JPH0327277B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an air classifier used in the production process of ultrafine powder of high-purity ceramics, metal compounds, engineering plastics, etc. used in high technology industries, especially The present invention relates to the rotating classification rotor.

[Conventional technology]

An example of this type of prior art is the one described in Japanese Patent Publication No. 61-212370.

That is, in this prior art shown in FIGS. 7 and 8, a tubular fine powder outlet 2 is provided on one side of the cylindrical upper part of the classifier body 1, and a bearing concentric with the outlet 2 is provided on the opposite side. 3 is provided, and a classification rotor 5 is fixed to the inner end of a drive shaft 4 supported by this bearing 3. Further, a lid 6 at the upper end of the main body 1 is provided with a conduit 7 for raw materials and primary air.

FIG. 8 shows details of the classification rotor 5, in which a drive disk 8 fixed to the drive shaft 4 and an outlet disk 9 facing this disk 8 are connected by a plurality of spacer pins 10.
A plurality of blades 1 made of a highly wear-resistant ceramic material are connected together with the spacer pins 10 between each spacer pin 10.
Install 1.

Both ends of each blade 11 are held in recesses provided in both discs 8 and 9 with some margin by fitting them through rings made of an elastic material.

Further, the spacer pin 10 is made of metal, and its outer side is surrounded by a sleeve 12 made of a highly wear-resistant ceramic material.

In the case of this prior art, the raw material conduit 7 along with the air
The raw material that has entered the main body 1 from around the classification rotor 5 flows into the rotor 5, is changed direction along the inner surface shape of the drive disk 8, and is passed through the central opening of the outlet disk 9 to the fine powder outlet. It flows through to 2.

[Problem that the invention seeks to solve]

In the above conventional technology, each blade 11 of the classification rotor is made of a highly wear-resistant ceramic material, so there is little wear, and the spacer pin 10 is also surrounded by a sleeve 12 made of a wear-resistant ceramic material. Wear is significantly lower.

In addition, the blade 11 is attached to the disk 8 with some margin.
9, there is an advantage that even if there are variations in the dimensions of the blades 11 that are characteristic of ceramics, there is no fear that the blades 11 will be damaged due to excessive force.

However, in the above conventional technology, the spacer pin 1
0 is fixed to the discs 8 and 9 by set screws, and the sleeve 12 is fitted on the outside thereof, so no blades can be provided in this part.

For example, in the case of a 200mmφ classification rotor, there are approximately 64 blades with a pitch of approximately 10mm, but if spacer pins are installed at four locations, two to three blades are required for the spacer pins and their outer sleeves. Therefore, the number of blades is reduced by 8 to 12, and the classification efficiency is considerably reduced.

Furthermore, if a cylindrical sleeve is made of ceramic material, it will not be the correct cylinder and will be slightly distorted, and precision machining will be required to fit the spacer pin into it, leading to higher costs. arise.

Therefore, it is an object of the present invention to provide an air classifier with improved wear resistance without using spacer pins or sleeves as in the above-mentioned prior art, and without reducing classification efficiency. .

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention uses composite blades in predetermined locations of the classification rotor as composite blades made by bonding metal plates and ceramic plates, and also uses the metal of the composite blades as a driving disk for transmitting rotational force. The blades are firmly fixed to the exit disk by welding, the other blades are made of ceramic material, and both ends are attached to the two disks with a slight gap, and all the blades of the classification rotor are is a composite structure of ceramic and metal plates, and the metal plates of certain blades of this composite structure are firmly fixed by welding to the drive disk and the exit disk for rotational force transmission, and both ends of the other blades are It is attached with a slight gap between the two discs.

[Effect]

When the classification rotor rotates inside the classifier, the raw material supplied into the classifier body is classified by the centrifugal force of the rotating classification rotor blades, and the fine powder is passed from the outer periphery of the classification rotor between the blades with the airflow. The powder flows toward the center, while the fine powder descends inside the classifier body.

During the above process, the raw material collides with the blades of the classification rotor, but since these blades are made of wear-resistant ceramic material or a composite material of ceramic and metal, wear is extremely low, and therefore, Contamination into the raw material due to this wear is extremely low.

Further, since the metal plate that transmits the rotational force of the drive disk to the outlet disk is also a composite blade equipped with a ceramic plate, it functions as a blade and does not reduce the classification efficiency.

〔Example〕

In the embodiment shown in FIGS. 1 to 3, 1
4 is the main body of the classifier, and there is a bearing 15 on the upper end of the main body.
A classification rotor 17 is provided at the lower end of the drive shaft 16 supported by this bearing 15, and the drive shaft 16 is connected to the motor 1.
8 via a belt.

Further, a fine powder outlet 19 is provided on one side of the main body 14,
Its inner end is bent upward to form a fine powder inlet 20 facing the classification rotor 17.

A raw material conduit 21 is provided on one side of the lower part of the main body 14,
The inner end is bent upward to form an opening 22.

2 and 3 show details of the classification rotor 17, 25 is a drive disk fixed to the lower end of the drive shaft 16, and 26 is an exit disk.

The above-mentioned disks 25 and 26 are joined together by a plurality of metal plates 27, and ceramic blades 28 are arranged between each metal plate 27 at a constant pitch.

Each of the metal plates 27 has both ends connected to both disks 25 and 2.
A ceramic plate 29 is attached to the side surface of the rotor 17, which becomes the front surface when the rotor 17 rotates.
are firmly bonded using an adhesive to form a composite blade 30. The ceramic plate 29 is divided into a plurality of parts as shown in FIG. 2 to prevent the ceramic plate 29 from being peeled off even if the metal plate 27 is slightly deformed.

Both ends of each ceramic blade 28 are provided with both discs 25, 2.
6 Fit into each recess 31, 32 with an appropriate gap. This gap is provided to allow movement of the blade 28 in the longitudinal direction and also to allow some movement in the circumferential direction.

In the above embodiment, when the classification rotor 17 is rotated by the motor 18 and the raw material is supplied into the main body 14 along with the airflow from the conduit 21, the raw material is generated by the exhaust fan installed at the fine powder outlet 19 (not shown). The airflow rises with the generated airflow, is classified by the blades 28 and 30 of the rotating classification rotor 17, passes between the blades 28 and 30, enters the rotor 17 from around the classification rotor 17, and is classified into fine powder. The particles change their direction in the axial direction along with the airflow, pass through the fine powder inlet 20, and exit from the fine powder outlet 19. On the other hand, the fine powder separated from the fine powder falls into the main body 14 and either rides on the upward airflow again or accumulates at the bottom of the main body 14.

During the rotation of the classification rotor 17 described above, the rotation of the drive disk 25 is controlled by the outlet disk 26 by each metal plate 27.
is transmitted, and each blade 28 rotates together with the disks 25 and 26.

In the embodiment shown in FIGS. 4 and 5, all the blades are composite blades in which a plurality of ceramic plates are attached to a metal plate.

In this case, the rotational force of the driving disk 25 is transferred to the exit disk 2.
Both ends of the metal plate 34 of the composite blade 33 transmitted to the blade 33 are fitted into the recesses of the discs 25 and 26 and firmly fixed by welding, and a plurality of ceramic plates 35 are fixed to the sides of the blade 33.

Further, as described above, both ends of the plurality of metal plates 36 located between the metal plates 34 fixed to the disks 25 and 26 have appropriate gaps in the recesses 37 and 38 of both disks 25 and 26. However, this gap allows movement of the metal plate 36 in the longitudinal direction and a slight movement in the circumferential direction.

Further, a plurality of ceramic plates 39 are attached to the side surfaces of the metal plate 36 to form a composite blade 40.

It goes without saying that the ceramic plates 35 and 39 are attached to the side surfaces of the metal plates 34 and 36, which are the front surfaces when the rotor 17 rotates.

In FIG. 6, a metal plate 34 and a ceramic plate 35 are provided with stepped portions a and b, respectively, and these stepped portions a and b are bonded together in an engaged state. Such a configuration improves adhesive strength.

In addition, in the case of ceramic materials that are difficult to form into a plate, for example, a mixed material of fine ceramic powder such as γ-alumina powder or silica (SiO ₂ ) powder and an appropriate binder is applied to the surface of the metal plate. In some cases, a metal plate with a wear-resistant ceramic layer provided on its surface is used as the blade. Furthermore, fine powder of the raw material may be used as long as it has wear resistance.

In this case, as in Figures 4 and 5, both ends of the metal plate for transmitting rotational force are welded to the drive disk and the exit disk, respectively, and both ends of the metal plate of the other blades are welded to the drive disk and the exit disk. Fit it into the recess of the plate with an appropriate gap.

When welding the metal plates 27, 34, etc. to the discs 25, 26 as in each of the above examples, the ceramic plates 29, 3
5 and the like to the metal plates 27 and 34 from deteriorating, it is preferable to use a method that is less affected by heat, such as argon welding. In addition, the classification rotor 17
Since it is firmly integrated by welding, it can be processed into a correct rotating body without eccentricity.

〔effect〕

As described above, this invention connects the drive disc and the exit disc of the classification rotor together by welding via a metal plate, and then attaches ceramic to this metal plate, or uses a composite structure of ceramic and metal plate. Since the blades are used as blades, there are no parts that do not function as blades as in the prior art. Therefore, most of the blades are made of ceramic or protected with a ceramic plate or ceramic layer to improve abrasion resistance, which reduces contamination and improves classification efficiency due to fewer blades than in the past. There will be no decrease in

In addition, since the classification rotor is firmly fixed to the drive disk and the exit disk by welding at both ends of the metal plate for transmitting rotation, the vibrations of mechanical parts other than the classification rotor affect the drive shaft. Compared to the conventional technology in which the spacer pins are screwed to the disc, there is no risk of loosening even if the spacer pins are screwed to the disk, and there is no deformation (twisting) of the classification rotor due to high-speed rotation. This has the effect of preventing blades from cracking.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view of an airflow classifier having a classification rotor according to the present invention, FIG. 2 is an enlarged longitudinal sectional front view showing an embodiment of the classification rotor of the first invention, and FIG. FIG. 4 is an enlarged longitudinal sectional view showing an embodiment of the classification rotor of the second invention, FIG. 5 is an enlarged partially cutaway sectional view along the line shown in FIG. 4, and FIG. FIG. 7 is a partially vertical front view showing an example of a conventional classifier, and FIG. 8 is an enlarged vertical cross-sectional front view of the same classification rotor. 17... Classification rotor, 25... Drive disk, 26
...Exit disk, 27, 34, 36...Metal plate, 2
8...Blade, 29,35,39...Ceramic board, 30,33,40...Composite blade.

Claims (1)

[Claims] 1 The classifier body has a rotating classification rotor through which classified air flows centripetally from the outside to the inside and then flows through it in the axial direction, and this classification rotor faces a driving disk. In an airflow classifier consisting of an outlet disk and a large number of blades arranged evenly in the circumferential direction between the two disks, the blades at predetermined locations on the classification rotor are composite blades made by bonding metal plates and ceramic plates. At the same time, the metal plate of this composite blade is firmly fixed by welding to the drive disk and the exit disk for rotational force transmission, and the other blades are formed of ceramic material, and both ends of the metal plate are fixed to the drive disk and the exit disk for rotational force transmission. An airflow classifier characterized by being installed with a slight gap between the plates. 2 The classifier body has a rotating classification rotor through which classified air flows centripetally from the outside to the inside and then flows through it in the axial direction. In an airflow classifier consisting of a large number of blades arranged evenly in the circumferential direction between both discs, all the blades of the classification rotor have a composite structure of ceramic and metal plates, and the number of blades of this composite structure is A metal plate for transmitting rotational force is firmly fixed to the drive disk and the outlet disk by welding, and both ends of the other blades are attached to both the disks with a slight gap. Airflow classifier. 3. The pneumatic classifier according to claim 2, wherein the blade having a composite structure of ceramic and metal plate is made by bonding a ceramic plate to a metal plate. 4. The airflow classifier according to claim 2, wherein the blade having a composite structure of ceramic and metal plate is a metal plate coated with a ceramic layer.