JP2651653B2 - Vacuum drying device and vacuum drying method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to electric parts, electronic parts,
The present invention relates to a vacuum drying apparatus for mainly drying industrial parts such as mechanical parts, and more particularly to drying these parts using hot air and a vacuum state, and cooling and condensing and recovering the evaporated solvent.

[0002]

2. Description of the Related Art Electric parts, electronic parts, mechanical parts, and the like are contaminated with processing oil, processing chips, fine dust, and the like in a manufacturing process. Leaving these contaminants not only lowers the quality of the product, but also causes a failure of the device or the like incorporating the components. Therefore, conventionally, components have been washed using an aqueous or non-aqueous solvent in order to remove these stains. Further, the solvent remaining on the parts must be dried and removed, but if the evaporated solvent is directly emitted into the atmosphere, it causes air pollution. Further, if the solvent remains on the object to be dried, there is also a problem that the remaining solvent deteriorates the quality, such as generation of rust and a ring pattern. For this reason, the applicant of the present invention has applied for the development of a vacuum drying apparatus for recovering the evaporated solvent while performing the drying treatment of the parts cleaned using the solvent, and has filed an application (Japanese Patent Application Laid-Open No. 6-58664). 4-212669
issue)). The vacuum drying device includes a drying chamber, an exhaust path having a blower connected to an exhaust port of the drying chamber, an intake path having a heating chamber connected to an intake port of the drying chamber, an exhaust path and an intake path. And a cooling chamber connected to the solvent recovery path, and an air circulation path is formed by the drying chamber, the exhaust path, and the suction path, and the air circulation path is connected to the air circulation path via a switching valve. Vacuum pump is provided. Then, the air heated in the heating chamber is sent into the drying chamber to elevate the temperature of the object to be dried in the drying chamber to evaporate and evaporate the solvent, and then the solvent gas is condensed and recovered in the cooling chamber. Next, the switching valve is switched, and the inside of the drying chamber is depressurized by a vacuum pump to promote evaporation and evaporation of the solvent adhering to the object to be dried.

[0003]

In the vacuum drying apparatus described above, air heated by the heating chamber is sent into the drying chamber in order to heat the object to be dried in the drying chamber. However, in the method in which the object to be dried in the drying chamber is heated only by the heated air, the temperature of the side wall of the drying chamber does not sufficiently rise, so that the solvent gas once evaporated is cooled down on the side wall of the drying chamber and condensed and adheres. However, there is a problem that drying cannot be performed efficiently. Also, it is difficult to adjust the temperature inside the drying room,
In this regard, efficient drying could not be performed. Furthermore, in a component having a complicated structure having a thin tube or the like inside, a solvent that has entered the complicated structure cannot be dried only by heated air. Therefore, the solvent adhered by hand is blown off in advance using an air gun or the like. However, this method is troublesome and it is difficult to completely blow off the solvent adhered to the details. In addition, since the air circulation path is a closed circulation path, there is a possibility that the solvent gradually evaporates and evaporates, and the vapor gas concentration in the air circulation path becomes abnormally high, causing ignition. In this vacuum drying apparatus, heated air is fed into the drying chamber from the lower part of the drying chamber, and exhaust air is discharged from the upper part of the drying chamber. However, in a part in which a large amount of solvent has adhered, there has been a problem that the solvent is dripped downward due to gravity, so that the solvent is accumulated at the bottom of the drying chamber and drying cannot be performed efficiently. In addition, the inside of the drying chamber is hot due to the heated air, and the temperature of the door of the drying chamber is high immediately after the drying is completed.Therefore, there is a danger that the operator may be burned when taking out the object to be dried. Was. Therefore, the present invention has been proposed in view of the above-mentioned problems of the conventional technology, and an object of the present invention is to efficiently and safely dry an object to be dried washed with an aqueous or non-aqueous solvent. It is to provide a vacuum drying device which can perform the drying.

[0004]

According to the first aspect of the present invention, there is provided a vacuum drying apparatus for vacuum-drying an object to be dried which has been washed with an aqueous or non-aqueous solvent. A storage container having a lid member for storing the object to be dried inside, and a heating tank provided at a lower portion,
A ventilation pipe connected to the containment vessel via the first on-off valve to blow heated air into the containment vessel, an oil heater for heating the flame-retardant oil circulated in the heating tank, and oil heating An oil circulation path for supplying oil from the outlet side of the vessel to the inlet side of the heating tank and returning oil from the outlet side of the heating tank to the inlet side of the oil heater; an oil circulation pump for circulating oil through the oil circulation path; An exhaust pipe connected to the container for discharging the solvent gas evaporated and vaporized in the containment vessel; a cooling device connected to the exhaust pipe for cooling and condensing and recovering the solvent gas in the exhaust pipe; and a downstream of the cooling device. Vacuum drying with an atmosphere opening pipe having a second on-off valve branched from the exhaust pipe on the side and a vacuum generating device connected to the distal end of the exhaust pipe through a third on-off valve to reduce the pressure in the containment vessel. Characterized by configuring the device To. The invention according to claim 2 is characterized in that the blower pipe is connected to the upper part of the containment vessel and the exhaust pipe is connected to the lower part of the containment vessel. The invention according to claim 3 is characterized in that the storage container is provided with a lid member cooling device for cooling the lid member. According to a fourth aspect of the present invention, the oil heater is provided with a temperature controller for maintaining the oil temperature at a predetermined constant temperature. Further, in the invention according to claim 5, a heat exchanger is provided in the middle of the blower pipe, and a three-way switching valve is provided between the heat exchanger and the heating tank in the oil circulation path. An oil bypass path for returning oil to the oil heating device without passing through the heating tank is provided.The three-way switching valve is selectively switched based on the detection output from the temperature detector provided in the heating tank, and the oil circulation path is changed. The temperature of the heating tank is adjusted by changing the temperature. According to a sixth aspect of the present invention, as a method for vacuum-drying an object to be dried, the object to be dried washed with an aqueous or non-aqueous solvent is stored in a storage container having an openable and closable lid member. The heated flame-retardant oil is circulated to the heating tank provided at the lower part of the container, and hot air is blown into the containment container by the blower tube to heat the inside of the container and remove the solvent gas evaporated and vaporized in the containment container. It is guided to the outside of the containment vessel through an exhaust pipe connected to the containment vessel, the solvent is condensed and recovered using a cooling device connected to the exhaust pipe, and the exhaust gas after collecting the solvent gas is exhausted on the downstream side of the cooling device. A first step of dissipating into the atmosphere by an atmosphere opening pipe branched from the first step, closing a first opening / closing valve provided in an air blowing pipe to stop supply of hot air, and closing a second opening / closing valve provided in the atmosphere opening pipe. Block the air communication with the exhaust pipe The inside of the containment vessel is depressurized using a vacuum generator connected to the distal end side, the solvent remaining in the containment vessel is evaporated and discharged to an exhaust pipe, and the solvent is removed using a cooling device connected to the exhaust pipe. The method is characterized in that the object to be dried is vacuum dried by the second step of condensing and recovering. In the invention described in claim 7, performing the first step and the second step is one step.
A cycle is repeated, and the object to be dried is dried by repeating this cycle.

[0005]

In the above-mentioned invention, first, as a first step, a dried object washed with an aqueous or non-aqueous solvent is stored in a storage container having an openable and closable lid member, and a heating tank provided at a lower portion of the storage container. The heated flame-retardant oil is circulated using an oil circulation pump, and hot air is blown into the containment vessel by a blower connected to the tip side of the blower tube to heat the material to be dried in the containment vessel. The solvent gas vaporized inside is guided to the outside of the containment vessel through an exhaust pipe connected to the containment vessel, and the solvent is condensed and recovered using a cooling device connected to the exhaust pipe, and the solvent gas is exhausted after recovery. Is discharged into the atmosphere by an open-to-atmosphere pipe branched from an exhaust pipe on the downstream side of the cooling device. Thus, in the first step, the evaporation of the solvent is promoted by the temperature rise of the object to be dried. Next, as a second step, the supply of hot air is stopped by closing the first opening / closing valve provided in the blower pipe, and the second opening / closing valve provided in the atmosphere opening pipe is closed to close the air communication state of the exhaust pipe. Then, the inside of the containment vessel is depressurized using a vacuum generator connected to the end of the exhaust pipe, the solvent remaining in the containment vessel is evaporated and discharged to the exhaust pipe, and the cooling connected to the exhaust pipe is connected. The solvent is condensed and recovered using an apparatus (claims 1 and 6). As described above, in the second step, the pressure is reduced while the object to be dried is heated, so that the boiling point of the solvent is reduced, and the evaporation is remarkably accelerated. Therefore, since the inside of the storage container for drying the object to be dried is heated by the hot air and heated by the heating tank, the vaporized solvent does not condense and reattach to the side wall of the storage container, and the efficiency is improved. Good drying can be performed. Further, since the exhaust gas from the storage container is discharged into the atmosphere from the open-to-atmosphere pipe after the solvent is condensed and recovered in the cooling device, the pressure of the solvent vapor gas in the device does not abnormally increase. The hot air blown into the storage container is blown from the upper portion of the storage container, and the exhaust from the storage container is performed from the lower portion of the storage container (claim 2). Therefore, the solvent adhering to the object to be dried is promoted to drip downward by the gravity due to gravity, and even if the solvent drip, the solvent is quickly discharged without remaining in the storage container. Therefore, the drying efficiency can be improved. Further, the lid member provided in the storage container is cooled by the lid member cooling device (claim 3). Therefore, the temperature rise of the lid member of the storage container is suppressed, and the object to be dried can be safely taken out of the storage container even immediately after the drying of the object to be dried is completed. Further, the oil used for heating is kept at a predetermined constant temperature by a temperature adjusting device provided in the oil heater (claim 4). Therefore, it is possible to efficiently perform the drying treatment of the object to be dried. Further, based on a detection output from a temperature detector provided in the heating tank, a three-way switching valve provided between the heat exchanger in the oil circulation path and the heating tank is switched, so that the temperature of the heating tank becomes a predetermined constant temperature. If the temperature is below, the oil is circulated to the heating tank, and if the temperature of the heating tank is equal to or higher than a predetermined temperature, the oil is heated via the oil bypass without circulating the oil to the heating tank. Return to the device (claim 5). Therefore, the drying treatment of the object to be dried can be performed more efficiently.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a vacuum drying device according to the present invention. This vacuum drying device 1 is provided with a storage container 2 for storing the object A to be dried therein, a heating tank 3 provided at a lower portion of the storage container 2, a blower tube 4 connected to the storage container 2, and provided in the middle of the blower tube 4. A heat exchanger 5, a blower 6 communicatively connected to the base end of the blower tube 4, an oil heater 7 for heating the flame-retardant oil circulated through the heating tank 3 and the heat exchanger 5, and a heating tank 3 for the oil.
An oil circulation path 8 for circulating the heat in the heat exchanger 5, an oil circulation pump 9 for circulating the oil in the oil circulation path 8, an exhaust pipe 10 connected to the containment vessel 2, a cooling device 11 connected to the exhaust pipe 10, and cooling. Exhaust pipe 1 downstream of device 11
The main components are an open-to-atmosphere pipe 12 branching from zero, a vacuum generator 13 connected to the distal end of the exhaust pipe 10, and the like.

The storage container 2 is a cylindrical metal container having an open upper portion, and a perforated shelf-shaped mounting portion 14 for mounting the object A to be dried is provided below the inside of the storage container 2. An air outlet 15 for communicating and connecting the blower tube 4 and an outside air communication port 17 for connecting and connecting the outside air communication tube 16 are provided on the side wall, and an exhaust port for connecting and connecting the exhaust pipe 10 is provided at the center of the bottom. 18
Is provided. A flange 19 extends from the upper opening edge toward the outside of the storage container 2. A lid member 20 is placed on the flange 19 to close the opening of the storage container 2. In addition, a sealing member 21 made of rubber or the like is interposed between the flange portion 19 and the lid member 20 to increase the airtightness of the opening of the storage container 2 by the lid member 20. Further, if a locking means (not shown) for locking the lid member 20 to the storage container 2 is provided, the lid member 20 can be more firmly attached to the storage container 2.

A lid cooling device 22 for cooling and protecting the upper portion of the storage container 2 and the lid member 20 is provided on the outer periphery of the upper portion of the storage container 2. This lid member cooling device 22
Is provided so as to surround the upper outer periphery of the storage container 2, and is cooled by flowing cooling water inside. This cooling water is taken into the inside of the lid member cooling device 22 from the cooling water inlet 23 and is guided to the outside from the cooling water outlet 24.

A blower pipe 4 is connected to the blower port 15 of the containment vessel 2 via a first opening / closing valve 25, and a base end of the blower pipe 4 for sending air into the blower pipe 4. Blower 6
Are connected. A heat exchanger 5 for heating the air in the blower tube 4 is provided in the middle of the blower tube 4.

In the outside air communication port 17 of the storage container 2,
The outside air communication pipe 16 is connected through an outside air opening / closing valve 26. The outside air communication pipe 16 is used for taking outside air into the storage container 2 after the vacuum drying is completed.

A heating tank 3 is provided at a lower portion of the outside of the storage container 2 so as to surround the bottom and side walls of the storage container 2. The heating tank 3 is used to heat the bottom and side walls of the containment vessel 2 with the flame-retardant oil circulated inside. The oil tank 27 is provided at the bottom, and the oil discharge port 2 is provided at the upper side.
8 are provided. Further, a temperature detector 29 for detecting the temperature of the heating tank 3 is provided on the outer wall of the heating tank 3.

The flame-retardant oil serving as a heat source for the heat exchanger 5 and the heating tank 3 provided in the blower pipe 4 is supplied to an oil circulation pump 9 which is connected to the oil outlet 30 of the oil heater 7.
It is sent to the heating tank 3 via the heat exchanger 5 and circulates in the oil circulation path 8 returning to the oil inlet 31 of the oil heater 7 again.

A three-way switching valve 32 is provided between the heat exchanger 5 and the heating tank 3 in the oil circulation path 8, and one side of the three-way switching valve 32 faces the oil inlet 31 of the oil heater 7. It is connected to the oil bypass passage 33 in communication. By switching the three-way switching valve 32, the oil circulation path is selectively switched so that the oil from the heat exchanger 5 is sent to the heating tank 3 or the oil from the heat exchanger 5 is passed through the heating tank 3 without passing through the heating tank 3. Whether to return directly to the oil heater 7 can be selected.

The oil heater 7 is a device for heating the flame-retardant oil by the electric heater 34. A temperature controller 35 for detecting the oil temperature and turning on / off the electric heater 34 is provided inside. It is provided. Further, an air vent 36 is provided at an upper portion of the oil heater 7 to prevent the oil heater 7 from being damaged even when the oil heater 7 is filled with oil vapor.

An exhaust port 18 provided at the center of the bottom of the storage container 2
Is connected to an exhaust pipe 10, and a cooling device 11 is connected to the exhaust pipe 10.

The cooling device 11 is a device for cooling the solvent gas sent through the exhaust pipe 10 by the cooling water taken in from the cooling water inlet 37, and is provided so as to double surround the exhaust pipe 10. A cooling section 38 and a solvent outlet 39 for removing the solvent condensed by cooling are provided. Cooling device 11
The cooling water passing through the inside is taken out from the cooling water outlet 40 and guided to the cooling water inlet 23 of the above-described lid member cooling device 22.

The exhaust pipe 10 on the downstream side of the cooling device 11 includes:
The atmosphere opening pipe 12 having the second on-off valve 41 is branched, and the exhaust gas after the solvent is condensed and recovered in the cooling device 11 is
It is discharged into the atmosphere from the open-to-atmosphere pipe 12.

A vacuum generator 13 is connected to a distal end of the exhaust pipe 10 via a third on-off valve 42.
The vacuum generating device 13 is a device for decompressing the inside of the storage container 2, and in this embodiment, is constituted by a vacuum pump. An oil mist removing device 44 is provided on the exhaust side of the vacuum generating device 13.
Is provided to prevent oil mist from diffusing into the atmosphere.

The procedure for vacuum-drying the object A to be dried, which has been washed with an aqueous or non-aqueous solvent, using the above-described vacuum generator 13 will be described. The object A to be dried such as an industrial part is washed with a hydrocarbon solvent such as petroleum. The object A to be dried after washing is loaded into the storage container 2 and
Place on top. Then, the opening of the storage container 2 is
0, the outside air opening / closing valve 26 is closed to close the outside air communication port 17, and the first opening / closing valve 25 is opened to allow the air outlet 15 to communicate with the air pipe 4.

In the oil heater 7, the oil is heated by the electric heater 34, and the three-way switching valve 32 provided in the oil circulation path 8 is opened to the heat exchanger 5 and the heating tank 3 side.
Then, the oil circulation pump 9 is operated to operate the oil circulation path 8.
Oil is circulated in the inside, the air in the blower tube 4 is heated by the heat exchanger 5, and the containment vessel 2 is heated by the heating tank 3.
Heat the bottom and side walls. At this time, the temperature controller 35
The temperature of the oil in the oil heater 7 is detected, and the on / off control of the electric heater 34 is performed to keep the oil temperature at a predetermined constant temperature, for example, 80 ° C.

Since air is blown into the blower tube 4 from the blower 6, the air heated by the heat exchanger 5 becomes hot air and flows into the containment vessel 2 from a blower port 15 provided at the upper part of the containment vessel 2. The drying target A in the storage container 2 is heated.
In this embodiment, the temperature of the heated air is 80 ° C.

The temperature of the heating bath 3 is detected by a temperature detector 29 provided on the outer wall of the heating bath 3. When the temperature of the heating bath 3 is equal to or lower than a predetermined temperature, for example, 80
When the temperature is lower than 0 ° C., the three-way switching valve 32 is open to the heat exchanger 5 and the heating tank 3 as described above, and the heating tank 3 is heated by oil. On the other hand, when the temperature of the heating tank 3 becomes equal to or higher than a predetermined temperature, for example, when the temperature exceeds 80 ° C., the three-way switching valve 32 is opened to the heat exchanger 5 and the oil bypass passage 33 to perform heat exchange. The oil from the heater 5 is returned to the oil heater 7 without being circulated to the heating tank 3. Thus, the heating tank 3 is maintained at a predetermined constant temperature, for example, 80 ° C.

The hot air blown into the storage container 2 heats the material A to be dried, and then is guided into the exhaust pipe 10 through an exhaust port 18 provided at the bottom of the storage container 2 together with the evaporated solvent gas. Since a cooling device 11 is connected to the exhaust pipe 10, the solvent gas is cooled and condensed by the cooling device 11 and collected. At this time, the third opening / closing valve 42 provided in the exhaust pipe 10 on the downstream side of the cooling device 11 is closed, and the second opening / closing valve 41 of the atmosphere opening pipe 12 branched from the exhaust pipe 10 is opened. ing. Therefore, the exhaust gas after the recovery of the solvent is discharged to the atmosphere through the atmosphere opening pipe 12.

After the above-described first step is performed for a predetermined time, the first on-off valve 25 is closed to close the ventilation port 15 of the storage container 2, and the second on-off valve 41 of the air opening pipe 12 is closed to communicate with the atmosphere. The state is closed, the third opening / closing valve 42 is opened, the vacuum generator 13 is operated, and the inside of the storage container 2 is depressurized to perform the second step.

Conditions for efficiently performing vacuum drying include increasing the degree of vacuum and increasing the drying temperature. However, the degree of vacuum cannot be extremely increased due to the capabilities of the vacuum drying device 1 and the vacuum pump. If the drying temperature is extremely increased, the solvent may be ignited, and the object to be dried may be adversely affected by heat. Therefore, the drying temperature and the degree of vacuum are appropriately set in consideration of the characteristics of the solvent used and the material of the material to be dried.

For example, when a petroleum-based solvent (trade name “Naphthesol” (registered trademark)) is used, the heating temperature is lowered below the flash point and the strength of the vacuum drying apparatus 1 is taken into consideration.
The temperature inside the storage container 2 is 80 ° C., and the degree of vacuum is 0.5 to 0.7.
torr is desirable.

In the second step, the exhaust pipe 10
Is cooled by cold water, the solvent gas is cooled and condensed by the cooling device 11 and collected.

The time required for the first step and the second step depends on the size and quantity of the object A to be dried. For example, when the contact terminal of about 5 mm is dried, the time required for the first step is reduced. 2 minutes, the second step takes 2.5 minutes,
The solvent could be completely evaporated and dried by both steps.

On the other hand, when the vacuum drying apparatus 1 according to the present invention is not used, for example, when drying is performed only with hot air of 80 ° C., it takes 20 minutes, and the dried material A having a complicated structure is required. Then, it took 5 minutes to blow off with an air gun and 40 minutes to dry with hot air.

That is, when the vacuum drying apparatus 1 according to the present invention is used, the drying time can be significantly reduced, and the solvent can be completely dried and removed.

Further, throughout the entire process, the lid member 20 is cooled by the lid member cooling device 22 provided above the storage container 2. Therefore, even immediately after the end of the drying process, the temperature of the lid member 20 does not rise, and there is no danger that the worker may be burned by the heat of the lid member 20.

Further, by performing vacuum drying, the temperature of the material A to be dried decreases due to latent heat. For example, the temperature of the material A to be dried was about 80.degree. ° C. Therefore, the dried material A immediately after drying
Can be easily handled, and workability can be improved.

FIG. 2 shows a schematic configuration of another embodiment of the vacuum drying apparatus. The members performing the same operations as those of the above-described vacuum drying apparatus 1 are denoted by the same reference numerals, and description thereof is omitted.

This vacuum drying device 50 uses a box-shaped container as the storage container 51, and has a door 52 that can be opened and closed on the front surface of the storage container 51.

The oil circulation path 8 has a first three-way switching valve 53 for switching the oil circulation path to the heat exchanger 5,
A second three-way switching valve 54 for switching the oil circulation path to the heating tank 3 is provided. The first three-way switching valve 53 is controlled based on the detection output from the exhaust gas temperature detector 55 provided in the exhaust pipe 10 to adjust the temperature of the air blown by the blower pipe 4. In addition, the temperature of the heating tank 3 is adjusted by controlling the second three-way switching valve 54 based on the detection output from the oil temperature detector 56 provided in the oil circulation path 8. An expansion tank 57 is provided in the oil circulation path 8,
The oil pressure in the oil circulation path 8 is prevented from rising.

Further, separately from the first cooling device 11a used in the first process, the second cooling device 1 used in the second process is used.
1b is provided in the exhaust pipe 10 to condense and recover the solvent gas. Further, the first cooling device 11a and the second cooling device 1
A cooling water temperature detector 59 is provided in a cooling water flow path 58 through which the cooling water for cooling the cooling water 1b flows to control the temperature of the cooling water.

In each of the above embodiments, the heat exchanger 5 for passing the flame-retardant oil is provided in the blower tube 4 to generate hot air. However, an electric heater may be provided instead of the heat exchanger.

In order to efficiently dry the object to be dried, it is important to perform the drying under conditions suitable for the characteristics of the object to be dried. That is, the component is dried under conditions suitable for the material, shape, and structure of the component. For example, a component having a simple shape and excellent heat resistance may be sufficiently dried only by the first step described above.

The cycle of performing the first step by hot air drying and the second step by vacuum drying is defined as one cycle, and this cycle is repeated. When the object to be dried is dried in this manner, for example, even when the object to be dried is weak to heat and the temperature cannot be raised so much, the object can be dried efficiently by repeating the first and second steps. When the solvent has a complicated shape, or there are fine holes or grooves, and the solvent is complicatedly penetrated by capillary action or the like, if the first and second steps are repeated as one cycle, a plurality of cycles are repeated. In addition, it is possible to efficiently and surely dry even the solvent that has entered the details.

[0040]

Since the present invention has the above-described structure,
The following effects can be obtained. According to the first and sixth aspects of the present invention, first, as a first step, an object to be dried is stored in a storage container, and the bottom and side walls of the storage container are heated by a heating tank provided at a lower portion of the storage container. Along with heating, hot air is blown into the containment vessel from a blower tube connected to the containment vessel to heat the object to be dried, thereby evaporating the solvent attached to the surface, and forming a complicated shape or the object to be dried. In order to efficiently dry the solvent that has entered inside due to holes, grooves and the like, the temperature of the entire object to be dried is increased. Then, the solvent gas guided into the exhaust pipe connected to the storage container is cooled and condensed and recovered by the cooling device, and the exhaust gas after the recovery of the solvent gas is discharged to the atmosphere from the open-to-atmosphere pipe. Next, as a second step, the intake side of the containment vessel is closed, and the atmosphere communication state of the exhaust pipe is closed, and the inside of the containment vessel is depressurized using a vacuum generator connected to the distal end side of the exhaust pipe, The solvent remaining in the storage container is evaporated and vaporized. Then, similarly to the first step, the solvent is condensed and recovered using a cooling device. Therefore, the inside of the storage container for drying the object to be dried is heated by the hot air and the bottom and the side wall are heated by the heating tank, so that the vaporized solvent condenses on the side wall of the storage container and adheres again. And efficient drying can be performed. In addition, the exhaust from the containment vessel is condensed and recovered in the cooling device,
Since the solvent gas is discharged into the atmosphere from the open-to-atmosphere pipe, the pressure of the solvent gas in the apparatus does not abnormally increase, and safe vacuum drying can be performed. In addition, since it is vacuum-dried, it is possible to dry it evenly and reliably not only on the surface of the material to be dried, but also on complicated and intricate parts and details, or even inside small holes and small grooves. The time required can be greatly reduced. Furthermore, since the object to be dried is once heated and then vacuum-dried, the solvent does not freeze, and the temperature of the object to be vacuum-dried is reduced to a temperature at which it can be touched manually. It can be taken out by hand, and work efficiency is good. According to the second aspect of the present invention, the hot air is blown from the upper portion of the storage container, and the exhaust is performed from the lower portion of the storage container. Therefore, the solvent adhering to the object to be dried is likely to drip downwardly of the containment vessel due to gravity, and the dripped solvent does not remain in the containment vessel and is quickly discharged from the exhaust port. Drying efficiency can be increased. Also,
According to the third aspect of the present invention, the lid member provided in the storage container is cooled by the lid member cooling device. Therefore, the lid member of the containment container does not become hot, and even immediately after the drying process of the matter to be dried is completed, the matter to be dried can be safely taken out of the containment container, and the operator can be burned. There is no danger of bearing. In the invention described in claim 4, the oil used for heating is maintained at a predetermined constant temperature by a temperature controller provided in the oil heater. Therefore, there is no waste in the heating energy, the drying process of the object to be dried can be performed efficiently, and an accident such as an explosion due to an abnormal rise in the oil temperature can be prevented. In the invention according to claim 5, the three-way switching valve provided between the heat exchanger in the oil circulation path and the heating tank is switched based on the detection output from the temperature detector provided in the heating tank, and the heating is performed. When the temperature of the tank is equal to or lower than a predetermined temperature, the oil is circulated to the heating tank, and when the temperature of the heating tank is equal to or higher than the predetermined temperature, the oil is not circulated to the heating tank. It is returned to the oil heater via the oil bypass. Therefore, waste of heating energy can be omitted, the drying process of the object to be dried can be performed more efficiently, and the storage container can be prevented from being overheated and the object to be dried can be prevented from being damaged.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vacuum drying device according to the present invention.

FIG. 2 is a schematic configuration diagram of another embodiment of a vacuum drying apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS A to-be-dried thing 1 Vacuum drying device 2 Containment container 3 Heating tank 4 Blower tube 5 Heat exchanger 6 Blower 7 Oil heater 8 Oil circulation path 9 Oil circulation pump 10 Exhaust pipe 11 Cooling device 12 Atmospheric open pipe 13 Vacuum generator 14 Placement part 15 Blow port 16 Outside air communication pipe 17 Outside air communication port 18 Exhaust port 19 Flange part 20 Cover member 21 Seal material 22 Cover member cooling device 23 Cooling water inlet 24 Cooling water outlet 25 First open / close valve 26 Open / close valve 27 Oil Inlet 28 Oil Outlet 29 Temperature Detector 30 Oil Outlet 31 Oil Inlet 32 Three-way Switching Valve 33 Oil Bypass Path 34 Electric Heater 35 Temperature Controller 36 Air Outlet 37 Cooling Water Inlet 38 Cooling Unit 39 Solvent Outlet 40 Cooling Water outlet 41 Second on-off valve 42 Third on-off valve 43 Oil mist removal device 50 Vacuum drying Location 51 storage containers 52 the door 53 first three-way switching valve 54 second three-way valve 55 exhaust temperature detector 56 oil temperature detector 57 expansion tank 58 coolant flow passage 59 the cooling water temperature detector

Claims (7)

(57) [Claims] 1. A vacuum drying device for vacuum-drying an object to be dried which has been washed with an aqueous or non-aqueous solvent, comprising a lid member which can be opened and closed, storing the object to be dried inside, and a heating tank at a lower portion. A containment vessel provided with: a blower pipe connected to the containment vessel via a first on-off valve to blow heated air into the containment vessel; and an oil heater for heating the flame-retardant oil circulated through the heating tank. Oil is supplied from the outlet of the oil heater to the inlet of the heating tank, and the oil is returned from the outlet of the heating tank to the inlet of the oil heater. An oil circulation pump that communicates with the containment vessel, an exhaust pipe that discharges the solvent gas evaporated and vaporized in the containment vessel, and a cooling pipe that communicates with the exhaust pipe to cool and condense and recover the solvent gas in the exhaust pipe Equipment and cold Is branched from the downstream side of the exhaust pipe of the apparatus, and the air release tube having a second opening and closing valve, are connected in communication through the third on-off valve on the distal end side of the exhaust pipe,
A vacuum generator, comprising: a vacuum generator for reducing the pressure in the storage container; 2. The vacuum drying apparatus according to claim 1, wherein the blower pipe is connected to an upper part of the containment vessel, and the exhaust pipe is connected to a lower part of the containment vessel. 3. The vacuum drying device according to claim 1, wherein a lid member cooling device for cooling the lid member is provided in the storage container. 4. The vacuum drying apparatus according to claim 1, wherein the oil heater is provided with a temperature controller for maintaining an oil temperature at a predetermined constant temperature. apparatus. 5. A heat exchanger in which the flame-retardant oil circulates is provided in the middle of the blower pipe, and a three-way switching valve is provided in the oil circulation path between the heat exchanger and the heating tank. An oil bypass is provided for returning oil from the switching valve to the oil heating device without passing through the heating tank, and the three-way switching valve is selectively switched based on the detection output from the temperature detector provided in the heating tank, and The temperature of the heating tank is adjusted by changing a circulation path.
The vacuum drying device according to claim 4 . 6. A storage container having an openable and closable lid member stores an object to be dried washed with an aqueous or non-aqueous solvent, and circulates the heated flame-retardant oil in a heating tank provided at a lower portion of the storage container. While circulating using a pump,
Hot air is blown into the containment vessel from the blower tube to heat the inside of the containment vessel, and the solvent gas evaporated and vaporized in the containment vessel is guided to the outside of the containment vessel through an exhaust pipe connected to the containment vessel, and then to the exhaust pipe. Solvent is condensed and recovered using a cooling device connected in communication,
A first step of dispersing the exhaust gas after collecting the solvent gas into the atmosphere by an atmosphere open pipe branched from an exhaust pipe on the downstream side of the cooling device; and supplying a hot air to the containment vessel by closing a first opening / closing valve provided in a blower pipe. Is stopped, the second on-off valve provided in the atmosphere opening pipe is closed, the atmosphere communication state of the exhaust pipe is closed, and the inside of the containment vessel is depressurized by using a vacuum generator connected to the end of the exhaust pipe, A second step of evaporating and evaporating the solvent remaining in the storage container, discharging the solvent to an exhaust pipe, and condensing and recovering the solvent using a cooling device connected to the exhaust pipe. 7. An object to be dried which has been washed with an aqueous or non-aqueous solvent is stored in a storage container having an openable and closable lid member, and the heated flame-retardant oil is circulated through a heating tank provided at a lower portion of the storage container. While circulating using a pump,
Hot air is blown into the containment vessel from the blower tube to heat the inside of the containment vessel, and the solvent gas evaporated and vaporized in the containment vessel is guided to the outside of the containment vessel through an exhaust pipe connected to the containment vessel, and then to the exhaust pipe. Solvent is condensed and recovered using a cooling device connected in communication,
A first step of dispersing the exhaust gas after collecting the solvent gas into the atmosphere by an atmosphere open pipe branched from an exhaust pipe on the downstream side of the cooling device; and supplying a hot air to the containment vessel by closing a first opening / closing valve provided in a blower pipe. Is stopped, the second on-off valve provided in the atmosphere opening pipe is closed, the atmosphere communication state of the exhaust pipe is closed, and the inside of the containment vessel is depressurized by using a vacuum generator connected to the end of the exhaust pipe, Performing a second step of evaporating and evaporating the solvent remaining in the containment vessel, discharging the solvent to an exhaust pipe, and condensing and recovering the solvent using a cooling device connected to the exhaust pipe, as one cycle. A vacuum drying method comprising repeatedly drying an object to be dried in a storage container.