JP2713597B2 - Centrifuge and classification method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a centrifuge and a classification method performed using the centrifuge.

(Prior Art) Classifying the solid particulate or powder according to the particle size is called classification, and this classification is used for industrial applications such as purification and analysis for analyzing particle size. The most commonly used classification method is a method using a screen (mesh).
It is difficult to classify particles of about 100 μm or less.
For this reason, a method of dispersing particles in a medium and classifying the particles is used.

Methods for analyzing the particle diameter of the particles contained in the suspension include a sedimentation method and a centrifugation method. In the sedimentation method, a sample container is left standing for a certain period of time, and the particle size distribution is detected because the speed at which particles settle in a medium varies depending on the particle size.The pipette method, balance method, hydrometer method, specific gravity method There are a balance method and a light transmission method.

The centrifugal method is a method in which a sample that is difficult to settle by gravity is classified and measured in a centrifugal force field. There is a method (density gradient centrifugation) in which a density gradient is applied and particles are separated into media having different densities according to the density.

A centrifugal separator that is often used for centrifuging and classifying a sample is a centrifugal separator in which a centrifuge tube is swingably supported and the centrifuge tube rotates horizontally by centrifugal force during centrifugation. This device is often used for separating a sample suspension into two layers. In addition, various types of centrifugal separators are provided.

(Problems to be Solved by the Invention) As described above, there are various methods for analyzing the particle size of particles in a suspension, but in the case of the ordinary sedimentation method or centrifugation method, the particle size distribution Can be measured or the particles can be separated and collected in two size ranges,
The particles cannot be separated and collected according to the particle size, and when the particle size distribution is measured using a combination of a centrifuge and a light transmission device, the apparatus must be complicated.

Also, when measuring with a density gradient, particles are separated not by particle size but by their density, and a medium with an appropriate density gradient must be selected according to the sample to be measured. Is difficult to set.

Accordingly, the present invention has been made in view of the above problems, and has as its object to provide a centrifugal separator and particles that can classify particles using a centrifugal separation method and can easily measure a particle size distribution. The purpose of the present invention is to provide a classification method.

(Means for Solving the Problems) The present invention has the following configuration to achieve the above object.

That is, the suspended sample solution is put in a centrifuge tube and sealed,
First, the particles in the sample liquid are classified by centrifugation so that the longitudinal direction of the centrifuge tube is horizontal, and then centrifuged while supporting the centrifuge tube so that the longitudinal direction of the centrifuge tube is vertical. It is characterized in that particles settle on the inner wall surface of the sink tube. It is also effective to install a collecting plate on the inner wall surface of the centrifuge tube and settle and collect particles on the collecting plate.

Further, a rotating unit that holds a centrifuge tube, and a centrifugal separator having a driving unit that rotationally drives the rotating unit, the rotating unit has a horizontal centrifugal unit that centrifuges the centrifuge tube in a horizontal direction,
Vertical centrifugal means for vertically supporting the centrifuge tube and centrifuging the centrifugal tube.

(Action) The centrifuge tube containing the suspended sample solution is centrifuged horizontally so as to classify the centrifuge tube in the longitudinal direction according to the particle diameter. Then, the centrifuge tube is supported vertically and centrifuged to settle on the inner wall surface of the centrifuge tube, and separated and collected in a distribution according to the particle diameter. When a collecting plate is used, the classified particles settle and adhere to the collecting plate.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 shows the configuration of a centrifuge tube used in the centrifugal separator of the present embodiment. In the figure, reference numeral 10 denotes a centrifuge tube, which is formed in a tubular body having a rectangular cross section and an open top. Reference numeral 12 denotes a collecting plate for collecting the classified particles, and is formed as a rectangular plate-like body that matches the inner surface shape of the centrifuge tube 10. The collecting plate 12 is set on one inner surface of the centrifuge tube 10 so as to be freely inserted and removed. Figure 3 shows the collecting plate 12
As shown in the drawing, groove-like irregularities are formed on the surface of the collecting plate 12 as shown in the figure.

FIG. 4 shows a state in which a collecting plate 12 is set in the centrifuge tube 10 and a sample to be classified is placed in the centrifuge tube 10. When putting the sample, first put the solution 14 into the centrifuge tube 10, then
A sample 16 in which particles to be classified are suspended is placed in the upper part of the sample. The specific gravity of the sample solution is set lower than the specific gravity of the solution 14 so that the two solutions do not mix before classification. After placing the sample solution in the centrifuge tube 10, the centrifuge tube 10 is
Seal. The solution 14 and the sample 16 are filled so that the centrifuge tube 10 is full, and when the centrifuge tube 10 is sealed with the cap 18, the centrifuge tube 10 is filled with both liquids.

FIG. 1 is an explanatory diagram showing a method of centrifuging and separating a sample prepared by the above method. The centrifuge is a disk 20 on which the centrifuge tube 10 is set, and the disk is fixed to the center of the disk 20
The rotary shaft 22 is configured to rotate integrally with the rotary shaft 20, and a drive unit 24 such as a motor connected to the rotary shaft 22 and driven to rotate.

The disk 20 on which the centrifuge tube 10 is set is provided with cells 26 with bottoms at equal intervals on the outer peripheral side thereof, into which the centrifuge tube 10 is inserted and set. Each cell 26 has approximately the same depth as the centrifuge tube 10. FIG. 5 is a plan view of the disk 20. Disk 20 as shown
Above, the upper part of the cell 26 is opened in a square shape, and the upper edge of each cell 26 is rotatably supported by a support shaft 28,
Is configured to be arbitrarily operable between a state where it can freely rotate with respect to the disc 20 and a state where it is locked with respect to the disc 20 in accordance with the classification operation.

FIG. 1 (a) shows a centrifuge in which a centrifuge tube 10 containing a sample to be classified is set. Here, when the centrifuge tube 10 is set, the collecting plate 12 is
When rotating, it is positioned on the outermost peripheral side.

When the setting of the centrifuge tube 10 is completed, the cell 26 is centrifuged in a state where the cell 26 is free with respect to the disk 20, that is, in a state where the centrifuge tube 10 swings. When centrifugation is performed in this state, the centrifugal tube 10 rotates substantially horizontally by centrifugal force as shown in FIG. 1 (b). This centrifugation operation is a normal centrifugation operation, and the centrifugation produces a particle size distribution in the longitudinal direction of the centrifuge tube 10 according to the particle size of the sample. That is, larger particles are distributed closer to the bottom of the centrifuge tube 10, and smaller particles are distributed closer to the mouth.

After the particles have been classified in the centrifuge tube 10 in the state shown in FIG. 1 (b) for a predetermined time, the centrifuge tube 10 is vertically supported and centrifuged as shown in FIG. 1 (c). Enter centrifugation.

When moving from FIG. 1 (b) to FIG. 1 (c), the rotation of the disk 20 may be stopped once or may be continuously performed. By locking the cell 26, the cell 26 is always held in the vertical position, does not swing even if the disc 20 rotates during centrifugation, and is centrifuged while facing vertically. When the centrifugation shown in FIG. 1C is performed, the centrifugation is performed in the centrifugal direction in the centrifuge tube 10.
Of the centrifugation in FIG. 1 (c).
The particles classified in FIG. 1 (b) settle on the top. That is, the particles in the sample are obtained on the collection plate 12 in a distribution state classified according to the particle diameter.

FIG. 6 illustrates the state of the centrifugal tube 10 after the centrifugal operation shown in FIG. 1 (c) is performed. The particles settle on the collecting plate 12 according to the particle size. Large-diameter particles settle on the collection plate 12 near the bottom of the centrifuge tube 10, and small-diameter particles settle near the upper opening of the centrifuge tube 10.

After the centrifugation operation, if the collecting plate 12 is taken out from the centrifuge tube 10, a sample classified according to the particle size as shown in FIG. 7 can be obtained. In this way, a sample having a specific particle size can be obtained, and by analyzing the classified sample, the particle size distribution of the sample or the identification of the substance can be performed. The groove is provided in the collecting plate 12 because the collecting plate is
This is to prevent particles adhering to the collecting plate from flowing when taking out 12.

The classification method described above is characterized in that after the centrifuge tube is horizontal and centrifuged, the centrifuge tube is supported in a vertical state and centrifuged. A sample classified according to the particle size can be obtained on the collected collecting plate. In this classification method, the direction in which the centrifuge tube is supported is changed by 90 ° and centrifugation is performed.
Further, the medium to be put in the centrifuge tube does not need to be special, and there is an advantage that the classification can be performed by a very simple operation of putting the suspension and centrifuging. In addition, since the sample is obtained by being classified on the collecting plate, by taking out the collecting plate from the solution, the collection and analysis of the classified particles can be performed very easily.

Note that the collecting plate 12 is not always necessary, and in some cases, the above-mentioned centrifugation is performed without the collecting plate, and the particles are settled on the inner wall surface of the centrifuge tube so as to be used for analysis and the like. Is also good.

In addition, the centrifugal separator may be any device capable of supporting the centrifuge tube in the horizontal direction and the vertical direction and performing centrifugation,
The centrifuge tube 10 may be inserted and set in the cell 26 as in the above embodiment, and the cell 26 may be locked to hold the centrifuge tube, or when moving from the swing state to the vertical support state, the centrifuge tube may be used. May be provided as appropriate.

Further, the shape of the centrifuge tube is not particularly limited, and may have a rectangular cross section as in the above example, or may have a cylindrical shape.

The most distinctive feature of the above-described classification method and centrifugal separator is that not only the particle size distribution of the sample is simply measured, but also that the particulate matter in the sample can be actually separated and obtained according to the particle size. is there.

As a result, industrial use such as purification of fine ceramics becomes possible, and it is also possible to easily separate and separate a specific substance from a sample, and select a minute amount such as microbial engineering. It can also be used for such purposes. Also, of course, it can be easily used for sample analysis and the like.

As described above, the present invention has been described variously with reference to the preferred embodiments. However, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. That is.

(Effects of the Invention) According to the classification method of the present invention, as described above, the centrifugal tube is centrifuged in the horizontal direction and the vertical direction to separate the particles according to the particle diameter in the sample liquid, so that classification is performed. The time required for the measurement can be shortened, and classification can be performed simply by centrifugation. Therefore, there is no difficulty in setting conditions such as setting a density gradient in the medium in which the sample is placed, and the sample can be classified by operation very easily. .

When performing this classification operation, effective classification can be performed using a centrifugal separator capable of supporting the centrifuge tube in both the horizontal direction and the vertical direction.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a classification method according to the present invention, FIG. 2 is an explanatory view showing an embodiment of a centrifuge tube, FIG. 3 is a perspective view showing an embodiment of a collecting plate, and FIG. Fig. 5 is a plan view of a disk, Fig. 6 is an explanatory view showing a state of a centrifuge tube after classification, and Fig. 7 is an illustration showing a collecting plate after classification. FIG. 10 ... centrifuge tube, 12 ... collection plate, 14 ... solution, 16 ... sample, 18 ... cap, 20 ... disk, 24 ... drive unit, 26 ...
... cell, 28 ... support shaft.

Claims (3)

(57) [Claims] 1. A suspended sample solution is sealed in a centrifuge tube,
First, the particles in the sample liquid are classified by centrifugation so that the longitudinal direction of the centrifuge tube is horizontal, and then centrifuged while supporting the centrifuge tube so that the longitudinal direction of the centrifuge tube is vertical. A method for classifying particles, wherein the particles are settled on an inner wall surface of a sink tube. 2. The classification method according to claim 1, wherein a collecting plate is provided on an inner wall surface of the centrifuge tube, and particles are settled on the collecting plate and collected. 3. A centrifugal separator having a rotating section for holding a centrifuge tube, and a driving section for rotating and driving the rotating section, wherein the rotating section horizontally centrifuges the centrifugal tube in a horizontal direction, and a centrifugal tube. And a vertical centrifugal means for vertically supporting the centrifuge and centrifuging the centrifugal force.