AU708041B2 - Rapid-freezing container - Google Patents

Description

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a rapid-freezing container effective in freezing so-called fresh food stuffs such as boiled rice, sushi, fresh sea urchins, sashimi, fishes with white flesh, matsutake mushrooms, etc., and capable of offering substantially the same taste as pre-freezing in the case of natural thawing.

Description of the Related Art In order to preserve food stuffs such as boiled rice, sushi, raw sea urchin eggs, sashimi, fishes with white flesh, matsutake mushrooms, etc., without degrading their freshness, they have been hitherto accommodated within a freezer for cooling and freezing.

Such a conventional freezer includes a simple one only spraying a cooling agent into the freezer or a coolant circulation type supplying a coolant gas in a .o 20 circulative manner by means of a refrigerator incorporated in the freezer, which were both merely intended to progressively cool and freeze the objects to be frozen.

For the conventional freezer, however, it took too much time to pass through the ice crystals generation 25 zone, which may often result in denaturation of starch contained in boiled rice or in destruction of cells constituting the food stuffs such as fish or meat. In addition, the taste which the food stuffs would otherwise offer turned into ice, and flowed out in drips when thawed, which was too hard to enjoy the taste.

Also, to produce such fresh food staffs in large quantities and to sell them quickly through distribution channels, brief cooling and freezing is required. It was however impossible for the conventional freezer to meet the requirement.

In such a cooling/freezing process by use of the conventional freezer, air within the freezer was not positively let in and out after placing of food stuffs into the freezer. They were cooled and frozen in the air initially residing within the freezer. Furthermore, since sterilization process did not precede the freezing process, miscellaneous germs, which may have adhered to food stuffs during the processes including their production to freezing, often remained left intactly in the food stuffs.

SUMMARY OF THE INVENTION It is therefore the object of the present invention 20 to provide a rapid-freezing container capable of passing through the ice crystals generation zone in a brief eriod of time by way of a rapid cooling of fresh air within the freezer which has been positively let in, to thereby perform a rapid freezing while keeping the freshness of perishable food stuffs which are the objects to be frozen, and capable of performing sterilization of the interior of the freezer and sanitization of the objects to be frozen at a substantially constant temperature, as well as ensuring a consecutive freezing processes of the objects to be frozen.

According to a first aspect of the present invention which has been conceived in order to achieve the above object, there is provided a rapid-freezing container comprising a freezer having an inner wall surface coated with a ceramic layer exposed to far infrared rays; a heat exchanger for cooling the interior of the freezer; a plurality of fans for sucking and convecting cold air within the freezer; the heat exchanger and the fans being arranged in such a manner that their front sides confront each other and that their back sides are respectively spaced apart from the inner wall surface at appropriate intervals; an appropriate number of spray nozzles located along substantially the overall front o surface of the heat exchanger for spraying a coolant in a jet of fine droplets; an exhaust portion with a damper operable on the exhaust mode under internal pressure when :o 20 the pressure within the freezer exceeds a predetermined temperature; a temperature sensor for detecting the temperature inside the freezer; a core-temperature sensor for detecting the central part of objects to be frozen, and a door allowing loading/unloading of racks with several tiered shelves on which the objects to be frozen are arranged, the rack being positioned between the heat exchanger and the fans, wherein the door of the freezer is temporarily opened and closed to thereby introduce external air into the freezer and to discharge the cooled air within the freezer from the exhaust portion, and newly introduced air is cooled to decompress the interior of the freezer, which step is followed by a series of operations at appropriate intervals in the mentioned order consisting of spraying the coolant from the nozzles into the freezer, opening the door to introduce the external air into the freezer, and automatically discharging the surplus gas residing within the freezer from the exhaust portion by the action of the damper.

According to a second aspect of the present invention, there is provided a rapid-freezing container comprising a freezer having an inner wall surface coated with a ceramic layer exposed to far infrared rays, the freezer including front rack loading and rear rack unloading ports each having a door, the freezer being of dimensions allowing in tandem an accommodation of a 20 plurality of racks each having several tiered shelves on e a. which objects to be frozen are arranged; a heat exchanger a a.for cooling the interior of the freezer; a plurality of fans for sucking and convecting cold air within the freezer; 25 the heat exchanger and the fans being arranged in such a manner that their back sides are respectively spaced apart from the inner wall surface at appropriate intervals and that their front sides confront each other with a space therebetween accommodating the plurality of racks; an appropriate number of spray nozzles located along substantially the overall front surface of the heat exchanger for spraying a coolant in a jet of fine droplets; an exhaust portion with a damper operable on the exhaust mode under internal pressure when the pressure within the freezer exceeds a predetermined temperature; a temperature sensor for detecting the temperature inside the freezer; a timer for setting the timing and duration to supply a coolant in a jet of fine droplets; a thrusting device for forcing a rack into the freezer through the front rack loading port, in synchronism with opening/closing actions of the front and rear doors, the rack having several tiered shelves on which objects to be *frozen are arranged and being previously positioned in e the vicinity of the freezer; and circulation means for positioning a rack with several tiered shelves forced out 20 of the rear rack unloading port, immediately in front of the front rack loading port, after reloading of objects oe. to be frozen.

BRIEF DESCRIPTION OF THE DRAWINGS S. The above and other objects, aspects, features and 25 advantages of the present invention will become more apparent from the following detailed description in light of the accompanying drawings, in which: Fig. 1 is a partially cut-away front elevational view of an embodiment of a rapid-freezing container in accordance with the present invention; Fig. 2 is a partially cut-away right side elevational view of the rapid-freezing container shown in Fig. 1; Fig. 3 is a partially cut-away left side elevational view of the rapid-freezing container shown in Fig. 1; and Fig. 4 is a side elevational view of another embodiment of the rapid-freezing container in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described with reference to the accompanying drawings which illustrate presently preferred exemplary embodiments thereof in a non-limitative manner. Fig. 1 is a partially cut-away front elevational view of an embodiment of a rapidfreezing container constructed and arranged in accordance 20 with the present invention; Fig. 2 is a partially cut-away ft* a.

right side elevational view of the freezer shown in Fig.

1; Fig. 3 is a partially cut-away left side elevational view of the freezer shown in Fig. 1; and Fig. 4 is a side elevational view of another embodiment of the freezer in 25 accordance with the present invention.

Referring to Figs. 1 to 3, the rapid-freezing container generally designated at 2 is mounted on a frame 1 and is thermally insulated from the exterior by means of an insulating member 3, the freezer 2 allowing cold air to circulate within the interior thereof. The inner wall surface of the freezer 2 is coated with a ceramic layer 4 which is exposed to far infrared rays. The coated ceramic layer 4 serves to keep constant a temperature within the freezer and suppress a propagation of bacteria within the freezer (sterilizing effect) and prevent frost from depositing on the inner wall surface at the time of freezing. Instead of coating, the ceramic surface may be formed by adhering to the freezer inner wall surface a sheet material having on its one side a ceramic layer to be exposed to far infrared rays. Ceramics include zirconia or alumina based ones but are not limited thereto as long as far infrared rays are emitted.

The rapid-freezing container 2 comprises a heat exchanger 5 for cooling air within the freezer 2, a plurality of axial flow fans 6 for sucking in and simultaneously convecting cold air within the freezer 2, C.o. 20 and a drive source 7 for the fans 6. As best seen in Fig. 2, the heat exchanger 5 includes a plurality of .i vertically properly spaced apart cooling conduits for circulating a refrigerant gas, the adjacent conduits defining spaces through which in-freezer air passes for 25 heat exchange. The heat exchanger 5 and the axial flow fans 6 are vertically arranged within the freezer 2 in such a manner that their respective front sides confront each other, while leaving their respective back sides apart from the inner wall surface of the freezer 2 so as to allow a circulation of in-freezer air. The distance between the heat exchanger 5 and the axial flow fans 6 is such enough to accommodate a rack L which will be described hereinafter. Although two axial flow fans 6 are provided in this embodiment, any number of axial flow fans 6 are available depending on the dimensions of the freezer 2.

The rapid-freezing container 2 further comprises a plurality of spray nozzles 8 for spraying a cooling agent in an atomized state. The spray nozzles 8 are fitted to the front side of the heat exchanger 5 so as to spray the coolant at substantially right angles relative to the direction of the rotational axes of the axial flow fans 6. In this case, as is apparent from Fig. 3, a total of four spray nozzles 8 are positioned vertically at appropriate intervals. More than four, for example, eight or more spray nozzles may be provided in such a manner as to alternately operate every other spray. The 20 number of the spray nozzles 8 and their operation modes 9*m can be arbitrarily determined based on the dimensions of the freezer 2 in the same manner as the fans 6. Externally coupled to the nozzles 8 are hoses each provided with a solenoid valve, which in turn are connected to a coolant 25 cylinder so that the supply or interruption of the coolant are controlled by the activation of the solenoid valve through the operation of an operating panel which will be described later. The freezer 2 further comprises an exhaust portion 9 with an damper D intended to operate on exhaust mode under the action of internal pressure when the pressure within the freezer 2 exceeds a predetermined value. In this embodiment, the damper D consists of a silicone rubber plate and a couple of semi-circular plates laminated on the silicone rubber plate with horizontal gaps formed in the central regions thereof. However, other material than the silicone rubber, such as for example a plastic material or a spring steel, is also available as long as it has an elasticity allowing deformation under the action of the internal pressure over a certain value within the freezer.

The rapid-freezing container 2 further comprises a door 10 which is fitted to its entrance and has a handle 11 for manually opening and closing the door 10. For ~loading/unloading of the rack L accommodating juxtaposed objects to be frozen into/from the freezer 2, the door is opened to a large extent by means of the handle 11.

20 Fig. 1 illustrates a state where the rack L is located between the axial flow fans 6 and the heat exchanger S. o *°°*within the freezer 2. The rack L is provided with a plurality of shelves M. In the shown example, a total of seven shelves M are provided at certain intervals in the 25 vertical direction, but the number of shelves M can be optionally selected depending on the sizes of the objects to be frozen. For example, twenty shelves M may be ~111 arranged at intervals of 70mm in the vertical direction.

K denotes the objects to be frozen which are placed on the shelves M. Prior to freezing, a core temperature sensor 12 with a connector is penetrated into some of the objects K to be frozen until the tip of the sensor 12 reaches the center of each of the selected objects K. The core temperature sensor 12 serves to measure the temperature of the central part of an object to be frozen to thereby judge whether the central part has become frozen or not.

An extensible compensating lead wire is connected to the connector and is fitted to the vicinity of the door 10 so as to ensure an easy penetration of the sensor 12 into the object K to be frozen when the rack L is loaded into the freezer 2. It would be difficult to remove the core temperature sensor as it stands from the object K to be frozen. An attempt to forcibly remove it might result in a bent or damage of the core temperature sensor 12.

Thus, in order to ensure an easy removal of the core temperature sensor 12, this embodiment employs a heater S*S 20 not shown which in place of a recorder is associated with the connector of the sensor 12, whereby activation of the *S S heater causes a certain current flow to pass through the core temperature sensor 12 to thereby heat the sensor 12 itself. The rapid-freezing container 2 further comprises 25 a temperature sensor not shown disposed therewithin for detecting a temperature of the interior of the freezer 2.

Reference numeral 13 denotes an operating unit which houses an instrument cluster indicating a temperature within the freezer 2 measured by the temperature sensor, temperatures of the central parts of the objects K to be frozen measured by the core temperature sensor 12 and a pressure within the freezer 2; a buzzer issuing an alarm which urges opening/closing operation of the door 10 when the in-freezer temperature reaches a predetermined temperature; a device for recording variations in temperature within the freezer and temperature of the central parts of the objects K to be frozen; devices for setting rotational speeds of the axial flow fans 6 and a cooling temperature to be achieved by the heat exchanger 5; and devices or times for setting timings and durations to supply the coolant and food sanitizer. The operating unit 13 is provided with an operating panel 13a for operating the instruments of the operating unit 13.

The rapid-freezing container of the present 5 invention is thus configured by way of example. In the 20 present invention, the freezer may additionally comprise a food sanitizer supply nozzle therewithin for spraying an externally supplied food sanitizer into the interior of the freezer. The food sanitizing liquid includes wasabi (Japanese horseradish) oil and mustard oil which achieves 25 an effective sanitization of the objects to be frozen which are food stuffs without impairing their freshness or taste. The wasabi oil and mustard oil are natural oils obtained by condensing ingredients extracted respectively from the wasabi and mustard seeds.

Description will now be given of an operative function of the thus configured rapid-freezing container of the present invention. When the temperature sensor detects a temperature within the freezer 2 falling below OOC, the door 10 is opened to a large extent, in this case about 90 0 C, and is then closed without delay. Exterior fresh air is thereby taken in into the interior of the freezer 2, allowing a rise of the internal pressure within the freezer 2. The thus raised internal pressure forces the damper D of the exhaust portion 9 to open, permitting air within the freezer 2 and the sprayed coolant and sanitizer to be discharged through the exhaust portion 9 to the exterior. After taking in the exterior fresh air, the interior of the freezer 2 becomes decompressed since the interior gas is cooled and reduced in volume by the action of the heat exchanger 5 and the axial flow fans 6.

When under such an decompressed condition the coolant is *20 supplied from the spray nozzle 8 toward the front side of the heat exchanger 5, the sprayed coolant is blown against the objects K to be frozen placed on the shelves M of the rack L with the aid of sucking actions of the axial flow fans 6, while on the contrary it impinges on the inner wall 25 surfaces of the freezer 2 to diverge into upper and lower directions as indicated by arrows and then flow along the top side, bottom side, front side and rear side of the rack L (that is, along the four outside surfaces of the rack L) and finally reach the back side of the heat exchanger 5, thereby achieving an effective convective circulation of the cold air within the freezer 2. In order to inhibit the cold air from transversely escaping, this embodiment employs a couple of shield plates T as shown in Fig. 2 which are mounted at anterior and posterior positions in the direction in which the rack L is accommodated. The wind velocity passing through the rack L is of the order of 20 m/sec. with no objects to be frozen placed on the shelves M. The wind velocity can be regulated by the operation of the operating panel 13a.

Due to the temperature of the coolant lower than the infreezer air temperature, the air within the freezer 2 is rapidly cooled down to 0 0 C to -70 0 C. The cooling agent includes liquefied carbon dioxide gas or liquefied

U

O oonitrogen gas.

Upon the completion of the spray of coolant into the interior of the freezer 2, the amount of gases inside 20 the freezer 2 is increased due to the residing air and the introduced coolant. A series of operations are thus repeated which consist of introduction of the external air performed by the opening/closing of the door 10 when the temperature within the freezer 2 falls below OOC; exhaust 25 by opening of the damper D due to increased internal pressure arising from the introduction of the external air; and spray of the coolant. As a result of this, a 1111 "respiring" state is presented in which the coolant is intermittently sprayed into the interior of the freezer 2, thereby ensuring an effective discharge of the heat (positive heat) of the objects K to be frozen to the outside of the freezer. Moreover, in the case where the temperatures of the objects K to be frozen are approaching an ice crystals generation zone it would be possible to pass through the ice crystals generation zone in a brief period of time, by virtue of rapid decompression within the freezer caused by exhaust of air within the freezer and the introduction of external air which are both effected by opening/closing the door 10, as well as the spray of the cooling gas into the freezer, thereby making it possible to perform a rapid freezing while keeping the freshness of the objects K to be frozen. In the case of providing the food sanitizer supply nozzles, the spray of ~food sanitizer is carried out within the freezer 2 previous to the freezing of the objects K to be frozen, for example, before accommodating the rack L, or immediately 20 after the accommodation of the rack L. Alternatively, it may be effected during the interruption of the supply of the coolant. For automatic supply, use may be made of a wtimer for setting the duration and timing to supply the sanitizer from the supply nozzles. In cooperation with the ceramic surface 4 exposed to the far infrared rays, the supply of the sanitizer in a spray will enhance the effects of sterilizing the interior of the freezer 2 and of sanitizing the objects K to be frozen.

In the freezing effected by the rapid-freezing container set forth hereinabove, the core temperature sensor 12 measures at all times the temperatures of the central parts of the objects K to be frozen, together with the measurement and recording of time of freezing and of the periods of time taken by the central parts to pass through the ice crystals generation zone It would therefore be possible to recognize extremely easily and quickly the states of freezing of the objects and the point of time of completion of freezing, on the basis of data on the in-freezer temperature and central temperatures, data on the door opening/closing circuit and timing, and the coolant spray data.

Thus, based on the data including temperature data o: of the central parts of the objects K to be frozen which have been obtained by the core temperature sensor 12, the timing and duration to supply the coolant from the spray nozzles 8 can be set for the subsequent freezing work by 20 means of the timer incorporated within the operating panel 13a. Due to the fact that the time the central part of an .object K to be frozen approaches the ice crystals "generation zone or the time it passes through the ice crystals generation zone differs depending on the type, 25 size and weight of the object K to be frozen, this will be useful in obtaining the data therefor.

The thus frozen food stuffs are restored to their pre-freezing states by natural thawing at a room temperature of the order of 15 0 C to 25°C, so that ones eating them can enjoy just the same taste as ordinary boiled rice, sushi, sashimi or the like. If rapid thawing is desired, they may be disposed within a thawing unit for melting them or alternatively they may be forcibly melted by immersion in warm water of the order of 37 0

C.

Referring now to Fig. 4, there will be described another embodiment of the rapid-freezing container in accordance with the present invention. The freezing process and sterilizing/sanitizing process for use in the rapid-freezing container shown in Fig. 4 are substantially the same as those in the rapid-freezing container shown in Figs. 1 to 3. However, the Fig. 4 rapid-freezing container 15 differs from the Figs. 1 to 3 rapid-freezing container in that the former employs a tunnellike continuous method (hereinafter, referred to simply as a tunnel method) 0 whereas latter employs a batch method and that in the former the timing or duration to spray the coolant are set 20 by a timer, based on accumulated data on the type, size, weight, etc. of the objects to be frozen whereas in the latter the timing to spray the coolant is set principally 0 oS by the core temperature sensor and the timer.

The following description is given of a 25 configuration of an apparatus for continuous freezing operation in the rapid-freezing container depicted in Fig.

4.

As can be seen in Fig. 4, the tunnel method rapidfreezing container is generally designated at reference numeral 20 and has a double-decker structure. The rapidfreezing container 20 comprises a cylindrical freezer 21, a rear rack unloading port 22, a front rack loading port 23, a slidable rear door 24 for opening/closing the rack unloading port 22, a slidable front door 25 for opening/closing the rack loading port 23, a device 26 for vertically moving the front door 25, a device 27 for 1 0 vertically moving the rear door 24, a rack 28 with several tiered shelves on which food stuffs, objects to be frozen, are arranged, a rear lifting device 29 disposed behind the oooo ooooo rear door 24, a front lifting device 30 disposed in front of the front door 25, a guide rail 31 extending between 15 the rear lifting device 29 and the front lifting device 30, and a thrusting device 32 positioned anterior to the "front lifting device 30 for forcing the rack 28 with several tiered shelves into the freezer 21.

The rapid-freezing container 20 shown in Fig. 4 has dimensions accommodating four racks 28 with several tiered shelves in tandem within the interior of the freezer 21. The dimensions thereof can be optionally designed depending on the number of racks to be accommodated in tandem.

Thus, in the Fig. 4 rapid-freezing container accommodating four racks 28 with several tiered shelves, air residing inside the freezer 21 is first cooled by a heat exchanger not shown and decreased in volume with the front 23 and rear 22 ports closed. A coolant is then supplied in a jet of fine droplets from a spray nozzle not shown into the thus decompressed interior of the freezer 21. Objects to be frozen is thereby rapidly cooled and frozen in a brief period of time. It is to be noted that the inner wall surface of the freezer 21 is coated with ceramics not shown subjected to far infrared rays so as to keep constant the temperature within the freezer 21 and to prevent frost from depositing on the inner wall surface.

i." Also, in the case of providing nozzles for supplying a food sanitizer in a jet of fine droplets, an effective oeooo sterilization and sanitization will be achieved with the aid of the food sanitizer sprayed from the nozzles.

In the rapid-freezing container 20 shown in Fig.

4, the front 25 and rear 24 doors are opened by the door moving devices 27 and 26, respectively, when a temperature sensor not shown detects a temperature of air within the 9eJ freezer 21 falling below 0 0 C. The timings to open or close the front 25 and rear 24 doors can be arbitrarily set by means of the timer.

By opening/closing actions of the front 25 and rear 24 doors, external air is introduced into the interior of the freezer 21 through the front rack loading port 23 and the rear rack unloading port 22. On the contrary, opening of the damper allows the volume-increased air, the coolant and sanitizer within the freezer 21 to be discharged to the exterior. After having been positioned anterior to the rack loading port 23 by the front lifting device 30 with the food stuffs, objects to be frozen, arranged on its several tiered shelves, while the front 25 and rear 24 doors are opened, the rack 28 is forced into the freezer 21 by the thrusting device 32, and simultaneously the rack 28 after the completion of freezing is forced out of the rack unloading port 22 onto the rear lifting device 29.

10 After having been forced out of the rack unloading o port 22, the rack 28 with several tiered shelves is lowered onto the guide rail 31 by the rear lifting device oooot 29 so that the frozen food stuffs are ejected by a tray ejecting device 37 onto an unloading conveyor 34. The 15 vacant rack 28 with several tiered shelves is conveyed to the front lifting device 30 by way of the guide rail 31.

With the aid of a loading conveyor 35 and a tray ejecting device 37, fresh objects to be frozen are accommodated into the vacant rack 28, which in turn is positioned anterior to the rack loading port 23.

In the rapid-freezing container depicted in Figs.

1 to 3, the core-temperature sensor for example records the point of time when the central part of the object to be frozen approaches the ice crystals generation zone, the period of time taken to pass through the generation zone, or the freezing completion time, together with the type, size, weight, etc, of the objects to be frozen. Based on the above data, therefore, depending on the objects to be frozen, the rapid-freezing container 20 depicted in Fig.

4 is capable of setting the timings to open or close the doors, the timing and duration to spray the coolant by means of a timer not shown, thus making it possible to automatically perform a rapid freezing of a mass of objects to be frozen in a continuous manner.

Although the rapid-freezing container 20 depicted in Fig. 4 has a double-decker structure, the freezer 21 may be level with a circulator 21 for the rack 28 with several tiered shelves. For example, the guide rail may be coupled in an annular form to the rack loading/unloading ports of the freezer.

As discussed hereinabove, the batch-method rapid- S 15 freezing container of the present invention is so .configured as to ensure a convective circulation of cold air within the freezer provided with a heat exchanger for cooling the interior of the freezer. The rapid-freezing container comprises an appropriate number of nozzles for spraying the coolant in a jet of fine droplets, a plurality of fans for sucking the coolant in a jet of fine droplets sprayed from the nozzles and blowing it against the objects to be frozen, a temperature sensor for measuring an air temperature within the freezer, doors capable of being opened or closed on the basis of the measurement of the temperature sensor, and an exhaust portion with a damper for discharging excess air and coolant within the freezer. Thus, the rapid-freezing container of the present invention allows the objects to be frozen to breathe by taking in fresh external air with the opening/closing actions of the doors, while simultaneously performing sterilization and sanitization and quickly decompressing the interior of the freezer when an ice crystals generation zone is being approached, to thereby enable the ice crystals generation zone to be passed through in a brief period of time for rapid freezing. This will be significantly effective in *.application to freezing of boiled rice or freezing of sashimi, raw sea urchin eggs, a fish with white flesh, o*oo a matsutake mushroom and the like.

*The batch-method rapid-freezing container of the present invention has another effect that the combination of a temperature sensor and a timer makes it possible to perform a freezing depending on the type, size and weight of the objects to be frozen through the operation of an operating panel, which contributes to a reduction in amount of cooling medium gas or coolant used.

Furthermore, according to the tunnel-method rapidfreezing container of the present invention, the timers serve to set the timings to open/close the doors and the time and duration to spray the coolant depending onthe type, size and weight of the objects to be frozen, based on the data derived from the core-temperature sensor or the like of the batch-method rapid-freezing container,

~I

thereby enabling large quantities of food stuffs to be automatically continuously frozen in a brief period of time, which will allow a quick response to an increase in demand. Moreover, in the present invention, the food stuffs are arranged on the rack having a plurality of shelves and are continuously frozen, with the result that a large amount of freezing processing can be executed in comparison with the belt-conveyor type continuous freezer.

No matter whether it employs the batch method or tunnel method, the rapid-freezing container of the present invention has an inner wall surface coated with ceramics oo exposed to far infrared so as to be able to keep the 999*99 interior of the freezer at an unvarying temperature to :'"'"achieve even freezing as well as preventing frost from S 15 depositing thereon.

While illustrative and presently preferred embodiments of the present invention have been described in detail herein, it is to be understood that the inventive 9.

:concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: i. A rapid-freezing container comprising: a freezer having an inner wall surface coated with a ceramic layer exposed to far infrared rays; a heat exchanger for cooling the interior of said freezer; a plurality of fans for sucking and convecting cold air within said freezer; said heat exchanger and said fans being arranged in such a manner that their front sides confront each other and that their back sides are respectively spaced apart from the inner wall surface at appropriate intervals; an appropriate number of spray nozzles located along substantially the overall front surface of said heat Se exchanger for spraying a coolant in a jet of fine droplets; .an exhaust portion with a damper operable on the exhaust mode under internal pressure when the pressure within said freezer exceeds a predetermined temperature; a temperature sensor for detecting the temperature inside said freezer; a core-temperature sensor for detecting the central part of objects to be frozen, and a door allowing loading/unloading of racks with several tiered shelves on which the objects to be frozen are arranged, said rack being positioned between said heat exchanger and said

Claims (4)

1. 2. A rapid-freezing container according to claim 1, S. wherein Swhen freezing of objects to be frozen is performed through operations consisting of supply of a coolant in a jet of fine droplets, introduction of external air into the interior of said freezer and discharge of gas residing within said freezer, there are recorded timings and durations to execute each of said operations as well as the period of time taken by the central part of an object to be frozen to pass through an ice crystals generation zone and wherein set into a timer depending on the objects to be frozen based on the results of said recording are the timings to start and stop the spray of a coolant and the duration of the spray, and the timings to open and close said door, said operations being performed on the basis of the thus set timings and duration.
2. 3. A rapid-freezing container comprising: a freezer having an inner wall surface coated with a ceramic layer exposed to far infrared rays, said freezer including front rack loading and rear rack unloading ports each having a door, said freezer being of dimensions allowing in tandem an accommodation of a plurality of racks each having several tiered shelves on which objects to be frozen are arranged; heat exchanger for cooling the interior of said freezer; a plurality of fans for sucking and convecting cold air within said freezer; said heat exchanger and said fans being arranged i in such a manner that their back sides are respectively spaced apart from the inner wall surface at appropriate intervals and that their front sides confront each other with a space therebetween accommodating said plurality of racks; an appropriate number of spray nozzles located along substantially the overall front surface of said heat exchanger for spraying a coolant in a jet of fine droplets; an exhaust portion with a damper operable on the exhaust mode under internal pressure when the pressure within said freezer exceeds a predetermined temperature; a temperature sensor for detecting the temperature inside said freezer; a timer for setting the timing and duration to supply a coolant in a jet of fine droplets; a thrusting device for forcing a rack into said freezer through said front rack loading port, in synchronism with opening/closing actions of said front and 10 rear doors, said rack having several tiered shelves on S..which objects to be frozen are arranged and being previously positioned in the vicinity of said freezer; and circulation means for positioning a rack with *a several tiered shelves forced out of said rear rack a 15 unloading port, immediately in front of said front rack loading port, after reloading of objects to be frozen.
3. 4. A rapid-freezing container according to claim 3, wherein said circulation means include: front and rear lifting devices for lifting/lowering racks with several tiered shelves positioned in the vicinity of said front and rear doors, respectively, of said freezer; a guide rail extending between said front and rear lifting devices; and a reloading device for reloading objects to be frozen. A rapid-freezing container according to any one of the preceding claims 1 to 4, wherein said freezer includes a plurality of nozzles for supplying a food sanitizer, said nozzles supplying the sanitizer in a jet of fine droplets into the interior of said freezer where spray of the coolant remains suspended.
4. 6. A rapid-freezing container substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. 0 Dated this 19th day of February 1997 TOP COMPANY By their Patent Attorneys COLLISON CO ABSTRACT A rapid-freezing container comprises a freezer; a heat exchanger for cooling the interior of the freezer; a plurality of fans for sucking and convecting cold air within the freezer; spray nozzles located along the front surface of the heat exchanger for spraying a coolant in a jet of fine droplets; an exhaust damper operable on the exhaust mode under internal pressure when the pressure within the freezer exceeds a predetermined temperature. The door of the freezer is temporarily opened and closed to thereby introduce external air into the freezer and 0 discharge the cooled air within the freezer from the exhaust portion whereby the introduced air is cooled to decompress the interior of the freezer followed by the steps of spraying the coolant from the nozzles into the freezer, opening the door to introduce the external air into the freezer, and automatically discharging the :surplus gas residing within the freezer from the exhaust portion by the action of the damper. S.. OOS G 0000 Ob' °S