Vacuum MM

Abstract

To promote drying even when hot air has difficulty reaching the object to be dried in the vacuum chamber of a vacuum dryer, or when a support device is used to hold the object to be dried. [Solution] The vacuum dryer includes a vacuum chamber 15 in which the object to be dried 1 is contained, an exhaust port 21 for discharging air from the vacuum chamber 15, a vacuum pump 23 communicating with the exhaust port 21 for reducing the pressure in the vacuum chamber 15, and an air supply box 31 located inside the vacuum chamber 15 and having a first nozzle 35 for spraying hot air. The air supply box 31 has a loading surface 33 that comes into contact with the object to be dried 1, and multiple first nozzles 35 may be arranged on the loading surface 33. A support 41 may be used to hold the object to be dried 1. In addition to hot air, the object to be dried 1 is heated by heat conduction from the heated air supply box 31, thereby accelerating drying.

Description

Technical Field

[0005] , , ,

[0001] The present invention relates to a vacuum dryer.

Background Art

[0002] In order to enhance drying capacity, a vacuum dryer that blows heated air is known (Japanese Unexamined Patent Application Publication No. 2017-110866). This vacuum dryer has an object heating discharge port and a container heating discharge port so that both the drying object and the vacuum container can be heated. Heated air is blown from both ports.

Summary of the Invention

Problems to be Solved by the Invention

[0003] During vacuum drying, there are cases where a plurality of drying objects are held by a support such as a basket. When the drying objects are adjacent to each other within the support, a portion with poor air permeability may occur, and heating by warm air may not progress. An object of the present invention is to promote drying even when warm air has difficulty reaching the drying object accommodated in the vacuum chamber of the vacuum dryer or when a support for holding the drying object is used.

Means for Solving the Problems

[0004] A first aspect of the present invention is a vacuum dryer for drying a drying object, comprising a vacuum chamber in which the drying object is accommodated, an exhaust port for discharging air in the vacuum chamber, a vacuum pump that communicates with the exhaust port and evacuates the vacuum chamber, an air supply box disposed in the vacuum chamber and having a plurality of first nozzles for injecting warm air, and having

[0005] The air supply box is hollow. The shape of the air supply box is arbitrary. The air supply box is made of, for example, metal. It is desirable that the heat conductivity of the air supply box is high. Supports may be used to hold the object to be dried in the reduced-pressure chamber. The support may be shaped to increase the contact area with the air supply box in order to promote heat conduction. [Effects of the Invention]

[0006] According to the present invention, drying can be promoted even when it is difficult for hot air to reach the object to be dried contained in the vacuum chamber of a vacuum dryer, or when a support device is used to hold the object to be dried. [Brief explanation of the drawing]

[0007] [Figure 1] Longitudinal cross-sectional view of Embodiment 1 of a vacuum dryer during vacuum drying. [Figure 2] Perspective view of the air supply box, support, and object to be dried according to Embodiment 1. [Figure 3] Longitudinal cross-sectional view of the vacuum dryer of Embodiment 2 [Figure 4] Longitudinal cross-sectional view of the vacuum dryer of Embodiment 3 [Modes for carrying out the invention]

[0008] <Embodiment 1> As shown in Figure 1, the vacuum dryer 10 of this embodiment includes a main body 13, a vacuum chamber 15, a lid 17, an exhaust port 21, a vacuum pump 23, an air supply box 31, and a support 41. The top of Figure 1 is vertically upward. The vacuum dryer 10 dries the object to be dried 1. The vacuum chamber 15 is a space inside the main body 13. The object to be dried 1 is placed inside the vacuum chamber 15. The lid 17 is positioned at the opening of the vacuum chamber 15 and can be opened and closed. The vacuum chamber 15 is sealed by closing the lid 17. The vacuum pump 23 discharges the air inside the sealed vacuum chamber 15. The exhaust port 21 opens into the vacuum chamber 15. The exhaust port 21 communicates with the vacuum pump 23. The vacuum pump 23 is operated after the lid 17 is closed.

[0009] The air supply box 31 is a hollow rectangular parallelepiped. The air supply box 31 has a loading surface 33, a first nozzle 35, and a joint 37. Hot air is supplied to the inside of the air supply box 31 via the joint 37. The loading surface 33 is the top surface of the air supply box 31. The loading surface 33 is a flat surface without irregularities. The loading surface 33 has a plurality of first nozzles 35. The first nozzles 35 are holes connecting the inside and outside of the air supply box 31. The supplied hot air is released to the outside from the first nozzles 35. The first nozzles 35 are arranged in a line with some space between them. The first nozzles 35 are distributed across the entire surface of the loading surface 33. The size and cross-sectional shape of the first nozzles 35 can be freely determined. The axis of the first nozzles 35 may be inclined with respect to the loading surface 33.

[0010] Hot air is supplied from outside the depressurization chamber 15. The hot air is supplied into the depressurization chamber 15 via the ventilation passage 19. The ventilation passage 19 is connected to the fitting 37. The ventilation passage 19 may use a flexible hose or the like. The flexibility of the ventilation passage 19 allows the air supply box 31 to be moved. When depressurizing the depressurization chamber 15, the hot air supplied to the air supply box 31 is shut off and the depressurization chamber 15 is completely sealed. The temperature of the hot air is, for example, 50 to 150 degrees Celsius.

[0011] The air supply box 31 is placed at the bottom of the decompression chamber 15. The loading surface 33 of the air supply box 31 faces upward. Hot air is discharged upward from the first nozzle 35. The air supply box 31 may be freely positioned inside the decompression chamber 15. The shape and size of the air supply box 31 may be determined based on the support 41. When hot air is supplied into the air supply box 31, the air supply box 31 is heated. The surface temperature of the air supply box 31 reaches, for example, 150°C to 130°C.

[0012] The object to be dried 1 can be various, such as metal, synthetic resin, ceramics, or composite material. Before drying in the vacuum dryer 10, the object to be dried 1 is washed with deionized water or the like. The support 41 holds the object to be dried 1. The object to be dried 1 is placed on the loading surface 33 while being held by the support 41. In Embodiment 1, the support 41 is a basket. The support 41 can hold multiple objects to be dried 1. The object to be dried 1 may also be placed directly on the loading surface 33 without using the support 41.

[0013] The effects and advantages of this embodiment will now be explained. The support 41 holds multiple objects to be dried 1. Moisture is present on both the objects to be dried 1 and the support 41. The support 41 is placed in the depressurization chamber 15. Then, the lid 17 is closed. Next, warm air is supplied to the ventilation passage 19. The warm air is discharged from the first nozzle 35. The objects to be dried 1 and the support 41 are heated by the warm air. The air supply box 31 is also heated by the warm air. Furthermore, the support 41 and the objects to be dried 1 are heated by heat conduction from the air supply box 31 through contact with the loading surface 33. Also, if the wind speed of the warm air is high, moisture attached to the support 41 and the objects to be dried 1 is blown away. The supply of hot air is stopped. Then, the vacuum pump 23 is activated to reduce the pressure inside the depressurization chamber 15. The reduced pressure lowers the boiling point. As a result, the moisture adhering to the object to be dried 1 and the support 41 evaporates, accelerating the drying of the object to be dried 1 and the support 41. The drying of the object to be dried 1 is completed by repeating the cycle of releasing hot air from the air supply box 31 and then depressurizing the depressurization chamber 15 multiple times. The time for releasing hot air and depressurizing is controlled by a timer or the like.

[0014] To promote heat conduction from the loading surface 33, the object to be dried 1 may be arranged so as to increase the contact area with the loading surface 33. If the object to be dried 1 has areas with poor ventilation, such as recesses, heating by heat conduction is effective. When the objects to be dried 1 are relatively small and multiple objects to be dried 1 are arranged overlapping inside the support 41, heat conduction from the loading surface 33 is promoted by contact between the objects to be dried 1.

[0015] When water evaporates, it takes away the latent heat of vaporization from the object to be dried 1 and the support 41. When the heat capacity of the object to be dried 1 and the support 41 is small, the latent heat of vaporization required for the water to dry is insufficient, and the water adhering to the object to be dried 1 and the support 41 may freeze. According to the present embodiment, the object to be dried 1 and the support 41 are pre-heated by warm air. Therefore, even when the heat capacity of the object to be dried 1 and the support 41 is small, it is possible to prevent the water adhering to them from freezing.

[0016] Also, when water adheres to the support 41, the water that could not be dried may adhere from the support 41 to the object to be dried 1. According to the present embodiment, since the loading surface 33 and the support 41 are in contact, the support 41 is directly heated by heat conduction. Thereby, the evaporation of the water adhering to the support 41 is promoted. Further, the support 41 is disposed above the air supply box 31. Since the loading surface 33 of the air supply box 31 is hot, when water drops from the support 41 to the loading surface 33, it immediately evaporates. According to the present embodiment, the number of cycles in the drying process can be reduced, and the cycle time can be shortened.

[0017] As shown in FIG. 2, the first nozzles 35 of the air supply box 31 are arranged at equal intervals over the entire area of the loading surface 33. The support 41 is placed on the loading surface 33. Since the entire support 41 is net-shaped, it does not obstruct the flow of the warm air discharged from the first nozzles 35. The loading surface 33 may be made of a material with high thermal conductivity in order to promote the vaporization of water and the heat conduction to the object to be dried 1. The material is, for example, stainless steel, copper, or aluminum.

[0018] <Embodiment 2> As shown in FIG. 3, the vacuum dryer 110 of the present embodiment includes a main body 113, a decompression chamber 15, a lid 17, an exhaust port 21, a vacuum pump 23, a blower box 31, and a support 141. The blower box 31 is the same as that in the first embodiment. The object to be dried 101 is rod-shaped with a flange 103 on one end face. The support 141 is used to maintain the posture of the object to be dried 101. The support 141 includes a holding portion 143 and a leg portion 147. The holding portion 143 is plate-shaped. The holding portion 143 has a plurality of guide holes 145. The guide holes 145 are arranged in the front-back direction and the left-right direction. The object to be dried 101 is inserted through the guide holes 145. The leg portion 147 extends downward from the holding portion 143 and rests on the loading surface 33 of the blower box 31. The leg portion 147 has a height such that the object to be dried 101 and the blower box 31 do not contact each other. The flange 103 is supported by the holding portion 143. When the object to be dried 101 is inserted into the support 141, a gap is ensured between the guide holes 145 and the object to be dried 101. During the drying process, warm air also enters the inside of the guide holes 145. The holding portion 143 is arranged so as to cover the upper part of the blower box 31. The warm air discharged from the first nozzle 35 stays between the loading surface 33 and the holding portion 143. The staying warm air promotes the heating of the object to be dried 101 and the support 141. This warm air also enters the gap between the guide holes 145 and the object to be dried 101 to promote heating.

[0019] <Embodiment 3> As shown in FIG. 4, the vacuum dryer 110 of the present embodiment includes a main body 113, a decompression chamber 15, a lid 17, an exhaust port 21, a vacuum pump 23, a blower box 31, a support 141, and a blower 151. Except for using the blower 151, it is the same as that in the second embodiment. The air blower 151 has a plurality of second nozzles 155 arranged in the front-to-back and left-to-right directions. The air blower 151 discharges warm air from above the object to be dried 101 downwards. The wall of the decompression chamber 15 has support pieces 25 to hold the air blower 151 in the air. Multiple support pieces 25 are arranged vertically so that the height of the air blower 151 can be adjusted. The warm air supplied to the air blower 151 is branched from a ventilation passage 19 connected to the air supply box 31. The shape of the air blower 151 is flexible. For example, the same object as the air supply box 31 may be placed upside down.

[0020] The present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. All technical matters included in the technical concept described in the claims are covered by the present invention. The embodiments described above are preferred examples, but those skilled in the art can realize various alternatives, modifications, variations, or improvements from the contents disclosed herein, and these are included in the technical scope described in the appended claims. [Explanation of Symbols]

[0021] 1.101 Items to be dried 10, 110 Vacuum Dryer 13, 113 Main unit 15. Decompression Chamber 21 Exhaust vent 23 Vacuum pump 31 Air supply box 33 Loading surface 35 No. 1 spout 41, 141 Supports 151 Air supply device 155 2nd spout

Claims

1. A vacuum dryer for drying objects, A depressurized chamber containing the object to be dried, An exhaust port for discharging air from the aforementioned depressurized chamber, A vacuum pump that communicates with the exhaust port and depressurizes the pressure chamber, An air supply box is placed in the depressurized chamber and has a plurality of first nozzles for injecting warm air, A vacuum dryer having a vacuum.

2. The air supply box is located at the bottom of the depressurization chamber. The vacuum dryer according to claim 1.

3. The air supply box has a loading surface that comes into contact with the object to be dried, The first nozzle is positioned on the loading surface, A vacuum dryer according to claim 1 or 2.

4. The support is placed on the loading surface and has a support capable of holding the object to be dried, and the support is in contact with the loading surface. The vacuum dryer according to claim 3.

5. Above the aforementioned air supply box, there is a second nozzle for spraying hot air. A vacuum dryer according to any one of claims 1 to 4.

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