JPH06190024A - Method and apparatus for high-pressure steam sterilization - Google Patents

Abstract

PURPOSE:To prevent secondary infection in a hospital by a process wherein after a treating tank wherein a specimen to be sterilized is stored is sealed, gas in the treating tank and a steam generating apparatus are evacuated through a bacteria elimination mechanism and a high temp. and high pressure steam is, fed into the bacteria elimination mechanism and the treating tank to keep insides of the bacteria elimination mechanism and the treating tank under a high temp. and high pressure condition. CONSTITUTION:A specimen 4 to be sterilized is stored in a treating tank 1, which is then sealed and gas in the treating tank 1 and a steam generating apparatus 2 is evacuated through a bacteria eliminating apparatus 16 and feeding water in the steam generating apparatus 2 is preheated and predeaerated. Then, a high temp. and high pressure gas is passed through the bacteria eliminating apparatus 16 to keep a high temp. and high pressure condition and both sterilization treatment of the bacteria eliminating apparatus 16 and preheating of the treating tank 1 are performed. Then, a high temp. and high pressure steam is fed into the treating tank 1 to keep a high temp. and high pressure condition and the specimen 4 to be sterilized in the treating tank 1 is sterilized and the high temp. and high pressure steam in the treating tank 1 is discharged under vacuum and cooling through an exhaust pipe to reduce the pressure in the treating tank 1 and to cool it by introducing a cooling water.

Description

Detailed Description of the Invention

[0001]

The high-pressure steam sterilizer and high-pressure steam sterilization method according to the present invention are used for sterilizing infectious medical waste discharged in hospitals and various laboratories.

[0002]

2. Description of the Related Art Many of the wastes discharged in hospitals and various laboratories have infectious pathogens attached to them, and conventionally medical wastes, particularly infectious wastes, are separated in medical institutions. , Was collected, transported, and incinerated by a professional waste disposal company, but there is a possibility that infectious waste may be scattered due to an accident on the way, and a method of monitoring by a manifest system is also adopted. However, there is a concern that the final treatment will be ensured.Therefore, there is a strong need for a method and device for treating infectious medical waste in hospitals that discharge infectious medical waste, that is, for in-hospital treatment. It is rare. As a method suitable for in-hospital treatment, there are high-pressure steam sterilization or incineration treatment, and these two heat treatment methods are said to be complete and the most excellent methods if properly carried out. However, if improperly implemented, there is a risk of secondary infection during post-treatment.

In the incineration process, combustible substances are made inorganic, so that they should be sufficiently sterilized and infectious microorganisms should disappear, but in the incinerator of a small fixed bed furnace currently installed in general hospitals. According to the results of the bacteria survey of the incineration ash, a large amount of unburned matter is contained in the incineration ash, so many general bacteria were detected, and many bacteria were also found in the dust accumulated in the flue of the incinerator. There was a report that it was done. In these fixed bed furnaces, the temperature of the furnace fluctuates sharply, especially at the rise and fall of incineration.
High temperature incineration is difficult.

Further, since most medical waste is made of plastic, the exhaust gas generated by decomposition of the plastic during incineration contains harmful substances, which causes a problem of secondary pollution, which is a major problem in exhaust gas treatment. Requires equipment.
In addition, the incinerator that emits high heat requires a large installation space,
It is unsuitable for equipment in hospitals in urban areas.

In the high-pressure steam sterilization treatment, even a spore of heat-resistant bacteria can exhibit a sufficient sterilizing effect by holding it under high-pressure steam at 121 ° C. for about 20 minutes, and at that temperature, the plastic used as a medical device is stable. Therefore, there is no problem of gas treatment. However, the conventional high-pressure steam sterilization equipment (autoclave) and its operating method focus on the sterilization of the object to be sterilized. Although care is taken not to attach bacteria etc. to the sterilized product, special consideration is not given to exhausting the inside of the processing tank with steam and discharging low-temperature drain by supply steam for sterilization. Instead, it was exhausted and discharged outside the processing tank as it was.

With the conventional high-pressure steam sterilizer as described above,
When the infectious waste is sterilized, infectious microorganisms may be mixed in the gas exhausted in the exhaust step, and the infectious microorganisms are scattered in the hospital together with the exhaust. In addition, the infectious microorganisms may be mixed in the drain discharged during the sterilization process, and the infectious microorganisms are released into the hospital together with the drain.

Further, in the case of sterilization of infectious waste, there is a possibility that infectious microorganisms may be attached to the inner surface of the processing tank and the inner surface of the pipe. There is a possibility of touching those parts when exchanging upper parts, and not only the object to be sterilized but also these parts must be surely sterilized, but the conventional high-pressure steam sterilizer does not give sufficient consideration. It was

The conventional high-pressure steam sterilizer, except for a small-sized one, adopts a method of sterilizing by introducing steam from a steam generating facility such as a boiler from the outside. In this case, it is generated in the initial stage of heating. If low-temperature drainage is heated with the drainage accumulated in the treatment tank, the drainage accumulation area will not be heated easily, and sterilization will take time and the sterilization effect will not be sufficient. Therefore, there is a device in which the steam drain is collected in another tank called a kill tank, heated and sterilized in the tank, and then discharged, but the apparatus is larger and complicated, and the processing steps and time increase. Further, in a small-scale hospital facility having 20 to 30 beds, there are many places where there is no steam generating equipment such as a boiler, and a new installation place and cost are required, which is not suitable.

[0009] The conventional high-pressure steam sterilizer is small,
A heater is provided at the bottom of the treatment tank, water is supplied to the bottom of the treatment tank to heat it to generate steam, and steam is generated by a steam generator with a separate heater installed inside the piping. There is one that introduces the steam into the processing tank. However, in the case where the heating heater is installed inside the processing tank, the drain generated inside the processing tank is reheat sterilized by the heating heater, so there is no problem of drain discharge, but for the capacity of the sterilized object It is necessary to discharge the heated feed water for safety every time the treatment tank becomes large and the sterilization treatment is completed, which is disadvantageous in terms of energy cost compared to the separate equipment, and the exhaust process It is necessary to separately perform the heating process of the feed water, which has a drawback that the processing time becomes long.

Further, since the conventional separate steam generator is installed for the purpose of a so-called simple boiler for generating steam and introducing it into the treatment tank, the drain generated in the treatment tank is Each time, it was discharged outside the treatment tank and not sterilized. As a method of sterilizing infectious microorganisms contained in the gas exhausted in the exhaust process, a method is proposed in which a sterilization filter is installed in the exhaust pipe to sterilize and the sterilization filter is sterilized with high-pressure steam. However, when a heating heater is installed inside the treatment tank, the steam generated in the treatment tank reaches the sterilization filter in the middle of the pipe and circulates the steam in order to heat it to the specified sterilization temperature. Since it is a natural circulation, there is a problem that it takes time and the temperature distribution inside tends to become unstable due to heat radiation in the middle of the piping and in the filter housing part. In addition, if steam is introduced from the outside and forced to flow through the sterilization filter part and piping to perform sterilization, the internal temperature will be made uniform and sterilization will be performed, but sterilization of the resulting drain is required. .

In the operation of the high-pressure steam sterilizer, when the gas in the processing tank is not exhausted sufficiently, the inside of the processing tank is not sufficiently replaced with steam, and the temperature of the portion exposed to air is hard to rise, and the high-pressure steam is not heated. It may not be sterilized even at the sterilization temperature. As a conventional exhaust method of the high-pressure steam sterilizer, a vacuum pump is used for exhaust, and a single vacuum method in which the process of performing vacuum exhaust and steam replacement is performed only once and a vacuum method are used. There is a pulsating prevacuum method in which exhaust / steam replacement is repeated several times. As a vacuum pump, the ultimate vacuum pressure is -600 to -700 mmH.
A water-sealing type rotary vacuum pump of about g does not cause any problem even if steam is sucked in, and is usually used because it is inexpensive.

When the above vacuum pump is used, a large amount of residual air is produced in the single vacuum method, and even if steam is introduced into the treatment facility, a partial pressure of air is generated in the saturated steam and a high pressure is exhibited, which is sufficient. In addition to not being able to replace steam, heat conduction is poor and the temperature distribution in the treatment tank is disturbed, resulting in non-uniformity, which may prevent effective sterilization of the object to be sterilized and the treatment tank. In the prevacuum method, residual air is diluted by repeating vacuum evacuation and steam replacement several times alternately, and the absolute amount of air can be reduced, so the temperature inside the processing groove can be made uniform, but a steam generator such as a boiler is used. However, if the steam supply capacity is sufficient, there is no problem, but the one with a built-in heater and the one like a simple boiler such as a separate steam generator have a small heating capacity, so vacuum exhaust / steam replacement is required. Repeat To return there is a problem that the time is too take long.

[0013]

SUMMARY OF THE INVENTION In view of the above problems, the present invention was devised to solve the above problems, and infectious medical waste discharged from hospitals and the like and a treatment for storing it. It is possible to reliably sterilize the inner surface of the tank with high-pressure steam, and to prevent secondary infection of the hospital due to exhaust gas and drainage generated in the process of high-pressure steam sterilization in a short time, and the device It is a technical issue to be solved that low energy cost, small installation space, and elimination of auxiliary equipment such as a boiler are required.

[0014]

[Means for Solving the Problems] To solve the above-mentioned problems, technical means include a high-pressure steam sterilizer, a treatment tank which can be hermetically sealed with an object to be sterilized therein, and a drain accumulated in the treatment tank. A steam generator having a heater for generating high-temperature and high-pressure steam inside, which is installed at a position where it returns by natural fall, and a return pipe for returning the drain accumulated at the bottom of the processing tank to the steam generator, Steam supply pipe for supplying the steam generated by the steam generator to the processing tank,
Exhaust means for exhausting the gas in the processing tank and the steam generator, and a disinfecting mechanism for disinfecting the bacteria in the exhaust provided in the middle of an exhaust pipe constituting the exhaust means, For sterilizing the sterilization mechanism, means for supplying high-temperature and high-pressure steam generated by the steam generator to the sterilization mechanism, and a bypass pipe for bypassing the sterilization mechanism and exhausting it That is.

Further, after the substance to be sterilized is stored in the treatment tank and the treatment tank is sealed, the gas in the treatment tank and the steam generator is discharged through the sterilization mechanism, and the water supplied to the steam generator is supplied. Degassing step of preheating and degassing, and following this degassing step, the high temperature and high pressure steam is forced to flow through the sterilization mechanism, and the sterilization mechanism is maintained at high temperature and high pressure. By performing the first sterilization step of preheating the steam treatment tank, and following this first sterilization step, high temperature and high pressure steam is fed into the treatment tank to bring the inside of the treatment tank to a high temperature and high pressure state. A second sterilization step to maintain and this second
Subsequent to the sterilization process, the high-temperature and high-pressure steam in the processing tank is decompressed / cooled and discharged through the exhaust pipe to reduce the pressure in the processing tank, and cooling water is introduced to cool the processing tank. It is to adopt a high-pressure steam sterilization method consisting of a step-down / cooling process.

[0016]

According to the high-pressure steam sterilization apparatus and high-pressure steam sterilization method of the present invention configured as described above, the infectious microorganisms contained in the gas in the processing tank and the steam generator are exhausted from the gas. Infectious microorganisms that are reliably captured by the sterilization mechanism or attached to the inner surface of the pipe are sterilized in a short time by forcing high-pressure steam to flow through them and keeping them at high temperature and high pressure. Drain that has been treated and generated will not be returned to the steam generator, reheat sterilized and discharged.

The infectious microorganisms adhering to the treatment tank and the sterilized object stored in the treatment tank are also exhausted through the sterilization mechanism at the stage when the gas is accumulated at the bottom of the treatment tank, so that the temperature inside the treatment tank is increased. Can be uniformly distributed, and can be surely sterilized in a short time. The drain generated in the processing tank is returned to the steam generator and reheat sterilized, so that it is not discharged to the outside.

Further, by closing the on-off valve installed in the middle of the pipe connecting the treatment tank and the steam generator, it is possible to simultaneously exhaust the treatment tank, supply water to the steam generator and heat the same, thereby shortening the process time. In the case of continuous operation, the water supplied to the steam generator needs to be heated only by the amount of heat radiation, thus saving energy.

During sterilization of the sterilization mechanism, the throttling mechanism provided near the processing tank in the middle of the exhaust pipe is adjusted so that the sterilization mechanism and the inside of the pipe are maintained at high temperature and high pressure so that the inside can be sterilized. Adjust the amount of steam flowing through the system so that it can be made uniform within the system, and adjust the treatment so that the decrease in the liquid level in the steam generator during sterilization mechanism does not cause overheating of the heater. Since the tank is preheated, the heating time can be shortened, and the supply in the steam generator occurs because the pressure and temperature differences between the inside of the steam tank and the steam tank are large when switching to sterilization of the processing tank. It is possible to reduce the amount of water that bumps into water and flows into the treatment tank due to the end of the water.Therefore, it is possible to prevent the liquid level of the supply water in the steam generator from decreasing and prevent overheating of the heating heater. The capacity of the device can be reduced.

Further, since the steam generator is installed near the processing tank and the connection position of the return pipe connected to the steam generator is connected to just above the supply water limiting liquid level in the steam generator. Can be made compact, the drain can be returned to the steam generator in a short time, and the return pipe can be sterilized reliably, and steam can be supplied from the bottom of the processing tank, so the temperature rise time can be shortened and the temperature inside the processing tank can be reduced. Uniformity can be measured.

[0021]

The present invention will be described in more detail with reference to the illustrated embodiments. FIG. 1 is a circuit diagram showing an embodiment of a high-pressure steam sterilizer of the present invention. Reference numeral 1 denotes a processing tank, which is in a state in which an object to be sterilized 4 is housed and can be sealed by a lid device (not shown). A steam generator 2 has a heater 3 for generating steam inside. One end of a return pipe 5 is connected to the bottom of the processing tank 1, and the other end of the return pipe 5 is connected to the upper side surface of the steam generator 2. Further, an on-off valve 6 that can shut off the processing tank 1 and the steam generator 2 is provided in the middle of the return pipe 5, and a first drain pipe 7 branched to the processing tank 1 side of the on-off valve 6 is further provided. And an on-off valve 8 is provided.

Further, one end of a steam supply pipe 9 is connected to the upper surface of the steam generator 2 and the other end of the steam supply pipe 9 is connected to the upper side surface of the processing tank. An on-off valve 10 that can shut off the processing tank 1 and the steam generator 2 is provided in the middle of the steam supply pipe 9. Further, one end of the first exhaust pipe 11 is connected to the lower side surface of the processing tank 1, and the other end of the first exhaust pipe 11 is connected to the suction port of the exhaust device 12. In the middle of the first exhaust pipe 11, the processing tank 1
An opening / closing valve 15 is provided in parallel with the throttle valve 13 and the opening / closing valve 14 in order from the side, and the sterilization device 16 (in this embodiment, a sterilization filter), the opening / closing valve 17, the flow rate adjusting valve 18, and the check valve 19 are provided. It is provided.

On the upper surface of the steam generator 2, one end of a sterilization device sterilization pipe 20 is connected, and the other end of the sterilization device pipe 20 is connected to the outlet of the sterilization device 16 and the opening / closing valve 17. Connected to. In addition, the on-off valve 21 is the sterilization device sterilization pipe 2
It is connected in the middle of 0. Further, one end of a supply water pipe 22 is connected to the bottom surface of the steam generator 2, and the other end of the supply water pipe 22 is connected to a water supply source valve (not shown). An on-off valve 23 and a throttle valve 24 are provided in the supply water pipe 22 in this order from the steam generator 2 side. A second drainage pipe 25 is branched from the steam generator 2 side of the on-off valve 23 in the middle of the supply water pipe 22, and an on-off valve 26 is provided in the middle thereof. 27
Has a role of adjusting the liquid level of the supply water in the steam generator 2 by opening and closing the on-off valve 23 with a liquid level controller. Again 28
Has a function of adjusting the supply water temperature in the steam generator 2 to a predetermined temperature by operating or stopping the heater 3 with a temperature controller.

In addition, 29 is a safety valve, and 30 and 31 are pressure switches, which have a role of detecting the pressure in the steam generator 2 and displaying a high pressure and notifying a high pressure abnormality. Further, one end of a cooling water pipe 32 is connected to the upper side surface of the treatment tank 1, and the other end of the cooling water pipe 32 is connected to a water supply source valve (not shown). An opening / closing valve 33 and a throttle valve 34 are provided in the middle of the cooling water pipe 32 in this order from the treatment tank 1 side. Further, on the upper side surface of the processing tank 1, a vacuum release pipe 35
Is connected to one end, and the other end of the vacuum release pipe 35 is open to the atmosphere via a filter 38. In the middle of the vacuum release pipe 35, the on-off valve 3 is sequentially installed from the processing tank 1 side.
6 and a throttle valve 37 are provided.

Reference numeral 39 denotes a second exhaust pipe of the exhaust device 12,
One end of the second exhaust pipe 39 is connected to the exhaust port of the exhaust device 12, and the other end of the second exhaust pipe 39 is connected to the exhaust manifold 48. Further, one end of a water sealing pipe 40 is connected to the suction port of the exhaust device 12, and the other end of the water sealing pipe 40 is connected to a water supply valve (not shown). An on-off valve 41 and a throttle valve 42 are provided in the middle of the water sealing pipe 40 in this order from the exhaust device 12 side. Reference numeral 43 denotes a temperature indicator with setting, which has a role of displaying the temperature in the processing bath 1 and detecting the arrival of the sterilization temperature and the cooling end temperature of the internal temperature of the processing bath 1. Also, 44 and 45 are pressure switches, which have a function of confirming deaeration and confirmation of pressure reduction, respectively.

When sterilizing an object to be sterilized by the processing method of the present invention using the high-pressure steam sterilizer of the present invention configured as described above, it is carried out as follows. First, the object to be sterilized 4 is stored in the treatment tank 1, the treatment tank 1 is hermetically sealed, and then the water sealing pipe 40 connected to the suction port of the exhaust device 12 which is the water sealing pump in the embodiment of the present invention. On-off valve 41 provided in
After opening the valve, the exhaust device 12 is operated to open the on-off valve 1
5 and 17 are opened and the gas in the treatment tank 1 is exhausted through the sterilization device 16 and at the same time, the opening / closing valve 2 is placed in the steam generator 2.
After opening 3 and supplying water to the position set by the liquid level controller 27, the internal heater 3 preheats the supplied water. This preheating control method has a gas layer on the feed water in the steam generator 2 in the case of start-up operation, and the pressure in the steam generator 2 is steam at the feed water temperature in accordance with the law of partial pressure with the heating of the feed water. The pressure becomes equal to or higher than the saturation pressure, and the temperature rises to the set temperature of the temperature control device 28 depending on the deaeration time. In that case, the pressure in the steam generator 2 exceeds the maximum working pressure of the steam generator 2. In that case, the operation of the device is stopped due to a high pressure abnormality, or the pressure is released from the safety valve 29, which is a safety problem. If the maximum working pressure of the steam generator 2 and the treatment tank 1 is increased, the above problem can be solved, but the device itself becomes oversized and expensive. Therefore, the temperature controller 2 is controlled by the pressure switch 30.
It is controlled so that the preheating is stopped at an arbitrary pressure equal to or lower than the saturation pressure of steam at the set temperature of 8.

Next, the pressure in the processing tank 1 is set to the pressure set by the pressure switch 44 by exhausting (-60 cm in this embodiment).
When Hg) is reached, the on-off valve 10 is opened for a predetermined time to deaerate the preheated feed water of the steam generator 2, and the steam supply pipe 9 and the sterilization mechanism sterilization pipe 20 are exhausted. After the end of the predetermined time, the on-off valve 10 is closed and the treatment tank 1 is evacuated until the temperature of the supply water in the steam generator 2 reaches the temperature set by the temperature controller 28. After reaching the set temperature, the first On-off valve 1 provided in the middle of exhaust pipe 11
7 is closed, then the on-off valve 41 provided in the middle of the water sealing pipe 40 is closed, the exhaust device 12 is stopped, and the deaeration process is completed.

Next, opening / closing valves 21 and 14 provided in the middle of the sterilization mechanism sterilization pipe 20 and in the middle of the first exhaust pipe 11 are opened, and the steam generated in the steam generator 2 is The steam led to the outlet side of the sterilization mechanism 16 through the sterilization mechanism sterilization pipe 20 and passed through the sterilization mechanism 16 passes through the first exhaust pipe 11, the on-off valve 14, and the throttle valve 13 to be destroyed. It is pressurized and guided into the processing tank 1 to preheat the inside of the processing tank 1 and the object to be sterilized 4. Of the drain generated by heating with steam, the drain generated in the sterilization mechanism sterilization pipe 20 is returned to the steam generator 2, and the drain generated in the first exhaust pipe 11 is returned to the treatment tank 1 by natural fall. , Processing tank 1
Drain generated inside is accumulated at the bottom of the processing tank 1. The opening degree of the throttle valve 13 is the pressure difference between the steam generator 2 and the processing tank 1, the heating capacity of the heater 3 installed in the steam generator 2, the sterilization mechanism 16 and the sterilization mechanism sterilization. The heat capacity required for heating the working pipe 20 and the first exhaust pipe 11 to the sterilization temperature, the heat capacity lost by heat radiation during sterilization, the heat capacity necessary for preheating the treatment tank 1 and the object to be sterilized 4, and the steam generator. 2 and the amount of supplied water. Further, the throttle valve 13 in the present embodiment is not limited to this, and any valve having a throttle function may be used. The high-pressure steam generated in the steam generator 2 is forced to flow through the sterilization mechanism 16 and the first exhaust pipe 11 for a predetermined time by the above method, and the system is saturated with saturated steam by the throttle valve 13 at a temperature required for sterilization. By maintaining the pressure and the pressure, the inside of the system can be uniformly heated, and the infectious microorganisms captured by the sterilization mechanism 16 during the deaerating process and attached to the first exhaust pipe 11 are surely sterilized. The treatment tank 1 is also preheated, and the first sterilization step is completed.

Next, the on-off valves 10, 15 and 6 are opened to supply steam into the processing tank 1, and the infectious microorganisms accumulated in the first sterilization step may be mixed in the bottom of the processing tank 1. A low-temperature drain having a certain temperature is returned to the steam generator 2 through the return pipe 5 and reheat sterilization is performed. In the above operation, by sufficiently preheating the processing tank 1 and the object to be sterilized 4 in the first sterilization step, due to the pressure difference and temperature difference between the processing tank 1 and the steam generator 2 at the time of switching the above operation, It is possible to prevent a significant decrease in the liquid level in the steam generator 2 caused by the supply water accompanying the bumping development of the supply water in the steam generator 2 flowing into the processing tank 1, and the steam generated by the decrease in the liquid level. It is possible to prevent damage to the heater 3 due to overheating of the heater 3 installed inside the generator 2, and also to reduce the capacity of the steam generator 2 itself and shorten the heating time of the supply water.

Next, in an arbitrary state where the temperature and pressure in the processing tank 1 are equal to or higher than the boiling temperature and pressure of atmospheric pressure and lower than the sterilization temperature set by the temperature indicator with setting 43 (121 ° C. in this embodiment), Open / close valves 14, 1 for a predetermined time (1 minute in this embodiment)
7 and 41 are opened to operate the exhaust device 12, and the gas accumulated in the bottom portion of the processing tank 1 is depressurized, sterilized and cooled through the throttle valve 13, the sterilization mechanism 16 and the exhaust device 12, and is released to the atmosphere.
By this operation, it is possible to discharge the gas when the residual gas in the processing tank 1 is separated and accumulated at the bottom of the processing tank 1 due to the density difference between the vapor and the gas during the temperature rising period, and this operation is performed. If not, in some cases, after the temperature at the temperature detection sensor mounting position of the temperature indicator with setting 43 reaches the sterilization setting temperature (121 ° C. in this embodiment), gas accumulates in the processing tank 1 and the temperature rises. It took 20 to 30 minutes or more for the difficult bottom temperature to reach the sterilization set temperature.
By carrying out this operation, the sterilization temperature can be reliably reached in 3 to 4 minutes, and the temperature in the processing tank 1 can be made uniform in a short time.

When the second evacuation operation is completed, the sterilization temperature of the temperature indicator 43 with setting is adjusted to the sterilization temperature of the indicator 43 in the processing tank 1.
After the temperature at the mounting position of the temperature detection sensor reaches, the temperature in the processing tank 1 is maintained at the sterilization temperature or higher for a predetermined time, and the second sterilization step is completed.

Next, the on-off valve 41 is opened, the exhaust device 12 is operated and the on-off valves 47 and 14 are opened, and the vapor in the processing tank 1 is depressurized, cooled and discharged through the throttle valve 13 and the exhaust device 12. The pressure in the processing tank 1 is reduced. In this embodiment, the exhaust device 12 was opened to the atmosphere, but when the pressure source of the supply water is always higher than the pressure in the processing tank 1, the above operation is omitted and the opening / closing valve 33 is opened to cool the cooling water. 1 can be introduced to condense the steam and reduce the pressure, and the time can be shortened. Further, the pressure can be reduced even if the exhaust device 12 is opened without being operated, but there is a problem that high-temperature steam is emitted from the exhaust port and an odor is emitted. Since the exhaust device 12 of this embodiment uses a water-sealing type vacuum pump to condense and cool the exhaust steam by sealing water and dilute it, odor can be suppressed without emitting high-temperature steam from the discharge port. When the pressure in the processing tank 1 becomes equal to or lower than the atmospheric pressure, the opening / closing valves 14 and 47 are closed, the exhaust device 12 is stopped, and the opening / closing valve 41 is closed. After that, the on-off valve 33 is opened to introduce the cooling water into the treatment tank 1 to cool the treatment tank 1 and the object to be sterilized 4. After cooling starts and the temperature in the treatment tank 1 becomes equal to or lower than the boiling temperature of the atmospheric pressure of water, the opening / closing valve 36 is opened, and after a predetermined time elapses, the opening / closing valve 8 is opened to pass through the first drain pipe 7,
Discharge from the discharge manifold 48.

The above operation is carried out in the treatment tank 1 in the step of lowering pressure.
Even if the internal pressure decreases, the temperature in the processing tank does not decrease, and when cooling water is introduced into the processing tank, the cooling water is heated immediately after the introduction into high-pressure steam, and flows back into the vacuum release pipe 35 to generate high-temperature steam. This is to prevent the steam from coming out and to suppress the generation of steam and odor accompanying it at the outlet of the discharge port due to the high temperature cooling water. After the inside of the treatment tank 1 is cooled to a predetermined temperature, the on-off valve 33 is closed to stop the supply of cooling water, and the on-off valves 8 and 36 are opened for a predetermined time in order to discharge the cooling water accumulated in the treatment tank 1. The on-off valve is closed and the step-down cooling process is completed.

According to the high-pressure steam sterilizer and sterilization method of the present invention configured as described above, the treatment tank 1 is used in the first sterilization step.
The infectious microorganisms contained in the gas in the inside are caught in the disinfection mechanism 16 part or attached to the first exhaust pipe 11 and forced into the disinfection mechanism 16 and the first exhaust pipe 11. It is possible to sterilize reliably by keeping the inside of the system at a high temperature and high pressure necessary for sterilization, filling it with saturated steam, and making the inside a uniform temperature, while preheating the treatment tank 1 at the same time. I can. In the second sterilization step, the residual gas that cannot be completely discharged in the exhaust step is separated from the steam when the treatment tank 1 is heated, and is sterilized in a short time when the residual gas is accumulated at the bottom of the treatment tank 1. By exhausting the gas through the mechanism 16, it is possible to heat, raise the temperature and make the temperature uniform in the processing tank 1 in a short time.
Infectious microorganisms attached to the inside of the sterilized object 4 and the processing tank 1 are sterilized reliably. Further, the low temperature drain generated in the initial stage of the first and second sterilization steps is also returned to the steam generator 2 by a natural drop without being discharged to the outside of the apparatus, and is surely sterilized by reheating.

[0035]

As described above, according to the present invention, sterilization of infectious microorganisms mixed in gas and drain, and sterilization of infectious microorganisms attached to the object to be sterilized and the inner surface of the processing tank, the sterilization mechanism and the inner surface of the pipe. Since the treatment can be reliably performed, secondary infection can be surely prevented.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a high-pressure steam sterilizer of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Treatment tank 2 Steam generator 3 Heater 4 Object to be sterilized 5 Return pipe 6 Open / close valve 7 First drainage pipe 8 Open / close valve 9 Steam supply pipe 10 Open / close valve 11 First exhaust pipe 12 Exhaust device 13 Throttle valve 14 Open / close Valve 15 Open / close valve 16 Sterilization device 17 Open / close valve 18 Flow control valve 19 Check valve 20 Sterilization device sterilization pipe 21 Open / close valve 22 Supply water pipe 23 Open / close valve 24 Throttle valve 25 Second drainage pipe 26 Open / close valve 27 Liquid Position controller 28 Temperature controller 29 Safety valve 30 Pressure switch 31 Pressure switch 32 Cooling water pipe 33 On-off valve 34 Throttle valve 35 Vacuum release pipe 36 On-off valve 37 Throttle valve 38 Filter 39 Second exhaust pipe 40 Seal water pipe 41 On-off valve 42 Throttle valve 43 Temperature indicator with setting 44 Pressure switch 45 Pressure switch 46 Bypass piping 47 Open / close valve 48 Discharge In manifold

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazutaka Fujihira 1-30 Oyama-cho, Sagamihara-shi, Kanagawa Nippon Metal Industry Co., Ltd. Sagamihara Factory (72) Inventor Kisaburo Yukimura Yatomi-cho, Kaifu-gun, Aichi Prefecture Mae Nitta 86-12 (72) Inventor Toshiro Asaoka 46, 51, Manganji, Hashizume, Inuyama, Aichi

Claims (4)

[Claims] 1. A treatment tank which can be hermetically sealed with a substance to be sterilized inside, and a drain which collects in the treatment tank and is set at a position where the drain can be returned by a natural fall to generate high temperature and high pressure steam inside. A steam generator having a heater, a return pipe for returning the drain accumulated at the bottom of the processing tank to the steam generator, and a steam supply pipe for supplying the steam generated by the steam generator to the processing tank An exhaust means for exhausting the gas in the processing tank and the steam generator, and a disinfection mechanism for disinfecting the bacteria in the exhaust provided in the middle of an exhaust pipe constituting the exhaust means. A means for supplying high temperature and high pressure steam generated by the steam generator to the sterilization mechanism for sterilization of the sterilization mechanism, and a bypass pipe for exhausting the sterilization mechanism by bypassing it. A high-pressure steam sterilizer. 2. In the means for sterilizing the disinfection mechanism with high-temperature high-pressure steam, on-off valves are arranged in parallel in the exhaust pipe downstream of the disinfection mechanism as seen from the steam generator, and one of the A throttling mechanism is arranged in series with the on-off valve, and the on-off valve is selectively switched so that steam is forced to flow into the system by the throttling mechanism, and the inside of the system can be maintained at high temperature and high pressure. 2. The high-pressure steam sterilizer according to claim 1, which has a mechanism capable of performing sufficient preheating. 3. A sterilizing object is housed in a treatment tank, the treatment tank is sealed, and then the gas in the treatment tank and in the steam generator is discharged through a sterilization mechanism, and the supply water in the steam generator is supplied. Degassing step of preheating and degassing, and following this degassing step, the high temperature and high pressure steam is forced to flow through the sterilization mechanism, and the sterilization mechanism is maintained at high temperature and high pressure. By performing the first sterilization step of preheating the steam treatment tank, and following this first sterilization step, high temperature and high pressure steam is fed into the treatment tank to bring the inside of the treatment tank to a high temperature and high pressure state. A second sterilization step of maintaining, and subsequent to this second sterilization step, high-temperature and high-pressure steam in the processing tank is decompressed and cooled through an exhaust pipe to be discharged, and the pressure in the processing tank is reduced to cool. It consists of a step-down / cooling process in which water is introduced to cool the inside of the processing tank. , High-pressure steam sterilization method. 4. High-temperature and high-pressure steam is fed into the processing tank,
When the temperature and pressure in the treatment tank reaches an arbitrary state that is equal to or higher than the boiling temperature and saturation pressure of water under atmospheric pressure and equal to or lower than the sterilization temperature, the gas accumulated at the bottom of the treatment tank for a predetermined time is exhausted and removed. The high-pressure steam sterilization method according to claim 3, wherein the high-pressure steam sterilization is performed by discharging the bacteria through a bacterial mechanism and then maintaining the inside of the processing tank at a high temperature and high pressure.