JP6226129B2 - Sterilizer - Google Patents

Description

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

  Conventionally, as disclosed in the following Patent Document 1, the sterilization tank (1) accommodates the article to be sterilized (2), stores water, and circulates the stored water between the heat exchanger (3). The circulating water is heated with steam in the heat exchanger (3) or with cooling water from the cooling tower (8) to switch between cooling and sterilization of the article to be sterilized (2) and subsequent cooling. Sterilizers are known.

Japanese Patent No. 4229420

  As in the sterilization apparatus described in Patent Document 1, while circulating water between the treatment tank and the heat exchanger, steam is supplied to the heat exchanger in the sterilization process, and then to the heat exchanger in the subsequent cooling process. When supplying cooling water, at the time of transfer from the sterilization process to the cooling process, the cooling water flows into the heat exchanger filled with steam. Along with this, steam condenses abruptly in the heat exchanger and the piping, and the steam is ejected from the safety valve of the heat exchanger or noise and vibration are generated from the piping due to the impact caused by the sudden decompression.

  The problem to be solved by the present invention is to prevent steam from spouting out from the safety valve or generating noise or vibration from the piping during the transition from the sterilization process to the cooling process.

  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. Circulating means for circulating between the heat exchanger, steaming means for supplying steam to the heat exchanger to heat the circulating water by the circulating means, and cooling the circulating water by the circulating means A cooling means for supplying cooling water to the heat exchanger, and after the steam supply to the heat exchanger by the steaming means is stopped, before the cooling water supply to the heat exchanger by the cooling means is started, A sterilizer comprising compressed air supply means for supplying compressed air to the heat exchanger.

  According to the first aspect of the present invention, since the compressed air is supplied to the heat exchanger after the stop of the steam supply and before the start of the cooling water supply, the steam is condensed by the cooling water when the cooling water is supplied. However, sudden pressure reduction is prevented. Thereby, the impact by sudden pressure reduction is prevented and it can prevent that a vapor spouts from a safety valve, or a sound and a vibration generate | occur | produce from piping.

  According to a second aspect of the present invention, the supply of compressed air to the heat exchanger by the compressed air supply means after the first set time has elapsed after the supply of steam to the heat exchanger by the steam supply means has been stopped. Starting a supply of compressed air to the heat exchanger by the compressed air supply means, after a second set time has elapsed, start supplying cooling water to the heat exchanger by the cooling means, The compressed air is supplied to the heat exchanger by the compressed air supply means until the start of the supply of the cooling water to the heat exchanger by the cooling means or the cooling water to the heat exchanger by the cooling means. The sterilizing apparatus according to claim 1, wherein the sterilizing apparatus is performed from the start of supply until a third set time elapses.

  According to the second aspect of the present invention, the heat exchanger is supplied with compressed air after the first set time has elapsed after the steam supply is stopped, and after the start of the compressed air supply, the second set time has elapsed. Then, cooling water is supplied. Then, the compressed air supply is continued at the start of the cooling water supply or until the third set time has elapsed. Thereby, it is possible to reliably prevent sudden pressure reduction during the supply of cooling water, and more reliably prevent the ejection of steam from the safety valve and the generation of noise and vibration from the piping.

  Furthermore, in the invention according to claim 3, water is stored in the treatment tank up to a water level at which the object to be treated is not immersed, and the circulation means supplies water from the bottom in the treatment tank to the heat. The cooling means circulates cooling water between the heat exchanger and the cooling tower, and cools the cooling tower to the heat exchanger via an exchanger. While the water feed path is provided with a cooling water feed valve, the cooling water return path from the heat exchanger to the cooling tower is provided with a cooling water return valve, and the steaming means is provided with a steam feed valve. The drain discharge means connected to the cooling water feed path downstream of the cooling water feed valve and discharges steam drained by the steam supply means to the outside includes a drain discharge path provided with a drain discharge valve. The cooling water return path upstream from The compressed air supply means is connected to the cooling water feed path downstream of the cooling water feed valve, or the downstream side of the steam supply valve. The steam supply passage is connected, and the cooling water feed valve, the cooling water return valve and the compressed air supply valve are closed, while the steam supply valve and the drain discharge valve are opened, and the steam from the steam supply means is By supplying to a heat exchanger and heating the circulating water, the object to be treated is sterilized, and when the inside of the treatment tank is at or above the sterilization temperature, the steam supply valve is closed and the steam supply valve is When the first set time elapses after closing, the compressed air supply valve is opened, and when the second set time elapses after the compressed air supply valve is opened, the cooling water feed valve and the cooling water return valve are opened, Close the drain discharge valve and Cooling water from a tower is supplied to the heat exchanger to cool the circulating water, thereby cooling the object to be processed, and starting from or at the time when cooling water supply to the heat exchanger is started. The sterilizer according to claim 1 or 2, wherein the compressed air supply valve is closed when a set time has elapsed.

  According to the third aspect of the present invention, the opening and closing control of the cooling water feed valve, the cooling water return valve, the steam supply valve, the drain discharge valve, and the compressed air supply valve allows the safety valve to be switched from the sterilization process to the cooling process. This prevents the generation of steam and the generation of noise and vibration from the piping. The heat exchanger is supplied with compressed air after the first set time elapses after the steam supply is stopped, and is supplied with cooling water after the second set time elapses after the compressed air supply starts. . Then, the compressed air supply is continued at the start of the cooling water supply or until the third set time has elapsed. Thereby, it is possible to reliably prevent sudden pressure reduction during the supply of cooling water, and more reliably prevent the ejection of steam from the safety valve and the generation of noise and vibration from the piping.

  ADVANTAGE OF THE INVENTION According to this invention, it can prevent that a vapor | steam spouts from a safety valve, or a sound and a vibration generate | occur | produce from piping at the time of transfer from a sterilization process to a cooling process.

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), a compressed air supply means 13 for supplying compressed air to the heat exchanger 8, and a control means (not shown) for controlling these means 4 to 7 and 9 to 13 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 14 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 14 may be provided not in the processing tank 3 but in the circulation path 15 described later (in particular, on the downstream side of the heat exchanger 8) in some cases.

  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. Further, as will be described later, after the supply of steam to the heat exchanger 8 is stopped and before the start of the cooling water supply, the heat exchanger 8 (the side through which the steam or cooling water is passed) is connected to the compressed air supply means 13. Of compressed air can be supplied. The pressurization of the heat exchanger 8 with the compressed air is terminated at the start of the cooling water supply or is continued until a predetermined timing immediately after the start of the cooling water supply.

  The circulation means 9 circulates water between the treatment tank 3 and the heat exchanger 8. The circulation means 9 includes a circulation path 15 and a circulation pump 25. One end of the circulation path 15 is connected to the bottom of the processing tank 3, and the circulation path 15 from the bottom of the processing tank 3 passes through the circulation pump 25 and the heat exchanger 8 in order, and the other end is connected to the processing 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.

  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 27 that supplies steam from the boiler to the heat exchanger 8, and a steam supply valve 28 is provided in the steam supply path 27. During the circulation by the circulation means 9, the temperature in the treatment tank 3 can be adjusted as desired by adjusting the opening degree of the steam supply valve 28 based on the temperature detected by the temperature sensor 14.

  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 29, and the water cooled in the cooling tower 29 is supplied to the heat exchanger 8 via the cooling water feed path 31 by the water pump 30, and the water after passing through the heat exchanger 8. Is returned to the cooling tower 29 via the cooling water return path 32. In the case of the illustrated example, the cooling water feed path 31 and the steam supply path 27 are a common pipe line on the heat exchanger 8 side.

  A cooling water feed valve 33 is provided in the cooling water feed path 31, while a cooling water return valve 34 is provided in the cooling water return path 32. The junction of the cooling water feed path 31 and the steam supply path 27 is disposed downstream (on the heat exchanger 8 side) from the cooling water feed valve 33 and the steam supply valve 28.

  When the water supply pump 30 is operated with the cooling water feed valve 33 and the cooling water return valve 34 opened, the cooling water can be circulated between the cooling tower 29 and the heat exchanger 8. On the other hand, if the cooling water feed valve 33 and the cooling water return valve 34 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 cooling water return valve 34 (on the heat exchanger 8 side) in the cooling water return path 32, and is connected to a drain discharge path 35 branched from the cooling water return path 32. 36, a steam trap 37 and a check valve 38 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 36.

  The compressed air supply means 13 supplies compressed air to the heat exchanger 8 to pressurize the heat exchanger 8. The compressed air supply means 13 includes a compressed air passage 39 that supplies compressed air from a compressed air source to the heat exchanger 8, and a compressed air supply valve 40 is provided in the compressed air passage 39. Although details will be described later, after the steam supply to the heat exchanger 8 by the steam supply means 10 is stopped, before the cooling water supply to the heat exchanger 8 by the cooling means 11 is started, the compressed air supply means 13 is used to heat the heat exchanger. By supplying compressed air to 8, the inside of the heat exchanger 8 and the pipes before and after it (the cooling water feed path 31 and the cooling water return path 32) are pressurized, and due to the sudden pressure reduction accompanying steam condensation at the time of cooling water supply Impact can be prevented.

  By the way, the compressed air passage 39 is provided in the cooling water feed passage 31 on the downstream side (the heat exchanger 8 side) from the cooling water feed valve 33. At this time, as in the illustrated example, the compressed air passage 39 is connected to the upstream of the junction with the steam supply passage 27 in the cooling water feed passage 31 and downstream of the cooling water feed valve 33. preferable. Alternatively, the compressed air passage 39 is preferably connected upstream of the joining portion with the cooling water feed passage 31 in the steam supply passage 27 and downstream of the steam supply valve 28.

  The control means is a controller (not shown) that controls each of the means 4 to 7 and 9 to 13 based on the elapsed time in addition to the detection signals of the temperature sensor 14 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 steam supply valve 28, the cooling tower 29, the water supply pump 30, the cooling water supply valve 33, and the cooling water return. In addition to the valve 34, the drain discharge valve 36, the compressed air supply valve 40, the temperature sensor 14 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, 28, 33, 34, 36, and 40 are closed, and the pumps 17, 25, and 30 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 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. During this circulation, the cooling water feed valve 33, the cooling water return valve 34 and the compressed air supply valve 40 are closed, and the steam supply valve 28 and the drain discharge valve 36 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 36, the steam condensate is discharged through the steam trap 37.

  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 pressurizing means 6 pressurizes the treatment tank 3 after the temperature in the treatment tank 3 rises to the sterilization temperature, and continues to a pressure higher than the saturated vapor pressure corresponding to the treatment tank temperature until the end of the cooling step. The

≪ (3) Sterilization process≫
In the sterilization step, the temperature in the treatment tank 3 is maintained at the sterilization temperature, and the workpiece 2 is heated and sterilized. Specifically, the opening degree of the steam supply valve 28 is adjusted so as to maintain the temperature detected by the temperature sensor 14 at the sterilization temperature while circulating the stored water in the treatment tank 3 by the circulation means 9. When the inside of the treatment tank 3 is at or above the sterilization temperature and the sterilization time has elapsed, the steam supply valve 28 is closed, the steam supply to the heat exchanger 8 is stopped, and the sterilization process is terminated.

  After the sterilization process is completed, before the cooling process is started, the compressed air supply means 13 supplies compressed air to the heat exchanger 8 (the side where the steam has been supplied), and pressurization of the heat exchanger 8 starts. Is done. And pressurization of the heat exchanger 8 by the compressed air supply means 13 is continued until the start of the cooling process or immediately after the start. More specifically, preferably, the transition operation, either the first operation shown in the following (a) or the second operation shown in (b), is executed.

<(A) First operation>
The supply of compressed air to the heat exchanger 8 by the compressed air supply means 13 is started after the first set time has elapsed since the supply of steam to the heat exchanger 8 by the steam supply means 10 is stopped (end of the sterilization step). Then, after the second set time has elapsed after the compressed air supply means 13 starts supplying compressed air to the heat exchanger 8, the cooling means 11 starts supplying cooling water to the heat exchanger 8 (cooling process start). To do. In the first operation, the compressed air is supplied to the heat exchanger 8 by the compressed air supply means 13 until the start of the cooling water supply to the heat exchanger 8 by the cooling means 11. More specifically, it is as follows.

  As described above, during the sterilization process, the cooling water feed valve 33, the cooling water return valve 34, and the compressed air supply valve 40 are closed, while the drain discharge valve 36 is opened to adjust the opening degree of the steam supply valve 28. At the end of the sterilization process, the steam supply valve 28 is closed. When the first set time (for example, 5 seconds) has elapsed since the steam supply valve 28 was closed, the compressed air supply valve 40 is opened and the water pump 30 is operated. Further, when the second set time (for example, 5 seconds) has elapsed since the compressed air supply valve 40 was opened, the cooling water feed valve 33 and the cooling water return valve 34 are opened, while the drain discharge valve 36 and the compressed air supply valve 40 are closed. The cooling process is started. That is, as will be described later, the workpiece 2 is cooled by supplying the cooling water from the cooling tower 29 to the heat exchanger 8 and cooling the circulating water.

<(B) Second operation>
The supply of compressed air to the heat exchanger 8 by the compressed air supply means 13 is started after the first set time has elapsed since the supply of steam to the heat exchanger 8 by the steam supply means 10 is stopped (end of the sterilization step). Then, after the second set time has elapsed after the compressed air supply means 13 starts supplying compressed air to the heat exchanger 8, the cooling means 11 starts supplying cooling water to the heat exchanger 8 (cooling process start). To do. In the second operation, the compressed air is supplied to the heat exchanger 8 by the compressed air supply means 13 from the start of the cooling water supply to the heat exchanger 8 by the cooling means 11 until the third set time has elapsed. . More specifically, it is as follows.

  As described above, during the sterilization process, the cooling water feed valve 33, the cooling water return valve 34, and the compressed air supply valve 40 are closed, while the drain discharge valve 36 is opened to adjust the opening degree of the steam supply valve 28. At the end of the sterilization process, the steam supply valve 28 is closed. When the first set time (for example, 5 seconds) has elapsed since the steam supply valve 28 was closed, the compressed air supply valve 40 is opened and the water pump 30 is operated. Further, when the second set time (for example, 5 seconds) has elapsed since the compressed air supply valve 40 was opened, the cooling water feed valve 33 and the cooling water return valve 34 are opened, while the drain discharge valve 36 is closed and the cooling process is started. To do. Thereby, the cooling water from the cooling tower 29 is passed through the heat exchanger 8, but the compressed air supply valve 40 is closed when a third set time (for example, 10 seconds) has elapsed from that point.

  As is clear from the above, the first operation and the second operation are both common by flowing compressed air into the heat exchanger 8 after the sterilization step, but in the first operation, the supply of compressed air was stopped. The second operation is different from the latter in that the cooling process is started while flowing compressed air, and the supply of compressed air is stopped after a predetermined time.

  In any case, by executing such a transition operation, the heat exchanger 8 is supplied with pressurized air and pressurized, so that sudden pressure reduction due to steam condensation during cooling water supply is prevented. This prevents steam from being ejected from the safety valve when cooling water is supplied, and also prevents noise and vibration from being generated from the piping. Also, supply of compressed air after the first set time has elapsed after the stop of steam supply, supply of cooling water after the second set time has elapsed after the start of supply of compressed air, or start of supply of cooling water The above-mentioned operation and effect are stabilized by continuing the compressed air supply until the time or the third set time elapses thereafter.

  By the way, even if the compressed air supply means 13 is pressurized, the cooling water return path 32 is open to the atmosphere in the cooling tower 29, so that the cooling water and compressed air are sent back to the cooling tower 29 without flowing back. In this embodiment, the pressure of the compressed air by the compressed air supply means 13 is equal to the discharge pressure of the water pump 30 (the pressure difference between the two is within a predetermined range).

≪ (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. During the circulation, the steam supply valve 28 and the drain discharge valve 36 are closed, while the cooling water feed valve 33 and the cooling water return valve 34 are opened, the cooling tower 29 and the water feed pump 30 are operated, and the heat exchanger What is necessary is just to circulate cooling water to 8.

  Supply of cooling water to the heat exchanger 8 by the cooling means 11 when the cooling time elapses from the start of the cooling process, when the temperature in the treatment tank 3 falls below the cooling temperature, or when a predetermined time elapses after falling below the cooling temperature. To stop 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.

≪ (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 pressurizing 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 is taken out from the processing tank 3. it can.

  The sterilization apparatus 1 of the present invention is not limited to the configuration of the above embodiment, and can be changed as appropriate. In particular, a compressed air supply means 13 for the heat exchanger 8 is provided, and after stopping the supply of steam to the heat exchanger 8 and before starting the cooling water supply, the compressed air is supplied to the heat exchanger 8 and pressurized. However, other configurations can be changed as appropriate. For example, the timing for starting the supply of compressed air after stopping the supply of steam to the heat exchanger 8 (first set time), the timing for starting the supply of cooling water after starting the supply of compressed air to the heat exchanger 8 (second set time) The timing (third set time) for stopping the supply of compressed air to the heat exchanger 8 is set as appropriate, and in some cases, based on the pressure in the heat exchanger 8 (side through which steam or cooling water is passed). It may be controlled.

  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. And what is necessary is just to be able to perform the said operation at the time of transfer at the time of transfer from a sterilization process to a cooling process.

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 Steam supply means 11 Cooling means 12 Drain discharge means 13 Compressed air supply means 27 Steam supply path 28 Steam supply valve 29 Cooling tower 30 Water feed pump 31 Cooling water feed path 32 Cooling water return path 33 Cooling water feed valve 34 Cooling water return valve 35 Drain discharge path 36 Drain discharge valve 39 Compressed air path 40 Compressed air supply valve

Claims (3)

A treatment tank in which water is stored while a workpiece is stored;
Circulation means for circulating the stored water in the treatment tank with the heat exchanger;
In order to heat the circulating water by the circulation means, steam supply means for supplying steam to the heat exchanger,
Cooling means for supplying cooling water to the heat exchanger in order to cool the circulating water by the circulation means;
Compressed air supply means for supplying compressed air to the heat exchanger after the steam supply to the heat exchanger is stopped by the steam supply means and before the cooling water supply to the heat exchanger is started by the cooling means; A sterilizing apparatus comprising: After the first set time has elapsed since stopping steam supply to the heat exchanger by the steam supply means, start supplying compressed air to the heat exchanger by the compressed air supply means,
After the second set time has elapsed since the compressed air supply means started the supply of compressed air to the heat exchanger, the cooling means started supplying cooling water to the heat exchanger,
Supply of compressed air to the heat exchanger by the compressed air supply means is performed until the start of supply of cooling water to the heat exchanger by the cooling means, or cooling to the heat exchanger by the cooling means The sterilization apparatus according to claim 1, wherein the sterilization apparatus is performed from the start of water supply until a third set time has elapsed. In the treatment tank, water is stored up to a water level where the workpiece is not immersed,
The circulating means jets water from the bottom in the processing tank back to the object to be processed in the processing tank via the heat exchanger,
The cooling means circulates cooling water between the heat exchanger and the cooling tower, and includes a cooling water feed valve in a cooling water feed path from the cooling tower to the heat exchanger, while from the heat exchanger to the cooling tower. A cooling water return valve is provided in the cooling water return path to
The steaming means is connected to the cooling water feed path downstream of the cooling water feed valve, a steam feed path having a steam feed valve,
The drain discharge means for discharging the steam drain by the steam supply means to the outside, a drain discharge path including a drain discharge valve is connected to the cooling water return path upstream of the cooling water return valve,
In the compressed air supply means, a compressed air path including a compressed air supply valve is connected to the cooling water feed path downstream from the cooling water feed valve, or the steam feed path downstream from the steam feed valve. Connected to
While closing the cooling water feed valve, the cooling water return valve, and the compressed air supply valve, the steam supply valve and the drain discharge valve are opened to supply steam from the steam supply means to the heat exchanger. By heating the circulating water, the object to be treated is sterilized,
When the inside of the treatment tank is at or above the sterilization temperature, the steam supply valve is closed,
When the first set time has elapsed after closing the steam supply valve, open the compressed air supply valve,
When the second set time elapses after opening the compressed air supply valve, the cooling water feed valve and the cooling water return valve are opened, the drain discharge valve is closed, and the cooling water from the cooling tower is supplied to the heat exchanger. And cooling the circulating water to cool the workpiece,
The sterilizer according to claim 1 or 2, wherein the compressed air supply valve is closed at the start of supply of cooling water to the heat exchanger, or when a third set time has elapsed since that time.

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