JP6737500B2 - Steam sterilizer - Google Patents

Description

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

The steam sterilizer keeps a chamber for accommodating an object to be sterilized such as medical equipment in a hermetically sealed state and fills the chamber with high-pressure steam to sterilize the object to be sterilized. A conventional steam sterilizer is disclosed, for example, in JP 2012-040183 A (Patent Document 1).

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

JP 2012-040183 A

After the sterilization process is completed, the heater arranged in the chamber is operated 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 completion of the previous sterilization process. When the water supplied into the chamber comes into contact with the high temperature heater, the water evaporates and the pressure in the chamber rises. The increase in pressure in the chamber results in backflow of water from the chamber to the feed pump.

An object of the present invention is to provide a steam sterilizer that can prevent backflow of liquid to a pump even when sterilization is continuously performed.

A steam sterilizer according to the present invention includes a chamber capable of accommodating an object to be sterilized and a heater for heating a liquid supplied into the chamber, and sterilizes the object to be sterilized by vapor of the liquid generated by heating the heater. .. The steam sterilizer is equipped with a liquid supply pump that transfers liquid to the chamber, a sensor that is arranged outside the chamber, detects that the amount of liquid necessary for the sterilization treatment of the object to be sterilized has been supplied to the chamber, and the steam. And a control unit for controlling the operation of the sterilizer. When supplying 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 stops the liquid supply pump based on the detection by the sensor. ..

The steam sterilizer further includes a ventilation portion configured to open and close a path that connects the inside and the outside of the chamber. When supplying liquid to the chamber, the controller opens the vent.

In the above steam sterilizer, when supplying the liquid to the chamber, the control unit supplies the liquid after starting the liquid supply pump and before the atmospheric 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 atmospheric pressure in the chamber drops until it becomes lower than the pressure of the liquid discharged from the liquid supply pump.

The above-mentioned steam sterilizer is equipped with an overflow pipe for discharging excess liquid from the chamber when liquid is supplied to the chamber. The sensor detects the flow of liquid flowing through the overflow pipe.

In the above steam sterilizer, the stop time of the liquid supply pump after the liquid supply pump is once 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 liquid from flowing back to the pump even when the sterilization process is continuously performed.

It is a schematic diagram which shows the structure of the steam sterilizer of embodiment. It is a block diagram which shows the electric constitution of a steam sterilizer. It is a timing chart which shows operation|movement of each apparatus of a steam sterilizer. It is a schematic diagram which shows operation|movement of each apparatus of a steam sterilizer in time T1-T2. It is a schematic diagram which shows operation|movement of each apparatus of a steam sterilizer in time T2-T3. It is a schematic diagram which shows operation|movement of each apparatus of a steam sterilizer in time T3-T4. It is a schematic diagram which shows operation|movement of each apparatus of a steam sterilizer in time T4-T5. It is a schematic diagram which shows operation|movement of each apparatus of a steam sterilizer in time T5-T6. It is a schematic diagram which shows operation|movement of each apparatus of a steam sterilizer in time T6-T7. It is a schematic diagram which shows operation|movement of each apparatus of a steam sterilizer in time T8.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts will be designated by the same reference numerals, and the description thereof will not be repeated.

FIG. 1 is a schematic diagram showing a configuration of a 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 medical instruments such as gauze and scalpel. The chamber 10 includes an openable/closable lid 11. The opening/closing lid 11 is attached to the side portion of the chamber 10. By opening the opening/closing lid 11, the sterilized object 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 maintained in a sealed state.

A heater 12 is installed near 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 100 to be sterilized with steam generated by heating the heater 12.

Water is an example of a liquid supplied into the chamber 10 for sterilization. The water may be ordinary 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 100 to be sterilized can be mounted is provided substantially parallel to the bottom surface 10b of the chamber 10.

A temperature sensor 16 that detects the temperature inside the chamber 10 is attached to the inner surface of the chamber 10 that faces the opening/closing lid 11. The temperature sensor 16 measures the temperature of the gas inside 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 storage 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 storage tank 20 is installed in the internal space of the water storage tank 20.

The chamber 10 and the water storage tank 20 communicate with each other through 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 storage 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 storage 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 storage 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 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 a direction of flowing from the water storage tank 20 toward the chamber 10 and supplies the 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 to be switchable 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 through which the water discharged from the chamber 10 flows. 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 through which the gas discharged from the chamber 10 flows. 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. Air, water vapor, or a mixed gas thereof in the chamber 10 is exhausted to the outside of the chamber 10 through the exhaust pipe 42.

The common pipe 43 is a path through which both water discharged from the chamber 10 and flowing in the drain pipe 41 and gas discharged from the chamber 10 and flowing in the exhaust pipe 42 flow. The common pipe 43 has a common path for gas flow and a common path for water 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 drainage 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 part 45 is submerged in the liquid phase part 21 in the water storage tank 20. In the condenser unit 45, heat is transferred from the high temperature water and steam passing through the common pipe 43 to the water stored inside the water tank 20, and the temperature of the fluid flowing through the common pipe 43 is lowered. As a result, the condenser unit 45 reduces noise when water is discharged into the water storage tank 20. The condenser unit 45 has a silent function of reducing the volume of 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 vapor phase portion 22. The common pipe 43 is bent at the bent portion 46 and extends downward. The other end of the common pipe 43 is arranged facing the liquid surface in the water storage tank 20. As a result, the water or steam discharged from the common pipe 43 into the water storage tank 20 flows out from the other end of the common pipe 43 toward the water stored in the water storage 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 switchable between an open state in which a fluid can flow from the chamber 10 toward the water storage tank 20 and a closed state in which the flow of the fluid from the chamber 10 to the water storage 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 at 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 opens at the upper part of the water storage tank 20. The overflow pipe 51 connects 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 storage 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 tank 20) on the path of the overflow pipe 51.

The overflow solenoid valve 53 is arranged upstream 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 to be switchable between an open state in which water can flow from the chamber 10 to the water storage tank 20 and a closed state in which the flow of water from the chamber 10 to the water storage 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 which flows into the overflow pipe 51 from the chamber 10 and flows toward the water storage tank 20 via the overflow pipe 51. The overflow sensor 54 may be, for example, a sensor having a specification including a float unit that moves according to 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 dielectric constants of water and 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 connects the air pump 63 and the chamber 10. The air pump 63 generates a flow of air.

The air solenoid valve 62 is provided on the blower pipe 61. The air solenoid valve 62 opens and closes the air passage 60. The air solenoid valve 62 is provided 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 in a direction from the other end of the blower pipe 61 to one end and supplies the 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 due to 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 tank 20 via the pressure pipe 71, the joint 72, the pressure pipe 73 and the safety valve 76 in this order. It This reduces the pressure in the chamber 10 and maintains the pressure in the chamber 10 in an appropriate range.

FIG. 2 is a block diagram showing the 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 controller 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 a detection value related to the temperature inside the chamber 10 from the temperature sensor 16. The control unit 80 receives, from the water level sensor 26, a detection value related to the water level in the water tank 20. The control unit 80 receives, from the overflow sensor 54, a detection value relating to the presence or absence of the flow of water flowing through the overflow pipe 51. The controller 80 receives a detection value related to the pressure inside the chamber 10 from the pressure gauge 74.

The control unit 80 also has an input unit 81. An operator who uses 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 controller 80 corresponds to each control step of the steam sterilizer 1, such as the heater 12, the discharge solenoid valve 44, the water supply solenoid valve 33, the air solenoid valve 62, the overflow solenoid valve 53, the water supply pump 32, and the air pump 63. A control signal is output to each device included in the steam sterilizer 1. When each device operates properly in response to the control signal from the control unit 80, the steam sterilizer 1 surely sterilizes the sterilized object.

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. Among the steps for sterilizing the object to be sterilized by the steam sterilizer 1, the operation of the steam sterilizer 1 in the water supply step will be described in detail according to the timing chart shown in FIG. The operation of the steam sterilizer 1 after the completion of the previous sterilization process when the sterilization process is continuously performed will be described below.

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

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

The vapor phase portion 22 of the water storage tank 20 is kept at atmospheric pressure. By opening the discharge solenoid valve 44, the internal space of the chamber 10 and the vapor 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 vapor phase portion 22. By communicating the internal space of the chamber 10 with the vapor phase portion 22 of the water storage tank 20, the air pressure and the external atmospheric pressure in the chamber 10 are made constant. As a result, the opening/closing lid 11 of the chamber 10 can be easily opened and 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 discharge solenoid valve 44 remains on. The air solenoid valve 62 remains 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 diagram showing the operation of each device of the steam sterilizer 1 at times T1 and T2. An arrow shown in each path in FIG. 4 and FIGS. 5 to 10 described later indicates a flow of a fluid (water, water vapor, or air) flowing in each path. By starting the water supply pump 32 with the opening and closing of each electromagnetic valve set as described above, water supply is started and water is supplied from the water tank 20 to the chamber 10.

Next, at time T2 after a lapse of a predetermined time from time T1 when the water supply to the chamber 10 is started, the water supply electromagnetic valve 33 is switched from on to off. 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 diagram which shows operation|movement of each apparatus of the steam sterilizer 1 in time T2-T3. When the sterilization process is continuously performed, the water supply to the chamber 10 is started with the heater 12 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, the water immediately evaporates and the pressure in the chamber 10 rapidly increases. Therefore, in the present embodiment, at a time T2 after a short time has elapsed from the time T1 at which water supply is started, the water supply pump 32 is temporarily stopped and the water supply solenoid valve 33 is closed.

The time T2 at which the water supply pump 32 is temporarily stopped is 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.

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

At the start of water supply to the chamber 10, the discharge solenoid valve 44 and the overflow solenoid valve 53 are open, and the chamber 10 and the water tank 20 are in communication via the discharge passage 40 and the overflow passage 50. Water vapor generated by evaporation of water supplied into the chamber 10 in the chamber 10 is discharged from the chamber 10 via the discharge path 40 and the overflow path 50. Therefore, the atmospheric pressure in the chamber 10 gradually decreases.

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

After the time T2, a sufficient time has elapsed and the pressure in the chamber 10 that has become higher 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 when the water supply pump 32 is restarted is the time after the time T2 at which the water supply pump 32 is temporarily stopped and the time after the atmospheric 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 once stopped, rather 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 is getting longer.

FIG. 6 is a schematic diagram 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, whereby the water supply to the chamber 10 is restarted and the water W is supplied from the water 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 the one end 56 of the overflow pipe 51, the one end 56 of the overflow pipe 51 exists in the air. Therefore, the air flows through the overflow pipe 51, but the water W does not flow through the overflow pipe 51.

Next, at a time T4 after a lapse of a predetermined time from the time T3 when the water supply to the chamber 10 is restarted, the discharge solenoid valve 44 switches from on to off and the air solenoid valve 62 switches from off to on. Replace 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 diagram which shows operation|movement of each apparatus of the steam sterilizer 1 in time T4-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 the water supply from the water storage tank 20 to the chamber 10 is continued. Since the discharge solenoid valve 44 is closed, the air in the chamber 10 is discharged from the chamber 10 via the overflow path 50.

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

When 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, which has exceeded 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, at time T5, the overflow sensor 54 is switched from off to on. It is estimated that the water surface Ws in the chamber 10 has exceeded the one end 56 of the overflow pipe 51 immediately before time T5. FIG. 8: is a schematic diagram which shows operation|movement of each apparatus of the steam sterilizer 1 in time T5-T6. Since the water W in the chamber 10 flows into the overflow pipe 51, a mixed flow of the water W and air flows through the overflow pipe 51. Since air is supplied to the chamber 10 by the air pump 63 when water is supplied to the chamber 10, the outflow of water from the chamber 10 to the overflow pipe 51 is promoted.

At a time T6 after a lapse of a predetermined time from the time T5 at which 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 diagram which shows operation|movement of each apparatus of the steam sterilizer 1 in time T6-T7. With the opening and closing of each solenoid valve set as described above, the air supply 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 continues to be in the ON state. As the water W flows out from the chamber 10, the water surface Ws in the chamber 10 gradually decreases.

When the water surface Ws in the chamber 10 lowers and reaches the position of the one end 56 of the overflow pipe 51, the outflow of the water W from the chamber 10 is stopped. When the water flow flowing 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, at time T7, the overflow sensor 54 is switched from on to off. It is estimated that the water surface Ws in the chamber 10 dropped to the one end 56 of the overflow pipe 51 immediately before time T7.

FIG. 10 is a schematic diagram showing the operation of each device of the steam sterilizer 1 at time T8. At time T8 after a lapse of a predetermined time from time T7 at which overflow sensor 54 is switched off, air solenoid valve 62 and overflow solenoid valve 53 are switched from on to off, and 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 the position of the one end 56 of the overflow pipe 51. In this way, the water supply process is completed and the heating process is started.

The overflow sensor 54 is switched from off to on during water supply to the chamber 10, and after the water supply to the chamber 10 is stopped, the overflow sensor 54 is switched from on to off, whereby the water surface Ws in the chamber 10 is changed to the overflow pipe 51. Is detected at the position of one end 56 of the. The overflow sensor 54 is used to detect that the amount of water required for the sterilization treatment of the object to be sterilized 100 is supplied to the chamber 10.

At time T8, the discharge solenoid valve 44 switches 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 vapor 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 operational effects of the steam sterilizer 1 according to the embodiment will be collectively described as follows. Note that reference numerals are given to the configurations of the embodiments, but this is an example.

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 and a heater 12 for heating water supplied into the chamber 10. This is a device 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 time T1, temporarily stops the water supply pump 32 at time T2, and then supplies water at time T3, as shown in FIG. Restart the pump 32.

When the sterilization process is continuously performed, the heater 12 in the chamber 10 is heated by the operation after the completion of the previous sterilization process. By starting the water supply pump and supplying water into the chamber 10 between times T1 and T2, the water comes into contact with the high temperature heater 12. Heat transfer from the heater 12 to the water allows the heater 12 to be cooled.

The water that contacts 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 time T2, which is a short time after the time T1 when water supply to the chamber 10 is started. As a result, it becomes 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, backflow of water from the chamber 10 to the water supply pump 32 can be prevented.

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 the discharge path 40 that connects the chamber 10 and the water storage tank 20, and is configured to open and close the discharge path 40. The overflow solenoid valve 53 is provided in the overflow path 50 that connects the chamber 10 and the water storage tank 20, and is configured 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 part.

Since the discharge solenoid valve 44 and the overflow solenoid valve 53 are open between times T1 and T3, the water vapor supplied to the chamber 10 can be discharged to the outside from the chamber 10. is there. Since the atmospheric pressure in the chamber 10 that has risen due to the generation of steam can be quickly lowered, the time from the time T2 when the water supply to the chamber 10 is temporarily stopped to the time T3 when 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 part.

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 atmospheric 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 lowers the atmospheric pressure in the chamber 10 that has become 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. To restart. The atmospheric pressure in the chamber 10 may be measured by the pressure gauge 74.

When the atmospheric pressure in the chamber 10 is higher than the pressure of the water discharged from the water supply pump 32, backflow of water from the chamber 10 to the water supply pump 32 occurs. By temporarily stopping the water supply pump 32 before the atmospheric pressure in the chamber 10 becomes larger 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. .. After the atmospheric pressure in the chamber 10 drops to less than the pressure of the water discharged from the water supply pump 32, the water supply pump 32 is restarted to restart the water supply pump 32 from the chamber 10 when the water supply pump 32 is restarted. Backflow of water to 32 can be prevented.

Further, as shown in FIG. 1, the steam sterilizer 1 includes an overflow sensor 54. The overflow sensor 54 detects that the amount of water required for the sterilization treatment of the object to be sterilized 100 has been supplied to the chamber 10. 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 necessary 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 prevent the sensitivity of the overflow sensor 54 from being lowered due to the 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 completion of water supply can be kept constant at the position of the one end 56 of the overflow pipe 51. As a result, 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 once stopped is shown rather than the time from the 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 thus defining the start/stop time of the water supply pump 32, it is possible to secure a sufficient time for the heater 12 to be cooled by the heat transfer to the water supplied to the chamber 10 between times T1 and T2. it can. Therefore, the heater 12 can be surely cooled.

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

1 steam sterilizer, 10 chamber, 10b bottom, 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 passage, 41 drainage pipe, 42 exhaust pipe, 43 common pipe, 44 discharge solenoid valve, 45 condenser part, 46 bent part, 50 overflow path, 51 overflow pipe, 52 rising part , 53 overflow solenoid valve, 54 overflow sensor, 55 other end, 56 one end, 60 air passage, 61 air pipe, 62 air solenoid valve, 63 air pump, 70 pressure passage, 71, 73, 75 pressure pipe, 72 joint, 74 pressure Total, 76 safety valve, 80 control section, 81 input section, 82 timer, 100 sterilized object, W water, Ws water surface.

Claims (4)

A chamber that can store the object to be sterilized,
A heater for heating the liquid supplied into the chamber,
Sterilize the object to be sterilized with the vapor of the liquid generated by heating the heater,
A liquid supply pump for transferring liquid to the chamber,
A sensor that is disposed outside the chamber and detects that the amount of liquid necessary for sterilizing the object to be sterilized has been supplied to the chamber;
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, Stop the feed pump ,
When supplying the liquid to the chamber, the control unit controls the liquid supply pump after starting the liquid supply pump and before the atmospheric pressure in the chamber becomes larger than the pressure of the liquid discharged from the liquid supply pump. A steam sterilizer that is stopped and then restarted the liquid supply pump after the pressure in the chamber dropped until it became lower than the pressure of the liquid discharged from the liquid supply pump . A chamber that can store the object to be sterilized,
A heater for heating the liquid supplied into the chamber,
Sterilize the object to be sterilized with the vapor of the liquid generated by heating the heater,
A liquid supply pump for transferring liquid to the chamber,
A sensor arranged outside the chamber, for detecting that the amount of liquid required for sterilizing the object to be sterilized is supplied to the chamber;
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, Stop the feed pump,
A steam sterilizer in which the stop time of the liquid supply pump after the liquid supply pump is once stopped is longer than the start time of the liquid supply pump at the start of liquid supply to the chamber. The chamber further includes a ventilation part configured to open and close a path communicating with the inside and the outside of the chamber,
When supplying the liquid to the chamber, wherein the control unit opens the vent, steam sterilizer according to claim 1 or 2. An overflow pipe is provided for discharging excess liquid from the chamber when liquid is supplied to the chamber,
The steam sterilizer according to any one of claims 1 to 3, wherein the sensor detects a flow of a liquid flowing through the overflow pipe.

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