JP2000237703A - Vacuum washing/drying method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum washing/drying method and device in which oil or dirt can be surely removed from work in a short time and also the work can be dried and safety can be secured. SOLUTION: After work 11 is immersed in a hydrocarbon solvent 12 stored in a washing tank 13 and the washing tank 13 is evacuated, impure oil stuck on the work 11 is eluted into the hydrocarbon solvent 12 while ultrasonic vibration and oscillation are given and also solid dirt is removed by a filter to wash the work 11. After the work 11 after washing is put in a finish washing/drying tank 16 and hydrocarbon vapor obtained by heating and vaporizing the hydrocarbon solvent 12 is introduced into the finish washing/drying tank 16 and the inner space of the finish washing/drying tank 16 is evacuated, it is opened to the air, and if necessary, this action is repeated plural times, thereby performing vapor washing and vacuum drying. After the impure oil stuck on the work 11 is removed, the work 11 is dried.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum cleaning / drying method and apparatus which can be used for cleaning various works such as semiconductor lead frames and pressed parts.

[0002]

2. Description of the Related Art Conventionally, a work such as a semiconductor lead frame or a pressed part having oil or dirt adhered to the surface or inside thereof has been washed with a solvent such as chlorofluorocarbon, trichloroethane or trifluoroethylene. However, since these contain environmental destructive substances, their use is being banned. Therefore, use of a hydrocarbon solvent (HC solvent) such as kerosene as an alternative solvent has been proposed. In this case, first, the opening and closing lid of the washing tank for storing kerosene, which is a hydrocarbon solvent, is opened to immerse the work, and then, after the opening and closing lid is closed, the inside of the washing tank is depressurized to a vacuum state, Ultrasonic vibration is applied to the work using an ultrasonic vibration generator, and impurity oil such as machine oil adhering to the work is eluted into kerosene to perform vacuum cleaning. Next, the opening and closing lid of the cleaning tank is opened, the work is taken out, and the work is dried by hot air drying.

[0003]

However, such washing and drying of the work has the following problems. (1) Since the work is hot-air-dried, it is necessary to heat the work to 160 ° C. or higher, which is the evaporation temperature of kerosene, in order to completely dry the work, and enormous energy is required for drying.
In addition, the energy cannot be recovered, and if released to the atmosphere, it causes pollution and global warming. (2) When the work is a lead frame, if hot air drying is performed at a heating temperature of 160 ° C. or more, the work is discolored, and the quality of the work cannot be improved. (3) Hydrocarbon solvents are designated as dangerous goods,
Although sufficient care is taken in its handling, measures have not been taken sufficiently.

The present invention has been made in view of such circumstances, and a vacuum cleaning and drying method and apparatus capable of reliably removing impurities and dirt from a work in a short time and drying and ensuring safety. The purpose is to provide.

[0005]

According to the present invention, there is provided a vacuum cleaning / drying method comprising a work cleaning step, a work vapor cleaning step, and a work drying step.
Then, in the work cleaning step, the work is immersed in a hydrocarbon-based solvent stored in the cleaning tank, hermetically sealed, and further depressurized to evacuate the internal air and deaerate oxygen in the hydrocarbon-based solvent. The work is cleaned by applying ultrasonic vibration and swing to the work, and in the work vapor cleaning process, the work after the work cleaning process is taken out of the cleaning tank, put into the finish cleaning / drying tank, and the inside is depressurized. After degassing, the hydrocarbon-based steam is supplied to the finish cleaning / drying tank to perform steam cleaning.In the work drying step, after finishing the work vapor cleaning step, the finish cleaning / drying tank is evacuated to the atmosphere. The hydrocarbon-based solvent containing the impure oil that has been opened and accumulated inside is discharged, and then the pressure in the finish washing / drying tank is reduced to evaporate the hydrocarbon-based solvent attached to the work.

[0006] Here, the impure oil refers to an object to be cleaned such as a machine oil that adheres to a work. The degree of vacuum inside the cleaning tank is preferably set to 40 to 50 Torr. The degree of vacuum in the cleaning tank is used to reliably prevent the danger of ignition and enhance safety, and to remove hydrocarbon-based vapor that is vaporized in cleaning the work with a hydrocarbon-based solvent in the cleaning tank to the outside. This is because vacuum evacuation is sufficient. Further, the degree of vacuum in the finish cleaning / drying tank for performing steam cleaning and drying of the work is preferably 3 to 5 times.
Torr. This is because a high degree of vacuum is required to perform vacuum drying.

As described above, in the vacuum cleaning / drying method according to the present invention, the work is immersed in the hydrocarbon-based solvent stored in the cleaning tank in which the inside is evacuated, and the work is applied while applying ultrasonic vibration and oscillation. After the work is put into the finish washing / drying tank,
Since steam cleaning and vacuum drying are performed, the number of processing tanks can be reduced. Further, since the finish cleaning and drying are performed in one finish cleaning / drying tank, the work for transporting the work can be omitted, and the processing can be simplified as a whole. Further, since all the steps are substantially performed in a vacuum, the safety of the operation can be sufficiently secured.

[0008] In the above vacuum cleaning and drying method, the hydrocarbon solvent accumulated in the cleaning tank is sufficiently removed from the boiling point of the hydrocarbon solvent at a temperature higher than the melting point of the impure oil adhering to the work in advance or in the cleaning tank. It is also possible to remove solid dirt contained in the hydrocarbon-based solvent that has been heated to a low temperature from the hydrocarbon-based solvent accumulated in the cleaning tank by using a filter unit including a circulation pump and a filter. In this case, the impure oil such as the machine oil attached to the work can be easily dissolved in the hydrocarbon solvent. In addition, since the hydrocarbon-based solvent accumulated in the cleaning tank is removed of solid dirt contained therein by a filter unit having a circulation pump and a filter, the work is caused by dirt mixed with the hydrocarbon-based solvent. Is less contaminated, and cleaner work can be washed, and the hydrocarbon solvent can be used repeatedly.

In the above-mentioned vacuum cleaning / drying method, the finish cleaning / drying tank may be heated in advance to a temperature close to or higher than the coagulation temperature of the hydrocarbon solvent to be subjected to steam cleaning. In this case, the steam supplied in the work steam cleaning step is unlikely to adhere to the side wall of the finish cleaning / drying tank, whereby the amount of steam used for cleaning can be reduced. In the vacuum cleaning and drying method described above, a single vacuum pump having a cooler on the upstream side may be driven to reduce the pressure inside the cleaning tank and the inside of the finishing cleaning / drying tank. In this case, since the work cleaning, the work vapor cleaning, and the work drying can be performed by a single vacuum pump, the vacuum cleaning and drying method can be efficiently performed. In addition, since a cooler is provided on the upstream side of the vacuum pump, most of the vapor content in the gas sucked by the vacuum pump is removed, thereby reducing the load on the vacuum pump and reducing the capacity of the vacuum pump. Thus, the cleaning tank and the final cleaning / drying can be performed efficiently.

[0010] In the above vacuum cleaning and drying method, the hydrocarbon-based solvent containing impurity oil exceeding a predetermined level in the cleaning tank is recovered in the solvent recovery tank through the overflow line, and the hydrocarbon-based solvent recovered by the cooler is recovered. The solvent is recovered in the solvent recovery tank through the solvent recovery line, and the hydrocarbon-based solvent stored in the solvent recovery tank is used to generate hydrocarbon-based solvent vapor using a still. While introducing as a system vapor, the remainder can be liquefied using a liquefaction apparatus to regenerate a hydrocarbon-based solvent that can be used as a cleaning agent. In this case, the surplus hydrocarbon solvent containing the impure oil from the cleaning tank and the hydrocarbon solvent containing the impure oil used in the finishing washing / drying tank are collected and used again as a cleaning agent. Since the solvent is recycled, the hydrocarbon solvent can be saved and the hydrocarbon solvent can be prevented from being released to the atmosphere.

According to the present invention, there is provided a vacuum cleaning / drying apparatus according to the present invention for storing a hydrocarbon-based solvent for cleaning a work housed in a cleaning basket and for closing an upper opening thereof, A vacuum tank, a first vacuum break valve, and a first exhaust valve, a cleaning tank for cleaning the work with a hydrocarbon-based solvent, and an ultrasonic wave for applying ultrasonic vibration and oscillation when the work is cleaned. A second vacuum gauge, a second vacuum unit, a vibration unit, a rocking mechanism, a filter unit for collecting solid dirt stored in the cleaning tank, and an opening / closing lid capable of sealing an upper opening. A finish cleaning / drying tank that includes a release valve and a second exhaust valve and performs finish cleaning of the work cleaned by the cleaning tank and subsequent drying of the work, and is connected to the cleaning tank and the finish cleaning / drying tank; Cooler immediately upstream A vacuum pump, a distillation unit for heating and vaporizing a hydrocarbon-based solvent containing impure oil sent from a cleaning tank and a finishing cleaning / drying tank, and a hydrocarbon-based solvent heated and vaporized by the distillation unit to be used as a cleaning agent. It has a distillation regeneration unit for regenerating a hydrocarbon solvent that can be produced, and control means for these units. As described above, since only two tanks for cleaning and drying the work are required: the cleaning tank and the finish cleaning / drying tank, the size of the equipment can be reduced, and the finish cleaning and drying of the work are performed. Sometimes, another work can be washed in the washing tank, so that the operation is continuous and a relatively large amount of work can be processed. The above vacuum cleaning and drying apparatus is further arranged downstream of the vacuum pump, and a gas cooler for recovering the impure oil and the hydrocarbon solvent contained in the gas that has passed through the vacuum pump, and at least the vacuum pump, And a cooling tower for cooling the gas cooler with cooling water. In this case, the amount of the hydrocarbon solvent contained in the gas released to the atmosphere can be significantly reduced. Further, since at least the vacuum pump, the cooler, and the cooling tower for performing cooling with the cooling water of the gas cooler are provided, it is possible to cool the gas and the equipment with relatively inexpensive equipment.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention.

First, referring to the block diagram shown in FIG.
A conceptual configuration of the vacuum cleaning / drying apparatus 10 according to one embodiment of the present invention will be described. As shown in the figure, work 1
A cleaning tank 13 for storing refined kerosene 12, which is an example of a hydrocarbon-based solvent for cleaning 1, has an opening / closing lid 14 capable of sealing an upper opening thereof, and a lower portion of an ultrasonic vibrating means. It has an ultrasonic vibration generator 15 as an example. As will be described later, the cleaning tank 13 includes a swing mechanism 68 (see FIG. 5) for swinging the work 11.
A finish cleaning / drying tank 16 is provided side by side on one side of the cleaning tank 13, and the finish cleaning / drying tank 16 is supplied with kerosene vapor therein, and can close the upper opening. It has an opening / closing lid 18.

The cleaning tank 13 is connected to a vacuum pump 21 through a first vacuum suction pipe 20 provided with a cooler 19 in the middle, and the inside of the cleaning tank 13 is driven by driving the vacuum pump 21. The pressure can be reduced to a vacuum. On the other hand, the finish cleaning / drying tank 16 is connected to the first vacuum suction pipe 20 via the second vacuum suction pipe 22 and is similarly driven by driving the vacuum pump 21. Can be evacuated to a vacuum.

In the present embodiment, the supply of kerosene 12 to the cleaning tank 13 and the supply of kerosene vapor to the finish cleaning / drying tank 16 are described below in order to regenerate them and to use them effectively. This is done using the configuration. That is, the cleaning tank 13 is connected to an inlet of a kerosene recovery tank 24, which is an example of a solvent recovery tank, through an overflow line 23 having an on-off valve 23a. The kerosene recovery line 25 is connected to another inlet of a kerosene recovery tank 24 through a kerosene recovery line 25 which is an example of a solvent recovery line provided on the downstream side of the vacuum pump 21.
A gas cooler 26 and a check valve 26a are mounted in the middle of the process. A base of an exhaust duct 24a whose front end is open to the atmosphere is connected to the upper space of the kerosene recovery tank 24, and an exhaust fan 24b is attached to a middle part of the exhaust duct 24a.

The outlet of the kerosene recovery tank 24 is connected to the inlet of a still 29 via a first kerosene supply line 27 having a filter 28 and an on-off valve 29a. A first kerosene vapor supply line 30 is connected to the outlet of the still 29. The downstream portion of the first kerosene vapor supply line 30 is branched into second and third kerosene vapor supply lines 31, 32 via a steam guide valve 30a formed of a three-way valve. Further, a drain valve 29b is attached to a pipe connected to a lower part of the still 29. The second kerosene vapor supply line 31 is communicatively connected to an inlet of a condenser 33 which is an example of a liquefier for producing kerosene 12 that can be used as a cleaning agent. On the other hand, the outlet of the condenser 33 is connected to the circulation tank 3
4. Check valve 33b, ejector 33c, open / close valve 34a
Cleaning tank 1 via a second kerosene supply line 35 equipped with
3 are connected in communication. Reference numeral 34b indicates a circulation pump. The downstream end of the third kerosene vapor line 32 is connected to the inside of the finish washing / drying tank 16.

According to the above-described configuration, the kerosene 1 in which the impure oil to be cleaned such as the machine oil is dissolved from the cleaning tank 13.
2, a portion exceeding a predetermined level can be taken out and collected in a kerosene collection tank 24 through an overflow line 23. Also, after the kerosene vapor contained in the air sucked from the cleaning tank 13 and the finish cleaning / drying tank 16 by the vacuum pump 21 is liquefied through the cooler 19 provided on the upstream side of the vacuum pump 21, the kerosene vapor remains in the sucked air. The slightly contained kerosene 12 also passes through a kerosene recovery tank 25 through a kerosene recovery line 25 provided on the downstream side of the vacuum pump 21.
Can be recovered as kerosene 12 containing impure oil.
Thereafter, a kerosene vapor containing no impure oil is generated from the recovered kerosene 12 containing the impure oil using the still 29, and a part of the kerosene vapor is introduced into the finish washing / drying tank 16 as kerosene vapor. After the remaining liquid is liquefied using a condenser 33 to produce kerosene 12 as a new liquid, it can be introduced into the cleaning tank 13 via the circulation tank 34.

As shown in FIG. 1, a first vacuum gauge 36, a first vacuum breaking valve 37, and a first exhaust valve 38 are attached to the cleaning tank 13. In the present embodiment, the first exhaust valve 38 is attached to a portion of the first vacuum suction pipe 20 close to the cleaning tank 13 for convenience.
On the other hand, the finish cleaning / drying tank 16 has a second vacuum gauge 3
9. A second vacuum break valve 40 and a second exhaust valve 41 are attached. Further, for convenience, the second vacuum break valve 40 and the second exhaust valve 41 are attached to a portion of the third kerosene vapor supply line 32 and the second vacuum suction pipe 22 near the finish cleaning / drying tank 16. Have been. Then, using a control device 76 (see FIGS. 2 and 3) which is an example of the control means, the vacuum pump 21, the first vacuum gauge 36, the first vacuum break valve 37, and the first exhaust valve 38 are connected. Drive control can be performed to adjust the degree of vacuum in the cleaning tank 13 to, for example, 40 to 50 Torr, and the vacuum pump 21, the second vacuum gauge 39, the second vacuum break valve 40, and the second exhaust valve 41 is controlled to drive the interior of the finish cleaning / drying tank 16 alternately into a vacuum state and an open-to-atmosphere state.
It can be adjusted to ４4 Torr.

Further, as shown in FIG. 1, in this embodiment, since the kerosene 12 is used, in order to ensure its safety, oil and dirt supplied into the still 29 are dissolved. The kerosene 12 is heated by using a heat medium oil. That is, the oil tank 42 filled with the flame-retardant heat medium oil to be heated by the heater or the like is provided by the circulating flow path including the heat medium oil supply line 43 to which the circulation pump 45 is attached and the heat medium oil return line 44. 29. In the present embodiment, the on-off valve 29a provided on the upstream side of the still 29 is closed to temporarily stop the flow of the kerosene 12 into the still 29. This is kerosene 1
The boiling point of the impure oil mixed in
° C) is higher than the boiling point (for example, 80 ° C) of the kerosene 12, the kerosene 12 is boiled down in the still 29, only the kerosene 12 is evaporated, and after the oil concentration is sufficiently increased, the drain valve 29 b is opened. By taking it out and discarding it,
This is because the amount of disposal and the number of disposals are reduced, and the operation stop time of the vacuum cleaning and drying apparatus 10 is shortened as much as possible.

Referring to FIG. 1, the bottom of the finish washing / drying tank 16 and the bottom of the cooler 19 are respectively provided with a first or second kerosene return pipe 46, as shown in FIG. 47 and is connected to a kerosene return tank 48 via a
Is connected to the bottom of the washing tank 13 through a kerosene return pipe 49. Note that a return pump 50 is attached to the third kerosene return pipe 49. Further, an opening / closing valve 46a is attached to the first kerosene return pipe 46, and a gas backflow prevention tank 19a is attached to the second kerosene return pipe 47. With this configuration, the finish cleaning / drying tank 16
The kerosene 12 dropped on the bottom of the finish washing / drying tank 16 by steam washing and the kerosene 12 generated by liquefaction by the cooler 19 are once passed through a kerosene return tank 48,
It can be returned to the cleaning tank 13 and reused.

As shown in FIG. 1, the cooler 19, gas cooler 26, vacuum pump 21, condenser 33, etc.
The operation is performed using the cooling water from the cooling tower 51 without using an expensive chiller. That is, the cooler 19, the gas cooler 26, the vacuum pump 21, the condenser 3
3 and the like are connected to the cooling tower 51 via a cooling water supply pipe 52 and a cooling water return pipe 53.

Further, as shown in FIG. 1, the washing tank 13 is provided with a filter unit 54 for removing inorganic dust contained in the kerosene 12. The filter unit 54 substantially includes the circulation pump 55 and the filter 5.
6 is formed from a kerosene circulation flow channel 57 to which a gas turbine 6 is attached.

Next, a vacuum cleaning / drying method using the vacuum cleaning / drying apparatus 10 having the above configuration will be described. As described below, the vacuum cleaning and drying method substantially comprises:
It comprises a work cleaning step, a work vapor cleaning step, and a work drying step. (1) First, kerosene 12 which is an example of a hydrocarbon-based solvent is put into the cleaning tank 13. In the initial state, it is preferable that the kerosene 12 is directly charged by opening the open / close lid 14 of the cleaning tank 13, but if the regenerated kerosene 12 remains in the circulation tank 34, the open / close valve 34 a is opened. It may be opened and supplied from the second kerosene supply line 35. The amount of kerosene 12 supplied into the cleaning tank 13 is detected by the second level sensor 72, and after confirming that the second level sensor 72 is operating, the following processing is performed. I have.

The washing tank 13 is heated by the heat transfer oil from the oil tank 42, and the temperature of the kerosene 12 inside is detected and controlled by a temperature sensor (not shown) to be about 40 ° C. This is because the melting temperature of the impure oil adhering to the work 11 is about 30 ° C., so that when the work 11 is put, it is about 40 ° C. (above the melting point of the impure oil and sufficiently higher than the boiling point of the kerosene 12). This is for dissolving the impure oil that has been heated to a low temperature) and adhered to the work 11 into the kerosene 12. (2) The filter unit 54 having an outlet and an inlet provided at a lower portion of the cleaning tank 13 is driven. As a result, dirt contained in the kerosene 12 is removed by the filter 56.
Since there is no dirt (SS) or the like immediately after the workpiece 11 is placed in the cleaning tank 13, this step may be performed after the workpiece 11 is placed in the cleaning tank 13.

(3) With the opening and closing cover 14 opened, the work 11 in the washing basket 67 (see FIG. 5) is immersed in the kerosene 12 in the washing tank 13 and the opening and closing cover 14 is closed. At this time, the overflowing kerosene 12 flows into the kerosene recovery tank 24 through the overflow line 23. (4) With the on-off valve 23a provided in the overflow line 23 closed, the vacuum pump 21 is operated to depressurize the inside of the washing tank 13 to evacuate the air inside, and to remove kerosene 1
The oxygen dissolved in 2 is degassed and the first vacuum gauge 36
When the degree of vacuum in the cleaning tank 13 measured in the step becomes 40 Torr, the first exhaust valve 38 is closed and the operation of the vacuum pump 21 is stopped.

(5) The ultrasonic vibration generator 15 attached to the bottom of the washing tank 13 is operated, and the swing mechanism 68 is operated to swing the washing basket 67 in which the work 11 is stored. As a result, the impure oil adhering to the work 11 is forcibly dissolved into the kerosene 12, and dirt is also removed from the work 11. This operation removes the solid dirt (SS) contained in the contaminated kerosene 12 by the filter unit 54. When the ultrasonic cleaning is performed, the temperature of the kerosene 12 gradually rises. Therefore, during the ultrasonic cleaning, the cleaning tank 13 is cooled with water so that the kerosene 12 always keeps about 40 ° C. (the work cleaning step ends).

(6) When the cleaning operation for a predetermined time is completed,
Stop the operation of the ultrasonic vibration generator 15 and the swing mechanism 68,
The first vacuum breaking valve 37 is operated to open the inside of the cleaning tank 13 to the atmosphere. Next, the opening / closing lid 14 of the cleaning tank 13 is opened,
The work 11 is taken out and transferred to a position immediately above a finish washing / drying tank 16 for performing finish washing and subsequent drying of the work 11. Here, the kerosene 12 is supplied from the kerosene return tank 48 to the cleaning tank 13 via the return pump 50, and the overflow is supplied to the kerosene recovery tank 24. This makes up for the lack of kerosene 12 in the washing tank 13 and reuses the kerosene 12 in the kerosene return tank 48 containing a small amount of impure oil in the washing tank 13.

(7) With the opening / closing lid 18 opened, the work 1 in which the liquid cleaning with the kerosene 12 as the cleaning agent is completed in the cleaning tank 13
1 is put into the finish cleaning / drying tank 16 by the elevating mechanism 65 as shown in FIGS. This finish cleaning
In the drying tank 16, a cage is provided at the bottom so that the work 11 in the washing basket 67 is arranged at an intermediate position of the finishing washing / drying tank 16. Here, the temperature of the work 11 is about 40 to 60 ° C., but the temperature of the side wall of the finish washing / drying tank 16 is about 80 ° C. (near or above the setting temperature of the kerosene 12 for performing steam cleaning). It is preheated by a heat transfer oil provided with a heater. This is because kerosene 12 supplied at the time of finish cleaning of work 11
This is for improving the cleaning efficiency by preventing the steam from adhering to the side wall of the finish cleaning / drying tank 16.

(8) The cover 18 is closed, the second exhaust valve 41 is opened, and the other valves are closed.
Is operated to decompress the inside of the finishing washing / drying tank 16 to remove air therein. This is because if there is air in the finish cleaning / drying tank 16, the steam cleaning as the finish cleaning (rinse cleaning) is not performed smoothly. (9) The degree of vacuum in the finish cleaning / drying tank 16 is 4 to 5 Torr.
At time r, the second exhaust valve 41 is closed, the vacuum pump 21 is stopped, the steam guide valve 30a is opened, and kerosene vapor at about 80 ° C. from the still 29 is fed into the finishing washing / drying tank 16. Lead. The kerosene vapor that has entered the finish washing / drying tank 16 contacts the work 11 at about 40 to 60 ° C. and condenses,
Thereby, the steam cleaning of the work 11 is performed. Kerosene 12 containing impure oil generated in the process of steam cleaning accumulates at the bottom of finish cleaning / drying tank 16.

(10) The temperature of the work 11 gradually rises due to the contact of the kerosene vapor heated to 80 ° C.
When the temperature reaches 0 ° C. or around 80 ° C., the steam cleaning is completed. This is because when the temperature of the work 11 is around 80 ° C., the adhesion of kerosene vapor becomes extremely poor, and the cleaning efficiency is significantly reduced (the work vapor cleaning step ends). (11) When the steam cleaning of the work 11 is completed, the steam guide valve 30a is closed, the second vacuum break valve 40 is opened to make the inside of the work 11 at atmospheric pressure, and then provided at the lower part of the finish washing / drying tank 16. The open / close valve 46a is opened, and the kerosene (including impure oil) 12 stored at the bottom of the finish washing / drying tank 16 is opened.
Into the kerosene return tank 48. As a result, the kerosene 12 in the finish washing / drying tank 16 is temporarily removed.

(12) Next, with the second vacuum break valve 40 and the opening / closing valve 46a closed, the second exhaust valve 41 is opened and the vacuum pump 21 is operated, so that the inside of the finishing washing / drying tank 16 is opened. Reduce pressure. Thereby, the kerosene 12 adhered to the work 11 evaporates as steam. In the course of the kerosene evaporation, the impure oil melted in the kerosene 12 also evaporates,
The surface of the work 11 is cleaned and dried. This drying treatment is performed while heating the finish washing / drying tank 16 with a heating medium.
The process is continued until the internal pressure of the finish washing / drying tank 16 becomes 4 to 5 Torr (the work drying step ends). If the work 11 has a blind hole or an oil reservoir, it is difficult to remove the impure oil sufficiently adhered by the above-described processing. Therefore, the work 11 is subjected to steam cleaning by putting steam into the finish cleaning / drying tank 16. The process and the decompression process of reducing the pressure in the finish washing / drying tank 16 to vaporize the condensed kerosene mixed with the impure oil are repeated a plurality of times. The temperature of the work 11 is increased by the work steam cleaning process, and the temperature is reduced by vaporization by the decompression process, so that the next process can be efficiently performed. It can be almost completely removed.

(13) After the above processing is completed, the second vacuum breaking valve 40 is opened, the other valves are closed, and the opening / closing lid 18 of the finishing washing / drying tank 16 is opened to open the dried workpiece 11. Take out.

Next, a process of regenerating the kerosene 12 used by the vacuum cleaning / drying apparatus 10 will be described. (1) On the upstream side of the vacuum pump 21,
A cooler 19 for cooling the gas to 0 ° C. or less is provided to liquefy most of the kerosene contained in the gas, and the liquefied kerosene 12 is liquefied via a gas backflow prevention tank 19 a at the lower part of the kerosene return tank 4.
It is stored at 8. As a result, the entrance of kerosene vapor sucked into the vacuum pump 21 is prevented, the load on the vacuum pump 21 is remarkably reduced, and the kerosene 12 in the suction gas is recovered. (2) The gas discharged from the vacuum pump 21 enters the kerosene recovery tank 24 via a check valve 26a for preventing a backflow of the gas to the vacuum pump 21 to reduce the load, and a gas cooler 26, After the contained kerosene 12 is further recovered, the kerosene 12 is opened to the atmosphere via an exhaust fan 24b.

(3) Since the kerosene 12 stored in the kerosene recovery tank 24 contains impure oil, it is supplied to the still 29 via the filter 28. The still 29 is heated to about 80 to 90 ° C. by the heat medium oil to vaporize the kerosene 12 and generate kerosene vapor from which the impure oil has been removed. This kerosene vapor is supplied to the finish cleaning / drying tank 16 or the condenser 33 via the vapor guide valve 30a. In addition,
Since the impure oil accumulates in the lower part of the still 29, the drain valve 29b is periodically opened to remove the oil. (4) A gas cooler 33a is provided on the upstream side of the condenser 33 to cool the kerosene vapor in advance and reduce the load on the condenser 33. Pure regenerated kerosene liquefied by the condenser 33 is supplied to the circulation tank 34 via the check valve 33b and the ejector 33c. Circulation tank 3
In No. 4, a circulation pump 34b is provided at a lower portion to circulate the regenerated kerosene therein, thereby contributing to the recovery of the regenerated kerosene from the condenser 33 by the ejector 33c and the sending of the regenerated kerosene to the circulation tank 34.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS.
The specific configuration of is shown. As shown in the figure, a tank mounting frame 62 is installed on a lower base 61 of a casing 60 made of a rectangular box, and the tank mounting frame 62 is finished with the cleaning tank 13 at intervals in the width direction. Washing / drying tank 1
6 are attached. As shown in FIG.
A traveling rail 63 is provided above the finishing washing / drying tank 16, and a work carrier 64 is mounted on the traveling rail 63 so as to be freely movable. As shown in FIGS. 3 and 5, a pair of elevating mechanisms 65 extend downward from the lower surface of the work carrier 64, and a swing table 66 is detachably mounted below the elevating mechanism 65. . Also,
The washing basket 67 containing the work 11 is provided on the upper surface of the swing table 66.
Is installed.

As shown in FIG. 5, on one side of the peripheral wall of the cleaning tank 13, a swing mechanism 68 that supports the swing table 66 in a cantilever state and can swing is mounted. The ultrasonic vibration generator mounting plate 69 is mounted on the bottom wall of the cleaning tank 13, and the ultrasonic vibration generator 15 is mounted on the ultrasonic vibration generator mounting plate 69. A normal first level sensor 71 of a water pressure detection type and a second level sensor 72 of a float type are mounted on both sides of the peripheral wall of the cleaning tank 13, respectively. Further, as shown in FIGS. 2 to 4, the open / close lids 14 and 18 are configured to be openable / closable by lid open / close cylinders 73 and 74, respectively.
On the lower base 61 of the casing 60, the cleaning tank 13
And the rear part of the finishing washing / drying tank 16, a distillation regeneration unit 75 including a still 29, a condenser 33, a circulation tank 34, an oil tank 42, etc., a vacuum pump 21, a kerosene recovery The tank 24 and the control device 76
Are arranged.

In the above-described configuration, the use of the work transport carriage 64 having the elevating mechanism 65 allows the work 11 to enter and exit the cleaning tank 13, move from the cleaning tank 13 to the finishing / drying tank 16, and finish cleaning.・ Drying tank 1
6 can be automatically performed, and the work 11 can be effectively cleaned and dried. Further, since the workpiece 11 can be washed while being rocked by the rocking mechanism 68, the cleaning effect can be promoted.

As described above, the present invention has been described with reference to an embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and is described in the claims. It also includes other embodiments and modifications that can be considered within the scope of the matters described. For example, arranging a washing tank and a finishing washing / drying tank on a conveyor, and sequentially passing the band-shaped work through the washing tank and the finishing washing / drying tank, thereby continuously washing and drying the band-like work. Can be. Further, in the above-described embodiment, kerosene is used as an example of the hydrocarbon solvent, but the present invention can be applied to hydrocarbon solvents other than kerosene. In this case, the treatment can be performed at a relatively low temperature as a whole by using a hydrocarbon-based solvent having a boiling point and a melting point close to those of kerosene.

[0039]

According to the vacuum cleaning and drying method of the first to fifth aspects, the work is immersed in a hydrocarbon-based solvent stored in a cleaning tank in which the internal space is evacuated, and ultrasonic vibration and oscillation are applied. After washing the work while putting it into the finishing washing / drying tank, steam cleaning and vacuum drying are performed in the finishing washing / drying tank, so the number of processing tanks is small. I'm done. Furthermore, one finish cleaning
Finish cleaning and drying are performed in the drying tank, eliminating the need to transport the work, simplifying the overall process,
Impurities and dirt can be reliably removed in a short time, and can be dried and safety can be ensured.

In particular, in the vacuum cleaning / drying method according to the second aspect, the hydrocarbon-based solvent accumulated in the cleaning tank is heated to a temperature higher than the melting point of the impure oil adhering to the workpiece in advance or in the cleaning tank. Since the heating is performed to a temperature sufficiently lower than the boiling point of the system solvent, the impure oil such as the machine oil adhered to the work easily dissolves in the hydrocarbon solvent.
Then, the hydrocarbon solvent accumulated in the cleaning tank is filtered by a filter unit including a circulation pump and a filter.
Since the solid dirt contained is removed, the work is not easily stained by dirt mixed in the hydrocarbon-based solvent and the like, and more clean work can be washed, and the hydrocarbon-based solvent can be used repeatedly. In the vacuum cleaning / drying method according to the third aspect, since the finish cleaning / drying tank is preliminarily heated to a temperature close to or higher than the coagulation temperature of the hydrocarbon solvent to be subjected to steam cleaning, it is supplied in the work vapor cleaning step. This makes it difficult for the steam to adhere to the side wall of the finish cleaning / drying tank, thereby reducing the amount of steam used for cleaning.

In the vacuum cleaning / drying method according to the fourth aspect, since the cooler is provided on the upstream side of the vacuum pump, most of the vapor content in the gas sucked by the vacuum pump is removed, whereby the vacuum is removed. The load on the pump is reduced, and the cleaning tank and the finishing cleaning / drying tank can be efficiently degassed with a smaller capacity vacuum pump. In the vacuum cleaning and drying method according to the fifth aspect, an excess hydrocarbon solvent containing the impure oil from the cleaning tank and a hydrocarbon solvent containing the impure oil used in the finish cleaning / drying tank are recovered. Is recycled into a hydrocarbon solvent that can be used again as a cleaning agent, so that the hydrocarbon solvent can be saved and
It is possible to prevent the hydrocarbon solvent from opening to the atmosphere.

In the vacuum cleaning and drying apparatus according to the sixth and seventh aspects, only two tanks, ie, a cleaning tank and a finish cleaning / drying tank, are required for cleaning and drying the work, so that the equipment can be downsized. In addition, when the work is being cleaned and dried, another work can be cleaned in the cleaning tank, so that the operation is continuous and a relatively large amount of work can be processed. In particular, the vacuum cleaning and drying apparatus according to claim 7 is provided with a gas cooler disposed downstream of the vacuum pump for recovering the impure oil and the hydrocarbon-based solvent contained in the gas that has passed through the vacuum pump. Therefore, the amount of the hydrocarbon solvent contained in the gas released into the atmosphere can be significantly reduced. And
Since at least a cooling tower for cooling with a cooling water of a vacuum pump, a cooler, and a gas cooler is provided, it is possible to cool gas, equipment, and the like with relatively inexpensive equipment.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a vacuum cleaning / drying apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a vacuum cleaning / drying apparatus according to one embodiment of the present invention.

FIG. 3 is a front view of the same.

FIG. 4 is a side view of the same.

FIG. 5 is a front view of a cleaning tank of the vacuum cleaning / drying apparatus according to one embodiment of the present invention.

[Explanation of symbols]

10: vacuum cleaning / drying device, 11: work, 12: kerosene (hydrocarbon solvent), 13: cleaning tank, 14: open / close lid, 1
5: Ultrasonic vibration generator (ultrasonic vibration means), 16: Finish cleaning / drying tank, 18: Opening / closing lid, 19: Cooler, 19
a: gas backflow prevention tank, 20: first vacuum suction pipe,
21: vacuum pump, 22: second vacuum suction pipe, 23:
Overflow line, 23a: open / close valve, 24: kerosene recovery tank, 24a: exhaust duct, 24b: exhaust fan,
25: kerosene recovery line (solvent recovery line), 26: gas cooler, 26a: check valve, 27: first kerosene supply line, 28: filter, 29: still, 29a: open / close valve,
29b: drain valve, 30: first kerosene steam supply line, 30a: steam guide valve, 31: second kerosene steam supply line, 32: third kerosene steam supply line, 33: condenser (liquefier), 33a : Gas cooler, 33b: check valve, 33c: ejector, 34: circulation tank, 34
a: open / close valve, 34b: circulation pump, 35: second kerosene supply line, 36: first vacuum gauge, 37: first vacuum release valve, 38: first exhaust valve, 39: second exhaust valve Vacuum gauge, 4
0: second vacuum release valve, 41: second exhaust valve, 42: oil tank, 43: heat medium oil supply line, 44: heat medium oil return line, 45: circulation pump, 46: first kerosene return Piping,
46a: open / close valve, 47: second kerosene return pipe, 48: kerosene return tank, 49: third kerosene return pipe, 50: pump, 51: cooling tower, 52: cooling water supply pipe,
53: cooling water return pipe, 54: filter unit, 5
5: Circulation pump, 56: Filter, 57: Kerosene circulation channel, 60: Casing, 61: Lower base, 62: Tank mounting frame, 63: Travel rail, 64: Work carrier
65: lifting mechanism, 66: rocking table, 67: washing basket, 68:
Swing mechanism, 69: ultrasonic vibration generator mounting plate, 71: first level sensor, 72: second level sensor, 73:
Lid opening / closing cylinder, 74: Lid opening / closing cylinder, 75: Distillation regeneration unit, 76: Control device (control means)

Claims (7)

[Claims] A work is immersed in a hydrocarbon-based solvent stored in a washing tank, hermetically sealed, and further depressurized to evacuate internal air and deaerate oxygen in the hydrocarbon-based solvent. A work cleaning step of applying ultrasonic vibration and swing to the work to clean the work, and removing the work after the work cleaning step from the cleaning tank, and performing a final cleaning process.
The work steam cleaning step of performing steam cleaning by supplying the hydrocarbon-based steam into the finish cleaning / drying tank after depressurizing the inside by putting the inside in a drying tank and depressurizing the inside, and terminating the work steam cleaning step. Thereafter, the inside of the finishing washing / drying tank was opened to the atmosphere to discharge the hydrocarbon-based solvent containing the impure oil accumulated therein, and then the inside of the finishing washing / drying tank was decompressed and adhered to the work. A work drying step of evaporating the hydrocarbon-based solvent. 2. The vacuum cleaning / drying method according to claim 1, wherein the hydrocarbon-based solvent accumulated in the cleaning tank has a melting point higher than or equal to the melting point of the impure oil attached to the work in advance or in the cleaning tank. The hydrocarbon-based solvent that has been heated to a temperature sufficiently lower than the boiling point of the hydrocarbon-based solvent and that has accumulated in the washing tank is removed by a filter unit including a circulation pump and a filter to remove solid dirt contained therein. A vacuum cleaning and drying method characterized by being performed. 3. The vacuum cleaning / drying method according to claim 1, wherein the finish cleaning / drying tank is heated in advance to a temperature close to or higher than the coagulation temperature of the hydrocarbon solvent to be subjected to steam cleaning. A vacuum cleaning and drying method. 4. The vacuum cleaning / drying method according to claim 1, wherein a single vacuum pump provided with a cooler on an upstream side is driven to clean the inside of the cleaning tank and the finish cleaning. A vacuum cleaning and drying method, wherein the inside of the drying tank is depressurized. 5. The vacuum cleaning / drying method according to claim 4, wherein the hydrocarbon-based solvent containing an impure oil exceeding a predetermined level in the cleaning tank is recovered in a solvent recovery tank through an overflow line, and the solvent is recovered by the cooler. The recovered hydrocarbon-based solvent is recovered in the solvent recovery tank through a solvent recovery line, and steam is generated from the hydrocarbon-based solvent stored in the solvent recovery tank using a still, and a part thereof is subjected to the final cleaning. -A vacuum cleaning and drying method comprising introducing the hydrocarbon-based vapor into a drying tank and liquefying the remainder using a liquefier to regenerate a hydrocarbon-based solvent that can be used as a cleaning agent. 6. An opening / closing lid for storing a hydrocarbon-based solvent for cleaning a work housed in a cleaning basket and capable of sealing an upper opening thereof, a first vacuum gauge, and a first vacuum release valve. A washing tank for washing the work with the hydrocarbon-based solvent, an ultrasonic vibration means and a swing mechanism for imparting ultrasonic vibration and oscillation when the work is washed, and A filter unit for collecting solid dirt stored in the cleaning tank, an opening / closing lid capable of sealing an upper opening, a second vacuum gauge, a second vacuum break valve, and a second exhaust valve A finish cleaning / drying tank for performing a final cleaning of the work cleaned by the cleaning tank and a subsequent drying process of the work; and a communication upstream and downstream of the cleaning tank and the finish cleaning / drying tank. Vacuum with a cooler A pump, a distiller for heating and evaporating a hydrocarbon-based solvent containing impure oil sent from the washing tank and the finishing washing / drying tank, and a hydrocarbon-based solvent heated and evaporated by the distiller can be used as a cleaning agent. A vacuum cleaning / drying apparatus comprising: a distillation regeneration unit for regenerating a hydrocarbon solvent; and control means for these units. 7. The vacuum cleaning / drying apparatus according to claim 6, further comprising a gas disposed downstream of the vacuum pump for recovering an impure oil and a hydrocarbon-based solvent contained in the gas passing through the vacuum pump. A vacuum cleaning / drying apparatus comprising: a cooler; and at least a cooling tower that cools the vacuum pump, the cooler, and the gas cooler with cooling water.