JP5704304B2 - Cleaning device - Google Patents

Description

  The present invention relates to a cleaning apparatus for cleaning electronic parts, machine parts and the like in addition to medical instruments.

  Conventionally, a cleaning device disclosed in Patent Document 1 below is known. As described in [0033] and [0034], the cleaning device described in Patent Document 1 opens the exhaust valve (23b) while the exhaust device (30) is in operation, and the cleaning tank (20). The inside is depressurized and the cleaning liquid (24) is boiled. Thereafter, as described in [0037], the leak valve (26) is opened with the exhaust valve (23b) closed, and the outside air is introduced from the air guide pipe (25) by the pressure difference between the inside and outside of the cleaning tank (20). . In this way, as described in [0038], the introduced outside air becomes bubbles to come into contact with the object to be cleaned, the cleaning liquid is oscillated by the bubbles, or an impact at the time of pressure release is applied to the cleaning effect. Is going to get.

Japanese Patent Laid-Open No. 10-10509 (paragraph numbers 0025-0041, FIG. 1)

  However, the cleaning apparatus described in Patent Document 1 causes the cleaning liquid in the cleaning tank to suddenly boil (violently boil), greatly oscillates the cleaning liquid by explosive spraying of the cleaning liquid and subsequent dropping, and It is not intended to clean the wash.

  That is, in the cleaning apparatus described in Patent Document 1, after the pressure in the cleaning tank is reduced, “exhaust valve 23b is closed and leak valve 26 is opened”, and outside air is introduced into the liquid phase portion. If the exhaust valve is closed inside, the gas phase part is immediately filled with steam, and boiling stops.

  As described above, the cleaning apparatus described in Patent Document 1 naturally introduces the outside air into the cleaning liquid using the pressure difference from the atmospheric pressure while continuing the operation of the decompression unit during the boiling of the cleaning liquid, The bubbles do not cause bumping in the cleaning liquid.

  On the other hand, the applicant first warms the liquid in the washing tank to the set temperature, then depressurizes the inside of the washing tank to boil the liquid, and during this boiling, outside air is poured into the liquid phase part in the washing tank. Introducing a cleaning device that cleans an object to be cleaned by bumping a liquid, has already filed a patent application (Japanese Patent Application No. 2010-43688).

  In this apparatus, while the liquid is boiling, the outside air is naturally sucked by the pressure difference from the atmospheric pressure. In this case, the pressure of the bubbles introduced into the liquid becomes the pressure in the cleaning tank itself until the first bubbles reach the gas phase portion. Therefore, by introducing air bubbles into the liquid, the introduced bubbles expand explosively using the introduced gas as the core of boiling. Specifically, the bubbles introduced into the liquid expand in the washing tank under reduced pressure, and further rise when the liquid boiling vapor enters, and then rise in the liquid phase part. In this way, the liquid can be boiled, and the liquid can be greatly swung by the explosive jetting of the liquid and the subsequent dropping, thereby effectively cleaning the object to be cleaned.

  As for the cleaning apparatus using such bumping, the inventor has made eager researches after that, and as a result, bumping due to supply of air to the liquid phase part can be said to be the temperature of the liquid in the cleaning tank (pressure in the cleaning tank). ). That is, the higher the temperature of the liquid (the pressure in the cleaning tank can be said to be high), the smaller the temperature difference between the upper and lower layers of the liquid in the cleaning tank, so even if air bubbles that become the core of boiling are introduced, It was found that overheating area was not possible and bumping was difficult to occur.

  Specifically, FIG. 3 is a diagram showing the relationship between the saturation pressure and the saturation temperature of the liquid in the cleaning tank, but the same pressure difference ΔP (specifically, the upper and lower layers of the stored liquid in the cleaning tank). It can be seen that the temperature difference ΔT, ΔT ′ corresponding to the water head pressure becomes smaller as the pressure becomes higher (ΔT> ΔT ′). In order to cause the liquid to bump, a superheated region is required in the liquid. Therefore, a small temperature difference is disadvantageous for inducing bumping.

  The present invention has been made in view of these circumstances, and an object of the present invention is to provide a cleaning device that reliably bumps a liquid and effectively cleans an object to be cleaned by the bumping.

The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 is a cleaning tank for storing an aqueous solution and immersing an object to be cleaned, and heating the aqueous solution in the cleaning tank. A heating means, a decompression means connected to a gas phase part in the cleaning tank, sucking and discharging the gas in the cleaning tank to the outside, and depressurizing the cleaning tank, and a liquid phase part in the cleaning tank And a liquid phase air supply means for opening a liquid phase air supply valve in a state where the inside of the cleaning tank is decompressed, and after heating the aqueous solution in the cleaning tank to the first set temperature by the heating means, Until the set condition is satisfied, the pressure in the cleaning tank is reduced by the pressure reducing means to boil the aqueous solution, and during the boiling, the liquid phase air supply valve is opened while the operation of the pressure reducing means is continued. Introducing outside air into the liquid in the cleaning tank from below the object to be cleaned by the pressure difference inside and outside, The aqueous solution in the washing tank is bumped and the setting condition is that the aqueous solution in the washing tank reaches a second set temperature or the inside of the washing tank reaches a second set pressure, and the second The set temperature is set to 60 ° C. or less, the second set pressure is set to 20 kPa or less, and the first set temperature is 0.5 to 2 ° C. higher than the saturation temperature at the second set temperature or the second set pressure. The cleaning device is characterized in that it is set as follows.

  According to the first aspect of the present invention, after the aqueous solution is heated to the first set temperature, the inside of the washing tank is depressurized to boil the aqueous solution, and during this boiling, the liquid phase supply is continued while the operation of the depressurization means is continued. Open the air valve and introduce the outside air into the liquid by the pressure difference inside and outside the washing tank. In this apparatus, while the aqueous solution is boiling, the outside air is naturally sucked by the differential pressure from the atmospheric pressure. In this case, the pressure of the bubbles introduced into the liquid becomes the pressure in the cleaning tank itself until the first bubbles reach the gas phase portion. Therefore, by introducing air bubbles into the liquid, the introduced bubbles expand explosively using the introduced gas as the core of boiling. Specifically, the bubbles introduced into the liquid expand in the washing tank under reduced pressure, and further rise when the boiling vapor of the aqueous solution enters, and rise in the liquid phase part. In this way, it is possible to effectively wash the object to be cleaned by causing the aqueous solution to boil and causing the aqueous solution to largely shake by the explosive jetting of the aqueous solution and the subsequent dropping. In particular, the temperature of the aqueous solution is set to 60 ° C. or lower or the inside of the washing tank is set to 20 kPa or less to introduce the outside air into the liquid, thereby ensuring a temperature difference between the upper layer and the lower layer of the aqueous solution, generating an overheating region, and bumping Can surely occur.

  The invention according to claim 2 is the cleaning apparatus according to claim 1, wherein the second set temperature is set to 50 ° C. or less, and the second set pressure is set to 12.3 kPa or less.

  According to the second aspect of the present invention, the aqueous solution is brought to 50 ° C. or lower, or the inside of the washing tank is set to 12.3 kPa or lower, and the aqueous solution is more reliably and violently bumped by introducing the outside air into the liquid. Can do.

  Further, the invention according to claim 3 is the heating of the aqueous solution up to the first set temperature by the heating means, and the pressure reducing means until the set condition is satisfied in a state where the liquid phase air supply valve is closed. 3. The pressure reduction in the washing tank by the step of the above, and the bumping of the aqueous solution by the introduction of the outside air into the liquid by the liquid phase air supply means during the boiling of the aqueous solution by the step are repeated in order. The cleaning apparatus according to claim 1.

  According to the invention described in claim 3, by repeatedly heating the aqueous solution, reducing the pressure in the cleaning tank, and thereby bumping the aqueous solution by introducing the outside air into the boiling liquid, Cleaning can be achieved more reliably.

  According to the present invention, it is possible to reliably bump an aqueous solution and effectively wash an object to be cleaned by the bumping.

It is the schematic which shows one Embodiment of the washing | cleaning apparatus of this invention, and shows a part in cross section. It is a figure which shows the driving | running state of the washing | cleaning apparatus of FIG. 1, and the graph has shown the relationship between the liquid temperature (vertical axis) and elapsed time (horizontal axis) in a washing tank, (A) to (C) is It is a time chart shown corresponding to a graph. It is a figure which shows the relationship between the saturation pressure of the aqueous solution in a washing tank, and saturation temperature.

  Hereinafter, an embodiment of a cleaning apparatus of the present invention will be described in detail with reference to the drawings. However, the cleaning apparatus of the present invention is not limited to the following embodiments, and can be appropriately changed.

  FIG. 1 is a schematic view showing an embodiment of the cleaning apparatus of the present invention, and a part thereof is shown in cross section. The cleaning apparatus 1 according to the present embodiment includes a cleaning tank 3 that stores liquid (cleaning liquid) and immerses an object to be cleaned 2, heating means 4 that heats the liquid in the cleaning tank 3, and the cleaning tank 3 Decompression means 5 that sucks and discharges the gas to the outside and decompresses the inside of the cleaning tank 3, liquid phase supply means 6 that introduces outside air into the liquid phase portion in the decompressed cleaning tank 3, and a decompressed cleaning tank 3 is provided with a gas-phase air supply means 7 for introducing outside air into the gas-phase portion in the apparatus 3. Furthermore, the cleaning apparatus 1 includes a pressure sensor 8 that detects the pressure of the gas phase portion in the cleaning tank 3, a temperature sensor 9 that detects the temperature of the liquid phase portion in the cleaning tank 3, and detection of these sensors 8 and 9. And control means (not shown) for controlling the means 4 to 7 based on signals and the like.

  The cleaning tank 3 is a hollow container that can withstand pressure reduction in the internal space. The cleaning tank 3 includes a main body 10 that opens upward and has a hollow portion, and a door 11 that opens and closes the opening of the main body 10. With the door 11 closed, the gap between the main body 10 and the door 11 is sealed with the packing 12. Thereby, the hollow part of the main body 10 is sealed, and a sealed space is formed in the cleaning tank 3.

  The object to be cleaned 2 is accommodated in the cleaning tank 3, and the liquid is stored up to a set liquid level (150 to 250 mm, for example, 200 mm in this embodiment) from the bottom surface in the cleaning tank 3 when the object to be cleaned 2 is immersed. Is done. The liquid stored in the cleaning tank 3 is not particularly limited as long as it is an aqueous solution, and is, for example, water (specifically pure water) or water containing a detergent. In this embodiment, it is water containing 0.5% detergent. The article to be cleaned 2 is an article to be cleaned, and is, for example, a medical instrument, an electronic component, or a mechanical component.

  The cleaning tank 3 is provided with a pressure sensor 8 that detects the pressure of the gas phase part in the cleaning tank 3 and a temperature sensor 9 that detects the temperature of the liquid phase part in the cleaning tank 3.

  The heating means 4 warms the liquid in the cleaning tank 3. Although the specific structure in particular is not ask | required, the heating means 4 is the electric heater 13 arrange | positioned in the bottom part in the washing tank 3 in this embodiment. In this case, the liquid in the cleaning tank 3 can be heated by energizing the electric heater 13 with the liquid stored in the cleaning tank 3.

  The decompression means 5 is connected to a gas phase portion in the cleaning tank 3 and sucks and discharges the gas in the cleaning tank 3 to the outside to decompress the inside of the cleaning tank 3. Specifically, the decompression unit 5 includes a vacuum generator 14, and the vacuum generator 14 is connected to a gas phase portion in the cleaning tank 3 through an exhaust passage 15. The specific structure of the vacuum generator 14 is not particularly limited. Typically, the vacuum generator 14 includes a water-sealed vacuum pump, and a heat exchanger that condenses the vapor in the exhaust passage 15 is provided upstream of the vacuum pump. Further, it may be provided. Further, the exhaust passage 15 may be provided with an air / water separator such as a demister in order to remove liquid droplets and solids contained in the gas from the cleaning tank 3 at the outlet of the cleaning tank 3. .

  The liquid phase air supply means 6 is connected to the liquid phase part in the cleaning tank 3, and external air is supplied to the liquid phase part in the cleaning tank 3 by the differential pressure between the pressure in the cleaning tank 3 and the atmospheric pressure outside the cleaning tank. Introduce. Specifically, the liquid phase air supply means 6 introduces outside air into the liquid phase portion in the pressure-reduced cleaning tank 3 through the liquid phase air supply path 16. The liquid phase air supply path 16 is provided with a filter 17 and a liquid phase air supply valve 18 in order toward the cleaning tank 3. Therefore, when the liquid-phase air supply valve 18 is opened in a state where the pressure in the cleaning tank 3 is reduced, air through the filter 17 is introduced into the liquid phase portion in the cleaning tank 3 due to the pressure difference inside and outside the cleaning tank 3. can do.

  By the way, in this embodiment, the air from the liquid phase air supply path 16 is introduced into the liquid in the cleaning tank 3 via the liquid phase air supply nozzle 19 provided at the bottom in the cleaning tank 3. The liquid-phase air supply nozzle 19 is a pipe disposed laterally at the bottom of the cleaning tank 3. In this embodiment, this pipe is provided so as to meander the bottom of the cleaning tank 3. In addition, the pipe is held at the bottom in the cleaning tank 3 but horizontally from the bottom. Furthermore, nozzle holes 20 are formed in the pipe so as to open downward on the peripheral side wall of the pipe at set intervals along the extending direction. Thereby, if the liquid phase air supply valve 18 is opened in a state where the inside of the cleaning tank 3 is depressurized, air can be uniformly introduced into the liquid in the cleaning tank 3.

  The gas-phase air supply means 7 is connected to the gas-phase part in the cleaning tank 3, and the outside air is supplied to the gas-phase part in the cleaning tank 3 by the differential pressure between the pressure in the cleaning tank 3 and the atmospheric pressure outside the cleaning tank 3. Is introduced. Specifically, the gas phase air supply means 7 introduces outside air into the gas phase portion in the pressure-reduced cleaning tank 3 through the gas phase air supply path 21. A filter 22 and a gas phase air supply valve 23 are provided in the gas phase air supply path 21 in order toward the cleaning tank 3. Therefore, when the gas-phase gas supply valve 23 is opened in a state where the pressure in the cleaning tank 3 is reduced, air through the filter 22 is introduced into the gas-phase portion in the cleaning tank 3 due to the differential pressure inside and outside the cleaning tank 3. can do.

  The control means controls the means 4 to 7 based on the detection signals of the sensors 8 and 9. Specifically, in addition to the electric heater 13, the vacuum generator 14, the liquid phase air supply valve 18, and the gas phase air supply valve 23, the pressure sensor 8 and the temperature sensor 9 are connected to control means. Then, as described below, the control means cleans the article 2 to be cleaned in the cleaning tank 3 according to a predetermined procedure (program).

Hereinafter, an example of the operation method of the cleaning apparatus 1 of the present embodiment will be described.
FIG. 2 is a diagram showing the operating state of the cleaning device 1 of the present embodiment, and the graph shows the relationship between the liquid temperature (vertical axis) and the elapsed time (horizontal axis) in the cleaning tank 3, A) to (C) are time charts corresponding to the graphs. Here, (A) shows the presence or absence of the operation of the electric heater 13, (B) shows the presence or absence of the operation of the vacuum generator 14, and (C) shows opening and closing of the liquid phase supply valve 18.

  First, the object to be cleaned 2 is accommodated in the cleaning tank 3 and the liquid is stored, so that the object to be cleaned 2 is immersed in the stored liquid in the cleaning tank 3. Thereafter, a heating operation S1 for heating the liquid in the cleaning tank 3 to the first set temperature T1, a decompression operation S2 for reducing the pressure in the cleaning tank 3 until the set condition is satisfied, and an outside air in the liquid in the cleaning tank 3 And the liquid-phase air supply operation S3 for causing the liquid in the cleaning tank 3 to boil off in order. Thereafter, the heating operation S1, the pressure reducing operation S2, and the liquid phase air supply operation S3 are repeated until desired end conditions are satisfied as desired. Hereinafter, the first operations S1 to S3 will be described first, and then the second and subsequent operations S1 to S3 will be described.

  In the first heating operation S1, the liquid in the cleaning tank 3 is heated until the liquid in the cleaning tank 3 reaches the first set temperature T1. Specifically, the electric heater 13 may be operated with the liquid phase supply valve 18 and the gas phase supply valve 23 closed and the vacuum generator 14 stopped. During the heating operation S1, the temperature of the liquid in the cleaning tank 3 is monitored by the temperature sensor 9, and when the liquid in the cleaning tank 3 reaches the first set temperature T1, the electric heater 13 is stopped and the heating operation S1 is performed. Exit.

  In the first decompression operation S2, the inside of the cleaning tank 3 is decompressed using the decompression means 5 until the set condition is satisfied. Specifically, the vacuum generator 14 may be operated with the liquid phase supply valve 18 and the gas phase supply valve 23 closed. The setting condition is that the liquid in the cleaning tank 3 reaches the second set temperature T2, the inside of the cleaning tank 3 reaches the second set pressure P2, or a set time that satisfies these conditions elapses. Note that the second set temperature T2 is the saturation temperature at the second set pressure P2, and conversely, the second set pressure P2 is the saturation pressure at the second set temperature T2, and the second set temperature T2 and the second set temperature T2. There is a predetermined relationship with the two set pressures P2.

  As will be clarified in Examples to be described later, the second set temperature T2 is set to 60 ° C. or less, and the second set pressure P2 is set to 20 kPa or less. In particular, the second set temperature T2 is preferably set to 50 ° C. or less, and the second set pressure P2 is set to 12.3 kPa or less. The first set temperature T1 may be set based on the second set temperature T2 (or the saturation temperature at the second set pressure P2). Specifically, the first set temperature T1 is set to a temperature that is higher than the second set temperature T2 by a predetermined temperature (for example, 0.5 to 2 ° C.). In any case, in the decompression operation S2, the liquid in the cleaning tank 3 boils, and during the boiling, a liquid phase air supply operation S3 described below is executed.

  The first liquid-phase air supply operation S3 is performed by using the liquid-phase air supply unit 6 while continuing the operation of the pressure-reducing unit 5 by the pressure-reducing operation S2. Outside air is introduced into the liquid in the cleaning tank 3 from below. Specifically, the liquid phase air supply valve 18 is opened while the operation of the vacuum generator 14 is continued, and the filter 17, the liquid phase air supply path 16, and the liquid phase air supply nozzle 19 are caused by the differential pressure from the atmospheric pressure. The outside air is introduced into the stored liquid via

  Thus, in the cleaning apparatus 1 of the present embodiment, the outside air is naturally sucked by the pressure difference from the atmospheric pressure without being pushed by the blower while the liquid in the cleaning tank 3 is boiling. In this case, the pressure of the bubbles introduced into the liquid becomes the pressure itself in the cleaning tank 3 until the first bubbles reach the gas phase portion. Therefore, by introducing air bubbles into the liquid, the introduced bubbles expand explosively using the introduced gas as the core of boiling. Specifically, the bubbles introduced into the liquid expand in the washing tank 3 under reduced pressure, and further rise when the liquid boiling vapor enters, and rise in the liquid phase part. In this way, the liquid to be cleaned can be effectively washed by causing the liquid to boil and oscillating the liquid largely by the explosive jetting of the liquid and the subsequent dropping.

  The air supplied to the liquid phase part by the liquid phase air supply means 6 eventually reaches the gas phase part and returns the pressure in the cleaning tank 3. In the liquid phase air supply operation S3, the inside of the cleaning tank 3 may be returned to atmospheric pressure. However, when the set of the heating operation S1, the pressure reduction operation S2, and the liquid phase air supply operation S3 is repeated, If the pressure is restored to atmospheric pressure, the decompression time is wasted in the next decompression operation. Therefore, it is preferable to close the liquid-phase air supply valve 18 so as to stop at the predetermined pressure below atmospheric pressure.

  Thereafter, if desired, the heating operation S1 is performed again. In the heating operation S1, the electric heater 13 is energized to heat the liquid in the cleaning tank 3 to the first set temperature T1. In this heating operation S1, the vacuum generator 14 continues to operate, but may be stopped depending on circumstances. When the operation of the vacuum generator 14 is continued in the heating operation S1, the liquid in the cleaning tank 3 will boil if the liquid-phase air supply valve 18 is closed. The operation of opening the air valve 18 is repeated. When the liquid in the cleaning tank 3 reaches the first set temperature T1, the electric heater 13 is stopped and the pressure reduction operation S2 is performed thereafter.

  The decompression operation S2 is the same as the first decompression operation S2 described above, and the liquid phase supply valve 18 is maintained in a closed state, for example, the liquid in the cleaning tank 3 reaches the second set temperature T2. Until the set condition is satisfied, the inside of the cleaning tank 3 is decompressed by the vacuum generator 14 to boil the stored liquid. When this setting condition is satisfied, the liquid phase air supply operation S3 is performed.

  The liquid phase air supply operation S3 is the same as the first liquid phase air supply operation S3 described above, and the liquid phase air supply valve 18 is opened during the boiling of the stored liquid so that the stored liquid in the cleaning tank 3 is in the stored liquid. The outside air is introduced, and the stored liquid is suddenly boiled using the introduced air bubbles as the core of boiling. By the explosive ejection of the liquid due to the bumping and the subsequent dropping, the liquid can be largely swung to effectively clean the article 2 to be cleaned.

  In this way, the heating operation S1, the pressure reducing operation S2, and the liquid phase air supply operation S3 are repeated until a predetermined end condition is satisfied. As the end condition, the end point of the first heating operation S1 is set. Elapsed time from the above and the number of executions of the liquid phase air supply operation S3 can be employed.

  If the end condition is satisfied, the liquid-phase supply valve 18 is closed, the electric heater 13 and the vacuum generator 14 are stopped, the gas-phase supply valve 23 is opened, and the inside of the cleaning tank 3 is returned to atmospheric pressure. Just press. Thereafter, if desired, the liquid in the cleaning tank 3 may be exchanged to clean the object to be cleaned 2 again, or the object to be cleaned 2 may be dried. In the present embodiment, the washing includes rinsing.

  By the way, in each pressure reduction operation | movement S2 mentioned above, although the heating means 4 was stopped, you may continue an action | operation depending on the case.

  Using the cleaning device 1 of the above embodiment, the relationship between the pressure in the cleaning tank 3 immediately before the liquid-phase air supply operation S3 and the bumping phenomenon was examined. The results are shown in Table 1.

  Table 1 shows the pressure in the cleaning tank 3 immediately before opening the liquid phase air supply valve 18, the temperature difference between the upper and lower layers of the stored liquid in the cleaning tank 3, the presence or absence of visual bumping, It is a table | surface which shows the relationship with the intensity | strength of sound in gas operation | movement S3 (during bumping). In addition, in the state which the to-be-cleaned object 2 was immersed in the stored liquid in the washing tank 3, the water depth of the stored liquid is 200 mm. In addition, the louder the bumps, the louder the sound, the greater the decibel value.

  As is apparent from this table, bumping occurs if the internal pressure of the washing tank 3 immediately before starting the liquid phase air supply operation S3 is 19.9 kPa or less (corresponding to a temperature of the stored liquid of 60 ° C. or less). When the pressure was 3 kPa (corresponding to the stored liquid temperature of 50 ° C. or lower), clear bumping was observed.

  As shown in FIG. 3, even if this cause is the same pressure difference ΔP (specifically, the pressure difference due to the head pressure between the upper layer and the lower layer of the stored liquid in the cleaning tank 3), the corresponding temperature difference ΔT , ΔT ′ becomes smaller as the pressure becomes higher (ΔT> ΔT ′). That is, the higher the temperature (that is, the higher the pressure in the cleaning tank 3), the smaller the temperature difference between the upper layer and the lower layer of the stored liquid, and even if air (boiling nuclei) is introduced, an overheating region is not formed and bumping does not occur. it is conceivable that. And it can be seen from Table 1 that the temperature difference in which bumping occurs between the upper layer and the lower layer of the stored liquid is 20 kPa or less, more preferably 15 kPa or less in the cleaning tank 3.

DESCRIPTION OF SYMBOLS 1 Cleaning apparatus 2 Object to be cleaned 3 Cleaning tank 4 Heating means 5 Depressurizing means 6 Liquid phase air supply means 7 Gas phase air supply means 8 Pressure sensor 9 Temperature sensor 13 Electric heater 14 Vacuum generator 18 Liquid phase air supply valve T1 No. 1 One set temperature T2 Second set temperature

Claims (3)

A cleaning tank for storing an aqueous solution and immersing an object to be cleaned;
A heating means for heating the aqueous solution in the washing tank;
A pressure reducing means connected to a gas phase portion in the cleaning tank, sucking and discharging the gas in the cleaning tank to the outside, and depressurizing the cleaning tank;
A liquid phase supply means connected to the liquid phase portion in the cleaning tank and opening the liquid phase supply valve in a state where the pressure in the cleaning tank is reduced,
After the aqueous solution in the cleaning tank is heated to the first set temperature by the heating means, the aqueous solution is boiled by reducing the pressure in the cleaning tank by the pressure reducing means until a set condition is satisfied. The liquid phase air supply valve is opened while the operation of the means is continued, and external air is introduced into the liquid in the cleaning tank from below the object to be cleaned by the differential pressure inside and outside the cleaning tank, and the cleaning Bump the aqueous solution in the tank,
The set condition is that the aqueous solution in the cleaning tank reaches a second set temperature, or the inside of the cleaning tank reaches a second set pressure, and the second set temperature is 60 ° C. or less, the second set temperature. The set pressure is set to 20 kPa or less ,
The first preset temperature is set to a temperature higher by 0.5 to 2 ° C than the saturation temperature at the second preset temperature or the second preset pressure . The cleaning apparatus according to claim 1, wherein the second set temperature is set to 50 ° C. or less, and the second set pressure is set to 12.3 kPa or less. Heating the aqueous solution to the first set temperature by the heating means;
Depressurization in the washing tank by the depressurization means until the set condition is satisfied in a state where the liquid phase air supply valve is closed,
The cleaning apparatus according to claim 1 or 2, wherein the aqueous solution bumping by the introduction of the outside air into the liquid by the liquid phase air supply means during the boiling of the aqueous solution is repeated in order.

Images