JP3831102B2 - Jet crusher - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a jet pulverizer for pulverizing various powders such as metals, pharmaceuticals, chemical substances, agricultural chemicals, and synthetic resins.
[0002]
[Prior art]
As a jet pulverizer for finely pulverizing powder, one described in Japanese Utility Model Laid-Open No. 51-1000037 has been conventionally known. This jet crusher has a crushing chamber in a casing and a classification chamber above it, and supplies powder together with high-pressure air from the powder supply nozzle provided on the peripheral wall of the crushing chamber to the outer periphery of the crushing chamber. The powder is pulverized by the collision of the particles and the collision of the high-pressure air by swirling and injecting high-pressure air from the plurality of air injection nozzles toward the swirling powder.
[0003]
In addition, the pulverized product after pulverization flows into the classification chamber, and the pulverized product is centrifuged into fine powder and coarse powder by swirling in the classification chamber. It discharges | emits from the formed exhaust pipe, returns coarse powder in an air injection nozzle, and grind | pulverizes it repeatedly.
[0004]
In the jet pulverizer, the pulverized product after pulverization is classified, and the coarse powder moved to the outer periphery of the classification chamber is returned to the air injection nozzle, so that there is little accumulation of coarse powder in the classification chamber, resulting in a product. It is possible to prevent the coarse powder from being mixed into the fine powder, and to obtain a product having a target particle size.
[0005]
[Problems to be solved by the invention]
By the way, in the jet pulverizer, the pulverized product having a relatively small particle size pulverized in the pulverization chamber flows toward the classification chamber, so that the coarse powder easily accumulates in the outer peripheral portion of the pulverization chamber. The increase in the pulverization efficiency lowers the pulverization efficiency, and there are points to be improved in improving the pulverization efficiency.
[0006]
In addition, due to the increase in the amount of accumulated coarse powder, coarse powder flows into the classification chamber, and the classification effect in the classification chamber is also reduced.
[0007]
An object of the present invention is to improve the pulverization efficiency and classification efficiency of the jet pulverizer.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, a crushing chamber is provided inside the casing, and a classification chamber communicating with the central portion of the crushing chamber is provided above the casing, and an outer periphery of the crushing chamber is provided on a peripheral wall of the crushing chamber. A plurality of air injection nozzles for injecting high-pressure air toward the part and a powder supply nozzle for supplying powder in the same direction as the high-pressure air, and the powder supplied from the powder supply nozzle to the grinding chamber Is crushed by the collision of high-pressure air injected from the air injection nozzle, and the pulverized material flowing into the classification chamber while swirling is centrifuged into coarse powder and fine powder in the classification chamber, and the fine powder is placed on the axis of the classification chamber. employed in the jet mill to discharge the fine powder discharge tube provided, on the peripheral wall of the grinding chamber, a structure in which a coarse powder return passage for guiding the powder to pivot the grinding chamber to the air injection nozzle in is doing.
Here, the outer peripheral part in the classification chamber and the inside of the air injection nozzle may be communicated with each other through a coarse powder return passage so that the coarse powder turning at the outer peripheral part in the classification chamber may be returned into the air injection nozzle.
[0009]
Here, the coarse powder return passage provided on the classification chamber side and the coarse powder return passage provided on the grinding chamber side may be communicated with each other with respect to one air injection nozzle. Alternatively, the number of coarse powder return passages on the classification chamber side and the coarse powder return passages on the pulverization chamber side is half the number of air injection nozzles, and one coarse powder return passage is communicated with one air injection nozzle. May be. In addition, the combination of the number of the two types of coarse powder return passages can be changed according to the type of pulverized material.
[0010]
As described above, by providing the coarse powder return passage on the peripheral wall of the grinding chamber, coarse powder swirling around the outer periphery of the grinding chamber is returned from the coarse powder return passage into the air injection nozzle. The accumulation of powder is reduced, and the pulverization efficiency can be improved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
As shown in FIG. 1, the casing 1 includes a cylindrical pulverizing casing 2 and a cylindrical classification chamber cover 3 provided on an upper portion thereof, and a liner 4 is attached to the inner periphery of the pulverizing casing 2. The inside is a grinding chamber 5.
[0013]
The classification cover 3 has a tapered cylindrical portion 6 at the lower portion, and a ring-shaped member 7 provided inside the tapered cylindrical portion 6 is attached to the upper portion of the crushing casing 2, and the classification cover 3 is attached by attaching the ring-shaped member 7. A classification chamber 9 is formed inside.
[0014]
The ring-shaped member 7 has a tapered inner surface 7a and a tapered outer surface 7b, and coarse powder return passages 8 are provided in the tapered outer surface 7b at intervals in the circumferential direction. As shown in FIG. 5, the coarse powder return passage 8 is tapered at the inlet of the coarse powder so that the coarse powder flows easily.
[0015]
As shown in FIGS. 1 and 2, a powder supply nozzle 10 that injects and supplies powder toward the outer peripheral portion of the pulverizing chamber 5 and a high pressure to the outer peripheral portion of the pulverizing chamber 5 are provided on the peripheral wall of the pulverizing chamber 5. A plurality of air injection nozzles 11 for injecting air are provided.
[0016]
As shown in FIG. 4, the air injection nozzle 11 is composed of a Laval tube, and the air injection nozzle 11 and the air supply tube 12 are connected by an air supply tube 13. Further, the air injection nozzle 11 is formed with a suction hole 15 communicating from the outer diameter surface to the inner diffuser portion 14. The number of air injection nozzles 11 is twice the number of coarse powder return passages 8, and half of the air injection nozzles 11 have these suction holes 15 located at the top, and the remaining air injection nozzles 11 have suction holes 15. The air injection nozzles 11 that are located on the side portions and have different positions of the suction holes 15 are alternately arranged in the circumferential direction.
[0017]
The suction hole 15 of the air injection nozzle 11 in which the suction hole 15 is located is in communication with the coarse powder return passage 8 provided on the tapered outer surface 7 b of the ring-shaped member 7.
[0018]
On the other hand, the coarse powder return passage 16 provided on the peripheral wall of the crushing chamber 5 communicates with the suction holes 15 located on the side of the remaining air injection nozzles 11. The coarse powder return passage 16 extends obliquely outward with respect to the tangential line in the swirling direction of the coarse powder swirling in the pulverizing chamber 5, so that the coarse powder swirling in the pulverizing chamber 5 easily enters.
[0019]
At the rear end of the powder supply nozzle 10, the front end of an air supply pipe 17 connected to the air supply pipe 12 is opposed to the air supply pipe 12 with an interval, and the powder is between the air supply pipe 17 and the opposed portion of the powder supply nozzle 10. The lower outlet of the supply hopper 18 faces and the high-pressure air is injected from the air supply pipe 17 into the powder supply nozzle 10, whereby the powder in the powder hopper 18 is sucked into the powder supply nozzle 10, and the high pressure It is injected into the crushing chamber 5 together with air.
[0020]
A fine powder discharge cylinder 19 is connected to the central portion of the top wall of the classification cover 3, and the lower end portion of the cylinder 20 provided at the lower inlet of the fine powder discharge cylinder 19 protrudes into the classification chamber 9. When coarse powder flows toward the center of the classification chamber 9 along the lower surface of the top wall, the coarse powder is prevented from flowing into the fine powder discharge cylinder 19.
[0021]
In the classification chamber 9, a classification plate 21 is provided for guiding the pulverized material flowing from the pulverization chamber 5 into the classification chamber 9 along the tapered inner surface 7 a of the ring-shaped member 7. The upper surface 22 of the classifying plate 21 is a concave curved surface, and the center is high.
[0022]
The jet pulverizer having the above-described configuration applies a suction force to the fine powder discharge cylinder 19 and pulverizes from the powder supply nozzle 10 in a state where high-pressure air is injected into the pulverization chamber 5 from each of the air injection nozzles 11. Powder is supplied into the chamber 5 and the powder is pulverized.
[0023]
Now, when powder is supplied from the powder supply nozzle 10 into the pulverization chamber 5 together with high-pressure air, the powder rotates at high speed in the pulverization chamber 5.
[0024]
At this time, since the high-pressure air is injected into the pulverization chamber 5 from the air injection nozzle 11, the powder swirling in the pulverization chamber 5 is pulverized by the collision with the high-pressure air and the collision between particles.
[0025]
The pulverized product is primarily classified by swirling in the pulverization chamber 5, and the pulverized product having a small particle size moves to the center of the pulverization chamber 5 and flows into the classification chamber 9 from the upper outlet 5 a. On the other hand, the pulverized material having a large particle diameter swirls around the outer periphery of the pulverization chamber 5.
[0026]
When high-pressure air is ejected from the air injection nozzle 11, a suction force acts on the suction hole 15 communicating with the diffuser portion 14 and the coarse powder return passage 16 communicating with the suction hole 15, and the suction force causes the inside of the grinding chamber 5. The coarse powder having a particle diameter swirling on the outer peripheral portion of the gas is returned into the air injection nozzle 11 from the coarse powder return passage 16 and is again injected into the pulverization chamber 5 together with the high-pressure air from the air injection nozzle 11.
[0027]
For this reason, the accumulation of coarse powder in the pulverization chamber 5 is reduced, and the coarse powder in the powder supplied to the pulverization chamber 5 is repeatedly pulverized, so that the powder can be pulverized very effectively. .
[0028]
The pulverized material that has flowed into the classification chamber 9 swirls in the classification chamber 9 and is centrifuged into fine powder and coarse powder.
[0029]
The fine powder moves to the center of the classification chamber 9 and is taken out from the fine powder discharge cylinder 19. On the other hand, the coarse powder swirls at the outer peripheral portion in the classification chamber 9, flows from the coarse powder return passage 8 to the diffuser portion 14 in the air injection nozzle 11, and is injected into the pulverization chamber 5 together with the high-pressure air flowing in the diffuser portion 14. , Repeatedly pulverized.
[0030]
Thus, since the coarse powder swirling at the outer peripheral portion in the classification chamber 9 is returned to the pulverization chamber 5, there is no stagnation of the coarse powder in the classification chamber 9, and the coarse powder is prevented from being mixed into the fine powder. can do.
[0031]
In the pulverization of the powder as described above, the coarse powder swirling at the outer peripheral portion in the pulverization chamber 5 is sucked into the air injection nozzle 11 from the coarse powder return passage 16, so the stagnation of the coarse powder in the pulverization chamber 5. Since the accumulation is reduced and the powder is pulverized very effectively, even if the diameter of the outlet 5a of the pulverization chamber 5 is reduced, the pulverized material can be sufficiently supplied into the pulverization chamber 5 to increase the processing amount. . Further, when the diameter of the outlet 5a is reduced, only the finely pulverized pulverized material flows into the classification chamber 9 and the mixing of coarse powder is reduced, so that the powder classification efficiency in the classification chamber 9 can be further improved. .
[0032]
In the embodiment, the fine powder discharge cylinder 19 is connected to the classification cover 3 and the fine powder is taken out upward. However, the upper part of the classification chamber 9 is completely closed, and the fine powder discharge cylinder is provided at the center of the classification plate 21. It may be connected to take out fine powder below the classification chamber 9.
[0033]
Moreover, you may use ejector nozzles other than a Laval pipe | tube as an air injection nozzle.
[0034]
【effect】
As described above, in the present invention, coarse powder swirling at the outer periphery of the pulverization chamber is returned from the coarse powder return passage into the air injection nozzle, and is repeatedly pulverized by being injected from the air injection nozzle into the pulverization chamber. Therefore, the accumulation of coarse powder in the grinding chamber is extremely small, and the powder can be ground very efficiently.
[0035]
In addition, since there is little stagnation of coarse powder in the grinding chamber, the particle size of the pulverized material flowing into the classification chamber is also reduced, and the classification efficiency in the classification chamber is improved. As a result, the processing capacity of the pulverizer is greatly improved. Can be made.
[Brief description of the drawings]
FIG. 1 is a longitudinal front view showing an embodiment of a crusher according to the present invention. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 4 is an enlarged cross-sectional view showing a mounting portion of the air injection nozzle shown in FIG. 1. FIG. 5 is a cross-sectional view taken along line VV in FIG.
DESCRIPTION OF SYMBOLS 1 Casing 5 Crushing chamber 8 Coarse powder return passage 9 Classification chamber 10 Powder supply nozzle 11 Air injection nozzle 15 Suction port 16 Coarse powder return passage 19 Fine powder discharge cylinder

Claims (2)

A plurality of air injection nozzles that provide a crushing chamber inside the casing and a classification chamber communicating with the central portion of the crushing chamber above the crushing chamber, and inject high-pressure air toward the outer peripheral portion of the crushing chamber on the peripheral wall of the crushing chamber And a powder supply nozzle for supplying powder in the same direction as the high-pressure air, and the powder supplied from the powder supply nozzle to the pulverization chamber is pulverized by collision of high-pressure air injected from the air injection nozzle and the pulverized product flowing into the classifying chamber while turning, and centrifuged coarse particles and pulverized particles in the classifying chamber was Unishi I for discharging fines from fine powder discharge tube provided on the axis of the classifying chamber jet A pulverizer, characterized in that a coarse powder return passage is provided on a peripheral wall of the pulverization chamber to guide powder swirling in the pulverization chamber into an air injection nozzle.   2. The jet according to claim 1, wherein the outer peripheral portion in the classification chamber and the inside of the air injection nozzle communicate with each other through a coarse powder return passage so that the coarse powder swirling in the outer peripheral portion in the classification chamber is returned into the air injection nozzle. Crusher.

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