JPH06154709A - Particle classifier - Google Patents

Abstract

PURPOSE:To easily adjust the classifying limit particle size of particles. CONSTITUTION:The secondary air passing through the gaps between the respective louver plates of a louver 40 is sucked into a classifying chamber 20 and a free vortex is formed in the classifying chamber 20. The particles in the classifying chamber 20 are classified by the free vortex and a fine powder flows in a fine powder taking-out pipe 25 and a course powder flows in a discharge passage 30. An adjusting sleeve 45 is connected to the base stand part 42 provided with the respective louver plates 41 by screws and raised to cover the outer peripheral parts of the louver plates 41 to raise the inflow position of the secondary air flowing in the classifying chamber 20. By this constitution, a classifying limit particle size is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a granular material classifier used for producing a granular material such as a toner used for an image forming apparatus. The present invention relates to a classifier capable of classifying powder particles at the classification limit.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electrophotographic copying machine or a printer, toner is attached to an electrostatic latent image formed on a photosensitive drum, and the electrostatic latent image is developed by toner.
An image is formed by transferring the toner image onto a sheet. The toner used in such an image forming apparatus is usually pulverized in a state where raw materials are kneaded and hardened, and a toner having a predetermined particle size is classified by a classifier and taken out.

FIG. 4 shows an example of a particle classifier. This classifier has a cylindrical main body 114. The main body 114
Conical center core 12
1 is arranged concentrically with the main body 114. The outer peripheral edge of the center core 121 is spaced apart from the inner peripheral surface of the main body 114 by a constant distance.
A dispersion chamber 110 in which raw materials are dispersed is formed above 121. The raw material dispersed in the dispersion chamber 110 flows downward through the gap between the outer peripheral edge of the center core 121 and the inner peripheral surface of the main body 114.

At the upper end of the dispersion chamber 110, a pressure feed pipe 11 for pressure-feeding the raw material powder and granules into the dispersion chamber 110 together with high-pressure primary air.
1 is connected in a horizontal state extending in the tangential direction of the dispersion chamber 10, and the primary air and the granular material which are introduced from the pressure feed pipe 111 form a swirling flow in the dispersion chamber 110.
A vertical exhaust pipe 112 penetrates through the central portion of the upper surface 117 of the dispersion chamber 110. A blower (not shown) for sucking excess primary air in the dispersion chamber 110 is connected to the exhaust pipe 112, and the primary air in the dispersion chamber 110 is sucked by the blower. The powdery particles discharged together with the next air are collected by a bag filter provided in the exhaust pipe 112.

A truncated cone-shaped separate core 122 is disposed below the center core 121 with an appropriate interval from the center core 121, and between the separate core 122 and the center core 121. A classification chamber 120 for classifying the raw materials dispersed in the dispersion chamber 110 is formed. Classroom 120
Is a constant gap in the vertical direction along the inclined surface of the separate core 122 except for the axial center portion. The separate core 122 is concentric with the main body 114, and a constant gap is formed over the entire circumference between the outer peripheral edge thereof and the inner peripheral surface of the main body 114.

A lower portion of the separate core 122 in the main body 114 has a discharge passage 130 for discharging coarse particles flowing down through a gap between an outer peripheral edge of the separate core 122 and an inner peripheral surface of the main body 114.
It has become.

As shown in FIG. 5, the separate core 122 is provided with a cylindrical support portion 129 extending downward at the axial center thereof, and the upper end surface of the support portion 129 is opened upward. There is. The upper end of the fine powder extraction tube 125 is inserted into the support portion 129. In order to adjust the height position of the separate core 122, an adjusting ring 150 is interposed in the support portion 129 into which the fine powder extracting pipe 125 is inserted, and the adjusting ring 150 is used for adjusting the fine powder extracting pipe. Mounted on 125. The fine powder take-out pipe 125 passes through the axial center of the discharge passage 130 and penetrates the side surface of the discharge passage 130.

An opening for sucking secondary air is provided around the entire circumference of the classification chamber 120, and the secondary air sucked into the classification chamber 120 is a semi-free vortex inside the opening. A louver 140 for controlling the direction is provided. The louver 140 is provided with a large number of louver plates 141 arranged in parallel with each other at equal intervals.
The secondary air sucked inside passes between the louver plates 141 and flows into the classification chamber 120. Each louver plate 141 is in a predetermined inclined state with respect to the inner peripheral surface of the classification chamber 120 so that the secondary air flowing into the classification chamber 120 becomes a swirling flow in the classification chamber 120. . The secondary air flowing into the classifying chamber 120 is made into a semi-free vortex in the classifying chamber 120, and the granular material flowing into the classifying chamber 120 by the centrifugal force of the semi-free vortex is a coarse particle and a fine powder. Be classified into. Then, the classified fine powder moves to the axial center of the semi-free vortex along the separate core 122, and flows into the fine powder take-out pipe 125 through the supporting portion 129 in the axial center of the separate core 122. Then, the fine powder is taken out from the take-out pipe 125. On the other hand, coarse powder moves to the outside of the semi-free vortex and separate core 122
It flows down from the outside of the peripheral portion into the discharge passage 130 and is taken out from the discharge passage 130.

[0009]

In such a classifier, the classifying limit particle size is adjusted by changing the height of the separate core 122 to change the vertical height in the classifying chamber 120. In this case, as shown in FIG. 5, the height of the separate core 122 with respect to the fine powder extraction pipe 125 is changed by changing the number of the adjustment rings 150 provided in the support portion 129 of the separate core 122. Separate core 122
Is raised, the classification limit particle size in the classification chamber 120 is increased, and conversely, by lowering the separate core 122, the classification limit particle size in the classification chamber 120 is decreased.
However, in order to attach / detach the adjustment ring 150, it is necessary to disassemble the main body 114 of the powder / particle classifier and remove the separate core 122 from the fine powder take-out pipe 125 with the classification work temporarily stopped. However, there is a problem that the classification work efficiency is reduced because it is troublesome.

The present invention solves such problems, and an object thereof is to provide a powdery or granular material classifier capable of easily adjusting a classification limit particle size.

[0011]

The powdery or granular material classifier of the present invention has a vertical shape, and a cylindrical classifying chamber into which the powdery or granular material is introduced, and the classifying chamber through an opening. The air chamber is arranged around the classifying chamber so as to communicate with each other, and is provided in the air chamber through which the air sucked into the classifying chamber passes and the opening in the air chamber, and at a predetermined angle with respect to the radial direction of the classifying chamber. A louver having a plurality of louver plates that are tilted at, the louver has an annular shape surrounding the lower part of the classification chamber, and a base part on which each louver plate is installed, It is characterized in that it has an adjusting sleeve which is fitted to the base portion and screwed together, and which sequentially covers the outer peripheral portion of each louver plate from the lower side by rotation to one side. The above object is achieved.

[0012]

In the powdery or granular material classifier of the present invention, the air that has passed between the louver plates of the louver and is sucked into the classifying chamber becomes a swirling flow in the classifying chamber and is introduced into the classifying chamber. The particles are classified by centrifugal force. An adjustment sleeve is screwed to the base part where each louver plate is provided on the upper surface, and by rotating the adjustment sleeve to cover the outer peripheral portion of each louver plate, the lower end of the air flowing into the classification chamber The position is moved upward, and the classification limit particle size in the classification chamber becomes smaller.

[0013]

EXAMPLES Examples of the present invention will be described below. The classifier of the present invention is used, for example, when manufacturing toner for an image forming apparatus. This powdery or granular material classifier has a cylindrical main body 14 as shown in FIG. The body 14
Conical center core 21
However, they are arranged concentrically with the main body portion 14. The outer peripheral edge of the center core 21 is slightly spaced from the inner peripheral surface of the main body 14, and a dispersion chamber 10 in which the raw materials are dispersed is formed above the center core 21. The raw material dispersed in the dispersion chamber 10 flows down through the gap between the outer peripheral edge of the center core 21 and the inner peripheral surface of the main body portion 14.

At the upper end of the side surface 14 of the dispersion chamber 10, the dispersion chamber is
A pressure-feeding pipe 11 for pressure-feeding the granular material together with high-pressure primary air in 10 is connected in a horizontal state extending in the tangential direction of the dispersion chamber 10, and the primary air and the powder introduced from this pressure-feeding pipe 11 are connected. The granular raw material forms a swirling flow in the dispersion chamber 10.
The exhaust pipe 12 in a vertical state penetrates through the central portion of the upper surface portion 17 of the dispersion chamber 10. The exhaust pipe 12 has a dispersion chamber.
Blower (not shown) that sucks excess primary air in 10
Is connected, and the primary air in the dispersion chamber 10 is sucked by the blower, and the granular material discharged together with the primary air is collected by a bag filter provided in the exhaust pipe 12. It has become.

A truncated cone-shaped separate core 22 is disposed below the center core 21 with an appropriate distance from the center core 21, and between the separate core 22 and the center core 21. A classification chamber 20 for classifying the raw materials dispersed in the dispersion chamber 10 is formed. The classification chamber 20 has a constant gap in the vertical direction along the inclined surface of the separate core 22. The separate core 22 is concentric with the main body portion 14, and a gap is formed between the outer peripheral edge thereof and the inner peripheral surface of the main body portion 14.

The lower portion of the separate core 22 in the main body portion 14 serves as a discharge passage 30 for discharging coarse particles flowing down through a gap between the outer peripheral edge of the separate core 22 and the inner peripheral surface of the main body portion 14.

An upper end portion of a fine powder take-out pipe 25 through which the classified fine powder is taken out is inserted through an axial center portion of the separate core 22, and an upper end surface of the fine powder take-out pipe 25 is provided with an axial center of the separate core 22. There is an opening on the upper surface of the part. The fine powder extracting pipe 25 passes through the axial center of the discharge passage 30 and penetrates the side surface of the discharge passage 30. The separate core 22 is attached to the upper end of the fine powder extraction pipe 25.

A secondary air chamber 26, which communicates with the classification chamber 20 through an opening extending over the entire circumference, is provided around the classification chamber 20 over the entire circumference. In the secondary air chamber 26,
Secondary air sucked from the fine powder extraction pipe 25 passes through. A louver is provided in the secondary air chamber 26.
40 are provided.

As shown in FIG. 1A, the louver 40 has an annular base portion 42 attached to the outer peripheral surface of the discharge passage 30 so as to cover the lower periphery of the classification chamber 20, and the base. Department
On the upper surface of 42, a louver body member 48 having a plurality of louver plates 41 arranged in parallel with each other at equal intervals in the circumferential direction and inclined by a predetermined angle with respect to the radial direction of the classification chamber 20, and Adjustment sleeve 45 fitted to the base part
And. The louver body member 48 is shown in FIG.
As shown in (b) and (b), the annular base portion 42 has a large diameter in the lower portion excluding the upper end portion extending a length L of several mm from the upper end surface, and the screw portion 43 is formed on the outer peripheral surface of the lower portion. Are formed. Each louver plate 41 provided on the upper surface of the base part 42
Has a streamlined shape in which the base end portion located on the outer peripheral side of the classification chamber 20 is thick and becomes gradually thinner toward the tip end portion located on the inner peripheral side.

The adjusting sleeve 45 fitted to the base 42 is
As shown in FIGS. 3 (c) and 3 (d), the upper end portion over the length L has substantially the same diameter as the upper end portion of the base portion 42, and the inner peripheral surface excluding the upper end portion, A screw groove 46 that is screwed into a screw portion 43 provided on the outer peripheral surface of the base 42 is provided. Therefore, in the most lowered state, the adjustment sleeve 45 has its upper end surface at the same height as the upper end surface of the base portion 42 as shown in FIG. 1A, and the adjustment sleeve 45 and the base portion. A thread groove 46 and a threaded portion on the upper end of 42 respectively
Since 43 is not formed, there is no possibility of further lowering from this height position. Then, as the adjusting sleeve 45 is rotated in a predetermined direction, the adjusting sleeve 45 is raised with respect to the base portion 42 to move the outer peripheral portion of each louver plate 41, as shown in FIG. It is designed to cover from the bottom side.

In the classifier having such a structure, the granular material introduced into the dispersion chamber 10 above the main body 14 is moved to the outer periphery of the dispersion chamber 10 by the swirling flow, and the center core 21 and the inner peripheral surface of the main body 14 to pass through the lower classification chamber 20.
Flows in. The secondary air that has passed between the louver plates 41 of the louver 40 is sucked into the classification chamber 20 so as to form a semi-free vortex, and the secondary air that has flowed into the classification chamber 20 is separated from the separate core 22. While flowing along the inclined upper surface, a semi-free vortex is formed, and the centrifugal force causes the powder or granular material that has flowed into the classification chamber to be classified into coarse particles and fine particles. Then, the classified fine powder is separated into the classifying plate 22 on the axis of the semi-free vortex.
Along with the fine powder take-out pipe 25, the fine powder takes out from the fine powder take-out pipe 25. On the other hand, the coarse powder moves to the outside of the semi-free vortex, flows into the discharge passage 30 through the space 22c between the shaft center portion 22a and the guide portion 22b of the separate core 22, and the discharge passage 30 Taken out from 30.

In such classification, the adjusting sleeve 45
As shown in FIG. 1 (a), the adjustment sleeve 45 is rotated to raise the adjustment sleeve 45 so that the louver plate is not covered with the outer peripheral portion of the louver plate 41. When the outer circumference of 41 is covered, the classification room
The classification limit particle diameter within 20 becomes small. This is because the inflow position of the secondary air is above the classification chamber 20. For example, if the height H of each louver plate 41 is 40 mm,
As shown in FIG. 1A, when the adjusting sleeve 45 is lowered to the lowermost position and each louver 41 is not covered with the adjusting sleeve 45, the fine particle extracting pipe 25 has a limit particle diameter of 1
While fine powder of 0.8 μm or less is taken out, Fig. 1
As shown in (b), the adjustment sleeve 45 is manually rotated to raise the adjustment sleeve 45, and the lower half of each louver plate 41 is covered with the adjustment sleeve 45. When the secondary air was passed through the upper half over H1 (= 20mm), the fine powder extraction pipe 25
A fine powder of 9.9 μm or less was taken out from.

As described above, the limit particle size of the fine powder to be classified can be adjusted steplessly by a simple operation of rotating the adjusting sleeve 45 while the classifier is operated.

[0024]

As described above, the powdery or granular material classifier of the present invention is
When air is sucked into the classification chamber through the louver plates of the louver, the adjustment sleeve screwed to the base part where the louver plate is installed is rotated to cover the outer peripheral part of each louver plate. By changing the inflow position of the air and thereby changing the classification limit particle size, the classification limit particle size can be adjusted easily and steplessly.

[Brief description of drawings]

FIG. 1A is a sectional view showing a louver used in a powder or granular material classifier of the present invention, and FIG. 1B is a sectional view for explaining the operation thereof.

FIG. 2 is a vertical sectional view showing an example of a powdery or granular material classifier of the present invention.

3A is a perspective view showing a louver main body member of a louver used in the powder or granular material classifier of the present invention, FIG. 3B is a side view thereof, and FIG. 3C is a perspective view showing an adjustment sleeve of the louver. , (D) is a side view of the adjusting sleeve.

FIG. 4 is a vertical cross-sectional view showing a conventional powder or granular material classifier.

FIG. 5 is a perspective view of a main part of a conventional powder or granular material classifier.

[Explanation of symbols]

 10 Dispersing chamber 20 Classifying chamber 21 Center core 22 Separate core 26 Secondary air chamber 30 Exhaust passage 40 Louver 41 Louver plate 42 Base part 43 Screw part 45 Adjustment sleeve 46 Screw groove 48 Louver body member

Claims (1)

[Claims] 1. A cylindrical classifying chamber having a vertical shape and into which powder particles are introduced, and the classifying chamber is arranged around the classifying chamber so as to communicate with each other through an opening, An air chamber through which the air sucked into the classification chamber passes, and a louver provided at the opening of the air chamber and having a plurality of louver plates inclined at a predetermined angle with respect to the radial direction of the classification chamber, The louver has an annular shape surrounding the lower part of the classification chamber, and a pedestal portion on which each louver plate is installed is fitted to the pedestal portion and screwed to the pedestal portion. , And an adjusting sleeve that sequentially covers the outer peripheral portion of each louver plate from below by rotating the louver plate in one direction.