JPH03210266A - Vapor heating and sterilizing device - Google Patents

Abstract

PURPOSE:To efficiently heat and sterilize an object to be sterilized with uniform temp. distribution by providing a cold trap which condenses and captures the steam in the exhaust gas from the interior of a sterilizer between this sterilizer and a vacuum pump of a vacuum evacuation system. CONSTITUTION:The steam in the exhaust gas from the sterilizer 1 is condensed and captured as shown by the black dots in Fig. by the cold trap 10 just before this steam enters the vacuum pump 6 as the cold trap 10 is provided at the time of evacuating the sterilizer 1 to a vacuum by the vacuum pump 6; therefore, the adverse influence, such as the degrading of the ultimate vacuum degree by condensing of the steam in the exhaust gas in the vacuum pump 6 or the generation of cavitation is eliminated. The vacuum pump 6 exhibits sufficient performance and increases the vacuum degree in the sterilizer 1. Sufficient steam substitution is thus executed and the object A to be sterilized is efficiently sterilized and heated by the uniform temp. distribution. In addition, the drying efficiency after the sterilization is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a steam heating sterilization apparatus used for sterilizing drugs and the like in pharmaceutical companies, medical institutions, various research institutes, and the like.

(Prior Art) Conventionally, this type of steam heating sterilizer has the following features, as shown in Fig. 3:
A steam supply system piping 2 is connected to a sterilizer (sealed container) 1 with an opening/closing Mla that stores an object to be sterilized A, and this steam supply system piping 2
Steam for heating is introduced from a steam supply source through a steam supply valve 3. In addition, a vacuum exhaust system piping 4 for evacuating the inside of the sterilizer 1 to replace it with water vapor as much as possible is connected, and a vacuum pump 6 is used to evacuate the sterilizer through a vacuum outlet valve 5 provided in the vacuum exhaust system piping 4. It is designed to suck and exhaust the air inside 1. As the vacuum pump 6, a water-sealed rotary vacuum pump with a vacuum attainment pressure of about -600 to -700 Hg is usually used. This sealed rotary vacuum pump 6 is provided with a water supply valve 6a. In addition to the water-sealing rotary vacuum pump 6,
Although not shown, a rotary booster pump with a vacuum pressure of about -45 msHg or a vacuum pressure of about -1×
10-2~-IXIO-' An oil rotary pump of approximately 100 lbs. of Hg may be used (the pressure unit is based on the atmosphere).

The sterilizer 1 is also provided with an intake and exhaust valve 7 that communicates with the atmosphere, and a drain valve 8 that discharges condensed water at the bottom.
has been established.

In such a steam sterilization heating device, the sterilization efficiency depends on how much air in the sterilizer 1 is exhausted to the outside and replaced with water vapor, so as shown in Figure 4, the pretreatment process is vacuum evacuation and steam replacement. Repeat several times.

That is, before introducing water vapor, the residual air in the sterilizer 1 is sucked and exhausted by the vacuum pump 6, but even with the normally used water-sealing rotary vacuum pump 6, the pressure is 15 to 30 torr.
A degree of vacuum up to r is the goal of performance, and there is a considerable amount of residual air in - times of vacuum evacuation.

If there is a large amount of residual air, even if steam is introduced into the sterilizer 1, a partial pressure of air will occur in the saturated steam, resulting in a high pressure, making it impossible to replace the steam sufficiently, and also impeding heat conduction. Unfortunately, the temperature distribution within the sterilizer 1 is disturbed and becomes non-uniform, making it impossible to effectively sterilize the object A to be sterilized.

For this purpose, as shown in FIG. 4, in the pretreatment process, the air in the sterilizer 1 is sucked and exhausted by the vacuum pump 6, and then the steam supply valve 3 is switched to introduce and replace water vapor into the sterilizer 1. After diluting the residual air, the air diffused in the water vapor in the sterilizer 1 is sucked and exhausted together with the water vapor by the vacuum pump 6, and the water vapor is introduced into the sterilizer 1 again for replacement to dilute the remaining air. Repeat the operation several times. By repeating such evacuation and steam replacement several times alternately, the absolute amount of air in the sterilizer 1 is reduced.

In this way, a large amount of water vapor is introduced at the end of the pretreatment process,
The steam sterilizes the object A in the sterilizer 1 by heating for a predetermined period of time. After that, the intake/exhaust valve 7 is opened to communicate with the atmosphere, thereby lowering the pressure inside the sterilizer 1 to atmospheric pressure, and then the vacuum pump 6 is used to evacuate the residual water vapor and reduce the pressure. Then, the intake and exhaust valves 7 are opened again to restore the pressure inside the sterilizer 1 to atmospheric pressure. This completes - times of steam sterilization work.

(Problem to be Solved by the Invention) Incidentally, in the steam heating sterilization described above, water vapor is a condensable gas and has a temperature of 100° C. or higher when introduced into the sterilizer 1. This water vapor is successively introduced into the sterilizer 1 and condensed at a temperature corresponding to its pressure, so that the pressure inside the sterilizer 1 is increased while being heated and replaced with water vapor.

Therefore, at the end of sterilization, high-temperature water vapor corresponding to a pressure of about 1 kg/cJ G exists in the sterilizer 1, as shown in FIG. 4. In this state, when evacuating the inside of the sterilizer 1 again to perform the next sterilization operation, first open the supply/exhaust valve 7 to reduce the pressure to atmospheric pressure. There is water vapor left that corresponds to the zero pressure.

Even if an attempt is made to further evacuate this using the vacuum pump 6, the inside of the sterilizer 1 is not at room temperature (low temperature) as in the first evacuation, but is heated, so the high temperature water vapor is pumped into the water-sealed rotary vacuum pump 6. Condensation occurs in the sealed water, which increases the temperature of the sealed water, worsens the ultimate vacuum, and causes the sterilizer 1 to
In addition to being unable to efficiently evacuate the interior to a sufficient degree of vacuum,
Cavitation occurs at a degree of vacuum commensurate with the sealing water temperature,
There are problems such as abnormal vibrations that can cause pump destruction or other equipment malfunctions. These abnormal developments are caused by the fact that, as shown in FIG. 5, the boiling point temperature of water changes in proportion to the degree of vacuum when the pressure is below atmospheric pressure, and the heat of condensation and boiling is greater than that of other substances.

Even if you use a rotary booster pump or oil rotary pump other than the water-sealed rotary vacuum pump,
Water vapor gets mixed into the lubricating oil or sealing oil in these pumps, making it impossible to obtain the ultimate vacuum, and similar problems occur.

Due to the adverse effects of the water vapor in the exhaust on the vacuum pump 6, it becomes impossible to increase the degree of vacuum in the sterilizer 1 and perform sufficient steam replacement, resulting in a large amount of residual air and sterilization!
The temperature distribution inside the iWl is uneven, making it impossible to effectively sterilize the object to be sterilized.There is a problem in not being able to fully comply with the GMP and varicity regulations that are being enforced, and the drying efficiency after sterilization is also poor. There is a problem.

The present invention was developed in view of the above circumstances, and by eliminating the adverse effect on the vacuum pump due to water vapor in the exhaust from the sterilizer, the performance of the vacuum pump can be fully demonstrated, and the degree of vacuum inside the sterilizer can be increased to ensure sufficient steam replacement. It is an object of the present invention to provide a steam heating sterilizer that enables efficient heat sterilization of objects to be sterilized with uniform temperature distribution.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention stores an object to be sterilized in a sterilizer and seals it, and in this state, evacuates the air in the sterilizer and replaces it with water vapor. In a steam heating sterilizer for heating and sterilizing objects to be sterilized by heating, a cold trap is provided between the sterilizer and a vacuum pump of a vacuum evacuation system to condense and collect water vapor in the exhaust from the sterilizer. It is characterized by being configured as follows.

(Function) In the steam heating sterilizer of the present invention having the above configuration, when the sterilizer is evacuated by the vacuum pump, the water vapor in the exhaust from the sterilizer is condensed and collected by the cold trap before entering the vacuum pump. Therefore, it is possible to eliminate adverse effects such as water vapor in the exhaust air condensing in the vacuum pump, worsening the degree of vacuum achieved, and causing cavitation. This allows the vacuum pump to fully demonstrate its performance, increases the degree of vacuum inside the sterilizer, enables sufficient steam replacement, and enables efficient heat sterilization of objects to be sterilized due to uniform temperature distribution. It will also be possible to improve the drying efficiency after sterilization.

(Example) An example of the present invention will be described below with reference to FIGS. 1 and 2. Components in the figure that are the same as those shown in FIG. 3 are given the same reference numerals to simplify the explanation.

FIG. 1 is a schematic configuration diagram showing a flow sheet of the steam heating sterilizer of the present invention, in which a steam supply system piping 2 and a vacuum exhaust system piping 4 are installed on the side of a sterilizer 1 in which objects to be sterilized A are stored, as in the conventional method. It is connected to the. Here, between the vacuum outlet valve 5 on the sterilizer 1 side of the vacuum exhaust system piping 4 and the water-sealed rotary vacuum pump 6, a cold trap is used to condense and collect water vapor in the exhaust from the sterilizer 1. 10 are provided. This cold trap 1o is a kind of condenser, and has a coil-shaped condensing pipe 11 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 via a water supply valve 12. conduction. This acts as a water trap that cools the water vapor in the exhaust gas sucked out from the inside of the sterilizer 1, condenses on the surface of the condensing tube 11, and collects the condensation. 6 side, so that the function of the vacuum pump 6 can be fully demonstrated.

In other words, most of the exhaust from the inside of the sterilizer 1 during steam heating is water vapor, which contains moisture and heat. The sealed water is heated and its temperature rises, worsening the degree of vacuum achieved. As a result, the predetermined degree of vacuum inside the sterilizer 1 cannot be obtained, and the degree of vacuum inside the sterilizer 1 cannot be increased to perform sufficient steam replacement.There is a lot of residual air inside the sterilizer 1, and the temperature distribution is Due to non-uniformity, the object to be sterilized A cannot be effectively sterilized. In order to fully demonstrate the function of the water-sealing rotary vacuum pump 6 without causing such adverse effects, a cold trap 1o is provided.

By providing this cold trap 10, when the sterilizer 1 is evacuated by the vacuum pump 6, the water vapor in the exhaust from the sterilizer 1 is transferred to the cold trap 10 before entering the vacuum pump 6, as shown in the black circle in FIG. Since the water vapor in the exhaust gas is condensed and collected as shown in the figure, it is possible to eliminate harmful effects such as condensation of water vapor in the exhaust gas in the vacuum pump 6, which deteriorates the degree of vacuum achieved and causes cavitation. This allows the vacuum pump to fully demonstrate its performance, increases the degree of vacuum inside the sterilizer 1, enables sufficient steam replacement, and enables efficient heat sterilization of the object A to be sterilized with uniform temperature distribution. It also becomes possible to improve the drying efficiency after sterilization.

By providing the cold trap 10 described above, even when a rotary booster pump or an oil rotary pump other than the water-sealing rotary vacuum pump 6 is used as a vacuum pump, the lubricating oil or sealing oil in the pump can be reduced. The adverse effects of water vapor contamination are eliminated, the sterilizer 1 can function satisfactorily, and the object A to be sterilized can be efficiently sterilized by heating due to the uniform temperature distribution inside the sterilizer 1.

Further, the cold trap 10 is equipped with an intake valve 13 for introducing outside air to restore the pressure to atmospheric pressure when sterilization is completed, and is connected to the bottom of the intake valve 13 to drain condensed water in the cold trap 10. A drain valve 14 is provided.

(Effects of the Invention) Since the steam heating sterilizer of the present invention is configured as described above,
When a sterilizer is evacuated by a vacuum pump, the water vapor in the exhaust air from the sterilizer can be condensed and collected in a cold trap before entering the vacuum pump, which prevents the water vapor in the exhaust from the sterilizer from having an adverse effect on the vacuum pump. This allows the vacuum pump to take full advantage of its performance, increases the degree of vacuum inside the sterilizer, enables sufficient steam replacement, and achieves the effect of efficiently heating and sterilizing objects to be sterilized through uniform temperature distribution. .

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a steam heating sterilization device showing an embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation of the same device, FIG. 3 is a schematic configuration diagram showing a conventional example, and FIG. FIG. 5, which is a process diagram of steam heating sterilization, is a characteristic diagram of the boiling point change depending on the atmospheric pressure of water. A: Item to be sterilized, 1: Sterilizer, 2: Steam supply system piping, 4: Vacuum exhaust system piping, 10: Cold trap.

Claims (1)

[Claims] A steam heating sterilizer that heat-sterilizes the object by storing the object to be sterilized in a sterilizer, sealing it, and evacuating the air in the sterilizer in this state and replacing it with water vapor,
A steam heating sterilization apparatus characterized in that a cold trap is provided between the sterilizer and a vacuum pump of a vacuum evacuation system for condensing and collecting water vapor in the exhaust from the sterilizer.