JPH03210267A - Vacuum low-temperature steam heating and sterilizing method and sterilizing device thereof - Google Patents

Abstract

PURPOSE:To maintain the interior of a sterilizer at a uniform temp. distribution and to sterilize an object to be sterilized by housing the object to be sterilized into the sterilizer, hermetically closing the sterilizer, reducing the pressure in the sterilizer to the vacuum degree corresponding to the low-temp. sterilization temp. of <=100 deg.C satd. steam and introducing steam into the sterilizer while maintaining this vacuum degree. CONSTITUTION:The sterilizer 1 contg. the object A to be sterilized is hermetically closed and a detector 5 for the pressure in the sterilizer is set to maintain the pressure in this sterilizer at the vacuum degree corresponding to 80 deg.C in the case of the execution of a sterilization treatment by setting, for example, the low-temp. sterilization temp. at 80 deg.C. A control valve 21 for the pressure in the sterilizer of a vacuum evacuation piping 20 is automatically controlled to open and close by this signal. A detector 26 for the pressure in a vacuum tank 22 is so provided that this tank has both functions of maintaining the pressure in the sterilizer 1 at the vacuum degree corresponding to 80 deg.C by differential pressure between the tank and the sterilizer 1 through a valve 21 and of receiving the discharge of the condensate in the sterilizer 1 via a steam trap 42. A control valve 23 for the pressure in the tank is automatically controlled to open and close by this signal. The vacuum pump 25 is operated in this state to introduce 80 deg.C steam into the sterilizer.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is a vacuum low-temperature steam heating system used for low-temperature sterilization of drugs, etc. in pharmaceutical companies, medical institutions, various medical laboratories, etc. This article relates to sterilization methods and sterilization equipment.

(Prior Art) Conventionally, for example, in preparations such as injections, drugs such as vitamins that are destroyed or decomposed by high heat need to be heat sterilized at a low temperature of 100'C or less after being filled into ampoules or vials. Low-temperature heat sterilization methods include circulation steam sterilization, in which the inside of the sterilizer is heated by releasing it to atmospheric pressure, and hot bath sterilization, in which water is heated to the sterilization temperature and the items to be sterilized are immersed in this hot water. There is a law.

(Problem to be solved by the invention) However, in conventional low-temperature heat sterilization methods such as the above-mentioned circulation steam sterilization method and hot bath sterilization method, the temperature distribution is non-uniform, and the current GMP and varicity standards are not met. There are problems with the regulations that cannot be applied, and there is an urgent need to resolve these problems with the low-temperature heat sterilization method.

The present invention was made in view of the above circumstances, and furthermore, the boiling point of water is the second
As shown in the figure, it changes depending on the atmospheric pressure.At atmospheric pressure, it boils to water vapor at a temperature of 100℃, but when the pressure is reduced from atmospheric pressure, the boiling point of water becomes lower than 100℃. By introducing water vapor while maintaining the vacuum inside the vessel at a vacuum level suitable for low-temperature sterilization temperature below 100℃,
A low-temperature steam-heat sterilization method and its sterilization, which can maintain a uniform temperature distribution in the sterilizer to sterilize objects to be sterilized by low-temperature steam heat, and exhibit excellent sterilization performance that is fully compatible with GMP and variance regulations. The purpose is to provide equipment.

(Structure of the Invention) (Means for Solving the Problems) In order to achieve the above object, the vacuum low temperature steam heat sterilization method of the first invention includes storing the object to be sterilized in a sterilizer and sealing it;
In this state, the inside of the sterilizer is depressurized to a degree of vacuum corresponding to the low-temperature sterilization temperature of saturated steam of 100°C or less, and while maintaining this degree of vacuum, steam is introduced to sterilize the object to be sterilized by low-temperature steam heating. shall be.

In order to achieve the above object, the vacuum low temperature steam heating sterilizer of the second invention includes a sterilizer for storing the object to be sterilized, and a low temperature sterilization temperature of saturated steam of 100° C. or less set in advance in the sterilizer. A steam supply means for supplying water vapor while controlling the condition to be maintained, and a vacuum pump inside the sterilizer are used to
The sterilizer is characterized by being equipped with a vacuum evacuation means for maintaining a reduced pressure at a degree of vacuum commensurate with the low-temperature sterilization temperature of saturated steam below .degree. C., and a drainage means for discharging condensed water in the sterilizer using a steam trap.

The vacuum low-temperature steam heating sterilizer of the invention is equipped with a vacuum tank which is vacuum-suctioned by a vacuum pump through a cold trap, and a pressure control valve is operated by the difference in the degree of vacuum between the vacuum tank and the inside of the sterilizer. Through this system, the inside of the sterilizer is maintained at a vacuum level corresponding to the low-temperature sterilization temperature of saturated steam of 100°C or less, and the condensed water inside the sterilizer is also drained by the differential pressure between the vacuum tank and the inside of the sterilizer. It is desirable that the condensed water in the sterilizer flow out to the vacuum tank side through the steam trap of the device.

(Function) In the vacuum low-temperature steam heat sterilization method of the present invention having the above configuration, the inside of the sterilizer containing the object to be sterilized is brought to the low-temperature sterilization temperature of saturated steam of 100°C or less by utilizing the change in the boiling point due to the pressure of water vapor. Since water vapor is introduced while maintaining reduced pressure to the appropriate degree of vacuum, the water vapor fills the sterilizer to a saturated state at low temperatures, and the objects to be sterilized can be sterilized by low-temperature steam heating with a uniform temperature distribution. It will be possible to demonstrate excellent sterilization performance that is fully compatible with the regulations of Japan.

The vacuum low-temperature steam heating sterilizer of the present invention having the above configuration includes a sterilizer for storing objects to be sterilized, and a sterilizer in which steam is sterilized while controlling the low-temperature sterilization temperature of saturated steam to be maintained at a preset temperature of 100° C. or lower. a steam supply means for supplying water, a vacuum evacuation means for maintaining the inside of the sterilizer at a vacuum level corresponding to the low temperature sterilization temperature of saturated steam of 100°C or less using a vacuum pump, and a steam trap for removing condensed water in the sterilizer. Since the sterilizer is equipped with a drainage means for discharging water using a water vapor, the above-mentioned excellent vacuum low-temperature steam heat sterilization method can be carried out using this sterilizer.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a schematic diagram showing a flow sheet of the vacuum low temperature steam heat sterilization apparatus of the present invention.

First, numeral 1 in the figure is a sterilizer in which an object to be sterilized A is stored, and is a closed container having an openable and closable M 1 a.

This sterilizer 1 is provided with a safety valve 2, a pressure gauge 3, a temperature controller 4, and a sterilizer internal pressure detector 5. The sterilizer 1 is also equipped with an air supply valve 6 and an air filter 7 for pressure recovery, so that outside air can be purified and introduced into the sterilizer 1 to restore the pressure to atmospheric pressure, such as when sterilization is completed.

In the figure, 10 is a steam supply system piping connected to the side of the sterilizer 1. This steam supply system piping 10 is connected to a steam supply source that generates steam at a temperature of 100° C. or higher, and a steam pressure reducing valve 11 and a steam filter 1 are provided in the middle of this steam supply system piping 10.
2 is provided. Furthermore, a steam supply control valve 13 is provided between the steam filter 12 and the sterilizer 1.

This steam supply control valve 13 is linked to the temperature controller 4 of the sterilizer 1, and opens when the temperature inside the sterilizer 1 is below the set temperature range for low temperature sterilization of 100°C or less to introduce water vapor into the sterilizer 1. If the temperature exceeds the set temperature range, it will automatically close and stop the introduction of water vapor.

In the figure, reference numeral 20 denotes a vacuum exhaust system piping connected to and led out from the upper part of the sterilizer 1. The vacuum exhaust system piping 20 includes, in order from the sterilizer 1 side, a sterilizer internal pressure control valve 21 and a vacuum tank 22.
, a tank internal pressure control valve 23, a cold trap 24, and a vacuum pump 25 are provided.

The sterilizer internal pressure control valve 21 is interlocked with the sterilizer internal pressure detector 5, and when the atmospheric pressure inside the sterilizer 1 is above the set atmospheric pressure (degree of vacuum corresponding to the low temperature sterilization temperature of saturated steam of 100°C or less) range. is opened to allow suction and exhaust to the vacuum tank 22 side, and when the pressure is below the set pressure range, it is automatically closed to stop exhaustion.

The vacuum tank 22 always maintains a vacuum state, and the steam inside the sterilizer 1 is forcibly sucked out via the sterilizer internal pressure control valve 21 due to the differential pressure. For this purpose, this vacuum tank 22 is provided with a tank internal pressure detector 26, and in conjunction with this tank internal pressure detector 26, the tank internal pressure control valve 23 automatically opens and closes to cool the inside of the vacuum tank 22. The inside of the sterilizer 1 is always kept in a vacuum state, which is reduced to a predetermined pressure or less, by a vacuum pump 25 via a trap 24.

The vacuum pump 25 has a vacuum attainment pressure of about -800 to -7.
This is a water-sealing type rotary vacuum pump of about 00mHg, and has a water-sealing water supply valve 25a, and a vacuum three-way valve 25b linked to the tank internal pressure detector 26 on the cold trap 24 side. . In addition to this water-sealing type rotary vacuum pump 25, although not shown, there is a rotary booster pump with a vacuum attainment pressure of approximately -450 lHg and a vacuum attainment pressure of -I X 10-2 to -I.
An oil rotary pump with a pressure of about 10 mwHg may be used (the pressure unit is based on atmospheric pressure).

The cold trap 24 is a kind of condenser, and has a coiled condensing pipe 24a for heat exchange inside, into which cooling water such as ordinary city water or well water is supplied as a refrigerant from a water supply source through a water supply valve 27. conduction. This serves as a water trap that cools the water vapor in the exhaust gas sucked out from inside the sterilizer 1 through the vacuum tank 22 and collects it so that it condenses on the surface of the condensing pipe 24a. is sent to the vacuum pump 25 side so that the function of the vacuum pump 25 can be fully demonstrated.

In other words, most of the exhaust from the sterilizer 1 during steam heating is water vapor, and contains moisture and heat. The sealing water for sealing No. 25 is heated and the temperature rises, worsening the ultimate vacuum degree. This makes it impossible to maintain a predetermined vacuum level and pressure in the vacuum tank 22, which upsets the balance of the internal pressure of the sterilizer 1, eventually making it impossible to perform low-temperature sterilization. Even if it were possible, the temperature distribution would be poor and abnormally high heat would occur in some areas, causing destruction or deterioration of the object A to be sterilized. A cold trap 24 is provided to allow the water-sealing rotary vacuum pump 25 to fully perform its functions without causing such adverse effects.

By providing this cold trap 24, not only the water-sealing rotary vacuum pump 25 mentioned above but also the lubrication inside the pump when a rotary booster pump or oil rotary pump is used as a vacuum pump. The negative effects of water vapor contamination with oil or sealing oil are eliminated, allowing it to function fully.

The vacuum tank 22 and the cold trap 24 are equipped with air supply valves 30 and 31 for introducing outside air and restoring the pressure to atmospheric pressure at the end of sterilization.

Further, in the figure, reference numeral 40 denotes a drainage system piping that is connected to the bottom of the sterilizer 1 to draw out the condensed water (drain) in the sterilizer 1. and a bypass drain valve 43, and is further connected to the vacuum tank 22 via a drain cooler 44. Then, the condensed water generated when the object A to be sterilized is heated with steam in the sterilizer 1 is transferred to the vacuum tank via the steam trap 42 and the drain cooler 44 due to the differential pressure of the degree of vacuum between the sterilizer 1 and the vacuum tank 22. It is configured to suck and flow out to the 22 side.

That is, the steam trap 42 required for discharging condensed water from inside the sterilizer 1 cannot operate to discharge condensed water unless there is a pressure difference before and after the steam trap 42 . The minimum value of the operating differential pressure P of the steam trap 42 is set by the manufacturer and is usually OJkg/eJ.
(228w Hg) or more. For this reason, for example, if the low temperature sterilization temperature (boiling point of water vapor) is set to 80°C, the corresponding vacuum degree P in the sterilizer 1 is the second
As shown in the figure, the vacuum level P in the vacuum tank 22 is maintained at -404,7∙Hg, so the degree of vacuum inside the vacuum tank 22 is P, <PI +P−−(404,7+228)−■
Setting and maintaining HgP 2<-832,7■@Hg, with the differential pressure between the vacuum tank 22 and the sterilizer 1, the condensed water in the sterilizer 1 is transferred to the vacuum tank 22 via the steam trap 42 and the drain cooler 44. It is designed to be sucked out to the side.

In other words, the vacuum tank 22 has a differential pressure with the sterilizer 1,
As mentioned above, it has both the functions of maintaining a degree of vacuum commensurate with the low temperature sterilization temperature of saturated steam of 100° C. or lower in the sterilizer 1 and as a discharge receiver for condensed water in the sterilizer 1.

The drain cooler 44 is supplied with cooling water from the water supply source via the water supply valve 45, which cools the condensed water coming from the sterilizer 1 via the steam trap 42 and flows into the vacuum tank 22. This reduces heat intrusion. In other words, as mentioned above, the vacuum tank 22 needs to be maintained at a vacuum level of 632.7 mHg or less in order to have a pressure difference higher than a predetermined level with respect to the inside of the sterilizer 1. If the temperature inside the vacuum tank 22 rises above the corresponding boiling point temperature of water (approximately 56 degrees Celsius, see Figure 2), the condensed water received in the vacuum tank 22 will evaporate, so the function of the vacuum pump 25 will be reduced. Changing the situation. Therefore, the drain cooler 44 cools the condensed water to prevent heat from entering the vacuum tank 22 as much as possible to reduce evaporation, and the cold trap 24 is provided as described above to ensure that the vacuum pump 25 functions sufficiently. A predetermined degree of vacuum within the vacuum tank 22 is maintained.

Cooling waste water from the drain cooler 44 is discharged through a drain pipe 46. Also, the vacuum tank 22 is connected to this water pipe 46.
and the condensed water in the cold trap 24 are drained from the drain valve 4.
7.48, and the cooling waste water passed through the condensing pipe 24a of the cold trap 24 is also drained through the check valve 49.
It is designed to be drained through.

A vacuum low-temperature steam heat sterilization method using the apparatus with the above configuration will now be described. As shown in Figure 2, water boils at 100°C above atmospheric pressure, and the water temperature does not rise even if more heat is added. Conversely, if you put water in a sealed container and reduce the pressure by evacuating the container, the boiling point of the water will drop, for example, to a degree of vacuum of -4.
At 04.7mm Hg, water evaporates and exists as water vapor at 80°C, and similarly, at a vacuum level of -810.8ms
At +Hg, water evaporates and exists as water vapor at 60°C. As the pressure is reduced, the boiling point of water changes and the water changes from a liquid state to a gaseous water vapor at a low temperature. Utilizing this characteristic, low temperature (100℃)
) The vacuum low temperature steam heat sterilization method of the present invention involves heat sterilization with steam.

For this purpose, the object A to be sterilized is sterilized by introducing steam into the sterilizer 1 while controlling the pressure inside the sterilizer 1 to be reduced to a pressure corresponding to the degree of vacuum at the low temperature sterilization temperature.

For example, when performing sterilization by setting the low-temperature sterilization temperature to 80°C, the sterilizer 1 containing the object to be sterilized A is hermetically sealed, and the inside is kept at a pressure (-404.7 mHg) corresponding to the degree of vacuum at 80°C.
), and the sterilizer pressure control valve 21 in the vacuum exhaust system piping 2° is automatically controlled to open and close using this signal. In addition, this sterilizer internal pressure control valve 21 allows the vacuum tank 22 to maintain a pressure corresponding to the vacuum level of 80° C. in the sterilizer 1 with a differential pressure between the vacuum tank 22 and the sterilizer 1. The internal pressure P2 of the vacuum tank 22 is set such that P2<p, so as to have both functions as a discharge receiver via the steam trap 42.
The tank internal pressure detector 26 is set to a state where +p --632,7wnHg, and this signal turns the tank internal pressure control valve 2 on.
3 is automatically controlled to open and close.

At the same time as operating the vacuum pump 25 in this state,
Water is supplied from a water supply source through each water supply valve 25a, 27.45.

With this, the inside of the vacuum tank 22 is maintained at a reduced pressure of -632.7 Hg by the tank internal pressure control valve 23, and due to the differential pressure from this, the inside of the sterilizer 1 is vacuumed via the sterilizer internal pressure control valve 21. The vacuum was maintained at -404.7 amHg. In this state, steam is introduced into the sterilizer 1 from the steam supply system piping 10 through the steam pressure reducing valve 11 and the steam filter 12, and through the steam supply control well 13 which is linked to the temperature controller 4 set at 80°C. go.

With the above steps, the inside of sterilizer 1 is replaced with water vapor and maintained at 80°C.
The object to be sterilized A is now subjected to vacuum low temperature steam heat sterilization.

At this time, as mentioned above, the inside of the sterilizer 1 is constantly maintained at a pressure corresponding to the degree of vacuum of 80°C due to the differential pressure with the vacuum tank 22, and the condensed water inside the sterilizer 1 is kept in the steam trap 42.
The sterilizer 1
Low-temperature sterilization can be performed very effectively without problems such as destruction or deterioration of the sterilized object A due to abnormally high heat in some areas due to imbalance of internal pressure and poor temperature distribution. .

Moreover, the exhaust gas from the inside of the sterilizer 1 during steam heating is mostly water vapor, and contains moisture and heat. Cold trap 24 in front of it
The water vapor in the exhaust air is cooled and condensed and collected, and only low-temperature air is sent to the vacuum pump 25.
can fully exhibit its function and maintain a predetermined vacuum degree and pressure in the vacuum tank 22. The vacuum tank 22 now fully exhibits the above-described function, and low-temperature sterilization within the sterilizer 1 can be performed more reliably.

〔Effect of the invention〕

Since the vacuum low-temperature steam heat sterilization method of the present invention is performed as described above, water vapor can be introduced into the sterilizer while maintaining the vacuum level within the sterilizer at a vacuum level corresponding to the low-temperature sterilization temperature of saturated steam of 100°C or less. The object to be sterilized can be sterilized by low-temperature steam heating while maintaining a uniform temperature distribution, and it is possible to achieve the effect of exhibiting excellent sterilization performance that is fully compatible with GMP and variance regulations.

Since the vacuum low-temperature steam heating sterilization apparatus of the present invention is constructed as described above, it is very effective in carrying out the low-temperature sterilization method.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a low-temperature steam heating sterilization apparatus showing an embodiment of the present invention, and FIG. 2 is a characteristic diagram of changes in boiling point temperature of water depending on atmospheric pressure. A...Object to be sterilized, 1...Sterilizer, 10...Steam supply means, 20...Evacuation means, 21...Pressure control valve, 22...Vacuum tank, 24... cold trap, 25... vacuum pump, 40... drainage means, 42.
··steam trap.

Claims (3)

[Claims] (1) Place the item to be sterilized in the sterilizer and seal it tightly. In this state, reduce the pressure inside the sterilizer to a degree of vacuum corresponding to the low-temperature sterilization temperature of saturated steam at 100°C or less. While maintaining this degree of vacuum, steam A vacuum low temperature steam heat sterilization method characterized in that the object to be sterilized is sterilized by low temperature steam heat. (2) A sterilizer for storing objects to be sterilized, a steam supply means for supplying steam while controlling the temperature to maintain a preset low temperature sterilization temperature of saturated steam of 100°C or less in the sterilizer, and The sterilizer is equipped with a vacuum evacuation means that uses a vacuum pump to maintain the reduced pressure at a degree of vacuum commensurate with the low temperature sterilization temperature of the saturated steam of 100° C. or less, and a drainage means that discharges condensed water in the sterilizer using a steam trap. A vacuum low temperature steam heating sterilizer characterized by: (3) The vacuum low-temperature steam heating sterilizer according to claim 1, wherein the vacuum evacuation means includes a vacuum tank that is vacuum-suctioned by a vacuum pump through a cold trap, and the difference in the degree of vacuum between this vacuum tank and the inside of the sterilizer. The inside of the sterilizer is maintained at a vacuum level corresponding to the low-temperature sterilization temperature of saturated steam of 100°C or less through a pressure control valve, and the sterilizer is also maintained at a vacuum level corresponding to the low-temperature sterilization temperature of saturated steam of 100°C or less, and also by the differential pressure between the vacuum tank and the inside of the sterilizer. 1. A vacuum low-temperature steam heating sterilizer characterized in that the condensed water in the sterilizer is made to flow out to the vacuum tank side through a steam trap of a drainage means.