JP2020168492A - Steam sterilizer - Google Patents

Abstract

To provide a steam sterilizer capable of preventing backflow of liquid into a pump.SOLUTION: A steam sterilizer includes a liquid supply pump for transferring liquid into a chamber, a sensor arranged outside the chamber, for detecting that liquid having a quantity necessary for a sterilization treatment of a sterilization object is supplied into the chamber, and a control part for controlling action of the steam sterilizer. When supplying the liquid into the chamber, the control part starts the liquid supply pump, then stops once the liquid supply pump, and thereafter restarts the liquid supply pump, and stops the liquid supply pump based on detection by the sensor.SELECTED DRAWING: Figure 3

Description

The present invention relates to a steam sterilizer that kills microorganisms such as bacteria by steam at high temperature and high pressure.

The steam sterilizer keeps the inside of the chamber for storing the object to be sterilized such as medical equipment in a sealed state, and sterilizes the object to be sterilized by filling the chamber with high-pressure steam. The conventional steam sterilizer is disclosed in, for example, Japanese Patent Application Laid-Open No. 2012-040183 (Patent Document 1).

Japanese Patent Application Laid-Open No. 2012-040183 (Patent Document 1) includes a water supply path for supplying water to the chamber, a drainage path for discharging water from the chamber, and a control unit for controlling the operation of the steam sterilizer. The unit discloses a steam sterilizer that controls the supply of water to the chamber via the water supply path so that the water can be discharged from the chamber via the drainage path.

Japanese Unexamined Patent Publication No. 2012-040183

After the sterilization process is completed, a heater arranged in the chamber is operated in order to dry the inside of the chamber containing the object to be sterilized. When the sterilization process is continuously performed, the water supply to the chamber is started with the heater heated by the operation after the previous sterilization process is completed. When the water supplied into the chamber comes into contact with the hot heater, the water evaporates and the pressure in the chamber rises. As a result of the increased pressure in the chamber, a backflow of water from the chamber to the water supply pump occurs.

An object of the present invention is to provide a steam sterilizer capable of preventing backflow of liquid into a pump even when sterilization is continuously performed.

The steam sterilizer according to the present invention includes a chamber capable of storing the object to be sterilized and a heater for heating the liquid supplied into the chamber, and sterilizes the object to be sterilized with the vapor of the liquid generated by heating the heater. .. The steam sterilizer is a liquid supply pump that transfers liquid to the chamber, a sensor that is placed outside the chamber and detects that the amount of liquid required for sterilization of the object to be sterilized has been supplied to the chamber, and steam. It is equipped with a control unit that controls the operation of the sterilizer. When supplying liquid to the chamber, the control unit starts the liquid supply pump, then stops the liquid supply pump, then restarts the liquid supply pump, and then stops the liquid supply pump based on the detection of the sensor. ..

The steam sterilizer described above further includes a vent that is configured to open and close a path that communicates the inside and outside of the chamber. When supplying the liquid to the chamber, the control unit opens the ventilation unit.

In the above vapor sterilizer, when supplying liquid to the chamber, the control unit supplies the liquid after starting the liquid supply pump and before the air pressure in the chamber becomes larger than the pressure of the liquid discharged from the liquid supply pump. Stop the liquid pump once. The control unit restarts the liquid supply pump after the air pressure in the chamber drops to be smaller than the pressure of the liquid discharged from the liquid supply pump.

The steam sterilizer described above includes an overflow pipe that drains excess liquid from the chamber when the liquid is supplied to the chamber. The sensor detects the flow of liquid through the overflow pipe.

In the above steam sterilizer, the stop time of the liquid supply pump after the liquid supply pump is temporarily stopped is longer than the start time of the liquid supply pump at the start of liquid supply to the chamber.

According to the steam sterilizer of the present invention, it is possible to prevent the backflow of liquid into the pump even when the sterilization process is continuously performed.

It is a schematic diagram which shows the structure of the steam sterilizer of an embodiment. It is a block diagram which shows the electrical structure of a steam sterilizer. It is a timing chart which shows the operation of each device of a steam sterilizer. It is a schematic diagram which shows the operation of each device of the steam sterilizer at time T1 ~ T2. It is a schematic diagram which shows the operation of each device of a steam sterilizer at time T2 ~ T3. It is a schematic diagram which shows the operation of each device of the steam sterilizer at time T3 to T4. It is a schematic diagram which shows the operation of each device of a steam sterilizer at time T4 to T5. It is a schematic diagram which shows the operation of each device of the steam sterilizer at time T5 to T6. It is a schematic diagram which shows the operation of each apparatus of a steam sterilizer at time T6 to T7. It is a schematic diagram which shows the operation of each device of a steam sterilizer at time T8.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings below, the same or corresponding parts are given the same reference number, and the description is not repeated.

FIG. 1 is a schematic view showing the configuration of the steam sterilizer 1 of the embodiment. As shown in FIG. 1, the steam sterilizer 1 of the present embodiment includes a chamber 10 capable of accommodating an object to be sterilized 100 represented by a medical device such as gauze or a scalpel. The chamber 10 includes an opening / closing lid 11 that can be opened / closed. The opening / closing lid 11 is attached to the side portion of the chamber 10. By opening the opening / closing lid 11, the object to be sterilized 100 can be carried in and out of the chamber 10. By closing the opening / closing lid 11, the inside of the chamber 10 is kept in a sealed state.

A heater 12 is installed in the vicinity of the bottom surface 10b of the chamber 10. The heater 12 is arranged so as to extend along the bottom surface 10b of the chamber 10. The heater 12 heats the water supplied into the chamber 10 to generate steam. The steam sterilizer 1 sterilizes the object to be sterilized 100 with steam generated by heating the heater 12.

Water is an example of a liquid supplied into chamber 10 for sterilization. The water may be normal water (tap water), well water, distilled water or purified water. The liquid supplied into the chamber 10 is not limited to water, and may be an aqueous solution such as physiological saline.

Above the heater 12, a mounting table 13 on which the object to be sterilized 100 can be placed is provided substantially parallel to the bottom surface 10b of the chamber 10.

A temperature sensor 16 for detecting the temperature inside the chamber 10 is attached to the inner surface of the chamber 10 facing the opening / closing lid 11. The temperature sensor 16 measures the temperature of the gas in the chamber 10.

The steam sterilizer 1 includes a water storage tank 20. The water storage tank 20 stores the water supplied into the chamber 10. The water discharged from the chamber 10 returns to the water tank 20. The water storage tank 20 stores the water discharged from the chamber 10. The internal space of the water storage tank 20 includes a liquid phase portion 21 in which water exists and a gas phase portion 22 in which air exists. A water level sensor 26 for detecting the water level in the water tank 20 is installed in the internal space of the water tank 20.

The chamber 10 and the water storage tank 20 are communicated with each other by a water supply path 30, a discharge path 40, and an overflow path 50. The water supply path 30 is a path for supplying water from the water tank 20 to the chamber 10. The discharge path 40 is a path for discharging water, water vapor, and air from the chamber 10 to the water tank 20. The overflow path 50 is a path for discharging an amount of water exceeding the set water level in the chamber 10 from the chamber 10 to the water tank 20.

The water supply path 30 includes a water supply pipe 31, a water supply pump 32, and a water supply solenoid valve 33. One end of the water supply pipe 31 is connected to the inside of the water storage tank 20, and the other end is connected to the chamber 10. The water supply pump 32 is provided on the upstream side (the side close to the water storage tank 20) on the path of the water supply pipe 31. The water supply solenoid valve 33 is provided on the downstream side (the side close to the chamber 10) on the path of the water supply pipe 31.

The water supply pump 32 transfers water in the direction of flow from the water storage tank 20 toward the chamber 10 to supply water into the chamber 10. The water supply solenoid valve 33 is arranged on the downstream side of the water supply path 30 with respect to the water supply pump 32, and opens and closes the water supply path 30. The water supply solenoid valve 33 is provided so as to be able to switch between an open state in which water can flow from the water storage tank 20 to the chamber 10 and a closed state in which the flow of water from the water storage tank 20 to the chamber 10 is prohibited.

The discharge path 40 includes a drain pipe 41, an exhaust pipe 42, a common pipe 43, and a discharge solenoid valve 44. The drain pipe 41 is a path for the water discharged from the chamber 10 to flow. One end of the drain pipe 41 is connected to the bottom surface 10b of the chamber 10. The water in the chamber 10 is discharged to the outside of the chamber 10 through the drain pipe 41.

The exhaust pipe 42 is a path for the gas discharged from the chamber 10 to flow. One end of the exhaust pipe 42 is connected to the chamber 10 at a position above the highest level of the water surface in the chamber 10. The exhaust pipe 42 is connected to the chamber 10 at a position above the position of the water surface when water is supplied into the chamber 10. The air, water vapor, or a mixed gas thereof in the chamber 10 is discharged to the outside of the chamber 10 through the exhaust pipe 42.

The common pipe 43 is a path for both the water discharged from the chamber 10 and flowing in the drain pipe 41 and the gas discharged from the chamber 10 and flowing in the exhaust pipe 42 to flow. The common pipe 43 has a common path for gas to flow and a path for water to flow. One end of the common pipe 43 communicates with both the drain pipe 41 and the exhaust pipe 42. One end of the common pipe 43, the other end of the drain pipe 41, and the other end of the exhaust pipe 42 may be connected to each other via a connecting portion formed of a joint. The other end of the common pipe 43 is arranged inside the water storage tank 20.

Inside the water storage tank 20, the common pipe 43 has a condenser portion 45. The condenser portion 45 is submerged in the liquid phase portion 21 in the water storage tank 20. In the condenser section 45, heat is transferred from the high-temperature water and water vapor passing through the inside of the common pipe 43 to the water stored inside the water storage tank 20, and the temperature of the fluid flowing through the common pipe 43 decreases. As a result, the condenser portion 45 reduces noise when water is discharged into the water storage tank 20. The condenser unit 45 has a silent function of reducing the loudness of the sound generated by the steam sterilizer 1.

Inside the water storage tank 20, the common pipe 43 has a bent portion 46. The common pipe 43 rises upward from the condenser portion 45 and extends from the liquid phase portion 21 in the water storage tank 20 to the gas phase portion 22. The common pipe 43 bends at the bent portion 46 and extends downward. The other end of the common pipe 43 is arranged so as to face the liquid level in the water storage tank 20. As a result, the water or steam discharged from the common pipe 43 into the water tank 20 flows out from the other end of the common pipe 43 toward the water stored in the water tank 20.

A discharge solenoid valve 44 is provided in the common pipe 43. The discharge solenoid valve 44 is arranged outside the water storage tank 20. The discharge solenoid valve 44 opens and closes the discharge path 40. The discharge solenoid valve 44 is provided so as to be able to switch between an open state in which fluid can flow from the chamber 10 to the water tank 20 and a closed state in which the flow of fluid from the chamber 10 to the water tank 20 is prohibited.

The overflow path 50 includes an overflow pipe 51, an overflow solenoid valve 53, and an overflow sensor 54. The overflow pipe 51 is a tubular member. The overflow pipe 51 is connected to the chamber 10. The overflow pipe 51 has a rising portion 52 that rises upward from the bottom surface 10b of the chamber 10. The upper end of the rising portion 52 constitutes one end 56 of the overflow pipe 51. One end 56 of the overflow pipe 51 is arranged in the chamber 10 and opens to the lower part in the chamber 10.

The overflow pipe 51 is connected to the water storage tank 20. The other end 55 of the overflow pipe 51 is arranged inside the water storage tank 20. The other end 55 of the overflow pipe 51 is open to the upper part of the water storage tank 20. The overflow pipe 51 communicates the chamber 10 with the inside of the water storage tank 20. The water flowing through the overflow pipe 51 flows out from the other end 55 into the water tank 20.

The overflow solenoid valve 53 and the overflow sensor 54 are arranged outside the chamber 10. The overflow solenoid valve 53 is provided on the upstream side (the side close to the chamber 10) on the path of the overflow pipe 51. The overflow sensor 54 is provided on the downstream side (the side close to the water storage tank 20) on the path of the overflow pipe 51.

The overflow solenoid valve 53 is arranged on the upstream side of the overflow pipe 51 with respect to the overflow sensor 54, and opens and closes the overflow path 50. The overflow solenoid valve 53 is provided so as to be able to switch between an open state in which water can flow from the chamber 10 to the water tank 20 and a closed state in which the flow of water from the chamber 10 to the water tank 20 is prohibited.

The overflow sensor 54 detects the flow of water flowing through the overflow pipe 51. The overflow sensor 54 detects the flow of water that flows into the overflow pipe 51 from inside the chamber 10 and flows toward the water tank 20 via the overflow pipe 51. The overflow sensor 54 may be, for example, a sensor having a float unit that moves by the flow of water passing through the overflow sensor 54. Alternatively, the overflow sensor 54 may be a capacitance sensor that detects the flow of water based on the difference between the permittivity of water and the permittivity of air.

The steam sterilizer 1 also includes a ventilation path 60. The blower path 60 includes a blower pipe 61, an air solenoid valve 62, and an air pump 63. The blower pipe 61 has one end connected to the chamber 10 and the other end connected to the air pump 63. The blower pipe 61 communicates the air pump 63 with the chamber 10. The air pump 63 generates a flow of air.

The air solenoid valve 62 is provided in the blower pipe 61. The air solenoid valve 62 opens and closes the air passage 60. The air solenoid valve 62 is provided so as to be switchable between an open state in which air can flow from the air pump 63 to the chamber 10 and a closed state in which the flow of air from the air pump 63 to the chamber 10 is prohibited.

The air pump 63 transfers air from the other end of the blower pipe 61 toward one end to supply air into the chamber 10. When air is sent into the chamber 10, water or water vapor in the chamber 10 is discharged to the outside of the chamber 10 by the pressure of the sent air.

The steam sterilizer 1 further includes a pressure path 70. The pressure path 70 includes pressure pipes 71, 73, 75, a joint 72, a pressure gauge 74, and a safety valve 76.

The pressure pipe 71 has one end connected to the vicinity of the upper surface of the chamber 10 and the other end connected to the joint 72. The pressure pipe 73 has one end connected to the joint 72 and the other end connected to the pressure gauge 74. The gas in the chamber 10 reaches the pressure gauge 74 via the pressure pipe 71, the joint 72 and the pressure pipe 73. The pressure gauge 74 measures the pressure of the gas in the chamber 10.

The pressure pipe 75 has one end connected to the joint 72 and the other end connected to the safety valve 76. The safety valve 76 is provided in the water storage tank 20. When the pressure of the gas in the chamber 10 rises excessively, the safety valve 76 opens, and the gas in the chamber 10 is discharged into the water storage tank 20 via the pressure pipe 71, the joint 72, the pressure pipe 73 and the safety valve 76 in this order. To. As a result, the pressure in the chamber 10 is reduced, and the pressure in the chamber 10 is maintained in an appropriate range.

FIG. 2 is a block diagram showing an electrical configuration of the steam sterilizer 1. As shown in FIG. 2, the steam sterilizer 1 includes a control unit 80 that controls the operation of the steam sterilizer 1. The control unit 80 is electrically connected to the temperature sensor 16, the water level sensor 26, the overflow sensor 54, and the pressure gauge 74. The control unit 80 receives input of a detected value related to the temperature inside the chamber 10 from the temperature sensor 16. The control unit 80 receives input of a detected value related to the water level in the water tank 20 from the water level sensor 26. The control unit 80 receives input from the overflow sensor 54 regarding the presence or absence of the flow of water flowing through the overflow pipe 51. The control unit 80 receives input of a detected value related to the pressure inside the chamber 10 from the pressure gauge 74.

The control unit 80 also has an input unit 81. The operator using the steam sterilizer 1 inputs set values such as heating temperature, sterilization time, and drying time from the input unit 81 to the control unit 80. The control unit 80 has a timer 82 that measures a predetermined time. The timer 82 is used to control the sterilization time and the drying time of the object to be sterilized 100, and is also used to control the timing of water supply into the chamber 10.

The control unit 80 corresponds to each control step of the steam sterilizer 1, and includes a heater 12, a discharge solenoid valve 44, a water supply solenoid valve 33, an air solenoid valve 62, an overflow solenoid valve 53, a water supply pump 32, an air pump 63, and the like. A control signal is output to each device included in the steam sterilizer 1. By receiving the control signal from the control unit 80 and operating each device appropriately, the sterilization process of the object to be sterilized by the steam sterilizer 1 is surely performed.

The operation of the steam sterilizer 1 having the above configuration will be described below. FIG. 3 is a timing chart showing the operation of each device of the steam sterilizer 1. The operation of the steam sterilizer 1 in the water supply step among the steps for sterilizing the object to be sterilized by the steam sterilizer 1 will be described in detail according to the timing chart shown in FIG. Hereinafter, the operation of the steam sterilizer 1 after the completion of the previous sterilization treatment when the sterilization treatment is continuously performed will be described.

As shown in FIG. 3, at time T0, the steam sterilizer 1 switches from the standby state after the completion of the previous sterilization process to the start state in which the sterilization process is started. Before starting the water supply, the operator using the steam sterilizer 1 opens the opening / closing lid 11 of the chamber 10, places the object to be sterilized 100 on the mounting table 13, and puts the object to be sterilized 100 in the chamber 10. Accommodate.

By switching the steam sterilizer 1 from the standby state to the starting state, the exhaust solenoid valve 44 is turned on as shown in FIG. In the present embodiment, the discharge solenoid valve 44, the water supply solenoid valve 33, the air solenoid valve 62, and the overflow (OF) solenoid valve 53 are all kept closed in the off (non-energized) state and in the on (energized) state. It is a solenoid valve that opens and is always closed.

The gas phase portion 22 of the water storage tank 20 is maintained at atmospheric pressure. By opening the discharge solenoid valve 44, the internal space of the chamber 10 and the gas phase portion 22 of the water storage tank 20 communicate with each other via the discharge path 40. As a result, the internal space of the chamber 10 is adjusted to the same atmospheric pressure as the gas phase portion 22. By communicating the internal space of the chamber 10 with the gas phase portion 22 of the water storage tank 20, the air pressure inside the chamber 10 and the outside air pressure are made constant. As a result, the opening / closing lid 11 of the chamber 10 can be easily opened / closed.

Next, at time T1, water supply is started. As shown in FIG. 3, the water supply solenoid valve 33 and the overflow solenoid valve 53 are switched from off to on. The exhaust solenoid valve 44 is left on. The air solenoid valve 62 is left off. As a result, the discharge solenoid valve 44, the water supply solenoid valve 33, and the overflow solenoid valve 53 are opened, and the air solenoid valve 62 is closed.

FIG. 4 is a schematic view showing the operation of each device of the steam sterilizer 1 at times T1 to T2. The arrows shown in FIGS. 4 and 5 to 10 described later indicate the flow of fluid (water, water vapor, or air) flowing through each path. By starting the water supply pump 32 with the opening and closing of each solenoid valve set as described above, water supply is started and water is supplied from the water storage tank 20 to the chamber 10.

Next, the water supply solenoid valve 33 is switched from on to off at a time T2 after a predetermined time has elapsed from the time T1 at which water supply to the chamber 10 is started. As a result, the discharge solenoid valve 44 and the overflow solenoid valve 53 are opened, and the water supply solenoid valve 33 and the air solenoid valve 62 are closed.

FIG. 5 is a schematic view showing the operation of each device of the steam sterilizer 1 at times T2 to T3. When the sterilization process is continuously performed, water supply to the chamber 10 is started in a state where the heater 12 is heated by the operation after the completion of the previous sterilization process. When the water supplied into the chamber 10 comes into contact with the high temperature heater 12, it immediately evaporates and the pressure in the chamber 10 rises sharply. Therefore, in the present embodiment, the water supply pump 32 is temporarily stopped and the water supply solenoid valve 33 is closed at the time T2 after a short time has elapsed from the time T1 when the water supply is started.

The time T2 at which the water supply pump 32 is temporarily stopped is set as the time after the time T1 at which the water supply pump 32 is started and before the pressure in the chamber 10 becomes higher than the pressure of the water discharged from the water supply pump 32. It is set.

The water supply electromagnetic valve 33 provided on the path of the water supply pipe 31 between the water supply pump 32 and the chamber 10 is closed before the pressure in the chamber 10 becomes higher than the pressure of the water discharged from the water supply pump 32. Put it in a state. As a result, the backflow of water from the chamber 10 to the water supply pump 32 is prevented, so that problems such as failure of the water supply pump 32 due to the backflow of water are prevented.

At the start of water supply to the chamber 10, the discharge solenoid valve 44 and the overflow solenoid valve 53 are opened, and the chamber 10 and the water storage tank 20 communicate with each other via the discharge path 40 and the overflow path 50. The water vapor supplied from the water supplied into the chamber 10 evaporates in the chamber 10 and is generated, and is discharged from the chamber 10 via the discharge path 40 and the overflow path 50. Therefore, the air pressure in the chamber 10 gradually decreases.

The heater 12 in the chamber 10 is cooled by contacting with the water supplied to the chamber 10 and transferring heat to the water.

After a sufficient time has passed after the time T2, until the air pressure in the chamber 10 that has become larger than the pressure of the water discharged from the water supply pump 32 becomes smaller than the pressure of the water discharged from the water supply pump 32. At time T3 after the descent, the water supply solenoid valve 33 switches from off to on. As a result, the discharge solenoid valve 44, the water supply solenoid valve 33, and the overflow solenoid valve 53 are opened, and the air solenoid valve 62 is closed.

The time T3 for restarting the water supply pump 32 is the time after the time T2 for temporarily stopping the water supply pump 32 and after the air pressure in the chamber 10 becomes smaller than the pressure of the water discharged from the water supply pump 32. It is set. The time T2 to T3 indicating the stop time of the water supply pump 32 after the water supply pump 32 is temporarily stopped is larger than the time T1 to T2 indicating the start time of the water supply pump 32 at the start of water supply to the chamber 10. But it's getting longer.

FIG. 6 is a schematic view showing the operation of each device of the steam sterilizer 1 at times T3 to T4. At time T3, the water supply solenoid valve 33 is opened and the water supply pump 32 is restarted, so that water supply to the chamber 10 is restarted and water W is supplied from the water storage tank 20 to the chamber 10. The air in the chamber 10 is discharged from the chamber 10 via the discharge path 40 and the overflow path 50. Therefore, it is avoided that the internal pressure of the chamber 10 rises and the water supply to the chamber 10 is hindered.

Since the water surface Ws in the chamber 10 is lower than the position of one end 56 of the overflow pipe 51, one end 56 of the overflow pipe 51 is present in the air. Therefore, air flows through the overflow pipe 51, but water W does not flow through the overflow pipe 51.

Next, at the time T4 after a predetermined time has elapsed from the time T3 when the water supply to the chamber 10 is restarted, the discharge solenoid valve 44 is switched from on to off, and the air solenoid valve 62 is switched from off to on. It changes. As a result, the discharge solenoid valve 44 is closed, and the water supply solenoid valve 33, the air solenoid valve 62, and the overflow solenoid valve 53 are opened.

FIG. 7 is a schematic view showing the operation of each device of the steam sterilizer 1 at times T4 to T5. By starting the air pump 63 with the opening and closing of each solenoid valve set as described above, the supply of air into the chamber 10 is started, and the inside of the chamber 10 is pressurized. The water supply pump 32 continues to operate, and water supply from the water storage tank 20 to the chamber 10 is continued. Since the exhaust solenoid valve 44 is closed, the air in the chamber 10 is exhausted from the chamber 10 via the overflow path 50.

Since the water surface Ws in the chamber 10 is higher than that in FIG. 6 but still lower than the position of one end 56 of the overflow pipe 51, one end 56 of the overflow pipe 51 is present in the air. Therefore, air flows through the overflow pipe 51, but water W does not flow through the overflow pipe 51.

When the water supply to the chamber 10 is further continued and the water level in the chamber 10 exceeds one end 56 of the overflow pipe 51, the water W in the chamber 10 flows into the overflow pipe 51. An excessive amount of water W exceeding one end 56 of the overflow pipe 51 is discharged from the chamber 10, and a water flow flowing through the overflow pipe 51 is generated. The flow of water flowing through the overflow pipe 51 via the overflow pipe 51 is detected by the overflow sensor 54.

As shown in FIG. 3, the overflow sensor 54 is switched from off to on at time T5. It is estimated that the water surface Ws in the chamber 10 has exceeded 56 at one end of the overflow pipe 51 just before time T5. FIG. 8 is a schematic view showing the operation of each device of the steam sterilizer 1 at times T5 to T6. Since the water W in the chamber 10 flows into the overflow pipe 51, a mixed flow of water W and air flows through the overflow pipe 51. Since air is supplied to the chamber 10 by the air pump 63 when the water is supplied to the chamber 10, the outflow of water from the chamber 10 to the overflow pipe 51 is promoted.

At time T6 after a predetermined time has elapsed from the time T5 when the overflow sensor 54 is switched on, the water supply pump 32 is stopped and the water supply solenoid valve 33 is switched from on to off. As a result, the discharge solenoid valve 44 and the water supply solenoid valve 33 are closed, and the air solenoid valve 62 and the overflow solenoid valve 53 are opened.

FIG. 9 is a schematic view showing the operation of each device of the steam sterilizer 1 at times T6 to T7. With the opening and closing of each solenoid valve set as described above, the supply of air to the chamber 10 by the air pump 63 is continued. While the mixed flow of water W and air is flowing through the overflow pipe 51, the overflow sensor 54 keeps on. As the water W flows out of the chamber 10, the water surface Ws in the chamber 10 gradually decreases.

When the water surface Ws in the chamber 10 drops and reaches the position of one end 56 of the overflow pipe 51, the outflow of water W from the chamber 10 stops. When the water flow through the overflow pipe 51 is stopped, the overflow sensor 54 that detects the flow of water flowing through the overflow pipe 51 via the overflow pipe 51 is switched from on to off. As shown in FIG. 3, the overflow sensor 54 is switched from on to off at time T7. It is estimated that the water surface Ws in the chamber 10 dropped to one end 56 of the overflow pipe 51 just before the time T7.

FIG. 10 is a schematic view showing the operation of each device of the steam sterilizer 1 at time T8. At a time T8 after a predetermined time has elapsed from the time T7 when the overflow sensor 54 is switched off, the air solenoid valve 62 and the overflow solenoid valve 53 are switched from on to off, and the air pump 63 is stopped. As a result, the supply of air to the chamber 10 is stopped. The water surface Ws in the chamber 10 is maintained at one end 56 of the overflow pipe 51. In this way, the water supply process is completed, and the process proceeds to the heating process.

The overflow sensor 54 switches from off to on during water supply to the chamber 10, and the overflow sensor 54 switches from on to off after stopping the water supply to the chamber 10, so that the water surface Ws in the chamber 10 becomes the overflow pipe 51. It is detected that it is located at one end 56 of the chamber. The overflow sensor 54 is used to detect that the chamber 10 has been supplied with the amount of water required for the sterilization process of the object 100 to be sterilized.

At time T8, the solenoid valve 44 is switched from off to on. As a result, the discharge solenoid valve 44 is opened, and the water supply solenoid valve 33, the air solenoid valve 62, and the overflow solenoid valve 53 are closed. The internal space of the chamber 10 and the gas phase portion 22 of the water storage tank 20 communicate with each other via the discharge path 40, whereby the internal space of the chamber 10 is adjusted to atmospheric pressure.

The configuration and operation / effect of the steam sterilizer 1 of the embodiment will be summarized as follows. A reference number is added to the configuration of the embodiment, which is an example.

As shown in FIG. 1, the steam sterilizer 1 of the present embodiment includes a chamber 10 capable of storing the object to be sterilized 100 and a heater 12 for heating the water supplied into the chamber 10. This is an apparatus for sterilizing the object to be sterilized 100 with steam generated by heating. As shown in FIG. 2, the steam sterilizer 1 includes a water supply pump 32 that transfers water to the chamber 10 and a control unit 80 that controls the operation of the steam sterilizer 1. When supplying water to the chamber 10, the control unit 80 starts the water supply pump 32 at the time T1 and temporarily stops the water supply pump 32 at the subsequent time T2, and then temporarily stops the water supply pump 32 at the subsequent time T3, as shown in FIG. The pump 32 is restarted.

When the sterilization process is continuously performed, the heater 12 in the chamber 10 is heated by the operation after the previous sterilization process is completed. By activating the water supply pump and supplying water into the chamber 10 between times T1 and T2, the water comes into contact with the hot heater 12. The heater 12 can be cooled by heat transfer from the heater 12 to water.

The water in contact with the heater 12 evaporates in the chamber 10. As a result, the internal pressure of the chamber 10 rises. In the steam sterilizer 1 of the present embodiment, the water supply pump 32 is stopped at a time T2 shortly after the time T1 when water supply to the chamber 10 is started. This makes it possible to close the water supply solenoid valve 33 provided on the path between the chamber 10 and the water supply pump 32. By closing the water supply solenoid valve 33, it is possible to prevent the backflow of water from the chamber 10 to the water supply pump 32.

Further, as shown in FIG. 1, the steam sterilizer 1 further includes a discharge solenoid valve 44 and an overflow solenoid valve 53. The discharge solenoid valve 44 is provided in a discharge path 40 that communicates the chamber 10 and the water storage tank 20, and is configured to be able to open and close the discharge path 40. The overflow solenoid valve 53 is provided in an overflow path 50 that communicates the chamber 10 and the water storage tank 20, and is configured to be able to open and close the overflow path 50. As shown in FIGS. 4 and 5, when water is supplied to the chamber 10, the control unit 80 opens the discharge solenoid valve 44 and the overflow solenoid valve 53. The discharge solenoid valve 44 and the overflow solenoid valve 53 of the embodiment correspond to a ventilation portion.

Since the discharge solenoid valve 44 and the overflow solenoid valve 53 are open during the times T1 to T3, the steam supplied to the chamber 10 and evaporated in the chamber 10 can be discharged from the chamber 10 to the outside. is there. Since the air pressure in the chamber 10 that has risen due to the generation of steam can be quickly lowered, the time from the time T2 at which the water supply to the chamber 10 is temporarily stopped to the time T3 at which the water supply to the chamber 10 is restarted can be shortened. Therefore, the time required for the sterilization process can be shortened.

In addition to the discharge solenoid valve 44 and the overflow solenoid valve 53, the opening / closing lid 11 may be automatically opened / closed so that the opening / closing lid 11 is opened when water is supplied to the chamber 10. In this case, the opening / closing lid 11 also corresponds to the ventilation portion.

When supplying water to the chamber 10, the control unit 80 temporarily stops the water supply pump 32 after starting the water supply pump 32 and before the air pressure in the chamber 10 becomes larger than the pressure of the water discharged from the water supply pump 32. To do. Further, the control unit 80 drops the air pressure in the chamber 10 which is larger than the pressure of the water discharged from the water supply pump 32 until it becomes smaller than the pressure of the water discharged from the water supply pump 32, and then the water supply pump 32. Restart. The air pressure in the chamber 10 may be measured by the pressure gauge 74.

When the air pressure in the chamber 10 is larger than the pressure of the water discharged from the water supply pump 32, a backflow of water from the chamber 10 to the water supply pump 32 occurs. By temporarily stopping the water supply pump 32 before the air pressure in the chamber 10 becomes higher than the pressure of the water discharged from the water supply pump 32, it is possible to prevent the backflow of water from the chamber 10 to the water supply pump 32. .. The water supply pump from the chamber 10 when the water supply pump 32 is restarted by restarting the water supply pump 32 after the air pressure in the chamber 10 drops to be smaller than the pressure of the water discharged from the water supply pump 32. It is possible to prevent the backflow of water to 32.

Further, as shown in FIG. 1, the steam sterilizer 1 includes an overflow sensor 54. The overflow sensor 54 detects that the chamber 10 has been supplied with the amount of water required for the sterilization process of the object to be sterilized 100. By stopping the water supply pump 32 based on the detection of the overflow sensor 54, it is possible to reliably supply the amount of water required for the sterilization process into the chamber 10.

The overflow sensor 54 is arranged outside the chamber 10. Since the overflow sensor 54 is arranged outside the chamber 10, impurities contained in the water supplied to the chamber 10 do not adhere to the overflow sensor 54 when the water evaporates. Therefore, it is possible to suppress a decrease in sensitivity of the overflow sensor 54 due to adhesion of impurities to the overflow sensor 54.

Further, as shown in FIG. 1, the steam sterilizer 1 includes an overflow pipe 51 that discharges excess water from the chamber 10 when water is supplied to the chamber 10. The overflow sensor 54 detects the flow of water flowing through the overflow pipe 51. By providing the overflow pipe 51, as shown in FIG. 10, the water surface Ws in the chamber 10 after the completion of water supply can be kept constant at the position of one end 56 of the overflow pipe 51. Thereby, the uniformity of the amount of water supplied into the chamber 10 can be improved. Since the overflow sensor 54 functions as a sensor for detecting the amount of water stored in the chamber 10, it is not necessary to separately provide a sensor for detecting the amount of water stored in the chamber 10, and the configuration of the steam sterilizer 1 is simplified. can do.

Further, as shown in FIG. 3, the stop time of the water supply pump 32 after the water supply pump 32 is temporarily stopped is shown rather than the time from time T1 to T2 indicating the start time of the water supply pump at the start of water supply to the chamber 10. The time from time T2 to T3 is longer. By defining the start / stop time of the water supply pump 32 in this way, it is possible to sufficiently secure the time for the heater 12 to be cooled by the heat transfer to the water supplied to the chamber 10 between the times T1 to T2. it can. Therefore, the heater 12 can be reliably cooled.

Although the embodiments of the present invention have been described above, it should be considered that the embodiments disclosed this time are examples in all respects and are not restrictive. The scope of the present invention is shown not by the above description but by the scope of claims, and is intended to include the meaning equivalent to the scope of claims and all modifications within the scope.

1 Steam sterilizer, 10 chamber, 10b bottom surface, 11 opening / closing lid, 12 heater, 13 stand, 16 temperature sensor, 20 water tank, 21 liquid phase part, 22 gas phase part, 26 water level sensor, 30 water supply path, 31 water supply pipe , 32 Water supply pump, 33 Water supply solenoid valve, 40 Discharge path, 41 Drainage pipe, 42 Exhaust pipe, 43 Common pipe, 44 Discharge solenoid valve, 45 Condenser part, 46 Bending part, 50 Overflow path, 51 Overflow pipe, 52 Rising part , 53 Overflow solenoid valve, 54 Overflow sensor, 55 other end, 56 one end, 60 blow path, 61 blow pipe, 62 air solenoid valve, 63 air pump, 70 pressure path, 71, 73, 75 pressure pipe, 72 joint, 74 pressure Total, 76 safety valve, 80 control unit, 81 input unit, 82 timer, 100 object to be sterilized, W water, Ws water surface.

The pressure pipe 75 has one end connected to the joint 72 and the other end connected to the safety valve 76. The safety valve 76 is provided in the water storage tank 20. When the pressure of the gas in the chamber 10 rises excessively, the safety valve 76 opens, and the gas in the chamber 10 is discharged into the water storage tank 20 via the pressure pipe 71, the joint 72, the pressure pipe 75 and the safety valve 76 in this order. To. As a result, the pressure in the chamber 10 is reduced, and the pressure in the chamber 10 is maintained in an appropriate range.

The steam sterilizer 1 also has an input section 81. The operator using the steam sterilizer 1 inputs set values such as heating temperature, sterilization time, and drying time from the input unit 81 to the control unit 80. The control unit 80 has a timer 82 that measures a predetermined time. The timer 82 is used to control the sterilization time and the drying time of the object to be sterilized 100, and is also used to control the timing of water supply into the chamber 10.

1 Steam sterilizer, 10 chambers, 10b bottom surface, 11 opening / closing lid, 12 heaters, 13 mounts , 16 temperature sensor, 20 water tank, 21 liquid phase part, 22 gas phase part, 26 water level sensor, 30 water supply path, 31 water supply Pipe, 32 water supply pump, 33 water supply solenoid valve, 40 discharge path, 41 drain pipe, 42 exhaust pipe, 43 common pipe, 44 discharge solenoid valve, 45 condenser part, 46 bend part, 50 overflow path, 51 overflow pipe, 52 rise Parts, 53 Overflow solenoid valve, 54 Overflow sensor, 55 other end, 56 one end, 60 blow path, 61 blow pipe, 62 air solenoid valve, 63 air pump, 70 pressure path, 71, 73, 75 pressure pipe, 72 joint, 74 Pressure gauge, 76 safety valve, 80 control unit, 81 input unit, 82 timer, 100 object to be sterilized, W water, Ws water surface.

Claims (5)

A chamber that can store objects to be sterilized and
A heater for heating the liquid supplied into the chamber is provided.
The object to be sterilized is sterilized with the liquid vapor generated by heating the heater.
A liquid supply pump that transfers liquid to the chamber and
A sensor that is placed outside the chamber and detects that the amount of liquid required for sterilization of the object to be sterilized has been supplied to the chamber.
Equipped with a control unit that controls the operation of the steam sterilizer
When supplying the liquid to the chamber, the control unit starts the liquid supply pump, then temporarily stops the liquid supply pump, then restarts the liquid supply pump, and then based on the detection of the sensor. A steam sterilizer that stops the liquid supply pump. Further provided with a ventilation portion configured to open and close a path communicating the inside and the outside of the chamber.
The steam sterilizer according to claim 1, wherein when the liquid is supplied to the chamber, the control unit opens the ventilation unit. When supplying the liquid to the chamber, the control unit starts the liquid supply pump and before the pressure in the chamber becomes larger than the pressure of the liquid discharged from the liquid supply pump. The steam sterilizer according to claim 1 or 2, wherein the steam sterilizer is stopped once, and the liquid supply pump is restarted after the pressure in the chamber drops to be smaller than the pressure of the liquid discharged from the liquid supply pump. An overflow pipe for draining excess liquid from the chamber when the liquid is supplied to the chamber is provided.
The vapor sterilizer according to any one of claims 1 to 3, wherein the sensor detects the flow of a liquid flowing through the overflow pipe. Any one of claims 1 to 4, wherein the stop time of the liquid supply pump after the liquid supply pump is temporarily stopped is longer than the start time of the liquid supply pump at the start of liquid supply to the chamber. The steam sterilizer described in the section.

Images