JP2018132293A - Manufacturing device and manufacturing method of slurry ice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing device and a manufacturing method of slurry ice capable of not only sufficiently keeping freshness of a cooled object such as fish, but also hardly damaging the cooled object.SOLUTION: A manufacturing method for manufacturing slurry ice from salt water in a circulation state, includes an air bubble production process for producing air bubbles mainly composed of a nitrogen gas in the salt water, and a cooling process for cooling the salt water in a state of keeping the air bubbles produced in the air bubble production process. The air bubble production process includes a first process for supplying a gas mainly composed of salt water and a nitrogen gas to a first chamber, a second process for supplying the salt water and the gas supplied to the first chamber to a second chamber communicated with the first chamber through a narrow communication port, and a third process for supplying the salt water and the gas supplied to the second chamber to a third chamber communicated with the second chamber through a narrow communication port.SELECTED DRAWING: Figure 1

Description

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

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

  For example, in Patent Document 1, the ice making efficiency is improved and simplified by reducing the contact surface between the slurry ice transferred from the ice making machine to the ice storage tank and the outside air, and making an ice making structure that does not require a pump. An apparatus for producing slurry ice is disclosed which can be miniaturized in structure and can make the best use of the ability of the apparatus for making slurry ice without clogging the tube with increased ice particles.

  Patent Document 2 includes a step of storing the collected seawater in a storage tank for the purpose of being able to be used in a variety of ways, such as cold storage of fish, as compared with the prior art, with ice from seawater with reduced oxygen content, Injecting nitrogen gas into the storage tank to release oxygen; sterilizing the stored seawater; transferring the sterilized seawater to a cooling tank and circulating and cooling between the cooling devices; , A step of sending seawater supercooled to −2 ° C. or less and generated ice to an ice separation tank, separating the generated ice and transporting it out of the ice separation tank, and the supercooled seawater separated from ice is a return pipe The method for producing ice from seawater is characterized in that the step of returning to the cooling tank is sequentially performed.

JP2013-0336628A 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 the ice particles come into contact with the fish and damage the fish cannot be solved.

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

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

  In the manufacturing method of the present invention, the salt water and the gas mainly containing nitrogen gas supplied to the first chamber are supplied to the second chamber through the narrowly formed communication port, and then supplied to the second chamber. By supplying the salt water and the gas to the third chamber through the narrowly formed communication port, fine bubbles mainly containing nitrogen gas are generated in the salt water when entering the third chamber. Thereby, the oxygen gas in salt water is expelled outside and the amount of oxygen in salt water can be reduced. And when 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 brought into a supercooled state (metastable state), so that the generation of ice particles is suppressed, Shake-like slurry ice with extremely high viscosity can be produced. And if the object to be cooled such as fish is stored using the shake-like slurry ice in which the oxygen concentration is extremely small and the generation of ice particles is suppressed, the object to be cooled is suppressed from being oxidized by salt water. The freshness of the object can be sufficiently maintained, and the cooling object such as fish can be hardly damaged. The “gas containing nitrogen gas as the main component” in the present specification refers to, for example, 19% by mass or more, preferably 23% by mass or more, more preferably 26% by mass of nitrogen gas with respect to the whole gas (% by mass) The gas containing above is said.

  The production method of the present invention includes a storage step of storing salt water in a storage device, and the salt water supplied in the first step is preferably salt water stored in the storage step. In the storage step, it is more preferable to perform nitrogen replacement after the atmosphere is in a reduced pressure state, and further includes a pressure reduction step in which nitrogen replacement is performed after the atmosphere of the storage device is in a reduced pressure 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) that can store the salt water. In addition, the “atmosphere” in the present specification refers to an upper space located above salt water stored in a storage device (for example, a chamber), for example. Further, the “depressurized state” referred to in the present specification means, for example, that the pressure in the upper space is less than atmospheric pressure, and is preferably as low as possible at atmospheric pressure. By performing nitrogen substitution after reducing the atmosphere to a reduced pressure state, the amount of oxygen in the atmosphere decreases, so that the dissolved amount of oxygen gas dissolved in the stored salt water can be further reduced. For this reason, it can suppress further that a cooling countermeasure thing is oxidized with salt water, and exists in the tendency which can maintain the freshness of a cooling target object further. Moreover, 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 in the bubble generating device, and the boiling point (0 ° C.) of the salt water during decompression is further reduced. can do. For this reason, it can suppress further that an ice particle produces | generates in salt water or slurry ice solidifies. It should be noted that after the atmosphere is depressurized and then replaced with nitrogen, the atmosphere is preferably in a pressurized state.

  It is preferable that the manufacturing method of this invention includes the stirring process which stirs the salt water in a circulation 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 salt water in the circulating state, it is possible to further suppress the formation of ice particles in the salt water and the solidification of the slurry ice, and that the generated bubbles merge to increase the size of the bubbles. It can be further suppressed. Further, when the salt water is in a supercooled state (metastable state), there is a tendency that no ice particles exist in the salt water, but as time elapses, ice particles may start to be generated in the salt water. Even in this case, it is possible to further suppress the formation of ice particles in the salt water over time by stirring the salt water in the circulating state.

  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 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 reduced, and the water in the salt water can be more surely brought into a supercooled state. Tends to be able to produce highly viscous shake-like slurry ice in which is further suppressed.

  A slurry ice production apparatus of the present invention for achieving the above object is a production apparatus for producing slurry ice from salt water, a storage device for storing salt water, and nitrogen gas in salt water. A bubble generating device that generates bubbles as a main component; a cooling device that cools salt water in a state where bubbles are generated by the bubble generating device; a pipe that forms a circulation path through which the salt water can circulate each of the devices; A pump that is connected to a pipe and supplies salt water stored in the storage device to the bubble generating device, and the bubble generating device includes a first chamber, a second chamber, and a third chamber. The first chamber includes a supply port for salt water stored in the storage device and a supply port for nitrogen gas, and the second chamber communicates with the first chamber; And a second communication port communicating with the third chamber, Three chambers are provided with a salt water discharge port, the first communication port and the second communication port are formed narrowly, and salt water and nitrogen gas are supplied to the first chamber, the second chamber, and By moving in the order of the third chamber, bubbles mainly composed of nitrogen gas can be generated in the salt water. The bubble generating device of the manufacturing apparatus of the present invention has a communication port that communicates between the first chamber and the second chamber, and a communication port that communicates between the second chamber and the third chamber. When salt water and nitrogen gas move in the order of the first chamber, the second chamber, and the third chamber, fine bubbles mainly containing nitrogen gas are generated in the salt water when entering the third chamber. Thereby, oxygen gas in salt water is expelled outside, and the amount of oxygen in salt water can be reduced. And when 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 brought into a supercooled state (metastable state), so that the generation of ice particles is suppressed, Shake-like slurry ice with extremely high viscosity can be produced. And if the object to be cooled such as fish is stored using the shake-like slurry ice in which the oxygen concentration is extremely small and the generation of ice particles is suppressed, the object to be cooled is suppressed from being oxidized by salt water. The freshness of the object can be sufficiently maintained, and the cooling object such as fish can be hardly damaged. As described above, the first communication port and the second communication port are formed with a narrow width. In other words, the first communication port and the second communication port each have a narrow portion.

  In the bubble generating device, the volume of the second chamber is preferably 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 first volume, 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 salt water and nitrogen gas supplied to the second chamber are changed more greatly when moving to the third chamber. Therefore, fine bubbles can be generated more stably and reliably.

  In the bubble generating device, 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. It 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. Since the generation time of the salt water and nitrogen gas from the first chamber to the third chamber can be further shortened, the production efficiency of slurry ice can be further improved, and the bubble generating device can be made more compact. .

  The bubble generating device is connected to the cooling device so that the salt water in which bubbles are 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 to be connected to the storage device so that salt water can be supplied.

  Thereby, the salt water in which bubbles are generated by the bubble generating device can be supplied to the cooling device, cooled, and the cooled salt water can be supplied into the storage device.

  The production apparatus of the present invention preferably includes a stirring device for stirring the salt water. For example, by providing the stirring device in the storage device, it is possible to further suppress the generation of ice particles in the salt water or 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 production apparatus of the present invention preferably includes a decompression device that decompresses the atmosphere of the storage device, and the decompression device includes an ejector having a drive port, a suction port, and a discharge port, It connects with the discharge port of the said 3rd chamber so that salt water can be supplied toward the said drive port from the discharge port of the said 3rd chamber, The said suction port and the said storage device can reduce the atmosphere of the said 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 includes the decompression device, the atmosphere of the storage device can be reduced. Thereby, the dissolved amount of oxygen gas dissolved in the stored salt water can be further reduced. For this reason, it can suppress further that a cooling countermeasure thing is oxidized with salt water, and exists in the tendency which can maintain the freshness of a cooling target object further. Moreover, 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 in the bubble generating device, and fine bubbles mainly composed of nitrogen gas are formed in the salt water. It tends to be more stable and reliable. The drive port may be called the primary side, the discharge port may be called the secondary side, the suction port may be called the suction side, and the ejector may be called the aspirator.

  The size of the bubble may be a size that does not scatter visually when light is applied to the bubble, and is preferably 50 μm or less, more preferably 10 μm or less, and more preferably 5 μm or less. More preferably. When the salt water is cooled in a state where 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 brought into a supercooled state (metastable state). There is a tendency to produce highly viscous shake-like slurry ice in which the generation of ice particles is further suppressed.

  In the slurry ice manufacturing device of the present invention, the bubble generating device preferably 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 generating device is preferably 0.2 × 10 ⁶ Pa or more and 0.6 × 10 ⁶ Pa or less.

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

  The storage device (for example, chamber) can be made of, for example, a metal, an alloy (for example, stainless steel), or a plastic material. The storage device is preferably sealed. What is necessary is just to determine the capacity | capacitance of a storage apparatus suitably according to the production capacity etc. of the slurry ice of the required slurry ice production apparatus, for example. The cooling device (for example, a refrigerator) is not particularly limited as long as it is a refrigerator having a configuration or structure capable of cooling salt water, for example, and the refrigerating capacity (capability of cooling salt water) is that of the required slurry ice production apparatus. What is necessary is just to determine suitably according to the manufacturing capacity of slurry ice, etc. The pipe may be made of, for example, metal, alloy (for example, stainless steel), plastic pipe (pipe), or the like. Examples of the pump include, for example, a centrifugal pump that has few failures and can easily form bubbles in salt water, but is not limited thereto, and examples thereof include a cyclone pump. The pump is not particularly limited as long as it has a configuration or structure capable of conveying salt water, and the capacity of the pump may be appropriately determined according to the required slurry ice production capacity of the slurry ice production apparatus, the required discharge pressure, and the like. .

  The salt water (also referred to as “brine”) in the present specification means a saturated aqueous solution of sodium chloride or an aqueous solution close to saturation, and may include seawater. The slurry ice obtained by the present invention is in a state containing bubbles mainly composed of nitrogen gas, but the bubbles may contain a gas component constituting air such as oxygen gas in addition to the nitrogen gas. .

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing apparatus and manufacturing method of the slurry ice which can keep a cooling target object, such as a fish hard, and can fully maintain the freshness of a cooling target object can be provided.

FIG. 1 is a configuration diagram of an apparatus for producing slurry ice according to the present embodiment. FIG. 2 is a schematic cross-sectional view of a bubble generating device in the slurry ice manufacturing apparatus shown in FIG.

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

  This embodiment demonstrates the manufacturing method of the slurry ice using the slurry ice manufacturing apparatus of this invention. However, the method for producing slurry ice of the present invention is not limited to using the slurry ice production apparatus of the present invention.

[Slurry ice production equipment]
FIG. 1 is a configuration diagram of an apparatus for producing slurry ice according to the present embodiment. A slurry ice production apparatus 1 shown in FIG. 1 (hereinafter, “slurry ice production apparatus” is also simply referred to as “production apparatus”) is stored in a storage apparatus (chamber) 10 that stores salt water and a storage apparatus 10. A bubble generating device 40 that mixes salt water and nitrogen gas to generate bubbles mainly composed of nitrogen gas in the salt water, and a cooling device that cools the salt water while maintaining the bubbles generated by the bubble generating device 40 ( A refrigerating machine 20, a decompression device 50 that depressurizes the atmosphere of the storage device 10, a stirring device (motor) 70 that stirs the circulating salt water, and salt water in each device (storage device 10, bubble generation device 40, cooling device 20 , And a pipe 60 that forms a circulation path that can circulate through the decompression device 50), 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 piping 60 of the manufacturing apparatus 1 of the present embodiment connects the storage device 10 and the pump 30, the first piping 61 for supplying salt water from the storage device 10 to the pump 30, the pump 30 and the bubble supply device 40. And a second pipe 62 for supplying salt water from the pump 30 to the bubble supply device 40, one end connected to the bubble supply device 40, the other end branched, and the other of the branched one. One end is connected to the cooling device 20, the other branched side is further branched, the other branched side is connected to the storage device 10, and the other branched side is connected to the decompression device 50. The 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, the cooling device 20 and the storage device 10 are connected, and the cooling device 20 is connected. Supply salt water to the storage device 10 A fourth pipe 64, one end connected to the pressure reducing device 50, the other end connected to the middle of the first pipe 61, and a fifth pipe for supplying salt water from the pressure reducing device 50 to the first pipe 61. 65. The pipe 60 includes a first pipe 61, a second pipe 62, a third pipe 63, a fourth pipe 64, and a fifth pipe 65, whereby each device (the storage device 10, the bubble generating device 40, the cooling device). A circulation path capable of circulating the device 20 and the decompression device 50) is formed. Each piping 61-65 shown in FIG. 1 is produced from the stainless steel pipe, for example.

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

[Storage device 10]
A storage device 10 shown in FIG. 1 is configured by a sealed chamber made of stainless steel.

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

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

  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, nitrogen gas and salt water are supplied to the second chamber 46 communicated with the first chamber 45 through the first communication port (suction side opening) 47A. In the second step, the nitrogen gas and salt water supplied to the second chamber 46 are mixed more uniformly. Next, the nitrogen gas and the salt water are supplied (entered) into the third chamber 48 communicating with the second chamber 46 via the second communication port (discharge side opening) 47B. As soon as the salt water and nitrogen gas enter the third chamber 48, fine bubbles mainly containing nitrogen gas are generated due to a rapid change in gas pressure. Then, it flows from the discharge port (discharge part) 49 of the third chamber 48 to the third pipe 63.

  The bubble generating device 40 is made of stainless steel.

  The nitrogen gas source 41 may be configured by, for example, a nitrogen gas separation device including 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 apparatus 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 spiral pump.

[Decompression device 50]
A decompression device 50 shown in FIG. 1 includes 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 supplied 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 (shown by a dotted line in FIG. 1), and can reduce the atmosphere of the storage device 10. A suction valve 94 for controlling the 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 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 disposed in the storage device 10 and stirs the salt water stored in the storage device 10. The stirring device 70 is configured by 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 manufacturing method of slurry ice of this embodiment includes the following processes, for example.

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

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

  Hereinafter, the manufacturing method of the slurry ice of this embodiment is demonstrated concretely.

(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 process). Prior to or in parallel with the storage step, 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 FIG. 1, circulation of salt water is started in a state where 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 being replaced with nitrogen, and the cooling temperature is, for example, −30 to 2 ° C. when cooling in a state where bubbles are not generated in the salt water, which will be described later. When salt water is cooled in a state where the bubbles generated by the bubble generation process are maintained, the temperature is, for example, −7 to 2 ° C.

(Decompression step)
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 tube 63, and the drive port 52 is supplied. The salt water supplied to the refrigerant flows through the decompression device 50 and is sent back from the discharge port 54 to the first pipe 61 via the fifth pipe 65. Thus, the upper space 11 of the storage device (chamber) 10 connected to the suction port (secondary side) 53 is decompressed via the suction pipe 85.

(Bubble generation process)
After the decompression state of the upper space 11 is set to a desired state, the bubble generating 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. Are supplied to the first chamber 45 of the bubble generating device 40 (first step of the bubble generating step). Next, nitrogen gas and salt water are supplied to the second chamber 46 communicated with the first chamber 45 through the first communication port (suction side opening) 47A (second step of the bubble generation step). In the second step, the nitrogen gas and salt water supplied to the second chamber 46 are mixed more uniformly. Next, nitrogen gas and salt water are supplied to the third chamber 48 communicated with the second chamber 46 through the second communication port (discharge side opening) 47B (third step). In the third step, at the moment when salt water and nitrogen gas enter the third chamber 48, fine bubbles mainly containing nitrogen gas are generated due to a rapid change in gas pressure. Then, salt water and nitrogen gas are sent out from the discharge port (discharge section) 49 of the third chamber 48 through the third pipe 63 and 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 measurement method described above, and was about 2 μm in diameter.

(Stirring process)
Bubbles mainly composed of nitrogen gas are generated in the salt water in a circulating state, and the salt water is continuously stirred while cooling the salt water 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 passed through the bubble generation process, a cooling process is performed. In the cooling step, the fifth valve 96 is changed from the closed state to the open state while continuing to circulate the salt water and generating bubbles mainly containing nitrogen gas in the salt water and maintaining this state. ) 20 is activated. Thus, salt water and nitrogen gas are supplied from the bubble generating device 40 toward the cooling device 20 via the third pipe 63, and the salt water is cooled in a state where the generated bubbles are maintained. 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 removed. Thus, it is possible to obtain shake-like slurry ice having extremely high viscosity in which the generation of ice particles is suppressed.

  As time elapses, ice particles may begin to form in the salt water, but even in such a case, the salt water continues to circulate and bubbles that are mainly composed of nitrogen gas are generated and maintained in this state. While cooling, the generation 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 mainly containing nitrogen gas are generated in the circulating salt water, and the salt water is cooled while maintaining the generated bubbles. Thereby, first, the oxygen gas in salt water is expelled outside, and the amount of oxygen in salt water can be reduced. Moreover, the freezing point of salt water falls, salt water is not frozen (it is not solidified), and the water in salt water will be in a supercooled state. As a result, the generation of ice particles is suppressed, and the resulting slurry ice has a highly viscous shake-like form. For this reason, when the object to be cooled such as fish is stored using the shake-like slurry ice in which the oxygen concentration is extremely small and the generation of ice particles is suppressed, the freshness of the object to be cooled can be sufficiently maintained, and The cooling object can be made difficult to be damaged.

  As mentioned above, although this invention was demonstrated based on this embodiment, this invention is not limited to this embodiment. Various devices, parts, and members that constitute the slurry ice manufacturing apparatus described in the present embodiment are exemplifications. Needless to say, the slurry ice manufacturing method described in the present embodiment is also exemplified. Needless to say, it can be appropriately changed.

DESCRIPTION OF SYMBOLS 1 ... Manufacturing apparatus, 10 ... Storage apparatus (chamber), 11 ... Upper space of storage apparatus (chamber), 20 ... Cooling apparatus (refrigerator), 30 ... Pump, 40 ... Bubble generating apparatus, 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 port (discharge side opening), 48 ... third chamber, 49 ... discharge port (discharge unit), 50 ... decompression device, 51 ... ejector (aspirator), 52 ... drive port (primary side), 53 ... suction Mouth (secondary side), 54 ... discharge port (suction side), 60 ... piping, 61 ... first piping, 62 ... second piping, 63 ... third piping, 64 ... fourth piping, 65 ... Fifth pipe, 70 ... stirrer, 85 ... suction pipe, 91 ... first valve, 92 ... second valve , 93 ... a third valve, 94 ... suction valve, 95 ... the fourth valve, 96 ... fifth valve

Claims (17)

A production method for producing slurry ice from salt water in a circulating state,
A bubble generating step for generating bubbles mainly containing nitrogen gas in salt water;
A cooling step of cooling the salt water while maintaining the bubbles generated by the bubble generation step,
The bubble generating step is a first step of supplying a gas mainly composed of salt water and nitrogen gas to the first chamber;
A second step of supplying the salt water and the gas supplied to the first chamber to a second chamber communicating with the first chamber via a narrow communication port;
A third step of supplying the salt water and the gas supplied to the second chamber to the third chamber through the narrow communication port and the third chamber having a discharge port. How to make ice. Including a storage step of storing salt water in a storage device;
The manufacturing method of Claim 1 whose salt water supplied in a said 1st process is the salt water stored by the said storage process.   The manufacturing method according to claim 2, wherein in the storage step, nitrogen substitution is performed after the atmosphere is in a reduced pressure state.   The manufacturing method of Claim 3 including the pressure reduction process of performing nitrogen substitution after making the atmosphere of the said storage apparatus into a pressure reduction state before the said bubble production | generation process.   The manufacturing method of any one of Claims 1 thru | or 4 including the stirring process which stirs the salt water in a circulation state.   The manufacturing method of any one of Claims 1 thru | or 5 whose magnitude | size of the bubble produced | generated in the said bubble production | generation process is 50 micrometers or less.   The manufacturing method of any one of Claims 1 thru | or 6 whose nitrogen gas dissolution rate in the said slurry ice is 2 times or more of the nitrogen gas dissolution rate of the salt water before the said bubble production | generation process. A production apparatus for producing slurry ice from salt water,
A storage device for storing salt water;
A bubble generating device that generates bubbles mainly containing nitrogen gas in salt water;
A cooling device for cooling salt water in a state where bubbles are generated by the bubble generating device;
Piping that forms a circulation path through which salt water can circulate through the devices;
A pump connected to the pipe and supplying the salt water stored in the storage device to the bubble generating device,
The bubble generating device has a first chamber, a second chamber, and a third chamber,
The first chamber includes a supply port for salt water stored in the storage device, and a supply port for nitrogen gas,
The second chamber includes a first communication port communicating with the first chamber and a second communication port communicating with the third chamber;
The third chamber has a salt water outlet;
The first communication port and the second communication port are each formed in a narrow width, and salt water and nitrogen gas move in the order of the first chamber, the second chamber, and the third chamber, so that the salt water A device for producing slurry ice, which can generate bubbles mainly composed of nitrogen gas.   The manufacturing apparatus according to claim 8, 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 first chamber and the third chamber are adjacent to each other;
The manufacturing apparatus of Claim 8 or 9 with which the said 2nd chamber is formed in the whole outer wall comprised by the said 1st chamber and the said 3rd chamber. The bubble generating device is connected to the cooling device so that salt water in which bubbles are generated by the bubble generating device can be supplied to the cooling device,
The manufacturing device according to any one of claims 8 to 10, wherein the cooling device is connected to the storage device so as to be able to supply salt water from the cooling device toward the storage device.   The manufacturing apparatus of any one of Claims 8 thru | or 11 provided with the stirring apparatus which stirs salt water.   The manufacturing apparatus of any one of Claims 8 thru | or 12 provided with the decompression device which decompresses the atmosphere of the said storage apparatus. The pressure reducing 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 reduced,
The manufacturing apparatus according to claim 13, 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 claim 8, wherein the size of the bubbles is 50 μm or less. The pressure of the salt water discharged toward the said bubble production | generation apparatus from the said pump is 0.2 * 10 < ⁶ > Pa or more and 0.6 * 10 < ⁶ > Pa or less of any one of Claims 8 thru | or 15. manufacturing device.   The method to suppress the production | generation of an ice particle in slurry ice using the manufacturing method of any one of Claims 10 thru | or 16.