JP2527648B2 - Microwave dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a microwave dryer.

(B) Conventional Technology Conventionally, a microwave drying device detects a supply amount near a side wall of a drying chamber as disclosed in Japanese Patent Application No. 2-2230 (Japanese Patent Application Laid-Open No. 3-207986). The level detecting means detects the amount of the material to be dried supplied to the drying chamber of the microwave drying device.

(C) Problem to be Solved by the Invention In the conventional example, the stirring member is rotated to smooth the upper surface of the material to be dried supplied into the drying chamber. Since it rotates to the outside, centrifugal force acts on the material to be dried, so that the central portion is dented and the peripheral portion is raised.

Furthermore, if the type of material to be dried changes, the specific gravity also changes, so the degree of denting in the central part also changes, and the way the surrounding parts rise up also changes.

Therefore, when the material to be dried changes, the amount detected by the level detecting means also changes, and there is a risk that the dried state may become uneven depending on the material to be dried.

 The present invention solves this problem.

(D) Means for Solving the Problems The present invention is to stir while smoothing the drying chamber to which the granular or powdery material to be dried is supplied and the upper surface of the material to be dried which is supplied and deposited in the drying chamber. For this purpose, an agitator provided at the bottom of the drying chamber, a level detecting means for detecting whether or not a predetermined amount of the material to be dried is supplied into the drying chamber, and a micro for drying the material to be dried in the drying chamber. A microwave supply unit that supplies a wave, and the level detection unit pushes up a tip of the level detection unit in contact with the object to be dried on the upper surface of the object to be dried as the object to be dried rises. An arm made of a low dielectric loss material, a detection unit for detecting that a predetermined amount of the material to be dried is supplied to the drying chamber when the movement amount of pushing up the arm reaches a predetermined movement amount, and the length of the arm. Adjustable part This is a configuration having

(E) Action When the object to be dried is supplied to the drying chamber, the object to be dried tries to flatten the upper surface of the object to be dried that is agitated by the agitator. At this time, depending on the type of material to be dried, the central part is depressed and the surrounding area rises, but by adjusting the length of the arm with the adjusting part in anticipation of this rise, even if the type is different in the level detection means in the drying chamber A certain amount of supply can be expected.

(F) Embodiment FIG. 1 shows the structure of a microwave drying apparatus according to an embodiment of the present invention. The apparatus comprises a drying apparatus main body 1 and its peripheral mechanism.

The main body of the drying device main body 1 is an upper lid 2 that can be opened and closed
There is provided a cylindrical drying chamber 3 having A supply pipe 4 is connected to the upper left portion of the drying chamber, and the tip of the supply pipe has a storage tank 6 for storing a granular or powdery material 5 to be dried.
It has reached inside. The storage tank 6 is provided for each type of material to be dried, and when changing the material to be dried, the supply pipe 4 is used.
Is replaced with the storage tank 6 in which the material to be dried is stored.
Examples of the material to be dried 5 include resin pellets and chemical powder particles. The resin pellets are molded after being melted, but if the resin pellets are dried prior to such melt molding, the subsequent molding will be performed well. In this embodiment, resin pellets are selected as the material to be dried 5. A suction hopper 7 is connected to the center of the upper lid 2 of the drying chamber 5. A filter wire mesh 8a having a mesh smaller than the material diameter of the material to be dried 5 and a filter paper 8 are arranged in the suction hopper 7, and a poppet valve 9 is provided above the filter paper 8. There is.
In the poppet valve 9, a suction blower 11 is connected to the suction hopper 7 via an intake pipe 10.
In this case, when the blower 11 is driven while the poppet valve 9 is driven to be opened, the intake action of the blower 11 extends to the supply pipe 4 through the intake pipe 10, the suction hopper 7 and the drying chamber 3 and the storage tank. The material 5 to be dried in 6 is the supply pipe 4
When it reaches the drying chamber 3 through the sheet, it falls into the drying chamber due to its own weight and accumulates therein. Here, the supply pipe 4, the suction hopper 7, the suction pipe 10, and the blower 11 form a supply device that supplies the material to be dried 5 to the drying chamber 3.

In the drying chamber 3, microwaves are supplied to the inside from a magnetron 12 which is a microwave supplying means through a waveguide 13, and a bottom wall is driven by a motor 14 to stir the material 5 to be dried. A body 15 is provided. A level detecting means 16 and a temperature detecting portion 17 are arranged on the side wall of the drying chamber 3. The level detecting means 16 detects whether or not a predetermined amount of the material to be dried 5 has accumulated in the drying chamber 3, which will be described in detail later. Further, a compressor 19 is connected to the left bottom portion of the drying chamber 3 via an intake valve 18, and the upper lid 2 of the drying chamber 3 is connected.
Is equipped with an exhaust valve 20. The driving of the compressor 19 and the opening of the intake valve 18 and the exhaust valve 20 are performed when the material to be dried 5 is dried by microwaves, and the water vapor generated at the time of drying passes through the exhaust valve 20 together with the air from the compressor 19. Are discharged to the outside. Further, at the bottom of the drying chamber 3, there is provided a piston discharge valve 21 forming a discharge device. The discharge valve 21 is driven to open when discharging the dried object 5 to be dried, and the object 5 is dried in the preliminary chamber 22.
It falls to and collects.

The level detecting means 16 will be described with reference to FIGS. 2 and 3. Bearing 16a fixed to the side wall of the drying chamber 3
The bearing 16a is rotatably supported, and the rotary shaft 16b made of a low dielectric loss material penetrates the side wall of the drying chamber 3, and the end of the rotary shaft 16b inside the drying chamber 3 is fixed by a pin 16c. Is connected to the upper surface of the material to be dried 5 in the drying chamber 3, and is fixed to the quantity detecting body made of a low dielectric loss material (polypropylene, Teflon, etc.), that is, the rod arm 16d, and the end of the rotating shaft 16b outside the drying chamber 3. The cam 16e is turned on and a limit switch 16f is turned on and off based on the movement of the cam 16e.

Here, the arm 16d is provided with a plurality of through holes 16g in the axial direction through which a pin 16c which serves as an adjusting portion fixed to the fixed shaft 16b is inserted. This is because the pin 16c is replaced and the length of the arm 16d is changed according to the type of the material to be dried 5 put into the drying chamber 3 so that the amount of the material to be dried supplied to the drying chamber 3 is always constant. It is what

Such level detection means 16 detects the amount of the material to be dried 5 supplied into the drying chamber 3 as described above, and the amount detection is performed as follows. That is, when the material to be dried 5 is supplied into the drying chamber 3, the material to be dried 5 is agitated by the agitator 15 and the upper surface of the material to be dried 5 is smoothed. At this time, the tip of the arm 16d is pushed up to the upper surface of the material to be dried 5 as the material to be dried 5 is rotationally moved by stirring. Then, the rotary shaft 16b rotates, and the cam 16e and the limit switch 16f
The relative relationship with changes. When the material to be dried 5 is accumulated in the drying chamber 3 by a predetermined amount in this way, the arm 16d is rotated by a predetermined angle so that the limit switch 16f causes the cam 1 to move.
It is pressed by 6e to turn on, and at this time, the level sensor 16 detects that the material to be dried 5 has accumulated in the drying chamber 3 by a predetermined amount.

Here, the arm 16d is a pin for fixing the rotary shaft 16b.
A plurality of through holes 16g through which 16c is passed are formed to change the length of the arm 16d. This is to stir the stirrer 15 and smooth the upper surface of the material to be dried 5 while the material is being put into the drying chamber 3. At this time, the degree of indentation in the central portion changes depending on the type of the material to be dried 5, and the surrounding swelling also changes accordingly. Therefore, since the amount detected by the level detecting means 16 changes, the length of the arm 16d can be changed to always detect quantitatively.

(G) Effect of the Invention According to the present invention, since the amount of the material to be dried supplied to the drying chamber is constant, it is easy to control the drying and the like even if the type of the material to be dried is changed.

[Brief description of drawings]

All of the drawings relate to the present invention. FIG. 1 is an external view of a microwave dryer, FIG. 2 is a front view of a main part, and FIG.
The figure is a side view of the main part without the drying chamber. 3 ... Drying room, 13 ... Magnetron, 16 ... Level detection means, 16c ... Rod arm

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G01F 23/34 G01F 23/34

Claims (1)

(57) [Claims] 1. A drying chamber to which a granular or powdery material to be dried is supplied, and a drying chamber provided at the bottom of the drying chamber for agitating while flattening the upper surface of the material to be dried accumulated in the drying chamber. An agitator, a level detection means for detecting whether or not a predetermined amount of the material to be dried is supplied to the drying chamber, and a microwave supply means for supplying a microwave for drying the material to be dried to the drying chamber. And the level detection means includes an arm made of a low dielectric loss material, the tip of which is pushed up by contacting with the object to be dried on the upper surface of the object to be dried as the upper surface of the object to be dried is raised by the supply of the object to be dried, A detection unit for detecting that a predetermined amount of the material to be dried is supplied to the drying chamber when the movement amount of pushing up the arm reaches a predetermined movement amount; and an adjustment unit for adjusting the length of the arm. What is characterized by Black wave drying apparatus.