JP6584241B2 - 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 sterilizes an object to be sterilized by holding the inside of a chamber for storing an object to be sterilized such as medical equipment in a sealed state and filling the chamber with high-pressure steam. A conventional steam sterilizer is disclosed in, for example, Japanese Utility Model Laid-Open No. 5-13445 (Patent Document 1).

Japanese Utility Model Publication No. 5-13445

  In the steam sterilizer described in Japanese Utility Model Laid-Open No. 5-13445 (Patent Document 1), an electromagnetic valve is provided in a path for discharging water in the chamber to the water storage tank, and the steam in the chamber is supplied to the water storage tank. A solenoid valve is also provided in the discharge path. Since the solenoid valve is provided in each of the two systems, there is a problem that the number of parts increases and the cost of the steam sterilizer increases.

  An object of the present invention is to provide a steam sterilizer capable of reducing the number of parts.

  A steam sterilizer according to the present invention includes a chamber capable of storing an object to be sterilized, and a heater for heating a liquid supplied into the chamber, and sterilizes the object to be sterilized with liquid vapor generated by heating the heater. . The steam sterilizer includes an exhaust path, a drainage path, a connecting portion, a common path, and an on-off valve. Gas exhausted from the chamber flows through the exhaust path. The exhaust path has an exhaust inlet end connected to the chamber and an exhaust outlet end opposite to the exhaust inlet end. The liquid discharged from the chamber flows through the drainage path. The drainage path has a drainage inlet end connected to the chamber and a drainage outlet end opposite to the drainage inlet end. The connecting portion connects the exhaust outlet end and the drain outlet end. The common path has one end communicating with both the exhaust path and the drainage path via the connecting portion, and the other end opposite to the one end. The on-off valve is provided in the common path.

  In the steam sterilizer, the chamber and the connecting portion are always in communication with each other via an exhaust path and a drain path.

  In the steam sterilizer, a part of the drainage path is disposed above the position of the liquid level when the liquid is supplied into the chamber.

  In the steam sterilizer, the drain outlet end is disposed above the position of the liquid level when the liquid is supplied into the chamber. The drain outlet end may be disposed above the upper surface of the chamber.

  The steam sterilizer further includes a control unit that controls the operation of the steam sterilizer. The control unit performs control so as to repeatedly start and stop the heater while generating steam in the chamber and discharging air from the chamber.

  The steam sterilizer further includes a temperature sensor that detects the temperature in the chamber. The control unit stops the heater when the temperature in the chamber detected by the temperature sensor is equal to or higher than the threshold, and starts the heater when the temperature in the chamber detected by the temperature sensor is lower than the threshold. The threshold value may be a temperature equal to or higher than the boiling point of the liquid supplied into the chamber.

  In the steam sterilizer, the control unit stops the heater when a predetermined time elapses after the heater is started, and starts the heater when the predetermined time elapses after the heater is stopped.

  The steam sterilizer further includes a liquid storage tank for storing the liquid discharged from the chamber. The other end of the common path communicates with the inside of the liquid storage tank.

  In the steam sterilizer, the connection part has a communication pipe part that communicates the exhaust path and the common path. The drain outlet end of the drain path communicates with the communication pipe part. The inner cross-sectional area of the communication pipe portion orthogonal to the flow direction of the fluid flowing through the communication pipe portion is smaller than the opening area of the exhaust outlet end and smaller than the opening area of one end of the common path.

  In the steam sterilizer, the liquid is water.

  According to the present invention, since the number of necessary parts of the steam sterilizer can be reduced, the cost of the steam sterilizer can be reduced.

It is a schematic diagram which shows the structure of a steam sterilizer. It is a schematic diagram which shows the chamber in which the to-be-sterilized thing was carried in. It is a perspective view which shows arrangement | positioning of the path | route of the fluid from a chamber to a water storage tank. It is a block diagram which shows the electric constitution of a steam sterilizer. It is a flowchart which shows the basic operation | movement process of a steam sterilizer. It is a timing chart which shows the 1st example of operation | movement of each apparatus of a steam sterilizer. It is a timing chart which shows the 2nd example of operation | movement of each apparatus of a steam sterilizer. It is a timing chart which shows the 3rd example of operation | movement of each apparatus of a steam sterilizer. It is a cross-sectional schematic diagram which shows the structure of the connection part vicinity of a modification. 6 is a schematic diagram showing a configuration of a steam sterilizer according to Embodiment 2. FIG. 6 is a schematic diagram showing a configuration of a steam sterilizer according to Embodiment 3. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a schematic diagram showing a configuration of a steam sterilizer 1 according to the present embodiment. As shown in FIG. 1, the steam sterilizer 1 according to the present embodiment includes a chamber 10 that can store an object to be sterilized typified by a medical instrument such as a gauze or a 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 object to be sterilized can be carried into and out of the chamber 10. By closing the open / close lid 11, the inside of the chamber 10 is held in a sealed state.

  A heater 12 is installed at the inner bottom of the chamber 10. The heater 12 is disposed so as to extend along the inner bottom portion of the chamber 10. The heater 12 heats the water supplied into the chamber 10 to generate steam. Water is an example of a liquid that is supplied into the chamber 10 for sterilization. The water may be ordinary water (tap water), well water, distilled water or purified water. The liquid 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 an object to be sterilized 100 (not shown in FIG. 1) can be mounted is provided substantially parallel to the inner bottom of the chamber 10.

  A temperature sensor 16 for detecting the temperature in the chamber 10 is attached to the inner surface of the chamber 10 facing the open / close 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 tank 20 stores water discharged from the chamber 10. A 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.

  A path that allows the chamber 10 and the water storage tank 20 to communicate with each other includes an exhaust path 30, a drain path 40, a connecting portion 50, and a common path 60. The exhaust path 30, the drainage path 40, the connecting portion 50, and the common path 60 are configured such that all the inner cross-sectional areas orthogonal to the flow direction of the fluid flowing through the exhaust path 30, the connecting portion 50, and the common path 60 are equal. The circular pipes constituting the exhaust path 30, the drain path 40, and the common path 60 all have the same inner diameter.

  The exhaust path 30 is a path through which the gas discharged from the chamber 10 flows. The exhaust path 30 has an exhaust inlet end 31 connected to the chamber 10 and an exhaust outlet end 32 opposite to the exhaust inlet end 31. The exhaust inlet end 31 constitutes one end of the exhaust path 30. The exhaust outlet end 32 constitutes the other end of the exhaust path 30.

  The exhaust inlet end 31 is connected to the chamber 10 at a position above the highest level of the water surface in the chamber 10. The exhaust inlet end 31 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 mixture thereof in the chamber 10 is discharged out of the chamber 10 through the exhaust inlet end 31 and flows in the exhaust path 30 from the exhaust inlet end 31 toward the exhaust outlet end 32.

  The drainage path 40 is a path through which water discharged from the chamber 10 flows. The drainage path 40 has a drainage inlet end 41 connected to the chamber 10 and a drainage outlet end 42 opposite to the drainage inlet end 41. The drainage inlet end 41 constitutes one end of the drainage path 40. The drain outlet end 42 constitutes the other end of the drain passage 40.

  The drain inlet end 41 is connected to the bottom 10 b of the chamber 10. The water supplied into the chamber 10 is collected near the bottom 10 b inside the chamber 10, and the drainage inlet end 41 is connected to a position where water is stored in the chamber 10. The water in the chamber 10 is discharged out of the chamber 10 through the drainage inlet end 41 and flows in the drainage path 40 from the drainage inlet end 41 toward the drainage outlet end 42.

  The connecting part 50 connects the exhaust path 30 and the drainage path 40. An exhaust outlet end 32 of the exhaust path 30 is connected to the connecting portion 50. A drain outlet end 42 of the drain passage 40 is connected to the connecting portion 50. The connecting portion 50 communicates the exhaust outlet end 32 and the drain outlet end 42.

  The connecting part 50 is disposed above the upper surface 10 t of the chamber 10. The exhaust path 30 has a rising portion that rises upward in the vertical direction between paths from the exhaust inlet end 31 to the exhaust outlet end 32. The drainage path 40 has a rising portion that rises upward in the vertical direction between paths from the drainage inlet end 41 to the drainage outlet end 42. Since the exhaust outlet end 32 of the exhaust passage 30 and the drain outlet end 42 of the drain passage 40 are connected to the connecting portion 50, they are disposed above the upper surface 10 t of the chamber 10.

  In the common path 60, both the gas discharged from the chamber 10 and reaching the connecting part 50 via the exhaust path 30 and the water discharged from the chamber 10 and reaching the connecting part 50 via the drainage path 40 flow. It is a route for. The common path 60 has a common path for the gas to flow and a path for the water to flow. The common path 60 has one end 61 and the other end 62 opposite to the one end 61.

  One end 61 of the common path 60 is connected to the connecting portion 50. The one end 61 communicates with both the exhaust passage 30 and the drainage passage 40 via the connecting portion 50.

  The connecting part 50 has a T-shape. The connecting part 50 has a tubular communication pipe part 51 and a tubular branch pipe part 52. The branch pipe part 52 is connected in the middle of the communication pipe part 51. The internal space of the hollow communication pipe part 51 and the internal space of the hollow branch pipe part 52 communicate with each other. The connection part 50 is comprised with the tee joint.

  The connection part 50 is not restricted to a tee joint, and may be comprised by arbitrary joints, such as a Y connector. Alternatively, the connecting portion 50 may be formed by directly joining a pipe constituting the drainage path 40 to a single pipe constituting the exhaust path 30 and the common path 60.

  An exhaust outlet end 32 of the exhaust path 30 is connected to one end of the communication pipe portion 51 of the connecting portion 50. One end 61 of the common path 60 is connected to the other end portion of the communication pipe portion 51 of the connecting portion 50. The communication pipe 51 communicates the internal space of the exhaust path 30 and the internal space of the common path 60 with each other.

  A drain outlet end 42 of the drain passage 40 is connected to the branch pipe portion 52 of the connecting portion 50. The internal space of the drainage path 40 and the internal space of the branch pipe portion 52 communicate with each other. The internal space of the exhaust passage 30 and the internal space of the drainage passage 40 communicate with each other through the branch pipe portion 52 and the communication pipe portion 51. The internal space of the common path 60 and the internal space of the drainage path 40 communicate with each other with the branch pipe part 52 and the communication pipe part 51 interposed.

  The exhaust path 30 and the drainage path 40 communicate with each other via the connecting portion 50, the exhaust path 30 and the common path 60 communicate with each other, and the drainage path 40 and the common path 60 communicate with each other.

  The other end 62 of the common path 60 is disposed inside the water tank 20. The other end 62 communicates with the inside of the water storage tank 20.

  Inside the water storage tank 20, the common path 60 has a capacitor portion 65. The capacitor portion 65 is formed in a cylindrical shape in which a plurality of annular portions formed by bending pipes constituting the common path 60 are concentrically overlapped. The capacitor portion 65 increases the tube length of the common path 60 that is submerged in the liquid phase portion in the water storage tank 20. Capacitor portion 65 is not limited to the shape described above, and may have any shape that can increase the tube length of common path 60, such as a meandering shape.

  The condenser unit 65 promotes heat transfer from the high-temperature water and water vapor passing through the common path 60 to the water stored in the water storage tank 20, and reduces the temperature of the fluid flowing through the common path 60. Thereby, the capacitor | condenser part 65 reduces the noise when water is discharged | emitted in the water storage tank 20. FIG. The condenser unit 65 has a silent function for reducing the loudness generated by the steam sterilizer 1.

  Inside the water storage tank 20, the common path 60 has a bent portion 66. The common path 60 rises upward from the capacitor unit 65 and extends from the liquid phase part to the gas phase part in the water storage tank 20. The common path 60 is bent at the bent portion 66 and extends downward. The other end 62 of the common path 60 is disposed toward the liquid level in the water tank 20. Thereby, the water or steam discharged from the common path 60 into the water tank 20 flows out from the other end 62 of the common path 60 toward the water stored in the water tank 20.

  An opening / closing valve 68 is provided in the common path 60. The on-off valve 68 is arranged in the middle of the common path 60. The on-off valve 68 opens and closes the common path 60. The on-off valve 68 is provided to be switchable between an open state in which fluid can flow from the connecting portion 50 toward the water storage tank 20 and a closed state in which the flow of fluid from the connecting portion 50 to the water storage tank 20 is prohibited. . The on-off valve 68 may be an electromagnetic valve or an electric valve.

  The common path 60 is provided with an opening / closing valve 68, while the exhaust path 30 and the drainage path 40 are not provided with valves for opening and closing the exhaust path 30 and the drainage path 40. The exhaust path 30 and the drainage path 40 are not provided with a configuration that can close the exhaust path 30 and the drainage path 40. The exhaust path 30 is normally open from the exhaust inlet end 31 to the exhaust outlet end 32. The drainage path 40 is normally open from the drainage inlet end 41 to the drainage outlet end 42. The chamber 10 and the connecting portion 50 are always in communication with each other via the exhaust path 30 and the drainage path 40.

  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 10 t of the chamber 10 and the other end connected to the joint 72. The pressure tube 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 tank 20. When the pressure of the gas in the chamber 10 rises excessively, the safety valve 76 is opened, and the gas in the chamber 10 is discharged into the water tank 20 through the pressure pipe 71, the joint 72, the pressure pipe 73, and the safety valve 76 in this order. The As a result, the pressure in the chamber 10 decreases, and the pressure in the chamber 10 is maintained in an appropriate range.

  FIG. 2 is a schematic diagram showing the chamber 10 into which the article to be sterilized 100 is carried. As described above, the article to be sterilized 100 is placed on the mounting table 13. An operator who uses the steam sterilizer 1 can carry the article to be sterilized 100 into the chamber 10 by opening the opening / closing lid 11 of the chamber 10.

  Water W is accommodated in the chamber 10 shown in FIG. An operator who uses the steam sterilizer 1 manually supplies the water W into the chamber 10 before starting the sterilization process of the article 100 to be sterilized. FIG. 2 shows the amount of water W when the water W is supplied into the chamber 10. Since the water W evaporates by heating with the heater 12 after the sterilization process is started, the amount of the water W shown in FIG. 2 is the maximum amount of the water W existing in the chamber 10.

  FIG. 2 shows the water surface Ws of the water W. The water surface Ws shown in FIG. 2 is the water surface Ws when the water W is supplied into the chamber 10 and indicates the highest level of the water surface Ws in the chamber 10. As described above, the exhaust inlet end 31 of the exhaust path 30 is connected to the chamber 10 at a position above the highest level of the water surface Ws in the chamber 10. The exhaust inlet end 31 is connected to the chamber 10 at a position higher than the highest level of the water surface Ws in the vertical direction and lower than the mounting table 13.

  FIG. 3 is a perspective view showing the arrangement of the fluid path from the chamber 10 to the water tank 20. In FIG. 3, among the main components of the steam sterilizer 1 shown in FIG. 1, the chamber 10 constituted by the chamber 10, the water storage tank 20, the exhaust path 30, the drainage path 40, the connecting portion 50, and the common path 60. And a path communicating with the water tank 20 is shown. Both the chamber 10 and the water tank 20 are mounted on the base portion 2.

  As described above, the connecting portion 50 is disposed above the upper surface 10 t of the chamber 10. The exhaust path 30 has a rising portion 33 that rises upward in the vertical direction between paths from the exhaust inlet end 31 to the exhaust outlet end 32. The drainage path 40 has a rising portion 43 that rises upward in the vertical direction between paths from the drainage inlet end 41 to the drainage outlet end 42. The rising portion 33 of the exhaust path 30 extends while being inclined with respect to the vertical direction. The rising portion 43 of the drainage path 40 extends along the vertical direction.

  Referring also to FIG. 2, the upper surface 10 t of the chamber 10 is located above the position of the water surface Ws when the water W is supplied into the chamber 10. The connecting part 50 is disposed above the upper surface 10 t of the chamber 10. Therefore, the connecting portion 50 is disposed above the position of the water surface Ws when the water W is supplied into the chamber 10. The connecting portion 50 is disposed above the highest level of the water surface Ws in the chamber 10.

  Since the exhaust outlet end 32 of the exhaust passage 30 and the drain outlet end 42 of the drain passage 40 are connected to the connecting portion 50, they are disposed above the upper surface 10 t of the chamber 10. The exhaust outlet end 32 of the exhaust passage 30 and the drain outlet end 42 of the drain passage 40 are disposed above the position of the water surface Ws when the water W is supplied into the chamber 10. A part of the exhaust path 30 including the exhaust outlet end 32 and a part of the drainage path 40 including the drain outlet end 42 are more than the position of the water surface Ws when the water W is supplied into the chamber 10. It is arranged above.

  On the other hand, the connection part 50 is arrange | positioned below the upper surface 20t of the water storage tank 20. FIG. The connecting portion 50 is disposed between the upper surface 10t of the chamber 10 and the upper surface 20t of the water tank 20 in the vertical direction. The connecting part 50 is arranged at a position higher than the upper surface 10t of the chamber 10 and lower than the upper surface 20t of the water tank 20 in the vertical direction. Since the connecting portion 50 is provided at a position lower than the upper surface 20t of the water storage tank 20, it is avoided that the arrangement of the connecting portion 50 affects the outer dimensions of the steam sterilizer 1, and the outer dimensions of the steam sterilizer 1 are increased. Is prevented.

  FIG. 4 is a block diagram showing an electrical configuration of the steam sterilizer 1. As shown in FIG. 4, 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 level sensor 26, and the pressure gauge 74. The control unit 80 receives an output of a detection value related to the temperature inside the chamber 10 from the temperature sensor 16. The control unit 80 receives an output of a detection value related to the water level in the water storage tank 20 from the level sensor 26. The control unit 80 receives an output of 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 a heating temperature, a sterilization time, and a drying time from the input unit 81 to the control unit 80. The control unit 80 further includes a timer 82 that measures a predetermined time. The timer 82 is used for recognizing the elapsed time in the permeation process and the replacement process, which will be described in detail later, and is used for controlling the sterilization time and drying time of the article 100 to be sterilized.

  The control unit 80 outputs a control signal to each device included in the steam sterilizer 1 such as the heater 12 and the on-off valve 68 corresponding to each control step of the steam sterilizer 1. By receiving the control signal from the control unit 80 and appropriately operating each device, the sterilization process of the article 100 to be sterilized by the steam sterilizer 1 is reliably performed.

  Operation | movement of the steam sterilizer 1 provided with the above structure is demonstrated below. FIG. 5 is a flowchart showing the basic operation steps of the steam sterilizer 1. The operation of the steam sterilizer 1 in each step for sterilization of an object to be sterilized by the steam sterilizer 1 will be described with reference to the flowchart shown in FIG.

  First, as an advance preparation, an operator who uses the steam sterilizer 1 opens the opening / closing lid 11 of the chamber 10 and places the article to be sterilized 100 on the mounting table 13. The operator also manually supplies water W into the chamber 10. When it is confirmed that a predetermined amount of water W is accommodated in the chamber 10, the operator turns on the steam sterilizer 1 and starts the steam sterilizer 1 in step (S10) shown in FIG. To do. Instead of the above operation, the operator may make advance preparations in a standby state in which the power of the steam sterilizer 1 is turned on.

  Next, in the step (S20), the inside of the chamber 10 is heated. By turning on the heater 12 on the bottom surface in the chamber 10, the water supplied into the chamber 10 is heated by the heater 12 and steam is generated. At the same time, the article to be sterilized 100 placed on the placing table 13 is also heated.

  Next, in the step (S30), the vapor generated in the chamber 10 is permeated into the inside of the article to be sterilized 100. By discharging the air remaining in the sterilized object 100 with steam, the steam is surely present around and inside the sterilized object 100.

  Next, in step (S40), a replacement step is performed. The air in the chamber 10 is pushed out by steam generated by heating the water by the heater 12, and the pushed-out air is exhausted to the outside of the chamber 10 through the exhaust path 30. The air in the chamber 10 is replaced with water vapor, and the air and water vapor in the chamber 10 are replaced. In the previous step (S30), the air is exhausted from the inside of the article to be sterilized 100, so that the residual air in the chamber 10 is reliably exhausted and the chamber 10 is filled with steam.

  Next, in step (S50), the heater 12 is kept on until the temperature in the chamber 10 reaches a temperature required for the sterilization of the article 100, and the pressure in the chamber 10 is increased.

  When the inside of the chamber 10 reaches a required temperature for a predetermined sterilization process, in a next step (S60), the sterilization processing of the article to be sterilized 100 is performed with the steam generated by the heating of the heater 12. During the sterilization process, the heater 12 is turned on and off as appropriate, and the temperature in the chamber 10 is controlled so that the temperature in the chamber 10 does not fall below a predetermined sterilization temperature.

  After a predetermined time has elapsed in the step (S60) and the sterilization process is completed, in the next step (S70), a steaming process is performed in which the heater 12 is turned off and the water and water vapor in the chamber 10 are discharged to the water tank 20. It is.

  Next, in step (S80), the object to be sterilized is dried. At the completion of the steaming step (S70), the heater 12 in the chamber is heated by energization at a constant cycle, and the sterilized material is dried for a predetermined time. In addition, you may dry a to-be-sterilized thing in the state which opened the opening-and-closing lid | cover 11 of the chamber 10 slightly.

  After the predetermined drying time has elapsed, the heater 12 is stopped, whereby the drying is completed, and all the steps for sterilizing the article to be sterilized are completed as shown in step (S90). In this state, the opening / closing lid 11 of the chamber 10 can be opened, and the sterilized article 100 that has been sterilized can be removed from the chamber 10.

  FIG. 6 is a timing chart showing a first example of the operation of each device of the steam sterilizer 1. 6 shows the operation of the heater 12 and the on-off valve 68 in the process from the heating process (S20) to the sterilization process (S60) described with reference to FIG. The temperature is shown. At the time of power activation in the step (S10), the on-off valve 68 is opened. The heater 12 remains off.

  As shown in FIG. 6, in the heating step (S20), the on-off valve 68 remains open and the heater 12 is turned on. A control signal for instructing the heater 12 to switch from OFF to ON is transmitted from the control unit 80 shown in FIG. 4, whereby the heater 12 is turned ON. By activation of the heater 12, water in the chamber 10 is heated by the heater 12, and steam is generated in the chamber 10. Thereby, the temperature in the chamber 10 detected by the temperature sensor 16 increases.

  Since the on-off valve 68 is open, the chamber 10 and the water storage tank 20 communicate with each other. A part of the air in the chamber 10 is pushed out of the chamber 10 by steam. A part of the air and a part of the steam generated by the evaporation of water are discharged from the exhaust inlet end 31 to the outside of the chamber 10. The discharged air / steam mixture flows to the water storage tank 20 through the exhaust path 30, the connecting portion 50, and the common path 60 in this order.

  The specific gravity of the unsaturated vapor whose pressure is less than the saturated vapor pressure is smaller than the specific gravity of air. Therefore, steam exists in a higher position in the internal space of the chamber 10, and air exists in a lower position near the water surface Ws. As described with reference to FIG. 2, the exhaust inlet end 31 of the exhaust path 30 is connected to the chamber 10 at a position slightly higher than the water surface Ws. The exhaust inlet end 31 is connected to the chamber 10 at a position where air exists in the chamber 10 during the heating step (S20). Thereby, it is possible to suppress the vapor generated in the chamber 10 from being discharged from the chamber 10 and to efficiently discharge air from the chamber 10.

  When a detection value indicating that the temperature in the chamber 10 has reached the boiling point of water is output from the temperature sensor 16 to the control unit 80, the process proceeds from the heating step (S20) to the permeation step (S30).

  After the start of the permeation step (S30), that is, after the temperature in the chamber 10 reaches the boiling point of water, the on-off valve 68 is opened and the heater 12 is kept on for 30 seconds. The controller 80 recognizes the elapsed time after the start of the infiltration step (S30) using the timer 82 shown in FIG.

  When 30 seconds have elapsed, the on-off valve 68 is closed. A control signal instructing switching from open to close is sent to the on-off valve 68 from the control unit 80 shown in FIG. 4, thereby closing the on-off valve 68. By closing the on-off valve 68, the internal space of the chamber 10 becomes a sealed space. When steam is further generated by heating by the heater 12, the pressure in the chamber 10 rises, and the temperature in the chamber 10 rises above the boiling point of water.

  By making the pressure in the chamber 10 higher than the atmospheric pressure, the vapor penetrates into the object to be sterilized 100, and the air remaining in the object to be sterilized 100 is discharged from the object to be sterilized 100.

  When the temperature in the chamber 10 rises to the boiling point of water plus 1 ° C. or higher, the heater 12 is stopped. A control signal instructing switching from ON to OFF is transmitted from the control unit 80 to the heater 12, thereby turning off the heater 12. When the heater 12 stops, the temperature in the chamber 10 decreases. When the temperature in the chamber 10 falls below the boiling point of water, the heater 12 is started again. The time during which the heater is repeatedly turned on and off while the on-off valve 68 is closed continues for 60 seconds. The control unit 80 recognizes the elapsed time after closing the on-off valve 68 using the timer 82 shown in FIG.

  When 60 seconds elapse, the process shifts from the permeation process (S30) to the replacement process (S40). If the heater 12 is OFF at the start of the replacement step (S40), the heater 12 is turned ON, and steam is generated in the chamber 10 by heating the heater 12. In the replacement step (S40), the on-off valve 68 is opened. A control signal instructing switching from the closed state to the open state is transmitted to the on-off valve 68, whereby the on-off valve 68 is opened. By opening the on-off valve 68, the internal space of the chamber 10 and the internal space of the water storage tank 20 communicate with each other via the exhaust path 30, the connecting portion 50, and the common path 60.

  Since the on-off valve 68 is open, as in the heating step (S20), the air in the chamber 10 and a part of the steam generated by the evaporation of water are discharged out of the chamber 10 from the exhaust inlet end 31. The The discharged air / steam mixture flows to the water storage tank 20 through the exhaust path 30, the connecting portion 50, and the common path 60 in this order.

  In the previous infiltration step (S30), the time for allowing the vapor to penetrate into the sterilized object 100 by closing the on-off valve 68 is set. Thereby, air is more reliably exhausted from the chamber 10, and the air remaining in the chamber 10 is further reduced. As a result, the air and steam in the chamber 10 are more reliably replaced.

  Due to the heating by the heater 12, the temperature in the chamber 10 detected by the temperature sensor 16 rises. When the temperature in the chamber 10 rises to the boiling point of water plus 2 ° C. or higher, the heater 12 is stopped. When the heater 12 stops, the temperature in the chamber 10 decreases. When the temperature in the chamber 10 falls below the boiling point of water plus 1 ° C., the heater 12 is started again.

  If the heater 12 is kept ON during the replacement step (S40), the amount of steam generated by evaporation of water in the chamber 10 becomes larger than the amount of air / steam mixture discharged from the chamber 10, The pressure in the chamber 10 increases. When the pressure in the chamber 10 rises excessively, water is pushed out of the chamber 10 by the steam and discharged from the drainage path 40. In this case, a situation may occur in which the common path 60 is blocked by the flow of water and air discharge is hindered, or water required for sterilization is insufficient in the chamber 10.

  Therefore, in the present embodiment, the heater 12 is controlled to be repeatedly started and stopped during the replacement step (S40) in which steam is generated in the chamber 10 and air is discharged from the chamber 10. Thereby, evaporation of water in the chamber 10 is appropriately controlled, a pressure increase in the chamber 10 is suppressed, and discharge of water from the chamber 10 is suppressed. In this way, control is performed so as to discharge only the air / steam mixture from the chamber 10.

  The connecting portion 50 that connects the exhaust path 30 and the drainage path 40 is disposed above the position of the water surface Ws in the chamber 10. The rising portion 43 is provided in the drainage path 40 by disposing the drainage outlet end 42 above the position of the water surface Ws. Even if water flows out from the chamber 10 to the drainage path 40, if the outflowed water is not retained in the rising part 43 and reaches the connecting part 50, the above-described water flow blocks the common path 60 or is sterilized. It is possible to avoid situations such as lack of necessary water. By providing the rising portion 43, in order for the water in the drainage path 40 to reach the connecting portion 50, it is necessary to raise the water level up to the connecting portion 50 against gravity. Thereby, it is suppressed that the water which flowed out from the chamber 10 reaches the connection part 50.

  By providing the rising portion 43, a small amount of water is allowed to be discharged from the chamber 10 during the replacement step (S40). Therefore, the pressure in the chamber 10 can be increased to atmospheric pressure or higher during the replacement step (S40). It becomes possible. As a result, control related to switching of the heater 12 between ON and OFF becomes easier.

  By providing the rising portion 43, water that has flowed out of the chamber 10 does not reach the connecting portion 50 even if the pressure in the chamber 10 is increased to atmospheric pressure or higher during the replacement step (S40). The temperature in the chamber 10 can be maintained at a temperature above the boiling point of water. Thereby, since the water in the chamber 10 can be evaporated more rapidly, the time required for the replacement step (S40) is shortened.

  When the time during which the temperature in the chamber 10 is maintained at the boiling point of water minus 1 ° C. or more continues for 120 seconds by repeating ON and OFF of the heater, the process proceeds from the replacement step (S40) to the pressurization step (S50). The control unit 80 recognizes the elapsed time during the replacement step (S40) using the timer 82 shown in FIG.

  If the heater 12 is OFF at the start of the pressurizing step (S50), the heater 12 is turned ON. In the pressurizing step (S50), the on-off valve 68 is closed. By closing the on-off valve 68, the internal space of the chamber 10 becomes a sealed space. The temperature in the chamber 10 rises due to the heating by the heater 12.

  The heater 12 is kept on until the temperature in the chamber 10 reaches a temperature required for the sterilization treatment of the article 100 to be sterilized plus 0.5 ° C., and the chamber 10 is heated. For example, the sterilization temperature may be set to 115 ° C, 121 ° C, or 135 ° C.

  When the inside of the chamber 10 reaches a required temperature for a predetermined sterilization process, the process proceeds from the pressurization step (S50) to the sterilization step (S60). During the sterilization process, the heater 12 is turned on and off as appropriate, and the temperature in the chamber 10 is set within the chamber 10 with a target of sterilization temperature + 0.5 ° C. to + 1.0 ° C. so that the temperature in the chamber 10 does not fall below a predetermined sterilization temperature. To manage the temperature. The object to be sterilized 100 is sterilized for a time longer than the minimum sterilization time at each sterilization temperature.

  When the predetermined time has elapsed and the sterilization process is completed, the process proceeds from the sterilization process (S60) to the steaming process (S70).

  Although not shown in FIG. 6, in the steaming process (S70), the on-off valve 68 is opened. By opening the on-off valve 68, the internal space of the chamber 10 and the internal space of the water storage tank 20 communicate with each other via the exhaust path 30, the connecting portion 50, and the common path 60.

  The steam in the chamber 10 is discharged to the water storage tank 20 through the exhaust path 30, the connecting portion 50, and the common path 60. Water is pushed out from the chamber 10 to the drainage path 40 due to the pressure of the steam, and further, the water level in the drainage path 40 rises due to the high flow velocity of the steam flowing through the connection part 50, and water flows from the drainage path 40 to the connection part 50. Sucked up facilitates drainage of water from the chamber 10. The water that has reached the connecting portion 50 flows along the common path 60 together with the flow of steam, and is discharged to the water storage tank 20.

  As described above, also in the heating step (S20) and the replacement step (S40), a gas flow is generated from the exhaust path 30 to the common path 60 via the connecting part 50. At this time, the connecting part 50 Therefore, even if the water level in the drainage path 40 rises, water does not reach the connecting part 50. Since the rising portion 43 is provided in the drainage path 40 and a part of the drainage path 40 is disposed above the position of the water surface Ws in the chamber 10, the volume of the drainage path 40 is increased. In the step (S20) and the replacement step (S40), it is possible to more reliably avoid the water flowing out from the chamber 10 reaching the connecting portion 50.

  FIG. 7 is a timing chart showing a second example of the operation of each device of the steam sterilizer 1. The first example shown in FIG. 6 and the second example shown in FIG. 7 are different in the set temperatures in the permeation step (S30) and the replacement step (S40).

  More specifically, in the first example shown in FIG. 6, in the infiltration step (S30), the boiling point of water plus 1 ° C. is set as the upper limit of the temperature in the chamber 10, and the boiling point of water is set as the lower limit of the temperature in the chamber 10. It is set as a value. In the replacement step (S40), the boiling point of water plus 2 ° C. is set as the upper limit of the temperature in the chamber 10, and the boiling point of water plus 1 ° C. is set as the lower limit value of the temperature in the chamber 10. In the first example shown in FIG. 6, two thresholds related to the temperature in the chamber 10 are set. In the chart shown in FIG. 6, the temperature starts to decrease immediately when the higher temperature reaches the threshold and the heater 12 is turned off, and immediately starts to increase when the lower temperature is reached and the heater 12 is turned on. Yes. However, since an overshoot actually occurs, the fluctuation width of the temperature in the chamber 10 becomes larger than 1 ° C.

  Therefore, in the second example shown in FIG. 7, the temperature threshold value in the infiltration step (S30) is set to one of the boiling point of water plus 1 ° C., and the temperature in the chamber 10 detected by the temperature sensor 16 is the boiling point of water plus. When the temperature becomes 1 ° C. or higher, the heater 12 is stopped, and when the temperature in the chamber 10 becomes less than the boiling point of water plus 1 ° C., the heater 12 is controlled to start. The threshold value of the temperature in the replacement step (S40) is set to one of the boiling point of water plus 2 ° C, and when the temperature in the chamber 10 exceeds the boiling point of water plus 2 ° C, the heater 12 is stopped and the temperature in the chamber 10 is reduced to water. The heater 12 is controlled to start when the boiling point of the water becomes less than 2 ° C.

  In this way, the fluctuation width of the temperature in the chamber 10 is only the amount of control overshoot, so that the fluctuation width of the temperature can be further reduced as shown in FIG. Therefore, the temperature in the chamber 10 can be further stabilized.

  FIG. 8 is a timing chart showing a third example of the operation of each device of the steam sterilizer 1. In the example shown in FIGS. 6 and 7, the example in which the heater 12 is started and stopped according to the detected value of the temperature in the chamber 10 in the replacement step (S40) has been described. In the third example shown in FIG. 8, in the replacement step (S40), the heater 12 is activated and stopped corresponding to the passage of a predetermined time. The control unit 80 recognizes the elapsed time during the replacement step (S40) using the timer 82 shown in FIG.

  More specifically, when the replacement step (S40) starts, the heater 12 is turned on. The heater 12 is kept on for 30 seconds, and after 30 seconds, the heater 12 is turned off. The heater 12 is kept off for 15 seconds, and after 15 seconds, the heater 12 is turned on. The heater 12 is kept on for 15 seconds, and after 15 seconds, the heater 12 is turned off. Thus, the heater 12 is stopped when a predetermined time elapses after the heater 12 is started, and the heater 12 is started when a predetermined time elapses after the heater 12 is stopped. The heater 12 is repeatedly turned on and off as time passes.

  Thus, in order to maintain the temperature in the chamber 10 at the boiling point of water minus 1 ° C. or more for 120 seconds, the heater 12 may be controlled corresponding to the passage of time.

  FIG. 9 is a schematic cross-sectional view showing a configuration in the vicinity of the connecting portion 50 according to a modification. Regarding the connecting portion 50, the example in which the inner cross-sectional area perpendicular to the flow direction of the fluid flowing through the connecting portion 50 is equal to that of the exhaust path 30, the drainage path 40, and the common path 60 has been described above. Not limited to this example, as shown in FIG. 9, the inner cross-sectional area of the connecting portion 50 may be smaller than the inner cross-sectional areas of the exhaust path 30, the drainage path 40, and the common path 60.

  The connecting part 50 has a communication pipe part 51 and a branch pipe part 52. The branch pipe part 52 is connected in the middle of the communication pipe part 51. The communication pipe portion 51 has one end portion 53 and the other end portion 54. The branch pipe part 52 has an end part 55. The vicinity of one end portion 53 of the communication pipe portion 51 is inserted into the exhaust path 30 from the exhaust outlet end 32. The vicinity of the other end portion 54 of the communication pipe portion 51 is inserted into the common path 60 from one end 61. The vicinity of the end portion 55 of the branch pipe portion 52 is inserted into the drainage path 40 from the drainage outlet end 42.

  The communication pipe portion 51 communicates the exhaust path 30 and the common path 60. The drain outlet end 42 of the drain passage 40 is in fluid communication with the communication pipe portion 51. The internal space of the drainage path 40 communicates with the internal space of the communication pipe portion 51. The water flowing through the drainage path 40 can flow into the communication pipe portion 51 via the branch pipe portion 52.

  The outer peripheral surface of the communication pipe portion 51 is in contact with the inner peripheral surface of the exhaust path 30 and is in contact with the inner peripheral surface of the common path 60. The outer diameter of the communication pipe portion 51 is substantially equal to the inner diameters of the exhaust path 30 and the common path 60. The outer peripheral surface of the branch pipe portion 52 is in contact with the inner peripheral surface of the drainage path 40. The outer diameter of the branch pipe portion 52 is substantially equal to the inner diameter of the drainage path 40. The inner diameter of the communication pipe portion 51 is smaller than the inner diameter of the exhaust path 30 and smaller than the inner diameter of the common path 60. The inner diameter of the branch pipe portion 52 is smaller than the inner diameter of the drainage path 40.

  The cross-sectional area of the internal space of the communication pipe portion 51 that is orthogonal to the direction in which the fluid flows is smaller than the cross-sectional area of the exhaust path 30 and smaller than the cross-sectional area of the common path 60. The inner cross-sectional area of the communication pipe part 51 orthogonal to the flow direction of the fluid flowing through the communication pipe part 51 is smaller than the opening area of the exhaust outlet end 32 and smaller than the opening area of the one end 61.

  A solid line arrow shown in FIG. 9 indicates the flow of gas flowing through the communication pipe portion 51 from the exhaust path 30 toward the common path 60. A broken-line arrow shown in FIG. 9 indicates the flow of water sucked up from the drainage path 40 to the connecting portion 50. As described above, in the steaming step (S <b> 70), water is sucked up from the drainage path 40 to the connecting portion 50 due to the high flow velocity of the steam flowing through the connecting portion 50.

  The air flowing through the exhaust path 30 and the common path 60 is formed by forming the communication pipe section 51 with a small diameter and reducing the inner cross-sectional area of the communication pipe section 51 as compared with the inner cross-sectional areas of the exhaust path 30 and the common path 60. The flow velocity of the air flowing through the communication pipe portion 51 is larger than the flow velocity of. Therefore, according to Bernoulli's theorem, the pressure in the communication pipe part 51 further decreases. Thereby, the capability to suck up water from the drainage path 40 by the venturi effect increases. Therefore, it is possible to increase the ability to suck water from the drainage path 40 to the connecting portion 50 in the steaming step (S70), and to transfer the water from the chamber 10 to the water tank 20 more easily.

(Embodiment 2)
FIG. 10 is a schematic diagram illustrating a configuration of the steam sterilizer 1 according to the second embodiment. Compared to the first embodiment, the steam sterilizer of the second embodiment is different in that it further includes a temperature sensor 17 as shown in FIG. The temperature sensor 17 is disposed at the bottom 10 b in the internal space of the chamber 10. The temperature sensor 17 is a second temperature sensor different from the temperature sensor 16 described in the first embodiment. The temperature sensor 17 detects the temperature of the water supplied into the chamber 10.

  The temperature sensor 17 is electrically connected to the control unit 80 shown in FIG. The control unit 80 receives an output of a detection value related to the temperature of water inside the chamber 10 from the temperature sensor 17. 1 and 10, the temperature sensor 16 is disposed above the mounting table 13 in the internal space of the chamber 10 and detects the temperature of the gas inside the chamber 10.

  In the second embodiment, the temperature sensor 17 is used to detect that the temperature of the chamber 10 has reached the boiling point of water. In the second embodiment, when the detection value indicating that the temperature of the water in the chamber 10 has reached the boiling point is output from the temperature sensor 17 to the control unit 80, the heating process (S20) is changed to the permeation process (S30). Transition.

  In the second embodiment, the temperature sensor 17 is used to detect that the temperature in the chamber 10 has risen to the boiling point of water plus 1 ° C. or more, and has dropped to below the boiling point of water. In Embodiment 2, when the detection value indicating that the temperature of water in the chamber 10 has risen to the boiling point plus 1 ° C. is output from the temperature sensor 17 to the control unit 80 in the infiltration step (S30), the heater 12 Is turned off. When a detection value indicating that the temperature of the water in the chamber 10 has dropped to below the boiling point is input from the temperature sensor 17 to the control unit 80, the heater 12 is turned on.

  In the second embodiment, the temperature sensor 17 is used to detect that the temperature in the chamber 10 has risen to the boiling point of water plus 2 ° C. or more, and has dropped to the boiling point of water plus less than 1 ° C. In the second embodiment, when the detection value indicating that the temperature of the water in the chamber 10 has risen to the boiling point plus 2 ° C. is output from the temperature sensor 17 to the control unit 80 in the replacement step (S40), the heater 12 Is turned off. When the temperature sensor 17 outputs a detection value indicating that the temperature of the water in the chamber 10 has decreased to the boiling point plus less than 1 ° C. to the controller 80, the heater 12 is turned on.

  Thus, the temperature sensor 17 for detecting the temperature of the water in the chamber 10 is provided, and from the heating step (S20) to the infiltration step (S30) according to the temperature of the water in the chamber 10 detected by the temperature sensor 17. May be switched, ON / OFF switching of the heater 12 in the permeation step (S30), and ON / OFF switching of the heater 12 in the replacement step (S40).

  Compared with the configuration in which the two temperature sensors 16 and 17 are provided in the chamber 10 of the second embodiment, the configuration having only the temperature sensor 16 of the first embodiment reduces the number of temperature sensors 17 and thus the steam. There is an effect that the number of parts of the sterilizer 1 can be reduced.

(Embodiment 3)
FIG. 11 is a schematic diagram illustrating a configuration of the steam sterilizer 1 according to the third embodiment. Compared to the first embodiment, the steam sterilizer of the third embodiment is different in that it further includes a pressure detection means 18 as shown in FIG. The pressure detection means 18 is provided on the upper surface 10 t in the internal space in the chamber 10. The pressure detection means 18 is a second pressure gauge that is different from the pressure gauge 74 described in the first embodiment. The pressure detection means 18 detects the pressure in the chamber 10.

  The pressure detection means 18 is electrically connected to the control unit 80 shown in FIG. The control unit 80 receives an output of a detection value related to the pressure of the gas phase inside the chamber 10 from the pressure detection means 18.

  In the first and second embodiments, an example in which ON / OFF switching of the heater 12 in the permeation step (S30) and ON / OFF switching of the heater 12 in the replacement step (S40) are performed according to the temperature in the chamber 10 will be described. did. In place of this example, the chamber 10 is provided with the pressure detection means 18, and the heater 12 is turned on according to the pressure in the chamber 10 detected by the pressure detection means 18 in the permeation step (S 30) and the replacement step (S 40). You may make it switch to OFF.

  In the permeation step (S30) and the replacement step (S40), the heater 12 is switched between ON and OFF according to the detected value related to the pressure of the gas phase inside the chamber 10 measured by the pressure gauge 74. May be.

  Although there is a part that overlaps with the above description, characteristic configurations of the present embodiment are listed below. As shown in FIG. 1, the steam sterilizer 1 of the present embodiment includes a chamber 10 that can accommodate an object to be sterilized 100, an exhaust path 30, a drainage path 40, a connecting portion 50, a common path 60, And an on-off valve 68. A gas discharged from the chamber 10 flows through the exhaust path 30. The exhaust path 30 has an exhaust inlet end 31 connected to the chamber 10 and an exhaust outlet end 32 opposite to the exhaust inlet end 31. Water discharged from the chamber 10 flows through the drainage path 40. The drainage path 40 has a drainage inlet end 41 connected to the chamber 10 and a drainage outlet end 42 opposite to the drainage inlet end 41. The connecting portion 50 connects the exhaust outlet end 32 and the drain outlet end 42. The common path 60 has one end 61 communicating with both the exhaust path 30 and the drainage path 40 via the connecting portion 50 and the other end 62 opposite to the one end. The on-off valve 68 is provided in the common path 60.

  The exhaust path 30 through which the gas exhausted from the chamber 10 flows and the drainage path 40 through which the water exhausted from the chamber 10 flows are connected by a connecting part 50, and only the common path 60 through which both gas and water flow can be opened and closed. The valve 68 is provided. Since the on-off valve for exhausting from the chamber 10 and the on-off valve for draining from the chamber 10 are made common, the number of necessary parts of the steam sterilizer 1 can be reduced. The cost can be reduced.

  As shown in FIG. 1, the exhaust path 30 is not provided with an on-off valve, and the exhaust path 30 is always in communication from the exhaust inlet end 31 to the exhaust outlet end 32. The drainage path 40 is not provided with an on-off valve, and the drainage path 40 is always in communication from the drainage inlet end 41 to the drainage outlet end 42. Therefore, the chamber 10 and the connecting part 50 are always in communication with each other via the exhaust path 30 and the drainage path 40. Since the opening / closing valve 68 is provided in the common path 60, it is not necessary to provide the opening / closing valve in the exhaust path 30 or the drainage path 40. Thereby, the number of required parts of the steam sterilizer 1 can be reduced, and the cost of the steam sterilizer 1 can be reduced.

  As shown in FIGS. 2 and 3, a part of the drainage path 40 is disposed above the position of the water surface Ws when water is supplied into the chamber 10. The drainage path 40 has a rising portion 43 that rises above the position of the water surface Ws in the chamber 10. If it does in this way, even if the pressure in the chamber 10 rises in the replacement step (S40), water can be retained at the rising portion 43 of the drainage path 40 and water can be prevented from reaching the connecting portion 50. The outflow of water to the water storage tank 20 can be prevented. Further, since the pressure in the chamber 10 is allowed to rise, the heater 12 can be controlled more easily, and in addition, the generation of steam can be promoted, so that the time required for the replacement step (S40) can be shortened.

  As shown in FIGS. 2 and 3, the drainage outlet end 42 of the drainage path 40 is disposed above the position of the water surface Ws when water is supplied into the chamber 10. The drainage path 40 has a rising portion 43 that rises upward from the position of the water surface Ws in the chamber 10 toward the drainage outlet end 42. If it does in this way, even if the pressure in the chamber 10 rises in the replacement step (S40), water can be retained at the rising portion 43 of the drainage path 40 and water can be prevented from reaching the connecting portion 50. The outflow of water to the water storage tank 20 can be prevented.

  Further, as shown in FIG. 3, the drain outlet end 42 of the drain path 40 is disposed above the upper surface 10 t of the chamber 10. In this way, the volume of the rising portion 43 of the drainage path 40 can be increased. Therefore, the effect which can prevent the outflow of the water to the water storage tank 20 during a substitution process (S40) can be acquired more notably.

  Even when the drain outlet end 42 of the drain passage 40 and the connecting portion 50 are disposed below the position of the water surface Ws in the chamber 10, a part of the path from the drain inlet end 41 to the drain outlet end 42 is part of the water surface. If it is arranged above the position of Ws, it is possible to suppress the flow of water that passes through the portion and travels toward the drain outlet end 42, and the function as a rising portion is exhibited. For this reason, a part of the drainage path 40 disposed above the position of the water surface Ws in the chamber 10 is not limited to the drainage outlet end 42, but is an arbitrary path from the drainage inlet end 41 to the drainage outlet end 42. It may be a part of

  As shown in FIG. 4, the steam sterilizer 1 further includes a control unit 80 that controls the operation of the steam sterilizer 1. As shown in FIGS. 6 to 8, the control unit 80 controls to repeatedly start and stop the heater 12 during the replacement step (S <b> 40) in which steam is generated in the chamber 10 and air is discharged from the chamber 10. To do.

  Since the exhaust path 30 and the drainage path 40 are connected, the drainage path 40 is opened in the replacement step (S40). When the amount of steam generated in the chamber 10 becomes excessive, the pressure in the chamber 10 increases, water is pushed out of the chamber 10 by the steam to the drainage path 40, and the flow velocity of the gas flowing through the exhaust path 30 increases. A situation occurs in which the water in the chamber 10 flows out to the water storage tank 20. For this reason, the heater 12 is not always turned on during the replacement step (S40), but is controlled so as to repeatedly start and stop the heater 12. In this way, the amount of steam generated in the chamber 10 can be appropriately controlled, and an excessive increase in the pressure in the chamber 10 can be prevented, so that water flowing out of the chamber 10 can be retained in the drainage path 40. And the outflow of water to the water tank 20 can be prevented.

  As shown in FIG. 1, the steam sterilizer 1 further includes a temperature sensor 16 that detects the temperature in the chamber 10. As shown in FIGS. 6 and 7, the controller 80 stops the heater 12 when the temperature in the chamber 10 detected by the temperature sensor 16 is equal to or higher than the threshold, and the temperature in the chamber 10 detected by the temperature sensor 16. Is less than the threshold value, the heater 12 is activated.

  In this way, since starting and stopping of the heater 12 can be controlled according to the detected value of the temperature in the chamber 10, it is possible to reliably prevent the temperature in the chamber 12 from rising excessively. As for the threshold value related to the temperature in the chamber 10, a plurality of threshold values may be set as described with reference to FIG. 6, or a single threshold value may be set as described with reference to FIG. Good.

  As shown in FIGS. 6 and 7, the threshold is a temperature equal to or higher than the boiling point of water. In this way, the temperature in the chamber 10 can be reliably maintained above the boiling point of the water in which steam can be generated in the chamber 10, so that the generation of steam can be promoted and the replacement step (S40) is required. Time can be shortened.

  As shown in FIG. 8, the control unit 80 stops the heater 12 when a predetermined time elapses after the heater 12 is started, and starts the heater 12 when a predetermined time elapses after the heater 12 is stopped. In this way, since starting and stopping of the heater 12 can be controlled as time passes, the heater 12 can be easily controlled.

  As shown in FIG. 1, the steam sterilizer 1 further includes a water storage tank 20 that stores water discharged from the chamber 10. The other end 62 of the common path 60 communicates with the inside of the water tank 20. In this way, water and steam discharged from the chamber 10 can be guided to the inside of the water storage tank 20, and water and steam can be discharged into the water storage tank 20.

  As shown in FIG. 9, the connecting portion 50 has a communication pipe portion 51 that connects the exhaust path 30 and the common path 60. A drain outlet end 42 of the drain passage 40 communicates with the communication pipe portion 51. The inner cross-sectional area of the communication pipe part 51 perpendicular to the flow direction of the fluid flowing through the communication pipe part 51 is smaller than the opening area of the exhaust outlet end 32 of the exhaust path 30 and is larger than the opening area of the one end 61 of the common path 60. Is also small.

  If it does in this way, since the flow velocity of the gas which flows through the communicating pipe part 51 becomes large, the pressure of the gas in the communicating pipe part 51 will fall. Thereby, the capability to suck up water from the drainage path 40 to the connection part 50 increases. Therefore, in the steaming step (S70), the water in the chamber 10 can be more easily discharged to the water tank 20.

  As shown in FIG. 2, water is used as the liquid supplied to the chamber 10. The sterilization object 100 can be sterilized by high-temperature and high-pressure saturated water vapor obtained by heating and evaporating inexpensive and easily available water by the heater 12 in the chamber 10.

  Although the embodiment of the present invention has been described as above, the embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Steam sterilizer, 10 chamber, 10b bottom part, 10t, 20t upper surface, 11 Opening / closing lid, 12 Heater, 13 Mounting stand, 16 Temperature sensor, 20 Water tank, 26 Level sensor, 30 Exhaust path, 31 Exhaust inlet end, 32 Exhaust Outlet end, 33, 43 Rising part, 40 Drainage path, 41 Drainage inlet end, 42 Drainage outlet end, 50 Connection part, 51 Communication pipe part, 52 Branch pipe part, 53 One end part, 54 Other end part, 55 End part, 60 common path, 61 one end, 62 other end, 65 condenser part, 66 bent part, 68 on-off valve, 70 pressure path, 71, 73, 75 pressure pipe, 72 joint, 74 pressure gauge, 76 safety valve, 80 control part, 81 input unit, 82 timer, 100 object to be sterilized, W water, Ws water surface.

Claims (12)

A chamber capable of storing objects to be sterilized;
A heater for heating the liquid supplied into the chamber,
In a steam sterilizer that sterilizes the object to be sterilized with the liquid vapor generated by heating the heater,
An exhaust inlet end connected to the chamber at a position above the liquid level when the liquid is supplied into the chamber, and an exhaust outlet end opposite to the exhaust inlet end. An exhaust path through which the gas to be discharged flows,
A drainage path having a drainage inlet end connected to the chamber and a drainage outlet end opposite to the drainage inlet end, through which a liquid discharged from the chamber flows;
A connecting portion for connecting the exhaust outlet end and the drain outlet end;
A common path having one end communicating with both the exhaust path and the drainage path via the connecting portion and the other end opposite to the one end;
An on-off valve provided in the common path ,
The exhaust path has a rising portion that rises upward in a path from the exhaust inlet end to the exhaust outlet end,
The drainage outlet end, the Ru is connected to the connecting portion at a position higher than the exhaust inlet end, steam sterilizer.   The steam sterilizer according to claim 1, wherein the chamber and the connecting portion are always in communication with each other via the exhaust path and the drainage path.   The steam sterilizer according to claim 1 or 2, wherein a part of the drainage path is disposed above a position of a liquid level when the liquid is supplied into the chamber.   The steam sterilizer according to claim 3, wherein the drain outlet end is disposed above a position of a liquid level when the liquid is supplied into the chamber.   The steam sterilizer according to claim 4, wherein the drain outlet end is disposed above an upper surface of the chamber. A controller for controlling the operation of the steam sterilizer;
6. The control unit according to claim 1, wherein the control unit performs control so as to repeatedly start and stop the heater while generating steam in the chamber and discharging air from the chamber. Steam sterilizer. A temperature sensor for detecting the temperature in the chamber;
The control unit stops the heater when the temperature in the chamber detected by the temperature sensor is equal to or higher than a threshold value, and turns off the heater when the temperature in the chamber detected by the temperature sensor is lower than the threshold value. The steam sterilizer according to claim 6, which is activated.   The steam sterilizer according to claim 7, wherein the threshold value is a temperature equal to or higher than a boiling point of the liquid supplied into the chamber.   The steam sterilizer according to claim 6, wherein the controller stops the heater when a predetermined time elapses after the heater is started, and starts the heater when a predetermined time elapses after the heater is stopped. A liquid storage tank for storing the liquid discharged from the chamber;
The steam sterilizer according to any one of claims 1 to 9, wherein the other end communicates with the inside of the liquid storage tank. The connecting portion has a communication pipe portion that communicates the exhaust path and the common path;
The drain outlet end communicates with the communication pipe portion,
The inner cross-sectional area of the communication pipe portion orthogonal to the flow direction of the fluid flowing through the communication pipe portion is smaller than the opening area of the exhaust outlet end and smaller than the opening area of the one end. The steam sterilizer described in 1.   The steam sterilizer according to any one of claims 1 to 11, wherein the liquid is water.

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