JP5590528B2 - Quick freezing device, quick cooling device, quick freezing method and fishing boat equipped with quick freezing device - Google Patents

Description

  The present invention relates to a quick freezing device that can suppress the occurrence of cracking when rapidly freezing meat pieces, a quick cooling tool and a quick freezing method used therefor, and a fishing boat equipped with the quick freezing device.

When storing large fish such as tuna (bonito) or skipjack (bonito) for a long period of time, freeze them after catching them with a tuna boat. For example, frozen tuna, which accounts for about 90% of the tuna eaten in Japan, is rapidly frozen at minus 50 to 60 degrees Celsius after drawing blood and removing gills and internal organs after landing.
Tuna caught in the sea is transported in ice-packed water, landed in a fishing port, and then distributed and consumed raw. On the other hand, tuna caught in the ocean is quickly frozen and landed on a tuna fishing boat, frozen and stored in a frozen container ship, etc., and auctioned at a fish market.

Techniques for freezing and freezing fish are roughly classified into quick freezing and slow freezing.
Slow refrigeration is based on refrigerators that do not have high performance (for example, household refrigerator-freezers). In slow freezing, the water that exists between the cells of the meat piece gathers around the ice particles that were frozen first, and the surrounding water gathers, and the particles grow as ice to grow and freeze. It will destroy. Therefore, when a frozen product that has been slowly frozen is thawed, a drip (juice) containing a large amount of umami components flows out of the destroyed cells, or a change in meat color occurs. As a result, quality deterioration such as deterioration of taste due to outflow of umami components and deterioration in appearance occurs. Therefore, the value when the meat piece is served with raw food such as sashimi or marinade is significantly reduced.

  Therefore, a freezing method that suppresses the increase of ice particles during freezing due to moisture present between the cells of the meat pieces is desirable. The freezing method is rapid freezing. The temperature zone in which the volume increases most when the moisture freezes is in the range of minus 1 degree to minus 5 degrees Celsius, and this is called “maximum freezing crystal formation zone”. 80% to 90% of the moisture in the meat piece freezes in the maximum freezing crystal formation zone, but if the time for passing through the maximum freezing crystal formation zone can be shortened, the water existing between cells freezes in small grains. That is, since the ice particles are frozen before they grow, as in the case of slow freezing, destruction of surrounding cells is suppressed.

  However, rapid freezing may cause a phenomenon called “brokenness” described below. In the case of rapid freezing, the fish is first frozen from the surface side of the skin of the fish and then gradually toward the center of the meat piece. As freezing progresses, the ice expansion site moves toward the center of the piece of meat. However, since the surface part of the fish has already been frozen, the ice generated at the center of the meat piece cannot expand inward. As a result, the expansion force of the ice at the center acts to push and spread the surface portion of the fish, causing a crack on the surface of the meat piece. This crack is called “cracking”.

  Examples of the quick freezing method include a method of spraying liquid nitrogen (liquefied gas freezing method), an air freezing method in which low-temperature air is blown, a metal plate contact freezing method, and a brine freezing method using a salt solvent as a cooling refrigerant. In these methods, air, a metal plate, and brine (salt solution) serving as a cooling medium are cooled, and meat pieces are brought into contact with the cooling medium to be frozen. In general, in addition to the above-described freezing method, a plurality of freezing methods may be combined.

The air freezing method requires air at a very low temperature (generally referred to as “ultra-low temperature”) such as minus 50 degrees Celsius to minus 60 degrees Celsius because the thermal conductivity of air is small. Therefore, a large refrigeration apparatus is required, and a large amount of energy is required to operate such a large refrigeration apparatus.
The brine freezing method is a method in which an aqueous solution of sodium chloride, calcium chloride, magnesium chloride or the like is cooled and immersed in the aqueous solution, or the aqueous piece is sprayed to freeze the meat pieces. Brine has a lower freezing point depending on the content of salts dissolved in water. In the case of freezing with a liquid such as brine, since the heat transfer coefficient is large, it can be rapidly frozen at a higher temperature than the air freezing method, for example, a temperature of about minus 30 degrees. Therefore, the refrigerator can be a relatively small one, but it is necessary to wrap the meat pieces so that the brine does not adhere to the meat pieces.
The metal contact freezing method is a method in which a refrigerant is interposed inside a hollow metal plate and the object to be frozen is brought into contact with the metal plate and frozen. This method has restrictions on the shape of the piece of meat to be frozen, and the configuration of the entire refrigeration apparatus becomes complicated.

Now, even when trying to freeze a large fish like tuna, it takes about 30 hours even at an ultra-low temperature of minus 60 degrees Celsius. Therefore, it becomes slow freezing and cell destruction and drip generation are likely to occur.
Therefore, after catching gills and internal organs, large fish such as tuna, which have been caught, are divided into four parts, vertically and horizontally, centering on the bone in a cross section perpendicular to the length direction of the fish body. Each of the four divided pieces is called a “fillet”. Each fillet has an angle formed by two cut surfaces other than the epidermis in the vertical cross section of about 90 degrees. With such a fillet, since the cross-sectional dimension is about half, if it is frozen at an ultra-low temperature, it can be frozen in about 8 hours, and cell destruction and drip generation are suppressed.
For example, in a metal contact freezing method in which tuna is to be frozen, it is common to adopt a shape and structure suitable for freezing the fillet.

When rapidly freezing an object to be frozen, various factors need to be considered in order to select various freezing methods such as a liquefied gas freezing method, an air freezing method, a metal plate contact freezing method, and a brine freezing method. The factors include the magnitude of thermal conductivity, the risk of foreign matter adhesion, product shape restrictions, and the difficulty of freezing operations. Furthermore, the size and complexity of the structure of the refrigeration apparatus, the size of power consumption, and maintenance (simpleness) are also available.
In addition, as a quick freezing device intended for freezing high-quality fish such as tuna, the risk of foreign matter adhesion is small, the freezing work is easy, the structure of the device is simple, the power consumption is small, etc. In addition to the above conditions, it has been demanded that no cracks (cracking of meat pieces) that would reduce the economic value occur.

  In the refrigeration techniques disclosed in Patent Document 1 and Patent Document 2, at the time of rapid freezing, at least one entire surface of the cut surface of the fillet is brought into surface contact with a heat transfer plate made of a material having high thermal conductivity. And the cold wind is ejected so that it may collide with a heat exchanger plate first, and the said fillet is rapidly frozen. Note that the storage temperature of minus 50 degrees Celsius or less is maintained even after reaching the final stage of distribution (such as a retail store) after rapid freezing.

JP 2002-119206 A JP 2003-225048 A

  Now, in the technique disclosed in Patent Document 1 and Patent Document 2, it is described that cracks caused by freezing due to large distortion are prevented. However, in reality, it has been difficult to prevent cracks caused by the expansion force that occurs during freezing near the center of the meat piece (fillet). There is a problem that a fillet with a broken body has a lower transaction price than a fillet that has not.

Moreover, in patent document 1 and patent document 2, although the air freezing method and the metal plate contact freezing method are combined, the very low temperature of minus 50 degrees C or less is required. Therefore, since a large refrigeration apparatus is required, it is difficult to save space, and large power consumption is required.
Ideally, it is desirable that large fish (eg, tuna and bonito) caught on a fishing boat can be processed into a fillet and quickly frozen in the fishing boat. However, as described above, in order to mount the refrigeration apparatus provided by the current technology on a fishing boat, there is a problem in that the space occupied by the apparatus and the power consumption increase.

The problem to be solved by the present invention is a rapid freezing apparatus capable of preventing cell destruction and breakage of meat pieces accompanying freezing, simplifying the freezing operation, and reducing power consumption during freezing, and It is to provide a fishing boat, a quick cooler, and a quick freezing method.

(First invention)
The first invention is a quick freezing device (10) installed in a freezing chamber (11) for rapidly freezing a piece of meat (40) having two cut surfaces (44, 44) adjacent to each other and having a predetermined angle. Concerning.
That is, the cooling plate (31, 31) provided with two contact surfaces (32, 32) that contact the cut surface (44, 44) in the meat piece (40), and each contact in the cooling plate (31, 31) A fin portion (33) in which a large number of fins (34) are arranged on the cooling plate (31) on the back surface of the surfaces (32, 32), and the quick cooler (30) provided with the fin (33) in the freezer compartment (11) And a blower (21) for blowing air to move the air in the freezer compartment (11) and a control device (16) for adjusting the air temperature in the freezer compartment (11).
The said fin part is for cooling the site | part which contacted the said cooling plate in the said meat piece faster than another site | part. In addition, the cooling plate is formed so that the upper part is opened in order to release the pressure caused by freezing that starts at a portion that contacts the cooling plate faster than the other portions.
The “blower” only needs to have a function of directing cold air toward the fins (34) by the movement of air in the freezer compartment (11). Even if it is not independent as a blower, for example, a fan for taking air into a refrigerator for lowering the temperature of the refrigerant (air) that takes away heat from the meat pieces (40) has a cold wind against the fins (34). If it also has a function of directing the fan, the fan becomes a “blower”.
Although the control device (16) controls the quick freezing device (10), the air volume of the blower (21) may also be controlled.
Moreover, although the meat piece (40) to be frozen is suitable for fish, it may be animal meat.

(Function)
The two cut surfaces (44) of the meat piece (40) are placed on the two contact surfaces (32) of the cooling plate (31) in the rapid cooling tool (30) so as to contact each other. The quick cooler (30) is installed in the freezer compartment (11) such that the longitudinal direction of the numerous fins (34) is the same as the flow direction of the low-temperature air in the freezer compartment (11). As the cold air passes between the plurality of fins (34), the cooling plate (31) is rapidly cooled. Therefore, the vicinity of the two cut surfaces (44) of the meat piece (40) in contact with the cooling plate (31) is rapidly cooled and frozen. Since the other portions are directly cooled by low-temperature air, the cooling rate is greatly delayed as compared with the cooling plate (31).
Although it freezes rapidly from a portion close to the cooling plate (31), freezing is delayed in the surface portion not in contact with the cooling plate (31). Therefore, there is flexibility. Therefore, the expansion force generated at the time of quick freezing escapes in a flexible direction where the cooling plate (31) does not exist. For that reason, since the whole piece of meat (40) is frozen in a state where the expansion force is suppressed below the cell's destructive limit pressure, occurrence of cracks in the piece of meat (40) is prevented. .
As the cold air passes between the plurality of fins (34), the cooling plate (31) is rapidly cooled. When the flow of low-temperature air passing between the numerous fins (34) becomes faster, the cooling rate of the cooling plate (31) increases, and the cooling rate of the flesh (40) in contact with the cooling plate (31) also increases. . The controller (16) adjusts the air temperature and controls the cooling rate of the cooling plate (31) so that the speed at which the meat piece (40) passes through the maximum freezing crystal formation zone is not slowed down.

In addition, various sensors (such as a temperature sensor that detects the surface temperature of the meat piece 40 and an image sensor that acquires the surface image of the meat piece 40) for detecting signs of cracking are provided, and based on data obtained from these sensors. Control by the control device may be executed.
Also, when installing the quick cooler (30) in the freezer compartment (11), if the longitudinal direction of many fins (34) is the same as the flow direction of the low-temperature air in the freezer compartment (11), the efficiency As a matter of course, in the present invention, the flow direction of the low-temperature air and the longitudinal direction of the fins (34) may not coincide with each other.
The control device (16) may control the operation of the blower.

(Variation 1 of the first invention)
The first invention can also provide the following variations.
That is, the angle of the two contact surfaces (32, 32) in the cooling plate (31, 31) is about 90 degrees.

(Function)
If the angle of the contact surface (32, 32) is about 90 degrees, the cooling plate (31, 31) can be easily manufactured because it is a general-purpose angle. The same applies to the meat pieces (40).
Since the angle of the two contact surfaces (32, 32) is about 90 degrees, even if the angle of the two cut surfaces (44, 44) of the meat piece (40) is less than 90 degrees, the weight of the meat piece (40) Thus, the two cut surfaces (44, 44) are brought into close contact with the two contact surfaces (32, 32).
On the other hand, even if the angle of the two cut surfaces (44, 44) of the meat piece (40) is larger than 90 degrees, the meat piece (40) is flexible, so the two cut surfaces (44, 44) are in contact with each other. It will adhere to the surfaces (32, 32).
Therefore, even if the fillet produced by cutting the fish is not exactly 90 degrees, the cut surfaces (44, 44) can be brought into close contact with the two contact surfaces (32, 32).

(Variation 2 of the first invention)
In the first invention, the cooling plate (31) and the fin portion (33) may be integrally bonded.
Since the cooling plate (31) and the fin portion (33) are manufactured separately and then bonded to each other, the specifications suitable for the purpose can be easily manufactured and can be manufactured at low cost.

(Variation 3 of the first invention)
In the first invention, contrary to the above variation, the cooling plate (31) and the fin portion (33) may be formed by integral molding.
Since the cooling plate (31) and the fin portion (33) are integrally manufactured by extrusion molding, a process of bonding them to each other is not necessary and can be manufactured at low cost.

(Variation 4 of the first invention)
In the first invention, the plurality of cooling plates (31) may be connected in parallel so that the plurality of contact surfaces (32) are corrugated.
By making the cooling plate (31) corrugated on the plurality of contact surfaces (32), the cooling plate (31) can be self-supported and placed on the work table, the product freezing shelf (20), etc., so that the freezing operation is facilitated.

(Variation 5 of the first invention)
In the first invention, each contact surface (32) of the cooling plate (31) may be formed so as to be easily peelable from the frozen meat.
Since each contact surface (32) of the cooling plate (31) has peelability, the product (40) can be easily taken out from the cooling plate (31) after freezing is completed. In addition, since the surface finish of the product (40) becomes smooth, the risk of foreign matter adhesion is reduced, contributing to the quality improvement of the product (40).
Further, the first invention may include a release sheet having peelability interposed between each contact surface (32) of the cooling plate (31) and a cut surface (44) of the meat piece (40). Good.
By interposing the release sheet, the piece of meat (40) is easily taken out of the cooling plate (31) after completion of freezing. In addition, when the meat piece (40) is shipped with the release sheet covered, it can be used as a product pack and also protects the cut surface (44) when the meat piece (40) is thawed.

(Variation 6 of the first invention)
In the first invention, the temperature in the freezer compartment is set to minus 30 degrees Celsius to minus 35 degrees Celsius.
Rapid freezing (freezing that can suppress the destruction of cells without elongating the maximum freezing crystal formation zone), which could not be achieved unless the temperature is −50 degrees Celsius or less until now, is from −30 degrees Celsius to −35 degrees Celsius. Can be achieved in degrees. This is the optimum temperature range where power consumption can be reduced without reducing the speed of passing through the maximum freezing crystal formation zone.
As a result, the same quick freezing is possible even if the power consumption is reduced compared with the quick freezing performed at minus 50 degrees Celsius or less, and even in the space saving compared with the quick freezing performed at minus 50 degrees Celsius or less. Similar quick freezing has become possible.
In addition, when achieving freezing faster than freezing by minus 30 degrees Celsius to minus 35 degrees Celsius, the temperature may be set to minus 35 degrees Celsius or less (for example, minus 40 degrees Celsius). In addition, when it is desired to save power more than freezing by minus 30 degrees Celsius to minus 35 degrees Celsius, the temperature may be changed from minus 25 degrees Celsius to minus 30 degrees Celsius.

(Second invention)
According to a second aspect of the present invention, the second aspect of the present invention relates to a rapid cooling tool (30) for placing a meat piece (40) having two cut surfaces (44) having a predetermined angle. That is, a cooling plate (31) provided with two contact surfaces (32) having an angle for contacting the two cut surfaces (44) of the meat piece (40), and the two in the cooling plate (31) A fin portion (33) in which a large number of fins (34) extending in the longitudinal direction of the cooling plate (31) are arranged in parallel on the back surface of the contact surface (32).
The said fin part is for cooling the site | part which contacted the said cooling plate in the said meat piece faster than another site | part. In addition, the cooling plate is formed so that the upper part is opened in order to release the pressure caused by freezing that starts at a portion that contacts the cooling plate faster than the other portions.

(Function)
When placing the piece of meat (40) on the quick cooler (30), place the two cut surfaces (44) of the piece of meat (40) in contact with the two contact surfaces (32) of the cooling plate (31). . As the cold air passes between the plurality of fins (34), the cooling plate (31) is rapidly cooled. Therefore, the vicinity of the two cut surfaces (44) of the meat piece (40) in contact with the cooling plate (31) is rapidly cooled and frozen. Since the other portions are directly cooled by low-temperature air, the cooling rate is greatly delayed as compared with the cooling plate (31).
Although it freezes rapidly from the piece of meat close to the cooling plate (31), the portion not in contact with the cooling plate (31) is flexible because the freezing is delayed. Therefore, the expansion force generated at the time of quick freezing escapes in the direction of the portion not in contact with the flexible cooling plate (31) (in the case of a skinned fillet, the direction of the fish skin). As a result, since the whole piece of meat (40) is frozen in a state where the expansion force is kept below the cell breaking limit pressure, occurrence of cracks in the piece of meat (40) is suppressed.
Even if the angle of the two cut surfaces (44) of the meat piece (40) is 90 degrees or less, the angle of the two contact surfaces (32) is about 90 degrees, so the two cut surfaces (44) of the meat piece (40). Adheres by the dead weight of the meat piece (40).

(Variation 1 of the second invention)
In the second invention, the cooling plate (31) and the fin portion (33) may be integrally bonded.
In this case, since the cooling plate (31) and the fin portion (33) are manufactured separately and then bonded to each other, the specification suitable for the purpose can be easily manufactured and the manufacturing can be performed at low cost.

(Variation 2 of the second invention)
In the second invention, contrary to the above-described variation, the cooling plate (31) and the fin portion (33) may be formed by integral molding.
In this case, since the cooling plate (31) and the fin portion (33) are integrally manufactured by extrusion molding, a process of adhering to each other is not necessary and can be manufactured at low cost.

(Variation 3 of the second invention)
The second invention can also provide the following variations.
That is, a plurality of the cooling plates (31) are connected in parallel so that the plurality of contact surfaces (32) are corrugated.
The cooling plate (31) can be placed on the work table, the product freezing shelf (20) and the like by making the plurality of contact surfaces (32) corrugated, so that the freezing operation is facilitated.

(Variation 4 of the second invention)
The second invention can also provide the following variations.
That is, each contact surface (32) of the cooling plate (31) is formed as a surface having peelability.
If each contact surface (32) of the cooling plate (31) is peelable, the product (40) can be easily taken out from the cooling plate (31) after freezing is completed. In addition, since the surface finish of the product (40) becomes smooth, the risk of foreign matter adhesion is reduced, contributing to the quality improvement of the product (40).

(Third invention)
The third invention relates to a quick freezing method using a quick freezing apparatus installed in a freezing room for quick freezing meat pieces having two cut surfaces adjacent to each other at a predetermined angle.
The rapid freezing apparatus includes: a cooling plate having two contact surfaces that contact both cut surfaces of the meat piece; and a plurality of fins extending in a longitudinal direction of the cooling plate on a back surface of each contact surface of the cooling plate The quick cooler provided with the fin portion having the fin disposed therein is installed in the freezer compartment, and a blower for blowing air to the fin portion is provided.
The said fin part is for cooling the site | part which contacted the said cooling plate in the said meat piece faster than another site | part. In addition, the cooling plate is formed so that the upper part is opened in order to release the pressure generated by freezing that begins at a portion that contacts the cooling plate faster than the other portions.
The quick freezing method includes a meat piece placing step for placing the meat piece by bringing the cut surface of the meat piece into contact with the cooling plate, a cold air producing step for producing cold air, and the cold air produced in the cold air producing step. Air flow for moving the inside of the freezing chamber, a detection step for detecting the surface state of the meat piece not in contact with the contact surface, and the cold air production from the surface state of the meat piece detected in the detection step And a control step for controlling the temperature of the cold air produced in the step and the amount of blown air in the blow step.

The “detecting step” is based on a temperature sensor for checking the temperature of the surface of the meat piece, an imaging means for continuously imaging the image data of the surface of the meat piece, or a combination thereof. The purpose is to detect signs of cracking.
The “control process” refers to the input of data such as the temperature of the cold air produced in the cold air production process and the temperature in the freezer, and the data regarding the surface state of the meat pieces obtained in the inspection process. The temperature of the cold air produced in the cold air production process and the air blowing amount in the air blowing process are controlled. When a sign of cracking is detected, for example, the temperature of the cold air is adjusted, or the total air volume is increased or decreased.

(Fourth invention)
4th invention concerns the fishing boat carrying the quick freezing apparatus which concerns on 1st invention.
This fishing boat is a large fishing boat that catches large fish such as tuna and bonito in the pelagic fishery. Since the refrigeration capacity of the quick freezing device is only about minus 30 degrees Celsius, space saving and power consumption reduction can be realized, so that the freezing device is advantageous to be installed as a large fishing boat facility. Therefore, it is possible to realize a fishing boat equipped with a quick freezing apparatus that suppresses the occurrence of cell destruction and breakage of meat pieces due to freezing and reduces power consumption during freezing.

According to the first invention, it is possible to provide a quick freezing apparatus that suppresses the occurrence of breakage due to cell destruction of meat pieces accompanying freezing and reduces power consumption during freezing.
Moreover, according to 2nd invention, generation | occurrence | production of the crack by the cell destruction of the meat piece accompanying freezing can be suppressed, and the quick cooling tool which reduced the power consumption at the time of freezing can be provided.
Furthermore, according to the third aspect of the invention, it is possible to provide a quick freezing method that suppresses the occurrence of breakage due to cell destruction of meat pieces accompanying freezing and reduces power consumption during freezing.
According to the fourth aspect of the invention, it is possible to provide a fishing boat equipped with a quick freezing device that suppresses the occurrence of cell destruction and breakage of meat pieces accompanying freezing and reduces power consumption during freezing.

It is explanatory drawing which shows schematically the quick freezing apparatus which concerns on embodiment of this invention. FIG. 2 is a side view seen from the arrow II-II line in FIG. FIG. 3A is a longitudinal sectional view of a fish fillet, and FIG. 3B is a perspective view of the fish fillet. It is a perspective view of the quick cooling tool which mounted the fillet. It is a longitudinal cross-sectional view of a quick cooling tool. It is sectional drawing which shows the freezing state inside the fillet after the start of freezing. It is sectional drawing which shows the freezing state inside the fillet near the completion of freezing. It is an experimental data table which imitated the freezing situation by a prior art. It is an experimental data table | surface which also had the freezing condition by this invention.

  Hereinafter, a quick freezing apparatus according to an embodiment of the present invention will be described with reference to the drawings. The drawings used here are FIGS. 1 to 7.

  FIG. 1 shows an overall view of the quick freezing apparatus 10. The quick freezing apparatus 10 includes a freezer compartment 11 having an opening / closing door for taking in and out a product 40 such as fish meat, and a freezer compartment that uses Freon 22 or ammonia as a refrigerant for creating low-temperature air for cooling the inside of the freezer compartment 11. And a cooling device 12. Further, the room temperature sensor 14 that detects the internal temperature of the freezer compartment 11, the product temperature sensor 15 that detects the temperature of the product 40, and the information in the room temperature sensor 14 and the product temperature sensor 15, And a control device 16 for controlling the cooling rate.

The freezer compartment cooling device 12 is disposed outside the freezer compartment 11. As a system of the freezer compartment cooling device 12, for example, refrigerant gas (fluorocarbon 22 or ammonia) in the evaporator 13 in the freezer compartment 11 is liquefied by a condenser, sent to an expansion valve, and adiabatically compressed by a compressor. The refrigerant adiabatically expanded by the expansion valve and the compressor has an extremely low temperature of, for example, minus 50 degrees Celsius to minus 70 degrees Celsius. This refrigerant is returned to the freezer compartment 11, and the air temperature in the freezer compartment 11 is lowered by the evaporator 13.
However, in this embodiment, minus 50 degrees Celsius is not required as the air temperature of the freezer compartment 11, and if the air of about minus 35 degrees Celsius can be created via the refrigerant, the maximum freezing crystal production zone can be quickly passed ( Slow freezing can be prevented), and cracking is unlikely to occur.

For example, when the condensation temperature is 35 degrees Celsius, the coefficient of performance of an ammonia refrigerator having evaporation temperatures of minus 60 degrees Celsius and minus 35 degrees Celsius is 0.267 and 0.622. This indicates that when the same refrigeration load is cooled, minus 60 degrees Celsius requires 2.33 times as much power as minus 35 degrees Celsius. Actually, the power of the refrigeration fan is also required, so the magnification is further increased.
Moreover, the ratio of the capability of minus 60 degrees Celsius and minus 35 degrees Celsius with the same compressor is 11.1 and 46.3. This indicates that refrigerators corresponding to the same refrigeration load require 4.2 times as large as minus 60 degrees Celsius compared to minus 35 degrees Celsius.
The case where the refrigerant is Freon 22 and the case where it is ammonia is almost the same.

  The low-temperature air in the freezer compartment 11 is blown into the freezer compartment 11 from the outlet on the right side of the evaporator 13 via the fan 21 provided on the left side of the evaporator 13 in FIG. The temperature of the low-temperature air is adjusted by controlling the operation state of the freezer cooling device 12 by the control device 16. In this embodiment, the low temperature air supplied to the freezer compartment 11 is controlled to be low temperature air of minus 35 degrees Celsius to minus 30 degrees Celsius.

In the freezer compartment 11, a product freezing shelf 20 on which products 40 are placed side by side is arranged below the evaporator 13. The product freezing shelf 20 is partitioned into shelves by punching metal having a large number of holes through which cold air passes. On each shelf, for example, a fillet such as a tuna or a block-like fish meat 40 is placed in a state of being placed on the quick cooling device 30.
In the present embodiment, in the freezer compartment 11, the low-temperature air blown from the evaporator 13 through the fan 21 circulates in the freezer compartment 11, so that the product freezing shelf 20 flows from right to left in FIG. 1. .
The motors 22 that drive the fans 21 are also connected to and controlled by the control device 16 so that the air volume can be controlled by adjusting the rotational speed of the fans 21.

FIG. 3A shows, for example, a longitudinal section of the tuna 41, and FIG. 3B shows a perspective view of the tuna 41 with the gills, tail fins and internal organs removed. The fillet 42 is divided into four parts by cutting vertically and horizontally in the longitudinal section of the tuna 41. Accordingly, each fillet 42 is a fish meat 40 having a fish skin 43 and two cut surfaces 44 forming a predetermined angle (about 90 degrees in this embodiment). The “predetermined angle” is not limited to about 90 degrees, but in the case of a large fish such as tuna 41, it is desirable to cut at about 90 degrees in order to serve raw fish such as sashimi. If the site such as blood clots is removed, it may be 90 degrees or less, but if it is close to 90 degrees, it will contact the cut surface with its own weight when placed.
The fish skin 43 may be removed before freezing.

FIG. 4 shows a state where the two cut surfaces 44 of the fillet 42 are placed on the rapid cooling tool 30 so as to be in contact with each other.
FIG. 5 shows a cross section of the rapid cooling tool 30. The rapid cooling tool 30 includes a cooling plate 31 on which the fillet 42 is placed and a fin portion 33 for rapidly cooling the cooling plate 31.

The cooling plate 31 includes two contact surfaces 32 having a predetermined angle for bringing the two cut surfaces 44 of the fillet 42 into contact with each other. In the present embodiment, the predetermined angle is about 90 degrees. In addition, the shape provided with the two contact surfaces 32 in which the cooling plate 31 has a predetermined angle is a single fundamental structure. The cooling plate 31 is formed by bending a metal plate having high thermal conductivity, such as iron, stainless steel, copper, or aluminum, at an angle of about 90 degrees. In addition, as a material of the cooling plate 31, other materials may be sufficient as long as it has high heat conductivity to some extent.
On the other hand, the fin portion 33 has a plate-like base portion 35 in which a large number of fins 34 extending in the longitudinal direction of the cooling plate 31 are arranged in parallel. The fin portion 33 is integrally formed with the cooling plate 31 by being bonded to the back surface of each contact surface 32 of the cooling plate 31. Moreover, the fin part 33 can be shape | molded by extrusion molding with the metal which has high heat conductivity like iron, stainless steel, copper, aluminum etc., for example.

In FIG. 4, the cooling plate 31 is bent at an angle of about 90 degrees at a plurality of locations where the bending directions are parallel to a metal plate having high thermal conductivity, whereby a plurality of the cooling plates of FIG. 31 are formed in parallel. That is, the rapid cooling tool 30 in FIG. 4 is formed by bending a single metal plate so that the plurality of contact surfaces 32 are corrugated. A fin portion 33 including a large number of fins 34 and a base portion 35 is bonded to the back surface of each contact surface 32 of the cooling plate 31.
4 may be configured such that a plurality of contact surfaces 32 are corrugated by connecting a plurality of individually formed cooling plates 31 in parallel as shown in FIG. . In addition, the fin portion 33 is bonded to the back surface of each of the plurality of contact surfaces 32.

In the rapid cooling tool 30 of the present embodiment, the cooling plate 31 has a thickness of 5 mm and a total length of 800 mm.
On the other hand, as the fin portion 33, the thickness of the plate-like base 35 is 5 mm, the width of the base 35 is 138 mm, and the total length of the base 35 is 800 mm. Further, the thickness of each fin 34 is 2 mm, the height of each fin 34 is 30 mm, the pitch of the fins 34 is 8 mm, and the total length of each fin 34 is 800 mm.
The surface of the base portion 35 of the fin portion 33 is bonded to the back surface of each contact surface 32 of the cooling plate 31.
The rapid cooling tool 30 is configured such that the total surface area of the large number of fins 34 is 10 times or more (about 20 times in this embodiment) with respect to the surface area of the cooling plate 31.

As described above, since the rapid cooling tool 30 of the present embodiment is configured by bonding the cooling plate 31 and the fin portion 33 after the cooling plate 31 is bent, it can be easily manufactured to a specification suitable for the purpose. Moreover, it can be manufactured at low cost.
Moreover, since the quick cooling tool 30 in which the plurality of contact surfaces 32 are corrugated can be self-supported and disposed on the work table, the product freezing shelf 20 or the like, the freezing operation can be facilitated.

  4 and 5, the cooling plate 31 and the fin portion 33 can be integrally formed by, for example, extrusion molding. In that case, the cooling plate 31 and the fin part 33 are comprised with the same material. The cooling plate 31 and the fin portion 33 do not need to be bonded to each other, and can be manufactured at low cost.

  One or a plurality of room temperature sensors 14 are installed at appropriate locations in the freezer compartment 11 and are connected to the control device 16. That is, measurement data measured by the room temperature sensor 14 is sent to the control device 16. In addition, if the room temperature sensor 14 is installed in the middle of the fan duct 23, for example, the temperature of the low-temperature air flowing through the product freezing shelf 20 can be measured, and the freezing operation is not disturbed. Furthermore, it is desirable in that the control device 16 adjusts the temperature of the low-temperature air passing around the fish meat 40 based on the measured temperature information.

  The product temperature sensor 15 is installed so as to be able to measure the surface temperature of the cooling plate 31 and the temperature at a plurality of locations of the fillet 42. Each product temperature sensor 15 is connected to a control device 16. That is, the measurement data measured by each product temperature sensor 15 is sent to the control device 16.

  The control device 16 controls the air volume by adjusting the rotational speed of the fan 21 based on the information of the room temperature sensor 14 and the product temperature sensor 15, or the compressor or the compressed air cooler of the freezer cooling device 12. The air temperature is controlled by controlling the capacity of the air.

The operation of the quick freezing apparatus 10 shown in FIG. 1 will be described.
The two cut surfaces 44 of the fillet 42 are placed on the two contact surfaces 32 of the cooling plate 31 of the rapid cooling tool 30 so as to contact each other. For example, the angle between the two cut surfaces 44 of the fillet 42 may be 90 degrees or less due to the removal of fish blood. However, if the two contact surfaces 32 are at an angle of about 90 degrees, the two cut surfaces 44 of the fillet 42 are in most cases brought into close contact by the weight of the fillet 42. If the degree of adhesion is not sufficient, the predetermined angle of the two contact surfaces 32 in the cooling plate 31 is slightly adjusted in advance.

  The quick cooler 30 on which the fillet 42 is placed as described above is placed on each shelf of the product freezing shelf 20 in the freezer compartment 11. At this time, the rapid cooling tool 30 is arranged so that the longitudinal direction of the numerous fins 34 is directed toward the flow direction of the low-temperature air in the freezer compartment 11 (left-right direction in FIG. 1).

  In the quick freezing device 10, the operation of the freezer compartment cooling device 12 is started and the fan 21 rotates, and low temperature air is blown into the freezer compartment 11 from the outlet on the left side wall in FIG. 1. In the freezer compartment 11, low-temperature air flows to the right in the product freezing shelf 20 in FIG. 1 and is sucked by the fans 21. That is, the low-temperature air smoothly flows between the numerous fins 34 in the rapid cooling tool 30.

Since the rapid cooling tool 30 has a large overall surface area of the large number of fins 34, when the low-temperature air passes between the large number of fins 34, the fin portion 33 is rapidly cooled compared to other places. The cooling plate 31 to which the fin portion 33 is bonded is rapidly cooled.
Therefore, the vicinity of the two cut surfaces 44 of the fillet 42 that is in contact with the cooling plate 31 is rapidly cooled and frozen (not slowly frozen). Since the portions other than the cooling plate 31 are directly cooled by the low-temperature air, the cooling rate is delayed as compared with the cooling plate 31. As a result, as shown in FIG. 6, the fillet 42 rapidly freezes from the fish portion near the cooling plate 31, but the fish portion near the skin 43 is delayed in freezing. Therefore, even if the fish meat portion close to the cooling plate 31 is frozen, the fish meat portion close to the skin 43 is flexible.

Therefore, when the moisture in the fish meat freezes and expands, the pressure (expansion force) of the unfrozen portion inside the fillet 42 increases, but the expansion force escapes toward the flexible skin 43. As described above, by releasing the internal pressure of the fillet 42 at the time of quick freezing, the expansion force can be suppressed to be equal to or lower than the cell destruction limit pressure. FIG. 7 shows a state in the immediate vicinity of completion of freezing. In the process of rapid freezing, the whole fillet 42 is frozen in a state below the cell breaking pressure limit, so that it is possible to prevent the outer surface of the fillet 42 from cracking (occurrence of cracks).
As described above, rapid freezing capable of preventing the occurrence of cracks (breaks) in the fillet 42 has been realized even with the rapid freezing method using air of minus about 30 degrees Celsius.

Next, a comparison is made between a case where quick freezing at an ultra-low temperature using the conventional air freezing method shown in Patent Documents 1 and 2 and a case where the fillet 42 is rapidly frozen using the quick cooling tool 30 of the present embodiment. To do.
FIG. 8 shows the cooling experiment value when the initial temperature is 0 degrees Celsius, the temperature in the freezer room is minus 60 degrees Celsius, and the heat transfer coefficient is 20 kcal / h degree for the fish meat having a cylindrical shape with a diameter of 130 mm. It is.
FIG. 9 shows a cooling experiment value when the initial temperature is 0 degrees Celsius, the temperature in the freezer room is minus 35 degrees Celsius, and the heat transfer coefficient is 200 kcal / h degrees for a fish meat having a cylindrical shape with a diameter of 130 mm. It is.

The experimental values shown in FIGS. 8 and 9 are the conventional values shown in Patent Documents 1 and 2 in FIG. 8, and the theoretical values simulating the present invention in FIG. This is because it is difficult to define each part including the center in the shape of the fillet. 1, 2, 3, and 4 between the surface temperature and the center temperature indicate portions that are equally divided from the surface to the center.
In FIG. 8, the heat transfer coefficient is set to 20 kcal / h degree, and the heat transfer coefficient is set to 200 kcal / h degree in FIG. This is because the heat transfer coefficient differs by 10 times or more depending on the presence or absence of the fin portion. The heat transfer coefficient of 200 kcal / h degree is substantially the same heat transfer coefficient as when calcium chloride is used in the conventional brine freezing method.
Further, the temperature in the freezer compartment in FIG. 8 is set to minus 60 degrees Celsius, and the temperature in the freezer compartment in FIG. 9 is set to minus 35 degrees Celsius, which is the temperature used in the prior art disclosed in Patent Documents 1 and 2. This is to compare the band with the temperature band used in the present invention.

From FIG. 8, it can be read that the center temperature becomes minus 52.3 degrees Celsius after 300 minutes. Moreover, it takes about 220 minutes for the central portion to be minus 31.0 degrees Celsius.
On the other hand, from FIG. 9, it can be read that the center temperature becomes minus 34.3 degrees Celsius after 240 minutes. Is shown. Moreover, it takes about 175 minutes for the central portion to be minus 31.3 degrees Celsius.

From the above, the prior art disclosed in Patent Documents 1 and 2 is compared with the present invention. When the cooling fin is provided and the heat transfer coefficient is 10 times as in the present invention, the speed at which the central portion is less than minus 30 degrees Celsius is estimated to be equal to or higher than that of the prior art.
Further, the time at which the central portion falls below minus 5 degrees Celsius, which is the maximum freezing crystal formation zone, is 170 minutes in FIG. 8 and 115 minutes in FIG.
However, in the present invention, the vicinity of the two cut surfaces 44 is rapidly cooled, and the cooling rate of the portion not in contact with the cooling plate 31 is slow, so even if there is an increase in volume when freezing, the pressure due to the increase in volume Since there is a part that escapes the rise, the occurrence of cracks is suppressed. On the other hand, in the prior art, since the difference in cooling speed between the part that is in contact with the cooling plate and the part that is not in contact is small, there is no part that releases the pressure rise because it freezes almost uniformly from the outer periphery. There is still a possibility of cracking.

From the above, the rapid freezing apparatus 10 described in the present embodiment can prevent the occurrence of cracks due to cell destruction of the product 40 such as fish meat. Further, since the air freezing method is used, the freezing operation is simpler than the brine freezing method. Furthermore, even if the temperature of the freezer compartment 11 is minus 35 degrees Celsius or minus 30 degrees Celsius, the product 40 such as fish meat can be sufficiently rapidly frozen using the quick cooling tool 30 having a simple structure. As a result, power consumption during freezing can be reduced (on the order of a fraction).
If the performance of the refrigerator is only a fraction of that, the capital investment will be small. In addition, since the refrigerator can be reduced in size, the entire facility can be saved. For example, the quick freezing apparatus according to the present invention can be designed and provided so as to be mounted on a tuna fishing boat that is not large.

  In addition, as for the quick cooling tool 30, it is desirable for each contact surface 32 of the cooling plate 31 to be a surface which has peelability which performed the mirror surface finishing process or the coating process of Teflon (trademark), for example. This is because the frozen product 40 can be easily taken out of the cooling plate 31 after the fillet 42 is completely frozen by forming it as a peelable surface. In addition, since the surface finish of the frozen product 40 becomes smooth, the risk of foreign matter adhesion is reduced and the quality of the product 40 is improved.

Further, a release sheet having peelability can be interposed between each contact surface 32 of the cooling plate 31 and the cut surface 44 of the fillet 42. Thereby, the frozen product 40 can be easily taken out from the cooling plate 31 after the freezing of the fillet 42 is completed. Further, if the frozen product 40 is shipped in a state where the release sheet is covered, it becomes a product pack and the cut surface 44 is protected when the frozen product 40 is thawed.
As the release sheet, a resin that is not solidified even when the product 40 is frozen, or other material is used.

  The present invention has applicability in the equipment industry that manufactures refrigeration equipment and freezing rooms, the equipment industry that manufactures refrigeration equipment mounted on fishing boats, the shipbuilding industry, and the software industry that develops control programs for refrigeration equipment and freezing rooms. Have.

DESCRIPTION OF SYMBOLS 10 Quick freeze apparatus 11 Freezer compartment 12 Freezer compartment cooler 13 Evaporator 14 Room temperature sensor 15 Product temperature sensor 16 Control apparatus 20 Product freeze shelf 21 Fan 22 Motor 23 Fan duct 30 Quick cooler 31 Cooling plate 32 Contact surface 33 Fin part 34 Fin 35 Base 40 Product (such as fish meat) 41 Tuna 42 Fillet 43 Fish skin 44 Cut surface

Claims (11)

A quick freezing device installed in a freezing room for freezing a piece of meat having two cut surfaces having a predetermined angle,
A cooling plate provided with two contact surfaces that contact adjacent cut surfaces in the meat piece, and a quick cooling tool provided with a fin portion in which a large number of fins are arranged on the cooling plate on the back surface of each contact surface of the cooling plate. And installing in the freezer compartment,
A blower that blows air to move the air in the freezer compartment;
A control device for adjusting the air temperature in the freezer compartment,
The fin portion is for cooling a portion of the meat piece that contacts the cooling plate faster than other portions,
The said cold plate is a quick freezing apparatus formed so that the part which contacted the cold plate might open | release an upper side in order to release the pressure which arises by the freezing which starts earlier than another part . The quick freezing apparatus according to claim 1, wherein the fin portion is 10 times or more the contact surface of the cooling plate.   The rapid freezing apparatus according to claim 1 or 2, wherein an angle between the two contact surfaces of the cooling plate is about 90 degrees.   The quick freezing apparatus according to any one of claims 1 to 3, wherein the cooling plate and the fin portion are integrally formed by bonding.   The rapid freezing apparatus according to any one of claims 1 to 3, wherein the cooling plate and the fin portion are formed by integral molding.   The rapid freezing apparatus according to any one of claims 1 to 5, wherein the plurality of cooling plates are configured to be connected in parallel so that the plurality of contact surfaces have a waveform.   The rapid freezing apparatus according to any one of claims 1 to 6, wherein each contact surface of the cooling plate is formed so as to be easily peelable from frozen meat.   The rapid freezing apparatus according to any one of claims 1 to 7, wherein the temperature in the freezer compartment is set to minus 30 degrees Celsius to minus 35 degrees Celsius. A quick cooling device for placing fish meat having two cut surfaces having a predetermined angle,
A plurality of fins extending in the longitudinal direction of the cooling plate are arranged in parallel on a cooling plate having two contact surfaces that contact adjacent cut surfaces of the meat piece, and on the back surface of the two contact surfaces of the cooling plate. A fin portion disposed,
The fin portion is for cooling a portion of the meat piece that contacts the cooling plate faster than other portions,
The said cooling plate is a quick cooling tool formed so that the part which contacted the cooling plate might open | release an upper side in order to release the pressure which arises by the freezing which starts earlier than another part . A quick freezing method using a quick freezing apparatus installed in a freezing chamber for freezing meat pieces having two cut surfaces adjacent to each other at a predetermined angle,
The rapid freezing apparatus includes a cooling plate having two contact surfaces that contact adjacent cut surfaces of the meat piece, and a plurality of surfaces extending in the longitudinal direction of the cooling plate on the back surface of each contact surface of the cooling plate. The quick cooler including the fin portion in which the fin is disposed is installed in the freezer compartment, and a blower that blows air to the fin portion is provided.
The fin portion is for cooling a portion of the meat piece that contacts the cooling plate faster than other portions,
The cooling plate is formed so that the part in contact with the cooling plate is opened on the upper side in order to release the pressure caused by freezing that starts earlier than other parts,
A meat piece placing step for placing the meat piece in contact with the cut surface of the meat piece against the cooling plate;
Cold air production process to create cold air,
An air blowing step for blowing air to move the cold air produced in the cold air producing step in the freezer compartment;
A detection step of detecting the state of the surface of the piece of meat that is not in contact with the contact surface;
A control process for controlling the temperature of the cold air created in the cold air production process from the state of the surface of the meat piece detected in the detection process and the air flow rate in the air blowing process;
Quick freezing method with. A fishing boat equipped with a quick freezing device installed in a freezing room for freezing meat pieces having two cut surfaces having a predetermined angle,
The rapid freezing apparatus includes a cooling plate having two contact surfaces that contact adjacent cut surfaces of the meat piece, and a plurality of surfaces extending in the longitudinal direction of the cooling plate on the back surface of each contact surface of the cooling plate. While installing the quick cooler provided with the fin portion where the fin is disposed in the freezer compartment,
A blower that blows air to move the air in the freezer compartment;
A control device for adjusting the air temperature in the freezer compartment,
The fin portion is for cooling a portion of the meat piece that contacts the cooling plate faster than other portions,
The said cooling plate is a fishing boat carrying the quick freezing apparatus formed so that the upper part might be open | released in order to release the pressure which arises by the freezing which the site | part which contacted the cooling plate started earlier than another site | part .

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