JP6909443B2

JP6909443B2 - Sterilizer

Info

Publication number: JP6909443B2
Application number: JP2018002269A
Authority: JP
Inventors: 泰三松川; 光央櫛部; 松藤　幸樹; 幸樹松藤; 祐太朗北島; 大祐駒井
Original assignee: Miura Co Ltd
Current assignee: Miura Co Ltd
Priority date: 2018-01-11
Filing date: 2018-01-11
Publication date: 2021-07-28
Anticipated expiration: 2038-01-11
Also published as: JP2019118724A

Description

本発明は、レトルト食品などの加熱殺菌に用いられる殺菌装置に関するものである。 The present invention relates to a sterilizer used for heat sterilization of retort foods and the like.

従来、下記特許文献１に開示される殺菌装置が知られている。当該文献の図面に基づき説明すると、殺菌装置は、殺菌槽（１）内に被殺菌物（２）を収容すると共に水を貯留し、この貯留水を熱交換器（３）との間で循環させる。そして、この循環水を熱交換器（３）において蒸気により加熱するか、クーリングタワー（８）からの冷却用水で冷却するかを切り替えて、被殺菌物（２）の加熱殺菌とその後の冷却が図られる。 Conventionally, a sterilizer disclosed in Patent Document 1 below is known. Explaining based on the drawings of the document, the sterilizer accommodates the object to be sterilized (2) in the sterilizer tank (1), stores water, and circulates the stored water with the heat exchanger (3). Let me. Then, the heat sterilization of the object to be sterilized (2) and the subsequent cooling are shown by switching between heating the circulating water with steam in the heat exchanger (3) and cooling with cooling water from the cooling tower (8). Be done.

特許第４２２９４２０号公報Japanese Patent No. 4229420

従来技術では、殺菌槽と熱交換器との間の循環水を加熱する際、熱交換器に蒸気を供給するが、その蒸気の凝縮水（ドレン）はスチームトラップを介して排出される。ところが、スチームトラップに詰まりが発生することで、ドレンの排出が不能となり、循環水を所望に昇温できないおそれがある。 In the prior art, when the circulating water between the sterilizer and the heat exchanger is heated, steam is supplied to the heat exchanger, but the condensed water (drain) of the steam is discharged through the steam trap. However, if the steam trap is clogged, drainage cannot be discharged, and the temperature of the circulating water may not be raised as desired.

スチームトラップに詰まりを発生させる原因として、スケール（水中の硬度成分が炭酸イオンやシリカ等と結合して析出したもの）や、配管内の錆がある。配管内の錆については、ステンレス配管を用いることで防止することもできるが、配管は装置設置場所の環境に左右される。また、スケールについては、殺菌装置に特有の次のような事情がある。 The causes of clogging of the steam trap are scale (hardness component in water bonded with carbonate ions, silica, etc. and precipitated) and rust in the pipe. Rust inside the pipe can be prevented by using stainless steel pipe, but the pipe depends on the environment of the equipment installation location. Further, regarding the scale, there are the following circumstances peculiar to the sterilizer.

すなわち、前提として、熱交換器において循環水を加熱するための蒸気は、通常、軟水や純水を蒸気化したものであるし、仮にそうでなくても、一旦蒸気化されることで純水化されたものである。そのため、蒸気によるスケール発生への影響は少ない。一方、熱交換器において循環水を冷却するための冷却用水は、通常、軟水や純水ではなく、硬度成分が残留した水（典型的には水道水）である。そのため、蒸気による加熱と冷却用水による冷却とを同一の熱交換器で行う場合、冷却用水によりスケールが発生し、スチームトラップに詰まりを生じさせるおそれがある。 That is, as a premise, the steam for heating the circulating water in the heat exchanger is usually vaporized soft water or pure water, and even if it is not, the pure water is once vaporized. It is a modified version. Therefore, the effect of steam on scale generation is small. On the other hand, the cooling water for cooling the circulating water in the heat exchanger is usually not soft water or pure water, but water having a residual hardness component (typically tap water). Therefore, when heating with steam and cooling with cooling water are performed in the same heat exchanger, scale is generated by the cooling water, which may cause clogging of the steam trap.

そこで、本発明が解決しようとする課題は、熱交換器からのドレン排出系統の詰まりを防止でき、また蒸気排出を抑えたドレン排出を可能とすることで、所期の殺菌を図ることのできる殺菌装置を提供することにある。 Therefore, the problem to be solved by the present invention is that it is possible to prevent clogging of the drain discharge system from the heat exchanger and to enable drain discharge with suppressed steam discharge, so that the desired sterilization can be achieved. The purpose is to provide a sterilizer.

請求項１に記載の発明は、被処理物が収容されると共に水が貯留される処理槽と、前記処理槽との間で水が循環され、その循環水を蒸気で加熱可能な熱交換器と、前記熱交換器に供給された蒸気の凝縮水を外部へ排出するドレン排出手段と、前記ドレン排出手段を制御する制御手段とを備え、前記ドレン排出手段として、前記熱交換器からのドレン排出路に、スチームトラップは設けられないが、ドレン排出弁が設けられている殺菌装置であって、前記処理槽内を殺菌温度または殺菌温度範囲まで上昇させる昇温工程と、前記処理槽内を殺菌温度または殺菌温度範囲に保持する殺菌工程とを順に実行し、ドレン排出可能流量が、前記殺菌工程より前記昇温工程で多くなるように前記ドレン排出弁を制御することを特徴とする殺菌装置である。 The invention according to claim 1 is a heat exchanger in which water is circulated between a treatment tank in which an object to be treated is stored and water is stored, and the circulating water can be heated by steam. A drain discharge means for discharging the condensed water of steam supplied to the heat exchanger to the outside and a control means for controlling the drain discharge means are provided, and the drain from the heat exchanger is provided as the drain discharge means. A sterilizer that is not provided with a steam trap but is provided with a drain discharge valve in the discharge path, and has a temperature raising step of raising the inside of the treatment tank to a sterilization temperature or a sterilization temperature range, and the inside of the treatment tank. a sterilization step of maintaining the sterilization temperature or sterilization temperature range executed sequentially, killing drainage can flow, you and controls said sterilizing said drainage valve said to be larger in the heating step the step It is a fungus device.

請求項１および後述の請求項２〜４に記載の発明によれば、処理槽と熱交換器との間で水を循環させつつ、熱交換器に蒸気を供給して循環水を加熱することで、処理槽内の被処理物を加熱して殺菌することができる。この際、熱交換器に供給された蒸気の凝縮水（ドレン）は、ドレン排出路を介して外部へ排出される。ドレン排出路には、スチームトラップは設けられないが、ドレン排出弁が設けられている。そのため、ドレン排出弁を制御することで、ドレンの排出を図ることができる。ドレン排出路にスチームトラップを設けないことで、スチームトラップの詰まりによるドレンの排出不良（ひいては処理槽内の昇温異常）を防止することができる。
請求項１に記載の発明によれば、ドレン排出可能流量が、殺菌工程より昇温工程で多くなるようにドレン排出弁を制御するので、昇温時に生じる比較的多くのドレンを円滑に排出することができる。 According to the invention of claim 1 and claims 2 to 4 described later, steam is supplied to the heat exchanger to heat the circulating water while circulating water between the treatment tank and the heat exchanger. Therefore, the object to be treated in the treatment tank can be heated and sterilized. At this time, the condensed water (drain) of steam supplied to the heat exchanger is discharged to the outside through the drain discharge path. A steam trap is not provided in the drain discharge path, but a drain discharge valve is provided. Therefore, the drain can be discharged by controlling the drain discharge valve. By not providing a steam trap in the drain discharge path, it is possible to prevent a drain discharge failure (and by extension, an abnormal temperature rise in the treatment tank) due to clogging of the steam trap.
According to the invention of claim 1 , since the drain discharge valve is controlled so that the flow rate at which drainage can be discharged is larger in the temperature rise step than in the sterilization step, a relatively large amount of drain generated at the time of temperature rise is smoothly discharged. be able to.

請求項２に記載の発明は、被処理物が収容されると共に水が貯留される処理槽と、前記処理槽との間で水が循環され、その循環水を蒸気で加熱可能な熱交換器と、前記熱交換器に供給された蒸気の凝縮水を外部へ排出するドレン排出手段と、前記ドレン排出手段を制御する制御手段とを備え、前記ドレン排出手段として、前記熱交換器からのドレン排出路に、スチームトラップは設けられないが、ドレン排出弁が設けられている殺菌装置であって、前記処理槽内を殺菌温度または殺菌温度範囲まで上昇させる昇温工程と、前記処理槽内を殺菌温度または殺菌温度範囲に保持する殺菌工程とを順に実行し、前記昇温工程では、前記ドレン排出弁を開放状態に維持するか、前記殺菌工程より開時間割合を大きくしつつ前記ドレン排出弁を開閉することを特徴とする殺菌装置である。 The invention according to claim 2 is a heat exchanger in which water is circulated between a treatment tank in which an object to be treated is stored and water is stored, and the circulating water can be heated by steam. A drain discharge means for discharging the condensed water of steam supplied to the heat exchanger to the outside and a control means for controlling the drain discharge means are provided, and the drain from the heat exchanger is provided as the drain discharge means. A sterilizer that is not provided with a steam trap but is provided with a drain discharge valve in the discharge path, and has a temperature raising step of raising the inside of the treatment tank to a sterilization temperature or a sterilization temperature range, and the inside of the treatment tank. The sterilization temperature or the sterilization step of maintaining the sterilization temperature range is executed in order, and in the temperature raising step, the drain discharge valve is maintained in an open state, or the drain discharge valve is opened while increasing the opening time ratio from the sterilization step. opening and closing the a filtering apparatus killing you characterized.

請求項２に記載の発明によれば、処理槽内を殺菌温度または殺菌温度範囲まで上昇させる昇温工程において、ドレン排出弁を開放状態に維持するか、殺菌工程より開時間割合を大きくしつつドレン排出弁を開閉することで、昇温時に生じる比較的多くのドレンを円滑に排出することができる。 According to the second aspect of the present invention, in the temperature raising step of raising the inside of the treatment tank to the sterilization temperature or the sterilization temperature range, the drain discharge valve is maintained in an open state or the opening time ratio is increased as compared with the sterilization step. By opening and closing the drain discharge valve, a relatively large amount of drain generated when the temperature rises can be smoothly discharged.

請求項３に記載の発明は、被処理物が収容されると共に水が貯留される処理槽と、前記処理槽との間で水が循環され、その循環水を蒸気で加熱可能な熱交換器と、前記熱交換器に供給された蒸気の凝縮水を外部へ排出するドレン排出手段と、前記ドレン排出手段を制御する制御手段とを備え、前記ドレン排出手段として、前記熱交換器からのドレン排出路に、スチームトラップは設けられないが、ドレン排出弁が設けられている殺菌装置であって、前記処理槽内を殺菌温度または殺菌温度範囲まで上昇させる昇温工程と、前記処理槽内を殺菌温度または殺菌温度範囲に保持する殺菌工程とを順に実行し、前記殺菌工程では、所定時間経過するまでは、第一設定時間ごとに前記ドレン排出弁を規定時間開放し、所定時間経過後には、前記第一設定時間よりも長い第二設定時間ごとに前記ドレン排出弁を規定時間開放することを特徴とする殺菌装置である。 The invention according to claim 3 is a heat exchanger in which water is circulated between a treatment tank in which an object to be treated is stored and water is stored, and the circulating water can be heated by steam. A drain discharge means for discharging the condensed water of steam supplied to the heat exchanger to the outside and a control means for controlling the drain discharge means are provided, and the drain from the heat exchanger is provided as the drain discharge means. A sterilizer that is not provided with a steam trap but is provided with a drain discharge valve in the discharge path, and has a temperature raising step of raising the inside of the treatment tank to a sterilization temperature or a sterilization temperature range, and the inside of the treatment tank. The sterilization step or the sterilization step of keeping in the sterilization temperature range is executed in order, and in the sterilization step, the drain discharge valve is opened for a specified time every first set time until a predetermined time elapses, and after the predetermined time elapses a filtering apparatus killing you wherein defining time opening the drain cock for each long second set time than the first set time.

請求項３に記載の発明によれば、殺菌工程の初期には、比較的短い間隔でドレン排出弁を開放する一方、その後は、比較的長い間隔でドレン排出弁を開放することになる。殺菌工程の初期ほど、ドレンが出やすいので、ドレン排出弁の開放間隔を短くすることで、蒸気の排出を抑えた円滑なドレンの排出を行うことができる。 According to the invention of claim 3 , the drain discharge valve is opened at a relatively short interval at the initial stage of the sterilization step, and the drain discharge valve is opened at a relatively long interval thereafter. Since drainage is more likely to occur at the beginning of the sterilization process, it is possible to smoothly discharge the drain by suppressing the discharge of steam by shortening the opening interval of the drain discharge valve.

請求項４に記載の発明は、被処理物が収容されると共に水が貯留される処理槽と、前記処理槽との間で水が循環され、その循環水を蒸気で加熱可能な熱交換器と、前記熱交換器に供給された蒸気の凝縮水を外部へ排出するドレン排出手段と、前記ドレン排出手段を制御する制御手段とを備え、前記ドレン排出手段として、前記熱交換器からのドレン排出路に、スチームトラップは設けられないが、ドレン排出弁が設けられている殺菌装置であって、前記処理槽内を殺菌温度または殺菌温度範囲まで上昇させる昇温工程と、前記処理槽内を殺菌温度または殺菌温度範囲に保持する殺菌工程とを順に実行し、前記昇温工程および／または前記殺菌工程では、前記ドレン排出路の温度に基づき前記ドレン排出弁の開閉または開度を調整することを特徴とする殺菌装置である。 The invention according to claim 4 is a heat exchanger in which water is circulated between a treatment tank in which an object to be treated is stored and water is stored, and the circulating water can be heated by steam. A drain discharge means for discharging the condensed water of steam supplied to the heat exchanger to the outside and a control means for controlling the drain discharge means are provided, and the drain from the heat exchanger is provided as the drain discharge means. A sterilizer that is not provided with a steam trap but is provided with a drain discharge valve in the discharge path, and has a temperature raising step of raising the inside of the treatment tank to a sterilization temperature or a sterilization temperature range, and the inside of the treatment tank. The sterilization temperature or the sterilization step of keeping in the sterilization temperature range is executed in order, and in the temperature raising step and / or the sterilization step, the opening / closing or opening degree of the drain discharge valve is adjusted based on the temperature of the drain discharge path. a filtering apparatus killing you characterized.

請求項４に記載の発明によれば、ドレン排出路の温度に基づきドレン排出弁の開閉または開度を調整することで、ドレンの溜まり具合に応じて、蒸気の排出を抑えつつ、ドレンの排出を図ることができる。
請求項５に記載の発明は、前記ドレン排出路に、ドレン排出弁と固定絞り部とが設けられ、前記制御手段は、前記ドレン排出弁の開閉を切り替えることを特徴とする請求項１〜４のいずれか１項に記載の殺菌装置である。
請求項５に記載の発明によれば、ドレン排出路に固定絞り部を設けることで、ドレン排出弁を開けた際のドレンの排出量を調整することができる。また、ドレン排出弁の開閉を切り替えるという簡易な制御で、ドレンを所望に排出することができる。
請求項６に記載の発明は、前記ドレン排出路に、ドレン排出弁が設けられ、前記制御手段は、前記ドレン排出弁の開度を調整することを特徴とする請求項１〜４のいずれか１項に記載の殺菌装置である。
請求項６に記載の発明によれば、ドレン排出路に設けたドレン排出弁の開度を調整することで、ドレンを所望に排出することができる。 According to the fourth aspect of the present invention, by adjusting the opening / closing or opening degree of the drain discharge valve based on the temperature of the drain discharge path, the drain is discharged while suppressing the discharge of steam according to the degree of accumulation of the drain. Can be planned.
The invention according to claim 5 is characterized in that a drain discharge valve and a fixed throttle portion are provided in the drain discharge path, and the control means switches the opening and closing of the drain discharge valve. The sterilizer according to any one of the above.
According to the fifth aspect of the present invention, the amount of drainage discharged when the drain discharge valve is opened can be adjusted by providing the drain discharge path with a fixed throttle portion. Further, the drain can be discharged as desired by a simple control of switching the opening and closing of the drain discharge valve.
The invention according to claim 6 is any one of claims 1 to 4, wherein a drain discharge valve is provided in the drain discharge path, and the control means adjusts the opening degree of the drain discharge valve. The sterilizer according to item 1.
According to the sixth aspect of the present invention, the drain can be discharged as desired by adjusting the opening degree of the drain discharge valve provided in the drain discharge path.

本発明の殺菌装置によれば、熱交換器からのドレン排出系統の詰まりを防止でき、また蒸気排出を抑えたドレン排出を可能とすることで、所期の殺菌を図ることができる。 According to the sterilizer of the present invention, clogging of the drain discharge system from the heat exchanger can be prevented, and drain discharge with suppressed steam discharge is possible, so that desired sterilization can be achieved.

本発明の一実施例の殺菌装置を示す概略図であり、一部を断面にして示している。It is the schematic which shows the sterilizer of one Example of this invention, and shows a part in cross-section. 図１の殺菌装置の運転例を示す概略図であり、横軸は時間ｔ、縦軸は処理槽内温度Ｔを示している。It is a schematic diagram which shows the operation example of the sterilizer of FIG. 1, the horizontal axis shows time t, and the vertical axis shows the temperature T in a processing tank.

以下、本発明の具体的実施例を図面に基づいて詳細に説明する。
図１は、本発明の一実施例の殺菌装置１を示す概略図であり、一部を断面にして示している。本実施例の殺菌装置１は、被処理物２を加熱して殺菌する装置であり、殺菌後には被処理物２を冷却可能に構成される。被処理物２は、特に問わないが、典型的にはレトルト食品または缶詰など、容器に密閉された食材である。 Hereinafter, specific examples of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing a sterilizer 1 according to an embodiment of the present invention, and a part of the sterilizer 1 is shown in a cross section. The sterilizer 1 of this embodiment is a device that heats and sterilizes the object 2 to be processed, and is configured to be able to cool the object 2 to be processed after sterilization. The object 2 to be processed is not particularly limited, but is typically a food material sealed in a container such as a retort food or a canned food.

本実施例の殺菌装置１は、被処理物２が収容される処理槽３と、この処理槽３内への給水手段４と、処理槽３外への排水手段５と、処理槽３内への圧縮空気供給手段６と、処理槽３外への排気手段７と、処理槽３内の真空解除手段８と、処理槽３と熱交換器９との間で水を循環させる循環手段１０と、循環手段１０による循環水を加熱するために熱交換器９に蒸気を供給する給蒸手段１１と、給蒸手段１１による蒸気の凝縮水（ドレン）を外部へ排出するドレン排出手段１２と、循環手段１０による循環水を冷却するために熱交換器９に冷却水を供給する冷却手段１３と、これら各手段４〜８，１０〜１３を制御する制御手段（図示省略）とを備える。 The sterilizer 1 of the present embodiment includes a treatment tank 3 in which the object to be treated 2 is housed, 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. Compressed air supply means 6, exhaust means 7 to the outside of the treatment tank 3, vacuum release means 8 in the treatment tank 3, and circulation means 10 for circulating water between the treatment tank 3 and the heat exchanger 9. , A steam supply means 11 that supplies steam to the heat exchanger 9 to heat the circulating water by the circulation means 10, and a drain discharge means 12 that discharges condensed water (drain) of steam by the steam supply means 11 to the outside. A cooling means 13 for supplying cooling water to the heat exchanger 9 for cooling the circulating water by the circulation means 10 and a control means (not shown) for controlling each of these means 4 to 8 and 10 to 13 are provided.

処理槽３は、被処理物２を収容する中空容器である。処理槽３は、その形状を特に問わないが、本実施例では水平に配置された円筒材を備え、この円筒材は、一方の開口部が閉塞されており、他方の開口部が扉で開閉可能とされている。扉を開けることで、処理槽３に対し被処理物２を出し入れすることができ、扉を閉じることで、処理槽３の開口部を気密に閉じることができる。なお、被処理物２は、台車に載せられるなどして、処理槽３内の底面よりも上方に保持される。 The treatment tank 3 is a hollow container for accommodating the object to be treated 2. The shape of the treatment tank 3 is not particularly limited, but in the present embodiment, the treatment tank 3 includes a cylindrical material arranged horizontally, and one opening of the cylindrical material is closed and the other opening is opened and closed by a door. It is possible. By opening the door, the object to be processed 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 airtightly. The object to be processed 2 is held above the bottom surface in the processing tank 3 by being placed on a trolley or the like.

処理槽３には、処理槽３内の温度を検出する温度センサ１４と、処理槽３内の水位を検出する水位検出器（図示省略）とが設けられる。但し、温度センサ１４は、処理槽３ではなく、場合により、後述する循環路１５（特に熱交換器９より下流側）に設けられてもよい。 The treatment tank 3 is provided with a temperature sensor 14 for detecting the temperature inside the treatment tank 3 and a water level detector (not shown) for detecting the water level in the treatment tank 3. However, the temperature sensor 14 may be provided not in the processing tank 3 but in the circulation path 15 (particularly on the downstream side of the heat exchanger 9) described later.

給水手段４は、給水路１６を介して処理槽３内へ水を供給する。給水路１６は、処理槽３の底部に接続され、処理槽３へ向けて給水ポンプ１７と給水弁１８とが設けられている。給水ポンプ１７を作動させた状態で給水弁１８を開けることで、給水源からの水を処理槽３内に供給して、処理槽３内に水を貯留することができる。本実施例では、処理槽３内に収容した被処理物を浸漬しない設定水位まで、処理槽３内に水が貯留される。 The water supply means 4 supplies water into the treatment tank 3 via the water supply channel 16. The water supply channel 16 is connected to the bottom of the treatment tank 3, and a water supply pump 17 and a water supply valve 18 are provided toward the treatment tank 3. By opening the water supply valve 18 with the water supply pump 17 operated, water from the water supply source can be supplied into the treatment tank 3 and the water can be stored in the treatment tank 3. In this embodiment, water is stored in the treatment tank 3 up to a set water level at which the object to be treated contained in the treatment tank 3 is not immersed.

排水手段５は、排水路１９を介して処理槽３内から水を排出する。排水路１９は、処理槽３の底部に接続され、排水弁２０が設けられている。排水弁２０を開けることで、処理槽３内の水を外部へ排出することができる。 The drainage means 5 discharges water from the treatment tank 3 via the drainage channel 19. The drainage channel 19 is connected to the bottom of the treatment tank 3 and is provided with a drainage valve 20. By opening the drain valve 20, the water in the treatment tank 3 can be discharged to the outside.

圧縮空気供給手段６は、圧縮空気供給路２１を介して処理槽３内へ圧縮空気を供給する。圧縮空気供給路２１は、処理槽３の上部に接続され、処理槽３へ向けて圧縮空気遮断弁２２と圧縮空気弁２３とが設けられている。圧縮空気遮断弁２２を開けた状態で、圧縮空気弁２３も開けることで、圧縮空気源からの圧縮空気を処理槽３内に供給して、大気圧を超える圧力に処理槽３内を加圧することができる。 The compressed air supply means 6 supplies compressed air into the processing tank 3 via the compressed air supply path 21. The compressed air supply path 21 is connected to the upper part of the processing tank 3, and a compressed air shutoff valve 22 and a compressed air valve 23 are provided toward the processing tank 3. By opening the compressed air valve 23 with the compressed air shutoff valve 22 open, the compressed air from the compressed air source is supplied into the processing tank 3 to pressurize the inside of the processing tank 3 to a pressure exceeding atmospheric pressure. be able to.

排気手段７は、大気圧を超える圧力下の処理槽３内から排気路２４を介して気体を排出する。排気路２４は、処理槽３の上部に接続され、排気弁２５が設けられている。処理槽３内が大気圧を超える圧力にある状態で、排気弁２５を開けると、処理槽３内の気体が排気路２４を介して外部へ排出され、処理槽３内の圧力を下げることができる。 The exhaust means 7 discharges gas from the inside of the processing tank 3 under a pressure exceeding atmospheric pressure through the exhaust passage 24. The exhaust passage 24 is connected to the upper part of the processing tank 3 and is provided with an exhaust valve 25. When the exhaust valve 25 is opened while the pressure inside the treatment tank 3 exceeds the atmospheric pressure, the gas in the treatment tank 3 is discharged to the outside through the exhaust passage 24, and the pressure inside the treatment tank 3 can be lowered. can.

真空解除手段８は、大気圧未満の圧力下の処理槽３内へ給気路２６を介して外気を導入する。給気路２６は、処理槽３の上部に接続され、真空解除弁２７が設けられている。処理槽３内が大気圧未満の圧力にある状態で、真空解除弁２７を開けると、給気路２６を介して外気が処理槽３内へ導入され、処理槽３内の圧力を大気圧まで戻すことができる。 The vacuum release means 8 introduces outside air into the processing tank 3 under a pressure lower than the atmospheric pressure through the air supply passage 26. The air supply passage 26 is connected to the upper part of the processing tank 3 and is provided with a vacuum release valve 27. When the vacuum release valve 27 is opened while the pressure inside the treatment tank 3 is lower than the atmospheric pressure, the outside air is introduced into the treatment tank 3 through the air supply passage 26, and the pressure inside the treatment tank 3 is raised to the atmospheric pressure. Can be returned.

熱交換器９は、処理槽３との間で水が循環され、その循環水と、蒸気または冷却水とを混ぜることなく熱交換する。つまり、熱交換器９は、循環手段１０により処理槽３からの水が通されると共に、この循環水を加熱するために給蒸手段１１による蒸気が通されるか、循環水を冷却するために冷却手段１３による冷却水が通される。 Water is circulated to and from the treatment tank 3 in the heat exchanger 9, and heat is exchanged between the circulating water and steam or cooling water without mixing. That is, in the heat exchanger 9, the water from the treatment tank 3 is passed by the circulation means 10, and the steam by the steam supply means 11 is passed to heat the circulating water, or the circulating water is cooled. The cooling water by the cooling means 13 is passed through the air.

循環手段１０は、処理槽３と熱交換器９との間で水を循環させる。循環手段１０は、循環路１５と循環ポンプ２８とを備える。循環路１５は、一端部が処理槽３の底部に接続され、処理槽３の底部からの循環路１５は、循環ポンプ２８と熱交換器９とを順に介して、他端部が処理槽３内のノズル２９に接続されている。このノズル２９は、処理槽３内の側部および／または上部に設けられており、循環ポンプ２８からの水を被処理物２へ向けて噴射する。 The circulation means 10 circulates water between the treatment tank 3 and the heat exchanger 9. The circulation means 10 includes a circulation path 15 and a circulation pump 28. One end of the circulation path 15 is connected to the bottom of the treatment tank 3, and the circulation path 15 from the bottom of the treatment tank 3 passes through the circulation pump 28 and the heat exchanger 9 in order, and the other end of the circulation path 15 is the treatment tank 3. It is connected to the nozzle 29 inside. The nozzle 29 is provided on a side portion and / or an upper portion in the processing tank 3, and injects water from the circulation pump 28 toward the object to be processed 2.

給蒸手段１１は、熱交換器９に蒸気を供給して、循環手段１０による循環水を加熱する。給蒸手段１１は、ボイラからの蒸気を熱交換器９へ供給する給蒸路３０を備え、この給蒸路３０には給蒸遮断弁３１と給蒸弁３２とが設けられている。循環手段１０による循環中、温度センサ１４の検出温度に基づき、給蒸弁３２の開閉または開度を制御して、処理槽３内の温度を所望に調整することができる。なお、給蒸遮断弁３１は、給蒸弁３２の開閉に連動して、開閉される。 The steaming means 11 supplies steam to the heat exchanger 9 to heat the circulating water by the circulating means 10. The steaming means 11 includes a steaming passage 30 that supplies steam from the boiler to the heat exchanger 9, and the steaming passage 30 is provided with a steaming shutoff valve 31 and a steaming valve 32. During circulation by the circulation means 10, the temperature inside the processing tank 3 can be adjusted as desired by controlling the opening / closing or opening degree of the steam supply valve 32 based on the temperature detected by the temperature sensor 14. The steam supply shutoff valve 31 is opened and closed in conjunction with the opening and closing of the steam supply valve 32.

ドレン排出手段１２は、給蒸手段１１により熱交換器９に供給された蒸気の凝縮水を、ドレン排出路３３を介して外部へ排出する。ドレン排出路３３は、熱交換器９から下方へ延出して設けられている。熱交換器９からのドレン排出路３３には、ドレン排出弁３４、オリフィス３５および逆止弁３６が順に設けられている。熱交換器９への蒸気供給中、ドレン排出弁３４を開けることで、蒸気の凝縮水を外部へ排出することができる。本実施例では、ドレン排出弁３４は、開閉をオンオフで切り替える弁（たとえば電磁弁）で足りるが、場合により開度調整可能な弁（たとえば電動弁）から構成されてもよい。ドレン排出路３３には、スチームトラップは設けられず、さらに図示例ではドレン貯留タンクも設けられない。なお、オリフィス３５に限らず、その他の固定絞り部を用いることもできる。 The drain discharge means 12 discharges the condensed water of steam supplied to the heat exchanger 9 by the steam supply means 11 to the outside through the drain discharge passage 33. The drain discharge path 33 is provided so as to extend downward from the heat exchanger 9. A drain discharge valve 34, an orifice 35, and a check valve 36 are provided in this order in the drain discharge path 33 from the heat exchanger 9. By opening the drain discharge valve 34 while the steam is being supplied to the heat exchanger 9, the condensed water of the steam can be discharged to the outside. In the present embodiment, the drain discharge valve 34 may be composed of a valve (for example, a solenoid valve) for switching on / off of opening / closing, but may be composed of a valve (for example, an electric valve) whose opening degree can be adjusted in some cases. A steam trap is not provided in the drain discharge path 33, and a drain storage tank is not provided in the illustrated example. Not limited to the orifice 35, other fixed throttle portions can also be used.

冷却手段１３は、熱交換器９に冷却水を供給して、循環手段１０による循環水を冷却する。冷却手段１３は、クーリングタワー３７を備え、クーリングタワー３７にて冷却された水は、送水ポンプ３８により、冷却水送り路３９を介して熱交換器９へ供給され、熱交換器９を通過後の水は冷却水戻し路４０を介してクーリングタワー３７へ戻される。図示例の場合、冷却水送り路３９と給蒸路３０とは、熱交換器９の側で共通管路とされている。また、冷却水戻し路４０とドレン排出路３３とは、熱交換器９の側で共通管路とされている。 The cooling means 13 supplies cooling water to the heat exchanger 9 to cool the circulating water by the circulation means 10. The cooling means 13 includes a cooling tower 37, and the water cooled by the cooling tower 37 is supplied to the heat exchanger 9 by the water supply pump 38 via the cooling water feed path 39, and the water after passing through the heat exchanger 9. Is returned to the cooling tower 37 via the cooling water return path 40. In the case of the illustrated example, the cooling water feed path 39 and the steam supply path 30 are common pipelines on the heat exchanger 9 side. Further, the cooling water return path 40 and the drain discharge path 33 are common pipelines on the heat exchanger 9 side.

冷却水送り路３９には冷却水送り弁４１が設けられる一方、冷却水戻し路４０には冷却水戻し弁４２が設けられている。冷却水送り路３９と給蒸路３０との合流部は、冷却水送り弁４１や給蒸弁３２より下流側（熱交換器９側）に配置されている。また、冷却水戻し路４０とドレン排出路３３との分岐部は、冷却水戻し弁４２やドレン排出弁３４よりも上流側（熱交換器９側）に配置されている。 The cooling water feed path 39 is provided with a cooling water feed valve 41, while the cooling water return path 40 is provided with a cooling water return valve 42. The confluence of the cooling water feed path 39 and the steam supply path 30 is arranged on the downstream side (heat exchanger 9 side) of the cooling water feed valve 41 and the steam supply valve 32. Further, the branch portion between the cooling water return path 40 and the drain discharge path 33 is arranged on the upstream side (heat exchanger 9 side) of the cooling water return valve 42 and the drain discharge valve 34.

給蒸弁３２およびドレン排出弁３４を閉じた状態で、冷却水送り弁４１および冷却水戻し弁４２を開けて、送水ポンプ３８を作動させると、クーリングタワー３７と熱交換器９との間で冷却水を循環させることができる。一方、冷却水送り弁４１および冷却水戻し弁４２を閉じた状態で、給蒸弁３２を開ければ、熱交換器９に蒸気を供給することができる。その際、適宜、ドレン排出弁３４を開けることで、ドレンの排出を図ることができる。 When the cooling water feed valve 41 and the cooling water return valve 42 are opened and the water supply pump 38 is operated with the steam supply valve 32 and the drain discharge valve 34 closed, cooling is performed between the cooling tower 37 and the heat exchanger 9. Water can be circulated. On the other hand, if the steam supply valve 32 is opened with the cooling water feed valve 41 and the cooling water return valve 42 closed, steam can be supplied to the heat exchanger 9. At that time, the drain can be discharged by opening the drain discharge valve 34 as appropriate.

制御手段は、温度センサ１４および水位検出器の検出信号の他、経過時間などに基づき、前記各手段４〜８，１０〜１３を制御する制御器（図示省略）である。具体的には、給水ポンプ１７、給水弁１８、排水弁２０、圧縮空気遮断弁２２、圧縮空気弁２３、排気弁２５、真空解除弁２７、循環ポンプ２８、給蒸遮断弁３１、給蒸弁３２、ドレン排出弁３４、クーリングタワー３７、送水ポンプ３８、冷却水送り弁４１、冷却水戻し弁４２の他、温度センサ１４および水位検出器などは、制御器に接続されている。そして、制御器は、以下に述べるように、所定の手順（プログラム）に従い、処理槽３内の被処理物２の加熱殺菌やその後の冷却を行う。 The control means is a controller (not shown) that controls each of the means 4 to 8, 10 to 13 based on the elapsed time and the like, 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 compressed air shutoff valve 22, the compressed air valve 23, the exhaust valve 25, the vacuum release valve 27, the circulation pump 28, the steam supply shutoff valve 31, and the steam supply valve. 32, a drain discharge valve 34, a cooling tower 37, a water pump 38, a cooling water feed valve 41, a cooling water return valve 42, a temperature sensor 14, a water level detector, and the like are connected to a controller. Then, as described below, the controller performs heat sterilization of the object to be processed 2 in the treatment tank 3 and subsequent cooling according to a predetermined procedure (program).

図２は、本実施例の殺菌装置１の運転例を示す概略図であり、横軸は時間ｔ、縦軸は処理槽３内温度Ｔを示している。殺菌装置１は、典型的には、給水工程Ｓ１の後、昇温工程Ｓ２と殺菌工程Ｓ３とを少なくとも一回含んで被処理物２の殺菌を図った後、冷却工程Ｓ４および排水工程Ｓ５を実行する。図２では、給水工程Ｓ１、第一昇温工程Ｓ２ａ、第一殺菌工程Ｓ３ａ、第二昇温工程Ｓ２ｂ、第二殺菌工程Ｓ３ｂ、冷却工程Ｓ４および排水工程Ｓ５を順次に実行する例を示している。 FIG. 2 is a schematic view showing an operation example of the sterilizer 1 of the present embodiment, in which the horizontal axis represents the time t and the vertical axis represents the temperature T in the processing tank 3. The sterilizer 1 typically includes the water supply step S1 and then the temperature raising step S2 and the sterilization step S3 at least once to sterilize the object 2 to be treated, and then performs the cooling step S4 and the drainage step S5. Execute. FIG. 2 shows an example in which the water supply step S1, the first temperature raising step S2a, the first sterilization step S3a, the second temperature rising step S2b, the second sterilization step S3b, the cooling step S4, and the drainage step S5 are sequentially executed. There is.

第一昇温工程Ｓ２ａと第二昇温工程Ｓ２ｂとは、昇温目標温度が異なるが、動作内容は同一である。そのため、各昇温工程Ｓ２ａ，Ｓ２ｂについて、以下、両者を特に区別する場合を除き、単に昇温工程Ｓ２ということがある。同様に、第一殺菌工程Ｓ３ａと第二殺菌工程Ｓ３ｂとは、保持目標温度が異なるが、動作内容は同一である。そのため、各殺菌工程Ｓ３ａ，Ｓ３ｂについて、以下、両者を特に区別する場合を除き、単に殺菌工程Ｓ３ということがある。 The first temperature rising step S2a and the second temperature rising step S2b have different temperature rise target temperatures, but the operation contents are the same. Therefore, each of the temperature raising steps S2a and S2b may be simply referred to as the temperature rising step S2, unless the two are particularly distinguished below. Similarly, the first sterilization step S3a and the second sterilization step S3b have different holding target temperatures, but the operation contents are the same. Therefore, each of the sterilization steps S3a and S3b may be simply referred to as the sterilization step S3, unless the two are particularly distinguished below.

以下、各工程について説明する。まず、殺菌装置１の運転に先立ち、処理槽３内には被処理物２が収容され、処理槽３の扉は気密に閉じられる。その状態では、上述した各弁の内、排水弁２０、排気弁２５、真空解除弁２７、ドレン排出弁３４は開けられているが、その他の弁１８，２２，２３，３１，３２，４１，４２は閉じられており、各ポンプ１７，２８，３８は停止している。 Hereinafter, each step will be described. First, prior to the operation of the sterilizer 1, the object 2 to be processed is housed in the processing tank 3, and the door of the processing tank 3 is airtightly closed. In that state, the drain valve 20, the exhaust valve 25, the vacuum release valve 27, and the drain discharge valve 34 are opened among the above-mentioned valves, but the other valves 18, 22, 23, 31, 32, 41, 42 is closed and pumps 17, 28 and 38 are stopped.

≪給水工程Ｓ１≫
給水工程Ｓ１では、処理槽３内の被処理物２を浸漬しない設定水位まで、給水手段４により処理槽３内に水を供給して、処理槽３内に水を貯留する。具体的には、排気弁２５を開けたまま、排水弁２０および真空解除弁２７を閉じる。そして、給水ポンプ１７を作動させた状態で給水弁１８を開ければよい。処理槽３内に設定水位まで水が貯留されると、給水弁１８を閉じると共に給水ポンプ１７を停止させて、給水工程Ｓ１を終了する。給水工程Ｓ１の後半、循環ポンプ２８を間欠運転し、昇温工程Ｓ２への移行に伴い連続運転に切り替えてもよい。 ≪Water supply process S1≫
In the water supply step S1, water is supplied into the treatment tank 3 by the water supply means 4 to a set water level at which the object 2 to be treated in the treatment tank 3 is not immersed, and the water is stored in the treatment tank 3. Specifically, the drain valve 20 and the vacuum release valve 27 are closed while the exhaust valve 25 is open. Then, the water supply valve 18 may be opened while the water supply pump 17 is 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 step S1. In the latter half of the water supply step S1, the circulation pump 28 may be intermittently operated and switched to continuous operation as the temperature rise step S2 shifts.

≪昇温工程Ｓ２≫
昇温工程Ｓ２では、循環手段１０により処理槽３と熱交換器９との間で水を循環させながら、その循環水を熱交換器９において給蒸手段１１により加熱して、処理槽３内の温度を殺菌温度Ｔ１（Ｔ２）まで上昇させる。具体的には、循環ポンプ２８を作動させることで、処理槽３内底部からの水を、熱交換器９を介して、ノズル２９から処理槽３内へ戻すことで、処理槽３と熱交換器９との間で循環させる。また、この循環中、冷却水送り弁４１および冷却水戻し弁４２を閉じる一方、給蒸遮断弁３１および給蒸弁３２を開けて、熱交換器９へ蒸気を供給する。この際、処理槽３内の温度が所望速度で上昇するように、給蒸弁３２の開度を比例制御するのが好ましい。 << Heating step S2 >>
In the temperature raising step S2, while water is circulated between the treatment tank 3 and the heat exchanger 9 by the circulation means 10, the circulating water is heated by the steaming means 11 in the heat exchanger 9 and inside the treatment tank 3. The temperature of is raised to the sterilization temperature T1 (T2). Specifically, by operating the circulation pump 28, water from the inner bottom of the treatment tank 3 is returned from the nozzle 29 to the inside of the treatment tank 3 via the heat exchanger 9, thereby exchanging heat with the treatment tank 3. Circulate with the vessel 9. Further, during this circulation, the cooling water feed valve 41 and the cooling water return valve 42 are closed, while the steam supply shutoff valve 31 and the steam supply valve 32 are opened to supply steam to the heat exchanger 9. At this time, it is preferable to proportionally control the opening degree of the steam supply valve 32 so that the temperature in the processing tank 3 rises at a desired speed.

昇温工程Ｓ２中、ドレン排出弁３４は、適宜開閉されてもよいが、開放状態に維持するのが簡易で好ましい。処理槽３内および被処理物２の温度を上昇させる昇温工程Ｓ２では、温度を維持する殺菌工程Ｓ３と比較して、多くの熱量が必要であり、比較的多くのドレンが発生する。そのため、本実施例では、ドレン排出弁３４を開放状態に維持する。但し、昇温工程Ｓ２において、ドレン排出弁３４を間欠的に開放してもよい。いずれにしても、昇温工程Ｓ２でのドレン排出可能流量が殺菌工程Ｓ３でのドレン排出可能流量よりも多くなるように、ドレン排出弁３４の開閉または開度を制御するのがよい。従って、昇温工程Ｓ２および殺菌工程Ｓ３においてドレン排出弁３４を間欠的に開閉制御する場合でも、昇温工程Ｓ２でのドレン排出弁３４の開時間割合（単位時間当たりの開放時間）は、殺菌工程Ｓ３でのドレン排出弁３４の開時間割合よりも長くするのがよい。 During the temperature raising step S2, the drain discharge valve 34 may be opened and closed as appropriate, but it is preferable to maintain the drain discharge valve 34 in an open state because it is simple. In the temperature raising step S2 for raising the temperature in the treatment tank 3 and the object 2 to be treated, a larger amount of heat is required and a relatively large amount of drainage is generated as compared with the sterilization step S3 for maintaining the temperature. Therefore, in this embodiment, the drain discharge valve 34 is maintained in the open state. However, in the temperature raising step S2, the drain discharge valve 34 may be opened intermittently. In any case, it is preferable to control the opening / closing or opening degree of the drain discharge valve 34 so that the flow rate at which drainage can be discharged in the temperature raising step S2 is larger than the flow rate at which drainage can be discharged in the sterilization step S3. Therefore, even when the drain discharge valve 34 is intermittently controlled to open and close in the temperature raising step S2 and the sterilization step S3, the opening time ratio (opening time per unit time) of the drain discharge valve 34 in the temperature rising step S2 is sterilized. It is preferable to make it longer than the opening time ratio of the drain discharge valve 34 in the step S3.

なお、標準的な運転環境での加熱負荷（処理槽３、水（貯留水・循環水）および被処理物２を殺菌温度まで加熱するのに必要な熱量）、ひいては発生するドレン量は、算出可能である。また、給蒸手段１１による蒸気の蒸気圧と大気圧との差圧に基づき、オリフィス３５を通過可能なドレン量も算出可能である。そのため、これらから最適なオリフィス３５が選択されるか、および／または、ドレン排出弁３４の開閉が制御される。つまり、昇温工程Ｓ２において、ドレン排出弁３４を開放状態にしても、給蒸手段１１による蒸気がそのまま（つまり一旦凝縮することなく蒸気のまま）外部へ排出されず、且つ熱交換器９にドレンが溜まらない範囲で、オリフィス３５が選択されたり、ドレン排出弁３４の開閉が制御されたりする。このことは、後述する殺菌工程Ｓ３についても同様である。 The heating load in a standard operating environment (the amount of heat required to heat the treatment tank 3, water (stored water / circulating water), and the object to be treated 2 to the sterilization temperature) and the amount of drainage generated are calculated. It is possible. Further, the amount of drain that can pass through the orifice 35 can be calculated based on the difference pressure between the vapor pressure of the steam by the steaming means 11 and the atmospheric pressure. Therefore, the optimum orifice 35 is selected from these, and / or the opening and closing of the drain discharge valve 34 is controlled. That is, in the temperature rising step S2, even if the drain discharge valve 34 is opened, the steam produced by the steaming means 11 is not discharged to the outside as it is (that is, as steam without being condensed once) and is sent to the heat exchanger 9. The orifice 35 is selected and the opening / closing of the drain discharge valve 34 is controlled within a range in which the drain does not collect. This also applies to the sterilization step S3 described later.

昇温工程Ｓ２では、熱交換器９において循環水と蒸気とを熱交換して、循環水の加熱を図ることができる。このようにして、昇温工程Ｓ２では処理槽３内の温度を徐々に上昇させるが、この際、処理槽３内は大気圧を超える圧力（処理槽３内温度相当の飽和蒸気圧力よりも高圧）とされる。これにより、１００℃を超える水温でも循環ポンプ２８のキャビテーションを起こすことなく循環を行うことができると共に、被処理物の膨張による容器（レトルトパウチなど）の破裂を防止できる。具体的には、圧縮空気弁２３と排気弁２５とを制御することにより、処理槽３内の温度に応じた加圧がなされる。 In the temperature raising step S2, the circulating water and steam can be heat-exchanged in the heat exchanger 9 to heat the circulating water. In this way, in the temperature raising step S2, the temperature inside the treatment tank 3 is gradually raised, but at this time, the pressure inside the treatment tank 3 exceeds the atmospheric pressure (higher than the saturated steam pressure corresponding to the temperature inside the treatment tank 3). ). As a result, circulation can be performed without causing cavitation of the circulation pump 28 even at a water temperature exceeding 100 ° C., and the container (retort pouch or the like) can be prevented from bursting due to expansion of the object to be processed. Specifically, by controlling the compressed air valve 23 and the exhaust valve 25, pressurization is performed according to the temperature inside the processing tank 3.

以後、循環手段１０による水の循環は、冷却工程Ｓ４の終了まで継続される。また、圧縮空気供給手段６による処理槽３内の加圧は、処理槽３内が殺菌温度まで上昇した後も、処理槽３内温度相当の飽和蒸気圧力よりも高圧に、排水工程Ｓ５の排水終了まで継続される。その間、圧縮空気遮断弁２２は開放状態に維持され、圧縮空気弁２３と排気弁２５の開閉が制御される。 After that, the circulation of water by the circulation means 10 is continued until the end of the cooling step S4. Further, the pressurization in the treatment tank 3 by the compressed air supply means 6 is made higher than the saturated steam pressure corresponding to the temperature in the treatment tank 3 even after the inside of the treatment tank 3 has risen to the sterilization temperature, and the drainage in the drainage step S5 is performed. It will continue until the end. During that time, the compressed air shutoff valve 22 is maintained in an open state, and the opening and closing of the compressed air valve 23 and the exhaust valve 25 is controlled.

≪殺菌工程Ｓ３≫
殺菌工程Ｓ３では、処理槽３内の温度を殺菌温度に保持して、被処理物２を加熱して殺菌する。具体的には、処理槽３内の貯留水を循環手段１０により循環させつつ、温度センサ１４の検出温度を殺菌温度に維持するように、給蒸弁３２の開度を調整する。 << Sterilization process S3 >>
In the sterilization step S3, the temperature inside the treatment tank 3 is maintained at the sterilization temperature, and the object 2 to be treated is heated to sterilize. Specifically, the opening degree of the steam supply valve 32 is adjusted so as to maintain the detection temperature of the temperature sensor 14 at the sterilization temperature while circulating the stored water in the treatment tank 3 by the circulation means 10.

殺菌工程Ｓ３では、殺菌工程Ｓ３開始から所定時間ｔａ経過するまでは、第一設定時間ごとにドレン排出弁３４を規定時間開放し、所定時間ｔａ経過後には、第一設定時間よりも長い第二設定時間ごとにドレン排出弁３４を規定時間開放する。所定時間ｔａ、規定時間、第一設定時間および第二設定時間は、オリフィス３５との関係で、給蒸手段１１による蒸気が直接に外部へ排出されず、且つ熱交換器９にドレンが溜まらない範囲で、実験により予め求められる。また、殺菌工程Ｓ３の進行に伴い、各時間を段階的に変更（たとえば設定時間を徐々に長くしたり、規定時間を徐々に短くしたり）してもよい。 In the sterilization step S3, the drain discharge valve 34 is opened for a specified time every first set time from the start of the sterilization step S3 until a predetermined time ta elapses, and after the predetermined time ta elapses, the second is longer than the first set time. The drain discharge valve 34 is opened for a specified time every set time. During the predetermined time ta, the specified time, the first set time, and the second set time, the steam by the steaming means 11 is not directly discharged to the outside and the drain does not collect in the heat exchanger 9 in relation to the orifice 35. In the range, it is determined in advance by experiment. Further, as the sterilization step S3 progresses, each time may be changed stepwise (for example, the set time may be gradually increased or the specified time may be gradually shortened).

いずれにしても、殺菌工程Ｓ３の初期には、比較的短い間隔でドレン排出弁３４を開放する一方、その後は、比較的長い間隔でドレン排出弁３４を開放することになる。殺菌工程Ｓ３の初期ほど、ドレンが出やすいので、ドレン排出弁３４の開放間隔を短くすることで、ドレンの排出を円滑に図ることができる。処理槽３内が殺菌温度以上で殺菌時間経過すると、給蒸弁３２および給蒸遮断弁３１を閉じて熱交換器９への給蒸を停止して、殺菌工程Ｓ３を終了する。 In any case, the drain discharge valve 34 is opened at a relatively short interval at the initial stage of the sterilization step S3, and the drain discharge valve 34 is opened at a relatively long interval thereafter. Since drainage is more likely to occur in the early stage of the sterilization step S3, the drainage can be smoothly discharged by shortening the opening interval of the drainage discharge valve 34. When the sterilization time elapses at the sterilization temperature or higher in the treatment tank 3, the steam supply valve 32 and the steam supply shutoff valve 31 are closed to stop the steam supply to the heat exchanger 9, and the sterilization step S3 is completed.

ところで、被処理物２の加熱殺菌中、殺菌温度を変更してもよい。図示例では、第一殺菌温度Ｔ１まで処理槽３内を昇温する第一昇温工程Ｓ２ａ、第一殺菌温度Ｔ１で第一殺菌時間保持する第一殺菌工程Ｓ３ａ、第一殺菌温度Ｔ１よりも高い第二殺菌温度Ｔ２まで処理槽３内を昇温する第二昇温工程Ｓ２ｂ、第二殺菌温度Ｔ２で第二殺菌時間保持する第二殺菌工程Ｓ３ｂを順次に実行する。典型的には、各昇温工程Ｓ２ａ，Ｓ２ｂでは、ドレン排出弁３４を開放しておけばよいし、各殺菌工程Ｓ３ａ，Ｓ３ｂでは、所定時間ｔａ経過するまでは、第一設定時間ごとにドレン排出弁３４を規定時間開放し、所定時間ｔａ経過後には、第一設定時間よりも長い第二設定時間ごとにドレン排出弁３４を規定時間開放すればよい。所定時間ｔａ、規定時間、第一設定時間および第二設定時間それぞれについて、各殺菌工程Ｓ３ａ，Ｓ３ｂで同一としてもよいし、異なったものとしてもよい。 By the way, the sterilization temperature may be changed during the heat sterilization of the object 2 to be treated. In the illustrated example, it is higher than the first sterilization step S2a for raising the temperature in the treatment tank 3 up to the first sterilization temperature T1, the first sterilization step S3a for holding the first sterilization time at the first sterilization temperature T1, and the first sterilization temperature T1. The second sterilization step S2b for raising the temperature in the treatment tank 3 to a high second sterilization temperature T2 and the second sterilization step S3b for holding the second sterilization time at the second sterilization temperature T2 are sequentially executed. Typically, in each of the temperature raising steps S2a and S2b, the drain discharge valve 34 may be opened, and in each of the sterilization steps S3a and S3b, drainage is performed every first set time until a predetermined time ta elapses. The discharge valve 34 may be opened for a specified time, and after the predetermined time ta has elapsed, the drain discharge valve 34 may be opened for a specified time at every second set time longer than the first set time. The predetermined time ta, the specified time, the first set time, and the second set time may be the same in each sterilization step S3a, S3b, or may be different.

図示例では、第一殺菌温度Ｔ１と第二殺菌温度Ｔ２との二段階に殺菌温度を変更したが、第一殺菌温度Ｔ１、第二殺菌温度Ｔ２および第三殺菌温度Ｔ３の三段階で殺菌温度を変更（段階的に上昇）してもよい。あるいは、四段階以上で殺菌温度を変更してもよいし、逆に、殺菌温度を変更しなくてもよい（つまり第一殺菌温度Ｔ１のみとしてもよい）。 In the illustrated example, the sterilization temperature was changed in two stages of the first sterilization temperature T1 and the second sterilization temperature T2, but the sterilization temperature was changed in three stages of the first sterilization temperature T1, the second sterilization temperature T2 and the third sterilization temperature T3. May be changed (increased in stages). Alternatively, the sterilization temperature may be changed in four or more steps, or conversely, the sterilization temperature may not be changed (that is, only the first sterilization temperature T1 may be used).

また、図示例では、殺菌温度を上げる例を示したが、殺菌温度を途中で下げてもよい。殺菌温度を下げる場合、給蒸手段１１による加熱を停止した状態で、後述する冷却工程Ｓ４と同様にして、循環手段１０による循環水を冷却手段１３による冷却水で冷却するか、給水手段４と排水手段５とを制御して、処理槽３内の貯留水を徐々に入れ替える降温工程を実施した後、殺菌工程Ｓ３を実施すればよい。 Further, in the illustrated example, an example in which the sterilization temperature is raised is shown, but the sterilization temperature may be lowered in the middle. When lowering the sterilization temperature, the circulating water by the circulating means 10 is cooled by the cooling water by the cooling means 13 or the water supply means 4 is used in the same manner as in the cooling step S4 described later with the heating by the steaming means 11 stopped. The sterilization step S3 may be carried out after performing the temperature lowering step of gradually replacing the stored water in the treatment tank 3 by controlling the drainage means 5.

いずれにしても、処理槽３内の温度を上昇させる昇温工程Ｓ２では、給蒸手段１１により熱交換器９に蒸気を供給して、循環手段１０による循環水を加熱するが、その際、ドレン排出弁３４を開けまま維持するのがよい。そして、殺菌工程Ｓ３では、所定時間ｔａ経過するまでは、第一設定時間ごとにドレン排出弁３４を規定時間開放し、所定時間ｔａ経過後には、第一設定時間よりも長い第二設定時間ごとにドレン排出弁３４を規定時間開放するのがよい。 In any case, in the temperature raising step S2 for raising the temperature in the treatment tank 3, steam is supplied to the heat exchanger 9 by the steaming means 11 to heat the circulating water by the circulating means 10, but at that time, It is preferable to keep the drain discharge valve 34 open. Then, in the sterilization step S3, the drain discharge valve 34 is opened for a specified time every first set time until the predetermined time ta elapses, and after the predetermined time ta elapses, every second set time longer than the first set time. It is preferable to open the drain discharge valve 34 for a specified time.

後述するように、殺菌工程Ｓ３において温度変化を伴う場合、前記「所定時間ｔａ経過するまで」は、「処理槽３内が所定温度に達するまで」であってもよい。言い換えれば、前記所定時間ｔａ内には、処理槽３内の温度が変化してもよい。 As will be described later, when the sterilization step S3 is accompanied by a temperature change, the “until the predetermined time ta elapses” may be “until the inside of the treatment tank 3 reaches the predetermined temperature”. In other words, the temperature in the treatment tank 3 may change within the predetermined time ta.

殺菌工程Ｓ３では、処理槽３内を殺菌温度に保持すると言っても、必ずしも一定温度に維持する必要はなく、所定範囲（殺菌温度範囲）に保持してもよい。たとえば、殺菌温度範囲の上限温度と下限温度との間に保持するように、給蒸手段１１を制御してもよい。この際、上限温度になるまで給蒸手段１１により加熱し、給蒸手段１１による加熱を停止した状態で下限温度になるまで待機し、下限温度になると給蒸手段１１による給蒸を再開してもよい。殺菌工程Ｓ３において殺菌温度範囲に保持する場合、その直前の昇温工程Ｓ２では、殺菌温度範囲に到達するまで給蒸手段１１による加熱を図ればよい。 In the sterilization step S3, although it is said that the inside of the treatment tank 3 is kept at the sterilization temperature, it is not always necessary to keep the temperature constant, and the inside of the treatment tank 3 may be kept within a predetermined range (sterilization temperature range). For example, the steaming means 11 may be controlled so as to be maintained between the upper limit temperature and the lower limit temperature of the sterilization temperature range. At this time, it is heated by the steaming means 11 until the upper limit temperature is reached, the heating by the steaming means 11 is stopped, and the waiting until the lower limit temperature is reached, and when the lower limit temperature is reached, the steaming by the steaming means 11 is restarted. May be good. When the temperature is maintained in the sterilization temperature range in the sterilization step S3, the steaming means 11 may be used for heating until the temperature rise step S2 immediately before the sterilization step S3 reaches the sterilization temperature range.

≪冷却工程Ｓ４≫
冷却工程Ｓ４では、循環手段１０により処理槽３と熱交換器９との間で水を循環させながら、その循環水を熱交換器９において冷却手段１３により冷却して、処理槽３内の被処理物２を冷却する。具体的には、循環ポンプ２８を作動させることで、処理槽３内底部からの水を、熱交換器９を介して、ノズル２９から処理槽３内へ戻すことで、処理槽３と熱交換器９との間で水を循環させる。また、この循環中、給蒸弁３２およびドレン排出弁３４を閉じる一方、冷却水送り弁４１および冷却水戻し弁４２を開けた状態で、クーリングタワー３７および送水ポンプ３８を作動させて、熱交換器９に冷却水を循環させればよい。 << Cooling process S4 >>
In the cooling step S4, while water is circulated between the treatment tank 3 and the heat exchanger 9 by the circulation means 10, the circulating water is cooled by the cooling means 13 in the heat exchanger 9 to cover the inside of the treatment tank 3. The processed material 2 is cooled. Specifically, by operating the circulation pump 28, water from the inner bottom of the treatment tank 3 is returned from the nozzle 29 to the inside of the treatment tank 3 via the heat exchanger 9, thereby exchanging heat with the treatment tank 3. Water is circulated with the vessel 9. Further, during this circulation, the cooling tower 37 and the water supply pump 38 are operated with the cooling water feed valve 41 and the cooling water return valve 42 open while the steam supply valve 32 and the drain discharge valve 34 are closed, and the heat exchanger is operated. Cooling water may be circulated in 9.

冷却工程Ｓ４の開始から冷却時間経過するか、処理槽３内の温度が冷却温度よりも下がるか、冷却温度よりも下がってから所定時間経過すると、冷却手段１３による熱交換器９への冷却水供給を停止して、冷却工程Ｓ４を終了する。この際、循環手段１０による循環も停止するが、圧縮空気供給手段６による処理槽３内の加圧は、排水工程Ｓ５における排水完了まで継続するのがよい。 When the cooling time elapses from the start of the cooling step S4, the temperature in the processing tank 3 drops below the cooling temperature, or a predetermined time elapses after the temperature drops below the cooling temperature, the cooling water to the heat exchanger 9 by the cooling means 13 The supply is stopped and the cooling step S4 is completed. At this time, the circulation by the circulation means 10 is also stopped, but the pressurization in the treatment tank 3 by the compressed air supply means 6 should be continued until the drainage is completed in the drainage step S5.

≪排水工程Ｓ５≫
排水工程Ｓ５では、排水手段５により処理槽３内から排水する。具体的には、排水弁２０を開けることで、外部へ水を排出する。圧縮空気供給手段６により処理槽３内を加圧したままで排水手段５により排水すれば、処理槽３内からの排水を迅速に行うことができる。また、ドレン排出弁３４を開けることで、熱交換器９の一次側に溜まった冷却水を外部へ排出する。 ≪Drainage process S5≫
In the drainage step S5, drainage is performed from the inside of the treatment tank 3 by the drainage means 5. Specifically, by opening the drain valve 20, water is discharged to the outside. If the inside of the treatment tank 3 is pressurized by the compressed air supply means 6 and drained by the drainage means 5, the drainage from the inside of the treatment tank 3 can be performed quickly. Further, by opening the drain discharge valve 34, the cooling water accumulated on the primary side of the heat exchanger 9 is discharged to the outside.

その後、圧縮空気遮断弁２２および圧縮空気弁２３を閉じる一方、排気弁２５を開いて、処理槽３内の加圧を解除した後、さらに真空解除弁２７を開放して、処理槽３内を確実に大気圧とする。これにより、処理槽３の扉を開けて、処理槽３内から被処理物２を取り出すことができる。 After that, while closing the compressed air shutoff valve 22 and the compressed air valve 23, the exhaust valve 25 is opened to release the pressurization in the processing tank 3, and then the vacuum release valve 27 is further opened to open the inside of the processing tank 3. Make sure to use atmospheric pressure. As a result, the door of the processing tank 3 can be opened and the object to be processed 2 can be taken out from the processing tank 3.

本実施例の殺菌装置１によれば、ドレン排出路３３には、スチームトラップは設けられないが、ドレン排出弁３４が設けられている。そして、ドレン排出弁３４を制御することで、ドレンの排出を図ることができる。ドレン排出路３３にスチームトラップを設けないことで、スチームトラップの詰まりによるドレンの排出不良（ひいては処理槽３内の昇温異常）を防止することができる。なお、排水工程Ｓ５では、熱交換器９およびドレン排出路３３に冷却水を残留させることなく、全て排出することができ、その場合、次回の殺菌運転における加熱負荷を軽減することができる。 According to the sterilizer 1 of this embodiment, the drain discharge path 33 is not provided with a steam trap, but is provided with a drain discharge valve 34. Then, by controlling the drain discharge valve 34, the drain can be discharged. By not providing the steam trap in the drain discharge path 33, it is possible to prevent a drain discharge failure due to clogging of the steam trap (and by extension, an abnormality in temperature rise in the treatment tank 3). In the drainage step S5, all the cooling water can be discharged without remaining in the heat exchanger 9 and the drain discharge path 33, and in that case, the heating load in the next sterilization operation can be reduced.

本発明の殺菌装置１は、前記実施例の構成に限らず、適宜変更可能である。特に、（ａ）被処理物２が収容されると共に水が貯留される処理槽３と、（ｂ）この処理槽３内の貯留水を熱交換器９との間で循環させる循環手段１０と、（ｃ）この循環手段１０による循環水を加熱するために、熱交換器９に蒸気を供給する給蒸手段１１と、（ｄ）この給蒸手段１１による蒸気の凝縮水を外部へ排出するドレン排出手段１２と、（ｅ）前記各手段を制御する制御手段とを備え、（ｆ）ドレン排出手段１２として、熱交換器９からのドレン排出路３３に、スチームトラップは設けられないが、ドレン排出弁３４が設けられているのであれは、その他の構成は適宜に変更可能である。 The sterilizer 1 of the present invention is not limited to the configuration of the above embodiment, and can be appropriately changed. In particular, (a) a treatment tank 3 in which the object to be treated 2 is accommodated and water is stored, and (b) a circulation means 10 for circulating the stored water in the treatment tank 3 between the heat exchanger 9. , (C) The steaming means 11 that supplies steam to the heat exchanger 9 in order to heat the circulating water by the circulating means 10, and (d) the condensed water of the steam by the steaming means 11 is discharged to the outside. A steam trap is not provided in the drain discharge path 33 from the heat exchanger 9 as the drain discharge means 12 and (e) a control means for controlling each of the means. If the drain discharge valve 34 is provided, other configurations can be appropriately changed.

たとえば、前記実施例では、ドレン排出弁３４は、基本的には時間制御により間欠的に開閉制御されたが、場合により、温度制御により開閉制御されてもよい。たとえば、ドレン排出弁３４の一次側の配管や装置表面温度またはドレン温度など、ドレン排出路３３の所定箇所の温度に基づき、第一温度（たとえば１００℃）以下になるとドレン排出弁３４を開け、第二温度（たとえば１１０℃）以上になるとドレン排出弁３４を閉じる制御を実施してもよい。 For example, in the above embodiment, the drain discharge valve 34 is basically controlled to open and close intermittently by time control, but may be controlled to open and close by temperature control in some cases. For example, based on the temperature at a predetermined location of the drain discharge path 33 such as the primary side piping of the drain discharge valve 34, the surface temperature of the device, or the drain temperature, the drain discharge valve 34 is opened when the temperature drops below the first temperature (for example, 100 ° C.). Control to close the drain discharge valve 34 may be performed when the temperature reaches the second temperature (for example, 110 ° C.) or higher.

また、前記実施例では、ドレン排出弁３４は、昇温工程Ｓ２では開放状態に維持され、殺菌工程Ｓ３では初期の開閉頻度をそれ以降よりも高くしたが、適宜に変更可能である。その際、昇温工程Ｓ２開始から殺菌工程Ｓ３終了までの間、最初はドレン排出弁３４を全開または単位時間当たりの開放時間を長くしておき、処理が進むに連れて、単位時間当たりの開放時間を短くしていくのがよい。 Further, in the above embodiment, the drain discharge valve 34 is maintained in an open state in the temperature raising step S2, and the initial opening / closing frequency is made higher in the sterilization step S3 than after that, but it can be changed as appropriate. At that time, from the start of the temperature rising step S2 to the end of the sterilization step S3, the drain discharge valve 34 is initially fully opened or the opening time per unit time is lengthened, and as the treatment progresses, the drain discharge valve 34 is opened per unit time. It is better to shorten the time.

また、前記実施例では、ドレン排出手段１２は、ドレン排出弁３４とオリフィス３５とを備え、ドレン排出弁３４の開閉を切り替えたが、オリフィス３５を設置せずに、ドレン排出弁３４の開度を調整してもよい。この際、ドレン排出弁３４は、開度調整可能な弁から構成されるが、特にボールタイプの自動弁（モータバルブやエア駆動弁）から構成されるのが好ましい。あるいは、ドレン排出弁３４として、開閉を切り替える弁と、開度調整可能な弁とを組み合わせてもよい。 Further, in the above embodiment, the drain discharge means 12 includes the drain discharge valve 34 and the orifice 35, and the opening and closing of the drain discharge valve 34 is switched, but the opening degree of the drain discharge valve 34 is opened without installing the orifice 35. May be adjusted. At this time, the drain discharge valve 34 is composed of a valve whose opening degree can be adjusted, and it is particularly preferable that the drain discharge valve 34 is composed of a ball type automatic valve (motor valve or air drive valve). Alternatively, as the drain discharge valve 34, a valve that switches between opening and closing and a valve whose opening degree can be adjusted may be combined.

そして、たとえば、昇温工程Ｓ２では、ドレン排出弁３４を全開または所定開度に維持しておき、殺菌工程Ｓ３では、所定時間ｔａ経過するまでは、第一設定時間ごとに、ドレン排出弁３４を全開または設定開度で規定時間開放し、所定時間ｔａ経過後には、第一設定時間よりも長い第二設定時間ごとに、ドレン排出弁３４を全開または設定開度で規定時間開放すればよい。あるいは、ドレン排出路３３（ドレン排出弁３４の一次側）に温度センサを設けておき、その温度センサを利用することで、昇温工程Ｓ２および／または殺菌工程Ｓ３では、ドレン排出路３３の温度に基づきドレン排出弁３４の開閉または開度を調整してもよい。 Then, for example, in the temperature raising step S2, the drain discharge valve 34 is kept fully open or at a predetermined opening degree, and in the sterilization step S3, the drain discharge valve 34 is held every first set time until a predetermined time ta elapses. Is fully opened or opened for a specified time at a set opening, and after a predetermined time ta elapses, the drain discharge valve 34 may be fully opened or opened for a specified time at a set opening every second set time longer than the first set time. .. Alternatively, a temperature sensor is provided in the drain discharge path 33 (primary side of the drain discharge valve 34), and by using the temperature sensor, the temperature of the drain discharge path 33 is obtained in the temperature raising step S2 and / or the sterilization step S3. The opening / closing or opening degree of the drain discharge valve 34 may be adjusted based on the above.

さらに、いわゆる貯湯式の殺菌装置１に適用することもできる。その場合、処理槽３内において、被処理物２を熱水に水没して殺菌を行うが、前記実施例と同様に、処理槽３内の貯留水を熱交換器９との間で循環させつつ、その循環水を、殺菌工程Ｓ３では蒸気により加熱し、冷却工程Ｓ４では冷却水により冷却する。 Further, it can be applied to the so-called hot water storage type sterilizer 1. In that case, the object to be treated 2 is submerged in hot water for sterilization in the treatment tank 3, but the stored water in the treatment tank 3 is circulated with the heat exchanger 9 as in the above embodiment. At the same time, the circulating water is heated by steam in the sterilization step S3 and cooled by the cooling water in the cooling step S4.

１殺菌装置
２被処理物
３処理槽
４給水手段
５排水手段
６圧縮空気供給手段
７排気手段
８真空解除手段
９熱交換器
１０循環手段
１１給蒸手段
１２ドレン排出手段
１３冷却手段
１４温度センサ
１５循環路
１６給水路
１７給水ポンプ
１８給水弁
１９排水路
２０排水弁
２１圧縮空気供給路
２２圧縮空気遮断弁
２３圧縮空気弁
２４排気路
２５排気弁
２６給気路
２７真空解除弁
２８循環ポンプ
２９ノズル
３０給蒸路
３１給蒸遮断弁
３２給蒸弁
３３ドレン排出路
３４ドレン排出弁
３５オリフィス（固定絞り部）
３６逆止弁
３７クーリングタワー
３８送水ポンプ
３９冷却水送り路
４０冷却水戻し路
４１冷却水送り弁
４２冷却水戻し弁
Ｓ１給水工程
Ｓ２昇温工程（Ｓ２ａ：第一昇温工程、Ｓ２ｂ：第二昇温工程）
Ｓ３殺菌工程（Ｓ３ａ：第一殺菌工程、Ｓ３ｂ：第二殺菌工程）
Ｓ４冷却工程
Ｓ５排水工程 1 Sterilizer 2 Processed object 3 Treatment tank 4 Water supply means 5 Drainage means 6 Compressed air supply means 7 Exhaust means 8 Vacuum release means 9 Heat exchanger 10 Circulation means 11 Steam supply means 12 Drain discharge means 13 Cooling means 14 Temperature sensor 15 Circulation path 16 Water supply channel 17 Water supply pump 18 Water supply valve 19 Drainage channel 20 Drain valve 21 Compressed air supply path 22 Compressed air shutoff valve 23 Compressed air valve 24 Exhaust channel 25 Exhaust valve 26 Air supply path 27 Vacuum release valve 28 Circulation pump 29 Nozzle 30 Steam supply path 31 Steam supply shutoff valve 32 Steam supply valve 33 Drain discharge path 34 Drain discharge valve 35 Orifice (fixed throttle part)
36 Check valve 37 Cooling tower 38 Water supply pump 39 Cooling water feed path 40 Cooling water return path 41 Cooling water feed valve 42 Cooling water return valve S1 Water supply process S2 Temperature rise process (S2a: First temperature rise process, S2b: Second rise Warm process)
S3 sterilization step (S3a: first sterilization step, S3b: second sterilization step)
S4 cooling process S5 drainage process

Claims

A treatment tank in which the object to be treated is stored and water is stored,
A heat exchanger in which water is circulated between the treatment tank and the circulating water can be heated by steam.
A drain discharge means for discharging the condensed water of steam supplied to the heat exchanger to the outside,
A control means for controlling the drain discharge means is provided.
As the drain discharge means, the sterilizer is provided with a drain discharge valve but not provided with a steam trap in the drain discharge path from the heat exchanger.
The temperature raising step of raising the inside of the treatment tank to the sterilization temperature or the sterilization temperature range and the sterilization step of keeping the inside of the treatment tank within the sterilization temperature or the sterilization temperature range are executed in order.
A sterilizer for controlling the drain discharge valve so that the flow rate at which drainage can be discharged is larger in the temperature rise step than in the sterilization step.

A treatment tank in which the object to be treated is stored and water is stored,
A heat exchanger in which water is circulated between the treatment tank and the circulating water can be heated by steam.
A drain discharge means for discharging the condensed water of steam supplied to the heat exchanger to the outside,
A control means for controlling the drain discharge means is provided.
As the drain discharge means, the sterilizer is provided with a drain discharge valve but not provided with a steam trap in the drain discharge path from the heat exchanger.
The temperature raising step of raising the inside of the treatment tank to the sterilization temperature or the sterilization temperature range and the sterilization step of keeping the inside of the treatment tank within the sterilization temperature or the sterilization temperature range are executed in order.
A sterilization apparatus characterized in that in the temperature raising step, the drain discharge valve is maintained in an open state, or the drain discharge valve is opened and closed while increasing the opening time ratio as compared with the sterilization step.

A treatment tank in which the object to be treated is stored and water is stored,
A heat exchanger in which water is circulated between the treatment tank and the circulating water can be heated by steam.
A drain discharge means for discharging the condensed water of steam supplied to the heat exchanger to the outside,
A control means for controlling the drain discharge means is provided.
As the drain discharge means, the sterilizer is provided with a drain discharge valve but not provided with a steam trap in the drain discharge path from the heat exchanger.
The temperature raising step of raising the inside of the treatment tank to the sterilization temperature or the sterilization temperature range and the sterilization step of keeping the inside of the treatment tank within the sterilization temperature or the sterilization temperature range are executed in order.
In the sterilization step, the drain discharge valve is opened for a specified time every first set time until a predetermined time elapses, and after the predetermined time elapses, the drain is drained every second set time longer than the first set time. A sterilizer characterized by opening the discharge valve for a specified time.

A treatment tank in which the object to be treated is stored and water is stored,
A heat exchanger in which water is circulated between the treatment tank and the circulating water can be heated by steam.
A drain discharge means for discharging the condensed water of steam supplied to the heat exchanger to the outside,
A control means for controlling the drain discharge means is provided.
As the drain discharge means, the sterilizer is provided with a drain discharge valve but not provided with a steam trap in the drain discharge path from the heat exchanger.
The temperature raising step of raising the inside of the treatment tank to the sterilization temperature or the sterilization temperature range and the sterilization step of keeping the inside of the treatment tank within the sterilization temperature or the sterilization temperature range are executed in order.
A sterilizer that adjusts the opening / closing or opening degree of the drain discharge valve based on the temperature of the drain discharge path in the temperature raising step and / or the sterilization step.

A drain discharge valve and a fixed throttle portion are provided in the drain discharge path.
The sterilizer according to any one of claims 1 to 4, wherein the control means switches the opening and closing of the drain discharge valve.

A drain discharge valve is provided in the drain discharge path.
The sterilizer according to any one of claims 1 to 4, wherein the control means adjusts an opening degree of the drain discharge valve.