JP2020099257A - Vacuum cooling device and vacuum cooling method - Google Patents

Abstract

To reduce useless consumption of water and electric power by shortening operation time during backup operation mode where only normal temperature water is used as water supplied to a water-sealed vacuum pump.SOLUTION: A vacuum cooling device comprises: a processing tank 2 in which food F is stored; depressurization means 3 having a water-sealed vacuum pump 11 for sucking and discharging gas in the processing tank 2 to the outside; pressure-recovering means 4 for introducing outside air into the decompressed room of the processing tank 2; a product temperature sensor 38 for detecting the temperature of the food F stored in the processing tank 2; a water temperature sensor 39 for detecting the temperature of water supplied to the vacuum pump 11; and control means. When the temperature detected by the product temperature sensor 38 becomes equal to or lower than "the temperature detected by the water temperature sensor 39+a set value" during depressurizing the inside of the processing tank 2 by the depressurization means 3, the depressurization in the processing tank 2 is stopped. In a case where the product temperature sensor 38 is replaced with a pressure sensor 37, the depressurization in the processing tank 2 may be stopped when saturation temperature at the pressure detected by the pressure sensor 37 becomes equal to or lower than "temperature detected by the water temperature sensor 39+a set value".SELECTED DRAWING: Figure 1

Description

The present invention relates to a vacuum cooling device and a vacuum cooling method for cooling food by reducing the pressure in a processing tank.

Conventionally, as disclosed in Patent Document 1 below, a vacuum provided with a heat exchanger (6) for steam condensation and a water-sealed vacuum pump (7) as means for reducing the pressure in the cooling tank (4). Cooling devices are known. In this apparatus, normal temperature water and cold water can be switched as water for the heat exchanger (6) and water for sealing the vacuum pump (7). Specifically, the heat exchanger (6) and the vacuum pump (7) are supplied with normal temperature water from the normal temperature water supply line (24) and cold water from the cold water tank (38) cooled by the chiller (25). It is possible to supply by switching. Then, the water that has passed through the heat exchanger (6) is drained from the drain line (31) or returned to the cold water tank (38).

In this device, first, as a standby step, water in the cold water tank (38) is circulated between the chiller (25) and cooled (FIG. 2 of Patent Document 1). Then, as an initial cooling step, the vacuum pump (7) is operated while the water flow through the heat exchanger (6) is stopped, and room temperature water is supplied as sealing water to reduce the pressure in the cooling tank (4). (FIG. 3 of Patent Document 1). After that, as the middle stage cooling step, water flow through the heat exchanger (6) is started (FIG. 4 of Patent Document 1), and as the latter stage cooling step, water flow through the heat exchanger (6) and the vacuum pump (7). The sealing water of the above is switched from normal temperature water to cold water to further reduce the pressure in the cooling tank (4) (FIG. 5 of Patent Document 1). When passing cold water through the heat exchanger (6), the cold water that has passed through the heat exchanger (6) is returned to the cold water tank (38).

JP-A-2004-170060 (paragraph 0046-0053, FIG. 1-5)

In the vacuum cooling device that operates by switching between normal temperature water and cold water as water supply to the heat exchanger and vacuum pump, when the chiller fails or is overloaded (when the water temperature in the cold water tank exceeds the upper limit temperature), the cold water There is a case where it is desired to operate only in normal temperature water without using (operating in backup operation mode).

Even if you have set as the cooling end condition whether the product temperature is below the cooling target temperature or whether the cooling time exceeds the maximum cooling time, in the backup operation mode, it is usually accompanied by using normal temperature water, The cooling to the cooling target temperature cannot be performed, and the elapse of the maximum cooling time is a substantial ending condition. Therefore, even if the pressure inside the tank reaches the limit (the limit of the degree of vacuum that can be reached), in other words, even if it is not possible to further cool it due to the pressure reduction capability, it is necessary to wait for the maximum cooling time to elapse. Therefore, time and energy (water and electric power of the vacuum pump) may be wasted.

Further, if the water temperature in the cold water tank exceeds the upper limit temperature and the backup operation mode is switched to normal temperature water suddenly, there are the above-mentioned adverse effects. Therefore, it is preferable to suppress this in advance. If it is possible to detect that the water temperature in the cold water tank has risen to some extent and delay the timing of switching from room temperature water to cold water in advance, the cooling load of the chiller can be reduced and switching to the backup operation mode can be suppressed. .. If the transition to the backup operation mode can be suppressed in advance as much as possible, it is possible to reduce unnecessary consumption of time and energy (water or electric power of the vacuum pump) in the backup operation mode.

Therefore, the problem to be solved by the present invention is to realize a vacuum cooling device and a vacuum cooling method that can reduce operating time and waste of water and electric power consumption. In particular, in a vacuum cooling device capable of switching between a normal operation mode and a backup operation mode, it is an object to shorten the operation time and reduce waste of water and power consumption when operating in the backup operation mode.

The present invention has been made to solve the above-mentioned problems. The invention according to claim 1 is a water-sealing type tank for sucking and discharging a processing tank containing food and a gas in the processing tank to the outside. A depressurizing unit having a vacuum pump, a depressurizing unit for introducing outside air into the depressurized processing tank, and a control unit for controlling each unit, and a pressure sensor for detecting the pressure in the processing tank, A water temperature sensor that includes at least one of a product temperature sensor that detects the temperature of food contained in the processing tank, and that detects the temperature of water supplied to the vacuum pump or sealing water in the vacuum pump. While decompressing the inside of the processing tank by the decompression means, the detection value of each sensor is monitored, and the detection temperature of the product temperature sensor or the saturation temperature at the detection pressure of the pressure sensor is “the water temperature sensor. The vacuum cooling device is characterized in that the depressurization in the processing tank is stopped under the condition that the detected temperature + the set value of "1.

According to the first aspect of the present invention, at least one of a pressure sensor that detects the pressure in the processing tank and an article temperature sensor that detects the temperature of the food contained in the processing tank is provided. , A water temperature sensor for detecting the temperature of the water supplied to the vacuum pump or the sealing water in the vacuum pump. Then, while decompressing the inside of the processing tank by the decompression means, the detection value of each sensor is monitored, and the detection temperature of the product temperature sensor or the saturation temperature at the detection pressure of the pressure sensor is “the detection temperature of the water temperature sensor+the set value”. The pressure reduction in the processing tank is stopped under the following conditions. Depending on the temperature of the water supplied to the vacuum pump or the sealing water in the vacuum pump, the reaching limit of the tank pressure, and thus the cooling limit of food, is determined. It is possible to prevent wasteful operation even if the above cooling cannot be performed effectively. As a result, it is possible to reduce operating time and reduce waste of water and electric power consumption as compared with a case where cooling is simply performed until the maximum cooling time elapses.

According to a second aspect of the present invention, the depressurizing means includes a heat exchanger for vapor condensation in addition to the vacuum pump, and normal temperature water and cold water are switched as water supply to the heat exchanger and the vacuum pump. It is possible, while decompressing the inside of the processing tank using normal temperature water as water supply to the heat exchanger and the vacuum pump, the temperature detected by the temperature sensor, or the saturation temperature at the pressure detected by the pressure sensor, The vacuum cooling device according to claim 1, wherein when the set time elapses after the temperature becomes equal to or lower than the “detected temperature of the water temperature sensor+the set value”, the depressurization in the processing tank is stopped.

According to the second aspect of the present invention, the temperature detected by the temperature sensor or the saturation temperature at the pressure detected by the pressure sensor is reduced while decompressing the inside of the processing tank by using room temperature water as water supply to the heat exchanger and the vacuum pump. , When the set time elapses after the temperature becomes equal to or lower than “the temperature detected by the water temperature sensor+the set value”, the depressurization in the processing tank is stopped. By controlling based on the temperature and the time, it is possible to more reliably and stably complete the cooling in the reaching limit region.

In the invention according to claim 3, as the depressurizing means, a heat exchanger for vapor condensation is provided in addition to the vacuum pump, the feed water to the heat exchanger and the vacuum pump is stored, and the stored water is stored by a chiller. It has a chilled water tank that can be cooled, and can be operated by switching between normal operation mode and backup operation mode.In the normal operation mode, when the product temperature falls below the water supply switching temperature, water supply to the heat exchanger and the vacuum pump is performed. Is switched from room temperature water to cold water to decompress the inside of the processing tank, and in the backup operation mode, using room temperature water as water supply to the heat exchanger and the vacuum pump to decompress the inside of the processing tank, The vacuum cooling device according to claim 1 or 2, wherein the feed water switching temperature is changed based on a water temperature in a cold water tank.

According to the third aspect of the invention, in the normal operation mode, when the product temperature becomes equal to or lower than the water supply switching temperature, normal temperature water is switched to cold water to depressurize the inside of the treatment tank, while in the backup operation mode, cold water is not used and normal temperature water is used. Is used to reduce the pressure inside the processing tank. Then, the water supply switching temperature in the normal operation mode can be changed based on the water temperature in the cold water tank. The load of the chiller can be suppressed by monitoring the load of the chiller based on the water temperature in the cold water tank and adjusting the timing of switching from normal temperature water to cold water.

In the invention according to claim 4, when the water temperature in the cold water tank becomes equal to or higher than the mode switching temperature, the normal operation mode is switched to the backup operation mode, and the water temperature in the cold water tank is a predetermined temperature lower than the mode switching temperature. The vacuum cooling device according to claim 3, wherein the water supply switching temperature in the normal operation mode is lowered when the above is achieved.

According to the invention described in claim 4, when the water temperature in the cold water tank becomes equal to or higher than the predetermined temperature lower than the mode switching temperature, the water supply switching temperature in the normal operation mode is lowered to thereby switch the normal temperature water to the cold water. Can be delayed. As a result, it is possible to suppress an increase in water temperature in the cold water tank and suppress switching to the backup operation mode.

The invention according to claim 5 is a vacuum cooling method for cooling food in the treatment tank by decompressing the inside of the treatment tank by using a pressure reducing means having a water-sealed vacuum pump. The temperature of the food in the tank, or the saturation temperature at the pressure in the processing tank is less than or equal to "the temperature of water supplied to the vacuum pump + set value" or less than "the temperature of sealed water in the vacuum pump + set value". The vacuum cooling method is characterized in that the depressurization in the processing tank is stopped under the condition that

According to the fifth aspect of the invention, the food in the treatment tank is cooled by reducing the pressure inside the treatment tank by using the decompression means having a water-sealed vacuum pump. Then, the temperature of the food in the treatment tank or the saturation temperature at the pressure in the treatment tank is less than or equal to the "water supply temperature to the vacuum pump + set value" or less than the "sealing water temperature in the vacuum pump + set value". The pressure reduction in the processing tank is stopped under the condition that Depending on the temperature of the water supplied to the vacuum pump or the sealing water in the vacuum pump, the reaching limit of the tank pressure, and thus the cooling limit of food, is determined. It is possible to prevent wasteful operation even if the above cooling cannot be performed effectively. As a result, it is possible to reduce operating time and reduce waste of water and electric power consumption as compared with a case where cooling is simply performed until the maximum cooling time elapses.

Further, in the invention according to claim 6, as the depressurizing means, a heat exchanger for vapor condensation is provided in addition to the vacuum pump, and normal temperature water and cold water are used as water supply to the heat exchanger and the vacuum pump. The heat exchanger and the vacuum pump can be decompressed in the treatment tank by using room temperature water as water supply to the heat exchanger and the vacuum pump, the temperature of the food in the treatment tank, or the saturation temperature at the pressure in the treatment tank. If the set time elapses after the temperature becomes equal to or lower than the "water supply temperature to the vacuum pump + set value" or the set time elapses after the temperature becomes equal to or lower than the "sealing water temperature in the vacuum pump + set value", The vacuum cooling method according to claim 5, wherein the pressure reduction in the tank is stopped.

According to the invention as set forth in claim 6, while decompressing the inside of the treatment tank by using room temperature water as water supply to the heat exchanger and the vacuum pump, the temperature of the food in the treatment tank or the saturation temperature at the pressure in the treatment tank. However, if the set time elapses after the temperature falls below the “water supply temperature to the vacuum pump + set value”, or if the set time elapses after the “sealed water temperature inside the vacuum pump + set value” falls, Stop decompression. By controlling based on the temperature and the time, it is possible to more reliably and stably complete the cooling in the reaching limit region.

According to the vacuum cooling device and the vacuum cooling method of the present invention, the operating time can be shortened and waste of water and electric power consumption can be reduced. In particular, in the vacuum cooling device capable of switching between the normal operation mode and the backup operation mode, when operating in the backup operation mode, it is possible to shorten the operation time and reduce waste of water and power consumption.

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 flow chart which shows the contents of operation in the normal operation mode. It is a flowchart which shows the operation content in backup operation mode.

Hereinafter, specific examples of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing a 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 this embodiment includes a processing tank 2 in which the food F is stored, a decompression unit 3 for sucking and discharging the gas in the processing tank 2 to the outside, and an outside air introduced into the decompressed processing tank 2. Inside the processing tank 2 by controlling the cooling means 4 for storing the water used in the decompression means 3 and the cold water tank 6 capable of cooling the stored water by the chiller 5, the respective means 3, 4 and the chiller 5. The control means (illustration omitted) which cools the foodstuff F is provided.

The processing tank 2 is a hollow container that withstands the 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 processing tank 2, and by closing the door, the opening of the processing 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 steam ejector 8, a heat exchanger 9 for steam condensation, a check valve 10, and a water-sealed vacuum pump 11 in the exhaust path 7 from the inside of the processing tank 2. ..

The vapor ejector 8 is provided with a suction port 8a connected to the processing tank 2, and the vapor from the ejector steam supply passage 12 can be ejected from a nozzle from the inlet 8b to the outlet 8c. By ejecting steam from the inlet 8b toward the outlet 8c, the gas in the processing tank 2 is also sucked and discharged to the outlet 8c through the suction port 8a. By operating the opening and closing of the ejector steam supply valve 13 provided in the ejector steam supply passage 12, the operation of the steam ejector 8 can be switched.

The heat exchanger 9 is an indirect heat exchanger that exchanges heat without mixing the fluid in the exhaust passage 7 and the cooling water. The heat exchanger 9 allows the steam in the exhaust passage 7 to be cooled and condensed by cooling water.

The vacuum pump 11 is a water-sealed type in this embodiment, and as is well known, it is operated while supplying water called sealing water. Therefore, water is supplied to the water supply port 11 a of the vacuum pump 11 via the sealed water supply channel 14. When the vacuum pump 11 is operated while supplying water from the sealed water supply passage 14, the vacuum pump 11 sucks gas from the intake port 11b and exhausts and drains the gas to the exhaust port 11c. The vacuum pump 11 may be on/off controlled, or the output thereof may be adjustable. For example, the vacuum pump 11 can change the drive frequency of the motor and thus the number of rotations by using an inverter.

The pressure restoration means 4 is a 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 means 4 is provided with an air filter 16 and an air supply valve 17 in order in the air supply passage 15 into the processing tank 2. When the air supply valve 17 is opened in a state where the inside of the processing tank 2 is depressurized, the outside air is introduced into the processing tank 2 through the air filter 16 and the pressure inside the processing tank 2 can be restored. The air supply valve 17 is preferably composed of a valve whose opening degree can be adjusted.

The chiller 5 includes a refrigerator (not shown) and cools the water from the cold water tank 6. As is well known, the refrigerator includes a compressor, a condenser, an expansion valve and an evaporator, and executes a refrigeration cycle of compression, condensation, expansion and evaporation of a refrigerant. Then, in the evaporator, heat is exchanged without mixing the refrigerant and water to cool the water from the cold water tank 6.

Water can be appropriately supplied to the cold water tank 6 through the makeup water passage 18. In this embodiment, normal temperature water is appropriately supplied to the cold water tank 6 from the makeup water passage 18 by the ball tap 19, and the inside of the cold water tank 6 is maintained at the set water level.

The stored water in the cold water tank 6 can be cooled by the chiller 5. To that end, the cold water tank 6 is connected to the chiller 5 via the chiller inlet channel 20. A water supply pump 21 is provided in the chiller inlet passage 20. When the water pump 21 is operated, the water from the cold water tank 6 is passed through the chiller inlet passage 20 to the chiller 5 (more specifically, the evaporator of the refrigerator) to be cooled, and the chiller outlet passage 22 is cooled as cold water. Is derived to.

The chiller outlet passage 22 from the chiller 5 is branched into a cold water supply passage 23 and a circulation return passage 24. It is possible to switch whether the cold water from the chiller outlet passage 22 is sent to the cold water supply passage 23 to the heat exchanger 9 or the vacuum pump 11 or the circulation return passage 24 to the cold water tank 6. In the present embodiment, the cold water from the chiller 5 is sent to the cold water supply passage 23 or the circulation return passage 24 by the switching valve 25 formed of a three-way valve provided at the branch portion between the cold water supply passage 23 and the circulation return passage 24. Can be switched. Specifically, the switching valve 25 can switch between a “water supply position” that allows the chiller outlet passage 22 and the cold water supply passage 23 to communicate with each other and a “circulation position” that allows the chiller outlet passage 22 and the circulation return passage 24 to communicate with each other. It is said that

The water supply system to the heat exchanger 9 and the vacuum pump 11 will be further described. In this embodiment, the heat exchanger 9 and the vacuum pump 11 can be supplied by switching between normal temperature water and cold water. Cold water is water that has been cooled by the chiller 5, and normal temperature water is water that cannot be cooled as such.

Normal temperature water can be supplied to the heat exchanger 9 and the vacuum pump 11 through the normal temperature water supply passage 26, while cold water can be supplied through the cold water supply passage 23. The room-temperature water supply passage 26 is provided with a room-temperature water supply valve 27 and a check valve 28. The normal temperature water supply passage 26 and the cold water supply passage 23 downstream of the valves 27 and 28 are joined to form a common water supply passage 29. The common water supply passage 29 is branched into a heat exchange water supply passage 30 to the heat exchanger 9 and a sealed water supply passage 14 to the vacuum pump 11. A sealing water supply valve 31 is provided in the sealing water supply passage 14.

The heat exchanger 9 is supplied with water via the heat exchange water supply passage 30 and discharged through the heat exchange drainage passage 32. The heat exchange drainage channel 32 is branched into a cold water return channel 33 to the cold water tank 6 and a drainage outlet channel 34 to the outside. The cold water return passage 33 is provided with a cold water return valve 35, and the drainage outlet passage 34 is provided with a drainage outlet valve 36. By the cold water return valve 35 and the drain outlet valve 36, the water after passing through the heat exchanger 9 is returned to the cold water tank 6 or discharged from the drain outlet passage 34, or the water is not passed through the heat exchanger 9. Whether to block water (that is, to close the cooling water outlet side of the heat exchanger 9) can be switched. In the illustrated example, the circulation return passage 24 from the switching valve 25 and the cold water return passage 33 from the cold water return valve 35 join and are connected to the cold water tank 6.

When supplying cold water to the heat exchanger 9, the chiller 5 and the water supply pump 21 may be operated and the switching valve 25 may be set to the water supply position. Thereby, the stored water in the cold water tank 6 is supplied to the heat exchanger 9 through the chiller inlet passage 20, the chiller 5, the chiller outlet passage 22, the cold water supply passage 23, the common water supply passage 29, and the heat exchange water supply passage 30. To be done. Further, if the sealing water supply valve 31 is opened, the cold water is supplied to the vacuum pump 11 via the sealing water supply passage 14. Further, by opening the cold water return valve 35 with the drain outlet valve 36 closed, the cold water after passing through the heat exchanger 9 is returned to the cold water tank 6.

On the other hand, when supplying room temperature water to the heat exchanger 9, the room temperature water supply valve 27 may be opened with the switching valve 25 in the circulation position. Also in this case, if the sealing water supply valve 31 is further opened, the room temperature water is supplied to the vacuum pump 11 via the sealing water supply passage 14. Further, by opening the drain outlet valve 36 with the cold water return valve 35 closed, the room temperature water after passing through the heat exchanger 9 is discharged from the drain outlet passage 34.

On the other hand, regardless of whether normal temperature water or cold water is supplied to the common water supply passage 29, the cold water return valve 35 and the drainage outlet valve 36 can be closed to stop the water flow through the heat exchanger 9. In that state, by opening the water sealing water supply valve 31, normal temperature water or cold water can be supplied to the vacuum pump 11.

The vacuum cooling device 1 includes a pressure sensor 37 that detects the pressure in the processing tank 2, an article temperature sensor 38 that detects the temperature of the food F stored in the processing tank 2, and a water supply (normal temperature water) to the vacuum pump 11. Or a water temperature sensor 39 for detecting the temperature of cold water). In this embodiment, the water temperature sensor 39 is provided in the sealed water supply passage 14, but may be provided in the common water supply passage 29 or the like depending on the case.

Further, the cold water tank 6 is provided with a stored water temperature sensor 40 for detecting the temperature of the stored water, while the chiller outlet passage 22 is provided with a cold water temperature sensor 41 for detecting the temperature of the cold water. In the present embodiment, the chilled water temperature sensor 41 is provided in the chiller outlet passage 22, but it may be built in the chiller 5, or in some cases, provided in the chiller inlet passage 20 or the like.

In addition, the cold water tank 6 is provided with, for example, a float switch 42 as a low water level detector. As described above, the cold water tank 6 is maintained at the set water level by the ball tap 19, but if the water level falls below the lower limit water level due to some malfunction, an abnormality can be detected by the float switch 42.

The control means is a controller (not shown) that controls the respective means 3, 4 and the chiller 5 based on the detection signals of the respective sensors 37 to 42 and the elapsed time. Specifically, the chiller 5, the vacuum pump 11, the water supply pump 21, the ejector vapor supply valve 13, the air supply valve 17, the switching valve 25, the room temperature water supply valve 27, the sealing water supply valve 31, the cold water return valve 35, the drainage outlet. In addition to the valve 36, a pressure sensor 37, a product temperature sensor 38, a water temperature sensor 39, a stored water temperature sensor 40, a cold water temperature sensor 41, a float switch 42, etc. are connected to the controller. Then, the controller performs vacuum cooling of the food F in the processing tank 2 according to a predetermined procedure (program). Hereinafter, an example of an operating method (vacuum cooling method) of the vacuum cooling device 1 will be described.

The vacuum cooling device 1 of the present embodiment can be operated by switching between the normal operation mode and the backup operation mode. Although details will be described later, in the normal operation mode, the water supply to the heat exchanger 9 and the vacuum pump 11 is switched from room temperature water to cold water during operation to depressurize the inside of the processing tank 2, while in the backup operation mode, cold water is supplied. The inside of the processing tank 2 is decompressed by using only normal temperature water without using.

The vacuum cooling device 1 is basically operated in the normal operation mode, but in a predetermined case, it is automatically or manually switched to the backup operation mode and operated. For example, the stored water temperature sensor 40 detects that the temperature of the stored water in the cold water tank 6 is equal to or higher than the upper limit temperature (mode switching temperature), and switches to the backup operation mode. Further, the fact that the stored water in the cold water tank 6 has fallen below the lower limit water level is detected by the float switch 42, and the backup operation mode is switched to. Alternatively, the failure of the chiller 5 is detected, and the operation mode is switched to the backup operation mode. Hereinafter, a specific example of the operation content in each operation mode will be described.

≪Normal operation mode≫
FIG. 2 is a flowchart showing the operation content in the normal operation mode.

Before the start of operation, the air supply valve 17 is opened, the switching valve 25 is in the circulation position (communication state between the chiller outlet passage 22 and the circulation return passage 24), and the other valves are closed. is there. Moreover, the chiller 5, the vacuum pump 11, and the water supply pump 21 are stopped.

The vacuum cooling device 1 starts the standby process when the power is turned on, and then when the start button is pressed to instruct the start of the cooling operation, the pressure inside the processing tank 2 is reduced according to FIG. Cool F. Although the food F is stored in the processing tank 2 after the standby process, it may be stored before or during the standby process before the cooling operation is started.

In the standby process, the stored water in the cold water tank 6 is circulated and cooled with the chiller 5. Specifically, the chiller 5 and the water supply pump 21 are operated in a state where the chiller outlet passage 22 and the circulation return passage 24 are communicated with each other by the switching valve 25. The cold water tank 6 is appropriately supplied with water by a ball tap 19 and maintained at a set water level.

By operating the water supply pump 21, the stored water in the cold water tank 6 is sent to the chiller 5 via the chiller inlet passage 20 to be cooled, and the stored water in the cold water tank 6 is passed through the chiller outlet passage 22 and the circulation return passage 24. Returned to. At this time, the chiller 5 is controlled so that the temperature detected by the cold water temperature sensor 41 is maintained at the set temperature (for example, 7° C.). Here, the compressor is inverter-controlled, but on-off control may be performed depending on the case.

The cooling operation shown in FIG. 2 is started when the detected temperature of the stored water temperature sensor 40 becomes equal to or lower than the set temperature or when a predetermined start button is pressed. After that, the water supply pump 21 basically continues to operate. During that time, the chiller 5 basically continues to operate, but as described above, the inverter control (inverter control so as to maintain the outlet side water temperature at the set temperature) is performed, so that the output is based on the water temperature passed through the chiller 5. Adjusted automatically.

When the cooling operation is started, first, the air supply valve 17 is closed, and while the water flow through the heat exchanger 9 is stopped, ambient temperature water is supplied as sealing water for the vacuum pump 11, and the treatment tank 2 is operated by the vacuum pump 11. The inside pressure is reduced (S1). Specifically, the air supply valve 17 is closed to seal the inside of the processing tank 2. Further, by keeping the cold water return valve 35 and the drain outlet valve 36 closed, water flow through the heat exchanger 9 is disabled. Further, the room temperature water supply valve 27 and the sealing water supply valve 31 are opened to supply the room temperature water as the sealing water to the vacuum pump 11, and the vacuum pump 11 is operated to reduce the pressure in the processing tank 2.

Then, when a predetermined water flow start condition is satisfied, water flow through the heat exchanger 9 is started (S2, S3). In the present embodiment, when the temperature detected by the product temperature sensor 38 becomes equal to or lower than the water flow start temperature (for example, 60° C.), the water flow through the heat exchanger 9 is started. At this time, the water supply to the heat exchanger 9 and the vacuum pump 11 is switched to cold water. That is, the normal temperature water supply valve 27 is closed, while the switching valve 25 is switched to the water passage position (the communication state between the chiller outlet passage 22 and the cold water supply passage 23). Further, by opening the cold water return valve 35, the cold water that has passed through the heat exchanger 9 is returned to the cold water tank 6.

After that, when the predetermined ejector operating condition is satisfied, the steam ejector 8 is operated (S4, S5). In the present embodiment, when the temperature detected by the product temperature sensor 38 becomes equal to or lower than the ejector operating temperature (for example, 30° C.), the ejector steam supply valve 13 is opened to operate the vapor ejector 8.

By closing the air supply valve 17 during the above-described series of depressurization, the pressure in the processing tank 2 can be rapidly lowered to rapidly cool the food F (rapid cooling control). However, in some cases, the food F may be gradually cooled while adjusting the opening degree of the air supply valve 17 and thus the pressure in the processing tank 2 (gradual cooling control).

In any case, the food F in the processing tank 2 can be cooled by the reduced pressure in the processing tank 2. Then, as a cooling end condition, for example, when the temperature detected by the product temperature sensor 38 becomes equal to or lower than the cooling target temperature (for example, 10° C.), the depressurization in the processing tank 2 is stopped (S6, S7). Specifically, the ejector steam supply valve 13, the sealing water supply valve 31, and the cold water return valve 35 are closed, and the switching valve 25 is switched to the circulation position (the communication state between the chiller outlet passage 22 and the circulation return passage 24). The steam ejector 8 and the vacuum pump 11 are stopped, and the water flow through the heat exchanger 9 is stopped.

Then, the air supply valve 17 may be opened to restore the pressure in the processing tank 2 to atmospheric pressure. At this time, the pressure inside the processing tank 2 can be gradually restored while adjusting the opening degree of the air supply valve 17. After switching the switching valve 25 to the circulation position, the standby process described above may be performed in preparation for the next cooling operation.

≪Backup operation mode≫
FIG. 3 is a flowchart showing the operation contents in the backup operation mode.

In the backup operation mode, room temperature water is used as the water supply to the heat exchanger 9 and the vacuum pump 11 without using cold water when the pressure in the processing tank 2 is reduced. Further, the steam ejector 8 is not operated. Furthermore, the cooling end conditions are different. The details will be described below.

In the backup operation mode, the standby process (the cooling process of the stored water in the cold water tank 6) is basically not performed because the chiller 5 may malfunction or the water level in the cold water tank 6 may be abnormal. However, if the standby process can be executed, it may be executed.

Also in the backup operation mode, as in the normal operation mode, when a predetermined start button is pressed, the cooling operation shown in FIG. 3 is started.

When the cooling operation is started, first, the air supply valve 17 is closed, and while the water flow through the heat exchanger 9 is stopped, ambient temperature water is supplied as sealing water for the vacuum pump 11, and the treatment tank 2 is operated by the vacuum pump 11. The inside pressure is reduced (S11). Specifically, the air supply valve 17 is closed to seal the inside of the processing tank 2. Further, by keeping the cold water return valve 35 and the drain outlet valve 36 closed, water flow through the heat exchanger 9 is disabled. Further, the room temperature water supply valve 27 and the sealing water supply valve 31 are opened to supply the room temperature water as the sealing water to the vacuum pump 11, and the vacuum pump 11 is operated to reduce the pressure in the processing tank 2.

Then, when the predetermined water flow start condition is satisfied, the water flow through the heat exchanger 9 is started (S12, S13). In the present embodiment, when the temperature detected by the product temperature sensor 38 becomes equal to or lower than the water passage start temperature (for example, 60° C.), the drain outlet valve 36 is opened to start water passage through the heat exchanger 9. At the start of water flow through the heat exchanger 9, it was switched to cold water in the normal operation mode, but kept at room temperature water in the backup operation mode. Then, the water used in the heat exchanger 9 is discharged from the drainage outlet passage 34.

After that, when the product temperature becomes equal to or lower than the “supply water temperature+set value”, the depressurization in the processing tank 2 is stopped (S14, S15). More preferably, when the set time elapses after the product temperature becomes equal to or lower than the “supply water temperature+set value”, the depressurization in the processing tank 2 is stopped. That is, the temperature detected by the product temperature sensor 38 and the water temperature sensor 39 are monitored during depressurization in the processing tank 2, and the temperature detected by the product temperature sensor 38 becomes equal to or lower than “the temperature detected by the water temperature sensor 39+the set value”. After a lapse of a set time from, the depressurization in the processing tank 2 is stopped. Specifically, the normal temperature water supply valve 27, the sealing water supply valve 31, and the drain outlet valve 36 are closed to stop the vacuum pump 11 and stop the water flow through the heat exchanger 9. Then, the air supply valve 17 may be opened to restore the pressure in the processing tank 2 to atmospheric pressure. The set value (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.

By determining the termination condition of the backup operation based on the relationship between the product temperature and the feed water temperature, not just the cooling time, it is possible to reduce the operation time and energy. That is, since the reaching limit of the tank pressure and thus the cooling limit of the food F are determined according to the temperature of the water supplied to the vacuum pump 11, the cooling is ended on the condition that it enters the limit region, and the operation is wastefully continued. Is prevented. As a result, the operation time can be shortened and the waste of water and electric power consumption can be reduced as compared with the case where the cooling is simply performed until the preset maximum cooling time elapses.

During depressurization in the treatment tank 2, the temperature detected by the product temperature sensor 38 and the water temperature sensor 39 is monitored to determine whether the product temperature is equal to or lower than the "water supply temperature + set value" or the product temperature is "supply water temperature + set value". When the set time elapses after the value becomes equal to or less than the "value", the depressurization in the processing tank 2 is stopped, but the pressure sensor 37 may be used instead of the product temperature sensor 38 to perform the following control. That is, the pressure detected by the pressure sensor 37 and the temperature detected by the water temperature sensor 39 are monitored during depressurization in the treatment tank 2, and the tank internal pressure conversion temperature (saturation temperature at the pressure detected by the pressure sensor 37) is set to “supply water temperature+setting”. When the set time elapses after the value “below” or the tank pressure conversion temperature becomes “water supply temperature+set value” or below, the depressurization in the processing tank 2 may be stopped. Even when the pressure sensor 37 is used for control, it is possible to obtain the same operational effect as when the product temperature sensor 38 is used for control.

Further, during depressurization in the processing tank 2, the detection values of the product temperature sensor 38 (or the pressure sensor 37) and the water temperature sensor 39 are monitored, and the product temperature (or the tank internal pressure conversion temperature) is “supply water temperature+set value. Or when the set time has elapsed after the product temperature (or the tank internal pressure conversion temperature) became below the "supply water temperature + set value", the depressurization in the processing tank 2 was automatically stopped by the controller. However, it may be configured as follows. That is, the product temperature (or tank internal pressure conversion temperature) is below the "water supply temperature + set value" or the product temperature (or tank internal pressure conversion temperature) is below the "water supply temperature + set value". After a lapse of time, the controller may give a notification to that effect by a notification means such as a buzzer or a lamp, and the decompression may be stopped manually based on the notification.

By the way, in the normal operation mode, when the product temperature becomes lower than or equal to a predetermined water supply switching temperature (which is the same as the water flow starting temperature of the heat exchanger 9 in the above-mentioned embodiment, it may be different), the heat exchanger 9 and the vacuum pump. Although the water supply to 11 is switched from room temperature water to cold water, the water supply switching temperature may be changed based on the water temperature in the cold water tank 6. When the water temperature in the cold water tank 6 rises, it is preferable to lower the feed water switching temperature and delay the timing of switching to cold water. For example, it can be configured as follows.

As a premise, as described above, as one of the switching conditions from the normal operation mode to the backup operation mode, the water temperature in the cold water tank 6 may be equal to or higher than the mode switching temperature (for example, 25° C.). In this case, when the water temperature in the cold water tank 6 becomes equal to or higher than a predetermined temperature (for example, 20° C.) lower than the mode switching temperature, it is preferable to lower the water supply switching temperature in the normal operation mode. For example, when the water temperature in the cold water tank 6 is lower than the predetermined temperature, the feed water switching temperature is set to the first set temperature (for example, 60° C.), while when the water temperature in the cold water tank 6 becomes equal to or higher than the predetermined temperature, the feed water switching temperature is set to the first temperature. The temperature is changed to a second set temperature (eg 40 to 50° C.) lower than the one set temperature. When the water supply switching temperature is lowered, the switching time from normal temperature water to cold water is delayed during the depressurization of the treatment tank 2 in the normal operation mode, and the use of cold water (and thus the cold water tank for cold water after use is delayed). (Return to 6) will be suppressed. Therefore, the rise of the water temperature in the cold water tank 6 (the load of the chiller) is suppressed, the stored water is suppressed from becoming the mode switching temperature or higher, and the switching to the backup operation mode is prevented.

Next, a modified example of the vacuum cooling device 1 of the present embodiment will be described.
In the above-described embodiment, the water temperature sensor 39 is provided in the sealed water supply passage 14 to monitor the temperature of the water supplied to the vacuum pump 11, but the water temperature sensor 39 is provided in the vacuum pump 11 to seal the inside of the vacuum pump 11. The temperature of the water may be monitored.

Also in this case, basically, the control can be performed in the same manner as the above-mentioned embodiment, but the set value of the cooling end condition in the backup operation mode (the set value of step S14) is changed. That is, in the above-described embodiment, the depressurization in the treatment tank 2 was stopped under the condition that the product temperature (or the tank internal pressure conversion temperature) was equal to or less than the “supply water temperature+set value (first set value)”, In this modification, the depressurization in the processing tank 2 is stopped under the condition that the product temperature (or the tank internal pressure conversion temperature) is equal to or lower than the “sealing water temperature+set value (second set value)”. Also in this case, the decompression may be stopped by manual stop based on the notification to the notification means instead of the automatic stop. It should be noted that the temperature of the condensate and the sealing water that is heated by the motor are higher than the temperature of the supply water. Therefore, the second set value of this 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 is omitted.

The vacuum cooling device 1 of the present invention is not limited to the configuration of the above-described embodiment, but can be modified as appropriate. In particular, (a) the processing tank 2 in which the food F is stored, the depressurizing means 3 having the water-sealed vacuum pump 11 for sucking and discharging the gas in the processing tank 2 to the outside, and the depressurized processing tank 2 The pressure sensor 37 for detecting the pressure in the processing tank 2 and the food F stored in the processing tank 2 are provided with the pressure-returning means 4 for introducing outside air into the processing tank 2 and the control means for controlling each means. At least one of the product temperature sensor 38 for detecting the temperature is provided, and a water temperature sensor 39 for detecting the temperature of the water supplied to the vacuum pump 11 or the sealing water in the vacuum pump 11 is provided. While the inside of the processing tank 2 is being depressurized by 3, the detection value of each sensor is monitored, and the saturation temperature at the detection temperature of the product temperature sensor 38 or the detection pressure of the pressure sensor 37 becomes "the detection temperature of the water temperature sensor 39+the set value. As long as the depressurization in the processing tank 2 is stopped on condition that it becomes the following, other configurations can be appropriately changed.

For example, in the above-described embodiment, the structure of the decompression unit 3 can be appropriately changed as long as it has the water-sealed vacuum pump 11. For example, although the steam ejector 8 is provided as the depressurizing means 3 in the above-described embodiment, the installation of the steam ejector 8 may be omitted depending on circumstances.

Furthermore, the vacuum cooling device 1 only needs to have at least a vacuum cooling function, and may have a heating function of the food F in the processing tank 2 in some cases. That is, after heating the food F in the processing tank 2, the food F may be vacuum-cooled in the same manner as in the above embodiment.

In the vacuum cooling method of the present invention, (x) a vacuum for cooling the food F in the processing tank 2 by depressurizing the processing tank 2 using the depressurizing means 3 having the water-sealed vacuum pump 11. In the cooling method, (y) the temperature of the food F in the treatment tank 2 or the saturation temperature at the pressure in the treatment tank 2 is equal to or lower than “the temperature of the water supplied to the vacuum pump 11+the set value” (preferably further If the depressurization in the treatment tank 2 is stopped under the condition that the set time elapses) or the “sealing water temperature in the vacuum pump 11+the set value” or less (preferably the set time elapses), Others can be changed appropriately. Therefore, if the conditions (x) and (y) are satisfied, it is not always necessary to use the vacuum cooling device 1 of the above embodiment. Further, when the depressurization is stopped based on the termination condition described in (y) above, when the notification means of the vacuum cooling device 1 notifies that the termination condition is satisfied, the decompression is manually performed based on the termination condition. May be stopped.

DESCRIPTION OF SYMBOLS 1 Vacuum cooling device 2 Processing tank 3 Decompression means 4 Recompression means 5 Chiller 6 Cold water tank 7 Exhaust passage 8 Steam ejector (8a: suction port, 8b: inlet, 8c: outlet)
9 heat exchanger 10 check valve 11 vacuum pump (11a: water supply port, 11b: intake port, 11c: exhaust port)
12 Ejector steam supply passage 13 Ejector steam supply valve 14 Sealing water supply passage 15 Air supply passage 16 Air filter 17 Air supply valve 18 Make-up water passage 19 Ball tap 20 Chiller inlet passage 21 Water pump 22 Chiller outlet passage 23 Cold water supply passage 24 Circulation return passage 25 Switching Valve 26 Room Temperature Water Supply Channel 27 Room Temperature Water Supply Valve 28 Check Valve 29 Common Water Supply Channel 30 Heat Exchange Water Supply Channel 31 Sealing Water Supply Valve 32 Heat Exchange Drainage Channel 33 Cold Water Return Channel 34 Drainage Exit Channel 35 Cold Water Return Valve 36 Drainage Outlet valve 37 Pressure sensor 38 Product temperature sensor 39 Water temperature sensor 40 Stored water temperature sensor 41 Cold water temperature sensor 42 Float switch

Claims (6)

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 control means for controlling each of the above means,
A pressure sensor for detecting the pressure in the processing tank, and an article temperature sensor for detecting the temperature of the food contained in the processing tank, with at least one sensor, water supply to the vacuum pump or the Equipped with a water temperature sensor that detects the temperature of the sealed water in the vacuum pump,
While decompressing the inside of the processing tank by the decompression unit, the detection value of each sensor is monitored, and the detection temperature of the product temperature sensor or the saturation temperature at the detection pressure of the pressure sensor is “the detection temperature of the water temperature sensor”. A vacuum cooling device, characterized in that the depressurization in the processing tank is stopped on condition that the value becomes equal to or less than a "set value". As the pressure reducing means, in addition to the vacuum pump, a heat exchanger for vapor condensation is provided,
As water supply to the heat exchanger and the vacuum pump, it is possible to switch between room temperature water and cold water,
While decompressing the inside of the processing tank using room temperature water as water supply to the heat exchanger and the vacuum pump, the detection temperature of the product temperature sensor, or the saturation temperature at the detection pressure of the pressure sensor, "the water temperature sensor The vacuum cooling device according to claim 1, wherein the depressurization in the processing tank is stopped when a set time elapses after being equal to or lower than the “detected temperature+set value”. As the pressure reducing means, in addition to the vacuum pump, a heat exchanger for vapor condensation is provided,
The water supply to the heat exchanger and the vacuum pump is stored, and a cold water tank capable of cooling the stored water by a chiller is provided,
It is possible to operate by switching between normal operation mode and backup operation mode,
In the normal operation mode, when the product temperature becomes equal to or lower than the water supply switching temperature, the water supply to the heat exchanger and the vacuum pump is switched from normal temperature water to cold water to reduce the pressure in the treatment tank,
In the backup operation mode, normal temperature water is used as water supply to the heat exchanger and the vacuum pump to reduce the pressure in the processing tank,
The vacuum cooling device according to claim 1 or 2, wherein the feed water switching temperature is changed based on a water temperature in the cold water tank. When the water temperature in the cold water tank becomes equal to or higher than the mode switching temperature, the normal operation mode is switched to the backup operation mode,
The vacuum cooling device according to claim 3, wherein when the water temperature in the cold water tank becomes equal to or higher than a predetermined temperature lower than the mode switching temperature, the water supply switching temperature in the normal operation mode is lowered. A vacuum cooling method for cooling the food in the processing tank by reducing the pressure in the processing tank using a pressure reducing means having a water-sealed vacuum pump,
The temperature of the food in the treatment tank or the saturation temperature at the pressure in the treatment tank is equal to or lower than "the temperature of the water supplied to the vacuum pump+the set value" or "the temperature of the sealed water in the vacuum pump+the set value". The vacuum cooling method is characterized in that the pressure reduction in the processing tank is stopped under the following conditions. As the pressure reducing means, in addition to the vacuum pump, a heat exchanger for vapor condensation is provided,
As water supply to the heat exchanger and the vacuum pump, it is possible to switch between room temperature water and cold water,
While decompressing the inside of the treatment tank by using room temperature water as water supply to the heat exchanger and the vacuum pump, the temperature of the food in the treatment tank, or the saturation temperature at the pressure in the treatment tank is “the vacuum pump. When the set time elapses after the temperature falls below the "supply water temperature + set value", or when the set time elapses after the "sealed water temperature inside the vacuum pump + set value", the depressurization in the treatment tank is stopped. The vacuum cooling method according to claim 5, wherein

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