JPH08155324A - Impact type pneumatic pulverizer - Google Patents

Abstract

PURPOSE: To make a material to be pulverized come into collision with an impact plate to improve pulverizing capacity without the velocity of gas being extremely reduced even downstream of a material to be pulverized feeding port by making at least the flaring angle of an accelerating pipe from the material to be pulverized feeding port to an outlet of the accelerating pipe smaller than that of the acceleration pipe to the material to be pulverized feeding port. CONSTITUTION: A high speed air current is fed from a compressed air feeding nozzle 2 and is passed through a throat part (section At) and fed into an accelerating pipe. The accelerating pipe is constituted of a nozzle part 3' having a flaring angle θ2 in which the high speed air current undergoes adiabatic expansion to accelerate its flow rate and a nozzle part 9 whose flaring angle θ1 meets 0<=θ1 <θ2 . A material to be pulverized 6 is fed into the nozzle part 9 from a feeding port 1, and the fed material to be pulverized is accelerated in the nozzle part 9 and is discharged from an outlet 7 of the accelerating pipe and comes into collision with an impact plate 4. In this way, kinetic energy of the pulverized material during impact is more increased than before to obtain large pulverizing capacity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collision type airflow crusher using a jet airflow (high pressure gas).

[0002]

2. Description of the Related Art A collision type air flow crusher using a jet airflow conveys and accelerates an object to be crushed by a jet airflow to collide with a collision member, and the impact force crushes the object to be crushed. This will be described below with reference to FIG.

By introducing high-pressure gas into a nozzle (so-called Laval nozzle) which is a combination of the compressed gas supply nozzle 2 and the acceleration pipe 3, the inside of the acceleration pipe becomes a supersonic flow. A large kinetic energy is given to the pulverized material by sucking the pulverized material from the pulverized material supply port 1. The object to be crushed to which this energy has been applied is crushed by colliding with the collision member 4 provided in the crushing chamber 5.

In such a conventional collision type airflow crusher,
A normal Laval nozzle is used as the acceleration tube 3. High-speed aerodynamics requires such a Laval nozzle in order to realize a supersonic flow at the material inlet.

However, if the Laval shape is maintained even downstream of the crushed material charging port, the pressure loss of the gas increases and the velocity of the air flow becomes extremely slow. As a result, the object to be crushed is not accelerated as much as desired and the crushing ability is deteriorated.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the object to be crushed is collided with a collision plate without extremely decelerating the flow velocity of gas even downstream from the object to be crushed. It is an object of the present invention to provide a collision type air flow crusher having improved crushing ability.

[0007]

That is, the present invention provides an accelerating tube for accelerating the object to be crushed by a high-speed gas, and a collision member for crushing the object to be crushed ejected from the accelerating tube by a collision force. In a collision type air flow pulverizer provided in the crushing chamber facing the accelerating pipe outlet, the accelerating pipe is provided with an object to be crushed, and at least from the object input port to the accelerating pipe outlet. The present invention relates to a collision type airflow crusher, wherein the divergence angle of the accelerating pipe is smaller than the divergence angle of the accelerating pipe up to the object to be ground.

According to the present invention, the accelerating pipe spread angle from the crushed material input port to the accelerating pipe outlet is made smaller than the accelerating pipe spread angle to the crushed material input port, whereby the velocity of the air flow at the crushed material input port Does not decelerate extremely toward the exit of the accelerating pipe, and the kinetic energy of the object to be crushed at the time of collision can be increased compared to the conventional collision-type airflow crusher, and thus a greater crushing capacity can be imparted. Becomes

The present invention will be described below with reference to the drawings. FIG. 1 shows a schematic sectional view of the collision type airflow crusher of the present invention.

A high-speed air stream is supplied from the compressed air supply nozzle 2. The high-speed airflow passes through the throat portion (cross section At) and is supplied to the acceleration tube 3. As shown in FIG. 2, the accelerating tube 3 of the present invention has a nozzle portion 3 ′ having a divergence angle θ ₂ at which compressed air is adiabatically expanded and the flow velocity is accelerated, and a nozzle portion having a divergence angle θ ₁ satisfying 0 ≦ θ ₁ <θ _2. It is composed of 9. In the conventional accelerating pipe shown in FIG. 3, the divergence angle of the nozzle from the crushed material input port 1 to the accelerating pipe outlet 7 is the same as the divergence angle of the nozzle from the throat portion At to the crushed material input port 1. Is a big difference. The material 6 to be crushed is supplied to the nozzle portion 9 from the charging port 1. The supplied pulverized material is accelerated in the nozzle portion 9 and discharged from the accelerating pipe outlet 7, and collides with the collision plate 4.

The position where the charging port 1 is provided is equal to the position where the velocity of the air flow in the nozzle is maximum so as to give maximum kinetic energy to the material to be crushed. The position where the velocity of this air flow is maximum is determined by the pressure ratio before and after the nozzle and the size of the nozzle cross-sectional area at any position relative to the nozzle throat cross-sectional area. In the present invention, "from the charging port" is not particularly limited as long as it is a range from the charging port downstream side a to the upstream side in Fig. 2, and is preferably the position of the upstream side b. Also, "to the acceleration tube outlet" means from the inlet to the crushing chamber 5
Is the position up to the tip of the nozzle, and its length is the most crushable because of the balance between the length required for the material to be uniformly dispersed in the air flow and the deceleration rate due to friction with the pipe. Determined to be higher.

The cross-sectional shape of the nozzle portion having the divergence angles θ ₁ and θ ₂ is preferably circular in order to realize a uniform velocity field in all directions, but the flow velocity at the crushed material inlet 1 is the outlet 7.
The shape may be an ellipse or the like as long as the speed is not decelerated to an extreme extent. Here, the fact that the flow velocity is not significantly reduced between the inlet 1 and the outlet 7 does not mean unavoidable deceleration due to friction with the pipe or the like, but deceleration due to extreme pressure loss due to the shape of the nozzle. To do.

The divergence angle θ ₂ of the accelerating tube 3'is 4 ° to 8 °, preferably 5 ° to 7 ° from the viewpoint of accelerating the compressed air adiabatically and accelerating it as efficiently as possible. The spread angle θ ₁ of the nozzle portion 9 is 0 ≦ θ _{1 with} respect to the above θ ₂ .
It suffices to satisfy <θ ₂ and preferably 0 °.

Although the collision member 4 has a planar shape shown in FIG. 1, it can be seen in, for example, Japanese Utility Model Laid-Open No. 1-148740, Japanese Unexamined Patent Publication No. 1-254266, and Japanese Unexamined Patent Publication No. 5-309287. Shapes 4a, 4b, 4 as shown in
It may be c and is not particularly limited in the present invention.

The distance from the outlet 7 to the collision member 4 may be arbitrarily changed with respect to the target particle size of the powder to be manufactured and is not particularly limited in the present invention.

By combining the crusher shown in FIG. 1 with a classifier, crushed particles having a desired particle size can be obtained. FIG. 4 shows a flow chart of a crushing device that combines a crushing process using a crusher and a classifying process using a classifier.

The crushed particles from the crushing chamber are sent to a classifier to take out particles within a desired particle size range as a product, the coarsely crushed particles are returned to the crusher, and the steps of crushing and classifying are repeated. .

Since the crusher of the present invention is excellent in crushing ability, the number of times of repeated crushing until crushing to a desired particle size can be reduced, which further improves the processing ability of the crushed material.

The collision-type airflow crusher melt-kneads a mixture containing at least a binder resin and a colorant, and cools the melt-kneaded product into coarse pulverization (or medium pulverization) by a mechanical impact pulverizer to obtain 10 μm to 2000 μm. It is useful when used in the step of further finely grinding the ground product. An example of the experimental results in such a case is shown below.

[0020]

Example 1 Preparation of Particles to be Grinded 100 parts by weight of styrene-n-butyl methacrylate resin (Tm: 132 ° C., Tg: 60 ° C.) 5 parts by weight of nigrosine dye (nigrosine base EX; manufactured by Orient Chemical Industry Co., Ltd.)・ Low molecular weight polypropylene 5 parts by weight (Viscor 550P; Sanyo Chemical Industry Co., Ltd.) 10 parts by weight ・ Carbon black (MA # 8; Mitsubishi Kasei Industry Co., Ltd.)

After mixing the above materials with a Henschel mixer, the resulting mixture was continuously extruded and kneaded with a kneader.
After cooling the kneaded material, it is roughly crushed with a hammer mill and the average particle size is 2 m.
m coarsely crushed particles were obtained. The resulting coarsely crushed particles are mechanical impact crushers (Kryptron KTMO type; manufactured by Kawasaki Heavy Industries, Ltd.)
Was pulverized to obtain pulverized particles having an average particle size of 16 μm to 23 μm.

A jet crusher (IDS-2 type; manufactured by Nippon Pneumatic Mfg. Co., Ltd.) was used for further crushing the particles to be crushed. At this time, as the nozzle, the conventional nozzle of the form shown in FIG. 3 having a spread angle of the acceleration tube 3 of θ ₂ = 6 °, and the spread angle of the acceleration tube 3 of θ ₂ =
6 °, the spread angle of the nozzle portion 9 is θ ₁ = 0 °, 3 °
Have. The nozzle of the present invention having the form shown in FIG. 2 was used. Further, the collision plates 4 and 4 shown in FIG.
a, 4b, and 4c were used.

The specific dimensions of each collision plate are as follows. Collision plate 4: d = φ46 mm Collision plate 4 a: d = φ46 mm, h = 25 mm, α = 50 ° Collision plate 4 b: d = φ46 mm, h = 25 mm, α = 50 °, β = 20 ° Collision plate 4 c: d = φ46mm, h = 25mm

The crushing conditions are a throughput of 2 kg / h and a crushing pressure: 6
At 5 Kgf / cm ² G, the particle size of the pulverized material was 16 μm and 23 μm for each of the collision plates.

The crushing ability is evaluated by removing the classifier of the jet crusher and examining the one-time crushing complete particle size obtained by passing the objects to be crushed having particle sizes of 16 μm and 23 μm once through the jet crusher. did.

The results are shown in FIG. From FIG. 6, the parallel nozzle of the present invention is 10% at θ ₁ = 0 ° as compared with the conventional nozzle,
When θ ₁ = 3 °, an improvement of about 5% in crushing capacity was observed.

In FIG. 6, the once-crushed complete particle size means the particle size of the crushed product after the crushed product has been passed through the jet crusher once. Dp50 means a particle diameter corresponding to 50% of the distribution of the particle size distribution of the pulverized material expressed by weight distribution.

Further, the feed amount is 2 kg / h to 30 kg
The crushing ability when changed to / h was evaluated. Other crushing conditions at this time are: collision plate 4, crushing pressure 6.5 Kgf /
It was fixed to cm ² G, and a material having a particle size of 23 μm was taken as a material to be crushed. FIG. 7 shows the results.

Further, the crushing ability was evaluated when the crushing pressure was changed to ³ Kgf / cm ² G. The other crushing conditions at this time were such that the collision plate 4 and the feed amount were fixed at 10 kg / h, and the crushed object had an average particle size of 23 μm.
The results are shown in Fig. 8. Next, an example of an experimental result showing the effect of improving the processing capacity of the present invention will be shown.

[0030]

Example 2 Preparation of Milled Particles Styrene-n-butyl methacrylate resin 100 parts by weight (Tm: 132 ° C., Tg: 60 ° C.) 5 parts by weight nigrosine dye (nigrosine base EX; manufactured by Orient Chemical Industry Co., Ltd.)・ Low molecular weight polypropylene 5 parts by weight (Viscor 550P; Sanyo Chemical Industry Co., Ltd.) 10 parts by weight ・ Carbon black (MA # 8; Mitsubishi Kasei Industry Co., Ltd.)

After mixing the above materials with a Henschel mixer, the resulting mixture was continuously extruded and kneaded with a kneader.
After cooling the kneaded product, coarsely crushed with a hammer mill to obtain an average particle size of 2
mm coarsely crushed particles were obtained.

A jet mill crusher (type I-5; manufactured by Nippon Pneumatic Mfg. Co., Ltd.) is used for further crushing the particles to be crushed, and the jet crusher is used to obtain a desired particle size (DS. -5 type; manufactured by Nippon Pneumatic Mfg. Co., Ltd.) was used in combination with the crushing flow of FIG. At this time, as the nozzle, a conventional nozzle having a configuration shown in FIG. 3 in which the divergence angle of the accelerating tube 3 is θ = 6 °, and a divergence angle of the accelerating tube 3 ′ is θ ₂ = 6 °, and a divergence angle of the nozzle portion 9 is The nozzle of the present invention having the configuration shown in FIG. 2 having θ ₁ = 0 ° was used. Also, as the collision plate, as shown in FIG.
The collision plate 4 shown in was used.

Throughput is such that the desired product particle size is 12-14.
It was evaluated by examining the feed amount of the powder when fixed to μm, that is, when the classification conditions were kept constant.

The results are shown in Table 1. It can be seen from Table 1 that the nozzle of the present invention (θ ₁ = 0 °) has an improvement of about 10% in pulverizing ability as compared with the conventional nozzle.

[0035]

[Table 1]

[0036]

According to the present invention, the accelerating tube spread angle from the crushed material input port to the accelerating tube outlet is made smaller than the accelerating tube spread angle to the crushed material input port, so that the crushed material can be held at the time of collision. The kinetic energy can be increased more than that of the conventional impingement type air flow crusher, so that a larger crushing ability can be given. Further, due to this large crushing ability, the number of times of repeated crushing until crushing to a desired particle size can be reduced in a crushing apparatus combining this crushed material and a classification step, and the processing capacity of the crushed material is improved.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a collision type airflow crusher of the present invention.

FIG. 2 is a schematic sectional view of an acceleration tube of the present invention.

FIG. 3 is a schematic sectional view of a conventional acceleration tube.

FIG. 4 is a flow chart diagram in which the collision type airflow crusher of the present invention and a classifier are combined.

FIG. 5 is a schematic cross-sectional view of various types of collision plates.

FIG. 6 is a graph showing the evaluation results of the crushing ability of the collision type airflow crusher of the present invention.

FIG. 7 is a graph showing the evaluation results of the crushing ability of the collision type airflow crusher of the present invention.

FIG. 8 is a graph showing the evaluation results of the crushing ability at the time of collision type air flow crushing of the present invention.

FIG. 9 is a schematic cross-sectional view of a conventional collision type airflow crusher.

[Explanation of symbols]

1: crushed material inlet, 2: compressed air supply nozzle, 3: accelerating tube, 3 ': accelerating section, 4: collision member, 6: crushed object,
7: Accelerator outlet, 9: Nozzle part of the present invention

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Nakamura 2-3-13 Azuchi-cho, Chuo-ku, Osaka City, Osaka Prefecture Osaka International Building Minolta Co., Ltd. (72) Inventor Masayuki Azuchi-cho, Chuo-ku, Osaka-shi, Osaka Prefecture 2-chome 3-13 Osaka International Building Minolta Co., Ltd.

Claims (2)

[Claims] 1. An acceleration tube for accelerating the object to be crushed by high-speed gas, and a collision member for crushing the object to be crushed ejected from the accelerating tube with a collision force. The collision member is accelerated. In a collision-type airflow crusher provided in the crushing chamber facing the tube outlet, the crushing object inlet is provided in the accelerating pipe, and the divergence angle of the accelerating tube from at least the crushing object inlet to the accelerating tube outlet is crushed Collision-type airflow crusher characterized in that the spread angle of the acceleration pipe to the material input port is smaller than the spread angle. 2. When the spread angle of the acceleration pipe from the crushed material input port provided to the accelerating pipe to the accelerating pipe outlet is θ, and the spread angle of the acceleration pipe to the crushed material input port is θ ₂ , θ ₁ and theta ₂ is 0 ≦ θ ₁ <θ ₂ collision type air pulverizer according to claim 1, characterized by satisfying the.