JP2005313060A - Washing apparatus and washing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively remove soil including stuck material while minimizing amount of solvents discharged to atmosphere. <P>SOLUTION: A washing apparatus is provided with a liquid tank 11 which stores liquid carbon dioxide, a washing tank 13 which is constituted so that matters to be washed 12 on a surface of which contaminants stick can be held therein and the tank can be tightly closed, a liquid feed pump 14 which forcibly feeds the liquid carbon dioxide to the washing tank, a separator 19 which separates contaminants from the liquid carbon dioxide discharged from the washing tank and a discharging pump 21 for returning the liquid carbon dioxide from which the contaminants are separated into the liquid tank. Further the washing apparatus is provided with a gas tank 36 for storing pressurized gaseous carbon dioxide and washing nozzles 37, 38 which are provided so that the liquid carbon dioxide can be turned to dry ice or dry snow by the gaseous carbon dioxide and can be injected to the matters to be washed. A washing method comprises a process of removing the contaminants by injecting the dry ice or the like, a process of washing the washing tank by filling it with the liquid carbon dioxide and a process of separating and removing the contaminants from the liquid carbon dioxide and recovering it into the liquid tank 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cleaning apparatus and a cleaning method for removing contaminants from an object to be cleaned using liquid carbon dioxide.

Conventionally, a cleaning method using liquid carbon dioxide as a cleaning medium in dry cleaning is known. (For example, refer to Patent Document 1). In this cleaning method, the combination of the solvent characteristic of carbon dioxide and a detergent makes it possible to effectively remove normal dirt without shrinking clothes and without dropping dye.
However, although the conventional cleaning method using carbon dioxide can effectively remove normal dirt, the solvent characteristics of carbon dioxide and the effect of the detergent are limited, and dirt including fixed matter, for example, There was a problem that sufficient cleaning was not possible when removing paint, rust, food residue, blood, etc.

On the other hand, for dirt containing paint, rust, food residue, blood, and other sticking substances, the liquid carbon dioxide or pressurized carbon dioxide gas is used as dry ice or dry snow and sprayed onto the object to be cleaned. There is known a cleaning method for removing dirt including fixed objects from an object to be cleaned (for example, see Patent Document 2).
Therefore, in order to clean the object to be cleaned, which is adhered to the surface with the normal dirt and the fixed object, after spraying dry ice or dry snow onto the object to be cleaned and removing the dirt including the fixed object, Cleaning with liquid carbon dioxide as the cleaning medium, or cleaning with liquid carbon dioxide as the cleaning medium and then spraying dry ice or dry snow onto the object to be cleaned can be considered to remove the dirt including the fixed matter.
JP-A-8-52297 (Claims) JP 2001-277116 A (Claims)

However, for the cleaning of the object to be cleaned, it is necessary to provide a process for removing dirt including fixed substances and a process for cleaning liquid carbon dioxide as a cleaning medium independently. There is a problem that causes an increase in process and complexity.
In recent years, restrictions and regulations on solvents used from the standpoint of avoiding environmental impacts have been strengthened, and secondary waste is generated due to processing of solvents used for cleaning and used cleaning aids. Is required to be reduced as much as possible. In dry cleaning using liquefied carbon dioxide, the liquefied carbon dioxide is used in a high pressure state. For this reason, when the object to be cleaned is put into and out of the cleaning tank in dry cleaning, it is necessary to reduce the pressure in the cleaning tank to atmospheric pressure, and at the time of this pressure reduction, liquefied carbon dioxide is released to the outside of the apparatus. Therefore, in order to improve the utilization rate of carbon dioxide and improve the economic efficiency, a method for reducing the amount of carbon dioxide released is required for putting in / out the object to be washed in the dry cleaning. For example, a compressor is used. A method for compressing and recovering carbon dioxide gas in a cleaning tank has been proposed. However, since this method takes time to recover carbon dioxide, a sufficient decompression time is required even though the drying process of the object to be cleaned is not required using liquefied carbon dioxide, and the feature of dry cleaning is There is a bug that cannot be used.
The objective of this invention is providing the washing | cleaning apparatus and washing | cleaning method which can remove effectively the stain | pollution | contamination containing a fixed matter, reducing the solvent discharged | emitted to air | atmosphere as much as possible.

As shown in FIG. 1, the invention according to claim 1 is configured so as to be able to accommodate and seal a liquid tank 11 for storing liquid carbon dioxide, and an object to be cleaned 12 having contaminants attached to the surface. The cleaning tank 13 for removing contaminants from the object to be cleaned 12, the liquid supply pump 14 for pumping liquid carbon dioxide from the liquid tank 11 to the cleaning tank 13, and the contaminants from the liquid carbon dioxide discharged from the cleaning tank 13 This is an improvement of a cleaning device including a separator 19 for separation and a discharge pump 21 for returning liquid carbon dioxide from which contaminants have been separated by the separator 19 to the liquid tank 11.
The characteristic configuration includes a gas tank 36 that stores pressurized carbon dioxide gas, and dry ice or dry snow that is stored in the washing tank 13 and liquid carbon dioxide that is pumped from the liquid tank 11 by pressurized carbon dioxide gas. And the cleaning nozzles 37 and 38 provided so as to be sprayable on the object to be cleaned.

  In the cleaning apparatus according to the first aspect, dry ice or dry snow can be sprayed onto the object to be cleaned 12 to remove the dirt including the fixed substance, and normal cleaning is performed using liquid carbon dioxide as a cleaning medium. As a result, it is possible to remove normal light dirt as well as dirt including fixed matter. Further, the cleaning device according to claim 1 is remarkably increased in size because it is simply piped to the cleaning nozzles 37 and 38 using the gas tank 36 for storing carbon dioxide gas in the conventional cleaning device using liquid carbon dioxide. There is nothing.

The invention according to claim 2 is the invention according to claim 1, wherein the cleaning basket 16 capable of accommodating the article to be cleaned 12 is provided so as to be able to be taken out into the cleaning tank 13, and the cleaning nozzle 16 is provided in the cleaning basket 16. Cleaning device.
In the cleaning apparatus according to the second aspect, it becomes possible to provide the cleaning nozzle 37 in the vicinity of the object 12 to be cleaned, and effectively remove the dirt including the fixed matter adhering to the surface of the object 12 to be cleaned. can do.
The invention according to a third aspect is the invention according to the first or second aspect, wherein the cleaning tank 13 is provided with a stirrer 33 for stirring the liquid carbon dioxide stored in the cleaning tank 13.
In the cleaning apparatus according to the third aspect, the liquid carbon dioxide in the cleaning tank 13 is stirred by the stirrer 33, whereby the cleaning effect at the time of normal cleaning can be improved.

The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein a liquid carbon dioxide circulation path 28 is provided between the discharge side of the liquid carbon dioxide of the discharge pump 21 and the cleaning tank 13. Cleaning device.
In the cleaning apparatus according to the fourth aspect, the liquid carbon dioxide in the cleaning tank 13 is circulated through the circulation path 28, thereby improving the cleaning effect during normal cleaning.
The invention according to claim 5 is the invention according to claim 4, wherein the detergent tank 29 stores the detergent, and the detergent supply pump 31 a that supplies the detergent stored in the detergent tank 29 to the liquid carbon dioxide circulation path 28. Is a cleaning device.
In the cleaning apparatus according to the fifth aspect, by supplying the detergent to the liquid carbon dioxide circulation path 28, the cleaning effect during normal cleaning can be further improved.

The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the liquid carbon dioxide is recovered between the liquid carbon dioxide discharge side of the discharge pump 21 and the liquid tank 11. The cleaning apparatus is provided with a recovery path 22 and a filter 24 in the middle of the first recovery path 22.
In the cleaning apparatus according to the sixth aspect, by recovering the liquid carbon dioxide in the cleaning tank 13 through the first recovery path 22, the amount of carbon dioxide released into the atmosphere can be reduced. The filter 24 in the middle of the first recovery path 22 can capture the contaminants and prevent the liquid tank 11 from being contaminated by the contaminants.
The invention according to a seventh aspect is the invention according to any one of the first to sixth aspects, wherein the liquid carbon dioxide is recovered between the liquid carbon dioxide discharge side of the discharge pump 21 and the liquid tank 11. The cleaning apparatus is provided with a recovery path 23 and a means 26 for evaporating liquid carbon dioxide in the middle of the second recovery path 23.
In the cleaning apparatus according to the seventh aspect, by recovering the liquid carbon dioxide in the cleaning tank 13 through the second recovery path 23, the amount of carbon dioxide released into the atmosphere can be reduced. And since the liquid carbon dioxide evaporation means 26 in the middle of the 2nd recovery path 23 evaporates and collect | recovers a liquid carbon dioxide contaminant, it can collect | recover the liquid carbon dioxide in the state which does not contain a contaminant.

The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein a third recovery path 27 for recovering carbon dioxide gas is provided between the upper portion of the cleaning tank 13 and the liquid tank 11. The cleaning device is provided with a carbon dioxide gas compressor 27 a in the middle of the third recovery path 27.
In the cleaning apparatus according to the eighth aspect, since the carbon dioxide gas remaining in the cleaning tank 13 can be recovered, the amount of carbon dioxide released into the atmosphere can be further reduced.
The invention according to claim 9 is the invention according to claim 8, wherein the liquid tank 11 is provided with a cooler 32, and the carbon dioxide gas recovered in the liquid tank 11 is compressed and cooled by the carbon dioxide gas compressor 27a. The cleaning device is configured to be cooled by the vessel 32 to liquid carbon dioxide.
In the cleaning apparatus according to the ninth aspect, since the carbon dioxide gas is converted into liquid carbon dioxide and recovered, the amount recovered can be increased.

The invention according to claim 10 is the invention according to any one of claims 1 to 9, wherein a fourth recovery path 46 for recovering carbon dioxide gas is provided between the upper portion of the cleaning tank 13 and the gas tank 36. It is a cleaning device.
When the gas in the cleaning tank 13 is compressed by the compressor 27a and recovered in the liquid tank 11, the internal pressure of the cleaning tank 13 decreases with the transfer of carbon dioxide, so the compressor 27a needs to operate at a high compression rate. The decompression may take time. However, in the cleaning apparatus according to the tenth aspect, the gas in the cleaning tank 13 is extracted into the gas tank 36 whose internal pressure has been lowered to the atmospheric pressure in advance, so that the pressure reduction time can be reduced. Carbon dioxide recovery time can be greatly reduced.

According to the eleventh aspect of the present invention, the object to be cleaned 12 having contaminants attached to the surface is accommodated in the cleaning tank 13, and dry ice or dry snow is sprayed on the object to be cleaned 12 to adhere to the surface of the object to be cleaned 12 A step of removing the contaminated material, a step of filling the cleaning tank 13 with the liquid carbon dioxide by supplying the liquid carbon dioxide from the liquid tank 11 storing the liquid carbon dioxide to the cleaning tank 13, and the cleaning tank 13 A step of washing or circulating liquid carbon dioxide to wash the object 12 to be washed, a step of discharging liquid carbon dioxide from the washing tank 13 to separate and remove contaminants from the liquid carbon dioxide, and a liquid from which contaminants have been separated and removed And a step of recovering carbon dioxide in the liquid tank 11.
In the cleaning method described in claim 11, after removing dirt including fixed substances by spraying dry ice or dry snow onto the object to be cleaned, normal cleaning is performed using liquid carbon dioxide as a cleaning medium, and then liquid Since carbon dioxide is recovered, carbon dioxide released to the atmosphere can be reduced, and normal dirt can be removed together with dirt containing fixed substances.

The invention according to claim 12 is the invention according to claim 11, wherein after recovering the liquid carbon dioxide in the cleaning tank 13 to the liquid tank 11, the carbon dioxide gas in the cleaning tank 13 is compressed and cooled to liquid carbon dioxide. The cleaning method further includes the step of converting to the liquid tank 11 and recovering it.
The invention according to claim 13 is the invention according to claim 11, wherein the liquid carbon dioxide pumped from the liquid tank 11 is sprayed with dry ice or dry snow by the carbon dioxide gas pumped from the gas tank 36, and the cleaning nozzle 37. , 38, and the method further includes the step of recovering the carbon dioxide gas in the cleaning tank 13 to the gas tank 36 after recovering the liquid carbon dioxide in the cleaning tank 13 to the liquid tank 11.
In the cleaning method described in claim 12, carbon dioxide released to the atmosphere can be remarkably reduced. In the cleaning method described in claim 13, the gas recovery time in the cleaning tank 13 is significantly shortened. can do.

  In the cleaning apparatus of the present invention, a cleaning apparatus using liquid carbon dioxide as a cleaning medium is improved, and a gas tank for storing pressurized carbon dioxide gas and liquid carbon dioxide housed in a cleaning tank and pumped from the liquid tank are used. Since it has a cleaning nozzle provided so that it can be sprayed onto the object to be cleaned by using dry carbon dioxide gas with pressurized carbon dioxide gas, it includes solid objects by spraying dry ice or dry snow onto the object to be cleaned It is possible to remove dirt and perform normal cleaning using liquid carbon dioxide as a cleaning medium. As a result, the cleaning apparatus of the present invention can remove normal dirt as well as dirt containing fixed substances, and only pipes the cleaning nozzle using a gas tank in a conventional cleaning apparatus using liquid carbon dioxide. Therefore, there is no significant increase in size.

  In addition, the cleaning method of the present invention includes a step of storing an object to be cleaned with a contaminant attached to the surface in a cleaning tank, and a contaminant adhered to the surface of the object to be cleaned by spraying dry ice or dry snow onto the object to be cleaned. A step of filling the cleaning tank with liquid carbon dioxide by supplying liquid carbon dioxide from the liquid tank storing liquid carbon dioxide to the cleaning tank, and stirring or circulating the liquid carbon dioxide filled in the cleaning tank Cleaning the object to be cleaned, discharging the liquid carbon dioxide from the cleaning tank to separate and remove the contaminants from the liquid carbon dioxide, and recovering the liquid carbon dioxide from which the contaminants have been separated and removed to the liquid tank Including. In other words, dry ice or dry snow is sprayed onto the object to be cleaned to remove dirt including fixed matter, and then normal cleaning is performed using liquid carbon dioxide as a cleaning medium, and then liquid carbon dioxide is recovered, which is released to the atmosphere. As well as reducing the carbon dioxide produced, it is possible to remove normal dirt as well as dirt containing fixed matter. Then, after collecting the liquid carbon dioxide in the washing tank into the liquid tank, the carbon dioxide gas in the washing tank is compressed and cooled, converted into liquid carbon dioxide and collected in the liquid tank, and then released into the atmosphere. Carbon dioxide can be further reduced, and if the carbon dioxide gas inside the cleaning tank is recovered in the gas tank, the recovery time of the gas can be greatly shortened.

Next, the best mode for carrying out the present invention will be described with reference to the drawings.
As shown in FIG. 1, a cleaning apparatus 10 according to the present invention includes a liquid tank 11 for storing liquid carbon dioxide and a cleaning tank configured to be capable of containing and sealing an object to be cleaned 12 having contaminants attached to its surface. 13 and a liquid supply pump 14 that pumps liquid carbon dioxide from the liquid tank 11 to the cleaning tank 13. The liquid tank 11 in this embodiment is a metal pressure-resistant tank, and the cleaning tank 13 can open the cleaning tank body 13a in which one of the horizontally long metal cylinders is closed and the other of the cleaning tank body 13a. And a lid 13b for closing. The cleaning tank 13 is provided with a cleaning basket 16 capable of accommodating the article to be cleaned 12 inside the cleaning tank body 13a with the lid 13b open. The liquid tank 11 and the cleaning tank 13 are connected by a supply pipe 17, and the liquid supply pump 14 is provided in the middle of the supply pipe 17. The supply pipe 17 downstream of the liquid supply pump 14 is provided with first and second opening / closing valves 17 a and 17 b that open and close the supply pipe 17.

  One end of a discharge pipe 18 is connected to the lower part of the cleaning tank 13, and the other end of the discharge pipe 18 is a separator 19 that separates contaminants from liquid carbon dioxide discharged from the cleaning tank 13 through the discharge pipe 18. Is provided. The separator 19 is connected to a discharge pump 21 that returns the liquid carbon dioxide from which contaminants have been separated by the separator 19 to the liquid tank 11 via the first and second recovery passages 22 and 23. That is, the first and second recovery paths 22 and 23 are provided in parallel between the liquid carbon dioxide discharge side of the discharge pump 21 and the liquid tank 11, and the filter 24 is provided in the middle of the first recovery path 22. In the middle of the second recovery path 23, means 26 for evaporating liquid carbon dioxide is provided. The liquid carbon dioxide evaporation means 26 in this embodiment includes an evaporator 26a that temporarily stores liquid carbon dioxide and a heat source supply device 26b that heats and evaporates the liquid carbon dioxide stored in the evaporator 26a. Is done. The first and second recovery passages 22 and 23 are connected to the third and fourth opening / closing valves 22a and 23a for opening and closing the first and second recovery passages 22 and 23, and from the liquid tank 11 to the discharge pump 21. Thus, backflow prevention valves 22b and 23b for preventing the backflow of liquid carbon dioxide are provided.

An open pipe 25 that opens the cleaning tank 13 to the atmosphere is provided above the cleaning tank 13. The open pipe 25 is provided with a vacuum pump 25 a and a valve 25 b for sucking the gas inside the cleaning tank 13 through the open pipe 25. The valve 25b is configured to close the tip of the open pipe 25 or open it to the atmosphere, or to connect the tip to a gas tank 36 described later via a fourth recovery path 46. And the inside of the washing tank 13 is comprised so that pressure reduction is possible by driving the vacuum pump 25a in the state which open | released the front-end | tip of the open pipe 25 to air | atmosphere with the valve | bulb 25b.
A third recovery path 27 for recovering carbon dioxide gas is provided between the upper portion of the cleaning tank 13 and the liquid tank 11, and a carbon dioxide gas compressor 27 a and the first recovery path 27 are provided in the middle of the third recovery path 27. 3 A fifth open / close valve 27b for opening and closing the recovery path 27 and a backflow prevention valve 27c for preventing the backflow of carbon dioxide from the liquid tank 11 toward the cleaning tank 13 are provided. The liquid tank 11 is provided with a cooler 32. The cooler 32 cools the carbon dioxide gas compressed by the carbon dioxide gas compressor 27a and collected in the liquid tank 11 into liquid carbon dioxide.

  A circulation path 28 is provided between the discharge side of the liquid carbon dioxide of the discharge pump 21 and the cleaning tank 13, and a sixth open / close valve 28 a is provided in the circulation path 28. The circulation path 28 is configured to circulate the liquid carbon dioxide discharged from the discharge pump 21 to the cleaning tank 13 by opening the sixth opening / closing valve 28a. A detergent tank 29 for storing detergent is provided in the vicinity of the circulation path 28. The detergent tank 29 and the circulation path 28 are connected by a detergent supply pipe 31, and the detergent supply pipe 31 supplies the detergent stored in the detergent tank 29 to the circulation path 28 and sends it to the washing tank 13. And a seventh opening / closing valve 31b for opening and closing the detergent supply pipe 31.

  The washing tank 13 is provided with a stirrer 33 for stirring the liquid carbon dioxide stored in the washing tank 13. The stirrer 33 in this embodiment includes a motor 33a provided outside the cleaning tank 13, and one end connected to the motor 33a and penetrating the outer wall of the cleaning tank body 13a, and the other end positioned inside the cleaning tank 13. The rotating shaft 33b, the rotating blade 33c connected to the other end of the rotating shaft 33b, the surrounding of the rotating blade 33c, and the rotation of the blade 33c causes liquid carbon dioxide to flow from below to above or from above to below. And a cylindrical body 33d for guiding. The cleaning tank 13 is configured to remove contaminants from the object to be cleaned 12 by stirring the liquid carbon dioxide filling the cleaning tank 13 by the stirrer 33 or circulating the liquid carbon dioxide using the circulation path 28.

  A gas tank 36 for storing pressurized carbon dioxide gas is connected to the liquid tank 11 via a pressure reducing valve 34. On the other hand, the cleaning basket 16 is provided with a first cleaning nozzle 37, and the cleaning tank 13 is provided with a second cleaning nozzle 38 above it. The first cleaning nozzle 37 and the gas tank 36 are connected by a first gas pipe 39 provided with an eighth opening / closing valve 39a, and the second cleaning nozzle 38 and the gas tank 36 are connected to a second gas provided with a ninth opening / closing valve 41a. Connected by a pipe 41. The other end of the supply pipe 17 is connected to the first cleaning nozzle 37 via the first square valve 17a, and the other end of the supply pipe 17 is connected to the second cleaning nozzle 38 via the second square valve 17b. Is done. Joints 42 and 42 are provided on the other end of the supply pipe 17 located inside the cleaning tank 13 and on the downstream side of the first flat valve 17a and the first gas pipe 39 located inside the cleaning tank 13, respectively. The other end of 17 and the first gas pipe 39 are configured to be separable at this portion. The first and second cleaning nozzles 37 and 38 are configured to be able to inject the liquid carbon dioxide pumped from the liquid tank 11 into the object to be cleaned 12 as dry ice or dry snow using the pressurized carbon dioxide gas. The

  Accordingly, the cleaning device of the present invention is simply piped to the cleaning nozzles 37 and 38 using the gas tank 36 for storing carbon dioxide gas in the conventional cleaning device using liquid carbon dioxide, so that the size of the cleaning device is significantly increased. Absent. Further, a downstream end of the open pipe 25 is connected to the downstream side of the pressure reducing valve 34 via the valve 25b and the fourth recovery path 46, and a backflow prevention valve for preventing the backflow of carbon dioxide from the liquid tank 11 toward the gas tank 36. 46a is provided. Then, the tip of the open pipe 25 is connected to the gas tank 36 via the fourth recovery path 46 by this valve 25b, and the carbon dioxide gas remaining in the cleaning tank 13 is driven into the gas tank 36 by driving the vacuum pump 25a in this state. Configured to be retrievable.

Next, the cleaning method of the present invention using the cleaning apparatus configured as described above will be described.
(1) Object to be cleaned accommodating step As shown in FIG. 2, first, the object to be cleaned 12 to be cleaned is stored in the cleaning tank 13. In this embodiment, since the cleaning basket 16 is provided in the cleaning tank 13, the article to be cleaned 12 is previously stored in the cleaning basket 16, the lid 13b in the cleaning tank 13 is opened, and the basket 16 is indicated by a solid arrow in the figure. It moves as shown and accommodates in the washing tank main body 13a, and then closes the lid 13b to accommodate the article 12 to be washed in the washing tank 13. Here, since the first cleaning nozzle 37 is provided in the cleaning basket 16, after the cleaning basket 16 is accommodated in the cleaning tank main body 13a, the other end of the supply pipe 17 separated by connecting the joints 42 and 42 and The first gas pipe 39 is communicated. In this way, the first cleaning nozzle 37 is connected to the liquid tank 11 and the gas tank 36, and then the lid 13b is closed to seal the cleaning tank 13. In addition, the to-be-washed | cleaned material 12 has adhered the contaminant on the surface, and fixed materials, such as a coating material, rust, a food residue, and blood, are mentioned as a contaminant.

(2) Blasting process After closing the lid 13b and sealing the cleaning tank 13, the tip of the open tube 25 is opened to the atmosphere by the valve 25b to open the inside of the cleaning tank 13 to the atmosphere and the vacuum pump 25a is driven. The air inside the cleaning tank 13 is discharged to the outside, and the inside of the cleaning tank 13 is decompressed. After the inside of the cleaning tank 13 is depressurized to about 3 × 10 ⁻⁵ Pa, the valve 25b is closed and the vacuum pump 25a is stopped. Thereafter, as shown in FIG. 1, the first and second open / close valves 17a and 17b and the eighth and ninth open / close valves 39a and 41a are opened, and the first and second cleaning nozzles 37 and 38 are passed through. The liquid carbon dioxide in the liquid tank 11 is sprayed onto the object 12 to be cleaned together with the carbon dioxide gas, and dry ice or dry snow generated by reducing the pressure of the liquefied carbon dioxide is directly sprayed on the object 12 to be cleaned. Remove contaminants attached to the surface.

(3) Liquefied carbon dioxide supply cleaning step After removing contaminants from the surface of the object 12 to be cleaned, the eighth and ninth open / close valves 39a, 41a are opened with the first and second open / close valves 17a, 17b opened. Close. As a result, the supply of carbon dioxide gas is stopped, and liquid carbon dioxide in the liquid tank 11 is supplied from the liquid tank 11 to the cleaning tank 13 via the first and second cleaning nozzles 37 and 38, and cleaning is performed as shown in FIG. Tank 13 is filled with the liquid carbon dioxide. Thereafter, the liquid carbon dioxide filling the cleaning tank 13 is stirred by the stirrer 33 or circulated using the circulation path 28 to remove the contaminants from the object 12 to be cleaned, thereby cleaning the object 12 to be cleaned. At this time, the seventh opening / closing valve 31b is opened and the detergent supply pump 31a is driven to supply the detergent stored in the detergent tank 29 to the circulation path 28 and send it to the washing tank 13 so that the washing object 12 The attached normal dirt can be effectively removed by this detergent.

(4) Contaminant Separation and Recovery Step After washing, as shown by the solid line arrow in FIG. 4, liquid carbon dioxide is discharged from the washing tank 13 together with the contaminants separated from the object to be washed 12, and is separated from the liquid carbon dioxide by the separator 19. Separate and remove contaminants. Then, the discharge pump 21 is driven and the fourth open / close valve 23 a is opened, and the liquid carbon dioxide from which contaminants are separated and removed is returned to the liquid tank 11 via the second recovery path 23. At this time, in the liquid carbon dioxide evaporating means 26 provided in the middle of the second recovery path 23, the liquid carbon dioxide is temporarily stored in the evaporator 26a and is heated and evaporated by the heat source supply device 26b to be a liquid tank. Return to 11. As a result, the contaminants not recovered by the separator 19 remain as a residue in the evaporator 26 a, and effectively prevent the contaminants from being transported to the liquid tank 11.

(5) Rinsing step After recovering the liquid carbon dioxide in the cleaning tank 13 through the second recovery path 23, the first and second open / close valves 17a and 17b are opened again for cleaning as shown in FIG. The tank 13 is filled with liquid carbon dioxide, the liquid carbon dioxide is stirred by the stirrer 33 or circulated using the circulation path 28, and the washed object 12 is rinsed lightly. Thereafter, the discharge pump 21 is driven and the third opening / closing valve 22 a is opened, and the liquid carbon dioxide inside the cleaning tank 13 is returned to the liquid tank 11 via the first recovery path 22. At this time, the filter 24 provided in the middle of the first recovery path 22 removes slight contaminants that have not been recovered by the separator 19.

(6) Step of removing object to be cleaned After recovering the liquid carbon dioxide in the cleaning tank 13, as shown in FIG. 6, the fifth open / close valve 27b is opened and the carbon dioxide gas compressor 27a is driven to The carbon dioxide gas inside the cleaning tank 13 is recovered in the liquid tank 11 via a third recovery path 27 provided between the upper part and the liquid tank 11. At this time, the carbon dioxide gas is compressed by the carbon dioxide gas compressor 27 a and cooled by the cooler 32, so that it is converted into liquid carbon dioxide and collected in the liquid tank 11.
After the carbon dioxide gas in the cleaning tank 13 is collected, the fifth open / close valve 27b is closed, and the valve 25b in the open pipe 25 is opened to open the inside of the cleaning tank 13 to the atmosphere as shown in FIG. Then, the lid 13b is opened, and the cleaning basket 16 is taken out from the inside of the cleaning tank body 13a together with the object to be cleaned 12 as indicated by the broken line arrow, and the series of cleaning operations is completed.
Therefore, in the cleaning method of the present invention, both the liquid carbon dioxide and carbon dioxide gas inside the cleaning tank 13 are recovered, so that dirt including fixed substances is effectively removed while the release of carbon dioxide to the atmosphere is minimized. be able to.

  In the above-described embodiment, after the liquid carbon dioxide in the cleaning tank 13 is recovered in the liquid tank 11, the carbon dioxide gas in the cleaning tank 13 is compressed and cooled to be converted into liquid carbon dioxide and recovered in the liquid tank 11. However, as shown in FIG. 7, the carbon dioxide gas in the cleaning tank 13 may be recovered in the gas tank 36 after the liquid carbon dioxide in the cleaning tank 13 is recovered in the liquid tank 11. In this embodiment, the tip of the open pipe 25 is connected to the gas tank 36 via the fourth recovery passage 46 by the valve 25b, and the carbon dioxide gas remaining in the cleaning tank 13 is driven by driving the vacuum pump 25a in this state. Can be recovered in the gas tank 36. That is, in the embodiment described above, the gas in the cleaning tank 13 is compressed by the compressor 27a, sent to the cooled liquid tank 11, and recovered as liquid charcoal. At this time, the compressor 27a Since the movement between the cleaning tank 13 and the liquid tank 11 starts from the same pressure, and the internal pressure of the cleaning tank 13 decreases with the transfer, the compressor 27a is required to operate at a higher compression rate. However, since the performance of the compressor 27a does not change, the transfer amount decreases with the increase in the compression ratio, so that the decompression time is required. For this reason, when the compressor ratio is increased and the amount of exhaust gas is reduced, the decompression time can be reduced by extracting the gas in the cleaning tank 13 into the gas tank 36 whose internal pressure has been lowered to the atmospheric pressure in advance. The carbon dioxide gas extracted into the gas tank 36 can be reused by using it together with liquid coal during dry ice blasting, or by using it for pressurizing the inside of the washing tank 13 before dry ice blasting and subsequent liquid coal filling. is there.

It is a block diagram which shows the state in which the dry ice or dry snow is sprayed on the to-be-cleaned object by the washing | cleaning apparatus of this invention embodiment. It is a block diagram which shows the state which carries in or carries out a to-be-cleaned object to the washing | cleaning apparatus. It is a block diagram which shows the state by which the to-be-cleaned object is wash | cleaned using liquid carbon dioxide as a washing | cleaning medium. It is a lineblock diagram showing the state where liquid carbon dioxide is collected via the 2nd recovery way. It is a block diagram which shows the state by which the to-be-cleaned object is rinsed and the liquid carbon dioxide is collect | recovered via the 1st collection path. It is a block diagram which shows the state in which the carbon dioxide gas is collect | recovered via the 3rd collection path. It is a block diagram which shows the state in which the carbon dioxide gas is collect | recovered via the 4th collection path.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Liquid tank 12 Object to be cleaned 13 Cleaning tank 14 Liquid supply pump 16 Washing basket 19 Separator 21 Discharge pump 22 First recovery path 23 Second recovery path 24 Filter 26 Liquid carbon dioxide evaporation means 27 Third recovery path 27a Carbon dioxide compression Machine 28 Liquid carbon dioxide circulation path 29 Detergent tank 31a Detergent supply pump 32 Cooler 33 Stirrer 36 Gas tank 37 First cleaning nozzle 38 Second cleaning nozzle 46 Fourth recovery path

Claims (13)

A liquid tank (11) for storing liquid carbon dioxide and an object to be cleaned (12) having contaminants attached to the surface thereof can be stored and sealed, and the liquid carbon dioxide contaminates the object to be cleaned (12). A cleaning tank (13) for removing matter, a liquid supply pump (14) for pumping liquid carbon dioxide from the liquid tank (11) to the cleaning tank (13), and a liquid discharged from the cleaning tank (13) A separator (19) for separating the contaminants from carbon dioxide and a discharge pump (21) for returning the liquid carbon dioxide from which the contaminants have been separated by the separator (19) to the liquid tank (11) In the device
A gas tank (36) for storing pressurized carbon dioxide gas;
Liquid carbon dioxide contained in the cleaning tank (13) and pumped from the liquid tank (11) is provided so as to be sprayed onto the object to be cleaned by making it dry ice or dry snow with the pressurized carbon dioxide gas. A cleaning apparatus comprising: a cleaning nozzle (37, 38).   The cleaning basket (16) capable of accommodating an object to be cleaned (12) is provided in a cleaning tank (13) so as to be removable, and the cleaning nozzle (37) is provided in the cleaning basket (16). Cleaning device.   The cleaning device according to claim 1 or 2, wherein a stirrer (33) for stirring liquid carbon dioxide stored in the cleaning tank (13) is provided in the cleaning tank (13).   The cleaning apparatus according to any one of claims 1 to 3, wherein a liquid carbon dioxide circulation path (28) is provided between the liquid carbon dioxide discharge side of the discharge pump (21) and the cleaning tank (13).   The cleaning according to claim 4, further comprising: a detergent tank (29) for storing detergent; and a detergent supply pump (31a) for supplying the detergent stored in the detergent tank (29) to the liquid carbon dioxide circulation path (28). apparatus.   A first recovery path (22) for recovering liquid carbon dioxide is provided between the discharge side of the liquid carbon dioxide of the discharge pump (21) and the liquid tank (11), and is located in the middle of the first recovery path (22). The cleaning device according to any one of claims 1 to 5, further comprising a filter (24).   A second recovery path (23) for recovering the liquid carbon dioxide is provided between the discharge side of the liquid carbon dioxide of the discharge pump (21) and the liquid tank (11), and in the middle of the second recovery path (23). The cleaning apparatus according to any one of claims 1 to 6, further comprising means (26) for evaporating liquid carbon dioxide.   A third recovery path (27) for recovering carbon dioxide gas is provided between the upper part of the washing tank (13) and the liquid tank (11), and a carbon dioxide gas compressor (27a) is provided in the middle of the third recovery path (27). The cleaning apparatus according to any one of claims 1 to 7, further comprising:   A cooler (32) is provided in the liquid tank (11), and the carbon dioxide gas recovered in the liquid tank (11) is compressed by the carbon dioxide gas compressor (27a) and cooled by the cooler (32). The cleaning device according to claim 8, wherein the cleaning device is configured to be liquid carbon dioxide.   The cleaning apparatus according to any one of claims 1 to 9, wherein a fourth recovery path (46) for recovering carbon dioxide gas is provided between the upper part of the cleaning tank (13) and the gas tank (36). Storing the object to be cleaned (12) with contaminants on the surface in the cleaning tank (13);
Removing the contaminants adhering to the surface of the object to be cleaned (12) by spraying dry ice or dry snow on the object to be cleaned (12);
Filling the cleaning tank (13) with liquid carbon dioxide by supplying liquid carbon dioxide from the liquid tank (11) storing liquid carbon dioxide to the cleaning tank (13);
Washing the object to be cleaned (12) by stirring or circulating liquid carbon dioxide filled in the cleaning tank (13);
Discharging liquid carbon dioxide from the cleaning tank (13) to separate and remove the contaminants from the liquid carbon dioxide;
Recovering the liquid carbon dioxide from which the contaminants have been separated and removed into the liquid tank (11).   After recovering the liquid carbon dioxide in the cleaning tank (13) in the liquid tank (11), the carbon dioxide gas in the cleaning tank (13) is compressed and cooled to convert into liquid carbon dioxide, and then into the liquid tank (11). The cleaning method according to claim 11, further comprising a collecting step. Injection of dry ice or dry snow is performed by injecting liquid carbon dioxide pumped from the liquid tank (11) from the cleaning nozzle (37, 38) with carbon dioxide gas pumped from the gas tank (36),
The cleaning method according to claim 11, further comprising the step of recovering the carbon dioxide gas in the cleaning tank (13) into the gas tank (36) after recovering the liquid carbon dioxide in the cleaning tank (13) into the liquid tank (11). .

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