JP2015139383A - Sterilization device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a number of electrically-driven proportional valves to be used for reducing cost.SOLUTION: A treatment tank 3 stores an object 2 to be treated and water. Circulation means 9 makes stored water in the treatment tank 3 between a heat exchanger 8. On a circulation path 14, a bypass path 15 connecting front and rear parts of the heat exchanger 8, is provided. A distribution ratio of the water from the treatment tank 3 to be returned to the treatment tank 3 via the heat exchanger 8 and the water to be returned to the treatment tank 3 via the bypass path 15, can be adjusted by a cross valve 27. Steam supply means 10 supplies steam to the heat exchanger 8 for heating the circulation water by circulated the circulation means 9. Cooling means 11 supplies cooling water to the heat exchanger 8 for cooling the water circulated by the circulation means 9. The steam supply means 10 has a steam supply valve 29 for switching presence/absence of steam supply to a steam supply path 28 toward the heat exchanger, by on-off. In a sterilization step, in a state that the steam supply valve 29 is opened, the cross valve 27 is controlled based on temperature in the treatment tank 3.

Description

  The present invention relates to a sterilizer used for heat sterilization and subsequent cooling of retort foods and the like.

  The applicant has previously proposed a sterilizer disclosed in Patent Document 1 below. In this sterilizer, the object to be treated is stored in the treatment tank (12) and water is stored. The stored water is circulated with the heat exchanger (26), and the circulating water is circulated to the heat exchanger (26). ) To switch between heating with the steam from the steam supply circuit (28) or cooling with the cooling water from the cooling water supply circuit (32), and heat sterilization of the object to be processed and subsequent cooling.

  In the sterilization process, the circulating water is not passed through the bypass passage (36), but is passed through the heat exchanger (26) (paragraph 0035, first sentence), the control target temperature of the treatment tank (12) and the temperature sensor (16). ), The opening degree of the steam supply valve (2804) is controlled (paragraph 0033). In the cooling process, the three-way valve (42) is controlled based on the difference between the control target temperature of the treatment tank (12) and the detected temperature of the temperature sensor (16) (paragraph 0035).

JP 2013-9642 A

  In the prior art, two electric proportional valves, a steam supply valve for adjusting the steam flow rate and a three-way valve for adjusting the bypass flow rate, are used, resulting in high costs. Further, not only in terms of configuration, but also in terms of control, the valves to be controlled differ between the sterilization process and the cooling process.

  Therefore, the problem to be solved by the present invention is to provide a sterilizer capable of reducing costs with a simple configuration and control.

  The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 includes a treatment tank in which an object to be treated is stored and water is stored, and stored water in the treatment tank. It circulates between the heat exchangers, and a bypass passage is provided in the circulation path by connecting the front and rear of the heat exchanger, and water from the treatment tank is passed to the treatment tank via the heat exchanger. In order to heat the circulating water by the circulation means that can be adjusted by the distribution amount adjusting means, the distribution ratio of whether to return to the treatment tank via the bypass path without going through the heat exchanger , Steam supply means for supplying steam to the heat exchanger, and cooling means for supplying cooling water to the heat exchanger for cooling the circulating water by the circulation means, the steam supply means, The steam supply path to the heat exchanger has a steam supply valve that switches on / off whether steam is supplied or not. The in sterilizing step of heating the object to be treated, with open the paper 蒸弁 a sterilizing apparatus and controls the distribution amount adjusting means based on the temperature of the processing bath.

  According to the first aspect of the present invention, in the sterilization step, the distribution amount adjusting means is controlled based on the temperature in the processing tank with the steam supply valve opened. Thereby, the circulating flow rate via a heat exchanger can be adjusted and the temperature in a processing tank can be adjusted as desired. Since it is sufficient to switch the presence or absence of steaming with the steaming valve, it is not necessary to adjust the opening of the steaming valve, so an on / off steam shut-off valve can be used as the steaming valve, and cost can be reduced. .

  According to a second aspect of the present invention, in the cooling step of cooling the workpiece, the steam supply valve is closed, while cooling water is supplied to the heat exchanger, based on the temperature in the processing tank. 2. The sterilizing apparatus according to claim 1, wherein the distribution amount adjusting means is controlled.

  According to the second aspect of the present invention, in the cooling step, the distribution amount adjusting means is controlled based on the temperature in the processing tank while passing the cooling water through the heat exchanger. Thereby, the circulating flow rate via a heat exchanger can be adjusted and the temperature in a processing tank can be adjusted as desired. Similarly to the sterilization process, it is sufficient to control the circulation amount adjusting means in the cooling process, and the control can be made uniform.

  Furthermore, in the sterilization step, the invention according to claim 3 controls the distribution amount adjusting means so as to maintain the inside of the treatment tank at a set temperature with the steam supply valve opened, and the sterilization step. In the state where the steam supply valve is closed, cooling water is supplied to the heat exchanger so that the operation for lowering the set temperature can be performed. When the set temperature is lowered, the temperature decreasing speed is set to the set speed. The disinfection apparatus according to claim 1 or 2, wherein the distribution amount adjusting means is controlled based on the temperature in the processing tank.

  According to invention of Claim 3, preset temperature can be lowered | hung by cooling circulating water in a heat exchanger in the middle of a sterilization process. Therefore, in actual cooking, the set temperature can be lowered in the middle of cooking that also serves as sterilization of retort foods, etc. so that it may be heated to a medium heat or a low heat after first being heated with a high heat. In addition, when the set temperature is lowered, the temperature drop rate can be adjusted as desired. In this way, optimal temperature control according to the object to be processed becomes possible, and for example, improvement in the taste and finish of the food can be expected. Furthermore, it is possible to shorten the sterilization time without degrading the taste by setting the temperature change as desired.

  ADVANTAGE OF THE INVENTION According to this invention, the sterilizer which can aim at cost reduction by simple structure and control is realizable.

It is the schematic which shows one Example of the sterilizer of this invention, and has shown one part in cross section.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing an embodiment of the sterilizing apparatus 1 of the present invention, and a part thereof is shown in cross section. The sterilization apparatus 1 of the present embodiment is an apparatus that cools the workpiece 2 after heat sterilization. The workpiece 2 is not particularly limited, but is typically a food material sealed in a container, such as retort food or canned food.

  The sterilization apparatus 1 of the present embodiment includes a treatment tank 3 in which an object to be treated 2 is accommodated, a water supply means 4 into the treatment tank 3, a drainage means 5 to the outside of the treatment tank 3, and a treatment tank 3 Pressurizing means 6, exhaust means 7 to the outside of the treatment tank 3, circulation means 9 for circulating water between the treatment tank 3 and the heat exchanger 8, and heat for heating the circulating water by the circulation means 9 Steam supply means 10 for supplying steam to the exchanger 8, cooling means 11 for supplying cooling water to the heat exchanger 8 to cool the circulating water by the circulation means 9, and steam condensate by the steam supply means 10 ( A drain discharge means 12 for discharging the drain) and a control means (not shown) for controlling these means 4 to 7 and 9 to 12 are provided.

  The treatment tank 3 is a hollow container that accommodates the workpiece 2. The shape of the treatment tank 3 is not particularly limited. In the present embodiment, the treatment tank 3 includes a horizontally disposed cylindrical material, and this cylindrical material has one opening closed and the other opening opened and closed by a door. It is possible. By opening the door, the workpiece 2 can be taken in and out of the processing tank 3, and by closing the door, the opening of the processing tank 3 can be closed airtight. In addition, the to-be-processed object 2 is hold | maintained above the bottom face in the processing tank 3 by mounting on the trolley | bogie.

  The processing tank 3 is provided with a temperature sensor 13 for detecting the temperature in the processing tank 3 and a water level detector (not shown) for detecting the water level in the processing tank 3. In addition, the temperature sensor 13 may be provided not in the processing tank 3 but in a circulation path 14 described later (in particular, on the downstream side of the junction with the bypass path 15).

  The water supply means 4 supplies water into the treatment tank 3 through the water supply path 16. The water supply path 16 is connected to the bottom of the processing tank 3, and a water supply pump 17 and a water supply valve 18 are provided toward the processing tank 3. By opening the water supply valve 18 in a state where the water supply pump 17 is operated, water from the water supply source can be supplied into the treatment tank 3 and water can be stored in the treatment tank 3. In a present Example, water is stored in the processing tank 3 to the setting water level which does not immerse the to-be-processed object 2 accommodated in the processing tank 3. FIG.

  The drainage means 5 discharges water from the treatment tank 3 through the drainage channel 19. The drainage channel 19 is connected to the bottom of the treatment tank 3 and a drainage valve 20 is provided. By opening the drain valve 20, the water in the processing tank 3 can be discharged to the outside.

  The pressurizing unit 6 supplies compressed air into the processing tank 3 through the pressurizing path 21. By opening the pressurization valve 22 provided in the pressurization path 21, the compressed air from a compressed air source can be supplied in the process tank 3, and the inside of the process tank 3 can be pressurized to the pressure exceeding atmospheric pressure.

  The exhaust means 7 exhausts the gas from the inside of the processing tank 3 under a pressure exceeding the atmospheric pressure through the exhaust path 23. The exhaust path 23 is connected to the upper part of the processing tank 3 and is provided with an exhaust valve 24. When the exhaust valve 24 is opened while the inside of the processing tank 3 is at a pressure exceeding the atmospheric pressure, the gas in the processing tank 3 is discharged to the outside through the exhaust path 23, and the pressure in the processing tank 3 may be lowered. it can.

  In the heat exchanger 8, water is circulated with the treatment tank 3, and the circulated water and steam or cooling water exchange heat indirectly. In other words, the heat exchanger 8 allows water from the treatment tank 3 to be passed by the circulation means 9 and also allows steam to pass from the steam supply means 10 to heat the circulating water or to cool the circulating water. Cooling water is passed through the cooling means 11.

  The circulation means 9 circulates water between the treatment tank 3 and the heat exchanger 8. The circulation means 9 includes a circulation path 14 and a circulation pump 25. One end of the circulation path 14 is connected to the bottom of the treatment tank 3, and the circulation path 14 from the bottom of the treatment tank 3 is sequentially passed through the circulation pump 25 and the heat exchanger 8, and the other end is connected to the treatment tank 3. It is connected to the nozzle 26 inside. This nozzle 26 is provided in the side part and / or upper part in the processing tank 3, and injects the water from the circulation pump 25 toward the to-be-processed object 2. FIG.

  A bypass path 15 is provided in the circulation path 14 so as to connect the front and rear of the heat exchanger 8. Further, a three-way valve 27 as a distribution amount adjusting means is provided at a branch portion between the circulation path 14 and the bypass path 15. By controlling the three-way valve 27, the circulating water from the circulation pump 25 is returned to the treatment tank 3 via the heat exchanger 8, or via the bypass path 15 without the heat exchanger 8. The distribution ratio of returning to can be adjusted.

  The steam supply means 10 supplies steam to the heat exchanger 8 to heat the circulating water by the circulation means 9. The steam supply means 10 includes a steam supply path 28 that supplies steam from the boiler to the heat exchanger 8, and a steam supply valve 29 is provided in the steam supply path 28. The steam supply valve 29 can be opened and closed only, and a valve whose opening degree cannot be adjusted is sufficient. That is, the steam supply valve 29 is a valve that switches on / off whether or not steam is supplied to the heat exchanger 8. In this embodiment, it is composed of an air drive valve.

  The cooling unit 11 supplies cooling water to the heat exchanger 8 to cool the circulating water by the circulation unit 9. The cooling means 11 includes a cooling tower 30, and the water cooled by the cooling tower 30 is supplied to the heat exchanger 8 via the cooling water feed path 32 by the water pump 31, and the water after passing through the heat exchanger 8. Is returned to the cooling tower 30 via the cooling water return path 33. In the case of the illustrated example, the cooling water feed path 32 and the steam supply path 28 are a common pipe line on the heat exchanger 8 side.

  A cooling water feed valve 34 is provided in the cooling water feed path 32, while a cooling water return valve 35 is provided in the cooling water return path 33. The junction between the cooling water feed path 32 and the steam supply path 28 is disposed downstream (on the heat exchanger 8 side) from the cooling water feed valve 34 and the steam supply valve 29.

  When the water supply pump 31 is operated with the cooling water feed valve 34 and the cooling water return valve 35 opened, the cooling water can be circulated between the cooling tower 30 and the heat exchanger 8. On the other hand, if the cooling water feed valve 34 and the cooling water return valve 35 are closed, the flow of the cooling water to the heat exchanger 8 can be stopped.

  The drain discharge means 12 discharges the condensed water of the steam supplied to the heat exchanger 8 by the steam supply means 10 to the outside. The drain discharge means 12 is provided upstream of the coolant return valve 35 (on the heat exchanger 8 side) in the coolant return path 33, and is connected to a drain discharge path 36 that branches from the coolant return path 33. 37, a steam trap 38 and a check valve 39 are provided in this order. When the steam is supplied to the heat exchanger 8, the condensate of the steam can be discharged to the outside by opening the drain discharge valve 37.

  The control means is a controller (not shown) that controls each of the means 4 to 7 and 9 to 12 based on the elapsed time as well as the detection signals of the temperature sensor 13 and the water level detector. Specifically, the water supply pump 17, the water supply valve 18, the drain valve 20, the pressurization valve 22, the exhaust valve 24, the circulation pump 25, the three-way valve 27, the steam supply valve 29, the cooling tower 30, the water supply pump 31, and the cooling water supply valve 34. In addition to the cooling water return valve 35 and the drain discharge valve 37, the temperature sensor 13 and the water level detector are connected to the controller. And a controller performs the heat sterilization of the to-be-processed object 2 in the processing tank 3, and subsequent cooling according to a predetermined procedure (program) so that it may mention below. Typically, a water supply process, a transition process, a sterilization process, a cooling process, and a drainage process are sequentially performed.

  Hereinafter, each step will be described. Prior to the operation of the sterilizer 1, the workpiece 2 is accommodated in the treatment tank 3, and the door of the treatment tank 3 is closed. In this state, the exhaust valve 24 is opened, the other valves 18, 20, 22, 29, 34, 35, 37 are closed, and the pumps 17, 25, 31 are stopped.

≪ (1) Water supply process≫
In the water supply process, water is supplied into the treatment tank 3 by the water supply means 4 to a set water level at which the workpiece 2 in the treatment tank 3 is not immersed, and the water is stored in the treatment tank 3. Specifically, the water supply valve 18 may be opened with the water supply pump 17 operated. When water is stored in the treatment tank 3 up to the set water level, the water supply valve 18 is closed and the water supply pump 17 is stopped to end the water supply process.

≪ (2) Transition process≫
In the transition step, while circulating water between the treatment tank 3 and the heat exchanger 8 by the circulation means 9, the circulating water is heated by the steam supply means 10 in the heat exchanger 8, so that the temperature in the treatment tank 3 is increased. Is raised to the set temperature (sterilization temperature). Specifically, by operating the circulation pump 25, the water from the inner bottom of the processing tank 3 is returned to the processing tank 3 from the nozzle 26 via the heat exchanger 8, thereby exchanging heat with the processing tank 3. Water is circulated to and from the vessel 8. At this time, it is sufficient for the three-way valve 27 to maintain the entire amount of circulating water from the circulation pump 25 so as to pass through the heat exchanger 8. In the transition process, the cooling water feed valve 34 and the cooling water return valve 35 are closed, while the steam supply valve 29 and the drain discharge valve 37 are opened to supply steam to the heat exchanger 8. Thereby, the circulating water and steam can be heat-exchanged in the heat exchanger 8, and the circulating water can be heated. By opening the drain discharge valve 37, the condensed water of the steam is discharged through the steam trap 38.

  Thus, although the temperature in the processing tank 3 is raised gradually, the to-be-processed object 2 expand | swells by heating, and there exists a possibility that a container (retort pouch etc.) may burst. Therefore, in order to prevent this, the inside of the processing tank 3 is gradually pressurized by the pressurizing means 6 to a pressure exceeding the atmospheric pressure (higher than the saturated vapor pressure corresponding to the temperature in the processing tank). Specifically, the pressurization according to the temperature in the processing tank 3 is performed by controlling the pressurization valve 22 and the exhaust valve 24.

  Thereafter, the circulation of water by the circulation means 9 is continued until the end of the cooling process. Further, the pressurization in the treatment tank 3 by the pressurizing means 6 is continued until the end of the cooling step to a pressure higher than the saturated vapor pressure corresponding to the temperature in the treatment tank even after the inside of the treatment tank 3 rises to the set temperature. The

≪ (3) Sterilization process≫
In the sterilization process, the temperature in the processing tank 3 is maintained at a set temperature, and the workpiece 2 is heated and sterilized. Specifically, the steam supply valve 29 and the drain discharge valve 37 are maintained in an open state, and the temperature detected by the temperature sensor 13 is maintained at the set temperature while circulating the water stored in the treatment tank 3 by the circulation means 9. Thus, the opening degree of the three-way valve 27 is adjusted. That is, the flow rate of circulating water to the heat exchanger 8 is adjusted so that the temperature detected by the temperature sensor 13 is maintained at the set temperature. When the set time elapses above the set temperature in the processing tank 3, the steam supply valve 29 and the drain discharge valve 37 are closed to stop the steam supply to the heat exchanger 8, and the sterilization process is ended.

  The set temperature can be raised or lowered during the sterilization process. For example, in the sterilization process, after maintaining the first set time at the first set temperature, the temperature is increased to a second set temperature higher than the first set temperature (or to a second set temperature lower than the first set temperature). The temperature can be lowered) and maintained at the second set temperature for a second set time. The set temperature is not limited to two stages, and may be changed to three or more stages.

  In order to increase the set temperature, the three-way valve 27 may be controlled based on the temperature detected by the temperature sensor 13. Normally, the three-way valve 27 is controlled so that the entire amount of circulating water from the circulation pump 25 is passed through the heat exchanger 8 with the steam supply valve 29 and the drain discharge valve 37 open, as in the transition step.

  In order to lower the set temperature, the circulating water may be cooled by the cooling means 11 in the heat exchanger 8 in the state where the heating by the steam supply means 10 is stopped, as in the cooling step described later. Specifically, the steam supply valve 29 and the drain discharge valve 37 are closed, while the cooling water feed valve 34 and the cooling water return valve 35 are opened, the cooling tower 30 and the water feed pump 31 are operated, and the heat exchanger 8 Cooling water may be circulated in the tank. At this time, the three-way valve 27 is controlled to adjust the flow rate of circulating water to the heat exchanger 8 so that the temperature in the treatment tank 3 can be lowered as desired.

  In addition, when lowering | hanging the temperature in the processing tank 3, it is preferable to adjust the flow volume of the circulating water passed through the heat exchanger 8 so that the temperature decreasing speed may become a setting speed. Specifically, the opening degree of the three-way valve 27 may be adjusted so that the temperature decreases at a set speed while monitoring the temperature detected by the temperature sensor 13. If the set temperature falls to the target temperature, the opening degree of the three-way valve 27 may be adjusted so as to maintain the set temperature.

  In this way, the set temperature can be raised or lowered as desired during the sterilization process. Therefore, optimum temperature control according to the workpiece 2 is possible. In particular, in accordance with the object to be treated 2, it is possible to perform an operation in which sterilization is performed at a high temperature at the initial stage of sterilization and then the set temperature is lowered. In other words, by lowering the set temperature in the middle, it is possible to perform a process of heating by changing to medium heat or low heat after first heating with high heat. Thereby, the improvement of the taste of a foodstuff and a finish can be expected. Also, for example, sterilization, which conventionally required X minutes at 80 ° C., reduces the taste while shortening the sterilization time, such as Y minutes at 100 ° C. and Z minutes at 80 ° C. (X> Y + Z). It becomes possible to cook without.

  Incidentally, during the sterilization process, if the temperature detected by the temperature sensor 13 exceeds the upper limit temperature, the steam supply valve 29 is preferably closed. In this case, after that, if the temperature detected by the temperature sensor 13 falls to a predetermined temperature lower than the upper limit temperature, the steam supply valve 29 may be opened again.

≪ (4) Cooling process≫
In the cooling process, while circulating water between the treatment tank 3 and the heat exchanger 8 by the circulation means 9, the circulating water is cooled by the cooling means 11 in the heat exchanger 8, and the treatment in the treatment tank 3 is performed. Item 2 is cooled. Specifically, by operating the circulation pump 25, the water from the inner bottom of the processing tank 3 is returned to the processing tank 3 from the nozzle 26 via the heat exchanger 8, thereby exchanging heat with the processing tank 3. Water is circulated to and from the vessel 8. Further, during this circulation, the steam supply valve 29 and the drain discharge valve 37 are closed, while the cooling water feed valve 34 and the cooling water return valve 35 are opened, the cooling tower 30 and the water feed pump 31 are operated, and the heat exchanger What is necessary is just to circulate cooling water to 8.

  When the cooling time elapses from the start of the cooling process, the temperature in the treatment tank 3 falls below the cooling temperature, or when a predetermined time elapses after the cooling temperature falls, the cooling means 11 supplies the cooling water to the heat exchanger. Stop and end the cooling process. At this time, the circulation by the circulation means 9 is also stopped, but the pressurization in the treatment tank 3 by the pressure means 6 may be continued until the drainage is completed in the drainage process.

  In the cooling step, the three-way valve 27 is controlled based on the temperature detected by the temperature sensor 13 to adjust the amount of water flowing into the heat exchanger 8 of the circulating water, thereby adjusting the temperature in the treatment tank 3. Thereby, the temperature in the processing tank 3 can be lowered while adjusting to a predetermined value in response to a change in the temperature of the cooling water supplied to the heat exchanger 8. Further, in the cooling process, the three-way valve 27 may be controlled so that the temperature lowering speed becomes the set speed as in the case of lowering the set temperature in the sterilization process. In addition, you may control so that the temperature in the processing tank 3 may be lowered | hung as desired by changing a temperature fall rate with time passage.

≪ (5) Drainage process≫
In the drainage process, the drainage means 5 drains the water from the treatment tank 3. Specifically, water is discharged to the outside by opening the drain valve 20. If the drainage means 5 drains while the inside of the treatment tank 3 is pressurized by the pressurizing means 6, drainage from the treatment tank 3 can be performed quickly. Thereafter, the pressurization valve 22 is closed, the exhaust valve 24 is opened, the inside of the processing tank 3 is returned to atmospheric pressure, the door of the processing tank 3 is opened, and the workpiece 2 can be taken out from the processing tank 3. it can.

  According to the sterilizer 1 of the present embodiment, only the three-way valve 27 is adjusted in opening, and the other valves are switched between open and closed. Therefore, the configuration and control become easy. By the way, if the circulation pump 25 is inverter-controlled to adjust the amount of circulating water flowing to the heat exchanger 8, the amount of spray from the nozzle 26 changes, and in some cases, the spray from the nozzle 26 is sprayed. May not be possible. However, in the sterilization apparatus 1 of the present embodiment, the entire circulation flow rate is maintained as desired, and the bypass flow rate is adjusted, so that the injection from the nozzle 26 to the workpiece 2 can be maintained as desired.

  The sterilization apparatus 1 of the present invention is not limited to the configuration of the above embodiment, and can be changed as appropriate. For example, in the above-described embodiment, the three-way valve 27 is installed at the branch portion between the circulation path 14 and the bypass path 15 as the distribution amount adjusting means, but the circulation path 14 between the branch section with the bypass path 15 and the junction section. A valve (opening adjustment valve) capable of adjusting the opening degree may be provided (particularly between the branch portion with the bypass passage 15 and the heat exchanger 8). In that case, the bypass passage 15 is preferably provided with a valve (open / close valve) that can only be opened and closed. And in order to adjust the flow volume of the circulating water to the heat exchanger 8, what is necessary is just to adjust the opening degree of an opening degree adjustment valve in the state which opened the on-off valve.

  Alternatively, conversely, a valve (opening adjustment valve) capable of adjusting the opening degree may be provided in the bypass passage 15. In that case, a valve (open / close valve) that can only be opened and closed in the circulation path 14 (particularly between the branch section with the bypass path 15 and the heat exchanger 8) between the branch section with the bypass path 15 and the junction section. Is preferably provided. And in order to adjust the flow volume of the circulating water to the heat exchanger 8, what is necessary is just to adjust the opening degree of an opening degree adjustment valve in the state which opened the on-off valve.

  Furthermore, it can also be applied to a so-called hot water storage type sterilizer. In that case, in the treatment tank 3, the object to be treated 2 is submerged in hot water for sterilization, but the stored water in the treatment tank 3 is circulated between the heat exchanger 8 as in the above embodiment. On the other hand, the circulating water is heated by steam in the sterilization process, and cooled by cooling water in the cooling process. In the sterilization process, the three-way valve 27 and the like may be controlled while keeping the steam supply valve 29 open. In the cooling process, the three-way valve 27 and the like may be controlled while passing cooling water through the heat exchanger 8.

DESCRIPTION OF SYMBOLS 1 Sterilizer 2 To-be-processed object 3 Processing tank 4 Water supply means 5 Drainage means 6 Pressurization means 7 Exhaust means 8 Heat exchanger 9 Circulation means 10 Steaming means 11 Cooling means 12 Drain discharge means 13 Temperature sensor 14 Circulation path 15 Bypass path 25 Circulating pump 27 Three-way valve (Distribution amount adjusting means)
28 Steam supply path 29 Steam supply valve 30 Cooling tower

Claims (3)

A treatment tank in which water is stored while a workpiece is stored;
The stored water in the treatment tank is circulated with the heat exchanger, and a bypass path is provided in the circulation path before and after the heat exchanger, and water from the treatment tank is exchanged with the heat exchanger. A circulation means capable of adjusting a distribution ratio of whether to return to the treatment tank via a vessel or to return to the treatment tank via the bypass without going through the heat exchanger,
In order to heat the circulating water by the circulation means, steam supply means for supplying steam to the heat exchanger,
A cooling means for supplying cooling water to the heat exchanger in order to cool the circulating water by the circulation means,
The steaming means comprises a steaming valve that switches on / off the presence or absence of steaming in the steaming path to the heat exchanger,
In the sterilization step of heating the object to be processed, the distribution amount adjusting means is controlled based on the temperature in the processing tank with the steam supply valve opened. In the cooling step of cooling the object to be treated, the distribution amount adjusting means is controlled based on the temperature in the treatment tank while the cooling valve is closed and the cooling water is supplied to the heat exchanger. The sterilizer according to claim 1, wherein In the sterilization step, with the steam supply valve opened, the distribution amount adjusting means is controlled so as to maintain the inside of the processing tank at a set temperature,
During the sterilization process, with the steam supply valve closed, cooling water is supplied to the heat exchanger, and an operation for lowering the set temperature can be performed.
The distribution amount adjusting means is controlled based on the temperature in the processing tank so that the temperature decreasing speed becomes a set speed when the set temperature is lowered. Sterilizer.

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