JP6970906B2 - Steam sterilizer - Google Patents

Description

The present invention relates to a steam sterilization equipment to sterilize an object to be sterilized with steam.

As is well known, a steam sterilizer is a device that stores an object to be sterilized in a sterilization tank and sterilizes it with steam. In addition, after sterilization, the pressure inside the sterilization tank is usually reduced to dry the object to be sterilized.

In such a steam sterilizer, a steam jacket is typically provided on the outer wall of the sterilizer. Then, steam is supplied to the steam jacket and maintained at a predetermined pressure in preparation for the next sterilization operation not only during a series of sterilization operations until the end of the drying process but also after the sterilization operation.

However, for example, when the last sterilization operation is started at the end of work and the person returns home, the steam supply (steaming) to the steam jacket is wasted for a long time until the start of work the next morning after the sterilization operation is completed. It will be continued. In this case, the energy loss due to heat dissipation becomes large, and the object to be sterilized left in the sterilization tank may be deteriorated by heat.

On the other hand, conventionally, as disclosed in Patent Document 1 below, a steam sterilizer that stops steaming to a steam jacket from the end of the sterilization operation to the start of the next sterilization operation is known. .. However, simply stopping the steaming to the steam jacket is not sufficient to prevent thermal deterioration of the object to be sterilized. In addition, if the door of the sterilization tank is left closed for a long time even after the sterilization operation, the water remaining in the piping etc. evaporates, the humidity in the sterilization tank increases, and condensation occurs when the object to be sterilized is taken out. It causes. In order to deal with such inconvenience, if the blow operation of operating the water-sealed vacuum pump is continued with the air supply valve into the sterilization tank open, the amount of electricity and water used in the vacuum pump Will increase.

Further, if the steaming to the steam jacket is stopped at the end of the sterilization operation, a warm-up operation is required prior to the next sterilization operation, for example, at the start of work the next morning. Regarding this point, conventionally, as disclosed in Patent Document 2 below, it has been proposed to perform warm-up operation when the time from when the power switch is turned off last time to when the power switch is turned on this time is a predetermined time or more. There is. However, it is premised that the power switch is turned off and on, and it cannot support night operation after the end of work and automatic startup before the start of work.

Further, the conventional warm-up operation is performed by supplying steam to the inside of the sterilization tank and the steam jacket without accommodating the object to be sterilized in the sterilization tank and with the door of the sterilization tank closed. Therefore, it is necessary to take out the object to be sterilized from the sterilization tank and close the door of the sterilization tank in advance. However, as described above, if the object to be sterilized in the final operation at the end of the previous day is still contained in the sterilization tank, the warm-up operation cannot be automatically performed. If the sterilizer is housed in the sterilizer, the door of the sterilizer is closed and the warm-up operation is performed, the sterilizer will be reheated.

JP 2011-245220 (Claim 1) JP-A-10-127740 (Claims 1, 3, paragraphs [0040]-[0041], [0059]-[0061])

The problem to be solved by the present invention is to prevent the steam supply to the steam jacket or the like from being unnecessarily continued for a long time after the sterilization operation is completed, to prevent energy loss, and to prevent the object to be sterilized. The purpose is to prevent thermal deterioration. Another object is to prevent the humidity in the sterilization tank from rising after the sterilization operation is completed. Further, when desired, for example, before starting work, the sterilization tank can be automatically heated to prepare for the sterilization operation. At that time, even if the sterilized material remains in the sterilization tank in the previous operation, the sterilized material can be sterilized. The task is to prevent the object from being heated unnecessarily.

The present invention has been made to solve the above problems, and the invention according to claim 1 is a sterilization tank in which an object to be sterilized is stored and steam is supplied to sterilize the object to be sterilized, and this sterilization. The presence or absence of heating of the sterilization tank provided on the outer wall of the tank and to which steam is supplied to heat the inside of the sterilization tank and the steam supply from the first boiler to the steam jacket or the steam pipe. The steam supply means that can be switched and the presence / absence of steam supply from the steam jacket, the steam pipe, the first boiler or the second boiler to the sterilization tank, and the gas in the sterilization tank are externally switched. The sterilization is performed by the differential pressure between the depressurizing means for sucking and discharging the inside of the sterilization tank to reduce the pressure, the repressurizing means for introducing outside air into the depressurized sterilization tank to repressurize the inside of the sterilization tank, and the atmospheric pressure. The exhaust means for discharging the gas in the tank to the outside and the respective means are controlled to heat the inside of the sterilization tank by the steam jacket or the steam pipe, and supply steam to the sterilization tank to supply the steam to the subject. The sterilization step of sterilizing the sterilized material, the exhaust step of discharging steam from the sterilization tank with the steam supply to the sterilization tank stopped, and the drying step of drying the sterilized material are executed at least in sequence. In the drying step, the inside of the sterilization tank is depressurized to a set drying pressure by the depressurizing means to vacuum dry the object to be sterilized, or the depressurizing means is depressurized and the depressurizing means is depressurized. Pulse drying that repeats the above steps, or blow drying that keeps the depressurizing means operating for a set drying time while allowing the introduction of outside air into the sterilization tank by the repressurizing means, or two or more of these. The control means is a step of steam sterilizing the object to be sterilized in the sterilization tank, stopping the heating of the sterilization tank by the steam jacket or the steam tube, and after the drying step is completed. It is a steam sterilization apparatus characterized in that the door of the sterilization tank is automatically opened while the pressure inside the sterilization tank is set to atmospheric pressure.

According to the invention of claim 1, after steam sterilizing the object to be sterilized in the sterilization tank, a steam jacket or a steam tube (in the present specification, when simply referred to as "steam tube", a sterilization tank is used instead of the steam jacket. The heating of the sterilization tank by the steam pipe provided on the outer wall) is stopped, and the door of the sterilization tank is automatically opened after the drying process is completed. Energy loss can be prevented by stopping the heating of the sterilization tank by the steam jacket or steam tube. Further, by stopping the heating of the sterilizing tank by the steam jacket or the steam tube and automatically opening the door of the sterilizing tank after the drying step is completed, it is possible to prevent the thermal deterioration of the object to be sterilized in the sterilizing tank. Further, by opening the door of the sterilization tank, it is possible to prevent the humidity in the sterilization tank from rising and prevent dew condensation on the object to be sterilized.

In the invention according to claim 2 , the decompression means includes an air supply valve in the air supply path into the sterilization tank, and the control means is the steam jacket or the steam pipe after the completion of the drying step. It is characterized in that the heating of the sterilization tank is stopped, the blow operation for operating the depressurizing means is performed with the air supply valve open, and then the depressurizing means is stopped and the door is opened. The steam sterilizer according to claim 1.

According to the second aspect of the present invention, after the drying step is completed, the heating of the sterilization tank by the steam jacket or the steam tube is stopped, and the blow operation for operating the decompression means with the air supply valve open is carried out. This makes it possible to ventilate the sterilization tank and cool the object to be sterilized. After that, by stopping the depressurizing means and opening the door, it is possible to prevent thermal deterioration of the object to be sterilized and to prevent dew condensation on the object to be sterilized.

Claim The invention according to claim 3, wherein, wherein said after a set waiting time from the end of the drying process, stopping the heating of the sterilization chamber by the steam jacket or the steam pipe 1 or the steam sterilization apparatus according to claim 2.

According to the third aspect of the present invention, the heating of the sterilization tank by the steam jacket or the steam tube is stopped after the set waiting time has elapsed from the end of the drying step. After the drying step is completed, the steam jacket or the steam pipe is steamed for a while, and the heating in the sterilization tank is continued, so that the object to be sterilized can be surely dried.

Invention according to claim 4, wherein, steam according to claim 2, wherein the blowing operation after performing setting blowdown time, characterized in that opening the door to stop the pressure reducing means It is a sterilization device.

According to the fourth aspect of the present invention, by carrying out the blow operation for the set blow time, it is possible to prevent the decompression means from being unnecessarily operated.

The invention according to claim 5 is characterized in that, at a setting timing after the door is opened, the control means resumes heating of the sterilization tank by the steam jacket or the steam tube while keeping the door open. The steam sterilizer according to any one of claims 1 to 4.

According to the invention of claim 5, after opening the door of the sterilization chamber stops the heating of the sterilization chamber with steam jacket or a steam tube, sterilized at set timings, by leaving the steam jacket or steam pipe was opened the door Resume heating the tank. As a result, the sterilization tank can be automatically heated to prepare for the sterilization operation when desired, for example, before the start of work. Moreover, even if the object to be sterilized remains in the sterilization tank in the previous operation, the door remains open, so there is no risk of unnecessarily reheating the object to be sterilized.

The invention according to claim 6 is capable of switching between a first operation mode and a second operation mode by an operation panel. In the first operation mode, after the drying step is completed , the steam jacket or the steam pipe is used. The steam jacket is not opened until the door opening command from the operation panel is received, and in the second operation mode, after the drying step is completed, the heating in the sterilization tank is continued. Alternatively, any one of claims 1 to 5 , wherein the heating in the sterilization tank by the steam pipe is stopped, and the door of the sterilization tank is opened without receiving a door opening command from the operation panel. The steam sterilizer according to the section.

According to the invention of claim 6 , by switching the operation mode, whether or not to stop the heating in the sterilization tank by the steam jacket or the steam tube after the completion of the drying step, and to automatically set the door of the sterilization tank. It is possible to switch whether to open or not. For example, in the daytime, as the first operation mode, even after the drying process is completed , the inside of the sterilization tank is continuously heated by the steam jacket or the steam tube, and the door of the sterilization tank is opened until the door opening command is received from the operation panel. By not doing so, it is convenient to repeat the sterilization operation. On the other hand, in the final sterilization operation at the end of work, as the second operation mode, after the drying process is completed , the heating in the sterilization tank by the steam jacket or the steam pipe is stopped, and the door opening command is received from the operation panel. By opening the door of the sterilization tank without doing so, the same functions and effects as those of the invention described in each of the above claims can be obtained.

The invention according to claim 7 is such that the steam jacket or the steam pipe is configured to be capable of generating steam by internally heating water supply, and by supplying steam from the first boiler to the steam jacket or the steam pipe. instead of controlling the presence or absence of heating of the sterilization chamber, any of claims 1 to 6, characterized by controlling the presence or absence of heating of the sterilization chamber with steam generated in the steam jacket or the steam pipe The steam sterilizer according to item 1.

According to the invention of claim 7, instead of controlling the presence or absence of heat sterilization chamber with steam supplied to the steam jacket or steam pipes, heat sterilization chamber with steam generated in the steam jacket or a steam pipe By controlling the presence or absence of the above-mentioned invention, the same effect as that of the invention described in each of the above-mentioned claims can be obtained.

The invention according to claim 8 is the steam sterilization apparatus according to any one of claims 1 to 7 , wherein the door is a shutter type or a slide type.

According to the eighth aspect of the present invention, since the door of the sterilization tank is not a swing type but a shutter type or a slide type, the door can be easily and safely opened automatically.

According to steam sterilization equipment of the present invention, after sterilization operation end, feeding steam to such a steam jacket for a long time is prevented from being uselessly continued, thereby preventing the energy loss, object to be sterilized It is possible to prevent thermal deterioration of. Further, it is possible to prevent the humidity in the sterilization tank from rising because the door of the sterilization tank is not opened for a long time after the sterilization operation is completed. Further, when desired, for example, before starting work, the sterilization tank can be automatically heated to prepare for the sterilization operation. At that time, even if the sterilized material remains in the sterilization tank in the previous operation, the sterilized material can be sterilized. Does not heat things unnecessarily.

It is a schematic diagram which shows the steam sterilization apparatus of one Example of this invention, and shows a part in a cross section. It is a flowchart which shows an example of the operation process of the steam sterilization apparatus of FIG. It is a flowchart which shows an example of the post-processing process in FIG.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing a steam sterilizer 1 according to an embodiment of the present invention, and is partially shown in cross section.

The steam sterilizer 1 of this embodiment includes a sterilization tank 2 in which an object to be sterilized (not shown) is housed, a steam jacket 3 provided on the outer wall of the sterilization tank 2 and heating the inside of the sterilization tank 2 from the outside. A depressurizing means 4 that sucks and discharges the gas in the sterilizing tank 2 to the outside to reduce the pressure in the sterilizing tank 2, and a depressurizing means 5 that introduces outside air into the depressurized sterilizing tank 2 to repressurize the inside of the sterilizing tank 2. , The steam supply means 6 that supplies steam to the inside of the sterilization tank 2 and the steam jacket 3, the drain discharge means 7 that discharges the condensed water of steam from the sterilization tank 2, and the inside of the sterilization tank 2 by the differential pressure with the atmospheric pressure. The exhaust means 8 for discharging the gas to the outside and the control means (not shown) for controlling each of these means are provided.

The object to be sterilized is not particularly limited, but is typically a medical device. The object to be sterilized is usually housed in the sterilization tank 2 in a state of being put in a packaging material such as a sterilization bag or a sterilization container. As a result, even if the door of the sterilization tank 2 is opened after sterilization, recontamination of the object to be sterilized is prevented. The object to be sterilized is placed on a shelf in the sterilization tank 2 or placed on a trolley and housed in the sterilization tank 2 together with the trolley.

The sterilization tank 2 is a hollow container that can withstand depressurization and pressurization of the internal space, and is typically formed in a substantially rectangular box shape. The sterilization tank 2 of this embodiment is provided with a door (not shown) for taking in and out the object to be sterilized on the front surface (front side perpendicular to the paper surface of FIG. 1). However, doors are provided on the front and back respectively, one door is used as a carry-in door for putting the object to be sterilized in the sterilization tank 2, and the other door is used as a carry-out door for taking out the object to be sterilized outside the sterilization tank 2. It may be a door. In any case, by closing the door, the opening of the sterilization tank 2 can be closed airtightly. That is, the gap between the sterilization tank 2 and the door is sealed with packing (not shown).

In this embodiment, the door can be opened and closed automatically. Specifically, the steam sterilizer 1 includes a door opening / closing mechanism (not shown), and the door is automatically opened / closed by controlling the door opening / closing mechanism by a control means. In order to easily and safely realize automatic opening and closing, it is preferable that the door is a shutter type or a sliding type instead of a swing type. That is, it is preferable that the door is not opened and closed like a hinged door, but is moved up and down or left and right to be opened and closed. However, the door may be closed manually as long as it can be opened and closed automatically, at least if it can be opened automatically.

The steam jacket 3 is provided on the outer wall of the sterilization tank 2, and steam is supplied to heat the inside of the sterilization tank 2 from the outside. Specifically, the steam sterilizer 1 includes an inner can 9 and an outer can 10 surrounding the inner can 9, and the sterilization tank 2 is composed of the inner can 9, and the gap between the inner can 9 and the outer can 10 is a steam jacket. It is set to 3. In this embodiment, the steam jacket 3 is continuously provided on the upper, lower, left, and right walls of the sterilization tank 2.

The depressurizing means 4 sucks and discharges the gas in the sterilization tank 2 to the outside through the vacuum exhaust passage 11. The vacuum exhaust passage 11 from the inside of the sterilization tank 2 is provided with a vacuum valve 12, a first check valve 13, a water-sealed vacuum pump 14, and a second check valve 15 in this order. Further, the vacuum exhaust passage 11 may be provided with a heat exchanger for steam condensing on the inlet side of the vacuum pump 14 (between the first check valve 13 and the water-sealed vacuum pump 14). .. By opening the vacuum valve 12 and operating the vacuum pump 14, the gas in the sterilization tank 2 can be sucked and discharged to the outside to reduce the pressure in the sterilization tank 2. At that time, when the heat exchanger for steam condensation is provided, the steam from the inside of the sterilization tank 2 can be condensed by passing cooling water through the heat exchanger. As is well known, when the water-sealed vacuum pump 14 operates, water-sealed water is supplied to the vacuum pump 14.

The decompression means 5 introduces outside air into the sterilization tank 2 under reduced pressure via the air supply passage 16. An air filter 17, an air supply valve 18, and a check valve 19 are sequentially provided in the air supply passage 16 into the sterilization tank 2. When the air supply valve 18 is opened while the inside of the sterilization tank 2 is depressurized, the outside air can be introduced into the sterilization tank 2 by the differential pressure to repressurize the inside of the sterilization tank 2. At that time, the air filter 17 can introduce clean air into the sterilization tank 2. If the air supply valve 18 is configured so that the opening degree can be adjusted, the pressure in the sterilization tank 2 can be gradually restored.

The steaming means 6 supplies steam (saturated steam) from the steam generation source to the inside of the sterilization tank 2 and the steam jacket 3. In this embodiment, the presence / absence of steaming in the sterilization tank 2 can be switched, and the presence / absence of steaming in the steam jacket 3 can be switched. The steam generation source is not particularly limited and may be a fuel-fired boiler, but in this embodiment, it is an electric boiler 20.

As is well known, the electric boiler 20 is configured by inserting a plurality of electric heaters 22 from above into a can body 21 provided with a water pipe in the illustrated example. Further, the electric boiler 20 is provided with a water level detector 23 in order to monitor the water level in the can body 21. Further, a water supply channel 24 is connected to the lower part of the can body 21, and a water supply pump 25 is provided in the water supply channel 24. By controlling the water supply into the can body 21 (here, the water supply pump 25 is controlled) based on the detection signal of the water level detector 23, the water level in the can body 21 can be maintained as desired. A drainage channel 26 is also connected to the lower part of the can body 21, and the drainage channel 26 is provided with a drainage valve 27 and a check valve 28.

In the case of this embodiment, steam from the electric boiler 20 can be supplied to the sterilization tank 2 and the steam jacket 3 as follows. That is, first, in the electric boiler 20, the stored water (typically soft water) in the can body 21 is heated by the electric heater 22 to be steam. The steam is supplied to the steam jacket 3 from the upper part of the can body 21 via the first steam supply passage 29. In this embodiment, the inside of the steam jacket 3 and the inside of the can body 21 are always in communication with each other. Therefore, by controlling the electric heater 22 based on the detection pressure of the outer can pressure sensor 30 (which can also be called a boiler pressure sensor) provided in the first steam supply passage 29 (or the steam jacket 3 or the can body 21), The pressure in the steam jacket 3 and thus the temperature can be adjusted as desired. In this embodiment, the electric heater 22 is on / off controlled, but the output may be controlled in some cases.

Then, in this embodiment, the steam in the steam jacket 3 can be supplied into the sterilization tank 2 via the second steam supply passage 31. That is, in this embodiment, the steam jacket 3 and the sterilization tank 2 are connected by the second steam supply passage 31, and the steam from the electric boiler 20 is sterilized through the steam jacket 3 and the second steam supply passage 31. It is possible to supply within 2. The second steam supply passage 31 is provided with an inner can steam supply valve 32 and a check valve 33 from the steam jacket 3 to the sterilization tank 2. In this embodiment, the opening and closing of the inner can steam supply valve 32 is controlled, but the opening degree may be adjusted as the case may be. In the case of the illustrated example, the downstream side of the second steam supply channel 31 (the connection side to the sterilization tank 2) is the downstream side of the air supply channel 16 and the common pipeline 34. In other words, the second steam supply passage 31 downstream from the check valve 33 is connected to the air supply passage 16 downstream from the check valve 19.

By the way, in this embodiment, the condensed water of steam supplied to the steam jacket 3 is returned to the electric boiler 20 via the drain return path 35. Specifically, the lower part of the steam jacket 3 (outer can 10) and the lower part of the electric boiler 20 (can body 21) are connected by a drain return path 35. In the case of the illustrated example, the downstream side of the drain return path 35 (the connection side to the electric boiler 20) is the downstream side of the water supply channel 24 and the common pipeline 36. In other words, the water supply channel 24 downstream from the water supply pump 25 is connected to the drain return path 35 from the steam jacket 3 to the electric boiler 20.

Further, the steam jacket 3 is provided with an air vent 37 and a vacuum break valve 38. The air vent 37 is an air vent valve, and automatically discharges the air in the steam jacket 3 to the outside when steaming to the steam jacket 3. Further, the vacuum break valve 38 introduces outside air into the steam jacket 3 when the inside of the steam jacket 3 becomes a vacuum. After the steam supply to the steam jacket 3 is stopped, even if the steam in the steam jacket 3 is condensed and the pressure inside the steam jacket 3 becomes lower than the atmospheric pressure, the vacuum state is released by the air supply by the vacuum break valve 38.

The drain discharge means 7 discharges condensed steam water from the sterilization tank 2 via the drain discharge passage 39. A steam trap 40 and a check valve 41 are sequentially provided in the drain discharge path 39 from the sterilization tank 2. While the steam is being supplied into the sterilization tank 2 by the steaming means 6, the condensed water of the steam is discharged to the outside of the sterilization tank 2 by the drain discharge means 7.

The exhaust means 8 draws a fluid from the sterilization tank 2 under pressure via the exhaust passage 42. An exhaust valve 43 and a check valve 44 are sequentially provided in the exhaust passage 42 from the inside of the sterilization tank 2. When the exhaust valve 43 is opened while the inside of the sterilization tank 2 is pressurized, the gas in the sterilization tank 2 can be led out to the outside by the differential pressure, and the pressure in the sterilization tank 2 can be reduced.

In the illustrated example, the vacuum exhaust passage 11, the drain discharge passage 39, and the exhaust passage 42 are set as a common pipeline 45 on the upstream side (the connection side to the sterilization tank 2). Further, the vacuum exhaust passage 11, the drain discharge passage 39, and the exhaust passage 42 are set as a common pipeline 46 on the downstream side of the check valves 15, 41, 44, respectively.

In addition, the sterilization tank 2 is provided with an inner can pressure sensor 47 for detecting the pressure in the sterilization tank 2 and an inner can temperature sensor 48 for detecting the temperature in the sterilization tank 2. The installation position of the inner can pressure sensor 47 is not particularly limited, but is provided on the side of the sterilization tank 2 as shown in the illustrated example. On the other hand, the inner can temperature sensor 48 is provided at a predetermined position in accordance with various standards for sterilization. In the illustrated example, the inner can temperature sensor 48 is provided at the outlet portion from the sterilization tank 2 in the common pipeline 45 (common pipeline between the vacuum exhaust passage 11 and the drain discharge passage 39 and the exhaust passage 42).

The control means is a controller (not shown) that controls each means based on the detection signal of each sensor, the elapsed time, and the like. Specifically, a vacuum valve 12, a vacuum pump 14, an air supply valve 18, an electric boiler 20 (particularly its electric heater 22), a water supply pump 25, a drain valve 27, an inner can steam supply valve 32, an exhaust valve 43, and an outer can. The pressure sensor 30, the inner can pressure sensor 47, the inner can temperature sensor 48, and the like are connected to the controller. Then, as described below, the controller attempts to sterilize the object to be sterilized in the sterilization tank 2 and then dry it according to a predetermined procedure (program).

The controller is also connected to an operation panel (not shown), and by the user operating this operation panel, in addition to starting the operation, opening or closing of the door is instructed as desired. When the controller is instructed to start operation, the controller sequentially executes each process described later. Further, when the controller receives the door opening command or the door closing command, the controller controls the door opening / closing mechanism to open or close the door.

Hereinafter, a specific example of the operation method of the steam sterilizer 1 of this embodiment will be described.
FIG. 2 is a flowchart showing an example of an operation process of the steam sterilizer 1 of this embodiment. As shown in this figure, the steam sterilizer 1 typically sequentially executes a preheating step S1, a pretreatment step S2, a sterilization step S3, an exhaust step S4, a drying step S5, and a posttreatment step S6. Hereinafter, each step will be described. In the initial state, the air supply valve 18 and the exhaust valve 43 are open, while the other valves 12, 27, 32 are closed, and the vacuum pump 14, the electric boiler 20, and the like are stopped. .. Then, at the latest, until the start of the pretreatment step S2 (that is, during or before or after the preheating step S1), the object to be sterilized is housed in the sterilization tank 2, and the door of the sterilization tank 2 is airtightly closed. At that time, the air supply valve 18 and the exhaust valve 43 are also closed.

In the preheating step S1, the inside of the sterilization tank 2 is preheated. The preheating step S1 is started based on the power on of the steam sterilizer 1 or a subsequent instruction from the operation panel, or at a predetermined set timing as described later. In the preheating step S1, the electric boiler 20 is activated to generate steam, and the steam is supplied to the steam jacket 3 to heat the inside of the sterilization tank 2 from the outside.

During the operation of the electric boiler 20, the water supply pump 25 is controlled based on the detection signal of the water level detector 23 to maintain the water level in the can body 21 as desired. Further, the electric heater 22 is controlled based on the detected pressure of the outer can pressure sensor 30 to maintain the inside of the steam jacket 3 at a predetermined pressure (in other words, a predetermined temperature). During steaming from the electric boiler 20 to the steam jacket 3, the air in the steam jacket 3 is discharged from the air vent 37. Further, the condensed water of steam supplied to the steam jacket 3 is returned to the electric boiler 20 via the drain return path 35.

After a predetermined time has elapsed from the start of the preheating step S1 (and / or based on the instruction from the operation panel), the pretreatment step S2 is started. However, the content of the preheating step S1 (that is, heating of the sterilization tank 2 by steaming to the steam jacket 3) is continuously carried out at least until the end of the drying step S5. Further, as described above, by the start of the pretreatment step S2, the object to be sterilized is housed in the sterilization tank 2, and the door of the sterilization tank 2 is airtightly closed. The target pressure in the steam jacket 3 may be changed depending on the process and the like.

In the pretreatment step S2, the air in the sterilization tank 2 is removed. Specifically, the pressure in the sterilization tank 2 is reduced by the depressurizing means 4, but at that time, steaming by the steaming means 6 may be accompanied. Further, after depressurizing the inside of the sterilization tank 2 by the depressurizing means 4, steaming by the steaming means 6 and depressurizing by the depressurizing means 4 may be repeated, or the pressure exceeds the atmospheric pressure by the steaming by the steaming means 6. When pressurizing the inside of the sterilization tank 2, steaming by the steaming means 6 and exhausting by the exhaust means 8 may be repeated. The steaming into the sterilization tank 2 by the steaming means 6 is performed by opening the inner can steaming valve 32 in this embodiment.

In any case, after the air is removed from the sterilization tank 2, the inside of the sterilization tank 2 is finally boosted to the sterilization pressure by steaming by the steaming means 6. Then, when the detection temperature of the inner can temperature sensor 48 becomes the sterilization temperature or the detection pressure of the inner can pressure sensor 47 becomes the sterilization pressure, the process proceeds to the next step.

In the sterilization step S3, the object to be sterilized in the sterilization tank 2 is sterilized with steam. Specifically, the steaming means 6 (more specifically, the inner can feeding in this embodiment) so that the detection temperature of the inner can temperature sensor 48 maintains the sterilization temperature (typically 121 ° C. or 135 ° C.). By controlling the steam valve 32) and holding the sterilization time, the object to be sterilized in the sterilization tank 2 is sterilized. Alternatively, the steam supply means 6 (inner can steam supply valve 32) is controlled to maintain the sterilization time so that the detection pressure of the inner can pressure sensor 47 maintains the sterilization pressure (saturated steam pressure equivalent to the sterilization temperature). Then, the object to be sterilized in the sterilization tank 2 is sterilized. After that, the steaming to the inside of the sterilization tank 2 by the steaming means 6 is stopped, and the process proceeds to the next step.

In the exhaust step S4, steam is discharged from the sterilization tank 2 under pressure to reduce the pressure in the sterilization tank 2 to the vicinity of atmospheric pressure. Specifically, the exhaust valve 43 is opened to discharge steam to the outside of the sterilization tank 2. When the set exhaust time elapses from the opening of the exhaust valve 43 or the pressure in the sterilization tank 2 drops to the set exhaust pressure (atmospheric pressure or a pressure slightly higher than that), the exhaust valve 43 is closed and the process proceeds to the next process. do.

In the drying step S5, the object to be sterilized in the sterilization tank 2 is dried. Specifically, the inside of the sterilization tank 2 is vacuum-dried by depressurizing the inside of the sterilization tank 2 to the set drying pressure (the capacity limit of the decompression means 4 may be sufficient) and holding the set drying time. Let (continuous vacuum drying). However, in the drying step S5, the depressurization to the set drying pressure by the depressurizing means 4 and the repressurizing to near the atmospheric pressure by the repressurizing means 5 may be repeated (pulse drying). Alternatively, the depressurizing means 4 may continue to operate for a set drying time with the air supply valve 18 open (blow drying). Of course, any two or more of these continuous vacuum drying, pulse drying, blow drying and the like may be carried out in an appropriate order. In any case, after the object to be sterilized is dried, the depressurizing means 4 is stopped, while the pressure reducing means 5 restores the pressure inside the sterilization tank 2 to atmospheric pressure, and the process proceeds to the next step.

In the post-treatment step S6, the steam supply to the steam jacket 3 is stopped, and the door of the sterilization tank 2 is automatically opened. That is, in this embodiment, the electric boiler 20 (more specifically, the electric heater 22) is stopped, and the door is opened without receiving a door opening command from the operation panel. The steam supply to the steam jacket 3 may be stopped at the start of the post-treatment step S6 (that is, at the end of the drying step S5), or may be delayed thereafter. Further, the door may be opened when the steam supply to the steam jacket 3 is stopped, or before or after that.

FIG. 3 is a flowchart showing an example of the post-processing step S6. As shown in this figure, the post-treatment step S6 is typically carried out as follows. That is, after the set waiting time (for example, 5 minutes) has elapsed from the end of the drying step S5 (S61), the steaming to the steam jacket 3 (in other words, heating of the sterilization tank 2) is stopped (S62), preferably blown. The operation is carried out (S63). By continuing heating in the sterilization tank 2 for a while after the completion of the drying step S5, it is possible to reliably dry the object to be sterilized. After that, the blow operation is performed with the steaming to the steam jacket 3 stopped.

In the blow operation (S63), the decompression means 4 is operated with the air supply valve 18 open to ventilate the inside of the sterilization tank 2. After the blow operation is performed for the set blow time, the decompression means 4 is stopped and the door is automatically opened (S64). In this embodiment, the door is fully open. In the case of the double-door type steam sterilizer 1 having front and rear doors, either one or both doors are opened. The set blow time is, for example, in the range of 1 to 99 minutes and can be set in advance by the operation panel.

Therefore, for example, even when the operator starts the final sterilization operation at the end of work and returns home without waiting for the end of this operation, the steaming to the steam jacket 3 is stopped after the drying step S5 is completed. , Energy loss can be prevented. Further, by stopping the steaming to the steam jacket 3 and automatically opening the door of the sterilization tank 2, it is possible to prevent the thermal deterioration of the object to be sterilized in the sterilization tank 2. Moreover, by performing a blow operation in which the decompression means 4 is operated with the air supply valve 18 open, ventilation in the sterilization tank 2 and cooling of the object to be sterilized can be achieved. Further, by opening the door of the sterilization tank 2, it is possible to cool the object to be sterilized without using the decompression means 4 (electricity or water). Moreover, it is possible to prevent an increase in humidity in the sterilization tank 2 and prevent dew condensation on the object to be sterilized.

After the completion of the post-treatment step S6 as described above, the preheating step S1 may be restarted at a set timing, if desired. That is, in the post-treatment step S6, after the steaming to the steam jacket 3 is stopped and the door of the sterilization tank 2 is opened, the steaming to the steam jacket 3 is restarted with the door open at the set timing. good. For example, if the last sterilization operation is started at the end of work and the person returns home, the restart time can be set in advance by the operation panel so that the steam supply to the steam jacket 3 is automatically restarted before the start of work the next morning. good. Specifically, for example, after a predetermined time has elapsed from the end of the last sterilization operation of the day (the end of the post-treatment step S6), the steam supply to the steam jacket 3 is restarted, or the steam sterilizer 1 functions as a clock. In the case of provision, the timing of restarting the preheating step S1 is set in advance by the operation panel so that the steaming to the steam jacket 3 is restarted at a predetermined time.

Then, at the set timing, the preheating step S1 is restarted. Specifically, the electric boiler 20 is activated to generate steam, and the steam is supplied to the steam jacket 3. Then, the inside of the steam jacket 3 is maintained at a predetermined pressure (in other words, a predetermined temperature). The inner can steam supply valve 32 is closed. During that time, for example, even if the sterilized material is housed in the sterilized tank 2 due to the final operation last night, the door of the sterilized tank 2 remains open, so there is no risk of unnecessarily reheating the sterilized material. Then, at the start of work, the sterilized object to be sterilized may be taken out from the sterilization tank 2 and the door of the sterilization tank 2 may be closed to prepare for the next sterilization operation. Alternatively, take out the sterilized object to be sterilized from the sterilization tank 2, store the object to be sterilized to be newly sterilized in the sterilization tank 2, close the door of the sterilization tank 2, and start the sterilization operation. Just do it. As a result, a series of operations from the above-mentioned pretreatment step S2 is performed. Since it can be steamed in advance with the electric boiler 20, the sterilization work can be performed quickly and efficiently when necessary such as at the start of work.

By restarting the steaming to the steam jacket 3 at the set timing and heating the inside of the sterilization tank 2, the conventional warm-up operation (before accommodating the object to be sterilized in the sterilization tank 2), the door It is not necessary to carry out the operation of heating the machine by steaming in the sterilization tank 2 and the steam jacket 3 with the above closed. However, if desired, in the preheating step S1, after the object to be sterilized is taken out from the sterilization tank 2, the door of the sterilization tank 2 may be closed to enable warm-up operation.

By the way, whether or not the post-treatment step S6 is performed may be changed by the operation panel. That is, after the completion of a series of sterilization operations from the start of the preheating step S1 to the end of the drying step S5, whether or not to stop the heating in the sterilization tank 2 by the steam jacket 3 and automatically open the door of the sterilization tank 2. It may be possible to set in advance whether or not to do so on the operation panel.

For example, it is possible to switch between the first operation mode in which the post-processing step S6 is not performed and the second operation mode in which the post-processing step S6 is performed. Then, in the first operation mode, after the drying step S5 is completed, the steam jacket 3 continues to heat the inside of the sterilization tank 2, and the door of the sterilization tank 2 is not opened until a door opening command is received from the operation panel. On the other hand, in the second operation mode, after the drying step S5 is completed, as the post-treatment step S6, as described above, the heating in the sterilization tank 2 by the steam jacket 3 is stopped and the door opening command is received from the operation panel. The door of the sterilization tank 2 is opened without any trouble. In the case of such a configuration, for example, the operator can repeatedly perform the sterilization operation as the first operation mode during the daytime, and return home as the second operation mode in the final sterilization operation at the end of work.

The steam sterilizer 1 of the present invention is not limited to the configuration (including control) of the above embodiment, and can be appropriately changed. In particular, a sterilization tank 2 in which the object to be sterilized is accommodated and steam is supplied to sterilize the object to be sterilized, and a steam jacket 3 provided on the outer wall of the sterilization tank 2 to heat the inside of the sterilization tank 2 from the outside. After steam sterilizing the object to be sterilized in the sterilization tank 2, other structures can be appropriately changed as long as it is provided with a control means for stopping the steam supply to the steam jacket 3 and automatically opening the door of the sterilization tank 2. Is.

For example, in the above embodiment, the steam sterilizer 1 sequentially executes the preheating step S1, the pretreatment step S2, the sterilization step S3, the exhaust step S4, the drying step S5, and the posttreatment step S6, but at least the sterilization step S3. If the post-treatment step S6 is sequentially included, the presence / absence and contents of other steps can be appropriately changed.

Further, in the post-treatment step S6, if the heating of the sterilization tank 2 by the steam jacket 3 is stopped and the door of the sterilization tank 2 is automatically opened (that is, without receiving a door opening command from the user), other Can be changed as appropriate. For example, in the post-processing step S6, the execution of the blow operation may be omitted. Further, in the above embodiment, in the post-treatment step S6, the door of the sterilization tank 2 was opened after the steam supply to the steam jacket 3 was stopped. Steaming to the jacket 3 may be stopped. Alternatively, the steam supply to the steam jacket 3 may be stopped and the door of the sterilization tank 2 may be opened at the same time. In either case, a blow operation may be performed if desired immediately before the door is opened.

Further, in the above embodiment, the steam from the electric boiler 20 can be supplied to the steam jacket 3, and the steam in the steam jacket 3 can be supplied to the sterilization tank 2, but the steam from the electric boiler 20 can be supplied to the sterilization tank 3. It may be possible to supply directly into 2. That is, the electric boiler 20 and the steam jacket 3 may be connected by the first steam supply passage 29, and the electric boiler 20 and the sterilization tank 2 may be connected by the second steam supply passage 31. Then, the inner can steam supply valve 32 is provided in the second steam supply passage 31, but the outer can steam supply valve may be provided in the first steam supply passage 29 as the case may be. Typically, the inner can steam supply valve 32 is controlled based on the detection signal of the inner can pressure sensor 47 or the inner can temperature sensor 48, and the outer can steam supply valve is controlled based on the detection signal of the outer can pressure sensor 30. Will be done.

Further, in the above embodiment, steam from the same electric boiler 20 is supplied to the sterilization tank 2 and the steam jacket 3, but steam from different boilers may be supplied in some cases. In that case, each boiler is not limited to the electric boiler. For example, the steam jacket 3 can be supplied with steam from a first boiler (for example, an electric boiler 20), and the sterilization tank 2 can be supplied with steam from a second boiler (for example, a fuel-fired boiler). NS. As described above, when the first boiler and the second boiler are provided, the steam from the first boiler and the steam from the second boiler may be switched as the steam supplied into the sterilization tank 2. Similarly, as the steam supplied to the steam jacket 3, the steam from the first boiler and the steam from the second boiler may be switchable.

Further, in the above embodiment, the steam jacket 3 is provided on the outer wall of the sterilization tank 2, but a steam tube may be provided instead of the steam jacket 3. For example, a steam tube may be wound around the outer wall of the sterilization tank 2, or a meandering steam tube may be provided. In this case as well, the inside of the sterilization tank 2 can be heated from the outside by steaming the steam pipe as in the case of the steam jacket 3.

Further, in the above embodiment, whether or not the inside of the sterilization tank 2 is heated from the outside is controlled by controlling the presence or absence of steam supply to the steam jacket 3 (or steam pipe), but in some cases, the steam jacket 3 ( Alternatively, the presence or absence of steam generation in the steam pipe) may be controlled. That is, the steam jacket 3 (or the steam pipe) may be provided with a function of heating the supply water to generate steam.

1 Steam sterilizer 2 Sterilization tank 3 Steam jacket 4 Decompression means 5 Decompression means 6 Steam supply means 7 Drain discharge means 8 Exhaust means 11 Vacuum exhaust passage 14 Vacuum pump 16 Air supply passage 18 Air supply valve 20 Electric boiler 29 First supply Steam passage 30 Outer can pressure sensor 31 Second steam supply passage 32 Inner can steam supply valve 35 Drain return passage 39 Drain discharge passage 42 Exhaust passage 47 Inner can pressure sensor 48 Inner can temperature sensor

Claims (8)

A sterilization tank in which the object to be sterilized is stored and steam is supplied to sterilize the object to be sterilized.
A steam jacket or steam tube provided on the outer wall of the sterilization tank and supplied with steam to heat the inside of the sterilization tank,
It is possible to switch whether or not the sterilization tank is heated by supplying steam from the first boiler to the steam jacket or the steam pipe, and from the steam jacket, the steam pipe, the first boiler or the second boiler to the sterilization tank. A steaming means that can switch the presence or absence of steam supply to the inside,
A decompression means for sucking and discharging the gas in the sterilization tank to the outside to reduce the pressure in the sterilization tank,
A decompression means for introducing outside air into the decompressed sterilization tank to repressurize the inside of the sterilization tank.
Exhaust means for discharging the gas in the sterilization tank to the outside by the differential pressure from the atmospheric pressure,
A sterilization step of controlling each of the means to supply steam into the sterilization tank to sterilize the object to be sterilized while heating the inside of the sterilization tank with the steam jacket or the steam tube, into the sterilization tank. It is provided with a control means for executing at least sequentially the exhaust step of discharging steam from the sterilization tank and the drying step of drying the object to be sterilized in a state where the steam supply is stopped.
In the drying step, the inside of the sterilization tank is depressurized to a set drying pressure by the depressurizing means to vacuum dry the object to be sterilized, or pulse drying in which depressurization by the depressurizing means and depressurization by the depressurizing means are repeated. Alternatively, the depressurizing means is blow-dried while being operated for a set drying time in a state where the outside air can be introduced into the sterilization tank by the depressurizing means, or any two or more of these are executed in the set order. It ’s a process,
The control means is
After steam sterilizing the object to be sterilized in the sterilization tank, the heating of the sterilization tank by the steam jacket or the steam tube is stopped.
A steam sterilization apparatus characterized in that the door of the sterilization tank is automatically opened while the pressure inside the sterilization tank is kept at atmospheric pressure after the completion of the drying step. The repressurizing means is provided with an air supply valve in the air supply path into the sterilization tank.
After the drying step is completed, the control means stops heating the sterilization tank by the steam jacket or the steam pipe, and performs a blow operation to operate the decompression means with the air supply valve open. The steam sterilizer according to claim 1, wherein the decompression means is stopped and the door is opened. The steam according to claim 1 or 2, wherein the control means stops heating of the sterilization tank by the steam jacket or the steam tube after a set standby time elapses from the end of the drying step. Sterilizer. The steam sterilization apparatus according to claim 2, wherein the control means performs the blow operation for a set blow time, then stops the decompression means and opens the door. Any of claims 1 to 4, wherein the control means restarts heating of the sterilization tank by the steam jacket or the steam tube while the door is open at a setting timing after the door is opened. The steam sterilizer according to item 1. The operation panel makes it possible to switch between the first operation mode and the second operation mode.
In the first operation mode, after the drying step is completed, the steam jacket or the steam tube continues to heat the inside of the sterilization tank, and the door of the sterilization tank is closed until a door opening command is received from the operation panel. Without opening,
In the second operation mode, after the drying step is completed, the heating in the sterilization tank by the steam jacket or the steam pipe is stopped, and the door of the sterilization tank is not received from the operation panel. The steam sterilizer according to any one of claims 1 to 5, wherein the steam sterilizer is opened. The steam jacket or the steam pipe is configured to heat the water supply internally to generate steam.
Instead of controlling the presence or absence of heating of the sterilization tank by supplying steam from the first boiler to the steam jacket or the steam pipe, heating of the sterilization tank by steam generation in the steam jacket or the steam pipe. The steam sterilizer according to any one of claims 1 to 6, wherein the presence or absence of the steam sterilizer is controlled. The steam sterilizer according to any one of claims 1 to 7, wherein the door is a shutter type or a slide type.

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