JPH05256547A - Method and device for manufacturing sea water ice - Google Patents

Abstract

PURPOSE:To enhance workability by reducing a manufacturing process for sea water ice, speed up its manufacturing process and further minimizing the process. CONSTITUTION:The manufacturing method of sea water ice is to provide sea water ice by supplying sea water into a sea water tank whose internal pressure is reduced to a pressure or below equivalent to the freezing temperature of sea water where the sea water is self-frozen instantly. More preferably, sea water is supplied in an atomized state. A manufacturing device of seat water ice comprises an ice making tank 11, a pressure reduction means (such as a vacuum pump 20) which reduces the internal pressure in the ice making tank to a pressure equivalent to the freezing temperature of sea water and a sea water supply means (such as sea water storage tank 41A, temporary cooling tank 41, sea water pump 40, feed water pipe and nozzle 42).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing seawater ice and an apparatus therefor, and more particularly to a method for producing seawater ice at a low cost and an apparatus for producing seawater ice at a high production speed.

[0002]

BACKGROUND OF THE INVENTION Conventionally, JP-A-1-184375 has been disclosed.
Japanese Patent Publication No. 2-225956 discloses a technique for producing salt water ice. The method described in the publication includes a step of first producing fresh water ice with an ice making machine, a step of spraying and mixing salt water on the fresh water ice, and a step of increasing the size of ice from a mixture of fresh water ice and salt water in a supercooled atmosphere. And a press-forming step.

However, in the above conventional technique,
Therefore, there is a problem in that the equipment is too large, the manufacturing time is long, and the workability is poor.

[0004]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a seawater ice production method and apparatus which have low equipment costs, extremely high production speed and excellent workability.

[0005]

The method for producing seawater ice according to the present invention, which achieves the above object, is a method of instantaneously supplying seawater into an ice-making tank whose pressure is reduced to a pressure corresponding to the freezing temperature of seawater or less. It is characterized by obtaining seawater ice by self-freezing.

By supplying seawater in a fog state,
Since the particle size is small, the amount of heat retained is small, and the free evaporation surface is large, so evaporation is likely to occur due to the latent heat held by it.
It is preferable because it instantly drops to a temperature corresponding to the freezing temperature of seawater and instantly self-freezes.

Further, the seawater ice producing apparatus according to the present invention comprises an ice making tank, a decompression means for decompressing the inside of the ice making tank to a pressure corresponding to the freezing temperature of the sea water or less, and a fog state of sea water inside the ice making tank. And a means for supplying seawater.

[0008]

Specific Structure of the Invention Next, the specific structure of the method for producing seawater ice according to the present invention will be described in more detail.

The features of the method for producing seawater ice according to the present invention are:
This is to obtain seawater ice by instantaneously self-freezing the seawater by supplying it to the inside of an ice making tank whose pressure is reduced to a pressure corresponding to the freezing temperature of the seawater or less. Therefore, the following devices and means are used to carry out the method of the present invention.

(Ice making tank) It is necessary to form a reduced pressure atmosphere at a pressure equal to or lower than the pressure corresponding to the freezing temperature of seawater. The size of the ice making tank is about 600 mm in diameter and 700 mm in height, if the ice making capacity per hour is 1 ton. This ice making tank is formed of a pressure resistant container and is formed of a material (for example, SUS or the like) in consideration of corrosiveness against seawater.

It is preferable that the ice making tank is provided with a means for scraping the seawater ice adhering to the inner wall and a means for discharging the seawater ice to the outside. Seawater ice may be continuously discharged to the outside by means of a screw type conveying means arranged at the bottom of the ice making tank, or a valve arranged at the lower end may be opened to discharge it intermittently at regular intervals. May be.

The ice particles in the ice making tank are not melted under a predetermined vacuum and are accumulated on the bottom as ice particles.

(Decompression means) The pressure inside the ice making tank is below the pressure relative to the freezing temperature of seawater, specifically 4.579 mm / H.
It is a means for maintaining a low pressure of less than g, preferably about 4.579 mm / Hg to 3.5 mm / Hg, and various types of vacuum pumps are used.

(Cooling Means) First for carrying out the method of the present invention
In the embodiment, no cooling means is used. That is, when seawater is supplied to an ice-making tank in a depressurized state, the seawater partially evaporates with the amount of heat it holds, the seawater loses the amount of heat it holds, and the seawater is cooled to a temperature equivalent to the pressure in the ice-making tank. This is because the seawater supplied is continuously frozen by keeping the pressure in the tank below the pressure at which the seawater freezes.

In a second mode of carrying out the method of the invention,
In order to stabilize the internal pressure of the ice making tank and to reduce the load on the vacuum exhaust device, cooling means for keeping the temperature below the freezing temperature of seawater is used.

For cooling, various cooling methods can be adopted, for example, a refrigerator is used.

(Seawater supply means) A means for supplying seawater into the ice making tank, for example, a seawater storage tank, a temporary cooling tank,
Includes seawater pumps, water pipes, nozzles, etc.

In the present invention, a seawater storage tank is preferably provided for receiving seawater, and a temporary cooling tank is preferably provided for temporarily cooling the seawater before supplying it to the ice making tank.

The temporary cooling tank is provided with a cooling means,
For example, it is cooled to 10 ° C. or lower. Cooling in the temporary cooling tank is preferable to direct cooling in the seawater storage tank because the thermal efficiency is better.

The seawater supplied to the ice making tank is preferably supplied in the form of mist, and the smaller the particle size, the more preferable.

In addition, it is a preferred embodiment that seawater is treated by filtration / precipitation or other method to separate suspended matters in the seawater storage tank or before being introduced into the seawater storage tank.

(Post-treatment / storage) The seawater ice discharged from the ice making tank becomes an ice block because it is released into the atmosphere, so it may be sent to a storage tank as it is and stored, or formed into a large ice block by pressing means. It may be stored after performing post-processing. It is also preferable to further supercool the obtained ice cube, and the supercooling may be performed in a storage tank.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a seawater ice producing apparatus according to the present invention will be described based on embodiments with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 denotes an ice making tank, which is a scraping means 11 for scraping seawater ice adhering to the wall surface.
And a discharging means 12 for discharging the obtained seawater ice to the outside.

As the scraping means 11, for example, a scraper rotated by a motor 13 arranged above the ice making tank 10 is used. Rotation speed of scraper is 1
The range of 0 to 20 rpm is preferred.

As the discharging means 12, a screw type conveying means may be arranged at the bottom of the ice making tank 10 in addition to opening and closing the valve as shown in the figure so as to continuously discharge the produced seawater ice. ..

As the depressurizing means, a vacuum pump 20 constructed so as to be suckable from an upper position of the ice making tank 10 is preferably used.

By operating the vacuum pump 20, the inside of the ice making tank 10 has a pressure lower than the pressure corresponding to the freezing temperature of seawater, specifically 4.579 mm / Hg or less, preferably 4.579 mm / Hg. The pressure is reduced to a low pressure of about 5 mm / Hg.

Reference numeral 30 is a refrigerator.

40 is a seawater pump, which is a temporary cooling tank 4.
1 supplies the seawater stored in the ice making tank 10 to the ice making tank 10, and the sea water is in a fog state via a nozzle 42 arranged at the upper part of the wall surface of the ice making tank 10 without hindering the drive of the scraping means 11. Supplied with. Temporary cooling tank 4
Although seawater may be directly introduced into the tank 1, it may be introduced from the seawater storage tank 41A.

Although not shown, it is a preferred embodiment that seawater is treated by filtration / precipitation or other method to separate suspended matters in the seawater storage tank 41A or before being introduced into the seawater storage tank 41A. is there.

Reference numeral 43 is a cooling coil, and the refrigerant is the refrigerator 3.
All or part of the stored seawater (20 to 25 ° C) sent from 0 is cooled to about 10 ° C.

Further, a condenser 44 is arranged in the middle of the pipe leading to the vacuum pump 20 to condense the vapor sucked from the ice making tank 10 and discharge it to the outside of the system.

50 is a stock section or a molding machine,
The produced ice cubes of seawater ice are discharged from the ice making tank 10 and stocked, or the produced ice cubes of seawater ice are filled into a container having a constant volume and pressed to form a large ice cube. By performing the press treatment in this way, it is possible to make it difficult to melt and easy to handle.

Further, as a post-treatment, supercooling the produced seawater ice to 0 ° C. or lower under normal pressure is also a preferred embodiment in order to make it difficult to melt. This supercooling process can also be performed by storing seawater ice in a cryogenic warehouse.

[0036]

[Experimental example] Next, an experimental example illustrates the method for producing seawater ice and the apparatus therefor according to the present invention. Experimental Example 1 Seawater ice A was produced using the apparatus shown in FIG.

As the ice making tank 10, a cylindrical tank having a diameter of 60 cm and a height of 70 cm was used, and the scraper as the scraping means 11 was rotated at 10 to 20 rpm. Operate the vacuum pump 20 to move the inside of the ice making tank 10 to 3.3-4 mm / Hg.
The pressure was reduced to. At this time, no special cooling means was applied to the ice making tank 10.

Seawater having a water temperature in the range of 20 ° C. to 25 ° C. is introduced into the seawater storage tank 41 A and then into the temporary storage tank 41.
Precooled to ° C. Seawater in the temporary cooling tank 41 was pressurized by the seawater pump 40, and was sprayed from the nozzle 42 into the ice making tank 10 in a mist state.

The supply amount of seawater was 1.1 t / Hr. The evaporated portion is condensed by the condenser 44 and then intermittently discharged out of the system.

Among the obtained ice blocks of seawater ice A, a plurality of ice blocks are randomly extracted to determine the salt concentration (JIS K 010).
When measured based on 2), they were all equal to the salt concentration of the original seawater.

Experimental Example 2 Using the apparatus shown in FIG. 1, the pressure in the ice making tank 10 was set to 4.5 mm / Hg, and an experiment similar to Experimental Example 1 was conducted. Results were obtained.

COMPARATIVE EXAMPLE 1 Using the apparatus shown in FIG. 1, the pressure in the ice making tank 10 was set to 760 mm / Hg and 6 mm / Hg, respectively. I couldn't get it.

[0043]

EFFECTS OF THE INVENTION According to the present invention, unlike the above-mentioned conventional techniques, many manufacturing steps are not required, the number of seawater ice manufacturing steps is small, and the manufacturing speed is extremely high. Therefore, the workability is good.

[Brief description of drawings]

FIG. 1 is a schematic view of a seawater ice manufacturing device.

[Explanation of symbols]

 10-ice tank 11-scraping means 12-discharging means 20-vacuum pump 30-refrigerator 40-seawater pump 41A-seawater storage tank 41-temporary cooling tank 42-nozzle 43-cooling coil 44-condenser 50-stock section or Molding machine

Claims (3)

[Claims] 1. A method for producing seawater ice, characterized in that seawater is supplied to the inside of an ice-making tank whose pressure is reduced to a pressure corresponding to the freezing temperature of seawater or less, and the seawater ice is instantaneously self-frozen to obtain seawater ice. 2. The method for producing seawater ice according to claim 1, wherein seawater is supplied in a mist state. 3. An ice making tank, and a pressure reducing means for reducing the pressure inside the ice making tank to a pressure below the pressure corresponding to the freezing temperature of seawater.
An apparatus for producing seawater ice, comprising: seawater supply means for supplying seawater into the ice making tank in a fog state.