JPS63194782A - Sorter for fine 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 [Industrial Application Field] The present invention relates to a fine powder classification apparatus, and more particularly to a dry fine powder classification apparatus for solid materials entrained in gas.

[Prior Art] In response to the demand for the production of micron-level particles and submicron-level particles, the above-mentioned fine particles are obtained by pulverizing the pulverized product using a pulverizer and classifying the pulverized product. There is a strong demand for precision.

Conventionally, various devices have been proposed as this type of fine powder classification device, depending on the operating force required for classification. Things are being suggested.

] The under effect is a phenomenon in which when fluid flows along a wall surface at high speed, it adheres to a curved surface such as a cylindrical wall and flows. (For example, "Mechanical Engineering Handbook" revised 6th edition (Showa 54.7)
．． 20), P8-15'').

As a conventional fine powder classifier that utilizes inertial force and the Coanda effect, an elbow jet classifier and the like have been attempted. (For example, the Society of Chemical Engineers, “Powder and Granule Engineering,” (1986,
11.1. ), Maki Shoten, P2S5).

Elbow-jet classifiers consist of a two-dimensional non-rotating classifier that uses the Coanda effect to change the direction of airflow without using any mechanical methods. Classification is performed using the operating force.
Air is blown in to carry away the particles, and the fine powder floats and moves on the streamlines of the airflow, and the coarse powder flows straight down due to inertia, so the fine powder is classified into fine powder and coarse powder. be able to.

In addition, in order to sufficiently generate the Coanda effect, the Re number determined by the width dimension (representative of the thickness) of the tip opening of the airflow inflow region, the speed of the airflow, and the viscosity of the air must exceed a predetermined Re number. It is necessary to blow out the airflow beyond.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional fine powder classification devices, especially in the classification devices that utilize the Coanda effect, the width of the opening at the end of the airflow inflow region is large, and the thickness of the airflow is large. In some cases, it has not been possible to generate a sufficient Coanda effect, and to avoid this it has been necessary to significantly increase the velocity of the airflow. On the other hand, if the width of the tip opening is small and the thickness of the airflow is small, the airflow membrane is likely to rupture and a stable Coanda effect cannot be generated. Furthermore, since the airflow cannot be guided over a wide range of the surface of the classifier, there is a problem in that the fine powder cannot be classified sufficiently and the classification accuracy is reduced.

The present invention solves these conventional problems,
The object of the present invention is to provide an excellent fine powder classification device that can significantly improve the Coanda effect and improve the classification accuracy when classifying fine powder entrained in gas.

Means for Solving Problems] In order to achieve the above object, the present invention includes a rotating cylindrical classifier, an inlet region for gas containing particles provided in the upper half of the classifier, A classification region, in which the gas flows along the surface of the classification body in the rotating direction of the classification body, provided in the lower half of the classification body, a plurality of partitioned areas provided in the circumferential direction of the classification area, and a classification area from the partitioned area. The particles are discharged individually, and
Adjacent to the inflow area of the gas containing particles, an inflow area of only gas having a flow direction substantially parallel to the inflow area is placed, and furthermore, the divided area of the classification area is a coarse powder area, It consists of an intermediate powder region and a fine powder region.

[Function] The present invention has the following effects due to the above configuration. In other words, when classifying fine powder that is accompanied by a gas, the gas containing particles becomes a viscous fluid and flows along the surface of the classifier without causing any airflow turbulence. Not only does this further promote the adhesion of the gas, but also the adhesion of the gas continues to the end of the surface of the classifier, so the fine powder is collected from the downstream side of the gas flow, and the fine powder, especially the fine powder, is mainly separated. As a result, the classification accuracy in fine powder classification can be significantly improved, corresponding to the inertial separation of coarse powder with less change in gas flow direction.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the configuration of an embodiment of the present invention.

In FIG. 1, 10 represents a classifier, 18 represents an inflow area for gas containing particles, and 12 represents a classifier. The classifier 12 has a cylindrical shape, has central shafts (not shown) at both ends, is rotatably supported, and is rotated clockwise as shown by the arrow using a drive device. 14 is a collar provided at both ends of the classifier 12. Reference numeral 16 indicates an upper casing, which is provided to accommodate the lower half of the classifier 12, and includes the gas inflow region 18, and the tip opening of the gas inflow region 18 is located in the upper half of the classifier 12. A fine powder supply port 22 is attached to the upper casing so as to be in contact with the cylindrical surface in a substantially perpendicular direction, and on the opposite side of the opening at the tip of the inflow region 18 . A classification region is formed in the lower half of the classification body 12 as the classification body 12 rotates, in which the inflowing gas flows along the cylindrical surface in the direction of rotation. The space away from the circumferential cylindrical surface of the classification area is divided into compartment areas 28.30°32,
The compartment area 28 is a coarse powder area, the compartment area 30 is an intermediate powder area, and the compartment area 3
2 are each divided as a fine powder area. Moreover, it is also possible to have a configuration in which the partition area 30 is omitted.

Reference numeral 26 indicates a lower casing, which is provided to accommodate the lower half of the classifier 12, 34 indicates an inductor fixedly attached to the lower casing 26, and similarly, 36 indicates an inductor of the lower casing 26. The inductor is shown fixedly attached at a position opposite to 34. The conductive plate 46 is the inductor 34
The conductive plate 48 and the conductive plate 46 together form a divided area 30 , and the inductor 36 and the conductive plate 48 form a divided area 32 .

The surface shapes of the inductor 34, the conductive plate 46, the conductive plate 48, and the inductor 36 are substantially streamlined to suppress the occurrence of turbulence in the airflow as much as possible.

The ends of the conductive plates 46 and 48 are each adjacent to the cylindrical surface of the classifier 12 to ensure the formation of a classified region as the gas flows along the cylindrical surface.

The other end of the conductive plate 46 is fixed to the shaft 50.
Due to the rotation of the guide plate 4, using a connecting member (not shown)
Since the position of 6 can be moved, the partitioned area can be adjusted movably and hung.

Reference numeral 38 indicates a coarse powder discharge port, 40 indicates an intermediate discharge port, and 42 indicates a fine powder discharge port, all of which are installed corresponding to the coarse powder area 28, intermediate powder area 30, and fine powder area 32 in the lower casing 26, respectively. The coarse powder, intermediate powder and fine powder from the classification area are separated and discharged with the air flow.

Upper casing 16 is provided with voids 56 and 58 on opposite sides of the cylindrical surface adjacent to fines zone 32 and connected to passages 52 and 54, respectively. Overpressure fluid is introduced into the passage 52 from the outside, while the overpressure fluid is sucked into the passage 54, thereby creating an airtight effect in the vicinity of the gaps 56 and 58 and maintaining fluid pressure balance. The gas flowing through the classification area is prevented from moving onto the surface of the upper half of the classification column.

Next, the operation of the above embodiment will be explained. In the above embodiment, when the classifier 12 rotates clockwise, the gas acts as a viscous fluid on the cylindrical surface, where a large viscous force acts, adheres to the surface, and flows, and at a location away from the surface, the gas has a strong viscous force. The flow is turbulent due to the large inertial force. The fine powder flows into the inflow area 1 as a gas containing particles along with the airflow.
8, the particles are sufficiently dispersed and suspended in the airflow to be in a state suitable for classification, and then flowed in from the tip opening of the inlet region 18 so as to be in contact with the cylindrical surface of the classifier 12. The inflowing gas adheres to the cylindrical surface of the classifier 12 due to the under effect and flows like a lump (as described above), forming a classified region of fine powder, and the direction of gas flow is sharply changed. The fine powder is guided to the end of the classifier 12 along with the airflow in the classification area, is discharged from the compartment area 28, and is collected by a collection device (not shown). In addition, the coarse powder component of the particles contained in the gas passing through the classification area is linearly moved in the inflow direction by the inertia force based on the velocity of the coarse powder that corresponds to the velocity of the gas. Flow, the above-mentioned classified body 1
The particles fly in a direction away from the cylindrical surface of 2, are guided along with the airflow, are discharged from the compartment 28, and are collected by a collecting device (not shown).

Similarly, the intermediate powder component among the particles contained in the gas passing through the classification region flies with a motion that is approximately intermediate to that of the fine powder component and the coarse powder component, and is guided along with the airflow. It is discharged from the compartment area 30.

As described above, the gas containing particles, especially ultrafine particles, becomes a viscous fluid and flows along the surface of the classifier, further promoting the adhesion of gas due to the Coanda effect and flowing to the end of the classifier, resulting in a flow of gas. Corresponding to the inertial separation of coarse powder with less direction change, the flow direction change of fine powder is significantly increased, and fine powder is collected from the end downstream of the gas flow. Fine powder classification is performed to separate the powder. In addition, the conductive plates 46 and 48 prevent coarse powder from being drawn into the fine powder side and intermediate measurement, or fine powder from being drawn into the coarse powder side and intermediate measurement.
The classification accuracy in classifying fine powder can be improved.

Next, other embodiments will be described. In the configuration shown in FIG. 1, reference numeral 20 indicates an inflow region for gas only, which is placed in the upper casing 16 in the upper half of the classifier 12, adjacent to the inflow region 18 for gas containing particles. In order to obtain a flow direction substantially parallel to the inflow region 18, the tip opening of the gas-only inflow region 20 is positioned to open substantially tangentially to the cylindrical surface of the upper half of the classifier 12. Further, on the opposite side of the opening at the tip of the inflow region 20, an air supply port 24 is attached to the upper casing. Therefore, in this embodiment, the gas containing particles from the inflow region 18 flows into the rapidly expanded area and the airflow is prevented from being disturbed by the jet of gas from the inflow region 20, and the classified body 12 is prevented from being disturbed. Since it can be smoothly transferred to the classification area, the classification accuracy of fine powder can be further improved.

Note that the embodiments of the present invention are not limited to the above-mentioned embodiments, and many embodiments such as a classification body, an inlet region, a partition region, etc. can be used.

[Effects of the Invention] As is clear from the above embodiments, the present invention roughly supports the adhesion of gas due to the under effect along the surface of the classified body, so that the gas adhesion continues to the end of the classified body. When classifying fine powders that are accompanied by gas, the Coanda effect can be significantly improved, and the fine powders, especially fine powders, adhere to the surface of the classifier and move to be separated, thereby significantly improving the classification accuracy. The practical effects that can be achieved are enormous.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a fine powder classification device in an embodiment of the present invention.

Claims (3)

[Claims] (1) A rotating cylindrical classifier, an inlet area of the gas containing particles provided in the upper half of the classifier, and a flow direction of the gas containing particles in the rotation direction of the classifier provided in the lower half of the classifier. A device for classifying fine powder, comprising: a classification region that flows along the surface of a classification body; a plurality of divisions provided in the circumferential direction of the classification region; and discharge of classified particles from each of the divisions. (2) Adjacent to the inflow region of gas containing particles, an inflow region of only gas having a flow direction substantially parallel to the inflow region is disposed. fine powder classification equipment. (3) The apparatus for classifying fine powder according to claim 1, wherein the classification area consists of a coarse powder area, an intermediate powder area, and a fine powder area.