JPS6178474A - Classification of powder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of industrial application> The present invention relates to a powder classification method for separating powders of different particle sizes into predetermined particle sizes.

<Prior Art> As such a classification method, methods using centrifugal force, such as those using a cyclone-type separator S*, are known. The one using the cyclone type minute JI It a is the fifth one.
As shown in the figure, a fluid containing one class of powder is fed from the inlet pipe C along the inner peripheral surface of the conical tube, the fluid is swirled and flows downward, and is reversed at the lowest end. A flow path is created in which the fluid is discharged from a discharge pipe d passing through the center of the conical cylinder, and while the fluid is swirling and descending, particles in the fluid are subjected to the action of centrifugal force. , it gradually comes into contact with the inner surface of the conical cylinder and falls down through its neck into the collection chamber e at the lowest end.

In other words, when looking at the particle recovery process in such a cyclone separator a, as shown in FIG. At the same time, the force y in the feeding direction due to the downward flow is obtained, and the combined force of these two forces causes large particles to be One by one, the object collides with the wall and slides down.

When classifying using this separator, as shown in Figure 6, the separators with different outlet diameters are arranged and connected in series so that the outlet diameter becomes smaller toward the downstream. I11
Each machine will be classified sequentially starting from the high flow side.

<Problems to be Solved by the Invention> By the way, in a method of sequentially connecting the cyclone type separating machines and collecting particles of a predetermined particle size with the machine,
The device becomes oversized, and the device cost and power load are large, making it extremely uneconomical.

The present invention corrects the conventional drawbacks and provides good classification.
The purpose of this invention is to provide a method for classifying powder.

Means for Solving the Problems> The uninvented invention provides one to several collection slits at predetermined intervals in the axial direction on the inner circumferential surface of the cylinder, and collects the powder-containing fluid fed into the cylinder. , the fluid is guided so as to form a swirling flow along the inner peripheral surface of the cylinder, and the powder in the fluid is sequentially collected from the large-diameter particles by the annular collection slit 111j.

Here, the term cylinder is a concept that includes all cylindrical bodies with a circular cross section, such as a right cylinder, a conical cylinder, or a combination of a straight cylinder and a conical cylinder.

Function: A fluid such as gas or liquid containing powder is fed along the inner peripheral surface of the cylinder. The particles in this fluid collide with the wall surface in order, mainly from large particles, due to the action of centrifugal force accompanying the swirling. At this time, collection slits are formed on the circumferential surface at predetermined intervals, and each collection slit sequentially collects items from large diameter items to small diameter items along the flow in the sleeve direction.

Then, along the axis, particles having a constant distribution of particle sizes are classified for each collection slot.

<Example> Figures 1 and 2 show an example in which the present invention is applied to a cyclone type separator.

Here, ■ is a cylinder, which is formed by coaxially connecting a right circle n2 on the inlet side and a conical cylinder 3 whose diameter becomes smaller toward the end, and the upper end of the right cylinder 2 is connected as shown in Fig. 2. As shown, an inlet pipe 4 is provided along the tangential direction of the circumferential surface.

In addition, a discharge pipe 5 is provided along the sleeve of the cylinder in the central part of the cylinder l.
is provided.

Further, the lower end of the conical cylinder 3 is open and communicates with the recovery chamber 6.

Annular collection slits 7 are formed at predetermined intervals on the outer periphery of the conical cylinder 3 on a surface perpendicular to the sleeve, and a collection chamber 8 is provided in which each annular collection slit 7 is communicated from the outer periphery of the cylinder 1 to a powder collecting tank.
covered with

The operation of the above embodiment will be explained.

Powder-containing gas (or liquid) fed from the artificial tube 4 of the cylinder 1 to the inner circumferential surface of the right cylinder 2 from the νJ line direction K) and swirls on the inner circumferential surface of the right cylinder 2. , gradually descending. As mentioned above, the particles in this fluid, during their swirling flow, exert a centrifugal force X that is proportional to their quality and a force Y in the feeding direction due to the downward flow of air! It can be done. Therefore, due to the combined force of the two forces, particles of large size collide with the wall side and fall in layers, and the coarse particles are absorbed by the annular collection slit 7 at the top and collected into the collection chamber 8. - The diameter of the particles absorbed by each annular collection slit 7 becomes smaller as one goes downstream, and finally the fine particles are collected into the collection chamber 6 communicating with the lower end of the conical cylinder 3. At this time, since annular collection slits 7 are formed at predetermined intervals in the conical cylinder 3, the radial distance from the sleeve of the cylinder, which is the center of one rotation, to the inner circumferential surface of the cylinder l becomes smaller as it goes downstream, and the inner circumferential surface of the particles in the fluid becomes smaller. As the distance traveled by the particle becomes shorter and the centrifugal force increases as the angular velocity increases, each particle rapidly collides with the inner surface 651.

Therefore, even if a large number of annular recovery slits 7 are formed in the conical cylinder 3 as shown in FIG. 1, one particle can be separated well.

After collecting such particles, the gas is reversed from the lower part of the cylinder 1 toward its center, ascends vertically through the center of the cylinder 1, and is discharged from the discharge pipe 5.

Therefore, it becomes possible to perform fine classification using - cyclone type separators. Incidentally, by connecting a plurality of the above-mentioned classifiers, it is possible to perform rough classification.

In the cyclone type separator, the number of annular recovery slind doors can be set as desired; one in the middle of the cylinder l and two in the recovery chamber 6 below, as shown in Figure 3. In the device shown in the m3 diagram, the inner diameter of the upper end of the conical cylinder 3 is larger than the inner diameter of the right cylinder 2, and
A reverse circle j41 whose diameter expands downward between the right circular cylinder 2° and the conical cylinder 3
They are connected by tube 9. This inverted conical cylinder 9 is similar to the right circular cylinder 2.
Powder in the gas fed by a swirling force from the upper end collides with the inner wall of the right cylinder 2, and due to the reaction, the powder in the gas
．． This prevents the pie and gas flow from being discharged from the discharge pipe 5 along with the flow of the pipe 1, and guides it to the inner circumferential surface of the conical cylinder 3 by the slope of the inverted conical cylinder 9.

In addition, in the case of such a configuration, +'t+
As the modification decreases, the centrifugal force weakens, and the particles slowly move toward the wall due to the downward flow. Therefore, the movement in the wall direction, which is proportional to the particle fixation, is expanded in the flow direction. Therefore, it becomes possible to selectively collect large-sized particles.

In addition, in order to generate a swirling flow in the tit body in the configuration shown in Fig. 1.3, guide vanes may be provided in the tube as shown in Fig. 4, and the flow may be generated by the guiding action of the guide vanes. good.

FIG. 4 shows the embodiment of the present invention using a cylinder 10 of four horizontal types.

The lnin diary 10 is composed of a right cylinder 11, a conical cylinder 12 coaxially continuous with the right cylinder 11 and whose diameter decreases as it goes downstream, and an outlet cylinder 13 communicating with the conical cylinder 12. A guide vane 14 is provided within the right cylinder 11. Also, between the right circle nll and the conical cylinder 12.

Approximately the center of the circle 'A cylinder 12, the conical cylinder 12 and the outlet cylinder 131
Annular recovery slits 15 are formed at predetermined intervals on the circumferential surface of each JI, and the outer periphery of each of the annular recovery slits 15 is covered with a recovery chamber 16 that communicates with a recovery tank.

In the above embodiment, the gas containing the powder was transferred to the right cylinder 11.
When the guide blade 14 is fed from the end, a turning force is applied by the guide vane 14. Therefore, the fluid swirls along the inner peripheral surface of the right cylindrical cylinder 111 and the conical cylinder 12, and then flows out into the cylinder 13.

During this turn, Iiii! By the collection mechanism described above, the powder in the gas is sequentially collected by the collection slit (15) and then collected into the collection chamber (16). With this! The diameter of the particles collected in each collection chamber 16 becomes smaller as it goes downstream, and each collection chamber 16 has the ability to collect different powders corresponding to the particle diameter (aj+l). becomes.

+iii In each embodiment, the cylinder axis of the cylinder 1.10 does not necessarily have to be a perfect 1tlZ line.

Further, the collection slits do not necessarily have to be annular along the circumference, and may be formed at appropriate intervals in the circumferential direction.

Furthermore, in each of the embodiments described above, the recovery slits were provided at or immediately before the conical tubes 3, 12, but they may be provided sequentially on the right cylinder.

In addition, there are various shapes of the cylinder into which the planar recovery slit is inserted, and various types of inflow paths for the fluid can be selected. ').

Effect> Recovery slits are formed at predetermined intervals in the axial direction on the inner circumferential surface of the cylinder, and a swirling flow is generated along the inner circumferential surface of the cylinder in the powder-containing fluid fed into the cylinder. Since the collection slit allows particles to be collected in order from large to large, it is possible to classify them even with a funeral device, and the particle size distribution of each collected particle can have a steep rise, allowing for good classification. There are excellent effects that can be achieved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view of a cyclone type separator to which the present invention is applied, and FIG. 2 is a sectional view taken along the line A--A in FIG. 1. Figure 3 is a longitudinal side view of another Cyclono-type molecular machine. Fig. 4 is a longitudinal side view of a horizontally placed separator to which the present invention is applied, Fig. 5 is a longitudinal side view of a conventional cyclone type separator, and Fig. 6 is a conventional method using the cyclone type separator. FIG. i, to...Cylinder 2.11...Right cylinder 3.12...Conical cylinder 7.15...Recovery slit 9...Inverted conical cylinder

Claims (1)

[Scope of Claims] 1) One to several collection slits are provided at predetermined intervals in the axial direction on the inner circumferential surface of the cylinder, and the powder-containing fluid fed into the cylinder is 2) A method for classifying powder in which the cylinder is guided to form a swirling flow along the flow, and the powder in the fluid is sequentially collected from large-diameter particles by the annular collection slit. Claim 1) The method for classifying powder according to claim 1) is characterized in that the cylinder is a conical cylinder whose diameter decreases as it goes downstream.3) Claim characterized in that the cylinder is a right cylinder. 4) The method for classifying powder according to claim 1), wherein the cylinder is a conical cylinder whose diameter increases as it goes downstream and further decreases in diameter. Classification method of powder described