Centrifugal vacuum dryer and drying method using the same

Abstract

This invention provides a centrifugal vacuum dryer that can shorten the drying time of washed objects. [Solution] The centrifugal vacuum dryer 1 is a centrifugal vacuum dryer 1 for drying a water-washed object 200, and comprises a reduced-pressure drying chamber having a bottom 20 where the ends are lower than the central part and drainage holes are formed at the ends, a rotatable base 30 provided in the central part on which the water-washed object 200 is placed, and a vacuum pump 80 for drawing in air from inside the reduced-pressure drying chamber.

Description

Technical Field

[0001] The present invention relates to a centrifugal vacuum dryer and a drying method using the same.

Background Art

[0002] Patent Document 1 discloses a vacuum spin dryer device including a decompression drying chamber, a rotatable pedestal, and a vacuum pump for sucking air inside the decompression drying chamber. The vacuum spin dryer device of Patent Document 1 stores an object after washing in the decompression drying chamber, gradually reduces the pressure, and then further reduces the pressure while rotating the pedestal to dry the chemical solution adhering to the object. In the vacuum spin dryer device of Patent Document 1, after the chemical solution is vaporized and exhausted by decompression, the remaining chemical solution can be dried by being blown off by the centrifugal force of the rotating pedestal.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the vacuum spin dryer device disclosed in Patent Document 1, when washed with water, moisture is difficult to vaporize by decompression, and in order to suppress reattachment of moisture to the object washed with water, it is necessary to gradually reduce the pressure, and a certain drying time is required. Therefore, it is required to shorten the drying time of the object washed with water.

[0005] The present invention has been made to solve the above-described problems, and an object thereof is to provide a centrifugal vacuum dryer capable of shortening the drying time of an object washed with water.

Means for Solving the Problems

[0006] To achieve the above objective, the basic configuration of the centrifugal vacuum dryer according to the first aspect of the present invention is as follows: A centrifugal vacuum dryer for drying objects that have been washed with water, A vacuum drying chamber having a bottom that is lower at the ends than in the center, with drainage holes formed at the ends, A rotatable base is provided in the center for placing the object that has been washed with water, A vacuum pump that draws in air from inside the reduced-pressure drying chamber, It is equipped with.

[0007] An exhaust vent is formed between the central part and the end. The vacuum pump may draw in air from inside the reduced-pressure drying chamber through its exhaust port.

[0008] The object that has been washed with water may be a metal processed part.

[0009] The bottom may have an inclined surface that slopes downward from the center towards the edges.

[0010] The reduced-pressure drying chamber has a drying chamber container fitted to the bottom, The drying chamber container may be equipped with a lifting mechanism that allows it to be raised and lowered.

[0011] The top surface of the drying chamber container may be curved.

[0012] A rotating shaft that penetrates the bottom and is attached to the base, A motor is installed outside the vacuum drying chamber to rotate the rotating shaft, Equipped with, The base may rotate on a pivot axis.

[0013] In the basic configuration of the drying method according to the second aspect of the present invention, A drying method using a centrifugal vacuum dryer, A vacuum pump is used to draw air from inside the reduced-pressure drying chamber, and the base is rotated to remove any water adhering to the washed object by centrifugal force. The splashed water is directed towards the edges and discharged through the drain holes.

Advantages of the Invention

[0014] In the centrifugal vacuum dryer according to the present invention, the vacuum drying chamber has a bottom portion that is lower at the end than at the central portion, and a drain hole is formed at the end. Therefore, the moisture flung by the centrifugal force of the rotating pedestal flows to the lower end and is discharged, suppressing the reattachment of moisture to the object to be washed. Therefore, in the present invention, the drying time of the object to be washed can be made shorter.

Brief Description of the Drawings

[0015] [Figure 1] It is a front view of the vacuum dryer according to the embodiment. [Figure 2] It is a sectional view taken along the line I-I' in FIG. 1. [Figure 3] It is an electrical and fluid circuit diagram of the vacuum dryer according to the embodiment. [Figure 4] It is a front view showing the state where the drying chamber container according to the embodiment is lowered. [Figure 5] It is a sectional view taken along the line IV-IV' in FIG. 4. [Figure 6] It is an enlarged view of the vacuum drying chamber in FIG. 5. [Figure 7] It is a plan view of the bottom portion according to the embodiment. [Figure 8] It is a plan view of the pedestal according to the embodiment. [Figure 9] It is a plan view of the pedestal on which the workpiece according to the embodiment is placed.

Embodiments for Carrying Out the Invention

[0016] Embodiment. Hereinafter, the centrifugal vacuum dryer 1 according to the embodiment of the present invention will be described based on the drawings. For ease of understanding, XYZ coordinates are set and referred to as appropriate.

[0017] The centrifugal vacuum dryer 1 is a device for removing moisture contained in a workpiece 200, which is an object that has been washed with water by a water-based washing machine, and drying it. As shown in Figures 1 to 3, the centrifugal vacuum dryer 1 comprises a housing 10, a bottom 20, a base 30, a capsule 40, a lifting mechanism 60, a piping chamber 70, a vacuum pump 80, and a control unit 100. In the reduced-pressure drying chamber consisting of the bottom 20 and the capsule 40, the centrifugal vacuum dryer 1, for example, reduces the pressure of drying the workpiece 200, which is a metal processed part, and rotates the workpiece 200 to remove moisture adhering to the workpiece 200 by centrifugal force, thereby drying the workpiece 200.

[0018] The housing 10 contains a base 20, a pedestal 30, a capsule 40, a lifting mechanism 60, a piping chamber 70, and a vacuum pump 80. The housing 10 also has a touch panel 11, a vacuum pressure gauge 12, and a cylindrical section 13.

[0019] The touch panel 11 is an operation panel located on the housing 10. The touch panel 11 is used to operate the centrifugal vacuum dryer 1.

[0020] The vacuum pressure gauge 12 displays the pressure inside the reduced-pressure drying chamber during the drying operation of the workpiece 200.

[0021] The cylindrical portion 13 is a slide shifter extending in a direction parallel to the Y-axis. Multiple cylindrical portions 13 are provided on the upper surface of the housing 10. The cylindrical portion 13 has a through hole that extends in a direction parallel to the Y-axis and penetrates the top surface of the housing 10.

[0022] The bottom portion 20 constitutes the floor of the vacuum drying chamber, as shown in Figures 4 and 5. The bottom portion 20 is formed from, for example, plated iron. The bottom portion 20 has a sealing material 23, as shown in Figures 6 and 7. The bottom portion 20 has an exhaust port 22 and a pair of drainage holes 25.

[0023] The bottom body 21 (bottom) is formed in a disc shape when viewed from above (+Y-axis direction). Furthermore, the upper surface of the bottom body 21 is formed in a tapered shape, with the peripheral end 21b being lower than the central part 21a. However, it is not limited to this. The upper surface of the bottom body 21 only needs to be formed in a shape that allows liquid to flow toward the end 21b. Preferably, the upper surface of the bottom body 21 is formed in a shape that spreads out so that the surface area of ​​the liquid increases as it flows. The bottom body 21 serves as the frame (base) on which the pedestal 30 is attached.

[0024] The exhaust port 22 is a hole that communicates with the outside of the vacuum drying chamber. The exhaust port 22 is formed near the central part 21a of the bottom 20. However, it is not limited to this. The exhaust port 22 only needs to be formed so as to be located inside the vacuum drying chamber. The exhaust port 22 is a hole for discharging the air inside the vacuum drying chamber to the outside when the vacuum drying chamber is depressurized.

[0025] The sealing material 23 is formed in an annular shape and is provided along the outer edge of the bottom body 21. The sealing material 23 is a packing provided on the upper surface of the bottom 20. However, it is not limited to this. The sealing material 23 can be any member that can maintain the airtightness of the reduced-pressure drying chamber.

[0026] The drainage holes 25 are holes that communicate with the outside of the vacuum drying chamber. The drainage holes 25 are formed at the end 21b of the bottom body 21. Two drainage holes 25 are formed so as to be located diagonally opposite each other. However, this is not limited to this. One or three or more drainage holes 25 may be formed. The drainage holes 25 are holes for discharging liquid flowing on the upper surface of the bottom body 21 to the outside of the vacuum drying chamber.

[0027] The base 30 is located in the center of the bottom 20. The base 30 supports the workpiece 200. A circular hole 30a is formed in the base 30. As shown in Figures 8 and 9, the base 30 includes a workpiece holder 31, a workpiece guide 32, and a rotating shaft 33. However, it is not limited to this. The base 30 is rotatable and can have any shape as long as it supports the workpiece 200. The body of the base 30 is supported by the rotating shaft 33 and does not directly contact the upper surface of the bottom 20. Multiple gaps are formed in the body of the base 30, penetrating it in the vertical direction (Z-axis direction). However, it is not limited to this. The body of the base 30 does not need to have gaps formed in it.

[0028] Multiple circular holes 30a are formed on the upper surface of the base 30. The multiple circular holes 30a are formed so as to be located on multiple identical circles, concentric circles, and radially from the center of the base 30. However, it is not limited to this. At least three circular holes 30a are formed at a certain distance from the center of the base 30. Female threads are formed on the inner side walls of the circular holes 30a.

[0029] The workpiece support 31 is provided on the upper surface of the base 30. The workpiece support 31 is on which the workpiece 200 is placed and supports the workpiece 200. Four workpiece support 31 are provided on the same circle centered on the center of the base 30. However, it is not limited to this. The workpiece support 31 only needs to be provided in a position where it can support the workpiece 200.

[0030] The work guide 32 is a columnar member with a rounded upper end, provided on the upper surface of the base 30. The work guide 32 guides the workpiece 200 so that it is placed on the work support 31. Four work guides 32 are provided on the same circle centered on the center of the bottom 20. However, it is not limited to this. The work guides 32 only need to be provided in a position that can guide the workpiece 200. The work guide 32 has a male threaded portion at its lower end. The work guide 32 is fixed by inserting the male threaded portion into the circular hole 30a of the base 30.

[0031] The rotating shaft 33 is the axis for rotating the base 30. As shown in Figure 6, the rotating shaft 33 is formed to extend in the Z-axis direction. The rotating shaft 33 is provided passing through the center of the bottom 20. The upper end of the rotating shaft 33 is attached to the lower surface of the center of the base 30. A motor 33a and a bearing 33b are attached to the rotating shaft 33.

[0032] Motor 33a rotates the rotating shaft 33. Motor 33a is located outside the vacuum drying chamber. By rotating the rotating shaft 33, motor 33a rotates the base 30.

[0033] The bearing 33b is positioned between the rotating shaft 33 and the bottom 20. The bearing 33b fills the gap between the rotating shaft 33 and the bottom 20 and rotatably supports the rotating shaft 33.

[0034] As shown in Figures 5 and 6, the capsule 40 (drying chamber container) is a housing with an open bottom that constitutes a reduced-pressure drying chamber. The capsule 40 abuts against the upper surface of the bottom 20. The capsule 40 is made of, for example, stainless steel. The capsule 40 has a capsule body 41, a flange 42, a viewing window 43, a support column 44, and a top plate 45.

[0035] The capsule body 41 (drying chamber container) is a hemispherical, half-bowl-shaped housing with an open bottom, and the top surface of the capsule body 41 is curved. However, it is not limited to this. The capsule body 41 only needs to have an internal space S1 that narrows towards the top. The capsule body 41 can house the base 30 and the workpiece 200 inside its internal space S1. The vacuum drying chamber consisting of the bottom 20 and the capsule body 41 can have a smaller internal space volume than conventional rectangular prism-shaped or spherical vacuum drying chambers. Furthermore, since the closer the vacuum drying chamber is to a sphere, its resistance to pressure improves, so the capsule body 41 can be made into a hemispherical, half-bowl-shaped housing to improve its durability.

[0036] As shown in Figures 5 and 6, the opening edge of the lower end of the capsule body 41 is placed on the sealing material 23 of the bottom 20, sealing the space between the bottom 20 and the capsule 40, thereby sealing the reduced-pressure drying chamber consisting of the bottom 20 and the capsule 40.

[0037] The flange portion 42 is a plate material composed of planes parallel to the XY plane. The flange portion 42 extends from the opening edge of the opening of the capsule body 41 to the external space of the capsule body 41.

[0038] The viewing window 43 is a window for viewing the inside of the capsule 40. The viewing window 43 is located on the side of the capsule body 41.

[0039] The lifting mechanism 60, as shown in Figures 4 and 5, is a mechanism for raising and lowering the capsule 40. The lifting mechanism 60 includes a lifting guide 61, a cylinder 62, and a rod 63.

[0040] The lifting guide 61 is an arm that transmits vertical force (in the Y-axis direction) to the capsule 40. The lifting guide 61 is an arm that extends in a direction parallel to the Z-axis. The lower end of the lifting guide 61 is fixed to the top plate 45 of the capsule 40. The lifting guide 61 extends upward through the cylindrical part 13 of the housing 10 to the housing 10. Two lifting guides 61 are provided. However, it is not limited to this. Three or more lifting guides 61 may be provided.

[0041] The cylinder 62 is a component that moves an object in the vertical direction. The cylinder 62 is located on the upper surface of the housing 10. The cylinder 62 is either an air cylinder or a hydraulic cylinder, but is not limited to these. The cylinder 62 only needs to be able to move the rod 63, which will be described later, in the vertical direction.

[0042] The rod 63 is a columnar member extending in a direction parallel to the Z-axis. The upper end of the rod 63 is fixed to the lifting guide 61. The upper end of the rod 63 is connected to a piston in the cylinder 62. The lower end of the rod 63 is fixed to the top plate 45 of the capsule 40. The rod 63 is moved vertically by the cylinder 62. As the rod 63 moves vertically, the capsule 40 and the lifting guide 61 also move vertically. The rod 63 is a piston rod. However, it is not limited to this. The rod 63 can be moved vertically by the cylinder 62, and the capsule 40 and the lifting guide 61 can also be moved vertically.

[0043] The piping chamber 70 houses piping and equipment that connects the vacuum drying chamber, which consists of a bottom section 20 and a capsule 40, to the outside of the vacuum pump 80 or the centrifugal vacuum dryer 1. As shown in Figure 3, the piping chamber 70 includes a first pipe 71, an air control mechanism 72, a second pipe 73, and a water distribution pipe 74.

[0044] The first pipe 71 is a pressure reducing pipe that connects the reduced-pressure drying chamber and the air control mechanism 72. One end of the first pipe 71 is connected to the exhaust port 22 at the bottom 20.

[0045] The air control mechanism 72 consists of equipment that controls the air exhausted from the reduced-pressure drying chamber. The air control mechanism 72 includes a vacuum release valve 72a that suppresses damage to equipment caused by the negative pressure generated by the vacuum pump 80, and a drain box 72b that collects condensed water droplets.

[0046] The second pipe 73 is a pressure reducing pipe that connects the air control mechanism 72 and the vacuum pump 80. One end of the second pipe 73 is connected to the vacuum pump 80.

[0047] The water distribution pipe 74 is a pipe that connects the reduced-pressure drying chamber to the outside of the centrifugal vacuum dryer 1. One end of the water distribution pipe 74 is connected to the drain hole 25 in the bottom 20. The other end of the water distribution pipe 74 is connected to the drain box 72b. The water distribution pipe 74 is used to collect the water discharged from the drain hole 25 into the drain box 72b.

[0048] The vacuum pump 80 is a pump that discharges gas and creates a reduced pressure state. The vacuum pump 80 is a pump that discharges air from the reduced pressure drying chamber via the piping chamber 70.

[0049] As shown in Figure 3, the control unit 100 includes a filter regulator 101, a solenoid valve 102, a silencer 103, a speed controller 104, a residual pressure exhaust valve 105, and a vacuum pressure detector 106.

[0050] The control unit 100 uses the filter regulator 101 to remove dust and moisture contained in the outside air taken into the cylinder 62 and vacuum breaking valve 72a of the centrifugal vacuum dryer 1, thereby suppressing the intrusion of dust and moisture. Furthermore, the control unit 100 uses the filter regulator 101 to maintain a constant pressure of the outside air.

[0051] The control unit 100 switches the operating state of the cylinder 62 of the lifting mechanism 60 when raising or lowering the capsule 40 using the solenoid valve 102. The control unit 100 then suppresses the operating noise of the cylinder 62 using the silencer 103. Furthermore, the control unit 100 controls the opening and closing speed of the cylinder valve of the cylinder 62 using the speed controller 104. After that, the control unit 100 exhausts the residual pressure inside the cylinder 62 using the residual pressure exhaust valve 105.

[0052] The control unit 100 uses a vacuum pressure detector 106 to measure the pressure from negative to positive within the capsule 40, the first piping 71, the air control mechanism 72, and the second piping 73. When the vacuum drying chamber, consisting of the bottom 20 and the capsule 40, is to be evacuated, the control unit 100 connects the vacuum drying chamber to the vacuum pump 80.

[0053] Next, we will explain how to use the centrifugal vacuum dryer 1 (drying method).

[0054] First, the centrifugal vacuum dryer 1 is used with the capsule 40 raised, as shown in Figure 2. The water-washed workpiece 200 is placed on the workpiece holder 31, guided by the workpiece guide 32 on the base 30.

[0055] Next, the user operates the touch panel 11 to start the drying process. First, the lifting mechanism 60 activates and lowers the capsule 40.

[0056] As shown in Figures 5 and 6, the descending capsule 40 comes into contact with the sealing material 23 of the bottom 20, and the workpiece 200 is housed in the internal space S1 of the capsule 40. In this way, the bottom 20 and the capsule 40 form a sealed, reduced-pressure drying chamber.

[0057] Subsequently, the drying process begins. The vacuum pump 80 is activated, exhausting the air from the reduced-pressure drying chamber and reducing the pressure inside the chamber. Simultaneously, the motor 33a is activated, causing the rotating shaft 33 to rotate, which in turn causes the base 30 to rotate. The inside of the reduced-pressure drying chamber becomes almost a vacuum due to the vacuum pump 80.

[0058] When the pressure inside the vacuum drying chamber is reduced, the evaporation of water is accelerated. Furthermore, as the base 30 rotates, the workpiece 200 on the base 30 also rotates, and any moisture adhering to the workpiece 200 is blown away by centrifugal force.

[0059] The rotational speed of the base 30 is 360 rpm. However, it is not limited to this. The rotational speed of the base 30 may be changed depending on the amount of moisture adhering to the workpiece 200. The rotational speed of the base 30 may be slower than 360 rpm or faster than 360 rpm. For example, the rotational speed of the base 30 may be 240 rpm or 480 rpm.

[0060] The moisture ejected by centrifugal force scatters onto the upper surface of the bottom 20 and flows along the inclined surface, which is the upper surface of the tapered bottom body 21, spreading out with force towards the end 21b. The moisture ejected by centrifugal force spreads out and becomes more easily evaporated due to the reduced pressure. The moisture ejected by centrifugal force is then discharged to the outside of the reduced-pressure drying chamber through the drainage holes 25 formed at the end 21b.

[0061] The moisture adhering to the workpiece 200 is reduced by the centrifugal force of the rotating workpiece 200, and the reduced pressure makes it easier to dry. The condition of the drying workpiece 200 can be checked by looking through the viewing window 43.

[0062] The centrifugal vacuum dryer 1 performs depressurization and rotation of the base 30 for 20 seconds. However, it is not limited to this. The time for depressurization and rotation of the base 30 may be shorter or longer than 20 seconds. For example, the time for depressurization and rotation of the base 30 may be 40 seconds, 60 seconds, 120 seconds, or 180 seconds.

[0063] The centrifugal vacuum dryer 1 takes in outside air through the vacuum-breaking valve 72a of the air control mechanism 72. The user can set the machine to periodically take in outside air through the vacuum-breaking valve 72a.

[0064] After drying is complete, the vacuum pump 80 and motor 33a automatically stop, and outside air is drawn into the reduced-pressure drying chamber by the vacuum release valve 72a.

[0065] Finally, the lifting mechanism 60 automatically activates, and the capsule 40 is lifted. This allows the workpiece 200 to be removed from the centrifugal vacuum dryer 1.

[0066] As described above, in the centrifugal vacuum dryer 1 according to this embodiment, the reduced-pressure drying chamber, which consists of a bottom portion 20 with a tapered upper surface and a capsule body 41 in which the internal space S1 converges towards the upper end, can reduce the volume of the internal space S1 compared to conventional rectangular prism-shaped or spherical reduced-pressure drying chambers. Therefore, in the centrifugal vacuum dryer 1, the vacuum pump 80 can reduce the pressure inside the reduced-pressure drying chamber in a shorter time than in conventional models.

[0067] Furthermore, in the centrifugal vacuum dryer 1, the closer the reduced pressure drying chamber is to a spherical shape, the better its resistance to pressure, thus improving durability compared to conventional rectangular prism-shaped reduced pressure drying chambers.

[0068] In the centrifugal vacuum dryer 1, when moisture on the workpiece 200 evaporates, the heat of the workpiece 200 decreases due to the heat of vaporization. However, as the base 30 rotates, the centrifugal force removes the moisture from the workpiece 200, and only the remaining moisture evaporates, thus suppressing the heat loss due to the heat of vaporization. Furthermore, in the centrifugal vacuum dryer 1, when the base 30 rotates and the centrifugal force removes the moisture from the workpiece 200, moisture remains in the gaps of the workpiece 200. However, due to the reduced pressure, the moisture in the gaps of the workpiece 200 evaporates, thus accelerating drying.

[0069] In conventional vacuum dryers, when cleaning with organic cleaning solutions, the organic cleaning solutions easily vaporize under reduced pressure, allowing for sufficient drying of the object. However, in conventional vacuum dryers, when washing with water, the water does not easily vaporize under reduced pressure, requiring a gradual reduction of pressure to suppress re-adhesion of water to the washed object, thus requiring a certain drying time. In the centrifugal vacuum dryer 1, the water is blown away by the centrifugal force of the rotating base and flows from the center 21a to the end 21b of the tapered bottom body 21, and is discharged through the drain hole 25 formed at the end 21b. As a result, in the centrifugal vacuum dryer 1, the amount of water inside the vacuum drying chamber is reduced, suppressing re-adhesion of water to the workpiece 200, eliminating the need for gradual reduction of pressure, and allowing for a near-vacuum state to be achieved in a shorter time. Furthermore, in the centrifugal vacuum dryer 1, only the remaining water adhering to the workpiece 200 is dried by reduced pressure, thus further shortening the drying time. Therefore, the centrifugal vacuum dryer 1 can shorten the drying time of the workpiece 200, which is the object that has been washed with water.

[0070] In this centrifugal vacuum dryer 1, the temperature change, the amount of water removed, and the amount of remaining water for the workpieces 200 of Comparative Examples 1 to 4, Example 1, and Example 2, as shown in Table 1 below, were investigated. The workpieces 200 used in this experiment were submerged in water and not drained. The workpieces 200 used in this experiment were submerged in water and lightly drained. The amount of water contained in the workpiece 200 was measured by comparing the weight of the workpiece 200 before water absorption with the weight after water absorption. In this comparative experiment, drying was performed at a room temperature of 15 degrees Celsius, with different drying methods.

[0071] [Table 1]

[0072] The verification results for Comparative Examples 1 to 4, and Examples 1 and 2 are shown in Table 2 below.

[0073] [Table 2]

[0074] The verification results from Comparative Examples 1 to 4, and Examples 1 and 2, showed that drying can be performed while suppressing the effect of liquid temperature by using reduced pressure and centrifugal force in combination. In particular, when the liquid temperature was 15 degrees Celsius, drying using reduced pressure alone resulted in a low drying effect, but drying using centrifugal force in combination improved the drying effect. Furthermore, the verification results from Comparative Examples 1 to 4, and Examples 1 and 2 showed that using reduced pressure and centrifugal force in combination suppressed the temperature drop more effectively than when drying using reduced pressure alone.

[0075] In centrifugal vacuum dryer 1, the temperature change, the amount of water removed, and the amount of remaining water were investigated for the workpieces 200 in Examples 3 to 18 shown in Table 3 below. In Examples 7 to 9, the workpieces 200 used in this experiment were submerged in water and not drained. In Examples 10 to 18, the workpieces 200 used in this experiment were submerged in water and lightly drained. The amount of water contained in the workpieces 200 was measured by comparing the weight of the workpiece 200 before water absorption with the weight after water absorption. In this comparative experiment, drying was performed at a room temperature of 15 degrees Celsius, while varying the rotation speed of the base 30.

[0076] [Table 3]

[0077] The verification results of the verification experiments in Examples 3 to 18 described above are shown in Table 4 below.

[0078] [Table 4]

[0079] The verification results from Examples 3 to 18 showed that by using reduced pressure and centrifugal force in combination, the liquid could be dried almost completely when the liquid temperature was 60 degrees Celsius and lightly drained. Furthermore, the verification results from Examples 3 to 18 showed that when the liquid temperature was 15 degrees Celsius, the rotation speed of the base 30 had a large impact on the drying effect, but when the liquid temperature was 60 degrees Celsius, the rotation speed of the base 30 had a small impact on the drying effect.

[0080] In centrifugal vacuum dryer 1, the temperature change, the amount of water removed, and the amount of remaining water were investigated for the workpieces 200 in Examples 19 to 28 shown in Table 5 below. In Examples 19 to 23, the workpieces 200 used in this experiment were submerged in water and not drained. In Examples 24 to 28, the workpieces 200 used in this experiment were submerged in water and lightly drained. The amount of water contained in the workpiece 200 was measured by comparing the weight of the workpiece 200 before water absorption with the weight after water absorption. In this comparative experiment, drying was performed at a room temperature of 15 degrees Celsius, with varying drying times.

[0081] [Table 5]

[0082] The verification results of the verification experiments for Examples 19 to 28 described above are shown in Table 6 below.

[0083] [Table 6]

[0084] The verification results from Examples 19 to 28 showed that by using reduced pressure and centrifugal force in combination, drying is possible even at a low liquid temperature of 20 degrees Celsius by extending the drying time. Furthermore, the verification results from Examples 19 to 28 showed that even at a low liquid temperature of 20 degrees Celsius, complete drying can be achieved in a short time of about 1 minute if the liquid has been lightly drained.

[0085] It was shown that the centrifugal vacuum dryer 1 can achieve a higher drying effect than a dryer using only reduced pressure. Furthermore, it was shown that the centrifugal vacuum dryer 1 can suppress the temperature drop of the workpiece 200 more effectively than a dryer using only reduced pressure. Moreover, because the centrifugal vacuum dryer 1 can suppress the temperature drop of the workpiece 200 more effectively than a dryer using only reduced pressure, it was shown that long-term drying is possible.

[0086] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above.

[0087] In the above embodiment, as shown in Figures 5 and 6, the bottom portion 20 according to this embodiment is equipped with a sealing material 23. However, the bottom portion 20 is not limited to this and does not need to be equipped with a sealing material 23.

[0088] In the above embodiment, as shown in Figures 6 and 7, the exhaust port 22 according to this embodiment is formed in the bottom portion 20. However, the exhaust port 22 may also be provided in the capsule 40.

[0089] The present invention can be implemented in various forms and modified without departing from the broad spirit and scope of the invention. The embodiments described above are for illustrative purposes only and do not limit the scope of the invention. [Explanation of Symbols]

[0090] 1 Centrifugal vacuum dryer, 10 Housing, 11 Touch panel, 12 Vacuum pressure gauge, 13 Cylindrical section, 20 Bottom section, 21 Bottom body (bottom section), 21a Center section, 21b End section, 22 Exhaust port, 23 Sealing material, 25 Drain hole, 30 Base, 30a Circular hole, 31 Workpiece holder, 32 Workpiece guide, 32a Upper guide member, 32b Circular support column, 33 Rotating shaft, 33a Motor, 33b Bearing, 40 Capsule, 41 Capsule body, 42 Flange section, 43 Viewing window, 44 Support column, 45 Top plate, 60 Lifting mechanism, 61 Lifting guide, 62 Cylinder, 63 Rod, 70 Piping chamber, 71 First piping, 72 Air control mechanism, 72a Vacuum release valve, 72b Drain box, 73 Second piping, 74 water pipe, 80 vacuum pump, 100 control unit, 101 filter regulator, 102 solenoid valve, 103 silencer, 104 speed controller, 105 residual pressure exhaust valve, 106 vacuum pressure sensor, 200 workpiece (water-washed object), S1 internal space

Claims

1. A centrifugal vacuum dryer for drying objects that have been washed with water, A vacuum drying chamber having a bottom that is lower at the ends than in the center, with drainage holes formed at the ends, A rotatable base provided in the central part on which the washed object is placed, A vacuum pump for drawing in air from inside the vacuum drying chamber, A centrifugal vacuum dryer equipped with the following features.

2. An exhaust port is formed between the central portion and the end portion. The centrifugal vacuum dryer according to claim 1, wherein the vacuum pump draws in air from inside the reduced-pressure drying chamber through the exhaust port.

3. The centrifugal vacuum dryer according to claim 1, wherein the object to be washed is a metal processed part.

4. The centrifugal vacuum dryer according to claim 1, wherein the bottom portion has an inclined surface that slopes downward from the central portion toward the end portion.

5. The vacuum drying chamber has a drying chamber container fitted to the bottom, The centrifugal vacuum dryer according to claim 1, further comprising a lifting mechanism capable of raising and lowering the drying chamber container.

6. The centrifugal vacuum dryer according to claim 5, wherein the top surface of the drying chamber container is curved.

7. A rotating shaft that penetrates the bottom and is attached to the base, A motor is provided outside the vacuum drying chamber to rotate the rotating shaft, Equipped with, The centrifugal vacuum dryer according to claim 1, wherein the base rotates on the rotation axis.

8. A drying method using a centrifugal vacuum dryer according to any one of claims 1 to 7, The vacuum pump is used to draw air from inside the reduced-pressure drying chamber, and the base is rotated to remove moisture adhering to the washed object by centrifugal force. A drying method comprising directing the expelled moisture toward the end and discharging it through the drain hole.

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