JPH0618580Y2 - Rotating disk used for surface modification device of solid particles - Google Patents

Description

Detailed Description of the Invention a. INDUSTRIAL APPLICABILITY The present invention is an apparatus for performing a surface modification treatment of solid particles or a spheroidization treatment of solid particles using an impact type impacting means, which is placed in an impact chamber of the treatment apparatus and rotates at high speed. , Giving impact impact force to solid particles while dispersing particles,
The present invention relates to a turntable capable of efficiently performing the above processing.

b. Conventional technology Conventionally, for the purpose of preventing solid particles from solidifying, preventing discoloration and alteration, improving dispersibility, improving fluidity, reducing the amount of useful (expensive) substances, etc., solid core particles (hereinafter referred to as mother particles) ), The fine particles smaller than the solid particles (hereinafter referred to as “child particles”) are forcibly embedded, fixed or formed into a film by a mechanical means to be fixed, and a uniform and stable mother particle is formed within an extremely short time. Examples of a solid particle surface reforming device for surface modification, or a device for spherically treating amorphous solid particles such as metal for the purpose of preventing sticking of solid particles, improving dispersibility, improving fluidity, etc. There is one described in JP-A-62-83029.

The solid particle surface modification device or the solid particle spheroidizing device (hereinafter, both devices are simply referred to as a processing device),
Shown in FIGS. 4 and 5. In the figure, 101 is a casing, 102 is a front cover, and 103 is a collision ring. Surrounded by these members, a powder impact chamber 104 is formed. A rotary disk 105 that rotates at high speed is provided in the impact chamber 104, and the rotary disk 105 is fixed to a rotary shaft 106 by a nut 107.

Further, 108 is a raw material feeding pipe, 109 is a raw material feeding hopper, 110
Is a raw material feeding valve, 111 is a circulation circuit, and the circulation circuit 111 communicates with the impact chamber 104 from a circulation port 112 opened in a part of the collision ring 103 through the center of the front cover 102. 11
Reference numeral 3 is an opening / closing valve for discharging the reforming powder, which is provided by cutting out a part of the collision ring 103, 114 is a valve shaft of the opening / closing valve, and 115 is a reforming powder discharging chute.

In this processing apparatus, the turntable 105, which rotates at high speed in the impact chamber 104, has a substantially rectangular parallelepiped (blade-shaped) or columnar impact pin 116 on its side surface, as shown in FIG. It is mounted radially around the center of rotation of. By rotating the turntable 105 having such a shape at a high speed, an air flow is generated in the processing apparatus, and the solid particle group put into the processing apparatus is dispersed and the impact action of the impact pin or the collision ring is generated. Then, various processes are performed.

c. DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the conventional processing apparatus, the processing apparatus is disposed in the impact chamber,
In the rotary disc 105 that gives impact to the particles, the shape of the impact pin 106 is a substantially rectangular parallelepiped (or a column), and since the rotary disc 105 is mounted radially around the rotation center of the rotary disc 105, the raw material feeding hopper 109 The object to be processed thrown into the impact chamber 104 is
After being impacted by an impact pin 116 attached to a rotating disc 105 rotating at a high speed, the impact pin 116 moves in an outer peripheral direction along a plane facing the rotation direction of the impact pin 116 and collides vertically with the impact ring 103. It was designed to be subjected to a strong impact by. Therefore, there are the following problems.

When the irregular-shaped fine particles are spheroidized, the pulverization proceeds with time while being spheronized, and the average particle diameter becomes smaller.

When immobilizing the child particles by embedding or fixing them on the surface of the mother particles, particularly when fixing the metal to the ceramics, the ceramics as the mother particles are crushed when the outer peripheral speed of the rotating disk is high, and When the peripheral velocity is low, the metal as a child particle is hard to be immobilized on the surface of the mother particle, so that the efficiency of the immobilization treatment is very poor.

The present invention has been made in view of the above-mentioned problems of the prior art, and is a solid particle treatment device capable of efficiently performing surface modification treatment of solid particles or spheroidization treatment of solid particles, more specifically, the above treatment. An object of the present invention is to provide a turntable which is disposed in the impact chamber of the apparatus, rotates at a high speed, and can efficiently perform the above reforming.

d. Means for Solving the Problems The present invention has been achieved in accordance with the above-mentioned object, and a surface reforming device of an air current impact type that modifies the surface of solid particles by immobilizing other substances on the surface of the solid particles to form a film, Alternatively, in a rotating disk used for a spheroidizing apparatus for solid particles and provided with impact pins circumferentially provided at intervals on the side surface, the impact pin is formed of a columnar body having a curved surface, and the curved surface is formed on the rotating disk. The above-mentioned problem is solved by providing a rotating disk that is arranged in the direction of rotation of and is inclined outward.

The rotating disk according to the present invention makes it possible to perform spheroidizing treatment of irregularly shaped fine particles with crushing suppressed as much as possible. Further, even if the peripheral speed of the rotating disk is low, it can be fixed, and even if the peripheral speed is high, mother particles It became possible to perform the immobilization treatment without crushing.

e. Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

1 to 3 show an embodiment of a solid particle processing apparatus using a rotating disk according to the present invention.

In FIG. 1, 1 is a casing, 2 is a front cover, 3 is a collision ring, 4 is an impact chamber, 5 is a rotary disk, 6 is a rotary shaft, and 7 is a rotary shaft.
Is a nut, 8 is a raw material feeding pipe, 9 is a raw material feeding hopper, 10
Is a raw material charging valve, 11 is a circulation circuit, 12 is a circulation port, 13 is an opening / closing valve, 14 is a valve shaft of the opening / closing valve, and 15 is a reforming powder discharge chute. It has the same structure as that of.

As shown in FIGS. 2 and 3, the turntable 5 has a plurality of substantially semi-cylindrical impact pins 16 on its side surface at predetermined intervals in a radially dispersed arrangement as shown. The impact pin 16 is provided with a curved surface portion 16a facing the rotational direction and a back surface portion 16b. In the illustrated embodiment, the back surface portion 16b is a flat surface and has a semicircular chord in cross section. The curved surface portion 16a is arranged so as to face the rotation direction of the turntable 5 and be inclined outward. The back surface 16b has a curved cross section,
It may be formed by a plane surface or a surface of a combination thereof, and further, these surfaces may be formed as a concave surface or a convex surface. That is, it is possible to adopt an arbitrary shape that does not hinder processing and is effective in processing.

Further, the curved surface of the curved surface portion 16a preferably has a constant curvature such as an arc, or may have different curvatures continuously combined.

In the embodiment shown in FIG. 2, the inclination angle θ formed by the straight line connecting the midpoint P of the chord forming the back surface 16b of the impact pin 16 and the center 0 of the turntable 5 is 0 ° <θ < The range is 90 °, and preferably 15 <θ <60 °. In addition, it is said that the impact pin is located at the position of the retracted wing when the impact pin is arranged in such an angular relationship.

The chord portion may be an imaginary line that connects both ends of the curved surface portion 16a with a straight line, and substantially the back surface portion 16b of the impact pin is provided.
It does not have to be a wall surface that forms the.

Next, two specific examples of the case where the fixed particles are actually processed by using the apparatus provided with the rotating disk having the above-mentioned structure will be described.

Example 1 First, in the apparatus shown in FIG. 1, the open / close valve 13 for discharging the reformed powder is kept closed, the rotary shaft 6 is driven by the driving means, and the rotary disk 5 is rotated at an outer peripheral speed of 50 to 150 m / m. Rotate with s. As a result, a sudden air flow is generated with the rotation of the impact pin 16 provided on the outer peripheral side surface of the turntable 5, and the air is opened to the impact chamber 4 by the fan effect based on the centrifugal force of this air flow. A circulation flow of the airflow that returns from the circulation port 12 to the vicinity of the central portion of the front cover 2 through the circulation circuit 11, that is, a complete self-circulation flow is formed. Since the amount of circulating air per unit time generated at this time is large, an enormous number of air flow circulation cycles are formed in a short time.

Next, the raw material feeding valve 10 is opened, and a predetermined amount of metal irregular-shaped fine particles is fed into the raw material feeding hopper 9 and fed into the apparatus through the raw material feeding pipe 8 in a short time. The raw material feeding valve 10 is closed. Impact chamber 4
After being impacted by a large number of impact pins 16 of the rotating disk 5 that rotates at a high speed, the particle group thrown into is moved along the curved surface portion 16a of the impact pin 16 in the outer peripheral direction while rolling on the curved surface. Between the gradually narrowing curved surface portion 16a and the collision ring 3 is mainly subjected to the action of compressive force and frictional force. Then, accompanying the flow of the circulating gas, the particle group circulates in the circulation circuit 11 and returns to the impact chamber 4 again, and is subjected to the same action again.

In this way, the irregularly shaped fine particles gradually become spherical due to repeated impacts, compression forces, and friction mainly in a short time. The time required for this spheroidizing process is from a few seconds to a few minutes.

After the above spheroidizing process is completed, the on-off valve 13 for discharging the modified powder is opened and discharged. The spheroidized particles are
Due to the centrifugal force acting on itself, it is discharged from the impact chamber 4 and the circulation circuit 11 in a short time, guided through a chute 15 to a powder collecting device such as a cyclone and a bag filter (both not shown), It is collected there.

Using the turntable of the present invention shown in FIGS. 2 and 3 each having an inclination of θ = 30 ° and a diameter of 230 mm, the peripheral speed of the turntable is 90.
Table 1 shows the results of spheroidizing the stainless amorphous particles having an average particle size of x50 = 134 μm at m / sec. The results are compared with the results obtained by using a conventional processing device having a rotating disk.
In the table, x25 / x75 is a ratio between the 25% particle size and the 75% particle size of the cumulative volume distribution, and is a numerical value showing the spread of the particle size distribution of the particles. The closer the value is to 1, the narrower the particle size distribution, and the closer the particles are to particles having a uniform particle size. The average particle diameter of the raw material stainless amorphous particles is 135 μm, and the equivalent spherical equivalent diameter is considered to be 90 to 100 μm.

The particle size distribution was measured using a standard sieve for the raw material and a laser light diffraction scattering particle size distribution measuring device (PRO-7000S manufactured by Seishin Enterprise Co., Ltd.) for the spheroidized product.

Further, FIG. 6 shows a scanning electron microscope (SEM) photograph of the grain structure. In the figure, (a) is the raw material before treatment, (b),
(c) and (d) are SEs of processed products that have been spheroidized with a conventional turntable.
In the M photograph, the processing time is 2 min, 4 min, and 7 min, respectively. In addition, (e), (f), and (g) of the same figure are SEM photographs of the processed products spherically processed by the rotating disk of the present invention, and the processing time is 2 mi each.
n, 4min, 7min.

The average particle size decreases with the processing time regardless of which rotating disk is used, but the change is larger in the conventional type. Further, the numerical value of x25 / x75 is also larger in the conventional type, and therefore, in the processing apparatus having the conventional rotating disk, although the irregular fine particles are spheroidized, it is considerably large. It can be seen that the quantity is crushed. From the SEM photograph shown in Fig. 6, it can be seen that the conventional rotary disk is more crushed and finer.

Example 2 Next, another example of producing composite thermal spray powder for improving wear resistance of a base metal by immobilizing other metal fine particles on the surface of ceramic particles using the same apparatus will be described. .

Change the peripheral speed of the turntable by putting an ordered mixture in which nickel fine particles with an average particle size of 0.3 μm have been attached in advance on the surface of molybdenum boride particles with an average particle diameter of 40 μm by using a mixer. Immobilization treatment was performed. Table 2 shows the status of immobilization treatment observed by SEM.

As shown in the table, when the conventional rotary disk was used, immobilization was poor in the low speed range, and most of the mother particles (molybdenum boride particles) were crushed in the high speed range. On the other hand, when using the turntable of the present invention,
The immobilization was good even in the low speed range, the pulverization of the mother particles was hardly confirmed in the high speed range, and the immobilization was also good. When the rotating disk of the present invention was used, the child particles were well fixed even in the recesses on the surface of the mother particles.

f. Effects of the Invention The following effects are produced by using the solid particle processing apparatus using the rotating disk of the invention.

By subjecting the curved surface of the impact pin and the collision ring mainly to the compressive force and the frictional force, it has become possible to perform the spheroidizing treatment of the irregular fine particles with the crushing suppressed as much as possible.

In particular, by placing the impact pin at the position of the swept wing, the force that disperses the particle group does not change, the impact force that directly acts on the particles becomes weaker than the conventional one, and instead the compression force / friction force is the same as the conventional type. Since it is larger than the ones, various processing can be performed efficiently.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view of a surface reforming apparatus equipped with a rotary disk according to the present invention, FIGS. 2 and 3 are plan and perspective views of the rotary disk, and FIG. 4 is a conventional surface modifying apparatus. Explanatory drawing of No. 5,
The figure is a perspective view of a conventional rotary disk used in the apparatus of FIG. 4, and FIG. 6 is a scanning electron micrograph of the particle structure of solid particles. (b), (c) and (d) show the case of processing with a conventional turntable, and (e), (f) and (g) of the same figure show the case of treating with the turntable according to the present invention. 1 ... Casing, 2 ... Front cover, 3 ... Collision ring, 4 ... Impact chamber, 5 ... Rotating plate, 8 ... Raw material feeding pipe, 9 ... Raw material feeding hopper, 11 ... Circulation circuit, 16 …… Impact pin, 16a …… Curved part.

Claims (3)

[Scope of utility model registration request] 1. A surface reforming device of an impact in an air current for immobilizing another substance on the surface of solid particles to form a film to modify the surface of the fixed particles, or a spheroidizing device for solid particles. A rotary disk provided with impact pins circumferentially provided at intervals on the side surface, the impact pin is formed of a columnar body having a curved surface, and the curved surface is directed in the rotation direction of the rotary disk and outwardly. A turntable characterized by being placed at an angle. 2. The rotary disk according to claim 1, wherein the impact pin is mounted at the position of the swept wing. 3. The rotary disk according to claim 1, wherein the columnar body is a substantially semi-cylindrical body.