JP6958143B2 - Steam kettle - Google Patents

Description

The present invention relates to a steam kettle that heats food by a steam jacket, and more particularly to a steam kettle that can heat food at a temperature of less than 100 ° C.

A steam kettle is known in which a jacket is provided around an inner kettle in which food is stored, and steam is supplied into the jacket to heat the food in the inner kettle. In a conventional steam kettle, food is heated by controlling the steam supply (steam supply) to the jacket and adjusting the pressure inside the jacket and thus the temperature. At this time, the inside of the jacket becomes positive pressure and is filled with steam of 100 ° C. or higher, and the wall surface temperature of the inner pot also exceeds 100 ° C. Therefore, depending on the food such as bean paste or cream sauce, seizure may occur and cooking may not be successful.

On the other hand, as disclosed in Patent Document 1 below, a steam kettle capable of low-temperature cooking at a temperature of less than 100 ° C. has also been proposed by reducing the pressure inside the jacket using a steam ejector. However, even if the inside of the jacket is under reduced pressure (that is, less than atmospheric pressure), the inside of the inner pot is under atmospheric pressure, so that the food in the inner pot cannot be stably heated in a saturated steam environment. Also, it is not possible to cool the food after heating. Even if the inner pot is composed of a can that can be sealed and the inside of the can is depressurized to vacuum-cool the food, sudden boiling occurs during vacuum cooling and the food is scattered inside the can or inside the vacuum pipe. Since there is a risk, countermeasures are desired.

Japanese Unexamined Patent Publication No. 7-328423 (paragraph 0017, FIG. 1)

An object to be solved by the present invention is to provide a steam kettle capable of heating food below 100 ° C. Further, it is possible to efficiently cool the food after heating, and at that time, it is an object to prevent the food from scattering due to bumping.

The present invention has been made to solve the above problems, and the invention according to claim 1 is provided on a can body which can be opened and closed with a lid material and which houses food, and on the outside of the can body. , A main jacket to which steam or water is supplied, a sub-jacket provided on the outside of the main jacket to which steam is supplied, and both the can body and the main jacket are connected to send their gases to the outside. The food in the can is depressurized by controlling the depressurizing means capable of sucking and discharging and depressurizing both, the steaming means capable of supplying at least steam into the sub-jacket, the depressurizing means and the steaming means. The control means is provided with a control means for heating underneath, and the control means puts the inside of the can and the inside of the main jacket into the sub-jacket while maintaining the inside of the can and the inside of the main jacket below atmospheric pressure by the decompression means as a step of heating the food. The steam kettle is characterized in that the stored water in the main jacket is heated by steaming to generate saturated steam, and the food in the can is heated by the saturated steam in the main jacket.

According to the invention of claim 1 and claims 3, 4 and 5 described later, both the can body and the main jacket are decompressed by a common decompression means, and the food in the can is decompressed to less than 100 ° C. Can be heated with. At that time, by controlling the steam supply into the sub-jacket, the temperature change in the main jacket can be suppressed and stable food heating becomes possible.

According to the invention of claim 1 , the food in the can is stably heated at less than 100 ° C. by the saturated steam in the main jacket while the inside of the can and the inside of the main jacket are maintained at a pressure below atmospheric pressure. Can be done. Since both the inside of the can and the inside of the main jacket can be depressurized by a common decompression means to make the pressure inside the can and the inside of the main jacket equal, the saturation temperature of the food (moisture) inside the can can be set to the main jacket. It becomes the same as the temperature of the saturated steam inside, and overheating of food can be prevented.

The invention according to claim 2 controls steaming into the sub-jacket based on the product temperature of the food in the can or the temperature inside the main jacket in the heating step, and / or The steam kettle according to claim 1 , wherein the depressurization by the depressurizing means is controlled.

According to the second aspect of the present invention, the food in the can can be prepared by controlling the steaming into the sub-jacket and / or the depressurization by the depressurizing means based on the product temperature in the can or the temperature in the main jacket. It can be heated to a desired temperature. If steaming to the inside of the main jacket (or inside the can) is controlled, the steam supplied into the main jacket may become decompressed superheated steam, which may make it impossible to stably heat the food. Such inconvenience can be prevented by not directly steaming to.

The invention according to claim 3 is a can body which can be opened and closed with a lid material and which houses food, a main jacket provided outside the can body to which steam or water is supplied, and the main jacket. A decompression means provided on the outside and connected to both the can body and the main jacket to which steam is supplied, and the gas of both can be sucked and discharged to the outside to reduce the pressure of both, and at least the above. A steaming means capable of supplying steam into the sub-jacket, a depressurizing means, and a controlling means for controlling the depressurizing means and the steaming means to heat the food in the can under reduced pressure are provided, and the main depressurizing means is used. A jacket vacuum valve is provided in the exhaust passage from the inside of the jacket upstream of the confluence with the exhaust passage from the inside of the can, and during exhaust by the decompression means from both the can and the main jacket. a steam kettle you and adjusts the opening of the jacket vacuum valve.

According to the third aspect of the present invention, the pressure balance between the can body and the main jacket can be adjusted by adjusting the opening degree of the jacket vacuum valve during exhaust by the depressurizing means.

The invention according to claim 4 is a can body that can be opened and closed with a lid material and contains food, a main jacket provided outside the can body to which steam or water is supplied, and the main jacket. A decompression means provided on the outside and connected to both the can body and the main jacket to which steam is supplied, and suction and discharge of both gases to the outside to depressurize both, and at least the above. The control means includes a steaming means capable of supplying steam into the sub-jacket, and a control means for controlling the depressurizing means and the steaming means to heat the food in the can under reduced pressure. Before the heating step of heating the food in the can at the target temperature, as an initial heating step, the inside of the main jacket and the sub-jacket until the inside of the main jacket reaches a predetermined preheating temperature set lower than the target temperature. a steam kettle you, characterized in that the feed Misir to the inner.

According to the fourth aspect of the present invention, as an initial temperature raising step before the heating step, steam is supplied into the main jacket and the sub-jacket to preheat each jacket and the can body. At that time, since the target temperature (preheating temperature) of the initial temperature raising step is set lower than the target temperature of the subsequent heating step, overheating of the food can be suppressed and the initial temperature raising can be performed promptly.

The invention according to claim 5 is a can body that can be opened and closed with a lid material and contains food, a main jacket provided outside the can body to which steam or water is supplied, and the main jacket. A decompression means provided on the outside, which is connected to both the can body and the main jacket to which steam is supplied, sucks and discharges the gas of both to the outside, and can reduce the pressure of both, and at least the above. The control means includes a steaming means capable of supplying steam into the sub-jacket, and a control means for controlling the depressurizing means and the steaming means to heat the food in the can under reduced pressure. After the heating step of heating the food in the can at the target temperature, as a slow cooling step, the inside of the can and the inside of the main jacket are depressurized with the steam supply into the main jacket and the sub jacket stopped. which is a steam kettle shall be the feature.

According to the invention of claim 5 , as a slow cooling step after the heating step, the inside of the can and the inside of the main jacket can be depressurized to achieve vacuum cooling. At that time, direct cooling of the food by decompression in the can body and indirect cooling of the food by decompression in the main jacket can be used in combination to efficiently achieve overall cooling. In addition, when the food is cooled, if only the inside of the can is decompressed from the beginning, the product temperature of the food remains relatively high, and the difference from the saturation temperature equivalent to the pressure inside the can due to the decompression opens, resulting in the food. There is a risk of sudden boiling and scattering, but first, by decompressing not only the can body but also the inside of the main jacket (the decompression rate drops by that amount), it is possible to prevent the sudden boiling of food and the scattering.

The invention according to claim 6 is characterized in that, after the slow cooling step, the control means further depressurizes the inside of the can body in a state where exhaust from the main jacket is stopped as the main cooling step. The steam kettle according to claim 5.

According to the sixth aspect of the present invention, as the main cooling step after the slow cooling step, the inside of the can is further depressurized while the exhaust from the main jacket is stopped to achieve vacuum cooling of the food. .. After the cooling has progressed to some extent, the food can be quickly and surely cooled to a desired temperature by performing vacuum cooling only by reducing the pressure inside the can.

The present invention as described in claim 7 is a steam kettle according to any one of claims 1 to 6, characterized in that it comprises a stirrer food of the can body.

According to the invention of claim 7 , by configuring as a steam kneader, the food in the can can be treated (heated and / or cooled) while being stirred by the stirring device.

According to the steam kettle of the present invention, it is possible to realize a steam kettle capable of heating food at a temperature lower than 100 ° C. In addition, the heated food can be efficiently cooled, and at that time, scattering of the food due to bumping can be prevented.

It is the schematic which shows the steam pot of one Example of this invention, and shows a part in cross-section.

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

The steam kettle 1 of the present embodiment includes a can body 2 for storing food, a main jacket 3 provided on the outside of the can body 2, a sub-jacket 4 provided on the outside of the main jacket 3, and a can body 2. A decompression means 5 capable of depressurizing both the main jacket 3 and the main jacket 3, a steam supply means 6 capable of supplying steam into at least the sub jacket 4, a water supply means 7 into the main jacket 3, and the inside and sub jacket 3. A drain discharge means 8 from the inside of the jacket 4 and a control means (not shown) for controlling each of the means are provided.

The can body 2 is a hollow container that can withstand decompression. The can body 2 includes a main body 2A having an opening and a lid material 2B for opening and closing the opening of the main body 2A. By opening the lid material 2B, food can be taken in and out of the main body 2A, and by closing the lid material 2B, the opening of the main body 2A can be closed airtightly.

The shape of the can body 2 is not particularly limited, and may be, for example, a horizontally oriented cylinder, but in this embodiment, it is a vertically oriented cylinder. Specifically, the main body 2A has a bottomed cylindrical shape that opens upward, and the bottom wall is formed by bulging downward in a substantially hemispherical shape. On the other hand, the lid material 2B is formed by bulging upward in a substantially hemispherical shape when the opening of the main body 2A is closed (FIG. 1).

The main jacket 3 is filled with saturated steam and heats the inside of the can body 2. The main jacket 3 is provided so as to surround at least a part of the can body 2. In this embodiment, the main jacket 3 is provided in a region below the middle portion of the can body 2 in the vertical direction.

Saturated steam is supplied to the sub-jacket 4 to heat the inside of the main jacket 3. The sub-jacket 4 is provided so as to surround at least a part of the main jacket 3 (in other words, outside the main jacket 3). In this embodiment, the sub-jacket 4 is provided below the main jacket 3.

More specifically, in the case of the illustrated example, the configuration is as follows. That is, the steam kettle 1 includes a hollow jacket body 9 having a substantially hemispherical shape (that is, a substantially lower half shape of the sphere) that bulges downward, and the upper opening of the jacket body 9 is closed by the upper wall 10 and the upper opening of the jacket body 9 is closed. The body of the can body 2 is hermetically fitted and held in the hole formed in the central portion of the upper wall 10. Further, the internal space of the jacket body 9 is divided into upper and lower parts by a partition wall 11. In the jacket body 9, the upper part of the partition wall 11 is the main jacket 3, while the lower part of the partition wall 11 is the sub-jacket 4.

The lower portion of the can body 2 is inserted into the main jacket 3, but is arranged above the partition wall 11. In the heating step described later, even when water is stored in the main jacket 3 up to the set water level, the can body 2 is held at a height at which it is not immersed in the stored water. In other words, in the first discharge passage 31A, which will be described later, the connection position with respect to the main jacket 3 is arranged below the lowermost end of the can body 2.

The decompression means 5 is a means that is connected to both the can body 2 and the main jacket 3 and can suck and discharge the gas (air or steam) of both to the outside to depressurize both. In this embodiment, in the depressurizing means 5, the steam ejector 13, the heat exchanger 14 for steam condensation, and the water-sealed vacuum pump 15 are sequentially arranged in the exhaust passages 12 from both the can body 2 and the main jacket 3. It is provided and configured. At this time, the first exhaust passage 12A from the inside of the can body 2 and the second exhaust passage 12B from the inside of the main jacket 3 are merged, and thereafter, they are connected to the steam ejector 13 as a common exhaust passage 12. .. The first exhaust passage 12A is provided with a check valve 16, while the second exhaust passage 12B is provided with a jacket vacuum valve 17 and a check valve 18 in this order from the main jacket 3 toward the steam ejector 13. ing. The jacket vacuum valve 17 is composed of an electric valve whose opening degree can be adjusted.

The steam ejector 13 is provided with a suction port 13a connected to the can body 2 and the main jacket 3 via the exhaust passages 12A and 12B, and steam from the ejector steam supply passage 19 from the inlet 13b to the outlet 13c. Can be ejected with a nozzle. By ejecting steam from the inlet 13b toward the outlet 13c, the gas in the can body 2 and the main jacket 3 is also sucked and discharged to the outlet 13c through the suction port 13a. By controlling the opening and closing of the ejector steaming valve 20 provided in the ejector steaming passage 19, it is possible to switch whether or not the steam ejector 13 is operating. Further, by controlling the opening degree of the ejector steam supply valve 20, the depressurizing capacity of the steam ejector 13 can be adjusted.

The heat exchanger 14 is an indirect heat exchanger that exchanges heat without mixing the fluid in the exhaust passage 12 with the cooling water thereof. During the operation of the vacuum pump 15, the heat exchange water supply valve (not shown) to the heat exchanger 14 is opened. As a result, in the heat exchanger 14, the steam in the exhaust passage 12 can be cooled and condensed by the cooling water.

The vacuum pump 15 is a water-sealing type, and as is well known, the vacuum pump 15 is operated while being supplied with water called water-sealing. While the vacuum pump 15 is operating, the water sealing water supply valve (not shown) to the vacuum pump 15 is opened.

The steaming means 6 supplies steam into the sub-jacket 4 via the jacket steaming passage 21. The jacket steam supply passage 21 is provided with a steam supply shutoff valve 22 and a steam supply control valve 23 in this order from the steam supply source to the sub-jacket 4. By opening the steaming shutoff valve 22 and the steaming control valve 23, steam can be supplied into the sub-jacket 4, and at that time, by adjusting the opening degree of the steaming control valve 23, the flow rate of steam can be increased. Can be adjusted. While the steam kettle 1 is operating, the steaming shutoff valve 22 is maintained in an open state to control the opening / closing and opening degree of the steaming control valve 23, or when the steaming control valve 23 is opened, the steaming shutoff valve 22 is opened. Let it open. It is preferable that the jacket steam supply passage 21 is provided with a safety valve 24 at the inlet to the sub-jacket 4.

In this embodiment, the steaming means 6 directly supplies steam into the sub-jacket 4, but the steam can also be supplied into the main jacket 3 via the communication passage 25. That is, the main jacket 3 and the sub-jacket 4 are connected by a communication passage 25, and the opening and closing of the communication valve 26 provided in the communication passage 25 is controlled to move the steam in the sub-jacket 4 into the main jacket 3. It is possible to switch whether to supply or not. That is, during steaming into the sub-jacket 4, if the communication valve 26 is opened, steam can be supplied into the main jacket 3, and if the communication valve 26 is closed, steaming into the main jacket 3 can be stopped. can.

However, steaming into the main jacket 3 may be possible directly from the jacket steaming passage 21 without going through the sub-jacket 4. In that case, the jacket steam supply path 21 to the sub-jacket 4 is provided with a branch steam supply path to the main jacket 3 on the upstream side of the steam supply control valve (first steam supply control valve) 23. A second steam supply control valve into the main jacket 3 is provided in the branched steam supply path.

The water supply means 7 supplies water (typically normal temperature water) into the main jacket 3 via the water supply channel 27. In the case of the illustrated example, the water supply channel 27 from the water supply source is branched into a plurality of water supply channels 27 after the strainer 28 and the water supply valve 29 are provided, and each branch path 27A is spaced apart from the upper part of the main jacket 3 in the circumferential direction. Is opened and connected. At that time, it is preferable that the water supply channel 27 (27A) is provided with the spray nozzle 30 at the opening into the main jacket 3. In this case, the water from the water supply channel 27 is sprayed into the main jacket 3, but at that time, it is preferable that the water is sprayed toward the wall surface of the can body 2.

The discharge means 8 is connected to both the main jacket 3 and the sub jacket 4, and discharges condensed water (drain) of steam to the outside. In this embodiment, the discharge means 8 is configured by providing a steam trap 32 in a discharge path 31 from the inside of the main jacket 3 and the inside of the sub jacket 4. At this time, the first discharge passage 31A from the inside of the main jacket 3 via the check valve 33 and the second discharge passage 31B from the inside of the sub jacket 4 merge, and thereafter, as a common discharge passage 31, steam It is connected to the trap 32.

The first discharge passage 31A is connected to a position higher than the bottom portion (partition wall 11) in the main jacket 3 by a set dimension so that water can be stored in the main jacket 3 up to the set water level. The first discharge path 31A functions not only as a drain discharge from the inside of the main jacket 3 but also as an overflow path for discharging a predetermined amount of water or more to the outside. If it is desired to store more water in the main jacket 3 when the food is cooled after being heated, an electromagnetic valve may be provided in the first discharge passage 31A. On the other hand, the second discharge passage 31B is connected to the bottom of the sub-jacket 4 to prevent drainage from accumulating in the sub-jacket 4.

Although not shown, the steam kettle 1 is further provided with a vacuum releasing means in the can body 2. The vacuum release means is a means for supplying outside air into the can body 2 under reduced pressure to restore the pressure inside the can body 2 to atmospheric pressure. The vacuum release means is provided with a vacuum release valve in the air supply path into the can body 2. The vacuum release valve may be composed of a manual valve, an electric valve whose opening / closing or opening degree is controlled, or the like.

The steam kettle 1 is provided with various sensors, if desired. In the case of the illustrated example, the can body 2 is provided with the pressure sensor 34 and the product temperature sensor 35, while the main jacket 3 is provided with the temperature sensor (gas phase portion temperature sensor 36, liquid phase portion temperature sensor 37). The pressure sensor 34 detects the pressure inside the can body 2, and the product temperature sensor 35 detects the temperature of the food inside the can body 2. On the other hand, the temperature sensor of the main jacket 3 detects the temperature inside the main jacket 3. As the temperature sensor, preferably, a gas phase portion temperature sensor 36 for detecting the temperature of the gas phase portion in the main jacket 3 and a liquid phase portion temperature sensor 37 for detecting the temperature of the liquid phase portion in the main jacket 3 are provided. Be done. In addition, in this embodiment, the water level sensor 38 is provided so that the water level in the main jacket 3 can be monitored.

The control means is a controller (not shown) that controls the means 5 to 8 based on the detection signals of the sensors 34 to 38, the elapsed time, and the like. Specifically, the jacket vacuum valve 17, the ejector steam supply valve 20, the heat exchange water supply valve (not shown), the vacuum pump 15, the sealed water supply valve (not shown), the steam supply shutoff valve 22, the steam supply control valve 23, In addition to the communication valve 26 and the water supply valve 29, the pressure sensor 34, the product temperature sensor 35, the gas phase temperature sensor 36, the liquid phase temperature sensor 37, the water level sensor 38, and the like are connected to the controller. Then, as described below, the controller heats the food in the can body 2 and then cools the food according to a predetermined procedure (program).

Prior to the start of operation, food is stored in the can body 2, and the opening of the can body 2 is airtightly closed by the lid material 2B. Then, when the start button is pressed or the like to instruct the start of operation, the controller heats the food in the can body 2 and then cools the food. In this embodiment, the initial temperature raising step, the heating step, the slow cooling step, and the main cooling step are sequentially executed. Hereinafter, each step will be described. Before the start of operation, the valves are closed and the vacuum pump 15 is stopped.

≪Initial temperature rise process≫
In the initial temperature raising step, steam is supplied into the main jacket 3 and the sub jacket 4 until the inside of the main jacket 3 reaches a predetermined preheating temperature. Specifically, the steam supply control valve 23 is opened to supply steam into the sub-jacket 4, and the communication valve 26 is opened to supply steam into the main jacket 3. The preheating temperature in the initial heating step is set lower than the target temperature in the subsequent heating step. For example, when the heating temperature of the food in the heating step is 80 ° C., the preheating temperature of the main jacket 3 in the initial heating step is set to a temperature lower than the heating temperature by a predetermined temperature (for example, 75 ° C.). When the detection temperature of the gas phase temperature sensor 36 becomes equal to or higher than the preheating temperature, the communication valve 26 is closed and the process proceeds to the next process.

However, in addition to performing the initial temperature raising step until the inside of the main jacket 3 reaches a predetermined preheating temperature, for example, it may be performed for a predetermined preheating time. Even in that case, the temperature reached by the initial temperature raising step should be controlled so as not to exceed the target temperature in the heating step.

In the initial temperature raising step, by steaming directly into both jackets 3 and 4, it is possible to quickly preheat both jackets 3 and 4 and the can body 2. At that time, by setting the preheating temperature in the initial temperature raising step to be lower than the target temperature in the heating step, overheating of the food can be suppressed. The condensed water of the steam supplied into the main jacket 3 in the initial temperature raising step is stored in the bottom portion in the main jacket 3, but the water exceeding a predetermined value is discharged to the outside from the first discharge passage 31A.

If desired, a standby step may be performed after the initial temperature raising step and before the heating step. In the standby step, with the communication valve 26 and the steaming control valve 23 closed, the main jacket 3 waits until the temperature falls below the specified temperature (or until the specified time elapses). The specified temperature is set at a temperature lower than the preheating temperature (for example, 75 ° C.) in the initial temperature raising step (for example, 50 ° C.). When the detection temperature of the gas phase temperature sensor 36 becomes lower than the specified temperature (or when the specified time elapses), the process proceeds to the next process.

In the standby step, it is possible to wait for the steam supplied into each of the jackets 3 and 4 to condense to some extent in the initial temperature raising step. As a result, the energy of the steam supplied into each of the jackets 3 and 4 in the initial temperature raising step is not wasted. In particular, in the next heating step, since the air is also exhausted from the inside of the main jacket 3, it is possible to prevent the steam supplied into the main jacket 3 from being wasted.

≪Heating process≫
In the heating step, the inside of the can body 2 and the inside of the main jacket 3 are depressurized by the depressurizing means 5, and both are maintained below the atmospheric pressure. Specifically, with the jacket vacuum valve 17 open, the ejector steam supply valve 20 is opened to operate the steam ejector 13, and the vacuum pump 15 is also operated. At this time, the heat exchange water supply valve to the heat exchanger 14 is opened, and the water sealing water supply valve to the vacuum pump 15 is also opened. However, the operation timing of each element of the decompression means 5 may be shifted, for example, the steam ejector 13 may be operated at a predetermined timing after the vacuum pump 15 starts depressurization.

In any case, by the operation of the depressurizing means 5, the gas in the can body 2 and the main jacket 3 is sucked and discharged to the outside, and the pressure in the can body 2 and the main jacket 3 is reduced. As will be described later, by controlling the depressurizing means 5 and / or the steaming means 6, the inside of the can body 2 and the inside of the main jacket 3 are maintained at predetermined pressures. Although not limited to the heating step, the pressure balance between the can body 2 and the main jacket 3 can be adjusted by adjusting the opening degree of the jacket vacuum valve 17 during exhaust by the decompression means 5. can.

In the heating step, steam is supplied into the sub-jacket 4 to heat the water in the main jacket 3 (condensed water of steam in the initial temperature raising step and / or water supplied by the water supply means 7) in the main jacket 3. Is filled with saturated steam. At this time, the water level in the main jacket 3 is monitored by the water level sensor 38, and when the water level falls below the lower limit water level, water is supplied into the main jacket 3 until the water supply valve 29 is opened and the upper limit water level is exceeded (or only for a predetermined time). As a result, the inside of the main jacket 3 can be filled with saturated steam (wet saturated steam) with some water remaining on the bottom of the main jacket 3. If the temperature detected by the liquid phase temperature sensor 37 exceeds the upper limit temperature (for example, 100 ° C.) while there is water above the lower limit water level in the main jacket 3, the steam supply shutoff valve 22 is closed. It is better to notify the user to that effect.

In the heating step, the steaming into the sub-jacket 4 is controlled based on the product temperature of the food in the can body 2 or the temperature in the main jacket 3, and / or the decompression by the depressurizing means 5 is controlled. .. For example, based on the detection temperature of the product temperature sensor 35, the steam supply control valve 23 may be controlled and / or the ejector steam supply valve 20 may be controlled so as to maintain the detected temperature at the target temperature. Alternatively, the steam supply control valve 23 may be controlled and / or the ejector steam supply valve 20 may be controlled so as to maintain the detected temperature at the target temperature based on the detected temperature of the gas phase temperature sensor 36. .. The control of the pressure reducing means 5 is not limited to adjusting the opening degree of the ejector steam supply valve 20, and various conventionally known methods can be used. For example, the opening degree of the outside air introduction valve provided in the exhaust passage 12 may be adjusted, or the flow rate of water flowing to the heat exchanger 14 may be adjusted. If a predetermined end condition is satisfied, such as the set time elapses from the start of the heating process, the steaming control valve 23 is closed and the process proceeds to the next process.

In the heating step, both the can body 2 and the main jacket 3 are depressurized by a common depressurizing means 5, and the food in the can body 2 is depressurized (in this embodiment, under a low vacuum (100 Pa or more) as defined by JIS standards. It can be heated at less than 100 ° C. under vacuum)). At that time, by controlling the steaming into the sub-jacket 4, the temperature change in the main jacket 3 can be suppressed and stable food heating becomes possible.

Further, in the heating step, the pressure inside the can body 2 and the inside of the main jacket 3 can be made equal by simultaneously depressurizing both the inside of the can body 2 and the inside of the main jacket 3 by the common depressurizing means 5. .. That is, the degree of vacuum in the can body 2 and the degree of vacuum in the main jacket 3 can be made substantially the same. As a result, the saturation temperature of the water content of the food in the can body 2 becomes the same as the temperature of the saturated steam in the main jacket 3, and overheating of the food can be prevented. That is, for example, if the gas phase temperature in the main jacket 3 is controlled by controlling the steam supply into the sub jacket 4 (the inside of the main jacket 3 is in a saturated steam environment, so it can be said to be the pressure in the main jacket 3). The pressure in the can body 2 heated by this is also adjusted to the same saturated steam pressure. Therefore, the inside of the can body 2 is always maintained at a saturated steam pressure corresponding to the temperature inside the main jacket 3, and is always in a state of boiling. In this way, the food is continuously cooked without being overheated while maintaining the low temperature boiling state.

By the way, in the heating step, if the steam supply to the inside of the main jacket 3 (or the inside of the can body 2) is directly controlled, the steam supplied into the main jacket 3 becomes decompressed superheated steam to produce food. It may not be possible to heat stably. However, in the present embodiment, such inconvenience can be prevented by not directly steaming into the main jacket 3 in the heating step.

≪Slow cooling process≫
In the slow cooling step, the inside of the can body 2 and the inside of the main jacket 3 are depressurized while the depressurizing means 5 is operated to cool the food in the can body 2. Specifically, with the jacket vacuum valve 17 and the ejector steam supply valve 20 open, the inside of the can body 2 and the inside of the main jacket 3 are depressurized by the vacuum pump 15. At that time, if desired, the water supply valve 29 is opened and water is sprayed into the main jacket 3. Thereby, the vacuum cooling of the food in the can body 2 can be achieved by the latent heat of evaporation of water in the main jacket 3 and the latent heat of evaporation of the food moisture in the can body 2. However, in the slow cooling step, in some cases, more water may be stored in the main jacket 3 and vacuum cooling may be performed with the lower part of the can body 2 immersed in the stored water. In any case, if the detection temperature of the product temperature sensor 35 becomes equal to or lower than the slow cooling end condition and other predetermined end conditions are satisfied, the process proceeds to the next step.

In the slow cooling step, direct cooling of the food by decompression in the can body 2 and indirect cooling of the food by decompression in the main jacket 3 can be used in combination to efficiently achieve overall cooling. .. Further, when the food is cooled, if only the inside of the can body 2 is depressurized from the beginning, the difference from the saturation temperature corresponding to the pressure inside the can body 2 due to the decompression opens while the product temperature of the food remains relatively high. Therefore, there is a risk that the food will suddenly boil and scatter, but first, by depressurizing not only the can body 2 but also the inside of the main jacket 3 (the decompression speed will decrease by that amount), the food will suddenly boil and prevent scattering. be able to.

≪Main cooling process≫
In this cooling step, the inside of the can body 2 is further depressurized while the exhaust from the inside of the main jacket 3 is stopped. Specifically, the operation of the pressure reducing means 5 may be continued with the jacket vacuum valve 17 closed. As the main cooling step after the slow cooling step, the inside of the can body 2 can be further depressurized in a state where the exhaust from the inside of the main jacket 3 is stopped to achieve vacuum cooling of the food. After the cooling has progressed to some extent, the food can be quickly and surely cooled to a desired temperature by performing vacuum cooling only by reducing the pressure inside the can body 2. When a predetermined termination condition such as the detection temperature of the product temperature sensor 35 reaching the cooling target temperature is satisfied, the decompression means 5 is stopped and a series of operations is terminated. After that, the inside of the can body 2 is restored to the atmospheric pressure by the vacuum releasing means, and the lid material 2B is opened, so that the food can be taken out from the inside of the can body 2.

The steam kettle 1 of the present invention is not limited to the configuration (including control) of the above embodiment, and can be appropriately changed. In particular, (a) a can body 2 which can be opened and closed by the lid material 2B and which houses food, and (b) a main jacket 3 provided outside the can body 2 to which steam or water is supplied, and (c). ) The sub-jacket 4 provided on the outside of the main jacket 3 and supplied with steam, and (d) connected to both the can body 2 and the main jacket 3, sucking and discharging the gas of both to the outside, and both are sucked and discharged to the outside. The food in the can body 2 is controlled by controlling the depressurizing means 5 capable of depressurizing, (e) the steaming means 6 capable of supplying steam into at least the sub-jacket 4, and (f) the depressurizing means 5 and the steaming means 6. Other configurations can be appropriately modified as long as it is provided with a control means for heating under reduced pressure.

For example, the configuration of the decompression means 5 and the method of adjusting the decompression capacity are not limited to the above-described embodiment, and can be appropriately changed. Further, in the above-described embodiment, the main jacket 3 is also configured so that steam can be supplied, but this is not essential. That is, the water supplied into the main jacket 3 by the water supply means 7 may be heated and vaporized by steaming into the sub jacket 4 (or other heating means provided in place of the water supply means 7).

Further, in the above embodiment, the steam kettle 1 may be configured as a steam kneader. That is, the steam kettle 1 may include a food agitator in the can body 2. For example, a shaft is provided so as to bridge the left and right sides of the can body 2, and a stirring blade is provided on the shaft via an arm extending outward in the radial direction, and the stirring blade is provided during heating and / or cooling of food. May be rotated.

1 Steam kettle 2 Can body (2A: main body, 2B: lid material)
3 Main jacket 4 Sub jacket 5 Decompression means 6 Steaming means 7 Water supply means 8 Discharge means 9 Jacket body 10 Upper wall 11 Partition wall 12 Exhaust passage (12A: 1st exhaust passage, 12B: 2nd exhaust passage)
13 Steam ejector (13a: suction port, 13b: inlet, 13c: outlet)
14 Heat exchanger 15 Vacuum pump 16 Check valve 17 Jacket vacuum valve 18 Check valve 19 Ejector steam supply path 20 Ejector steam supply valve 21 Jacket steam supply path 22 Steam supply shutoff valve 23 Steam supply control valve 24 Safety valve 25 Communication passage 26 Communication valve 27 Water supply channel (27A: branch path)
28 Strainer 29 Water supply valve 30 Spray nozzle 31 Discharge passage (31A: 1st discharge passage, 31B: 2nd discharge passage)
32 Steam trap 33 Check valve 34 Pressure sensor 35 Product temperature sensor 36 Gas phase temperature sensor 37 Liquid phase temperature sensor 38 Water level sensor

Claims (7)

A can body that can be opened and closed with a lid and stores food,
The main jacket, which is provided on the outside of this can and is supplied with steam or water,
The sub-jacket, which is provided on the outside of this main jacket and is supplied with steam,
A decompression means that is connected to both the can body and the main jacket and can suck and discharge the gas of both to the outside to reduce the pressure of both.
A steaming means capable of supplying steam into at least the sub-jacket,
A control means for controlling the depressurizing means and the steaming means to heat the food in the can under reduced pressure is provided .
As a food heating step, the control means stores the inside of the can and the inside of the main jacket by steaming into the sub-jacket while keeping the inside of the can and the inside of the main jacket below atmospheric pressure by the decompression means. A steam kettle characterized in that water is heated to generate saturated steam, and the saturated steam in the main jacket heats the food in the can. In the heating step, steaming into the sub-jacket is controlled based on the product temperature of the food in the can or the temperature in the main jacket, and / or decompression by the depressurizing means is controlled. The steam kettle according to claim 1. A can body that can be opened and closed with a lid and stores food,
The main jacket, which is provided on the outside of this can and is supplied with steam or water,
The sub-jacket, which is provided on the outside of this main jacket and is supplied with steam,
A decompression means that is connected to both the can body and the main jacket and can suck and discharge the gas of both to the outside to reduce the pressure of both.
A steaming means capable of supplying steam into at least the sub-jacket,
A control means for controlling the depressurizing means and the steaming means to heat the food in the can under reduced pressure is provided .
The exhaust passage from the inside of the main jacket by the decompression means is provided with a jacket vacuum valve upstream of the confluence with the exhaust passage from the inside of the can.
A steam kettle characterized in that the opening degree of the jacket vacuum valve is adjusted during exhaust by the decompression means from both the can body and the main jacket. A can body that can be opened and closed with a lid and holds food,
The main jacket, which is provided on the outside of this can and is supplied with steam or water,
The sub-jacket, which is provided on the outside of this main jacket and is supplied with steam,
A decompression means that is connected to both the can body and the main jacket and can suck and discharge the gas of both to the outside to reduce the pressure of both.
A steaming means capable of supplying steam into at least the sub-jacket,
A control means for controlling the depressurizing means and the steaming means to heat the food in the can under reduced pressure is provided .
The control means is used as an initial temperature raising step before the heating step of heating the food in the can at a target temperature until the inside of the main jacket reaches a predetermined preheating temperature set lower than the target temperature. A steam kettle characterized in that steam is supplied into the jacket and the sub-jacket. A can body that can be opened and closed with a lid and stores food,
The main jacket, which is provided on the outside of this can and is supplied with steam or water,
The sub-jacket, which is provided on the outside of this main jacket and is supplied with steam,
A decompression means that is connected to both the can body and the main jacket and can suck and discharge the gas of both to the outside to reduce the pressure of both.
A steaming means capable of supplying steam into at least the sub-jacket,
A control means for controlling the depressurizing means and the steaming means to heat the food in the can under reduced pressure is provided .
The control means is a heating step of heating the food in the can at a target temperature, and then as a slow cooling step, in a state where steaming into the main jacket and the sub jacket is stopped, the inside of the can and the main. A steam kettle characterized by depressurizing the inside of the jacket. The steam kettle according to claim 5 , wherein the control means further depressurizes the inside of the can in a state where exhaust from the main jacket is stopped as the main cooling step after the slow cooling step. The steam kettle according to any one of claims 1 to 6 , further comprising a food agitator in the can.

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