JPS63279772A - Method for freezing food in loosened state and apparatus therefor - Google Patents

Abstract

PURPOSE:To reduce the size and power cost for the preparation of frozen food and to obtain a frozen food of loosened state at a low cost, by supplying a cooling gas from the lower part to the upper part of a cylindrical apparatus having plural partition sections and successively transferring a food from the partition section of upper state to that of lower stage. CONSTITUTION:Chilled gas for cooling is passed upward through a cylindrical apparatus 21 having plural partition sections 22a-22d vertically divided with gas-permeable trays 22. Separately, granules or small pieces of a food A to be cooled are supplied from the upper feeding port 29 of the cylindrical apparatus 21 and successively and intermittently transferred to the lower partition sections 22a-22d. If necessary, the food is agitated in each partition section. The frozen food is taken out of the cylindrical apparatus through the lower delivery port 30.

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention allows foods such as granular vegetables, granular fruits, granular meat, cooked rice, and small shrimp to be kept in a separate state without being individually attached. This invention relates to a method for freezing bulk pieces and an apparatus therefor.

``Prior art'' Frozen foods include granular or small pieces of granular vegetables and fruits such as green peas, corn, potatoes, and carrots, granular meat, cooked rice, and small shrimp. Frozen foods in the form of pieces are frozen in pieces to prevent them from sticking to each other, so that they can be divided into the required amount for cooking, or distributed and measured appropriately.

Conventionally, as a method for freezing such granular or small pieces into pieces, for example, for granular materials such as cooked rice, after steaming, pre-cooling to a temperature of about 40 ° C.
It can be flattened into a flat plate, frozen in a block shape at a low temperature of -40°C or lower, and then broken up into pieces by impact with a hammer, or pre-cooled by being steamed in a rotating rotating drum. There is a method of dropping snow-like dry ice along with a bowl of rice, stirring it while cooling, and freezing it in pieces.

Furthermore, a method using a freezing device having a structure as shown in FIG. 4 is known. In this figure, the freezing device 1 has a rectangular parallelepiped-shaped device main body 2 with a processing space inside, and a supply port 3 and a discharge port 4 are formed on opposing walls, respectively. A floor 5 is installed between the supply port 3 and the discharge port 4 in an inclined manner so that the discharge port 4 side is located downward. Further, a supply tube 6 is attached to the side on the supply port 3 side, and a discharge tube 7 is attached to the side on the discharge port 4 side so as to face outside of the apparatus main body 2. The fluidized bed 5 has a large number of small-diameter ventilation holes 8,8, which do not allow the processed material A such as cooked rice to pass through, and is vibrated by a vibration mechanism (not shown) to keep it horizontal. Or it vibrates slightly in the vertical direction. Further, a heat exchanger 10 is disposed below the fluidized bed 5, which introduces and circulates a refrigerant from a refrigerant source 9 outside the apparatus main body 2, and a blower 11 disposed below the upstream heat exchanger 10, The air sent from No. 11 is designed to cool the room.

In order to freeze the processed material A with the freezing treatment apparatus l having such a structure, the processed material A is placed onto the fluidized bed 5 via the supply cylinder 6.
is continuously supplied, and the agitator 12.12 disposed on the top surface of the apparatus main body 2 stirs the material to be treated A to prevent it from sticking, while the blower 11.11 blows cold air through the heat exchanger 10. The material to be processed A is vented and circulated within the apparatus main body 2 to freeze the material to be processed A. At the same time, the fluidized bed 5 is slightly vibrated, thereby guiding the processed material A along the slope of the fluidized bed 5 to the discharge pipe 7, and continuously transporting the processed material A, which has been frozen and made into a product, outside the main body 2 of the apparatus. to be discharged.

Furthermore, another conventional freezing method is shown in FIG.

The apparatus used in this method is as shown in FIG.
16 is disposed such that one side end portion 5a, 16a of each is located outside the main body 14 of the device. These fluidized beds 15 and 16 are arranged along the transfer direction shown by arrow B in FIG. The end 15b is disposed directly above the side end 16b of the fluidized bed 16 in the apparatus main body 14, with the end 15b located below.

In order to freeze the processed material A using the freezing device 13 having such a structure, the processed material A is placed at the side end 15a of the fluidized bed 15.
is continuously supplied, and the material to be processed A is transferred from the fluidized bed 15 to the fluidized bed 16 along the transfer direction B. At the same time, the material to be processed A is stirred by impeller-shaped stirrers 17, 17, etc. While preventing sticking, the blowers 18, 18, . . . blow cold air through the heat exchangers 19, 19 to the object A to be processed, and circulate it within the apparatus main body 14 to freeze the object A.

Then, this frozen product A is placed in a fluidized bed 16.
It is continuously discharged outside the main body 12 of the apparatus.

"Problems to be Solved by the Invention" By the way, the conventional freezing method described above has the following disadvantages.

That is, in the method of flattening the material into a thin plate and then applying an impact with a hammer or the like to break it into pieces, the impact is applied after the material has been frozen into a block, which may damage small pieces such as particles. There is a problem in that not only the quality of the product is impaired, but also broken powder is generated and the yield of bulk products is reduced. In addition, in the method of introducing a cold agent such as snow-like dry ice into a rotating drum together with the object and cooling it while stirring, it is necessary to prevent the cooling agent from freezing in a compartment like the rotating drum and from caking. Since it is necessary to rapidly freeze the surface, a soft solid refrigerant such as snow-like dry ice is preferable to a cold gas that easily transmits cold to the object because it yields a good product, but it is expensive.

Furthermore, in both of the methods shown in Figures 4 and 5, the object to be treated is moved horizontally while freezing, so it is necessary to increase the area of the fluidized bed. Because of the large size, a large installation area is required. In addition, it is necessary to ventilate the entire area of the fluidized bed where the material to be processed is transferred, and therefore a large amount of air is required to carry out the ventilating at the linear velocity required for freezing processing, and therefore the power of the blower etc. Expenses increase. In addition, since cold air is used only temporarily, it is uneconomical as it is discharged from the equipment without fully using the cold air it possesses.Therefore, in order to make effective use of this, the discharged cold air is recycled. However, this not only increases the size of the entire freezing treatment equipment and increases operating costs, but also causes the cold air with the material to be circulated to pass through the heat exchanger again. This may cause the heat exchanger tubes in the heat exchanger to become clogged, resulting in a decrease in air volume and insufficient freezing treatment, and there are other inconveniences such as maintenance such as cleaning being very time-consuming. .

"Means for Solving the Problem" Therefore, in this invention, low-temperature gas for cooling is directed from the bottom to the top in a cylindrical device having at least two or more compartments vertically partitioned by breathable shelves. At the same time, the food to be cooled in the form of small pieces such as particles is supplied to the upper part of the tube device, and is intermittently transferred to the compartments in the lower stage, and is stirred as necessary in each compartment. A method for freezing foods in bulk form, which is characterized in that food is frozen in bulk form, and the food is brought out from the bottom of a cylindrical device, and for carrying out this method, a plurality of stages that partition the processing space in the vertical direction of the device body are ventilable and openable and closable. The above-mentioned problem was solved by a freezing device which is provided with a shelf board, which can be opened and closed by an opening/closing device, and which introduces cold air into the processing space.

Embodiment FIG. 1 shows an example of a freezing processing apparatus for carrying out the present invention, and reference numeral 20 in the figure indicates the freezing processing apparatus. This freezing processing apparatus 1 includes an apparatus main body 21 having a processing space therein, and a plurality of compartments 22a, 22b, 22c, and 22d arranged to partition the processing space in the vertical direction of the processing space. Openable shelf board 22.22
．． 22, an opening/closing device 23.23.23 that allows these shelf boards 22.22.22 to open and close freely, an agitator 24 that stirs the object to be processed A, and a blower mechanism 25 that introduces cold air into the processing space. It consists of

The device main body 21 includes a large diameter cylindrical portion 26 having a central axis extending in the vertical direction, a truncated conical portion 27 formed at the lower end of this cylindrical portion 26, and a small diameter cylindrical portion 27 formed at the lower end of this truncated conical portion 27. It consists of a cylindrical part 28, which is a large diameter cylindrical part 2.
The upper opening of 6 is used as a supply port 29 for the object to be processed A, and the opening of the small diameter cylindrical portion 28 is used as a discharge port 30. A processing space 31 is provided within the large diameter cylindrical portion 26 of this device main body 21.
A take-out valve 32 made of a rotary valve or the like is airtightly attached to the small diameter cylindrical portion 28. Further, in the large diameter cylindrical portion 26 of this device main body 21, slits 33, 33, 33 for mounting shelves (hereinafter referred to as slits) are provided at predetermined intervals in the vertical direction.
They are each formed along the circumferential direction of the cylindrical portion 26 and over half the circumference. These installations are slit 33.33.3
3, shelf boards 22, 22, 22 are attached airtightly and movably in the direction of arrow C in FIG. 1 via gaskets (not shown). These shelf boards 22.22.22 are
All of them are made of a plate material such as punched metal or mesh plate having a large number of ventilation holes 34, 34, etc., and as shown in FIG. A slit 35 for protecting the shaft of the stirrer 24 is formed toward the shaft. In this case, the diameter of the ventilation holes 34, 34, etc. is sufficiently smaller than the diameter of the workpiece A, and there is a hole below the shaft shielding slit 35 to prevent the workpiece A from falling. The receiver is plate 35 a-
, 358% 35 a are located. With such a configuration, the shelf boards 22, 22, 22 allow ventilation in the vertical direction, and also allow opening and closing of the partition in the vertical direction by moving in the direction of arrow C in FIG. Also,
When the slit 33 is installed as a gap that slides into both the upper and lower surfaces of the shelf board 22, frost generated during cooling can be removed by sliding the shelf board 22 open and close, thereby improving cooling efficiency and making smooth operation possible. .

The shelf boards 22.22.22 are attached using the slits 33.33.
Opening/closing devices 23.23.23 consisting of air cylinders etc. are connected to the ends on the 33 side, respectively, and the shelf boards 22.22.22 are controlled to be movable by this.
Therefore, opening and closing of the partition can be freely controlled. A stirrer 24 is disposed in the processing space 3I of the apparatus main body 21.

This stirrer 24 includes a drive section 36, a stirring shaft 37, and a stirrer 3.
8.38.38, the stirring operation is performed by rotating the stirring shaft 37, and the drive unit 36 is attached to a mounting plate (not shown) above the device main body 21,
A stirring shaft 37 is rotatably attached and fixed to a bearing 39 disposed below the lowest shelf board 22. The stirring shaft 37 is rotatably inserted into the shaft-protecting slit 35.35.35 of the shelf board 22.22.22, and the stirrer 38.38. They are arranged with gaps. Also,
The stirrer 38 has a plurality of stirrers 40, 40, etc. arranged at non-equidistant distances from the stirring shaft 37, so that when stirring is performed, the object to be processed A This prevents the mixture from forming into blocks and allows for efficient stirring.

A blower mechanism 25 for introducing cold air into the processing space 31 via an air pipe 41 communicating with the processing space 31 is disposed at the lower part of the large-diameter cylindrical portion 26 of the apparatus body 21 . The blower mechanism 25 obtains cold air by expanding compressed air from which moisture, oil, etc. have been removed through an expansion turbine, and
A mechanism for supplying this cold air through the air supply pipe 41, a known cold air generator, low-temperature nitrogen gas, etc. are used as appropriate.

In order to freeze the processed material A using the freezing processing apparatus 20 having such a structure, the processed material A is first introduced through the supply port 29 and supplied onto the shelf board 22 located at the top, and then opened and closed. The device 23.23.23 opens and closes the shelf boards 22.22.22 sequentially from the bottom at predetermined time intervals, thereby sequentially disposing the workpieces A = 11-22d from the lower compartment 22c and 22c from '22b.
, 22a and 22b onto the respective shelf boards 22 and take-out valves 32, and are retained therein.

At the same time, the agitator 24 is driven to remove the shelves 22.
The blower mechanism 25 is driven to introduce cold air into the processing space 31 through the air pipe 41 provided at the lower part of the processing space 31 while preventing the object A to be processed from sticking on the processing space 22.22. Then, the object to be processed A
The air remains on each shelf board 22 of each compartment 22a, 22b, and 22c for a predetermined time, is cooled by contact with the cold air blown from below, freezes, and accumulates on the take-out valve 32. On the other hand, the introduced cold air flows through each compartment 22'a, 22b,
It comes into contact with the object to be processed A on the shelf board 22. . Thereafter, the take-out valve 32 is opened, and the frozen product A is discharged from the discharge port 30.

In such a freezing method, since the object to be processed A is transferred vertically from top to bottom, the floor area of the apparatus can be reduced, and the required installation area can therefore be reduced. Further, during the cooling process, the object to be processed A is transferred by falling by gravity due to its own weight, so a transfer device is not required, and therefore energy is saved. In addition, in this freezing method, since the cold air comes into ventilation contact with the layer A of the object to be processed in a plurality of compartments, the cold air is used effectively, and the heat exchange between the cold air and the object A is large, and the temperature of the supplied cold air increases. The temperature difference ΔT between the temperature of the exhaust gas and the temperature of the exhaust gas becomes large, and therefore, good cooling efficiency can be obtained. Therefore, it is possible to exhaust the air without the need to circulate cold air, so that the powder etc. of the object to be processed A is discharged together with the cold air, so that the powder etc. do not accumulate and stick inside the device main body 21, and the food Not only is this extremely convenient from a sanitary standpoint, but maintenance such as cleaning becomes easy.

Furthermore, since the apparatus main body 21 used in this method is vertical and approximately cylindrical, if the cross-sectional shape of the processing space 31 is circular, it can be effectively stirred by the rotary stirrer 24. It is possible to sufficiently prevent the object A from sticking.

Further, in the freezing device of the above example, the shelf boards 22, 22, and 22 are each formed from a single plate material as shown in FIG. 2, but in addition, for example, as shown in FIG. is composed of a pair of semicircular plates 22a, 22a, and a pair of opening/closing devices 23'a, corresponding to these semicircular plates 22a, 22a.
23a, which opens and closes the semicircular plates 22a, 22a both to the left and right, respectively.
In that case, it is not necessary to provide the plate 35a in the shaft-shielding slit 35 of the shelf board 22 shown in FIG. 2 and the corresponding support.

In the above example, the number of shelves is three, but the number of shelves may be increased or decreased as appropriate depending on the required degree of connectivity of the object to be processed A.
There may be two stages or four or more stages.

In addition, in the above example, stirring was performed using a stirrer to prevent the object A from sticking, but if there is no risk of sticking due to various properties of the object A, such as moisture content or stickiness, stirring may be performed. It is not necessary to do this.

Furthermore, even when using a stirrer, it is possible to stir only the material to be treated in the uppermost fluidized bed, which has a low degree of connectivity, without stirring all stages of the fluidized bed.

[Experimental Example] In order to carry out the present invention, an experiment was conducted on freezing seasoned cooked rice using the freezing processing apparatus shown in FIG. 1, in which the inner diameter of the large diameter cylindrical portion was 190 mm. In this case, the freezing treatment conditions are as follows: The temperature of the cold air from the blower mechanism is -40℃, the air volume is 35 Q m"/hr, and the residence time (freezing treatment time) of seasoned cooked rice in the fluidized bed is set at each stage. 40 seconds for each stage (total freezing treatment time is 120 seconds for 40 seconds x 3 stages), and the processing amount per stage of the fluidized bed is approximately 750 g.
And so.

Under these conditions, seasoned cooked rice at about +50°C was intermittently fed into the device body and frozen, resulting in a temperature of about -30°C with sufficient connection. It had a certain degree of graininess and maintained its granular shape without sticking to each other. Moreover, the throughput at this time was about 67.5 kg/hr.

Using the above freezing processing equipment, the freezing processing conditions were a cold air temperature of -60°C and an air volume of 350 m3/hr.

A freezing treatment experiment was conducted by setting the residence time of seasoned cooked rice in the fluidized bed for 30 seconds in each stage and the amount of processing per fluidized bed being approximately 750 g.

As a result of freezing the seasoned cooked rice at approximately +50°C under these conditions, the temperature of the seasoned cooked rice obtained was approximately -33°C.
It had a sufficient degree of connectivity and maintained a granular shape. Also,
The throughput at this time was approximately 90 kg/hr.

In addition, using the freezing treatment apparatus shown in Fig. 1 with an inner diameter of 960 mm in the large diameter cylindrical part, the temperature was raised to approximately +5°C in the same manner.
An experiment was conducted on freezing seasoned cooked rice. In this case, the processing conditions are as follows: the temperature of the cold air is -60℃, and the landscape is 9000℃.
m3/hr, the residence time of seasoned cooked rice in the fluidized bed is 30 seconds for each stage (the total freezing processing time is 30 seconds x 3 stages is 90 seconds), and the processing amount per fluidized bed is approximately The weight was 19.2 kg.

As a result, the temperature of the seasoned cooked rice was approximately -33°C, it had a sufficient degree of connectivity, and maintained a granular shape. In addition, the processing amount at this time is approximately 2300 kg/hr
Met.

In the above experiments, the temperature of the exhaust gas after heat exchange with the object to be treated by the cold air was approximately +10° C. in all cases.

``Effects of the Invention'' As explained above, according to the present invention, low-temperature gas for cooling is supplied from the lower part to the upper part of a cylindrical device having at least two or more compartments vertically partitioned by breathable shelves. At the same time, the food to be cooled in the form of small pieces such as particles is supplied to the upper part of the tube device, and is intermittently transferred to the compartments in the lower stage. Since the material to be treated is stirred appropriately and taken out from the bottom of the tube device, the material to be treated is transferred vertically from top to bottom, which reduces the floor area of the tube device, thereby reducing the required installation area. Since the blower mechanism and the like can be disposed outside the main body of the device, for example, by installing the blower mechanism outside the building, it can be installed in a narrow space inside the building. Furthermore, in this freezing method and the apparatus for carrying out the freezing method, since the cold air passes through and comes into contact with the layer of the object to be processed multiple times, heat exchange between the cold air and the object to be processed A is large, and therefore thermal efficiency is high. The power cost of the drive source can be reduced.

[Brief explanation of drawings]

1 and 2 are diagrams showing an example of a freezing device for carrying out the present invention, FIG. 1 is a schematic configuration diagram of the freezing device, and FIG. 2 is a line taken along the line ■-■ in FIG. 1. The arrow view and FIG. 3 are main part sectional views for explaining another example of a freezing device for carrying out the present invention, and FIGS. 4 and 5 both show examples of conventional freezing processing devices. FIG. 2 is a schematic configuration diagram. 20...Freezing device, 21...Device body, 22...Shelf board, 22a, 22b, 22c
, 22d-compartment, 23...Switching device, 25
...Blower mechanism, 31...Processing space.

Claims (2)

[Claims] (1) Low-temperature cooling gas is supplied from the bottom to the top of a cylindrical device having at least two or more compartments vertically partitioned by air-permeable shelves, and is ventilated to prevent small particles such as particles. The food to be cooled is supplied to the upper part of the cylindrical device, and is intermittently transferred to the compartments in the lower stage, and is appropriately stirred in each compartment as necessary,
A method for freezing food in bulk form, characterized in that food is extracted from the lower part of a cylinder device. (2) A cylindrical device in which an input port and an exhaust port for cooled products are arranged in the upper part, and a discharge port for cooled products and a cold air supply port are arranged in the lower part, and a processing space is formed between the upper part and the lower part. a ventilable and openable/closable shelf board that vertically divides the processing space into a plurality of sections; an opening/closing device connected to the shelf board for opening and closing the shelf board; and supplying cold air to the processing space. An apparatus for freezing foods in bulk, comprising: a blower mechanism connected to the cold air supply port.