JP7223319B2 - vacuum cooling system - Google Patents

vacuum cooling system Download PDF

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JP7223319B2
JP7223319B2 JP2018235196A JP2018235196A JP7223319B2 JP 7223319 B2 JP7223319 B2 JP 7223319B2 JP 2018235196 A JP2018235196 A JP 2018235196A JP 2018235196 A JP2018235196 A JP 2018235196A JP 7223319 B2 JP7223319 B2 JP 7223319B2
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freezing
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JP2020098039A (en
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拓也 松本
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Miura Co Ltd
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Description

本発明は、処理槽内を減圧して食品を冷却する真空冷却装置に関するものである。 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum cooling apparatus that cools food by decompressing the inside of a processing tank.

従来、下記特許文献1に開示されるように、処理槽内の気体を外部へ吸引排出して処理槽内を減圧することで、食品からの水分蒸発を促し、その気化潜熱で食品の冷却を図る真空冷却装置が知られている。 Conventionally, as disclosed in the following Patent Document 1, the gas in the processing tank is sucked and discharged to the outside to reduce the pressure in the processing tank, thereby promoting the evaporation of moisture from the food and cooling the food with the latent heat of vaporization. A vacuum cooling system is known.

特開平9-296975号公報JP-A-9-296975

真空冷却装置により液物食品を冷却する場合、冷却終盤に食品表面(液面)が凍結してしまうと、水分蒸発が制限されて、冷却が進まなくなる。品温センサにより品温(食品温度)を監視して、品温が冷却目標温度になるまで真空冷却を図り、且つ、冷却目標温度が凍結点を超える温度に設定されていても、食品内の温度ムラにより、食品の一部が凍結するおそれがある。 When liquid food is cooled by a vacuum cooling device, if the food surface (liquid surface) freezes at the end of cooling, water evaporation is restricted and cooling does not progress. Monitor the product temperature (food temperature) with a product temperature sensor, attempt vacuum cooling until the product temperature reaches the cooling target temperature, and even if the cooling target temperature is set to a temperature exceeding the freezing point, Some food may freeze due to uneven temperature.

たとえば、液物食品を貯留した容器に品温センサが上方から差し込まれる場合、品温センサの温度検出点(プローブ先端)は容器の底部付近に配置されることが多い。その場合、液深の影響により、品温センサの検出温度が凍結点に到達していなくても、表面(液面付近)の温度はさらに低下しており、凍結するおそれがある。特に、水よりも粘性の高い食品の場合、減圧沸騰による撹拌効果が小さく、表面で凍結を生じやすい。表面で凍結が生じた場合、蒸発が生じにくく、冷却が進まなくなったり、冷却時間が長くなったりする。 For example, when a product temperature sensor is inserted from above into a container storing liquid food, the temperature detection point (probe tip) of the product temperature sensor is often arranged near the bottom of the container. In that case, even if the temperature detected by the product temperature sensor has not reached the freezing point, the temperature of the surface (near the liquid surface) is still lower due to the influence of the liquid depth, and there is a risk of freezing. In particular, in the case of food that is more viscous than water, the stirring effect of boiling under reduced pressure is small, and the surface of the food tends to freeze. When freezing occurs on the surface, evaporation is difficult to occur, and cooling does not progress or the cooling time is lengthened.

本発明が解決しようとする課題は、食品の凍結を防止して、食品を迅速で確実に冷却することができる真空冷却装置を提供することにある。 The problem to be solved by the present invention is to provide a vacuum cooling device capable of preventing food from freezing and cooling the food quickly and reliably.

本発明は、前記課題を解決するためになされたもので、請求項1に記載の発明は、食品が収容される処理槽と、この処理槽内の気体を外部へ吸引排出する減圧手段と、減圧された前記処理槽内へ外気を導入する復圧手段と、前記処理槽内の圧力を検出する圧力センサと、前記処理槽内に収容された食品の温度を検出する品温センサと、前記各手段を制御する制御手段とを備え、前記減圧手段により前記処理槽内を減圧中、凍結防止制御として、前記圧力センサの検出圧力が凍結防止圧力以下になると、前記処理槽内を「凍結防止圧力+設定回復圧力」になるまで復圧させるか、その復圧に要する設定回復時間だけ復圧させ、前記復圧手段として、前記処理槽内への第一給気路に開度調整可能な第一給気弁を備えると共に、前記処理槽内への第二給気路に開閉切替される第二給気弁を備え、前記減圧手段により前記処理槽内を減圧中、前記凍結防止制御として、前記圧力センサの検出圧力が凍結防止圧力以下になるたびに、前記第二給気弁を一時的に開放することを繰り返すことを特徴とする真空冷却装置である。 The present invention has been made to solve the above problems, and the invention according to claim 1 comprises a processing tank in which food is stored, a depressurizing means for sucking and discharging the gas in the processing tank to the outside, pressure restoring means for introducing outside air into the decompressed processing tank, a pressure sensor for detecting the pressure in the processing tank, a food temperature sensor for detecting the temperature of the food contained in the processing tank, and the and a control means for controlling each means, and when the pressure detected by the pressure sensor becomes equal to or less than the anti-freezing pressure during the decompression of the processing tank by the decompressing means, the inside of the processing tank is controlled as anti-freezing. The pressure is restored until it reaches "pressure + set recovery pressure", or the pressure is restored for a set recovery time required for the pressure recovery, and as the pressure recovery means, the opening of the first air supply passage to the inside of the processing tank can be adjusted. A first air supply valve is provided, and a second air supply valve that is switched between opening and closing in a second air supply path to the inside of the processing tank is provided. The vacuum cooling device is characterized in that the second air supply valve is repeatedly temporarily opened every time the pressure detected by the pressure sensor becomes equal to or lower than the anti-freezing pressure.

請求項1に記載の発明によれば、減圧手段により前記処理槽内を減圧中、凍結防止制御を実行可能とされる。凍結防止制御では、処理槽内の圧力が凍結防止圧力以下になると、処理槽内を一時的に所定まで復圧することで、食品の凍結を防止することができる。すなわち、凍結防止制御では、処理槽内の圧力低下を一時的に停止して、食品のそれ以上の温度低下を防止すると共に、処理槽内への給気により、槽内温度を回復させることで、食品が凝固点に達することを抑制して、食品(特に表面)の凍結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、復圧手段として、開度調整可能な第一給気弁の他、開閉切替される第二給気弁を備える。そのため、凍結防止制御では、処理槽内の圧力が凍結防止圧力以下になるたびに、第二給気弁を一時的に開放することを繰り返せばよい。このようにして、簡易な構成および制御で、凍結防止制御を実施することができる。
According to the first aspect of the invention, anti-freezing control can be executed while the inside of the processing tank is being decompressed by the decompressing means. In the anti-freezing control, when the pressure in the processing tank falls below the anti-freezing pressure, the pressure in the processing tank is temporarily restored to a predetermined level, thereby preventing the food from freezing. That is, in the anti-freezing control, the pressure drop in the processing tank is temporarily stopped to prevent further temperature drop of the food, and the temperature in the processing tank is restored by supplying air to the processing tank. , the food can be prevented from freezing (especially the surface) by suppressing the food from reaching the freezing point.
According to the first aspect of the invention, the pressure restoring means includes the first air supply valve whose degree of opening is adjustable and the second air supply valve that is switched between opening and closing. Therefore, in anti-freezing control, the second air supply valve may be temporarily opened repeatedly each time the pressure in the processing tank becomes equal to or lower than the anti-freezing pressure. In this way, anti-freezing control can be implemented with a simple configuration and control.

請求項2に記載の発明は、前記凍結防止圧力は、0℃における水の飽和圧力に基づき設定されることを特徴とする請求項1に記載の真空冷却装置である。 The invention according to claim 2 is the vacuum cooling device according to claim 1, wherein the anti-freezing pressure is set based on the saturation pressure of water at 0°C.

請求項2に記載の発明によれば、冷却しようとする実際の食品は、水以外に各種成分を含んでおり、凝固点降下があるため、凍結防止圧力を0℃における水の飽和圧力に基づき設定しても、食品の凍結を有効に防止することができる。 According to the second aspect of the invention, since the actual food to be cooled contains various components other than water and has a freezing point depression, the anti-freezing pressure is set based on the saturation pressure of water at 0 ° C. However, freezing of food can be effectively prevented.

さらに、請求項3に記載の発明は、前記制御手段により、温度差一定制御も実行可能とされ、前記温度差一定制御では、前記品温センサの検出温度と前記圧力センサの検出圧力における飽和温度との温度差が設定温度差になるように、前記処理槽内の圧力を調整しつつ前記処理槽内を減圧し、前記品温センサの検出温度が所定温度以下になると、前記温度差一定制御を停止して、最終減圧制御として、前記処理槽内をさらに減圧し、前記温度差一定制御および前記最終減圧制御を含んだ前記処理槽内の減圧中、前記凍結防止制御を実行することを特徴とする請求項1または請求項2に記載の真空冷却装置である。 Further, according to the third aspect of the invention , the constant temperature difference control can also be executed by the control means. The pressure in the processing bath is adjusted while reducing the pressure in the processing bath so that the temperature difference between the is stopped, the pressure in the processing tank is further reduced as final pressure reduction control, and the anti-freezing control is executed during the pressure reduction in the processing tank including the temperature difference constant control and the final pressure reduction control. The vacuum cooling device according to claim 1 or claim 2 , wherein:

請求項3に記載の発明によれば、真空冷却装置は、温度差一定制御も実行可能とされる。温度差一定制御では、品温と槽内圧力換算温度との温度差を設定温度差に抑えることで、食品からの水分蒸発を所定の速度に制御し、突沸を抑制しつつ食品の冷却を図ることができる。また、品温が所定温度以下になると、温度差一定制御を停止して、最終減圧制御により、食品の迅速な冷却を図ることができる。冷却終盤、冷却時間が長くなると、突沸の発生リスクが大きくなるが、冷却時間の短縮を図ることで、突沸の発生を防止することができる。そして、これら一連の減圧中、凍結防止制御により、食品の凍結を防止することができる。 According to the third aspect of the invention , the vacuum cooling device can also perform temperature difference constant control. In the constant temperature difference control, the temperature difference between the product temperature and the pressure conversion temperature inside the tank is suppressed to the set temperature difference, which controls the evaporation of water from the food at a predetermined rate, suppressing bumping and cooling the food. be able to. Further, when the product temperature becomes equal to or lower than a predetermined temperature, the constant temperature difference control is stopped, and the food can be quickly cooled by the final depressurization control. At the final stage of cooling, if the cooling time is long, the risk of bumping will increase, but by shortening the cooling time, bumping can be prevented. During this series of depressurization, freezing of food can be prevented by anti-freezing control.

本発明の真空冷却装置によれば、食品の凍結を防止して、食品を迅速で確実に冷却することができる。 According to the vacuum cooling device of the present invention, it is possible to prevent food from freezing and cool the food quickly and reliably.

本発明の一実施例の真空冷却装置を示す概略図であり、一部を断面にして示している。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a vacuum cooling device according to one embodiment of the present invention, partly in cross section; 図1の真空冷却装置による冷却運転の一例を示すグラフであり、品温TFと槽内圧力換算温度TSとの変化を示しており、縦軸は温度T、横軸は運転開始からの経過時間tを示している。It is a graph showing an example of the cooling operation by the vacuum cooling device of FIG. 1, showing the change in the product temperature TF and the tank internal pressure conversion temperature TS, the vertical axis is the temperature T, the horizontal axis is the elapsed time from the start of operation t. 図1の真空冷却装置による凍結防止制御の一例を示すグラフであり、槽内圧力の変化を示しており、縦軸は圧力P、横軸は時間tを示している。It is a graph which shows an example of the anti-freezing control by the vacuum cooling device of FIG. 1, and has shown the change of the pressure in a tank, The vertical axis|shaft has shown the pressure P, and the horizontal axis has shown the time t.

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真空冷却装置1を示す概略図であり、一部を断面にして示している。
Specific embodiments of the present invention will now be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing a vacuum cooling device 1 according to one embodiment of the present invention, and shows a part thereof in cross section.

本実施例の真空冷却装置1は、食品Fが収容される処理槽2と、この処理槽2内の気体を外部へ吸引排出する減圧手段3と、減圧された処理槽2内へ外気を導入する復圧手段4と、これら各手段3,4を制御して処理槽2内の食品Fを冷却する制御手段(図示省略)とを備える。 The vacuum cooling device 1 of this embodiment includes a processing tank 2 containing food F, a depressurizing means 3 for sucking and discharging the gas in the processing tank 2 to the outside, and introducing outside air into the decompressed processing tank 2. and a control means (not shown) for controlling the means 3 and 4 to cool the food F in the processing tank 2 .

処理槽2は、内部空間の減圧に耐える中空容器であり、ドア(図示省略)で開閉可能とされる。処理槽2は、典型的には略矩形の箱状に形成され、正面の開口部がドアで開閉可能とされる。ドアを開けることで、処理槽2に食品Fを出し入れすることができ、ドアを閉じることで、処理槽2の開口部を気密に閉じることができる。ドアは、処理槽2の正面および背面の双方に設けられてもよい。なお、図示例では、食品Fは、液物とされ、ホテルパンや番重のような食品容器に入れられて、処理槽2内に収容されている。 The processing tank 2 is a hollow container that can withstand the pressure reduction of the internal space, and can be opened and closed with a door (not shown). The processing tank 2 is typically formed in a substantially rectangular box shape, and the front opening can be opened and closed with a door. By opening the door, the food F can be taken in and out of the processing tank 2, and by closing the door, the opening of the processing tank 2 can be airtightly closed. Doors may be provided on both the front and back sides of the processing tank 2 . In the illustrated example, the food F is a liquid, placed in a food container such as a hotel pan or a tray, and stored in the processing tank 2 .

減圧手段3は、処理槽2内の気体(空気や蒸気)を外部へ吸引排出して、処理槽2内を減圧する手段である。本実施例では、減圧手段3は、処理槽2内からの排気路5に、蒸気エゼクタ6、蒸気凝縮用の熱交換器7、逆止弁8、および水封式の真空ポンプ9を順に備える。 The decompression means 3 is a means for decompressing the inside of the processing bath 2 by sucking and discharging the gas (air or steam) in the processing bath 2 to the outside. In this embodiment, the decompression means 3 includes a steam ejector 6, a heat exchanger 7 for steam condensation, a check valve 8, and a water-sealed vacuum pump 9 in the exhaust path 5 from the processing tank 2 in this order. .

蒸気エゼクタ6は、吸引口6aが処理槽2に接続されて設けられ、入口6bから出口6cへ向けて、エゼクタ給蒸路10からの蒸気がノズルで噴出可能とされる。入口6bから出口6cへ向けて蒸気を噴出させることで、処理槽2内の気体も吸引口6aを介して出口6cへ吸引排出される。エゼクタ給蒸路10に設けたエゼクタ給蒸弁11の開閉を操作することで、蒸気エゼクタ6の作動の有無を切り替えることができる。 The steam ejector 6 is provided with a suction port 6a connected to the processing tank 2, and steam from the ejector steam supply passage 10 can be ejected from the nozzle from the inlet 6b toward the outlet 6c. By jetting steam from the inlet 6b to the outlet 6c, the gas in the processing tank 2 is also sucked and discharged to the outlet 6c through the suction port 6a. By operating the opening/closing of the ejector steam supply valve 11 provided in the ejector steam supply path 10, the presence/absence of operation of the steam ejector 6 can be switched.

熱交換器7は、排気路5内の流体と冷却水とを混ぜることなく熱交換する間接熱交換器である。熱交換器7により、排気路5内の蒸気を、冷却水により冷却し凝縮させることができる。 The heat exchanger 7 is an indirect heat exchanger that exchanges heat between the fluid in the exhaust path 5 and the cooling water without mixing. The heat exchanger 7 allows the steam in the exhaust line 5 to be cooled and condensed with cooling water.

真空ポンプ9は、本実施例では水封式であり、周知のとおり、封水と呼ばれる水が供給されつつ運転される。そのために、真空ポンプ9の給水口9aには、封水給水路12を介して水が供給される。封水給水路12には封水給水弁13が設けられており、封水給水弁13を開けることで、真空ポンプ9に封水を供給することができる。封水給水弁13を開けた状態で真空ポンプ9を作動させると、真空ポンプ9は、吸気口9bから気体を吸入し、排気口9cへ排気および排水する。真空ポンプ9は、オンオフ制御されてもよいし、出力を調整可能とされてもよい。本実施例では、真空ポンプ9は、インバータを用いて、モータの駆動周波数ひいては回転数を変更可能とされる。 The vacuum pump 9 is of a water ring type in this embodiment, and as is well known, is operated while being supplied with water called seal water. Therefore, water is supplied to the water supply port 9 a of the vacuum pump 9 through the sealed water supply path 12 . A sealed water supply valve 13 is provided in the sealed water supply path 12 , and sealing water can be supplied to the vacuum pump 9 by opening the sealed water supply valve 13 . When the vacuum pump 9 is operated with the sealing water supply valve 13 open, the vacuum pump 9 sucks gas from the intake port 9b and exhausts and drains the gas to the exhaust port 9c. The vacuum pump 9 may be on/off controlled, or its output may be adjustable. In this embodiment, the vacuum pump 9 uses an inverter to change the driving frequency of the motor and thus the number of revolutions.

熱交換器7および真空ポンプ9への給水系統について説明すると、本実施例では、熱交換器7および真空ポンプ9には、常温水と冷水とを切り替えて供給可能とされる。冷水とは、チラー(図示省略)により所定温度に冷却を図られた水であり、常温水とは、そのような冷却を図られない水である。 To explain the water supply system to the heat exchanger 7 and the vacuum pump 9, in this embodiment, the heat exchanger 7 and the vacuum pump 9 can be supplied with normal temperature water and cold water by switching. Cold water is water that has been cooled to a predetermined temperature by a chiller (not shown), and room temperature water is water that is not cooled in such a manner.

図示例の場合、常温水と冷水の切り替えは、常温水給水路14に設けられた常温水給水弁15と、冷水給水路16に設けられた冷水給水弁17で行われる。常温水給水弁15より下流の常温水給水路14と、冷水給水弁17より下流の冷水給水路16とは、合流して共通給水路18とされている。そして、この共通給水路18は、熱交換器7への熱交給水路19と、真空ポンプ9への封水給水路12とに分岐されている。封水給水路12には、封水給水弁13が設けられている。常温水給水弁15または冷水給水弁17を開けることで、熱交換器7に給水され、さらに封水給水弁13を開けると、真空ポンプ9に給水される。 In the illustrated example, normal temperature water and cold water are switched by a normal temperature water supply valve 15 provided in the normal temperature water supply path 14 and a cold water supply valve 17 provided in the cold water supply path 16 . The room temperature water supply channel 14 downstream from the room temperature water supply valve 15 and the cold water supply channel 16 downstream from the cold water supply valve 17 join together to form a common water supply channel 18 . The common water supply line 18 branches into a heat exchange water supply line 19 to the heat exchanger 7 and a sealing water supply line 12 to the vacuum pump 9 . A sealed water supply valve 13 is provided in the sealed water supply path 12 . By opening the room temperature water supply valve 15 or the cold water supply valve 17, water is supplied to the heat exchanger 7, and when the sealed water supply valve 13 is opened, the vacuum pump 9 is supplied with water.

熱交換器7は、熱交給水路19を介して水が供給され、熱交排水路20を介して水が排出される。熱交排水路20は、冷水タンク(チラーの給水源)への冷水戻し路21と、外部への排水出口路22とに分岐されており、冷水戻し路21には冷水戻し弁23が設けられ、排水出口路22には排水出口弁24が設けられている。冷水戻し弁23および排水出口弁24により、熱交換器7を通過後の水を、冷水タンクへ戻すか、排水出口路22から排出するか、あるいはいずれも行わずに熱交換器7の通水を阻止するか(つまり熱交換器7の冷却水出口側を閉じるか)を切り替えることができる。 The heat exchanger 7 is supplied with water through a heat exchange water supply line 19 and discharged through a heat exchange discharge line 20 . The heat exchange drainage path 20 is branched into a cold water return path 21 to the cold water tank (chiller water supply source) and a drainage outlet path 22 to the outside, and the cold water return path 21 is provided with a cold water return valve 23. A drainage outlet valve 24 is provided in the drainage outlet passage 22 . The cold water return valve 23 and the waste water outlet valve 24 allow the water that has passed through the heat exchanger 7 to be returned to the cold water tank, discharged from the waste water outlet passage 22, or passed through the heat exchanger 7 without doing either. can be switched between blocking (that is, closing the cooling water outlet side of the heat exchanger 7).

熱交換器7に冷水を供給する場合、排水出口弁24を閉じると共に冷水戻し弁23を開けることで、熱交換器7を通過後の冷水は冷水タンクへ戻される。冷水タンク内の貯留水は、チラーで冷却されて再び冷水給水路16へ供給可能とされる。一方、熱交換器7に常温水を供給する場合、冷水戻し弁23を閉じると共に排水出口弁24を開けることで、熱交換器7を通過後の常温水は排水出口路22から排出される。 When cold water is supplied to the heat exchanger 7 , the cold water after passing through the heat exchanger 7 is returned to the cold water tank by closing the drain outlet valve 24 and opening the cold water return valve 23 . The water stored in the cold water tank can be cooled by the chiller and supplied to the cold water supply path 16 again. On the other hand, when normal temperature water is supplied to the heat exchanger 7 , the cold water return valve 23 is closed and the drainage outlet valve 24 is opened, whereby the normal temperature water after passing through the heat exchanger 7 is discharged from the drainage outlet channel 22 .

復圧手段4は、減圧された処理槽2内へ外気を導入して、処理槽2内を復圧する手段である。本実施例では、復圧手段4は、処理槽2内への第一給気路25に、第一エアフィルタ26および第一給気弁27を順に備えると共に、処理槽2内への第二給気路28に、第二エアフィルタ29および第二給気弁30を順に備える。第一給気路25および第二給気路28は、図示例では、それぞれが処理槽2に接続されているが、場合により、各給気弁27,30よりも下流側で合流して処理槽2に接続されてもよい。また、第二給気路28(たとえば第二エアフィルタ29と第二給気弁30との間)には、オリフィスを設けてもよい。 The pressure restoring means 4 is a means for introducing outside air into the decompressed processing tank 2 to restore the pressure inside the processing tank 2 . In this embodiment, the pressure recovery means 4 includes a first air filter 26 and a first air supply valve 27 in order in the first air supply passage 25 into the processing tank 2 , and a second air supply into the processing tank 2 . The air supply path 28 is provided with a second air filter 29 and a second air supply valve 30 in this order. In the illustrated example, the first air supply path 25 and the second air supply path 28 are each connected to the processing tank 2, but in some cases they are joined downstream of the respective air supply valves 27 and 30 for processing. It may be connected to tank 2 . Also, an orifice may be provided in the second air supply passage 28 (for example, between the second air filter 29 and the second air supply valve 30).

第一給気弁27は、電動弁のように、開度調整可能な弁から構成される。一方、第二給気弁30は、電磁弁のように、オンオフで開閉切替可能な弁から構成される。処理槽2内が減圧された状態で、第一給気弁27または第二給気弁30を開けると、外気がエアフィルタ26,29を介して処理槽2内へ導入され、処理槽2内を復圧することができる。その際、第一給気弁27の開度調整により、処理槽2内の圧力を調整することができ、第二給気弁30の開放により、処理槽2内を比較的短時間に復圧することができる。 The first air supply valve 27 is composed of a valve whose degree of opening can be adjusted like an electric valve. On the other hand, the second air supply valve 30 is composed of a valve that can be opened and closed by turning it on and off, like a solenoid valve. When the first air supply valve 27 or the second air supply valve 30 is opened while the inside of the processing tank 2 is depressurized, outside air is introduced into the processing tank 2 through the air filters 26 and 29, and the inside of the processing tank 2 is can be repressurized. At this time, the pressure in the processing tank 2 can be adjusted by adjusting the opening degree of the first air supply valve 27, and the pressure in the processing tank 2 is restored in a relatively short time by opening the second air supply valve 30. be able to.

処理槽2には、さらに、処理槽2内の圧力を検出する圧力センサ31と、処理槽2内に収容された食品Fの温度(品温)を検出する品温センサ32とが設けられる。図示例の場合、品温センサ32は、棒状のプローブが食品F内に差し込まれて、そのプローブの先端部にて温度を検知する。 The processing tank 2 is further provided with a pressure sensor 31 for detecting the pressure inside the processing tank 2 and a product temperature sensor 32 for detecting the temperature (product temperature) of the food F contained in the processing tank 2 . In the illustrated example, the product temperature sensor 32 has a rod-shaped probe inserted into the food F and detects the temperature at the tip of the probe.

制御手段は、前記各センサ31,32の検出信号や経過時間などに基づき、前記各手段3,4を制御する制御器(図示省略)である。具体的には、真空ポンプ9、エゼクタ給蒸弁11、封水給水弁13、常温水給水弁15、冷水給水弁17、冷水戻し弁23、排水出口弁24、第一給気弁27、第二給気弁30の他、圧力センサ31および品温センサ32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2内の食品Fの真空冷却を図る。 The control means is a controller (not shown) that controls the means 3 and 4 based on detection signals from the sensors 31 and 32, elapsed time, and the like. Specifically, the vacuum pump 9, the ejector steam supply valve 11, the sealed water supply valve 13, the normal temperature water supply valve 15, the cold water supply valve 17, the cold water return valve 23, the drainage outlet valve 24, the first air supply valve 27, the second In addition to the two air supply valves 30, the pressure sensor 31 and the product temperature sensor 32 are connected to the controller. Then, the controller attempts to vacuum-cool the food F in the processing tank 2 according to a predetermined procedure (program), as described below.

以下、本実施例の真空冷却装置1の運転方法の具体例について説明する。
本実施例の真空冷却装置1は、処理槽2内に食品Fを収容した状態で、減圧手段3により処理槽2内を減圧して、所定の終了条件を満たすまで(たとえば品温が冷却目標温度TZになるまで)冷却する。減圧手段3の作動中、各給気弁27,30を閉じて処理槽2内の圧力を迅速に低下させて食品Fを急冷してもよいし(急冷制御)、第一給気弁27の開度ひいては処理槽2内の圧力を調整して食品Fを徐冷してもよい(徐冷制御)。徐冷制御の場合、後述する温度差一定制御S2の他、たとえば次のような制御を行ってもよい。すなわち、運転開始からの経過時間と槽内圧力との関係(冷却パターン)が予め制御器に設定されており、制御器は、その冷却パターンに沿うように処理槽2内の圧力を調整しつつ、食品Fを冷却する。その際、冷却パターンとして複数種が登録されており、その内のいずれかを設定器から選択して実行可能に構成されてもよい。
A specific example of the operating method of the vacuum cooling device 1 of this embodiment will be described below.
The vacuum cooling apparatus 1 of the present embodiment decompresses the inside of the processing tank 2 with the food F stored in the processing tank 2 by the decompression means 3 until a predetermined end condition is satisfied (for example, the product temperature is the target cooling target). Cool to temperature TZ). During the operation of the decompression means 3, the air supply valves 27 and 30 may be closed to quickly reduce the pressure in the processing tank 2 to quickly cool the food F (quenching control), or the first air supply valve 27 may be closed. The food F may be slowly cooled by adjusting the degree of opening and thus the pressure in the treatment tank 2 (slow cooling control). In the case of slow cooling control, in addition to temperature difference constant control S2, which will be described later, for example, the following control may be performed. That is, the relationship (cooling pattern) between the elapsed time from the start of operation and the internal pressure of the tank (cooling pattern) is set in the controller in advance, and the controller adjusts the internal pressure of the processing tank 2 so as to follow the cooling pattern. , to cool food F. At that time, a plurality of types of cooling patterns are registered, and one of them may be selected from the setting device and executed.

なお、急冷制御後に徐冷制御を行ったり、徐冷制御後に急冷制御を行ったりするなど、両制御を適宜組み合わせて、食品Fを冷却してもよい。いずれにしても、減圧手段3の作動中、真空ポンプ9の作動、熱交換器7の通水、蒸気エゼクタ6の作動は、段階的に実行されるのがよく、その詳細は、図2の例に基づき後述する。 The food F may be cooled by appropriately combining both controls, such as performing slow cooling control after rapid cooling control or performing rapid cooling control after slow cooling control. In any case, the operation of the vacuum pump 9, the flow of water through the heat exchanger 7, and the operation of the steam ejector 6 during the operation of the depressurizing means 3 are preferably carried out stepwise. Examples will be described later.

さらに、急冷制御か徐冷制御かを問わず、処理槽2内を減圧中、圧力センサ31の検出圧力が凍結防止圧力PL以下になると、後述する凍結防止制御S4(図3)を実行する。以下、図2および図3に基づき、具体的な運転方法の一例について、説明する。 Further, regardless of rapid cooling control or slow cooling control, when the pressure detected by the pressure sensor 31 becomes equal to or lower than the anti-freezing pressure PL while the inside of the processing tank 2 is being depressurized, the anti-freezing control S4 (FIG. 3), which will be described later, is executed. An example of a specific operating method will be described below with reference to FIGS. 2 and 3. FIG.

図2は、本実施例の真空冷却装置1による冷却運転の一例を示すグラフであり、品温TFと槽内圧力換算温度TSとの変化を示しており、縦軸は温度T、横軸は運転開始からの経過時間tを示している。 FIG. 2 is a graph showing an example of the cooling operation by the vacuum cooling device 1 of the present embodiment, showing changes in the product temperature TF and the in-tank pressure conversion temperature TS, where the vertical axis is the temperature T and the horizontal axis is Elapsed time t from the start of operation is indicated.

運転開始前、第一給気弁27は開けられた状態にある一方、その他の前記各弁は閉じられた状態にあり、真空ポンプ9は停止している。その状態で、処理槽2内に食品Fが収容され、処理槽2のドアは気密に閉じられる。そして、スタートボタンが押されるなど運転開始が指示されると、制御器は、第一給気弁27を閉じると共に減圧手段3を作動させて、品温TFが予め設定された冷却目標温度TZになるまで、処理槽2内を減圧する。この際、本実施例では、初期減圧制御S1、温度差一定制御S2、および最終減圧制御S3を順次に実行する。また、詳細は後述するが、処理槽2内を減圧中、圧力センサ31の検出圧力が凍結防止圧力PL以下になると処理槽2内を所定に復圧する凍結防止制御S4(図3)も実行する。なお、初期減圧制御S1および最終減圧制御S3は、前述した急冷制御に相当し、温度差一定制御S2は、前述した徐冷制御に相当する。 Before starting operation, the first air supply valve 27 is open, the other valves are closed, and the vacuum pump 9 is stopped. In this state, the food F is stored in the processing tank 2, and the door of the processing tank 2 is airtightly closed. When the start button is pushed or the like is instructed to start operation, the controller closes the first air supply valve 27 and operates the decompression means 3 so that the product temperature TF reaches the preset cooling target temperature TZ. The inside of the processing tank 2 is depressurized until the At this time, in this embodiment, the initial pressure reduction control S1, the constant temperature difference control S2, and the final pressure reduction control S3 are sequentially executed. Further, although the details will be described later, when the pressure detected by the pressure sensor 31 becomes equal to or lower than the anti-freezing pressure PL while the inside of the processing tank 2 is being depressurized, the anti-freezing control S4 (FIG. 3) is also executed to restore the pressure inside the processing tank 2 to a predetermined value. . The initial pressure reduction control S1 and the final pressure reduction control S3 correspond to the rapid cooling control described above, and the constant temperature difference control S2 corresponds to the slow cooling control described above.

初期減圧制御S1は、所定の終了条件を満たすまで行われる。たとえば、品温TFが第一設定温度TA(たとえば60℃)以下になるまで、初期減圧制御S1が行われる。初期減圧制御S1では、各給気弁27,30を閉じた状態で、減圧手段3により処理槽2内を減圧する。品温TFが第一設定温度TAに下がるまでの冷却初期は、食品Fに沸騰が生じないか、沸騰が生じても細かい沸騰となる。そのため、各給気弁27,30を全閉した状態で、減圧手段3により処理槽2内の圧力を迅速に低下させても、突沸や吹きこぼれを起こすおそれは少ない。 The initial pressure reduction control S1 is performed until a predetermined end condition is satisfied. For example, the initial pressure reduction control S1 is performed until the product temperature TF becomes equal to or lower than the first set temperature TA (eg, 60° C.). In the initial depressurization control S1, the inside of the processing bath 2 is depressurized by the depressurizing means 3 while the air supply valves 27 and 30 are closed. In the early stages of cooling until the product temperature TF drops to the first set temperature TA, the food F does not boil, or if it does boil, it boils finely. Therefore, even if the pressure in the processing tank 2 is quickly reduced by the decompression means 3 with the air supply valves 27 and 30 fully closed, there is little risk of bumping or boiling over.

温度差一定制御S2は、所定の終了条件を満たすまで行われる。たとえば、品温TFが第二設定温度TB(たとえば25℃)以下になるまで、温度差一定制御S2が行われる。温度差一定制御S2では、品温TF(処理槽内の食品温度)と槽内圧力換算温度TS(処理槽内圧力における飽和温度)との温度差ΔTが設定温度差(たとえば2℃)になるように、処理槽2内の圧力を調整しつつ処理槽2内を減圧する。つまり、品温センサ32の検出温度TFと圧力センサ31の検出圧力における飽和温度TSとの温度差ΔTが設定温度差になるように、処理槽2内の圧力を調整しつつ処理槽2内を減圧する。なお、制御器は、予め登録された所定の演算式(またはテーブル)に基づき、圧力センサ31の検出圧力から飽和温度としての槽内圧力換算温度TSを求めることができる。 The constant temperature difference control S2 is performed until a predetermined termination condition is satisfied. For example, the constant temperature difference control S2 is performed until the product temperature TF becomes equal to or lower than the second set temperature TB (for example, 25°C). In the temperature difference constant control S2, the temperature difference ΔT between the product temperature TF (food temperature in the treatment tank) and the pressure conversion temperature TS (saturation temperature in the treatment tank pressure) becomes the set temperature difference (for example, 2°C). The inside of the processing bath 2 is decompressed while adjusting the pressure inside the processing bath 2 as shown in FIG. That is, the pressure in the processing bath 2 is adjusted so that the temperature difference ΔT between the temperature TF detected by the product temperature sensor 32 and the saturation temperature TS at the pressure detected by the pressure sensor 31 becomes the set temperature difference. Reduce pressure. Note that the controller can obtain the tank internal pressure conversion temperature TS as the saturation temperature from the pressure detected by the pressure sensor 31 based on a predetermined arithmetic expression (or table) registered in advance.

処理槽2内の圧力の調整は、典型的には、減圧手段3を作動させた状態で、復圧手段4による給気量を調整すればよい。具体的には、減圧手段3(少なくとも真空ポンプ9)を作動させた状態で、第一給気弁27の開度を調整すればよい。但し、これに代えてまたはこれに加えて、減圧手段3による減圧能力を調整してもよい。 The pressure in the processing tank 2 is typically adjusted by adjusting the amount of air supplied by the pressure recovery means 4 while the decompression means 3 is in operation. Specifically, the opening degree of the first air supply valve 27 may be adjusted while the pressure reducing means 3 (at least the vacuum pump 9) is in operation. However, instead of or in addition to this, the decompression capability of the decompression means 3 may be adjusted.

温度差一定制御S2において、槽内圧力換算温度TSが品温TFよりも設定温度低くなるように、処理槽2内の圧力を調整すると、品温TFが低下してくるので、その品温TFの低下に合わせて、槽内圧力(槽内圧力換算温度TS)を低下させていけばよい。品温TFと槽内圧力換算温度TSとの温度差ΔTを設定温度差に抑えることで、食品Fからの水分蒸発を所定の速度に制御し、突沸を抑制しつつ食品Fの冷却を図ることができる。つまり、仮に前記温度差ΔTを考慮せずに減圧した場合、品温TFが槽内圧力換算温度TSに追従できず、温度差ΔT(圧力差)が大きくなると、突然一気に沸騰する突沸を生じさせるおそれがあるが、温度差ΔTを設定温度差に抑えることで、突沸の発生を抑えることができる。 In the temperature difference constant control S2, if the pressure in the processing tank 2 is adjusted so that the pressure conversion temperature TS in the tank is lower than the product temperature TF, the product temperature TF will decrease. The pressure in the tank (temperature TS converted to pressure in the tank) should be lowered in accordance with the decrease in . By suppressing the temperature difference ΔT between the product temperature TF and the pressure conversion temperature TS in the tank to the set temperature difference, the evaporation of water from the food F is controlled at a predetermined rate, and the food F is cooled while suppressing bumping. can be done. That is, if the pressure is reduced without considering the temperature difference ΔT, the product temperature TF cannot follow the tank internal pressure conversion temperature TS, and when the temperature difference ΔT (pressure difference) increases, sudden boiling occurs at once. Although there is a risk, the occurrence of bumping can be suppressed by suppressing the temperature difference ΔT to the set temperature difference.

温度差一定制御S2中、品温センサ32の検出温度を監視し、この検出温度の設定時間Δt内の品温の温度下降幅が設定値未満になると、前記設定温度差を所定温度(たとえば0.5~1℃)増加させるのがよい。これにより、冷えにくい食品でも、設定温度差を増加させつつ食品Fの冷却を図ることができ、冷却が完了しなかったり、冷却時間が長くなり過ぎたりするのを防止できる。 During the constant temperature difference control S2, the temperature detected by the product temperature sensor 32 is monitored. .5-1°C) should be increased. As a result, even if the food is hard to cool, the food F can be cooled while increasing the set temperature difference, and it is possible to prevent incomplete cooling or an excessively long cooling time.

たとえば、品温TFと槽内圧力換算温度TSとの温度差ΔTが第一温度差ΔT1(たとえば2℃)となるように圧力制御中、品温TFの低下速度が遅くなり、設定時間Δt(たとえば1分)内の品温TFの温度下降幅が設定値(たとえば1℃)未満になると、前記温度差ΔTを第一温度差ΔT1よりも大きな第二温度差ΔT2(たとえば3℃)となるように圧力制御することで、品温TFの低下を促すことができる。その後、再び、品温TFの低下速度が遅くなり、設定時間Δt内の品温TFの温度下降幅が設定値未満になると、前記温度差ΔTを第二温度差ΔT2よりも大きな第三温度差ΔT3(たとえば4℃)となるように圧力制御して、品温TFの低下を促すということを繰り返せばよい。 For example, during pressure control so that the temperature difference ΔT between the product temperature TF and the in-tank pressure conversion temperature TS becomes the first temperature difference ΔT1 (for example, 2°C), the rate of decrease in the product temperature TF slows down, and the set time Δt ( When the temperature drop width of the product temperature TF within 1 minute) becomes less than a set value (eg 1°C), the temperature difference ΔT becomes a second temperature difference ΔT2 (eg 3°C) larger than the first temperature difference ΔT1. A decrease in the product temperature TF can be promoted by controlling the pressure in such a manner. After that, the rate of decrease of the product temperature TF slows down again, and when the temperature drop width of the product temperature TF within the set time Δt becomes less than the set value, the temperature difference ΔT is set to a third temperature difference larger than the second temperature difference ΔT2. It suffices to repeat pressure control so as to achieve ΔT3 (for example, 4° C.) to promote a decrease in the product temperature TF.

なお、初期減圧制御S1から温度差一定制御S2へ移行する際、真空ポンプ9の回転数を下げてもよい。たとえば、初期減圧制御S1では、真空ポンプ9の電源周波数を第一周波数(たとえば60Hz)とするが、温度差一定制御S2への移行に伴い、第一周波数よりも低い第二周波数(たとえば50Hz)とする。その後、最終減圧制御S3へ移行する際、真空ポンプ9の電源周波数を第一周波数に戻すなど、真空ポンプ9の回転数を再び上げてもよい。 It should be noted that the rotational speed of the vacuum pump 9 may be decreased when shifting from the initial pressure reduction control S1 to the constant temperature difference control S2. For example, in the initial depressurization control S1, the power supply frequency of the vacuum pump 9 is set to the first frequency (eg, 60 Hz). and After that, when shifting to the final depressurization control S3, the rotation speed of the vacuum pump 9 may be increased again, such as returning the power supply frequency of the vacuum pump 9 to the first frequency.

初期減圧制御S1と温度差一定制御S2とを含む一連の冷却運転において、熱交換器7および真空ポンプ9への給水や、蒸気エゼクタ6の作動は、たとえば次のように制御される。すなわち、冷却運転の開始時には、熱交換器7の通水を停止した状態で、真空ポンプ9に常温水を供給しつつ、真空ポンプ9により処理槽2内を減圧する。この段階では、エゼクタ給蒸弁11は閉じられており、蒸気エゼクタ6は作動していない。その後、通水開始条件として、たとえば品温センサ32の検出温度が通水開始温度(たとえば60℃)以下になると、熱交換器7の通水を開始する。この際、熱交換器7および真空ポンプ9には、冷水が供給される。その後、エゼクタ作動条件として、たとえば品温センサ32の検出温度がエゼクタ作動温度(たとえば30℃)以下になると、エゼクタ給蒸弁11を開けて蒸気エゼクタ6を作動させる。 In a series of cooling operations including initial pressure reduction control S1 and temperature difference constant control S2, water supply to heat exchanger 7 and vacuum pump 9 and operation of steam ejector 6 are controlled as follows, for example. That is, at the start of the cooling operation, the inside of the processing tank 2 is decompressed by the vacuum pump 9 while the normal temperature water is being supplied to the vacuum pump 9 in a state where the water supply to the heat exchanger 7 is stopped. At this stage, the ejector steam valve 11 is closed and the steam ejector 6 is not operating. After that, as a water supply start condition, for example, when the temperature detected by the product temperature sensor 32 becomes equal to or lower than the water supply start temperature (for example, 60° C.), the water supply to the heat exchanger 7 is started. At this time, cold water is supplied to the heat exchanger 7 and the vacuum pump 9 . After that, as an ejector operating condition, for example, when the temperature detected by the product temperature sensor 32 becomes equal to or lower than the ejector operating temperature (for example, 30° C.), the ejector steam supply valve 11 is opened to operate the steam ejector 6 .

最終減圧制御S3は、所定の終了条件を満たすまで行われる。たとえば、品温が冷却目標温度TZ(たとえば10℃)以下になるまで、最終減圧制御S3が行われる。最終減圧制御S3では、基本的には各給気弁27,30を閉じた状態で、減圧手段3により処理槽2内を減圧する。品温が第二設定温度TBを下回った冷却終盤は、沸騰(突沸を含む)しにくいが、冷却時間が延びると突沸発生リスクが大きくなるため、急冷により冷却時間の短縮を図ることで、突沸の発生を抑制することができる。そのために、初期減圧制御S1と同様に、各給気弁27,30を全閉した状態で(但し後述する凍結防止制御S4において第二給気弁30は一時的に開放され得る)、減圧手段3により処理槽2内の圧力を迅速に低下させるのがよい。 The final pressure reduction control S3 is performed until a predetermined termination condition is satisfied. For example, the final pressure reduction control S3 is performed until the product temperature becomes equal to or lower than the cooling target temperature TZ (for example, 10°C). In the final decompression control S3, basically, the inside of the processing tank 2 is decompressed by the decompression means 3 while the air supply valves 27 and 30 are closed. Boiling (including bumping) is difficult in the final stage of cooling when the product temperature is below the second set temperature TB, but if the cooling time is extended, the risk of bumping will increase. can be suppressed. Therefore, similarly to the initial decompression control S1, the decompression means is operated while the intake valves 27 and 30 are fully closed (however, the second intake valve 30 can be temporarily opened in the freeze prevention control S4, which will be described later). It is preferable that the pressure in the processing bath 2 is quickly lowered by 3.

そして、品温センサ32の検出温度が冷却目標温度TZ(たとえば10℃)になると、処理槽2内の減圧を停止する。具体的には、エゼクタ給蒸弁11、封水給水弁13および冷水給水弁17などを閉じて、蒸気エゼクタ6および真空ポンプ9を停止すると共に、熱交換器7の通水を停止する。その後、第一給気弁27を開けて、処理槽2内を大気圧まで復圧すればよい。この際、第一給気弁27の開度を調整しつつ、処理槽2内を徐々に復圧することができる。但し、場合により、第一給気弁27に代えてまたは加えて、第二給気弁30を開けてもよい。 Then, when the temperature detected by the product temperature sensor 32 reaches the cooling target temperature TZ (for example, 10° C.), the pressure reduction in the processing tank 2 is stopped. Specifically, the ejector steam supply valve 11, the sealed water supply valve 13, the cold water supply valve 17, etc. are closed, the steam ejector 6 and the vacuum pump 9 are stopped, and the water supply to the heat exchanger 7 is stopped. After that, the first air supply valve 27 is opened to restore the pressure in the processing bath 2 to the atmospheric pressure. At this time, the pressure inside the processing bath 2 can be gradually restored while adjusting the degree of opening of the first air supply valve 27 . However, depending on the situation, the second air supply valve 30 may be opened instead of or in addition to the first air supply valve 27 .

上記一連の制御により処理槽2内を減圧中、圧力センサ31の検出圧力が凍結防止圧力PL以下になると、凍結防止制御S4が並行して行われる。以下、凍結防止制御S4について説明する。 When the pressure detected by the pressure sensor 31 becomes equal to or lower than the anti-freezing pressure PL while the inside of the processing tank 2 is decompressed by the series of controls described above, the anti-freezing control S4 is performed in parallel. The anti-freezing control S4 will be described below.

図3は、凍結防止制御S4の一例を示すグラフであり、槽内圧力の変化を示しており、縦軸は圧力P、横軸は時間tを示している。なお、図3において、槽内圧力の低下は便宜上直線で示しているが、実際には図2のように緩やかな曲線となる。 FIG. 3 is a graph showing an example of the anti-freezing control S4, showing changes in the internal tank pressure, with the vertical axis representing the pressure P and the horizontal axis representing the time t. In FIG. 3, the decrease in tank internal pressure is indicated by a straight line for the sake of convenience, but in reality it is a gentle curve as shown in FIG.

凍結防止制御S4は、減圧手段3により処理槽2内を減圧中、圧力センサ31の検出圧力を監視して、圧力センサ31の検出圧力が凍結防止圧力PL以下になると、処理槽2内を設定回復圧力αまたは設定回復時間だけ復圧させる。この復圧中、減圧手段3は、作動させたままでよい。 The anti-freezing control S4 monitors the pressure detected by the pressure sensor 31 while the inside of the processing tank 2 is being decompressed by the decompression means 3, and when the detected pressure of the pressure sensor 31 becomes equal to or less than the anti-freezing pressure PL, the inside of the processing tank 2 is set. Restore pressure for the recovery pressure α or the set recovery time. During this pressure recovery, the decompression means 3 may be left in operation.

本実施例では、処理槽2内を減圧中、圧力センサ31の検出圧力が凍結防止圧力PL以下になると、処理槽2内の圧力が現在の圧力よりも設定回復圧力α(たとえば5hPa)だけ回復するまで、第二給気弁30を開ける。たとえば、圧力センサ31の検出圧力が所定圧力PH(=凍結防止圧力PL+設定回復圧力α)になるまで、第二給気弁30を開ければよい。第二給気弁30は電磁弁から構成されるので、処理槽2内を比較的短時間(典型的には瞬時)に復圧することができる。そして、設定回復圧力αだけ復圧後(言い換えれば槽内圧力が所定圧力PHになると)、第二給気弁30を閉じることで、再び処理槽2内は減圧される。以後も同様に、圧力センサ31の検出圧力が凍結防止圧力PL以下になるたびに、第二給気弁30を開けて、処理槽2内を所定まで復圧することを繰り返せばよい。 In this embodiment, when the pressure detected by the pressure sensor 31 becomes lower than the anti-freezing pressure PL while the inside of the processing tank 2 is decompressed, the pressure inside the processing tank 2 recovers from the current pressure by the set recovery pressure α (for example, 5 hPa). Open the second air supply valve 30 until For example, the second air supply valve 30 may be opened until the pressure detected by the pressure sensor 31 reaches a predetermined pressure PH (=anti-freezing pressure PL+set recovery pressure α). Since the second air supply valve 30 is composed of an electromagnetic valve, it is possible to restore the pressure in the processing tank 2 in a relatively short time (typically instantaneously). After the pressure is restored by the set recovery pressure α (in other words, when the pressure in the tank reaches the predetermined pressure PH), the inside of the processing tank 2 is again decompressed by closing the second air supply valve 30 . Similarly, every time the pressure detected by the pressure sensor 31 becomes equal to or lower than the antifreeze pressure PL, the second air supply valve 30 is opened to restore the pressure in the processing tank 2 to a predetermined level.

なお、制御器は、凍結防止制御S4による初回の復圧時、設定回復圧力αだけ復圧するのに要した復圧時間(第二給気弁30の開放時間)を計測し、この復圧時間を、以後の凍結防止制御S4の復圧時間(設定回復時間)として設定(保存)し、以後の復圧時には、復圧時間だけ第二給気弁30を開けることで制御してもよい。あるいは、凍結防止制御S4では、初回の復圧時も含めて、毎回、所定の復圧時間だけ第二給気弁30を開けてもよい。 In addition, the controller measures the pressure recovery time (opening time of the second air supply valve 30) required to recover the set recovery pressure α at the initial pressure recovery by the anti-freezing control S4, and this pressure recovery time may be set (stored) as the pressure recovery time (set recovery time) of the anti-freeze control S4 thereafter, and the second air supply valve 30 may be opened for the pressure recovery time thereafter. Alternatively, in the antifreeze control S4, the second air supply valve 30 may be opened for a predetermined pressure recovery time each time, including the initial pressure recovery.

凍結防止制御S4では、処理槽2内の圧力が凍結防止圧力PL以下になると、処理槽2内を一時的に所定まで復圧することで、食品Fの凍結を防止することができる。すなわち、凍結防止制御S4では、処理槽2内の圧力低下を一時的に停止して、食品Fのそれ以上の温度低下を防止すると共に、処理槽2内への給気により、槽内温度を回復させることで、食品Fが凝固点に達することを抑制して、食品F(特に表面)の凍結を防止することができる。 In the anti-freezing control S4, when the pressure in the processing tank 2 becomes equal to or lower than the anti-freezing pressure PL, the pressure in the processing tank 2 is temporarily restored to a predetermined level, thereby preventing the food F from freezing. That is, in the anti-freezing control S4, the pressure drop in the processing tank 2 is temporarily stopped to prevent the temperature of the food F from dropping further, and the temperature inside the processing tank 2 is lowered by supplying air to the processing tank 2. By recovering, it is possible to suppress the food F from reaching the freezing point and prevent freezing of the food F (especially the surface).

ところで、前述したとおり、凍結防止制御S4では、圧力センサ31の検出圧力が凍結防止圧力PL以下になると所定まで処理槽2内を復圧するが、この凍結防止圧力PLは、食品Fに凍結が生じる圧力よりも高い圧力で設定され、簡易には、0℃における水の飽和圧力に基づき設定される。 By the way, as described above, in the anti-freezing control S4, when the pressure detected by the pressure sensor 31 becomes equal to or lower than the anti-freezing pressure PL, the inside of the processing tank 2 is restored to a predetermined pressure. It is set at a pressure higher than the pressure, simply based on the saturation pressure of water at 0°C.

具体的には、水の飽和圧力としての6.1hPaか、この数値に対し許容範囲(たとえばセンサ誤差などを考慮した範囲)にある圧力として、凍結防止圧力PLが設定される。冷却しようとする実際の食品Fは、水以外に各種成分を含んでおり、凝固点降下があるため、凍結防止圧力PLを0℃における水の飽和圧力に基づき設定しても、食品Fの凍結を有効に防止することができる。たとえば、凍結防止圧力PLは、6±2hPaに設定することで、凝固点降下や一般的なセンサ誤差の影響を考慮した食品Fの凍結防止を図ることができる。また、凍結防止制御S4の開始タイミングを、処理槽2内の圧力に基づき決定することで、品温を用いた場合のような温度ムラや液深の影響を受けない。 Specifically, the anti-freeze pressure PL is set to 6.1 hPa as the saturation pressure of water, or to a pressure within an allowable range (for example, a range considering sensor error, etc.) with respect to this value. The actual food F to be cooled contains various components in addition to water and has a freezing point depression. can be effectively prevented. For example, by setting the anti-freezing pressure PL to 6±2 hPa, it is possible to prevent freezing of the food F considering the effects of freezing point depression and general sensor error. Further, by determining the start timing of the anti-freezing control S4 based on the pressure in the processing tank 2, there is no influence of temperature unevenness or liquid depth, unlike the case where the product temperature is used.

なお、凍結防止制御S4では、冷却時間に大きく影響しない範囲であれば、減圧手段3を一時的に停止するなどにより復圧状態を短時間保持してもよい。また、食品Fの凍結の防止効果が得られる程度に吸気速度を小さくして復圧時間を調整してもよい。 In the freeze prevention control S4, the pressure recovery state may be maintained for a short period of time by temporarily stopping the depressurizing means 3 as long as it does not greatly affect the cooling time. Alternatively, the pressure recovery time may be adjusted by decreasing the intake speed to such an extent that the freezing prevention effect of the food F can be obtained.

本発明の真空冷却装置1は、前記実施例の構成(制御を含む)に限らず適宜変更可能である。特に、食品Fが収容される処理槽2と、この処理槽2内の気体を外部へ吸引排出する減圧手段3と、減圧された処理槽2内へ外気を導入する復圧手段4と、処理槽2内の圧力を検出する圧力センサ31と、処理槽2内に収容された食品Fの温度を検出する品温センサ32と、前記各手段を制御する制御手段とを備え、減圧手段3により処理槽2内を減圧中、凍結防止制御S4として、圧力センサ31の検出圧力が凍結防止圧力PL以下になると、処理槽2内を設定回復圧力αまたは設定回復時間だけ復圧させるのであれば、その他の構成は適宜に変更可能である。 The vacuum cooling device 1 of the present invention is not limited to the configuration (including control) of the above embodiment, and can be modified as appropriate. In particular, a processing tank 2 containing food F, a depressurizing means 3 for sucking and discharging the gas in the processing tank 2 to the outside, a pressure restoring means 4 for introducing outside air into the decompressed processing tank 2, and a processing A pressure sensor 31 for detecting the pressure in the tank 2, a product temperature sensor 32 for detecting the temperature of the food F contained in the processing tank 2, and a control means for controlling each of the above means. When the pressure detected by the pressure sensor 31 becomes equal to or lower than the antifreeze pressure PL during depressurization in the processing tank 2, if the pressure in the processing tank 2 is restored by the set recovery pressure α or the set recovery time, Other configurations can be changed as appropriate.

たとえば、前記実施例において、初期減圧制御S1と最終減圧制御S3との内、一方または双方は、省略したり、他の減圧方法に変更したりしてもよい。たとえば、吹きこぼれしやすい食品については、初期減圧制御S1を実施せずに、最初から温度差一定制御S2を実施してもよい。また、吹きこぼれと突沸の一層の抑制のために、処理槽2内を減圧する過程で、処理槽2内を所定だけ復圧することを繰り返すパルス制御を、温度差一定制御S2において並行して実施してもよい。 For example, in the above embodiment, one or both of the initial pressure reduction control S1 and the final pressure reduction control S3 may be omitted or changed to another pressure reduction method. For example, for foodstuffs that easily boil over, the constant temperature difference control S2 may be performed from the beginning without performing the initial pressure reduction control S1. Further, in order to further suppress boiling over and bumping, in the process of decompressing the inside of the processing tank 2, pulse control is performed in parallel with the constant temperature difference control S2 to repeat the pressure recovery in the processing tank 2 by a predetermined amount. may

また、凍結防止制御S4では、処理槽2内の圧力が凍結防止圧力PL以下になると処理槽2内を所定に復圧させるが、処理槽2内の圧力が凍結防止圧力PLに達してから所定時間経過後に復圧させてもよい。すなわち、処理槽2内を減圧中、凍結防止圧力PL以下になると、処理槽2内を凍結防止圧力PLに保持し、所定時間経過後に処理槽2内を所定まで復圧させてもよい。なお、凍結防止制御S4では、パルス状に減復圧が繰り返されるが、初回のみ(つまり減圧開始後初めて凍結防止圧力PL以下になったときのみ)、凍結防止圧力PLでの所定時間の保持を行ってもよい。 In the anti-freezing control S4, when the pressure in the processing tank 2 becomes equal to or lower than the anti-freezing pressure PL, the pressure in the processing tank 2 is restored to a predetermined level. The pressure may be restored after a lapse of time. That is, when the inside of the processing tank 2 is decompressed and the pressure in the processing tank 2 becomes lower than the antifreezing pressure PL, the inside of the processing tank 2 may be maintained at the antifreezing pressure PL, and after a predetermined time has passed, the pressure in the processing tank 2 may be restored to a predetermined level. In the anti-freezing control S4, the depressurizing pressure is repeated in a pulsed manner, but only for the first time (that is, only when the anti-freezing pressure PL drops below the anti-freezing pressure PL for the first time after the start of decompression), the anti-freezing pressure PL is maintained for a predetermined time. you can go

また、凍結防止制御S4により、減復圧を繰り返す場合、各回における設定回復圧力(または設定回復時間)は、同一でもよいし、異なってもよい。 Further, when the anti-freeze control S4 repeats the pressure reduction and recovery, the set recovery pressure (or the set recovery time) may be the same or different each time.

また、前記実施例において、減圧手段3の構成は、適宜変更可能である。たとえば、前記実施例では、減圧手段3として蒸気エゼクタ6を備えたが、場合により蒸気エゼクタ6の設置を省略してもよい。 Moreover, in the above embodiment, the configuration of the decompression means 3 can be changed as appropriate. For example, in the above embodiment, the steam ejector 6 is provided as the decompression means 3, but installation of the steam ejector 6 may be omitted depending on the case.

さらに、前記実施例では、真空冷却装置1は、冷却専用機として説明したが、真空冷却機能を有するのであれば、適宜に変更可能である。たとえば、蒸気による加熱手段を備えることで、蒸煮冷却装置や飽和蒸気調理装置のように構成されてもよい。あるいは、冷凍機やファンを用いた冷風冷却手段を備えることで、冷風真空複合冷却装置のように構成されてもよい。 Furthermore, in the above embodiment, the vacuum cooling device 1 has been described as a dedicated cooling machine, but it can be modified appropriately as long as it has a vacuum cooling function. For example, by providing heating means using steam, it may be configured like a steaming cooling device or a saturated steam cooking device. Alternatively, by providing cold air cooling means using a refrigerator or a fan, it may be configured like a cold air/vacuum combined cooling device.

1 真空冷却装置
2 処理槽
3 減圧手段
4 復圧手段
5 排気路
6 蒸気エゼクタ(6a:吸引口、6b:入口、6c:出口)
7 熱交換器
8 逆止弁
9 真空ポンプ(9a:給水口、9b:吸気口、9c:排気口)
10 エゼクタ給蒸路
11 エゼクタ給蒸弁
12 封水給水路
13 封水給水弁
14 常温水給水路
15 常温水給水弁
16 冷水給水路
17 冷水給水弁
18 共通給水路
19 熱交給水路
20 熱交排水路
21 冷水戻し路
22 排水出口路
23 冷水戻し弁
24 排水出口弁
25 第一給気路
26 第一エアフィルタ
27 第一給気弁
28 第二給気路
29 第二エアフィルタ
30 第二給気弁
31 圧力センサ
32 品温センサ
S1 初期減圧制御
S2 温度差一定制御
S3 最終減圧制御
S4 凍結防止制御
REFERENCE SIGNS LIST 1 vacuum cooling device 2 treatment tank 3 decompression means 4 pressure recovery means 5 exhaust path 6 steam ejector (6a: suction port, 6b: inlet, 6c: outlet)
7 heat exchanger 8 check valve 9 vacuum pump (9a: water supply port, 9b: intake port, 9c: exhaust port)
10 ejector steam supply path 11 ejector steam supply valve 12 seal water supply path 13 seal water supply valve 14 normal temperature water supply path 15 normal temperature water supply valve 16 cold water supply path 17 cold water supply valve 18 common water supply path 19 heat exchange water supply path 20 heat exchanger Drainage path 21 Cold water return path 22 Drainage outlet path 23 Cold water return valve 24 Drainage outlet valve 25 First air supply path 26 First air filter 27 First air supply valve 28 Second air supply path 29 Second air filter 30 Second supply Air valve 31 Pressure sensor 32 Product temperature sensor S1 Initial pressure reduction control S2 Constant temperature difference control S3 Final pressure reduction control S4 Freeze prevention control

Claims (3)

食品が収容される処理槽と、この処理槽内の気体を外部へ吸引排出する減圧手段と、減圧された前記処理槽内へ外気を導入する復圧手段と、前記処理槽内の圧力を検出する圧力センサと、前記処理槽内に収容された食品の温度を検出する品温センサと、前記各手段を制御する制御手段とを備え、
前記減圧手段により前記処理槽内を減圧中、凍結防止制御として、前記圧力センサの検出圧力が凍結防止圧力以下になると、前記処理槽内を「凍結防止圧力+設定回復圧力」になるまで復圧させるか、その復圧に要する設定回復時間だけ復圧させ
前記復圧手段として、前記処理槽内への第一給気路に開度調整可能な第一給気弁を備えると共に、前記処理槽内への第二給気路に開閉切替される第二給気弁を備え、
前記減圧手段により前記処理槽内を減圧中、前記凍結防止制御として、前記圧力センサの検出圧力が凍結防止圧力以下になるたびに、前記第二給気弁を一時的に開放することを繰り返す
ことを特徴とする真空冷却装置。
A processing tank containing food, decompression means for sucking and discharging the gas in the processing tank to the outside, pressure recovery means for introducing outside air into the decompressed processing tank, and detecting the pressure in the processing tank. a pressure sensor, a temperature sensor for detecting the temperature of the food contained in the processing tank, and a control means for controlling each means,
When the pressure detected by the pressure sensor becomes equal to or lower than the anti-freezing pressure while the inside of the processing tank is decompressed by the decompressing means, the inside of the processing tank is restored to "anti-freezing pressure + set recovery pressure" as anti-freezing control. or restore pressure only for the set recovery time required for that pressure return ,
As the pressure restoring means, a first air supply valve whose opening degree can be adjusted is provided in the first air supply path to the processing tank, and a second air supply valve that is switched to open and close to the second air supply path to the processing tank. Equipped with an air supply valve,
While the inside of the processing tank is being decompressed by the decompressing means, the anti-freezing control repeatedly temporarily opens the second air supply valve every time the pressure detected by the pressure sensor becomes equal to or lower than the anti-freezing pressure.
A vacuum cooling device characterized by:
前記凍結防止圧力は、0℃における水の飽和圧力に基づき設定される
ことを特徴とする請求項1に記載の真空冷却装置。
The vacuum cooling device according to claim 1, wherein the anti-freezing pressure is set based on the saturation pressure of water at 0°C.
前記制御手段により、温度差一定制御も実行可能とされ、
前記温度差一定制御では、前記品温センサの検出温度と前記圧力センサの検出圧力における飽和温度との温度差が設定温度差になるように、前記処理槽内の圧力を調整しつつ前記処理槽内を減圧し、
前記品温センサの検出温度が所定温度以下になると、前記温度差一定制御を停止して、最終減圧制御として、前記処理槽内をさらに減圧し、
前記温度差一定制御および前記最終減圧制御を含んだ前記処理槽内の減圧中、前記凍結防止制御を実行する
ことを特徴とする請求項1または請求項2に記載の真空冷却装置。
The control means can also perform temperature difference constant control,
In the temperature difference constant control, the pressure in the processing bath is adjusted so that the temperature difference between the temperature detected by the product temperature sensor and the saturated temperature at the pressure detected by the pressure sensor becomes a set temperature difference. reduce the pressure inside
When the temperature detected by the product temperature sensor becomes equal to or lower than a predetermined temperature, the constant temperature difference control is stopped, and the inside of the processing tank is further decompressed as final decompression control,
3. The vacuum cooling apparatus according to claim 1, wherein the anti-freezing control is executed during depressurization in the processing bath including the constant temperature difference control and the final depressurization control.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004218957A (en) 2003-01-16 2004-08-05 Miura Co Ltd Vacuum cooling method
JP2004218958A (en) 2003-01-16 2004-08-05 Miura Co Ltd Vacuum cooling method
JP2010181042A (en) 2009-02-03 2010-08-19 Miura Co Ltd Cooling device and cooling method
JP2016031181A (en) 2014-07-29 2016-03-07 株式会社サムソン Vacuum cooling device

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5277031A (en) * 1991-11-27 1994-01-11 Western Precooling Systems Method and apparatus for cooling produce
JP3077602B2 (en) * 1996-03-06 2000-08-14 三浦工業株式会社 Vacuum cooling device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004218957A (en) 2003-01-16 2004-08-05 Miura Co Ltd Vacuum cooling method
JP2004218958A (en) 2003-01-16 2004-08-05 Miura Co Ltd Vacuum cooling method
JP2010181042A (en) 2009-02-03 2010-08-19 Miura Co Ltd Cooling device and cooling method
JP2016031181A (en) 2014-07-29 2016-03-07 株式会社サムソン Vacuum cooling device

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