JPS6136458B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a classifier, and particularly to an improvement in an air classifier.

Traditionally, airflow classifiers include gravity classifiers,
There are classifiers that use inertial force, centrifugal force classifiers, etc. Among these, the most commonly used centrifugal force classifiers include forced vortex type, free vortex type, etc. There are various types of air classifiers, and there are many types of air classifiers. However, these air classifiers basically have a series of functions for supplying, dispersing, classifying, and discharging the material to be classified.
It is usually used in conjunction with a pulverizer and pneumatic conveyance equipment. The processing process of this pulverization and classification equipment is
To explain with a diagram, a material to be crushed supplied to a fine crusher 1 is crushed, and the crushed product is driven by an exhaust fan 4 to pass through a discharge pipe 2 to a bag filter 3.
The pulverized product is air-transported to the hopper 6, where the pulverized product is separated by the air, and the air is exhausted from the exhaust pipe 5 through the exhaust fan 4, and the pulverized product is temporarily stored in the hopper 6. The pulverized product in the hopper 6 is sent to a transport pipe 8 by a feeder 7, and is supplied as a material to be classified to a classifier 9 through the transport pipe 8, where it is classified into fine powder and coarse powder. Then, the fine powder is air-transported to the bag filter 12 through the transport pipe 11 by the drive of the exhaust fan 10, where it is separated into air and fine powder. is stored in Further, the coarse powder is air-transported to the bag filter 18 through the transport pipe 17 by the drive of the exhaust fan 16, where it is separated into air and coarse powder.The air is exhausted from the exhaust pipe 20 through the exhaust fan 16, and the coarse powder is is stored in the hopper 21.

In this way, the material to be crushed is first pulverized by the pulverizer 1, and then the pulverized product is used as the material to be classified by the classifier 9.
In the pulverization and classification processing equipment that performs classification using a pulverizer 1, large-scale pneumatic transportation equipment is required to supply the pulverized product from the pulverizer 1 to the classifier 9 as a material to be classified.
Not only are the equipment costs and operating costs enormous, but also a great deal of labor and time is spent on maintenance, inspection, maintenance, etc.

On the other hand, in terms of its performance, an air classifier must ideally disperse particles one by one without agglomerating the particles when they enter the classification zone. In addition, in order to achieve good classification accuracy when classifying materials, it is necessary that particles of the same particle size maintain equilibrium with the airflow no matter where they are located in the radial position of the classification chamber. It is necessary to reduce turbulence in the airflow.

The present invention was developed in view of the above circumstances, and it is possible to finely pulverize the material to be classified as a pretreatment for classification, and also to ideally disperse the finely pulverized particles. The purpose is to provide a classifier that can perform classification.

An embodiment of the classifier according to the present invention will be described below with reference to FIGS. 2 to 5. Reference numeral 25 denotes a cylindrical rotor, which is vertically supported rotatably on a pedestal 28 by bearings 26 and 27. It is supported by a rotating shaft 29, and its outer surface is provided with a large number of convex portions 30 along the generatrix line to form an uneven surface. Reference numeral 31 denotes a stator fitted around the outer periphery of the rotor 25 with a constant gap 32, and the inner surface of the stator is provided with a number of convex portions 33 along the generatrix line to form an uneven surface. An annular gap 32 between the rotor 25 and the rotor 25
This is a pre-classification processing section that finely pulverizes the material to be classified by the rotation of the . A centrifugal blade 34 is provided on the outer periphery of the upper end plate 25a of the rotor 25, and correspondingly an inverted conical casing 35 is provided at the upper end of the stator 31, so that a space 36 between the two is provided. This serves as a classification object dispersion section that disperses the finely pulverized object to be classified by the rotation of centrifugal blades 34. An upper disk 37 is provided at the upper end of the centrifugal blade 34, on which a large number of classification plates 38, 12 in this example, are provided radially.A classification disk 89 is provided at the upper end of the classification plate 38, and these three The classification rotor 40 is constructed by the following. A classification casing 41 is provided at the upper end of the inverted conical casing 35 corresponding to the classification rotor 40, and a coarse powder discharge port is provided at a tangential position of the classification casing 41, that is, at a position opposite to the rotational direction of the rotor 25. 42 are provided.
An upper lid casing 43 is provided at the upper end of the classification casing 41, and a fine powder discharge port 45 is vertically provided in the center of the upper lid casing 43, the base end of which fits into the through hole 44 at the center of the classification disk 39. A secondary air intake port 46 with a damper 46a is provided outside the outlet 45. Classifying rotor 4
0, a space 47 formed by the classification casing 41 and the upper lid casing 43 serves as a classification section in which the material to be classified is classified into coarse powder and fine powder by the rotation of the classification rotor 40. A stirring blade 49 is provided on the lower end plate 25b of the rotor 25, and an inverted conical lower casing 50 is provided at the lower end of the stator 31.
9, and a classified material supply port 51 which also serves as an air introduction port is provided on the bottom surface of the container.
The inside of the lower casing 50 uses the airflow generated by the rotation of the stirring blade 49 to feed the material to be classified from the material supply port 51 into the annular gap 32 between the rotor 25 and the stator 81. This serves as a supply section for the classified material. 52 is a pulley fixed to the lower end of the vertical rotating shaft 29, and 53 is a drive belt, which is stretched around the pulley 52 and a pulley (not shown) on the rotating shaft of the electric motor.

As shown in FIG. 6, transport pipes 11 and 17 are connected to the fine powder discharge port 45 and coarse powder discharge port 42 of the classifier 54 of the present invention having such a structure, and bag filters 12 and 18 are provided at the tips of these pipes. An exhaust pipe 14 with an exhaust fan 10 and a hopper 15 are connected to the bag filter 12, and an exhaust pipe 20 with an exhaust fan 16 and a hopper 21 are connected to the bag filter 18.

Next, the operation of the classifier 54 of the present invention will be explained. First, the exhaust fans 10 and 16 shown in FIG. 6 are operated to suck air from the material supply port 51 on the lower surface of the lower casing 50, and
Secondary air is sucked in through the open secondary air intake port 46, and an electric motor (not shown) is driven to drive the drive belt 5.
Classifier 5 when the rotor 25 is rotated at high speed by 3.
The air flow inside 4 will be explained.

The air that is sucked in from the material supply port 51 to be classified and vertically enters the machine is turned into an outward swirling airflow by the stirring blade 49 that rotates at high speed together with the rotor 25, and is sent along the inverted conical inner surface of the lower casing 50. It then rises and enters the gap 32 between the rotor 25 and the stator 31. The airflow entering this gap 32 becomes an upward spiral airflow due to the high speed rotation of the rotor. The airflow that has risen to the vicinity of the centrifugal blades 34 is further rotated by the high-speed rotating centrifugal blades 34, but at this time, since there is an inverted conical casing 35 on the outside, the airflow is While moving upward along the inner surface of the casing 35, the flow becomes an outward swirling flow and reaches the inner surface of the classification casing 41. The outward swirling airflow that has reached the inner surface of the classification casing 41 merges with the secondary air taken in from the secondary air intake port 46, a portion of which is exhausted to the outside of the machine from the coarse powder discharge port 42, and most of the air flows to the rotor. The classifying rotor 40 rotates at high speed together with the classifying rotor 25, which creates an inward swirling airflow that passes through the classifying rotor 40 and is discharged from the fine powder outlet 4.
5 is exhausted to the outside of the aircraft.

Next, a description will be given of the pulverizing and classifying action when a material to be classified is supplied into the air flow inside the classifier 54. The powder and granular material, which is the material to be classified, supplied from the material supply port 51 rides on the outward swirling airflow generated by the high-speed rotation of the stirring blade 49 and flows along the inverted conical inner surface of the lower casing 50. It rises and enters the gap 32 between the rotor 25 and the stator 31. The powder and granular material that has entered this gap 32 is given velocity energy by the rotational force of the rotor 25 rotating at high speed, collides with the stator 31, is crushed, and is crushed by the protrusions 30 of the rotor 25. The particles are subjected to a grinding action between the particles and the protrusions 33 of the stator 31 and are further pulverized into fine particles, which are carried upward by the upward swirling airflow generated by the high-speed rotation of the rotor 25. The fine powder that has risen to the upper end of the gap 32 is sent to the centrifugal blade 34.
Due to the high speed rotation of the particles, the particles are well dispersed without agglomeration and are carried along the inner surface of the inverted conical casing 35 to the inner surface of the classification casing 41 on the outward swirling air current. Further, the fine powder adhering to the coarse powder is separated by the high speed rotation of the centrifugal blade 84 while being conveyed to the inner surface of the classification casing 41. Then, all the fine particles are transferred to the classification rotor 4 by riding the inward swirling airflow generated by the classification rotor 40 rotating at high speed.
0 side, is classified by the classification rotor 40, and only the fine powder passes between the classification plates 38 and is discharged from the machine from the fine powder discharge port 45 along with the air flow, while the coarse powder is classified by the classification plate 38. The particles are blown away and rotated along the inner surface of the classification casing 41 in the same direction as the rotation direction of the classification rotor 40, and are discharged from the coarse powder discharge port 42 to the outside of the machine along with the airflow. The fine powder discharged outside the machine from the fine powder outlet 45 is air-transported to the bag filter 12 through the transport pipe 11 shown in FIG. 6, where it is separated into air and fine powder. The fine powder is exhausted from hopper 1.
5 is stored. Further, the coarse powder discharged outside the machine from the coarse powder outlet 42 is air-transported to the bag filter 18 through the transport pipe 17, where it is separated into air and coarse powder, and the air passes through the exhaust fan 16 to the exhaust pipe. 20
The coarse powder is stored in the hopper 21.

As described above, the classifier of the present invention finely pulverizes the powder or granular material to be classified within the annular gap 32 between the rotor 25 and the stator 31 as a pretreatment for classification, so that the particle size is averaged. In addition, drying is also performed. Further, the finely pulverized particles are well dispersed without agglomeration by the high-speed rotation of the centrifugal blade 34, and the fine powder adhering to the coarse powder is separated, and the inverted conical casing 35
Since the particles are carried to the inner surface of the classification casing 41 along the outward swirling air current along the inner surface of the particle, the particles are uniformly dispersed in the circumferential direction, and the concentration is approximately uniform in the circumferential direction. Furthermore, the fine powder that has entered the classification casing 41 maintains an equilibrium with the airflow, with particles having the same particle size at any radial position, and the airflow inside the classification casing 41 is internalized by the high-speed rotation of the classification rotor 40. The airflow is rectified into a swirling direction, and there is extremely little turbulence in the airflow. Therefore, the classification by the classification rotor 40 is highly accurate, and the amount of fine powder discharged outside the machine together with coarse powder is extremely small. Furthermore, since the classifier of the present invention can perform pulverization of the material to be classified as a pre-treatment for classification, there is no need to combine the pulverizer and pneumatic transport equipment as in the past. It is possible to omit the machine and the pneumatic transportation equipment connected thereto, which has excellent effects such as reducing equipment costs and operating costs for using the classifier, and making maintenance, inspection, maintenance, etc. easier.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a pulverization and classification processing facility in which a conventional classifier and a pulverizer are combined using pneumatic transportation equipment, and FIG. 2 is a longitudinal sectional view showing an embodiment of the classifier according to the present invention. Figure 3 is a cross-sectional view taken along line A-A in Figure 2, Figure 4 is a cross-sectional view taken along line B-B in Figure 2, Figure 5 is a cross-sectional view taken along line C-C in Figure 2, and Figure 6 is a cross-sectional view taken along line C-C in Figure 2. 1 is a schematic diagram showing the pneumatic transportation equipment for fine powder and coarse powder of the classifier of the present invention. 25... Cylindrical rotor, 25a... Upper end plate, 25
b...Lower end plate, 29...Vertical rotation axis, 30...Convex portion, 3
DESCRIPTION OF SYMBOLS 1... Stator, 32... Gap, 33... Convex part, 34... Centrifugal vane, 35... Inverted conical casing, 36... Space of the object distribution part, 37... Upper disk, 38...
Classifying plate, 39... Classifying disk, 40... Classifying rotor, 41... Classifying casing, 42... Coarse powder discharge port,
43... Upper lid casing, 44... Through hole, 45... Fine powder outlet, 46... Secondary air intake port, 47... Space of classification section, 49... Stirring blade, 50... Lower casing,
51... Classified material supply port that also serves as an air introduction port.

Claims (1)

[Scope of Claims] 1. A cylindrical rotor supported by a vertical rotation shaft and having a large number of convex portions along the generatrix of the outer surface, and a rotor fitted with a constant gap between the rotor and the inner surface of the rotor. A classification pretreatment section that finely pulverizes the material to be classified by the rotation of a rotor between a stator having a large number of convex portions along a generatrix, and a centrifugal blade provided on the outer periphery of an upper end plate of the rotor; a to-be-classified material dispersing section that disperses the finely pulverized material to be classified between the inverted conical casing provided at the upper end of the stator corresponding to the blades by the rotation of the centrifugal blade; a classification casing having a coarse powder discharge port in a direction opposite to the rotational direction of the rotor; a classification rotor provided at the upper end of the centrifugal blade and having a through hole in the center; and a classification rotor provided at the upper end of the classification casing and having a centrally located through hole. The upper lid casing has a fine powder discharge port whose base end fits into a through hole, and a secondary air intake port on the outside thereof, and the material to be classified is classified into coarse powder and fine powder by the rotation of the classification rotor and discharged. a classification section, a stirring blade provided on the lower end plate of the rotor, an inverted conical lower casing provided at the lower end of the stator to cover the stirring blade, and an air introduction provided on the lower surface of the lower casing. A classifier having a material supplying part to be classified consisting of a material supplying port that also serves as a material to be classified.