JP2000320961A - Drying machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drying machine capable of drying efficiently matters to be dried, such as tea leaves, vegetable leaves, granular grains, sliced vegetables or fruits and the like, within a short period of time, and capable of drying easily the matters to be dried to the cores of them, without generating any crack or the like on the surface of the same. SOLUTION: An annular opening 13 is formed at the lower end of a hopper type vessel 10 constituted of an upper cylindrical part 11 and a lower conical part 12 while the upper end thereof is opened, and hot air is blown upwardly through the opening 13 to form the stream of hot air blown upward along the inner wall surface of the vessel 10. A low-pressure condition is produced in the central part of the vessel 10, whereby matters to be dried P, such as tea leaves, vegetable leaves, granular grains, sliced vegetables or fruits and the like which are charged into the vessel, are heated and dried while being circulated and levitated in the vessel by the upward hot air and the low pressure condition in the central part of the vessel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dryer for drying tea leaves, rape leaves, granular cereals, sliced vegetables, fruits and the like by hot air.

[0002]

2. Description of the Related Art Conventionally, a dryer for drying tea leaves, rape leaves, granular cereals, sliced vegetables, fruits, and the like by hot air is configured to blow hot air from a side of a container containing a material to be dried. I was

[0003]

However, in this type of conventional dryer, only the hot air blown from the side is used for drying, so that only the heat of the hot air is used for drying. There is a technical problem that the efficiency is low, it takes time for drying, and it is difficult to sufficiently dry the material to be dried without causing surface cracks up to the center.

[0004] The present invention has been made in view of such technical problems, and an object of the present invention is to enable the object to be dried to be dried efficiently and in a short time, and to form a crack or the like on the surface of the object to be dried. It is an object of the present invention to provide a dryer capable of easily drying up to the center without causing the drying.

[0005]

In order to achieve the above object, a dryer according to the present invention (Claim 1) has a cylindrical portion having a vertical axis and a cone whose diameter is reduced downward from the lower end of the cylindrical portion. Forming an annular opening at the lower end of a hopper-shaped container having an open top and having a portion, and blowing hot air upward through the annular opening to form hot air that blows upward along the inner wall surface of the container. , Tea leaves placed in the container,
It is characterized in that dried objects such as rape leaves, granular grains, sliced vegetables and fruits are dried while being floated by the hot air.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, far-infrared radiation that emits far-infrared rays toward the center of the container when heated on the inner wall surface of the container. Means for opening the opening when hot air is blown into the annular opening, and providing an opening / closing mechanism for closing the opening when the blowing of hot air is stopped. A communication hole for injecting hot air into the container, an opening / closing mechanism for opening the communication hole when hot air is blown, and closing the communication hole when hot air blowing is stopped; A configuration in which a spraying means for spraying water is provided, a configuration in which temperature adjusting means for adjusting the temperature of hot air blown from the annular opening is formed, and a pressure difference is generated from the inner wall surface of the container toward the center. The above-described configuration is more efficiently achieved by adopting a configuration in which the inside of the container is depressurized or a configuration in which a perforated member such as a net or a punch plate is attached to the upper end opening of the hopper-shaped container. The purpose is achieved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing one embodiment of a dryer to which the present invention is applied, and FIG. 2 is a schematic vertical sectional view showing the inside of a container of the dryer of FIG. 1 and 2, a container 10 in which a material P to be dried, such as tea leaves, rape leaves or granular cereals, is placed has a cylindrical portion 11 having a vertical axis and a cone whose diameter is reduced downward from the lower end of the cylindrical portion. And a hopper-shaped container having an upper end and an open end.

An opening 13 for introducing hot air as an upward airflow is formed at the lower end surface of the container 10, that is, at the lower end surface of the conical portion 12. This opening 13
As shown in FIG. 2, by fixing a circular boss 14 to the center of a concentric circular opening formed at the lower end surface of the conical portion 12, an annular opening formed around the boss 14 is formed. It is formed as. The boss 14 is
A plurality (for example, 3 to 6) of ribs 1 provided radially
It is provided in a state of being connected to the container 10 by 5.

In FIG. 1 and FIG.
A blower 17 is connected to 3 via a duct 16. In the illustrated example, a heater 18 is provided in the middle of the duct 16, and the heater 1 is provided by the heater.
6 is configured to heat the air flowing through the inside to a predetermined temperature. In this way, hot air is generated by the blower 17 and the heater 18, and the hot air is
It is configured to blow upward into the container 10 through 3. In the illustrated embodiment, the case where the upper end of the hopper-shaped container 10 is completely open is shown. However, if necessary, a desired mesh size is formed on the upper end surface (upper end open portion). It may be an upper end open portion of a structure in which a perforated member such as a net or a punch plate having
With such an open portion structure, it is possible to reliably prevent a part of the object to be dried from being released to the outside when performing a drying process of the object to be dried P as described later.

The hot air blown into the container 10 from the annular opening 13 is blown upward along the inner wall surface of the container, as shown by a dashed arrow in FIG. The hot air that is blown up, that is, the hot air that is formed so as to blow up along the inner wall surface of the conical portion 12, causes the tea leaves, rape leaves, granular cereals, sliced vegetables and fruits, etc. put in the container 10. The object P to be dried is dried while being circulated and circulated in hot air as schematically shown by a solid line in FIG. As for the hot air that blows upward along the inner wall surface of the container and floats the object P to be dried, the inner wall surface of the container and its peripheral edge generate stronger hot air than the center of the container. The pressure becomes higher, and the force for pushing up the object to be dried P increases.

That is, the hot air blown into the container 10 is first blown up along an inverted conical surface, then blown up along a cylindrical surface having a maximum inner diameter, as indicated by a dashed arrow, and the upper part of the container 10 is opened. Container 1
The pressure distribution is such that the pressure is high at the peripheral portion inside 0 and the pressure is low at the center portion. Usually, the material to be dried P is blown up at the peripheral portion of the container as indicated by a solid arrow.
Due to such a pressure distribution, the object to be dried P, which has risen, gathers in the central part having a low pressure at the upper part of the container, as shown by the solid line arrow, falls again to the lower part of the container at the central part, and falls under the low pressure while falling. Promotes drying. The falling object P moves again to the container periphery as shown by the solid arrow, and is blown up. Depending on the pressure distribution due to the wind pressure, the distribution of the material P to be dried and the flow of the hot air in the container 10 are made uniform, and the inside of the container 10 is in the same state as when the pressure is reduced. Drying is promoted, and efficient hot air drying is performed. For example, when the flow rate of the hot air was 5 m / sec, a pressure difference of about 1.6 mmH ₂ O was measured between the central part and the peripheral part.

The inner wall surface of the container 10 (part of the inner wall surface of the cylindrical portion 11 and part of the inner wall surface of the conical portion 12 in the illustrated example)
Is provided with far-infrared radiation means 21 which emits far-infrared rays toward the center of the container 10 when heated. The far-infrared ray radiating means 21 is formed of a material that emits far-infrared rays when heated, such as ceramic or metal, and is heated by a not-shown energizing wiring or a separately provided heater. It is configured.
The far-infrared ray radiating means 21 is for heating the object P to be dried in the container 10 from the center thereof together with the hot air to promote the drying thereof.

In FIG. 2, the annular opening 13 is configured to be opened when hot air is blown, and to be closed when the blowing of hot air is stopped. In the example shown in the figure, the opening 13 is opened when hot air is blown in automatically by using the dynamic pressure of hot air by a flap-type check valve type opening / closing mechanism 22 pivotally supported by the boss portion 14. When the blowing of hot air is stopped, the opening 13
It is configured to close. The opening 13 may have a configuration in which the size (opening area) can be adjusted manually or the like. The opening / closing mechanism 22 promotes drying while floating the object to be dried P when hot air is blown, and the object to be dried P drops when the hot air is not blown and clogs the opening 13. This is to prevent intrusion into.

In FIG. 2, a communication hole 3 for communicating between the inside of the duct 16 and the inside of the container 10 is formed at the center of the boss portion 14.
A flap-type check valve type opening / closing mechanism 30 that is opened by upward hot air is provided at the opening of the communication hole 31 (in the illustrated example, the opening on the container 10 side). . That is, a communication hole 31 for blowing upward hot air is provided at the concentric center portion of the annular opening 13, and the communication hole 31 is opened when hot air is blown into the communication hole 31, and when the blowing of hot air is stopped. An opening / closing mechanism 30 configured to close the communication hole 31 is provided. When the hot air is blown, the opening / closing mechanism 30
By blowing up the object P to be dropped at the center (low-pressure part) of the container 10 and pushing it up with hot air, drying is promoted while keeping the object P in a floating state as much as possible. This is for preventing the object to be dried P from dropping and clogging the communication hole 31 or entering the duct 16 through the communication hole 31. The communication hole 31 may not only be automatically opened as described above, but also may be configured such that the opening area is adjusted by operating the opening / closing mechanism 30 manually or the like so that the air volume and the air velocity can be adjusted. .

In FIG. 1 and FIG. 2, the container 10 has a side surface and an upper portion (in the illustrated example, a cylindrical portion 1).
Spraying means 23 capable of spraying moisture from the inside of the container 10 to the inside of the container 10 is connected. In the example shown in the figure, the spraying means 23 pumps water pumped from a water tank 24 through a tube 27 by a pump 25.
By the opening and closing operation of the switching valves 28A and 28B, the nozzle 26 connected to the side surface of the container 10 and the plurality of tips of the tube 27B arranged at the upper portion of the container 10 pass through one (or both) of the branch tubes 27A and 27B. Is sprayed into the inside of the container 10 from any one (both in some cases) of the spray ports 29 of the above. In this case, when spraying only from the upper part of the container 10, the valve 28A leading to the nozzle 26 on the side face may be closed and only the valve 28B to the upper part may be opened. Container 1
In the case of spraying only from the 0 side, only the valve 28A on the side needs to be opened. Alternatively, the valve 28A and the valve 28B may be simultaneously opened to spray water from both.

The spraying means 23 imparts moisture to the outer surface of the object P to soften the surface so that moisture and the like inside can easily go to the outside. Is heated from the inside to prevent surface cracks of the object P to be dried. That is, if the surface of the object to be dried P is dried before the inside, the surface is solidified and it becomes difficult for moisture and the like to come out. For this reason, the moisture and the like are forced to come out and cracks and the like are caused on the outside. The spraying means 23 softens the surface of the object P to be dried to make it easy for moisture or the like inside to go out, or heats the object P to be dried first by far infrared rays. By making it easy, it is for preventing the surface crack etc. of the to-be-dried material P as needed.

The amount and speed of the hot air blown from the opening 13 can be adjusted by adjusting the size and the number of rotations of the blower 17 in order to efficiently dry the object to be dried P efficiently.
The opening degree of the opening / closing mechanism 22 (the opening area of the opening 13) may be appropriately adjusted by adjusting the opening degree automatically or manually. The opening 1
The opening area of 3 itself may be adjusted manually or the like. On the other hand, the amount and speed of the hot air blown from the communication hole 31 also adjust the opening degree of the opening and closing mechanism 22 manually or automatically, or adjust the cross-sectional area of the communication hole 31 itself,
Adjustment may be made as appropriate. The communication hole 3
1 may be kept closed even when hot air is blown from the opening 31. Further, the angle (opening) position of the flap constituting the opening / closing mechanism 22 may be manually held at a predetermined position.

Further, the dryer shown in FIGS. 1 and 2 includes:
Temperature control means (not shown) for controlling the temperature of hot air blown into the container 10 from the annular opening 13 is provided. This temperature adjusting means can be constituted by, for example, a current control means for adjusting a driving current in order to adjust an amount of heat generated by the heater 18. The temperature adjusting means is for adjusting the drying time of the material P to be dried, and includes, for example, an appropriate drying speed according to the type of the material P to be dried, an initial drying degree, and a spray amount from the spraying means 23. Is set according to the contents of the drying process.

According to the embodiment described above, the following operation and effect can be obtained. First, since the hot air is blown into the drying container 10 upward from the lower portion, the amount of the hot air, the speed of the hot air, the temperature of the hot air, and the like can be easily determined according to the type, weight, amount, and the like of the object P to be dried. It can be adjusted, and even large or heavy items can be floated and dried efficiently. Second, the hot air blown into the container 10 from the annular opening 13 is first blown up along the inverted conical surface, then blown up along the cylindrical surface having the largest inner diameter, and since the upper part is open, the surrounding air is blown. Since the pressure at the center is smaller than the pressure at the periphery when the pressure applied to the dried material P and the pressure of the dried material P are pushed up to the upper portion and the pressure becomes equal to the outside, the pressure applied to the dried material P is reduced inside. Therefore, the pressure distribution can be made such that the pressure inside the container 10 is high at the peripheral portion and the pressure is low at the center portion. It is possible to facilitate the movement of the moisture contained in the material to be dried P and the like to the outside, and at the same time, to make the distribution of the hot air flow uniform, thereby realizing highly efficient hot air drying.

Third, since far-infrared rays are radiated toward the center of the container 10, the object to be dried P can be efficiently dried to the inside. Fourth, when the surface of the object P to be dried solidifies, moisture and the like inside the surface of the object P are cracked when they come to the outside, and the surface of the object P goes out of the surface. You can spray water on P,
Even in the case of an object to be dried whose surface has hardened or a dry film has been formed by drying only the outside first and cracks are likely to occur, the outer surface is softened by imparting moisture to the outer surface. By making it easy for moisture or the like to come out to the outside, or by allowing the object to be dried to be heated from the inside by far infrared rays, efficient drying can be performed and surface cracks of the object to be dried can also be prevented. .

Fifth, since a temperature adjusting means (not shown) for adjusting the temperature of the hot air blown into the container 10 is provided, the degree of drying and the drying time of the object P can be adjusted. Sixth, since the hot air is blown by the blower 17, the speed and pressure of the hot air in the container can be easily adjusted, and the above-described depressurizing effect at the center of the container is adjusted according to the type of the material to be dried. Can also. The pressure inside the container 10 can be reduced by giving the hot air blown through the annular opening 13 a left turn, and the container 1
The pressure difference between the depressurized center portion within 0 and the peripheral portion where the wind force is strong (dynamic pressure is high) can be increased.

[0022]

As is apparent from the above description, according to the dryer of the present invention (claim 1), the cylindrical portion having the vertical axis and the conical portion whose diameter is reduced downward from the lower end of the cylindrical portion. Forming an annular opening at the lower end of a hopper-shaped container having an open top and having hot air blown upward along the inner wall surface of the container by blowing hot air upward through the annular opening; Tea leaves, rape leaves placed in the container,
Since the dried material such as granular cereals, sliced vegetables and fruits is dried while being floated by the hot air, the dried material can be efficiently dried in a short time, and the surface of the dried material can be cracked. There is provided a dryer capable of easily drying up to the center without causing drying.

According to the second to eighth aspects of the present invention, in addition to the configuration of the first aspect, a far-infrared ray radiating far-infrared rays toward the center of the container when heated on the inner wall surface of the container. A configuration to provide infrared radiation means, a configuration to provide an opening and closing mechanism to open the opening when hot air is blown into the annular opening, and to close the opening when the blowing of hot air is stopped;
A communication hole for blowing hot air upward is provided at the concentric center portion of the annular opening. A structure having a mechanism, a structure having spray means for spraying moisture into the inside of the container, a structure having temperature adjusting means for adjusting the temperature of hot air blown from the annular opening, and a central portion from the inner wall surface of the container A pressure difference is generated toward the container, and the same state as when the inside of the container is depressurized is provided, or a perforated member such as a net or a punch plate is attached to an open upper end of the hopper-shaped container. Therefore, the above effects can be more efficiently achieved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of a dryer to which the present invention is applied.

FIG. 2 is a schematic longitudinal sectional view showing the inside of the container in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Container 11 Cylindrical part 12 Conical part 13 Annular opening 14 Boss part 16 Duct 17 Blower 18 Heater 21 Far infrared radiation means 22 Opening / closing mechanism 23 Injecting means 25 Pump 26 Nozzle 27 Tube 28 Switching valve 29 Spray port 30 Opening / closing mechanism 31 Communication hole

Claims (10)

[Claims] An annular opening is formed at a lower end of a hopper-shaped container having an open top having a cylindrical portion having a vertical axis and a conical portion having a diameter reduced downward from a lower end of the cylindrical portion,
By blowing hot air upward through the annular opening to form hot air that blows up along the inner wall surface of the container, tea leaves, rape leaves, granular cereals, sliced vegetables and fruits, etc. put in the container A dryer for drying an object to be dried while floating the object with the hot air. 2. The dryer according to claim 1, further comprising a far-infrared ray radiating means for radiating far-infrared rays toward the center of the vessel when heated, on an inner wall surface of the vessel. 3. The opening and closing mechanism according to claim 1, wherein the opening is opened when hot air is blown into the annular opening, and the opening and closing mechanism is closed when the blowing of hot air is stopped. Dryer. 4. A communication hole for blowing hot air upward is provided at a concentric central portion of said annular opening, said communication hole is opened when hot air is blown into said communication hole, and said communication hole is opened when hot air blowing is stopped. The dryer according to any one of claims 1 to 3, further comprising an opening / closing mechanism for closing the communication hole. 5. The dryer according to claim 1, further comprising a spray unit for spraying moisture into the container. 6. The dryer according to claim 1, further comprising a temperature adjusting unit for adjusting a temperature of the hot air blown from the annular opening. 7. The container according to claim 1, wherein a pressure difference is generated from an inner wall surface of the container toward a central portion, and a state similar to a case where the pressure in the container is reduced is obtained. Dryer. 8. The dryer according to claim 1, wherein a perforated member such as a net or a punch plate is attached to an open upper end of the hopper-shaped container. 9. The dryer according to claim 1, wherein an amount or a velocity of the hot air blown from the annular opening is adjustable. 10. The dryer according to claim 4, wherein, even when hot air is blown upward from the annular opening, the communication hole is kept closed as necessary. .