JP3197429B2 - Refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a transport path for a cooled object from an entrance of a tunnel-shaped cooling space to an exit side, and transferring the cooled object along the transport path. The present invention relates to an invention applied as a refrigerating device for performing cooling.

[0002]

2. Description of the Related Art Conventionally, as a freezing device for cooling a frozen object to a desired low temperature and producing a frozen product continuously in the manufacture of frozen foods and the like, a heat insulation tunnel to which cold air is supplied is provided. The frozen object is transferred by a transport means such as a belt conveyor provided between the carry-in part and the outlet side opening, and the frozen object is cooled by the cool air supplied into the tunnel during this time, and as a frozen product from the outlet side. An unloading device is used. However, such a device requires a large amount of power, equipment cost, and installation space in order to mechanically transfer the inside of the tunnel by a belt conveyor having a driving unit, and the driving unit is a noise vibration source. Was.

Further, in the above-mentioned apparatus, the indirect cooling system by air flow is used on the upper surface side, and since the conveyor belt is grounded on the bottom side, heat is not efficiently transferred by cold air, so that there is a problem in cooling efficiency. Moreover, while passing through the above-mentioned tunnel, the object to be cooled is cooled while having a wide temperature difference from the normal temperature range to the freezing range, so that heat distortion is inevitably generated in the conveyor belt or the like. Complex distortion adjustment techniques were required to absorb the distortion. In order to solve such a drawback, a metal belt having good heat conductivity such as stainless steel is knitted into a mesh to form a mesh belt, and a cold heat source is brought into contact with the mesh belt from the back side to form a so-called freezer belt. Although such devices exist, such devices are advantageous in terms of cooling efficiency and thermal strain, but are still mechanical transfer devices, and consume power, equipment costs, installation space, and drive noise. The problem of becoming a source remains.

[0004] In order to solve such a drawback, for freezing granular foods such as pilaf, for example, a double-barrel conveyor containing a refrigerant between an outer cylinder and an inner cylinder is arranged to be inclined downward toward the outlet side. Japanese Patent Application Laid-Open No. Hei 4-26 discloses a method in which the granular food is dropped on the entrance side while rotating the double-body conveyor, thereby causing the granulated food to fall in the multi-body conveyor by gravity and freeze.
No. 3,773. However, in such a method, when the food is rapidly frozen, there is a high possibility that the granular food will adhere to the inside of the multi-body conveyor, and it is difficult to smoothly transport the food.

[0005] In order to solve such a drawback, Japanese Patent Laid-Open No.
No. 83784, a tunnel body rotatable about a longitudinal axis is inclined downward toward an exit side, a pool of liquid nitrogen is provided on the inner surface of the tunnel, and a cooling object is passed through the liquid nitrogen while being immersed in the liquid nitrogen. Thus, there is disclosed a technique in which, while freezing the cooled object, a film-like film of liquid nitrogen is formed on the surface thereof, and the film prevents freezing while preventing the adjacent cooled object and the inner surface of the tunnel from sticking to each other. ing.

[0006] However, liquid nitrogen is not only expensive, but its liquefaction temperature is extremely low, around -70 to -80 ° C. Therefore, frozen foods are liable to undergo various quality deteriorations due to low-temperature brittleness. Since a material that can withstand this low temperature must be used, equipment costs increase. In view of the drawbacks of the prior art, the present invention provides an invention which is applied as a refrigeration apparatus which can be smoothly transported to an exit side without using mechanical transporting means and preventing sticking to the inner surface of a tunnel. It is in. Another object of the present invention is to provide an invention which is applied as a refrigeration apparatus capable of significantly reducing power cost, equipment cost, installation space, and noise and vibration while improving cooling efficiency.

[0007]

The present invention relates to a so-called tunnel type refrigeration apparatus, wherein the transport path is formed as a slope-shaped transport path surface having a downward slope from a loading section toward an exit side. The same as above, but further interposed a solidified carbon dioxide gas body or a sublimation gas film between the conveyance path surface and the cooled object, and preferably, when the cooled object is introduced to the loading section side, with initial velocity An initial speed generating means is provided so that it can be introduced.

In such a configuration, an injection section for injecting the liquefied carbon dioxide gas is provided at least on the carry-in section side, and the liquefied carbon dioxide gas is ejected from the injection section to the space between the cooled object introduced into the carry-in section and the conveying path surface. As a result, a powdery or granular solidified carbon dioxide gas body that can roll between the conveying path surface and the object to be cooled is generated. Further, an injection unit for injecting liquefied carbon dioxide gas is provided at an appropriate position in the conveyance path located from the loading section to the exit side of the conveyance path for transferring the cooled object, and the liquefied carbon dioxide gas ejected from the injection section is provided. Thereby, a powdery or granular solidified carbon dioxide gas body is generated between the conveyance path surface and the object to be cooled, and the solidified carbon dioxide gas body is continuously interposed between the conveyance path surface and the object to be cooled until the outlet position. Is preferred.

[0009]

The operation of the present invention will be described by way of example. First, when the object to be cooled enters the entrance of the tunnel-shaped cooling space with an appropriate initial velocity, all or one of the amount of refrigerant required for cooling or freezing is placed between the bottom surface of the object to be cooled and the surface of the transport path. A quantity of liquefied carbon dioxide gas corresponding to the part is injected from the jetting part.
The injected liquefied carbon dioxide gas is decompressed and adiabatically expanded below the triple point (near the atmospheric pressure) to generate solidified carbon dioxide gas particles, which are scattered between the cooled object and the conveyance path surface. . The powder of the solidified carbon dioxide gas sublimates and directly cools the bottom of the object to be cooled, and at the same time, maintains the state in which the object to be cooled is floated from the conveyance path surface by the solidified carbon dioxide gas or the sublimated gas film, and has an initial velocity. Is transported to the exit side by the downward slope of the conveying path surface. In such a state, the friction between the object to be cooled and the transfer surface is the rolling friction of the solidified carbon dioxide gas body and / or
In addition, since the sublimation gas film greatly reduces the temperature, and the conveyance path surface does not come into direct contact with the object to be cooled, sticking between the two during freezing can be completely prevented. During the transportation, the solidified carbon dioxide body is sublimated and cooled by the latent heat and sensible heat, and then carried out of the refrigerator from the outlet side.

In the case where the powdered solidified carbon dioxide gas sublimates in the middle of the transportation, an injection unit for injecting the liquefied carbon dioxide gas is provided at an appropriate position in the transportation path, and the solidified carbon dioxide gas body reaches the outlet position. Continue to be interposed between the conveyance path surface and the object to be cooled.
Therefore, according to this configuration, the conveyance path with the cooled object is provided at a downward slope from the loading section toward the exit side, and the cooled object is conveyed by using the gravity to discharge the frozen product. Since the solidified carbon dioxide gas or its sublimation gas film is interposed between the transfer path surface and the cooled object, the transfer path surface of the gas body and the cooled object do not come into direct contact with each other. Can be completely prevented, and since the solidified carbon dioxide gas also becomes a sublimation gas film even by the heat of the cooled object, the so-called floating state of the cooled object can be maintained, and the inclination angle of the transport path is small. However, smooth conveyance is possible.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the invention, but are merely illustrative examples, unless otherwise specified. Absent.

FIG. 1 is an overall schematic diagram showing a refrigeration apparatus according to an embodiment of the present invention. In FIG. 1, a refrigeration apparatus 1 is provided with a casing 2 formed in a substantially rectangular cylindrical or cylindrical shape constituted by a heat insulating wall, and for introducing a cooled body into a carry-in portion 2 a at an entrance side of the casing 2. And a discharge conveyer 6 for discharging the object to be cooled from the outlet 2b on the outlet side of the housing 2. The housing 2
Is a carry-in portion 2a into which the cooled object 3 transferred from the carry-in conveyor 5 is carried, an outlet portion 2b through which the cooled object 3 is sent out to the discharge conveyor 6, and an exhaust portion 2c having a fan 17
The housing 2 has an outlet 2 from the loading unit 2a side.
The transport path 4 is set to have a downward slope toward the side b. Further, a slit-shaped air supply pipe 15 for blocking the invasion of warm air from the outside is provided adjacent to the inner wall of the loading section 2a with its open end facing upward as an air curtain of the loading section 2a.

As shown in FIG. 2, an ejection pipe 11 is bent in a key shape adjacent to the air supply pipe 15 so that liquefied carbon dioxide gas can be ejected along the conveying surface. Reference numeral 11 is connected to the liquefied carbon dioxide container 7 via a valve 8 and a pipe 12. The liquefied carbon dioxide gas container 7 stores liquefied carbon dioxide gas under a predetermined pressure. The liquefied carbon dioxide gas container 7 is provided with a second ejection pipe 13 that extends through the pipe 14 and the valve 9 at a substantially intermediate position of the transport path 4. Carbon dioxide (CO
_As shown in FIG. 3 (pt diagram of CO ₂ ), 5.2) of the triple point Tr where liquid, gas and solidification coexist is shown in FIG.
It can exist as a liquid in the range where the pressure is higher than 8 kg / cm ^{2 and the} temperature is higher than -56.6 ° C. In the range of the line S below the triple point, solidified carbon dioxide and gas, commonly called dry ice, can coexist, and when solidification is melted, it does not become a liquid but directly sublimates into a gas. The cooling of the body 3 is performed. Liquefied carbon dioxide gas container 7
When the liquefied carbon dioxide gas stored in the nozzle is ejected from the ejection ports 16 and 23 at the tip of the ejection pipe 11 or the pipe 13, the liquefied carbon dioxide gas is decompressed and expanded to near the atmospheric pressure below the triple point, and solidified into powdery or granular form. A carbon dioxide body 19 is generated.

FIG. 2 is an enlarged view of the inlet side of the conveying path. In FIG.
An opening is formed on the upper surface of the transfer path 4 from the tip 4a of the transfer path 4 toward the transfer direction of the cooled object 3, and the tip of the air supply pipe 15 is opened upward.

Next, the operation of this embodiment will be described with reference to FIGS.
This will be described with reference to FIG. The cooled object 3 carried into the housing 2 from the carry-in conveyor 2 through the carry-in opening 2a at an appropriate initial speed from the carry-in conveyor 5.
After passing through the air curtain by the air supply pipe 15,
When the liquefied carbon dioxide gas is ejected along the upper surface of the transport path 4, the injected liquefied carbon dioxide gas is reduced in pressure and adiabatically expanded to a triple point or lower (near the atmospheric pressure), and the powdered particles of the solidified carbon dioxide gas body 19 Is generated, and the conveying path surface is slid toward the exit side while being scattered on the upper surface of the conveying path. When the cooled body 3 enters the surface of the transport path 4 in this state, the solidified carbon dioxide body 19 directly cools the bottom of the cooled body 3 while sublimating, and at the same time, the solidified carbon dioxide body 19 and the sublimated gas are cooled. While maintaining the state in which the cooled object 3 is floated from the surface of the transport path, the object 3 is transferred to the outlet side by the initial speed and the downward slope of the surface of the transport path 4.

Since there is a possibility that the powdered solid matter of the solidified carbon dioxide gas body 19 may be sublimated in the course of the transportation, the liquefied carbon dioxide gas is supplied from the ejection port of the ejection pipe 13 provided at an intermediate position in the transportation path 4. The powder of the solidified carbon dioxide gas body 19 is replenished to the surface of the conveying path 4 again, and the powdered and solidified carbon dioxide gas body 19 is scattered continuously to the outlet 2c.

During the transportation, the solidified carbon dioxide gas body 19
Is cooled by the latent heat and the sensible heat while sublimating, and then carried out of the warehouse from the outlet side using the discharge conveyor 6.
The number of the ejection pipes 13 provided in the middle of the transport path 4 is not limited to one, and a plurality of ejection pipes may be provided as necessary.

FIG. 4 shows an example of the structure of the above-mentioned liquefied carbon dioxide gas ejection pipe, and the ejection port 16 located at the opening side of the loading section 2b.
Has a flat slit shape extending over substantially the entire width of the conveying surface, and powdery and solidified carbon dioxide gas body 19 ejected and generated from the ejection port 16.
Are scattered over the entire width of the transport surface. A second jet port 23 disposed at a position halfway on the exit side of the transport path 4 surface.
Has a pair of ejection ports 13a, 13b parallel to the upper surface of the transport path 4 and deflected by a predetermined angle toward the exit side. By the injection ports 13 a and 13 b, the powdered particles 19 of the solidified carbon dioxide gas body 19 can be sufficiently supplied between the surface of the cooled object 3 and the surface of the transport path 4. Incidentally, if necessary, only one of the ejection ports 13a and 13b may be provided.
A plurality of pairs may be provided along the transport direction of the transport path 4.

[0019]

According to the present invention, as described above, the transfer path for the object to be cooled is provided with a downward slope from the carry-in portion toward the outlet side, and is floating from the transfer surface by the solidified carbon dioxide gas body. It can be smoothly transferred by gravity with small frictional resistance. Therefore, the transfer path of the present invention does not require power for driving the transfer, which saves equipment space and significantly reduces noise and vibration. Further, according to the present invention, since the object to be cooled is floating above the conveying surface by the solidified carbon dioxide gas body 19 and the sublimation gas film in the conveying path, the object to be cooled does not adhere to the conveying path, and is directly cooled. Since the cooling is possible, the cooling target can be efficiently and uniformly cooled.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of a refrigeration apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged view of the cooled object carrying-in side in FIG. 1;

FIG. 3 is a pt diagram of carbon dioxide gas.

FIG. 4 is a perspective view illustrating the shape of a liquefied carbon dioxide gas ejection pipe disposed on a transport path.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigeration apparatus 2 Housing | casing 3 Object to be cooled 4 Conveyance path 16, 23 Spouting port 19 Solidified carbon dioxide gas body

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) F25D 3/11 A23L 3/36 F25D 3/12

Claims (4)

(57) [Claims] 1. A refrigeration apparatus that forms a transport path for a cooled object from an entrance of a tunnel-shaped cooling space toward an outlet side, and cools the cooled object while transferring the cooled object along the transport path. In the above-mentioned tunnel-shaped cooling space, while forming a slope-shaped conveying path surface having a downward slope from the carry-in part toward the outlet side, a solidified carbon dioxide gas body or a sublimation gas film thereof between the conveying path surface and the object to be cooled A refrigeration apparatus configured to be capable of transporting the object to be cooled along the transport path surface while interposing a cooling medium. 2. A refrigerating apparatus that forms a transport path for a cooled object from an entrance of a tunnel-shaped cooling space toward an outlet side, and cools the cooled object while transferring the cooled object along the transport path. In the above, the transport path is formed as a slope-shaped transport path surface having a downward slope from the loading section toward the exit side, and an injection section for injecting liquefied carbon dioxide gas is provided at least on the loading section side, and the loading section is provided from the injection section. A refrigeration apparatus characterized in that liquefied carbon dioxide gas is ejected between the cooled object introduced into the cooling path and the conveying path surface, and a powdered or granular solidified carbon dioxide gas substance can be generated between the conveying path surface and the cooled object. 3. When the object to be cooled is introduced into the loading section,
2. The refrigeration system according to claim 1, further comprising an initial speed generating means that can be introduced at an initial speed. 4. An injection section for injecting liquefied carbon dioxide gas is provided at an appropriate position in the transport path located from the loading section to the exit side of the transport path for transporting the cooled object, and the liquefied carbon dioxide ejected from the injection section is provided. By the gas, a powdery or granular solidified carbon dioxide gas is generated between the conveying path surface and the cooled object, and the solidified carbon dioxide gas is continuously interposed between the conveying path surface and the cooled object until the outlet position. 3. The refrigeration apparatus according to claim 2, wherein: