JP7056901B2 - Ice and how to make ice - Google Patents

Description

The present invention relates to ice, a refrigerant, a method for producing ice, and a method for producing an object to be cooled.

Conventionally, ice has been used for cooling an object to be cooled for the purpose of maintaining the freshness of fish.

Patent Document 1 discloses a method of cooling a fish by bringing ice made of a saline solution into contact with the fish to maintain the freshness of the fish. Patent Document 1 discloses a method of storing an aqueous salt solution in a container and cooling it from the outside as a method for producing ice composed of a saline solution.

Japanese Unexamined Patent Publication No. 2000-354542

However, in the ice produced by cooling from the outside described in Patent Document 1, the temperature of the ice itself tends to rise during cooling, and the ability to cool the object to be cooled is not sufficient.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide ice having excellent cooling ability, a method for producing the same, a method for producing an object to be cooled, and a refrigerant. Another object of the present invention is to provide ice in a non-separable state and a method for producing the same.

The present inventors have found that the ice of the aqueous solution itself having a lowered freezing point can be produced by a predetermined method, and have completed the present invention. More specifically, the present invention provides the following.

(1) An aqueous solution containing a solute and a liquid containing oil in a non-separable state, which satisfy the following conditions (a) and (b), are frozen ice in a state where the oil is not separated .
(A) The temperature at the completion of melting is less than 0 ° C. (b) The rate of change in the solute concentration of the aqueous solution generated from the ice during the melting process is within 30%.

(2) The ice according to (1), wherein the liquid is raw milk .

(3) The ice according to (1) , wherein the oil is fat .

( 4 ) It is a method of producing ice .
By spraying an aqueous solution containing a solute and a liquid containing oil in a non-separable state onto a wall surface held at a temperature below the freezing point of the aqueous solution, the liquid is not separated from the oil on the wall surface. The process of producing frozen ice and
It has a step of recovering the ice generated on the wall surface.
The method according to (1) to (3), wherein the water pressure of the spray, the temperature of the wall surface, and the holding time of ice on the wall surface until recovery are the conditions for producing ice .

( 5 ) The method according to ( 4 ), wherein in the step of forming the ice, the wall surface is maintained at a temperature 5 ° C. or higher lower than the freezing point of the aqueous solution.

According to the present invention, it is possible to provide ice having excellent cooling ability, a method for producing the same, a method for producing an object to be cooled, and a refrigerant. Further, the present invention can provide ice in a non-separable state and a method for producing the same.

It is a partial cross-sectional perspective view of the ice making machine used in the manufacturing method of the animal and plant or the refrigerated article of the part of this invention. It is a schematic diagram of the ice making system using the ice making machine shown in FIG. It is a graph which shows the time-dependent temperature change about the ice and the high-concentration saline solution which concerns on Example 1. FIG. The temperature of the fish core when the fish is cooled by the ice according to Example 2 (solution: saturated saline solution), the ice according to Example 2 (solution: saturated saline solution + CU), and the saturated saline solution (-20 ° C aqueous solution). Shows the change over time.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto.

<Ice>
The ice of the present invention is a liquid ice containing an aqueous solution containing a solute, which satisfies the following conditions (a) and (b).
(A) The temperature at the completion of melting is less than 0 ° C. (b) The rate of change in the solute concentration of the aqueous solution generated from the ice during the melting process is within 30%.

It is known that when a solute is melted in water, a freezing point depression occurs in which the freezing point of the aqueous solution is lowered. Due to the action of lowering the freezing point, the freezing point of the aqueous solution in which the solute such as salt described in the above-mentioned Patent Document 1 is melted is lowered. That is, ice composed of such an aqueous solution is ice that solidifies at a lower temperature than ice composed of fresh water. Here, the heat required when ice changes to water is called "latent heat", and this latent heat is not accompanied by a temperature change. Due to the effect of such latent heat, the ice having a lowered freezing point as described above remains stable at a temperature equal to or lower than the freezing point of fresh water at the time of melting, so that the state in which cold energy is stored is maintained. Therefore, the cooling capacity of the object to be cooled should be higher than that of ice made of fresh water. However, the present inventors have found that the ice described in Patent Document 1 does not have sufficient ability to cool an object to be cooled, such as its own temperature rising rapidly with time during cooling. As a result of investigating the reason, the present inventors have investigated. No ice is produced first, resulting in a mixture of solute-free ice and solute, or ice with a lower freezing point is produced in very small quantities, resulting in cooling capacity. It turned out that high ice was not produced.

However, the present inventors have succeeded in producing liquid ice containing an aqueous solution having a lowered freezing point by a predetermined method (details will be described later). Such ice of the present invention satisfies the above-mentioned conditions (a) and (b). Hereinafter, the above-mentioned conditions (a) and (b) will be described.

(Temperature at the completion of melting)
Regarding (a) above, since the ice of the present invention is liquid ice containing an aqueous solution containing a solute, the temperature of the freezing point is lower than the freezing point of fresh water (water containing no solute). Therefore, it has a feature that the temperature at the time of completion of melting is less than 0 ° C. The "temperature at the completion of melting" means that the ice of the present invention is placed in an environment above the melting point (for example, at room temperature or at atmospheric pressure) to start melting the ice, and all the ice melts into water. It refers to the temperature of the water at that time.

The temperature at the completion of melting is not particularly limited as long as it is less than 0 ° C., and can be appropriately changed by adjusting the type and concentration of the solute. The temperature at the time of completion of melting is preferably lower than the temperature in terms of higher cooling capacity, specifically, -1 ° C or lower (-2 ° C or lower, -3 ° C or lower, -4 ° C or lower, -5 ° C). ℃ or less, -6 ℃ or less, -7 ℃ or less, -8 ℃ or less, -9 ℃ or less, -10 ℃ or less, -11 ℃ or less, -12 ℃ or less, -13 ℃ or less, -14 ℃ or less, -15 ° C or lower, -16 ° C or lower, -17 ° C or lower, -18 ° C or lower, -19 ° C or lower, -20 ° C or lower, etc.). On the other hand, it may be preferable to bring the freezing point closer to the freezing point of the object to be cooled (for example, to prevent damage to fresh animals and plants). Preferably, for example, -21 ° C or higher (-20 ° C or higher, -19 ° C or higher, -18 ° C or higher, -17 ° C or higher, -16 ° C or higher, -15 ° C or higher, -14 ° C or higher, -13 ° C or higher, − 12 ° C or higher, -11 ° C or higher, -10 ° C or higher, -9 ° C or higher, -8 ° C or higher, -7 ° C or higher, -6 ° C or higher, -5 ° C or higher, -4 ° C or higher, -3 ° C or higher,- 2 ° C or higher, -1 ° C or higher, −0.5 ° C or higher, etc.).

(Rate of change in solute concentration)
Regarding (b) above, the ice of the present invention has a rate of change in the solute concentration of the aqueous solution generated from the ice during the melting process (hereinafter, may be abbreviated as "rate of change in solute concentration" in the present specification) of 30. It has the characteristic that it is within%. Even with the method described in Patent Document 1, ice with a slightly lowered freezing point may be produced, but most of them are a mixture of solute-free water ice and solute crystals, and thus have a cooling ability. Is not enough. When a large amount of a mixture of solute-free water ice and solute crystals is contained in this way, the elution rate of the solute associated with melting is unstable when the ice is placed under melting conditions, and the time point near the start of melting The more the solute elutes, the less the solute elutes as the melting progresses, and the closer to the time when the melting is completed, the less the solute elutes. On the other hand, since the ice of the present invention is composed of liquid ice containing an aqueous solution containing a solute, it has a feature that the change in the elution rate of the solute during the melting process is small. Specifically, the rate of change in the solute concentration of the aqueous solution generated from ice during the melting process is 30%. The "rate of change in the solute concentration of the aqueous solution generated from ice in the melting process" means the ratio of the concentration of the aqueous solution at the completion of melting to the solute concentration in the aqueous solution generated at any time in the melting process. The "solute concentration" means the concentration of the mass of the solute in the aqueous solution.

The rate of change in the solute concentration in the ice of the present invention is not particularly limited as long as it is within 30%, but the smaller the rate of change, the higher the purity of the ice in the aqueous solution having a lowered freezing point, that is, the higher the cooling ability. Means. From this point of view, the rate of change in solute concentration is within 25% (within 24%, within 23%, within 22%, within 21%, within 20%, within 19%, within 18%, within 17%, within 16%. , 15% or less, 14% or less, 13% or less, 12% or less, 11% or less, 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3 % Within, 2% or less, 1% or less, 0.5% or less, etc.). On the other hand, the rate of change in solute concentration is 0.1% or more (0.5% or more, 1% or more, 2% or more, 3% or more, 4% or more, 5% or more, 6% or more, 7% or more, 8). % Or more, 9% or more, 10% or more, 11% or more, 12% or more, 13% or more, 14% or more, 15% or more, 16% or more, 17% or more, 18% or more, 19% or more, 20% or more Etc.).

(Solute)
The type of solute contained in the ice of the present invention is not particularly limited as long as it is a solute when water is used as a solvent, and can be appropriately selected depending on a desired freezing point, use of ice to be used, and the like. Examples of the solute include solid solutes and liquid solutes, and typical solid solutes include salts (inorganic salts, organic salts, etc.). In particular, among salts, sodium chloride (NaCl) is preferable because it does not excessively lower the temperature of the freezing point and is suitable for cooling fresh animals and plants or a part thereof. In addition, since salt is contained in seawater, it is preferable in that it is easy to procure. Examples of the liquid solute include ethylene glycol and the like. The solute may be contained alone or in combination of two or more.

The concentration of the solute contained in the ice of the present invention is not particularly limited, and can be appropriately selected depending on the type of solute, the desired freezing point, the use of the ice to be used, and the like. For example, when salt is used as the solute, the concentration of salt is 0.5% (w / v) or more (1% (w / w /)) in that the freezing point of the aqueous solution can be further lowered to obtain a high cooling capacity. v) or more, 2% (w / v) or more, 3% (w / v) or more, 4% (w / v) or more, 5% (w / v) or more, 6% (w / v) or more, 7 % (W / v) or more, 8% (w / v) or more, 9% (w / v) or more, 10% (w / v) or more, 11% (w / v) or more, 12% (w / v) ) Or more, 13% (w / v) or more, 14% (w / v) or more, 15% (w / v) or more, 16% (w / v) or more, 17% (w / v) or more, 18% (W / v) or more, 19% (w / v) or more, 20% (w / v) or more, etc.) is preferable. On the other hand, when the ice of the present invention is used for cooling fresh animals and plants or a part thereof, it is preferable not to excessively lower the temperature of the freezing point, and from this viewpoint, 23% (w / v) or less (20%). (W / v) or less, 19% (w / v) or less, 18% (w / v) or less, 17% (w / v) or less, 16% (w / v) or less, 15% (w / v) 14% (w / v) or less, 13% (w / v) or less, 12% (w / v) or less, 11% (w / v) or less, 10% (w / v) or less, 9% ( w / v) or less, 8% (w / v) or less, 7% (w / v) or less, 6% (w / v) or less, 5% (w / v) or less, 4% (w / v) or less 3% (w / v) or less, 2% (w / v) or less, 1% (w / v) or less, etc.) is preferable.

Since the ice of the present invention has excellent cooling ability, it is suitable for use as a refrigerant. Examples of the low-temperature refrigerant include organic solvents used as antifreeze liquids such as ethanol in addition to ice, but ice has a higher thermal conductivity and a higher specific heat than these antifreeze liquids. Therefore, the ice having a low freezing point by melting an ice-like solute of the present invention is also useful in that it has a better cooling ability than other refrigerants having a cooling capacity of less than 0 ° C. such as antifreeze.

The ice of the present invention may or may not contain components other than the above solutes.

In the present invention, "ice" refers to a frozen liquid containing an aqueous solution.

Further, the ice of the present invention remains stable at a temperature below the freezing point of fresh water, that is, it can be in a non-separable state. Therefore, for example, as described later, when the liquid constituting the ice of the present invention is a liquid containing oil in addition to the aqueous solution containing the above solute, the uniform state of the oil lasts for a long time, that is, , Can be in a non-separable state. In the present invention, the "non-separable state" means a state in which the layers are not separated from a macroscopic point of view (a state in which the layer states are not separated), and a portion separated from a microscopic point of view. (For example, some water and oil) are included.

As described above, the liquid constituting the ice of the present invention may be a liquid containing oil in addition to the aqueous solution containing the above solute. Examples of such liquids include raw milk, industrial waste containing water and oil (waste milk, etc.). When the liquid is raw milk, it is preferable in that the sensuality when eating the ice is improved. It is presumed that the reason why the sensuality is improved in this way is that the oil (fat) contained in the raw milk is trapped in the ice. The ice of the present invention may be composed only of a frozen aqueous solution containing the above solute.

When the liquid constituting the ice of the present invention further contains oil, the ratio of water to oil in the liquid is not particularly limited, and is, for example, 1:99 to 99: 1 (10:90 to 90:10, 20). : 80 to 80:20, 30:80 to 80:30, 40 to 60:40 to 60, etc.) may be appropriately selected.

Further, the ice of the present invention may be ice in an aqueous solution containing two or more kinds of solutes having different degrees of freezing point depression. In this case, the ice of the present invention may be a mixture of an aqueous solution containing one solute and an aqueous solution containing the other solute. In such a case, for example, the melting of ice in an aqueous solution containing ethylene glycol can be delayed by adding ice in an aqueous solution containing sodium chloride as a solute having a different degree of freezing point depression from ethylene glycol to ice in an aqueous solution containing ethylene glycol as a solute. can. Alternatively, the ice of the present invention may be an aqueous solution of two or more kinds of solutes dissolved in the same aqueous solution. Further, when two or more kinds of solutes having different degrees of freezing point depression are used in combination, it is also useful in lowering the melting point of ice in an aqueous solution containing a target solute. For example, when salt is used as a solute, the melting point of ice in a saline solution can be lowered by using a solute (ethylene glycol, calcium chloride, etc.) that can further lower the melting point of the salt solution, for example, a saline solution. It is possible to achieve a temperature around -30 ° C, which cannot be achieved with ice alone. The ratio of two or more solutes having different degrees of freezing point depression can be appropriately changed according to the purpose.

<Refrigerant>
The present invention includes the above-mentioned ice-containing refrigerants. As described above, the ice of the present invention has excellent cooling ability and is therefore suitable as a refrigerant.

The refrigerant of the present invention may contain other components of ice as described above, and may be composed of a mixture of ice and water by containing water in addition to the ice as described above. For example, when water containing the same solute as the solute contained in ice is further contained, it is preferable that the concentration of the solute in ice and the concentration of the solute in water are close to each other. The reason is as follows.

When the solute concentration of ice is higher than the solute concentration of water, the temperature of ice is lower than the saturation freezing point of water, so that the water freezes immediately after mixing water having a low solute concentration. On the other hand, when the solute concentration of ice is lower than the solute concentration of water, the saturated freezing point of water is lower than the saturated freezing point of ice, so that the ice melts and the temperature of the refrigerant consisting of a mixture of ice and water decreases. .. That is, in order not to change the state of the mixture of ice and water (the state of the ice slurry), it is preferable that the solute concentrations of the mixed ice and water are about the same as described above. Further, in the case of a mixture of ice and water, the water may be one obtained by melting the above ice or a separately prepared one, but the above-mentioned ice is melted. Is preferable.

Specifically, when the refrigerant of the present invention is composed of a mixture of ice and water, the ratio of the concentration of the solute in ice to the concentration of the solute in water is 75:25 to 20:80. It is more preferably 70:30 to 30:70, even more preferably 60:40 to 40:60, even more preferably 55:45 to 45:55, and even more preferably 52:48 to 52:48. It is particularly preferably 48:52 and most preferably 50:50. In particular, when salt is used as the solute, it is preferable that the ratio of the solute concentration in ice to the solute concentration in water is within the above range.

The cooling target of the refrigerant of the present invention is not particularly limited, but is suitable for cooling fresh animals and plants or parts thereof. Examples of fresh animals and plants include fresh fish such as saltwater fish and fresh vegetables. Examples of fresh animals and plants include organs of animals (humans and the like).

The water used as a raw material for the ice of the present invention is not particularly limited, but when salt is used as the solute, it is preferably seawater, water obtained by adding salt to seawater, or diluted water of seawater. Seawater, salt-added water, or diluted seawater can be easily procured, which can reduce costs.

The refrigerant of the present invention may or may not contain a solid having a higher thermal conductivity than the ice of the present invention described above, but is preferably contained. When trying to cool an object to be cooled in a short time, it can be achieved by using a solid with high thermal conductivity, but in this case, the solid itself loses cooling energy in a short time and the temperature tends to rise. Not suitable for long-term cooling. On the other hand, it is more suitable for cooling for a long time without using a solid having high thermal conductivity, but it is not suitable for cooling an object to be cooled in a short time. However, since the ice of the present invention has a high cooling capacity as described above, it is useful in that it can be cooled for a long time while obtaining a cooling capacity for a short time by a solid having a high thermal conductivity. Examples of the solid having higher thermal conductivity than the ice of the present invention include metals (aluminum, silver, copper, gold, duralumin, antimony, cadmium, zinc, tin, bismuth, tungsten, titanium, iron, lead, nickel and platinum. , Magnesium, molybdenum, zirconium, berylium, indium, niobium, chromium, cobalt, iridium, palladium), alloys (steel (carbon steel, chromium steel, nickel steel, chromium nickel steel, silicon steel, tungsten steel, manganese steel, etc.), Nickel-chrome alloy, aluminum bronze, gun metal, brass, manganin, western silver, constantan, solder, alumel, chromel, monel metal, platinum iridium, etc.), silicon, carbon, ceramics (alumina ceramics, forsterite ceramics, steatite ceramics, etc.), marble , Steel (magnesia brick, Kolhardt brick, etc.) and the like, which have higher thermal conductivity than the ice of the present invention. The solid having a higher thermal conductivity than the ice of the present invention is a solid having a thermal conductivity of 2.3 W / m K or more (3 W / m K or more, 5 W / m K or more, 8 W / m K or more, etc.). It is more preferable that the solid has a thermal conductivity of 10 W / m K or more (20 W / m K or more, 30 W / m K or more, 40 W / m K or more, etc.), and the thermal conductivity is 50 W / m or more. It is more preferable that it is a solid of K or more (60 W / m K or more, 75 W / m K or more, 90 W / m K or more, etc.), and the thermal conductivity is 100 W / m K or more (125 W / m K or more, 150 W / m). It is more preferable that it is a solid of K or more, 175 W / m K or more, and has a thermal conductivity of 200 W / m K or more (250 W / m K or more, 300 W / m K or more, 350 W / m K or more, etc.). A solid is still more preferable, a solid having a thermal conductivity of 200 W / m K or more is still preferable, and a solid having a thermal conductivity of 400 W / m K or more (410 W / m K or more, etc.) is particularly preferable. preferable.

When the refrigerant of the present invention contains a solid having a higher thermal conductivity than the ice of the present invention, as described above, even if it contains a large amount of solid, it is suitable for long-term cooling. For example, the ice of the present invention. The mass of the solid having higher thermal conductivity / the mass of the ice of the present invention contained in the refrigerant (or the total mass of the ice of the present invention contained in the refrigerant and the liquid containing the aqueous solution) is 1/10000 or more (1 /). 50,000 or more, 1/10000 or more, 1/5000 or more, 1/1000 or more, 1/500 or more, 1/100 or more, 1/50 or more, 1/10 or more, 1/5 or more, 1/4 or more, 1 / 3 or more, 1/2 or more, etc.) may be used.

The solid in the present invention may have any shape, but is preferably in the form of particles. Further, the solid may be contained in the form contained inside the ice of the present invention, or may be contained in the form contained outside the ice, but may be contained outside the ice. If it is contained in, it will be easier to come into direct contact with the object to be cooled, and the cooling capacity will be higher. For this reason, it is preferable that the ice is contained in a form contained outside the ice. When the refrigerant of the present invention contains the solid, it may be mixed with the solid after the ice is produced by the method for producing ice of the present invention described later, or it may be mixed with water as a raw material in advance. , Ice may be produced.

<Ice manufacturing method>
The present invention is a method for producing a liquid ice containing an aqueous solution containing a solute, by spraying the liquid containing the aqueous solution containing the solute onto a wall surface maintained at a temperature below the freezing point of the aqueous solution. It includes a step of producing liquid ice containing an aqueous solution on the wall surface, a step of recovering the ice generated on the wall surface, and a method of having the ice. By such a method, the ice of the present invention satisfying the above conditions (a) and (b) can be produced.

(Ice generation process)
The present invention is a method for producing a liquid ice containing an aqueous solution containing a solute, by spraying the liquid containing the aqueous solution containing the solute onto a wall surface maintained at a temperature below the freezing point of the aqueous solution. It has a step of generating liquid ice containing an aqueous solution on the wall surface and a step of recovering the ice generated on the wall surface.

The ice of the present invention cannot be produced even if the liquid containing the aqueous solution stored in the container is cooled from the outside as in Patent Document 1 described above. This is thought to be due to insufficient cooling rate. However, in the production method of the present invention, an aqueous solution atomized by spraying a liquid containing an aqueous solution containing a solute directly comes into direct contact with a wall surface maintained at a temperature below the freezing point, thereby achieving rapid cooling that has not been possible in the past. It is possible. Thereby, it is considered that the present invention can produce ice having a high cooling ability, which satisfies the above conditions (a) and (b).

The wall surface may be, for example, an inner wall of a cylindrical structure such as the vertical drum 11 in FIG. 1, which will be described later, but is not particularly limited as long as the wall surface can be maintained at a temperature equal to or lower than the freezing point of the aqueous solution. The temperature of the wall surface is not particularly limited as long as it is maintained at a temperature equal to or lower than the freezing point of the aqueous solution, but it is higher than the freezing point of the aqueous solution in that it can produce ice having high purity of ice satisfying the above conditions (a) and (b). 1 ° C or higher temperature (2 ° C or lower temperature, 3 ° C lower temperature, 4 ° C lower temperature, 5 ° C lower temperature, 6 ° C lower temperature, 7 ° C lower temperature, 8 ° C lower temperature, 9 ° C lower temperature Low temperature or higher, 10 ° C or lower, 11 ° C lower, 12 ° C lower, 13 ° C lower, 14 ° C lower, 15 ° C lower, 16 ° C lower, 17 ° C lower Temperature, temperature 18 ° C or higher, temperature 19 ° C lower, temperature 20 ° C lower, temperature 21 ° C lower, temperature 22 ° C lower, temperature 23 ° C lower, temperature 24 ° C lower, temperature 25 ° C lower, etc. ) Is preferably held.

The method of spraying is not particularly limited, but spraying can be performed by spraying from an injection means provided with an injection hole, for example, as in the pipe 13 in FIG. 1 described later. In this case, the water pressure at the time of injection is, for example, 0.001 MPa or more (0.002 MPa or more, 0.005 MPa or more, 0.01 MPa or more, 0.05 MPa or more, 0.1 MPa or more, 0.2 MPa or more, etc.). It may be 1 MPa or less (0.8 MPa or less, 0.7 MPa or less, 0.6 MPa or less, 0.5 MPa or less, 0.3 MPa or less, 0.1 MPa or less, 0.05 MPa or less, 0.01 MPa or less, etc.). There may be.

Further, as shown in FIG. 1 to be described later, a rotating means such as providing a rotatable rotating shaft 12 on the central axis of the vertical drum 11 is provided, and spraying is performed while rotating the drum 11 by continuous spraying. May be good.

(Recovery process)
The present invention includes a step of recovering the ice generated on the wall surface after the above-mentioned ice forming step.

The method of collecting the ice is not particularly limited, and for example, as shown in FIG. 2 described later, the ice on the wall surface may be scraped off by means such as a blade 15 to recover the fallen ice.

In addition, ice making heat is generated when ice is generated, and the ice making heat may affect the actual melting completion temperature. As described above, the melting completion temperature is considered to be influenced not only by the type and concentration of the solute but also by the heat of ice making. Therefore, the actual melting completion temperature can be adjusted by adjusting the amount of heat of ice making remaining on the ice. In order to adjust the heat of ice making, the recovery step in the present invention can be performed by adjusting the holding time of ice on the wall surface.

[Ice maker and ice maker system]
An aspect of an ice maker and an ice making system that can be used to produce the ice of the present invention will be described below with reference to FIGS. 1 and 2. The following examples of ice makers use salt as a solute.

A partial cross-sectional perspective view of the ice machine 10 is shown in FIG. 1, and an ice making system including the ice machine 10 is shown in FIG. The ice maker 10 includes a vertical drum 11 whose inner peripheral surface is cooled by a refrigerant, and a rotating shaft 12 rotated by a geared motor 20 is arranged on the central axis of the vertical drum 11. The rotary shaft 12 has a plurality of pipes 13 having injection holes 13a at the tip thereof, which rotate together with the rotary shaft 12 and inject salt water toward the inner peripheral surface of the vertical drum 11, in the radial direction of the vertical drum 11. An arm 14 that extends and rotates together with the rotating shaft 12 is attached. A blade 15 for scraping ice generated on the inner peripheral surface of the vertical drum 11 is attached to the tip of the arm 14.

The vertical drum 11 has an inner cylinder 22 in which ice is generated on the inner peripheral surface, and an outer cylinder 23 surrounding the inner cylinder 22. The inner cylinder 22 and the outer cylinder 23 are made of steel, and a clearance is provided between the inner cylinder 22 and the outer cylinder 23. Refrigerant is supplied from the refrigerator (not shown) to the clearance via the pipe 35. The outer peripheral surface of the vertical drum 11 is covered with a cylindrical protective cover 19.

The upper surface of the vertical drum 11 is sealed with an upper bearing member 17 having an inverted pan shape. A bush 28 that supports the rotating shaft 12 is fitted in the center of the upper bearing member 17. The rotating shaft 12 is supported only by the upper bearing member 17, and the lower end portion of the rotating shaft 12 is not pivotally supported. Therefore, there is no obstacle below the vertical drum 11 when the ice scraped off by the blade 15 falls, and the lower surface of the vertical drum 11 is a discharge port 16 for discharging the ice. The ice that has fallen from the discharge port 16 is stored in an ice storage tank 34 arranged directly under the ice maker 10 (see FIG. 2).

The rotary shaft 12 is rotated around a material shaft by a geared motor 20 installed above the upper bearing member 17. A vertical hole 12a extending in the direction of the material axis and communicating with each pipe 13 is formed in the upper part of the rotating shaft 12 (see FIG. 2). Further, a rotary joint 21 is attached to the top of the rotating shaft 12. The salt water that is the raw material of ice is supplied from the salt water storage tank 30 to the rotary joint 21 via the pipe 32 (see FIG. 2). The salt water supplied to the rotary joint 21 is supplied from the rotary joint 21 to the vertical hole 12a formed in the rotary shaft 12, and is supplied from the vertical hole 12a to each pipe 13.

The pipe 13 extends radially from the rotating shaft 12 in the radial direction of the vertical drum 11. The installation height of each pipe 13 is set to the upper position of the height of the inner cylinder 22 of the vertical drum 11, and salt water is sprayed toward the upper part of the inner peripheral surface of the inner cylinder 22 (see FIG. 1). The water pressure when injecting salt water from the injection hole 13a is, for example, about 0.01 MPa. A spray nozzle or the like may be used instead of the pipe 13. In this case, the injection pressure can be, for example, 0.2 to 0.5 MPa.

The arm 14 is mounted so as to be symmetrical with respect to the rotation axis 12. In the present embodiment, the number of arms 14 is two. The blade 15 attached to the tip of each arm 14 is made of a stainless steel plate having a length substantially equal to the total length (total height) of the inner cylinder 22, and a plurality of saw teeth 15a are provided on the end surface facing the inner cylinder 22. Is formed.

Next, the operation of the ice making machine 10 and the ice making system having the above configuration will be described. By operating the refrigerator, the refrigerant is supplied to the vertical drum 11 and the temperature of the inner peripheral surface of the vertical drum 11 is set to −20 to −25 ° C. Next, the geared motor 20 is operated to rotate the rotary shaft 12 around the material shaft, and salt water is supplied into the rotary shaft 12 via the rotary joint 21. The rotation speed of the rotating shaft 12 is 2 to 4 rpm. When a spray nozzle is used instead of the pipe 13, the rotation speed of the rotating shaft 12 is 10 to 15 rpm.

The salt water jetted from the pipe 13 rotating together with the rotating shaft 12 toward the inner peripheral surface of the vertical drum 11 freezes instantly when it comes into contact with the inner peripheral surface of the vertical drum 11. The ice generated on the inner peripheral surface of the vertical drum 11 is scraped off by the blade 15 that rotates with the arm 14. The scraped ice falls from the discharge port 16. The ice that has fallen from the discharge port 16 is stored in an ice storage tank 34 arranged directly under the ice maker 10, and is used to maintain the freshness of fresh seafood.

On the other hand, the salt water that does not become ice and flows down the inner peripheral surface of the vertical drum 11 is stored in the salt water storage tank 30, and is again supplied to the rotary joint 21 via the pipe 32 by operating the pump 31 (). See Figure 2). When the amount of salt water in the salt water storage tank 30 is low, the salt water stored in the salt water tank 33 is supplied to the salt water storage tank 30.

<Manufacturing method of object to be cooled>
The present invention includes a method for producing a cooled object to be cooled, which comprises a step of cooling the object to be cooled by using the above-mentioned refrigerant.

The object to be cooled is not particularly limited, and examples thereof include fresh animals and plants or parts thereof. Examples of fresh animals and plants include fresh fish such as saltwater fish and fresh vegetables. Examples of fresh animals and plants include organs of animals (humans and the like).

The cooling method is not particularly limited, and the above-mentioned refrigerant may be directly brought into contact with the object to be cooled for cooling, or indirectly (for example, a heat conductive means that can transmit a heat source is cooled by the refrigerant and cooled. It may be cooled (via heat transfer means).

Further, when the above-mentioned refrigerant of the present invention contains a solid having a higher thermal conductivity than ice, it has a higher thermal conductivity than ice between the ice contained in the refrigerant and the object to be cooled in the cooling step. It is preferable to perform cooling so that a solid is present. As a result, it is possible to cool for a long time while obtaining a cooling capacity for a short time by a solid having high thermal conductivity. In such a case, another object may be interposed between the ice, the solid having a higher thermal conductivity than the ice, and the object to be cooled, depending on the purpose. For example, a refrigerant that is not preferable to be in direct contact with the object to be cooled (for example, a solid (metal, etc.) having a higher thermal conductivity than ice, which is not preferable to be in contact with the object to be cooled from the viewpoint of safety). If it is contained, either the refrigerant or the object to be cooled may be contained in the bag to be cooled so that the refrigerant and the object to be cooled do not come into direct contact with each other.

<Example 1>
Using the above-mentioned ice maker 10, an aqueous solution (saturated saline solution) ice containing 23.1% of salt as a solute (hereinafter referred to as "ice according to Example 1") was produced. The temperature of the ice according to Example 1 (a) at the time of completion of melting was less than 0 ° C. In addition, the concentration of the aqueous saline solution in the melting process was substantially constant, that is, (b) the rate of change in the solute concentration of the aqueous solution generated from the ice in the melting process was within 30%. Regarding the temperature of the ice according to Example 1, the change with time was measured under the outside air temperature. Further, the temperature change with time was similarly measured for the saline solution having the same concentration as the ice according to Example 1 (“high-concentration saline solution” in FIG. 3). The results are shown in FIG. In FIG. 3, the vertical axis is temperature (° C.) and the horizontal axis is time (minutes).

As shown in FIG. 3, since the high-concentration saline solution was not frozen, the temperature increased in proportion to the passage of time. On the other hand, the ice according to Example 1 showed almost no temperature change at around −20 ° C. until the melting was completed, and thus it was found that the ice had a high cooling ability due to the effect of latent heat. ..

<Example 2> Similar to Example 1, ice in an aqueous solution (saturated saline solution) containing 23.1% of salt as a solute using the above-mentioned ice making machine 10 (hereinafter, "ice according to Example 2 (hereinafter," Ice " Solution: Saturated saline solution) ".) Was produced. Further, ice (solution: saturated saline solution) according to Example 2 to which copper was added was prepared, and this was used as ice according to Example 2 (solution: saturated saline solution + CU). Further, an unfrozen saturated saline solution (-20 ° C aqueous solution) was prepared.

The fish was cooled using the ice according to Example 2 (solution: saturated saline solution), the ice according to Example 2 (solution: saturated saline solution + CU), and saturated saline solution (-20 ° C aqueous solution), and the fish core temperature. The change over time was measured. The results are shown in FIG. In FIG. 4, the vertical axis is temperature (° C.) and the horizontal axis is time (minutes).

As shown in FIG. 4, it was found that the ice according to Example 2 (solution: saturated saline solution + CU) has a higher cooling ability of fish than the ice according to Example 2 (solution: saturated saline solution). From this result, it was found that the cooling capacity is increased by further adding a solid having a higher thermal conductivity than ice, such as copper.

<Example 3>
Using the above-mentioned ice maker 10, raw milk is used instead of the 23.1% aqueous solution (saturated saline solution) to produce ice for raw milk according to Example 3 in the same manner as for ice according to Example 1. bottom. When the ice according to Example 3 was tasted, it was confirmed that it was difficult to separate while eating and the solid state could be maintained for a long time, and it was delicious. Moreover, when the same ice was left uneaten and melted, the melted raw milk was not separated. Further, when the separated state when the raw milk ice according to Example 3 was produced by using the above-mentioned ice maker 10 was confirmed, oil remained on the wall surface even after the ice was recovered from the wall surface sprayed with the liquid. It was confirmed that it was not separated even at the time of manufacture. From these facts, it was found that the ice of the present invention can be in a non-separable state.

10: Ice maker, 11: Vertical drum, 12: Rotating shaft, 12a: Vertical hole, 13: Pipe, 13a: Injection hole, 14: Arm, 15: Blade, 15a: Sawtooth, 16: Discharge port, 17: Top bearing Members, 19: Protective cover, 20: Geared motor, 21: Rotary joint, 22: Inner cylinder, 23: Outer cylinder, 28: Bush, 30: Salt water storage tank, 31: Pump, 32, 35: Piping, 33: Salt water Tank, 34: Ice storage tank

Claims (3)

An aqueous solution containing a solute and a liquid containing oil in a non-separable state, which satisfy the following conditions (a) and (b), are ice frozen in a state where the oil is not separated , and the liquid is raw milk. Ice whose oil is fat .
(A) The temperature at the completion of melting is less than 0 ° C. (b) The rate of change in the solute concentration of the aqueous solution generated from the ice during the melting process is within 30%. It ’s a method of making ice.
By spraying an aqueous solution containing a solute and a liquid containing oil in a non-separable state onto a wall surface held at a temperature below the freezing point of the aqueous solution, the liquid is not separated from the oil on the wall surface. The process of producing frozen ice and
It has a step of recovering the ice generated on the wall surface.
The method according to claim 1 , wherein the water pressure of the spray, the temperature of the wall surface, and the holding time of ice on the wall surface until recovery are the conditions for producing ice. The method according to claim 2 , wherein in the step of forming ice, the wall surface is maintained at a temperature lower than the freezing point of the aqueous solution by 5 ° C. or more.

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