JPH0615239A - Method for vacuum washing and drying and equipment therefor - Google Patents

Abstract

PURPOSE:To safely and efficiently perform washing and drying of a work by using a combustible solvent such as a petroleum-based solvent as a detergent. CONSTITUTION:In a vacuum washing and drying equipment, a work W is immersed in a petroleum-based solvent 2 stored in a vessel 1. The vessel 1 is vacuumized by a water-sealing type vacuum pump 8. An ultrasonic element 5 is driven to perform ultrasonic washing of the work. After washing is finished, vacuum drying of the work is successively performed. Stagnation of air stuck on the work is eliminated by vacuum washing. Since permeability of the solvent is enhanced, the work is surely washed in every nook and corner. Further, the work is dried for a short time because boiling point of the petroleum-based solvent can be lowered. Since the inside of the vessel is held in a vacuum state, the concentration of oxygen is low and safety is high. Further, since gas is not leaked to the outside, the working environment is safe and held in a state free from environmental pollution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning and drying method in which a work such as a metal or a plastic part is cleaned in a vacuum using a flammable solvent such as a petroleum solvent and then dried in the vacuum. is there.

The present invention also relates to a vacuum cleaning and drying apparatus to which such a vacuum cleaning and drying method is applied.

[0003]

2. Description of the Related Art In recent years, in order to prevent environmental pollution, work-cleaning / drying devices have been promoted to be chlorofluorocarbon-free and triethane-free. For this reason, it is conceivable to adopt a water cleaning method that does not cause environmental pollution, but in the case of water cleaning, there is a problem in that drainage facilities and pure water facilities are expensive. There is also a problem that the drying process cannot be performed quickly. Furthermore, there is a problem that rust prevention measures must be taken into consideration when cleaning metal parts. Therefore, petroleum-based solvents such as isoparaffin and naphthene are attracting attention as alternative cleaning agents for freon and triethane. Even if such a petroleum solvent is discharged into the atmosphere, there is no fear of environmental pollution caused by CFCs, triethane, etc., and it is inexpensive and has a cleaning power. However, there are two problems: safety due to its low flash point, and poorer drying than CFCs and triethane due to its high boiling point.

[0004]

In view of these problems, the object of the present invention is to use a flammable solvent typified by a petroleum-based solvent having a low flash point and a high boiling point as a cleaning agent to produce a metal. Another object of the present invention is to propose a cleaning and drying method capable of safely and efficiently cleaning and drying a work such as a plastic part.

Further, the present invention is to realize a cleaning device and a drying device to which such a novel method is applied.

[0006]

In the method and apparatus of the present invention, in order to solve the problems of safety and dryness when a flammable solvent such as a petroleum solvent is used as a cleaning agent, vacuum cleaning and Vacuum drying is performed.

As the vacuum cleaning method, immersion cleaning such as ultrasonic cleaning, steam cleaning, shower cleaning or the like can be adopted. Alternatively, jet cleaning in a state of being immersed in a flammable solvent may be adopted.

Further, the cleaning method may be a method including a plurality of cleaning steps of the same type or different types. For example, rough cleaning may be performed to remove most stains on the work, and then final cleaning may be performed to completely remove stains on the work. Specifically, an example can be given in which immersion cleaning is performed in a vacuum or atmospheric pressure, and subsequently vacuum vapor cleaning is performed. In addition, preliminary cleaning,
The work may be washed after three steps of rough washing and finish washing or more washing steps.

When performing vacuum vapor cleaning here, the vapor of the solvent is generated by heating the combustible solvent stored in the vacuum cleaning tank containing the work and reducing the pressure below the vapor pressure of the solvent. It should be done by. Alternatively, it may be performed by introducing the vapor of the flammable solvent from the outside into the vacuum cleaning tank containing the work.

In any case, when the flammable solvent is evacuated while being heated to a predetermined temperature, the solvent automatically boils and vapor is generated when the vacuum pressure becomes lower than the vapor pressure of the solvent. Generation can be controlled by solvent temperature and vacuum pressure.

On the other hand, when the combustible solvent is stored in the vacuum cleaning chamber for cleaning, such as immersion cleaning, the combustible solvent in the vacuum cleaning chamber may be regenerated by vacuum distillation.

Next, the vacuum drying step can be performed after the vacuum cleaning is completed in the vacuum cleaning chamber where the vacuum cleaning is performed. In this case, the vacuum cleaning chamber may be partitioned into upper and lower parts by a gate valve, and the cleaning may be performed in the upper compartment. Instead of this, a cooling pipe is placed at an intermediate position in the vertical direction in the vacuum cleaning tank,
After the cleaning step is completed, the vapor of the flammable solvent may be condensed and captured by the cooling pipe, and vacuum drying may be performed in the upper space in which the vapor concentration is suppressed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a vacuum cleaning / drying apparatus to which the present invention is applied. In the figure, reference numeral 1 is a vacuum container that constitutes a vacuum cleaning / drying chamber, and a lid 1 that can be sealed at the top
a is attached. In this vacuum cleaning / drying room 1,
A petroleum solvent can be supplied through a supply pipe (not shown). Further, the work W to be cleaned is set in the work transfer mechanism. At the time of cleaning, a fixed amount of the petroleum solvent 2 is stored as shown in the figure, and the work W is immersed therein.

An ultrasonic element 5 is attached to the outer bottom surface of the vacuum container 1. Further, at the bottom of the vacuum container 1, a discharge pipe 6 for the petroleum solvent stored inside is discharged.
Is connected, and a drain valve 7 is attached to the discharge pipe 6. Further, an exhaust pipe 3 is connected to the upper side surface of the vacuum cleaning chamber 1. The exhaust pipe 3 is connected to a suction port 8 a of a water-sealed vacuum pump 8 via a valve 4.

The discharge port 8b of the water-sealed vacuum pump 8 is connected to a steam / water mixture drainage pipe 9. Further, the water seal vacuum pump 8 is supplied with seal water through a water supply pipe 10 by a seal water supply mechanism (not shown). An end 9a of the steam / water mixture drainage pipe 9 opens into the stored water 11a of the gas / liquid separation tank 11. An exhaust pipe 12 extending upward is connected to the upper end of the gas-liquid separation tank 11, and a drain pipe 13 as an overflow pipe is connected to the side surface thereof. The drain pipe 13 extends horizontally and then downwardly, and is connected to the suction port 14 a of the oil-water separator 14. The oil discharge outlet 14b of the oil / water separator 14 opens into the oil recovery tank. The water from which oil has been removed is the drain outlet 1
It is discharged from 4c.

In the vacuum cleaning / drying apparatus of the present embodiment configured as described above, a predetermined amount of the petroleum solvent 2 is stored in the vacuum container 1 through a petroleum solvent supply system (not shown), and the cleaning target is also used. The work W is opened by opening the lid 1a and immersed in the petroleum solvent 2 stored in the vacuum container 1. After that, the lid 1
The vacuum container 1 is closed by closing a. After that,
The water-sealed vacuum pump 8 evacuates the inside of the cleaning chamber 1. After the predetermined vacuum state is formed, while maintaining the vacuum state, the ultrasonic element 5 is driven to ultrasonically clean the work W immersed in the petroleum solvent 2.

Here, the exhaust containing the mist and vapor of the petroleum solvent sucked from the vacuum container is the water-sealed vacuum pump 8
After being sucked from the suction port 8a, it is dissolved or mixed in the sealing water filled in the pump chamber and discharged together with the sealing water from the discharge port 8b to the air / water mixing drain pipe 9. After passing through the air / water mixture drainage pipe 9, the sealed water is discharged into the water 11a stored in the gas / liquid separation tank 11. In this gas-liquid separation tank 11, the petroleum solvent in the sealed water is further dissolved or mixed in the stored water and recovered. Also,
The oil contained therein separates and floats on the surface. The exhaust gas after the petroleum solvent is sufficiently removed is exhausted to the atmosphere through the exhaust pipe 12.

On the other hand, the oil floating on the surface of the stored water in the gas-liquid separation tank 11 is discharged together with the overflow water through the drain pipe 13. Here, in the oil / water separator 14, the petroleum-based solvent and the oil component (washing residue) contained therein are recovered from the discharged water. The recovered oil and the like is recovered from the oil discharge outlet 14b into a recovery tank or the like.

After the cleaning of the work W is completed, the drain valve 7 of the discharge pipe 6 on the bottom surface of the vacuum container is opened to open the vacuum container 1
The petroleum solvent 2 inside is discharged.

Next, as shown in FIG. 2, the cleaned work W is vacuum dried in the vacuum container 1. Also in this case, the water-sealed vacuum pump 8 is driven to evacuate the inside of the vacuum container 1. Further, the mist or vapor of the petroleum solvent contained in the exhaust gas from the cleaning chamber is recovered in the same manner as the above-described cleaning.

As described above, in the vacuum cleaning / drying apparatus of this embodiment, the work W is cleaned in the vacuum atmosphere.
Therefore, the accumulation of air adhering to the work is eliminated, and the effect of improving the permeability of the solvent can be obtained. As a result, it is possible to reliably perform the cleaning of blind holes, fine holes, downward holes and the like, or porous parts, which were difficult to clean by the conventional cleaning method. Further, when a large number of works as the works W are washed together, the gap between the works can be surely washed.

Further, the air in the stored petroleum solvent is degassed and ultrasonic cavitation is efficiently generated, so that the ultrasonic cleaning power is improved.

Further, by performing vacuum drying as in this example, the boiling point of the petroleum solvent 2 stored in the vacuum container 1 can be lowered. Therefore, since the evaporation of the petroleum solvent is promoted even at a low temperature, the drying property of the petroleum solvent can be dramatically improved as compared with the conventional method. Further, although solvent gas may remain as an adsorption layer on the surface of the work in air drying, such an adsorption layer can be removed by vacuum drying. Therefore, it is possible to solve the problem that the post-treatment of the work surface after drying, such as adhesion and coating, is adversely affected by the adsorption layer.

In addition to this, when cleaning rust-prone parts such as metal parts, since the cleaning and drying are performed in a vacuum having an extremely low oxygen concentration, rust may occur in the cleaning and drying process. There is no.

In addition to these advantages, in this example,
Since the inside of the vacuum container 1 is maintained at a predetermined degree of vacuum, the oxygen concentration is low and it is in a sealed state. Further, since the inside is under negative pressure, even if a leak should occur, the petroleum solvent and solvent vapor will not leak outside. Therefore,
High safety. Moreover, since the cleaning and drying of the work are performed in the same sealed vacuum container 1, the gas of the petroleum solvent stored therein does not leak outside. Therefore,
There is an advantage that the external work environment can be kept safe and free from environmental pollution.

Further, in this example, a water-sealed vacuum pump 8 is used as an exhaust system for evacuating the inside of the vacuum container 1, and a mist or vapor of a flammable petroleum solvent is dissolved in the sealed water. Alternatively, since the gas is discharged in a mixed state, the concentration of the petroleum solvent gas contained in the exhaust gas can be reduced. Therefore, also from this aspect, according to the apparatus of this example, the external environment can be kept safe and free from environmental pollution. Also,
In this way, the risk of petroleum-based solvent leaking to the outside is extremely low, so explosion-proof specifications, fire extinguishing equipment, etc. are not necessary or can be minimized. Therefore, the device price can be reduced.

To increase the suction force of the water-sealed vacuum pump 8, a water-sealed vacuum pump with an air ejector may be used. To further increase the suction power,
A mechanical booster pump may be connected in front of the water-sealed vacuum pump. Of course, both the air ejector and the mechanical booster pump may be arranged.

FIG. 3 shows a modification of the embodiment shown in FIG. In the example shown in this figure, shower cleaning is performed instead of ultrasonic cleaning. That is, as shown in FIG. 3, a plurality of shower nozzles 15 for spraying the petroleum solvent onto the work W are arranged on the inner peripheral surface of the vacuum container 1. The petroleum solvent sprayed from the shower nozzle 15 onto the work W is the vacuum container 1
The circulation system that collects at the bottom of the
Used in circulation.

As the cleaning method, in addition to the shower cleaning, a jet cleaning method such as spraying a pressure flow of the petroleum solvent onto the work while the work is immersed in the petroleum solvent 2 stored in the vacuum container 1 May be adopted. Alternatively, the vacuum vapor cleaning method shown in FIG. 4 may be adopted.

The vacuum cleaning apparatus shown in FIG. 4 is configured to perform vacuum steam cleaning instead of ultrasonic cleaning in the apparatus shown in FIG. As shown in this figure, the vacuum container 1
A vapor supply pipe 17 for supplying the vapor of the petroleum solvent into the container is connected to the lower side surface. This steam connection pipe 17 is connected to the steam generation tank 1 via a valve 18.
9 is connected. A predetermined amount of the petroleum solvent 2 is stored in the steam generation tank 19, and the petroleum solvent 2 is heated and evaporated by the heating source 20 arranged on the outer bottom surface thereof. The vapor of the solvent thus obtained is supplied into the vacuum container 1 via the valve 18. The other structure is the same as that of the apparatus of FIG. 1, and the corresponding portions are denoted by the same reference numerals.

Even in the vacuum steam cleaning of this example, the petroleum solvent is safe because it does not leak to the outside. Also,
Since the boiling point of the petroleum solvent is reduced under reduced pressure, the heating temperature can be lowered. As a result, heating energy can be saved. Further, by lowering the heating temperature in this way, deterioration of the petroleum solvent can be suppressed.

When the valve 18 is opened while the vacuum container 1 is evacuated, the steam generation tank 19 is also evacuated, so that the petroleum solvent 2 in it can be heated to a predetermined temperature. For example, when the pressure is reduced to below the vapor pressure of the solvent, boiling automatically starts and vapor of the solvent can be generated.

Next, FIG. 5 shows another modification of the apparatus shown in FIG. In the apparatus shown in FIG. 5, the work lifting cylinder 21 is used to move the work W in the vacuum container 1.
Can be raised and lowered. In this apparatus, vacuum immersion cleaning is performed in the same manner as the apparatus shown in FIG. However, vacuum drying is performed as follows. After cleaning, the work W immersed in the petroleum solvent 2 is
The lifting cylinder 21 lifts it up and holds it there, as indicated by the imaginary line in the figure. In this state, the work W is vacuum-dried while the water-sealed vacuum pump 8 is evacuated. Even when vacuum drying is performed as in this example, the same effect as in the case of the apparatus shown in FIG. 1 can be obtained.

6 and 7 show modified examples of the apparatus of FIG. 5, respectively.

First, in the apparatus shown in FIG. 6, a gate valve 2 for vertically dividing the internal space of the vacuum container 1 into two parts.
2 are installed. The upper space of the vacuum container 1 partitioned by the gate valve 22 is used as a vacuum drying chamber 1b, and the exhaust pipe 3 is connected to this side surface.

In the apparatus of this example, the gate valve 22
In the open state as shown by the solid line in the figure, the work W is subjected to immersion ultrasonic cleaning. After the cleaning is completed, the lifting cylinder 21 raises the work W to a position higher than the partition position by the gate valve and holds the work W at the broken line position in the figure. After that, the gate valve 22 is pulled out as shown by a broken line in the figure, and the inside of the vacuum container 1 is divided into upper and lower parts. After this, the work W is vacuum dried in the upper vacuum drying chamber 1b. Other operations are similar to those of the device shown in FIG.

According to the apparatus of this example configured as described above,
The volume of the vacuum drying chamber 1b can be reduced. Further, when the gate valve 22 is closed, the petroleum solvent 2 accumulated at the bottom of the vacuum container does not enter the upper vacuum drying chamber 1b. Therefore, the degree of vacuum in the vacuum drying chamber 1b can be increased, and the drying time can be shortened. Further, when the work W after drying is taken out, the petroleum solvent 2 in the vacuum container is separated from the atmosphere side by the gate valve 22, so that the petroleum solvent 2 is not exposed to the atmosphere. Therefore, the petroleum solvent can be prevented from evaporating into the atmosphere, and the external environment can be kept safe and free from pollution.

The apparatus shown in FIG. 7 is provided with a circulation system for petroleum solvent in order to perform vacuum distillation regeneration of the petroleum solvent 2 in the vacuum container 1. As shown in the figure, the discharge pipe 6 connected to the bottom surface of the vacuum container 1 includes a pressure pump 23 and a valve 2.
4 is connected to the side surface of the distillation tank 25.

In the distillation tank 25, a float 26 for liquid level control is installed, and the valve 24 is opened / closed so that the liquid level of the petroleum solvent stored in the tank is always at a constant level. Take control. A heating source 27 is installed on the bottom surface of the tank 25. Further, a discharge pipe 28 for discharging the distillation residue left here is connected,
The discharge pipe 28 is connected to a recovery tank (not shown) side via a valve 29.

A solvent vapor supply pipe 30 is connected to the upper end of the tank 25. This solvent vapor supply pipe 30 is
It is connected to a heat exchanger 31 for liquefying the solvent vapor. The heat exchanger 31 again stores the liquefied solvent in the vacuum container 1
A supply pipe 32 for refluxing the inside is connected. The supply pipe 32 is connected to the side surface of the vacuum container 1 via a pressure pump 33.

In the thus constructed apparatus of this example, the petroleum solvent 2 in the vacuum vessel 1 is recovered in the distillation tank 25, and vacuum distillation / regeneration is performed therein. The solvent vapor that has been regenerated is liquefied again in the heat exchanger 31, and is recirculated into the vacuum pump 1. Therefore, according to this example, the deterioration of the petroleum solvent in the vacuum tank can be prevented, and the cleaning quality of the work can be maintained for a long time.

Next, FIGS. 8, 9, 10 and 11 respectively show examples of apparatuses for performing steam cleaning and vacuum drying in the same vacuum container.

First, in the apparatus shown in FIG. 8, a solvent supply pipe 35 is connected to the side surface of the vacuum container 1.
5 is connected via a solvent supply valve 36 to a solvent tank 37 in which a petroleum solvent is stored. On the other hand, on the vacuum container 1 side, a float 38 for controlling the liquid level of the petroleum solvent stored therein is installed. In addition, a heating source 39 for heating the petroleum solvent stored therein into solvent vapor is installed on the bottom surface. Further, a discharge pipe 40 for discharging the petroleum solvent stored inside is connected. The discharge pipe 40 is connected to a solvent recovery tank (not shown) via a drain valve 41.

In the apparatus of this example, the solvent supply valve 3
6 is opened, and a fixed amount of petroleum solvent is supplied into the vacuum container 1 from the solvent tank 37 side. After a certain amount of the petroleum solvent is stored in the vacuum container 1 in this way, the valve 36 is closed and the heating source is driven to heat the stored petroleum solvent 2. Next, when the water-sealed vacuum pump 8 is driven to evacuate the inside of the vacuum container, the boiling point of the petroleum solvent decreases as the pressure decreases, and the petroleum solvent 2 automatically boils when the vacuum pressure is less than the vapor pressure of the solvent. And generate steam. In this way, the work W contained in the vacuum container 1 is vacuum-vapor cleaned. After the solvent is completely evaporated, the work W is vacuum dried in the vacuum container 1.

In the apparatus shown in FIG. 9, a heating source 43 is installed on the side of the solvent tank 37, and a fixed amount of heated petroleum-based solvent is supplied into the vacuum container 1 to perform vacuum vapor cleaning. . Other configurations and vapor generation mechanism are the same as those of the apparatus shown in FIG.

The apparatus shown in FIG. 10 is provided with a gate valve 22 for dividing the inside of the vacuum container 1 into upper and lower parts with respect to the apparatus shown in FIG. The structure in which the cylinder 21 is installed is adopted. Exhaust pipe 3 connected to the side surface of the vacuum container 1
Are connected to the upper drying space defined by the gate valve 22. In the apparatus of this example, steam cleaning is performed in the same manner as the apparatus of FIG. 8, but during vacuum drying,
The lifted cylinder 21 lifts the cleaned work W above the gate valve 22 as shown by the broken line in the figure, and then closes the gate valve 22. In this way, the work W is vacuum-dried in the upper drying space 1b partitioned by the gate valve 22. According to the apparatus of this example, the space during vacuum drying can be reduced, and the work W is isolated from the petroleum solvent in the vacuum container. Therefore, the degree of vacuum can be increased to efficiently vacuum dry the work W. It can be performed.

Further, when the work W after drying is taken out, the petroleum solvent in the vacuum container is separated from the atmosphere side by the gate valve 22, so that the petroleum solvent is not exposed to the atmosphere. . Therefore, the petroleum solvent can be prevented from evaporating into the atmosphere, and the external environment can be kept safe and free from pollution.

The apparatus shown in FIG. 11 employs a construction in which the cooling pipe 45 is installed in the vacuum container 1 at an intermediate position in the vertical direction instead of the gate valve shown in FIG. In the apparatus of this example, the lifting cylinder 21 is used during vacuum drying.
The work W is lifted up above the cooling pipe 45 as shown by the broken line. When vacuum drying is performed in this state, the vapor generated from the petroleum solvent that accumulates at the bottom of the vacuum container 1 touches the cooling pipe 45, condenses and is trapped there, and reaches the work W above it. Does not reach. Therefore, vacuum drying can be efficiently performed also by the apparatus of this example.

Next, FIGS. 12, 13, 14, and 15 respectively show devices adopting a combination of the structures of the above-mentioned embodiments.

First, in the apparatus shown in FIG. 12, the work is immersed and washed in a vacuum or at atmospheric pressure, and then vacuum vapor cleaning is performed in the same vacuum container, and thereafter, vacuum work is performed in the same vacuum container. It is configured to be dried.
In the apparatus of this example, the work W is immersed in the petroleum solvent 2 stored in the vacuum container 1 and ultrasonic waves are applied by the ultrasonic element 5 to perform ultrasonic cleaning. This immersion cleaning can be performed under a vacuum or at atmospheric pressure. After immersion cleaning, lift cylinder 21
The work W is pulled up from the petroleum solvent by. In this state, the vacuum container 1 is evacuated, the valve 18 is opened, the vapor generation tank 19 is evacuated to boil the petroleum solvent therein, and the vapor of the petroleum solvent is supplied into the vacuum container 1 to produce a vacuum. Perform steam cleaning. After completing the vacuum steam cleaning, the work W
Vacuum dry.

In the apparatus shown in FIG. 13, the upper space of the petroleum solvent 2 is vertically partitioned by the gate valve 22 in the vacuum container 1, and the partitioned upper space is used as the drying space 1b. In the apparatus of this example, first, the work W is immersed in the petroleum solvent 2 and evacuated, or ultrasonic cleaning is performed at atmospheric pressure. After that, the work W is pulled up to the middle height position shown by an imaginary line in the drawing by the elevating cylinder 21. In this state, the inside of the vacuum container 1 is evacuated, and the vapor of the petroleum solvent is supplied from the vapor generation tank 19 side to supply the work W.
Perform vacuum steam cleaning. After that, the work W is further raised by the elevating cylinder 21 to be positioned above the gate valve 22, and the gate valve 22 is closed. In this state, the work W is vacuum dried.

In the apparatus shown in FIG. 14, instead of using the steam generation tank 19 in the apparatus shown in FIG. 13, a heating source 39 is installed at the bottom of the vacuum container 1 to generate a vapor of a petroleum solvent to perform vacuum vapor cleaning. Is to do. Other configurations and operations are the same as those of the device shown in FIG. In this case, by controlling the pressure in the vacuum container 1, the petroleum solvent 2 may not be boiled during the immersion ultrasonic cleaning, but may be boiled only during the steam cleaning to generate steam.

The apparatus shown in FIG. 15 uses a cooling pipe 45 instead of the gate valve 22 in the apparatus shown in FIG. Other configurations and operations are similar to those of the device shown in FIG.

Here, in each of the above-mentioned embodiments,
This is a so-called one-tank type cleaning / drying device. But,
It goes without saying that the present invention can be applied to a two-tank type or a multi-tank type of more than that. Such a device is shown in FIGS. 16, 17, 18 and 19, respectively.

The apparatus shown in FIGS. 16 and 17 is an example of a two-tank type in which the rough cleaning of the work is performed first, and then the final cleaning is performed. In the apparatus of this example, the inside of the vacuum container 51 can be vertically partitioned by the gate valve 52. In the vacuum container below the gate valve 52, a vertically extending partition plate 64 divides it into left and right parts, one side of which is a rough cleaning chamber 53 and the other side of which is a finishing cleaning chamber 54. ing. Ultrasonic elements 55 and 56 are installed on the bottom surfaces of the cleaning chambers 53 and 54, respectively. In addition, the rough cleaning chamber 53
A circulation pipe 57 for the solvent from the bottom surface to the bottom surface of the finish cleaning chamber 54 is connected to the pipe 57. A pressure pump 58, a filter 59 and a vacuum distillation regenerator 60 are connected to the pipe 57.
However, it is inserted in this order from the side of the rough cleaning chamber.

Here, the petroleum solvent 2 in the finish cleaning chamber 54
B overflows and flows into the rough cleaning chamber 53, from which it is passed through the circulation pipe 57, filtered and regenerated by the filter 59 and the vacuum distillation regenerator 60, and becomes a clean petroleum solvent to be supplied to the finish cleaning chamber 54. To be done.

On the other hand, two lifting cylinders 61, 62 are installed, and the work W is loaded into the rough cleaning chamber 53,
It is possible to move up and down between the petroleum solvent 2A and 2B stored in the finish cleaning chamber 54 and the drying chamber 63 above the gate valve 52. In addition, the horizontal transfer cylinder 6
5 is installed, and the lifting cylinder 6 from the rough cleaning chamber 53
The work W pulled up by 1 can be delivered to the elevating cylinder 62 on the side of the finishing cleaning chamber via the carrier table 66. Note that lids 51a and 51b are attached to the upper end of the vacuum container 51, respectively. Further, the exhaust pipe 3 is connected to the side surface of the drying chamber 63 on the side of the finish cleaning chamber, which is connected to the suction side of the water-sealed vacuum pump 8 via the valve 4.

In the apparatus of this example, the lid 51a is opened, the work W is put therein, and the work W is immersed in the petroleum solvent 2A stored in the rough cleaning chamber 53 using the lifting cylinder 61. In this state, the ultrasonic element 56 is driven to roughly clean the work W. Next, the work W is once pulled up to the drying chamber 63 shown by the solid line in the figure, and thereafter, the work W is laterally fed by using the horizontal transport cylinder 65 and handed over to the lifting cylinder 62 side. After this, the lifting cylinder 62
Thus, the work W is immersed in the petroleum solvent 2B stored in the finish cleaning chamber 54, the ultrasonic element 55 is driven, and the finish cleaning of the work W is performed. After finishing cleaning, the work W is pulled up to the drying chamber 63 again.

After that, the gate valve 52 is closed to partition the drying chamber 63 from the rough cleaning chamber 53 and the finish cleaning chamber 54. In this state, the work W is vacuum dried. After the vacuum drying is completed, air leaks, the lid 51b is opened, and the work W is taken out.

According to the apparatus of the present embodiment, the work W is first roughly washed to remove most of the dirt, and then the slight dirt of the remaining work W is cleaned by the final cleaning. Therefore, there is an advantage that the life of the petroleum solvent can be extended and the cleaning quality can be maintained for a long time. Further, according to the apparatus of this example, the rough cleaning chamber 5
The petroleum solvent 2A stored in No. 3 is regenerated by using the filter 59 and the vacuum distillation regenerator 60, and the finishing cleaning chamber 5
I am trying to supply to 4. Therefore, the dirt concentration of the petroleum-based solvent in each cleaning chamber can be suppressed to a low level, which also improves the solvent life and cleaning quality.

The apparatus shown in FIG. 18 is an example in which the finish cleaning in the apparatus shown in FIG. 16 is vacuum steam cleaning. That is, a small amount of the petroleum solvent 2 in the finish cleaning chamber 54.
B is stored, and the heating source 71 is installed in it. At the time of finish cleaning, the petroleum solvent 2B is heated by the heating source 71 to generate solvent vapor, and the work W is subjected to finish cleaning. Other configurations and operations are the same as those of the device shown in FIGS.

The apparatus shown in FIG. 19 is provided with a cooling pipe 81 instead of the gate valve in the apparatus shown in FIG. 16 so that the cleaning chambers 53 and 54 side and the drying chamber 63 side are substantially separated from each other. It was done. In addition, the cooling pipe 81
A gutter 82 for collecting the petroleum-based solvent that has come into contact with the cooling pipe 81 and condensed in the finish cleaning chamber 54 is installed on the lower side of the. That is, since the evaporated solvent is clean, if it is condensed and collected by the cooling pipe and put into the cleaning chamber 54, the cleanliness of the petroleum solvent in the cleaning chamber 54 can be increased. Other configurations are the same as those of the apparatus shown in FIG.

In the multi-tank type cleaning device, various cleaning methods such as shower cleaning and jet cleaning can be adopted as the cleaning method in addition to the immersion ultrasonic cleaning and vacuum steam cleaning.

In each of the above embodiments, the vacuum cleaning chamber and the vacuum drying chamber are vertically partitioned by the gate valve, but they are not necessarily vertically arranged and may be horizontally partitioned.

Further, in each of the above-mentioned embodiments, the water-sealed vacuum pump is used as a means for evacuating the inside of the vacuum container, but a dry pump can be used instead. In this case, as a recovery mechanism for reliably recovering the petroleum-based solvent from the exhaust gas from the dry pump, the petroleum-based solvent is dissolved or mixed in water to be recovered, and the petroleum-based solvent contained in the exhaust gas is also recovered. The concentration may be reduced.

Furthermore, in each of the above-mentioned embodiments, the case where a petroleum solvent is used as a cleaning agent is explained. However, other flammable solvents, such as alcohol,
Even when using acetone, a silicon-based solvent, or a terpene-based solvent, using the same means as in each of the above examples,
Work can be washed.

[0068]

As described above, in the method and apparatus of the present invention, in order to solve the problems of safety and dryness when a flammable solvent such as a petroleum solvent is used as a cleaning agent, a vacuum is used. Cleaning and vacuum drying are performed. As described above, cleaning in vacuum eliminates the accumulation of air adhering to the work and improves the permeability of the solvent. As a result, it is possible to surely clean the blind holes, fine holes, downward holes of the work, parts such as gaps between the works, or the porous parts, which were conventionally difficult to clean. Further, when ultrasonic cleaning is adopted, air in the solvent is degassed, so that cavitation of ultrasonic waves is efficiently generated, and ultrasonic cleaning can be efficiently performed.

By performing vacuum drying, the boiling point of the flammable solvent is lowered, and the solvent can be evaporated even at a low temperature. Therefore, the drying property of the solvent can be dramatically improved.

Further, although solvent gas may remain as an adsorption layer on the surface of the work during atmospheric drying, such an adsorption layer can be removed by vacuum drying.
Therefore, it is possible to solve the problem that the post-treatment of the work surface after drying, such as adhesion and coating, is adversely affected by the adsorption layer.

Further, the vacuum container for vacuum cleaning and vacuum drying is a closed container, and the inside of the container is kept in a vacuum state, and the oxygen concentration therein is extremely low, so that there is a risk of ignition and explosion. Is low, and since the vacuum container has a negative pressure, even if there is a leak,
Since petroleum-based solvents and solvent vapors do not leak outside, it is safe and avoids pollution of the working environment.

In addition to this, when cleaning rust-prone parts such as metal parts, since the cleaning and drying are performed in a vacuum having an extremely low oxygen concentration, rust may occur in the cleaning and drying process. There is also an advantage that there is no.

When a plurality of cleaning steps, for example, rough cleaning and finish cleaning steps are included, the deterioration of the solvent can be prevented for a long time, and the cleaning quality can be kept good for a long time. it can. Furthermore, when the flammable solvent is vacuum-distilled and regenerated, it is possible to prevent deterioration of the solvent and maintain the cleaning quality for a longer period of time.

Next, when vacuum cleaning and vacuum drying are carried out in the same vacuum container, when the inside of the vacuum container is partitioned into upper and lower parts by using a gate valve and the upper side is used as a drying chamber, Since the space volume of the drying chamber can be reduced and solvent vapor can be prevented from entering from the lower cleaning chamber, the degree of vacuum in the drying chamber can be increased and the drying can be performed in a short time. Further, when the work is taken out from the vacuum container after drying, the side where the solvent is stored in the container is kept closed by the gate valve, so there is no risk of the solvent leaking into the atmosphere. Therefore, there is an advantage that it is safe and there is no fear of air pollution.

Similarly, even when a cooling pipe is installed in the vacuum container and the inside of the container is partitioned substantially up and down, the solvent vapor rising from the lower side can be captured by the cooling pipe. It has the same effect as partitioning with.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a vacuum cleaning / drying apparatus to which the method of the present invention is applied.

FIG. 2 is a schematic configuration diagram showing a state during vacuum drying in the apparatus of FIG.

FIG. 3 is a schematic configuration diagram showing a modified example of the apparatus of FIG. 1 and showing a configuration when shower cleaning is adopted instead of ultrasonic cleaning.

FIG. 4 is a schematic configuration diagram showing a vacuum cleaning / drying device that performs vacuum vapor cleaning to which the method of the present invention is applied.

FIG. 5 is a schematic diagram showing a configuration in which the apparatus of FIG. 4 employs immersion cleaning instead of vacuum vapor cleaning, and employs a configuration in which an elevating cylinder is used to lift a workpiece from a solvent during vacuum drying. It is a block diagram.

6 is a schematic configuration diagram showing a case in which a configuration in which a gate valve is attached to the apparatus of FIG. 5 to vertically divide the interior of a vacuum container is adopted.

7 is a schematic configuration diagram showing a case in which a configuration in which a solvent vacuum distillation regeneration mechanism is additionally provided in the apparatus of FIG. 6 is adopted.

FIG. 8 is a schematic configuration diagram showing another embodiment in which vacuum vapor cleaning to which the method of the present invention is applied is performed.

9 is a schematic configuration diagram showing a modified example of the apparatus of FIG.

10 is a schematic configuration diagram showing an example in which a gate valve is attached to the apparatus of FIG.

11 is a schematic configuration diagram showing an example in which a cooling pipe is attached to the apparatus of FIG.

FIG. 12 is a schematic configuration diagram showing another embodiment to which the present invention is applied.

13 is a schematic configuration diagram showing an example in which a gate valve is attached to the apparatus of FIG.

FIG. 14 is a schematic configuration diagram showing still another embodiment to which the present invention is applied.

15 is a schematic configuration diagram showing an example in which a cooling pipe is attached instead of the gate valve of the apparatus of FIG.

FIG. 16 is a schematic configuration diagram showing a two-tank type vacuum cleaning / drying apparatus to which the present invention is applied.

17 is a schematic configuration diagram showing a configuration of a cross section orthogonal to each other in the device of FIG.

FIG. 18 is a schematic configuration diagram showing another example of a two-tank type vacuum cleaning / drying apparatus to which the present invention is applied.

FIG. 19 is a schematic configuration diagram showing still another example of a two-tank type vacuum cleaning / drying apparatus to which the present invention is applied.

[Explanation of symbols]

 1 ... Vacuum container 1a ... Lid 1b ... Drying chamber 2 ... Petroleum solvent 3 ... Exhaust pipe 4 ... Valve 5 ... Ultrasonic element 6 ... Discharge pipe 7 ... ..Drain valve 8 ... Water-sealed vacuum pump 9 ... Air-water mixing drainage pipe 10 ... Water supply pipe 11 ... Gas-liquid separation tank 12 ... Exhaust pipe 13 ... Drainage pipe 14 ..Oil water separator 15 ... Shower nozzle 16 ... Pressure pump 17 ... Solvent vapor supply pipe 18 ... Valve 19 ... Steam generation tank 20 ... Heating source 21 ... Lift cylinder 22・ ・ ・ Gate valve 23 ・ ・ ・ Pressure pump 24 ・ ・ ・ Valve 25 ・ ・ ・ Distillation tank 26 ・ ・ ・ Float 27 ・ ・ ・ Heating source 28 ・ ・ ・ Discharge pipe 29 ・ ・ ・ Valve 30 ・ ・ ・ Solvent vapor Supply pipe 31 ... Heat exchanger 32 ... Supply pipe 33 ... Pump 3・ ・ ・ Solvent supply pipe 36 ・ ・ ・ Solvent supply valve 37 ・ ・ ・ Solvent tank 38 ・ ・ ・ Float 39 ・ ・ ・ Heating source 40 ・ ・ ・ Discharging pipe 41 ・ ・ ・ Valve 43 ・ ・ ・ Heating source 45 ・ ・・ Cooling pipe 51 ・ ・ ・ Vacuum container 52 ・ ・ ・ Gate valve 53 ・ ・ ・ Rough cleaning chamber 54 ・ ・ ・ Finishing cleaning chamber 55, 56 ・ ・ ・ Ultrasonic element 57 ・ ・ ・ Circulation pipe 58 ・ ・ ・ Pressure pump 59 ... Filter 60 ... Vacuum distillation regenerator 61, 62 ... Elevating cylinder 63 ... Drying chamber 64 ... Partitioning plate 65 ... Horizontal transfer cylinder 71 ... Heating source 81 ...・ Cooling pipe 82 ・ ・ ・ Gutter W ・ ・ ・ Work

Claims (30)

[Claims] 1. A vacuum cleaning method characterized in that the step of cleaning a work using a flammable solvent such as a petroleum solvent as a cleaning agent is performed in a vacuum. 2. The vacuum cleaning method according to claim 1, wherein the cleaning step is performed by at least one cleaning method of immersion cleaning, steam cleaning and shower cleaning. 3. The vacuum cleaning method according to claim 2, wherein the cleaning step includes a plurality of cleaning steps. 4. The vacuum cleaning according to claim 2 or 3, wherein the cleaning step includes an immersion cleaning step performed in vacuum or atmospheric pressure, and a vacuum vapor cleaning step performed subsequently. Method. 5. The cleaning process according to claim 2, 3 or 4, wherein the cleaning process includes a steam cleaning process. In the cleaning process, the flammable solvent stored in a vacuum cleaning tank containing a work is heated and the solvent is removed. The vacuum cleaning method is performed by generating vapor of the solvent by reducing the vapor pressure to or below. 6. The cleaning process according to claim 2, 3 or 4, wherein the cleaning process includes a steam cleaning process, and in this cleaning process, a vapor of a flammable solvent is introduced into a vacuum cleaning tank containing a work from the outside. A vacuum cleaning method characterized by being performed by 7. The vacuum cleaning / drying method according to claim 1, wherein the flammable solvent in the vacuum cleaning chamber is regenerated by vacuum distillation. 8. The vacuum cleaning / processing according to any one of claims 1, 2, 3, 4, 5 and 6, further comprising: a vacuum drying step of vacuum-drying the work after the cleaning step. Drying method. 9. The chamber according to claim 8, wherein the vacuum drying step is performed by partitioning the internal space into upper and lower parts by a gate valve in the vacuum cleaning tank after the vacuum cleaning step of the work. Vacuum cleaning and drying method characterized in that 10. The vacuum drying step according to claim 8, wherein vapor of a flammable solvent is condensed and captured by a cooling pipe in a space on the upper side in the vacuum cleaning tank after the vacuum cleaning step of the work, A vacuum cleaning / drying method characterized in that it is carried out with the vapor concentration suppressed. 11. The vacuum cleaning / drying method according to claim 8, wherein the flammable solvent in the vacuum cleaning chamber is regenerated by vacuum distillation. 12. A cleaning / drying apparatus for cleaning and drying a work by using a flammable solvent such as a petroleum solvent as a cleaning agent, and a vacuum container for vacuum cleaning and drying the work, and A vacuum cleaning / drying apparatus comprising: a vacuuming means for vacuuming the inside of the vacuum container, and vacuum cleaning and vacuum drying of the work in the vacuum container. 13. The work raising / lowering means according to claim 12, wherein the work raising / lowering means is capable of holding the work in a lower portion and an upper portion in the vacuum container, and the work is placed in a lower portion in the vacuum container during vacuum cleaning. A vacuum cleaning / drying apparatus, characterized in that the work is held in the upper portion of the vacuum container during vacuum drying. 14. The exhaust system according to claim 13, further comprising a gate valve for partitioning the inside of the vacuum container into upper and lower parts, and an exhaust pipe by the vacuuming means is connected to an upper part of the vacuum container partitioned by the gate valve. Vacuum cleaning / drying device characterized by being 15. The vacuum cleaning chamber according to claim 14, wherein a lower part of the vacuum container is formed with an immersion cleaning chamber for storing a combustible solvent, and an upper part of the vacuum container is closed with a gate valve. Vacuum cleaning / drying device. 16. The vacuum cleaning / drying device according to claim 15, further comprising means for performing vacuum distillation regeneration of the flammable solvent stored in the immersion cleaning chamber. 17. The vacuum cleaning chamber according to claim 14, wherein a vapor cleaning chamber to which vapor of a combustible solvent is supplied is formed in a lower portion of the vacuum container, and a vacuum valve is provided in an upper portion of the vacuum container by closing a gate valve. A vacuum cleaning / drying device characterized in that a drying chamber is formed. 18. The heating means and the pressure reducing means according to claim 17, for heating the combustible solvent stored in the vapor cleaning chamber and reducing the pressure to a vapor pressure of the solvent or less to generate solvent vapor. Vacuum cleaning / drying device. 19. The vacuum cleaning / drying device according to claim 17, further comprising solvent vapor supply means for supplying vapor of a combustible solvent into the vapor cleaning chamber from the outside. 20. The shower cleaning chamber in which a nozzle for spraying a combustible solvent onto a work is arranged in the lower portion of the vacuum container, and the upper portion of the vacuum container is formed in the shower cleaning chamber. A vacuum cleaning / drying device characterized in that a vacuum drying chamber is formed by closing a gate valve. 21. The work elevating means capable of holding a work in a lower part, an intermediate part and an upper part in the vacuum container, and an upper part in the vacuum container.
With a gate valve for partitioning between the middle part,
An exhaust pipe by the evacuation means is connected to an upper part in the vacuum container partitioned by the gate valve, and an immersion cleaning chamber in which a flammable solvent is stored is formed in a lower part in the vacuum container. A vapor cleaning chamber for cleaning the work by vapor of a combustible solvent is formed in the intermediate portion, and a vacuum drying chamber is formed in the upper portion by closing a gate valve. Vacuum cleaning / drying device. 22. A cooling means for trapping vapor of a combustible solvent is provided at an intermediate position in a vertical direction in the vacuum container, and a portion above the cooling means is provided with the vacuuming means. A vacuum cleaning / drying device characterized by being connected to an exhaust pipe. 23. An immersion cleaning chamber for storing a flammable solvent is formed in a portion below the cooling means in the vacuum container, and a vacuum drying chamber is formed in an upper portion of the vacuum container. Vacuum cleaning / drying device. 24. The steam cleaning chamber to which the vapor of a combustible solvent is supplied is formed in a lower portion of the vacuum container, and the vacuum drying chamber is formed in an upper portion of the vacuum container. Vacuum cleaning / drying device characterized in that 25. The shower cleaning chamber according to claim 22, wherein a nozzle for spraying a flammable solvent onto a work is arranged in a lower part of the vacuum container, and an upper part of the vacuum container is formed in an upper part of the vacuum container. A vacuum cleaning / drying device characterized in that a vacuum drying chamber is formed. 26. A work elevating means capable of holding a work in a lower part, an intermediate part and an upper part in the vacuum container, and an upper part in the vacuum container.
And a cooling means for capturing the vapor of the flammable solvent arranged between the intermediate portion and the upper portion of the inside of the vacuum vessel, the exhaust pipe by the vacuuming means is connected, the vacuum vessel An immersion cleaning chamber in which a flammable solvent is stored is formed in the lower part of the inside, a steam cleaning chamber for cleaning the work by the vapor of the combustible solvent is formed in the intermediate part, and a vacuum drying chamber is formed in the upper part. Vacuum cleaning / drying device characterized by being formed. 27. A cleaning / drying apparatus for cleaning and drying a work by using a flammable solvent such as a petroleum solvent as a cleaning agent, and a vacuum container for vacuum cleaning and drying the work. A vacuum evacuation means for evacuating the inside of the vacuum container, a work elevating means capable of holding a work in a lower part and an upper part of the vacuum container, and a gate valve for partitioning the interior of the vacuum container into upper and lower parts, An exhaust pipe by the evacuation means is connected to an upper part in the vacuum container partitioned by the gate valve, and a plurality of cleaning chambers are formed in a lower part in the vacuum container. Characteristic vacuum cleaning and drying device. 28. The vacuum cleaning / drying apparatus according to claim 27, wherein the plurality of cleaning chambers formed in the lower portion of the vacuum container include an immersion cleaning chamber and a steam cleaning chamber. 29. The vacuum cleaning / drying device according to claim 27, wherein instead of the gate valve, a cooling means for capturing vapor of a combustible solvent is provided. 30. The vacuum cleaning / drying device according to claim 29, wherein the plurality of cleaning chambers formed in the lower portion of the vacuum container include an immersion cleaning chamber and a steam cleaning chamber.