JP7060397B2 - Slurry ice manufacturing equipment and manufacturing method - Google Patents

Description

The present invention relates to an apparatus and a method for producing slurry ice.

In order to maintain the freshness of the object to be cooled such as fish for a long time, slurry ice is produced from brine such as seawater, and the object to be cooled is cooled and stored using the slurry ice.

For example, in Patent Document 1, ice making efficiency is improved and simplified by reducing the contact surface between the slurry ice transferred from the ice maker to the ice storage tank and the outside air and adopting an ice making structure that does not require a pump. Disclosed is a slurry ice making device that can be miniaturized in structure and can maximize the ability of the device for making slurry ice without clogging the tube due to the increased ice particles.

Patent Document 2 describes a process of storing taken seawater in a storage tank for the purpose of making it possible to use ice from seawater with a reduced amount of oxygen for various purposes such as keeping fish cooler than before. A step of injecting nitrogen gas into the storage tank to release oxygen, a step of sterilizing the stored seawater, and a step of transferring the sterilized seawater to a cooling tank and circulating it between the cooling device for cooling. , The process of sending the seawater supercooled to -2 ° C or less and the generated ice to the ice separation tank, separating the generated ice and carrying it out of the ice separation tank, and the supercooled seawater separated from the ice is a return pipe. Disclosed is a method for producing ice from seawater, which comprises sequentially performing a step of returning the ice to a cooling tank.

Japanese Unexamined Patent Publication No. 2013-306628 Japanese Patent No. 6044019

However, the slurry ice obtained by the methods described in these documents has a sherbet-like form, and the problem that ice particles come into contact with the fish body and damage the fish body cannot be solved.

Therefore, an object of the present invention is to provide a manufacturing apparatus and a manufacturing method for manufacturing slurry ice (slurry ice), which can not only sufficiently maintain the freshness of a cooling object such as fish but also hardly damage the cooling object. There is something in it.

The slurry ice (slurry ice) production method of the present invention for achieving the above object is a production method for producing slurry ice from salt water in a circulating state, and bubbles containing nitrogen gas as a main component are contained in the salt water. The bubble generation step includes a bubble generation step and a cooling step of cooling the salt water while maintaining the bubbles generated by the bubble generation step, and the bubble generation step first comprises a gas containing salt water and nitrogen gas as main components. A first step of supplying the chamber, and a second step of supplying the salt water and the gas supplied to the first chamber to the second chamber communicating with the first chamber through a narrow communication port. , A third step of communicating the salt water and the gas supplied to the second chamber with the second chamber through a narrow communication port and supplying the third chamber provided with the discharge port.

In the production method of the present invention, the gas mainly composed of salt water and nitrogen gas supplied to the first chamber was supplied to the second chamber through a narrowly formed communication port and supplied to the second chamber. By supplying the salt water and the gas to the third chamber through a communication port formed in a narrow width, when entering the third chamber, fine bubbles containing nitrogen gas as a main component are generated in the salt water. As a result, the oxygen gas in the salt water is expelled to the outside, and the amount of oxygen in the salt water can be reduced. When the salt water is cooled in a state where fine bubbles are generated, the freezing point of the salt water is lowered and the water in the salt water can be in a supercooled state (metastable state), so that the generation of ice particles is suppressed. Shake-shaped slurry ice with extremely high viscosity can be produced. When the object to be cooled such as fish is stored using shake-shaped slurry ice having an extremely low oxygen concentration and suppressed formation of ice particles, the object to be cooled is suppressed from being oxidized by salt water, so that the object is cooled. It is possible to sufficiently maintain the freshness of the object and to prevent the cooling object such as fish from being damaged. The term "gas containing nitrogen gas as a main component" as used herein means, for example, 19% by mass or more, preferably 23% by mass or more, and more preferably 26% by mass of nitrogen gas with respect to the total gas (% by mass). The gas containing the above.

The production method of the present invention includes a storage step of storing salt water in a storage device, and it is preferable that the salt water supplied in the first step is the salt water stored in the storage step. In the storage step, it is more preferable to perform nitrogen substitution after the atmosphere is in a reduced pressure state, and further include a decompression step in which nitrogen substitution is performed after the atmosphere of the storage device is in a depressurized state before the bubble generation step. preferable.

The salt water may be stored in a storage device (for example, a storage container such as a chamber) capable of storing the salt water. Further, the "atmosphere" as used herein means, for example, an upper space located above the salt water stored in the storage device (for example, a chamber). Further, the "decompressed state" referred to in the present specification means, for example, that the pressure in the upper space is less than the atmospheric pressure, and is preferably lower than the atmospheric pressure as much as possible. By performing nitrogen substitution after reducing the pressure of the atmosphere, the amount of oxygen in the atmosphere is reduced, so that the amount of oxygen gas dissolved in the stored salt water can be further reduced. Therefore, it is possible to further suppress the oxidation of the cooling object by salt water, and there is a tendency that the freshness of the cooling object can be further maintained. In addition, since the dissolved amount of oxygen gas in the stored salt water can be reduced, it is easier to dissolve nitrogen gas in the salt water supplied by the bubble generator, and the boiling point (0 ° C) of the salt water at the time of depressurization is further lowered. can do. Therefore, it is possible to further suppress the formation of ice particles in salt water and the solidification of slurry ice. It is preferable to put the atmosphere in a pressurized state after performing nitrogen substitution after putting the atmosphere in a reduced pressure state.

The production method of the present invention preferably includes a stirring step of stirring salt water in a circulating state. In the stirring step, it is preferable that bubbles containing nitrogen gas as a main component are generated in the circulating salt water, and the salt water is continuously stirred while the salt water is cooled in the state where the bubbles are generated. By stirring the circulating salt water, it is possible to further suppress the formation of ice particles in the salt water and the solidification of the slurry ice, and at the same time, the generated bubbles are united to increase the size of the bubbles. It can be further suppressed. Further, when the salt water is in a supercooled state (semi-stable state), ice particles tend not to be present in the salt water, but with the passage of time, ice particles may start to be generated in the salt water. Even in this case, by stirring the circulating salt water, it is possible to further suppress the formation of ice particles in the salt water with the passage of time.

The size of the bubbles generated in the bubble generation step is preferably 50 μm or less, more preferably 10 μm or less, and further preferably 5 μm or less. When the salt water is cooled in a state where bubbles having a size of 50 μm or less are generated, the freezing point of the salt water is further lowered and the water in the salt water can be more reliably supercooled, so that ice particles are generated. There is a tendency to produce highly viscous shake-shaped slurry ice in which the amount of water is further suppressed.

The slurry ice (slurry ice) manufacturing apparatus of the present invention for achieving the above object is a manufacturing apparatus for producing slurry ice from salt water, and is a storage device for storing salt water and nitrogen gas in salt water. A bubble generator that generates bubbles as a main component, a cooling device that cools salt water in a state where bubbles are generated by the bubble generator, a pipe that forms a circulation path through which salt water can circulate each device, and the like. A pump connected to a pipe and supplying salt water stored in the storage device to the bubble generator is provided, and the bubble generator has a first chamber, a second chamber, and a third chamber. The first room is provided with a supply port for salt water stored in the storage device and a supply port for nitrogen gas, and the second room is a first communication port communicating with the first room. The third chamber is provided with a second communication port for communicating with the third chamber, the third chamber is provided with a salt water discharge port, and the first communication port and the second communication port are each narrow. It is formed in the width, and by moving the salt water and the nitrogen gas in the order of the first chamber, the second chamber, and the third chamber, it is possible to generate bubbles mainly composed of the nitrogen gas in the salt water. In the bubble generation device of the manufacturing apparatus of the present invention, the communication port connecting the first chamber and the second chamber and the communication port communicating the second chamber and the third chamber are formed in a narrow width. When the salt water and the nitrogen gas move in the order of the first chamber, the second chamber, and the third chamber, when they invade the third chamber, fine bubbles containing nitrogen gas as a main component are generated in the salt water. As a result, the oxygen gas in the salt water is expelled to the outside, and the amount of oxygen in the salt water can be reduced. When the salt water is cooled in a state where fine bubbles are generated, the freezing point of the salt water is lowered and the water in the salt water can be in a supercooled state (metastable state), so that the generation of ice particles is suppressed. Shake-shaped slurry ice with extremely high viscosity can be produced. When the object to be cooled such as fish is stored using shake-shaped slurry ice having an extremely low oxygen concentration and suppressed formation of ice particles, the object to be cooled is suppressed from being oxidized by salt water, so that the object is cooled. It is possible to sufficiently maintain the freshness of the object and to prevent the cooling object such as fish from being damaged. The first communication port and the second communication port are formed to have a narrow width as described above, in other words, the first communication port and the second communication port each have a narrow width portion.

In the bubble generator, it is preferable that the volume of the second chamber is smaller than the volume of the first chamber and smaller than the volume of the third chamber. Since the volume of the second chamber is smaller than the volume of the first chamber, the salt water and nitrogen gas supplied to the second chamber can be mixed more uniformly. Since the volume of the second chamber is smaller than the volume of the third chamber, the gas pressure is further changed when the salt water and nitrogen gas supplied to the second chamber are moved to the third chamber. Therefore, fine bubbles can be generated more stably and reliably.

In the bubble generator, the first chamber and the third chamber are adjacent to each other, and the second chamber is formed in the entire outer wall composed of the first chamber and the third chamber. Is preferable. The first chamber and the third chamber are adjacent to each other, and the second chamber is formed in the entire outer wall composed of the first chamber and the third chamber, so that air bubbles are formed. Since the moving time for the salt water and nitrogen gas to move from the first chamber to the third chamber of the generator can be further shortened, the efficiency of producing slurry ice can be further improved and the bubble generator can be made more compact. ..

The bubble generating device is connected to the cooling device so that the salt water generated by the bubble generating device can be supplied to the cooling device, and the cooling device is directed from the cooling device to the storage device. It is preferable that the storage device is connected to the storage device so that salt water can be supplied.

As a result, the salt water generated by the bubbles generated by the bubble generating device can be supplied to the cooling device to be cooled, and the cooled salt water can be supplied to the storage device.

The manufacturing apparatus of the present invention preferably includes a stirring device for stirring salt water. For example, by providing a stirring device in the storage device, it is possible to further suppress the formation of ice particles in the salt water and the solidification of the slurry ice with the passage of time in the storage device. In the present invention, the stirring device may be provided in the bubble generating device and / or the cooling device.

The manufacturing apparatus of the present invention preferably includes a decompression device that decompresses the atmosphere of the storage device, and the decompression device is composed of an ejector having a drive port, a suction port, and a discharge port. It is connected to the discharge port of the third chamber so that salt water can be supplied from the discharge port of the third chamber toward the drive port, and the suction port can reduce the atmosphere of the storage device with the storage device. It is preferable that the discharge port is connected to the pump so that salt water can be supplied from the discharge port toward the pump. Since the manufacturing apparatus of the present invention is provided with a decompression device, the atmosphere of the storage device can be decompressed. As a result, the amount of oxygen gas dissolved in the stored salt water can be further reduced. Therefore, it is possible to further suppress the oxidation of the cooling object by the salt water, and there is a tendency that the freshness of the cooling object can be further maintained. In addition, since the dissolved amount of oxygen gas in the stored salt water can be reduced, it is easier to dissolve nitrogen gas in the salt water supplied by the bubble generator, and fine bubbles containing nitrogen gas as the main component are formed in the salt water. It tends to be more stable and reliable. The drive port may be the primary side, the discharge port may be the secondary side, the suction port may be the suction side, and the ejector may be an aspirator.

The size of the bubble may be such that it does not scatter visually when the bubble is exposed to light, and is preferably 50 μm or less, more preferably 10 μm or less, and 5 μm or less. Is even more preferable. When the salt water is cooled while the bubbles having the above size are generated, the freezing point of the salt water is further lowered, and the water in the salt water can be more reliably supercooled (metastable state). There is a tendency to produce highly viscous shake-shaped slurry ice in which the formation of ice particles is further suppressed.

In the slurry ice producing apparatus of the present invention, it is preferable that the bubble generating apparatus includes a nitrogen gas source. The nitrogen gas source can be composed of, for example, a nitrogen gas separation device having a nitrogen gas separation membrane that separates nitrogen gas from air.

The pressure of the salt water discharged from the pump toward the bubble generator is preferably 0.2 × 10 ⁶ Pa or more and 0.6 × 10 ⁶ Pa or less.

The present invention includes a method of suppressing the formation of ice particles in slurry ice by using the method for producing slurry ice of the present invention.

The storage device (eg, chamber) can be made from, for example, a metal, an alloy (eg, stainless steel), or a plastic material. The storage device is preferably a closed type. The capacity of the storage device may be appropriately determined depending on, for example, the required slurry ice production capacity of the slurry ice production device. The cooling device (for example, a refrigerator) is not particularly limited as long as it is a refrigerator having a structure or structure capable of cooling salt water, and the refrigerating capacity (capacity to cool salt water) is required for the slurry ice production device. It may be appropriately determined depending on the production capacity of the slurry ice and the like. The pipe may be made of, for example, a metal pipe, an alloy pipe (for example, stainless steel pipe), a plastic pipe, or the like. The pump can be exemplified by, for example, a centrifugal pump which has few failures and can easily form bubbles in salt water, but is not limited to this, and for example, a cyclone type pump can be mentioned. The pump is not particularly limited as long as it is a pump having a structure or structure capable of transporting salt water, and the pump capacity may be appropriately determined depending on the required slurry ice production capacity of the slurry ice production apparatus, the required discharge pressure, and the like. ..

The term "salt water" (also referred to as "brine") as used herein means a saturated aqueous solution of sodium chloride or an aqueous solution close to a saturated state, and may contain seawater. The slurry ice obtained by the present invention is in a state of containing bubbles containing nitrogen gas as a main component, and the bubbles may contain gas components constituting air such as oxygen gas in addition to nitrogen gas. ..

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an apparatus and a method for producing slurry ice that does not easily damage an object to be cooled such as fish and can sufficiently maintain the freshness of the object to be cooled.

FIG. 1 is a block diagram of the slurry ice manufacturing apparatus of the present embodiment. FIG. 2 is a schematic cross-sectional view of the bubble generation device in the slurry ice manufacturing device shown in FIG.

Hereinafter, the present invention will be described with reference to the drawings based on the embodiment for carrying out the present invention (hereinafter referred to as “the present embodiment”), but the present invention is not limited to the present embodiment. The various numerical values and materials in the present embodiment are merely examples, and the present invention is not limited to these examples.

In this embodiment, a method for producing slurry ice using the slurry ice producing apparatus of the present invention will be described. However, the method for producing slurry ice of the present invention is not limited to using the apparatus for producing slurry ice of the present invention.

[Slurry ice manufacturing equipment]
FIG. 1 is a block diagram of the slurry ice manufacturing apparatus of the present embodiment. The slurry ice manufacturing device 1 shown in FIG. 1 (hereinafter, the “slurry ice manufacturing device” is also simply referred to as a “manufacturing device”) is stored in a storage device (chamber) 10 for storing salt water and a storage device 10. A bubble generator 40 that mixes salt water and nitrogen gas to generate bubbles containing nitrogen gas as the main component in the salt water, and a cooling device that cools the salt water while maintaining the bubbles generated by the bubble generator 40 ( Refrigerator) 20, decompression device 50 that reduces the atmosphere of the storage device 10, stirring device (motor) 70 that stirs circulating salt water, and each device (storage device 10, bubble generation device 40, cooling device 20) for salt water. , And a pipe 60 that forms a circulation path through which the decompression device 50) can be circulated, and a pump 30 that is connected to the pipe 60 and supplies the salt water stored in the storage device 10 to the bubble generation device 40.

[Piping 60]
The pipe 60 of the manufacturing apparatus 1 of the present embodiment is a first pipe 61 for connecting the storage device 10 and the pump 30 and supplying salt water from the storage device 10 to the pump 30, the pump 30 and the bubble supply device 40. A second pipe 62 for supplying salt water from the pump 30 to the bubble supply device 40, and one end connected to the bubble supply device 40 and the other end being branched and branched. The end is connected to the cooling device 20, the other branched side is further branched, the other end of the branched connection is connected to the storage device 10, and the other end of the branched connection is connected to the decompression device 50. A third pipe 63 for supplying salt water from the bubble supply device 40 to each of the cooling device 20, the storage device 10, and the decompression device 50, and the cooling device 20 and the storage device 10 are connected to each other to connect the cooling device 20. A fourth pipe 64 for supplying salt water from the storage device 10 and one end connected to the decompression device 50 and the other end connected in the middle of the first pipe 61, and the decompression device 50 to the first pipe 61. A fifth pipe 65 for supplying salt water to the water is provided. By providing the pipe 60 with the first pipe 61, the second pipe 62, the third pipe 63, the fourth pipe 64, and the fifth pipe 65, each device (storage device 10, bubble generation device 40, cooling) is provided. A circulation path capable of circulating the device 20 and the decompression device 50) is formed. Each of the pipes 61 to 65 shown in FIG. 1 is made of, for example, a stainless steel pipe.

The manufacturing apparatus 1 of the present embodiment has a first valve 91 for controlling the supply (flow) of salt water from the storage device 10 to the pump 30 via the first pipe 61, and air bubbles via the third pipe 63. Supply (distribution) of salt water from the bubble supply device 40 to the decompression device 50 via the second valve 92 for controlling the supply (distribution) of salt water from the supply device 40 to the storage device 10 and the third pipe 63. A third valve 93 for controlling the supply (flow) of salt water from the decompression device 50 to the pump 30 via the fifth pipe 65, and a third valve 95 and a third pipe 63. A fifth valve 96 for controlling the supply of salt water from the bubble supply device 40 to the cooling device 20 via the air bubble supply device 40 is provided.

[Storage device 10]
The storage device 10 shown in FIG. 1 is composed of a closed chamber made of stainless steel.

[Bubble generator 40]
FIG. 2 is a schematic cross-sectional view of the bubble generation device 40 in the manufacturing device 1 shown in FIG. The bubble generation device 40 shown in FIG. 2 has a bubble generation chamber 42 including a first chamber 45, a second chamber 46, and a third chamber 48, and a nitrogen gas source 41, and the first chamber 40. And the third room 48 are adjacent to each other, and the second room 46 is formed in the entire outer wall composed of the first room 45 and the third room 48, and the volume of the second room 46 is the first room. It is configured to be smaller than the volume of 45 and smaller than the volume of the third chamber 48.

The first chamber 45 includes a supply port 44 for supplying the salt water stored in the storage device 10 via the second pipe 62, and a nitrogen gas supply port 43 generated by the nitrogen gas source 41. The second chamber 46 includes two first communication ports (suction side openings) 47A that communicate with the first chamber 45, and a second communication port (discharge side opening) 47B that communicates with the third chamber 48. The first communication port 47A and the second communication port 47B are each formed to have a narrow width, in other words, the first communication port 47A and the second communication port 47B have narrow portions, respectively. have. The third chamber 48 is provided with a discharge port (discharge unit) 49 for discharging salt water to the cooling device 20 via the third pipe 63.

The nitrogen gas and salt water supplied from the nitrogen gas supply port 43 and the salt water supply port 44 to the first chamber 45 are mixed in the first chamber 45 to form a spiral shape. Next, the nitrogen gas and the salt water are supplied to the second chamber 46 communicating with the first chamber 45 via the first communication port (suction side opening) 47A. In the second step, the nitrogen gas and the salt water supplied to the second chamber 46 are more uniformly mixed. Next, the nitrogen gas and the salt water are supplied (invaded) to the third chamber 48 communicating with the second chamber 46 through the second communication port (exhaust side opening) 47B. At the moment when salt water and nitrogen gas invade the third chamber 48, fine bubbles containing nitrogen gas as a main component are generated due to a sudden change in gas pressure. Then, it circulates from the discharge port (discharge part) 49 of the third chamber 48 to the third pipe 63.

The bubble generator 40 is made of stainless steel.

The nitrogen gas source 41 may be composed of, for example, a nitrogen gas separation device provided with a nitrogen gas separation membrane that separates nitrogen gas from air. In the present embodiment, the nitrogen gas source is not necessarily a component of the bubble generating device, and may be configured to supply nitrogen gas to the supply port of the first chamber from the outside of the manufacturing device of the present embodiment.

[Cooling device 20]
The cooling device 20 is composed of a general refrigerator.

[Pump 30]
The pump 30 is composed of a centrifugal pump.

[Decompression device 50]
The decompression device 50 shown in FIG. 1 is composed of an ejector (aspirator) 51 having a drive port (primary side) 52, a suction port (secondary side) 53, and a discharge port (suction side) 54. The drive port 52 is connected to the discharge port 49 of the third chamber 48 of the bubble supply device 40 via the third pipe 63, and salt water is discharged from the discharge port 49 of the third chamber 48 toward the drive port 52. It can be supplied. The suction port 53 is connected to the upper space 11 of the storage device 10 via a suction pipe 85 (indicated by a dotted line in FIG. 1), and the atmosphere of the storage device 10 can be depressurized, and the atmosphere of the storage device 10 can be reduced. A suction valve 94 for controlling suction is provided. The discharge port 54 is connected to the suction portion side of the pump 30 via a fifth pipe 65, and salt water can be supplied from the discharge port 54 toward the pump 30.

The ejector 51 is made of stainless steel.

In the present embodiment, the pressure of the salt water discharged from the pump 30 toward the bubble supply device 40 was 0.4 × 10 ⁶ Pa.

[Agitator 70]
The stirring device 70 is arranged in the storage device 10 and stirs the salt water stored in the storage device 10. The stirring device 70 is composed of a general motor.

In the method for producing slurry ice of the present embodiment, for example, bubbles containing nitrogen gas as a main component are generated in salt water in a circulating state, and the salt water is cooled while maintaining the generated bubbles.

That is, the method for producing slurry ice of the present embodiment includes, for example, the following steps.

[Bubble generation process]
In the bubble generation step, bubbles containing nitrogen gas as a main component are generated in the circulating salt water.

[Cooling process]
After the [bubble generation step], the salt water is further circulated to generate bubbles containing nitrogen gas as a main component, and the salt water is cooled while maintaining this state. More specifically, for example, in the method for producing slurry ice of the present embodiment, nitrogen substitution is performed in salt water in a circulating state after the atmosphere is reduced to a reduced pressure state, and then nitrogen gas is used as a main component in a pressurized state. Generate bubbles to cool the salt water. In the present embodiment, nitrogen substitution is performed after the atmosphere is decompressed before the bubble generation step (decompression step). Further, bubbles containing nitrogen gas as a main component are generated in the circulating salt water, and the salt water is continuously stirred while the salt water is cooled in the state where the bubbles are generated (stirring step). The stirring step may be performed in parallel with the bubble generation step and / or the cooling step.

Hereinafter, the method for producing slurry ice of the present embodiment will be specifically described.

(Storage process)
First, salt water obtained by dissolving a predetermined amount of sodium chloride in drinking water is prepared and stored in the storage device (chamber) 10 (storage step). Prior to or in parallel with the storage process, the first valve 91, the second valve 92, the third valve 93, the fourth valve 95, the fifth valve 96, and the suction valve 94 are closed. .. After the storage step, the first valve 91, the second valve 92, the third valve 93, the fourth valve 95, and the suction valve 94 in the closed state are opened, and the pump 30 is operated. In the circulation path shown in 1, the circulation of salt water is started in a state where the supply of salt water from the bubble supply device 40 to the cooling device 20 is stopped. In the storage step, the salt water may be cooled while substituting with nitrogen, and the cooling temperature is, for example, −30 to 2 ° C. when cooling in a state where no bubbles are generated in the salt water, which will be described later. When the salt water is cooled while maintaining the bubbles generated by the bubble generation step, the temperature is, for example, −7 to 2 ° C.

(Decompression process)
Further, the salt water pressurized toward the bubble supply device 40 via the second pipe 62 is supplied to the drive port 52 of the decompression device 50 (ejector 51) via the third pipe 63, and the drive port 52 is supplied. The salt water supplied to is circulated in the decompression device 50, and is sent back from the discharge port 54 to the first pipe 61 via the fifth pipe 65. In this way, the pressure is reduced in the upper space 11 of the storage device (chamber) 10 connected to the suction port (secondary side) 53 via the suction pipe 85.

(Bubble generation process)
After setting the decompression state of the upper space 11 to a desired state, the bubble generation device 40 is operated while continuing the decompression of the upper space 11, and the salt water stored in the storage device 10 and the nitrogen from the nitrogen gas source 41 are operated. And are supplied to the first chamber 45 of the bubble generation device 40 (the first step of the bubble generation step). Next, nitrogen gas and salt water are supplied to the second chamber 46 communicating with the first chamber 45 via the first communication port (suction side opening) 47A (second step of the bubble generation step). In the second step, the nitrogen gas and the salt water supplied to the second chamber 46 are more uniformly mixed. Next, the nitrogen gas and the salt water are supplied to the third chamber 48 communicating with the second chamber 46 through the second communication port (discharge side opening) 47B (third step). In the third step, at the moment when the salt water and the nitrogen gas invade the third chamber 48, fine bubbles containing nitrogen gas as a main component are generated due to the sudden change in the gas pressure. Then, salt water and nitrogen gas are sent out from the discharge port (discharge part) 49 of the third chamber 48 through the third pipe 63, and are sent out to the salt water in the storage device (chamber) 10. The pressure of the salt water in the storage device (chamber) 10 was about 0.4 × 10 ⁶ Pa.

In the present embodiment, the size of the generated bubbles was measured by the above-mentioned measuring method and found to have a diameter of about 2 μm.

(Stirring process)
Bubbles containing nitrogen gas as a main component are generated in the circulating salt water, and the salt water is continuously stirred while the salt water is cooled in the state where the bubbles are generated (stirring step). The stirring step may be performed in parallel with the bubble generation step and / or the cooling step.

(Cooling process)
After a predetermined time has elapsed from the bubble generation step, a cooling step is performed. In the cooling step, the fifth valve 96 is opened from the closed state while the salt water continues to circulate and bubbles containing nitrogen gas as the main component are generated in the salt water to maintain this state, and the cooling device (refrigerator). ) 20 is activated. As a result, salt water and nitrogen gas are supplied from the bubble generation device 40 toward the cooling device 20 through the third pipe 63, and the salt water is cooled while maintaining the generated bubbles. Next, when the cooled salt water and nitrogen gas are supplied to the storage device (chamber) 10 via the fourth pipe 64, the salt water in the storage device (chamber) 10 is cooled and the salt water in the storage device (chamber) is cooled. , It is possible to obtain a shake-shaped slurry ice having extremely high viscosity in which the formation of ice particles is suppressed.

With the passage of time, ice particles may begin to form in the salt water, but even in such cases, the salt water continues to circulate and bubbles containing nitrogen gas as the main component are generated to maintain this state. By cooling while cooling, the formation of ice particles in the salt water in the storage device 10 can be suppressed.

In the method for producing slurry ice of the present embodiment, bubbles containing nitrogen gas as a main component are generated in the circulating salt water, and the salt water is cooled while maintaining the generated bubbles. As a result, first, the oxygen gas in the salt water is expelled to the outside, and the amount of oxygen in the salt water can be reduced. In addition, the freezing point of the salt water drops, the salt water is not frozen (not solidified), and the water in the salt water becomes supercooled. As a result, the formation of ice particles is suppressed, and the resulting slurry ice has a highly viscous shake-like morphology. For this reason, if a cooling object such as a fish is stored using shake-shaped slurry ice having an extremely low oxygen concentration and suppressed formation of ice particles, the freshness of the cooling object can be sufficiently maintained and the freshness of the cooling object can be sufficiently maintained. It is possible to prevent the object to be cooled from being damaged.

Although the present invention has been described above based on the present embodiment, the present invention is not limited to the present embodiment. It goes without saying that various devices, parts, and members constituting the slurry ice manufacturing apparatus described in the present embodiment are examples and can be appropriately changed, and the slurry ice manufacturing method described in the present embodiment is also exemplified. Needless to say, it can be changed as appropriate.

1 ... Manufacturing device, 10 ... Storage device (chamber), 11 ... Storage device (chamber) upper space, 20 ... Cooling device (refrigerator), 30 ... Pump, 40 ... Bubble generator, 41 ... Nitrogen gas source, 42 ... Bubble generation chamber, 43 ... Nitrogen gas supply port, 44 ... Salt water supply port, 45 ... First chamber, 46 ... Second chamber 46, 47A ... First communication port (suction side opening), 47B ... First 2 communication ports (opening on the discharge side), 48 ... 3rd chamber, 49 ... discharge port (discharge part), 50 ... decompression device, 51 ... ejector (aspirator), 52 ... drive port (primary side), 53 ... suction Port (secondary side), 54 ... Discharge port (suction side), 60 ... Piping, 61 ... First pipe, 62 ... Second pipe, 63 ... Third pipe, 64 ... Fourth pipe, 65 ... Fifth pipe, 70 ... Stirrer, 85 ... Suction pipe, 91 ... First valve, 92 ... Second valve, 93 ... Third valve, 94 ... Suction valve, 95 ... Fourth valve, 96 ... 5th valve

Claims (15)

A manufacturing device for manufacturing slurry ice from salt water.
A storage device that stores salt water and
A bubble generator that generates bubbles containing nitrogen gas as the main component in salt water,
A cooling device that cools salt water while bubbles are generated by the bubble generator,
Piping that forms a circulation path through which salt water can circulate each device,
A pump connected to the pipe and supplying the salt water stored in the storage device to the bubble generation device is provided.
The bubble generator has a first chamber, a second chamber, and a third chamber.
The first chamber is provided with a supply port for salt water stored in the storage device and a supply port for nitrogen gas.
The second room includes a first communication port that communicates with the first room and a second communication port that communicates with the third room.
The third room is equipped with a salt water outlet.
The first communication port and the second communication port are each formed to have a narrow width, and salt water and nitrogen gas move in the order of the first chamber, the second chamber, and the third chamber, whereby the salt water is formed. It is possible to generate bubbles whose main component is nitrogen gas .
The first room and the third room are adjacent to each other.
A slurry ice making apparatus in which the second chamber is formed in the entire outer wall composed of the first chamber and the third chamber . The manufacturing apparatus according to claim 1 , wherein the volume of the second chamber is smaller than the volume of the first chamber and smaller than the volume of the third chamber. The bubble generating device is connected to the cooling device so that the salt water generated by the bubble generating device can be supplied to the cooling device.
The manufacturing apparatus according to claim 1 or 2 , wherein the cooling device is connected to the storage device so as to be able to supply salt water from the cooling device to the storage device. The manufacturing apparatus according to any one of claims 1 to 3 , further comprising a stirring device for stirring salt water. The manufacturing apparatus according to any one of claims 1 to 4 , further comprising a decompression device for reducing the atmosphere of the storage device. The decompression device is composed of an ejector having a drive port, a suction port and a discharge port.
The drive port is connected to the discharge port of the third chamber so that salt water can be supplied from the discharge port of the third chamber toward the drive port.
The suction port is connected to the storage device so that the atmosphere of the storage device can be depressurized.
The manufacturing apparatus according to claim 5 , wherein the discharge port is connected to the pump so that salt water can be supplied from the discharge port toward the pump. The manufacturing apparatus according to any one of claims 1 to 6 , wherein the size of the bubbles is 50 μm or less. The one according to any one of claims 1 to 7 , wherein the pressure of the salt water discharged from the pump toward the bubble generator is 0.2 × 10 ⁶ Pa or more and 0.6 × 10 ⁶ Pa or less. manufacturing device. A production method for producing slurry ice from salt water in a circulating state by using the slurry ice production apparatus according to any one of claims 1 to 8 .
A bubble generation process that generates bubbles containing nitrogen gas as the main component in salt water,
A cooling step of cooling the salt water while maintaining the bubbles generated by the bubble generation step is included.
The bubble generation step includes a first step of supplying a gas containing salt water and nitrogen gas as main components to the first chamber.
A second step of supplying the salt water and the gas supplied to the first chamber to the second chamber communicating with the first chamber through a narrow communication port.
A slurry comprising a third step of communicating the salt water and the gas supplied to the second chamber with the second chamber through a narrow communication port and supplying the third chamber having an discharge port. How to make ice. Includes a storage process for storing salt water in a storage device
The production method according to claim 9 , wherein the salt water supplied in the first step is the salt water stored in the storage step. The production method according to claim 10, wherein in the storage step, nitrogen substitution is performed after the atmosphere is reduced in pressure. The production method according to claim 11, further comprising a decompression step of performing nitrogen substitution after depressurizing the atmosphere of the storage device before the bubble generation step. The production method according to any one of claims 9 to 12 , which comprises a stirring step of stirring the salt water in a circulating state. The production method according to any one of claims 9 to 13 , wherein the size of the bubbles generated in the bubble generation step is 50 μm or less. A method for suppressing the formation of ice particles in slurry ice by using the production method according to any one of claims 9 to 14 .

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