JP2017219206A - Tunnel type cooler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tunnel type cooler capable of efficiently and evenly cooling a cooling object, and further capable of avoiding occurrence of a crack or the like with abrupt temperature change.SOLUTION: A tunnel type cooler, where a cooling object 3 travels on a central axis portion of a cooling treatment unit 2 formed into a tunnel shape, is configured such that a cooling refrigerant jetting nozzle 7 configured to jet low-temperature liquefied gas from a casing outer peripheral surface side toward a travel route center is arranged on a cooling object carrying-out port side with respect to a center in a movement direction in the cooling treatment unit 2, and a nozzle port 13 of the cooling refrigerant jetting nozzle 7 is formed inclinedly so that a jetting direction of the low-temperature liquefied gas jetted from the nozzle port 13 is on a cooling object carrying-in side in the cooling treatment unit 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tunnel-type cooling device that uses cold heat of a low-temperature liquefied gas, and more particularly to a tunnel-type cooling device that rapidly cools an object to be cooled that moves in a tunnel by applying a low-temperature liquefied gas.

  2. Description of the Related Art Conventionally, when food or industrial products are cooled or frozen, a liquid or gas that serves as a refrigerant in the processing chamber is jetted and the stored cold heat and heat of vaporization are used. In order to cool or freeze the object to be cooled uniformly and sufficiently, various studies have been made on the refrigerant injection method.

  For example, in Patent Document 1, by providing a plurality of liquefied nitrogen injection nozzles and liquefied carbon dioxide injection nozzles in a heat insulating case serving as a freezing treatment chamber, liquid nitrogen is brought into contact with a frozen object uniformly and efficiently. A tunnel-type freezing device has been proposed.

  Further, in Patent Document 2, a low temperature liquefied gas spray nozzle for spraying liquid nitrogen toward the object to be cooled is provided on the lower side in the transport direction in the tunnel type cooling device, and the low temperature gas in the tunnel is agitated. A tunnel-type freezing apparatus provided with a plurality of stirring fans has been proposed. In this freezing apparatus, the liquid nitrogen sprayed from the spray nozzle contacts the object to be cooled and vaporizes into a low-temperature gas, and comes into uniform contact with the object to be cooled by the turbulent flow generated by the stirring fan. .

  Further, in Patent Document 3, when forming a steel pipe by hot working, a plurality of injection nozzles for injecting refrigerant in the axial direction of the steel pipe are positioned on the outer periphery of the traveling steel pipe, and the refrigerant is cooled from the circumferential direction to the object to be cooled. A cooling device adapted to act is disclosed.

Japanese Patent Laid-Open No. 7-294085 JP 2001-174118 A JP 2005-288661 A

  However, in the case where liquid nitrogen (refrigerant) as shown in Patent Document 1 is directly sprayed from a plurality of injection nozzles arranged in the moving direction of the object to be cooled, the length of the liquid nitrogen supply pipe to each nozzle is long. Since they are different, there is a problem that it is difficult to supply uniform and fine liquid nitrogen. Moreover, since the liquid low temperature gas used as a refrigerant | coolant is -196 degreeC and extremely low temperature, for example in the case of liquid nitrogen, if it sprays directly with respect to the cooling target object in a room temperature state, it will be rapid with respect to a cooling target object. Since a temperature change is given, there is a possibility that cracks or the like may occur in the cooling target.

  Further, in the cooling system as shown in Patent Document 2, the cooling object is gradually cooled in contact with the flow of the low-temperature gas generated in the tunnel until the object to be cooled reaches the location where the refrigerant nozzle is provided. Therefore, it is possible to suppress the occurrence of cracks due to sudden temperature changes, but the installation of a large number of agitating fans in the cooling device to form a flow of vaporized gas increases the equipment size and equipment costs. There was also a problem of becoming larger.

  In addition, what is disclosed in Patent Document 3 has a plurality of injection nozzles arranged on the outer periphery of the cooling object and a plurality of injection nozzle groups arranged in the moving direction of the cooling object. However, even in this case, when a liquid low-temperature gas such as liquefied nitrogen acts as a refrigerant, a sudden temperature change is given to the object to be cooled. The risk of cracks and the like in the object to be cooled cannot be eliminated.

  The present invention has been proposed in view of such a problem, and can cool an object to be cooled efficiently and uniformly. In addition, the occurrence of cracks and the like accompanying a rapid temperature change is avoided. It is an object of the present invention to provide a tunnel-type cooling device that can be used.

  In order to achieve the above object, the invention described in claim 1 is a tunnel-type cooling device in which a cooling object travels in a central axis portion of a cooling chamber within a tunnel-shaped cooling chamber, A refrigerant injection nozzle for injecting a low-temperature liquefied gas from the outer peripheral surface of the casing toward the center of the travel path is disposed closer to the object to be cooled than the center of the moving direction in the chamber, and the nozzle port of the refrigerant injection nozzle is connected to the nozzle port. The low-temperature liquefied gas to be ejected is inclined such that the ejection direction is on the cooling object carry-in side in the cooling chamber.

  In addition to the configuration of the first aspect, the invention described in claim 2 includes the flow rate adjusting valve for the low-temperature liquefied gas in the low-temperature liquefied gas supply path to the refrigerant injection nozzle and the flow rate based on the temperature in the cooling chamber. A temperature regulator for controlling the opening degree of the regulating valve is arranged, and the opening degree of the flow rate regulating valve is controlled based on the room temperature detected on the cooling object carry-in side of the cooling chamber.

  In the present invention, the refrigerant (liquid nitrogen) ejected from the refrigerant injection nozzle toward the object to be cooled directly cools the object to be cooled, and the cooling object in which the low-temperature liquefied gas vaporized after the ejection is introduced into the cooling chamber Since the object is pre-cooled to a certain temperature in advance, the temperature change when the refrigerant is in direct contact can be reduced, and cracks in the cooling target portion caused thereby can be suppressed.

  Further, when the jet direction of the refrigerant jetted from the refrigerant jet nozzle is inclined toward the cooling object inlet side of the cooling chamber, the jet position of the low-temperature liquefied gas is closer to the outlet side than the center in the running direction of the cylindrical cooling device. Therefore, it is possible to perform pre-cooling from the vicinity introduced into the cooling device by using the vaporized low-temperature liquefied gas, and to cool by increasing the distance until direct contact with the low-temperature liquefied gas. A time for sufficiently pre-cooling the object can be secured.

  Furthermore, since pre-cooling with the low-temperature gas vaporized in the same cooling device and cooling by direct contact with the low-temperature liquefied gas are performed at the same time, the latent heat of the low-temperature liquefied gas can be used efficiently and cooling The device itself can be made compact.

It is a schematic block diagram of the cooling device to which this invention is applied. It is taking out explanatory drawing of a cooling process part. FIG. 3A is a front view and FIG. 3B is a longitudinal sectional view showing one embodiment of a low-temperature liquefied gas jet nozzle. It is a graph which shows the relationship between a valve opening degree and the elapsed time change of the temperature in a cooling device. It is a graph which shows the relationship between the weight of a low-temperature liquefied gas, and the elapsed time change of the temperature in a cooling device.

  FIG. 1 is a schematic configuration diagram illustrating an example of a cooling device. The cooling device (1) includes a cooling processing unit (2) formed in a cylindrical shape, a cooling object (3) that is cooled by running inside the cooling processing unit (2), and a cooling processing unit (2 And a cooling refrigerant supply unit (4) for supplying a cooling refrigerant).

  As shown in FIG. 2, the cooling processing unit (2) includes a stainless steel tube (6) in which a cylindrical space (5) in which an object to be cooled travels, and a low-temperature liquefied gas serving as a cooling refrigerant is placed in the center of the travel path. An annular cooling refrigerant jet nozzle (7) that jets out in the axial direction is installed on the lower side (outlet side) in the cooling object traveling direction than the center of the cylindrical space (5).

  The cooling refrigerant jet nozzle (7) is connected to the low temperature liquefied gas storage tank (8) through a cooling refrigerant supply section (4) including a low temperature liquefied gas lead-out path (9). Liquid nitrogen as a low temperature liquefied gas is stored in the low temperature liquefied gas storage tank (8). A subcooler (10) and a flow rate adjustment valve (11) are attached to the low temperature liquefied gas lead-out path (9) from the low temperature liquefied gas storage tank (8) side, and a cylindrical space ( 5) The temperature of the vaporized gas at the inlet side (the upper side in the running direction of the object to be cooled) is controlled by the temperature regulator (12), and the output signal is fed back to the flow rate adjustment valve (11), so that the coolant The amount of liquid nitrogen ejected from the ejection nozzle (7) can be finely adjusted.

  As shown in FIG. 3, the cooling refrigerant jet nozzle (7) arranged on the outlet side of the cylindrical space (5) is formed in an annular shape with the inside as a travel path of the cooling object (3). On the inner peripheral surface of the cooling refrigerant jet nozzle (7), eight cooling refrigerant jet holes (nozzle ports) (13) having a diameter of 0.4 mm are formed at equal intervals on the peripheral surface. The cooling refrigerant jet hole (13) is formed such that its jet axis forms an angle of 30 degrees upstream with respect to a plane perpendicular to the traveling axis of the cooling object (3). When the low-temperature liquefied gas as the cooling refrigerant is jetted in a state inclined to the upstream side, the sprayed low-temperature liquefied gas directly acts on the surface of the cooling object (3), and the sprayed low-temperature liquefied gas travels. Since there is a component ejected to the upstream side (inlet side) in the direction, a moving component of the vaporized gas that has vaporized due to the ejection to the upstream side in the traveling direction is formed, and the cooling target (3) is precooled by the low-temperature gas. This can be done gradually from the hose inlet side.

  In this embodiment, since the subcooler is arranged in the low temperature liquefied gas storage tank (8) of the low temperature liquefied gas lead-out path (9) from the low temperature liquefied gas storage tank (8), the low temperature liquefied gas is in a gas-liquid mixed state. However, the supercooling effect of the subcooler makes it possible to stably supply the cooling refrigerant by changing it to a less expected liquid state, and the inlet side outlet cooling refrigerant of the cooling processing unit (2) has already vaporized and the temperature is increased. Since it is stable, as described above, the temperature regulator (12) detects the vaporized gas temperature on the inlet side (upper side in the running direction of the object to be cooled) of the cylindrical space (5) of the cooling processing unit (2). ) Is controlled constantly.

  FIG. 4 shows an elapsed time and a temperature change at the inlet of the cooling device when −100 ° C. is set as a set value (target value) in a valve opening range of 6 to 30%. FIG. 5 shows the elapsed time, the temperature change at the inlet of the cooling device, and the weight change of the coolant (liquid nitrogen) when −100 ° C. is set as the set value (target value).

  From these detection results, it can be seen that the temperature at the inlet of the cooling device is stable at about −100 ° C., and the flow rate of the cooling liquid can be stably controlled at 0.13 kg / min.

 DESCRIPTION OF SYMBOLS 1 ... Cooling device, 2 ... Cooling process part, 3 ... Cooling target object, 4 ... Cooling refrigerant supply part, 7 ... Cooling refrigerant jet nozzle, 9 ... Low-temperature liquefied gas lead-out path, 11 ... Flow control valve, 12 ... Temperature regulator , 13 ... Cooling refrigerant ejection holes (nozzle ports).

Claims (2)

  A tunnel-type cooling device in which a cooling object (3) travels on a central axis portion of a cooling processing unit (2) inside a tunnel-type cooling processing unit (2), the cooling processing unit (2) A cooling refrigerant jet nozzle (7) for jetting a low-temperature liquefied gas from the outer peripheral surface side of the casing toward the center of the travel path is arranged closer to the cooling object carry-out side than the center of the moving direction in Tunnel type characterized in that the nozzle port (13) is inclined so that the jetting direction of the low-temperature liquefied gas ejected from the nozzle port (13) is on the cooling object carrying side in the cooling processing unit (2). Cooling system.   The low-temperature liquefied gas supply unit (4) to the cooling refrigerant jet nozzle (7) has a low-temperature liquefied gas flow rate adjustment valve (11) and the flow rate adjustment valve (11) is opened based on the temperature in the cooling processing unit (2). And a temperature regulator (12) for controlling the temperature, and the opening of the flow rate regulating valve (11) is controlled based on the room temperature detected on the cooling object carry-in side of the cooling chamber. Cooling device.

Images