JPH10160346A - Dryer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of station of stain on a surface of material to be dried by shortening a drying time. SOLUTION: A spiral drying passage 4 is fixed in a drying tank 1, and an upper opening is substantially sealed by a disc-like cover 2. An upper end of the passage 4 is projected out of the tank 1 via a material-to-be-dried exhaust port 8 at an upper part of the tank 1. A material-to-be-dried inlet 6 in which material to be dried is introduced in a lower part of the tank 1 to communicate with the passage 4. A hot air introducing tube 15 is connected to a hot air inlet 3 to introduce the dried hot air from a hot air generator 5 into the tank 1. The tank 1 is vibrated in a circumferential direction and vertical direction by an exciter 7, and the material is rolled on the passage 4. Most of moisture, amount adhered to the material is mainly removed by the vibration in this process. Since the direction of conveying the material is reverse to that of passing the hot air, and relative speed of the hot air to the material can be accelerated. Thus, the material can be extremely rapidly dried by composite operation of the both.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drying apparatus for drying a liquid such as water adhered to the surface of an object to be dried.

[0002]

2. Description of the Related Art In general, a substance (hereinafter referred to as dirt) which hinders the intrinsic properties and performance of an object is attached to the surface of the object made of a material such as metal, plastic, ceramic or the like. In order to ensure the properties and performance of the above, these stains are removed using a liquid such as water (usually, such a treatment is called washing). When the cleaning with such a liquid is performed, the liquid used for the cleaning adheres to the surface of the object, and thus, such a liquid is conventionally dried to clean the surface of the object. For this purpose, a drying apparatus is used.

Conventionally, the most widely used drying apparatus includes a centrifugal dewatering hot air drying (hereinafter referred to as centrifugal drying) type. In this method, an object to be dried is placed in a basket in a centrifugal dryer, and the basket is rotated at a high speed to shake off (dehydrate) the adhered liquid and simultaneously send hot air to dry. When this technique is used, since the drying is performed using both the dewatering action and the hot air action, there is an advantage that the drying time can be relatively shortened and the energy required for the drying can be reduced. However, this conventional apparatus has a drawback that the object to be dried is likely to be deformed because the object to be dried jumps before sufficient centrifugal force is applied, and the objects to be dried collide with each other or collides in the basket. I have. In addition, since the drying basket is cylindrical to take out the material to be dried from the drying basket, a special take-out device is required to take out the material to be dried without flawing it, and the whole device becomes complicated. there were.

[0004] As another conventional apparatus which compensates for the drawbacks of the conventional apparatus of the centrifugal drying method, an object to be dried is placed on a net-shaped transporting conveyor, and the conveyor is passed through a heating tunnel. In this conventional apparatus, after the material to be dried is drained by a net, it is heated and dried in a heating tunnel. In this case, there is an advantage that the object to be dried is not deformed due to the collision between the objects to be dried and the inner surface of the car, which is generated in the conventional apparatus of the centrifugal drying method. However, in this conventional device,
Since there is only a draining action by gravity on the net, most of the liquid attached to the object to be dried at the time of cleaning must be evaporated and dried in the heating tunnel, which requires a large amount of heating energy and a long drying time. . For this reason, the equipment becomes long, and when the object to be dried is a metal member (particularly remarkable for an iron member), a liquid (for example,
Since the heating is carried out for a long time in a state where water is attached, there is a disadvantage that the risk of rust generation increases.

[0005] Further, as is common to any of the above-described conventional apparatuses, there are many cases where the objects to be dried are dried in an overlapping state at the time of drying. Liquid is very likely to remain until the end. Therefore, the residue after drying the liquid (scale in the case of water) tends to accumulate in the overlapped portions of the objects to be dried. However, there is a serious disadvantage that only washing remains and reliable washing and drying cannot be performed.

[0006]

As described above, in the conventional drying apparatus, the batch processing requires a long time for the drying process, and the drying time required for one drying is reduced if the drying time is shortened. Things are likely to deform,
In order to prevent this deformation, there is a contradictory problem that the drying time is prolonged. In addition, no matter which drying method is adopted, the stains generated in the overlapping portions of the objects to be dried which are dried in an overlapping state are caused. There was a problem that it could not be prevented.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a drying apparatus capable of shortening a drying time and preventing occurrence of a stain on a surface of an object to be dried.

[0008]

In order to achieve the above object, a first aspect of the present invention is to provide a drying tank comprising a hollow body having a vertically-circular center line and having a substantially circular cross-section and having a substantially closed center.
A hot air inlet provided at the top of the drying tank, a spirally formed drying path along the inner peripheral surface of the drying tank, a hot air generator for blowing hot air from the hot air inlet into the drying path, and drying. An object to be dried which is provided below the hot air inlet of the tank and into which an object to be dried is charged, and an object to be dried which is input from the object to be dried are conveyed in an ascending direction on a drying path. Vibrator that applies vertical and circumferential vibrations to the drying tank, and the material to be dried that is provided at the top of the drying tank and conveyed through the drying path is discharged out of the drying tank. It is equipped with a material discharge port, and the material to be dried is put in from the lower part of the drying tank and discharged from the upper part, and hot air is introduced from the upper part of the drying tank, so that the liquid on the surface is dried. The adhered liquid is gradually removed by rolling the material at the bottom of the drying tank, After removing the liquid adhering to the surface to some extent, exposed to the upper portion of the hot hot air drying tank can be completely dry the material to be dried. As a result, the object to be dried can be completely dried with a relatively small amount of heat, and the amount of energy required to generate hot air can be reduced. Moreover, since the liquid on the surface of the object to be dried is removed to some extent by vibration and then dried at a high temperature, there is almost no possibility that a stain remains on the surface of the object to be dried as compared with a case where the liquid is dried at a high temperature with water droplets remaining. . Further, since the object to be dried is conveyed in one direction and dried, the drying process can be performed continuously, and the time required for the drying process can be reduced as compared with the conventional batch process.

According to a second aspect of the present invention, in the first aspect of the invention, a large number of drain holes are formed at least in the bottom of the drying path at the lower part of the drying tank near the inlet for the material to be dried. Thus, the liquid removed from the object to be dried can be discharged from the drain hole to the outside of the drying path. Claim 3
The invention of claim 2 is characterized in that, in the invention of claim 2, a receiving gutter is formed spirally along the drying path and receives a liquid dropped from the drain hole, and is removed from the object to be dried and removed from the drain hole. The liquid discharged to the outside of the drying path can be prevented from attaching to the object to be dried on the drying path again.

According to a fourth aspect of the present invention, in the first aspect of the present invention, a protrusion protruding upward is provided at an appropriate position on the bottom of the drying path, and the protrusion forms irregularities on the bottom of the drying path. Therefore, the object to be dried can be prevented from slipping on the drying path. According to a fifth aspect of the present invention, in the first aspect of the present invention, a heat insulating material is provided on an outer peripheral surface of the drying tank. Can be raised.

According to a sixth aspect of the present invention, in the first aspect of the present invention, a shield is provided to shield the hot air from the drying path inside the drying tank in the drying tank. It can concentrate and increase the efficiency of drying.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments. The drying apparatus A according to the present invention is used, for example, in a drying step of drying water remaining on the surface of the processing target in the final step of the surface treatment system as shown in FIG. Here, the surface treatment system will be briefly described.

The surface treatment system shown in FIG. 8 has a surface treatment step in the order of degreasing → plating → post-treatment, has a rinsing step for each surface treatment step, and performs post-treatment and rinsing. It has a drying step by the drying device according to the present invention. Therefore, a total of six processing tanks 30a to 30f are provided except for the drying step. The object to be processed is transferred from the processing tanks 30a, 30c, 30e in each surface processing step to the processing tanks 30b, 30d, 30f in the rinsing step by the chute 31. That is, the processing tank 30
The objects to be processed discharged from a, 30c, and 30e are dropped from the chute 31 and received by the chute 32 provided in the processing tanks 30b, 30d, and 30f.
0b, 30d, and 30f. The processing tank 30
The transfer of the object to be processed from b, 30d to the processing tanks 30c, 30e can be performed using a chute without any manual operation, or using a conveyor (not shown). The treatment tanks 30a, 30c, and 30e in each surface treatment step are exhausted through an exhaust duct 33, and the water used in each of the treatment tanks 30b, 30d, and 30f in the rinsing step is
The rinsed water is reprocessed and supplied in the reprocessing device 34.

Hereinafter, embodiments of a drying apparatus according to the present invention will be described in detail with reference to the drawings. Note that the technical concept of the present invention can be applied to a device other than the drying device used in the drying process of the surface treatment system as described above. In the following description of the embodiments, the object to be processed is referred to as an object to be dried. (Embodiment 1) FIG. 1 is a partially cutaway front view showing the present embodiment, and FIG. 2 is a partially cutaway plan view showing a state in which a lid 2 described later is removed.

The drying apparatus A according to the present embodiment includes a drying tank 1 having a vertically-centered center line and a substantially closed hollow body having a circular cross section, a hot air inlet 3 provided at an upper portion of the drying tank 1, and A spirally formed drying path 4 along the inner peripheral surface of the drying tank 1, a hot air generator 5 for blowing hot air from the hot air inlet 3 into the drying path 4, and a hot air inlet 3 of the drying tank 1. The drying object input port 6 is provided below the drying object, and receives the drying object. The drying object input from the drying object input port 6 is conveyed in the ascending direction on the drying path 4. A vibrator 7 for applying vibrations in the vertical and circumferential directions to the drying tank 1, and an object to be dried provided on the drying tank 1 and conveyed through the drying path 4 is discharged out of the drying tank 1. And an outlet 8 for drying the object to be dried.

The drying tank 1 has a bottomed cylindrical shape arranged with its center line in the vertical direction, and has a spiral drying path 4 inside.
Is fixed, and a heat insulating material 10 for preventing internal heat from being released is provided in the outer peripheral portion, and an upper opening is closed by a disk-shaped lid 2 to be substantially sealed. The drying path 4 is a flat floor piece 4 a having one end fixed to the peripheral wall of the drying tank 1.
And the side piece 4b projecting upward from the inner edge of the floor piece 4a are continuously and integrally provided, and a gutter-like path is formed by the peripheral wall of the drying tank 1 and the drying path 4. In addition, the upper end of the drying path 4
It protrudes to the outside of the drying tank 1 through a drying target discharge port 8 opened in the peripheral wall on the upper part of the drying tank 1. Further, as shown in FIG. 3, a large number of substantially rectangular through holes 4c are arranged in two rows in the floor piece 4a, and a wire mesh 9 is laid thereon. An object to be dried (not shown) is conveyed on a gutter-like path by being placed on the floor piece 4a (wire mesh 9).

In the lower part of the drying tank 1, an object to be dried 6 is opened which communicates with the lower end of the drying path 4 and into which the object to be dried is introduced. Further, a funnel-shaped chute 14 penetrates and is attached to the material-to-be-dried inlet 6, so that the material to be dried is easily introduced into the material-to-be-dried inlet 6. The lower end of the drying path 4 below the material to be dried 6 is connected to the floor piece 4.
The end of the wire mesh 9 laid on a is closed by welding.

A vibrating table 11 of a vibrator 7 is provided on a lower surface of the drying tank 1.
Are joined together. The vibration oscillating table 11 is placed on the mounting table 13 via the vibration proof spring 12, and the vibration of the vibration oscillating table 11 is attenuated by the vibration proof spring 12 and is hardly transmitted to the mounting table 13. That is, the vibration transmitted to the floor on which the mounting table 12 is placed is reduced. A vibration motor 17 having a flat plate shape is attached to the excitation table 11. The vibration motor 17 is configured such that a weight is eccentrically attached to a rotation shaft of the motor 17a, and the motor 17a and the weight are housed in a motor housing. Therefore, the motor housing vibrates in a plane substantially perpendicular to the rotation axis of the motor 17a with the rotation of the motor 17a. The drying tank 1 is vibrated vertically and circumferentially with the operation of the vibration motor 17 by being attached to the vibration table 11 such that the rotation axis of the vibration motor 17 is inclined with respect to the vertical direction. Becomes possible. That is, the vibration motor 17
By adjusting the inclination of the vibration motor 17, the vibration component in the circumferential direction of the drying tank 1 increases as the rotation axis of the vibration motor 17 approaches the vertical direction, and the vertical axis of the drying tank 1 increases as the rotation axis of the vibration motor 17 approaches the horizontal direction. The vibration component in the direction increases. Therefore, if the inclination of the vibration motor 17 with respect to the vibration table 11 is adjusted, the vibration component of the drying tank 1 can be appropriately set.

As described above, when the drying tank 1 is vibrated in the vertical and circumferential directions by the vibration motor 17, the drying path 4
The object to be dried placed on the surface moves along the drying path 4. Whether the object to be dried moves clockwise or counterclockwise as viewed from above on the drying path 4 depends on whether the rotation axis of the vibration motor 17 is inclined left or right with respect to the vertical direction. Further, by adjusting the tilt angle, it is possible to adjust the moving speed of the object to be dried.

A hot air introduction pipe 15 is connected to the hot air introduction port 3 provided at the upper part of the drying tank 1, and dried hot air from the hot air generator 5 is introduced into the drying tank 1 through the hot air introduction pipe 15. Is done. Here, since the sheet-like shielding body 16 having heat resistance is attached to the side piece 4 b of the drying path 4, the hot air introduced from the hot air inlet 3 is not diffused along the drying path 4. It can be passed down.

Next, the operation of the drying apparatus A of the present embodiment will be described. First, the object to be dried having water droplets adhered thereto after being washed is put into the object to be dried 6 through the chute 14 and sent to the lower end of the drying path 4. Since the drying tank 1 is vibrated in the circumferential direction and the vertical direction by the vibrator 7, a large number of objects to be dried placed on the drying path 4 are fixed to the drying path 4. Rolling on the top,
At this time, since there are a large number of objects to be dried on the drying path 4, the objects to be dried on the drying path 4 are individually and sequentially rolled upward in a spiral having no objects to be dried. Here, the floor piece 4a of the drying path 4
Is provided with a through hole 4c and a wire mesh 9 is laid thereon, so that the material to be dried rises while being rolled on the wire mesh 9, and in this process, the amount of water adhering to the material to be dried is reduced. Most (depending on the shape of the object to be dried, but usually about two-thirds) is removed from the surface of the object to be dried by vibrating and hot air (mainly vibration). Moreover, since the wire mesh 9 is laid at the bottom of the drying path 4, the contact area between the bottom of the drying path 4 and the object to be dried is reduced,
Drying can be performed efficiently. The removed water is dropped downward through the mesh of the wire mesh 9 and the through holes 4c of the floor piece 4a.

In the drying path 4, the material to be dried rolls by the draining action of the through hole 4 c provided in the floor piece 4 a and the wire mesh 9 laid thereon, and the vibration of the vibrator 7. That it can take sufficient contact with hot air,
Further, since the direction in which the object to be dried is conveyed and the direction in which the hot air passes are opposite, the relative speed of the hot air to the object to be dried can be increased, so that the drying can be performed very rapidly. In addition, since the material to be dried is rolling, there is no occurrence of a stain due to the water accumulated in the overlap between the materials to be dried as in the related art. The completely dried object is conveyed to the top of the drying path 4 and finally discharged out of the drying tank 1 through the object to be dried 8.

FIG. 4 shows the relationship between the surface temperature of the object to be dried and the amount of adhered moisture inside the drying tank 1 and the temperature and humidity of the hot air. That is, the hot air introduced from the hot air inlet 3 has a low humidity and a high temperature because it is dry at first, but increases the surface temperature of the material to be dried while moving down in the drying path 4 and increases the temperature. By removing moisture adhering to the surface of the dried product, the temperature decreases and the humidity increases.
On the other hand, when the material to be dried is put into the drying tank 1 through the material to be dried 6, the surface temperature is low and the humidity is high because moisture is attached. During the ascent while moving, the water adhering to the surface is gradually removed by the draining action and the hot air, so that the surface temperature gradually increases and the humidity decreases. As described above, the object to be dried rises in the drying tank 1 from the vicinity of the object inlet 6 having a low temperature and a relatively high humidity while rolling and being sequentially exposed to an environment in which the object is easily dried. In addition, there is no waste of energy spent for drying, the drying speed can be increased, and efficient drying can be performed.

(Embodiment 2) FIG. 5 is a partially cutaway front view showing the present embodiment. Since the basic configuration of the present embodiment is the same as that of the first embodiment, common portions are denoted by the same reference numerals, and description thereof will be omitted. Only the features that are characteristic of the present embodiment will be described. In the present embodiment,
A number of drain holes 4f are provided at appropriate places on the floor piece 4a of the drying path 4, and a receiving trough 18 spirally formed along the drying path 4 is provided below the drying path 4. That is, the drying path 4 of the present embodiment has a double floor, and receives the water dropped from the drain hole 4f and sends it downward as shown in FIG. A drain 19 is provided in the vicinity of the lower end of the receiving gutter 18 so that water dropped and collected on the receiving gutter 18 is discharged to the outside of the drying tank 1.

According to the above configuration, the provision of the receiving gutter 18 below the drying path 4 prevents the water dropped from the drain hole 4f from re-adhering to the material to be dried on the lower drying path 4. In addition to the above, there is an advantage that it is possible to avoid that the humidity inside the drying tank 1 rises and the drying time is lengthened by discharging the removed water to the outside of the drying tank 1.

As shown in FIG. 7, the floor of the drying path 4 may be formed into a shape having a large number of irregularities on the surface by using a punching metal made of stainless steel or the like. Drain holes 4e are formed in concave portions 4e surrounded by such convex portions (projections) 4d.
f, the slippage of the object to be dried is suppressed by the convex portion 4d, and the contact area between the object to be dried and the floor of the drying path 4 is reduced, so that the contact area between the object to be dried and the hot air is reduced. Has the advantage that it can be more efficiently spread and dried.

[0027]

According to the first aspect of the present invention, there is provided a drying tank comprising a hollow body having a vertical center line and having a substantially circular cross-section and having a substantially circular cross section, a hot air inlet provided at an upper portion of the drying tank, and a drying tank. A drying path formed in a spiral shape along the inner peripheral surface of the hot air generator that blows hot air into the drying path from a hot air inlet;
An object to be dried which is provided below the hot air inlet of the drying tank and into which an object to be dried is charged, and an object to be dried which is input from the object to be dried, are conveyed in an ascending direction on a drying path. And a vibrator that vibrates the drying tank in the vertical and circumferential directions so that the object to be dried provided above the drying tank and conveyed through the drying path is discharged out of the drying tank. A drying material discharge port is provided, so that the material to be dried is put in from the lower part of the drying tank and discharged from the upper part. The liquid adhering to the surface of the object to be dried is gradually removed by tumbling the lower part of the drying tank, and the liquid adhering to the surface of the object to be dried is removed to some extent. It can be completely dried and, as a result, The object can be completely dried, the amount of energy required to generate hot air can be reduced, and the liquid on the surface of the object to be dried is removed to some extent by vibration and then dried at a high temperature. There is almost no possibility that stains will remain on the surface of the object to be dried as compared with the case of drying at a high temperature in a state where the object is dried, and furthermore, since the object to be dried is transported in one direction and dried, the drying process is continuously performed. Thus, there is an effect that the time required for the drying process can be reduced as compared with the conventional batch process.

According to the second aspect of the present invention, since a large number of drain holes are formed at the bottom of the drying path at least in the lower part of the drying tank near the inlet for the material to be dried, the liquid removed from the material to be dried by rolling can be removed. The water can be discharged from the drain hole to the outside of the drying path, and there is an effect that the drying efficiency can be improved. The invention according to claim 3 is provided with a receiving gutter spirally formed along the drying path and receiving the liquid dropped from the drain hole, so that it is removed from the object to be dried and discharged from the drain hole to the outside of the drying path. There is an effect that it is possible to prevent the liquid that has adhered to the object to be dried on the drying path again.

According to the fourth aspect of the present invention, since the protrusion is provided at an appropriate position at the bottom of the drying path, the protrusion forms irregularities on the bottom of the drying path, so that the object to be dried with respect to the drying path is formed. There is an effect that slip can be prevented. According to the fifth aspect of the present invention, since the heat insulating material is provided on the outer peripheral surface of the drying tank, it is possible to prevent the high temperature caused by the hot air from escaping from the wall surface of the drying tank to the outside, thereby improving the drying efficiency.

According to the sixth aspect of the present invention, since the shield for shielding the hot air is provided inside the drying path in the drying tank, the hot air can be concentrated on the drying path by the shielding to increase the drying efficiency. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a partially broken front view showing a first embodiment.

FIG. 2 is a plan view showing a state in which the lid is removed.

FIGS. 3A and 3B show a drying path in the above, wherein FIG. 3A is a plan view partially omitted, and FIG. 3B is a side sectional view.

FIG. 4 is an explanatory diagram for explaining the operation of the above.

FIG. 5 is a partially broken front view showing the second embodiment.

FIG. 6 is a sectional view showing a main part of the above.

FIG. 7 shows another configuration of the drying path in the same embodiment, and (a)
Is a plan view partially omitted, and (b) is a side sectional view.

FIG. 8 is a system configuration diagram showing a surface treatment system in which the drying device according to the present invention is used.

[Explanation of symbols]

 Reference Signs List A Drying device 1 Drying tank 2 Lid 3 Hot air inlet 4 Drying path 5 Hot air generator 6 Dry material input port 7 Vibrator 8 Dry material discharge port

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 9, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

A vibrating table 11 of a vibrator 7 is provided on a lower surface of the drying tank 1.
Are joined together. The vibration oscillating table 11 is placed on the mounting table 13 via the vibration proof spring 12, and the vibration of the vibration oscillating table 11 is attenuated by the vibration proof spring 12 and is hardly transmitted to the mounting table 13. That is, the vibration transmitted to the floor on which the mounting table 12 is placed is reduced. The shaker table 11
Vibration motor 17 is mounted. This vibration motor 17
Is obtained by accommodating the motor and the weight of the motor housing is attached by decentering the weight to the rotary shaft of the motor. Accordingly, the motor housing will vibrate in a plane substantially perpendicular to the axis of rotation of the motor with the rotation of the motor. The drying tank 1 is vibrated vertically and circumferentially with the operation of the vibration motor 17 by being attached to the vibration table 11 such that the rotation axis of the vibration motor 17 is inclined with respect to the vertical direction. Becomes possible. In other words, by adjusting the inclination of the vibration motor 17, the vibration component in the circumferential direction of the drying tank 1 increases as the rotation axis of the vibration motor 17 is closer to the vertical direction, and as the rotation axis of the vibration motor 17 is closer to the horizontal direction. The vertical vibration component of the drying tank 1 increases. Therefore, if the inclination of the vibration motor 17 with respect to the vibration table 11 is adjusted, the vibration component of the drying tank 1 can be appropriately set.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

[Procedure amendment 3]

[Document name to be amended] Drawing

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

FIG. 5

Continuation of front page (72) Inventor Yasuo Miyake 1048 Odakadoma, Kadoma-shi, Osaka Matsushita Electric Works, Ltd.

Claims (6)

[Claims] 1. A drying tank comprising a hollow body having a vertical center line and a substantially circular cross section having a substantially circular shape, a hot air inlet provided at an upper portion of the drying tank, and a spiral along an inner peripheral surface of the drying tank. Drying path formed in a shape, a hot air generator for blowing hot air from the hot air inlet into the drying path, and a material to be dried which is provided below the hot air inlet of the drying tank and into which the material to be dried is introduced. An input port, a vibrator that applies vertical and circumferential vibrations to the drying tank so that the object to be dried input from the object to be dried is conveyed in an ascending direction on the drying path; A drying device provided at an upper portion of the tub and having a drying material discharge port for discharging a drying material conveyed through a drying path out of the drying tub. 2. The drying apparatus according to claim 1, wherein a plurality of drain holes are formed at the bottom of the drying path at least in the lower part of the drying tank close to the material inlet. 3. The drying device according to claim 2, further comprising a receiving gutter formed spirally along the drying path and receiving a liquid dropped from the drain hole. 4. The drying apparatus according to claim 1, further comprising a protrusion protruding upward at an appropriate position on the bottom of the drying path. 5. The drying apparatus according to claim 1, wherein a heat insulating material is provided on an outer peripheral surface of the drying tank. 6. The drying apparatus according to claim 1, further comprising a shielding member for shielding hot air from a drying path in the drying tank.