TW201734392A - Vacuum cooling device - Google Patents

Abstract

This invention provides a vacuum cooling device capable of cooling a foodstuff to a target temperature. The vacuum cooling device 1 contains: a first cooling control unit 501 which reduces the internal pressure of a cooling tank 2 to a first target pressure value by pressure reducing means 3 and maintains the internal pressure of the cooling tank 2 at the fist target pressure value for a first time period after the internal pressure has reached the first target pressure value; a foodstuff temperature judging unit 502 which determines, after the cooling by the first cooling control unit 501, whether the detection temperature of a foodstuff temperature sensor 21 has reached the target temperature; and a second cooling control unit 503 which contains a second cooling hold control unit 5033 which newly sets the temperature when the temperature determined by the foodstuff temperature judgement unit 502 has not reached the target temperature, by reducing the first temperature from the set temperature, reducing the pressure by the pressure reducing means 3 to a set pressure value, and maintains the internal pressure of the cooling tank 2 at a set pressure value for a second time period when the internal pressure of cooling tank 2 has reduced to the set pressure value.

Description

Vacuum cooling device

The present invention relates to a vacuum cooling device for cooling foodstuffs, foods, and the like.

As disclosed in Patent Document 1, a vacuum cooling device is known in which a pressure in a treatment tank in which a target object is stored is reduced to vaporize moisture in the object to be cooled, and the object to be cooled is cooled by the heat of vaporization. In the vacuum cooling device, the article temperature sensor is attached to the object to be cooled, and the temperature of the object to be cooled measured by the temperature sensor of the article is vacuum-cooled to the target temperature zone.

Patent Document 2 discloses a vacuum cooling device and a vacuum cooling method. Even when the different food materials are simultaneously cooled, the temperature difference after cooling can be reduced and the cooling can be stably cooled. Specifically, the supercooling prevention device for preventing excessive cooling of the food material reduces the pressure in the treatment tank to a predetermined set pressure during vacuum cooling, and the pressure in the treatment tank reaches the set pressure, and then the inside of the treatment tank Maintain at its set pressure. Thereby, the food material which is easy to cool is cooled to a temperature close to the saturation temperature corresponding to the set pressure without falling below the saturation temperature. On the other hand, the food material that is difficult to cool takes more time to cool so that the temperature of the food material approaches the saturation temperature in the treatment tank. Such as Therefore, by controlling the maximum degree of vacuum in the treatment tank, the pressure in the treatment tank is not reduced to the pressure that can be attained by the pressure reduction means, thereby avoiding overcooling of the object to be cooled and insufficient cooling of the object to be cooled, and stabilizing Cool the different ingredients.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open Publication No. Hei 9-296975

Patent Document 2: Japanese Patent Laid-Open Publication No. 2006-266649

When the food material that is difficult to cool is cooled to the target temperature by the vacuum cooling device having the supercooling prevention function described in Patent Document 2, for example, a temperature slightly lower than the target temperature is set as the first target temperature, and the inside of the treatment tank is The pressure is reduced to a saturation pressure value (first target pressure value) corresponding to the first target temperature, and the pressure in the treatment tank is maintained at the first target pressure value after the pressure in the treatment tank reaches the first target pressure value. . In this way, the temperature of the food material that is difficult to cool can be lowered to the target temperature.

However, depending on the type of the foodstuff, there is a case where the temperature of the article stops at a higher temperature in the middle without falling to the target temperature.

It is an object of the present invention to provide a vacuum cooling device that monitors the actual temperature of the food material over a period of time and, when the temperature of the food material is no longer reduced, gradually lowers the target pressure to reach the target temperature.

The present invention relates to a vacuum cooling device comprising: a cooling bath for accommodating a cooled object; an article temperature sensor for detecting a temperature of the object to be cooled; and a decompression means for decompressing an internal space of the cooling tank; and controlling The control unit includes a first cooling control unit including a first pressure reducing control unit that depressurizes a pressure value inside the cooling tank to a predetermined target temperature by the pressure reducing means. a first target pressure value; and a first cooling and holding control unit that maintains a pressure value inside the cooling tank at the first target pressure after the pressure value inside the cooling tank reaches the first target pressure value The value continues for the first time; the article temperature determining unit determines whether the detected temperature of the article temperature sensor reaches the target temperature after cooling by the first cooling control unit; and the second cooling control unit includes: second cooling The parameter setting unit reduces the target temperature from when the article temperature determination unit determines that the target temperature has not been reached. The temperature after the preset first temperature is set to the set temperature, and the pressure value of the pressure conversion value of the set temperature is set as the set pressure value; and the second pressure reduction control unit is decompressed by the pressure reducing means to the aforementioned The set pressure value set by the second cooling parameter setting unit; and the second cooling and holding control unit maintains the pressure value inside the cooling tank after the pressure value inside the cooling tank reaches the set pressure value Set the pressure value for a second time that is preset.

Further, the article temperature determining unit determines whether the detected temperature of the article temperature sensor reaches the target temperature when the control of the second cooling and holding control unit is completed, and the second cooling parameter setting When the article temperature determining unit determines that the target temperature has not been reached, the fixed portion replaces the set temperature with a value obtained by subtracting the first temperature, and replaces the set pressure value with the replaced one. The pressure value of the pressure conversion value of the set temperature is preferable.

Further, the control unit preferably stops the cooling when the article temperature determination unit determines that the target temperature has been reached.

Further, after the cooling of the second cooling control unit, the control unit passes the vacuum cooling operation from the inside of the cooling tank even if the article temperature determination unit determines that the target temperature has not been reached. When the maximum cooling time is set in advance, it is preferable to stop the cooling.

Further, the vacuum cooling device includes a storage unit that sequentially stores the detected temperature of the article temperature sensor after being cooled by the second cooling control unit, and the control unit is cooled by the second cooling control unit. When the detected temperature of the article temperature sensor is higher than the detected temperature of the previous article temperature sensor stored in the memory unit, an abnormal alarm is issued and the operation is interrupted.

Further, after the control unit cools by the second cooling control unit, the detected temperature of the article temperature sensor is lower than the detected temperature of the previous article temperature sensor stored in the memory unit. When the detected temperature difference is equal to or lower than a predetermined value, it is preferable to stop the cooling.

In addition, the aforementioned first target pressure value is from the aforementioned target The pressure conversion value of the temperature after subtracting the temperature difference of the preset cooling lower limit is preferable.

Further, the first temperature system is set in advance to each sequence number executed by the second cooling control unit, and the second time is preferably set in advance by each of the sequence numbers executed by the second cooling and holding control unit.

According to the present invention, the temperature of the foodstuff can be brought to the target temperature regardless of the type of the foodstuff.

1‧‧‧ Vacuum Cooling Unit

2‧‧‧Cooling trough

3‧‧‧Decompression

4‧‧‧Repression means

5‧‧‧Control device

21‧‧‧ Item Temperature Sensor

22‧‧‧ Pressure Sensor

23‧‧‧Detained objects

31‧‧‧vacuum unit

32‧‧‧heat converter

33‧‧‧Decompression line

41‧‧‧Filter

42‧‧‧Re-pressure line

43‧‧‧Repressing operation valve

50‧‧‧Control Department

51‧‧‧Memory Department

501‧‧‧First Cooling Control Department

502‧‧‧ Item Temperature Judgment Department

503‧‧‧Second Cooling Control Department

504‧‧‧Cool interruption

505‧‧‧Cooling stop

5011‧‧‧First Decompression Control Department

5012‧‧‧First Cooling Control Unit

5031‧‧‧Second cooling parameter setting unit

5032‧‧‧Secondary Pressure Reducing Control Department

5033‧‧‧Second Cooling Control Unit

Fig. 1 is a view schematically showing a vacuum cooling apparatus of the present embodiment.

Fig. 2 is a functional block diagram showing the functional configuration of the control device provided in the vacuum cooling device of the present embodiment.

Fig. 3 is a view showing an example of a cooling operation of a control device provided in the vacuum cooling device of the present embodiment.

Hereinafter, a preferred embodiment of the vacuum cooling apparatus of the present invention will be described with reference to the drawings. Fig. 1 is a view showing an embodiment of a vacuum cooling device of the present invention.

As shown in Fig. 1, the vacuum cooling device 1 includes a cooling tank 2, a pressure reducing means 3, a pressure reducing means 4, and a control device 5.

The cooling tank 2 accommodates the object 23 to be cooled. The cooling tank 2 is provided with an opening and closing door (not shown) for allowing the object to be cooled 23 to enter and exit, and the cooling tank 2 can be sealed by closing the opening and closing door. In this embodiment, the food material is contained in The object 23 to be cooled in the cooling tank 2 is cooled.

The cooling tank 2 is provided with an article temperature sensor 21, and detects the temperature of the foodstuff of the object to be cooled accommodated in the cooling tank 2. The article temperature sensor 21 is provided in the food material accommodated in the cooling tank 2 by insertion or the like to measure the temperature of the portion thereof.

The cooling tank 2 is provided with a pressure sensor 22 for detecting the pressure in the cooling tank 2.

The decompression means 3 includes a vacuum unit 31 that is connected to the cooling tank 2 via a pressure reducing line 33.

The vacuum unit 31 is configured, for example, by a liquid-sealed vacuum pump.

It is preferable to provide the heat exchanger 32 in the pressure reducing line 33. Further, a steam ejector (not shown) may be provided on the upstream side of the heat exchanger 32 of the pressure reducing line 33.

The heat exchanger 32 cools and aggregates the food vapor in the decompression line 33 and the vapor of the steam ejector (when the steam ejector is provided). By pre-cooling and aggregating the food vapor in the decompression line 33 and the vapor of the steam ejector, the temperature of the fluid in the cooling bath 2 is lowered, and the volume of the discharged fluid is reduced. Thereby, the load of the vacuum unit 31 can be reduced, and the pressure reduction in the cooling tank 2 can be effectively achieved.

The steam ejector sucks and discharges the fluid in the cooling tank 2 by ejecting steam. The pressure on the suction side of the vacuum unit 31 can be increased by the steam ejector, and the pressure reduction in the cooling tank 2 can be effectively achieved.

The recompression means 4 is a means for introducing the outside air into the reduced pressure cooling tank 2 to release the vacuum and recompress. Specifically, the external air can be filtered The device 41 is introduced and supplied to the cooling tank 2 via the pressure equalizing line 42.

The double pressure line 42 is provided with a recompression operation valve 43 for switching the presence or absence of communication between the outside air and the cooling tank 2. According to this, in the state in which the pressure reducing operation valve 43 is closed, the pressure in the cooling tank 2 is reduced by the pressure reducing means 3, and then the pressure reduction of the pressure reducing means 3 is stopped, and the pressure is released by opening the double pressure operation valve 43. The vacuum state in the cooling bath 2 is restored to atmospheric pressure.

The double pressure operation valve 43 is configured to be arbitrarily adjustable in opening degree like a proportional control valve. Accordingly, when the pressure reduction in the cooling tank 2 is performed by the decompression means 3, the pressure in the cooling tank 2 can be arbitrarily adjusted by adjusting the opening degree of the double pressure operation valve 43. More specifically, the opening of the pressure-receiving operation valve 43 is adjusted in accordance with the output of the pressure sensor 22, and the pressure reduction operation is performed by the pressure reducing means 3, whereby the pressure adjustment in the cooling tank 2 can be easily performed.

The control device 5 controls the decompression means 3, the recompression means 4, and the like. In the present embodiment, the vacuum unit 31, the re-pressure operation valve 43, the article temperature sensor 21, and the pressure sensor 22 are connected to the control device 5, and various controls can be performed by the control device 5.

Specifically, the control device 5 adjusts the opening degree of the double pressure operation valve 43 in accordance with the detection signal from the pressure sensor 22, and adjusts the degree of pressure reduction in the cooling tank 2 by the vacuum unit 31.

When the pressure in the cooling tank 2 is maintained at a set pressure, the control device 5 can stop the pressure reducing means 3 and the pressure reducing means 4 in a state where the pressure in the cooling tank 2 is maintained at a set pressure, thereby achieving uniform temperature stability after cooling. Vacuum cooling.

At the end of the vacuum cooling process, the control device 5 opens the double pressure operation valve 43 and recompresses the inside of the cooling tank 2 to atmospheric pressure. And based on the sense of pressure The detection signal of the detector 22 confirms that the recompression in the cooling bath 2 by the re-pressure operation valve 43 is completed.

Fig. 2 is a functional block diagram showing the functional configuration of the control device 5. As shown in FIG. 2, the control device 5 includes a control unit 50 and a storage unit 51.

The control unit 50 connects the article temperature sensor 21, the pressure sensor 22, the vacuum unit 31, the double pressure operation valve 43, and the like, and controls the cooling of the food material.

Here, in the present embodiment, the control unit 50 is configured to include: a first cooling control unit that decompresses the inside of the cooling tank to a first target pressure value; and when the temperature of the article is not lowered to the target temperature, The first cooling control unit decompresses the inside of the cooling tank to the second cooling control unit set to a set pressure value lower than the first target pressure value. Therefore, the food material temperature can be brought to the target temperature regardless of the type of the food material.

More specifically, as shown in FIG. 2 , the control unit 50 includes a first cooling control unit 501 , an article temperature determination unit 502 , a second cooling control unit 503 , a cooling interruption unit 504 , and a cooling stop unit 505 . The first cooling control unit 501 includes a first pressure reduction control unit 5011 and a first cooling and holding control unit 5012, and the second cooling control unit 503 includes a second cooling parameter setting unit 5031 and a second pressure reduction control unit 5032. And a second cooling retention control unit 5033.

The first cooling control unit 501 is configured by the first pressure reduction control unit 5011 to reduce the pressure value inside the cooling tank 2 to the first target pressure value set according to the preset target temperature, and then to perform the first cooling. The holding control unit 5012 maintains the pressure value inside the cooling tank 2 at the first target pressure value for the first time set in advance as the cooling holding time.

Specifically, the first pressure reduction control unit 5011 sets the saturation pressure value corresponding to the first target temperature after subtracting the preset cooling minimum temperature difference from the target temperature as the first target pressure value, and by the decompression means 3 The pressure inside the cooling tank 2 is reduced to a first target pressure value.

In the case of the cooling lower limit temperature difference, it is preferable to set a temperature difference corresponding to the pressure reduction range in which the cooling phenomenon of the object 23 does not cause an excessive cooling phenomenon such as supercooling of the object 23 to be cooled. Further, the optimum cooling lower limit temperature difference varies depending on the object to be cooled 23, and is generally preferably 3 degrees or less.

The first cooling retention control unit 5012 maintains the pressure value inside the cooling tank 2 at the first target pressure value for a first time (for example, 15 minutes) after the pressure inside the cooling tank 2 reaches the first target pressure value.

More specifically, the first cooling and holding control unit 5012 adjusts the opening degree of the double pressure operation valve 43 in accordance with the output of the pressure sensor 22, and performs a pressure reduction operation by the pressure reducing means 3, thereby the inside of the cooling tank 2 The pressure is maintained at the first target pressure value for the first time.

The article temperature determination unit 502 determines whether or not the detected temperature of the article temperature sensor 21 (the temperature of the object to be cooled 23) reaches the target temperature after being cooled by the first cooling control unit 501.

Further, when the control of the second cooling and holding control unit 5033 is completed, the article temperature determination unit 502 determines whether or not the detected temperature of the article temperature sensor 21 (the temperature of the object to be cooled 23) has reached the target temperature.

The second cooling control unit 503 determines that the detected temperature of the article temperature sensor 21 does not reach the target temperature after cooling by the first cooling control unit 501 and after cooling by the second cooling control unit 503, and further reduces the set pressure. The value is vacuum cooled for a predetermined time.

Here, the cooling by the second cooling control unit 503 immediately after cooling by the first cooling control unit 501 is referred to as the first second cooling; the second cooling after the first cooling is performed. The cooling by the second cooling control unit 503 is referred to as the second second cooling; the cooling by the second cooling control unit 503 after the nth second cooling is referred to as the (n+1)thth Two cooling. In this manner, the cooling system that identifies the current second cooling and holding control unit 5033 is numbered the first time from the start of cooling by the second cooling control unit 503, and is referred to as a second cooling sequence number. Hereinafter, the second cooling of the nth time is also referred to as second cooling (n).

In this manner, when the second cooling control unit 503 determines that the detected temperature of the article temperature sensor 21 does not reach the target temperature after cooling by the first cooling control unit 501 or the second cooling control unit 503, the second cooling control unit 503 The second cooling parameter setting unit 5031 sets the set pressure value down, and the second pressure reducing control unit 5032 depressurizes the pressure value inside the cooling tank 2 to the set pressure value, and holds it by the second cooling. The control unit 5033 maintains the pressure value inside the cooling tank 2 at the set pressure value for the second time. The second cooling control unit 503 performs the foregoing processing in a reverse (return) until the detected temperature of the article temperature sensor 21 reaches the target temperature. In this way, regardless of the type of the ingredients, the temperature of the ingredients can reach the target temperature.

More specifically, the second cooling parameter setting unit 5031, the second decompression control unit 5032, and the second cooling and holding control unit 5033 perform processing as follows.

When the second cooling parameter setting unit 5031 ends the control by the first cooling and holding control unit 5012, the article temperature determining unit 502 determines that the detected temperature of the article temperature sensor 21 has not reached the target temperature, and will The temperature after the target temperature is subtracted from the preset first temperature (for example, 1 degree) is set as the set temperature, and is stored in the memory unit 51. At the same time, the second cooling parameter setting unit 5031 sets the pressure value of the pressure conversion value of the set temperature as the set pressure value, and stores it in the memory unit 51.

When the second cooling parameter setting unit 5031 terminates the cooling by the second cooling and holding control unit 5033, the article temperature determining unit 502 determines that the detected temperature of the article temperature sensor 21 has not reached the target temperature. The value of the first temperature is subtracted from the previously set set temperature, and is set as the set temperature, and is again stored in the memory unit 51. At the same time, the second cooling parameter setting unit 5031 sets the pressure value of the pressure conversion value of the reset set temperature as the set pressure value, and stores it in the memory unit 51.

Here, when the first temperature is set to a large value of, for example, 5 degrees, cooling control that is different from the supercooling prevention function may be caused, so the first temperature is equal to or lower than the cooling lower limit temperature difference. Preferably.

When the processing of the second cooling parameter setting unit 5031 corresponds to the processing of the second (n≧1)th second cooling control unit 503, the second cooling parameter setting processing is referred to as the nth time. In order to simplify the description, the nth time is set by the nth second cooling parameter setting process. The set temperature and the nth set pressure value are described as the set temperature (n) and the set pressure value (n).

The second pressure reduction control unit 5032 is depressurized by the pressure reducing means 3 to the set pressure value set in the memory unit 51. When the processing of the second decompression control unit 5032 is equivalent to the processing of the nth second cooling control unit 503, it is referred to as the nth second decompression control unit process.

The second cooling and holding control unit 5033 sets the pressure inside the cooling tank 2 to the inside of the cooling tank 2 after the pressure reduction by the second pressure reducing control unit 5032 reaches the set pressure value set in the memory unit 51. The pressure is maintained at the set pressure value for a second time (for example, 2 minutes) set in advance as the cooling hold time. When the processing of the second cooling and holding control unit 5033 corresponds to the processing of the nth second cooling control unit 503, the second cooling and holding control unit processing is referred to as the nth time.

The second cooling and holding control unit 5033 connects the detected temperature of the article temperature sensor 21 to the second cooling sequence number n (n≧1) for identifying the cooling by the second cooling control unit 503 after the end of the control. ) and memorized in the memory unit 51. The detected temperature of the article temperature sensor 21 after the processing of the nth second cooling and holding control unit is referred to as the nth detection, and is described as the detected temperature (n) for simplification of description.

Further, the first temperature is not constant, but may be set in advance according to each sequence number n executed by the second cooling control unit 503, and the second time may be set in advance according to the sequence number n executed by the second cooling and holding control unit 5033. . Thereby, for example, the first temperature and the second time may be configured to gradually decrease as the n increases, for example, to converge.

The cooling interruption unit 504 emits an abnormality when the detected temperature of the article temperature sensor 21 is higher than the detected temperature of the previous article temperature sensor 21 memorized by the storage unit 51 after being cooled by the second cooling control unit 503. The alarm is interrupted and the operation is interrupted.

That is, the temperature (n) of the article temperature sensor 21 after the cooling interruption unit 504 is cooled by the second cooling control unit 503 (nth time) is higher than the previous time (n-1th time) When the detected temperature (n-1) of the article temperature sensor 21 after the second cooling control unit 503 is cooled, it is determined that a cooling abnormality has occurred, and an abnormality alarm is issued and the operation is interrupted.

The cooling stop unit 505 is preset after the vacuum cooling operation from the inside of the cooling tank 2, even if the article temperature determination unit 502 determines that the target temperature has not been reached after the cooling by the second cooling control unit 503. When the maximum cooling time is reached, the cooling is stopped.

Specifically, when the maximum cooling time has elapsed from the start of the vacuum cooling operation inside the cooling bath 2, the cooling stop portion 505 opens the double pressure operation valve 43 and recompresses the inside of the cooling tank 2 to the atmospheric pressure. Then, based on the detection signal from the pressure sensor 22, it is confirmed that the recompression in the cooling bath 2 by the double pressure operation valve 43 is completed.

Further, after the cooling stop unit 505 is cooled by the second cooling control unit 503 this time (nth time), even if the detected temperature (n) of the article temperature sensor 21 is lower than the previous time memorized by the storage unit 51 In the case of the detected temperature (n-1) of the article temperature sensor 21 (n-1st), when the detected temperature difference is equal to or less than a predetermined value, the cooling is stopped.

Thereby, the cooling stop unit 505 can be repeated even if When the second cooling control unit 503 processes but anticipates that the cooling effect is also poor, the cooling is stopped to prevent waste.

The control unit 50 is configured as described above.

The memory unit 51 stores the above-described cooling lower limit temperature difference, the first time, the first temperature, the second time, the maximum cooling time, the first target temperature, the first target pressure value, and the like.

Further, the memory unit 51 stores the set temperature (n) and the set pressure value (n) set by the second cooling parameter setting process for the nth time (n≧1) described above.

Further, the memory unit 51 stores the detected temperature (n) detected by the second cooling control unit 503 after the cooling process of the nth time (n≧1) described above.

[Action Description]

Next, the cooling operation of this embodiment will be described with reference to Fig. 3 . Fig. 3 is a view showing an example of the cooling operation of the vacuum cooling device 1 of the present embodiment. The horizontal axis represents time t, the vertical axis (left side) represents pressure P, and the vertical axis (right side) represents temperature T. Here, the temperature T refers to the saturation temperature corresponding to the pressure P, and the pressure P refers to the saturation pressure corresponding to the temperature T.

In Fig. 3, the cooling parameter of the vacuum cooling device 1 sets the target temperature to 17 degrees, the saturation pressure value corresponding to the target temperature is 19 hPa, the cooling lower limit temperature difference is set to 2 degrees, and the first target temperature is set to 15 degrees ( 17 degrees minus 2 degrees), the first target pressure value corresponding to the first target temperature is 17 hPa, the cooling retention time (first time) of the first cooling retention control unit 5012 is set to 15 minutes, and the first temperature is set to 1 degree. The cooling hold time (second time) of the second cooling hold control unit 5033 is set to 2 points. Clock, the maximum cooling time is set to 40 minutes.

Further, the temperature of the object to be cooled 23 before cooling was 100 degrees (the saturated pressure value was 1013 hPa), and it was cooled to a target temperature of 17 degrees.

First, the food material of the object to be cooled 23 is housed in the cooling bath 2, and the article temperature sensor 21 is inserted into the food material. Then, the opening and closing door for the operation of the cooling tank 2 is closed. At this time, the control unit causes the double pressure operation valve 43 to be in the locked state, and stops the operation of the vacuum unit 31.

Next, at time t ₀ , the first pressure reduction control unit 5011 operates the vacuum unit 31. The air in the cooling tank 2 is vacuum-sucked via the pressure reducing line 33 by the operation of the vacuum unit 31. Since the saturation temperature decreases as the pressure in the cooling bath 2 decreases, the moisture of the foodstuff in the cooling tank 2 evaporates rapidly, and this vapor is also sucked along with the air through the pressure reducing line 33. Then, the foodstuff is cooled by the heat of vaporization which occurs with the evaporation of the moisture in the foodstuff.

Time _{t. 1,} the pressure in the cooling tank 2 reaches the first target pressure value 17hPa (saturation temperature corresponding to 15 degrees), the control unit 5012 holding the first cooling system in a first elapsed time (15 minutes) at time t matter _In the period until ₂ , by adjusting the opening degree of the pressure control valve and operating the vacuum unit 31, the pressure in the cooling tank 2 is maintained at 17 hPa (corresponding to a saturation temperature of 15 degrees).

On the other hand, the temperature sensor detects a temperature of article 21 at times t ₁ showed over 25 degrees and does not reach the target temperature of 17 degrees. Then, at time t ₂ after the first time (15 minutes) elapsed, 25 degrees was also displayed, and it was found that the target temperature was not reached 17 degrees.

In this regard, the second cooling parameter setting unit 5031 will set The temperature (1) is set to subtract the first temperature (1 degree) temperature by 14 degrees from 15 degrees of the first target temperature, and set the set pressure (1) to a saturation pressure corresponding to 14 degrees of the set temperature (1). 16hPa.

After pressure by the second control unit 5032 is reduced to the set pressure (1) t the pressure in the tank ₂₃ to the cooling time, holding the second cooling system control unit 5033 has elapsed since the second time (2 minutes) matter during a period of time t _4, by adjusting the opening degree of complex pressure control valve unit 31 and the operation of vacuum, the pressure in the cooling tank 2 is maintained at 16hPa (saturation temperature corresponding to 14 degrees).

On the other hand, the detected temperature of the article temperature sensor 21 is 20 degrees at time t ₄ , and it is understood that the target temperature has not reached 17 degrees.

On the other hand, the second cooling parameter setting unit 5031 sets the set temperature (2) to a temperature of 13 degrees minus the first temperature (1 degree) from 14 degrees of the set temperature (1), and sets the set pressure (2). It is a saturation pressure of 15 hPa corresponding to 13 degrees of the set temperature (2).

After pressure by the second pressure control section ₅₀₃₂₅ in the cooling tank 2 is reduced to the set pressure (2) at time t, the control unit 5033 holding the second cooling system since the second elapsed time (2 minutes) matter time during a period of ₆ t, by adjusting the opening degree of complex pressure control valve unit 31 and the operation of vacuum, the pressure in the cooling tank 2 is maintained at 15 hPa (corresponding to a saturation temperature of 13 degrees).

On the other hand, the temperature sensor detects a temperature of the article 21 of the display 17 at time t ₆ degrees, 17 degrees has reached the apparent target temperature.

The cooling stop unit 505 stops the cooling. Specifically, the cooling stop portion 505 stops the vacuum unit 31 and opens the double pressure operation valve 43.

So, if the ingredients do not reach the target temperature, by targeting The pressure is lowered little by little to get close to the target temperature.

[Effect description]

As described above, the vacuum cooling device 1 of the present embodiment includes the first cooling control unit 501 that decompresses the internal pressure of the cooling tank 2 to the first target pressure value, and the internal pressure of the cooling tank 2 reaches the first target. After the pressure value, the internal pressure of the cooling tank 2 is maintained at the first target pressure value for a first time (for example, 15 minutes); and the second cooling control portion 503, after being cooled by the first cooling control portion 501, the temperature of the article When the detected temperature of the sensor 21 does not reach the target temperature, the pressure conversion value of the temperature of the first temperature (for example, 1 degree) is subtracted, the pressure value is reset to the set pressure value, and the pressure is reduced to the set pressure value, and the cooling tank 2 is cooled. After the internal pressure reaches the new set pressure value, the internal pressure of the cooling tank 2 is maintained at the new set pressure value for the second time (for example, 2 minutes).

Thereby, even if the food material which is difficult to cool is processed by the first cooling control unit 501, the article temperature is stopped at a higher temperature in the middle without falling to the target temperature, and may be lowered by the second cooling control unit 503. The target pressure is cooled again to bring it closer to the target temperature.

Further, in the vacuum cooling device 1 of the present embodiment, when the control of the article temperature sensor 21 does not reach the target temperature when the control by the second cooling control unit 503 is completed, the set temperature is further subtracted. A temperature is substituted for the pressure value of the pressure conversion value of the set temperature after the subtraction.

Thereby, even if the food material which is difficult to cool is processed by the second cooling control unit 503, the temperature of the article stops at a higher temperature without falling in the middle. In the case of the target temperature, the target pressure may be further lowered and cooled by the second cooling control unit 503 to approach the target temperature.

Further, in the vacuum cooling device 1 of the present embodiment, when the detected temperature of the article temperature sensor 21 reaches the target temperature, the cooling is stopped.

Thereby, overcooling of the foodstuff can be prevented.

Further, in the vacuum cooling device 1 of the present embodiment, after the cooling by the second cooling control unit 503, even if the detected temperature of the article temperature sensor 21 does not reach the target temperature, the vacuum in the cooling tank 2 is When the preset maximum cooling time has elapsed since the start of the cooling operation, the cooling is stopped.

Thereby, the waste by the processing of the second cooling control unit 503 is prevented from being excessively repeated.

Further, in the vacuum cooling device 1 of the present embodiment, after the n+1th time is cooled by the second cooling control unit 503, the detected temperature of the article temperature sensor 21 is higher than that of the previous (nth)th. When the detected temperature of the article temperature sensor 21 after the second cooling control unit 503 is cooled, an abnormality alarm is issued and the operation is interrupted.

Thereby, the abnormality of the vacuum cooling device 1 can be detected early, and the abnormal operation can be interrupted early.

Further, in the vacuum cooling device 1 of the present embodiment, the detected temperature (n+1) of the article temperature sensor 21 after being cooled by the second cooling control unit 503 (n+1st time) is low. Detection of the article temperature sensor 21 after being cooled by the second cooling control unit 503 in the previous (nth time) In the case of the temperature (n), when the detected temperature difference is equal to or lower than a predetermined value, the cooling is stopped.

Thereby, the cooling stop portion 505 can stop the cooling to prevent waste even if the cooling effect is expected to be poor even if it is further processed by the second cooling control portion 503.

Further, the first target pressure value in the vacuum cooling device 1 of the present embodiment may be a pressure conversion value obtained by subtracting a temperature lower than a preset cooling lower limit temperature difference from the target temperature.

Thereby, the detected temperature of the article temperature sensor 21 can be brought close to the target temperature as soon as possible.

Further, the first temperature and the second time in the vacuum cooling device 1 of the present embodiment can be set in advance according to the respective sequence numbers executed by the second cooling control unit 503.

Thereby, for example, the first temperature and the second time may be configured to gradually decrease as n increases.

In addition, the implementation form is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

[variation]

For example, in the present embodiment, a steam ejector may be provided on the cooling groove 2 side of the pressure reducing line 33. At this time, the heat exchanger 32 cools and aggregates the food vapor in the decompression line 33 and the vapor of the steam ejector in advance to lower the temperature of the fluid in the cooling bath 2 and to reduce the volume of the discharged fluid. Thereby, the pressure on the suction side of the vacuum unit 31 can be increased by the steam ejector, and the pressure reduction in the cooling tank 2 can be effectively achieved.

1‧‧‧ Vacuum Cooling Unit

2‧‧‧Cooling trough

3‧‧‧Decompression

4‧‧‧Repression means

5‧‧‧Control device

21‧‧‧ Item Temperature Sensor

22‧‧‧ Pressure Sensor

23‧‧‧Detained objects

31‧‧‧vacuum unit

32‧‧‧heat converter

33‧‧‧Decompression line

41‧‧‧Filter

42‧‧‧Re-pressure line

43‧‧‧Repressing operation valve

Claims (8)

A vacuum cooling device comprising: a cooling tank for accommodating a cooled object; an article temperature sensor for detecting a temperature of the object to be cooled; a pressure reducing means for decompressing an internal space of the cooling tank; and a control unit; The control unit includes: a first cooling control unit; and a first pressure reduction control unit that depressurizes a pressure value inside the cooling tank to a first value set according to a preset target temperature by the pressure reducing means a target pressure value; and the first cooling retention control unit, after the pressure value inside the cooling tank reaches the first target pressure value, maintaining the pressure value inside the cooling tank at the first target pressure value for the first time a time; the article temperature determining unit determines whether the detected temperature of the article temperature sensor reaches the target temperature after the first cooling control unit is cooled; and the second cooling control unit includes a second cooling parameter setting unit, When the article temperature determination unit determines that the target temperature has not been reached, the preset target temperature is subtracted from the target temperature. Temperature after the temperature is set to a preset temperature, pressure and the pressure of the converted value of the set temperature value is set to the set pressure value; and a second pressure controlling portion, by means of the reduced pressure according to the second cooling parameters a set pressure value set by the setting unit; and a second cooling hold control unit that maintains the pressure value inside the cooling tank at the set pressure value after the pressure value inside the cooling tank reaches the set pressure value The second time set in advance. The vacuum cooling device according to claim 1, wherein the article temperature determining unit determines whether the detected temperature of the article temperature sensor reaches the target temperature when the control of the second cooling and holding control unit is completed. When the article temperature determination unit determines that the target temperature has not been reached, the second cooling parameter setting unit replaces the set temperature with a value obtained by subtracting the first temperature, and replaces the set pressure value. The pressure value of the pressure-converted value of the set temperature after the replacement. The vacuum cooling device according to the first or second aspect of the invention, wherein the control unit stops cooling when the article temperature determining unit determines that the target temperature has been reached. The vacuum cooling device according to claim 2, wherein the control unit is configured to cool the second cooling control unit, and if the article temperature determination unit determines that the target temperature has not been reached, When a predetermined maximum cooling time elapses from the start of the vacuum cooling operation inside the cooling tank, the cooling is stopped. The vacuum cooling device according to claim 2, wherein the vacuum cooling device includes a memory portion, and sequentially stores the detection temperature of the article temperature sensor after being cooled by the second cooling control portion. The control unit sends out when the detected temperature of the article temperature sensor is higher than the detected temperature of the previous item temperature sensor stored in the memory unit after being cooled by the second cooling control unit. An abnormal alarm and interrupted operation. The vacuum cooling device according to claim 5, wherein the control unit is cooled by the second cooling control unit, even if the detected temperature of the article temperature sensor is lower than that of the memory unit. In the case where the temperature of the previous article temperature sensor is detected, when the detected temperature difference is equal to or lower than a predetermined value, the cooling is stopped. The vacuum cooling device according to any one of claims 1 to 2, wherein the first target pressure value is a pressure conversion of a temperature obtained by subtracting a predetermined lower limit temperature difference from the target temperature value. The vacuum cooling device according to any one of claims 1 to 2, wherein the first temperature system is set in advance to each sequence number executed by the second cooling control unit; and the second time is in advance It is set to each sequence number executed by the second cooling and holding control unit.