JP2006046675A - Freezing method of food and freezing storage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a freezing method of food and a freezer capable of preventing loss of weight of frozen food due to water vapor dissipating from surface of food in a freezing process and crack generation at a frozen food surface as much as possible and capable of improving article value . <P>SOLUTION: A freezing storage 20 is equipped with a refrigerating coil 8 and an air blower 10 in a cabinet 2, a surface temperature sensor 24 for detecting surface temperature of food F and a heat exchange load increase/decrease means 28 for increasing/decreasing heat exchange load at an evaporator consisting of the refrigerating coil and an air blower and raising or lowering evaporation temperature. Till the food surface temperature detected by the surface temperature sensor is lowered to a temperature at which a film of ice can be generated on the surface, the evaporation temperature at the refrigerating coil is lowered by operating the heat exchange load increase/decrease means to a heat load decreasing side and temperature of air circulated in the storage by the air blower is lowered to a low temperature. After the surface temperature is lowered to a temperature at which the film of ice can be generated, the heat exchange load increase/decrease means is operated to a heat exchange load increasing side to conduct quick freezing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for freezing foods that can prevent the loss of frozen food due to the dissipation of water vapor from the food surface during the cooling process (weight reduction) and the occurrence of cracks on the frozen food surface as much as possible. , And freezer technology.

  As a conventional food freezer, as shown in FIG. 9, a shelf or a tray 4 for storing the food F of the object to be frozen is provided in the center of the inside of the cabinet 2 of the heat insulating structure, and behind the refrigerator 6 The cooling coil 8 and the blower 10 are arranged, the inside air present in the food storage unit is sucked by the blower 10, and the entire amount of the air flow is cooled by passing through the cooling coil 8, and then the ceiling or side surface. There is a type in which the cool air is blown out to the opening / closing door 14 through the air passage 12 formed in the above and circulated to the food storage unit.

  Alternatively, as shown in FIG. 10, a cooling coil 8 is provided in the interior rear of the cabinet 2 of the heat insulating structure, and two small blowers 10 are placed up and down in front of the cooling coil 8 with respect to the cooling coil 8. Arranged on a diagonal line, air is blown by the blower toward the food storage section partitioned further forward than these blowers 10 and the inside air is circulated, so that only a part of the inside air is cooled during the circulation. There is a type configured to pass through the coil 8 (see, for example, Patent Document 1).

In both types of freezers, the blower 10 is fully operated over the entire operation period immediately after the start of operation until the freezing is completed, so that the entire air volume is blown.
Japanese Patent No. 3366777

  By the way, the amount of air present in the freezer compartment is constant as long as the airtightness of the inside of the compartment and the door 14 is ensured, so that the sensible heat amount is intended to cool and freeze in view of the thermal properties of the air. Compared to the amount of heat of the food F to be processed, it is only a little, and can be cooled in a relatively short time. Similarly, the amount of water vapor that the internal air has from the beginning is also limited.

  However, since the water vapor generated from the food material F is a latent heat amount, the heat amount becomes a large amount of heat that cannot be ignored depending on the temperature, properties, and shape of the food material F. Further, the steam is generated in a larger amount as the air blown toward the food F is stronger, and the water is forcibly stripped from the surface of the food F. And when this water vapor passes the cooling coil 8, it is cooled by the refrigerator 6, and it condenses on the cooling coil 8 part and freezes. That is, the generation and condensation / freezing of the water vapor not only dry and reduce the amount of the food F, but also deprive the scent of scent, which is a cause of quality deterioration as food.

  In particular, when high-temperature food F, for example, 85 ° C. food immediately after cooking, is packed in a freezer and frozen, water vapor generated from the surface of the food F at the initial stage of the cooling process. The partial pressure is high because of the high temperature, and the amount of air blown from the blower 10 is increased to rapidly cool and freeze the food F, and the surface wind speed of the food F is increased to cool the food F. It just strips off in the form of water vapor.

  Further, the water vapor evaporated from the surface of the food F gradually grows on the cooling coil 8 by frosting, and the grown frost heats the refrigerant and air in the freezing process at the end of the operation at which the temperature is most lowered. Interfering with replacement will deteriorate cooling efficiency. In the worst case, the suction surface of the cooling coil 8 is blocked by frost formation, the fin coil becomes clogged, air cannot flow in, and the flow of air, which is an essential heat medium, is lost. As a result, the heat transfer from the food F also stops, and after that, it does not cool.

  Moreover, in the conventional freezer as shown in FIG. 9, when the shape of the food F is large, if the surface is frozen and hardened in the initial stage of operation, the moisture contained in the food (free water) It has also occurred that the product value of the foodstuff F is damaged by expanding (about 8-9%) during freezing and breaking the food surface.

  The present invention has been made in view of the above-described conventional circumstances, and its purpose is to reduce frozen food (foodstuff) due to the dissipation of water vapor from the food surface during the cooling process, and to reduce the surface of the frozen food. It is an object of the present invention to provide a food freezing method and a freezing device that can prevent cracks from occurring as much as possible and can improve the commercial value.

  In order to achieve the above object, in the method for freezing foods according to the first aspect of the present invention, in a freezer comprising a cooling coil and a blower of a refrigerator inside a cabinet of a heat insulating structure, In storing and freezing the food to be frozen, in the cooling process until the temperature of the surface of the food decreases to a temperature at which an ice film can be formed on the surface, the heat in the evaporator comprising the cooling coil and the blower By reducing the exchange load and lowering the evaporation temperature in the cooling coil, the air temperature circulated in the cabinet by the blower is lowered to a low temperature where the absolute value of the saturated water vapor amount is smaller, while the temperature of the food surface is reduced. In the freezing process after the temperature is lowered to a temperature at which an ice film can be formed on the surface, the heat exchange load in the evaporator is increased and quick freezing is performed.

  In the food freezing method according to the invention of claim 2, the heat exchange load in the evaporator is increased / decreased by increasing / decreasing the air flow rate of the blower.

  In the method for freezing foodstuff according to claim 3, the heat exchange load in the evaporator is increased or decreased by increasing or decreasing the heat transfer area of the cooling coil.

  In the food freezing method of the invention according to claim 4, the heat exchange load in the evaporator is increased / decreased by increasing / decreasing the blowing amount of the blower and increasing / decreasing the heat transfer area of the cooling coil. It is characterized by that.

  In the method for freezing foodstuff according to the invention according to claim 5, the amount of air blown by the blower is increased or decreased by switching the air blowing speed of the blower.

  In the food freezing method of the invention according to claim 6, switching of the blowing speed of the blower is performed by switching between forward / reverse operation of the blower.

  In the food freezing method of the invention according to claim 7, switching of the blowing speed of the blower is performed by switching of the rotational speed of the blower.

  In the food freezing method according to an eighth aspect of the present invention, the amount of air blown by the blower is increased or decreased by switching the number of blower units provided.

  In the food freezing method of the invention according to claim 9, the heat transfer area of the cooling coil is increased or decreased by switching the number of operating cooling coils provided before and after the air flow direction. Features.

  In the food freezer of the invention according to claim 10, in the food freezer in which the cooling coil and the blower of the refrigerator are provided inside the cabinet of the heat insulating structure, the cooling coil and the blower A heat exchange load increasing / decreasing means for increasing or decreasing the evaporation temperature in the cooling coil by increasing or decreasing the heat exchange load in the evaporator, and a temperature at which the surface of the food material can generate an ice film on the surface In the cooling process until the air temperature decreases to the above, the heat exchange load increasing / decreasing means is operated to the heat load decreasing side, and the evaporation temperature in the cooling coil is decreased, so that the air temperature circulated in the warehouse by the blower is further increased. While the absolute value of the saturated water vapor amount is lowered to a low temperature side, the freezing process after the temperature is lowered to a temperature at which an ice film can be formed on the surface, the heat exchange load increasing / decreasing means is operated to the heat exchange load increasing side. The Fast freezing, characterized by comprising an actuating control means of the heat exchange duty adjusting unit, the.

    In the food freezer of the invention according to claim 11, a surface temperature sensor for detecting a surface temperature of the food is provided in the cabinet, and the operation control means detects the surface of the food detected by the surface temperature sensor. The heat exchanging load increasing / decreasing means is controlled to operate according to the temperature.

  In the food freezer of the invention according to claim 12, the heat exchange load increasing / decreasing means of the evaporator is an air flow increasing / decreasing means of the blower.

  In the food freezer of the invention according to claim 13, the heat exchange load increasing / decreasing means of the evaporator is a heat transfer area increasing / decreasing means of the cooling coil.

  In the food freezer of the invention according to claim 14, the heat exchange load increasing / decreasing means in the evaporator comprises the air flow increasing / decreasing means and the heat transfer area increasing / decreasing means.

  In the food freezer of the invention according to claim 15, the air flow rate increase / decrease means is a blow speed switching means for switching the blow speed of the blower.

  In the food freezer of the invention according to claim 16, the blowing speed switching means is a forward / reverse operation switching means of a blower.

  The food freezing method according to claim 14, characterized in that in the food freezer of the invention according to claim 17, the blowing speed switching means is a rotation speed switching means of a blower.

  In the food freezer according to the eighteenth aspect of the invention, the air flow rate increase / decrease means is a fan operation number switching means for switching the number of operating fans.

  In the food freezer of the invention according to claim 19, the heat transfer area increasing / decreasing means switches the number of operating cooling coil units for switching the number of operating cooling coils provided at the front and rear along the air flow direction. It is characterized by being.

  In the food freezing method and the food freezer configured as described above, in the cooling process, the amount of air passing through the cooling coil section is suppressed by reducing or reversing the amount of air blown by the blower, by controlling the number of units, or a combination thereof. Because it reduces or reduces the heat transfer area of the cooling coil, the heat exchange load in the evaporator composed of the cooling coil and the blower of the refrigerator is reduced, and the compressor has the capacity of the compressor, thereby The evaporating temperature in the cooling coil is lowered, and as a result, the air temperature at the cooler outlet, that is, the blower outlet is lowered. If the internal air temperature is lowered in this way, the absolute value of the saturated water vapor amount of the air circulated by the blower becomes small, so that the moisture that is transpirationed and taken away from the surface of the food is possible. This reduces the weight of the food and prevents drying.

  In addition, since the amount of water vapor transpiration from the surface of the food is reduced, the amount of frost that freezes due to condensation on the cooling coil is greatly reduced, and it is possible to prevent deterioration of the cooling performance during the freezing process due to frost as much as possible. It becomes like this.

  In addition, in the cooling process, the cooling capacity of the refrigerator is reduced, so that the surface of the food is not frozen and solidified in the initial stage of the cooling process, and the moisture contained in the food ( It is possible to prevent as much as possible that free water) expands (about 8 to 9%) during freezing and breaks the food surface.

  That is, in the present invention, while the steam partial pressure of the internal air during the cooling process is high, the wind speed is suppressed, the air temperature applied to the food is lowered as much as possible, and the maximum amount of water vapor that the air can contain at the low temperature The food surface temperature is lowered while maintaining a low (saturated humidity of air).

  In the initial stage of cooling, the amount of air blown is suppressed, and relatively cool air (relatively cool air contains a small amount of water vapor, that is, the absolute humidity is low, so the moisture transported by the air is also small) is sent into the cabinet to The water vapor inside is condensed and dripped on the entire interior of the chamber, especially on the inner wall surface, shelf side, and back surface (thin metal materials with small specific heat cool relatively quickly because of their small heat capacity), and the initial stage of the cooling At the stage, it is allowed to flow out as dew condensation water to the outside, and a part is finally attached to the wall surface as frost to prevent frost formation on the cooling coil as much as possible.

  After the internal air temperature drops to the extent that the surface temperature of the food is frozen, moisture evaporation from the surface of the food is slightly sublimated. In the case of speed-up rotation by full speed or inverter control, etc., in the case of unit control, by operating all units at full speed, the amount of heat exchange with the refrigerant is drawn out from the cooling coil to the maximum, and the amount of heat transfer between the cooling air and the ingredients The maximum freezing time is then frozen.

  As described above, according to the method for freezing food and the freezer according to the present invention, it is possible to suppress the evaporation of water vapor from the surface of the food and to prevent the drying of the food and the weight loss as much as possible. At the same time, the surface of the food is not frozen and hardened in the initial stage of the cooling process, and the moisture (free water) contained in the food can expand during freezing and break the food surface. Therefore, the product value can be improved.

  Hereinafter, preferred embodiments of a food freezing method according to the present invention and a freezer to which the freezing method is applied will be described in detail with reference to the accompanying drawings.

=== First Embodiment ===
1 to 3 show a first embodiment of a food freezing method and a food freezer according to the present invention, FIG. 1 is a schematic configuration diagram for explaining a cooling process, and FIG. 2 shows a freezing process. FIG. FIG. 3 is a schematic configuration diagram of the front in a state where the opening / closing door is removed.

  As shown in FIGS. 1 to 3, the freezer 20 is basically the same as the conventional freezer shown in FIG. 9. A food storage unit provided with shelves 22 and trays 4 for storing F is partitioned and a cooling coil 8 and a blower 10 of the refrigerator 6 are arranged behind the storage unit. An air passage 12 is defined along the inner wall surface of the cabinet 2 on both the left and right sides or the upper side of the food storage portion. The air passage 12 and the food storage portion communicate with each other on the opening / closing door 14 side. Yes.

  By the way, in this 1st Embodiment, the surface temperature sensor 24 which detects the surface temperature is provided in at least 1 of the foodstuff F accommodated in the said foodstuff storage part. The evaporator 26 comprising the cooling coil 8 and the blower 10 is provided with heat exchange load increasing / decreasing means 28 for increasing or decreasing the heat exchange load to increase or decrease the evaporation temperature in the cooling coil 8. Further, the heat exchange load increasing / decreasing means 28 is provided with an operation control means 30 for controlling the operation thereof.

  The operation control means 30 is an electric control circuit using a microcomputer or a relay switch, receives a signal from the surface temperature sensor 24, and according to the detected temperature of the surface of the food F, the heat exchange load increasing / decreasing means. The operation of 28 is switched to the load decreasing side and the load increasing side for control.

  That is, in the cooling process until the surface temperature of the food material F decreases to a temperature at which an ice film can be formed on the surface, the control means 30 operates the heat exchange load increasing / decreasing means 28 to the decrease side of the heat exchange load. The evaporation temperature in the cooling coil 8 is lowered, thereby lowering the temperature of the air circulated by the blower 10 to a lower temperature to reduce the absolute value of the saturated water vapor amount, while the surface temperature forms an ice film on the surface. In the freezing process after the temperature is lowered to a temperature that can be generated, the heat exchange load increasing / decreasing means 28 is operated to the side where the heat exchange load is increased to increase the cooling capacity, and the food is rapidly frozen at once.

  Here, as a method of increasing / decreasing the heat exchange load, there are a method of increasing / decreasing the amount of air blown through the cooling coil 8 and a method of increasing / decreasing the heat transfer area of the cooling coil 8, but the first embodiment. Then, the method of increasing / decreasing the air flow rate is adopted, and the heat exchange load increasing / decreasing means 28 is configured as an air flow rate increasing / decreasing means. That is, the air flow rate increase / decrease means is composed of the blower 10 and a drive electric circuit that drives the blower, and the control means 30 switches and controls the operation of the drive electric circuit between the air volume increase side and the decrease side. .

  In particular, in the illustrated embodiment, the control means 30 switches the rotation direction of the blower 10 forward and backward to rotate it, and when increased, the fan 10 is fully rotated in the direction of high fan efficiency to fully demonstrate the ability of the blower 10. While the total air volume operation is performed, the capacity is reduced by reversely rotating the fan in a direction where the fan efficiency is low, thereby reducing the air volume.

  At this time, it is desirable to set the direction of the blower 10 so that the air blowing direction at the time of reverse rotation in which the air blowing ability is reduced becomes the food storage unit side. Thereby, the air immediately after passing through the cooling coil 8 and cooled to a low temperature can be quickly made to flow toward the food F while maintaining the state where the absolute value of the saturated water vapor amount is small at the low temperature, Accordingly, the food can be cooled while suppressing the transpiration of moisture from the surface of the food F as much as possible.

  Note that the blower 10 as the air volume increasing / decreasing means may be provided with an inverter circuit or the like so as to have a variable rotation speed configuration, and the rotation speed thereof may be switched by the controller 30 to increase or decrease the air volume.

  Furthermore, as a modification of the first embodiment, as shown in FIG. 4, a plurality of small fans 10 (for example, four) are provided, and the operation of the plurality of fans 10 is controlled by a controller 30. When setting to the increase side, all the blowers 10 are operated, while when setting to the decrease side, half (for example, two) of the blowers 10 are operated. May be switched.

  And in the freezer 20 of the foodstuff comprised as mentioned above, in the freezer 20 by which the cooling coil 8 of the refrigerator 6 and the air blower 10 are provided in the inside of the cabinet 2 of a heat insulation structure, When the food F to be frozen is stored and frozen, the evaporator comprising the cooling coil 8 and the blower 10 is used in the cooling process until the surface temperature of the food F decreases to a temperature at which an ice film can be formed on the surface. The heat exchange load is reduced and operation is performed.

  This reduction operation of the heat exchange load can be easily performed by suppressing the blown air amount of the blower 10 by decelerating or reversing, controlling the number of units, or a combination thereof, and can surely reduce the passing air amount of the cooling coil 8 part. In particular, if the amount of blown air is reduced by the reversing operation of the blower 10, the number of components hardly increases, and it can be configured very simply and inexpensively by simply adding the reversing function of the blower to the conventional configuration.

  And if the heat exchange load in an evaporator is reduced, the refrigerator 6 will have the capability of the compressor 32, and the evaporation temperature in the cooling coil 8 will fall by this, As a result, the cooler exit, ie, the fan 10's The temperature of the blown air decreases.

  In this way, if the temperature of the air passing through the cooling coil 8 is lowered and allowed to flow toward the food F at a low speed, the absolute value of the saturated water vapor amount of the air flowing through the surface of the food F is obtained. Since it can be made as small as possible and the wind speed is low, the moisture that evaporates from the surface of the food F is suppressed and reduced as much as possible, thereby preventing the weight of the food F from being reduced. Is done. Moreover, since the amount of water vapor transpiration from the surface of the food F decreases, even if it circulates in the interior and returns to the cooling coil 8, the absolute amount of frost formation that condenses and freezes on the cooling coil 8 is greatly increased. Thus, a decrease in cooling performance during the freezing process due to the frost formation is prevented as much as possible.

  On the other hand, in the freezing process after the surface temperature of the food material F has dropped to a temperature at which an ice film can be formed on the surface, water transpiration from the surface of the food material F due to sublimation, but transpiration from water vapor Since the blower 10 is restrained by the film, the blower 10 is operated at the full speed operation of the forward rotation or the speed-up rotation by the inverter control or the like. The food F can be rapidly frozen at a stretch by pulling out the exchange amount to the maximum from the cooling coil 8 to enhance the refrigeration capacity and maximizing the heat transfer amount between the cooling air and the food F.

  In the embodiment, the surface temperature of the food F is detected by the surface temperature sensor 24, and it is determined whether the detected temperature is lowered to a temperature at which an ice film can be generated on the surface of the food. The operation of the exchange load increasing / decreasing means 28 is controlled by switching between the load decreasing side and the load increasing side, but the heat exchange load is previously determined according to initial conditions such as the type of food, its initial temperature, and the amount of food. An operation program is incorporated in the operation control unit 30 so that the operation of the increase / decrease unit 28 is automatically switched, and the operation is controlled by inputting the initial condition from an input unit provided on an operation panel, a remote control or the like. May be. Furthermore, a timer for setting the switching timing may be provided so that the switching operation is automatically performed after a predetermined time has elapsed.

=== Second Embodiment ===
5 and 6 show a second embodiment of a food freezing method and a food freezer according to the present invention, FIG. 1 is a schematic configuration diagram for explaining a cooling process, and FIG. 2 shows a freezing process. It is a schematic block diagram. Here, even in the second embodiment, the basic configuration as a freezer is the same as that of the first embodiment described above. Therefore, the same reference numerals are given to the same members, and detailed descriptions thereof are omitted. The different parts will be described in detail.

  As shown in the figure, the second embodiment differs from the first embodiment described above in the configuration of the heat exchange load increasing / decreasing means 28. That is, as described above, as a method of increasing or decreasing the heat exchange load, a method of increasing or decreasing the amount of air passing through the cooling coil 8 and a method of increasing or decreasing the heat transfer area of the cooling coil 8 as in the first embodiment. However, in the second embodiment, a method of increasing or decreasing the heat transfer area of the latter cooling coil 8 is adopted.

  That is, the cooling coil 8 of the refrigerator 6 disposed in the rear of the cabinet 2 is divided into two parts in the front and rear along the air flow direction and arranged in parallel, and the electromagnetic expansion valve 38a is provided for each of the cooling coils 8a and 8b. , 38b are provided. And the air blower 10 is arrange | positioned in front of these cooling coils 8a and 8b in the column state.

  Then, the controller 30 controls the operation of the electromagnetic expansion valves 8a and 8 to cut off the flow of the refrigerant into one of the cooling coils 8a and 8b, so that the substantial heat transfer area of the cooling coil 8 is reached. Is supposed to decrease. Here, the flow of the refrigerant into the cooling coil 8b provided at the rearmost position in the cabinet 2 is turned ON / OFF, and the controller 30 sets the electromagnetic expansion valve 38b to the heat exchange load. It is closed at the time of decrease to block the flow of the refrigerant into the cooling coil 8b, and the heat transfer area of the cooling coil 8 is reduced. Moreover, the air blower 10 is always operated at full speed with forward rotation, and the air blowing direction is on the side of the food storage unit.

  In the food freezer 20A of the second embodiment configured as described above, in the cooling process until the surface temperature of the food F decreases to a temperature at which an ice film can be formed on the surface, electromagnetic The expansion valve 38b is closed to block the refrigerant from flowing into the cooling coil 8b. On the other hand, the electromagnetic expansion valve 38a is kept open at a predetermined opening, and the refrigerant flows only to the cooling coil 8a side.

  That is, in this way, the substantial heat transfer area of the cooling coil 8 is reduced by half, thereby reducing the heat exchange load in the evaporator composed of the cooling coil 8 and the blower 10 of the refrigerator 6. . For this reason, the capacity of the compressor 32 of the refrigerator 6 is superior, and as a result, the evaporation temperature in the cooling coil 8 is lowered, and as a result, the air temperature at the cooler outlet, that is, the blower outlet is lowered.

=== Third Embodiment ===
7 and 8 show a third embodiment of the food freezing method and food freezer according to the present invention, FIG. 7 is a schematic configuration diagram for explaining the cooling process, and FIG. 8 shows the freezing process. It is a schematic block diagram. Here, even in the third embodiment, the basic configuration as a freezer is the same as in the first and second embodiments described above, the same reference numerals are attached to the same members, and the detailed description thereof is as follows. Omitted, the different parts will be described in detail.

  As illustrated, the food freezer 20B of the third embodiment is a combination of the first and second examples described above. That is, as a method of increasing / decreasing the heat exchange load as described above, the method of increasing / decreasing the amount of air flowing through the cooling coil 8 as in the first embodiment, and the method of increasing / decreasing the cooling coil 8 as in the second embodiment. There is a method of increasing or decreasing the heat transfer area, and in the third embodiment, both of these methods are adopted.

  That is, as shown in the drawing, the cooling coils 8a and 8b divided in two are arranged in front and rear in the rear of the food storage unit in the cabinet 2 and connected in parallel, and further, the blower 10 is provided in the rear. The cooling coils 8a and 8b are connected to electromagnetic expansion valves 38a and 38b, respectively. The electromagnetic expansion valves 38a and 38b and the blower 10 are controlled by the control unit according to the first embodiment and The operation is controlled in the same manner as in the second embodiment.

  Therefore, in this third embodiment, the heat exchange load increasing / decreasing means 28 is composed of two parts: an air flow increasing / decreasing means by the blower 10 and a heat transfer area increasing / decreasing means by the cooling coils 8a and 8b and the electromagnetic expansion valves 38a and 38b. Therefore, the degree of reduction of the heat exchange load can be greatly increased.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic block diagram which shows 1st Embodiment of the freezing method of the foodstuffs concerning this invention, and the freezer of foodstuffs, and demonstrates a cooling process. It is a schematic block diagram which shows a freezing process same as the above. It is a front view which shows the state which removed the opening / closing door of the freezer of FIG. FIG. 5 is a front view showing a schematic configuration in a state in which a door, a shelf, and a tray are removed, which is a modification of the first embodiment configured by providing a plurality of blowers. The food freezing method concerning this invention and 2nd Embodiment of the food freezer are shown, and it is a schematic block diagram explaining a cooling process. It is a schematic block diagram which shows a freezing process same as the above. The food freezing method concerning this invention and 3rd Embodiment of the food freezer are shown, and it is a schematic block diagram explaining a cooling process. It is a schematic block diagram which shows a freezing process same as the above. It is a figure which shows schematic structure of an example of the conventional freezer. It is a figure which shows schematic structure of the other example of the conventional freezer.

Explanation of symbols

2 Cabinet 4 Tray 6 Refrigerator 8, 8a, 8b Cooling coil 10 Blower
12 Air passage 14 Open / close door 20, 20A, 20B Freezer 24 Surface temperature sensor 28 Heat exchange load increase / decrease means 30 Operation control means

Claims (19)

When storing and freezing the food to be frozen in the freezer in which the cooling coil of the refrigerator and the blower are provided inside the cabinet of the heat insulating structure,
In the cooling process until the temperature of the food material surface is lowered to a temperature at which an ice film can be formed on the surface, the heat exchange load in the evaporator comprising the cooling coil and the blower is reduced to evaporate in the cooling coil. By lowering the temperature, the air temperature circulated in the warehouse by the blower is lowered to a low temperature where the absolute value of the saturated water vapor amount is small,
In the freezing process after the temperature of the food material surface is lowered to a temperature at which an ice film can be formed on the surface, the heat exchange load in the evaporator is increased and the ice is rapidly frozen.
A method of freezing foodstuffs characterized by the above.   The method for freezing foodstuffs according to claim 1, wherein the heat exchange load in the evaporator is increased or decreased by increasing or decreasing the amount of air blown from the blower.   The method for freezing foodstuffs according to claim 1, wherein the heat exchange load in the evaporator is increased or decreased by increasing or decreasing the heat transfer area of the cooling coil.   The method for freezing foodstuffs according to claim 1, wherein the heat exchange load in the evaporator is increased / decreased by increasing / decreasing the flow rate of the blower and increasing / decreasing the heat transfer area of the cooling coil.   The method for freezing foodstuff according to any one of claims 2 and 4, wherein the air flow rate of the blower is increased or decreased by switching the blower speed of the blower.   The method for freezing foodstuffs according to claim 5, wherein switching of the blowing speed of the blower is performed by switching between forward and reverse operation of the blower.   The method for freezing foodstuffs according to claim 5, wherein switching of the blowing speed of the blower is performed by switching of the rotational speed of the blower.   The method for freezing foodstuffs according to claim 2 or 4, wherein the increase or decrease in the amount of air blown by the blower is performed by switching the number of blower units provided.   The method for freezing foodstuffs according to claim 3 or 4, wherein the heat transfer area of the cooling coil is increased or decreased by switching the number of operating cooling coils provided before and after the air flow direction. In the freezer of the foodstuff in which the cooling coil and the blower of the refrigerator are provided inside the cabinet of the heat insulating structure,
Heat exchange load increasing / decreasing means for increasing or decreasing the evaporation temperature in the cooling coil by increasing or decreasing the heat exchange load in the evaporator comprising the cooling coil and the blower;
In the cooling process until the temperature of the food surface decreases to a temperature at which an ice film can be formed on the surface, the heat exchange load increasing / decreasing means is operated to the heat load decreasing side, and the evaporation temperature in the cooling coil is increased. By lowering the temperature of the air circulated by the blower to the low temperature side where the absolute value of the saturated water vapor amount becomes smaller, the freezing process after the temperature is lowered to a temperature at which an ice film can be formed on the surface Then, the operation control means of the heat exchange load increasing / decreasing means for operating the heat exchange load increasing / decreasing means on the heat exchange load increasing side and rapidly freezing,
A freezer for foodstuffs characterized by comprising.   A surface temperature sensor for detecting the surface temperature of the food material is provided in the cabinet, and the operation control means controls the operation of the heat exchange load increase / decrease means according to the temperature of the food material surface detected by the surface temperature sensor. The food freezer according to claim 10.   12. The food freezer according to claim 10, wherein the heat exchange load increasing / decreasing means of the evaporator is an air flow increasing / decreasing means of the blower.   The food freezer according to claim 10 or 11, wherein the heat exchange load increasing / decreasing means of the evaporator is a heat transfer area increasing / decreasing means of the cooling coil.   The method for freezing food according to claim 10 or 11, wherein the heat exchange load increasing / decreasing means in the evaporator comprises the air flow rate increasing / decreasing means and a heat transfer area increasing / decreasing means.   The food freezer according to any one of claims 12 and 14, wherein the blowing amount increasing / decreasing means is a blowing speed switching means for switching a blowing speed of the blower.   16. The food freezer according to claim 15, wherein the blowing speed switching means is a forward / reverse operation switching means of a blower.   The food material freezing method according to claim 15, wherein the air blowing speed switching means is a rotational speed switching means of a blower.   The method for freezing foodstuff according to claim 12 or 14, wherein the air flow rate increasing / decreasing means is a fan operating number switching means for switching the number of operating fans. The heat transfer area increasing / decreasing means is cooling coil operation number switching means for switching the number of operation of a plurality of cooling coils provided at the front and rear along the air flow direction. The method for freezing the ingredients described.

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