JP2005058985A - Classifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new classifier capable of efficiently classifying required fine particles from fine particles of a particle size of ≤10 μm. <P>SOLUTION: A filter with pass-through holes having a size preventing falling of classifying media of ceramics, plastics or metals is provided at a bottom part of a cylindrical or rectangular casing, and the classifying media are placed on the filter. One or more discharge ports or supply ports are respectively provided to the classifier, and a supply cone having one or more supply ports or discharge ports is attached to the lower part of the classifier. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

Detailed Description of the Invention

  The present invention is very effective when mainly classifying fine particles of 10 μm or less.

  The present invention has a great effect in the field where impurities are hardly mixed because the contamination medium is hardly mixed by selecting the material of the classification medium.

  The conventional classification methods can be broadly divided into a method using wind power in a cyclone format, a method using mechanically rotating a fan and utilizing the centrifugal force, a method using a screen, and gravity sedimentation using water and a solvent. There are methods. There is no technique using a classification medium like the present invention.

  The disadvantage of the conventional classifier is that the classifier has a lot of wear due to movement of the classifier at a high speed, and the wear is mixed as impurities into the classifier.

  Further, the classifying device that mechanically rotates the fan has a rotating shaft portion, and powder of the classified material enters the rotating shaft portion, thereby causing wear and requiring a lot of maintenance.

  Also, in the cyclone type mechanical fan rotation classifier, the classification of powder particles of 10 μm or less has poor classification efficiency (efficiency due to classification cut point), especially the classification efficiency for 1 μm or less (efficiency due to classification cut point). Is unreliable.

  Moreover, the gravity sedimentation method using water and a solvent has the fault that time required for classification becomes very long.

  In addition, it is difficult to classify powder particles of 10 μm or less by the method using a screen, and further, to classify 1 μm or less.

  The present invention solves the above problems by the following configuration.

  The present invention is characterized in that it enables classification of fine particles of 10 μm or less, particularly fine particles of 1 μm or less by using a classification medium, hardly contaminating impurities, and eliminating maintenance of mechanical parts.

  In addition, the classification device of the present invention applies the space between the classification media by filling the classification medium in the classification container, and changes the classification by changing the space by applying vibration to the classification medium. Is possible.

  Although the classification medium in the classification apparatus of the present invention varies depending on the classification object, it is desirable to use zirconia beads of 50 μm or less when the particle diameter of the classification object is 1 μm or less. Other classification media include metal beads, alumina beads, and plastic beads.

  It can be used continuously as the classifier of the present invention.

  The classifying apparatus of the present invention can be vibrated for the purpose of removing the classified matter adhering to the classification medium, the dispersion of the aggregates of the classified items, and the purpose of improving the classification accuracy.

  Next, the best mode for carrying out the present invention will be described by taking as an example the case of application to wet classification.

  The wet classification here will be described by taking as an example a case where a substance to be classified is slurried in water or a solvent and well dispersed, and the slurry is applied to the classification apparatus of the present invention.

  The classification device according to the present invention includes a classification container having a nozzle having one or more discharge ports or supply ports, and a supply cone having one or more supply ports and discharge ports attached under the classification container. It is made up of.

  Further, by attaching another classification container to the upper part of the classification device of the present invention, the classification container becomes two stages, and by using these two stages, the classification efficiency is further increased.

  Specifically, in FIG. 1, the classification container 1 has a cylindrical shape with a discharge nozzle at the top, has 2 filters, and 3 zirconia beads are charged therein.

  Four supply cones are attached to this, and two classification motors are attached to one classification container as a vibration source. In addition, in order not to transmit vibration to the outside by the vibration motor, transmission of vibration is transmitted from the outside by 12 flexible hoses in the same way as 6 cushioning materials are attached to 11 racks in 1 classification container. It is preventing.

  On the other hand, the slurry is put into the tank 7 and the classification object is stirred with the stirrer 8. The slurry is supplied to the supply cone of 4 with the pump of 9. The supplied slurry enters 3 classification media through 2 filters.

  The oversized slurry classified by 2 filters and 3 classification media is discharged from 4 feed cones and returned to 7 tanks. On the other hand, the slurry classified by the vibration by the classification medium 3 and the vibration source 5 is discharged from the classification container 1 and enters the product tank 10.

  The drawing of FIG. 2 illustrates the present invention in which the classification is a dry classification and the classification container has two stages.

  1 classification container is filled with 3 classification media. Similarly, a 1 'classification container is filled with a 3' classification medium, and 1 and 1 'classification containers are separated by two filters, and the 3 and 3' classification mediums have the same diameter or different diameters. But it is possible. The 1 'classifying vessel is fitted with a 2' filter, with a lower 4 supply cone, and an 8 supply blower for supplying the product to be classified from the 8 supply tank to the 4 supply cone. Yes. On the other hand, the classification container has 5 vibration sources, and the transmission of vibration is prevented by 7 flexible hoses at the joints of the pipes to the outside. The classified material that has passed through the classification medium 3 is collected in 10 bag filters by 11 exhaust blowers and received in 12 product tanks. On the other hand, a part of the classified material that has passed through 3 'is collected by 15 bag exhaust blowers by 14 bag filters and received by 8 supply tanks.

Effects and effects of the invention

  In the present invention, the gap between the media changes depending on the size of the classification medium and its filling property. That is, if the voids are large, the particles to be classified are easy to pass, and if the voids are small, they are difficult to pass. The size of the air gap affects the size of the classification medium, and the frequency and amplitude for vibrating the classification medium. Also, the specific gravity of the classification medium should be large.

  For example, when the classification point is cut at 2 μm with alumina of 10 μm or less and an average particle size of 1 μm, 50 μm zirconia beads were used as the classification medium, and the effect was confirmed. Zirconia beads were selected because they have a large specific gravity among ceramics and 50 μm fine particles are manufactured and sold.

  The classification container is filled with zirconia beads, and the zirconia beads are vibrated by vibrating the classification container. The alumina slurry is passed through the bottom of the vibrating zirconia beads. The alumina slurry has a concentration of 10%, and the classification point for classifying the alumina is 2 μm, which is about 80% of 2 μm or less.

  At this time, alumina finer than 2 μm passes through the layer of zirconia beads and is discharged out of the machine as a target product. Also, alumina larger than 2 μm cannot pass through the zirconia beads and is discharged out of the machine from the lower part. Of course, 2 μm of alumina is not completely classified into a product, but is slightly accompanied by 2 μm or more of alumina without passing through zirconia beads.

  In this way, there is an effect that fine particles can be classified into target particles. In conventional devices, it is difficult to classify fine particles of 2 μm or less and not to contain particles of 2 μm or more in 2 μm or less. The only way to do this was to classify the water ratio over a long period of time.

  Since a high classification accuracy can be obtained by using the classification apparatus of the present invention, a wrapping material such as an IC-related silicon wafer using fine particles has a great effect.

  Here, when beads having a diameter of 50 μm are filled in a classification container, the minimum gap between the beads when stationary is about 18 μm. Here, by applying vibration to the classification container, the resistance to the classification object supplied from the lower part changes depending on whether the vibration is large or small. Further, the resistance varies depending on the speed of supplying the classification object.

  These resistances determine the particle size of the classified material that passes through the bead space. Thereby, the classification point (cut point) of the classification object is determined.

Test example

  Hereinafter, test examples conducted for confirming the effects of the present invention will be described.

The test machine is a zirconia bead having a classification container 200φ × 150H, a stainless steel product discharge nozzle diameter 25φ, a filter vent 30 μm, and a classification medium 50 μm.
Vibration motor: 60W x 6P-2 units Frequency: 1200rpm
Total amplitude: 4m / m
Classification object: Alumina of 10 μm or less (average particle size 1 μm, 2 μm or less 80%)
Slurry supply amount: 0.2 L / min
Slurry concentration: 10%
Classification point: 2μm
Operation time: Continuous 60 min operation

As a result, 0.85 kg of alumina powder of 2 μm or less was recovered as a product.
Recovery rate 0.2L / min × 60 = 12L
12L × 0.1 = 1.2kg …… Alumina powder
1.2 kg × 0.80 = 0.96 kg …… Aluminum powder recovery of 2 μm or less (0.85 ÷ 0.96) × 100 = 88.5%
The remaining 11.5% returned to the stock solution tank.

Industrial applicability

  The present invention has a great potential for use in industries aiming at fine classification of fine particles, particularly in the electronics industry.

It is a model figure by the classification device of this invention.

Claims (4)

  A discharge port or a supply port in which the classification medium is put on a filter having a vent hole of a size that prevents the classification medium such as ceramics, plastics, or metal from dropping at the bottom of a cylindrical or rectangular tube case. A classification device having one or more of each, and a supply cone having one or more supply ports or discharge ports attached to the lower part of the classification container.   The classification device is a classification device that can be stacked in two or more stages.   The classifying device is a classifying device capable of dealing with a material to be classified in either a powder state or a slurry state.   The classification device is a classification device having one or more vibration motors in a classification container in order to give vibration to the classification medium.

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