JP5241770B2 - Carbon dioxide recovery device in dry ice manufacturing process - Google Patents

Description

  The present invention relates to a carbon dioxide recovery device in a dry ice production process, and more particularly, carbon dioxide recovery in a dry ice production process for recovering, liquefying and reusing carbon dioxide (CO2) generated in the dry ice production process. It relates to the device.

  Conventionally, solid dry ice has been used in a wide range of industrial fields (for example, see Patent Document 1).

  Further, dry ice is formed in a wide variety of product shapes and sizes, but is usually manufactured by a dry ice manufacturing apparatus as shown in FIG.

  In the dry ice production apparatus 1 shown in FIG. 2, a conduit 2 leads from a liquefied carbon dioxide gas storage tank 3 for storing liquefied carbon dioxide gas to a plurality of dry ice production machines 5, 5. Yes. The supercooler 4 is connected to a brachinler 6 for cooling the inside of the supercooler 4.

  And the liquefied carbon dioxide gas which is the temperature of about -20 degreeC is stored in the said liquefied carbon dioxide storage tank 3 of the said dry ice manufacturing apparatus 1, The liquefied carbon dioxide gas in this liquefied carbon dioxide storage tank 3 is not shown in figure. When the valve is opened, it is sent into the supercooler 4 through the conduit 2, further cooled in the supercooler 4, and then sent to the dry ice making machines 5, 5. Further, the liquefied carbon dioxide gas sent to the dry ice making machines 5, 5... Is sprayed into the respective chambers of the dry ice making machines 5, 5. ℃ dry ice. Further, when the snow-like dry ice is compressed by the piston and formed into solid dry ice having a predetermined product shape and size, the process is completed.

  By the way, in the dry ice production apparatus 1, vaporization is intense when the snow-like dry ice is produced and when the snow-like dry ice is compression-molded and solidified. For this reason, only about 40% of the liquefied carbon dioxide gas sprayed by the nozzles into the chambers of the dry ice making machines 5, 5... Contributes to the generation of dry ice, and the remaining 60% becomes carbon dioxide gas. The actual situation is that it is released into the atmosphere.

  Therefore, from the viewpoints of cost reduction and prevention of global warming, this vaporized carbon dioxide gas is recovered and re-liquefied so that it can be reused as a raw material for dry ice production. In order to make use, a carbon dioxide recovery device provided with a waste carbon dioxide recovery system has been proposed (see, for example, Patent Document 2).

  The conventional waste exhaust carbon dioxide is normally recovered by using a carbon dioxide recovery device as shown in FIG.

  A carbon dioxide gas recovery device 100 shown in FIG. 3, for example, converts carbon dioxide gas recovered from the dry ice production device 1 through a recovery conduit 7 into a carbon dioxide gas compressor 11 with a cooler 10 via a blower 9 with an inverter 8. The carbon dioxide gas compressed by the carbon dioxide gas compressor 11 to about 2.2 MPaG, and the carbon dioxide gas compressed by the carbon dioxide gas compressor 11 is further sent to a cooler 12 configured as a refrigerator. To about 30-40 ° C.

  Further, the carbon dioxide gas cooled to a low temperature of about 30 to 40 ° C. by the cooler 12 is sequentially dehumidified and impurities removed through the dehumidifying cylinder 13 and the filter 14, and then sent to the liquefier 15. The carbon dioxide gas sent into the liquefier 15 is cooled to about −20 ° C. in the liquefier 15 by the brachinler 16 and liquefied by this cooling to become liquefied carbon dioxide gas.

  The liquefied carbon dioxide gas liquefied in the liquefier 15 in this way is stored in the primary receiving tank 17 and then stored in the liquefied carbon dioxide storage tank 3 and sold for reuse or reuse.

  In the carbon dioxide recovery device 100, as a valve for controlling the flow rate of the recovered carbon dioxide, surplus recovered carbon dioxide recovered from the dry ice manufacturing machines 5, 5... A control valve CV1 that discharges to the atmosphere; a control valve CV2 that returns the recovered carbon dioxide gas, which has exceeded the compression processing capacity in the carbon dioxide compressor 11 and could not be compressed, to the suction side of the blower 9; A control valve CV3 for controlling the amount of liquefied carbon dioxide gas stored in the primary receiving tank 17 to the liquefied carbon dioxide gas storage tank 3 is provided.

  Further, as a sensor for detecting the pressure and the liquid amount in each part of the carbon dioxide gas recovery device 100, a pressure sensor PIC1 for detecting the pressure in the recovery carbon dioxide recovery conduit 7 supplied to the carbon dioxide gas compressor 11; A pressure sensor PIC2 for detecting the pressure in the liquefier 15, a sensor PIC3 for detecting the pressure in the liquefied carbon dioxide storage tank 3, and a liquid for detecting the amount of liquefied carbon dioxide stored in the primary receiving tank 17 A quantity sensor LIC is provided.

  In the carbon dioxide recovery device 100 configured as described above, normally, the follow-up to the recovery of the recovered carbon dioxide amount is performed by the blower 9 based on the pressure detected by the pressure sensor PIC1, that is, the pressure in the recovery conduit 7. The inverter control and the capacity control of the carbon dioxide compressor 11 are performed.

  However, in the carbon dioxide gas recovery apparatus 100, the inverter control of the blower 9 has a minimum rotational speed limit, and the carbon dioxide gas compressor 11 has 50% and 100% step capacity control, so that it fluctuates. It is impossible to follow linearly for all flow rates in the area. When the amount of recovered carbon dioxide gas increases and cannot follow, a part of the recovered carbon dioxide gas is not sent to the carbon dioxide gas compressor 11 side, so that the recovered carbon dioxide gas is released from the control valve CV1 to the atmosphere. Therefore, in order to minimize the release of recovered carbon dioxide into the atmosphere, the carbon dioxide released from the carbon dioxide compressor 11 is returned to the suction side of the blower 9 by the control valve CV2 so that it can follow as much as possible. I have to.

JP 2006-193377 A. Japanese Patent Application Laid-Open No. 7-33423.

However, the conventional dry ice production process and carbon dioxide gas recovery apparatus described above have the following problems (1) to (4).
(1) In the dry ice production apparatus, about half of the sucked carbon dioxide gas is released to the atmosphere.
(2) Since the carbon dioxide gas generated from the dry ice production apparatus is about −80 ° C., it is outside the use range (0 ° C. or higher) of the equipment used (carbon dioxide compressor). For this reason, the carbon dioxide gas generated in the dry ice production apparatus cannot be used as it is.
(3) Since the dry ice production apparatus is a press mechanism and the generated carbon dioxide gas is intermittently generated, the amount of the recovered gas fluctuates rapidly and cannot be followed by the conventional carbon dioxide recovery apparatus described above. When the amount of the recovered gas cannot be increased and follow-up cannot be performed, a part of carbon dioxide gas is not sent to the recovery device and must be discharged to the atmosphere, so that the recovery efficiency is lowered. On the other hand, when the amount of the recovered gas decreases and cannot follow, the upstream side of the blower is in a vacuum state, and the purity of carbon dioxide gas and impurities are mixed due to air mixing.
(4) When the liquefied carbon dioxide purified by the carbon dioxide recovery device is received into the liquefied carbon dioxide storage tank of the dry ice production device, it will mix with the purchased product liquefied carbon dioxide gas. Risk of contaminating liquefied carbon dioxide storage tank and purchased carbon dioxide gas. In particular, since the dry ice discharge port of the dry ice production apparatus is in an open state, there is a high possibility of air mixing due to a malfunction of the production equipment.

  Therefore, there is a technical problem to be solved in order to provide a carbon dioxide recovery device in a dry ice production process that can follow a rapid change in the amount of recovered carbon dioxide and has high recovery efficiency. Aims to solve this problem.

  The present invention has been proposed in order to achieve the above object, and the invention according to claim 1 is characterized in that a carbon dioxide gas recovered from a dry ice making machine is supplied with a blower, a carbon dioxide gas compressor, a cooler, and a liquefier. In the carbon dioxide gas recovery apparatus in the dry ice production process for liquefying and reusing in order, the recovered carbon dioxide gas is temporarily stored upstream of the carbon dioxide gas compressor, and the carbon dioxide gas compression is performed. There is provided a carbon dioxide gas recovery apparatus in a dry ice production process, comprising buffer tank means capable of supplying a required amount of the recovered carbon dioxide gas to the carbon dioxide gas compressor side according to the compression processing capacity of the machine.

  According to this configuration, the carbon dioxide gas recovered from the dry ice making machine is temporarily stored in the buffer tank means, and the recovered carbon dioxide gas is supplied from the buffer tank means according to the compression processing capacity of the carbon dioxide gas compressor. The required amount can be supplied to the compressor side. Therefore, it becomes possible to follow the fluctuations in the recovered carbon dioxide gas, and the amount of released air can be reduced.

  According to a second aspect of the present invention, in the dry ice manufacturing process according to the first aspect of the present invention, a heater for heating the recovered carbon dioxide gas to 0 ° C. or higher is provided upstream of the buffer tank means. A carbon dioxide recovery device is provided.

  According to this configuration, the carbon dioxide gas collected from the dry ice making machine is preheated to 0 ° C. or higher, which is the range of use of the carbon dioxide compressor, by a heater and stored in the buffer tank means. be able to.

  According to a third aspect of the present invention, in the configuration according to the second aspect, the buffer tank means includes primary buffer tank means disposed between the heater and the blower, the blower, and the carbon dioxide gas compressor. Return means for returning the recovered carbon dioxide gas between the blower and the secondary buffer tank means to the primary buffer tank means side. Provided is a carbon dioxide gas recovery apparatus in a dry ice production process, comprising a return means for returning the recovered carbon dioxide gas between the carbon dioxide compressor and the cooler to the secondary buffer tank means side.

  According to this configuration, the carbon dioxide gas collected from the dry ice making machine is stored in the primary buffer tank means, and the carbon dioxide gas that cannot be processed by exceeding the capacity of the compression process by the carbon dioxide gas compressor is stored in the primary buffer tank means and The supply amount can be adjusted by collecting the secondary buffer tank means. As a result, it becomes possible to further follow fluctuations in the recovered carbon dioxide gas, and the amount of atmospheric discharge can be reduced.

A fourth aspect of the present invention is the dry ice according to any one of the first, second or third aspect, wherein a primary receiving tank for storing the carbon dioxide gas liquefied by the liquefier is provided downstream of the liquefier. Provided is a carbon dioxide recovery device in a manufacturing process.

  According to this configuration, the recovered and liquefied carbon dioxide gas is temporarily stored in the primary receiving tank, and when the carbon dioxide gas is required on the dry ice maker side, the recovered liquefied carbon dioxide is transferred from the primary receiving tank to the dry ice maker side. The required amount of gas can be supplied. Therefore, it is possible to follow the fluctuation of the recovered carbon dioxide gas, and effective utilization can be achieved.

  According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the pressure of the liquefied carbon dioxide gas stored in the primary receiving tank is liquefied carbon dioxide on the dry ice making machine side connected via a control valve. Carbon dioxide in the process of dry ice production that is set higher than the pressure in the gas tank and that connects the recovery gas receiving port of the carbon dioxide recovery device and the carbon dioxide atmospheric discharge port from the dry ice manufacturing machine as a closed circuit A gas recovery apparatus is provided.

  According to this configuration, the pressure of the liquefied carbon dioxide gas stored in the primary receiving tank is set higher than the pressure in the liquefied carbon dioxide tank on the dry ice making machine side. The liquefied carbon dioxide gas supplied to the manufacturing machine side is merged with the liquefied carbon dioxide gas in the liquefied carbon dioxide tank without being sent to the liquefied carbon dioxide tank on the dry ice making machine side, and then sent to the dry ice making machine. Liquid feeding becomes possible. That is, when the recovered liquefied carbon dioxide gas is supplied to the dry ice making machine, it is only during the operation of the dry ice making machine, and the dry ice making machine side during the operation is always at atmospheric pressure, so the primary receiving tank The recovered liquefied carbon dioxide gas does not flow into the liquefied carbon dioxide gas storage tank, but joins the liquefied carbon dioxide gas in the liquefied carbon dioxide gas tank and is sent to the dry ice making machine.

The invention described in claim 6 is the humidifier according to any one of claims 2, 3, 4 or 5, wherein the water or brine is cooled by exchanging heat between the carbon dioxide gas and water or brine. A carbon dioxide recovery device in the process of producing dry ice is provided.

  According to this configuration, the recovered carbon dioxide gas and water or brine can be heat-exchanged in the heater, and the water or brine can be cooled.

  The invention according to claim 1 can follow any fluctuations in the increase or decrease of the recovered carbon dioxide gas, reduce the atmospheric emission amount, and recycle most of the recovered carbon dioxide gas. Since it can be utilized, it can contribute to cost reduction and prevention of global warming. In addition, since the suction side upstream of the blower is in a vacuum state at the time of fluctuation, it is possible to eliminate inconveniences such as a decrease in purity of carbon dioxide gas due to air mixing and contamination of impurities.

  According to the second aspect of the present invention, the carbon dioxide gas recovered from the dry ice making machine is preheated to a temperature range usable by the carbon dioxide compressor by a heater and stored in the buffer tank means. Therefore, in addition to the effect of the first aspect of the invention, the recovery efficiency of the recovered carbon dioxide gas can be improved.

  The invention according to claim 3 can absorb any fluctuations in the increase and decrease of the recovered carbon dioxide gas by the two buffer tank means, the primary buffer tank means and the secondary buffer tank means. In addition to the effects of the invention, it is possible to follow further, and the collection efficiency can be further improved.

  The invention according to claim 4 can supply the required amount of recovered liquefied carbon dioxide from the primary receiving tank to the dry ice maker when carbon dioxide is required on the dry ice maker side. Alternatively, in addition to the effects of the invention described in 3, effective utilization can be further improved.

  According to the fifth aspect of the present invention, the liquefied carbon dioxide purified by the carbon dioxide recovery device and the product liquefied carbon dioxide purchased in the liquefied carbon dioxide storage tank of the dry ice production device are supplied to the dry ice production device without mixing. Therefore, in addition to the effect of the invention of claim 4, improvement in usability can be expected.

  In the invention described in claim 6, since the recovered carbon dioxide gas and water or brine are heat-exchanged in a heater to cool the water or brine, in addition to the effects of the invention described in claims 2, 3, 4 or 5, Thus, the dry ice cooling heat can be effectively utilized in the heater.

Explanatory drawing of the Example of the carbon dioxide recovery apparatus in the dry ice manufacturing process which concerns on this invention. Explanatory drawing which shows an example of the conventional dry ice manufacturing apparatus. Explanatory drawing which shows an example of the conventional carbon dioxide recovery apparatus.

  In order to achieve the object of the present invention to provide a carbon dioxide gas recovery device in a dry ice production process that can follow a rapid fluctuation in the amount of carbon dioxide recovered and has high recovery efficiency, the present invention is recovered from a dry ice making machine. The carbon dioxide gas is liquefied through a blower, a carbon dioxide gas compressor, a cooler, and a liquefier in order, and in the carbon dioxide gas recovery device in the dry ice production process for reuse, upstream of the carbon dioxide gas compressor on the suction side And a buffer tank means for temporarily storing the recovered carbon dioxide gas and supplying the required amount of the recovered carbon dioxide gas to the carbon dioxide gas compressor side according to the compression processing capacity of the carbon dioxide gas compressor. Realized by.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a carbon dioxide recovery apparatus in a dry ice production process according to the present invention together with a dry ice production apparatus. In the following description, the members corresponding to those in the dry ice production apparatus shown in FIG. 2 and the carbon dioxide recovery apparatus shown in FIG.

  In FIG. 1, a dry ice production apparatus 1 includes a plurality of dry ice production machines in which a conduit 2 is connected to, for example, a liquefied carbon dioxide storage tank 3 as a storage tank for storing purchased product liquefied carbon dioxide via a supercooler 4. Leads to 5, 5 ... The supercooler 4 is connected to a brachinler 6 that cools the inside of the subcooler 4, and the liquefied carbon dioxide storage tank 3 is attached with a pressure sensor PIC 3 that detects the pressure in the liquefied carbon dioxide storage tank 3. ing. Further, in the middle of the conduit 2 between the liquefied carbon dioxide storage tank 3 and the supercooler 4, a final recovery port of a recovery conduit 7 communicating with a primary receiving tank 17 of a carbon dioxide recovery device 20 described later is provided as a control valve. The liquefied carbon dioxide gas stored in the primary receiving tank 17 can be supplied to the upstream side of the suction side of the subcooler 4.

  The liquefied carbon dioxide storage tank 3 of the dry ice production apparatus 1 normally stores purchased liquefied carbon dioxide that is liquefied at a temperature of about −20 ° C. When the valve (not shown) is opened, the liquefied carbon dioxide gas in the liquefied carbon dioxide storage tank 3 is sent into the supercooler 4 through the conduit 2 and further cooled in the supercooler 4. Then, it is sent to the dry ice making machines 5, 5.

  In this embodiment, when the control valve CV3 of the carbon dioxide recovery device 20 is opened, the recovered liquefied carbon dioxide stored in the primary receiving tank 17 is stored in the liquefied carbon dioxide storage tank 3. The storage tank pressure in the liquefier 15 and the primary receiving tank 17 is set to be higher than the pressure in the liquefied carbon dioxide storage tank 3 so as to be sent to the dry ice making machines 5, 5. The pressure is set high so that the recovered liquefied carbon dioxide gas is not fed into the liquefied carbon dioxide gas storage tank 3 even when the control valve CV3 is fully opened. That is, when the recovered liquefied carbon dioxide gas is supplied to the dry ice making machines 5, 5,..., It is only during the operation of the dry ice making machines 5, 5,. , 5... Are always at atmospheric pressure, so that the recovered liquefied carbon dioxide gas from the primary receiving tank 17 does not flow into the liquefied carbon dioxide gas storage tank 3 but merges with the liquefied carbon dioxide gas in the liquefied carbon dioxide gas storage tank 3. Then, it is supplied toward the dry ice making machines 5, 5.

  Therefore, when the dry ice production apparatus 1 is operated, the recovered liquefied carbon dioxide gas from the carbon dioxide gas collection apparatus 20 is sent preferentially to the dry ice production machines 5, 5. The liquefied carbon dioxide gas is combined with the recovered liquefied carbon dioxide gas so as to compensate for the shortage, and is supplied to the dry ice making machines 5, 5.

  Further, the liquefied carbon dioxide gas sent to the dry ice making machines 5, 5... Is sprayed into the respective chambers of the dry ice making machines 5, 5. ℃ dry ice. Further, when the snow-like dry ice is compressed by the piston and formed into solid dry ice having a predetermined product shape and size, the process is completed.

  Next, the carbon dioxide recovery device 20 will be described. As described above, the carbon dioxide recovery device 20 of the present embodiment connects the final recovery port of the recovery conduit 7 of the carbon dioxide recovery device 20 in the middle of the conduit 2 of the dry ice production device 1 and A carbon dioxide atmosphere discharge port from the ice making machines 5, 5... Is connected to the recovery conduit 7 to constitute a closed circuit. Further, in addition to the configuration of the conventional carbon dioxide recovery device 100 shown in FIG. 3, the carbon dioxide recovery device 20 is further connected to the upstream side of the blower 9 with the inverter 8 from the dry ice production devices 5, 5. A warmer 21 that raises the carbon dioxide gas recovered through the recovery conduit 7 to 0 ° C. or higher, and a primary buffer tank for primarily storing the recovered carbon dioxide gas heated by the heater 21 A primary buffer tank 22 is provided as a means, and the carbon dioxide gas sent through the blower 9 is temporarily stored between the discharge side of the blower 9 and the suction side of the carbon dioxide gas compressor 11. A secondary buffer tank 23 is provided as a secondary buffer tank means for placing the tank.

  In the carbon dioxide gas recovery process in the carbon dioxide gas recovery device 20, first, the carbon dioxide gas recovered from the dry ice production device 1 through the recovery conduit 7 is supplied to the carbon dioxide gas compressor 11 by the heater 21. After raising the temperature to 0 ° C. or higher, which is the operating temperature, the carbon dioxide gas compressor 11 is supplied to the carbon dioxide gas compressor 11 with the cooler 10 via the primary buffer tank 22, the blower 9, and the secondary buffer tank 23. 11 to compress to about 2,2 MPaG. The carbon dioxide gas compressed by the carbon dioxide gas compressor 11 is sent to a cooler 12 configured as a refrigerator, and is cooled to about 30 to 40 ° C. by the cooler 12.

  Further, the carbon dioxide gas cooled to a low temperature of about 30 to 40 ° C. by the cooler 12 is dehumidified and impurities are removed through the dehumidifying cylinder 13 and the filter 14, and then sent to the liquefier 15. The carbon dioxide gas sent into the liquefier 15 is cooled to about −20 ° C. in the liquefier 15 by the brachinler 16 and liquefied by this cooling to become liquefied carbon dioxide gas.

  The liquefied carbon dioxide gas liquefied in the liquefier 15 in this way is stored in the primary receiving tank 17, and then sent to the conduit 2 of the dry ice production apparatus 1 for reuse.

  The carbon dioxide recovery device 20 uses the recovered carbon dioxide gas stored in the primary buffer tank 22 in the atmosphere as a valve for controlling the amount of carbon dioxide recovered in the primary buffer tank 22. And a control valve CV2a as a return means for returning the recovered carbon dioxide gas, which has exceeded the capacity of the compression process in the carbon dioxide gas compressor 11 and could not be compressed, into the primary buffer tank 22. And a control valve CV2b as return means for returning to the secondary buffer tank 23 side, and the control valve CV3 for controlling the amount of liquefied carbon dioxide gas stored in the primary receiving tank 17 to the dry ice production apparatus 1 side. ing.

  Further, as sensors for detecting the pressure and the amount of liquid in each part of the carbon dioxide recovery device 20, a pressure sensor PIC1a for detecting the pressure of carbon dioxide in the primary buffer tank 22, and the secondary buffer tank 23 The pressure sensor PIC1b for detecting the pressure of the carbon dioxide gas, the pressure sensor PIC2 for detecting the pressure in the liquefier 15, the sensor PIC3 for detecting the pressure in the liquefied carbon dioxide storage tank 3, and the primary receiving tank 17 are stored. A liquid amount sensor LIC for detecting the amount of liquefied carbon dioxide gas is provided.

  And even in the carbon dioxide recovery device 20 of the present embodiment configured in this way, similarly to the conventional carbon dioxide recovery device, the inverter control of the blower 9 has a minimum rotational speed limit. The carbon dioxide gas compressor 11 cannot linearly follow all the flow rates in the fluctuating region with the step capacity control of 50% and 100%. However, in the carbon dioxide recovery device 20 of the present embodiment, the follow-up to the recovered carbon dioxide amount fluctuation is normally detected by the inverter control of the blower 9 based on the pressure detected by the pressure sensor PIC1a and the pressure sensor PIC1b. The capacity of the carbon dioxide compressor 11 is controlled based on the pressure of the carbon dioxide, and the excess capacity of carbon dioxide is returned to the primary buffer tank 22 and the secondary buffer tank 23 via the control valves CV2a and CV2b, respectively. In the case of a decrease, carbon dioxide gas is supplied from the primary buffer tank 22 and the secondary buffer tank 23 so as to follow all the flow rates in the fluctuation range.

  Therefore, according to the carbon dioxide recovery device 20 in the dry ice production process according to the present embodiment, it is possible to follow any fluctuations in the increase or decrease in the recovered carbon dioxide, thereby reducing the amount of atmospheric emission and recovery. Most of the carbon dioxide that has been used can be reused for effective utilization. This can contribute to cost reduction and prevention of global warming. Furthermore, when the suction side of the blower 9 is in a vacuum state at the time of a decrease, it is possible to eliminate inconveniences such as a decrease in purity of carbon dioxide gas due to air contamination and contamination of impurities.

  Further, the primary buffer tank 22 and the secondary buffer are made by heating the carbon dioxide gas recovered from the dry ice production apparatus to a temperature range of 0 ° C. or higher, which can be used in the carbon dioxide compressor 11, in advance by the heater 21. Since it is stored in the tank 23, it becomes possible to further follow the fluctuation of the recovered carbon dioxide gas, and the recovery efficiency can be improved.

  Furthermore, since the pressure of the liquefied carbon dioxide gas stored in the liquefier 15 and the primary receiving tank 17 is set higher than the pressure in the liquefied carbon dioxide gas storage tank 3 on the dry ice production apparatus 1 side, The liquefied carbon dioxide purified by the carbon dioxide recovery device 20 and the product liquefied carbon dioxide purchased in the liquefied carbon dioxide storage tank 3 of the dry ice production device 1 can be supplied to the dry ice production device without mixing.

  In the heater 21 in the configuration of the above-described embodiment, when the recovered carbon dioxide gas and water or brine are heat-exchanged to cool the water or brine, the dry ice cooling heat can be effectively utilized. Is possible.

  The present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

  The present invention can also be applied as a device for recovering carbon dioxide in the fermentation gas of a beer factory or the like.

DESCRIPTION OF SYMBOLS 1 Dry ice production apparatus 2 Conduit 3 Liquefied carbon dioxide storage tank 4 Supercooler 5 Dry ice production machine 6 Blinchler 7 Recovery conduit 8 Inverter 9 Blower 10 Cooler 11 Carbon dioxide compressor 12 Cooler 13 Dehumidification cylinder 14 Filter 15 Liquefier 16 Brainchler 17 Primary tank 20 Carbon dioxide recovery device 21 Heater 22 Primary buffer tank (primary buffer tank means)
23 Secondary buffer tank (secondary buffer tank means)
CV2a, CV2b Control valve (return means)

Claims (6)

In the carbon dioxide gas recovery device in the dry ice production process for liquefying and reusing the carbon dioxide gas collected from the dry ice production machine through the blower, the carbon dioxide gas compressor, the cooler and the liquefier in order,
Temporarily storing the recovered carbon dioxide gas upstream of the suction side of the carbon dioxide gas compressor,
And carbon dioxide gas recovery in the dry ice production process, comprising buffer tank means capable of supplying a required amount of the recovered carbon dioxide gas to the carbon dioxide gas compressor side according to the compression processing capacity of the carbon dioxide gas compressor apparatus.   2. A carbon dioxide gas recovery apparatus in a dry ice production process according to claim 1, wherein a humidifier for heating the recovered carbon dioxide gas to 0 [deg.] C. or higher is provided upstream of the buffer tank means.   The buffer tank means includes: a primary buffer tank means disposed between the humidifier and the floor; and a secondary buffer tank means disposed between the blower and the suction side of the carbon dioxide gas compressor. A return means for returning the recovered carbon dioxide gas between the blower and the secondary buffer tank means to the primary buffer tank means side, and the recovered carbon dioxide gas between the carbon dioxide compressor and the cooler. 3. A carbon dioxide gas recovery apparatus in a dry ice production process according to claim 2, further comprising return means for returning the gas to the secondary buffer tank means side. 4. The dry ice production process according to claim 1, wherein a primary receiving tank for storing carbon dioxide gas liquefied by the liquefier is provided downstream of the liquefier. 5. Carbon dioxide recovery device.   The pressure of the liquefied carbon dioxide gas in the primary receiving tank is set to be higher than the pressure in the liquefied carbon dioxide gas tank on the dry ice making machine side, and the recovered gas receiving port of the carbon dioxide gas collecting device and the dry ice making machine The carbon dioxide gas recovery apparatus in the dry ice production process according to claim 4, wherein the carbon dioxide atmospheric discharge ports from the two are connected to each other to form a sealed circuit. 6. The dry ice according to claim 2, wherein the humidifier cools the water or brine by exchanging heat between the carbon dioxide gas and water or brine. 7. Carbon dioxide recovery device in the manufacturing process.

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