JP3223560U - Dry ice cleaning equipment - Google Patents

Abstract

Provided is a dry ice cleaning apparatus capable of dealing with a fragile object to be cleaned by adopting a structure capable of maintaining a cleaning ability while lowering an injection gas pressure. A liquefied carbon dioxide gas cylinder 2 for supplying liquefied carbon dioxide gas to a horizontal hole portion 11 for carbon dioxide and an injection gas cylinder 3 for supplying injection gas to a horizontal hole portion 12 for injection gas are connected, and a housing body 10 is connected. In a dry ice cleaning apparatus comprising a mixing unit 20 that mixes each gas to produce a mixed gas, and a nozzle 30 that is connected to the mixing unit and injects the mixed gas, the nozzle has a Laval nozzle shape The mixing unit includes an adjustment chamber 21 that communicates with the carbon dioxide horizontal hole portion, a communication portion 22 that connects the lower surface of the adjustment chamber and the upper surface of the injection gas horizontal hole portion, and an adjustment valve that adjusts the opening of the communication portion. 23 and is supplied in a liquefied state so that the carbon dioxide horizontal hole is filled with liquefied carbon dioxide. [Selection] Figure 1

Description

  The present invention relates to a dry ice cleaning apparatus that removes contamination by colliding dry ice using liquefied carbon dioxide as a raw material with a cleaning object. In particular, the present invention can be used for a thin and fragile object to be cleaned. The present invention relates to a structure for effectively consuming liquefied carbon dioxide gas in a gas cylinder when a gas bomb filled with liquefied carbon dioxide gas is used for an ice cleaning device.

In recent years, in consideration of social and environmental issues, the use of cleaning agents used in industrial products, such as hydrocarbon cleaners and industrial cleaners such as strongly acidic and strongly alkaline, is prohibited or requires strict management. It has come to be.
Under such circumstances, a cleaning apparatus that removes contamination by causing dry ice made of liquefied carbon dioxide gas, which has a low environmental load, to collide with a cleaning object has been attracting attention.

  Conventionally, in this type of equipment, solidified dry ice in the form of pellets is discharged with dry air or nitrogen gas into a high-pressure flow path of 0.5 MPa or more and made to collide with the cleaning object. There is a method of scraping off contaminants, and a method of scraping contaminants by forming fine dry ice by discharging liquefied carbon dioxide gas from the tip of the nozzle in that state and causing it to collide with a cleaning object with a carrier gas. As in the former, the latter method often uses a high-pressure carrier gas of 0.5 MPa or more, or uses a large amount of carbon dioxide gas (for example, an amount of 9 kg / h or more).

  Since the dry ice cleaning apparatus described above uses a high-pressure carrier gas of 0.5 MPa or more, when the object to be cleaned is thin and easily broken, such as a wafer used in a semiconductor, the object to be cleaned is used. There was a problem of high possibility of breakage.

  In addition, if the amount of carbon dioxide used is large, it is necessary to replace the gas cylinder that supplies liquefied carbon dioxide with a large remaining amount remaining in order to maintain a good dry ice discharge state from the nozzle tip. There was a problem of incurring high costs.

  In Patent Document 1, a liquefied carbon dioxide supply system, an injection gas (carrier gas) supply system, and a carbon dioxide gas containing dry ice snow generated through a throttling portion and an injection gas are mixed and mixed. There is disclosed a dry ice snow cleaning apparatus that includes a mixing unit that generates gas and a nozzle that injects a mixed gas, and that can exhibit stable cleaning performance by devising the structure of the nozzle.

Japanese Patent No. 6338515

  However, according to the dry ice snow cleaning device disclosed in Patent Document 1, the flow rate of the liquefied carbon dioxide gas is described as 7 kg / h and the injection gas pressure is 0.5 MPa. There wasn't.

  The present invention has been proposed in view of the above circumstances, and provides a dry ice cleaning apparatus capable of dealing with a fragile cleaning object by adopting a structure capable of maintaining the cleaning ability while reducing the injection gas pressure. The purpose is that.

In order to achieve the above object, the present invention provides a liquefied carbon dioxide supply means (liquefied carbon dioxide cylinder 2) for supplying liquefied carbon dioxide to a carbon dioxide horizontal hole (11) provided in the main body (housing main body 10), The injection gas supply means (injection gas cylinder 3) for supplying the injection gas to the injection gas horizontal hole (12) provided in the housing main body 10) is connected, and the main body (housing main body 10) has the above-mentioned In a dry ice cleaning apparatus including a mixing unit (20) that mixes each gas to generate a mixed gas, and a nozzle (30) that is connected to the mixing unit (20) and injects the mixed gas, the following configuration It is characterized by including.
The nozzle (30) has a Laval nozzle shape.
The mixing unit (20) connects the adjustment chamber (21) communicating with the carbon dioxide horizontal hole (11), the lower surface of the adjustment chamber (21), and the upper surface of the horizontal hole for injection gas (12). It is provided with a communication part (22) and an adjusting valve (23) for adjusting the opening of the communication part (22), and liquefied so that the carbon dioxide horizontal hole part (11) is filled with liquefied carbon dioxide gas. Supplied in state.

Claim 2 is the dry ice cleaning apparatus of claim 1,
The supply in the liquefied state to the horizontal hole for carbon dioxide (11) is made by connecting a plurality of pipes (4) having a diameter gradually reduced from the liquefied carbon dioxide supply means (liquefied carbon dioxide cylinder 2). It is characterized by realizing.

Claim 3 is the dry ice cleaning apparatus of claim 1,
The Laval nozzle shape of the nozzle (30) is:
A throttle portion (31) communicating with the mixing portion (20) and having a tapered inner diameter that gradually decreases,
An injection part (32) formed with the same diameter communicating with the throttle part (31);
An enlarged portion (33) communicating with the injection portion (32) and having a tapered inner diameter that gradually increases;
It is characterized by having.

Claim 4 is the dry ice cleaning apparatus of claim 3,
A taper shape of the enlarged portion (33) is steeper than the narrowed portion (31).

Claim 5 is the dry ice cleaning apparatus of claim 1,
The inner surface of the nozzle (30) is subjected to electrolytic polishing.

Claim 6 is the dry ice cleaning apparatus of claim 1,
A heating means (heater 6) is provided in the middle of the pipe (5) leading from the injection gas supply means (injection gas cylinder 3) to the injection gas horizontal hole (12).

Claim 7 is the dry ice cleaning apparatus of claim 1,
The supply flow rate of the liquefied carbon dioxide gas is 7 kg / h or less.

Claim 8 is the dry ice cleaning apparatus of claim 1,
The injection pressure from the nozzle (30) is 0.18 to 0.22 MPa.

According to the dry ice cleaning apparatus of claim 1, by making the nozzle (30) into a Laval nozzle shape, the flow velocity of the injection gas can be made higher than the sonic velocity, and the injection pressure is low (for example, 0.2 MPa). Can be released into the atmosphere, and a dry ice cleaning device suitable for a fragile object to be cleaned can be obtained.
In addition, since the liquefied liquefied carbon dioxide gas is released from the adjustment chamber (21) to the injection gas horizontal hole (12) in a substantially liquefied state, the dry ice can be removed from the liquefied state even at a low pressure of about 0.2 MPa. The particles immediately after the change can be ejected from the nozzle (30) in a small state.

  According to the dry ice cleaning apparatus of the second aspect, a plurality of pipes, which are gradually reduced in diameter, are connected from the liquefied carbon dioxide supply means (liquefied carbon dioxide cylinder 2) to allow the liquefied carbon dioxide to flow into the carbon dioxide horizontal holes (11). The liquefied carbon dioxide gas in the adjustment chamber (21) can be maintained in a liquefied state.

  According to the dry ice cleaning apparatus of the third aspect, the nozzle (30) can be formed into a Laval nozzle shape by forming the throttle portion (31), the injection portion (32), and the enlarged portion (33).

  According to the dry ice cleaning apparatus of the fourth aspect, the flow velocity of the jetting gas discharged from the nozzle (30) to the atmosphere is higher than the sonic velocity by making the taper shape of the enlarged portion (33) sharper than the throttle portion (31). Can be.

  According to the dry ice cleaning apparatus of claim 5, the inner surface of the nozzle (30) is subjected to an electropolishing treatment so that the surface is leveled and moisture in the liquefied carbon dioxide gas or moisture present in the atmosphere is prevented from adhering. Thus, the tip of the nozzle (30) can be prevented from being blocked.

  According to the dry ice cleaning apparatus of the sixth aspect, the surface of the cleaning object is condensed by providing the heating means (6) in the pipe (5) to which the injection gas is supplied to heat the injection gas. Can be prevented and the cleaning effect can be improved.

  According to the dry ice cleaning apparatus of the seventh aspect, by setting the supply flow rate of the liquefied carbon dioxide gas to 7 kg / h or less, it is possible to exert a good cleaning effect on a fragile cleaning object.

  According to the dry ice cleaning apparatus of the eighth aspect, by setting the injection pressure from the nozzle (30) to 0.18 to 0.22 MPa, even a fragile object can be a cleaning object.

It is a schematic diagram which shows the structure of the dry ice cleaning apparatus which concerns on embodiment of this invention. It is expansion sectional explanatory drawing of the adjustment chamber part of a dry ice cleaning apparatus.

An example of an embodiment of the dry ice cleaning apparatus of the present invention will be described with reference to FIG.
The dry ice cleaning apparatus 1 includes a liquefied carbon dioxide cylinder (liquefied carbon dioxide supply means) 2 that supplies liquefied carbon dioxide gas to a carbon dioxide horizontal hole portion 11 provided in the housing body 10, and a jet gas horizontal position provided in the housing body 10. An injection gas cylinder (injection gas supply means) 3 for supplying the injection gas to the hole 12 is provided. The carbon dioxide gas horizontal hole portion 11 and the injection gas horizontal hole portion 12 are each formed in a cylindrical shape in the horizontal direction in the housing body 10.
As the injection gas (carrier gas), for example, a gas inert to carbon dioxide such as dry air, nitrogen gas, argon gas or carbon dioxide can be used.
The housing body 10 includes a mixing unit 20 that mixes each gas to generate a mixed gas, and a nozzle 30 that is connected to the mixing unit 20 and injects the mixed gas.

The mixing unit 20 adjusts the adjustment chamber 21 communicating with the carbon dioxide horizontal hole portion 11, the communication portion 22 connecting the lower surface of the adjustment chamber 21 and the upper surface of the injection gas horizontal hole portion 12, and the opening of the communication portion 22. And a regulating valve 23. The adjusting valve 23 is configured to be a valve that can be opened and closed by adjusting the opening degree by configuring the lower end in a conical shape and moving it forward and backward with respect to the upper opening of the communicating portion 22 by manual (or automatic) operation.
Further, the carbon dioxide gas horizontal hole 11 is supplied from the liquefied carbon dioxide cylinder 2 while maintaining the liquefied state so as to be filled with the liquefied carbon dioxide gas.

  That is, as shown in FIG. 2, the adjustment chamber 21 is filled with liquefied carbon dioxide gas that has been kept liquefied up to a position slightly higher than the uppermost position 11a where the opening of the horizontal hole portion 11 for carbon dioxide gas faces. It has become. In order to fill the carbon dioxide gas horizontal hole portion 11 with the liquefied carbon dioxide gas maintained to be liquefied, the liquefied carbon dioxide gas is led from the liquefied carbon dioxide gas cylinder 2 to the carbon dioxide gas horizontal hole portion 11 through the pipe 4. By connecting a plurality of pipes that are gradually reduced in diameter from the liquefied carbon dioxide cylinder 2, it is possible to maintain liquefaction of the liquefied carbon dioxide gas that is supplied while preventing a pressure drop at the pipe tip.

  The gas supplied from the liquefied carbon dioxide cylinder 2 has the property that the pressure drops and vaporizes (mist-like gas-liquid mixed state) as it goes to the end of the pipe, but the pipe is made narrower (the volume is reduced). ), The pressure in the pipe is maintained at a high level, and the carbon dioxide gas in a liquid state can be flowed to the vicinity of the communication portion 22 serving as the injection port without being affected by the ambient temperature.

  In the mixing unit 20, the opening degree is adjusted by the adjusting valve 23, so that the liquefied carbon dioxide gas is released from the adjusting chamber 21 through the communication unit 22 in a substantially liquefied state to the mixing unit (chamber) 20. Dry ice is formed.

The nozzle 30 includes a narrowed portion 31 that gradually decreases in inner diameter in a tapered shape, an injection portion 32 that communicates with the narrowed portion 31, and an enlarged portion 33 that communicates with the ejection portion 32 and gradually increases in inner diameter in a tapered shape. Thus, a Laval nozzle shape is formed. The inner surface on the tip side of the mixing unit 20 is continuous with the inner surface of the throttle unit 31 of the nozzle 30.
In other words, the nozzle 30 communicates with the mixing unit 20, a throttle part 31 having a tapered inner diameter that gradually decreases, an injection part 32 formed with the same diameter communicating with the throttle part 31, and the injection part 32. Thus, a Laval nozzle shape having an enlarged portion 33 whose inner diameter gradually increases in a tapered shape is formed. The Laval nozzle shape is formed such that the taper shape of the enlarged portion 33 is steeper than the throttle portion 31. More specifically, the apex angle of the enlarged portion 33 is smaller than the apex angle of the section of the throttle portion 31, and the enlarged portion 33 is steeper than the throttle portion 31 relative to the injection portion 32. It has become.
Therefore, after the flow passage area perpendicular to the flow of the fluid decreases in the portion ahead of the mixing portion 20 in the horizontal hole portion 12 for the jet gas (throttle portion 31) and after passing through the jet portion 32. The channel area is gradually increased, so that the kinetic energy can be given to the dry ice by making the carrier gas sound velocity. Further, when the speed at the throat, which is the minimum area of the enlarged portion 33, becomes the sound speed, the flow rate does not flow any further.

  The inner surfaces of the throttle part 31, the injection part 32, and the enlargement part 33 of the nozzle 30 are leveled by electrolytic polishing, and the moisture in the liquefied carbon dioxide gas and the moisture present in the atmosphere are discharged from the nozzle 30 during the injection. By preventing it from adhering to the nozzle 30, the throttle part 31, the injection part 32, and the enlargement part 33 of the nozzle 30 are prevented from being blocked.

  Also, by providing a heating means by a heater 6 such as a heater in the middle of the pipe 5 leading from the injection gas cylinder 3 to the injection gas horizontal hole portion 12, the supplied carrier gas can be heated, and the nozzle When the gas jetted from 30 collides with the cleaning object, the surface of the cleaning object is prevented from condensing and the cleaning effect is improved.

  In the dry ice cleaning apparatus described above, the flow rate of the liquefied carbon dioxide gas supplied to the carbon dioxide horizontal hole 11 is 3 to 7 kg / h, and the injection pressure injected from the nozzle 30 is 0.18 to 0.22 MPa. . Since low pressure injection gas of about 0.2 MPa can be injected from the nozzle 30 with a low flow rate and a flow rate that can exert a cleaning effect, it is used for cleaning fragile cleaning objects (for example, semiconductors). can do.

  According to the configuration of the dry ice cleaning device described above, the flow path is adjusted from the adjustment chamber 21 to the adjustment valve 23 by eliminating the components that cause a change in the state of liquefied carbon dioxide from the carbon dioxide horizontal hole 11 to the adjustment chamber 21. Is discharged into the mixing section (chamber) 20 in a substantially liquefied carbon dioxide state, and formed into fine dry ice in the chamber is a low-pressure jet gas (carrier gas) of 0.18 to 0.22 PMa. ) And is injected from the injection portion 33 at the tip of the nozzle 30.

  Since the tip side of the nozzle 30 is formed in a Laval nozzle shape and a jet at a sonic speed is obtained, even when a low pressure injection gas (carrier gas) of 0.2 PMa is used, the liquid carbon dioxide injected from the communicating portion 22 Sufficient kinetic energy can be given. As a result, when the fine dry ice collides with the cleaning object, it returns to the liquefied carbon dioxide gas again, and adheres to the contaminants of the cleaning object or enters between the cleaning object and the contaminants, so that the liquid carbon dioxide gas Contaminants can be peeled off simultaneously when vaporizing.

DESCRIPTION OF SYMBOLS 1 ... Dry ice washing apparatus 2 ... Liquefied carbon dioxide cylinder (liquefied carbon dioxide supply means)
3 ... Gas cylinder for injection (gas supply means for injection)
4 ... Piping 5 ... Piping 6 ... Heater (heating means)
10 ... Housing body (main body)
DESCRIPTION OF SYMBOLS 11 ... Horizontal hole part for carbon dioxide gas 12 ... Horizontal hole part for injection gas 20 ... Mixing part 21 ... Adjustment chamber 22 ... Communication part 23 ... Adjustment valve 30 ... Nozzle 31 ... Restriction part 32 ... Injection part 33 ... Expansion part

Claims (8)

A liquefied carbon dioxide supply means for supplying liquefied carbon dioxide gas to a horizontal hole portion for carbon dioxide gas provided in the main body and an injection gas supply means for supplying injection gas to a horizontal hole portion for injection gas provided in the main body are connected. In the dry ice cleaning apparatus comprising: a mixing unit that mixes each gas in the housing to generate a mixed gas; and a nozzle that is connected to the mixing unit and injects the mixed gas.
While making the nozzle into a Laval nozzle shape,
The mixing section includes an adjustment chamber communicating with the carbon dioxide horizontal hole portion, a communication portion connecting the lower surface of the adjustment chamber and the upper surface of the horizontal hole portion for injection gas, and an adjustment valve for adjusting the opening of the communication portion. With
A dry ice cleaning apparatus, wherein the carbon dioxide gas horizontal hole is supplied in a liquefied state so as to be filled with liquefied carbon dioxide gas.   The dry ice cleaning apparatus according to claim 1, wherein the supply in the liquefied state to the carbon dioxide horizontal hole portion is realized by connecting a plurality of pipes that are gradually reduced in diameter from the liquefied carbon dioxide supply means. The Laval nozzle shape of the nozzle is
A throttle portion communicating with the mixing portion and having a tapered inner diameter that gradually decreases;
An injection part formed with the same diameter communicating with the throttle part;
An enlarged portion that gradually communicates with the injection portion and has an inner diameter that gradually increases in a tapered shape;
The dry ice cleaning apparatus according to claim 1, comprising:   The dry ice cleaning apparatus according to claim 3, wherein the taper of the enlarged portion is steeper than the throttle portion.   The dry ice cleaning apparatus according to claim 1, wherein an inner surface of the nozzle is subjected to an electrolytic polishing process.   The dry ice cleaning apparatus according to claim 1, wherein a heating means is provided in the middle of a pipe leading from the injection gas supply means to the injection gas horizontal hole.   The dry ice cleaning apparatus according to claim 1, wherein a supply flow rate of the liquefied carbon dioxide gas is 7 kg / h or less.   The dry ice cleaning apparatus according to claim 1, wherein an injection pressure from the nozzle is 0.18 to 0.22 MPa.

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