JP4880427B2 - Cleaning method and cleaning apparatus - Google Patents

Description

  The present invention relates to a cleaning method and a cleaning apparatus for cleaning electronic and mechanical parts, instruments and the like related to immersion ultrasonic cleaning, and more particularly to a cleaning method and a cleaning apparatus suitable for cleaning tubular objects.

  Immersion ultrasonic cleaning that cleans an object to be cleaned by adding ultrasonic vibration to the cleaning liquid while the object to be cleaned is immersed in the cleaning liquid is used for cleaning electronic parts, machinery, medical-related parts and instruments, etc. Widely adopted.

  For cleaning electronic parts and machine parts, chlorofluorocarbon solvents such as chlorofluorocarbon or trichloroethane were widely used. However, since chlorofluorocarbon was completely abolished for environmental protection, various cleaning methods using alternative solvents have been proposed. Cleaning using a so-called aqueous cleaning liquid containing a surfactant as a main component has been widely performed. Also, in the cleaning of medical parts and instruments, aqueous cleaning using a neutral cleaning liquid containing a surfactant is performed. Even when an aqueous cleaning solution is used, immersion ultrasonic cleaning is useful, and it has been proposed to perform not only under atmospheric pressure but also under reduced pressure.

  In water-based cleaning, the cleaning agent itself has a low ability to dissolve dirt, so ultrasonic cleaning using ultrasonic cavitation or bubbling cleaning that dissolves gas in the cleaning liquid and generates bubbles is performed physically. The liquid flow is improved and the cleaning power is improved.

  An example of a conventional immersion ultrasonic cleaning method is shown in FIG. The object to be cleaned 21 is immersed in the cleaning liquid 2 stored in the cleaning tank 1, and ultrasonic vibration is applied to the cleaning liquid 2 by the ultrasonic wave irradiated from the ultrasonic transducer unit 4, and adheres to the surface of the object 21 to be cleaned. Remove dirt.

  Next, FIG. 7 shows an example of a conventional air bubbling cleaning method for cleaning an object to be cleaned by stirring the cleaning liquid with bubbles.

  The object 21 to be cleaned is immersed in the cleaning liquid 2 stored in the cleaning tank 1, and compressed air is sent to a nozzle (porous body) 22 installed in the cleaning liquid 2 to generate bubbles. Remove dirt on the surface.

  The degreasing and cleaning apparatus described in Patent Document 1 has two functions of ultrasonic cleaning and air bubbling cleaning. The gas pressurizing and mixing means 5 sucks the cleaning liquid and the rinsing liquid from the inlet side, and simultaneously sucks air or nitrogen gas and discharges them while applying pressure. Then, a cleaning liquid containing a large amount of gas in a dissolved or fine bubble state is supplied to the cleaning tank 1, decompressed by the nozzle 7, foamed, and dispersed in the liquid. Next, the object to be cleaned 10 is immersed in the tank, and at the same time, the ultrasonic oscillation means 3 is excited to drive the ultrasonic vibration means 3 disposed in the tank to irradiate the cleaning liquid with ultrasonic waves intermittently. While the ultrasonic irradiation is stopped, the object to be washed is pulled up to the atmosphere, and then immersed again in the liquid and irradiated with ultrasonic waves. This procedure is repeated to finish the cleaning.

JP 7-278860 A

  In the conventional immersion ultrasonic cleaning method as described above, since the surface tension of the aqueous cleaning liquid is larger than that of the solvent, when cleaning is performed under atmospheric pressure, a fine structure such as a bag hole or a groove on the surface of the object to be cleaned It may be difficult for the cleaning liquid to enter the part of this area, air bubbles may remain, and partial cleaning may not be possible. Further, even if the surfaces of the objects to be cleaned are smooth, if the objects to be cleaned are in contact with each other on a smooth surface, the cleaning liquid is difficult to enter there, and cleaning may be insufficient. In particular, when the object to be cleaned is an elongated tubular object, the cleaning liquid does not enter the inside of the object and often cannot be cleaned.

  When cleaning is performed under reduced pressure, bubbles remaining in the bag hole and the tubular cleaning object can be removed, and the cleaning liquid can be introduced into the fine structure portion. However, since the surface tension of water is large, the cleaning liquid once entering the fine structure portion cannot be removed, and the cleaning liquid is not replaced, so that the dirt remains in the fine structure portion.

  In addition, since the pressure resistance of the apparatus including the cleaning tank is naturally required to make the cleaning tank vacuum, the structure and size of the apparatus are limited, and the amount of objects to be cleaned at one time can be reduced. It will be limited or it will increase the cost of the device. Furthermore, since time is required for evacuation, the cleaning time becomes long.

  Further, in the conventional air bubbling cleaning method as described above, since the size of the bubbles is as large as 0.5 mm to several mm, the fine structure portion on the surface of the object to be cleaned, the inside of the tubular object, as in the case of immersion ultrasonic cleaning Insufficient cleaning may occur. In addition, it is difficult to perform uniform air bubbling over the entire cleaning liquid, resulting in uneven cleaning, and foaming is increased by injecting bubbles for a certain period of time, and continuous cleaning may not be possible. is there.

  In the degreasing and cleaning apparatus described in Patent Document 1, the object to be cleaned 10 is immersed in a tank and subjected to ultrasonic irradiation after foaming a cleaning liquid containing fine bubbles. The ultrasonic wave is irradiated without introducing bubbles into the film, and the cleaning effect hardly increases.

  An object of the present invention is to provide a cleaning method and a cleaning apparatus capable of cleaning an object to be cleaned more effectively and continuously cleaning for a long time.

The present invention is a cleaning method of cleaning an object to be cleaned by immersing the object in a cleaning liquid stored in a cleaning tank and applying ultrasonic vibration to the cleaning liquid.
While the cleaning object is immersed in the cleaning liquid, the cleaning liquid in which one or more kinds of gases are dissolved is circulated, and fine bubbles are generated by the gas inside the cleaning tank to clean the cleaning object for a first predetermined time. A circulating cleaning process to be performed;
In the cleaning method, the ultrasonic cleaning process is performed separately for a second predetermined time by applying ultrasonic vibration to the cleaning liquid in a state where the cleaning target is immersed in the cleaning liquid.

  In the present invention, the ultrasonic cleaning step is performed in a state where the inside of the cleaning tank is decompressed.

  Further, the present invention is characterized in that the circulation cleaning step and the ultrasonic cleaning step are one cycle, and this cycle is repeated a plurality of times.

  Further, the present invention is characterized in that, in the circulation cleaning step, the cleaning liquid is introduced into a tube of the tubular object through a holder that holds the tubular object that is the object to be cleaned.

Further, the present invention provides a cleaning apparatus for cleaning an object to be cleaned by immersing the object to be cleaned in a cleaning liquid stored in a cleaning tank and applying ultrasonic vibration to the cleaning liquid.
A cleaning tank for storing the cleaning liquid;
Circulating means for circulating a cleaning liquid in which one or more kinds of gas are dissolved, and generating fine bubbles by the gas inside the cleaning tank;
Ultrasonic application means for applying ultrasonic vibration to the cleaning liquid;
Holding means for holding the object to be cleaned inside the cleaning tank,
By operating the circulation means, a circulation cleaning mode in which fine bubbles are generated by the gas inside the cleaning tank and cleaning the object to be cleaned is performed for a first predetermined time, and the ultrasonic wave applying means is operated. The cleaning apparatus is configured to be switchable to any one of an ultrasonic cleaning mode in which cleaning of an object to be cleaned is performed for a second predetermined time by applying ultrasonic vibration to the cleaning liquid.

Further, the present invention is characterized by having a decompression means for decompressing the inside of the cleaning tank.
Further, according to the present invention, the holding means has a hollow container shape, and can hold a plurality of tubular objects in a state where an open end of the tubular object that is an object to be cleaned is inserted into the internal space. The cleaning liquid from the circulation means is configured to flow into the internal space.

  Further, the present invention is characterized in that the holding means holds a tubular object as an object to be cleaned in parallel with the vertical direction.

  Further, the present invention is characterized in that the holding means is configured to be detachable from the cleaning tank.

According to the present invention, in the circulation cleaning step, while the cleaning object is immersed in the cleaning liquid, the cleaning liquid in which one or more kinds of gases are dissolved is circulated, and fine bubbles are generated by the gas inside the cleaning tank. Then, the object to be cleaned is cleaned for a first predetermined time . In the ultrasonic cleaning process, the object to be cleaned is cleaned for a second predetermined time by applying ultrasonic vibration to the cleaning liquid in a state where the object to be cleaned is immersed in the cleaning liquid.

  Accordingly, in the circulation cleaning step, for example, a cleaning liquid containing fine bubbles of 100 μm (0.1 mm) or less is circulated, thereby generating a physical liquid flow and reducing frictional resistance due to finer bubbles. Microbubbles can be effectively introduced into the fine structure portions such as fine bag holes and grooves on the surface of the object to be cleaned.

  Furthermore, in the ultrasonic cleaning process, the fine bubbles introduced into the fine structure portion of the surface of the object to be cleaned are destroyed by ultrasonic cavitation, and a strong liquid flow is generated locally, which can be cleaned extremely effectively. It becomes possible. Further, by destroying the bubbles by the addition of ultrasonic waves, it is possible to prevent the fine bubbles in the cleaning liquid from collecting and forming large bubbles, so that it is possible to perform cleaning for a long time continuously.

  According to the invention, in the ultrasonic cleaning step, cleaning is performed in a state where the inside of the cleaning tank is decompressed. By depressurizing the inside of the cleaning tank, bubbles remaining in the fine structure portion on the surface of the object to be cleaned can be removed, and a new cleaning liquid can be introduced. In addition, the dissolved gas in the cleaning liquid is degassed to increase the sound pressure when cavitation occurs, and cleaning can be performed more strongly than cleaning under atmospheric pressure.

  According to the present invention, the circulation cleaning step and the ultrasonic cleaning step are set as one cycle, and this cycle is repeated a plurality of times.

  Thereby, the fluidity | liquidity and substitution efficiency of a washing | cleaning liquid improve, and higher cleaning power can be achieved.

  According to the invention, in the circulation cleaning step, the cleaning liquid is introduced into the tube of the tubular object through the holder that holds the tubular object that is the object to be cleaned.

  Thereby, a washing | cleaning liquid can be efficiently introduce | transduced in the pipe | tube from the open end part of a tubular thing.

According to the present invention, the circulation means operates to generate fine bubbles by the gas dissolved in the washing liquid inside the washing tank to wash the object to be washed for a first predetermined time, By operating the sound wave applying means, the object to be cleaned is cleaned by switching to one of the ultrasonic cleaning modes in which the object to be cleaned is cleaned for a second predetermined time by applying ultrasonic vibration to the cleaning liquid.

  Thereby, in the circulation cleaning mode, for example, by circulating a cleaning liquid containing fine bubbles of 100 μm (0.1 mm) or less, a physical liquid flow is generated, and a frictional resistance is reduced by miniaturization of the bubbles. Microbubbles can be effectively introduced into the fine structure portions such as fine bag holes and grooves on the surface of the object to be cleaned.

  Furthermore, in the ultrasonic cleaning mode, fine bubbles introduced into the fine structure of the surface of the object to be cleaned are destroyed by ultrasonic cavitation, and a strong liquid flow is generated locally, which can be cleaned extremely effectively. It becomes possible. Further, by destroying the bubbles by the addition of ultrasonic waves, it is possible to prevent the fine bubbles in the cleaning liquid from collecting and forming large bubbles, so that it is possible to perform cleaning for a long time continuously.

  Moreover, according to this invention, it has a pressure reduction means which pressure-reduces the inside of the said washing tank. By depressurizing the inside of the cleaning tank, bubbles remaining in the fine structure portion on the surface of the object to be cleaned can be removed, and a new cleaning liquid can be introduced. In addition, the dissolved gas in the cleaning liquid is degassed to increase the sound pressure when cavitation occurs, and cleaning can be performed more strongly than cleaning under atmospheric pressure.

  Further, according to the present invention, the holding means has a hollow container shape and can hold a plurality of tubular objects in a state where the open end of the tubular object to be cleaned is inserted into the internal space. The cleaning liquid from the circulation means is configured to flow into the internal space.

  Accordingly, the cleaning liquid can be efficiently introduced into the pipe from the open end of the tubular article inserted into the holding means.

  According to the invention, the holding means holds the tubular object that is the object to be cleaned in parallel to the vertical direction.

  As a result, the inside of the tubular object can be effectively cleaned without hindering the upward movement of the fine bubbles.

According to the invention, the holding means is configured to be detachable from the cleaning tank.
As a result, the object to be cleaned can be held by the holding means in a state where it is detached from the cleaning tank, so that workability is improved.

FIG. 1 is a schematic diagram showing a configuration of a cleaning apparatus 100 according to an embodiment of the present invention.
The cleaning apparatus 100 mainly includes a cleaning tank 1 having a lid 3 that can be sealed, an ultrasonic transducer 4, a basket receiver 10, a heater 11, an ultrasonic oscillator 5, a fine bubble generating unit 6, a filter 12, a vacuum pump 7, A pressure gauge 13, a temperature controller 14, and a valve 15 are included. An ultrasonic transducer 4, a basket receiver 10 and a heater 11 are arranged in the internal space of the cleaning tank 1.

  The basket receiver 10 stores a basket 8 having a holder 9 that is a holding means for holding a tubular object 20 that is an object to be cleaned. The cleaning tank 1 is opened upward, and the cleaning tank 1 can be hermetically closed by closing the lid 3 provided with packing at the contact portion with the cleaning tank 1.

  The cleaning liquid 2 stored in the cleaning tank 1 is a neutral or alkaline aqueous cleaning liquid containing a surfactant, heated by the heater 11 in the cleaning tank 1, and the temperature of the liquid is 40 ° C. to 40 ° C. It is adjusted to a range of 60 ° C. The cleaning liquid 2 is preferably an aqueous solution of a neutral detergent containing a nonionic surfactant and having a detergent concentration of 0.5% by weight.

  The fine bubbles have a diameter that increases in proportion to the temperature, but in the cleaning liquid 2 containing a surfactant, the diameter decreases and the rising speed in the liquid becomes slow, that is, it is known that the lifetime is long in cleaning. . The type of cleaning agent and the heating temperature may be selected according to the object to be cleaned, and are not limited.

  The fine bubble generating unit 6 is connected to the cleaning tank 1 and the basket receiver 10 in the cleaning tank 1 through pipes, and the cleaning liquid is connected between the cleaning tank 1 and the basket receiver 10 using an internal pump. It is a circulation means for circulating 2. A filter 12 is installed on the path from the cleaning tank 1 back to the fine bubble generating unit 6, and foreign substances contained in the circulating cleaning liquid 2 can be collected and removed.

  The fine bubble generating unit 6 is provided with a gas supply port, and by supplying one or more kinds of air or a gas such as nitrogen or ozone, the gas is mixed while being pressurized in the circulating cleaning liquid 2. A gas solution containing a supersaturated concentration and a large amount of bubbles can be generated. When this pressurized gas solution is sent out to the washing tank 1 and the basket receiver 10, the pressure is reduced and fine bubbles are generated. The fine bubble generating unit 6 used in the present embodiment can generate fine bubbles having a diameter of 100 μm (0.1 mm) or less by, for example, a pressure dissolution method.

  The holder 9 of the basket 8 accommodated in the cleaning tank 1 is supplied with the cleaning liquid 2 containing fine bubbles via the basket receiver 10. As a result, the cleaning liquid 2 containing fine bubbles flows into the inner surface of the tubular object 20 set in the holder 9, and the inner surface of the tubular object 20 that is the object to be cleaned can be effectively circulated and washed.

  The ultrasonic vibrator 4 is installed in the lower part of the internal space of the cleaning tank 1 and applies ultrasonic vibrations to the cleaning liquid 2 stored in the cleaning tank 1. The ultrasonic oscillator 5 applies a signal having a predetermined frequency to the ultrasonic transducer 4 and vibrates it to generate ultrasonic waves. The ultrasonic oscillator 5 used in the present embodiment has an oscillation frequency of 28 kHz to 40 kHz, for example. The oscillation frequency may be selected according to the object to be cleaned, and is not limited. The ultrasonic transducer 4 and the ultrasonic oscillator 5 constitute ultrasonic applying means.

  The vacuum pump 7 is water-sealed and is connected to the upper part of the interior space of the cleaning tank 1 via a pipe. The gas in the cleaning tank 1 is sucked and exhausted to the outside. Reduce pressure. The vacuum pump 7 used in the present embodiment can reach a degree of vacuum of, for example, several thousand Pa (several tens of Torr).

  The valve 15 includes an atmosphere release valve 15a and a vacuum exhaust valve 15b. The vacuum exhaust valve 15 b is provided in a pipe connecting the cleaning tank 1 and the vacuum pump 7, and opens and closes a gas discharge path from the cleaning tank 1 by the vacuum pump 7.

  The air release valve 15a is provided in a pipe branched from the middle of the pipe connecting the cleaning tank 1 and the vacuum exhaust valve 15b, and opens and closes an air introduction path to the cleaning tank 1. The pressure gauge 13 is attached between a pipe connecting the cleaning tank 1 and the vacuum exhaust valve 15b, and measures the pressure inside the cleaning tank 1. The vacuum pump 7 and the valve 15 constitute decompression means.

  A method of cleaning the tubular object 20 that is an object to be cleaned using the cleaning apparatus 100 shown in FIG. 1 will be described.

  First, a plurality of tubular objects 20 to be cleaned are arranged in the holder 9 of the basket 8 and the cleaning liquid 2 is supplied to the cleaning tank 1. The tubular object 20 to be cleaned may be disposed directly on the holder 9 of the basket 8 accommodated in the cleaning tank 1, and the basket 8 is removed from the basket receiver 10 in the cleaning tank 1 and the work is performed. The tubular object 20 may be arranged in the holder 9 in a good place, and the basket 8 in which the tubular object 20 is arranged may be mounted on the basket receiver 10 in the cleaning tank 1.

  A gas solution containing one or more types of gas generated in the fine bubble generating unit 6 and dissolved in a supersaturated concentration and containing a large amount of bubbles is tubular through the lower portion of the internal space of the cleaning tank 1 and the basket receiver 10. The product 20 is supplied to the holder 9 of the basket 8 in which the product 20 is disposed, and is circulated and washed with the liquid containing fine bubbles for a predetermined time.

  As a result, the cleaning liquid 2 containing fine bubbles flows into the tube of the tubular object 20 arranged in the holder 9, and the inner surface of the tubular object 20 is cleaned. Similarly, fine bubbles are generated in the lower part of the internal space of the cleaning tank 1 and the outer surface of the tubular object 20 is cleaned.

  The cleaning liquid 2 containing fine bubbles of 100 μm (0.1 mm) or less generated by the pressure dissolution method is circulated by the fine bubble generating unit 6 to continuously generate the fine bubbles, thereby cleaning the cleaning liquid in the cleaning tank 1. 2 generates a physical liquid flow and reduces frictional resistance due to the refinement of bubbles, which is effective in a fine structure such as a fine bag hole or groove on the surface of the object to be cleaned and in a pipe of the tubular object 20. Microbubbles can be introduced into the.

  Further, the ultrasonic oscillator 5 applies a signal of a predetermined frequency to the ultrasonic vibrator 4 installed in the lower part of the cleaning tank 1 and performs ultrasonic cleaning for adding ultrasonic vibration to the cleaning liquid 2 for a predetermined time. Therefore, the fine structure part on the surface of the object to be cleaned and the fine bubbles introduced into the tubular object 20 are destroyed by ultrasonic cavitation, and a strong liquid flow is generated locally, which can be cleaned extremely effectively. It becomes. Further, by destroying the bubbles by the addition of ultrasonic waves, it is possible to prevent the fine bubbles in the cleaning liquid 2 from collecting and forming large bubbles, and therefore it is possible to perform cleaning for a long time continuously.

  In the present invention, during the ultrasonic cleaning, the air release valve 15a is closed, the vacuum exhaust valve 15b is opened, and the gas in the cleaning tank 1 is exhausted to the outside by the vacuum pump 7 to perform the vacuum ultrasonic cleaning. Is possible. By depressurizing the inside of the cleaning tank 1, the fine structure portion on the surface of the object to be cleaned and bubbles remaining in the tube of the tubular object 20 can be removed, and a new cleaning liquid 2 can be introduced. In addition, the dissolved gas in the cleaning liquid 2 is degassed to increase the sound pressure when cavitation occurs, and cleaning can be performed more strongly than cleaning under atmospheric pressure.

  However, the pressure resistance of the cleaning tank 1 is required, so that there are disadvantages due to reduced pressure, such as an increase in cost, a limited amount of cleaning materials, and a longer cleaning time because more time is required for evacuation. Therefore, for example, it is desirable to perform the vacuum ultrasonic cleaning only when cleaning the object to be cleaned which is difficult to clean, for example, the structure of the object to be cleaned is complicated or the surface has many fine structure portions. In the present embodiment, as described above, the valve 15 and the vacuum pump 7 are operated when necessary to switch between atmospheric pressure ultrasonic cleaning and vacuum ultrasonic cleaning.

  After performing vacuum ultrasonic cleaning for a predetermined time, outside air is introduced by closing the vacuum exhaust valve 15b and opening the air release valve 15a, and the inside of the cleaning tank 1 is returned to atmospheric pressure.

  As described above, in the cleaning method of the present invention, the gas solution containing a supersaturated concentration and a large amount of bubbles in which one or more kinds of gases are dissolved is used as the cleaning liquid 2 and the inside of the cleaning tank 1 is at atmospheric pressure. A circulating cleaning process for performing cleaning by circulating the cleaning liquid 2 for a predetermined time; and an ultrasonic cleaning process for performing ultrasonic cleaning for applying ultrasonic vibration to the cleaning liquid 2 for a predetermined time under the atmospheric pressure or reduced pressure inside the cleaning tank 1; As described above, the order of the circulating cleaning process and the ultrasonic cleaning process may be performed after the circulating cleaning process or after the ultrasonic cleaning process. Also good.

  If the object to be cleaned is a tubular object having a relatively large inner diameter, it is more effective to perform the circulation cleaning process after the ultrasonic cleaning process because the cleaning liquid 2 flows into the pipe simply by being immersed in the cleaning liquid 2. When bubbles are destroyed in a narrow place such as a tube with a small inner diameter, intense liquid flow occurs. However, in a wide place such as a tube with a large inner diameter, if the cleaning liquid enters the inside of the pipe, the inner surface is subjected to ultrasonic cavitation. It is more effective to remove the dirt first and then take it away with fine bubbles. Even when it is desired to clean the surface exposed to the outside of the object to be cleaned, it is more effective to first perform ultrasonic cleaning and then perform cyclic cleaning.

  Furthermore, the combination of the circulation cleaning step and the ultrasonic cleaning step is set as one cycle, and by repeating this cycle a plurality of times, the fluidity and replacement efficiency of the cleaning liquid 2 are improved, and higher cleaning power can be achieved. Assuming that the same cleaning time is 10 minutes, for example, the cycle cleaning process is performed for 5 minutes, and the ultrasonic cleaning process is performed for 5 minutes. Repeating a plurality of times, for example, performing a cycle cleaning process for 1 minute, and performing a ultrasonic cleaning process for 1 minute for 5 minutes to perform a total of 10 minutes of cleaning for a total of 10 minutes will prevent bubbles in the cleaning liquid 2 from becoming larger in diameter. Because it can.

  It is possible to perform good cleaning regardless of the shape of the object to be cleaned such as the inner diameter of the tubular object 20 by repeating the cycle of the circulating cleaning process and the ultrasonic cleaning process a plurality of times.

  In the cleaning apparatus 100 of the present invention, the basket 8 having the holder 9 for holding the object to be cleaned is configured to be detachable from the basket receiver 10, and the basket 8 is placed in the basket receiver 10 when the object to be cleaned is arranged and collected. It is possible to arrange and collect the objects to be cleaned in a place with good workability.

  FIG. 2 is a schematic diagram showing the configuration of the holder 9. FIG. 2A shows a top view of the holder 9, and FIG. 2B shows a side view of the holder 9. As shown in FIG. 2, the holder 9 has a hollow container shape, and holds a plurality of pieces (for example, 16 pieces, 32 pieces, etc.) together in a state where the open end portion of the tubular object 20 is inserted into the internal space. It is configured to be possible. The cleaning liquid 2 from the fine bubble generating unit 6 flows into the inner space of the holder 9 via the basket receiver 10, and the cleaning liquid 2 can be efficiently introduced into the pipe from the open end of the inserted tubular object 20. It has a possible structure.

FIG. 3 is a schematic diagram showing a configuration of a cleaning apparatus 101 according to another embodiment of the present invention.
In the present embodiment, the basket 8 is mounted so that the holder 9 is positioned downward in the vertical direction. As a result, the object to be cleaned that is held by the holder 9 is arranged above the holder 9 in the vertical direction, and is held in parallel with the vertical direction. The inside of the pipe | tube of the thing 20 can be wash | cleaned effectively.

  Hereinafter, a configuration different from the cleaning apparatus 100 illustrated in FIG. 1 will be mainly described, and overlapping description may be omitted.

  As shown in FIG. 3, the ultrasonic vibrator 4 and the basket receiver 10 are disposed in the cleaning tank 1 and include an ultrasonic oscillator 5, a fine bubble generating unit 6, a filter 12, a temperature controller 14, and the like. An overflow tank 16 is provided on the side of the cleaning tank 1, and a heater 11 is provided in the overflow tank 16.

  Inside the cleaning tank 1, a basket 8 having a holder 9 for setting a tubular object 20, which is an object to be cleaned, is stored, and the cleaning liquid 2 is supplied.

  The cleaning liquid 2 is the same as that used in the above-described cleaning apparatus 100, and is a neutral or alkaline aqueous cleaning liquid containing a surfactant, heated by the heater 11 in the cleaning tank 1, and heated by the temperature controller 14. The liquid temperature is adjusted to a range of 40 ° C to 60 ° C. The type of cleaning agent and the heating temperature may be selected according to the object to be cleaned, and are not limited.

  The fine bubble generating unit 6 is connected to the cleaning tank 1, the basket receiver 10 in the cleaning tank 1 and the overflow tank 16 through pipes, and between the cleaning tank 1 and the overflow tank 16 using an internal pump. And the cleaning liquid 2 are circulated between the basket receiver 10 and the basket receiver 10. A filter 12 is installed on the path from the overflow tank 16 back to the fine bubble generating unit 6, and foreign substances contained in the circulating cleaning liquid 2 can be collected and removed.

  The fine bubble generating unit 6 is provided with a gas supply port, and by supplying one or more kinds of air or a gas such as nitrogen or ozone, the gas is mixed while being pressurized in the circulating cleaning liquid 2. A gas solution containing a supersaturated concentration and a large amount of bubbles can be generated. When this pressurized gas solution is sent out to the washing tank 1 and the basket receiver 10, the pressure is reduced and fine bubbles are generated. The fine bubble generating unit 6 used in the present embodiment can generate fine bubbles having a diameter of 100 μm (0.1 mm) or less by, for example, a pressure dissolution method.

  The holder 9 of the basket 8 accommodated in the cleaning tank 1 is supplied with the cleaning liquid 2 containing fine bubbles via the basket receiver 10. As a result, the cleaning liquid 2 containing fine bubbles flows into the inner surface of the tubular object 20 set in the holder 9, and the inner surface of the tubular object 20 that is the object to be cleaned can be effectively circulated and washed.

  The basket 8 is mounted on the basket receiver 10 inside the cleaning tank 1 so that the holder 9 is positioned vertically downward. The holder 9 has a hollow container shape, and is configured to be able to hold a plurality of pieces together in a state where the open end of the tubular object 20 is inserted into the internal space. The cleaning liquid 2 from the fine bubble generating unit 6 flows into the inner space of the holder 9 via the basket receiver 10, and the cleaning liquid 2 can be efficiently introduced into the pipe from the open end of the inserted tubular object 20. It has a possible structure.

  With such a structure, the object to be cleaned held in the holder 9 is arranged vertically above the holder 9, and the cleaning is effectively performed without hindering the upward movement of the fine bubbles. be able to. Furthermore, since it is sufficient that the width of the bottom surface of the basket 8 is about the size of the holder 9, the width of the bottom surface of the basket 8 can be reduced, and the installation area of the cleaning device 101 itself can be reduced.

  It should be noted that the reduction in frictional resistance due to the refinement of bubbles and the influence of the surfactant on the bubble size and behavior have been confirmed by many recent experiments. For example, in the March 2006 issue of “Monthly Eco Industry” published by CMC Publishing Co., Ltd., the behavior of bubbles by surfactants (see page 8 and after) and the miniaturization of bubble diameter by surfactants are described. (Refer to page 29 et seq.), The reduction of the frictional resistance of fine bubbles (see page 42) is described.

  Example 1 in which actual cleaning was performed using the cleaning apparatus 100 illustrated in FIG. 1 and Example 2 in which actual cleaning was performed using the cleaning apparatus 101 illustrated in FIG. 3 will be described.

  The object to be cleaned is made of stainless steel, and has a straight tube shape having an outer diameter of 2.0 mm, an inner diameter of 0.8 mm, and a length of 600 mm, and is mounted on the basket receiver 10 while being held by the holder 9 of the basket 8. .

  As the cleaning liquid, a neutral detergent containing a nonionic surfactant (trade name: M-700L, manufactured by Sharp Manufacturing System Co., Ltd.), which was dissolved in water so that the concentration was 0.5% by weight, was compared. The temperature was adjusted to 40 ° C., which is a low temperature.

FIG. 4 is a process flow diagram illustrating the cleaning method of the first embodiment.
Step A is a circulation cleaning step using fine bubbles. In this step, the circulation cleaning is performed with the operation conditions of the fine bubble generating unit 6 being a cleaning liquid pressure of 0.4 MPa, a flow rate of 15 L / min, and a gas (air) injection amount of 900 mL / min. For 60 seconds.

  The process B includes processes B1 to B4. In the process B1, the ultrasonic oscillator 5 is operated at an output of 600 W and a frequency of 40 kHz, and application of ultrasonic vibration is started. In step B2, for cleaning under reduced pressure, the inside of the cleaning tank 1 is depressurized to 10 kPa (about 75 Torr), the vacuum state is maintained for 30 seconds, and then the atmosphere is released in step B3. Ultrasonic cleaning was performed for 90 seconds from the start of application of ultrasonic vibration, including the vacuum holding time of 30 seconds.

  Step A and step B were set to one cycle (150 seconds), and this cycle was repeated four times for a total of 10 minutes of washing.

FIG. 5 is a process flow diagram illustrating the cleaning method of the second embodiment.
The process A is a circulating cleaning process using fine bubbles as in the first embodiment. In this process, the operating conditions of the fine bubble generating unit 6 are the cleaning liquid pressure 0.4 MPa, the flow rate 15 L / min, and the gas (air) injection amount 900 mL. Circulating washing was performed for 90 seconds at a rate of / min.

  Step B is an ultrasonic cleaning step by ultrasonic vibration performed after the circulation cleaning step. In this step, ultrasonic cleaning was performed for 90 seconds at an output of 300 W and a frequency of 40 kHz.

  Process A and process B were set to 1 cycle (180 seconds), and this cycle was repeated 5 times for a total of 10 minutes of washing.

In the above embodiment, operations such as introduction of detergent and supply / drainage of cleaning liquid are omitted.
As a comparative example, the cleaning apparatus 100 shown in FIG. 1 does not have the configuration for performing the circulating cleaning, that is, the cleaning is performed by the cleaning apparatus that does not perform the circulating cleaning process.

  The tubular article, which is the object to be cleaned, was stained with simulated blood (sheep blood mixed with egg yolk and mucin (pig stomach nuff)), and then washed. For the evaluation, a protein detection method using amide black 10B was used to detect residual stains after washing.

  In the cleaning according to Example 1, residual dirt was not detected after cleaning, and in the cleaning according to the comparative example, residual dirt was detected after cleaning.

It is the schematic which shows the structure of the washing | cleaning apparatus 100 which is embodiment of this invention. 3 is a schematic view showing a configuration of a holder 9. FIG. It is the schematic which shows the structure of the washing | cleaning apparatus 101 which is other embodiment of this invention. 2 is a process flow diagram illustrating a cleaning method of Example 1. FIG. 6 is a process flow diagram illustrating a cleaning method of Example 2. FIG. It is a figure which shows one example of the conventional immersion ultrasonic cleaning method. It is a figure which shows one example of the conventional air bubbling washing | cleaning method which stirs a washing | cleaning liquid with a bubble and wash | cleans to-be-washed | cleaned material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cleaning tank 2 Cleaning liquid 3 Lid 4 Ultrasonic vibrator 5 Ultrasonic oscillator 6 Fine bubble generation unit 7 Vacuum pump 8 Basket 9 Holder 10 Basket holder 11 Heating heater 12 Filter 13 Pressure gauge 14 Temperature controller 15a Atmospheric release valve 15b Vacuum exhaust Valve 16 Overflow tank 20 Tubular material 21 Object to be cleaned 22 Nozzle (porous body)
100, 101 Cleaning device

Claims (9)

In a cleaning method of cleaning an object to be cleaned by immersing the object in a cleaning liquid stored in a cleaning tank and applying ultrasonic vibration to the cleaning liquid,
While the cleaning object is immersed in the cleaning liquid, the cleaning liquid in which one or more kinds of gases are dissolved is circulated, and fine bubbles are generated by the gas inside the cleaning tank to clean the cleaning object for a first predetermined time. A circulating cleaning process to be performed;
A cleaning method, wherein the cleaning object is separately performed in an ultrasonic cleaning step in which the object to be cleaned is immersed in the cleaning liquid to apply ultrasonic vibration to the cleaning liquid to clean the object to be cleaned for a second predetermined time .   The cleaning method according to claim 1, wherein the ultrasonic cleaning step is performed in a state where the inside of the cleaning tank is decompressed.   The cleaning method according to claim 1 or 2, wherein the circulation cleaning step and the ultrasonic cleaning step are defined as one cycle, and the cycle is repeated a plurality of times.   The cleaning method according to any one of claims 1 to 3, wherein in the circulation cleaning step, the cleaning liquid is introduced into a tube of the tubular object through a holder that holds the tubular object that is the object to be cleaned. . In a cleaning device for cleaning an object to be cleaned by immersing the object in a cleaning liquid stored in a cleaning tank and applying ultrasonic vibration to the cleaning liquid,
A cleaning tank for storing the cleaning liquid;
Circulating means for circulating a cleaning liquid in which one or more kinds of gas are dissolved, and generating fine bubbles by the gas inside the cleaning tank;
Ultrasonic application means for applying ultrasonic vibration to the cleaning liquid;
Holding means for holding the object to be cleaned inside the cleaning tank,
By operating the circulation means, a circulation cleaning mode in which fine bubbles are generated by the gas inside the cleaning tank and cleaning the object to be cleaned is performed for a first predetermined time, and the ultrasonic wave applying means is operated. A cleaning apparatus configured to be capable of switching to any one of an ultrasonic cleaning mode in which an ultrasonic vibration is applied to a cleaning liquid to clean an object to be cleaned for a second predetermined time.   The cleaning apparatus according to claim 5, further comprising a decompression unit that decompresses the inside of the cleaning tank.   The holding means has a hollow container shape and is configured to be able to hold a plurality of tubular objects in a state in which an open end portion of the tubular object to be cleaned is inserted into the internal space, The cleaning apparatus according to claim 5 or 6, wherein the cleaning liquid from the circulation means is configured to flow into the internal space.   The cleaning device according to any one of claims 5 to 7, wherein the holding means holds a tubular object to be cleaned in parallel with a vertical direction.   The cleaning apparatus according to claim 5, wherein the holding unit is configured to be detachable from the cleaning tank.

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