WO2010137212A1

WO2010137212A1 - Cleaning device and cleaning method

Info

Publication number: WO2010137212A1
Application number: PCT/JP2010/001596
Authority: WO
Inventors: 藤井慎二
Original assignee: 三浦工業株式会社
Priority date: 2009-05-28
Filing date: 2010-03-08
Publication date: 2010-12-02
Also published as: JP2011005480A; JP5582450B2; KR20120022850A; CN102413952B; KR101369848B1; CN102413952A

Abstract

A cleaning liquid is contained in a cleaning tank (3), and an object (2) to be cleaned is immersed in the cleaning liquid. A pressure reducing means (5) reduces the pressure in the cleaning tank (3) by sucking gas in the cleaning tank (3) and discharging the gas to the outside. A heating means (7) heats the cleaning liquid within the cleaning tank (3). A gas supply means (6) introduces gas into the cleaning liquid within the cleaning tank (3) from a position below the object (2) to be cleaned. After the cleaning liquid is heated to a preset temperature by the heating means (7), the pressure within the cleaning tank (3) is reduced by the pressure reducing means (5) to boil the cleaning liquid, and the gas is introduced into the cleaning liquid by the gas supply means (6) during the boiling. By this, the cleaning liquid is fiercely boiled to increase the effect of cleaning of the object (2) to be cleaned.

Description

Cleaning apparatus and cleaning method

The present invention relates to a cleaning apparatus and a cleaning method for cleaning electronic parts, machine parts and the like in addition to medical instruments. This application claims priority based on Japanese Patent Application No. 2009-128369 filed in Japan on May 28, 2009 and Japanese Patent Application No. 2010-043688 filed in Japan on March 1, 2010, and the contents thereof. Is hereby incorporated by reference.

Conventionally, as disclosed in Patent Document 1 below, a chamber that contains an object to be cleaned is filled with cleaning water, and the chamber is depressurized to boil the cleaning water. A cleaning method for cleaning an object to be cleaned by a rocking motion using bubbles is known. In this case, the lower layer of the cleaning water is less likely to boil than the upper layer due to the difference in water pressure between the upper and lower positions of the cleaning water, and the amount of bubbles generated is reduced. Therefore, the lower layer of the cleaning water is heated by the heater.

Conventionally, as disclosed in Patent Document 2 below, a gas solution containing a supersaturated concentration and a large amount of bubbles in which one or more kinds of gas are dissolved is used as a cleaning liquid, and the inside of the cleaning tank is at atmospheric pressure. , A circulating cleaning process for performing cleaning by circulating cleaning liquid for a predetermined time, and an ultrasonic cleaning process for performing ultrasonic cleaning for a predetermined time by applying ultrasonic vibration to the cleaning liquid in a state where the inside of the cleaning tank is at atmospheric pressure or reduced pressure There is known a cleaning method including:

JP-A-61-109567 JP 2008-119642 A (paragraph number 0061)

However, in the case of the invention described in Patent Document 1, a heater is necessary to eliminate the influence of water pressure at the upper and lower positions of the cleaning water. Nor does it create "boiling nuclei" to induce boiling, nor does it explodely intensify boiling. When the pressure is reduced from the bottom of the cleaning tank while heating with a heater or the like, the bubbles generated from below the cleaning water dissolve into the surrounding cleaning liquid as it rises, and finely shrink and break up. The effect is not obtained.

Further, in the case of the invention described in Patent Document 2, the object to be cleaned is supplied by supplying bubbles into the cleaning liquid, but the cleaning is performed at atmospheric pressure, and the cleaning liquid is boiled. Absent.

The problem to be solved by the present invention is to achieve effective cleaning of an object to be cleaned by causing boiling with a simple configuration and control and causing boiling to occur vigorously.

The present invention has been made to solve the above-mentioned problems, and the first invention thereof is a cleaning tank in which a cleaning liquid is stored and an object to be cleaned is immersed in the cleaning liquid, and a gas in the cleaning tank is externally provided. In a state in which the pressure of the gas phase portion in the cleaning tank is lowered to a pressure equal to or lower than the vapor pressure of the cleaning liquid in the cleaning tank by the pressure reducing means for reducing the pressure in the cleaning tank by sucking and discharging, The cleaning apparatus includes an air supply unit that introduces gas into the cleaning liquid in the cleaning tank from below the object to be cleaned.

According to the first invention, in the state where the object to be cleaned is immersed in the cleaning liquid in the cleaning tank, the cleaning liquid is boiled by reducing the pressure in the cleaning tank, and the object to be cleaned is cleaned by the oscillation of the cleaning liquid. it can. When boiling the cleaning liquid, based on the difference in water pressure at the upper and lower positions of the cleaning liquid and the difference in liquid temperature depending on the location, boiling does not occur overall, boiling is slow and explosive and intense boiling does not occur, There is a risk that even if such intense boiling occurs, it may occur locally and sporadically. However, according to the first invention, by introducing gas into the cleaning liquid by the air supply means, Can be prevented. In other words, when the gas is temporarily introduced from the bottom of the washing tank while boiling, the introduced gas becomes the core of the boiling, and a violent boiling occurs in the boundary layer between the introduced gas and the cleaning liquid, particularly in the lower layer, Large bubbles are formed. As the large bubbles are raised, the cleaning liquid is greatly blown up. Immediately after that, the sprayed cleaning liquid falls. The explosive cleaning liquid spraying and the subsequent dropping can greatly oscillate the cleaning liquid in the cleaning tank and can effectively clean the object to be cleaned.

In addition to the constituent features of the first invention, the second invention further includes heating means for heating the cleaning liquid in the cleaning tank, and after heating the cleaning liquid to a set temperature by the heating means, the pressure reducing means causes the cleaning tank to be used. The cleaning apparatus is characterized in that the inside is decompressed to boil the cleaning liquid, and the gas is introduced into the cleaning liquid by the air supply means during the boiling.

According to the second aspect of the present invention, the cleaning liquid is heated up to the set temperature by the heating means in advance, so that boiling can be stably and surely generated, and the cleaning effect can be stabilized. Moreover, by introducing a gas into the cleaning liquid during the boiling of at least a part of the cleaning liquid, the gas supplied into the cleaning liquid is used as a “boiling core” to surely cause boiling and explosive boiling. be able to.

In addition to the constituent features of the second invention, the third invention stops the introduction of gas into the cleaning liquid by the air supply means, and re-boils the cleaning liquid without reheating the cleaning liquid to the set temperature or without reheating. The cleaning apparatus is characterized by repeating the pressure reduction in the cleaning tank until and the introduction of gas into the cleaning liquid by the air supply means during boiling.

According to the third invention, the object to be cleaned can be reliably cleaned by repeating the decompression in the cleaning tank, the introduction of the gas into the boiling cleaning liquid, and the stop of the introduction of the gas. . Before the pressure in the cleaning tank is reduced, the cleaning liquid may be heated to a set temperature or may not be heated. If heated to the set temperature, the cleaning effect can be stabilized, and if not heated to the set temperature, the cleaning time can be shortened accordingly.

A fourth aspect of the present invention, in addition to the constituent elements of the second aspect or the third aspect, introduces a gas into the gas phase portion in the cleaning tank that has been decompressed by the decompression means, and restores the pressure in the cleaning tank. Means for further heating, holding the cleaning liquid up to the set temperature by the heating means, and continuing the pressure reduction in the cleaning tank by the pressure reducing means so that the cleaning liquid continues to boil, and during the pressure reduction, the cleaning The pressure inside the tank is repeatedly temporarily restored until boiling of the cleaning liquid stops, and while the cleaning liquid is maintained at the set temperature, the pressure in the cleaning tank is reduced by the pressure reducing means, and the boiling of the cleaning liquid is thereby caused. The cleaning apparatus is characterized by performing gas introduction by an air supply means.

According to the fourth aspect of the invention, in addition to the means for supplying air to the liquid phase part of the cleaning tank, and the means for returning pressure to the gas phase part of the cleaning tank, it is possible to use in combination with the following cleaning method. That is, the pressure in the cleaning tank is reduced by the pressure reducing means to boil the cleaning liquid, and during this boiling, the pressure in the cleaning tank is instantaneously restored by the pressure recovery means to stop the boiling of the cleaning liquid at once. At the time of this pressure recovery, water vapor bubbles generated in the cleaning liquid due to boiling until then are condensed instantly. Therefore, the cleaning liquid is stirred and transferred by the pressure wave and pressure difference during the condensation, and the object to be cleaned is cleaned. In addition, although the pressure in the cleaning tank causes a vapor pool in the pipe or hole of the object to be cleaned, such a vapor pool disappears instantaneously due to the return pressure in the cleaning tank. Accordingly, the cleaning liquid can be vigorously moved into and out of the pipe or hole of the object to be cleaned, thereby cleaning the object to be cleaned. Before such a process, it is preferable to heat and maintain the cleaning liquid at a set temperature. During that time, the object to be cleaned is removed by reducing the pressure in the cleaning tank and introducing gas into the boiling cleaning liquid. If cleaning is performed, the heating and holding time of the cleaning liquid is not wasted.

According to a fifth aspect of the invention, in addition to any of the constituent features of the first to fourth aspects of the invention, the air supply means includes a pipe disposed sideways at the bottom of the cleaning tank, The cleaning apparatus is characterized in that the gas outlet holes are opened downward at set intervals.

According to the fifth aspect of the present invention, the pipe is arranged horizontally at the bottom of the cleaning tank, and the gas is led out from the holes opened at the set intervals on the peripheral side wall of the pipe, so that the cleaning liquid in the cleaning tank is uniformly distributed. A gas can be introduced into the liquid to cause boiling of the entire cleaning liquid. In addition, since the hole formed in the pipe opens only downward, it is possible to uniformly introduce gas into the cleaning liquid and cause boiling of the entire cleaning liquid.

A sixth invention is a cleaning method for immersing an object to be cleaned in a cleaning liquid stored in a cleaning tank and cleaning the object, wherein the pressure in the gas phase portion in the cleaning tank is reduced by reducing the pressure in the cleaning tank. In the cleaning method, gas is introduced into the cleaning liquid in the cleaning tank from below the object to be cleaned in a state where the pressure is equal to or lower than the vapor pressure of the cleaning liquid in the cleaning tank.

According to the sixth aspect of the invention, in the state where the object to be cleaned is immersed in the cleaning liquid in the cleaning tank, the cleaning liquid is boiled by reducing the pressure in the cleaning tank, and the object to be cleaned is cleaned by the oscillation of the cleaning liquid. it can. When boiling the cleaning liquid, based on the difference in water pressure at the upper and lower positions of the cleaning liquid and the difference in liquid temperature depending on the location, boiling does not occur overall, boiling is slow and explosive and intense boiling does not occur, Even if such a violent boiling occurs, there is a possibility that it may occur locally and sporadically. However, according to the sixth invention, by introducing a gas into the cleaning liquid, such inconvenience is prevented. can do. In other words, when the gas is temporarily introduced from the bottom of the washing tank while boiling, the introduced gas becomes the core of the boiling, and a violent boiling occurs in the boundary layer between the introduced gas and the cleaning liquid, particularly in the lower layer, Large bubbles are formed. As the large bubbles are raised, the cleaning liquid is greatly blown up. Immediately after that, the sprayed cleaning liquid falls. The explosive cleaning liquid spraying and the subsequent dropping can greatly oscillate the cleaning liquid in the cleaning tank and can effectively clean the object to be cleaned.

Furthermore, in addition to the constituent features of the sixth invention, the seventh invention heats the cleaning liquid in the cleaning tank to a set temperature, and then depressurizes the cleaning tank to boil the cleaning liquid. A cleaning method is characterized by introducing a gas into the gas.

According to the seventh invention, by heating the cleaning liquid to the set temperature in advance, it is possible to stably and surely boil and stabilize the cleaning effect. Moreover, by introducing a gas into the cleaning liquid during the boiling of at least a part of the cleaning liquid, the gas supplied into the cleaning liquid is used as a “boiling core” to surely cause boiling and explosive boiling. be able to.

According to the present invention, it is possible to achieve effective cleaning of an object to be cleaned by causing boiling with a simple configuration and control and causing boiling to occur vigorously.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows Example 1 of the washing | cleaning apparatus of this invention, and shows a part in cross section. It is a schematic cross-sectional view of the cleaning tank of the cleaning apparatus of FIG. It is a schematic longitudinal cross-sectional view in a part of FIG. It is a figure which shows the modification of FIG. It is a schematic block diagram which shows Example 2 of the washing | cleaning apparatus of this invention, and shows a part in cross section. It is a figure which shows an example of the cleaning method using the cleaning apparatus of FIG. 5, and shows the relationship between the elapsed time from the start of cleaning and the pressure in the cleaning tank, and the relationship between the elapsed time from the start of cleaning and the temperature of the cleaning liquid. ing. It is a flowchart which shows an example of the washing | cleaning method using the washing | cleaning apparatus of FIG. It is a figure which shows the modification of the heating means in the washing | cleaning apparatus of FIG. 1 and FIG. 5, and has abbreviate | omitted and shown structures other than a heating means.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a first embodiment of the cleaning apparatus of the present invention, and a part thereof is shown in cross section. FIG. 2 is a schematic cross-sectional view of the cleaning tank of this cleaning apparatus. Further, FIG. 3 is a schematic longitudinal sectional view of a part of FIG. 2 and shows a state of introducing gas into the cleaning liquid.

The cleaning apparatus 1 according to the present embodiment includes a cleaning tank 3 in which a cleaning liquid is stored and an object to be cleaned 2 is immersed, a water supply means 4 that supplies the cleaning liquid into the cleaning tank 3, and a gas in the cleaning tank 3 is externally supplied. Pressure reducing means 5 that sucks and discharges to the inside of the cleaning tank 3, an air supply means 6 that introduces gas into the cleaning liquid in the cleaning tank 3, a heating means 7 that heats the cleaning liquid in the cleaning tank 3, and a cleaning The drain means 8 for discharging the cleaning liquid in the tank 3, the pressure sensor 9 for detecting the pressure of the gas phase part in the cleaning tank 3, and the temperature of the liquid phase part in the cleaning tank 3 (that is, the temperature of the cleaning liquid) are detected. A liquid temperature sensor 10 and control means 11 for controlling the means 4 to 8 based on detection signals of these

sensors

9 and 10 are provided. A temperature sensor (not shown) for detecting the temperature of the gas phase part in the cleaning tank 3 may be provided instead of or in addition to the pressure sensor 9 for detecting the pressure of the gas phase part in the cleaning tank 3. Good.

The cleaning liquid is not particularly limited as long as it can be boiled by the pressure reduction in the cleaning tank 3 by the pressure reducing means 5, but is water, for example. In this embodiment, the cleaning liquid is water containing about 0.5% of detergent. However, the cleaning liquid may be water that does not contain detergent as well as water that contains detergent. The cleaning liquid may be other liquid that can be used for cleaning, such as soft water, pure water, and a solvent.

The object to be cleaned 2 is an article to be cleaned, for example, a medical instrument, an electronic component, or a mechanical component. The cleaning device 1 of the present embodiment uses the boiling of the cleaning liquid to clean the object to be cleaned 2, but the object to be cleaned 2 may or may not have a portion where vapor due to boiling accumulates. . That is, the object to be cleaned 2 may have a place where steam accumulates, such as a tubular article or an article with a hole, or may not have a place where steam accumulates, like a forceps.

The washing tank 3 is a hollow container that can withstand the decompression of the internal space. The cleaning tank 3 of the present embodiment includes a main body 12 that opens upward and has a hollow portion, and a lid 13 that opens and closes the opening of the main body 12. In a state where the main body 12 is covered with the lid 13, the gap between the main body 12 and the lid 13 is sealed with the packing 14. Thereby, the hollow part of the main body 12 is sealed, and a sealed space is formed in the cleaning tank 3.

A water supply means 4 for supplying a cleaning liquid into the cleaning tank 3 is connected to the cleaning tank 3. The water supply means 4 of the present embodiment supplies the cleaning liquid into the cleaning tank 3 through the water supply path 15. A water supply valve 16 is provided in the water supply path 15, and the water supply valve 16 is opened when supplying water into the cleaning tank 3.

The cleaning tank 3 is connected to a decompression means 5 that sucks and discharges the gas in the cleaning tank 3 to reduce the pressure in the cleaning tank 3. The decompression means 5 of the present embodiment is a vacuum generator 18 that sucks and discharges the gas in the cleaning tank 3 through the exhaust passage 17. The vacuum generator 18 is not particularly limited, but typically includes a water-sealed vacuum pump, and further includes an indirect heat exchanger that condenses the vapor in the exhaust passage 17 upstream of the vacuum pump. Good.

It is preferable to provide a check valve 19 between the cleaning tank 3 and the vacuum generator 18 in the exhaust passage 17. However, a vacuum valve may be provided instead of the check valve 19. In this case, the opening and closing of the vacuum valve is linked with the presence or absence of the operation of the vacuum generator 18. That is, when the vacuum generator 18 is activated, the vacuum valve is opened.

The cleaning tank 3 is provided with an air supply means 6 for introducing a gas into the cleaning liquid in the cleaning tank 3. The air supply means 6 of the present embodiment introduces outside air into the cleaning liquid in the cleaning tank 3 under reduced pressure via the air supply path 20. An air supply valve 21 is provided in the air supply path 20. When the air supply valve 21 is opened in a state in which the inside of the cleaning tank 3 is decompressed, outside air can be introduced into the cleaning tank 3 by a differential pressure. It is preferable that a filter 22 is provided in the air supply path 20 at an end upstream of the air supply valve 21. In this case, air through the filter 22 is introduced into the cleaning liquid in the cleaning tank 3.

In this embodiment, the gas from the air supply path 20 is introduced into the cleaning liquid via the air supply pipe 23 provided at the bottom of the cleaning tank 3. The air supply pipe 23 is disposed sideways at the bottom of the cleaning tank 3. Specifically, the air supply pipe 23 is a bottom portion in the cleaning tank 3 but is spaced apart from the bottom surface and is held horizontally. In this embodiment, as shown in FIG. 2, an air supply pipe 23 is provided so as to meander the bottom of the cleaning tank 3. However, the structure of the air supply pipe 23 is not limited to FIG. 2 and can be changed as appropriate. For example, as shown in FIG. 4, a plurality of straight tubular

air supply pipes

23, 23,... May be arranged in parallel at equal intervals. In that case, it is preferable that one end portion of each straight tubular air supply pipe 23 is gathered as one air supply path 20.

One end of the air supply pipe 23 is connected to the air supply path 20, while the other end is closed or connected to the one end to form a loop, and the gas is led out at set intervals along the extending direction. A hole (nozzle) 24 is formed. At this time, as shown in FIG. 3, the gas outlet hole 24 is formed to open only downward. By opening the gas outlet hole 24 downward, the gas can be uniformly introduced into the cleaning liquid. If the gas outlet hole 24 is opened upward, the amount of gas discharged decreases toward the downstream of the air supply pipe 23 and affects the cleaning effect. However, as in this embodiment, the gas outlet hole 24 is Such an inconvenience can be avoided by opening downward.

The gas outlet holes 24 are evenly arranged on the bottom surface in the cleaning tank 3. Specifically, when it is assumed that the bottom surface in the cleaning tank 3 is partitioned into a grid having a side of 100 mm, at least one gas outlet hole 24 is formed in each grid. At this time, the larger the number of gas outlet holes 24, the better. And it is preferable that all of those gas outlet holes 24 open downward as described above. Further, the air supply pipe 23 with the gas outlet hole 24 is disposed below the object to be cleaned 2. The diameter of the gas outlet hole 24 is not particularly limited. For example, in this embodiment, it is 1 mm.

In the present embodiment, the air supply means 6 is configured to introduce air into the cleaning liquid in the cleaning tank 3, but may be configured to introduce a gas other than air. That is, the gas introduced into the cleaning liquid by the air supply means 6 may be nitrogen, carbon dioxide, steam, or the like, in addition to air. The gas introduced into the cleaning liquid is preferably a gas that is difficult to dissolve in the cleaning liquid in order to make the cleaning liquid a boiling nucleus. Even when a gas other than air is used, the gas is introduced into the cleaning liquid from the gas outlet hole 24 via the air supply valve 21 and the air supply pipe 23.

The cleaning tank 3 is provided with a heating means 7 for heating the cleaning liquid in the cleaning tank 3. The heating means 7 of the present embodiment heats the cleaning liquid by blowing steam into the cleaning liquid in the cleaning tank 3. Specifically, steam can be supplied to the cleaning tank 3 through a steam supply path 25 from a steam supply source such as a boiler. By opening and closing the steam supply valve 26 provided in the steam supply path 25, it is possible to switch the presence or absence of steam supply into the cleaning tank 3.

However, in addition to directly blowing steam into the cleaning liquid in the cleaning tank 3, the heating means 7 is provided with an electric heater in the cleaning tank 3, or a container equipped with an electric heater is provided separately. The cleaning liquid or the heat medium is circulated with a circulation pump between them, or the cleaning tank 3 is made into a jacket structure (internal / external double structure), and a heat medium such as steam is put into the hollow portion to indirectly supply the cleaning liquid in the cleaning tank 3 It may be heated. However, from the viewpoint of energy efficiency and simplification of the configuration of the cleaning tank 3, it is preferable to heat the cleaning liquid by blowing steam into the cleaning liquid as in this embodiment.

A drainage means 8 for discharging the cleaning liquid in the cleaning tank 3 is connected to the cleaning tank 3. The drainage means 8 of this embodiment discharges the cleaning liquid in the cleaning tank 3 from the bottom of the cleaning tank 3 through the drainage channel 27. The drainage passage 27 is provided with a drainage valve 28. When the drainage valve 28 is opened in a state where the cleaning liquid is stored in the cleaning tank 3, the cleaning liquid can be naturally led out of the cleaning tank 3.

The cleaning tank 3 is provided with a pressure sensor 9 that detects the pressure of the gas phase in the cleaning tank 3 and a liquid temperature sensor 10 that detects the temperature of the cleaning liquid in the cleaning tank 3. If desired, a temperature sensor can be used instead of the pressure sensor 9 by converting the pressure and the temperature.

The water supply means 4, the decompression means 5, the air supply means 6, the heating means 7 and the drainage means 8 are controlled by the control means 11. The control means 11 is a controller 29 that controls the means 4 to 8 based on the detection signals of the

sensors

9 and 10. Specifically, in addition to the water supply valve 16, the vacuum generator 18, the air supply valve 21, the steam supply valve 26, the drain valve 28, the pressure sensor 9 and the liquid temperature sensor 10 are connected to the controller 29. The controller 29 then cleans the article 2 to be cleaned in the cleaning tank 3 according to a predetermined procedure (program) as described below.

Hereinafter, a cleaning method using the cleaning apparatus 1 of the present embodiment will be described. Here, after the water injection step, the temperature raising step, the pressure reduction step, the air supply step, and the drainage step are sequentially executed.

The water injection process is a process in which the cleaning liquid is put into the cleaning tank 3 by the water supply means 4. Specifically, the water supply valve 16 is opened to put the cleaning liquid into the cleaning tank 3, and when a desired amount of cleaning liquid is stored in the cleaning tank 3, the water supply valve 16 is closed. In the water injection process, the cleaning liquid is not filled in the cleaning tank 3 with the cleaning liquid, but the cleaning liquid is put in the middle of the cleaning tank 3. Thereby, the inside of the washing tank 3 is divided into a lower liquid phase part and an upper gas phase part.

The object to be cleaned 2 may be put in the cleaning tank 3 before putting the cleaning liquid in the cleaning tank 3 or may be put in the cleaning tank 3 after putting the cleaning liquid in the cleaning tank 3. In any case, the article to be cleaned 2 is immersed in the cleaning liquid in the cleaning tank 3. At this time, the object to be cleaned 2 is held in a net-like basket or the like above the air supply pipe 23. In this way, the cleaning liquid is stored in the cleaning tank 3, and the cleaning object 2 is immersed in the cleaning liquid. Further, the lid 13 of the cleaning tank 3 is closed.

The temperature raising step is a step of heating the cleaning liquid in the cleaning tank 3 to a set temperature (for example, 50 ° C.). Specifically, the cleaning liquid is heated by the heating means 7 until the cleaning liquid reaches the set temperature. In this embodiment, the steam supply valve 26 is opened, and steam is blown into the cleaning liquid in the cleaning tank 3 to heat the cleaning liquid. During this steaming, the temperature of the cleaning liquid is monitored by the liquid temperature sensor 10, and when the cleaning liquid reaches the set temperature, the steam supply valve 26 is closed and the process proceeds to the next step.

When the cleaning liquid reaches the set temperature, the opening / closing of the steam supply valve 26 is controlled (holding step) based on the detection signal of the liquid temperature sensor 10 so that the temperature is maintained for a set time, and then the steam supply valve 26 is closed. You may make it transfer to the next process. By holding the cleaning liquid at the set temperature for a set time, the temperature of the cleaning liquid can be made constant.

The decompression step is a step of decompressing the inside of the cleaning tank 3 by the decompression means 5. Specifically, the vacuum generator 18 is operated to suck and discharge the gas in the cleaning tank 3 to the outside. During this decompression, the temperature of the cleaning liquid detected by the liquid temperature sensor 10 decreases to a predetermined temperature (for example, 49.5 ° C.), the pressure in the cleaning tank 3 detected by the pressure sensor 9 decreases to a predetermined pressure, or When the predetermined time has elapsed, the air supply process is started.

Any one of the predetermined temperature, the predetermined pressure, and the predetermined time is adopted and used for the control as described above, but is set so that the cleaning liquid in the cleaning tank 3 can be boiled. In other words, the cleaning liquid in the cleaning tank 3 is brought into a boilable state by reducing the pressure to the predetermined temperature, the predetermined pressure, or the predetermined time. That is, the pressure in the gas phase portion in the cleaning tank 3 is set to a state where the pressure is equal to or lower than the vapor pressure of the cleaning liquid in the cleaning tank 3 or just before that. In this state, boiling usually occurs in at least a part of the cleaning liquid in the cleaning tank 3.

In order to bring the cleaning liquid in the cleaning tank 3 into a boilable state, basically, the pressure in the gas phase portion in the cleaning tank 3 needs to be equal to or lower than the vapor pressure of the cleaning liquid in the cleaning tank 3. However, in reality, even if the pressure is slightly higher than the vapor pressure of the cleaning liquid in the cleaning tank 3, a part of the cleaning liquid is overheated, so that gas is introduced into the cleaning liquid in the air supply process described below. In some cases, boiling may occur. Therefore, the air supply process is started with the pressure in the gas phase portion in the cleaning tank 3 being lowered to the vapor pressure of the cleaning liquid in the cleaning tank 3 or in some cases just before that.

In the air supply process, the pressure in the gas phase portion in the cleaning tank 3 is reduced to a pressure equal to or lower than the vapor pressure of the cleaning liquid in the cleaning tank 3 (or immediately before) by the decompression means 5 and the object is cleaned from below. In this step, gas is introduced into the cleaning liquid in the tank 3. As a result, the cleaning liquid can be boiled and violently boiled, and the object to be cleaned 2 can be cleaned.

When boiling the cleaning liquid, based on the difference in water pressure at the upper and lower positions of the cleaning liquid and the difference in liquid temperature depending on the location, boiling does not occur overall, boiling is slow and explosive and intense boiling does not occur, Even if such a violent boiling occurs, there is a possibility that it may occur locally and sporadically. However, by introducing a gas into the cleaning liquid by the air supply means 6, such inconvenience can be prevented. it can. In other words, when gas is temporarily introduced from the bottom of the washing tank 3 while boiling, the introduced gas becomes the core of boiling, and intense boiling occurs in the boundary layer between the introduced gas and the cleaning liquid, particularly in the lower layer. Large bubbles are formed. As the large bubbles are raised, the cleaning liquid is greatly blown up. Immediately after that, the sprayed cleaning liquid falls. The explosive cleaning liquid spraying and the subsequent drop can cause the cleaning liquid in the cleaning tank 3 to be greatly swung, and the object to be cleaned 2 can be effectively cleaned.

The air supply process is terminated when a predetermined time or a predetermined pressure is reached. This end is measured by, for example, a timer of the controller 29 or detected by the pressure sensor 9 and grasped.

Incidentally, the operation of the decompression means 5 started in the decompression process may be completed simultaneously with the end of the air supply process, or may be continued. That is, as will be described below, when the above steps are repeated, the operation of the decompression means 5 may be continued.

After completion of the air supply process, the temperature raising process, the pressure reducing process and the air supply process described above are repeated as desired. For example, after returning to the temperature raising step, the cleaning liquid is reheated to a set temperature (for example, 50 ° C.), the pressure in the cleaning tank 3 is reduced to a predetermined level as a pressure reduction step, and then a gas is introduced into the cleaning liquid as an air supply step. That's fine. However, the temperature raising step may be omitted and the decompression step and the air supply step may be repeated. In this case, the pressure in the cleaning tank 3 is gradually reduced at each decompression step. For example, in the first depressurization step, when the pressure of the cleaning liquid is reduced to a first predetermined temperature (for example, 49.5 ° C.), in the next depressurization step, the pressure of the cleaning liquid is decreased to a second predetermined temperature (for example, 49 ° C.). Is done.

The subsequent draining step is a step of returning the pressure in the cleaning tank 3 to atmospheric pressure and discharging the cleaning liquid in the cleaning tank 3. In order to return the pressure in the cleaning tank 3 to atmospheric pressure, outside air may be introduced into the cleaning tank 3 by the air supply means 6, but a return pressure means (in the drawing) for introducing outside air into the gas phase portion in the cleaning tank 3. (Omitted) may be further provided, and the pressure inside the cleaning tank 3 may be restored to atmospheric pressure by this decompression means. In this way, after the pressure in the cleaning tank 3 is restored to atmospheric pressure, the drain valve 28 is opened to drain the cleaning liquid. Thereafter, the object to be cleaned 2 may be rinsed or the object to be cleaned 2 may be further dried if desired. The rinsing means that the cleaning liquid remaining on the object to be cleaned 2 is cleaned using another cleaning liquid. Even in this rinsing step, in the state where the cleaning liquid in the cleaning tank 3 is reduced in pressure until it can be boiled, gas is introduced into the cleaning liquid in the cleaning tank 3, and the cleaning liquid is boiled vigorously to clean the object to be cleaned 2. You may plan.

FIG. 5 is a schematic configuration diagram showing a second embodiment of the cleaning apparatus 1 of the present invention, and a part thereof is shown in cross section. The cleaning device 1 of the second embodiment is basically the same as that of the first embodiment. Therefore, in the following description, differences between the two will be mainly described, and corresponding portions will be described with the same reference numerals.

The cleaning apparatus 1 of the second embodiment includes a cleaning tank 3 in which cleaning liquid is stored and an object to be cleaned 2 is immersed, water supply means 4 for supplying the cleaning liquid into the cleaning tank 3, and gas in the cleaning tank 3. Depressurization means 5 that sucks and discharges to the outside and depressurizes the inside of the cleaning tank 3, decompression means 30 that introduces outside air into the gas phase portion of the depressurized cleaning tank 3 and restores the pressure in the cleaning tank 3, and decompression An air supply means 6 for introducing gas into the liquid phase portion (that is, in the cleaning liquid) in the cleaning tank 3, a heating means 7 for heating the cleaning liquid in the cleaning tank 3, and a drain means for discharging the cleaning liquid in the cleaning tank 3. 8, a pressure sensor 9 for detecting the pressure of the gas phase part in the cleaning tank 3, a liquid temperature sensor 10 for detecting the temperature of the liquid phase part in the cleaning tank 3 (that is, the temperature of the cleaning liquid), And a control means 11 for controlling the means 4 to 8, 30 based on 10 detection signals. A temperature sensor (not shown) for detecting the temperature of the gas phase part in the cleaning tank 3 may be provided instead of or in addition to the pressure sensor 9 for detecting the pressure of the gas phase part in the cleaning tank 3. Good.

Since the washing tank 3, the water supply means 4, the air supply means 6, the heating means 7, the drainage means 8, the pressure sensor 9 and the liquid temperature sensor 10 are the same as those in the first embodiment, description thereof will be omitted.

The depressurization means 5 will be described. The specific configuration of the depressurization means 5 is not particularly limited as in the first embodiment, but in the second embodiment, the exhaust path 17 is provided in order from the cleaning tank 3 side. A check valve 19, a heat exchanger 31, a check valve 32, and a water-sealed vacuum pump 33 are provided. The heat exchanger 31 cools and condenses the steam in the exhaust passage 17. For this purpose, water is supplied to the heat exchanger 31 via the heat exchange water supply valve 34 and discharged. By condensing the vapor in the exhaust passage 17 in advance, the subsequent load on the vacuum pump 33 can be reduced, and the pressure in the cleaning tank 3 can be effectively reduced.

As is well known, the water-sealed vacuum pump 33 is operated by supplying water called sealed water. Therefore, water is supplied to the vacuum pump 33 through the sealed water supply valve 35 and discharged. When the vacuum pump 33 is operated, the sealed water supply valve 35 is opened in conjunction with the vacuum pump 33.

The decompression means 30 will be described. In the second embodiment, the decompression means 30 for introducing external air into the gas phase portion in the washing tank 3 under reduced pressure and restoring the pressure in the washing tank 3 is provided in the cleaning tank 3. Provided. That is, the decompression means 30 introduces outside air into the cleaning tank 3 under reduced pressure via the vacuum release path 36. The vacuum release path 36 is provided with a vacuum release valve 37. When the vacuum release valve 37 is opened in a state where the inside of the cleaning tank 3 is decompressed, outside air is introduced into the cleaning tank 3 by the differential pressure, and the cleaning tank The pressure inside 3 can be restored.

The water supply means 4, the decompression means 5, the decompression means 30, the air supply means 6, the heating means 7 and the drainage means 8 are controlled by the control means 11. The control means 11 is a controller 29 that controls the means 4 to 8, 30 based on the detection signals of the

sensors

9, 10 and the like. Specifically, in addition to the water supply valve 16, the heat exchange water supply valve 34, the sealed water supply water valve 35, the vacuum pump 33, the vacuum release valve 37, the air supply valve 21, the steam supply valve 26, the drain valve 28, the pressure sensor 9 and The liquid temperature sensor 10 is connected to the controller 29. The controller 29 then cleans the article 2 to be cleaned in the cleaning tank 3 according to a predetermined procedure (program) as described below.

Hereinafter, a cleaning method using the cleaning apparatus 1 of the second embodiment will be specifically described. FIG. 6 is a diagram illustrating the cleaning method of the second embodiment. Line P indicates the relationship between the elapsed time from the start of cleaning and the pressure in the cleaning tank 3, and line T indicates the elapsed time from the start of cleaning and the cleaning liquid. The relationship with the temperature is shown. FIG. 7 is a flowchart showing the cleaning method of the second embodiment.

In the initial state, there is no cleaning liquid in the cleaning tank 3, the

valves

16, 19, 34, 35, 21, 26, 28 other than the vacuum release valve 37 are closed, and the vacuum pump 33 stops operating. From this initial state, the water pouring step S1, the temperature raising step S2, the holding step S3, the depressurizing pressure pulse step S4 and the draining step S5 are sequentially performed.

Water injection step S <b> 1 is a step in which the cleaning liquid is put into the cleaning tank 3 by the water supply means 4. Specifically, the water supply valve 16 is opened, the cleaning liquid is put into the cleaning tank 3, and when a desired amount of cleaning liquid is stored in the cleaning tank 3, the water supply valve 16 is closed. In the water injection step S <b> 1, when the lid 13 of the cleaning tank 3 is closed, the air in the cleaning tank 3 is discharged from the vacuum release path 36 with water injection into the cleaning tank 3. However, the pressure reducing means 5 may be operated instead of closing the vacuum release valve 37. In that case, air can be reliably removed from the cleaning tank 3 while the cleaning liquid is supplied to the cleaning tank 3.

Prior to the water injection step S1, the object to be cleaned 2 is placed in the cleaning tank 3, and the lid 13 of the cleaning tank 3 is closed. However, the object to be cleaned 2 may be placed in the cleaning tank 3 immediately after the water injection step S1, and in this case, the lid 13 of the cleaning tank 3 is closed after the object 2 to be cleaned is placed in the cleaning tank 3. It is done. In any case, the article to be cleaned 2 is immersed in the cleaning liquid in the cleaning tank 3.

Temperature raising step S2 (S21, S22) is a step of heating the cleaning liquid in the cleaning tank 3 to a set temperature (for example, 50 ° C., hereinafter referred to as a depressurization pressure start temperature). Specifically, the cleaning liquid is heated by the heating means 7 until the cleaning liquid reaches the depressurization pressure start temperature. In this embodiment, the steam supply valve 26 is opened, steam is blown into the cleaning liquid in the cleaning tank 3, and the cleaning liquid is heated (S21). During this steaming, the temperature of the cleaning liquid is monitored by the liquid temperature sensor 10, and when the cleaning liquid reaches the depressurization pressure start temperature, the process proceeds to the next step (S22).

Incidentally, in the temperature raising step S2, as shown in FIG. 6, the pressure reduction in the cleaning tank 3 and the return pressure thereof may be performed once or a plurality of times. That is, during the heating of the cleaning liquid by the heating means 7, after the pressure inside the cleaning tank 3 is reduced to a desired level by the pressure reducing means 5, the pressure inside the cleaning tank 3 is returned to near atmospheric pressure once or a plurality of times. You may go.

Depressurization in the washing tank 3 by the decompression means 5 may be performed by operating the vacuum pump 33 with the vacuum release valve 37 closed and the heat exchange water supply valve 34 and the sealed water supply valve 35 open. This depressurization can be stopped up to a pressure at which the cleaning liquid does not boil. Unless the cleaning liquid is boiled, it is preferable that the pressure reduction target pressure is low. Since the cleaning liquid is not boiled, the cleaning liquid is prevented from being cooled. On the other hand, the return pressure by the return pressure means 30 may be achieved by opening the vacuum release valve 37. At the time of the return pressure, the pressure reducing means 5 may be kept operating or may be stopped.

Thus, the object 2 to be cleaned can be easily cleaned by changing the pressure in the cleaning tank 3 in the temperature raising step S2. In particular, when the object to be cleaned 2 has a tube or a hole, the air remaining inside these can be expanded or compressed to eliminate air or perform cleaning by entering and exiting the cleaning liquid.

The holding step S3 is a step of holding the cleaning liquid in the cleaning tank 3 at the reduced pressure pulse start temperature for a set time. Specifically, the opening / closing of the steam supply valve 26 is controlled based on the temperature detected by the liquid temperature sensor 10 so that the cleaning liquid in the cleaning tank 3 maintains the depressurization pressure start temperature. Then, after controlling the cleaning liquid at the decompression pressure start temperature for the set time in this way, the steam supply valve 26 is closed and the process proceeds to the next step. By holding the cleaning liquid at the pressure reduction pulse start temperature for a set time, the temperature of the cleaning liquid can be made constant regardless of the location.

Incidentally, in the holding step S3, as shown in FIG. 6, the pressure reducing step and the air supplying step in the cleaning method of the first embodiment are executed. That is, first, the inside of the cleaning tank 3 is decompressed by the decompression means 5. Specifically, the vacuum pump 33 may be operated with the vacuum release valve 37 closed and the heat exchange water supply valve 34 and the sealed water supply valve 35 open. During this decompression, is the temperature of the cleaning liquid detected by the liquid temperature sensor 10 lowered to a predetermined temperature (for example, 49.5 ° C.), or is the pressure in the cleaning tank 3 detected by the pressure sensor 9 reduced to a predetermined pressure? Alternatively, when a predetermined time has elapsed, gas is introduced into the cleaning liquid by the air supply means 6. The predetermined temperature, the predetermined pressure, or the predetermined time is the same as that of the first embodiment in that the cleaning liquid in the cleaning tank 3 is set to be in a boilable state.

In this way, the object to be cleaned is supplied by the air supply means 6 in a state where the pressure of the gas phase in the cleaning tank 3 is lowered to the vapor pressure of the cleaning liquid in the cleaning tank 3 (or immediately before) by the decompression means 5. A gas is introduced into the cleaning liquid in the cleaning tank 3 from below below 2. As a result, the cleaning liquid can be boiled and violently boiled, and the object to be cleaned 2 can be cleaned. Thereafter, if desired, after the cleaning liquid is reheated to the depressurization pressure start temperature, the pressure reduction to a predetermined value and the induction of bumping by the introduction of gas into the cleaning liquid that can be boiled by the pressure reduction are repeated a plurality of times ( Typically) until the holding step S3 is completed. And if such holding | maintenance process S3 is performed for setting time, it will transfer to the following process.

In the pressure reducing pulse step S4 (S41 to S45), the pressure in the cleaning tank 3 is reduced so that the cleaning liquid continues to boil until the cleaning liquid in the cleaning tank 3 reaches the temperature at which the pressure reduction pulse ends (for example, 30 ° C.). (S41, S42). During this time, during the boiling of the cleaning liquid, the operation of instantaneously restoring the pressure in the cleaning tank 3 at a predetermined timing and temporarily interrupting the boiling of the cleaning liquid is repeated (S43, S44). In this way, the pressure reduction and the instantaneous return pressure are repeated.

More specifically, in the depressurization pressure pulse step S4, the operation of the decompression means 5 is continued to gradually reduce the pressure in the cleaning tank 3, thereby continuing the boiling of the cleaning liquid (S41, S41). S42). However, during this time, the temperature of the cleaning liquid is monitored by the liquid temperature sensor 10, and each time the temperature of the cleaning liquid decreases by a predetermined amount, the pressure in the cleaning tank 3 is temporarily restored by the pressure-reducing means 30 (S43, S44). The decompression means 5 may be decompressed by operating the vacuum pump 33 with the vacuum release valve 37 closed and the heat exchange water supply valve 34 and the sealed water supply valve 35 open. In addition, for the instantaneous return pressure to the set pressure by the return pressure means 30, the vacuum release valve 37 made of an electromagnetic valve may be opened. The decompression means 5 may remain operated even during the return pressure. After opening the vacuum release valve 37 and restoring the pressure in the cleaning tank 3 to interrupt the boiling of the cleaning liquid, the vacuum release valve 37 is closed again to reduce the pressure in the cleaning tank 3 and the boiling of the cleaning liquid. It is illustrated (S41).

In the pressure reduction pulse step S4, the timing of the pressure recovery is not particularly limited as long as the pressure recovery is performed while the cleaning liquid is boiling. In this embodiment, the temperature of the cleaning liquid is monitored based on the liquid temperature sensor 10, and the pressure is restored whenever the temperature decreases by a predetermined temperature. However, the pressure in the cleaning tank 3 is monitored based on the pressure sensor 9, Each time the pressure decreases by a predetermined pressure, the pressure may be restored. Alternatively, a temperature sensor may be provided in the gas phase part in the cleaning tank 3, and the temperature of the gas phase part in the cleaning tank 3 may be monitored based on the temperature sensor, and the pressure may be restored each time the temperature decreases by a predetermined temperature. .

The predetermined temperature (the predetermined pressure is similarly determined similarly) as the pressure recovery timing in the pressure reducing pulse step S4 is appropriately set. In this embodiment, for example, 2 ° C. is adopted. . Therefore, when the cleaning liquid is heated to 50 ° C. in the temperature raising step S2, the first return pressure is executed when the cleaning liquid reaches 48 ° C. On the other hand, the instantaneous return pressure is made up to a pressure at which the boiling of the cleaning liquid stops. As long as the boiling of the cleaning liquid stops, the pressure may be less than atmospheric pressure, and this is preferable from the viewpoint of shortening the processing time. The return pressure in the cleaning tank 3 can be obtained by introducing gas into the liquid phase part by the air supply means 6, but by introducing gas into the gas phase part by the return pressure means 30, Instantaneous pressure recovery is realized.

In this way, in the depressurization pressure pulse step S4, the inside of the cleaning tank 3 is decompressed to boil the cleaning liquid, and during this boiling, the inside of the cleaning tank 3 is instantaneously restored to the set pressure to stop boiling of the cleaning liquid all at once. It will be. Therefore, when the pressure is restored, the bubbles of water vapor generated in the cleaning liquid due to boiling until then are condensed instantly. The cleaning liquid is stirred and transferred by the pressure wave and pressure difference during the condensation, and the object to be cleaned 2 is cleaned. In addition, when the object to be cleaned 2 has a pipe or a hole, a vapor accumulation occurs in the pipe or the hole of the object to be cleaned 2 due to the decompression in the cleaning tank 3. The vapor pool disappears instantly. Therefore, the cleaning liquid can be vigorously moved in and out of the pipe or hole of the object to be cleaned 2, thereby cleaning the object 2 to be cleaned.

Such a depressurizing pressure step S4 is performed until the cleaning liquid reaches the depressurizing pressure end temperature (S42). When the cleaning liquid reaches the depressurization pressure end temperature, the operation of the decompression means 5 is stopped. Thereafter, the vacuum release valve 37 may be opened to return the pressure in the cleaning tank 3 to atmospheric pressure and the cleaning may be terminated. However, the set from the temperature raising step S2 to the depressurizing pressure pulse step S4 may be repeated a plurality of times. Good (S45).

That is, when the cleaning liquid reaches the depressurizing pressure pulse end temperature, it is reheated until the cleaning liquid reaches the depressurizing pressure pulse starting temperature, and the pressure reduction and the repressurizing are repeated until the cleaning liquid reaches the depressurizing pressure pulse end temperature again. Also good. Then, a cycle including heating of the cleaning liquid until the cleaning liquid reaches the depressurizing pressure pulse start temperature and repetition of the depressurizing pressure in the cleaning tank 3 until the cleaning liquid reaches the depressurizing pressure pulse end temperature is performed a set number of times. It is good. In one cycle, the cleaning liquid temperature gradually decreases due to repeated depressurization pressure. For example, fat content hardens and the cleaning effect may be diminished. However, after the cleaning liquid temperature is raised again, the depressurization pressure is repeated. Thus, more reliable and stable cleaning can be performed.

It should be noted that the depressurization and return pressure in the cleaning tank 3 were repeated until the cleaning liquid reached the depressurization pressure pulse end temperature. However, the cleaning tank 3 reached the depressurization pressure pulse end pressure or the cleaning tank 3 decreased. The depressurization and return pressure in the cleaning tank 3 may be repeated until the return pressure pulse end temperature is reached.

The subsequent draining step S5 is a step of returning the pressure in the cleaning tank 3 to atmospheric pressure and discharging the cleaning liquid in the cleaning tank 3. Specifically, after opening the vacuum release valve 37 and returning the pressure in the cleaning tank 3 to atmospheric pressure, the drainage valve 28 is opened to drain the cleaning liquid. Thereafter, the object to be cleaned 2 is rinsed or dried as desired.

The cleaning apparatus and the cleaning method of the present invention are not limited to the configuration of each of the embodiments described above, and can be changed as appropriate. For example, in the air supply means 6 and / or the return pressure means 30, outside air (air) is introduced, but as described above, a gas other than air may be introduced in some cases.

In the decompression step and the air supply step in the first embodiment, the heating of the cleaning liquid by the heating unit 7 is stopped. However, the heating unit 7 may continue to heat the cleaning liquid. In that case, the cleaning method of the present invention can be carried out while maintaining the cleaning liquid at a set temperature or while raising the temperature of the cleaning liquid.

In the first embodiment, the temperature raising step can be omitted. In that case, the object to be cleaned 2 can be cleaned by the depressurization process or the air supply process by grasping the vapor pressure of the cleaning liquid based on the temperature detected by the liquid temperature sensor 10.

In each of the above embodiments, the air supply means 6 is provided with the air supply pipe 23 at the bottom of the cleaning tank 3 and gas is introduced into the cleaning liquid from the gas outlet hole 24 of the air supply pipe 23. The method for introducing the gas into the cleaning liquid can be changed as appropriate. For example, the bottom of the cleaning tank 3 may be partitioned by a plate material having a large number of small holes such as a punching plate so that the bottom surface in the cleaning tank 3 has a double structure, and gas may be introduced therein. In this case, gas can be introduced upward from a number of holes formed in the plate.

Further, in each of the above embodiments, the heating means 7 is configured to heat the cleaning liquid by directly blowing steam into the cleaning liquid. However, as shown in FIG. 8, an indirect heat exchanger 38 is provided in the cleaning tank 3. It is good also as a structure which arrange | positions and carries out indirect heat exchange of a washing | cleaning liquid and a vapor | steam, and heats a washing | cleaning liquid. In this case, steam condensate supplied from the steam supply path 25 to the indirect heat exchanger 38 is discharged via the steam trap 39. In the case of such a configuration, the object to be cleaned 2 can be dried with the same apparatus by supplying the steam to the indirect heat exchanger 38 after discharging the cleaning liquid from the cleaning tank 3. In FIG. 8, only the cleaning tank 3 and the heating means 7 are shown, and other configurations are omitted.

In the second embodiment, the cleaning method including the water injection step S1, the temperature raising step S2, the holding step S3, the depressurizing pressure pulse step S4 and the draining step S5 has been described. However, the cleaning method of the present invention is limited to this. It is not something. In particular, if the holding step S3 is included, the contents of each step can be changed as appropriate in addition to the presence or absence of other steps, addition and deletion of other steps. In short, a step of introducing a gas into the cleaning liquid in the cleaning tank 3 and boiling the cleaning liquid vigorously in a state where the pressure of the cleaning liquid in the cleaning tank 3 is reduced to a boiling possible state may be included.

Furthermore, the cleaning methods of the above embodiments may be combined. That is, after the cleaning method of the first embodiment is performed, the cleaning method of the second embodiment may be performed to clean the article 2 to be cleaned. In that case, in holding process S3, you may abbreviate | omit execution of the decompression process and the air supply process in the cleaning method of the first embodiment.

Finally, in each of the above embodiments, in the state immediately after the objects to be cleaned 2 are accommodated in the cleaning tank 3, not all the objects to be cleaned 2 need be immersed in the cleaning liquid. For example, in the case where the rack containing the article to be cleaned 2 is accommodated in the cleaning tank 3 in a plurality of stages, the uppermost rack may not be immersed. Even in that case, the cleaning liquid can be applied to all the objects to be cleaned 2 and cleaned by boiling the cleaning liquid (particularly, bumping by introducing air into the liquid phase part). As described above, the object to be cleaned 2 is not immersed in the cleaning liquid before the cleaning liquid in the cleaning tank 3 is boiled, but the cleaning liquid in the cleaning tank 3 is boiled, or the cleaning liquid is spouted by introducing gas into the cleaning liquid. When doing so, it can also be placed at a position soaked in the cleaning liquid. In this case, the installation space for the objects to be cleaned 2 can be increased, and more objects to be cleaned 2 can be cleaned in one operation. Further, since the liquid level can be lowered and the operation can be performed, the amount of the cleaning liquid used is suppressed.

DESCRIPTION OF SYMBOLS 1 Cleaning apparatus 2 Object to be cleaned 3 Cleaning tank 4 Water supply means 5 Pressure reducing means 6 Air supply means 7 Heating means 8 Drainage means 9 Pressure sensor 10 Liquid temperature sensor 11 Control means 20 Air supply path 21 Air supply valve 22 Filter 23 Air supply pipe 24 Gas outlet hole 30 Pressure recovery means

Claims

A cleaning tank in which the cleaning liquid is stored, and an object to be cleaned is immersed in the cleaning liquid;
Vacuuming means for sucking and discharging the gas in the cleaning tank to the outside, and reducing the pressure in the cleaning tank;
With this pressure reducing means, the pressure in the gas phase portion in the cleaning tank is lowered below the vapor pressure of the cleaning liquid in the cleaning tank or just before it, and enters the cleaning liquid in the cleaning tank from below the object to be cleaned. An air supply means for introducing a gas.
A heating means for heating the cleaning liquid in the cleaning tank;
The heating liquid is heated to a set temperature by the heating means, and then the cleaning tank is depressurized by the pressure reducing means to boil the cleaning liquid, and a gas is introduced into the cleaning liquid by the air supply means during the boiling. The cleaning apparatus according to claim 1.
Stopping the introduction of gas into the cleaning liquid by the air supply means, reducing the pressure in the cleaning tank until the cleaning liquid is boiled again without reheating the cleaning liquid to the set temperature, and the boiling during the boiling The cleaning apparatus according to claim 2, wherein gas introduction into the cleaning liquid by the air supply unit is repeated.
Introducing a gas into the gas phase portion in the cleaning tank decompressed by the decompression means, further comprising a decompression means for returning the pressure in the cleaning tank,
After the cleaning liquid is heated to the set temperature and held by the heating means, the pressure in the cleaning tank is continuously reduced by the pressure reducing means so that the cleaning liquid continues to boil. Repeatedly re-pressure instantaneously until boiling stops,
The pressure in the cleaning tank by the pressure reducing means and the gas introduction by the air supply means during boiling of the cleaning liquid are performed while the cleaning liquid is maintained at the set temperature. 3. The cleaning apparatus according to 3.
The air supply means includes a pipe arranged in a horizontal direction at the bottom of the cleaning tank,
The cleaning apparatus according to any one of claims 1 to 4, wherein the pipe is formed with gas outlet holes opened downward at set intervals.
A cleaning method for cleaning by immersing an object to be cleaned in a cleaning liquid stored in a cleaning tank,
The pressure in the cleaning tank is reduced, and the pressure in the gas phase portion in the cleaning tank is reduced to a value equal to or lower than the vapor pressure of the cleaning liquid in the cleaning tank or just before the cleaning tank. A cleaning method characterized by introducing a gas into the cleaning liquid inside.
The cleaning liquid according to claim 6, wherein after the cleaning liquid in the cleaning tank is heated to a set temperature, the pressure in the cleaning tank is reduced to boil the cleaning liquid, and a gas is introduced into the cleaning liquid during the boiling. Method.