JP2010105837A - Apparatus and method for producing dry ice - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for producing snow-like dry ice by inflating liquefied carbon dioxide to atmospheric pressure, in particular, in which a supercooling heat exchanger having a simple configuration is provided in the middle of a flow passage for supplying liquefied carbon dioxide, and a method for producing the snow-like dry ice. <P>SOLUTION: In the apparatus for producing the snow-like dry ice and in the method for producing the snow-like dry ice, the supercooling heat exchanger equipped with a cooling pipe that cools liquefied carbon dioxide into a supercooled state is formed in the middle of the flow passage for supplying the liquefied carbon dioxide to a dry ice production nozzle, and liquefied carbon dioxide is ejected through an ejection nozzle to the supercooling heat exchanger to supercool the liquefied carbon dioxide flowing through the cooling pipe. Consequently, supercooling of liquefied carbon dioxide can be carried out in a simple configuration using liquefied carbon dioxide the same as the source material of the dry ice as a cooling source. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for producing snow-like dry ice by expanding liquefied carbon dioxide to atmospheric pressure, and in particular, a supercooling heat having a simple structure in the middle of a flow path for supplying liquefied carbon dioxide. An exchange is provided.

2. Description of the Related Art Conventionally, an apparatus or a method for producing snowy dry ice, in which the liquefied carbon dioxide supplied to the nozzle is supercooled in order to improve the yield of snowy dry ice or to produce it stably and satisfactorily. Is known (see, for example, Patent Documents 1 to 3).
And all the cooling sources for supercooling the conventional liquefied carbon dioxide use a refrigerator, and what was described in patent documents 1 as an example is shown in FIG.

In FIG. 3, 51 is a dry ice production apparatus, and a conduit is provided from a liquefied carbon dioxide storage tank 52 with a safety valve 53, an on-off valve 54, an efficiency improvement device 60 for increasing the production efficiency of dry ice, a safety valve 55, a pressure gauge. 56, through open / close valves 57a, 57b, and 57c in order to the dry ice manufacturing apparatus main bodies 58a, 58b, and 58c.
The efficiency improving device 60 is connected to the refrigerator 61 through conduits 62 and 63, and the primary refrigerant flows from the refrigerator 61 to the efficiency improving device 60 through the conduit 62, and from the efficiency improving device 60 to the refrigerator through the conduit 63. Return to 61.

The efficiency improving device 60 includes a first heat exchanger 71, a second heat exchanger 72, and a secondary refrigerant tank 73 in which a secondary refrigerant is stored. The secondary refrigerant is an antifreeze liquid (brine). ) Is included.
One of the conduits 75 is connected to the storage tank 52 via the on-off valve 54, and the other is connected to the dry ice production apparatus main bodies 58a, 58b, 58c and the like via the safety valve 55.

The pump 76 gives kinetic energy to the secondary refrigerant returning from the secondary refrigerant tank 73 through the first heat exchanger 71 through the conduit 78 to the secondary refrigerant tank 73, and the pump 77 is used for the secondary refrigerant. Kinetic energy is given to the secondary refrigerant returning from the tank 73 to the secondary refrigerant tank 73 through the second heat exchanger 72 via the conduit 79.
In order to absorb the fluctuation of the secondary refrigerant liquid level inside the secondary refrigerant tank 73, dry nitrogen gas is sent into the secondary refrigerant tank 73 via the conduit 80, and the expansion tank 81 is connected to the secondary refrigerant tank 73. Absorbs fluctuations in the amount of dry nitrogen gas inside.

The secondary refrigerant stored in the secondary refrigerant tank 73 reaches the first heat exchanger 71 through the conduit 78, and the primary refrigerant passes through the conduit 62 from the refrigerator 61 through the first heat exchanger 71. The cold heat transported through the pipe is received and returned to the secondary refrigerant tank 73 through the conduit 78.
Next, the secondary refrigerant reaches the second heat exchanger 72 via the conduit 79, and passes cold heat from the storage tank 52 to the liquefied carbon dioxide supplied via the conduit 75 in the second heat exchanger 72. Further, the refrigerant is returned to the secondary refrigerant tank 73 through the conduit 79, and cold heat is transported from the refrigerator 61 to the liquefied carbon dioxide by such circulation of the secondary refrigerant.
JP 2006-193377 A JP 2003-206122 A JP 2007-160244 A

The conventional dry ice production apparatus described in Patent Document 1 and the like includes a supercooling device for liquefied carbon dioxide in order to increase the production efficiency (yield) of dry ice. There was a problem that the equipment for cooling became large.
Furthermore, the conventional dry ice production apparatus 51 described in Patent Document 1 also requires a brine storage tank 73, two brine circulation pumps 76 and 77, two heat exchangers 71 and 72, and the like. there were.

  The present invention seeks to solve the problems of such a conventional configuration, and uses the same liquefied carbon dioxide as the raw material of snow-like dry ice as a cooling source for supercooling. It is intended to be able to be performed with a simple configuration.

The present invention according to claim 1 supplies a storage container that stores liquefied carbon dioxide, a dry ice generation nozzle that generates liquefied carbon dioxide by jetting liquefied carbon dioxide, and liquefied carbon dioxide from the storage container to the generation nozzle. In a dry ice production apparatus equipped with a supply pipe,
A supercooling heat exchanger with a cooling pipe that cools the liquefied carbon dioxide from the supply pipe to a supercooled state is formed in the middle of the supply pipe, and the liquefied carbon dioxide is ejected to the supercooling heat exchanger by the ejection nozzle. This is a dry ice production apparatus in which the liquefied carbon dioxide flowing through the cooling pipe is supercooled.

The present invention according to claim 2 supplies a storage container for storing liquefied carbon dioxide, a dry ice generation nozzle for generating liquefied carbon dioxide to generate dry ice, and supplying liquefied carbon dioxide from the storage container to the generation nozzle. In a dry ice production apparatus equipped with a supply pipe,
In the middle of the supply pipe, a supercooling heat exchanger with a cooling pipe that cools the liquefied carbon dioxide from the supply pipe to a supercooled state is formed, a heat exchange tank containing brine is provided, and the inside of the heat exchange tank The subcooling heat exchanger was immersed in the brine, and liquefied carbon dioxide was ejected from the ejection nozzle provided in the brine, and the liquefied carbon dioxide circulating in the cooling pipe was supercooled using the brine as a cooling medium. It is a dry ice production device.

  According to a third aspect of the present invention, in addition to the configuration of the present invention according to the first or second aspect, an electromagnetic on-off valve is provided in a supply passage for supplying liquefied carbon dioxide to the ejection nozzle, and liquefaction by a supercooling heat exchanger is provided. This is a dry ice production apparatus in which the degree of supercooling of carbon dioxide is controlled by opening and closing an electromagnetic on-off valve.

The present invention according to claim 4 is a dry ice production method for producing dry ice by ejecting liquefied carbon dioxide from a storage container for storing liquefied carbon dioxide by a dry ice production nozzle.
The supercooled heat exchanger equipped with a cooling pipe that cools the liquefied carbon dioxide supplied to the dry ice production nozzle and puts it into a supercooled state is ejected by the jet nozzle and the liquefied carbon dioxide flowing through the cooling pipe is passed through. A method for producing dry ice that is cooled.

The present invention according to claim 5 is a dry ice production method for producing dry ice by ejecting liquefied carbon dioxide from a storage container for storing liquefied carbon dioxide by a dry ice production nozzle.
In the middle of the passage for supplying liquefied carbon dioxide to the dry ice generation nozzle, a supercooling heat exchanger having a cooling pipe that cools the liquefied carbon dioxide and puts it in a supercooled state is formed, and in the heat exchange tank containing the brine This is a dry ice manufacturing method in which liquefied carbon dioxide is jetted from a jet nozzle provided in the brine and liquefied carbon dioxide flowing through the cooling pipe is supercooled using brine as a cooling medium while being immersed in the brine.

  According to a sixth aspect of the present invention, in addition to the configuration of the present invention according to the fourth or fifth aspect, the degree of supercooling of liquefied carbon dioxide by a supercooling heat exchanger is supplied, and the supply of liquefied carbon dioxide to a jet nozzle is provided. This is a dry ice manufacturing method that is controlled by opening and closing an electromagnetic on-off valve provided on a road.

  The present invention according to claim 1 forms a supercooling heat exchanger having a cooling pipe for cooling the liquefied carbon dioxide supplied to the dry ice production nozzle to bring it into a supercooled state. Since liquefied carbon dioxide is jetted and liquefied carbon dioxide circulating in the cooling pipe is supercooled, the same liquefied carbon dioxide as the dry ice raw material is used as a cooling source for supercooling, and liquefied carbon dioxide can be easily supercooled. It can be set as the dry ice manufacturing apparatus performed by a structure.

  According to a second aspect of the present invention, a supercooling heat exchanger having a cooling pipe that cools liquefied carbon dioxide supplied to a dry ice production nozzle and makes it supercooled is formed, and a heat exchange tank containing brine is provided. The subcooling heat exchanger is immersed in the brine in the heat exchange tank, and liquefied carbon dioxide is circulated through the cooling pipe using the brine as a cooling medium by ejecting liquefied carbon dioxide from the ejection nozzle provided in the brine. Since supercooling is performed, the same liquefied carbon dioxide as the raw material of dry ice can be used as a cooling source for supercooling, and the liquefied carbon dioxide can be supercooled with a simple configuration, and the liquefied carbon dioxide of the cooling source can be contained in brine. Since carbon is ejected, the stirring of the brine is good, and a dry ice production apparatus with good heat exchange with the supercooling heat exchanger can be obtained.

  According to the third aspect of the present invention, in addition to the effect of the present invention according to the first or second aspect, the degree of supercooling of liquefied carbon dioxide by the supercooling heat exchanger is controlled by opening / closing an electromagnetic on-off valve. Therefore, a dry ice production apparatus capable of controlling the degree of supercooling can be obtained.

  According to the fourth aspect of the present invention, the liquefied carbon dioxide is cooled by causing the liquefied carbon dioxide to be ejected by the ejection nozzle to the supercooling heat exchanger having a cooling pipe that cools the liquefied carbon dioxide supplied to the dry ice production nozzle and brings it into a supercooled state. Since the liquefied carbon dioxide circulating in the tube is supercooled, the dry liquefied carbon dioxide is supercooled with a simple configuration using the same liquefied carbon dioxide as the dry ice raw material as a cooling source, and It can be done.

  The present invention according to claim 5 forms a supercooling heat exchanger having a cooling pipe that cools liquefied carbon dioxide and puts it in a supercooled state and immerses it in a brine in a heat exchange tank containing brine, Since liquefied carbon dioxide is ejected from the ejection nozzle provided in the brine and the brine is used as a cooling medium, the liquefied carbon dioxide circulating in the cooling pipe is supercooled, so the same liquefied carbon dioxide as the dry ice raw material is supercooled. As a cooling source, liquefied carbon dioxide can be supercooled with a simple configuration, and since the liquefied carbon dioxide from the cooling source is jetted into the brine, the brine is stirred well and heat exchange with the supercooling heat exchanger is performed. Is a good dry ice production method.

  According to a sixth aspect of the present invention, in addition to the effect of the present invention according to the fourth or fifth aspect, the degree of supercooling of liquefied carbon dioxide by a supercooling heat exchanger is determined, and a passage for supplying liquefied carbon dioxide to an ejection nozzle Therefore, it is possible to provide a dry ice production method capable of controlling the degree of supercooling.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic view of a dry ice manufacturing apparatus according to a first embodiment of the present invention, which is an embodiment applied to a cleaning application.

The dry ice production apparatus 1 according to the first embodiment includes storage containers 2a and 2b that store liquefied carbon dioxide, and a dry ice generation nozzle 3a that generates liquefied carbon dioxide and generates dry ice. And a supply pipe 4 for supplying liquefied carbon dioxide from the storage containers 2 a and 2 b to the dry ice generation nozzle 3 a of the cleaning nozzle 3.
A supercooling heat exchanger 5 having a cooling pipe 5a that cools the liquefied carbon dioxide from the supply pipe 4 to a supercooled state is formed in the middle of the supply pipe 4, and is stored in a heat insulating chamber 6 that is insulated. is doing.

Further, in the heat exchange chamber 6, a jet nozzle 7 for jetting liquefied carbon dioxide from the branch supply path 4 a branched from the middle of the supply pipe 4 is provided, and the subcooled heat exchanger 5 is liquefied with carbon dioxide by the jet nozzle 7. Carbon is ejected and the liquefied carbon dioxide flowing through the cooling pipe 5a is supercooled by the latent heat of vaporization.
Control of the degree of supercooling of liquefied carbon dioxide in the supercooling heat exchanger 5 is performed by providing an electromagnetic on-off valve 8 in the branch supply path 4a, and controlling the temperature of liquefied carbon dioxide at the inlet and outlet of the supercooling heat exchanger 5 with a temperature sensor 9i. 9o, and the temperature control device 10 opens and closes the electromagnetic on-off valve 8 so that the temperature difference between the inlet temperature and the outlet temperature falls within a predetermined range.

A mass flow meter 11 is provided in the supply pipe 4 on the outlet side of the supercooling heat exchanger 5 and upstream of the branch point of the branch supply path 4a, and the measured flow rate by the mass flow meter 11 is stored in the storage container switching device. 12, the storage containers 2a and 2b are switched.
Since the mass flow meter 11 is provided in the supply pipe 4 on the outlet side of the supercooling heat exchanger 5 and upstream of the branch point of the branch supply path 4a, the liquefied carbon dioxide flowing through the mass flow meter 11 is liquid. This is only a phase and improves the measurement accuracy failure in the two phases of gas and liquid, and measures the flow rate of liquefied carbon dioxide supplied to the dry ice generation nozzle 3a and the ejection nozzle 7 together.

6a is a discharge port for carbon dioxide gas generated by heat exchange performed in the heat exchange chamber 6, 13a and 13b are switching solenoid valves, 14 is a stop solenoid valve, 15 is an air compressor, and 15a is An air pipe that supplies the compressed air compressed by the air compressor 5 to the cleaning nozzle 3, 16 is a safety valve, and 17 is a pressure gauge.
Next, a method for manufacturing dry ice using the dry ice manufacturing apparatus 1 shown in FIG. 1 will be described.

The liquefied carbon dioxide from the storage containers 2a and 2b for storing the liquefied carbon dioxide is ejected by the cleaning nozzle 3 incorporating the dry ice generating nozzle 3a to produce dry ice, and the dry ice produced for the object to be cleaned is It is ejected stably by compressed air.
And when manufacturing dry ice, the liquefied carbon dioxide supplied to the dry ice production | generation nozzle 3a incorporated in the washing | cleaning nozzle 3 is cooled, and the liquefaction is provided in the supercooling heat exchanger 5 provided with the cooling pipe 5a which makes a supercooled state. A dry ice production method in which carbon dioxide is jetted by the jet nozzle 7 to supercool the liquefied carbon dioxide flowing through the cooling pipe 5a so that the liquefied carbon dioxide supplied to the dry ice generation nozzle 3a is supercooled. It is.

Control of the degree of supercooling in the supercooling heat exchanger 5 is detected by temperature sensors 9i, 9o provided at the inlet and outlet of the supercooling heat exchanger 5, and the temperature controller 10 is used to control the temperature difference between the inlet temperature and the outlet temperature. The electromagnetic on-off valve 8 is opened and closed so that is within a predetermined range.
In addition, the switching of the storage containers 2a and 2b is changed from one to the other when the flow meter side value of the mass flow meter 11 reaches the storage amount of liquefied carbon dioxide in the storage containers 2a and 2b determined in advance by the storage container switching device 12. This is performed by the switching solenoid valves 13a and 13b.

In the first embodiment described above, the degree of supercooling in the supercooling heat exchanger 5 is controlled by detecting the inlet temperature and outlet temperature of the supercooling heat exchanger 5, but the liquefied carbon dioxide to be used is used. Since the temperature of the saturated liquid is previously determined by the storage containers 2a and 2b to be used, it may be performed only by detecting the outlet temperature of the supercooling heat exchanger 5.
Further, the required amount of liquefied carbon dioxide ejected for supercooling from the ejection nozzle 7 is determined from the amount ejected from the dry ice generation nozzle 3a, and the supply pipe 4, the branch supply path 4a, By determining the flow resistance of the ejection nozzle 7 or the like, neither the inlet temperature nor the outlet temperature of the supercooling heat exchanger 5 may be detected.

Next, a dry ice manufacturing apparatus according to a second embodiment of the present invention will be described with reference to FIG.
FIG. 2 is a schematic view of a dry ice production apparatus, which is an embodiment applied to a cleaning application, similarly to the first embodiment of the present invention.

In the second embodiment, the supercooling heat exchanger in the first embodiment is a brine immersion type.
Hereinafter, the same components as those in the first embodiment will be described with the same reference numerals.

The dry ice production device 21 according to the second embodiment includes a storage container 2a, 2b for storing liquefied carbon dioxide and a dry ice generating nozzle 3a for generating dry ice by ejecting liquefied carbon dioxide. And a supply pipe 4 for supplying liquefied carbon dioxide from the storage containers 2 a and 2 b to the dry ice generation nozzle 3 a of the cleaning nozzle 3.
A supercooling heat exchanger 5 provided with a cooling pipe 5 a that cools the liquefied carbon dioxide from the supply pipe 4 to a supercooled state is formed in the middle of the supply pipe 4 and accommodated in an insulated brine tank 22. It is immersed in the brine 22a.

Further, in the brine 22a in the brine tank 22, a jet nozzle 7 for jetting liquefied carbon dioxide from the branch supply path 4a branched from the middle of the supply pipe 4 on the inlet side of the supercooling heat exchanger 5 is provided. Brine 22a is cooled by ejecting liquefied carbon dioxide from the ejection nozzle 7.
Then, the liquefied carbon dioxide flowing through the cooling pipe 5a of the supercooling heat exchanger 5 is supercooled using the brine 22a cooled by the latent heat of vaporization of the liquefied carbon dioxide as a cooling medium.

Control of the degree of supercooling of liquefied carbon dioxide in the supercooling heat exchanger 5 is performed by providing an electromagnetic on-off valve 8 above the brine tank 22 in the branch supply path 4a, and the temperature provided at the inlet of the supercooling heat exchanger 5. Each temperature is detected by the sensor 23 and the temperature sensor 24 provided in the brine 22a, and the temperature controller 10 electromagnetically controls the brine 22a so that the brine 22a temperature falls within a predetermined temperature range with respect to the inlet temperature of the supercooling heat exchanger 5. The on-off valve 8 is opened and closed.
Further, a mass flow meter 11 is provided in the supply pipe 4 on the outlet side of the supercooling heat exchanger 5 so that a measured flow rate by the mass flow meter 11 is input to the storage container switching device 12.

Since the mass flow meter 11 is provided in the supply pipe 4 on the outlet side of the supercooling heat exchanger 5, the liquefied carbon dioxide flowing through the mass flow meter 11 is only the liquid phase, and the measurement accuracy in the gas-liquid two phase is poor. To improve.
The temperature control device 10 measures the opening time of the electromagnetic on-off valve 8, grasps in advance the amount of liquefied carbon dioxide used per unit time, and determines from the ejection nozzle 7 based on the measured opening time of the electromagnetic on-off valve 8. The consumption of liquefied carbon dioxide is calculated.

Then, in the storage container switching device 12, the sum of the liquefied carbon dioxide is obtained by summing the flow rate measurement value by the mass flow meter 11 and the calculated ejection amount value at the ejection nozzle 7 calculated from the opening time of the electromagnetic on-off valve 8. It is used by calculating the consumption amount and transmitting a switching signal to the switching electromagnetic valves 13a and 13b when the calculated consumption amount reaches the storage amount of liquefied carbon dioxide in the predetermined storage container 2a or 2b. The storage containers 2a and 2b are switched.
In addition, 14 is a solenoid valve for stop, 15 is an air compressor, 15a is an air pipe which supplies the compressed air compressed by the air compressor 5 to the washing nozzle 3, 16 is a safety valve, 17 is a pressure gauge, 22b is a brine tank 22 A discharge port of carbon dioxide gas generated by heat exchange performed in the atmosphere, 22c is a brine liquid surface, and 22d is a gas phase.

Next, a method for manufacturing dry ice using the dry ice manufacturing apparatus 21 shown in FIG. 2 will be described.
Dry ice produced from the storage containers 2a and 2b for storing liquefied carbon dioxide is ejected by a washing nozzle 3 having a built-in dry ice generating nozzle 3a to produce dry ice, and is produced on an object to be washed by compressed air. Is spouted.

And when manufacturing dry ice, the subcooling heat exchanger 5 provided with the cooling pipe 5a which cools the liquefied carbon dioxide supplied to the dry ice production | generation nozzle 3a incorporated in the washing nozzle 3 and makes it a supercooling state is made into brine. It is immersed in the brine 22a in the tank 22, liquefied carbon dioxide is ejected into the brine 22a by the ejection nozzle 7, the brine 22a is cooled, and the cooled brine 22a is used as a cooling medium to circulate in the cooling pipe 5a. In this method, the liquefied carbon dioxide to be cooled is supercooled, and the liquefied carbon dioxide supplied to the dry ice generation nozzle 3a is supercooled.
Control of the degree of supercooling in the supercooling heat exchanger 5 is detected by the temperature sensor 23 provided at the inlet of the supercooling heat exchanger 5 and the temperature sensor 24 provided in the brine 22a, and the temperature control device 10 determines the inlet temperature. The electromagnetic on-off valve 8 is opened and closed so that the difference from the temperature of the brine 22a falls within a predetermined range.

Further, the storage containers 2a and 2b are switched by adding the flow meter side value of the mass flow meter 11 and the calculated ejection amount value from the ejection nozzle 7 calculated from the opening time of the electromagnetic on-off valve 8 to the total amount of liquefied carbon dioxide. When the consumption amount of liquefied carbon dioxide reaches the storage amount of liquefied carbon dioxide in the storage container 2a or 2b determined in advance by the storage container switching device 12, the switching electromagnetic valves 13a and 13b are opened and closed. By doing that.
In the second embodiment described above, the degree of supercooling in the supercooling heat exchanger 5 is controlled by detecting the inlet temperature of the supercooling heat exchanger 5 and the temperature of the brine 22a. Similarly to the embodiment, the inlet temperature and the outlet temperature of the liquefied carbon dioxide in the supercooling heat exchanger 5 may be detected and controlled so that the temperature difference falls within a predetermined range.

However, the liquefied carbon dioxide flowing through the supercooling heat exchanger 5 is supercooled by the brine 22a, and the detection of the temperature of the brine 22a is more responsive than the detection of the outlet temperature of the supercooling heat exchanger 5. And the controllability of the degree of supercooling is good.
Further, since the saturated liquid temperature of the liquefied carbon dioxide to be used is known in advance by the storage containers 2a and 2b to be used, the degree of supercooling may be controlled only by detecting the temperature of the brine 22a.

Further, the required amount of liquefied carbon dioxide ejected for supercooling from the ejection nozzle 7 is determined from the amount ejected from the dry ice generation nozzle 3a, and the supply pipe 4, the branch supply path 4a, By determining the flow resistance of the ejection nozzle 7 or the like, neither the inlet temperature of the supercooling heat exchanger 5 nor the temperature of the brine 22a may be detected.
Furthermore, in the second embodiment, the branch supply path 4a is branched from the inlet side of the supercooling heat exchanger 5 in the supply pipe 4, but the branch position is supercooled as in the first embodiment. You may make it branch from the exit side of the heat exchanger 5. FIG.

In this way, the branch position is set as the outlet side of the supercooling heat exchanger 5 because the operation of the dry ice production apparatus 21 is continuous and the temperature of the brine 22a stored in the brine tank 22 in a short pause is short. Is preferred when does not rise to near ambient temperature.
When the dry ice production device 21 has a long downtime and the temperature of the brine 22a has risen to near the ambient temperature, as a preparation for operating the dry ice production device 21, the liquefied carbon dioxide is ejected from the ejection nozzle 7. Although it is necessary to cool the brine 22a to a predetermined temperature, the liquefied carbon dioxide supplied to the jet nozzle 7 is heat-exchanged with the brine 22a on the outlet side of the supercooling heat exchanger 5, and a part thereof becomes carbon dioxide gas. This is because the ejection amount from 7 is greatly reduced, and there is a problem that it takes a long time to cool the brine 22a to a predetermined temperature.

As the brine 22a used in the second embodiment, an aqueous calcium chloride solution, a fluorinated hydrocarbon, an alcohol-based solvent, etc. are appropriately selected and stored in the brine tank 22 in a state suitable for the range of use, and dry ice production The device 21 is appropriately adjusted every predetermined operating time.
In the first and second embodiments described above, the liquefied carbon dioxide for supercooling the supercooling heat exchanger 5 is branched from the liquefied carbon dioxide supply pipe 4 for producing dry ice to the ejection nozzle 7. Although it supplies, it is good also as a supply path for exclusive use to the ejection nozzle 7 from the storage container which stores another liquefied carbon dioxide.

When a dedicated supply path to the ejection nozzle 7 is used, specifications of a storage container for storing liquefied carbon dioxide ejected from the dry ice generation nozzle 3a and liquefied carbon dioxide ejected from the ejection nozzle 7, for example, pressure (temperature) The storage amount can be made suitable for each.
In the first and second embodiments, the degree of supercooling in the supercooling heat exchanger 5 is performed by opening and closing the electromagnetic on-off valve 8, but the opening degree is continuously controlled instead of the electromagnetic on-off valve 8. It is good also as an electric valve which can be done.

In the case of a motor-operated valve, it is necessary to take care not to cause nozzle clogging due to generation of dry ice in the ejection nozzle 7 due to a decrease in the pressure of liquefied carbon dioxide in control with a small opening of the motor-operated valve.
Furthermore, in 1st and 2nd embodiment, although description about the specification of the storage container was abbreviate | omitted, any of LGC (portable liquefied carbon dioxide container), CE (cold evaporator), and a cylinder (liquefied carbon dioxide container) is used. May be used.

  In the first and second embodiments, the dry ice production apparatus and the dry ice production method are applied to the cleaning application. However, it is needless to say that the dry ice production apparatus and the dry ice production method can be applied to the production of pelletized or granular dry ice as a final product. .

BRIEF DESCRIPTION OF THE DRAWINGS Schematic of the dry ice manufacturing apparatus which concerns on 1st embodiment of this invention. The schematic of the dry ice manufacturing apparatus which concerns on 2nd embodiment of this invention. Schematic of the conventional dry ice manufacturing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dry ice production apparatus 2a, 2b Storage container 3a Dry ice production nozzle 4 Supply pipe 4a Branch supply path 5 Supercooling heat exchanger 5a Cooling pipe 7 Ejection nozzle 8 Electromagnetic on-off valve 21 Dry ice production apparatus 22 Brine tank 22a Brine

Claims (6)

Dry ice production comprising a storage container for storing liquefied carbon dioxide, a dry ice generating nozzle for generating liquefied carbon dioxide by jetting liquefied carbon dioxide, and a supply pipe for supplying liquefied carbon dioxide from the storage container to the generating nozzle In the device
A supercooling heat exchanger with a cooling pipe that cools the liquefied carbon dioxide from the supply pipe to a supercooled state is formed in the middle of the supply pipe, and the liquefied carbon dioxide is ejected to the supercooling heat exchanger by the ejection nozzle. A dry ice production apparatus characterized by supercooling the liquefied carbon dioxide flowing through the cooling pipe. Dry ice production comprising a storage container for storing liquefied carbon dioxide, a dry ice generating nozzle for generating liquefied carbon dioxide by jetting liquefied carbon dioxide, and a supply pipe for supplying liquefied carbon dioxide from the storage container to the generating nozzle In the device
In the middle of the supply pipe, a supercooling heat exchanger with a cooling pipe that cools the liquefied carbon dioxide from the supply pipe to a supercooled state is formed, and a heat exchange tank containing brine is provided. The subcooling heat exchanger is immersed in the brine, and liquefied carbon dioxide is jetted from the jet nozzle provided in the brine, and the liquefied carbon dioxide circulating in the cooling pipe is supercooled using the brine as a cooling medium. Dry ice manufacturing equipment.   2. An electromagnetic on-off valve is provided in a supply path for supplying liquefied carbon dioxide to an ejection nozzle, and the degree of supercooling of liquefied carbon dioxide by a supercooling heat exchanger is controlled by opening and closing the electromagnetic on-off valve. Item 3. The dry ice production apparatus according to Item 2. In a dry ice production method for producing dry ice by ejecting liquefied carbon dioxide from a storage container for storing liquefied carbon dioxide by a dry ice production nozzle,
The supercooled heat exchanger equipped with a cooling pipe that cools the liquefied carbon dioxide supplied to the dry ice production nozzle and puts it into a supercooled state is ejected by the jet nozzle and the liquefied carbon dioxide flowing through the cooling pipe is passed through. A method for producing dry ice, comprising cooling. In a dry ice production method for producing dry ice by ejecting liquefied carbon dioxide from a storage container for storing liquefied carbon dioxide by a dry ice production nozzle,
In the middle of the passage for supplying liquefied carbon dioxide to the dry ice generation nozzle, a supercooling heat exchanger having a cooling pipe that cools the liquefied carbon dioxide and puts it in a supercooled state is formed, and in the heat exchange tank containing the brine A method for producing dry ice, comprising: dipping in brine and ejecting liquefied carbon dioxide from an ejection nozzle provided in the brine to supercool the liquefied carbon dioxide flowing through the cooling pipe using the brine as a cooling medium.   6. The degree of supercooling of liquefied carbon dioxide by the supercooling heat exchanger is controlled by opening and closing an electromagnetic on-off valve provided in a supply path for supplying liquefied carbon dioxide to a jet nozzle. The dry ice manufacturing method as described.

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