JPH035683A - Cooling device and cooling method - Google Patents

Abstract

PURPOSE:To perform an efficient cooling of cooled liquid in a cooling device for oil by a method wherein liquefied gas and cooled liquid are fed into a mixing part, some gas bubbles are vibrated by agitating vanes oscillated axially, divided into some parts and dispersed. CONSTITUTION:Cooled liquid in a storing tank 10 and liquefied gas in a thermal insulated container 12 are fed into a mixing part 20. The liquefied gas may generate gas bubbles under a heat exchanging with the cooled liquid. The gaseous bubbles are divided into some fine parts and dispersed by agitating member 30 so as to perform an efficient cooling of the cooled liquid. Then, the liquid is fed to a gas-liquid tank 40, stored there, the gasified gas is separated from it, only the cooled liquid flows out through a buffle 42. In this way, it is possible to perform an efficient cooling of the cooled liquid.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a cooling device and a cooling method for continuously cooling a liquid to be cooled such as oil using liquefied gas, and in particular a cooling device and method for continuously cooling a liquid to be cooled such as oil using liquefied gas. Concerning efficient mixing.

[Prior Art] Cooling operation has conventionally been one of thermal operations, and has been used in various fields. That is, cooling operations are required for cooling raw materials in food processing processes, cooling refrigerants in air conditioning and freezing equipment, and the like.

The cooling operation generally employs a method using a mechanical refrigerator such as a refrigerator or a freezer, or a method using a heat exchanger that circulates liquefied gas. In this method, cooling is performed by indirect contact with the refrigerant, which takes time and the cooling rate is slow. In addition, sufficient cooling cannot be achieved unless the contact area between the two is wide, which makes the equipment difficult to cool. There was a problem with the size.

Therefore, if you want to rapidly cool raw materials, etc., use a liquefied gas with a low boiling point (for example, liquid nitrogen with a boiling point or
-196℃) toward the object to be cooled,
Due to the latent heat of vaporization caused by the vaporization of the low-temperature liquefied gas, or even when the object to be cooled is immersed in the liquefied gas,
Rapid cooling of raw materials by mixing is also practiced.

For example, in the case of a liquid raw material, it is stored in a suitable storage tank, and in this state, liquefied gas is introduced into the raw material. This liquefied gas uses liquid nitrogen, liquid argon, etc., which can be obtained relatively cheaply and is inert because air is used as a raw material. is maintained.

If such liquefied gas is introduced into raw materials at room temperature and pressure, it will instantly vaporize, and at this time a large amount of heat will be removed from the raw materials, allowing rapid cooling of the raw materials. .

Furthermore, liquefied gases such as liquid nitrogen and liquid argon can be obtained with extremely high purity during the manufacturing process, and even when mixed with raw materials, they are vaporized after mixing and separated from the raw materials as a gas. In many cases, there is no negative impact on product quality. Moreover, nitrogen gas, argon, etc. are chemically inert and stable, and can be cooled without causing chemical changes in the raw materials.

[Problems to be Solved by the Invention] As described above, a rapid cooling process can be performed by directly mixing liquefied gas into raw materials. However, as mentioned above, the liquefied gas instantaneously vaporizes in the raw material. When the liquefied gas is vaporized, its volume usually expands approximately 1,000 times. For this reason, bubbles generated in the raw material tend to have a very large diameter, rise at a high speed, and often escape from the raw material immediately.

Under such conditions that almost no air bubbles remain in the raw material, there is almost no contact between the low-temperature gas and the raw material, resulting in a problem that the cooling efficiency becomes extremely poor.

On the other hand, if the raw material is a very viscous substance, the air bubbles will not be sufficiently dispersed in the raw material, and only the areas near the air bubbles will be partially cooled, making it impossible to cool the entire material effectively. There was a problem.

Furthermore, if you start introducing liquefied gas with the liquid to be cooled entering the liquefied gas introduction path, there is the problem that the liquid to be cooled will freeze in this introduction path, causing a blockage in the introduction path. Ta.

This invention was made with the aim of solving the above-mentioned problems, and provides a cooling device and cooling device that can effectively mix liquefied gas and a liquid to be cooled, which is a raw material, and efficiently perform rapid cooling. The purpose is to provide a method.

[Means for Solving the Problems] The invention described in claim (1) includes a liquefied gas storage section that stores liquefied gas, a mixing section that receives and mixes the liquefied gas and the liquid to be cooled, and an air flow from the mixing section. a gas-liquid separation section that performs gas-liquid separation by receiving a mixture and retaining the mixture; The liquid to be cooled is cooled by subdividing and dispersing gas bubbles produced by vaporization from the liquefied gas in the mixing section by the vibrating stirring blades. The invention according to claim (2) is characterized in that, in the cooling device according to claim (1), the mixing section is provided with a liquefied gas jetting nozzle having a backflow prevention means, and the liquefied gas jetting nozzle section is provided with a liquefied gas jetting nozzle having a backflow prevention means. The invention as set forth in claim (3), characterized in that the liquid to be cooled is prevented from entering, includes the step of introducing the liquefied gas into the mixing section, and the step of introducing the liquid to be cooled into the mixing section in this state of introducing the liquefied gas. the step of introducing the liquefied gas and the liquid to be cooled, while vibrating the stirring blade in the mixing section;
The method includes a step of dispersing and mixing gas bubbles generated by vaporization from liquefied gas into a liquid to be cooled in a finely divided state, and a step of receiving the liquid to be cooled in which gas bubbles are dispersed and mixed and separating the gas and liquid. Features.

[Function] According to the invention described in claim (1), the liquefied gas and the liquid to be cooled are mixed in the mixing section, the liquid to be cooled is cooled here, and the liquid is generated from the liquefied gas in the gas-liquid separation section. The removed gas is removed, and the liquid to be cooled is cooled. The mixing section in this invention has a stirring blade that vibrates in the axial direction within the casing. Therefore, in the mixing section, gas bubbles produced by vaporization from the liquefied gas,
Vibrating stirrer blades provide a highly effective mixing of the liquid to be cooled and the cold gas, which is finely divided and dispersed.

Therefore, the gas bubbles do not immediately escape from the liquid to be cooled, allowing efficient cooling, and since the gas bubbles are widely dispersed in the liquid to be cooled, the entire liquid to be cooled is effectively cooled. Ru.

According to the cooling device according to claim (2), the liquefied gas is ejected from the liquefied gas ejection nozzle, and the liquid to be cooled is prevented from flowing into the liquefied gas ejection nozzle by the backflow prevention means provided in the liquefied gas ejection nozzle. can be prevented from invading.

Therefore, the liquid to be cooled solidifies inside the jet nozzle,
It is possible to prevent clogging from occurring.

In the invention described in claim (3), first, the liquefied gas is introduced into the mixing section. Then, in this liquefied gas introduced state, the liquid to be cooled is introduced into the mixing section.

Therefore, the liquid to be cooled does not enter the liquefied gas introduction path or the like and is cooled and solidified there, thereby making it possible to prevent clogging of the liquefied gas introduction section.

[Example] Hereinafter, regarding the cooling device and cooling method according to the present invention,
The explanation will be based on the drawings.

FIG. 1 is a block diagram showing a schematic configuration of a cooling device according to the present invention, in which a liquid to be cooled (for example, a raw material to be cooled such as antifreeze, oil, refrigerant, etc.) is stored in a storage tank 10. has been done. Further, the liquefied gas (for example, liquid nitrogen) is stored under pressure in the low-temperature liquefied gas insulation container 12. The liquid to be cooled stored in the storage tank 10 and the liquid nitrogen in the heat insulating container 12 are both introduced into the mixing section 20.

The valves 16 and 18 provided in the path from the storage tank 10 and the heat insulating container 12 to the mixing section 20 are for flow rate adjustment.

The mixing section 20 has at its bottom a raw material introduction section 22 for receiving the liquid to be cooled and a liquefied gas introduction section 24 for receiving the liquefied gas. Further, the main body of the mixing section 20 is composed of a cylindrical casing 26, and an outlet 28 is provided at the upper part of the casing 26, through which a mixture of the liquid to be cooled and the liquefied gas flows out. Furthermore, a stirring body 30 having a spiral stirring blade or the like is disposed within the casing 26,
This stirring body 30 is moved to the casing 26 by a vibration device 32.
It is designed to vibrate reciprocatingly in the axial direction.

The mixture discharged from the outlet 28 of the mixing device 20 is introduced into a gas-liquid separation tank 40, and this gas-liquid separation tank 40 is designed to remove bubbles separated and removed from the introduced mixture from the effluent. It has a baffle 42.

In such a device, both the liquid to be cooled from the storage tank 10 and the liquefied gas from the heat insulating container 12 are introduced into the bottom of the mixing device 20 . The two are mixed in the mixing section 20 and discharged from the outlet 28.
In this embodiment, the mixing section 20 has an agitator 30 inside it.
have.

This stirring body 30 is reciprocated by a vibration device 32. That is, this stirring body 30 is the vibration device 3
2, the vibration is reciprocated at several Hz to several tens of Hz and with a stroke of several to several tens of meters.

When such an agitator 30 exists, the gas bubbles vaporized in the mixing section 20 come into contact with the lower surface of the stirring blade in the agitator 30 during the process of rising inside the mixing section 20, where they are dispersed, subdivided. This is because the stirring body 30 vibrates as described above, and the bubbles that come into contact with it are destroyed and fragmented by the movement of the stirring blade.

This stirring body 30 is connected to the casing 20 as shown in the figure.
Since the bubbles are formed to extend upward along the axial direction of the mixing section 20, the bubbles reliably come into contact with the stirring blades in the process of moving upward in the mixing section 20, and are fragmented. and,
Since the liquid to be cooled passing through the casing 26 is also stirred by the reciprocating vibration of the stirring body 30, the bubbles in the liquid to be cooled are almost uniformly dispersed. Therefore, the liquefied gas supplied from the heat insulating container 12 is transferred to the mixing section 20.
In this process, the liquid is uniformly dispersed and mixed as fine bubbles in the liquid to be cooled.

When the air bubbles are dispersed in the liquid as fine air bubbles, the contact area between the two becomes large and the rising speed of the air bubbles becomes small, so that the contact time between the air bubbles and the liquid to be cooled becomes longer. Furthermore, since the liquid to be cooled is stirred by the vibration of the agitator 30, heat transfer within the liquid to be cooled is also promoted. Therefore, heat transfer between the bubbles and the liquid to be cooled is effectively performed, and the temperatures of the bubbles and the liquid to be cooled become approximately the same. Therefore, almost 100% of the cooling capacity of the liquefied gas can be used to effectively cool the liquid to be cooled.

In this way, the mixture of the liquid to be cooled and the bubbles obtained in the mixing section 20 is retained in the gas-liquid separation tank 40. When the gas-liquid mixture is stored, the air bubbles contained in the liquid escape upward from the mixture due to its low specific gravity. Therefore, the gas in the gas-liquid mixture can be removed in the gas-liquid separation tank 40. Since the gas-liquid separation tank has a baffle 42 surrounding the outflow part, air bubbles moving upward in the gas-liquid separation tank 40 are not mixed into the outflow liquid, and are effectively Gas-liquid separation can be performed.

In this way, the liquid to be cooled can be obtained by being cooled by the liquefied gas supplied from the heat insulating container 12 as the effluent of the gas-liquid separation tank 40.

Examples of liquids to be cooled that perform such cooling include, for example, oil containing particles of about 1111 to 2 layers for manufacturing drugs, antifreeze that is a refrigerant in various cooling devices, and ice cream before freezing. There are raw materials etc.

Next, in this device, characteristic matters at the time of starting operation will be explained.

In other words, both the liquid to be cooled and the liquefied gas are introduced into the mixing section 20, but the liquefied gas introduction section 24 is heated due to the fact that the liquefied gas is at a very low temperature under normal pressure. , the temperature becomes very low. Therefore, if the liquid to be cooled enters the liquefied gas introduction 24 and its upstream path, the cooling medium will solidify in this path when the valve 16 is opened and the liquefied gas introduction begins. It may cause blockage. If such clogging occurs, there are problems in that the path (pipe) may burst or the liquefied gas cannot be introduced.

Therefore, in this invention, at the beginning of operation,
First, liquefied gas from the heat insulating container 12 is introduced into the mixing section 20 . Then, in this state of introducing the liquefied gas, introduction of the liquid to be cooled into the mixing section 20 is started. Therefore,
When the liquid to be cooled has started to be introduced, the introduction of the liquefied gas has already started, and the liquid to be cooled does not enter the liquefied gas introduction section 24 or its upstream path. Therefore, clogging as described above can be prevented.

Next, FIG. 2 shows a mixing section 2 suitable for this invention.
FIG. 2 is a partial cross-sectional view showing an example of the configuration of 0.

In this way, the stirring body 30 includes a shaft 300 connected to the vibration device 32 and a spiral blade 3 fixed to the shaft 300.
02. A plurality of notches 304 are formed in this blade 302. This notch 304
The blade 302 has an opening 304a formed at the outer edge and an opening 304b formed at the inner edge. These openings 304 are the openings 3 of the next stage in the axial direction of the shaft 300.
It is arranged so that the phase is different from that of 04.

Therefore, the liquid to be cooled flowing in the mixing section 20 becomes a composite of two types of flow: a flow flowing along the surface of the spiral blade 302 and a flow flowing through the opening 304. . Furthermore, the openings 304 have different phases and two types of radial positions. Therefore, the flow of the liquid to be cooled in the mixing section 20 becomes turbulent, and mixing of the liquid to be cooled and the bubbles contained therein is promoted.

Further, this stirring body 30 is vibrated in a predetermined manner in the vertical direction by a vibration device 32. Therefore, this spiral blade 302
Turbulent flow due to the vibration is generated near the surface of the cooling liquid, further promoting mixing of the liquid to be cooled and the bubbles contained therein.

FIGS. 3 and 4 show other embodiments of the stirring body 30, and in the example shown in FIG. 3, half-moon-shaped blades 306 are provided in multiple stages on the shaft 300. The blades 306 in one stage are fixed so that the angles of inclination with respect to the axial direction are exactly opposite, and the phase of the blades 306 in the next stage is different from that of the previous stage by 90 degrees. .

Even if the stirring body 30 having this blade 306 is employed, the same effect as in the above case can be obtained.

Furthermore, in the example shown in FIG. 4, rod-shaped blades 308 are provided on the shaft 302 in the shape of a ribbon screw. Similar effects can be obtained in this example as well.

Next, FIG. 5 shows another embodiment of the liquefied gas introducing section 24 in the mixing section 20. In this example,
Tip opening 242 of the jet nozzle 240 for introducing liquefied gas
A tapered needle 244 is provided so as to be able to move forward and backward. That is, one end of the needle 244 is fixed to a motor 246, and the needle 244 is rotatable by the motor 246. A threaded portion 244a is provided at the intermediate portion of the needle 244, and this threaded portion 244a is connected to the nozzle 2.
It is adapted to be screwed into a threaded portion 240a provided on the inner surface of 40. Therefore, depending on the rotation of the motor 246,
The needle 244 moves relative to the opening 242 of the nozzle 240. Therefore, the gap between the needle 244 and the opening 242 can be adjusted by moving the needle 244.

Therefore, if the opening 242 is closed by the needle 244, the liquid to be cooled in the mixing section 20 will not flow back into the liquefied gas jet nozzle 240 and its upstream path.

Therefore, if the opening 242 is closed by the needle 244 at the end of the operation, the liquid to be cooled will not enter the liquefied gas introduction path. Then, the liquefied gas is introduced by valve 4.
2 is opened and a predetermined pressure is applied within the introduction path, and then the needle 244 is moved downward in the figure to introduce liquefied gas into the mixing section 20. If the introduction of the liquefied gas is started in this manner, even if the liquid to be cooled exists in the mixing section 20, the liquid to be cooled will not enter the liquefied gas introduction path. Therefore, it is possible to effectively prevent the liquid to be cooled from clogging the ejection nozzle 240 or the like.

[Effects of the Invention] As explained above, according to the cooling device and cooling method according to the present invention, the liquid to be cooled and the liquefied gas can be directly mixed very efficiently, and the liquid to be cooled can be effectively mixed. Cooling can be performed. Furthermore, since the liquid to be cooled can be prevented from entering the liquefied gas introduction path at the beginning of operation, clogging will not occur here.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing the overall configuration of a cooling device according to the present invention, FIG. 2 is a partial sectional view showing the configuration of a mixing section 20 in the same embodiment, and FIGS. 3 and 4 are a stirring body 30. FIG. 5 is a sectional view showing another embodiment of the jet nozzle 24. FIG. 10...Storage tank 12...Insulated container 20...Mixing section 30...Agitator 32...Vibrator 40...Gas-liquid separation tank 240...Blowout nozzle 242...Needle

Claims (3)

[Claims] (1) A liquefied gas storage section that stores liquefied gas, a mixing section that receives and mixes the liquefied gas and the liquid to be cooled, and performs gas-liquid separation by receiving the mixture from this mixing section and retaining it. a gas-liquid separation section; the mixing section includes: a casing having an inflow section and an outflow section formed at both ends; a stirring blade disposed inside the casing and vibrating in the axial direction of the casing; A cooling device characterized in that the liquid to be cooled is continuously cooled by subdividing and dispersing gas bubbles produced by vaporization from the liquefied gas in the mixing section using a vibrating stirring blade. (2) In the cooling device according to claim (1), the mixing section is provided with a liquefied gas jetting nozzle having a backflow prevention means to prevent the liquid to be cooled from entering the liquefied gas jetting nozzle section. A cooling device featuring: (3) A step of introducing the liquefied gas into the mixing section, and a step of introducing the liquid to be cooled into the mixing section in this state of introduction of the liquefied gas, and a step of introducing a stirring blade in the mixing section while introducing the liquefied gas and the liquid to be cooled. A step of vibrating and dispersing and mixing gas bubbles generated by vaporization from the liquefied gas into a liquid to be cooled in a finely divided state, and a step of receiving the liquid to be cooled in which the gas bubbles are dispersed and mixed, and separating the gas and liquid. A cooling method characterized by having the following.