JP3225843B2 - Autoclave - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for storing objects to be treated such as various medical instruments and experimental instruments in a processing chamber, introducing steam into the processing chamber, and bringing the object into contact with the steam under pressure. More specifically, the present invention relates to an autoclave provided with means for performing a sterilization process on a drain generated in a processing chamber during the sterilization process.

[0002]

2. Description of the Related Art When sterilizing various medical instruments and laboratory instruments, these objects to be treated are housed in a closed processing chamber, and steam is introduced into the processing chamber to reduce the pressure. In general, a sterilization apparatus called an autoclave, which performs heat-pressure sterilization by bringing steam into contact with an object to be processed, is generally used.

In this case, before the temperature of the processing chamber is sufficiently raised to the sterilization temperature, the introduced steam comes into contact with the surface of the processing object having a low temperature or the inner wall of the processing chamber to form dew. The sterilization process is performed while draining the drain from the processing chamber as needed.

The drain is generated even after the temperature in the processing chamber reaches the sterilization temperature. However, most of the drain is generated before the temperature of the object to be processed or the inner wall of the processing chamber is increased to a sufficient sterilization temperature. And viruses may exist in an active state. Therefore, such a drain should be originally sterilized and discarded sufficiently, and in fact, in some hospitals such as research laboratories and university hospitals, the drain was once collected in a treatment tank together with other waste liquid and treated. Later, drainage is performed to sewage or the like. However, since providing such a wastewater treatment facility requires a large capital investment, such hospitals are hardly provided in general hospitals and the like.

In the past, there has been no autoclave that has devised any method for drain treatment. Therefore, in general hospitals and the like, the drain is drained to sewage without any treatment. It is.

The present invention has been made in view of the above circumstances, and it is possible to sterilize and discharge drain generated during sterilization, without requiring large-scale equipment such as a drainage treatment facility and the like. It is an object of the present invention to provide an autoclave capable of draining a drain.

[0007]

According to the present invention, in order to achieve the above object, the object to be treated is housed and sealed, steam is introduced into the inside, and steam is applied to the object under pressure. The contact chamber is formed inside a processing chamber for sterilizing an object to be processed, a drain tank for temporarily storing the drain discharged from the processing chamber, and a jacket portion covering at least a part of the drain tank. Drain tank cooling means for cooling the inside of the drain tank by introducing a cooling medium into the steam introduction space, and heat sterilizing the drain contained in the drain tank by introducing steam into the steam introduction space. A drain heating unit, a filter that passes exhaust gas from the processing chamber and the drain tank to purify the exhaust gas, and a jacket portion that covers at least a part of the filter. Filter heating means for heating and sterilizing the filter by introducing steam into the steam introduction space formed on the side, and cooling the inside of the drain tank once by the drain tank cooling means to thereby cool the inside of the drain tank. After liquefaction of the water vapor, the drain in the drain tank is heat-sterilized and discharged by the drain heating means, and the filter is heated by the filter heating means to prevent dew condensation in the filter. An autoclave characterized in that a filter is configured to be subjected to heat sterilization.

In the autoclave of the present invention, similarly to the conventional autoclave, objects to be treated such as various medical instruments and experimental instruments are accommodated in the processing chamber, the processing chamber is sealed, and steam is introduced into the processing chamber. The object to be processed is subjected to pressure and heat sterilization by bringing steam into contact with the object to be processed under pressure, so that during sterilization, as in a conventional autoclave, steam is applied to the object having a low temperature. Condensation is generated by contact with the surface of the processing object or the inner wall of the processing chamber to generate drain.

In this case, according to the autoclave of the present invention, the drain is once collected from the processing chamber and stored in a drain tank, and steam is supplied to the steam introduction space formed inside the jacket covering the drain tank. By introducing, the drain tank can be heated under pressure, the drain can be sterilized under pressure, and then drained. Further, in the autoclave of the present invention, the sterilization of the drain is performed each time the sterilization is performed, and the sterilization can be performed immediately after the generation of the drain, so that bacteria can be propagated while the drain is stored. Without any problem, the sterilization treatment can be reliably performed, and the drain can be drained safely and inexpensively.

Further, the autoclave of the present invention is configured to purify exhaust gas discharged from the processing chamber and the drain tank through a filter, and then discharge the exhaust gas to the outside. By introducing steam into the steam introduction space formed inside the jacket covering the filter, the filter is heated,
The exhaust can be reliably performed while preventing the occurrence of clogging due to dew condensation in the filter, and the occurrence of inconvenience due to the clogging of the filter can be reliably prevented.
In addition, the filter can be sterilized by this heat treatment, so that the filter can be safely evacuated and the filter with reduced capacity can be safely discarded.

Here, in the autoclave of the present invention, as described above, the jacket covering at least a part of each of the drain tank and the filter is provided, and the steam introduction space covering the periphery of the drain tank and the filter is provided inside the jacket. Is formed, cooling water is introduced into a steam introduction space covering the periphery of the drain tank to cool the drain tank, and then steam is introduced into the steam introduction space to heat-sterilize the drain in the drain tank. The drain tank cooling unit and the drain heating unit are configured as described above, and the filter heating unit is configured to introduce steam into the steam introduction space covering the periphery of the filter and heat sterilize the filter. Thus, as the drain heating means and the filter heating means,
Since a method utilizing steam is employed, it is not necessary to use a heating device in particular, and a pipe and a steam for introducing a part of the steam generated for the sterilization treatment to the steam introduction space are used. The heat sterilization of the drain and the filter can be easily performed by a simple mechanism that only requires a valve for controlling the introduction. In the drain tank, a cooling medium such as water is introduced into the steam introduction space to completely liquefy the steam in the drain tank, and then steam is introduced into the steam introduction space to perform heat sterilization. By doing so, the drain can be sterilized more reliably.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be shown, and the present invention will be described more specifically. FIGS. 1 to 8 show an autoclave according to an embodiment of the present invention. As shown in FIG. 1, this autoclave accommodates objects to be treated such as various medical instruments and laboratory instruments, and covers these objects. A processing chamber 1 for sterilizing the processed material, a drain tank 2 for sterilizing the drain generated in the processing chamber 1, two air filters F1 and F2, a vacuum pump VP, and a steam supply device (FIG. Not shown), and these are connected by a number of pipes, and the electromagnetic valves V1 to V16 provided in these pipes are automatically opened and closed by a control device (not shown) such as a microcomputer. Thus, the movement of water vapor, air, and liquids is controlled.

As shown in FIGS. 2 to 4, the processing chamber 1 is provided with a jacket 12 so as to cover the periphery of a box-shaped processing chamber body 11 having an open front surface. The introduction space 13 is formed. In the drawing, reference numeral 11a denotes the processing chamber main body 11 and the jacket 1
It is a base that supports 2.

As shown in FIGS. 2 to 4, the processing chamber 1 has an inner water vapor supply port 14a, a discharge air inlet 14b, and an inner drain discharge port 1a communicating with the processing chamber body 11.
4d and the steam introduction space 13 in the jacket 12
Are provided with an outer steam supply port 14c and an outer drain discharge port 14e that communicate with the outside. The processing chamber body 1
Pressure regulating valve 15 for maintaining the inside of the vessel 1 at a predetermined pressure
a, and an outside pressure regulating valve 15b for maintaining the inside of the steam introduction space 13 at a predetermined pressure, and an inside pressure gauge 16a for measuring the pressure inside the processing chamber body 11 in FIG. (Not shown), an inner pressure gauge (not shown) for measuring the pressure in the steam introduction space 13 is attached to 16b, and the pressure and atmosphere in the processing chamber body 11 are further attached to 16c. Instruments (not shown) for measuring the temperature and the temperature of the object to be processed are attached.

Although not shown in FIGS. 2 to 4, the processing chamber 1 is provided with a well-known hatch-type door 17 that opens and closes the entire opening as shown in FIG. The inside of the processing chamber 1 can be sealed by the door 17.

As shown in FIGS. 5 to 7, the drain tank 2 is provided with a jacket 22 so as to cover a periphery of a tank-shaped tank body 21, and a steam introduction space 23 is provided around the tank body 21. The tank body 21 and the jacket 22 are hermetically sealed by closing the tank body 21 and the jacket 22 with the lid 24 and fixing them with twelve bolt nuts.

The drain tank 2 has a tank body 21
A drain inlet 26a and an exhaust port 26b communicating with the inside are provided in the lid 24, and an inner drain outlet 26c communicating with the bottom in the tank body 21 is provided in the bottom wall. The jacket 22 has a water vapor inlet 27a, an outer drain outlet 27b, and a drain / suction port 2 which communicate with the water vapor inlet space 23 in the jacket 22.
7c is provided. In the drawing, reference numeral 26d denotes a sensor mounting hole communicating with the inside of the tank main body 21, and a temperature sensor (not shown) is disposed in the tank main body 21 through the sensor mounting hole 26d, and the inside of the tank main body 21 is provided by the temperature sensor. The temperature of the contained drain is measured.

Although not shown, the tank main body 21 and the jacket 22 each have an inner pressure adjusting valve for adjusting the pressure in the tank main body 21 and the pressure in the steam introducing space 23. An outside pressure regulating valve is provided so that the inside of the tank body 21 and the inside of the steam introduction space 23 can be maintained at a predetermined pressure.

As shown in FIG. 8, the air filter F2 has a jacket f2 provided so as to cover the periphery of a substantially cylindrical filter body f1, and a water vapor introduction space f3 formed around the filter body f1. The cartridge filter f4 is exchangeably housed in the filter body f1.

The air filter F2 is provided with an air inlet f5 and an air outlet f6 communicating with the inside of the filter body f1, and air is introduced from the air inlet f5 and passes through the cartridge filter f4. As a result, the air is purified and exhausted from the air outlet f6. Further, the jacket f2 is provided with a steam inlet f7 and a drain outlet f8 communicating with the steam inlet space f3 in the jacket f2. In the figure, f9 indicates the filtration efficiency (clogging) of the cartridge filter f4 disposed in the filter body f1.
And a differential pressure gauge (not shown) for measuring the pressure difference between the air inlet f5 and the air outlet f6.

Although not shown, the jacket f2 is provided with a pressure regulating valve for regulating the pressure in the steam introduction space f3, and a predetermined pressure is established in the steam introduction space f3. Can be held.

The air filter F1 in FIG.
It is an ordinary cartridge type air filter having no jacket portion, and a known vacuum pump can be used as the vacuum pump VP. Further, a known device can be used as a steam generator (not shown).

As shown in FIG. 1, the autoclave according to the present embodiment connects the processing chamber 1, the drain tank 2, the air filters F1 and F2, the vacuum pump VP, and the steam generator (not shown) by piping. Connected.

That is, as shown in FIG. 1, a steam generator (not shown) is connected to the inner steam supply port 14a and the outer steam supply port 14c of the processing chamber 1 via valves V1 and V11, respectively. Are connected, and steam is supplied into the processing chamber 1 and the steam introduction space 13 of the processing chamber 1. Further, the exhaust air inlet 1 of the processing chamber 1
4b is connected to the air filter F1, the vacuum pump VP, and the air filter F2 by three branched pipes, and valves V2, V3, and V4 are interposed in the three branched pipes, respectively. Further, the inner drain outlet 14d of the processing chamber 1 is connected to the drain inlet 26a of the drain tank 2 via the valve V6, and the drain generated in the processing chamber 1 is guided to the drain tank 2. . In this case, the pipe connecting the inner drain outlet 14d and the drain inlet 26a is provided with a valve V5.
Is provided, and the drain can be drained through this branch pipe by operating a valve. Furthermore, a drain outlet 14 outside the processing chamber 1 is provided.
A water distribution pipe having a valve V12 is connected to e, and the drain generated in the steam introduction space 13 is drained out of the apparatus through this pipe.

Next, the exhaust port 26b of the drain tank 2
Is connected to the air inlet f5 of the air filter F2 together with a pipe from the exhaust port 14b of the processing chamber 1 by a pipe having a valve V7. Drain tank 2
The steam inlet 27a is connected to a steam generator (not shown) via a valve V13, and steam is supplied from the steam generator into the steam inlet space 23 through the steam inlet 27a. ing. Furthermore,
Pipes having valves V10, V15, and V14 are connected to the inner drain outlet 26c, the outer drain outlet 27b, and the drain inlet 27c of the drain tank 2, respectively. In this case, the outer drain outlet 27b is also connected to a water absorbing mechanism (not shown), and cooling water can be introduced into the steam introduction space 23 through the outer drain outlet 27b. It has become.

Further, a steam generator (not shown) is connected to the steam inlet f7 of the air filter F2 via a valve V12, and steam is supplied from the steam generator through the steam inlet f7. The water is supplied into the water vapor introduction space f3 of the filter F2. The air outlet f6 of the air filter F2 can be opened to the atmosphere via a pipe having a valve V8. In this case, this pipe is located on the front side of the valve V8,
And a vacuum pump VP via a valve V9. Further, a valve V16 is connected to the drain outlet f8 of the air filter F2.
Is connected, and the drain generated in the water vapor introduction space f3 is drained out of the apparatus through the pipe.

The drain port 1 inside the processing chamber 1
4d, an outer drain outlet 14e, an outer drain outlet 27b of the drain tank 2, and a drain outlet f8 of the air filter F2 and a connection portion between each pipe are provided with a steam trap. It is possible to discharge only the condensed water without lowering the water content.

Next, the operation of the autoclave will be described. In the following description, each valve V1
V16 is assumed to be closed unless otherwise stated. When performing a sterilization process using this autoclave, various medical instruments and laboratory instruments are accommodated in the processing chamber 1, and the door 17 is closed to seal the inside of the processing chamber 1. In this state, first, the valve V11 is opened to supply steam from a steam generator (not shown) to the steam introduction space 13 formed in the jacket 12 of the processing chamber 1, and the inside of the steam introduction space 13 is added. By heating in a pressure state, the inside of the processing chamber 1 is heated. Thereby, the amount of drain generated at the time of introducing steam later is reduced. At the same time as the introduction of the steam, the valve V12 is also opened, the drain generated in the steam introduction space 13 is separated by the trap, and the outer drain outlet 1
From 4e, it is discharged outside through a pipe and a valve V12.

At the same time as the heating operation, the valves V4 and V9 are opened, and the air in the processing chamber 1 is removed by the vacuum pump VP through the filter F2. Thereby, the steam introduced later into the processing chamber 1 can satisfactorily come into contact with the object to be processed, and the sterilization can be surely performed. Further, simultaneously with these operations, while the valves V15 and V14 are open, cooling water is supplied to the steam introduction space 23 of the drain tank 1 through the valve V15, and the drain / inlet 27
The drain tank 2 is cooled by discharging and flowing from c.

Next, the valves V4 and V9 are closed, and the vacuum pump VP is stopped.
7, V8 is opened, whereby steam is introduced from the steam generator (not shown) into the processing chamber 1 through the inner steam supply port 14a, and the inside of the processing chamber 1 is maintained at a predetermined pressurized state and sterilized. The temperature is raised to the temperature, and the sterilization of the object is started. At this time, the drain generated in the processing chamber 1 is separated by the trap, guided into the drain tank 2 through a pipe from the inner drain discharge port 14d, and temporarily stored in the drain tank. In this case, since the valves V7 and V8 are opened so that the back pressure is not applied, the drain can be smoothly collected in the drain tank 1, and the gas exhausted when the drain is discharged is filtered by the filter F2.
, And exhausted through a valve V8. The water vapor generated from the drain is cooled in the drain tank 2, liquefied, and stored in the drain tank 2.

When the temperature in the processing chamber 1 rises and reaches a predetermined sterilization temperature, a timer is started and the sterilization temperature is maintained for a predetermined time, and the object to be processed is sterilized. Next, after a lapse of a predetermined time, the valves V1, V6, V7, and V8 are closed to stop the supply of steam into the processing chamber 1, and
The collection of the drain into the drain tank 2 is stopped, and the inside of the drain tank 1 is sealed. Then, the valve V5 is opened to discharge the steam in the processing chamber 1 as drain to the outside of the apparatus. In this case, since the drain to be discharged is kept at a sterilization temperature for a predetermined time and is completely sterilized, the drain can be directly discharged out of the apparatus.

Thereafter, the drying operation in the processing chamber 1 and the drain sterilization operation in the drain tank 2 proceed simultaneously. First,
The drying operation in the processing chamber 1 will be described.
After the steam in the processing chamber is drained out of the apparatus as a drain, the valve 5 is closed, and the processing in the processing chamber 1 is performed by repeating the next evacuation process and suction process a predetermined number of times. Evacuation Step The valves V3 and V9 are opened, and the air in the processing chamber 1 is exhausted by the vacuum pump VP. In this case, the exhaust air is
Since the inside of the processing chamber 1 is kept at a sterilizing temperature for a predetermined time and is completely sterilized, it can be evacuated without passing through a filter. Intake process The valves V3 and V9 are closed, and the vacuum pump VP is stopped. Next, the valve V2 is opened, and air is introduced into the processing chamber 1 through the air filter F1.

The above-mentioned exhaust step and intake step are as follows:
Normally, the process is repeated about 3 to 6 times, whereby the inside of the processing chamber 1 is almost completely dried.
Can be opened to take out the object to be sterilized. During the drying process, the supply of steam to the steam introduction space 13 formed in the jacket 12 of the processing chamber 1 is continued, and the inside of the processing chamber 1 is maintained in a heated state, so that the drying process can be performed satisfactorily and quickly. Is performed. Then, after the drying operation is completed, the valves V11 and V12 are closed, and the supply of steam to the steam introduction space 13 is stopped.

On the other hand, the drain sterilization operation in the drain tank 2 is performed as follows in parallel with the drying operation. First, the supply of the cooling water into the water vapor introduction space 23 formed in the jacket 22 of the drain tank 2 is stopped, and conversely, the outer drain outlet 27b and the valve V15
The cooling water in the water vapor introduction space 23 is drained through the passage.
At this time, air is sucked into the steam introduction space 23 through the valve V14 and the drain / suction port 27c, and the cooling water is drained satisfactorily and quickly.

After draining the cooling water, the valve V14 is closed and the valve V13 is opened to supply steam from the steam generating device (not shown) into the steam introducing space 23, and Is heated in a pressurized state to heat the inside of the drain tank 2. The drain generated in the water vapor introduction space 23 is separated via a trap and discharged to the outside through the outer drain outlet 27b and the valve V15.

As a result, the inside of the drain tank 1 is heated in a sealed state (the valves V6 and V7 are closed), and is raised while being maintained in a predetermined pressurized state by a pressure regulating valve (not shown). Warm up. After the drain contained therein reaches a predetermined sterilization temperature, the temperature is maintained for a predetermined time, and the drain is sterilized by heating under a pressurized state. After a lapse of a predetermined time, the valve V13 is closed and the steam introduction space 23 is closed.
The supply of water vapor to the inside is stopped, the valve V10 is opened, and the drain subjected to the sterilization treatment is discharged out of the apparatus.

After the drying operation in the processing chamber 1 and the drain sterilization operation are completed, all the valves are closed to return to the initial state. Here, in the autoclave of the present embodiment, the drying operation in the processing chamber 1 is completed, and the drain sterilization operation is continued even after the sterilized workpiece is removed from the processing chamber 1. If so, the next sterilization operation cannot be performed.

In the autoclave of this embodiment, the cartridge filter f4 (see FIG. 8) mounted in the air filter F2 is heated during sterilization or as needed, so that water vapor passing through the air filter F2 is The occurrence of clogging due to dew condensation in the filter f4 can be reliably prevented, and the sterilization operation can be stably performed.

That is, during the above sterilization process or as needed, the valve V1
2 is opened to supply steam from a steam generator (not shown) into a steam introduction space f3 formed in the jacket f2 of the air filter F2.
The cartridge filter f4 in the air filter F2 is heated by heating the inside of the filter 3 in a pressurized state. This reliably prevents water vapor passing through the air filter F2 from condensing in the cartridge filter f4, preventing the occurrence of clogging, and allowing the captured bacteria to propagate in the cartridge filter f4. Can also be effectively prevented. Further, this heating process causes the cartridge filter f4.
Can be sterilized, the exhaust can be performed safely, and the cartridge filter f4 with reduced capacity can be safely discarded. During this heat treatment, the drain generated in the water vapor introduction space f3 is separated via a trap and discharged to the outside through the drain outlet f8 and the valve V16.

As described above, according to the autoclave of this embodiment, the drain generated in the processing chamber 1 during the sterilization process is temporarily collected from the processing chamber 1 into the drain tank 2 and stored therein. After heating under pressure to sterilize the drain under pressure, the liquid can be drained. Therefore, the drain can be safely drained without requiring a large-scale facility such as a drainage treatment facility. In this autoclave, the drain is sterilized each time sterilization is performed, and the sterilization can be performed immediately after the drain is generated, so that bacteria may proliferate while the drain is stored. Therefore, the sterilization can be reliably performed, and the drain can be safely and inexpensively drained.

In the autoclave of the present embodiment, a jacket 22 (see FIG. 7) is provided in the drain tank 2 to form a steam introduction space 23 around the tank body 21 (see FIG. 7). Since the drain accommodated in the drain tank 2 is configured to be heat-sterilized by introducing steam into the space 23, it is not necessary to use a heating device, and the object to be processed is sterilized. Easily heat-sterilize the drain with a simple mechanism that only requires a pipe for guiding a part of the generated steam into the steam introduction space 23 and valves for controlling the introduction of the steam. Can be done. Also,
Cooling water is introduced into the steam introduction space 23 to completely liquefy the steam in the drain tank 2, and then steam is introduced into the steam introduction space 23 to perform heat sterilization, thereby sterilizing the drain. It can be performed more reliably.

Further, as described above, in the autoclave of the present embodiment, the air filter F2 can be heated to prevent the clogging due to the dew condensation in the filter, and the air can be reliably exhausted. The occurrence of inconvenience due to clogging can be reliably prevented. Moreover,
By this heat treatment, the cartridge filter f4 mounted in the air filter F2 can be sterilized, and the exhaust can be performed safely, and the cartridge filter f4 with reduced capacity can be safely discarded. .

The autoclave of the present invention is not limited to the above embodiment, and the configuration of each part may be changed as appropriate without departing from the gist of the present invention.

[0044]

[0045]

As described above, according to the autoclave of the present invention, drain generated during sterilization can be sterilized and discharged, requiring large-scale facilities such as a drainage treatment facility. And the drain can be safely drained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an autoclave system according to one embodiment of the present invention.

FIG. 2 is a plan view in which a part of a processing chamber constituting the same autoclave is cut away and sectioned.

FIG. 3 is a front view showing a cross section of a part of the processing chamber cut away.

FIG. 4 is a side view of the processing chamber in which a part is cut away and a cross section is formed.

FIG. 5 is a plan view showing a drain tank constituting the autoclave.

FIG. 6 is a front view showing the drain tank.

FIG. 7 is a sectional view showing the drain tank.

FIG. 8 is a partially cutaway side view showing an air filter constituting the autoclave.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing room 11 Processing room main body 12 Processing room jacket part 13 Processing room water vapor introduction space part 2 Drain tank 21 Tank body 22 Drain tank jacket part 23 Drain tank water vapor introduction space part F2 Air filter (filter) f1 Filter main body f2 Jacket part of filter body f3 Water vapor introduction space part of filter body

──────────────────────────────────────────────────続 き Continued from the front page (56) References JP-A-58-86164 (JP, A) JP-A 62-50643 (JP, U) JP-A 2-61347 (JP, U) JP-A 3-86 43849 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61L 2/06

Claims (1)

(57) [Claims] 1. A processing chamber for accommodating and sealing an object to be treated, introducing steam therein, and bringing the object into contact with the steam under pressure to sterilize the object to be treated. A drain tank that temporarily holds the drain discharged from the processing chamber, and a cooling medium introduced into a steam introduction space formed inside a jacket portion that covers at least a part of the drain tank, so that the inside of the drain tank is reduced. Drain tank cooling means for cooling, Drain heating means for heating and sterilizing the drain housed in the drain tank by introducing steam into the steam introduction space, and passing exhaust air from the processing chamber and the drain tank. A filter for purifying the exhaust gas, and introducing steam into a steam introduction space formed inside a jacket covering at least a part of the filter. And a filter heating means for heating and sterilizing the filter. After the inside of the drain tank is once cooled by the drain tank cooling means to liquefy water vapor in the drain tank, the inside of the drain tank is drained by the drain heating means. The drain is heated and sterilized and discharged, and the filter is heated by the filter heating means to prevent dew condensation in the filter, and the filter is heated and sterilized. Autoclave.