure determination unit that determines a failure of the first solenoid valve and / or the second solenoid valve depending on whether or not the value measured by the pressure gauge exceeds a preset threshold value.
It is in the point that it is equipped with.

(effect)
In the gas sterilizer of this configuration, the inspection operation is performed by alternately opening the first solenoid valve and the second solenoid valve, and the pressure change due to the sterilized gas flowing into the sterilized can body from each solenoid valve is measured. Can be done. This measured value means the amount of sterilized gas leaked from the first solenoid valve and / or the second solenoid valve. By comparing the pressure measurement result with a preset threshold value in the failure determination unit, it is possible to identify the solenoid valve in which the sterilizing gas is leaking. As described above, in the gas sterilizer having this configuration, the subsequent repair work of the solenoid valve can be performed quickly, and the state of the gas sterilizer can always be maintained in a healthy state.

Further, the pressure gauge used for detecting the leakage of the sterilized gas is equipped from the beginning for measuring the internal pressure of the sterilized can body. Therefore, with this configuration, the leak detection ability of sterilized gas can be enhanced without adding any special equipment.

(Characteristic composition)
In the gas sterilizer according to the present invention, in the inspection operation, first, the first solenoid valve is closed, the second solenoid valve is opened and operated, measurement by the pressure gauge is performed, and then the first solenoid valve is opened and operated. It is convenient that the second solenoid valve is closed, the first solenoid valve is opened and operated, and the measurement by the pressure gauge is performed.

(effect)
In this configuration, first, the first solenoid valve near the gas container side is closed. By opening and operating the main plug of the gas container in this state, the sterilized gas is filled in the upstream portion of the first solenoid valve in the gas supply path. When the second solenoid valve is opened and operated in this state, if the airtightness of the first solenoid valve is impaired, the sterilizing gas passes through the first solenoid valve and the second solenoid valve to the sterilized can body. It circulates and the inflow of sterilized gas is detected by a pressure gauge.

When it is determined by this operation that the first solenoid valve maintains the airtightness, the second solenoid valve is closed again and the first solenoid valve is opened and operated. As a result, the sterilizing gas flows to the position of the second solenoid valve. If a leak occurs in the second solenoid valve, a part of the sterilized gas flows into the sterilized can body.

In these inspection operations, when the sterilizing gas flows into the sterilized can body, the sterilized gas is only the one leaked from the closed solenoid valve. Therefore, the internal pressure of the sterilized can body does not increase excessively, and the possibility that the internal pressure of the sterilized can body becomes a positive pressure and the sterilized gas leaks to the outside is extremely reduced.

On the other hand, when the inspection operation is reversed in the above order, the result is as follows. First, when the second solenoid valve is closed and the first solenoid valve is opened and operated, the sterilized gas is filled in the gas supply path between the first solenoid valve and the second solenoid valve. In this state, when the first solenoid valve is subsequently closed and the second solenoid valve is opened and operated, the sterilized gas filled in the gas supply path between the first solenoid valve and the second solenoid valve is sterilized can. It flows into the inside of the body.

Therefore, when the first solenoid valve and the second solenoid valve are largely separated from each other, the amount of sterilized gas stored in the gas supply path between them increases, and this sterilized gas flows into the sterilized can body. This may cause the internal pressure of the sterilized can body to rise excessively. In addition to this, if there is a leak in the first solenoid valve, the sterilized gas may further flow into the inside of the sterilized can and the internal pressure of the sterilized can becomes positive, causing the sterilized gas to leak to the outside. Will increase.

In order to prevent such a situation, in the inspection operation of this configuration, first, the first solenoid valve is closed and the second solenoid valve is opened for operation.

(Characteristic composition)
In the gas sterilizer according to the present invention, the sterilized can body is provided with a decompression pump, and the internal pressure of the sterilized can body is raised from atmospheric pressure by the decompression pump prior to the supply of the sterilized gas to the sterilized can body. is also a preset pressure has low, the when the sterilizing gas in the test operation is introduced into the sterilization can body, so that the internal pressure of the sterilization can body remains lower than the atmospheric pressure, the first solenoid valve And it is convenient that the opening time of the second electromagnetic valve is set.

(effect)
When the inside of the sterilized can body is filled with sterilized gas under reduced pressure, for example, the lid of the sterilized can body may be configured to be pressed against the sterilized can body by using an external atmospheric pressure. With such a configuration, the degree of sealing of the lid can be relatively easily increased. However, if the internal pressure becomes excessive, such a closed state of the lid portion is easily impaired.

Therefore, in this configuration, even if the sterilized gas flows into the inside of the sterilized can body from the gas supply path during the inspection operation, the inflow amount is limited and the increase in the internal pressure stays within a predetermined range. And the valve opening time of the second solenoid valve is set. This prevents the sterilizing gas that has flowed into the sterilizing can body from accidentally leaking to the outside.

(Characteristic composition)
In the gas sterilizer according to the present invention, the opening operation of the first solenoid valve and the second solenoid valve in the inspection operation is set to repeat the opening operation a predetermined number of times for a preset time. It is convenient.

(effect)
By setting the solenoid valve to repeat the opening operation as in this configuration, if a leak occurs in the other solenoid valve, the sterilized gas does not flow into the sterilized can body at once, and the sterilized gas can be used. The inflow amount can be fine-tuned. Therefore, when an increase in the gas pressure of the sterilized can body is detected, the inflow of the sterilized gas can be stopped before the internal pressure of the sterilized can body becomes a positive pressure by closing the other solenoid valve.

(Characteristic composition)
The gas sterilizer according to the present invention is provided with a notification unit that identifies and notifies the failed solenoid valve when the failure of the first solenoid valve or the second solenoid valve is determined. It is convenient to be there.

(effect)
By identifying and notifying the malfunctioning solenoid valve as in this configuration, the subsequent repair work becomes even quicker.

(Characteristic composition)
In the gas sterilizer according to the present invention, after the inspection operation, the first solenoid valve and the second solenoid valve are opened and operated to supply the sterilized gas to the sterilized can body. And at least one of the second solenoid valves can be configured to repeat the operation of opening the valve a predetermined number of times for a preset time.

(effect)
As in this configuration, when the sterilizing gas is supplied to the sterilized can body after the inspection operation of the first solenoid valve and the second solenoid valve, sterilization is performed by intermittently opening and closing at least one of the two solenoid valves. It is possible to prevent the gas from being vigorously supplied to the sterilized can body. This makes it possible to prevent the internal pressure of the sterilized can body from rising at once when the pressure of the gas container is high, for example, and prevent the internal pressure of the sterilized can body from rising above the atmospheric pressure, for example. It is possible to prevent the sterilizing gas from leaking from the sterilizing can body.

(Characteristic composition)
In the gas sterilizer according to the present invention, when the sterilization process in the sterilized can body is completed and the sterilized gas remaining inside the sterilized can body is discharged, the control unit causes the first solenoid valve. It is convenient that the second solenoid valve is configured to be in the closed state and the second solenoid valve is in the open state.

(effect)
With this configuration, when the sterilization process is completed and the used gas inside the gas sterilizer is discharged, the sterilization gas remaining in the gas supply path from the first solenoid valve to the gas sterilizer can be discharged. it can. As a result, at least the second solenoid valve is maintained in a non-contact state with the sterilizing gas until the next sterilization process. That is, deterioration of at least one of the two solenoid valves due to contact with the sterilized gas is alleviated, and the function of the solenoid valve of blocking the gas supply path from the gas container to the sterilized can body can be reliably ensured.

Further, since the sterilized gas discharged is limited to the one on the downstream side from the first solenoid valve, the amount of sterilized gas discharged can be suppressed. Therefore, the frequency of replacing the gas container is reduced, and the efficiency of the sterilization process is improved.

(Characteristic composition)
In the gas sterilizer according to the present invention, a heater for heating the sterilized can body is provided, and at least a part of the gas supply path is made of a material having excellent thermal conductivity and is close to the heater. It is convenient if it is arranged in such a state.

(effect)
With this configuration, it is possible to prevent the sterilizing gas discharged from the gas container into the gas supply path from expanding and lowering the temperature, or when the sterilizing gas is used by raising the temperature, the sterilizing gas is heated. The sterilizing gas before being supplied to the sterilized can body can be brought close to the holding temperature in the sterilized can body. Therefore, it is possible to prevent the sterilizing gas having an excessively low temperature from being supplied to the sterilized can body, and the internal pressure of the sterilized can body becoming higher than the expected value due to the subsequent temperature rise.

Explanatory drawing which shows the structure of the gas sterilizer which concerns on this invention Perspective view showing the appearance of the gas sterilizer according to the present invention. Sectional drawing which shows the structure of the gas solenoid valve which concerns on this invention. Explanatory drawing which shows failure determination procedure of the gas sterilizer which concerns on this invention Explanatory drawing which shows operation procedure of the gas sterilizer which concerns on this invention

[Embodiment]
An embodiment of the gas sterilizer G according to the present invention will be described with reference to FIGS. 1 to 5.
In this gas sterilizer G, a sterilized object such as a medical instrument or an experimental instrument is housed inside a sterilized can body 4, and sterilized using sterilized gas for a predetermined time. In this gas sterilizer G, when filling the sterilized gas from the gas container T into the sterilized can body 4, the filling amount is adjusted by using a solenoid valve, and the solenoid valve of the present embodiment determines a failure prior to filling the sterilized gas. It can be performed.

The appearance of the gas sterilizer G of this embodiment is shown in FIG. The gas sterilizer G has a size that can be placed on a table, for example, and the front panel 1 is configured as a door as it is. On the other hand, the main body 2 has a sterilized can body 4 built in the back of the panel 1 opened. Since the inside of the sterilization can body 4 is depressurized during the sterilization process, it is provided with, for example, a cylindrical peripheral wall surface and a substantially spherical bottom surface in order to ensure pressure resistance.

The panel 1 is provided with a display unit 3 that displays information such as the internal pressure of the sterilized can body 4, the working time, the working process, and an alarm. The operation of the gas sterilizer G is very simple, and the sterilization process can proceed almost fully automatically by operating the switch 5 provided on the side surface of the main body 2. A limit switch 6 is provided on the front surface of the main body 2 to abut on the back surface of the closed panel 1 to check the closed state of the panel 1.

The gas container T for sterilizing gas is installed, for example, on a carriage 7 provided below the main body 2. The trolley 7 is provided with casters 8, which facilitates replacement of the gas container T and movement of the gas sterilizer G, and can enhance versatility.

As shown in FIG. 1, the gas sterilizer G of the present embodiment has the configuration described in the region shown by the broken line. The gas sterilizer G includes a sterilized can body 4 for accommodating an object to be sterilized and a pressure gauge 9 for measuring the internal pressure of the sterilized can body 4. Before filling with the sterilizing gas, the gas inside the sterilizing can body 4 is discharged to reduce the pressure, and it is necessary to maintain the internal pressure at a predetermined level during the sterilization process. Monitor internal pressure.

A gas supply path R1 for supplying the sterilized gas to the sterilized can body 4 is provided from the gas container T filled with the sterilized gas to the sterilized can body 4. The gas supply path R1 must not leak internal sterilized gas, can cope with the difference between the internal pressure of the sterilized can body 4 and the pressure of the gas container T, and further, as will be described later, the heater H. It is made of a durable material because it may be heated by. In this embodiment, for example, a copper tube is used.

A first solenoid valve V1 and a second solenoid valve V2 are provided in series in the gas supply path R1 from upstream to downstream. As shown in FIG. 3, the first solenoid valve V1 and the second solenoid valve V2 drive the valve body 24 by, for example, the solenoid 21, and are driven and controlled by the control unit S. Further, a check valve C1 and a gas filter F are provided between the gas container T and the first solenoid valve V1.

FIG. 3 shows the structures of the first solenoid valve V1 and the second solenoid valve V2. A cylindrical solenoid 21 is provided inside the case 20, and a cylindrical cylinder 22 is also formed on the central side thereof. Inside the cylinder 22, a plunger 23 that can reciprocate along the axis X of the cylinder 22 is provided, and a valve body 24 is provided at the tip of the plunger 23. The valve body 24 is made of, for example, EPDM (ethylene, propylene, diene rubber) or the like so as to have resistance to sterilizing gas. A coil spring 25 is provided between the plunger 23 and the case 20 at the end opposite to the valve body 24, and is urged in the direction of pushing out the plunger 23.

A valve seat 26 is provided on the side of the case 20 on which the valve body 24 is pushed out. The space around the valve seat 26 leads to an inlet 27 to which the sterilizing gas is supplied, and the center of the valve seat 26 leads to an outlet 28 to which the sterilizing gas is discharged. With these configurations, the valve body 24 always comes into contact with the valve seat 26 to block the flow of sterilizing gas. On the other hand, when the solenoid 21 is energized, the plunger 23 is pulled against the urging force of the coil spring 25, the valve seat 26 is opened, and the sterilized gas flows.

As shown in FIG. 1, the sterilized can body 4 is connected to an air supply path R2 that supplies air taken in from the air intake 12 to the sterilized can body 4. An air supply solenoid valve V4 is provided in the middle of the air supply path R2, and is driven and controlled by the control unit S. The air supply solenoid valve V4 is opened and operated when air is supplied to the sterilized can body 4 after discharging the sterilized gas inside the sterilized can body 4. Therefore, the air supply solenoid valve V4 is normally opened and driven in a state where the inside of the sterilized can body 4 is in a negative pressure, and the outside air is sucked into the inside of the sterilized can body 4.

As shown in FIG. 1, a vacuum passage R3 and a vacuum pump P are connected to the sterilized can body 4. The vacuum pump P is also driven and controlled by the control unit S. The vacuum pump P is driven during a so-called replacement step of discharging the sterilized gas inside the sterilized can body 4, and after this replacement step, air is supplied to the inside of the sterilized can body 4 and aeration is performed to exhaust the air. To. A vacuum solenoid valve V5 is provided between the sterilized can body 4 and the vacuum pump P. The control unit S can maintain the inside of the sterilized can body 4 in an appropriate vacuum state by controlling the vacuum pump P and the vacuum solenoid valve V5 together. The discharged sterilized gas is collected in a collector or the like (not shown) through the exhaust passage R4 provided with the check valve C2 and the exhaust port 13.

Further, as shown in FIG. 1, a safety path R5 is provided between the downstream side of the vacuum pump P and the sterilized can body 4. The safety path R5 is provided with a pressure sensor 11 and a safety valve V6. If the pressure inside the sterilized can body 4 drops too much due to excessive exhaust by the vacuum pump P, the pressure sensor 11 The control unit S opens and operates the safety valve V6 according to the output. As a result, the exhaust gas of the vacuum pump P is returned to the sterilized can body 4, and the internal pressure of the sterilized can body 4 is maintained.

The gas sterilizer G is provided with a heater H for heating the sterilized can body 4, and at least a part of the gas supply path R1 is made of a material having excellent thermal conductivity and is close to the heater H. Arranged in a state. FIG. 1 shows an example in which the gas supply path R1 between the first solenoid valve V1 and the second solenoid valve V2 is arranged close to the heater H.

With this configuration, the sterilizing gas discharged from the gas container T to the gas supply path R1 is prevented from expanding to a low temperature, or the sterilizing gas is heated when the sterilizing gas is used by raising the temperature. Therefore, the sterilizing gas before being supplied to the sterilizing can body 4 can be brought close to the holding temperature in the sterilizing can body 4. Therefore, it is possible to prevent the sterilized gas having an excessively low temperature from being supplied to the sterilized can body 4 and the internal pressure of the sterilized can body 4 being increased to more than the expected value due to the subsequent temperature rise.

[Failure judgment of the first solenoid valve and the second solenoid valve]
Due to its characteristics, ethylene oxide gas and formalin gas as sterilizing gas used in the sterilization process must not leak to the outside. Leakage of sterilized gas is particularly caused by malfunction of the first solenoid valve V1 and second solenoid valve V2 provided in the gas supply path R1 from the gas container T to the sterilized can body 4, and the connection of these solenoid valves or the gas container T. It tends to occur in places. In the present embodiment, the failure determination unit J determines the failure of these solenoid valves for the purpose of detecting the malfunction of the first solenoid valve V1 and the second solenoid valve V2 itself at an early stage.

If the first solenoid valve V1 or the second solenoid valve V2 fails and the sterilizing gas passes through the first solenoid valve V1, the internal pressure of the sterilizing can body 4 rises and the sterilization conditions change. Further, if the inflow of the sterilizing gas continues, the internal pressure of the sterilizing can body 4 becomes excessive, and there is a possibility that the sterilizing gas leaks to the outside through the gap between the main body 2 and the panel 1. This relates to the structure of the lid member D of the sterile can body 4.

The sterilized can body 4 is usually sterilized under reduced pressure, and when the panel 1 of the sterilized can body 4 is closed, the lid member D provided on the panel 1 is pressed by the urging portion 10. It is configured to be pressed against the sterilized can body 4. After that, by lowering the internal pressure of the sterilized can body 4, the lid member D is strongly attracted to the sterilized can body 4 and the degree of sealing is increased. In the case of such a configuration, if the sterilized gas is not completely shut off in the first solenoid valve V1 and the second solenoid valve V2 provided in the gas supply path R1, the internal pressure of the sterilized can body 4 gradually increases, and the lid member D The suction effect of the sterilizing gas may be impaired and the sterilizing gas may be released to the outside.

Therefore, in the present embodiment, prior to filling the sterilized can body 4 with the sterilized gas, a failure determination is performed in which the first solenoid valve V1 and the second solenoid valve V2 are selectively opened. In the failure determination, the control unit S performs an inspection operation in which the first solenoid valve V1 and the second solenoid valve V2 are alternately opened, and the pressure due to the sterilized gas flowing into the sterilized can body 4 from each solenoid valve. Measure the change. The pressure of the sterilized can body 4 rises due to the leakage of the sterilized gas in the first solenoid valve V1 and / or the second solenoid valve V2. The fault determination unit J can identify the solenoid valve in which the sterilizing gas is leaking by comparing the pressure measurement result with a preset threshold value. The details of the inspection operation will be described later.

By providing the first solenoid valve V1 and the second solenoid valve V2 in this way, it is possible to prevent leakage of the sterilizing gas even if one of them fails. Further, the failed solenoid valve can be identified and quickly repaired, and the state of the gas sterilizer G can be always maintained in a healthy state.

The pressure gauge 9 used for detecting the leakage of the sterilized gas is equipped from the beginning for measuring the internal pressure of the sterilized can body 4. Therefore, with this configuration, the leak detection ability of sterilized gas can be enhanced without adding any special equipment.

[Operation mode of sterilizer]
The operation mode of the gas sterilizer G is shown below, including the inspection operation of the first solenoid valve V1 and the second solenoid valve V2, based on FIGS. 4 and 5.

The operation is first performed by a vacuum step of discharging the gas inside the sterilized can body 4 (# 10). The vacuum process is started by pressing the switch 5 of the main body 2. Normally, the degree of vacuum is increased up to point A of the preset pressure in FIG. 4A, for example.

When the internal pressure reaches point A, the gas container open buzzer sounds to urge the operator to open the manual valve V3 of the gas container T (# 20). The operator opens the manual valve V3 of the gas container T within a predetermined time from this buzzer.

[Solenoid valve failure judgment]
Next, the inspection operation is performed. First, the closed state of the first solenoid valve V1 is maintained, and the second solenoid valve V2 is intermittently opened and operated (FIGS. 4 (a) and 5 # 30). Measurement is performed by the pressure gauge 9, and the presence or absence of a pressure rise is confirmed (# 40). The start of intermittent opening and closing of the second solenoid valve V2 is at point B in FIG. 4A, and if there is no pressure rise, the process shifts toward point C.

If the pressure rises from point B to point C'as shown in FIG. 4B and exceeds a preset threshold value, the failure determination unit J determines that the first solenoid valve V1 has a leak ( # 130), the notification unit 3a provided in a part of the display unit 3 of the panel 1 is displayed to the effect that the first solenoid valve V1 is in error (# 140). It should be noted that such an error display may be one that lights or blinks an alarm lamp provided on the ceiling of the panel 1 or the main body 2.

Even if the sterilized gas flows into the sterilized can body 4 during the inspection operation, the internal pressure of the sterilized can body 4 stays at a value lower than the atmospheric pressure, and the second sterilized gas is prevented from accidentally leaking to the outside. The opening time of the solenoid valve V2 is set short in advance. Further, by configuring the second solenoid valve V2 not to open all at once but to repeat the opening operation for a short time a plurality of times, it is possible to prevent an excessive amount of sterilizing gas from flowing into the sterilizing can body 4 at once. To. Specifically, the conditions for the opening operation can be appropriately set, for example, the opening operation for less than one second is repeated three times. The mode of such an opening operation is the same for the subsequent opening / closing operation of the first solenoid valve V1.

If there is no increase in pressure, the control unit S subsequently closes the second solenoid valve V2 as shown in FIG. 4 (c) (# 50), and intermittently opens and operates the first solenoid valve V1. (# 60), measurement is performed by the pressure gauge 9 (# 70). The start of intermittent opening and closing of the first solenoid valve V1 is at point B'in FIG. 4 (c). Here, if there is no leakage in the second solenoid valve V2 and the pressure does not rise, the pressure value becomes constant from the point B'to the point C in FIG. 4 (c). When it is confirmed that there is no leakage in the first solenoid valve V1 and the second solenoid valve V2, the sterilizing gas is supplied to the inside of the sterilizing can body 4 (# 80 or later).

On the other hand, when a leak occurs as shown in FIG. 4D and the internal pressure of the sterilized can body 4 rises from the B'point to the C'point and exceeds a preset threshold value, the failure determination unit J is set to the third. 2 It is determined that the solenoid valve V2 has a leak (# 150), and the notification unit 3a provided in a part of the display unit 3 of the panel 1 indicates that the second solenoid valve V2 is an error (# 160). ).

When the inspection operation of the upstream first solenoid valve V1 is followed by the inspection operation of the downstream second solenoid valve V2 in this way, the following advantages can be obtained. When the sterilizing gas flows into the sterilizing can body 4 in these inspection operations, the amount of the sterilizing gas flowing in is only a slight leak from the solenoid valve which is originally in the closed state. Therefore, the total amount of sterilized gas flowing into the sterilized can body 4 is small, and the internal pressure of the sterilized can body 4 does not increase excessively. Therefore, the possibility that the internal pressure of the sterilized can body 4 becomes positive and the sterilized gas leaks to the outside is extremely reduced.

On the other hand, when the inspection operation is reversed in the above order, the result is as follows. First, when the second solenoid valve V2 is closed and the first solenoid valve V1 is opened and operated, the sterilizing gas is filled in the gas supply path R1 between the first solenoid valve V1 and the second solenoid valve V2. In this state, when the first solenoid valve V1 is subsequently closed and the second solenoid valve V2 is opened and operated, the gas supply path R1 between the first solenoid valve V1 and the second solenoid valve V2 is filled. The sterilizing gas flows into the sterilizing can body 4.

Therefore, when the first solenoid valve V1 and the second solenoid valve V2 are largely separated from each other, the amount of sterilized gas stored in the gas supply path R1 between them increases, and this sterilized gas becomes a sterilized can. By flowing into the body 4, the internal pressure of the sterilized can body 4 may rise excessively. In addition to this, when the first solenoid valve V1 leaks, the sterilizing gas further flows into the sterilizing can body 4, the internal pressure of the sterilizing can body becomes positive, and the sterilizing gas leaks to the outside. The possibility of doing it increases.

In order to prevent such a situation, in the inspection operation of this configuration, first, the first solenoid valve V1 is closed and the second solenoid valve V2 is opened and operated.

[Sterilized gas filling process]
When the inspection operation is completed and it is confirmed that there is no failure in the first solenoid valve V1 and the second solenoid valve V2, the first solenoid valve V1 and the second solenoid valve V2 are opened and operated to sterilize the sterilized gas. Supply to 4 (# 80). At this time, at least one of the first solenoid valve V1 and the second solenoid valve V2 repeats the operation of opening the valve a predetermined number of times for a preset time.

By intermittently opening and closing at least one of the two solenoid valves in this way, it is possible to prevent the sterilizing gas from being vigorously supplied to the sterilizing can body 4. As a result, for example, when the pressure of the gas container T is high, the internal pressure of the sterilized can body 4 does not rise at once, and the internal pressure of the sterilized can body 4 is prevented from rising above the atmospheric pressure, for example, and sterilization is performed. It is possible to prevent the gas from leaking from the sterilized can body 4.

When the internal pressure of the sterilized can body 4 shifts from the point C to the point D in FIGS. 4 (a) and 4 (c) and the internal pressure of the sterilized can body 4 rises to a preset value (# 90), the first solenoid valve The operation of closing V1 and the second solenoid valve V2 is performed (# 100). The operator closes and operates the manual valve V3 of the gas container T. Subsequently, the heater H sets the temperature of the sterilizing gas to a preset temperature (# 110).

[Sterilization process]
In the subsequent sterilization step, the sterilization process is performed for a preset time (# 120). The sterilization temperature is, for example, 40 to 80 ° C., and the standard sterilization time is, for example, 5 to 8 hours.

[Gas replacement process and aeration]
After the completion of the sterilization step, for example, a gas replacement step of discharging the sterilized gas for 30 minutes is performed (# 170,180), and the sterilized gas inside the sterilized can body 4 is discharged by the vacuum pump P and the vacuum solenoid valve V5. To do. Subsequently, external air is supplied to the inside of the sterilized can body 4, and aeration for discharging the air by the vacuum pump P is performed for, for example, 15 hours (# 190). As a result, the sterilizing gas remaining inside the sterilizing can body 4 and the sterilizing gas permeating the constituent members inside the sterilizing can body 4 are removed.

During this gas replacement step and aeration, the control unit S keeps the first solenoid valve V1 in the closed state and opens the second solenoid valve V2 (# 170).

By opening only the second solenoid valve V2, when the sterilization process is completed and the used gas inside the gas sterilizer G is discharged, the gas supply path R1 from the first solenoid valve V1 to the sterilization can body 4 is reached. The remaining sterilizing gas can be discharged. As a result, at least the second solenoid valve V2 is maintained in a non-contact state with the sterilizing gas until the next sterilization process.

In the first solenoid valve V1 and the second solenoid valve V2, for example, EPDM having resistance to sterilizing gas is used as a material constituting the valve body 24. However, the longer the contact time with the sterilizing gas, the more the deterioration of the valve body 24 progresses. Therefore, even when the contact time with the sterilizing gas is shortened only for the second solenoid valve V2 as in this configuration, deterioration due to contact with the sterilizing gas is alleviated in at least one of the two solenoid valves, and the gas container T The function of blocking the gas supply path R1 leading from the sterilized can body 4 to the sterilized can body 4 can be reliably ensured.

Further, if the sterilized gas discharged is limited to the one on the downstream side of the first solenoid valve V1, the amount of sterilized gas discharged can be suppressed. Therefore, the frequency of replacement of the gas container T is reduced, and the efficiency of the sterilization process is improved.

When the gas replacement step and the aeration are completed, the control unit S closes the second solenoid valve V2 (# 200), and a series of sterilization processes is completed.

However, during the gas replacement step and aeration, the control unit S opens both the first solenoid valve V1 and the second solenoid valve V2, and discharges the sterilized gas on the downstream side of the manual valve V3 of the gas container T. It may be that.

With this configuration, the first solenoid valve V1 and the second solenoid valve V2 are in a non-contact state with the sterilizing gas until the next sterilization process, and deterioration of both solenoid valves is suppressed. Therefore, the reliability of the gas sterilizer G can be further improved.

When both the first solenoid valve V1 and the second solenoid valve V2 are opened in the gas replacement step or the like, if the manual valve V3 of the gas container T is not completely closed, the gas replacement step takes a predetermined time. The sterilized gas will continue to be discharged even after the above. In this case, the control unit S detects that the internal pressure of the sterilized can body 4 does not drop to a preset threshold value, stops the gas replacement step, and closes the first solenoid valve V1 and the second solenoid valve V2. It will be operated. Further, it is more preferable that the control unit S displays on the notification unit 3a to confirm the closed state of the manual valve V3.

The gas sterilizer according to the present invention detects leakage of sterilized gas in the gas supply path from the gas container to the sterilized can body when filling the sterilized can body containing the sterilized object with sterilized gas from the gas container. It can be widely applied to possible gas sterilizers.

3a Notification unit 4 Sterilized can body 9 Pressure gauge G Gas sterilizer H Heater J Failure determination unit R1 Gas supply path S Control unit T Gas container V1 1st solenoid valve V2 2nd solenoid valve

Claims (8)

A sterilized can that houses the sterilized object and
A pressure gauge for measuring the internal pressure of the sterilized can body and
A gas supply path for supplying the sterilized gas having a pressure higher than the internal pressure of the sterilized can body from a gas container filled with the sterilized gas to the sterilized can body.
An upstream first solenoid valve and a downstream second solenoid valve provided in series with the gas supply path ,
And a pre-Symbol first solenoid valve and the second solenoid valve was alternatively carried out an inspection operation of valve opening operating, the pressure gauge the pressure change in the sterilized can body when the sterilizing gas is flowed into the case With the control unit that measures in
A failure determination unit that determines a failure of the first solenoid valve and / or the second solenoid valve depending on whether or not the value measured by the pressure gauge exceeds a preset threshold value.
Gas sterilizer equipped with. The inspection operation
First, the first solenoid valve is closed, the second solenoid valve is opened and operated, and measurement by the pressure gauge is performed.
The gas sterilizer according to claim 1, wherein the second solenoid valve is subsequently closed, the first solenoid valve is opened and operated, and measurement is performed by the pressure gauge. A decompression pump is provided in the sterilized can body.
Is said pressure the internal pressure of the sterilization can body prior to supplying sterile gas is set in advance not lower than atmospheric pressure by the vacuum pump to the sterilization can body,
When the sterilized gas flows into the sterilized can body in the inspection operation, the opening times of the first electromagnetic valve and the second electromagnetic valve are set so that the internal pressure of the sterilized can body remains lower than the atmospheric pressure. The gas sterilizer according to claim 1 or 2. Any one of claims 1 to 3, wherein the opening operation of the first solenoid valve and the second solenoid valve in the inspection operation is set to repeat the valve opening operation a predetermined number of times for a preset time. The gas sterilizer described in. Any one of claims 1 to 4 provided with a notification unit that identifies and notifies the failed solenoid valve when the failure of the first solenoid valve and the second solenoid valve is determined. The gas sterilizer described in the section. After the inspection operation, when the first solenoid valve and the second solenoid valve are opened and operated to supply the sterilized gas to the sterilized can body, at least one of the first solenoid valve and the second solenoid valve is used. The gas sterilizer according to any one of claims 1 to 5, wherein one of them is configured to repeat the operation of opening the valve for a preset time a predetermined number of times. When the sterilization process in the sterilized can body is completed and the sterilized gas remaining inside the sterilized can body is discharged, the control unit closes the first solenoid valve and the second solenoid valve is closed. The gas sterilizer according to any one of claims 1 to 6, which is configured to open the valve. Claims that a heater for heating the sterilized can body is provided, and at least a part of the gas supply path is made of a material having excellent thermal conductivity and is arranged in a state close to the heater. Item 2. The gas sterilizer according to any one of Items 1 to 7.

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