JP3463851B2 - Sedimentation classifier - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a sedimentation classifier.

[0002]

2. Description of the Related Art A sedimentation classifier is a classification tank (classification duct).
A liquid is made to flow inside, and the seeds of the plant, which is the classification target, are allowed to settle in a direction that crosses the flow of the liquid, and the distance moved until the classification target completely settles differs for each classification target. This is what is used to classify objects to be classified. At this time, in order to accurately classify the objects to be classified, the flow velocity of the liquid (the velocity distribution of the flow, that is, both the direction and the velocity of the flow) in the virtual cross section orthogonal to the flow in the classification tank is made uniform. Will be required.

Therefore, in a conventional settling / classifying apparatus, as disclosed in, for example, Japanese Patent Application Laid-Open No. 6-328002 filed by the applicant of the present invention, a rectifying grid in which a liquid flowing in a classifying tank is formed in a grid pattern. It adopted a structure that rectifies with. That is, as shown in FIG. 7, this settling / classifying apparatus passes through a pump 2 that delivers a liquid 1 (schematically indicated by an arrow) such as a culture solution, and a pipe 3 that is delivered by the pump 2 and passes through a pipe 3. A first conical conduit 4 having a so-called diffuser shape for enlarging the cross section of the liquid 1 to be supplied to a large diameter, and a rectifying grid 5 for rectifying the liquid 1 whose cross section of the flow is enlarged to a large diameter. And a classification tank 8 which is formed in a cylindrical duct shape and which allows the seeds of a plant, which is a classification target 7, to settle from an input port 6 on the upper side thereof for classification, and the liquid 1
The main part is composed of the second conical pipe line 10 for converging the cross-sectional diameter of the flow of the fluid to the size of the diameter of the pipe 9, and the pipe 9 for circulating the liquid 1 thus converged to the pump 2. Has been done.

In such a conventional settling / classifying apparatus, the flow direction of the liquid 1 can be made uniform in almost one direction by the rectifying grid 5 used therein.

[0005]

However, in the conventional structure as described above, as shown schematically in FIG. 8, the flow speed in the cross section orthogonal to the flow of the liquid 1 in the classification tank 8 is suppressed. It has been found from various experiments by the inventor of the present inventor and its analysis that the variations in the positional distribution cannot be effectively averaged under a certain condition or more.

The variation in the flow velocity of the flow of the liquid 1 in an imaginary cross section orthogonal to the central axis of the classification tank 8 becomes larger as the classification tank 8 becomes longer and its cross-sectional area becomes larger. It will be remarkable. In addition, in the settling / classifying apparatus, generally, in order to classify more kinds of classification objects 7 more accurately, the cross-sectional diameter of the classification tank 8 is increased and the flow speed of the liquid 1 is increased to some extent. Required to do so. However, by increasing the cross-sectional diameter of the classifying tank 8 and increasing the speed of the flow of the liquid 1 in this way, the Reynolds number as the fluid of the liquid 1 flowing in the classifying tank 8 increases, and The variation in the positional distribution of the flow velocity of the liquid 1 becomes more remarkable, and turbulence and the like are likely to occur, so that the rectifying grid 5 having the structure shown in FIG.
Even if it is used, it becomes more difficult to make it uniform.

Also, when the diameter of the flow of the liquid 1 is expanded in the first conical conduit 4 or when the liquid 1 is delivered by the pump 2, the flow of the liquid 1 is caused by the viscosity of the liquid 1. Turbulence occurs in the turbulence, which becomes more noticeable due to the increased diameter of the flow. However, reducing the cross-sectional diameter or slowing the flow rate of the liquid 1 in order to avoid such a problem leads to low deterioration of the characteristics of the sedimentation classifier and cannot be adopted. That is, the liquid 1 as described above
It can be said that the problem of the variation in the positional distribution of the flow velocity of s is an unavoidable problem especially in order to realize the function of classification more effectively in the sedimentation classifier.

As a result of the above-mentioned inconvenience, the classification object 7 settles at a position deviated from the theoretical settling position due to the variation in the flow speed of the liquid 1, and accurate classification can be performed. There was a problem of disappearing. Further, in the case where the variation in the flow speed of the liquid 1 is more serious, the liquid 1 flows through the classification tank even if the direction of the liquid 1 can be certainly made uniform by the rectifying grid 5. In time, as shown in FIG. 8, the turbulence of the flow further expands, and not only the turbulent flow 15 but also the vortex 11 may occur. As a result, the settling trajectory 12 of the classification target 7
Is further disturbed by the turbulent flow 15 and the vortex 11 and the like, and even for the same classification object 7, the settling position (horizontal movement distance 13 at the time of settling) is from the theoretical position 16 to the settling locus. There is a problem in that accurate classification is not possible at all because it is disturbed and it shifts unpredictably, and even that shift cannot be corrected.

The present invention has been made in order to solve such a problem, and is based on the positional variation of the flow speed of the liquid 1 within the cross section 14 of the flow in the classification tank 8 as described above. It is an object of the present invention to solve the problem that accurate classification of the classification target 7 becomes impossible at all, and to provide a sedimentation classification device capable of accurate classification.

[0010]

First, in the sedimentation classifying apparatus of the present invention, the object to be classified is introduced into a liquid flowing in a certain direction in a cylinder having a constant cross section, and the object to be classified is passed across the flow. In the sedimentation classifying device for classifying the classification object for each sedimentation landing point in the direction along the flow according to the density and the outer dimension, the classification tank for the flow of the liquid. The meshes for averaging the velocity distributions in the inner cross section (that is, in the imaginary cross section of the flow orthogonal to the flow) are each one of the cross section diameters of the classification tank.
/ 3 or more intervals, the position of the classification target
The feature is that a plurality of sheets are arranged on the upstream side from immediately before .

That is, according to the present invention, the averaging of the flow velocity of the liquid in the classifying tank, which was difficult with the rectifying grid used in the conventional settling and classifying apparatus, can be achieved by using the above mesh. It can be realized suitably. The present inventors have conducted various experiments in order to solve the problems described in the prior art in the conventional sedimentation classifier using the rectifying grid. As a result, an analysis result was obtained that the positional variation in the flow velocity of the liquid as described in the conventional technique occurs because the grid of the rectifying grid is coarse.

In other words, although the conventional settling / classifying apparatus used the rectifying grid, this rectifying grid functions as a so-called rectifying blade, which aligns the direction of liquid flow in the position direction. Therefore, with respect to the flow component in the direction parallel to the flow straightening vanes, the flow straightening grid can, so to speak, only pass through. Therefore, in the conventional rectifier grid,
It is theoretically difficult to obtain a sufficient effect of averaging or homogenizing the positional distribution of the flow velocity in the cross section orthogonal to the liquid flow.

Therefore, according to the present invention, by using the mesh as described above, it is possible to effectively realize both the homogenization of the liquid flow direction and the homogenization of the flow speed. That is, the liquid 1 in which the flow velocity vector having non-uniform direction and speed as shown in FIG.
When reaching the mesh according to the present invention, the flow becomes a resistance that does not impair the speed of the flow that is substantially required for classification, and as shown in FIG. Is decelerated here, while the kinetic energy of the flow corresponding to the deceleration is given to the slow flow component in the neighborhood, so that the slow flow component in the neighborhood is accelerated.

In this way, the distribution of the flow velocity in the plane of the mesh according to the present invention is made uniform. Moreover, at this time, since the mesh has a planar shape, the flow direction of the liquid flowing from the upstream side to the downstream side of the mesh is also aligned in a uniform direction.

To make the flow direction uniform, in other words, after the liquid according to the present invention is once blocked by the appropriate resistance of the mesh, the liquid is separated due to the pressure difference between the liquid before and after the mesh. It can be thought of as being pushed toward the downstream side. At this time, since the mesh is formed homogeneously in a plane, it goes without saying that the pressure applied to the liquid in the plane of the mesh becomes uniform according to Pascal's law, so that the mesh is extruded to the downstream side. The liquid to be discharged flows out in a direction aligned almost perpendicular to the plane of the mesh and at a uniform speed.

Here, since the conventional rectifying grid 5 as shown in FIG. 9 functions as a rectifying blade in the flow in the theory of its operation, the size of each grid 501 is temporarily set. When the mesh of the present invention is miniaturized to obtain the effect of the above-mentioned mesh of the present invention, the vertical and horizontal frames forming the lattice 501, that is, the flow direction of the flow straightening vanes 502 is relatively formed. Has a long length, that is, when the vertical / horizontal straightening vanes 502 are regarded as wings in the flow, the wing cord 503 becomes relatively longer than the size of the lattice 501, and The turbulent flow or eddy as described above as a problem in the passing liquid is even more likely to occur.

In addition, since the thickness of each of the flow straightening vanes 502 of the flow straightening grid 5 needs to be a certain thickness due to the necessity of the mechanical strength in the manufacturing method and the use, after the flow straightening vanes 502. In some cases, turbulence or eddies may be more likely to occur in the flow. Therefore, it was difficult to downsize the conventional rectifying grid 5 to the extent that the effect of the mesh according to the present invention can be obtained.

As described above, the mesh according to the present invention is completely different from the conventional rectifying grid in the theory of operation, and is more effective than the conventional one in the speed of liquid flow (direction of flow). And the distribution of speed) can be made uniform, and in particular, the positional distribution of the speed of the flow in the cross section orthogonal to the flow can be made uniform.

The reason why it is preferable to dispose the above-mentioned mesh immediately before the position where the object to be classified is introduced in the flow direction is that the flow of the liquid after the speed of the flow is made uniform is generally that flow. As the distance becomes longer, the laminar flow state, which has been homogenized and arranged, gradually increases in variation in the flow velocity and transitions to turbulent flow.Therefore, in order to perform the sedimentation classification as accurately as possible, the classification target This is because it is preferable to start the sedimentation of the substance from a position where the liquid flow is most uniformly arranged.

In the technique described in the first aspect,
It is characteristic to use a plurality of sheets.

[0021] Mr. or even this time, it is needless to say not may be used simply hodgepodge a plurality of mesh. By using a plurality of them, it is possible to more effectively realize the uniformization of the flow velocity by applying the action and the effect described above to the liquid flow in multiple stages. It is a feature that each of the plurality of meshes is arranged with an interval of 1/3 or more of the cross-sectional diameter of the cylindrical classification tank so that the meshes can be arranged.

That is, the present inventor conducted various experiments using a plurality of meshes according to the present invention in order to further homogenize the speed of the flow and realize more accurate classification and settling. As a result, in order to achieve a higher degree of uniformization of the flow speed substantially as described above using a plurality of meshes, two or more meshes should be arranged such that adjacent meshes are It has been found that it is preferable to arrange such that the interval is 1/3 or more of the sectional diameter of the classification tank as described above.

Since the technique of the present invention is deeply involved in the field of fluid dynamics, which generally has a strong experimental rule, the meshes used when a plurality of meshes as described above are used. Regarding the theoretical analysis that the effect on the interval can be realized, the present inventors could only confirm the effectiveness and effect by confirming it by experiment. For this reason, a detailed theoretical analysis was not possible, but if it is stated within the range that can be inferred, in the case where the spacing between meshes is too narrow and less than 1/3 of the cross-sectional diameter of the classification tank, it is substantially The effect of only one of the adjacent meshes can be obtained, but when the distance between the meshes is set to 1/3 or more of the cross-sectional diameter of the classification tank, the first mesh However, the remaining flow velocity variation that could not be completely homogenized is enlarged as the liquid travels a distance of 1/3 of the cross-sectional diameter of the classification tank, and eventually turbulence or vortex may occur. Even if such a turbulent flow occurs, it is considered that the turbulent flow and the vortex can be eliminated by the second mesh and the third mesh after that.

The mesh may be a metal mesh formed by meshing fine metal wires, or a metal plate having a large number of slots or round holes formed by etching or press die cutting. You may. In particular, the above-mentioned metal reticulum is structurally simple to manufacture and can be manufactured at low cost, and the thickness of the metal fine wire and the size of the mesh weaving can be freely set. It can be said that it is particularly suitable as a mesh. When such a metal reticulum is used, a mesh having a mesh as described in the second item below is particularly suitable.

[0025] That is, the second, settling classifier of the present invention,
In the settling / classifying apparatus according to the first or second aspect, the size of one mesh of the mesh is 1 mm or more and 10 mm square or less, and the diameter of each fine wire forming the mesh is 0.1 mm or more and 1 mm. A settling / classifying apparatus comprising a mesh having the following network structure.

That is, as the metal net used as the mesh according to the present invention, the size of the mesh and the fine wire forming the mesh are set as described above, so that the description of the technique of the first aspect will be made. The effects described above can be realized more effectively. In addition, the lower limit of the size of one mesh of the mesh is set to 1 mm or more, and the diameter of each thin wire is set to 1 mm or less, because the size of the mesh is less than this and the diameter of the thin wire is more than this. The relative openness of the mesh in the mesh is relatively low, and the resistance of the mesh to the flow of liquid increases, and the flow of liquid is significantly slowed down by this mesh. This is because the speed may not be obtained.

On the other hand, the upper limit of the size of each mesh of the mesh is set to 10 mm or less, and the lower limit of the diameter of the fine wire is set to 0.1 mm or more. Is not durable enough,
When the size of the mesh is 10 mm or more and the diameter of the fine wire is 0.1 mm or less, the aperture ratio of the mesh in the mesh is too high this time, and the liquid flow is This is because there is a possibility of passing through the mesh.

[0028] Thirdly, settling classifier of the present invention is a precipitation classifier of the first or second aspect, the velocity distribution in the cross section of the classification tank of flow of said liquid by averaging as the mesh, In the case of using the mesh, particularly a plurality of meshes, it is a mesh that does not generate turbulence in the flow from after passing through the mesh arranged at the most downstream side of the flow to the sedimentation landing point. It has a feature.

That is, it is needless to say that the most preferable function of the mesh according to the present invention is that the speed of the liquid flow after passing through the mesh is quite uniform.
A high degree of complete homogenization of such flow rates is practically difficult. This is due to the turbulence of the liquid flow caused by the movement of the pump that constitutes the settling / classifying device, and the turbulence of the liquid due to the viscosity of the liquid in the conical pipe line or classifier that is called a diffuser. It is considered that this is because various and various causative factors are intertwined with each other, and the flow speed of the liquid varies.

Further, pursuing even such an extremely high degree of homogenization is rather wasteful since it only requires quality improvement more than necessary in view of the effect obtained thereby. Therefore, in the technique described in the third aspect , since the essence of the technique according to the present invention is to realize accurate classification, it is said that the flow should be made uniform within a range in which substantially accurate classification is possible. Paying attention to the points, if turbulence impairs the accurate sedimentation classification in the target sedimentation classifier, turbulent flow occurs between the flow of liquid and the sedimentation and landing point. To avoid this, the mesh according to the present invention is used. As described above, by classifying the flow speed after passing through the mesh so that turbulence does not occur in the liquid flow until the completion of the sedimentation classification, an error is substantially generated in the classification action. It is possible to solve this problem and achieve accurate classification.

As described above, it is sufficient to make the flow speed uniform to the extent that it is possible to substantially eliminate the error in the classification action. Even if there is a non-uniformity in the speed of flow to the extent that
If the order of the actual settling and landing points of multiple types of classification objects is the same as the order of the theoretical settling and landing points, then the classification can be performed accurately. There is also.

[0032] Therefore, the fourth, the settling classifier of the first or second aspect, wherein the mesh is a velocity distribution in the cross section perpendicular to the flow of said liquid by averaging a plurality of types of the classification target It is a mesh that makes the order in the direction along the flow of the sedimentation landing point of each object the same as the order in the direction along the flow of the theoretical landing landing spot without being the same. There is.

[0033] In summary, in the above-described third and fourth aspect of the technology, the accuracy of such a classification action number of the first to second mesh mesh size and use of the network of the eye and fine lines as described That is, it is preferable to make it suitable for the purpose of making the flow velocity uniform so as not to damage

Fifth , the settling / classifying apparatus of the present invention is the settling / classifying apparatus according to any one of the first to fourth aspects, wherein the mesh has a mesh size and a distribution density of the mesh through which the liquid passes. It is characterized in that at least one of them is a mesh arranged so as to be different at each position in the plane of the mesh.

That is, in one settling / classifying device, due to, for example, the shape of a diffuser of a conical pipe line, a specific habit is generated in the deviation of the distribution of the flow velocity of the liquid flowing in the classifying tank. If it is found, it is preferable to make the flow velocity of the liquid at a position where the distribution of the flow velocity is particularly biased particularly uniform.

Therefore, the technique described in the fifth aspect is suitable for the above-mentioned priority in order to make the flow velocity uniform, that is, to correct the velocity at each position in the flow cross section. In addition, at least one of the mesh size and distribution density of the mesh is arranged so as to be different for each position in the plane.

For example, in a region of about 3 cm inward from the wall surface of the cylindrical classification tank, due to the friction between the liquid flow and the wall surface, the distribution gradient is found in the flow speed at that portion. If there is a tendency for non-uniform flow or turbulent flow to occur, the mesh mesh size increases as it gets closer to the wall surface, for example, so as to eliminate the distribution gradient of the flow velocity. The size of the mesh is adjusted so that the flow in the area that tends to be slow is adjusted so that the speed is not impaired by the larger mesh, and conversely the flow in the area that tends to be faster than average. With respect to the above, a mesh in which the distribution of the size of the mesh is positionally changed within its main surface may be used, such that the speed is adjusted to be decreased by the above-mentioned smaller mesh.

[0038]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the settling / classifying apparatus according to the present invention will be described in detail with reference to the drawings. (Embodiment 1) As shown in the main part of this settling / classifying apparatus, a liquid 200 flowing in a cylindrical classifying tank 101 having a diameter of 310 mm and a constant cross section is filled with a liquid to be classified 200 from a charging port 102 to a classification object 300. Injecting and allowing the classification target 300 to settle in the direction crossing the flow of the liquid 200, each settling landing point in the direction along the flow according to the density and external dimensions of the classification target 300. The partitioning objects 103 to 107 respectively arranged in the
Which is a settling classifier for classifying the meshes, and the meshes 108 and 109 for averaging the velocity distribution in the cross section orthogonal to the flow of the liquid 200 are provided on the upstream side of the charging port 102, which is the charging position of the classification target 300. In addition, the main part of the sedimentation classifier is configured in a structure in which two 200 mm, which are at intervals of ⅓ or more of the cross-sectional diameter of the classification tank 101, are arranged apart from each other.

By the way, the flow of the liquid 200 is supplied by the pump 110 through the pipe 111 to the first conical pipe line 112 having a shape like a divergent end called a diffuser, where the liquid 200 is The cross section of the flow is expanded to the cross sectional diameter of the classification tank 101 and then introduced into the classification tank 101. Then, after the classification is performed in the classification tank 101, the cross-sectional diameter of the flow is a second conical conduit 113 having a shape opposite to that of the first conical conduit 112.
Is refocused to the size of the diameter of the pipe 114, guided to the pipe 114, and circulated again through the pipe 114 to the pump 110. The settling / classifying apparatus of the present embodiment is formed so that the flow of the liquid 200 circulates in such a series of closed paths.

In this embodiment, a 0.1% aqueous solution of sodium alginate is used as the liquid 200.
Liquid 2 near the inlet 102 of the classification tank 101
The circulation of the liquid 200 by the pump 110 was controlled so that the average flow velocity of the flow of 00 was 3 mm / s. Further, the first conical conduit 112 is formed in such a shape that the apex angle of the conical shape is 30 degrees. As an example of the classification target 300, a large number of carrot somatic embryos having major axis lengths varying from 1 to 4 mm were used in experiments and the like described later.

As shown in FIG. 2, the meshes 108 and 109 used in the settling / classifying apparatus of this embodiment have a mesh 400 of 5 mm × 5 mm, and the mesh is vertically
The diameter of the thin metal wire 401 formed horizontally is about 0.4 m
m, the diameter of the entire main surface of the mesh 108, 109 is about 31
It is a metal mesh having a thickness of 0 mm and a thickness of about 0.8 mm.

In the settling / classifying apparatus according to the present invention, the main part of which is configured as described above, the flow of the liquid 200 by the two meshes 108 and 109 as described above causes the velocity in a cross section orthogonal to the flow. It goes without saying that the distribution (that is, the distribution of the speed and direction of the flow) is effectively homogenized, and no vortex is generated in the flow after the mesh 109 on the downstream side, and turbulence is generated to such an extent that it can be almost ignored. It has been confirmed as a result of various experiments using the above-mentioned sedimentation classifier that it can be suppressed.

That is, an experiment was carried out using the settling / classifying apparatus of the present embodiment, the main part of which was constructed as described above, and the measurement was performed from the mesh 109 on the downstream side, and the point 50 mm downstream, 3
When the generation states of turbulent flow were investigated at a point 50 mm downstream and a point 650 mm downstream, almost no turbulent flow was generated at any point.

However, at a point 50 mm downstream, there was a case where a slight turbulent flow was generated although there was substantially no adverse effect on the sedimentation classification action. Although accurate confirmation of the cause of the occurrence of such turbulence is not possible at this point, the fine metal wire 401 forming the mesh 109 causes turbulence such as a minute Karman vortex in the flow on the downstream side. It is thought that this may be caused by the occurrence of Then, a set of small turbulences generated by such Karman vortices disappears due to the viscosity of the liquid 200 while the flow proceeds to the downstream side, and therefore the liquid 200 at the downstream point of 350 mm or 650 mm.
It is considered that the turbulent flow did not occur and was observed as a substantially regular laminar flow.

In any case, however, even if such minute turbulences and vortices as described above occur, the use of the meshes 108 and 109 according to the present invention has no substantial adverse effect on the sedimentation classification action. Liquid 200 to the extent that there is no
It is possible to equalize the flow velocity of the. As a result, the classification target 30 which is supposed to be determined for each physical characteristic such as a plurality of kinds or the same kind of different density by the theoretical settling landing point and the actual settling landing point of the classification target 300.
Since the order of the settling positions of 0 was not disturbed, it was confirmed that accurate classification according to theory could be realized.

(Embodiment 2) In the first embodiment, the mesh according to the present invention is the mesh 108, 109.
, But the mesh is not limited to only two,
Further uniformization of the flow can be realized by using three sheets as in this embodiment.

Therefore, in the second embodiment, as shown in FIG. 3, three meshes 108, 109, 11 having the same mesh as the first embodiment are provided in the cylinder of the classification tank 101.
The major faces of adjacent meshes of 5 are 150 mm from each other.
A sedimentation classifier was prepared in which they were arranged so as to be arranged at a distance of. In the description of the second embodiment and FIG. 3, the same parts as those of the first embodiment are designated by the same reference numerals.

Using the settling / classifying apparatus of the second embodiment having such a structure, an experiment of a classification operation similar to that of the first embodiment was actually conducted. As a result, as a result of investigating the turbulent flow generation conditions at the point 50 mm downstream, the point 350 mm downstream, and the point 650 mm downstream measured from the mesh 109 on the downstream side, the turbulent flow is substantially observed at any point. The velocity of the flow of the liquid 200 can be made uniform to such an extent that it does not occur and there is no substantial adverse effect on the sedimentation classification action, and as a result, the classification object 300 can be classified substantially accurately. We were able to confirm that

Moreover, at this time, the mesh 1 according to the present invention is used.
Since the three meshes 08, 109, and 115 were used in parallel with the flow of the liquid 200, the liquid 200 was caused by the resistance of the three meshes to the liquid 200.
It was feared that the flow of water would be significantly slowed down overall, but according to the measurement of the flow velocity carried out during the above experiment, no substantial slowdown was observed that had a negative effect on the classification effect. .

Therefore, an experiment using a finer mesh was conducted. In the settling / classifying apparatus of the present embodiment having the above structure, the meshes 108, 10 used
The size of the mesh of 9,115 was changed from the above 5 mm × 5 mm to 1 mm × 1 mm, and the distance between adjacent meshes was changed to 110 mm, and the other structures were made the same as above. As a result of conducting the same experiment as above, it was confirmed that a substantial deceleration that would adversely affect the classification action was not observed, and that a substantially accurate classification could be realized.

(Embodiment 3) In each of the above embodiments, the case where a plurality of meshes 108, 109 and the like are used in parallel has been described, but the mesh according to the present invention can also be used in a single sheet. Is. Therefore, this third
In the embodiment, as shown in FIG. 4, a sedimentation classifying apparatus using only one mesh 109 was manufactured. In addition, in the description of the third embodiment and FIG.
The same parts as those in the first and second embodiments are designated by the same reference numerals.

As the mesh 109 of the settling / classifying apparatus of the third embodiment, the mesh is 5 mm × 5 mm, which is the same as that of the first embodiment, and the diameter of the thin metal wire 401 constituting the mesh 109. Of the same as above was used. As a result, it was observed that some turbulence was generated in the flow after the mesh 109. This is the mesh 109
Only one sheet is used, and the mesh is 5 mm x 5
Since it is mm, it is considered that this may be caused by the fact that the flow velocity cannot be sufficiently made uniform only by the mesh 109. Therefore, the same experiment was conducted by reducing the mesh size of the mesh 109 to 1 mm × 1 mm, and using the fine metal wire 401 constituting the mesh having the same diameter of 0.4 mm.

As a result, the point measured 50 mm downstream from the downstream side mesh 109, the point 350 mm downstream, 6
As a result of investigating the turbulent flow generation conditions at the point 50 mm downstream, it was confirmed that no turbulent flow was generated at any point and the flow velocity of the liquid 200 was substantially uniform.

(Embodiment 4) The first conical conduit 11 in which the flow of the liquid 200 is divergent like a diffuser.
When passing through 2, the flow velocity distribution generally tends to be as shown in FIG. Here, in FIG. 5, each arrow vector 5
00 and 501 indicate the flow velocity of the liquid 200 for each position, and when the flow velocity is lower than the average value of the flow velocity (when the flow velocity is slow), the vector pointing to the left with respect to the center line 502 is used. In the case of 500 or more (when the flow velocity is high), it is schematically shown as a vector 501 pointing rightward with respect to the center line 502.

As described above, when it is assumed in advance that the flow velocities become uneven, and the tendency of the flow velocity distribution or the flow velocity gradient can be grasped in advance, the tendency of the flow non-uniformity is taken into consideration. Therefore, it is preferable to partially change the distribution of the mesh size in the main surface of the mesh or the density distribution of the mesh so that the flow velocity distribution can be made more uniform. However, it is not impossible but not easy to form the mesh of the mesh formed by the thin metal wires 401 as shown in each of the above-mentioned embodiments by partially changing the mesh of the mesh.

Therefore, as the mesh used in the fourth embodiment, a metal plate having a plate thickness of about 0.1 to 1 mm has a size of 1 mm square or more and 10 mm by etching or the like.
A mesh 600 formed by forming a large number of holes each having a size less than a corner
Can be preferably used.

That is, as an example thereof is shown in FIG. 6, in the main surface of the mesh 600, the size of the holes 601 in the region where the vector 500 is distributed is formed to be 4 mm × 4 mm, while the vector 501 is formed. The size of the holes 602 in the region where the is distributed is 2 mm × 2 mm. In this way, by controlling the flow speed of the liquid 200 so as to more positively make it uniform, it is possible to more effectively perform the classification accuracy.

[0058]

As clearly shown in the above detailed description, according to the present invention, the flow velocity of the liquid in the classification tank can be made uniform, and as a result, accurate classification by the sedimentation classifier can be performed. Can be realized.

[Brief description of drawings]

FIG. 1 is a diagram showing a sedimentation classification device according to a first embodiment.

FIG. 2 is a diagram showing a mesh according to the present invention.

FIG. 3 is a diagram showing a sedimentation classification device according to a second embodiment.

FIG. 4 is a diagram showing a sedimentation classification device according to a third embodiment.

FIG. 5 is a diagram showing a flow velocity distribution of the liquid 200 generated in the first conical conduit 112.

FIG. 6 is a diagram showing a mesh used in a fourth embodiment.

FIG. 7 is a diagram showing a conventional settling / classifying apparatus using a rectifying grid.

FIG. 8 is a diagram showing variations in positional distribution of flow velocity in a conventional sedimentation classifier.

FIG. 9 is a view showing a rectifying grid used in a conventional sedimentation classifier.

[Explanation of symbols]

101 ... Classifying tank, 112 ... First conical conduit, 108,
109, 115 ... Mesh, 200 ... Liquid, 300 ... Classification target (carrot somatic embryo)

Claims (5)

(57) [Claims] 1. An object to be classified is introduced into a liquid flowing in a tubular classification tank having a constant cross section, and the object to be classified is allowed to settle in a direction traversing the flow to make the object to be classified into a density and an external dimension. According to a sedimentation classifying device for classifying the classification object for each sedimentation landing point in the direction along the flow, meshes for averaging the velocity distribution in the cross section of the flow of the liquid in the classification tank are mutually Straight section of the classification tank
Inserting the above classification target at intervals of 1/3 or more of the diameter
A settling classifier characterized by arranging a plurality of sheets from immediately before the position to the upstream side . 2. The settling / classifying apparatus according to claim 1 , wherein, as the mesh, the size of one mesh is 10 mm square or less and 1 mm or more, and the diameter of one mesh is 1 mm or less and 0.1 mm or more. A sedimentation classifier characterized by comprising a structural mesh. 3. A precipitation classifying device according to claim 1 or 2, wherein said mesh, the velocity distribution in the cross section of the classification tank of flow of said liquid by averaging, the precipitation deposition the mesh after passing A sedimentation classifier characterized by a mesh that does not generate turbulence in the flow up to the point. 4. A precipitation classifying device according to claim 1 or 2, wherein said mesh, the velocity distribution in the cross section of the classification tank of flow of said liquid by averaging, a plurality of types for each of the classified object A sedimentation classifying device, which is a mesh that makes the order of the sedimentation landing points in the direction along the flow the same as the order of the theoretical landing landings in the direction along the flow without any difference. . 5. The settling classifier according to any one of claims 1 to 4, wherein the mesh is at least one of the mesh size and the distribution density of the mesh passing the liquid, the mesh A sedimentation classifying device, characterized in that the mesh is arranged so as to change depending on the position within the plane.