JP2020091052A - Vacuum cooling device - Google Patents

Abstract

To provide a vacuum cooling device capable of cooling foods as desired while reducing a water supply amount to a vacuum pump even when a product temperature sensor is not used or cannot be used.SOLUTION: A vacuum cooling device includes: a processing tank 2 for storing foods F; decompression means 3 having a water-sealing type vacuum pump 9 sucking and discharging gas in the processing tank 2 to the outside; pressure-restoring means 4 for introducing outside air into the decompressed processing tank 2; a pressure sensor 31 detecting pressure in the processing tank 2; and a water temperature sensor 32 detecting a water supply temperature to the vacuum pump 9. A water supply amount to the vacuum pump 9 is increased when a saturation temperature in detected pressure of the pressure sensor 31 becomes lower than a detection temperature of the temperature sensor 32+a set value while the processing tank 2 is decompressed by the decompression means 3. For instance, when a saturation temperature in detected pressure of the pressure sensor 31 becomes lower than a detection temperature of the temperature sensor 32+a set value while a first water-sealing valve 13 is opened to decompress, a second water-sealing valve 14 is also opened.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vacuum cooling device that cools food by decompressing the inside of a processing tank.

Conventionally, as disclosed in, for example, Patent Document 1 below, there is known a vacuum cooling device that further includes a steam ejector and a heat exchanger for steam condensation and a water-sealed vacuum pump. In this type of vacuum cooling device, the amount of water supplied to the vacuum pump is maintained at a predetermined level. That is, the amount of water supplied to the vacuum pump is set as a specified value that satisfies a predetermined capacity, and the vacuum pump is always operated at that specified value.

JP-A-9-296975

When the vacuum pump is operated, if the water supply amount to the vacuum pump is always operated at the full amount (the specified value), the water consumption cannot be suppressed. On the other hand, there is a possibility that the food cannot be cooled to a desired level simply by reducing the amount of water supplied to the vacuum pump.

Also, during vacuum cooling, the temperature of the food in the processing tank is usually monitored by the product temperature sensor, but there are cases where the product temperature sensor is not used or the product temperature sensor cannot be used due to disconnection, etc. Water saving control considering these cases is desired.

The problem to be solved by the present invention is to provide a vacuum cooling device capable of cooling food to a desired level while reducing the amount of water supplied to the vacuum pump even when the product temperature sensor is not used or cannot be used. This is an issue.

The present invention has been made to solve the above problems, and the invention according to claim 1 is of a water-sealing type in which a processing tank in which food is stored and a gas in the processing tank is sucked and discharged to the outside. A decompression means having a vacuum pump, a decompression means for introducing outside air into the decompressed processing tank, a pressure sensor for detecting the pressure in the processing tank, and water supply to the vacuum pump or in the vacuum pump. A water temperature sensor for detecting the temperature of the sealed water and a control means for controlling each of the means are provided, and while the decompression means is depressurizing the inside of the processing tank, the saturation temperature at the pressure detected by the pressure sensor is “the water temperature sensor When it is lower than the "detected temperature + set value", (a) the amount of water supplied to the vacuum pump is increased, or (b) the saturation temperature at the detected pressure of the pressure sensor is "detected temperature of the water temperature sensor + set value" or more. The amount of water supplied to the vacuum pump is adjusted so that

According to the invention described in claim 1, in addition to the pressure sensor that detects the pressure in the processing tank, a water temperature sensor that detects the temperature of the water supplied to the vacuum pump or the sealing water in the vacuum pump is provided. When the pressure inside the processing tank is being reduced by the pressure reducing means, the temperature converted into the tank pressure (saturation temperature at the pressure detected by the pressure sensor) falls below the “temperature detected by the water temperature sensor+set value” (a) water supply to the vacuum pump Increase the amount or (b) adjust the amount of water supplied to the vacuum pump so that the temperature conversion temperature inside the tank is equal to or higher than the "temperature detected by the water temperature sensor + set value", to further reduce the pressure inside the processing tank. You can proceed. Water can be saved by suppressing the amount of water supplied to the vacuum pump until the tank internal pressure conversion temperature falls below the “temperature detected by the water temperature sensor+set value”. Moreover, the control can be performed without using the product temperature sensor, and even when the product temperature sensor is not used or cannot be used, it is possible to cool the food to a desired amount while reducing the amount of water supplied to the vacuum pump.

In the invention according to claim 2, as a water supply passage to the vacuum pump, a parallel portion of a first sealed water passage having a first constant flow valve and a second sealed water passage having a second constant flow valve is provided. While supplying water to the vacuum pump through the first water sealing passage, the saturation temperature at the pressure detected by the pressure sensor is “the temperature detected by the water temperature sensor+the set value” while the pressure in the processing tank is being reduced by the pressure reducing means. When it is less than, the vacuum cooling device according to claim 1, wherein water is supplied to the vacuum pump through the second sealed water passage instead of or in addition to the first sealed water passage.

According to the second aspect of the present invention, when the inside pressure of the tank is reduced below the “temperature detected by the water temperature sensor+set value” while depressurizing the inside of the processing tank while supplying water to the vacuum pump through the first sealed water passage. By supplying water to the vacuum pump via the second sealed water passage instead of or in addition to the first sealed water passage, it is possible to increase the amount of water supplied to the vacuum pump and further reduce the pressure in the treatment tank. Water can be saved by suppressing the amount of water supplied to the vacuum pump until the tank internal pressure conversion temperature falls below the “temperature detected by the water temperature sensor+set value”. Moreover, it can be realized with a simple configuration and control.

According to a third aspect of the present invention, as a water supply passage to the vacuum pump, a parallel portion of a first sealing passage having a constant flow valve and a second sealing passage having a flow rate adjusting valve is provided, and the first sealing pipe is provided. While supplying water to the vacuum pump via a water sealing passage, while depressurizing the inside of the processing tank by the depressurizing means, when the saturation temperature at the pressure detected by the pressure sensor is lower than the "temperature detected by the water temperature sensor+set value", The vacuum cooling according to claim 1, wherein the opening degree of the flow rate adjusting valve is adjusted so that the saturation temperature at the pressure detected by the pressure sensor becomes equal to or higher than the "temperature detected by the water temperature sensor+set value". It is a device.

According to the invention as set forth in claim 3, when the inside pressure of the tank is reduced below the “temperature detected by the water temperature sensor+set value” while depressurizing the inside of the processing tank while supplying water to the vacuum pump through the first sealed water passage. The pressure in the processing tank can be further reduced by adjusting the opening of the flow rate adjusting valve so that the temperature converted into the tank pressure becomes equal to or higher than the “temperature detected by the water temperature sensor+set value”. Water can be saved by suppressing the amount of water supplied to the vacuum pump until the tank internal pressure conversion temperature falls below the “temperature detected by the water temperature sensor+set value”. Moreover, it can be realized with a simple configuration and control.

Further, the invention according to claim 4 further comprises a steam ejector as the decompression means, and when the steam ejector is operated before increasing the amount of water supplied to the vacuum pump, when the steam ejector is operated, The vacuum cooling device according to any one of claims 1 to 3, wherein a water supply amount to the vacuum pump is increased.

According to the invention described in claim 4, when the steam ejector is activated at the latest, the amount of water supplied to the vacuum pump is increased. Thereby, even if the steam ejector is operated, the pressure in the processing tank can be further reduced while preventing the temperature of the sealing water from rising. Until the amount of water supplied to the vacuum pump is increased, water can be supplied to the water supply pump at a relatively small flow rate, and water can be saved.

According to the vacuum cooling device of the present invention, food can be cooled to a desired level while reducing the amount of water supplied to the vacuum pump even when the product temperature sensor is not used or cannot be used.

It is the schematic which shows the vacuum cooling apparatus of one Example of this invention, and has shown one part in section. It is a flowchart which shows an example of the operating method of the vacuum cooling device of FIG. It is a figure which shows the modification of the vacuum cooling device of FIG. 1, and has shown the sealing water supply path to a vacuum pump.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing a vacuum cooling device 1 according to an embodiment of the present invention, a part of which is shown in cross section.

The vacuum cooling device 1 of the present embodiment introduces outside air into the processing tank 2 in which the food F is stored, decompression means 3 for sucking and discharging the gas in the processing tank 2 to the outside, and decompressed processing tank 2. And a control unit (not shown) for controlling the respective units 3 and 4 to cool the food F in the processing tank 2.

The processing tank 2 is a hollow container that withstands a reduced pressure in the internal space, and can be opened and closed by a door (not shown). The processing tank 2 is typically formed in a substantially rectangular box shape, and its front opening can be opened and closed by a door. By opening the door, the food F can be put in and taken out of the treatment tank 2, and by closing the door, the opening of the treatment tank 2 can be airtightly closed. The doors may be provided on both the front surface and the back surface of the processing tank 2. In addition, in the illustrated example, the food F is put in a food container such as hotel bread or Banju and stored in the processing tank 2.

The decompression means 3 is a means for decompressing the inside of the processing tank 2 by sucking and discharging the gas (air or steam) in the processing tank 2 to the outside. In the present embodiment, the decompression unit 3 is provided with a vapor ejector 6, a heat exchanger 7 for vapor condensation, a check valve 8, and a water-sealed vacuum pump 9 in the exhaust passage 5 from the inside of the processing tank 2. ..

The vapor ejector 6 is provided with a suction port 6a connected to the processing tank 2, and vapor from the ejector steam supply passage 10 can be ejected from a nozzle from the inlet 6b to the outlet 6c. By ejecting steam from the inlet 6b toward the outlet 6c, the gas in the processing tank 2 is also sucked and discharged to the outlet 6c via the suction port 6a. By operating the opening and closing of the ejector steam supply valve 11 provided in the ejector steam supply passage 10, the operation of the steam ejector 6 can be switched.

The heat exchanger 7 is an indirect heat exchanger that exchanges heat without mixing the fluid in the exhaust passage 5 with the cooling water. The heat exchanger 7 allows the steam in the exhaust passage 5 to be cooled and condensed by cooling water.

The vacuum pump 9 is a water seal type in the present embodiment, and as is well known, it is operated while supplying water called seal water. Therefore, water is supplied to the water supply port 9a of the vacuum pump 9 through the sealed water supply passage 12 (12a to 12d). When the vacuum pump 9 is operated while supplying water from the sealed water supply passage 12, 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 the output thereof may be adjustable. For example, the vacuum pump 9 can change the drive frequency of the motor and thus the number of rotations by using an inverter.

The amount of water supplied to the vacuum pump 9 can be changed. In this embodiment, it is configured as follows. That is, first, the sealed water supply channel 12 includes a parallel portion of the first sealed channel 12a and the second sealed channel 12b. Specifically, the upstream side water sealing path 12c from the water supply source is branched into the first water sealing path 12a and the second water sealing path 12b, and then merges again to be connected to the vacuum pump 9 as the downstream side water sealing path 12d. It A first water sealing valve 13 is provided on the upstream side water sealing passage 12c (or the first water sealing passage 12a), while a second water sealing valve 14 is provided on the second water sealing passage 12b. Further, the first constant flow valve 12a is provided with the first constant flow valve 15, while the second constant flow valve 12b is provided with the second constant flow valve 16. As is well known, the constant flow valves 15 and 16 are configured to be able to pass water at a constant flow rate. The set flow rates of the constant flow valves 15 and 16 may be the same or different from each other, but in the present embodiment, the first constant flow valve 15 is set to a smaller flow rate than the second constant flow valve 16. The water sealing valves 13 and 14 are electromagnetic valves.

When the first water sealing valve 13 is opened with the second water sealing valve 14 closed, the sealing water is supplied to the vacuum pump 9 via the first water sealing passage 12a at a relatively small flow rate (first set water amount). can do. When the second water sealing valve 14 is also opened, the vacuum pump 9 is supplied with a relatively large flow rate (second set water amount larger than the first set water amount) via the first water sealing passage 12a and the second water sealing passage 12b. Sealing water can be supplied. That is, when both water sealing valves 13 and 14 are opened, the sealing water is supplied to the vacuum pump 9 at the sum of the set flow rates of the constant flow valves 15 and 16. In addition, it is preferable that the first set amount of water is set to a minimum flow rate that can maintain a desired depressurization rate until the second sealing valve 14 is opened.

The water supply system to the heat exchanger 7 and the vacuum pump 9 will be further described. In this embodiment, the heat exchanger 7 and the vacuum pump 9 can be switched between normal temperature water and cold water to be supplied. Cold water is water that has been cooled to a predetermined temperature by a chiller (not shown), and room temperature water is water that cannot be cooled as such.

In the case of the illustrated example, switching between normal temperature water and cold water is performed by a normal temperature water supply valve 18 provided in the normal temperature water supply passage 17 and a cold water supply valve 20 provided in the cold water supply passage 19. The normal temperature water supply passage 17 downstream of the normal temperature water supply valve 18 and the cold water supply passage 19 downstream of the cold water supply valve 20 join together to form a common water supply passage 21. The common water supply passage 21 is branched into a heat exchange water supply passage 22 to the heat exchanger and a water sealing water supply passage 12 (upstream side water sealing passage 12c) to the vacuum pump 9. Water is supplied to the heat exchanger 7 by opening the room temperature water supply valve 18 or the cold water supply valve 20, and when the first water sealing valve 13 (and further the second water sealing valve 14 if desired) is opened, water is supplied to the vacuum pump 9. To be done.

The heat exchanger 7 is supplied with water via the heat exchange water supply passage 22 and discharged through the heat exchange drainage passage 23. The heat exchange drainage channel 23 is branched into a cold water return channel 24 to a cold water tank (water supply source of the chiller) and a drainage outlet channel 25 to the outside, and the cold water return channel 24 is provided with a cold water return valve 26. A drain outlet valve 27 is provided in the drain outlet passage 25. By the cold water return valve 26 and the drain outlet valve 27, the water after passing through the heat exchanger 7 is returned to the cold water tank, discharged from the drain outlet passage 25, or neither of them is passed through the heat exchanger 7. Can be switched (that is, whether the cooling water outlet side of the heat exchanger 7 is closed).

When supplying cold water 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 27 and opening the cold water return valve 26. The stored water in the cold water tank is cooled by the chiller and can be supplied to the cold water supply passage 19 again. On the other hand, when the room temperature water is supplied to the heat exchanger 7, the room temperature water after passing through the heat exchanger 7 is discharged from the drainage outlet passage 25 by closing the cold water return valve 26 and opening the drainage outlet valve 27. In addition, by closing the cold water return valve 26 and the drain outlet valve 27, the water flow through the heat exchanger 7 can be stopped.

The pressure restoration means 4 is means for introducing outside air into the depressurized processing tank 2 to restore the pressure in the processing tank 2. In the present embodiment, the pressure restoration unit 4 is provided with an air filter 29 and an air supply valve 30 in order in the air supply passage 28 into the processing tank 2. When the air supply valve 30 is opened while the inside of the processing tank 2 is depressurized, the outside air is introduced into the processing tank 2 through the air filter 29, and the inside of the processing tank 2 can be restored in pressure. The air supply valve 30 is preferably composed of a valve whose opening degree can be adjusted.

The vacuum cooling device 1 further includes a pressure sensor 31 that detects the pressure in the processing tank 2 and a water temperature sensor 32 that detects the temperature of the water supplied to the vacuum pump 9. In the present embodiment, in FIG. 1, the water temperature sensor 32 is provided in the upstream water sealing passage 12c of the water sealing water supply passage 12, but may be provided in the downstream water sealing passage 12d or the first water sealing passage 12a. It may be provided in the common water supply passage 21 or the like.

The vacuum cooling device 1 may further be provided with a product temperature sensor (not shown) that detects the temperature (product temperature) of the food F stored in the processing tank 2. However, in the vacuum cooling device 1 of the present embodiment, it is not necessary to install the product temperature sensor, and even if the product temperature sensor is provided, as will be described later, the product temperature sensor is not used, or the product temperature sensor is broken due to a disconnection or the like. Even if the food cannot be used, the food F can be cooled to a desired level.

The control means is a controller (not shown) that controls the respective means 3, 4 based on the detection signals of the respective sensors 31, 32 and the elapsed time. Specifically, the vacuum pump 9, the ejector steam supply valve 11, the first water seal valve 13, the second water seal valve 14, the room temperature water water supply valve 18, the cold water water supply valve 20, the cold water return valve 26, the drainage outlet valve 27, In addition to the air supply valve 30, the pressure sensor 31, the water temperature sensor 32, and the like are connected to the controller. Then, as described below, the controller vacuum-cools the food F in the processing tank 2 according to a predetermined procedure (program). The controller can obtain the tank internal pressure conversion temperature as the saturation temperature from the pressure detected by the pressure sensor 31 based on a predetermined arithmetic expression (or table) registered in advance.

Hereinafter, a specific example of the operation method of the vacuum cooling device 1 of the present embodiment will be described.
FIG. 2 is a flowchart showing an example of the operating method of the vacuum cooling device 1 of this embodiment.

Before the start of operation, the air supply valve 30 is in the open state, while the other valves are in the closed state, and the vacuum pump 9 is stopped. In that state, the food F is stored in the processing tank 2, and the door of the processing tank 2 is airtightly closed. Then, when the operation start is instructed such as by pressing the start button, the controller closes the air supply valve 30 and starts depressurizing the processing tank 2 by the depressurizing means 3.

At the start of depressurization, first, in a state in which water flow through the heat exchanger 7 is stopped, room temperature water is supplied to the vacuum pump 9 and the inside of the processing tank 2 is depressurized by the vacuum pump 9 (step S1). At this time, the first water sealing valve 13 is opened with the second water sealing valve 14 closed, and water is supplied to the vacuum pump 9 at a small flow rate. Further, the ejector steam supply valve 11 is closed, and the steam ejector 6 is not operating.

Then, when a predetermined water flow start condition is satisfied, water flow through the heat exchanger 7 is started. In the present embodiment, when the tank internal pressure conversion temperature (saturation temperature at the pressure detected by the pressure sensor 31) becomes equal to or lower than the water passage start temperature (for example, 60° C.), water passage through the heat exchanger 7 is started (S2, S3). .. At this time, the water supply to the heat exchanger 7 and the vacuum pump 9 is switched to cold water.

After that, at a predetermined timing according to the tank-converted temperature, while increasing the amount of water supplied to the vacuum pump 9 or operating the steam ejector 6, the pressure inside the processing tank 2 is reduced until a predetermined end condition is satisfied. To do. In the present embodiment, the pressure inside the processing tank 2 is reduced until the tank internal pressure conversion temperature becomes equal to or lower than the cooling target temperature (for example, 10° C.). Then, during this pressure reduction, the amount of water supplied to the vacuum pump 9 can be increased by the control of [A] (or [B]) described below, and the steam ejector 6 can be operated by the control of [B] described below. To be done.

[A] While the second sealing valve 14 is closed and the steam ejector 6 is stopped, the pressure inside the processing tank 2 is being reduced, and the tank internal pressure conversion temperature is equal to “supply water temperature+set value (first set value)”. If it is lower, the second water sealing valve 14 is opened to increase the amount of water supplied to the vacuum pump 9 (S4, S5). That is, when the saturation temperature at the pressure detected by the pressure sensor 31 falls below “the temperature detected by the water temperature sensor 32+the first set value”, the limit reached (the limit of the degree of vacuum that can be reached) with the current water supply amount is reached ( Or approaching), the second water sealing valve 14 is opened to increase the amount of water supplied to the vacuum pump 9 to a large flow rate. As a result, the pressure in the processing tank 2 can be further reduced. It should be noted that if the first set value is too large, the water-saving effect described below is diminished, while if the first set value is too small, the food cannot be cooled as desired. Considering this point, the first set value is set in the range of 5 to 10°C, preferably 6 to 8°C. In this embodiment, the first set value is set to, for example, 7°C.

[B] When the ejector operating condition is satisfied while the pressure inside the processing tank 2 is being reduced while the vapor ejector 6 is stopped, the vapor ejector 6 is activated. In this embodiment, when the tank internal pressure conversion temperature becomes equal to or lower than the ejector operating temperature (for example, 30° C.), the ejector steam supply valve 11 is opened and the steam ejector 6 is operated (S6, S7). At this time, if the second water sealing valve 14 is closed, the second water sealing valve 14 is opened when the steam ejector 6 is operated to increase the amount of water supplied to the vacuum pump 9. That is, if the water supply amount to the vacuum pump 9 is not increased before the steam ejector 6 is operated, the water supply amount to the vacuum pump 9 is increased when the steam ejector 6 is operated.

As described above, when the second water sealing valve 14 is closed and the steam ejector 6 is stopped during the depressurization in the processing tank 2, the tank pressure conversion is performed while monitoring the above [A] and [B]. The pressure inside the processing tank 2 is reduced until the temperature reaches the cooling target temperature. On the other hand, when the second water sealing valve 14 is in the open state and the steam ejector 6 is in the stopped state, the inside of the processing tank 2 is depressurized while monitoring the above [B] until the tank internal pressure conversion temperature reaches the cooling target temperature. To do. After performing the above [B] (that is, the steam ejector 6 is operating), the inside of the processing tank 2 can be depressurized while simply monitoring whether or not the tank internal pressure conversion temperature is equal to or lower than the cooling target temperature. Good.

When the tank internal pressure conversion temperature reaches the cooling target temperature (for example, 10° C.), the depressurization in the processing tank 2 is stopped (S8, S9). Specifically, the ejector steam supply valve 11, the water sealing valves 13 and 14, the cold water supply valve 20 and the like are closed to stop the steam ejector 6 and the vacuum pump 9 and also stop the water flow through the heat exchanger 7. .. Then, the air supply valve 30 may be opened to restore the pressure in the processing tank 2 to atmospheric pressure.

By the way, during the operation of the depressurizing means 3, the opening degree of the air supply valve 30 and thus the pressure in the processing tank 2 can be adjusted to gradually cool the food F (gradual cooling control). For example, the relationship (cooling pattern) between the elapsed time from the start of operation and the pressure in the tank is set in the controller in advance, and the controller adjusts the pressure in the processing tank 2 so as to follow the cooling pattern. , Cool the food F. At that time, a plurality of types are registered as the cooling pattern, and any one of them may be configured to be executable by being selected from the setter.

According to the vacuum cooling device 1 of the present embodiment, water is saved by suppressing the amount of water supplied to the vacuum pump 9 until the tank internal pressure conversion temperature falls below the “temperature detected by the water temperature sensor 32+first set value”. Can be planned. Moreover, it is possible to control without using the product temperature sensor, and even when the product temperature sensor is not used or cannot be used, it is possible to cool the food F to a desired level while reducing the amount of water supplied to the vacuum pump 9. it can.

Next, a modified example of the vacuum cooling device 1 of the present embodiment will be described.
FIG. 3 is a diagram showing a modified example of the sealing water supply passage 12 (12a to 12d) to the vacuum pump 9, and the other parts are the same as those in FIG.

In the above-described embodiment, the second water sealing valve 12 and the second constant flow valve 16 are installed in the second water sealing passage 12b, but in the present modification, the second constant flow valve 12b is installed in the second water sealing passage 12b. 16 is not installed but the second water sealing valve 14 is installed. In addition, in the above-described embodiment, the second water sealing valve 14 is composed of an electromagnetic valve that is switched on and off by turning it on and off, but in the present modification, the second water sealing valve 14 is a motor-operated valve whose opening can be adjusted ( Flow control valve). Further, in the above-described embodiment, the water temperature sensor 32 is provided in the sealed water supply passage 12 to monitor the temperature of the water supplied to the vacuum pump 9, but in the present modification, the water temperature sensor 32 is provided in the vacuum pump 9. Then, the temperature of the sealing water in the vacuum pump 9 is monitored.

Also in the case of this modification, when the second water sealing valve 14 is opened, it can be controlled in the same manner as in the above embodiment by opening it to a predetermined opening (for example, fully open). However, in the case of this modification, it is also possible to control as follows.

Specifically, this modified example is also basically controlled based on FIG. 2, but the following points are different. That is, in the control of the above [A], while the second sealing valve 14 is closed and the steam ejector 6 is stopped, while decompressing the inside of the processing tank 2, the tank internal pressure conversion temperature is “sealing water temperature+set value”. (Second set value)”, the second water sealing valve 14 is opened to increase the amount of water supplied to the vacuum pump 9. At this time, it is preferable to control the water supply amount so as to satisfy “the tank pressure conversion temperature≧sealing temperature+second set value”. That is, when the saturation temperature at the pressure detected by the pressure sensor 31 falls below “the temperature detected by the water temperature sensor 32+the second set value”, the saturation temperature at the pressure detected by the pressure sensor 31 becomes “the temperature detected by the water temperature sensor 32+the second set value”. The opening degree of the second water sealing valve 14 may be adjusted so as to be equal to or more than “value” (typically, “the temperature detected by the water temperature sensor 32+the second set value”). Such an opening degree adjustment control of the second water sealing valve 14 can be executed even after the steam ejector 6 is operated in the above [B]. However, after activating the steam ejector 6, the second water sealing valve 14 may be set to a predetermined opening degree (for example, fully open) as in the above embodiment. It should be noted that the temperature of the confined water to which the condensed water and the heat generated by the motor are added to the supplied water rises above the supplied water temperature. Therefore, the second set value of the present modification is set smaller than the first set value of the above-described embodiment, and is set to, for example, 0 to 5°C, preferably 2 to 3°C. The other configurations and controls are the same as those in the above-described embodiment, and thus the description thereof will be omitted.

The vacuum cooling device 1 of the present invention is not limited to the configuration (including control) of the above-described embodiment (including modified examples), and can be appropriately changed. In particular, the processing tank 2 in which the food F is housed, the depressurizing means 3 having a water-sealed vacuum pump 9 for sucking and discharging the gas in the processing tank 2 to the outside, and the depressurized processing tank 2 to discharge the outside air. Reintroducing pressure means 4, a pressure sensor 31 for detecting the pressure in the processing tank 2, a water temperature sensor 32 for detecting the temperature of the water supplied to the vacuum pump 9 or the sealing water in the vacuum pump 9, and the respective means 3 , 4 for controlling the pressure inside the processing tank 2 by the pressure reducing means 3 and the saturation temperature at the pressure detected by the pressure sensor 31 falls below the “temperature detected by the water temperature sensor 32+set value” (a ) Increase the amount of water supplied to the vacuum pump 9 or (b) supply the amount of water to the vacuum pump 9 so that the saturation temperature at the pressure detected by the pressure sensor 31 is equal to or higher than the "temperature detected by the water temperature sensor 32 + set value". Other configurations can be appropriately changed as long as the above is adjusted.

Further, although the steam ejector 6 is provided as the depressurizing means 3 in the above-mentioned embodiment, the installation of the steam ejector 6 may be omitted in some cases. In that case, steps S6 and S7 may be omitted in FIG.

Further, in the above-described embodiment, the water supply flow rate to the vacuum pump 9 is such that only the first water sealing valve 13 of the first water sealing valve 13 and the second water sealing valve 14 is opened or the second water sealing valve 14 is used. Although the flow rate is switched in two steps depending on whether or not it is opened, it may be changed in multiple steps or steplessly. Further, if the first water sealing valve 13 is provided not in the upstream water sealing passage 12c but in the first water sealing passage 12a and the first constant flow valve 15 and the second constant flow valve 16 have different flow rates, The flow rate may be switched by selectively opening the first water sealing valve 13 and the second water sealing valve 14.

Furthermore, in the above-described embodiment, the vacuum cooling device 1 has been described as a cooling-only machine, but it can be appropriately modified as long as it has a vacuum cooling function. For example, a steam cooling device or a saturated steam cooking device may be provided by including a heating device using steam. Alternatively, it may be configured as a cold air vacuum composite cooling device by including a cold air cooling means using a refrigerator or a fan.

DESCRIPTION OF SYMBOLS 1 Vacuum cooling device 2 Processing tank 3 Decompression means 4 Recompression 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 Channel 11 Ejector Steam Supply Valve 12 Sealing Water Supply Channel (12a: First Sealing Channel, 12b: Second Sealing Channel, 12c: Upstream Sealing Channel, 12d: Downstream Sealing Channel)
13 1st water sealing valve 14 2nd water sealing valve 15 1st constant flow valve 16 2nd constant flow valve 17 Normal temperature water supply channel 18 Normal temperature water supply valve 19 Cold water supply channel 20 Cold water supply valve 21 Common water supply channel 22 Heat exchange water supply Channel 23 Heat exchange drainage channel 24 Cold water return channel 25 Drainage outlet channel 26 Cold water return valve 27 Drainage outlet valve 28 Air supply passage 29 Air filter 30 Air supply valve 31 Pressure sensor 32 Water temperature sensor

Claims (4)

A processing tank in which food is stored, a depressurizing means having a water-sealed vacuum pump for sucking and discharging the gas in the processing tank to the outside, and a pressure-reducing means for introducing outside air into the depressurized processing tank, A pressure sensor for detecting the pressure in the processing tank, a water temperature sensor for detecting the temperature of water supplied to the vacuum pump or sealing water in the vacuum pump, and a control means for controlling the respective means,
When the saturation temperature at the pressure detected by the pressure sensor falls below “the temperature detected by the water temperature sensor+the set value” while the pressure in the processing tank is being reduced by the pressure reducing means, (a) the amount of water supplied to the vacuum pump is increased. Alternatively, (b) the amount of water supplied to the vacuum pump is adjusted so that the saturation temperature at the pressure detected by the pressure sensor becomes equal to or higher than the “temperature detected by the water temperature sensor+set value”. . As a water supply path to the vacuum pump, a first sealed water path having a first constant flow valve, and a parallel portion of a second sealed water path having a second constant flow valve,
While the water is being supplied to the vacuum pump via the first water sealing passage, the saturation temperature at the pressure detected by the pressure sensor is “the temperature detected by the water temperature sensor+the set value” while the pressure in the processing tank is being reduced by the pressure reducing means. When it falls below, in place of or in addition to the first sealed water passage, water is supplied to the vacuum pump through the second sealed water passage. As a water supply passage to the vacuum pump, a parallel portion of a first water seal passage having a constant flow valve and a second water seal passage having a flow rate adjusting valve,
While the water is being supplied to the vacuum pump via the first water sealing passage, the saturation temperature at the pressure detected by the pressure sensor is “the temperature detected by the water temperature sensor+the set value” while the pressure in the processing tank is being reduced by the pressure reducing means. The opening degree of the flow rate adjusting valve is adjusted so that the saturation temperature at the pressure detected by the pressure sensor becomes equal to or higher than “the temperature detected by the water temperature sensor+the set value” when the temperature falls below the temperature. Vacuum cooling device. As the pressure reducing means, a steam ejector is further provided.
When the steam ejector is operated before increasing the water supply amount to the vacuum pump, the water supply amount to the vacuum pump is increased when the steam ejector is operated. The vacuum cooling device according to item 1.

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