JPH11164676A - Quick freezing of food and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for quickly freezing foods, suitable for cooling and freezing treatment of foods to be frozen in a small quantity and a large variety of kinds by shortening the freezing treatment time by heightening the freezing efficiency of the material to be frozen and economically utilizing the cold wind, enabling an apparatus to be miniaturized and efficiently operated, and reducing the initial cost by lowering the apparatus cost and decreasing the installation space, and the running cost by improvement of the economical utilization of the cold wind and the operating efficiency. SOLUTION: This method for quickly freezing foods comprises rapidly freezing a food F to be frozen by directly cooling the food to be frozen or by a cooling means for directly cooling food to be frozen from a surface and indirectly cooling the food to be frozen via a conveyer 3 for conveyance from a back surface by perpendicularly jetting cold air supplied from a cold air-circulating unit 5 to the food F to be frozen on the net-like conveyer 3 for conveyance so as to direct to the conveyer 3 for conveyance from a horizontal direction positions at the upper and lower sides of the going movement side of the conveyer 3 for conveyance and crossing to the conveying direction in an oblong freezing room 1 surrounded by insulation walls 2, allowing the cold air after jetting to flow to the interior of the freezing room 1 so as not to influence the back pressure of the jetting or the like and returning the cold air to the cold air-circulating unit 5 so as to be circulated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rapid freezing of food, in which flat frozen seafood dough, fried food, raw hamburger hamburger, or semi-frozen food of raw hamburger is used as an object to be subjected to freezing processing, and is continuously frozen. It relates to a method and an apparatus.

[0002]

2. Description of the Related Art Conventionally, as a method for continuously freezing food using a belt conveyor as a conveying means, for example, a low-temperature liquid (for example, calcium chloride brine, etc.)
・ Hereinafter referred to as low-temperature brine) Double contact method using double contact belt (freezer) b Single contact method using low-temperature brine and cool air [steel belt freezer] c Cycling and forming a parallel flow of freezing air on a belt conveyor Freezing method using only cold air [Steel Belt Freezer "Tunnel Freezer" (registered trademark)) d Low temperature liquefied gas such as liquefied nitrogen or liquefied carbon dioxide is directly sprayed on the food to be frozen, and the latent heat of vaporization and sensible heat are used. A liquefied gas freezing method for quick freezing by heating is known.

[0003] Of these known continuous freezing methods, a and b each use low-temperature brine, and a is a method in which the lower surface of the food to be frozen is brought into contact with a low-temperature steel belt, and the upper surface of the food to be frozen. And the side surface is covered with a container formed of a thin film so as to circulate a low-temperature brine therein, and is contact frozen from almost the entire surface of the food to be frozen, and b is an endless belt made of stainless steel. Use, the belt itself is cooled with low-temperature brine from the lower surface, and the upper surface of the frozen food is frozen by cold air circulating auxiliary, so it can be relatively short time regardless of the shape of the frozen food. Although there is a merit in the fact that it can be frozen, the initial cost and running cost are high, and the heat generated by the air film covering the upper surface of the frozen food is high. Reach is inhibited, there is a problem in that it affects the cooling and freezing time.

[0004] Further, c is cold air (−35 to −40 ° C.) that circulates the frozen food conveyed by the endless belt at a speed of 5 to 10 m / s in a direction parallel or lateral to the belt.
This is a method of quick freezing only by using only a, b, although the initial cost and running cost are slightly better than a, b, but the heat transfer by the air film covering the surface of the frozen food is hindered more than a, b, and the freezing treatment is performed. As the time becomes longer, the processing capacity becomes lower and, in addition, the equipment itself becomes larger in the length direction, which increases the economic burden associated with equipment production, transportation, storage, installation work, securing an occupied installation area, and the like. There was an issue in the point.

Further, d uses a low temperature of -196 ° C. (liquefied nitrogen gas) and -79 ° C. (liquefied carbon dioxide gas) at normal pressure, so that the freezing time is short, the quality is good, and the loss of dehydration is small. Although there are features that cannot be expected from the above a to c, such as miniaturization and a small installation space, there is a problem in that the running cost is high, so that it is limited to applications such as high-end products and small-scale production.

[0006]

In order to solve such a problem, conventionally, granular processed materials (objects to be processed), such as snack confectionery, bread crumbs, etc., are heated with hot air, hot air or cold air. The technique implemented in the means for applying the aeration process, that is, in addition to the object to be conveyed by the conveyor belt conveyor, the object to be processed in addition to the collision with the conveyor belt conveyor surface at right angles from above or the feeding by the conveyor belt, Technology for continuously drying and cooling the object to be processed by colliding it in the direction of feeding
It is beneficial to reduce the freezing time and reduce the economic burden associated therewith with reference to the claims of the '648 patent or the prior art described in the patent. Turned out to be.

That is, according to the above conventional processing apparatus,
The aeration process can be performed efficiently in a short time. However, such a factor of the efficiency of the aeration process not only increases the chance of contact with the jet air due to the disturbance of the object to be processed, but also increases the efficiency of the process. The purpose is to destroy the air film (temperature boundary layer) formed on the surface of the object and improve the thermal conductivity. In particular, the air film formed on the surface of the object is destroyed and the object is cooled. The problem is how to perform the freezing and freezing economically and efficiently, and to use the above-mentioned reference technology advantageously in a continuous freezing treatment apparatus for foods.

The present invention has been made to solve the above-mentioned problem, and aims to shorten the freezing processing time by increasing the freezing efficiency of a semi-frozen food such as a plate-shaped raw hamburger to be frozen. , Enabling the economical use of cold air,
Optimized for cooling and freezing of small and large variety of foods, and enabling downsizing and efficient operation of equipment, economical use and operation of initial costs and cold air by lowering equipment costs, reducing installation space, etc. It is an object of the present invention to provide a method and an apparatus for rapidly freezing food, which can reduce running costs by improving efficiency.

[0009]

SUMMARY OF THE INVENTION The present invention comprises a method and an apparatus for quick freezing of food, the method comprising an endless transfer into a horizontally long freezing chamber (1) surrounded by a heat insulating wall (2). When the frozen food (F) is transported and passed through the conveyor (3) for cooling or freezing, the forward and backward movements of the transport conveyor (3) in the freezing chamber (1) are Cold air supplied from the cool air circulation unit (5) is jetted vertically from the horizontal position intersecting with the conveyor (3) to collide with it, Cooling means that freezes the frozen food (F) quickly by direct cooling or direct cooling from the front and indirect cooling via the conveyor (3) from the back, and cools the jetted cold air back to jet jet etc. After flowing into the freezing chamber (1) so as not to be affected by the A method for circulating back to the unit (5).

Further, in the quick freezing apparatus according to the present invention, an endless transport conveyor (3) for transporting the frozen food (F) in a horizontal direction is a net conveyor, which is a horizontally long elongated wall surrounded by a heat insulating wall (2). The freezing chamber (1) extends through the freezing chamber (1).
In the vertical direction of the forward and backward movements of the conveyor (3) in (1), a vertical slit opened toward the conveyor or a longitudinal slit opened toward the conveyor is provided. A cold air injection section with a large number of cold air injection pipes (7) provided with injection ports formed of small holes is provided with sufficient clearance between the frozen food (F) and the cold air injection section. The cooling and freezing action in the freezing chamber (1) is ensured, and the suction side of the cold air circulation unit (5) is opened and communicated with the inside of the freezing chamber (1) to form a cooling air circulation passage. .

In the above-mentioned apparatus, a case has been described in which a net conveyor is used as the transfer conveyor (3). However, when the transfer conveyor (3) is used as a steel conveyor, the forward movement is from above and below the arm. Of the cooling, cooling from above is performed by vertical injection of cold air, and from below is indirect cooling through a steel conveyor. In addition, the distance between the injection port of the upper cool air injection section and the upper surface of the conveyor (3) should be adjusted according to the thickness of the food to be frozen (F) or the thickness and the transport speed. To be adjustable by changing the height of
By making the vertical cross-sectional shape of (1) a hexagon having vertical walls on the left and right sides and providing a device for cleaning and sterilizing the inside of the freezing chamber (1), the effects of the invention described below are further improved. It can be.

[0012]

According to the method and the apparatus for rapidly freezing food according to the present invention, the forward movement of the conveyor (3) in the freezing chamber (1) is horizontal and intersects the transport direction at the top and bottom. Cooling air circulation unit from the direction position to the conveyor (3)
By vertically jetting the cool air supplied from (5), if the conveyor (3) is a steel conveyor, the cool air injected from above impinges on the surface of the frozen food (F) due to the collision of cool air injected from above. The air film (temperature boundary layer) is destroyed and is directly cooled efficiently, and the back surface of the food to be frozen (F) is transported through the conveyor (3) by spraying from below or circulating cool air. Indirect cooling,
In addition, the suction side of the cool air circulation unit (5) is opened inside the freezing chamber (1) for collection, and
(1) Since the cooling and freezing functions of the inside are reserved to form a circulation path for cool air, compared to the conventional freezing means that jets from the top and collides and collects without circulating, the food to be frozen (F) becomes extremely efficient,
A rapid freezing process can be achieved.

In particular, when a net conveyor is used as the transport conveyor (3), freezing from the lower part of the food to be frozen (F) is not indirect, but is directly freezing up and down.
If a steel conveyor is used, the frozen food
Since the upper part of (F) is freezing directly and the lower part is freezing in direct contact with the steel conveyor, the quick cooling or quick freezing efficiency should be equal to or higher than brine freezing and freezing by liquefied gas. it can.

Further, by flowing the cool air after the injection into the freezing chamber (1) so as not to affect the jet injection by back pressure or the like, the cool air is returned to the cool air circulation unit (5) and circulated. It not only works effectively to cool the whole inside of the freezing chamber (1) but also cools the air cooler (5
Energy for air cooling in 1) is greatly reduced as compared with freezing by liquefied gas, which can greatly contribute to a reduction in running cost.

[0015] Therefore, since the freezing time can be shortened and the cold air can be economically used, it is only suitable for cooling and quick freezing of a small quantity of various kinds of frozen food (F). In addition, it is possible to provide an inexpensive food freezing method and apparatus that can reduce the initial cost and running cost by reducing the apparatus cost, reducing the installation space, etc., enabling the apparatus to be reduced in size and operating efficiently. It is.

According to a fourth aspect of the present invention, at least the injection port of the upper cool air injection pipe (7) and the transport conveyor are provided.
The height of the frozen food (F) can be changed and adjusted in accordance with the thickness of the frozen food (F) or in accordance with the thickness and the transporting speed of the frozen food (F). ) Can achieve high rapid cooling or rapid freezing efficiency corresponding to the size.

Furthermore, the horizontal cross section of the freezing chamber (1) has a hexagonal shape with vertical walls on the left and right sides, so that it is easier to transport and has a smaller installation area than a cylindrical type. At the same time, the inner bottom of the freezing chamber (1) is formed into a groove shape by corners, and a cleaning liquid and a sterilizing device (for example, a CIP cleaning / sterilizing apparatus) for cleaning and sterilizing the inside of the freezing chamber (1) are used. Since the flow of condensed water is guaranteed and no pool is formed, the sanitary control of the quick-freezing device and the sanitary control of the frozen food (F) can be systematically managed.
(Hazard analysis / important control point method for frozen foods)

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a schematic view of the configuration of a rapid freezing apparatus for food according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view taken along line AA of FIG. 1, and FIG. It is a partial enlarged view showing a state and a cold air recovery course after injection.

The basic structure of the apparatus of this embodiment is as follows.
A horizontal tunnel-shaped freezing chamber (1) surrounded by (2) is directly connected, and an endless net conveyor is passed through it as a transport conveyor (3), and inside each freezing chamber (1). A cold air circulation unit (5), which is a freezing means, is built in and the frozen food (F) transported by the conveyor (3) is cooled or frozen by the cool air sent from here. It is configured.

The apparatus according to the embodiment of the present invention has a length of about 4.6 m, an inner width of 1.4 m, and an inner height of 2 m, based on the above basic configuration.
Two freezing chambers (1), each of which is a horizontal tunnel and has a hexagonal cross section and a height of about 2.5 m, surrounded by insulating walls (2),
Endless (endless) transport conveyor (3) driven by a motor etc. in the longitudinal and horizontal direction, penetrates 0.85m in height and connects the two ends to each other in a horizontal direction so that both sides are vertical surfaces. The supply side (G) of the food to be frozen (F) and the terminal end protrude as the carry-out side (H).

In each of the freezing chambers (1), a cleaning liquid spray pipe (4), which is provided as a part of an externally controlled CIP cleaning apparatus (K), is provided. In order to be able to mainly clean the conveyor (3), such as the conveyor (3), the support stand (6) described below, and the cool air injection pipe (7), the pipes are branched and evenly distributed throughout the room on average. At the same time, the cooling air circulation unit (5) is mounted on a support frame (6) made of an angle member with the lower inside of the heat insulating wall (2) incorporated and fixed as a support base so as not to hinder the movement of the conveyor (3). ) Is supported and fixed.

A cold air injection pipe (71) formed with a cold air injection slit (71) below the cold air circulation unit (5) installation position and above and below the forward side of the conveyor (3). 7)
Of the food to be frozen (F) on the conveyor (3) at a distance equal to or greater than the thickness of the frozen food (F).
(71) is vertically fixed to the forward side (front and back) of the conveyor (3) and is supported and fixed to the support base (6) at predetermined intervals along the transport direction.

The cool air circulation unit (5) is an air cooling and blowing means connected to an external refrigeration unit (C), and an air cooler (51) for lowering the temperature of the sucked circulating air. And a high air pressure blower (52) typified by a turbo fan that blows cold air into the room.The configuration of jetting the cold air from the cold air supply source to the frozen food (F) and recovering the cold air is as described above. Cooling air injection pipes (7) arranged above and below the blowing port of the high wind pressure blower (52) and the forward side of the conveyor (3)
And the air duct (8),
The cool air jet-formed from the cool air jet slit (71) of (7) toward the conveyor (3) at a speed of about 20 to 40 m / s in the form of an air curtain, The cooling air circulation unit (5) in each freezing chamber (1) has the effect of freezing the frozen food (F). For the sake of efficiency, a configuration is adopted in which the high air pressure blower (52) faces the partition wall (9) of the interconnecting part.

Further, the mutual connection of the plurality of freezing chambers (1) secures a passage through which the food to be frozen (F) and the conveyor (3) pass, and the periphery of the passage is a partition wall (9). The freezing chamber is constructed so that the flow in the circulation path in each freezing chamber (1) is not disturbed as much as possible. In addition, a liquid outlet (10) is opened at the bottom of the inner surface of each freezing chamber (1) (a groove-shaped bottom formed by a hexagonal section having a vertically long cross section), and a liquid outlet (10) is formed along the slope attached to the groove-shaped bottom. After the washing liquid or the like that has flowed down to the liquid outlet (10) flows out through the valve (V) and is washed ,
Again, the water is returned to the water supply source of the CIP cleaning device (K) for use or as waste liquid.

The above CIP cleaning device (K) and sterilizing device
The description of (M) is omitted because it is a conventionally known device.However, whether it is installed individually in a plurality of freezing chambers (1) or installed so as to be commonly used depends on whether it is installed. It is to be selected according to the degree of dirt that varies depending on the frozen food (F). The freezing chamber (1) is provided with an opening / closing door for internal confirmation, but is omitted in the drawing.

Further, in the above embodiment, the cold air injection pipe (7) is injected into the cold air injection pipe (7) in consideration of the effect of the back pressure, which is a factor that hinders the contact of the jetted cold air with the frozen food (F). A slit (71) was formed and jetted in the form of an air curtain toward the conveyor (3) for transport.However, a large number of cold air injection holes were arranged so that the injected cold air could be injected into the frozen food (F). You may make it collide.

When the food to be frozen (F) is stored in a perforated tray, only jet jetting is carried out in the form of an air curtain from above the conveyor (3), and cooling from below is performed by ordinary cooling air circulation means. In some cases, indirect cooling is used.

Further, in the above embodiment, the transport conveyor
Although the description has been made on the assumption that the height interval of the cold air injection pipe (7) with respect to (3) is constant, height adjusting means, for example, an air duct ( 8), the cool air injection pipe (7) is provided with a structure in which it is connected using a flange or the like with a long hole so that it can be adjusted up and down while ensuring an airtight state. In addition to being able to adjust and set the cold air injection pipe (7) at the height position where the freezing efficiency is best, the versatility of the device can be enhanced.

To explain an example of the internal cleaning procedure, after the freezing operation is completed, first, the inside of the freezing chamber (1) is inspected for abnormalities, and then the fresh water is supplied from the upper part of the air cooler (51). Shower for several minutes to defrost, and then wash the inner wall of the conveyor (3) and the freezing chamber (1) with fresh water, and then wash with the cleaning liquid from the cleaning liquid spray pipe (4) (for forming cleaning). 5 to 10 with detergent foam attached
), And finally rinse with clean water to wash out the washing solution completely. Of course, for the conveyor (3)
A known conveyor cleaning device is equipped on the movement path, and after cleaning, decompressed steam is put into the freezing chamber (1), and the conveyor (3), the cool air circulation unit (5), and the cool air injection pipe (7 ), The interior of the freezing chamber (1) shall be sterilized, and the conveyor (3) shall always be operated under sanitary conditions.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a configuration of a food quick-freezing apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along line AA of FIG.

FIG. 3 is a partially enlarged view showing a state in which cold air is sprayed on the frozen food in the food quick freezing apparatus according to the embodiment of the present invention.

[Explanation of symbols]

 (1) Freezing room (2) Insulated wall (3) Conveyor for conveyor (4) Cleaning liquid spray tube (5) Cool air circulation unit (51) Air cooler (52) High air pressure blower (6) Support stand (7) Cold air Injection pipe (71) Cold air injection slit (8) Ventilation duct (9) Partition wall (10) Liquid outlet (C) Refrigerator (F) Food to be frozen (G) Supply side (H) Delivery side (K) CIP cleaning Equipment (M) Steam sterilizer (V) Valve

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[Procedure amendment]

[Submission date] February 12, 1998

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

Claims (5)

[Claims] 1. A horizontally long freezing chamber surrounded by a heat insulating wall (2).
In (1), the food to be frozen (F) is transported and passed through the endless transport conveyor (3) to perform cooling or freezing processing, when the transport conveyor (3) in the freezing chamber (1) is used. Cold air supplied from the cool air circulation unit (5) is vertically jetted toward the conveyor (3) from the horizontal position at least above and below the forward motion and intersecting the transport direction, and collides. The frozen food (F) is quickly cooled by cooling means that cools the frozen food (F) directly from the front and back, or directly from the front and back, and indirectly through the conveyor (3) from the back. After freezing and flowing the cool air after the injection into the freezing chamber (1) so as not to affect the jet injection by the back pressure or the like, the cool air is returned to the cool air circulation unit (5) and circulated. A quick freezing method for food, characterized by the following. 2. An endless transport conveyor (3) for transporting the food to be frozen (F) in a horizontal direction is a net conveyor,
This is penetrated into a horizontally long freezing chamber (1) surrounded by a heat insulating wall (2), and the conveyor (3) in the freezing chamber (1) is moved vertically above and below the conveyor. A large number of cold air injection pipes (7) provided with injection holes formed in the form of longitudinal slits or small holes arranged along the longitudinal direction, which are orthogonal to the conveying direction of A cold air injection section with an installed pipe is provided with a sufficient interval between the frozen food (F) and the cooling and freezing action in the freezing chamber (1) by the recovered cold air is ensured. ), Wherein the suction side of (1) is opened to the inside of the freezing chamber (1) to form a cooling air circulation passage. 3. The quick-freezing apparatus for food according to claim 2, wherein the conveyor (3) is a steel conveyor, and the cooling from at least the top and bottom of the forward and backward movements of the wobble is vertical injection of cold air. 4. The space between at least the upper outlet of the cold air injection pipe (7) and the upper surface of the conveyor (3) corresponds to the thickness of the food to be frozen (F) or to the transport movement. 4. The quick freezing apparatus for food according to claim 2, wherein the quick freezing apparatus can be changed and adjusted. 5. The freezing chamber (1) has a hexagonal vertical cross-sectional shape with left and right vertical walls, and a device for washing and sterilizing the inside of the freezing chamber (1) is provided. 2, 3 or 4
A food quick-freezing device as described.