JPH0245225Y2 - - Google Patents

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) The present invention relates to a rotary leaf feeder for supplying powder to a transportation system.

(Prior art) Generally, when feeding starch or thermoplastic powder with a low yield point against temperature changes by a rotary leaf feeder, inside the rotary leaf feeder, there is a gap between the rotor blades and the casing. Frictional heat is generated at the gap. Therefore, the powder inside the casing is gelled by this frictional heat and rolled along the inner peripheral surface of the casing to form a sheet-like coating. When this film becomes thick, the gap inside the casing becomes blocked, making it difficult to rotate the rotor, and the motor used to rotate the rotor sometimes seizes up. In addition, the shape of the rotor blades of a normal rotary leaf feeder either extends linearly in the radial direction from the rotor axis, or has a slight receding angle formed at the tip of the linearly extending tip (forming an advancing angle). very few have done so). Therefore, when a rotor having such a blade shape is rotated, the powder that has entered the rotary pocket moves toward the tip along the surface of the rotor blade due to the centrifugal force caused by the rotation. The moving force is greatest at the side edge portions of the rotor blades, which further promotes the formation of sheet-like films at the gap portions.

Therefore, in order to prevent the formation of a powder film on the gap between the tip of the rotor blade and the inner periphery of the casing, high-pressure air is blown into the gap or air is applied to the tip of the rotor blade. A structure in which a wear-resistant elastic member is attached and the sheet-like membrane is rubbed off by this elastic member has also been considered. However, with a rotary leaf feeder having such a structure, although it is possible to prevent the formation of a sheet-like film to some extent, once a sheet-like film is formed, it is impossible to remove this sheet-like film, and the sheet-like film cannot be removed. The effect has decreased significantly. Further, in the case of a technique in which the sheet-like film is rubbed off at the tip of the rotor blade, there is a problem in that the tip of the rotor blade is worn out due to friction with the inner circumferential surface of the casing.

(Problem to be solved by the present invention) Therefore, this invention uses a special blade at the tip of the rotor blade to cut off the powder film and powder adherents that have formed on the inner surface of the casing, and remove them to ensure smooth rotation of the rotor. This is to maintain the rotor blades and prevent wear on the tips of the rotor blades.

Structure of the invention (Means for solving the problems) In order to solve the above-mentioned problems, the present invention provides a powder supply port 1 in the upper part of the casing 2 and a discharge port 3 in the lower part. 2 is rotatably provided with a rotor 4 for powder transfer, which is constituted by a plurality of rotor blades 6 whose ends reach a position immediately adjacent to the inner surface of the casing 2, and whose end surfaces face the end surfaces of the rotor blades 6. The cutting edges 9a, 8b are formed so as to be substantially parallel to the inner surface of the casing 2, and grooves 8a, 8b forming a front rake angle are provided on the front edge of the rotor blade 6 in the rotational direction. 9b forms blades 7a and 7b facing toward the front side in the direction of rotation.

(Function) In the rotary feeder configured as described above, with the rotor 4 actively rotating, starch and thermoplastic plastic powder with a low yield point against temperature changes are fed into the casing 2 from the supply port 1. When supplied, the powder is transferred downward within the casing 2 as the rotor 4 rotates. When the powder is transferred in this way, the rotor blades 6 transfer the powder downward, and at the same time the blades 7 at the edges of the rotor blades 6 remove the powder from the powder film formed on the inner surface of the casing 2. Cut it into a thin roll paper shape using the cutting edges 9a and 9b. Finally, the powder is discharged from the discharge port 3.

(Embodiment) An embodiment embodying the present invention will be described below with reference to the drawings. 1 is a powder supply port provided at the upper part of the rotary feeder, 2 is a casing continuing below the powder supply port, and 2 is a drum section. 2a and a pair of side plate portions 2b that cover both left and right ends of the side plate portion 2a. 3 is a powder discharge port continuing below. 4 is a rotor provided within the casing, and is actively rotated by a motor (not shown). Reference numeral 5 denotes a rotating shaft of the rotor 4, and 6 indicates a large number of rotor blades of the rotor 4, all of which extend radially outward from the rotating shaft 5. The tips of these rotor blades 6 are all connected to the casing 2
Each side end of the rotor blade 6 reaches a position closest to the inner circumferential surface of each side plate portion 2b of the casing 2. 7a is a blade formed on the tip edge of each rotor blade 6; 7b is a pair of blades formed on both side edges of each rotor blade 6 so as to be orthogonal to this blade 7a; It is located on the front side (in the direction of the arrow in Figure 1). These blades 7a and 7b each have an arc-shaped concave groove 8a extending over the entire width direction at the tip of the rotor blade 6, and an arcuate groove 8a extending over the entire length direction at both end portions of the rotor blade 6. Similarly, it is formed by providing an arcuate groove 8b. The portions where the outer edges of these grooves 8a and 8b contact the tip and side surfaces of the rotor blade 6, respectively, serve as cutting edges 9a and 9b. Further, these cutting edges 9a and 9b have a front rake angle formed by the grooves 8a and 8b,
It faces toward the front side in the rotational direction of the rotor 4, and is adapted to cut the powder film on the inner circumferential surface of the drum portion 2a into a rolled paper shape.

Now, in the rotary feeder configured as described above, with the rotor 4 actively rotating in the direction of the arrow, starch or thermoplastic powder having a low yield point against temperature changes is fed into the casing from the supply port 1. 2, the powder is first fed into the rotary pocket 10 between each rotor blade 6, as in the case of a conventional rotary feeder.
Go inside. Then, as the rotor 4 rotates, it is transferred downward within the casing 2 and finally discharged from the discharge port 3. When the powder is transferred in this way, frictional heat is generated at the gap 11 between the tip of the rotor blade 6 and the inner peripheral surface of the casing 2, and this heat melts the powder and gels. Even if a powder film is formed by oxidation, this film will not completely close the gap 11. That is, since blades 7a are formed at the tip of each rotor blade 6, these blades 7a scrape off the powder film on the inner circumferential surface of the drum portion 2a of the casing 2 into a rolled paper shape during powder transfer. It gets hot. Therefore, the powder film does not become so thick as to prevent the rotation of the rotor 4 on the inner peripheral surface of the drum portion 2a. Therefore, there is no frictional heat generated due to rolling of the powder film, and smooth rotation of the rotor 4 is maintained. Note that the powder film scraped off is the blade 7a.
The drum part 2 of the casing 2 is taken in toward the center of the rotor 4 along the groove 8a.
There is no possibility that the gap 11 inside a will become clogged.

Further, the blades 7 are provided on both side edges of each rotor blade 6.
Since a pair of blades 7b are formed perpendicularly to a, these blades 7b scrape off the powder film on both side plate portions 2b of the casing 2 during powder transfer, as described above. Therefore, the powder film is formed on both side plate portions 2.
Even on the inner surface b, it does not become so thick as to prevent rotation of the rotor 4. Therefore, smooth rotation of the rotor 4 is maintained without frictional heat generated by rolling the powder film. The scraped powder film is taken inward from both sides of the casing 2 along the groove 8b of the blade 7b, and does not get stuck in the gap 11 inside the side plate portions 2b.

Further, since the blades 7a of each of the rotor blades 6 are each formed by providing an arc-shaped concave groove 8a, the powder pressure applied to each rotor blade 6 due to the rotation of the rotor 4 is reduced by the rotor blade. The pressure is slightly reduced at the tip edge of No. 6, and the maximum pressure point of the tip edge moves from the cutting edge 9a toward the rotation axis direction. Therefore, a powder film is less likely to be generated on the inner circumferential surface of the drum portion 2a of the casing 2.

Therefore, unlike the conventional method of scraping off a sheet-like membrane using an elastic member, it is possible to scrape off the powder membrane at the powder membrane stage. Therefore, the generation of sheet-like films itself can be suppressed, so the sheet-like film of starch and thermoplastic powder, which has a low yield point against temperature changes, does not interfere with the rotation of the rotor, and the motor for rotating the rotor There is no burning sensation.

(Another Embodiment) The present invention is not limited to the above-mentioned embodiment, and arbitrary changes can be made without departing from the spirit of the invention.

For example, instead of forming the grooves 8a and 8b forming the blades 7a and 7b of each rotor blade 6 into an arc shape, they may be formed into a V-shaped cross section.

Effects of the Invention As detailed above, the present invention provides a powder supply port in the upper part of the casing and a discharge port in the lower part. A rotor for powder transfer consisting of rotor blades is rotatably provided, the end surfaces of the rotor blades are formed so as to be substantially parallel to the inner surface of the opposing casing, and the rotor blades are By providing a groove forming a front rake angle on the edge of the front side in the direction of rotation, a blade whose cutting edge faces toward the front side in the direction of rotation is formed. As a result, the tip of the blade is thin and has the sharpness of a razor blade, making it possible to cut the powder film on the inner surface of the casing into a thin paper roll, while the base of the blade is thick and has the strength to not break. You can have it. Moreover, since the cutting edge does not make sliding contact with the inner surface of the casing, it is possible to prevent the cutting edge from wearing out.Furthermore, since the cutting chips move inside the rotor along the concave grooves, it is possible to prevent the formation of a sheet-like film in the gap area, and to ensure smooth rotation of the rotor. It has the unique effect of being able to be maintained.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment embodying the present invention, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, Fig. 3 is an enlarged view of the rotor blade tip, and Fig. 4 is an enlarged view of the rotor blade tip. FIG. 2 is a sectional view taken along line BB in FIG. 2; Supply port...1, Casing...2, Discharge port...
3. Rotor...4. Rotor blade...6. Blade...
...7a, 7b, groove...8a, 8b, cutting edge...9
a, 9b.

Claims (1)

[Claims for Utility Model Registration] 1. A powder supply port 1 is provided in the upper part of the casing 2, and a discharge port 3 is provided in the lower part, and within the casing 2 there are a plurality of powder supply ports whose ends reach the closest position to the inner surface of the casing 2. A rotor 4 for transferring powder composed of rotor blades 6 is rotatably provided, and the end surfaces of the rotor blades 6 are formed so as to be substantially parallel to the inner surface of the casing 2 facing each other, Furthermore, grooves 8a and 8b forming front rake angles are provided on the edges of the rotor blades 6 on the front side in the rotational direction, so that the cutting edges 9a and 9b of the blades 7a and 7 face toward the front side in the rotational direction.
A rotary leaf feeder characterized by forming a b. 2. The rotary leaf feeder according to claim 1, wherein the blades 7a and 7b are provided at the leading edge and both side edges of each rotor blade 6. 3. The rotary leaf feeder according to claim 2, wherein the blades 7a, 7b are formed by providing arcuate grooves 8a, 8b at the tip and both side ends of each rotor blade 6. .