JP2007083142A - Washing method and washing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a washing method and a washing apparatus capable of obtaining higher washing grade than that of a dipping process in a washing solution or a shower washing process, and eliminating the need of a complicated mechanism such a pump or a rotary system in a washing method for washing objects by supplying numerous bubbles. <P>SOLUTION: In the conventional washing method, washing objects are dipped in a washing solution, and micro-bubbles are made to act. In the bubble washing method of the present invention, the washing objects are washed near the boundary part of the foaming part formed by floating up bubbles and gas. Thus, breaking effect of the bubbles can be used to enhance washing grade. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for cleaning an object to be cleaned such as a part with bubbles.

Traditionally, in the field of industrial cleaning, fluorocarbon solvents, organic solvents, and other special cleaning agents such as petroleum have been used, but they induce environmental problems such as destruction of the ozone layer, groundwater, rivers, and ocean pollution. Therefore, the development of a cleaning method and a cleaning apparatus that do not use these special cleaning agents is underway.
As a technique for meeting this demand, a technique for generating fine bubbles in a cleaning liquid mainly composed of water has been developed.
For example, there is a method in which the object to be cleaned collides with bubbles due to the relative speed obtained by rotating the object to be cleaned immersed in the cleaning apparatus, and the cleaning efficiency is increased (for example, Patent Document 1).
In addition, fine bubbles and bubbles of a size that can agitate the cleaning liquid are alternately generated from the bottom of the immersion tank, oil is adhered to the surface of the fine bubbles, and large bubbles are supplied thereto to give buoyancy to There is a method of cleaning by floating on the water surface (for example, Patent Document 2).
Further, in the high-pressure vessel, the gas dissolved water generated in the high-pressure vessel is sprayed from the washing water injection nozzle of the washing water injection system onto the object to be cleaned, so that it is covered by the impact force at the time of the washing water collision with the object to be cleaned. The foreign matter adhering to the cleaning object is peeled off and removed, and the object is cleaned by the impact force when many bubbles generated by separation of the gas dissolved in the cleaning water collide with the object to be cleaned and burst. There is also a cleaning method in which foreign matter adhering to the body is removed by peeling (for example, Patent Document 3).

Japanese Patent Laid-Open No. 7-227582 (FIG. 6 and others) JP-A-6-177991 ([0008] et al.) JP-A-6-71233 ([0005], FIG. 1 and others)

  In the conventional cleaning method using air bubbles, a rotating mechanism is required, which complicates the device and increases the cost. Since only air bubbles are supplied from the lower part of the cleaning tank, it is not possible to clean a workpiece with a complicated shape. There was a problem that the oil desorbed from the oil reattached to other parts and the degree of cleaning could not be secured. In addition, in order to supply the cleaning liquid to the object to be cleaned at high speed, there is a problem that a lot of energy is required and the uniformity of cleaning is poor.

  The present invention has been made to solve the above-described problems, and includes a phenomenon in which bubbles rise due to their own buoyancy and a phenomenon in which the bubbles that have risen collapse due to contact with gas (bubble breakage). In other words, the object to be cleaned is installed in the vicinity where bubble breakage occurs most efficiently, and the removal target (foreign matter such as oil or particles) attached to the object to be cleaned is removed by the impact force generated by the bubble breaking phenomenon. An object of the present invention is to provide a cleaning method and a cleaning apparatus that have both the interfacial adsorption of an object to be removed to the bubble surface and the separation by bubble breaking.

  In the cleaning method according to the present invention, an object to be cleaned is disposed in a foaming portion in which bubbles of the cleaning liquid generated by the bubble generating means are formed by the bubbles of the cleaning liquid floating above the surface of the cleaning liquid, and the foaming Cleaning is performed by causing the bubble breakage at the part to act on the surface to be cleaned of the object to be cleaned.

  The cleaning apparatus according to the present invention includes a bubble generating means for generating bubbles in the cleaning liquid in the cleaning tank, and the foaming portion formed by the bubbles generated by the bubble generating means floating on the liquid surface of the cleaning liquid, And means for arranging an object to be cleaned in the vicinity of the cleaning liquid.

  According to the present invention, cleaning is performed using the bubble breaking action in the vicinity of the gas-liquid interface where bubbles are broken, so that it is possible to remove dirt on fine concave portions that have remained in the past, and the degree of cleaning is improved. It becomes possible to improve.

First, the principle of cleaning in the present invention will be described. As a method for making the cleaning method of the present invention effective, it is possible to use fine bubbles of several hundred μm to several μm called microbubbles. Since normal bubbles have a large bubble diameter, they cannot be cleaned efficiently due to factors such as a small surface area per unit volume and a low bubble density. On the other hand, when microbubbles are used, since the surface area per unit volume is large and the bubble density is high, efficient cleaning and uniform cleaning are possible, and sufficient effects can be obtained. . Furthermore, in the present invention, the effect of the impact force at the time of bubble breakage is also combined, so that it is possible to remove the introductory objects such as oil or particles adhering to the structure smaller than the bubble diameter. Microbubbles can increase the number of bubbles generated exponentially by placing the object to be cleaned near the gas-liquid interface, that is, in the vicinity of the gas-liquid interface. The probability can be improved in the same manner, and the cleaning processing speed and uniformity of the workpiece can be improved.
This will be described below based on specific embodiments.

Embodiment 1 FIG.
FIG. 1 is a view for explaining the cleaning method of the present invention. In the figure, for example, bubbles 6 generated by supplying air and water from the gas introduction part 4 and the liquid introduction part 5 of the venturi type microbubble generator 3 are supplied into the cleaning liquid 9 stored in the cleaning tank 2. To do. A foaming portion 7 in which bubbles 6 are gathered is formed on the surface layer of the cleaning liquid 9, and the processing surface of the article to be cleaned 1 is disposed so as to be in contact with the boundary portion 8 of the foaming portion 7. FIG. 2 is a diagram for explaining a conventional cleaning method. Conventionally, an object to be cleaned 1 is put in a cleaning basket or the like, and its processing surface is located at a passage part of bubbles 6. A feature of the present invention is that what is conventionally performed in the cleaning tank in which cleaning including bubbles is performed in the vicinity of the boundary between the gas and the liquid, which is clearly shown in FIG.

Next, the principle of the cleaning method of the present invention will be described. First, in FIG. 1, the object to be cleaned 1 is installed at the boundary portion 8 between the gas and the liquid. This boundary portion will be described.
In the case of a liquid containing innumerable microbubbles, a large number of bubbles 6 rise all at once, so that a layer called a foaming part is formed on the upper part of the liquid. In the case of the cleaning according to the present invention, there are a liquid portion (cleaning liquid) 9 and a foaming portion 7 as shown in FIG. In FIG. 1, the position where the bubble breakage occurs most efficiently is the boundary 8 where the foaming portion 7 contacts the gas. Therefore, the boundary part 8 of the present invention refers to the boundary between the foaming part and the gas. As a result, as described above, cleaning using the impact force of foam breakage becomes possible.

FIG. 3 conceptually shows the difference between (a) conventional cleaning in liquid and (b) gas-liquid interface of the present invention. There are very fine irregularities of several μm or less on the surface of precision / mechanical parts that are generally used as objects to be cleaned. For example, when the object to be removed is made of oil and fat stains, a desired degree of cleaning cannot be obtained unless the oil that has entered the fine recesses 1a is removed. The simplest method is to generate bubbles having a size smaller than the irregularities and wash them using them. However, even with the use of pioneering bubble miniaturization technology, it is not easy to generate bubbles on the order of μm with high density, and bubbles of several tens to several hundreds of micrometers that are one to two orders of magnitude larger than the surface irregularities. Must be used for cleaning. Therefore, normally, as shown in FIG. 3 (a), the bubbles cannot act on the removal target such as fats and oils present in the recess 1a sufficiently smaller than the bubble diameter, and the fats and oils cannot be removed. It has been found that increasing the flow rate improves the cleanliness, but this utilizes the impact force when the bubbles break. In order to increase the flow velocity, it is necessary to accelerate the entire liquid containing bubbles, which requires a great deal of energy and complicates the apparatus. Further, since the flow velocity exponentially drops depending on the distance in the liquid, it is not easy to maintain the uniformity of the treatment.
FIG. 3B shows the cleaning mechanism at the boundary between the foaming portion and the gas of the present invention. At the boundary 8, the bubbles are most efficiently broken 6b to generate an impact force. It is possible to remove the dirt such as fats and oils sinking into the fine recess 1a by using the impact force, so that it can be removed from the surface of the object to be cleaned, and the degree of cleaning can be improved.

  FIG. 4 is a diagram for explaining the cleaning method of the present invention. In the figure, (a) shows the state of the object to be cleaned 1 before the generation of microbubbles, and (b) shows the state of the object to be cleaned 1 when the microbubbles are generated. As shown in FIG. 1A, the surface to be processed of the object to be cleaned 1 is disposed up to the vicinity of the surface of the cleaning liquid so as to face the cleaning liquid. When microbubbles are generated in (b), the foaming portion 7 is formed by the rising of the bubbles, and the interface rises 10. The position of the workpiece 1 is adjusted so as to receive the bubble breaking action at the boundary as described above.

In the embodiment, in order to improve the degree of cleaning, the bubble diameter is reduced to increase the surface area per unit volume, the temperature of the cleaning liquid is increased, the flow rate is increased, and the like.
A circulation pump may be attached to circulate the cleaning liquid, and a temperature controller may be attached to increase the temperature of the cleaning liquid.

Embodiment 2. FIG.
The cleaning effect using the cleaning apparatus and the cleaning method of the first embodiment will be described in comparison with the prior art. FIG. 5 shows the effect of conventional submerged cleaning and cleaning at the boundary portion (foaming portion-gas interface portion) of the present invention, and shows the amount of residual oil after cleaning. In FIG. 2, the conventional submerged cleaning is performed by fixing the processing surface of the cleaning object 1 to face the microbubble generating unit 3 at a position 4 cm from the microbubble generating unit 3 on the side wall of the cleaning tank 2. In the practice of the present invention, as shown in FIG. 1, the processing surface of the article to be cleaned 1 was disposed substantially at the boundary and interface. Conventionally, in any of the experimental conditions of the present invention, the capacity of the cleaning tank was 35 L, the liquid temperature at the time of cleaning was 50 ° C., the supply amount of the cleaning liquid was 14 L / min, and the supply amount of the gas was 14 L / min. Moreover, 0.5 wt% of acetic acid was added as an additive for refining bubbles. SUS316 flat plate coated with a predetermined area and a predetermined amount of oil, each with hydrophobic oil (here, using hydrophobic cutting oil cut max manufactured by Nippon Horton), kerosene, salad oil, and washed for 1 minute did. The residual oil content of the object to be cleaned after washing was measured using an oil concentration meter OCMA-300 (manufactured by Horiba Seisakusho) after dissolving the oil adhering after the experiment in a hydrocarbon solvent. From the measured oil concentration value, the residual oil content (μg / cm ² ) per 1 cm ^{2 of} the part was determined.

  From FIG. 5, it was confirmed that when the cleaning method of the present invention was used, the cleaning degree was improved several times or more for any oil compared to the conventional cleaning method. In this Embodiment, it confirmed that there existed the same effect with respect to all oils, such as cutting oil used for general metal processing, processing oil, heat processing oil, and lubricating oil. In addition to industrial oils, we confirmed that they are effective against butter, lard, beef tallow, fish oil, soybean oil, rapeseed oil, sesame oil, olive oil, palm oil, palm oil, etc. .

  Moreover, the experiment which supplied the washing | cleaning liquid containing a bubble with the shower form which is another technique of the prior art was performed using the same experiment conditions. That is, the cleaning liquid was directly supplied to the object to be cleaned under the same conditions as the cleaning liquid supply amount, the gas supply amount additive, and the like. Even in this case, it was confirmed that the cleaning method of the present invention has a cleaning degree several times or more.

  Regarding the concentration of the additive, it is effective up to a concentration range having an effect on the refinement of the bubbles, specifically, 0.0001 wt% to 10 wt%, and preferably 0.001 wt% to 1 wt%. The higher the temperature during washing, the higher the effect. However, an excessively high temperature is not preferable from the viewpoint of workplace safety and energy consumption due to mist problems. Preferably 40 to 80 degrees is appropriate.

Furthermore, the particle removal effect was also verified. Silica, alumina, polystyrene, and metal oxide fine particles (0.2 μm, 0.5 μm, 2.0 μm, and 10 μm, respectively) were forcibly contaminated on the substrate by a predetermined amount, and the removal effect was examined. As a result, for any particle type, the number of residual particles after cleaning by one or more orders of magnitude was smaller with interfacial cleaning. In addition, with respect to the particle types other than the above, the number of residual particles after cleaning was smaller in the interface cleaning of the present invention.
In addition to the stainless steel, which was also examined for the material of the substrate, metal substrates such as brass, copper, iron and aluminum, vinyl chloride, fluororesin, acrylic, polypropylene, polyvinyl, polyethylene, polystyrene, glass, silicon, galley Similar effects were confirmed for substrates and base materials such as photocatalysts such as arsenic and titanium oxide, ceramics, and superconductors, that is, cleaning effects more sufficient than conventional submerged cleaning and shower cleaning.

Embodiment 3 FIG.
Hereinafter, the effect of fine bubbles at the boundary will be described. The cleaning conditions were the same as those in Embodiment 2, and the cleaning effect was confirmed by the presence or absence of additives and the presence or absence of bubbles. FIG. 6 shows the results of the residual oil amount when washed with fine bubbles, when the additive for generating fine bubbles is not included, and when washed with only the additive without bubbles. In the case of washing with bubbles, the degree of washing improved by 4 times or more compared with washing without bubbles. Furthermore, it was confirmed that cleaning with fine bubbles containing an additive had a cleaning effect 5 times or more higher than cleaning using bubbles (several mmΦ or more) without additives. In addition, it confirmed that there existed an effect with respect to any oil similarly to Embodiment 2. FIG.

Next, in order to clarify the cleaning effect of fine bubbles, the cleaning effect on the average bubble diameter of the cleaning liquid was examined. In addition, since it is difficult to make the bubble diameter in the cleaning liquid uniform, the average value of the bubble diameter distribution and the bubble diameter of the cleaning liquid is calculated by imaging and processing the cleaning liquid with a high-speed camera. Defined as diameter. The cleaning effect was seen more than the average bubble diameter of several mm or more which does not contain an additive at all in the range of the average bubble diameter from 1 μm to 500 μm. Furthermore, this effect was improved from 1 μm to 300 μm. In particular, it was confirmed that the most cleaning effect was observed when the average cell diameter was 10 μm to 100 μm.
It should be noted that the results shown in the embodiment of the present invention showed the same effect even when, for example, the liquid temperature, the type / concentration of the additive, and the amount of injected gas were changed regardless of the main cleaning conditions. .

Embodiment 4 FIG.
Next, the position where the object to be cleaned was installed was examined. In the description of the cleaning principle of the present invention of Embodiment 1, it has been shown that the object to be cleaned is easily subjected to the bubble breaking action of the bubbles when placed at the boundary interface. The relationship was examined in detail.
FIG. 7 shows a change in the cleaning degree in the height direction when the boundary at the time of cleaning is set to coordinate 0. FIG. In the figure, 0 to -1 cm means washing with a foaming part, -1 cm or less means washing with a liquid part, and 0 cm or more means washing with a gas part. From this result, a clear change in the cleaning degree with respect to the depth direction can be seen. The boundary part has the best cleaning degree, and the foaming part gradually decreases the cleaning degree. Furthermore, the cleaning power is rapidly lost in the liquid part. This is because the bubble breaking effect is lost in the liquid. The reason why the degree of cleaning is better in the gas part (+1 cm) near the boundary than in the far part (+2 cm) is that the impact force is propagated by the scattering of bubbles due to bubble breakage, and the cleaning effect is obtained. As a matter of course, no cleaning effect can be obtained in a gas part sufficiently far from the boundary part. Therefore, according to this embodiment, it has been found that an optimum position exists in the cleaning method of the present invention. The optimum position is the boundary between the foaming portion and the gas in the liquid portion and the portion that is foamed by the bubbles in the cleaning liquid containing an infinite number of bubbles, and it is most desirable to clean in this vicinity. Moreover, even if it wash | cleans by a foaming part even if it is not a boundary part, the cleaning effect close | similar to it is acquired. In addition, the cleaning effect can be obtained even slightly above the gas from the boundary. When the type and concentration of the additive and the amount of gas to be injected are changed, the height of the foaming part changes, but the cleaning position of this embodiment is within 1 cm above the foaming part and the boundary part (the foaming part or Within 1 cm above the surface of the cleaning liquid), and within this range, the same cleaning effect can be obtained without depending on the height of the foaming portion.

Embodiment 5. FIG.
Next, the removal result of the oil-and-fat dirt adhering to the surface where the unevenness | corrugation finer than a bubble exists was examined. FIG. 8 shows the cleaning degree dependency on the unevenness (surface roughness: Ra and Rz, respectively) of the object to be cleaned when the average bubble diameter is 50 μm (minimum 20 μm, maximum 500 μm). Ra and Rz are abbreviations for arithmetic average roughness and ten-point average roughness, respectively, and are defined in JIS B0601-1994 as roughness shape parameters. Ra is the average value of absolute value deviation from the average line of the roughness curve (surface shape curve), Rz is the value when 5 points from the highest peak and 5 points from the lowest valley are selected for each reference length. Defined as average height.
In both Ra and Rz results, the degree of cleansing was higher when washing at the boundary. What is also characteristic is that the larger the Ra and Rz values, the greater the difference in cleanliness between the liquid and the boundary. As shown in the model of FIG. 3, in the cleaning in the liquid, the concave portion becomes narrower, and as the depth becomes deeper, the bubbles cannot act, and the area increases on the entire cleaning surface, so the cleaning degree deteriorates. On the other hand, the boundary is similarly affected by roughness, but the effect of removing contaminants by foam breakage is maintained, and the degree of cleaning is only gradually deteriorated. For this reason, it is presumed that the difference in the cleaning degree between the two cleaning methods becomes more remarkable as the surface becomes rougher.

Embodiment 6 FIG.
In the said Embodiment 1-5, the cleaning effect was acquired by using the bubble breaking phenomenon of the bubble which floated to the boundary part. In order to further improve the cleaning efficiency, a means for forcibly breaking bubbles may be provided. In the present embodiment, ultrasonic waves are used as means for efficiently breaking bubbles.
FIG. 9 shows a configuration diagram of a cleaning apparatus including an ultrasonic element used in the embodiment of the present invention. In the figure, (a) is a top view, and (b) is a view seen from the direction of the arrow in (a). In the figure, the ultrasonic transducer 12 connected to the ultrasonic transmitter 11 is arranged so that the ultrasonic wave propagates to the quartz rod 13. In this apparatus, quartz rods 13 having a diameter of 1 to 2 cm are installed at regular intervals so as to straddle the washing tank in the vicinity of the foaming portion.

The bubbles 6 generated from the microbubble generator 3 are accelerated by the ultrasonic wave from the quartz rod 13 and the bubbles are efficiently broken. Thereby, in addition to the bubble breakage at the gas-liquid interface shown in the first to fifth embodiments, the bubble breakage by the ultrasonic wave is also added, and the degree of cleaning can be further improved. Actually, under the same conditions, the degree of cleaning with and without the application of ultrasonic waves was examined. When ultrasonic waves were applied, the degree of cleaning was tripled (the amount of residual oil was 1/3) compared to when no ultrasonic waves were applied. It was confirmed.
Furthermore, the ultrasonic frequency was effective in the range of 20 kHz to 3 MHz. In the present embodiment, a method of applying ultrasonic waves via a quartz rod is used. However, the present invention is not limited to this, and an effect can be obtained if ultrasonic waves are applied to the foaming portion. For example, the ultrasonic element itself may be disposed in the vicinity of the liquid surface, or a rod made of a metal such as stainless steel or the like, which is an ultrasonic propagation material, instead of quartz, may be disposed. .

Embodiment 7 FIG.
In the cleaning method in the above embodiment, it is important not to cause redeposition of dirt such as oil and fat removed from the object to be cleaned. When washing is performed under conditions where the foaming part does not flow, there is a risk that the removed substance will drift in the liquid surface and adhere to the object to be cleaned again even if there is an active defoaming action. It is. Under the condition that there was no actual flow, the amount of residual oil was saturated, and a high level of cleaning at the target level could not be obtained. In this embodiment, there is provided means for preventing reattachment of contaminants such as oil removed from the object to be cleaned.
In order to suppress re-adhesion, it is an effective means to provide fluidity of the liquid surface. For example, when the cleaning tank is tilted slightly, the liquid level flows from higher to lower, so that the removed dirt component is naturally carried out of the substrate surface. Even when the flow of the liquid is controlled so that a horizontal flow is generated in the vicinity of the boundary portion, it is possible to prevent reattachment to the substrate.

  FIG. 10 is a diagram showing the configuration of the cleaning apparatus according to the present embodiment. The washing | cleaning apparatus which added the apparatus 14 which controls a flow in the boundary part or foaming part of the washing tank 2 is shown. In this apparatus, as indicated by an arrow 15 in the figure, the flow is controlled to flow from the cleaning tank 2 to the overflow tank 16 in one direction. As a result, the removed dirt can be quickly flowed to the overflow tank. As the fluid control device, a means for blowing air near the liquid surface may be used. In other words, oil that floats lighter than water and floats on the liquid surface can be moved by blowing air to the boundary, and a high degree of cleaning can be obtained. It was also confirmed that the residual oil amount after washing was further reduced to 1/2 to 1/10 by providing the device 14 for controlling the flow at the foaming portion. Further, even when the apparatus 14 for controlling the flow at the foaming part was not provided, the effect of reducing the residual oil amount was recognized even when the boundary part was moved by increasing or decreasing the cleaning liquid.

Embodiment 8 FIG.
In the first to seventh embodiments, the basic characteristics have been described by taking the simple shape of the object to be cleaned as a flat plate. In general parts and precision cleaning, there are many cases where three-dimensionally complicated shapes are washed. In the present embodiment, a method for efficiently cleaning these cleaning objects will be described.

  FIG. 11 is a diagram showing the configuration of the cleaning apparatus according to the present embodiment. In the figure, a cleaning basket 18 containing a three-dimensional shape to be cleaned 17 is moved up and down at a predetermined speed so as to pass through a boundary portion and a foaming portion. At this time, the cleaning basket 18 is preferably rotated so that the processing surface of the object to be cleaned 17 is exposed to the boundary portion or the foaming portion as indicated by an arrow in the figure. It is important to optimize the movable range and speed of the cleaning basket 18.

FIG. 12 is a diagram showing the configuration of another cleaning apparatus according to the present embodiment. 11 shows an example in which the cleaning basket 18 containing the article 17 to be cleaned is moved up and down, FIG. 12 shows a configuration diagram of an apparatus for moving the vapor-liquid interface. A preliminary tank 20 connected by a pump 19 is provided in parallel with the cleaning tank. When the liquid is transferred to the auxiliary tank using this pump, the gas-liquid interface is lowered. When it is desired to return the lowered interface to the base, the liquid in the preliminary tank may be returned to the cleaning tank side. This makes it possible to easily control the position of the gas-liquid interface in the cleaning tank.
Controlling the position of the gas-liquid interface in this way also has the effect of preventing the reattachment of contaminants. However, if a filter is provided in the vicinity of the pump 19 to collect the removed matter, the effect of preventing the reattachment can be obtained. Further improve.

  As in the present embodiment, even if the workpiece has a complicated shape, the boundary portion and the foaming portion are allowed to pass through, and the cleaning effect can be enhanced by the bubble breaking action of bubbles.

In the said Embodiment 1-8, although the washing | cleaning effect in the boundary of a foaming part and gas was shown, as gas, it is not restricted to the above air, You may use oxidizing gas. . In particular, when ozone gas was used, it was confirmed that it exhibited an effect not only for removing fats and oils but also for decomposing and removing organic substances. It was also confirmed that it was effective in inactivating bacteria by the energy of breaking bubbles. A reducing gas such as hydrogen or methane may be used. The cleaning solution can be washed with water without preparing a special cleaning solution, but it can generate bubbles, for example, general organic solvents ((alcohols, esters, organic acids, ketones, ethers, benzene, aldehydes, hexanes) In addition, an example of using acetic acid as an additive for promoting bubbles when water is used as a cleaning liquid has been shown, but carboxylic acid compounds such as acetic acid, methanol, etc. In addition to alcohol compounds, sodium chloride, anionic / cationic / nonionic surfactants, etc., fatty acids and derivatives thereof, glycerin and derivatives thereof, and amine compounds can be used.
In addition, when an oxidizing gas such as ozone is used as the gas, it is preferable to avoid using it together with a substance that is highly reactive with ozone gas. As the cleaning liquid or additive, alcohol-based, anion-cation-nonionic interfaces such as methanol The use of activators, fatty acids and derivatives thereof, glycerin and derivatives thereof, and amine compounds is not preferred. It is necessary to pay attention to ozone gas concentration and additive concentration.
In the above-described embodiments, the removal of oily and fat stains has been described as an example. However, for the particle stains, the action of desorbing particles adhering to the substrate and the object to be processed by the energy of bubble breaking and the bubble surface Needless to say, effects such as prevention of reattachment to the substrate and the object to be processed due to the adhesion of particles to the substrate are expected.

It is a block diagram which shows the microbubble washing | cleaning apparatus by Embodiment 1 of this invention. It is a block diagram which shows the conventional microbubble washing | cleaning apparatus and the washing | cleaning method. The conceptual diagram explaining the cleaning principle of this invention in contrast with a prior art, (a) is the figure in the case of the conventional submerged cleaning, (b) is the figure which shows the case of the cleaning in the gas-liquid interface of this invention. . It is a figure for demonstrating the washing | cleaning method of this invention, (a) is the state before microbubble production | generation, (b) is a figure which shows the position of the to-be-cleaned object at the time of microbubble production | generation. It is a figure which shows the cleaning effect by Embodiment 2 of this invention. It is a figure which shows the cleaning effect by Embodiment 3 of this invention. It is a figure which shows the cleaning effect by Embodiment 4 of this invention, and is the figure which showed the relationship between the position of to-be-cleaned object, and the amount of residual oil. It is a figure which shows the cleaning effect by Embodiment 5 of this invention, (a) is the relationship between the surface roughness (Ra) of the processed surface of a to-be-cleaned object, and residual oil amount, (b) is the processed surface of a to-be-cleaned object. It is the figure which showed the relationship between surface roughness (Rz) and residual oil amount. It is a block diagram which shows the washing | cleaning apparatus by Embodiment 6 of this invention, (a) is a top view, (b) is the figure seen from the direction of the arrow in (a). It is a block diagram which shows the washing | cleaning apparatus by Embodiment 7 of this invention. It is a block diagram which shows the washing | cleaning apparatus by Embodiment 8 of this invention. It is a block diagram which shows another washing | cleaning apparatus by Embodiment 8 of this invention.

Explanation of symbols

1 Object to be cleaned, 1a Processed surface of object to be cleaned, 2 Cleaning tank,
3 micro-bubble generating part, 4 gas introducing part, 5 liquid introducing part,
6, 6a bubbles, 6b broken bubbles, 7 foaming part,
8 boundary, 9 cleaning liquid, 10 rise of interface,
11 Ultrasonic transmitter, 12 Ultrasonic vibrator, 13 Quartz rod,
14 Surface fluid movement control device, 15 Flow direction of removed material, 16 Overflow tank,
17 Object to be cleaned, 18 Cleaning basket, 19 Pump, 20 Spare tank.

Claims (7)

Washing characterized in that bubbles generated in the cleaning liquid generated by the bubble generating means float on the liquid surface of the cleaning liquid, and bubbles are broken on the surface to be cleaned of the object to be cleaned. Method. The cleaning method according to claim 1, wherein the object to be cleaned is disposed within 1 cm above the foaming part or the foaming part or the cleaning liquid surface. The cleaning method according to claim 1, wherein the bubble diameter is 1 μm to 500 μm. A bubble generating means for generating bubbles in the cleaning liquid in the cleaning tank, and a foamed part formed by the bubbles generated by the bubble generating means floating on the liquid surface of the cleaning liquid or an object to be cleaned in the vicinity of the cleaning liquid surface And a means for arranging the cleaning device. The cleaning apparatus according to claim 4, further comprising a bubble breakage promoting means. 5. The cleaning apparatus according to claim 4, wherein the means for arranging the object to be cleaned includes a control means for changing a position of the object to be cleaned. The cleaning apparatus according to claim 4, further comprising a cleaning liquid circulation means.

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