JP2008142680A - Wet centrifugal classifier - Google Patents

Abstract

The present invention provides a wet centrifugal classification device capable of enhancing the classification performance of a powder slurry.
In a wet centrifugal classifier 1, a discharge area 11a for fine powder slurry 11 and a discharge area 112a for coarse powder slurry 12 are formed in an opening 23 at the upper end of an outer cylinder 2. The annular member 5 is provided at the upper end 312 of the four stirring blades 31. The size of the annular member 5 is set so as to divide the discharge area 11 a of the fine powder slurry 11 and the discharge area 112 a of the coarse powder slurry 12.
[Selection] Figure 3

Description

  The present invention relates to a wet centrifugal classifier that classifies powder slurry using centrifugal force.

  Conventionally, there is an increasing demand for uniform particle size for various powders used in various applications. In order to meet such a demand, various classifiers are used. In particular, when classifying nano- or micron-sized powder, a wet centrifugal classification apparatus is used because a classification apparatus using wind power cannot be used or is unsuitable (see Patent Document 1). This wet centrifugal classifier classifies powder slurry using centrifugal force.

  Some wet centrifugal classifiers classify powder slurry while feeding the slurry from the lower side to the upper side. In order to classify the powder slurry using the wet centrifugal classifier, the powder slurry is caused to flow into the inside through the opening at the lower end of the centrifuge tube. And the powder slurry which flowed into the inside of a centrifuge tube is stirred with a stirring mechanism. Then, centrifugal force is generated in the slurry. By this centrifugal force, the powder slurry is classified into a fine slurry and a coarse slurry. The fine slurry moves to the center of the cross section of the centrifuge tube. The coarse powder slurry moves in the outward direction of the cross section of the centrifuge tube. And the classified fine powder slurry and coarse powder slurry are discharged | emitted from the opening part of the upper end of a centrifuge tube using the inflow water pressure applied inside from the lower end side of a centrifuge tube.

  Therefore, in such a wet centrifugal classifier, a fine slurry discharge area is formed in the center of the opening at the upper end of the centrifuge tube. In addition, a discharge area for the coarse powder slurry is formed outside the opening at the upper end of the centrifuge tube.

JP 2005-334865 A

  However, in the conventional wet centrifugal classifier, the discharge area for the fine powder slurry and the discharge area for the coarse powder slurry are in contact with each other. For this reason, a fine powder slurry and a coarse powder slurry may mix at the time of discharge. Therefore, conventional wet centrifugal classifiers have poor powder slurry classification performance.

  This invention is made | formed in view of this conventional subject, and it aims at providing the wet centrifugal classification apparatus which can improve the classification performance of a powder slurry.

  Therefore, as a result of intensive studies, the present inventors have adopted the following wet centrifugal classifier to solve the above problems.

  The wet centrifugal classifier of the present invention includes a cylindrical centrifuge tube, a motor for rotating the centrifuge tube, and a cylindrical outer cylinder surrounding the centrifuge tube, and a powder is provided at the lower end of the centrifuge tube. An opening for allowing the slurry to flow in is provided, and a stirring mechanism for stirring and classifying the powder slurry that has flowed in is provided in the centrifuge tube. The classified fine powder slurry is provided at the upper end of the centrifuge tube. A wet centrifuge classification measure provided with a central opening for discharging and an outer peripheral side opening for discharging the classified coarse powder slurry, wherein the central opening and the outer peripheral opening of the centrifuge tube A partition member is provided between them.

  In such a configuration, the partition region separates the fine slurry discharge region and the coarse slurry discharge region. For this reason, when a coarse powder slurry and a fine powder slurry are discharged | emitted from a centrifuge tube, mixing of both slurry is prevented.

  In the wet centrifugal classifier of the present invention, the partition member has an annular shape.

  In such a configuration, the discharge area of the fine powder slurry and the discharge area of the coarse powder slurry are completely independent from each other.

  Further, in the wet centrifugal classifier of the present invention, the stirring mechanism is a stirring blade whose side end is fixed to the inner peripheral wall of the centrifugal tube, and the partition member is disposed at the upper end of the stirring blade. It is characterized by being fixed and installed.

  In such a configuration, when an operator assembles the wet centrifugal classifier, first, the partition member is installed on the upper end of the stirring blade. Next, the stirring blade on which the partition member is installed is installed in the centrifuge tube. Therefore, the operator can install the partition member and the stirring mechanism together in the centrifuge tube. Further, when the operator disassembles the wet centrifugal classifier, the partition member and the stirring mechanism can be taken out from the centrifuge tube together.

  Further, the wet centrifugal classifier of the present invention includes a cap that closes the opening at the upper end of the centrifuge tube, and the cap includes fine powder slurry discharged from the central opening of the centrifuge tube and the outer peripheral side opening. It is characterized in that a discharge path for separately discharging the coarse powder slurry discharged from is provided.

  In such a configuration, the classified fine powder slurry and coarse powder slurry are discharged from the centrifuge tube in different directions by the cap.

  In the wet centrifugal classifier of the present invention, the partitioning performance of the powder slurry can be enhanced by the partition member. Moreover, in the wet centrifugal classifier of the present invention, an assembling operation and a disassembling operation can be efficiently performed with a preferable specific structure. Furthermore, in the wet centrifugal classifier of the present invention, the classified fine powder slurry and coarse powder slurry can be efficiently recovered.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic longitudinal sectional view of a wet centrifugal classifier 1 showing an embodiment of the present invention. The wet centrifugal classifier 1 of the present embodiment includes a cylindrical outer cylinder 2, a stirring mechanism 3, a motor 4, an annular member 5, a cap 6, and a cylindrical centrifuge tube 7.

  The outer cylinder 2 is configured such that the powder slurry 10 flows into the inside 22 from the opening 21 at the lower end.

  Further, one end side of the supply pipe 100 is connected to the lower end side of the outer cylinder 2. A slurry tank (not shown) is connected to the other end side of the supply pipe 100 via a pump (not shown). The slurry slurry 10 is stored in this slurry tank. Further, the supply pipe 100 and the pump allow the powder slurry 10 to flow into the inside 22 of the outer cylinder 2.

  The centrifuge tube 7 is provided close to the inside 22 of the outer cylinder 2. The centrifuge tube 7 is formed to extend from the upper end side to the lower end side of the outer cylinder 2. Further, the centrifuge tube 7 is configured to send the powder slurry 10 that has flowed into the interior 71 from the opening 701 at the lower end to the opening 23 at the upper end of the outer cylinder 2 from the opening 702 at the upper end.

  On the other hand, the stirring mechanism 3 applies a centrifugal force to the powder slurry 10 while stirring the powder slurry 10 flowing into the inside 22 of the outer cylinder 2. The stirring mechanism 3 is composed of a plurality of stirring blades 31. In the present embodiment, an example having four stirring blades 31 is shown.

  Four stirring blades 31 are provided in the inside 71 of the centrifuge tube 7. Each stirring blade 31 is formed to extend from the upper end side to the lower end side of the centrifuge tube 7. The four stirring blades 31 are coupled so as to form a cross when viewed from above. Further, the four stirring blades 31 that are joined are installed with the side ends 311 fixed to the inner peripheral wall 7 a of the centrifuge tube 7.

  On the other hand, the annular member 5 is provided at the upper end of the stirring mechanism 3. Specifically, as shown in FIG. 2, the annular member 5 is provided with four grooves 51 on the bottom surface 5 a side. The installation position of each groove 51 corresponds to each stirring blade 31 of the stirring mechanism 3. Each groove 51 is fitted to the upper end 312 of each stirring blade 31. Thus, each groove 51 is fitted to the upper end 312 of each stirring blade 31, so that the annular member 5 is positioned at the upper end of the stirring mechanism 3.

  As shown in FIG. 2, a hole 52 is provided at the center of the annular member 5. The hole 52 is formed so that the center 52a thereof coincides with the center of the coupling portion 31a (see FIG. 1) of the four stirring blades 31 in a state where the annular member 5 is provided at the upper end of the stirring mechanism 3. ing. Further, the hole 52 is formed so that the drive shaft 41 of the motor 4 is inserted.

  Further, as shown in FIG. 3, the annular member 5 is provided at the upper end of the stirring mechanism 3 so as to partition the discharge region 11 a of the fine slurry 11 and the discharge region 12 a of the coarse powder slurry 12. Its size is set. In addition, the discharge area | region 11a of the fine powder slurry 11 is an area | region formed in the center part (center opening part of the upper end of the centrifuge tube 7) of the opening part 23 of the upper end of the outer cylinder 2. FIG. Moreover, the discharge area | region 12a of the coarse powder slurry 12 is an area | region formed in the outer side (outer peripheral side opening part of the upper end of the centrifuge tube 7) of the center part of the opening part 23. FIG. In FIG. 3, the motor 4 is omitted.

  On the other hand, the cap 6 includes a cap body 61 and an insertion portion 62. The cap body 61 is provided so as to close the opening 23 at the upper end of the outer cylinder 2 (the opening 702 at the upper end of the centrifuge tube 7) in a state where the annular member 5 is provided at the upper end of the stirring mechanism 3. Specifically, the lower surface 61 a of the cap body 61 closes the opening 23 at the upper end of the outer cylinder 2. And the recessed part 611 is provided in the center part by the side of this lower surface 61a. The recess 611 is formed so as to overlap the hole 52 of the annular member 5. Furthermore, the recessed part 611 is formed so that the drive shaft 41 of the motor 4 may be inserted, as shown in FIG.

  As shown in FIG. 3, two discharge paths 612 and 613 are provided inside the cap body 61. The fine slurry discharge path 612 is formed so as to pass from the recess 611 of the cap body 61 to the outside of the side surface 61 b of the cap body 61. The coarse powder slurry discharge path 613 is formed so as to pass from the outside of the lower surface 61 a of the cap body 61 to the outside of the upper surface 61 c of the cap body 61.

  Further, the insertion portion 62 is provided at the center of the upper surface 61 c of the cap body 61. Further, as shown in FIG. 1, an insertion path 63 is provided in the insertion portion 62 and the cap body 61 from the upper surface 62 a to the recess 611. The insertion passage 63 is formed so that the drive shaft 41 of the motor 4 is inserted.

  On the other hand, the motor 4 drives the stirring mechanism 3. In the motor 4, the drive shaft 41 is inserted into the insertion path 63 of the cap 6, the recess 611, and the hole 52 of the annular member 5, and is coupled to the upper end 31 b of the coupling portion 31 a of the four stirring blades 31. ing. Thus, the motor 4 is configured to rotate the centrifuge tube 7 and the four stirring blades 31 together by the rotation of the drive shaft 41.

  With this configuration, the operation of the wet centrifugal classifier 1 will be described below. When the pump is driven, the powder slurry 10 flows from the slurry tank through the supply pipe 100 to the inside 22 through the opening 21 at the lower end of the outer cylinder 2. The powder slurry 10 that has flowed into the interior 22 passes through the interior 71 of the centrifuge tube 7 and is sent to the opening 23 at the upper end.

  When the motor 4 is turned on, the stirring mechanism 3 is driven. Thereby, the stirring blade 31 stirs the powder slurry 10 that has flowed into the inside 71 of the centrifuge tube 7. Then, centrifugal force is generated in the slurry 10. With this centrifugal force, as shown in FIG. 3, the slurry 10 is classified into a fine powder slurry 11 and a coarse powder slurry 12. The fine powder slurry 11 moves to the central portion 2a of the cross section of the outer cylinder 2 (centrifugal tube 7). And the coarse powder slurry 12 moves to the outer peripheral part 2b of the center part 2a of the cross section of the outer cylinder 2 (centrifugal tube 7).

  Then, the classified fine powder slurry 11 and coarse powder slurry 12 are discharged from the opening 23 at the upper end using the inflow water pressure 10a (see FIG. 1) applied to the inside 22 from the lower end side of the outer cylinder 2. At this time, in the opening 23 at the upper end, the discharge region 11 a of the fine powder slurry 11 and the discharge region 12 a of the coarse powder slurry 12 are separated by the annular member 5. For this reason, when the fine powder slurry 11 and the coarse powder slurry 12 are discharged | emitted from the outer cylinder 2, both slurry 11 and 12 are prevented from mixing. Therefore, the wet centrifugal classification apparatus 1 of the present embodiment can improve the classification performance of the powder slurry 10.

  The fine powder slurry 11 is discharged from the outer cylinder 2, and then discharged to the side of the cap 6 through the fine powder slurry discharge path 612. The coarse powder slurry 12 is discharged from the outer cylinder 2 and then discharged to the upper side of the cap 6 through the coarse powder slurry discharge path 613.

  Thus, the fine powder slurry 11 and the coarse powder slurry 12 are discharged from the outer cylinder 2 in different directions by the cap 6. Therefore, even after the fine powder slurry 11 and the coarse powder slurry 12 are discharged from the outer cylinder 2, both the slurries 11 and 12 do not mix. Therefore, the wet centrifugal classification apparatus 1 of the present embodiment can further improve the classification performance of the powder slurry 10.

  Moreover, in the wet centrifugal classification apparatus 1 of the present embodiment, the partition member of the present invention is configured from the annular member 5. Thereby, the discharge area | region 11a of the fine powder slurry 11 and the discharge area | region 12a of the coarse powder slurry 12 will be in a completely independent state, respectively. Therefore, when the fine powder slurry 11 and the coarse powder slurry 12 are discharged from the outer cylinder 2, the slurry 11 and 12 are reliably prevented from mixing with each other. Therefore, the wet centrifugal classification apparatus 1 of the present embodiment can further improve the classification performance of the powder slurry 10.

  Furthermore, in the wet centrifugal classifier 1 of the present embodiment, by using the annular member 5, the discharge area 11a of the fine powder slurry 11 and the discharge area 12a of the coarse powder slurry 12 can be distinguished with a simple configuration. Therefore, the wet centrifugal classifier 1 of the present embodiment can also reduce the cost. The partition member need not be limited to the annular member 5 as long as it separates the discharge region 11 a of the fine powder slurry 11 and the discharge region 12 a of the coarse powder slurry 12.

  In the wet centrifugal classifier 1 of the present embodiment, the annular member 5 is provided at the upper end of the stirring mechanism 3 (the upper end 312 of the four stirring blades 31 combined). Therefore, when the operator assembles the wet centrifugal classifier 1, first, the annular member 5 is installed at the upper end of the stirring mechanism 3. Next, the operator installs the stirring mechanism 3 in the centrifuge tube 7. Thereby, the annular member 5 is installed in the centrifuge tube 7 via the stirring mechanism 3. Next, the operator installs the centrifuge tube 7 on which the annular member 5 is installed on the outer cylinder 2. Therefore, the operator can install the annular member 5 and the stirring mechanism 3 together with the outer cylinder 2 via the centrifuge tube 7. Further, when the operator disassembles the wet centrifugal classifier 1, the annular member 5 and the stirring mechanism 3 can be taken out from the outer cylinder 2 through the centrifugal tube 7 together. Therefore, the wet centrifugal classification apparatus 1 of the present embodiment can increase the work efficiency of the assembly work and the disassembly work.

  In the wet centrifugal classifier 1 of the present embodiment, four stirring blades 31 are used for the stirring mechanism 3. However, the number of the stirring blades 31 may not be particularly limited as long as the stirring mechanism can stir the powder slurry 10 even when receiving the inflow water pressure 10a. Further, the installation positions and number of the discharge paths 612 and 613 of the cap 6 are not limited to the present embodiment as long as the fine powder slurry 11 and the coarse powder slurry 12 can be discharged in different directions.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In addition, this invention is not limited to a following example.

In this example, the wet centrifugal classifier 1 described in the embodiment was used. Silica was used for the powder used for the powder slurry 10. This silica has a median diameter of 0.7 μm and a true density of 2300 kg / m ³ . In addition, water was used as the solvent used for the powder slurry 10. And the powder slurry 10 used what the content of silica was adjusted to 0.5 wt%.

  The flow rate of the powder slurry 10 flowing into the outer cylinder 2 was set to 0.8 L / min. The flow rate of the powder slurry 10 discharged from the outer cylinder 2 is set to 0.2 L / min on the discharge region 11a side of the fine powder slurry 11, and 0.6 L / min on the discharge region 12a side of the coarse powder slurry 12. Set to. The rotation speed of the motor 4 was set to 6000 rpm. And the partial separation efficiency curve of the silica classified under these conditions is shown in FIG. 4 (curve A).

Comparative example

  In the comparative example, the one obtained by removing the annular member 5 from the wet centrifugal classifier 1 described in the embodiment was used. Other conditions are the same as those described in the embodiment. And the partial separation efficiency curve of the silica classified under these conditions is shown in FIG. 4 (curve B).

<Comparison of Examples and Comparative Examples>
As can be seen from FIG. 4, the wet centrifugal classifier equipped with the annular member has higher classification performance than the wet centrifugal classifier equipped with no annular member.

  As described above, the wet centrifugal classifier of the present invention can improve the classification performance of the powder slurry. Therefore, in the powder slurry classification technical field, the wet centrifugal classification apparatus of the present invention can be fully utilized.

It is a model longitudinal cross-sectional view of the wet centrifugal classification apparatus which shows one embodiment of this invention. It is the perspective view which looked at the annular member of the embodiment from the back side. It is a figure which shows the flow of the powder slurry at the time of the drive of the wet centrifugal classification apparatus of the embodiment. It is a figure which shows the partial separation efficiency curve of the silica of an Example and a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wet centrifugal classifier 2 Outer cylinder 3 Stirring mechanism 4 Motor 5 Ring member 6 Cap 7 Centrifugal tube 7a Inner peripheral wall 10 Powder slurry 11 Fine powder slurry 12 Coarse powder slurry 31 Stirring blade 71 Inside 311 Side end 312 Upper end 612 For fine powder slurry Discharge path 613 Coarse powder slurry discharge path 701 Opening at lower end 702 Opening at upper end

Claims (4)

A cylindrical centrifuge tube, a motor for rotating the centrifuge tube, and a cylindrical outer cylinder surrounding the centrifuge tube are provided, and an opening through which powder slurry flows is provided at the lower end of the centrifuge tube. The centrifuge tube is provided with a stirring mechanism for stirring and classifying the flowing powder slurry, and at the upper end of the centrifuge tube, a central opening for discharging the classified fine powder slurry, and classification A wet centrifugal classification measure provided with an outer peripheral side opening for discharging the coarse powder slurry,
A wet centrifugal classifier comprising a partition member provided between the central opening of the centrifuge tube and the outer peripheral opening. The wet centrifugal classifier according to claim 1, wherein the partition member has an annular shape. The stirring mechanism is a stirring blade installed with a side end fixed to the inner peripheral wall of the centrifuge tube,
The wet centrifugal classifier according to claim 1 or 2, wherein the partition member is fixedly installed at an upper end of the stirring blade. A cap for closing the opening at the upper end of the centrifuge tube is provided. In this cap, the fine powder slurry discharged from the central opening of the centrifuge tube and the coarse powder slurry discharged from the outer peripheral side opening are separately provided. The wet centrifugal classification apparatus according to any one of claims 1 to 3, wherein a discharge passage for discharging is provided.

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