JP2018204860A - Vacuum cooler - Google Patents

Abstract

To quickly vacuum-cool food while preventing bumping or boiling-over.SOLUTION: A device for decompressing a treatment tank to vacuum-cool food, is configured to monitor a food temperature and pressure in the treatment tank, and based on the monitoring information, repeat decompressing operation and retaining operation. In the decompressing operation, the device decompresses the treatment tank until the temperature difference between a food temperature TF in the treatment tank and a saturation temperature TS depending on the pressure in the treatment tank becomes a setting value ΔT1. In the retaining operation, the device retains the pressure in the treatment tank to pressure after the decompressing operation. For example, the device is configured to, based on the food temperature TF in the treatment tank and the saturation temperature TS depending on the pressure in the treatment tank, repeat the decompressing operation of decompressing the treatment tank until the temperature difference becomes the first setting value ΔT1, and the retaining operation of retaining the pressure in the treatment tank until the temperature difference becomes a second setting value ΔT2 smaller than the first setting value.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vacuum cooling device that depressurizes the inside of a processing tank to cool food.

  The vacuum cooling device disclosed in the following Patent Document 1 includes a rapid cooling step in which the inside of the treatment tank is depressurized to a set pressure (P1), and a slow cooling step in which the pressure inside the treatment tank is further reduced by lowering the decompression capacity than the rapid cooling step. And in order. The set pressure (P1) is set to a pressure that is higher by a margin pressure (P3) than the product temperature conversion pressure (P2) at which the saturated steam temperature in the treatment tank becomes equal to the temperature of the object to be cooled, and the margin pressure (P3 ) Is set to be smaller as the product temperature equivalent pressure (P2) is lower.

  In addition, the vacuum cooling device disclosed in Patent Document 2 below performs pressure reduction in the processing tank so that the pressure in the processing tank becomes a predetermined holding pressure, and the time change of the temperature of the object to be cooled is below a reference value. It is determined that the temperature of the object to be cooled has almost approached the saturation temperature equal to the holding pressure, and the pressure of the processing tank becomes a predetermined holding pressure that is reduced by a predetermined value from the predetermined holding pressure. The inside of the treatment tank is decompressed, and the determination of the change in temperature of the object to be cooled over time and the decompression by reducing the predetermined holding pressure are repeated.

JP 2010-181042 A (Claims, FIGS. 1 and 2) JP 2004-218958 A (Claims, FIGS. 1 to 3)

  In the invention described in Patent Document 1, the product is gradually cooled to a pressure that is higher than the product temperature conversion pressure by a marginal pressure, and then slowly cooled, but in the subsequent cooling process, the product temperature is not monitored and is set along a preset pressure curve. The decompression speed is adjusted to (paragraph [0044]). For this reason, in the slow cooling process, it is necessary to control the safety direction to prevent bumping and spilling, and there is a possibility that it takes time for cooling.

  In the invention described in Patent Document 2, the pressure is first reduced to a predetermined holding pressure, but the predetermined holding pressure is defined in advance (the opening degree of the motor-operated valve 6 at the time of pressure reduction), and the product temperature that changes every moment. (Paragraph [0050], S2 in FIG. 2). In addition, by closing the motorized valve every predetermined time, the predetermined holding pressure in the pressure holding process is lowered step by step. At each pressure holding process, the motor is held at a predetermined holding pressure according to the opening of the motorized valve. The actual pressure in the treatment tank is not monitored and has been achieved (paragraphs [0052]-[0059], FIG. 2). Further, the predetermined holding pressure is not determined in consideration of the product temperature. For this reason, there is a possibility that the optimum holding pressure according to the actual cooling situation may not be obtained.

  Therefore, the problem to be solved by the present invention is to provide a vacuum cooling device capable of rapidly cooling food while preventing bumping and spilling.

  The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 is an apparatus for vacuum-cooling food by decompressing the inside of the treatment tank, wherein the food temperature in the treatment tank is A pressure reducing operation for reducing the pressure in the treatment tank until a temperature difference between a food temperature in the treatment tank and a saturation temperature corresponding to the pressure in the treatment tank reaches a set value based on the monitoring information. The vacuum cooling apparatus is characterized in that the food in the processing tank is vacuum-cooled by repeating a holding operation for maintaining the pressure in the processing tank at the pressure after the pressure reducing operation.

  According to the first aspect of the invention, the product temperature and the tank pressure are monitored, and the pressure is reduced until the temperature difference between the product temperature and the tank saturation temperature (saturation temperature corresponding to the tank pressure) reaches a set value. By repeating the depressurizing operation and the holding operation for maintaining the pressure after the depressurizing operation, the food can be quickly cooled while preventing bumping and spilling.

  The invention according to claim 2 is a depressurization operation for depressurizing the inside of the treatment tank until the temperature difference between the food temperature in the treatment tank and a saturation temperature corresponding to the pressure in the treatment tank reaches a first set value, The food in the processing tank is vacuum-cooled by repeating a holding operation for holding the pressure in the processing tank until the temperature difference becomes a second set value smaller than the first set value. Item 2. The vacuum cooling device according to Item 1.

  According to the second aspect of the present invention, the temperature difference between the product temperature and the tank saturation temperature is monitored, and the decompression operation until the temperature difference reaches the first set value and the second set value. By repeating this holding operation, the food can be quickly cooled by simple control while preventing bumping and spilling.

  The invention according to claim 3 is a depressurization operation for depressurizing the inside of the treatment tank until a temperature difference between the food temperature in the treatment tank and a saturation temperature corresponding to the pressure in the treatment tank reaches a set value, and a set time. The vacuum cooling apparatus according to claim 1, wherein the food in the processing tank is vacuum-cooled by repeating a holding operation for maintaining the pressure in the processing tank until the time has elapsed.

  According to the third aspect of the present invention, the temperature difference between the product temperature and the tank saturation temperature is monitored, the pressure reducing operation until the temperature difference reaches the set value, and the holding operation until the set time elapses. By repeating the above, it is possible to quickly cool the food with simple control while preventing bumping and spilling.

Invention of Claim 4 is the said processing tank in which a foodstuff is accommodated, the pressure reduction means which attracts | sucks and discharges the gas in this processing tank outside, and depressurizes the inside of the said processing tank, The said processing tank in which pressure was reduced A holding means comprising: a return pressure means for introducing outside air into the processing tank to return the pressure in the processing tank; and a control means for controlling the pressure reducing means and the return pressure means to cool the food in the processing tank. In operation, the pressure in the said processing tank is hold | maintained using any one or more of following (a)-(e), The vacuum of any one of Claims 1-3 characterized by the above-mentioned. It is a cooling device.
(A) The air supply amount by the return pressure means is adjusted in a state where the pressure reducing means is operated.
(B) The number of rotations of the vacuum pump constituting the pressure reducing means is adjusted.
(C) The sealed water flow rate to the water-sealed vacuum pump constituting the pressure reducing means is adjusted.
(D) The sealing water temperature to the water-sealed vacuum pump constituting the pressure reducing means is adjusted.
(E) Stop the decompression means.

  According to the invention described in claim 4, in the holding operation, by using any one or more of the above (a) to (e), the inside of the processing tank is held at a desired pressure with simple control. Can do.

  Furthermore, the invention described in claim 5 is characterized in that, in the holding operation, instead of holding the pressure in the processing tank, the pressure in the processing tank is restored by a predetermined amount. It is a vacuum cooling device of any one of -4.

  According to the fifth aspect of the present invention, in the holding operation, the pressure in the processing tank can be restored by a predetermined amount to prevent bumping and spilling.

  According to the vacuum cooling device of the present invention, food can be rapidly cooled while preventing bumping and spilling.

It is the schematic which shows the vacuum cooling device of one Example of this invention, and shows a part in cross section. It is a graph which shows an example of bumping blowout prevention control by the vacuum cooling device of FIG. 1, the vertical axis | shaft shows temperature and the horizontal axis shows the elapsed time from the start of operation. It is a graph which shows the modification of bumping blowout prevention control by the vacuum cooling device of FIG. 1, and the vertical axis | shaft has shown temperature and the horizontal axis | shaft has elapsed time from the operation start.

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 apparatus 1 according to an embodiment of the present invention, and a part thereof is shown in cross section.

  The vacuum cooling device 1 of the present embodiment was reduced in pressure in the processing tank 2 in which the food F is stored, the decompression means 3 that sucks and discharges the gas in the processing tank 2 to the outside, and decompresses the inside of the processing tank 2. A decompression means 4 for introducing outside air into the treatment tank 2 to restore the pressure in the treatment tank 2 and a control means (not shown) for controlling these means to cool the food F in the treatment tank 2 are provided.

  The processing tank 2 is a hollow container that can withstand the decompression of the internal space, and is typically formed in a substantially rectangular box shape. The processing tank 2 is provided with a door (not shown) for taking in and out the food F on the front surface (the front side perpendicular to the paper surface of FIG. 1). However, a door may be provided on each of the front and back surfaces, one door may be a door for carrying food F into the processing tank 2, and the other door may be a door for carrying the food F out of the processing tank 2. . In any case, by closing the door, the opening of the processing tank 2 can be airtightly closed via the packing.

  In the processing tank 2, food F (including food) to be cooled is accommodated. The food F is placed in a food container such as hotel bread or watch weight and is accommodated in the processing tank 2.

  The decompression means 3 decompresses 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 this embodiment, the decompression means 3 is provided with a steam ejector 6, a heat exchanger 7 for steam condensation, a check valve 8, and a water-sealed vacuum pump 9 in this order in the exhaust path 5 from the inside of the treatment tank 2. Configured.

  The steam ejector 6 is provided with a suction port 6a connected to the processing tank 2, and steam from the steam supply path 10 can be ejected from the inlet 6b toward the outlet 6c by a nozzle. By ejecting steam from the inlet 6b toward the outlet 6c, the gas in the processing tank 2 is sucked and discharged to the outlet 6c through the suction port 6a. By operating opening and closing of the steam supply valve 11 provided in the steam supply path 10, the presence or absence of the operation of the steam ejector 6 can be switched. Note that the decompression capacity of the steam ejector 6 may be adjustable by adjusting the opening of the steam supply valve 11 or the like.

  The heat exchanger 7 is an indirect heat exchanger that exchanges heat without mixing the fluid in the exhaust passage 5 and its cooling water. The heat exchanger 7 can cool and condense the steam in the exhaust passage 5 with cooling water. Cooling water is supplied to the heat exchanger 7 through the heat exchange water supply channel 12, and the cooling water is discharged through the heat exchange drainage channel 13. A heat exchange water supply valve 14 is provided in the heat exchange water supply channel 12. On the other hand, although not shown, the heat exchange drainage channel 13 is branched into a return channel to the tank and a drainage channel to the outside, and a heat exchange drainage valve (not shown) is provided in each of these channels or a branch portion thereof. It has been. Whether the water after passing through the heat exchanger 7 is returned to the tank, drained without returning by the heat exchanger drainage valve, or water flow to the heat exchanger 7 is prevented without performing either (that is, heat The cooling water outlet side of the exchanger 7 can be closed).

  The vacuum pump 9 is a water seal type in this embodiment, and is operated while being supplied with water called sealed water as is well known. For this purpose, water is supplied to the water supply port 9 a of the vacuum pump 9 through the sealed water supply channel 15. A sealed water supply valve 16 is provided in the sealed water supply channel 15, and the sealed water can be supplied to the vacuum pump 9 by opening the sealed water supply valve 16. When the vacuum pump 9 is operated with the sealed water supply valve 16 opened, the vacuum pump 9 draws gas from the intake port 9b and exhausts and drains it to the exhaust port 9c. The vacuum pump 9 may be controlled to be turned on / off, and the output may be adjustable. In the present embodiment, the vacuum pump 9 can change the drive frequency of the motor and thus the rotational speed by using an inverter.

  By the way, in the example of illustration, the sealed water supply path 15 is made into the heat exchange water supply path 12 and the common pipe line 17 in the upstream, and the heat exchange water supply valve 14 is provided in the common pipe line 17. In this case, when the heat exchange water supply valve 14 is opened, water can be passed through the heat exchanger 7. When the sealed water supply valve 16 is further opened, water is supplied to the vacuum pump 9. In addition, as water supply to the heat exchanger 7 and the vacuum pump 9, normal temperature water and cold water (water cooled by a chiller) may be switchable.

  The return pressure means 4 introduces outside air into the reduced processing tank 2 to return the pressure in the processing tank 2. In the present embodiment, the return pressure means 4 is configured such that an air filter 19 and an air supply valve 20 are sequentially provided in an air supply path 18 into the processing tank 2. When the air supply valve 20 is opened in a state where the inside of the processing tank 2 is depressurized, outside air is introduced into the processing tank 2 through the air filter 19 and the inside of the processing tank 2 can be decompressed. The air supply valve 20 is preferably composed of an electric valve whose opening degree can be adjusted.

  The processing tank 2 is further provided with a pressure sensor 21 that detects the pressure in the processing tank 2 and a product temperature sensor 22 that detects the temperature (product temperature) of the food F stored in the processing tank 2.

  The control means is a controller (not shown) that controls the means 3 and 4 based on the detection signals and elapsed time of the sensors 21 and 22. Specifically, in addition to the vacuum pump 9, the steam supply valve 11, the heat exchange water supply valve 14, the heat exchange drainage valve (not shown), the sealed water supply valve 16, the air supply valve 20, the pressure sensor 21 and the product temperature sensor 22. Etc. are connected to the controller. And a controller aims at the vacuum cooling of the foodstuff F in the processing tank 2 according to a predetermined | prescribed procedure (program) so that it may mention below.

Hereinafter, an example of the operation method of the vacuum cooling device 1 of the present embodiment will be described.
Before starting operation, the air supply valve 20 is in an open state, while the steam supply valve 11, the heat exchange water supply valve 14, and the sealed water supply water valve 16 are in a closed state, and the vacuum pump 9 is stopped. In this state, the food F to be cooled is accommodated in the processing tank 2, and the door of the processing tank 2 is closed in an airtight manner. Then, when the start of operation is instructed by pressing a start button or the like, the controller closes the air supply valve 20 and operates the pressure reducing means 3 until the product temperature reaches a preset cooling target temperature. The food F is cooled by depressurizing the inside.

  In this embodiment, the decompression means 3 includes a steam ejector 6, a heat exchanger 7 for steam condensation, and a water-sealed vacuum pump 9, which are preferably operated sequentially as follows. .

  That is, when the inside of the processing tank 2 is depressurized, the inside of the processing tank 2 is first depressurized by the vacuum pump 9 while sealing water is supplied to the vacuum pump 9 in a state where water flow to the heat exchanger 7 is stopped. Specifically, by closing a heat exchange drainage valve (not shown) provided in the heat exchange drainage channel 13, the heat exchange water supply valve 14 and the sealed water supply water are set in a state in which the water flow to the heat exchanger 7 is disabled. While the valve 16 is opened and the sealing water is supplied to the vacuum pump 9, the vacuum pump 9 is operated to depressurize the inside of the processing tank 2. At this time, the vacuum pump 9 is operated at a predetermined frequency (and hence the rotational speed). At this stage, the steam supply valve 11 is closed, and the steam ejector 6 is stopped.

  When a predetermined water flow start condition is satisfied while the inside of the treatment tank 2 is being decompressed by the vacuum pump 9, the heat exchange drainage valve is operated to start water flow to the heat exchanger 7. As the water flow start condition, for example, the product temperature is equal to or lower than the water flow start temperature (for example, 60 ° C.), or the water flow start time (for example, 5 minutes) has elapsed from the start of operation. In addition, when it is comprised so that normal temperature water and cold water can be switched as water flow to the heat exchanger 7 and sealing water to the vacuum pump 9, it switches from normal temperature water to cold water at a predetermined switching timing.

  Thereafter, when a predetermined ejector operation start condition is satisfied, the steam supply valve 11 is opened and the steam ejector 6 is also operated. As the ejector operation start condition, for example, the product temperature is equal to or lower than the ejector operation start temperature (for example, 30 ° C.) and the inside of the processing tank 2 is equal to or less than the ejector operation start pressure (for example, 45 hPa), or the ejector operation start time ( For example, 10 minutes).

  As described above, in this embodiment, the vacuum pump 9, the heat exchanger 7, and the steam ejector 6 constituting the decompression unit 3 are operated in stages while the inside of the treatment tank 2 is decompressed. Basically, the inside of the processing tank 2 is depressurized by such control, and at this time, the following bump boiling prevention control is executed. In the bumping blowout prevention control, the pressure reducing operation and the holding operation in the treatment tank 2 are repeated. At this time, first, after the first pressure reducing operation is started only by the vacuum pump 9, the timing satisfying the above-mentioned predetermined condition (the first time depending on the situation) At a timing that may be before or after the start of the holding operation, the water flow to the heat exchanger 7 is started and the operation of the steam ejector 6 is started.

  In bumping blowout prevention control, the product temperature and pressure in the treatment tank 2 are monitored while the food is being cooled by the reduced pressure in the treatment tank 2 (during decompression operation and holding operation). And based on this monitoring information, the decompression operation which decompresses the inside of the processing tank 2 until the temperature difference between the product temperature and the saturation temperature in the tank (saturation temperature corresponding to the pressure in the processing tank 2) reaches a set value, The food F in the processing tank 2 is vacuum-cooled by repeating the holding operation for holding the pressure in 2 at the pressure after the pressure reducing operation. Hereinafter, the bumping blowout prevention control will be described more specifically. Here, the temperature difference is expressed as an absolute value.

  FIG. 2 is a graph showing an example of bump boiling spill prevention control, in which the vertical axis represents temperature T and the horizontal axis represents elapsed time t from the start of operation. The solid line indicates the product temperature TF, the alternate long and short dash line indicates the tank saturation temperature TS, and the latter half of the operation is not shown.

  In the bumping spill prevention control of the present embodiment, the food F is cooled until the product temperature by the product temperature sensor 22 reaches the cooling target temperature by repeating a predetermined decompression operation and a holding operation. In FIG. 2, a portion where the in-vessel saturation temperature TS falls to the right is under pressure reduction operation, and a portion in which the in-vessel saturation temperature TS is substantially horizontal is in the holding operation.

  In the depressurization operation, the temperature difference between the product temperature (food temperature in the treatment tank 2) TF and the saturation temperature in the tank (saturation temperature corresponding to the pressure in the treatment tank 2, in other words, the temperature conversion value of the pressure in the tank) TS. Until the first set value ΔT1 is reached, the inside of the processing tank 2 is depressurized. Specifically, after the decompression means 3 is operated and decompression in the treatment tank 2 is started, the detection temperature TF of the product temperature sensor 22 and the saturation temperature TS in the tank based on the detection pressure of the pressure sensor 21 are monitored. The inside of the processing tank 2 is depressurized until the temperature difference reaches the first set value ΔT1.

  In the illustrated example, the tank saturation temperature TS is made lower than the product temperature TF, and the inside of the treatment tank 2 is depressurized until “product temperature TF−tank saturation temperature TS = first set value ΔT1”, and the temperature difference is When the first set value ΔT1 or more is reached, the operation proceeds to the holding operation. However, the tank saturation temperature TS is made higher than the product temperature TF, and the inside of the treatment tank 2 is depressurized until “saturation temperature TS−product temperature TF = first set value ΔT1”, and the temperature difference is first. When the set value ΔT1 or less is reached, the holding operation may be started. The first set value ΔT1 is set according to the food F or the like, but is set at, for example, 5 ° C. or less (here, set to a positive value).

  In the holding operation, the pressure in the processing tank 2 is held until the temperature difference becomes the second set value ΔT2 smaller than the first set value ΔT1. When obtaining the temperature difference between the product temperature TF and the tank saturation temperature TS, which of the product temperature TF and the tank saturation temperature TS is larger is the same as the pressure reduction operation. In other words, if the tank saturation temperature TS is lower than the product temperature TF in the depressurization operation, the temperature difference between the two is set to a second value while maintaining the relationship (the tank saturation temperature TS <product temperature TF) in the holding operation. The holding operation is performed until the value ΔT2 is reduced. Alternatively, if the tank saturation temperature TS is higher than the product temperature TF in the depressurization operation, the temperature difference between the two is set to a second value while maintaining the relationship (tank saturation temperature TS> product temperature TF) in the holding operation. The holding operation is performed until the value ΔT2 is reduced. The second set value ΔT2 is a value smaller than the first set value ΔT1, and is set at, for example, 2 ° C. or less (here, set to a positive value).

  Then, the food F is cooled until the product temperature TF reaches the cooling target temperature by repeating such decompression operation and holding operation. In the case of the illustrated example, the tank saturation temperature TS falls below the product temperature TF in the decompression operation, and when the temperature difference reaches the first set value ΔT1, the operation shifts to the holding operation, and when the temperature difference reaches the second set value ΔT2, the pressure is reduced again. When the temperature difference reaches the first set value ΔT1 again, the operation moves to the holding operation, and when the temperature difference reaches the second set value ΔT2, the pressure reducing operation and the holding operation are repeated. F is cooled to the cooling target temperature. When the product temperature TF reaches the cooling target temperature, the decompression means 3 is stopped, the return pressure means 4 returns the inside of the treatment tank 2 to atmospheric pressure, and a series of operations is completed.

  By the way, in holding operation, the pressure in the processing tank 2 is hold | maintained using any one or more among following (a)-(e), for example.

  (A) In the state where the decompression means 3 is operated, the amount of air supplied by the decompression means 4 is adjusted. Specifically, the opening degree of the air supply valve 20 may be adjusted so that the pressure detected by the pressure sensor 21 is maintained at a predetermined level with the decompression means 3 (at least the vacuum pump 9 as described above) being operated. .

  (B) The rotational speed of the vacuum pump 9 constituting the decompression means 3 is adjusted. Specifically, an inverter may be used to adjust the drive frequency of the motor of the vacuum pump 9 and thus the rotational speed so as to maintain the detection pressure of the pressure sensor 21 at a predetermined level.

  (C) The sealing water flow rate to the water-sealed vacuum pump 9 constituting the decompression means 3 is adjusted. Specifically, the sealed water supply valve 16 may be configured by an electric valve that can adjust the opening, and the opening of the sealed water supply valve 16 may be adjusted so that the pressure detected by the pressure sensor 21 is maintained at a predetermined level. Alternatively, a parallel sealed water supply passage 15 may be provided, a sealed water supply valve 16 may be provided for each, and the seal water flow rate may be adjusted by opening either valve or both valves. Good.

  (D) The sealing water temperature to the water-sealed vacuum pump 9 constituting the decompression means 3 is adjusted. Specifically, normal water and cold water can be mixed and supplied as the water supply to the sealed water supply passage 15 (and the heat exchange water supply passage 12 if necessary), and the detection pressure of the pressure sensor 21 is maintained at a predetermined level. Thus, what is necessary is just to adjust the mixing ratio of normal temperature water and cold water. Alternatively, when the cold water from the chiller using the vapor compression refrigerator is supplied to the sealed water supply channel 15 (and, if desired, the heat exchange supply channel 12), the pressure detected by the pressure sensor 21 is maintained at a predetermined level. The cooling capacity of the chiller may be adjusted (for example, the compressor motor is inverter-controlled).

  (E) The decompression means 3 is stopped. Specifically, the vacuum pump 9 is stopped, the heat exchange water supply valve 14 is closed to stop water flow to the heat exchanger 7, or the steam supply valve 11 is closed to stop the steam ejector 6. In this case, only a part of the decompression means 3 (for example, the steam ejector 6) may be stopped. In addition, when the decompression operation is resumed after the decompression means 3 is stopped and the holding operation is performed, the vacuum pump 9 is operated and, as described above, if the water passage start condition is satisfied, the heat exchanger 7 is If the water is passed and the ejector operation start condition is satisfied, the steam ejector 6 may be operated.

  According to the vacuum cooling device 1 of the present embodiment, the temperature difference between the product temperature TF and the saturation temperature TS in the bath is monitored based on the product temperature and pressure in the processing bath 2, and the temperature difference is the first set value. By repeating the pressure reducing operation until ΔT1 and the holding operation until reaching the second set value ΔT2, the food F can be quickly cooled with simple control while preventing bumping and spilling.

  FIG. 3 is a graph showing a modified example of the bump boiling prevention control, where the vertical axis indicates the temperature T and the horizontal axis indicates the elapsed time t from the start of operation. The solid line indicates the product temperature TF, the alternate long and short dash line indicates the tank saturation temperature TS, and the latter half of the operation is not shown.

  The modification shown in FIG. 3 is basically the same as the embodiment shown in FIG. Therefore, the following description will focus on the differences between the two, and the description of the same points will be omitted.

  Also in the bumping and spill prevention control of this modification, the food F is cooled until the product temperature TF by the product temperature sensor 22 reaches the cooling target temperature by repeating the predetermined pressure reduction operation and the holding operation.

  In the depressurization operation, the inside of the processing tank 2 is depressurized until the temperature difference between the product temperature TF and the tank saturation temperature TS reaches a set value (first set value in the above example) ΔT1 as in the above embodiment.

  In the holding operation, the point in which the pressure in the processing tank 2 is held at the pressure at the end of the immediately preceding depressurization operation is the same as in the above embodiment, but the end condition is different. That is, in the above embodiment, the pressure in the processing tank 2 is maintained until the temperature difference between the product temperature TF and the tank saturation temperature TS reaches the second set value ΔT2, but in this modification, the set time x has elapsed. Until then, the pressure in the treatment tank 2 is maintained.

  Then, the food F is cooled until the product temperature reaches the cooling target temperature by repeating such decompression operation and holding operation. In the case of the illustrated example, in the decompression operation, the tank saturation temperature TS falls below the product temperature TF, and when the temperature difference reaches the set value ΔT1, the operation proceeds to the holding operation, and after the set time x, the operation proceeds to the decompression operation again. When the temperature difference reaches the set value ΔT1, the operation shifts to the holding operation, and when the set time x elapses, the pressure reducing operation and the holding operation are repeated so that the food F is cooled to the cooling target temperature. Others are the same as those in the above embodiment, and the description is omitted.

  The vacuum cooling device 1 of the present invention is not limited to the configuration of the above-described embodiments (including modifications) and can be changed as appropriate. In particular, it is an apparatus for vacuum-cooling the food F by depressurizing the inside of the processing tank 2, monitoring the product temperature and pressure in the processing tank 2, and based on this monitoring information, the product temperature TF and the tank saturation temperature TS. The pressure reducing operation for reducing the pressure inside the processing tank 2 until the temperature difference with the set value reaches the set value, and the holding operation for holding the pressure inside the processing tank 2 at the pressure after the pressure reducing operation are repeated, so that the food F in the processing tank 2 As long as the vacuum is cooled, other configurations can be changed as appropriate.

  For example, in the above-described embodiment, the food F is cooled until the product temperature reaches the cooling target temperature by repeating the decompression operation and the holding operation, but the cooling end condition can be changed as appropriate. In addition, as long as it includes a repetition process of the decompression operation and the holding operation (cooling process by the control to prevent bumping and spilling), another process may be included before and / or after the repetition process.

  In the holding operation, instead of holding the pressure in the processing tank 2, the pressure in the processing tank 2 may be restored by a predetermined amount. That is, in the holding operation, when the pressure is slightly restored rather than holding the pressure, the inside of the treatment tank 2 may be slightly restored. In that case, even if the decompression means 3 is simply stopped as described above, the inside of the treatment tank 2 can be decompressed with the steam from the food F in some cases. Alternatively, the inside of the processing tank 2 may be decompressed to a predetermined level by the decompression unit 4 while the decompression unit 3 is stopped (or the decompression unit 3 is operated). When returning the pressure in the processing tank 2, the food F can be stirred.

  Moreover, in the said Example, you may make it change the setting value (1st setting value, 2nd setting value, setting time) used for completion | finish conditions of pressure reduction operation and holding | maintenance operation in the middle of a driving | operation. For example, as the cooling progresses, any one or more of these set values may be changed in stages.

  In the embodiment, in the holding operation, the pressure in the processing tank 2 is set to a predetermined value until the temperature difference between the product temperature TF and the tank saturation temperature TS reaches the second set value ΔT2 or the set time x has elapsed. Although it hold | maintained, depending on the case, the fall rate of product temperature may be monitored and the pressure in the processing tank 2 may be hold | maintained predetermined until it falls below setting speed.

  Moreover, in the said Example, the structure of the pressure reduction means 3 can be changed suitably. For example, in the above embodiment, the steam ejector 6 is provided as the decompression means 3, but the installation of the steam ejector 6 may be omitted depending on circumstances. Alternatively, a vacuum pump other than the water ring type or a water ejector may be used as the decompression means 3.

  Furthermore, in the said Example, although the vacuum cooling device 1 was demonstrated as a cooling only machine, if it has a vacuum cooling function, it can change suitably. For example, it may be configured like a steaming cooling device or a saturated steam cooking device by providing a heating means with steam. Or it may be comprised like a cold wind vacuum compound cooling device by providing the cold air cooling means using a refrigerator and a fan.

DESCRIPTION OF SYMBOLS 1 Vacuum cooling device 2 Processing tank 3 Pressure reducing means 4 Pressure-reducing 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: Inlet port, 9c: Exhaust port)
DESCRIPTION OF SYMBOLS 10 Steam supply path 11 Steam supply valve 12 Heat exchange water supply path 13 Heat exchange water supply path 14 Heat exchange water supply valve 15 Sealed water supply water path 16 Sealed water supply water valve 17 Common pipe 18 Air supply path 19 Air filter 20 Air supply valve 21 Pressure Sensor 22 Product temperature sensor t Elapsed time T Temperature TF Product temperature (food temperature)
TS Saturation temperature in tank ΔT1 First set value ΔT2 Second set value x Set time

Claims (5)

A device for vacuum-cooling food by reducing the pressure inside the treatment tank,
Monitoring the food temperature and pressure in the treatment tank;
Based on this monitoring information, the decompression operation for depressurizing the inside of the processing tank until the temperature difference between the food temperature in the processing tank and the saturation temperature corresponding to the pressure in the processing tank reaches a set value, A vacuum cooling apparatus, wherein the food in the processing tank is vacuum-cooled by repeating a holding operation for holding the pressure at the pressure after the pressure-reducing operation. Depressurization operation for depressurizing the inside of the treatment tank until the temperature difference between the food temperature in the treatment tank and the saturation temperature corresponding to the pressure in the treatment tank reaches a first set value, and the temperature difference from the first set value The vacuum cooling apparatus according to claim 1, wherein the food in the processing tank is vacuum-cooled by repeating a holding operation for maintaining the pressure in the processing tank until the second set value becomes a small second value. Pressure reducing operation to depressurize the processing tank until the temperature difference between the food temperature in the processing tank and the saturation temperature corresponding to the pressure in the processing tank reaches a set value, and the pressure in the processing tank until a set time elapses. The vacuum cooling apparatus according to claim 1, wherein the food in the processing tank is vacuum-cooled by repeating a holding operation for holding the food. The treatment tank in which food is stored;
Depressurizing means for sucking and discharging the gas in the processing tank to the outside and reducing the pressure in the processing tank;
A return pressure means for introducing outside air into the reduced processing tank and returning the pressure in the processing tank;
Control means for cooling the food in the processing tank by controlling the decompression means and the decompression means,
In the said holding operation, the pressure in the said processing tank is hold | maintained using any one or more among following (a)-(e). The any one of Claims 1-3 characterized by the above-mentioned. Vacuum cooling equipment.
(A) The air supply amount by the return pressure means is adjusted in a state where the pressure reducing means is operated.
(B) The number of rotations of the vacuum pump constituting the pressure reducing means is adjusted.
(C) The sealed water flow rate to the water-sealed vacuum pump constituting the pressure reducing means is adjusted.
(D) The sealing water temperature to the water-sealed vacuum pump constituting the pressure reducing means is adjusted.
(E) Stop the decompression means. The vacuum according to any one of claims 1 to 4, wherein, in the holding operation, instead of holding the pressure in the processing tank, the pressure in the processing tank is restored by a predetermined amount. Cooling system.

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