WO2011024402A1

WO2011024402A1 - Method for drying object to be dried and device therefor

Info

Publication number: WO2011024402A1
Application number: PCT/JP2010/005039
Authority: WO
Inventors: 正英内野
Original assignee: ジャパン・フィールド株式会社
Priority date: 2009-08-26
Filing date: 2010-08-11
Publication date: 2011-03-03
Also published as: JP4575513B1; CN102472576A; JP2011047570A

Abstract

Disclosed is a method for drying an object to be dried, wherein an object to be dried can be safely removed from a device by boiling and evaporating a high-boiling-point solvent used to dry the object to be dried, to remove the high-boiling-point solvent from the surface of the object to be dried, so that the burden on the environment and the running cost can be reduced. Within a solvent introduction tank (1) to which a high-boiling-point solvent (2), the boiling point of which is higher than that of water, is introduced, an object to be dried (25) is brought into contact with the high-boiling-point solvent (2) which has been heated to the boiling point of water or more, to boil and evaporate moisture attached to the object to be dried (25). After that, the object to be dried (25) is transferred to a vacuum drying tank (10) within a hermetically sealed space, and the inside of the vacuum drying tank (10) is decompressed and heated to the boiling point of the high-boiling-point solvent (2) or more while the communication between the solvent introduction tank (1) and the vacuum drying tank (10) is blocked, so that the high-boiling-point solvent (2) attached to the surface of the object to be dried (25) is evaporated to dry the object to be dried (25).

Description

Method and apparatus for drying an object to be dried

The present invention relates to a method for drying an object to be dried for removing moisture adhering to the object to be dried such as an electronic component, a printed circuit board, and a machine part, and an apparatus used for the method.

Conventionally, as a method for removing moisture adhering to an object to be dried such as an electronic component, a printed circuit board, or a machine part by a cleaning operation, a method of separating moisture by a centrifugal force, hot air is blown to the object to be dried. A method of evaporating, a method of separating water by immersing an object to be dried in a water separation liquid having a specific gravity different from that of water are known.

However, the above-mentioned method using centrifugal force and the method of blowing hot air on the material to be dried cause moisture to remain in the recesses and cavities when the material to be dried has the recesses and cavities. It was difficult to remove. In addition, the method using the above water separation liquid does not mix the water separation liquid and the water, so there is no certainty in the removal and separation of water from the material to be dried.

Therefore, a method for drying an object to be dried as shown in Patent Document 1 is known. This method involves immersing a material to be dried with moisture in a high-boiling solvent having a boiling point higher than that of water, and heating the high-boiling solvent to a temperature higher than the boiling point of water and lower than the boiling point of the high-boiling solvent. The water adhering to the dried product is boiled and evaporated. By using such a method, even if the object to be dried has a recess or a cavity, the high boiling point solvent enters the recess or the cavity, so that the water adhering to the object to be dried is surely boiled and evaporated. It can be removed.

Japanese Patent Laid-Open No. 6-7611

In the method of Patent Document 1, after the water adhering to the object to be dried is evaporated and removed as described above by heating the high boiling point solvent, the high boiling point solvent remains on the surface of the object to be dried. The removal of the high boiling point solvent remaining on the surface of the material to be dried is not described. For this reason, when the object to be dried is taken out from the apparatus with the high boiling point solvent attached, it is exposed to the outside air, and the high boiling point solvent may diffuse into the atmosphere, which may adversely affect the environment. In addition, when handled as described above, the high boiling point solvent diffuses into the atmosphere, so that the high boiling point solvent must be replenished during the next drying operation, resulting in high running costs. It was.

In addition, when the above-mentioned handling is performed, the high-boiling solvent in the apparatus comes into contact with the outside air when the material to be dried is taken out from the apparatus. Will be. For this reason, the high boiling point solvent must be frequently replaced, and in this respect, the running cost is high. In addition, when a flammable solvent is used as a high boiling point solvent, if the high boiling point solvent diffuses into the atmosphere, the flammable high boiling point solvent may ignite in response to fire, static electricity, etc. outside the washing tank. was there.

Therefore, the present invention is intended to solve the above-described problems, and the high boiling point solvent used for drying the object to be dried is boiled and evaporated in a vacuum drying tank to be removed from the surface of the object to be dried. In this way, it is possible to safely take out the material to be dried from the apparatus and to recover the high boiling point solvent, to reduce the burden on the environment, and to reduce the running cost. .

In order to solve the problems as described above, the first invention of the present application is a method for drying an object to be dried, wherein the object to be dried to which moisture is attached is introduced into a solvent introduction tank into which a high boiling point solvent having a boiling point higher than that of water is introduced. Then, the water adhering to the material to be dried is boiled and evaporated by contacting with the high boiling point solvent heated to the boiling point of water or higher. In addition, the heating of the high boiling point solvent to the above boiling point of water may be a heating to a temperature lower than the boiling point of the high boiling point solvent, or a heating to a boiling point or more of the high boiling point solvent. In addition, in the claims and the present specification, the “dried material to which moisture adheres” includes “the dried material to which only moisture adheres” and “liquid such as moisture, processing oil, and surfactant”. To be dried ”to which the mixed solution is attached.

Then, after the water adhering to the object to be dried is boiled and evaporated as described above, the object to be dried is transferred in a sealed space to a vacuum drying tank capable of blocking communication with the solvent introduction tank. Then, with the communication between the solvent introduction tank and the vacuum drying tank blocked, the inside of the vacuum drying tank is depressurized and heated above the boiling point of the high boiling solvent to evaporate the high boiling solvent adhering to the surface of the object to be dried. The object to be dried is dried.

Further, the second invention of the present application is an apparatus embodying the above method, wherein an object to be dried is brought into contact with a high-boiling solvent having a boiling point higher than that of water when the object to be dried is heated to a temperature higher than the boiling point of water. A solvent introduction tank for boiling and evaporating the water adhering to the water, and introducing the material to be dried after boiling and evaporating the water, and the tank is depressurized by a depressurization mechanism and heated to a temperature higher than the boiling point of the high boiling point solvent by a heating mechanism, A vacuum drying tank capable of blocking the communication with the solvent introduction tank, enabling the drying object to be dried by evaporating the high boiling point solvent adhering to the surface of the substance to be dried, and from the solvent introduction tank to the vacuum drying tank And a vertical movement mechanism for transferring an object to be dried in a sealed space.

Further, the solvent introduction tank may be a tank capable of depressurizing the inside of the tank. By forming in this way, in the solvent introduction tank, the object to be dried is brought into contact with the high boiling point solvent heated to the boiling point of water or more, and the water adhering to the object to be dried is boiled or evaporated. When the object to be dried is immersed in a solvent to perform immersion cleaning of the object to be dried, these operations can be performed under reduced pressure. In the reduced pressure state, oxygen is less than that in the normal pressure, so that it is possible to suppress the oxidative deterioration of the high boiling point solvent due to the above operation. Therefore, it is possible to extend the service life of the high boiling point solvent, reduce the frequency of replacement of the high boiling point solvent, and reduce the running cost. In addition, as described above, since there is little oxygen under reduced pressure, even when a flammable solvent is used as the high boiling point solvent, the risk of ignition can be reduced, and the apparatus can be used safely.

Further, the vacuum drying tank may be connected to a steam generation tank so that the object to be dried can be cleaned with steam. By forming in this way, it becomes possible to perform not only vacuum drying of the object to be dried but also reduced-pressure steam cleaning of the object to be dried in a vacuum drying tank with reduced pressure, thereby improving the usability of the apparatus. It becomes possible. Further, as compared with the case where a vacuum drying tank and a steam cleaning tank are provided separately, space saving can be achieved and the manufacturing cost of the apparatus can be reduced.

Further, the sealed space may be formed by a solvent introduction tank and a vacuum drying tank.

The present invention is configured as described above. In the solvent introduction tank, the material to be dried is brought into contact with a high-boiling solvent having a boiling point higher than that of water and heated to a temperature higher than that of water. The water adhering to the dried product is boiled and evaporated, and even if the material to be dried has recesses and cavities, the high boiling point solvent enters the recesses and cavities, so that It can be removed by boiling and evaporating. Further, since the water evaporates and evaporates as described above, there is no possibility that the water dissolves in the high boiling point solvent and a new waste liquid is generated, and the load on the environment can be reduced. Further, as described above, since no water is mixed into the high boiling point solvent, the high boiling point solvent can be used repeatedly, and the running cost can be reduced.

In addition, in order to transfer the material to be dried, in which the water is boiled and evaporated in the solvent introduction tank by the above-described method, to the vacuum drying tank capable of blocking the communication with the solvent introduction tank, the “sealed space” is used. In the process of transferring the dried product, there is no possibility that the dried product and the high boiling point solvent adhering to the surface of the dried product come into contact with the outside air. When the transfer is completed, the high-boiling solvent adhering to the surface of the object to be dried is evaporated in the vacuum drying tank to dry the object to be dried. Can be taken out from the apparatus in a completely dry state in which no is attached to the surface. That is, there is no possibility that the high-boiling solvent comes into contact with the outside air when the material to be dried is taken out from the apparatus.

In the present invention, in this way, in the entire process of removing moisture from the object to be dried, transferring the object to be dried, drying and taking out from the apparatus, the high boiling point solvent does not come into contact with the atmosphere, Since there is no possibility that the boiling point solvent diffuses into the atmosphere, there is no risk of adverse effects on the environment. Further, it is not necessary to replenish the high boiling point solvent accompanying the diffusion into the atmosphere, and the running cost can be reduced. Even when a flammable solvent is used as the high-boiling solvent, the high-boiling solvent does not come into contact with the outside air, and there is no risk of igniting in response to fire or static electricity outside the device. Can be used.

In Example 1, sectional drawing which shows the state which has arrange | positioned to-be-dried material in a solvent introduction tank. Sectional drawing of Example 1 which shows the completion state of "1st transfer". Sectional drawing of Example 1 which shows the completion state of "2nd transfer."

1-3 of the present invention will be described with reference to FIGS. 1 to 3. (1) is a pressure-resistant solvent introduction tank that can introduce a high-boiling solvent (2) having a boiling point higher than that of water. The high boiling point solvent (2) is a non-aqueous solvent such as a fluorinated solvent, a silicone solvent or a hydrocarbon solvent, a hydrophilic alcohol such as a higher alcohol, N-methyl-2-pyrrolidone or 3-methyl-3-methoxybutanol. A solvent can be used.

Further, a first heating mechanism (3) for heating the high boiling point solvent (2) is disposed at the lower end in the solvent introduction tank (1). For the first heating mechanism (3) and the second heating mechanism (4) described later, an appropriate heating device such as an electric heater or a high-pressure steam flow pipe can be used. A first opening / closing valve (5) for releasing the vacuum communicating with the outside air is connected to the upper one side of the solvent introduction tank (1) via the outside air communicating pipe (6).

Further, as shown in FIG. 1, a pressure-resistant vacuum drying tank (10) is provided above the solvent introduction tank (1), and the upper end inlet / outlet (7) is hermetically sealed with a lid (8). ing. And the upper end opening part (12) opened to the top plate (11) of the solvent introduction tank (1) and the vacuum drying tank (10) inside the vacuum drying tank (10) and the inside of the solvent introduction tank (1). ) Through a bottom opening (14) opened to the bottom plate (13). Further, between the lower surface of the bottom plate (13) of the vacuum drying tank (10) and the upper surface of the top plate (11) of the solvent introduction tank (1), an upper end opening (12) of the solvent introduction tank (1) and A first seal member (15) formed by an O-ring is interposed along the outer periphery of the lower end opening (14) of the vacuum drying tank (10), so that the vacuum drying tank (10) and the solvent introduction tank (1) Maintains the airtightness of the connection part. A second seal member (16) formed by an O-ring is fixedly disposed along the outer periphery of the upper end opening (12) on the lower surface of the top plate (11) of the solvent introduction tank (1). .

In this embodiment, the solvent introduction tank (1) and the vacuum drying tank (10) are formed separately as described above. However, in other different embodiments, the solvent introduction tank is formed. It is also possible to integrally form (1) and the vacuum drying tank (10). In this case, the first sealing member (15) for covering the space between the solvent introduction tank (1) and the vacuum drying tank (10) becomes unnecessary, so the solvent introduction tank (1) and the vacuum drying tank (10 ) Can be simplified as compared with the case of forming the device separately.

Further, an insertion hole (17) communicating with the outside is formed through the top plate (11) of the solvent introduction tank (1), and the support (18) is inserted into the insertion hole (17). An annular housing (20) is tightly fixed to the top surface of the top plate (11) of the solvent introduction tank (1) along the outer periphery of the insertion hole (17). In addition, a third seal member (21) that maintains airtightness in the solvent introduction tank (1) corresponding to the vertical movement of the support (18) is disposed inside the housing (20). . Therefore, as will be described later, when the support (18) is moved up and down in a state where the pressure in the solvent introduction tank (1) and the vacuum drying tank (10) is reduced, airtightness is maintained, and the solvent introduction tank (1) and the outside air are maintained. It becomes possible to cut off communication with. The third seal member (21) is formed of an O-ring, like the first and second seal members (15) and (16).

Further, the upper end of the support (18) is connected to the cylinder rod (24) of the hydraulic cylinder (23) via a connecting rod (22), and the object (25) to be dried is connected to the lower end of the support (18). The mounting table (26) is connected and fixed at a right angle to constitute a vertical movement mechanism (27) for the object to be dried (25). The vertical movement mechanism (27) operates the hydraulic cylinder (23) to move the cylinder rod (24) up and down, thereby supporting the support (18) and the mounting table (22) via the connection rod (22). 26) can be moved up and down. In this embodiment, the hydraulic cylinder (23) is used as the vertical movement mechanism (27). However, in other different embodiments, a pneumatic cylinder, a screw screw, a chain block, etc. A configuration can be used.

Further, on the upper surface of the mounting table (26), a mounting portion (28) for mounting the object to be dried (25) is fixedly disposed. Then, with the object to be dried (25) placed on the placement part (28), the hydraulic cylinder (23) of the vertical movement mechanism (27) is operated to move the cylinder rod (24) up and down. 1, the connecting rod (22), the support (18), the mounting table (26), the mounting unit (28) and the object to be dried (25) mounted on the mounting unit (28) are moved up and down. As shown in FIG. 3, the object to be dried (25) can be transferred from the solvent introduction tank (1) to the vacuum drying tank (10). The formation width of the placement portion (28) is narrower than the inner diameter of the upper end opening (12) of the solvent introduction tank (1) and the inner diameter of the lower end opening (14) of the vacuum drying tank (10). The introduction of the material to be dried (25) into the vacuum drying tank (10) is not hindered. Further, as shown in FIG. 3, the mounting table (26) presses the outer periphery of the upper surface to the lower surface of the top plate (11) of the solvent introduction tank (1) via the second seal member (16). Thus, the upper end opening (12) is hermetically sealed, and the communication between the solvent introduction tank (1) and the vacuum drying tank (10) can be blocked.

Moreover, the said vacuum drying tank (10) is connected with the pressure reduction mechanism (30) comprised with an ejector, a vacuum pump, etc., and communication with a solvent introduction tank (1) and a vacuum drying tank (10) is the above-mentioned mounting base In the case of being blocked by (26), only the vacuum drying tank (10) can be depressurized by the pressure reducing mechanism (30), and if not blocked, the vacuum drying tank (10) and the solvent introduction tank (1) Both can be decompressed by the decompression mechanism (30). The vacuum drying tank (10) and the decompression mechanism (30) are connected by connecting one end of a vacuum pipe (32) provided with a second on-off valve (31) to the upper side of the vacuum drying tank (10). Yes. The vacuum pipe (32) is provided with a third release valve (33) for releasing the vacuum communicating with the outside air between the vacuum drying tank (10) and the second on-off valve (31).

As shown in FIGS. 1 to 3, the other end of the vacuum pipe (32) is branched, and the water cooler (34) and the solvent cooler (35) are respectively connected to the fourth and sixth on-off valves ( 36) It is connected via (38). The water cooler (34) is connected to the pressure reducing mechanism (30) via the fifth on-off valve (37), and the solvent cooler (35) is connected to the pressure reducing mechanism (30) via the seventh on-off valve (40). 30). The first, third, sixth, and seventh on-off valves (5), (33), (38), and (40) are closed and the second, fourth, and fifth on-off valves (31), (36), and (37) are closed. By operating the depressurization mechanism (30) in a state in which is opened, the inside of the vacuum drying tank (10) and the inside of the solvent introduction tank (1) can be depressurized via the moisture cooler (34). The first, third, fourth, and fifth on-off valves (5), (33), (36), and (37) are closed and the second, sixth, and seventh on-off valves (31), (38), and (40) are closed. By operating the pressure-reducing mechanism (30) in a state where is opened, the inside of the vacuum drying tank (10) and the inside of the solvent introduction tank (1) can be depressurized via the solvent cooler (35).

The lower end of the moisture cooler (34) is connected to a moisture recovery tank (42) provided with an eighth on-off valve (41) for releasing the vacuum. A ninth on-off valve (43) is provided. In addition, a solvent recovery tank (46) provided with an eleventh on-off valve (45) capable of communicating with outside air is connected to the lower end of the solvent cooler (35) via a tenth on-off valve (44). The solvent recovery tank (46) is connected to the solvent introduction tank (1) through the twelfth on-off valve (47) and the thirteenth on-off valve (48) to constitute a solvent return line (50).

The solvent introduction tank (1) is provided in a reserve tank (53) via an overflow pipe (52) provided with a fourteenth on-off valve (51) at a position lower than a connection position with the solvent return line (50). When the high boiling point solvent (2) in the solvent introduction tank (1) exceeds a certain water level, the high boiling point solvent (2) in the solvent introduction tank (1) is connected to the overflow pipe (52 ) Through the reserve tank (53). In addition, the reserve tank (53) is provided with a first liquid level sensor (54) at the lower end for detecting the shortage of the high boiling point solvent (2).

Further, the reserve tank (53) is connected to a pressure-generating steam generation tank (56) via a fifteenth opening / closing valve (55), and the steam generation tank (56) is connected to the sixteenth opening / closing valve (57). And connected to a vacuum drying tank (10). The inside of the steam generation tank (56) can be decompressed by operating the decompression mechanism (30) with the sixteenth on-off valve (57) opened. In addition, by opening the fourteenth and fifteenth on-off valves (51) and (55) in a state where the pressure in the steam generation tank (56) is reduced in this way, the negative pressure in the steam generation tank (56) is utilized. Thus, the high boiling point solvent (2) in the reserve tank (53) can be introduced into the steam generation tank (56).

Further, in the steam generation tank (56), a second heating mechanism (4) is disposed in the lower part, and a second liquid level sensor (58) for preventing empty boiling of the high boiling point solvent (2) is provided. The second heating mechanism (4) is disposed at a higher position. Then, in the steam generation tank (56) depressurized by the depressurization mechanism (30), the solvent vapor generated by heating the high boiling point solvent (2) by the second heating mechanism (4) is supplied to the sixteenth on-off valve. (57) can be introduced into the vacuum drying tank (10) with the valve opened. This makes it possible to perform normal-pressure steam cleaning or reduced-pressure steam cleaning of the object to be dried (25) in the vacuum drying tank (10).

A method for performing the drying operation of the object to be dried (25) having the above-described structure will be described below. In this embodiment, the object to be dried (25) is subjected to vacuum immersion cleaning and vacuum steam cleaning in parallel with the drying operation of the object to be dried (25). First, as shown in FIG. 3, in a state where the mounting part (28) is disposed in the vacuum drying tank (10), the lid (8) provided in the vacuum drying tank (10) is opened, and the mounting part (28 ) To be dried is placed (25), and the lid (8) is closed. In this state, the mounting table (26) presses the outer periphery of the upper surface to the lower surface of the top plate (11) of the solvent introduction tank (1) via the second seal member (16), and the solvent introduction tank (1). ) And the vacuum drying tank (10) are disconnected. Therefore, inflow of solvent vapor from the solvent introduction tank (1) to the vacuum drying tank (10) can be prevented.

And after sealing an entrance / exit (7) with the said cover body (8), the hydraulic cylinder (23) of a vertical movement mechanism (27) is operated, and the to-be-dried object (25) mounted in the mounting part (28) As shown in FIG. 1, the material (25) to be dried is immersed in the high boiling point solvent (2) previously filled in the solvent introduction tank (1).

The first, third, sixth to sixteenth on-off valves (5) (33) (38) (40) (41) (43) (44) (45) (47) (48) (51) (55) ) (57) is closed and the second, fourth and fifth on-off valves (31), (36) and (37) are opened, the pressure reducing mechanism (30) is operated, and the solvent introduction tank (1) and vacuum drying are performed. The inside of the tank (10) is decompressed to a certain degree of decompression. And the said 1st heating mechanism (3) arrange | positioned in a solvent introduction tank (1) is operated, and the high boiling-point solvent (2) in a solvent introduction tank (1) is more than the boiling point of water in said pressure reduction state. Heat to below the boiling point of the high boiling point solvent (2). Thereby, the water | moisture content adhering to the surface of to-be-dried object (25) is boiled and evaporated.

In the present embodiment, in the solvent introduction tank (1) having a reduced pressure as described above, the object to be dried (25) to which moisture has adhered is heated to a temperature higher than the boiling point of water. The water adhering to the object to be dried (25) is boiled and evaporated by contacting with the solvent (2). Even if the object to be dried (25) has a recess or a cavity, Since the air present in the cavity is excluded and the high boiling point solvent (2) enters, it is possible to remove the water adhering to the material to be dried (25) by boiling and evaporating with certainty. In addition, since the water evaporates and evaporates as described above, there is no possibility that the water dissolves in the high boiling point solvent (2) and a new waste liquid is generated, and the burden on the environment can be reduced. Moreover, since the water evaporates as described above and the water does not enter the high boiling point solvent (2), the high boiling point solvent (2) can be used repeatedly, and the running cost can be reduced.

In this embodiment, as described above, the object to be dried (25) is brought into contact with the high boiling point solvent (2) heated to the boiling point of water or more, and the water adhering to the object to be dried (25) is boiled. Since the operation of evaporating is performed in a pressure-reduced solvent introduction tank (1) in a reduced pressure state, since there is less oxygen than normal pressure, oxidative deterioration of the high boiling point solvent (2) due to the above operation is suppressed. It becomes possible. Therefore, it becomes possible to lengthen the useful life of the high-boiling solvent (2), reduce the replacement frequency of the high-boiling solvent (2), and reduce the running cost. In addition, since oxygen is low at reduced pressure as described above, even if a flammable solvent such as a hydrocarbon solvent or a hydrophilic solvent is used as the high boiling point solvent (2), the risk of ignition may be reduced. Can be used safely.

In this embodiment, the removal of moisture from the object to be dried (25) is performed by reducing the pressure in the pressure-resistant solvent introduction tank (1). In the example, it is also possible to perform the operation of removing moisture from the material to be dried (25) at normal pressure using the solvent introduction tank (1) for normal pressure. In this case, it is possible to reduce the manufacturing cost of the apparatus as compared with the case where both the solvent introduction tank (1) and the vacuum drying tank (10) are made pressure-resistant. The effect is not obtained.

Moreover, the to-be-dried substance (25) to which moisture adheres is immersed in the high boiling point solvent (2) heated to the boiling point of water or more, and the boiling evaporation work of the moisture adhering to the to-be-dried object (25) is performed as described above. Along with this, it becomes possible to perform immersion cleaning of the object to be dried (25). That is, when a solid material such as grinding waste or cutting waste or a liquid such as cutting oil, grinding oil, or press oil adheres to moisture on the surface of the material to be dried (25), the material to be dried (25) is removed. By bringing into contact with the heated high-boiling solvent (2) as described above, these solids and liquids can be removed from the object to be dried (25). In particular, when the above-mentioned hydrophilic solvent is used as the high-boiling solvent (2), it is possible to dissolve a liquid such as a surfactant or a hydrocarbon solvent dissolved in water and wash it off in the hydrophilic solvent. Therefore, it becomes possible to further enhance the cleaning effect.

Further, the water boiled and evaporated from the surface of the object to be dried (25) as described above is sucked into the moisture cooler (34) by the decompression mechanism (30), and is condensed and liquefied by the moisture cooler (34). The condensed and liquefied water flows into the water recovery tank (42) by its own weight. Then, after the above-described work of boiling and evaporating the water is completed, the fourth and fifth on-off valves (36) and (37) are closed, and the eighth on-off valve (41) is opened and the water collecting tank (42) is opened. After releasing the vacuum state, the ninth on-off valve (43) is opened, so that the water flowing into the water recovery tank (42) can be discharged as described above.

In addition, after the water adhering to the surface of the object to be dried (25) is boiled and evaporated as described above, in this embodiment, the object to be dried (25) is subjected to vacuum steam cleaning in the vacuum drying tank (10). I do. In order to perform this reduced-pressure steam cleaning, the hydraulic cylinder (23) of the vertical movement mechanism (27) is operated, and the upper surface of the mounting table (26) and the second seal member (16) are fixed as shown in FIG. The mounting portion (28) and the object to be dried (25) are raised to a position facing each other through the facing interval (60) of the material, and the object to be dried (25) is transferred into the vacuum drying tank (10) ( This is hereinafter referred to as “first transfer”). At that time, as described above, since the airtightness of the contact portion between the support (18) and the insertion hole (17) of the solvent introduction tank (1) is held by the third seal member (21), the support ( 18) There is no possibility that the airtightness is impaired along with the vertical movement, and the “first transfer” can be performed in a sealed space constituted by the solvent introduction tank (1) and the vacuum drying tank (10). . Therefore, the reduced pressure state of the solvent introduction tank (1) and the vacuum drying tank (10) is maintained.

And the 2nd heating mechanism (4) arrange | positioned in a steam generation tank (56) is operated, the high boiling-point solvent (2) in a steam generation tank (56) is heated more than the boiling point, and solvent vapor | steam is generated. . In addition, when the high boiling point solvent (2) in the steam generation tank (56) is insufficient, this shortage is detected by the second liquid level sensor (58), and the steam generation tank (53) is detected from the reserve tank (53). 56) The high-boiling solvent (2) is introduced. Then, the solvent vapor generated as described above is introduced into the vacuum drying tank (10) by opening the sixteenth on-off valve (57) and brought into contact with the object to be dried (25). The vacuum steam cleaning of 25) is performed. The solvent vapor used for this reduced-pressure steam cleaning is condensed and liquefied by contact with the material to be dried (25), and is restored into the solvent introduction tank (1) by its own weight through the facing distance (60).

In this embodiment, the vacuum drying tank (10) is connected to the steam generation tank (56) in this way, and the reduced-pressure steam of the object (25) to be dried in the reduced-pressure vacuum drying tank (10). It is possible to perform cleaning. Therefore, it is possible to improve the usability of the apparatus as compared with the case where only the object to be dried (25) described later is vacuum-dried in the vacuum drying tank (10). Further, as compared with a case where a vacuum drying tank (10) and a tank for performing steam cleaning are separately provided, space can be saved and the manufacturing cost of the apparatus can be reduced.

Further, in this embodiment, as the moisture is boiled and evaporated from the surface of the material to be dried (25), the material to be dried (25) is immersed and washed as described above, and the above-mentioned boiling and evaporating operation of the water is completed. Later, as described above, the object to be dried (25) is subjected to steam cleaning. Therefore, it is possible to further increase the degree of cleaning of the object to be dried (25) by the above-described immersion cleaning and steam cleaning of the object to be dried (25).

Further, the above-described steam cleaning operation of the material to be dried (25) also serves as a distillation regeneration operation of the high boiling point solvent (2). That is, when the high boiling point solvent (2) introduced into the steam generation tank (56) is mixed with processing oil such as cutting oil, grinding oil, and press oil, and solid waste such as cutting waste and grinding waste, The high boiling point solvent (2) is heated to a boiling point or higher in the steam generation tank (56), so that the above contaminants remain in the steam generation tank (56) and the solvent of the high boiling point solvent (2). Only steam can be introduced into the vacuum drying bath (10). Therefore, the high boiling point solvent (2) can be reused, the running cost can be reduced, and the burden on the environment can be reduced.

Then, after the above-described object to be dried (25) is cleaned with steam, the object to be dried (25) is vacuum dried. For this purpose, first, by operating the hydraulic cylinder (23) of the vertical movement mechanism (27), the cylinder rod (24), the connecting rod (22), the support (18), the mounting table (26), the mounting table, Raising the placing portion (28) and the object to be dried (25) placed on the placing portion (28), the lower surface of the second seal member (16) and the upper surface of the placing table (26) As shown in FIG. 3, the contact is made between the solvent introduction tank (1) and the vacuum drying tank (10) (hereinafter referred to as "second transfer"). In this way, the communication between the solvent introduction tank (1) and the vacuum drying tank (10) is cut off, so that the high temperature in the solvent introduction tank (1) can be reduced when the object to be dried (25) described later is vacuum dried. It becomes possible to prevent the boiling point solvent (2) from flowing into the vacuum drying tank (10) and coming into contact with the object to be dried (25). As described above, since the airtightness of the contact portion between the support (18) and the insertion hole (17) of the solvent introduction tank (1) is held by the third seal member (21), the second seal described above is used. This transfer can be performed in a sealed space constituted by the solvent introduction tank (1) and the vacuum drying tank (10), similarly to the first transfer. Therefore, it is possible to maintain the reduced pressure state of the solvent introduction tank (1) and the vacuum drying tank (10).

Then, the fourth and fifth on-off valves (36) and (37) are closed, the sixth and seventh on-off valves (38) and (40) are opened, the decompression mechanism (30) is operated, and the vacuum drying tank (10 ) Increase the degree of decompression. Thereby, the boiling point of the high boiling point solvent (2) adhering to the surface of the material to be dried (25) is lowered, the high boiling point solvent (2) is boiled and evaporated, and the material to be dried (25) is dried. When this vacuum drying operation is completed, the second on-off valve (31) is closed, the third on-off valve (33) is opened to release the vacuum state in the vacuum drying tank (10), and the vacuum drying tank (10 The lid (8) provided at the upper end of) is opened, and the material (25) to be dried is taken out from the inlet / outlet (7) of the vacuum drying tank (10).

In the present invention, the high-boiling point solvent (2) adhering to the surface of the object to be dried (25) is evaporated in the vacuum drying tank (10) to dry the object to be dried (25). Therefore, it becomes possible to take out the material to be dried (25) from the apparatus in a completely dry state in which moisture and the high boiling point solvent (2) are not attached to the surface. That is, there is no possibility that the high boiling point solvent (2) comes into contact with the outside air when the material to be dried (25) is taken out from the apparatus. In addition, as described above, the boiling and evaporating operation of water in the solvent introduction tank (1) and the first and second transfer operations are composed of the solvent introduction tank (1) and the vacuum drying tank (10). Therefore, there is no possibility that the high boiling point solvent (2) comes into contact with the outside air in the course of these operations.

That is, the high boiling point solvent (2) does not come into contact with the atmosphere in the entire process of removing moisture from the object to be dried (25), transferring the object to be dried (25), drying and taking out from the apparatus. The boiling point solvent (2) is not likely to diffuse into the atmosphere. As a result, there is no risk of adverse effects on the environment, and there is no need to replenish the high-boiling solvent (2) accompanying diffusion into the atmosphere, and the running cost can be reduced. Further, even when a flammable solvent such as a hydrocarbon solvent or a hydrophilic solvent is used as the high boiling point solvent (2), the high boiling point solvent (2) does not come into contact with the outside air, and the fire outside the apparatus. Since there is no risk of ignition in response to static electricity or the like, the apparatus can be used safely.

Further, the high boiling point solvent (2) boiled and evaporated from the surface of the object to be dried (25) as described above is sucked into the solvent cooler (35) through the sixth on-off valve (38) by the pressure reducing mechanism (30). Introduce and condense. The condensed high boiling point solvent (2) flows into the solvent recovery tank (46) through its tenth on-off valve (44) by its own weight. Then, after the above-described boiling evaporation of the high boiling point solvent (2) is completed, the tenth on-off valve (44) is closed, the eleventh on-off valve (45) is opened, and the inside of the solvent recovery tank (46) is opened. After releasing the vacuum state, the twelfth and thirteenth on-off valves (47) and (48) are opened, so that the high boiling point solvent (2) flowing into the solvent recovery tank (46) as described above is removed from the solvent return line. (50) is refluxed into the solvent introduction tank (1). Thereby, the high boiling point solvent (2) can be reused.

In this embodiment, when the heating temperature in the vacuum drying tank (10) is raised to the boiling point of the high boiling point solvent (2) to evaporate the high boiling point solvent (2) to the boiling point, The on-off valve (36) is closed and the sixth on-off valve (38) is opened, and the boiling-evaporated high boiling point solvent (2) is recovered in the solvent cooler (35). In addition, as described above, in the solvent introduction tank (1), the high boiling point solvent (2) is heated to the boiling point of water to be lower than the boiling point of the high boiling point solvent (2), and the moisture adhering to the material to be dried (25). When the water is evaporated by boiling, the sixth on-off valve (38) is closed and the fourth on-off valve (36) is opened, and the water evaporated to the boil is collected in the moisture cooler (34). Thus, since it becomes possible to collect | recover the water | moisture content boiled and evaporated in the vacuum-drying tank (10) and the high boiling-point solvent (2) separately, respectively, collection efficiency is raised and the usability of an apparatus is improved. It becomes possible.

In the present embodiment, the water cooler (34) and the solvent cooler (35) are separately formed as described above, but a non-aqueous solvent is used as the high boiling point solvent (2). In this case, the moisture cooler (34) and the solvent cooler (35) are not provided separately, but the moisture and the high boiling point solvent (2) are condensed by a single cooler. May be used to separate the water and the high boiling point solvent (2) using the difference in specific gravity. In this case, compared with the case where the moisture cooler (34) and the solvent cooler (35) are formed separately, the configuration of the apparatus can be simplified and the manufacturing cost of the apparatus can be kept low. Become.

On the other hand, when a hydrophilic solvent is used as the high boiling point solvent (2), when the water and the high boiling point solvent (2) are condensed in the same condenser, the water is dissolved in the high boiling point solvent (2). Therefore, after that, the water and the high boiling point solvent (2) cannot be separated using a water separator, and a large amount of new waste liquid may be generated. Therefore, in this case, the moisture cooler (34) and the solvent cooler (35) are separately provided as in this embodiment, and the moisture and the high boiling point solvent (2) are condensed by separate coolers. It is necessary to collect.

1 Solvent introduction tank
2 High boiling point solvent
3, 4 Heating mechanism
10 Vacuum drying tank 25
27 Vertical movement mechanism 30 Pressure reduction mechanism
56 Steam generation tank

Claims

In a solvent introduction tank in which a high-boiling solvent having a boiling point higher than that of water is introduced, the material to be dried is brought into contact with the high-boiling solvent heated to a temperature higher than the boiling point of water to boil the water adhering to the material to be dried. After evaporation, the object to be dried is transferred in a sealed space to a vacuum drying tank that can block communication with the solvent introduction tank, and the communication between the solvent introduction tank and the vacuum drying tank is blocked. A method for drying an object to be dried, wherein the interior of the object is depressurized and heated to the boiling point of the high-boiling solvent or more to evaporate the high-boiling solvent adhering to the surface of the object to be dried to dry the object to be dried.
A solvent introduction tank for boiling and evaporating the moisture adhering to the dried material by contacting the dried material to which the moisture adheres with a high boiling point solvent whose boiling point is higher than that of water and boiling the water. Of the object to be dried, the inside of the tank is depressurized by the pressure reducing mechanism and heated to a temperature higher than the boiling point of the high boiling point solvent by the heating mechanism to evaporate the high boiling point solvent adhering to the surface of the object to be dried. A vacuum drying tank capable of blocking communication with the solvent introduction tank, and a vertical movement mechanism for transferring a material to be dried in the sealed space from the solvent introduction tank to the vacuum drying tank. An apparatus for drying an object to be dried.
The method for drying an object to be dried according to claim 1, wherein the solvent introduction tank is capable of depressurizing the inside of the tank.
The apparatus for drying an object to be dried according to claim 2, wherein the solvent introduction tank is capable of depressurizing the inside of the tank.
The method for drying an object to be dried according to claim 1, wherein the vacuum drying tank is connected to a steam generation tank to enable steam cleaning of the object to be dried.
The apparatus for drying an object to be dried according to claim 2, wherein the vacuum drying tank is connected to a steam generation tank to enable steam cleaning of the object to be dried.
The method for drying an object to be dried according to claim 1, wherein the sealed space is formed by a solvent introduction tank and a vacuum drying tank.
The apparatus for drying an object to be dried according to claim 2, wherein the sealed space is formed by a solvent introduction tank and a vacuum drying tank.