JP5907424B2 - Sterilizer - Google Patents

Description

  The present invention relates to a sterilization apparatus used for heat sterilization of a retort food or the like and subsequent cooling. In particular, the present invention relates to a sterilizer that circulates water between a treatment tank and a heat exchanger and switches between circulating water being heated by steam or cooling by cooling water in the heat exchanger.

  Conventionally, as disclosed in Patent Document 1 below, the processing object (2) is accommodated in the processing tank (1) and water is stored, and the stored water is circulated between the heat exchanger (3). The circulating water is heated with steam in the heat exchanger (3) or cooled with cooling water from the cooling tower (8) to switch the sterilization of the workpiece (2) and subsequent cooling. Sterilizers that can do this are known.

Japanese Patent No. 4229420

  In this type of sterilizer, steam is supplied to the heat exchanger in the sterilization step while circulating water between the treatment tank and the heat exchanger, and cooling water is supplied to the heat exchanger in the subsequent cooling step. . Therefore, immediately after the transition from the sterilization process to the cooling process, cooling water is suddenly introduced into the heat exchanger filled with steam, water hammer is generated, and noise and impact are generated from the piping to the heat exchanger. There are inconveniences that occur or residual steam in the piping is ejected from the safety valve.

  Therefore, the problem to be solved by the present invention is to prevent the occurrence of water hammer in the cooling process after the sterilization process, to eliminate or reduce the noise and impact from the piping to the heat exchanger, and from the safety valve. It is to prevent the jet of steam.

The present invention has been made in order to solve the above-mentioned problems. The invention according to claim 1 is a treatment tank in which water is stored while an object to be treated is stored, and the stored water is treated as 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 steam supplied to the heat exchanger during the steam supply to the heat exchanger by the steam supplying means to the outside through a steam trap Drain discharge means for discharging, and steam discharge from the heat exchanger after the steam supply to the heat exchanger by the steam supply means is stopped and before the cooling water supply to the heat exchanger is started by the cooling means. It is characterized by having a steaming means for achieving A filtering apparatus.

  According to the first aspect of the present invention, after the steam supply to the heat exchanger by the steam supply means is stopped, before the cooling water supply to the heat exchanger by the cooling means is started, the steam exhausting means removes the heat exchanger from the heat exchanger. The steam can be discharged. Therefore, even if cooling water is supplied to the heat exchanger by the cooling means thereafter, the generation of a water hammer can be prevented, and the noise and impact from the piping to the heat exchanger can be eliminated or reduced. Further, it is possible to prevent the vapor from being ejected from the safety valve.

  According to a second aspect of the present invention, the steam supply means includes a steam supply valve in a steam supply path to the heat exchanger, and the steam exhaust means has a steam exhaust valve in a steam supply path from the heat exchanger. The cooling means includes a cooling water feed valve in the cooling water feed path to the heat exchanger, and the exhaust steam path is a pipe line connected to the steam feed path downstream from the steam feed valve. Or a pipe line connected to the cooling water feed path downstream from the cooling water feed valve, wherein the exhaust steam valve is provided in the pipe line. Device.

  According to the second aspect of the present invention, the steam supply to the heat exchanger, the exhaust from the heat exchanger, and the flow of the cooling water to the heat exchanger can be controlled by opening and closing the valves, respectively. In addition, by providing the exhaust steam valve in the pipe connected to the steam supply path or the cooling water feed path, the steam can be smoothly discharged from the heat exchanger and the piping to it.

  Furthermore, the invention according to claim 3 closes the exhaust steam valve and the cooling water feed valve, and opens the steam supply valve to supply steam from the steam supply means to the heat exchanger. By heating the circulating water, the object to be treated is sterilized, and when the inside of the treatment tank is at a sterilization temperature or higher and the sterilization time has elapsed, the steam supply valve is closed while the steaming valve is opened. When the evacuation time has elapsed since opening, the evacuation valve is closed, the cooling water feed valve is opened, the cooling water from the cooling means is supplied to the heat exchanger, and the circulating water is cooled. The sterilization apparatus according to claim 2, wherein the object to be treated is cooled.

  According to the third aspect of the present invention, the sterilization process of the object to be processed, the steaming process from the heat exchanger and the piping to the heat exchanger, and the cooling process of the object to be processed are sequentially performed, and cooling is performed after the steaming process. By executing the process, there is no possibility of causing a water hammer in the cooling process.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of a water hammer can be prevented in the cooling process after a sterilization process, and the sound and impact from piping to a heat exchanger can be eliminated or reduced. Further, it is possible to prevent the vapor from being ejected from the safety valve.

It is the schematic which shows one Example of the sterilizer of this invention.

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 retort 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 from the treatment tank 3, and a treatment tank 3. Pressurizing means 6, exhaust means 7 from inside 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 steam discharge means 13 for discharging the steam from the heat exchanger 8 and the piping to the heat exchanger 8, and a control means (not shown) for controlling these means.

  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. Therefore, the workpiece 2 can be taken in and out of the processing tank 3 by opening the door, and the opening of the processing tank 3 can be airtightly closed by closing the door.

  The treatment tank 3 is provided with a temperature sensor 14 for detecting the temperature in the treatment tank 3 and a water level detector (not shown) for detecting the water level in the treatment tank 3.

  In the case of the illustrated example, the objects to be processed 2 are arranged in a tray 15, and such trays 15 are stacked in the vertical direction and accommodated in the processing tank 3. The tray 15 is a shallow rectangular container that opens upward. At least a plurality of openings are formed on the bottom surface, and the upper and lower trays 15 and 15 are stacked with gaps on the side surfaces. However, the workpiece 2 may be accommodated in the processing tank 3 by placing it on a shelf of the processing tank 3 or by placing it on a wagon.

  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 the to-be-processed object 2 accommodated in the processing tank 3 does not immerse.

  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 pressurized air (in other words, compressed air) into the processing tank 3 through the pressurizing passage 21. By opening the pressurizing valve 22 provided in the pressurizing passage 21, pressurized air from a pressurized air source can be supplied into the processing tank 3, and the inside of the processing tank 3 can be pressurized to a pressure exceeding the 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 an exhaust valve 24 and a check valve 25 are provided in order from the processing tank 3 side. 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. In addition, although the structure in particular is not ask | required for the heat exchanger 8, it is set as the plate type heat exchanger in a present Example.

  The circulation means 9 circulates water between the treatment tank 3 and the heat exchanger 8. The circulation means 9 includes a circulation path 26 and a circulation pump 27. One end of the circulation path 26 is connected to the bottom of the treatment tank 3, and the circulation path 26 from the bottom of the treatment tank 3 passes through the circulation pump 27 and the heat exchanger 8 in this order, and the other end is the treatment tank 3. It is connected to the inner nozzle 28. This nozzle 28 is provided in the side part and / or upper part in the processing tank 3, and injects the water from the circulation pump 27 toward the to-be-processed object 2. FIG. In the case of the illustrated example, the water supply path 16 and the circulation path 26 are a common pipe line on the bottom side of the treatment tank 3.

  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 29 that supplies steam from the boiler to the heat exchanger 8, and a shutoff valve 30 and a steam supply valve 31 are provided in the steam supply path 29. When supplying steam to the heat exchanger 8 by the steam supply means 10, the shutoff valve 30 is maintained in an open state, and the opening degree of the steam supply valve 31 is adjusted. By adjusting the opening degree of the steam supply valve 31, the temperature of the circulating water by the circulation means 9 and thus the temperature in the treatment tank 3 can be adjusted as desired. Specifically, the opening degree of the steam supply valve 31 is adjusted 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 32, and water cooled by the cooling tower 32 is supplied to the heat exchanger 8 by the water pump 33 via the cooling water feed path 34, and the water after passing through the heat exchanger 8. Is returned to the cooling tower 32 via the cooling water return path 35. In the case of the illustrated example, the cooling water feed path 34 and the steam supply path 29 are common pipe lines on the heat exchanger 8 side. The cooling tower 32 is appropriately supplied with water via a ball tap 36.

  A cooling water feed valve 37 is provided in the cooling water feed path 34, while a cooling water return valve 38 is provided in the cooling water return path 35. The junction between the cooling water feed path 34 and the steam supply path 29 is disposed downstream of the cooling water feed valve 37 and the steam supply valve 31 (on the heat exchanger 8 side). Further, a cooling water feed path 34 on the upstream side (cooling tower 32 side) from the cooling water feed valve 37 and a cooling water return path 35 on the downstream side (cooling tower 32 side) from the cooling water return valve 38 are connected by a bypass path 39. A bypass valve 40 is provided in the bypass passage 39.

  Accordingly, when the water feed pump 33 is operated with the bypass valve 40 closed and the coolant feed valve 37 and the coolant return valve 38 opened, the coolant is circulated between the cooling tower 32 and the heat exchanger 8. be able to. On the other hand, if the cooling water feed valve 37 and the cooling water return valve 38 are closed, the flow of the cooling water to the heat exchanger 8 can be stopped. At this time, the water pump 33 may be stopped, but the water pump 33 may be operated with the bypass valve 40 opened in order to prevent the cooling tower 32 from freezing.

  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 on the upstream side (heat exchanger 8 side) of the cooling water return valve 38 in the cooling water return path 35, and is connected to the drain discharge path 41 branched from the cooling water return path 35. 42, a steam trap 43 and a check valve 44 are provided in this order. When the steam is supplied to the heat exchanger 8, by opening the drain discharge valve 42, the condensed water of the steam can be dropped downward and discharged to the outside.

  After the steam supply to the heat exchanger 8 is stopped by the steam supply means 10, the exhaust steam means 13 remains in the heat exchanger 8 or the piping before the cooling means 11 starts supplying the cooling water to the heat exchanger 8. The steam is discharged to the outside. The steaming means 13 includes a steaming path 45 from the heat exchanger 8 side, and a steaming valve 46 and a check valve 47 are provided in the steaming path 45. The exhaust steam path 45 includes a pipe line connected to the steam feed path 29 downstream of the steam feed valve 31 or a pipe line connected to the cooling water feed path 34 downstream of the cooling water feed valve 37. In other words, the exhaust steam passage 45 is provided so as to branch from the steam supply passage 29 downstream of the steam supply valve 31 or the cooling water feed passage 34 downstream of the cooling water feed valve 37. In the present embodiment, in the steam supply passage 29, the exhaust steam passage 45 is provided so as to branch downstream from the steam supply valve 31 and upstream from the junction with the cooling water feed passage 34. Further, a safety valve 48 is provided in the exhaust steam path 45 between the branching section with the steam supply path 29 and the exhaust steam valve 46.

  The control means is a controller (not shown) that controls each means based on the detection signal of the temperature sensor 14 and the water level detector, the elapsed time, and the like. 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 27, the shutoff valve 30, the steam supply valve 31, the cooling tower 32, the water supply pump 33, and the cooling water supply valve 37. In addition to the cooling water return valve 38, the bypass valve 40, the drain discharge valve 42, and the steam exhaust valve 46, the temperature sensor 14 and the water level detector are connected to the controller.

  As will be described below, the controller performs heat sterilization of the workpiece 2 in the processing tank 3 and subsequent cooling in accordance with a predetermined procedure (program). Typically, a water supply process, a transition process, a sterilization process, a steaming process, a cooling process, and a draining 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 and the exhaust valve 46 are opened, the other valves are closed, and the respective pumps are stopped.

(1) Water supply step In the water supply step, 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. At this time, the drain valve 20 and the pressurizing valve 22 are closed, and the exhaust valve 24 is opened. 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 process, 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 and processed. The temperature in the tank 3 is raised to the sterilization temperature. Specifically, by operating the circulation pump 27, the water from the inner bottom of the processing tank 3 is returned to the processing tank 3 from the nozzle 28 via the heat exchanger 8, thereby exchanging heat with the processing tank 3. Water is circulated to and from the vessel 8. Further, the steam supply valve 31 is 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. At this time, the cooling water feed valve 37, the cooling water return valve 38, and the exhaust steam valve 46 are closed, and the drain discharge valve 42 is opened. By opening the drain discharge valve 42, the steam condensate is discharged through the steam trap 43.

  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 packaging (a 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 (slightly 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 water circulation by the circulation means 9 and the pressurization in the treatment tank 3 are continued until the end of the cooling step. That is, 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 to a slightly higher pressure than the saturated vapor pressure corresponding to the sterilization temperature after the inside of the treatment tank 3 rises to the sterilization temperature until the end of the cooling process. .

(3) Sterilization process In a sterilization process, the temperature in the processing tank 3 is hold | maintained at the sterilization temperature, and the to-be-processed object 2 is heated and sterilized. Specifically, the opening degree of the steam supply valve 31 is adjusted so that the temperature detected by the temperature sensor 14 is maintained at the sterilization temperature while water is circulated between the treatment tank 3 and the heat exchanger 8. 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 31 and the drain discharge valve 42 are closed, the steam supply to the heat exchanger 8 is stopped, and the sterilization process is terminated.

(4) Steaming process In the steaming process, the steam is discharged from the heat exchanger 8 and the pipe connected thereto by the steaming means 13 to the outside. Specifically, by opening the steam exhaust valve 46, the pressure in the heat exchanger 8 and the piping is released, and the steam supply path 29 (the steam supply valve 31 and the heat exchanger 8) to the heat exchanger 8 and to the heat exchanger 8 is released. The steam remaining in the steam supply path 29) and the cooling water feed path 34 (the cooling water feed path 34 between the cooling water feed valve 37 and the heat exchanger 8) is discharged to the outside. When a predetermined steaming time elapses from the opening of the steaming valve 46, the steaming valve 46 is closed and the steaming process is terminated.

(5) Cooling step In the cooling step, while circulating water between the treatment tank 3 and the heat exchanger 8, the circulating water is cooled by the cooling means in the heat exchanger 8, thereby The workpiece 2 is cooled. Specifically, the cooling water may be circulated through the heat exchanger 8 by operating the cooling tower 32 and the water pump 33 with the cooling water feed valve 37 and the cooling water return valve 38 opened. At this time, the steam supply valve 31, the drain discharge valve 42, the steam discharge valve 46, and the bypass valve 40 are closed.

  When the set time elapses from the start of the cooling process or when the set time elapses after the temperature in the treatment tank 3 (cooling water temperature) falls below the set temperature, the cooling water feed valve 37 and the cooling water return valve 38 are closed. The cooling process is finished. 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.

(6) 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.

  According to the sterilization apparatus 1 of the present embodiment, 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 starts, the steaming means 13. As a result, the steam in the heat exchanger 8 and the pipes (29, 34) is discharged and the pressure is released. Therefore, even if the cooling water is supplied to the heat exchanger 8 by the cooling means 11 thereafter, the generation of water hammer can be prevented, and the noise and impact from the piping to the heat exchanger 8 can be eliminated or reduced. . Further, it is possible to prevent the vapor from being ejected from the safety valve 48.

  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, in the sterilization apparatus 1 including the heat exchanger 8, the steam is discharged from the heat exchanger 8 after the supply of steam to the heat exchanger 8 is stopped and before the cooling water supply to the heat exchanger 8 is started. If it is a structure, other structures and controls, such as the installation position of the dehumidification means 13, can be changed suitably.

  Further, although the pressurizing means 6 uses pressurized air in the above embodiment, an inert gas may be used in some cases.

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 Dehumidification means 29 Steam supply path 31 Steam supply valve 45 Waste steam path 46 Waste steam valve 34 Cooling water feed path 35 Cooling water return path 37 Cooling water feed valve 38 Cooling water return valve

Claims (3)

A treatment tank in which water is stored while a workpiece is stored;
A circulating means for circulating the stored water between the treatment tank and 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;
During steam supply to the heat exchanger by the steam supply means, drain discharge means for discharging the condensed water of the steam supplied to the heat exchanger to the outside through a steam trap;
After the steam supply to the heat exchanger by the steam supply means is stopped, and before the cooling water supply to the heat exchanger is started by the cooling means, steam exhaust means for discharging steam from the heat exchanger; A sterilizer characterized by comprising. The steam supply means includes a steam supply valve in a steam supply path to the heat exchanger,
The steaming means includes a steaming valve in a steaming path from the heat exchanger,
The cooling means includes a cooling water feed valve in a cooling water feed path to the heat exchanger,
The exhaust steam path includes a pipe line connected to the steam feed path downstream from the steam feed valve, or a pipe line connected to the cooling water feed path downstream from the cooling water feed valve. The sterilizer according to claim 1, wherein the steaming valve is provided in a pipe line. The steaming valve and the cooling water feed valve are closed, while the steaming valve is opened, and steam from the steaming means is supplied to the heat exchanger to heat the circulating water, thereby Sterilize the processed material,
When the inside of the treatment tank is at a sterilization temperature or higher and the sterilization time has elapsed, while closing the steam supply valve, the exhaust steam valve is opened,
When the steaming time has elapsed after opening the steaming valve, the steaming valve is closed,
3. The object to be treated is cooled by opening the cooling water feed valve and supplying cooling water from the cooling means to the heat exchanger to cool the circulating water. The sterilizer described.

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