JPWO2012165560A1 - Classification device and classification method, and blasting device and blasting method provided with the classification device - Google Patents

Abstract

Disclosed are a classification device for classifying particles dispersed in a slurry by using a difference in sedimentation speed, and a blasting device equipped with this device. The classifier includes a casing that introduces slurry and classifies into large particles and small particles, and a slurry introducing mechanism for introducing the slurry. The housing is partitioned into a slurry introduction chamber, a first collection chamber, and a second collection chamber by a classification member and a slurry introduction member that are erected from the bottom surface of the classification chamber main body. This classification device can be used as a sorting mechanism for sorting particles in the slurry into reusable abrasive grains and other particles in a wet blasting apparatus. [Selection] Figure 1

Description

The present invention relates to a wet classifier for classifying particles dispersed in a liquid to a predetermined size.

An apparatus for sorting solid particles dispersed in a slurry with a predetermined size is widely used in a wet blasting apparatus or the like (for example, JP-A-2005-335044). As such an apparatus, a cyclone classifier, a method using a filter opened to a predetermined size such as a filter cloth or a net, and a sedimentation separation method using a thickener or the like are known. Separation by a filter has a problem that the opening is closed by particles when used for a long time. Sedimentation separation can be applied only to particles that require a long time to settle or have a large specific gravity. As other methods, for example, Japanese Patent Application Laid-Open No. 10-066685 and Japanese Patent Application Laid-Open No. 2000-005626 disclose separation devices that combine hydraulic power and sedimentation separation.

  In Japanese Patent Application Laid-Open No. 10-066685, the slurry is allowed to flow in parallel to be discharged from the outlet through the first and second sorting chambers from the inlet at the top of the sorting chamber, and the fine particles are separated from the coarse particles. For this purpose, the liquid at the bottom of the second sorting chamber is allowed to flow through a pump. Since relatively light particles are accumulated at the bottom of the second sorting chamber, the path to the pump may be closed by the particles that have settled. Moreover, since the said pump is required, an apparatus becomes complicated. In Patent Document 3, water is allowed to flow from the lower part of the sorting cylinder, and particles that are to be sorted are introduced from above the sorting cylinder. The heavy particles settle to the bottom of the sorting cylinder, and the light particles are discharged from the sorting cylinder together with the overflowed (overflowed) water. Therefore, the apparatus itself becomes a large scale, and it is necessary to replace the sorting cylinder itself in order to change the size and classification point of the object to be sorted. The present invention provides a wet classification apparatus and classification method that can classify solid particles in a slurry with a simple structure and high accuracy, and a wet blast processing apparatus and blast processing method that include this classification apparatus.

  A first aspect of the present invention is an apparatus for classifying solid particles dispersed in a slurry by utilizing a difference in sedimentation speed, wherein the classification apparatus introduces the slurry and introduces large-diameter particles. And a slurry introduction mechanism for introducing slurry into the casing, the casing standing from the bottom surface of the casing, and the ceiling of the casing The housing is partitioned into a first recovery chamber and a second recovery chamber by a plate-shaped classification member having a tip provided with a gap between the first recovery chamber and the first recovery chamber. A plate-like slurry introducing member erected from the bottom surface of the recovery chamber, or the slurry introducing member and the wall surface of the first recovery chamber form a side wall, and a lower end of the slurry connected to the slurry introducing mechanism. A slurry introduction chamber is formed with an inlet and an open top. To.

  A second invention of the present invention is an apparatus for classifying solid particles dispersed in a slurry by utilizing a difference in sedimentation speed, and the classification apparatus introduces the slurry and has a large size. A housing for classifying into particles and small-diameter particles, and a slurry introduction mechanism for introducing slurry into the housing, wherein the housing is erected from the bottom surface of the housing and has a plurality of closures The housing is partitioned into a first recovery chamber and a second recovery chamber by a plate-shaped classification member provided with a possible opening, and the first recovery chamber is separated from the bottom of the first recovery chamber. A plate-like slurry introduction member standing upright, or the slurry introduction member and the wall surface of the first recovery chamber form a side wall, and a slurry introduction port connected to the slurry introduction mechanism is formed at the lower end. And a slurry introduction chamber having an open upper end. A slurry introduction chamber having an upper end opened by a slurry introduction member is formed. Of the slurry introduced into the first recovery chamber from the slurry introduction chamber, relatively heavy large-diameter particles settle at the bottom of the first recovery chamber. On the other hand, the relatively light small-diameter particles move to the second collection chamber through the gap between the classification member and the ceiling or the opening provided in the classification member.

  A third invention is the classification device according to the first or second invention, wherein at least a part of the classification member is detachable. The particle diameter recovered in the first recovery chamber and the second recovery chamber can be changed by changing the height by attaching / detaching at least a part of the classification member.

  A fourth invention is the classification apparatus according to any one of the first to third inventions, wherein the slurry introduction chamber has a cross-sectional area that increases upward. The solid particles in the slurry may aggregate to form secondary particles. Secondary particles lead to a decrease in classification accuracy. By adopting the structure of the present invention, the secondary particles can be crushed into primary particles when passing through the slurry introduction chamber. Note that “the cross-sectional area increases upward” is a concept that includes not only the case of continuous enlargement but also the case where only a part thereof is enlarged. For example, it is good also as a structure which has the same cross-sectional area continuously in the upper end part vicinity. Further, as described later, after the cross-sectional area is enlarged upward, the cross-sectional area may be reduced in the vicinity of the upper end portion.

  5th and 6th invention is a classification apparatus as described in any one of 1st thru | or 4th invention, Comprising: The acceleration mechanism for accelerating a slurry is provided in the upper end part of the said slurry introduction chamber. It is characterized by. The classification accuracy can be improved by increasing the speed when passing through the upper end of the slurry introduction chamber.

  7th and 8th invention is a classification apparatus as described in 5th or 6th invention, Comprising: The cross-sectional area of the said slurry is reduced upwards by the said acceleration mechanism, It is characterized by the above-mentioned. According to the present invention, the speed of the slurry passing through the upper end portion of the slurry introduction chamber can be increased with a simple structure.

  A ninth invention is the classification apparatus according to any one of the first to eighth inventions, wherein the slurry introduction mechanism includes a lift mechanism for lifting the slurry, and the slurry introduction port and the An introduction speed adjusting mechanism for adjusting the introduction speed of the slurry is disposed between the lift mechanism and the lift mechanism. The classification point can be finely adjusted by adjusting the speed of the slurry introduced from the slurry inlet.

  A tenth aspect of the invention is a blasting apparatus for performing a blasting process by spraying a slurry in which abrasive grains are dispersed in a liquid together with a high-pressure gas onto a workpiece, and the blasting apparatus includes an injection nozzle inside A slurry processing chamber, a slurry tank for storing the slurry, a sorting mechanism for classifying particles in the slurry in the slurry tank, and a slurry containing small-diameter particles classified by the classification device And a separation mechanism for separating the solid and liquid, wherein the sorting mechanism is the classification device according to any one of claims 1 to 9. The classifying apparatus of the present invention is a wet blasting apparatus for sorting abrasive grains that can be blasted again, and abrasive grains that have become unsuitable for blasting and cutting particles of the workpiece. It can be suitably used as a mechanism.

  An eleventh aspect of the invention is the blast processing apparatus according to the tenth aspect of the invention, wherein the separation mechanism is a magnetic force separation apparatus. When the abrasive grains and the workpiece have magnetism, solid-liquid separation can be easily performed with a magnetic separator.

  A twelfth invention is the blasting apparatus according to the tenth or eleventh invention, wherein a cleaning nozzle for cleaning the workpiece after blasting is disposed in the blasting chamber, The cleaning nozzle ejects the liquid separated by the separation mechanism. Abrasive grains, cutting particles of the workpiece or the like are attached to the workpiece after blasting, and it is necessary to clean the workpiece, and a solid-liquid separated liquid can be used as the cleaning medium.

  A thirteenth invention is a method for classifying solid particles dispersed in a slurry using the classification device according to any one of the first to twelfth inventions, wherein the slurry is fed from the slurry inlet to the slurry. Introducing the slurry into the introduction chamber; diffusing and discharging the introduced slurry from the opening at the upper end of the slurry introduction chamber; and the small diameter particles in the solid particles in the slurry, the classification member and the ceiling Passing through the gap or an opening provided in the classification member and moving into the second recovery chamber, and sinking large particles in the solid particles in the slurry to the bottom of the first recovery chamber; And a step of allowing the small-sized particles that have moved into the second collection chamber to settle at the bottom of the second collection chamber. Among the solid particles that are diffused and discharged from the slurry introduction chamber, the relatively large heavy-sized particles settle on the bottom of the first recovery chamber without moving to the second recovery chamber. On the other hand, the relatively light small-diameter particles move to the second recovery chamber and settle to the bottom of the second recovery chamber. The sedimentation to the bottoms of the first recovery chamber and the second recovery chamber may be performed only by the self-weight of the solid particles, or may be combined with the discharge force from the opening provided at each bottom.

  A fourteenth invention is the classification method according to the thirteenth invention, wherein the solid moves to the second recovery chamber by changing the height of the classification member or the distance between the lower end of the opening and the ceiling. The particle diameter is changed. By adjusting the height from the bottom surface of the classification member, that is, the distance between the upper end of the classification member and the ceiling of the housing, the diameter of the solid particles moving to the second recovery chamber can be changed. That is, the classification point can be changed. For example, by reducing the height, the diameter of the solid particles moving to the second recovery chamber is increased, so that the classification point can be increased.

  The fifteenth and sixteenth inventions are methods for classifying solid particles dispersed in a slurry using the classifying device according to the fifth or sixth, wherein the slurry is introduced into the slurry introduction chamber from the slurry introduction port. A step of accelerating the introduced slurry by the acceleration mechanism, and diffusing and discharging the slurry from an opening at the upper end of the slurry introduction chamber; and the small-diameter particles in the solid particles in the slurry; While passing through the gap with the ceiling or the opening provided in the classification member and moving into the second recovery chamber, the large-diameter particles in the solid particles in the slurry are allowed to settle at the bottom of the first recovery chamber. And a step of allowing the small-sized particles that have moved into the second collection chamber to settle to the bottom of the second collection chamber. By increasing the speed of the slurry, the small diameter particles can be moved to the second recovery chamber without staying in the first recovery chamber. As a result, the classification system can be improved or the classification point can be increased.

  A seventeenth aspect of the invention is a method for classifying solid particles dispersed in a slurry using the classification device according to the ninth aspect of the invention, wherein the introduction speed of the slurry is changed by the introduction speed adjusting mechanism, and the second recovery chamber is changed. It is characterized by changing the diameter of the solid particles that move to the surface. By changing the slurry introduction speed by the introduction speed adjustment mechanism, the classification point can be easily adjusted.

  An eighteenth aspect of the invention is a blasting method using the blasting apparatus according to any one of the tenth to twelfth aspects of the invention, and a slurry is obtained by introducing and dispersing liquid and abrasive grains into the slurry tank. A step of transferring the slurry in the slurry tank to the injection nozzle, mixing the high pressure gas and injecting the slurry toward the workpiece from the injection nozzle, and the injected slurry and the cutting particles of the workpiece. Slurry tank as solid particles for re-blasting the step of storing in the slurry tank, the step of transferring the slurry in the slurry tank to the classifier, and the large diameter particles recovered in the first recovery chamber And a step of recovering small-sized particles recovered in the second recovery chamber as sludge. According to the present invention, solid particles in a slurry can be separated into abrasive grains suitable for performing blasting again, abrasive grains having a size unsuitable for blasting, and cutting particles of a workpiece. .

  A nineteenth aspect of the invention is a blasting method using the blasting apparatus according to the eleventh aspect of the invention, in which a slurry having liquid and magnetism is introduced and dispersed in the slurry tank to obtain a slurry, and the slurry Transferring the slurry in the tank to the injection nozzle, mixing the high pressure gas and injecting the slurry toward the magnetic workpiece from the injection nozzle, and the injected slurry and the cutting particles of the workpiece in the slurry tank The step of storing the slurry, the step of transferring the slurry in the slurry tank to the classifier, and the large-sized particles recovered in the first recovery chamber being transferred to the slurry tank as solid particles for blasting again. A step of transferring the slurry containing the small-sized particles recovered in the second recovery chamber to the magnetic separator, and the slurry transferred to the magnetic separator is solid-liquid separated by a magnetic force. Characterized in that it comprises a step. When the abrasive grains and the workpiece have magnetism, a slurry containing the second recovered small-diameter particles (that is, abrasive grains having a size unsuitable for blasting, cutting particles of the workpiece, etc.) Solid-liquid separation can be easily performed, and the small-diameter particles can be recovered as sludge.

  A twentieth aspect of the invention is an apparatus for classifying solid particles dispersed in a slurry by utilizing a difference in settling speed, wherein the classification apparatus introduces the slurry and introduces a large particle and a small particle. And a slurry introduction mechanism for introducing the slurry, and the case is provided with a gap between a bottom surface of the case and a ceiling surface of the case. A plate-shaped classification member for partitioning the housing into a first recovery chamber in which a large particle discharge port is formed on the bottom surface and a second recovery chamber in which a small particle discharge port is formed on the bottom surface; Disposed upward from the bottom surface between the slurry inlet opening at the bottom of the first recovery chamber and the large particle outlet, and the slurry introduced into the first recovery chamber from the slurry inlet is upward. A plate-like slurry introducing member for diffusing toward the surface, and the slurry introducing machine Wherein the one end is the other end communicated with the communicated and lift mechanism to the slurry inlet port. According to the present invention, it is possible to provide an apparatus capable of classifying with a simple structure and high accuracy.

  The present invention can provide a classification device and a classification method with a simple structure and high classification accuracy.

  Moreover, the classification apparatus of this invention can classify more efficiently the one where the specific gravity difference of a large diameter particle and a small diameter particle is large. Slurry classification in a wet blasting machine is performed with abrasive particles that have a size that is not suitable for re-use due to cutting particles generated by blasting and cracking or chipping caused by collision with the workpiece. Therefore, the specific gravity difference with the reusable abrasive grains that are large-diameter particles is large. Therefore, the classification device of the present invention can be used preferably.

  The diameter and specific gravity of the solid particles that can be classified according to the present invention are not particularly limited, but classification can be performed with higher accuracy when the specific gravity difference between the large diameter particles and the small diameter particles and the difference in particle diameter are larger. In addition, the specific gravity difference between the large-sized particles and the small-sized particles and the difference in the particle size are large, but the classification point is particularly good if the classification point is in the range of 100 to 1000 μm for the slurry S with respect to the slurry S having a broad particle size distribution. It can be performed.

This application is based on Japanese Patent Application No. 2011-123863 filed on June 2, 2011 and Japanese Patent Application No. 2012-051173 filed on March 8, 2012 in Japan. A part of it is formed.
The present invention will also be more fully understood from the following detailed description. However, the detailed description and specific examples are preferred embodiments of the present invention and are described for illustrative purposes only. This is because various changes and modifications will be apparent to those skilled in the art from this detailed description.
The applicant does not intend to contribute any of the described embodiments to the public, and the disclosed modifications and alternatives that may not be included in the scope of the claims are equivalent. It is part of the invention under discussion.
In this specification or in the claims, the use of nouns and similar directives should be interpreted to include both the singular and the plural unless specifically stated otherwise or clearly denied by context. The use of any examples or exemplary terms provided herein (eg, “etc.”) is merely intended to facilitate the description of the invention and is not specifically recited in the claims. As long as it does not limit the scope of the present invention.

It is explanatory drawing for demonstrating the classification apparatus in this embodiment. 1A is a schematic view showing a longitudinal section, and FIG. 1B is a sectional view taken along line AA in FIG. It is explanatory drawing for demonstrating the example of a change of the slurry introduction chamber of this embodiment. It is explanatory drawing for demonstrating the acceleration mechanism of this embodiment. It is explanatory drawing for demonstrating the structure of the wet blast processing apparatus in this embodiment. It is explanatory drawing for demonstrating the example of a change of the wet blast processing apparatus of this embodiment.

  The classification device of the present invention and the case where this classification device is used in a wet blasting apparatus will be described as an example. In addition, the classification apparatus of this invention is not limited to the form as described in embodiment, It can change suitably as needed. Moreover, the left-right and up-down direction as described in this embodiment points out the direction in a figure unless there is particular notice.

(Classification device)
First, the classification device will be described. The classification device 10 includes a housing 11 and a slurry introduction mechanism 17. As shown in FIG. 1A, the housing 11 has a cylindrical shape with a quadrangular cross section, and the ceiling portion (the uppermost portion in the figure) is closed by a top plate. A slurry introduction port 12a, a large-diameter particle discharge port 13a, and a small-diameter particle discharge port 14a are opened in order from the left in FIG.

  In the middle of the large particle discharge port 13a and the small particle discharge port 14a, a classification member 16 is erected on the bottom of the housing 11, and the space inside the housing 11 is located upstream of the slurry flow. It is divided into a first recovery chamber 13 and a second recovery chamber 14 on the downstream side of the slurry flow. The classifying member 16 has a plate shape and is disposed so that a gap is formed between the upper end and the ceiling of the housing 11.

  In the vicinity of the slurry introduction port 12a, a slurry introduction member 15 is disposed upward from the bottom of the housing. The slurry introduction member 15 has a plate shape, and the height position of the upper end (the vertical direction in FIG. 1A) is lower than the height position of the upper end of the classification member 16. The slurry introduction member 15 is disposed so as to surround the slurry introduction port, and partitions the slurry introduction chamber 12 into the space inside the first recovery chamber 13. In the present embodiment, as shown in FIG. 1B, the slurry is introduced by the slurry introduction member 15 arranged in three directions (upper, lower, right) and the side wall of the casing 11 located in the left direction. A slurry introduction chamber 12, which is a space including the introduction port 12a, is formed. In addition, if this space is formed, the direction and shape in which the slurry introduction member 15 is arranged are not particularly limited. For example, three directions (upper, lower, leftward in the figure) may be the wall surface of the first recovery chamber 13, and only the remaining one wall surface (rightward in the figure) may be the slurry introduction member 15 (see FIG. 2A). ), Or a slurry introduction member 15 arranged in four directions (up, down, left, right) (see FIG. 2B). The cross section of the slurry introduction chamber 12 (the cross section in the direction perpendicular to the paper surface in FIG. 1A) is not limited to a quadrangle as in the embodiment, and is formed by, for example, a cylindrical slurry introduction member 15 and the side wall of the housing 11. It may be a semicircular shape (see FIG. 2C) or a circular shape formed only by the cylindrical slurry introduction member 15 (see FIG. 2D).

  As described above, the internal space of the housing 11 is partitioned by the slurry introduction member 15 and the classification member 16. Thus, in order from the left, the slurry introduction chamber 12, which is a space including the slurry introduction port 12a, the first collection chamber 13, which is a space including the slurry introduction chamber 12, and the large particle discharge port 13a, and the small particle discharge port 14a are included. A second recovery chamber 14, which is a space, is formed.

  The large particle discharge port 13a and the small particle discharge port 14a are preferably connected to a large particle discharge valve and a small particle discharge valve, which are valves each having a closing and flow rate adjusting mechanism (not shown). ). Before the start of classification, the large particle discharge valve and the small particle discharge valve are closed.

A slurry introduction mechanism 17 is connected to the slurry introduction port 12a. Slurry introducing mechanism 17 includes a lift mechanism P1 (canned motor pump in the present embodiment), and the hose H _1, a. By a hose H _1, and the lift mechanism 17 and the slurry inlet 12a is connected. Moreover, the lift mechanism P1 is connected hose H2 is, the hose H _2, and the lift mechanism 17 and the slurry tank 22 is connected.

  First, the slurry S in which solid particles to be classified are dispersed in a liquid is put into the slurry tank 22. In order to prevent the solid particles in the slurry S from accumulating on the bottom, it is preferable to arrange a stirring mechanism (not shown) in the slurry tank. The stirring mechanism may be either stirring the slurry with a stirring blade, stirring using a water flow, circulating the slurry with a pump or the like, and select other known methods as appropriate. can do.

  Next, the slurry S is introduced into the housing 11 from the slurry introduction port 12a by operating the lift mechanism P1. The flow rate of the slurry S is preferably 0.5 to 5 m / s so that the solid particles do not settle in the slurry introduction chamber 12 and do not affect the classification.

  In some cases, the slurry S introduced from the slurry introduction port 12a may be formed by agglomerating solid particles to form an aggregate (secondary particle). The classifying apparatus of the present invention performs classification using the difference in the sedimentation rate of solid particles. If the small particles form aggregates and the aggregates have a sedimentation rate equal to or higher than that of the large particles, the aggregates are collected together with the large particles, resulting in poor classification accuracy. Therefore, it is preferable to break up the aggregation of small-diameter particles into single particles (primary particles). By forming the slurry introduction chamber 12 as in this embodiment, the secondary particles of small diameter particles can be crushed. When the slurry S passes through the upper end of the slurry introduction chamber 12 and flows into the first recovery chamber, the small diameter particles are primary particles.

In order to perform crushing more reliably, the cross-sectional area of the cross section of the slurry introduction chamber 12 (the cross section in the direction perpendicular to the paper surface in FIG. 1A) is expanded upward in FIG. The slurry introducing member 15 is preferably disposed. The ratio (S ₁ / S ₂ ) between the cross-sectional area S ₁ at the position where the cross-sectional area is the maximum and the cross-sectional area S ₂ at the position where the cross-sectional area is the minimum is as follows. 2.5-5.0 are preferable and 3.0-4.0 are more preferable. For example, the slurry introduction member 15 on the right side in FIG. 1B is inclined to the right by 2 to 8 ° (preferably 2 to 4 °) from the vertical to the right, and the slurry introduction member 15 on the vertical direction is inclined. It is possible to enlarge the cross-sectional area of the cross section by standing up without doing. If the inclination is less than 2 °, the secondary particles cannot be sufficiently crushed. If the inclination exceeds 8 °, the slurry flow is separated from the slurry introduction member 15, so that the slurry flow becomes unstable. In this embodiment, the inclination is 4 °. As a result, the classification accuracy κ (D ₇₅ / D ₂₅ ) of the large-sized particles recovered in the first recovery chamber is 1.20 to 1.75. The classification accuracy κ (D ₇₅ / D ₂₅ ) is the lower ¼ value (same 75) with respect to the upper ¼ value (particle size where particles larger than the particle size are 25% of the cumulative particle size frequency curve). % Of the particle size).

  Note that “the cross-sectional area is enlarged upward” is not limited to a case where the cross-sectional area is continuously enlarged upward, and a part of the cross-sectional area may continuously have the same cross-section. For example, after the cross-sectional area is continuously increased upward from the lower end, the same cross-section can be continuously formed toward the upper end.

  In order to improve the classification accuracy or raise the upper limit of the classification point, it is preferable to arrange an acceleration mechanism in the vicinity of the upper end of the slurry introduction chamber 12. The acceleration mechanism desirably increases the speed of the slurry S without disturbing the flow of the slurry S. In the present embodiment, as shown in FIG. 3, the acceleration member 19 having a triangular longitudinal section is disposed in the vicinity of the upper end of the slurry introduction chamber 12 so that the cross-sectional area of the transverse section expands upward. Further, the vicinity of the upper end portion of the slurry introducing member 15 is vertical. After the cross-sectional area of the cross section is enlarged upward by the inclined portion 15a of the slurry introduction member 15, it is directed toward the upper end by an acceleration mechanism composed of the acceleration member 19 and the vertical portion 15b of the slurry introduction member 15. Is gradually reduced. Because the acceleration mechanism increases the flow rate of the slurry S when passing through the upper end of the slurry introduction chamber 12, the straightness of the small diameter particles is improved. For this reason, the small-diameter particles easily move to the second recovery chamber. If the small diameter particles do not move to the second recovery chamber and stay in the first recovery chamber for a long time, the small diameter particles may aggregate to form secondary particles and settle in the first recovery chamber. By increasing the flow rate of the slurry S, aggregation of small-diameter particles can be prevented, and the classification accuracy κ can be improved. The acceleration mechanism may increase the flow rate of the slurry S by disposing a member having another shape, and configure the side wall of the slurry introduction chamber 12 so that the cross-sectional area of the slurry introduction chamber 12 becomes narrow near the upper end. Thus, the flow rate of the slurry S may be increased.

  Moreover, the larger the flow rate of the slurry S, the easier it is to move the large-diameter particles having a higher settling speed to the second recovery chamber. As described above, the upper limit of the classification point can be increased by increasing the flow rate of the slurry S by the acceleration mechanism.

  The classification point is a particle size in which the masses of the large and small diameter particles are the same in the particle size distribution (distribution of writing amount with respect to the particle diameter) of the small and large particles after classification.

  The speed at which the slurry passes the upper end of the slurry introduction chamber 12 by the acceleration mechanism is preferably 1.0 to 5.0 m / s. When this speed is less than 1.0 m / s, the effect of the acceleration mechanism cannot be obtained. When this speed exceeds 5.0 m / s, the flow of the slurry in the first recovery is disturbed, and the classification accuracy decreases. In addition, since it is possible to improve the rising speed of the slurry in accordance with the slurry liquid level in the first recovery chamber, it is possible to sufficiently obtain a propulsive force for moving the small-diameter particles to the second recovery chamber. . As a result, the upper limit value of the classification point can be increased. By selecting the slurry speed from the above range, the classification point can be adjusted and classification can be performed with high accuracy.

In addition, the ratio (h ₃ / h ₁ ) of the height h ₃ of the acceleration member 19 to the height h ₁ of the slurry introduction chamber 12 is preferably 0.2 to 1.0. If it is less than 0.2, the acceleration distance of the slurry is insufficient, so that the slurry S cannot be accelerated sufficiently. Therefore, the upper limit value of the classification point is reduced, and the adjustment range of the classification point is narrowed. If the ratio exceeds 1.0, the wall resistance generated at the boundary between the acceleration mechanism and the slurry S increases, so that the acceleration of the particles is hindered.

  When the binding force of the secondary particles is weak and can be easily crushed, the cross-sectional area of the slurry introduction chamber 12 may not be gradually increased upward. Also in this case, the acceleration mechanism can be arranged in the slurry introduction chamber 12 as necessary.

  The slurry S that has passed through the slurry introduction chamber 12 flows into the first recovery chamber 13. As the slurry S is filled in the first recovery chamber, large-diameter particles having a high settling velocity sink to the bottom of the first recovery chamber. On the other hand, small-diameter particles having a slow sedimentation rate stay near the liquid surface of the slurry S.

  When the amount of the slurry S in the first recovery chamber increases and the liquid level exceeds the upper end of the classification member 16, the slurry S passes through a gap formed between the upper end of the classification member 16 and the ceiling of the casing 11. And flows into the second recovery chamber 14. As a result, the small diameter particles staying near the liquid surface of the slurry S in the first recovery chamber 13 move to the second recovery chamber 14.

  Next, the large-diameter particle discharge valve and the small-diameter particle discharge valve are opened, and the slurry in which the large-diameter particles are dispersed and the slurry in which the small-diameter particles are dispersed are recovered from the classifier. At this time, the flow rate is adjusted so that the discharge amount (slurry flow rate) from the large particle discharge port 13a and the small particle discharge port 14a becomes appropriate. For example, if the discharge amount from the large particle discharge port 13a is too large, the slurry S will not move to the second recovery chamber. On the other hand, if the amount is too small, the amount of movement to the second collection chamber increases, and as a result, particles larger than the target particle size collected in the second collection chamber move to the second collection chamber.

  In the vicinity of the bottoms of the first recovery chamber 13 and the second recovery chamber 14, the cross-sectional areas of the cross sections are reduced toward the large particle discharge port 13a and the small particle discharge port 14a, respectively. Therefore, the large diameter particles and the small diameter particles are efficiently discharged from the housing 11 without accumulating on the bottoms of the first recovery chamber 13 and the second recovery chamber 14.

If the cross-sectional area of the cross section of the first recovery chamber 13 is too wide, the small-diameter particles settle in the first recovery chamber 13 before reaching the second recovery chamber 14, and if too narrow, the large-diameter particles sink before the large-diameter particles settle. Collides with classification member 16. Therefore, the ratio (S ₃ / S ₂ ) of the cross-sectional area S ₃ of the first recovery chamber at the uppermost surface of the slurry introduction chamber 12 to the cross-sectional area S ₂ of the cross-section of the slurry introduction chamber 12 is 2-10. It is preferable to select from.

In the classification device of the present invention, the classification point can be easily changed by changing the interval between the classification member 16 and the top plate. In the present embodiment, the classification member 16 can be attached and detached, and the classification point can be easily changed within a range of 100 to 1000 μm by changing the classification member 16 with a different height (vertical direction in FIG. 1A). be able to. If the difference in height between the uppermost end of the slurry introduction chamber 12 and the uppermost end of the classification member 16 is too small, large-diameter particles are also sent to the second recovery chamber 14, and if the difference is too large, the housing 11 is unnecessarily large. Height increases. Thus, the ratio of the height _{h 1} of the classification slurry introduction chamber 12 of the height _{h 2} of the member 16 _(h 2 / _{h 1)} is preferably from 1.2 to 5.0, it is 1.2 to 3.0 More preferred.

  The classifying device of the present invention is divided into a first recovery chamber 13 and a second recovery chamber 14 by a classification member 16, and has a gap through which slurry can move from the first recovery chamber 13 to the second recovery chamber 14. If it does, it is not limited to the above-mentioned structure. For example, you may arrange | position the classification member 16 provided with the opening part which can each be closed. The classification point can be changed by selecting the opening to be opened. For the same reason as in the previous paragraph, the ratio of the height to the lower portion of the opened opening to the height of the slurry introduction chamber is preferably in the range of 1.2 to 5.0.

Further, the classification point can be further adjusted by disposing an introduction speed adjusting mechanism 18 for adjusting the introduction speed of the slurry S into the housing 11 between the slurry introduction port 12a and the pump P1 as the lifting mechanism. Can do. The introduction rate adjustment mechanism 18 in this embodiment includes a hose _H 3, _{H 4,} which is connected to the valve _{V 1,} and the valve _{V 1.} The hose H ₁ was branched, a hose H ₃ was connected to the branch point, and the hose H ₄ was connected to the slurry tank 22. The path between the slurry introducing port 12a and the pump P1 is branched, one of them connected to the slurry introducing port 12a, and the other is connected to the valve V _1. The valve V _1, by opening while adjusting the degree of opening, a portion of the predetermined amount of the slurry S is returned to the slurry tank 22. Therefore, the introduction speed of the slurry S into the housing 11 can be adjusted.

  The lower limit of the classification point can be lowered by lowering the rising speed of the slurry in the vicinity of the slurry liquid level in the first recovery chamber. However, if the rising speed is lower than necessary, sufficient propulsive force for moving the small-diameter particles to the second recovery chamber cannot be obtained. For this reason, in this embodiment, the rising speed of the slurry was selected from 0.003 to 0.050 m / s. Further, as described above, the speed of the slurry passing through the upper end of the slurry introduction chamber by the acceleration mechanism was set to 1.0 to 5.0 m / s. Thereby, the classification point can be selected from the range of 50 to 300 μm.

(Blasting equipment)
Next, the case where the classifying apparatus of the present invention is used in a wet blasting apparatus will be described. In FIG. 4, the structure of the wet blasting apparatus 20 of this invention is shown. The blasting apparatus 20 includes a blasting chamber 21, a slurry tank 22 disposed below the blasting chamber, and a sorting mechanism that classifies particles in the slurry S in the slurry tank 22. In addition, an injection nozzle 23 for injecting the slurry S is disposed inside the blast processing chamber 21.

  The slurry tank 22 stores slurry S in which abrasive grains (abrasive material) for blasting are dispersed in a liquid (in this embodiment, water). The abrasive grains are various particles that can be generally used for blasting regardless of whether dry or wet, such as iron and non-ferrous particles (shots, grids, cut wires, etc.), ceramic particles, plant particles, and resin particles. If it is, it will not be specifically limited. The abrasive grains are mixed and dispersed in water so as to be 5 to 60% by volume of the entire slurry.

  In order to prevent abrasive grains from sinking to the bottom of the slurry tank 22, it is preferable to arrange a stirring mechanism (not shown) for stirring and dispersing the abrasive grains in the slurry tank 22 as described above.

  The slurry S in the slurry tank 22 is sucked up by a lifting mechanism P2 (canned motor pump in the present embodiment) and sent to an injection nozzle 23 disposed in the blast processing chamber 21. The slurry S sent to the injection nozzle 23 is mixed with the high-pressure gas (compressed air in this embodiment) sent from the high-pressure gas generation source 24, and is injected toward the workpiece W as a solid-gas liquid three-phase flow. The The injected slurry flows into the slurry tank 22. At this time, abrasive grains that are cracked or chipped by colliding with the workpiece W, cutting particles of the workpiece W generated by blasting, and the like also flow into the slurry tank 22. In normal blasting, the abrasive grains are circulated and used many times. Among the abrasive grains with cracks and chips, there are abrasive grains having a diameter that is not suitable for blasting. That is, the slurry S in the slurry tank 22 includes abrasive grains that have a diameter unsuitable for blasting (cannot be reused), cutting particles of the workpiece W, and the like. is there. Therefore, as described above, blasting is performed and sorting is performed by the sorting mechanism. Reusable abrasive grains sorted by the sorting mechanism are returned to the slurry tank 22 and sprayed from the spray nozzle 23 again.

  The classification device 10 of the present invention can be suitably used for the sorting mechanism. That is, the reusable abrasive grains in the slurry S can be separated as large-diameter particles, and the abrasive grains that have become non-reusable size and the cutting particles of the workpiece can be separated as small-diameter particles. The slurry in which the reusable abrasive grains are dispersed is discharged from the large-diameter particle discharge port 13 a and returned to the slurry tank 22. On the other hand, the slurry in which abrasive grains having a size that cannot be reused or cutting particles of the workpiece are dispersed is discharged from the small-diameter particle discharge port 14a.

  The slurry discharged from the small particle outlet 14a is sent to the separation mechanism 25, where solid-liquid separation is performed. For the solid-liquid separation, a known method such as a thickener, a filter press, a centrifugal separator, a sieve, or a magnetic separator can be used. For example, when both abrasive grains and workpiece have magnetism, such as when removing burrs from forged products (cold / hot) such as chrome / molybdenum steel using abrasive grains such as iron grids, etc. A magnetic separator can be suitably used.

  The solid particles separated by the separation mechanism 25 are collected as sludge. The separated solid is recovered in the sludge tank 26 as sludge. The separated liquid is stored in the liquid storage tank 27. The liquid can be used to adjust the concentration of the slurry when the slurry tank 22 is replenished with abrasive grains reduced in amount as the blasting progresses. Or you may use in order to wash the to-be-processed object W which the blasting process was complete | finished. By the lift mechanism P3, the liquid is sent to the cleaning spray nozzle 28 and sprayed toward the workpiece W together with the high-pressure gas sent from the high-pressure gas generation source 24, thereby remaining on the surface of the workpiece W. Grains and cutting particles can be removed.

The lift mechanism P1 and the lift mechanism P2 can be made the same. For example, as shown in FIG. 5, when only the lift mechanism P1 is used, the hose H ₁ (see FIG. 1A) can be branched and the branch point can be connected to the injection nozzle 23 via the hose. . At this time, an injection amount adjusting mechanism 29 for adjusting the introduction amount of the slurry S to the injection nozzle 23 may be disposed on the path from the branch point to the injection nozzle 23. For example, the injection amount adjusting mechanism 29 can use a tubular body having one end connected to the valve V ₂ and the other end disposed in the vicinity of the slurry tank 22. When opening the valve V ₂ slurry S may adjust the rate of introduction of slurry S to the injection nozzle 23 by adjusting the opening degree of the valve for will return to the slurry tank 22.

Also, the hose H ₁ described above, the introduction rate adjustment mechanism 18 for adjusting the rate of introduction of slurry S to the classification device 10 may be located (see FIG. 1 (A)).

  When adjusting the speed of introduction of the slurry S into the classifier 10 and the amount of introduction into the injection nozzle 23, if fine adjustment like a valve is not necessary, a pipe having a smaller diameter than the pipe (throttle) is used instead of the valve. Tube) may be used. Since the internal structure of the valve is complicated, there is a risk of failure when using a slurry S that is heavily worn. The throttle tube has fewer failures than the valve, and even if internal wear progresses and adjustment of the rate of introduction of the slurry S becomes difficult, it is cheaper than the valve and can be easily replaced.

  Although not shown, a densitometer for measuring the concentration of the slurry may be arranged in order to stabilize the blasting capability. Depending on the measurement result of the densitometer, the abrasive concentration or liquid can be charged automatically or manually into the slurry tank to make the slurry concentration constant.

  A result of classifying a slurry in which an iron grid (GH-3: average particle size 300 μm) and white alundum (WA # 320: average particle size 40 μm) are mixed by the classification device of the present invention will be described as a first example. . The slurry is prepared by dispersing slurry in water so that the solid particle (abrasive) content is 40% by volume and 10% by volume, respectively, and the flow rate of the slurry at the slurry inlet is 2.5 m / s. Thus, it introduced into the classification apparatus of this embodiment, and performed classification. The slurry discharged from the large particle outlet and the small particle outlet is passed through a sieve having a mesh size of 125 μm, and the color of the slurry that has passed through the sieve is visually confirmed to be classified into large particles and small particles. Judged whether it has been.

  As a result of classifying the slurry discharged from the large particle discharge port with a sieve, a large amount of iron grid was confirmed on the sieve. In addition, although the slurry that passed through the sieve was slightly cloudy, it was almost colorless and transparent, so it was found that the mixture of white alundum, which is a small particle, was slight. Moreover, as a result of classifying the slurry discharged from the small-diameter particle discharge port with a sieve, no iron grid was confirmed on the sieve. Moreover, since the slurry that passed through the sieve became cloudy, it was found that a large amount of white alundum was mixed and dispersed. As a result, it has been found that classification can be performed with high accuracy by the classification device of the present embodiment.

  Next, an example in which the classification device of this embodiment is used as a sorting device for a blast processing device will be described as a second example. The slurry used was an iron grid (GH-3: average particle size 300 μm) dispersed in water so that the concentration was 30% by mass. This slurry was sprayed from a suction-type spray nozzle toward a chrome steel (SCr) for blasting. The distance between the nozzle and the workpiece was 100 mm, the pressure of the lift mechanism P1 was 0.33 MPa, and the pressure of the high-pressure gas (compressed air) was 0.4 MPa.

Blasting was performed by changing the inclination angle of the slurry introduction member 15 and the ratio of the height of the acceleration member 19 to the height of the slurry introduction chamber (h ₃ / h ₁ ) as shown in Table 1. At the time when 30 minutes passed after the injection, the slurry was recovered from the large particle outlet 13a and the small particle outlet 14a, respectively. After the recovered slurry was dried at 90 ° C., the particle size distribution was measured with a laser diffraction particle size distribution analyzer (SALD-2100: manufactured by Shimadzu Corporation). Based on the measured particle size distribution, the classification point and classification accuracy κ (D ₇₅ / D ₂₅ ) of the large-diameter particles were calculated.

The classification point could be changed by changing the ratio of the inclination angle of the slurry introduction member 15 and the height of the acceleration member 19 to the height of the slurry introduction chamber (h ₃ / h ₁ ). In general, when the classification accuracy κ is 1.0 or more, classification can be performed satisfactorily, and when the classification accuracy κ is 1.5 or more, classification can be performed extremely satisfactorily. In each of Examples 1 to 13, the classification accuracy was 1.2 or more, and good results were shown. Another object of the present invention is to remove small-diameter particles (such as abrasive grains having a size that cannot be reused or cutting particles of a workpiece) from a slurry when a classification device is used as a sorting device for a blasting device. Therefore, when the classification point is set to about 90 μm, the classification accuracy κ is 1.60 as shown in Example 5. This suggests that the classifying device of the present invention can be favorably used as a separating device for a blast processing apparatus.

The main symbols used in the present specification and drawings are shown below.
DESCRIPTION OF SYMBOLS 10 Classifier 11 Case 12 Slurry introduction chamber 12a Slurry introduction port 13 First collection chamber 13a Large diameter particle discharge port 14 Second collection chamber 14a Small diameter particle discharge port 15 Slurry introduction member 16 Classification member 17 Slurry introduction mechanism 18 Introduction speed adjustment Mechanism 19 Acceleration member 20 Blasting device 21 Blasting chamber 22 Slurry tank 23 Injection nozzle 24 High-pressure gas generation source 25 Separation mechanism 26 Sludge tank 27 Storage tank 28 Cleaning injection nozzle 29 Injection amount adjustment mechanisms P1, P2, P3 Lifting mechanism W workpiece S slurry _V 1, _{V 2} valve

[Possibility of industrial use]

  In the embodiment, the example applied to the classifying device for selecting the reusable abrasive grains and other particles from the slurry in the wet blast processing apparatus has been described, but the classifying device of the present invention is a foreign object in the slurry. It can be applied to all wet classification applications such as removal, beneficiation, sorting and liquid purification.

Claims (20)

An apparatus for classifying solid particles dispersed in a slurry using a difference in settling velocity,
The classifying device introduces the slurry and classifies the particles into large particles and small particles,
A slurry introduction mechanism for introducing slurry into the housing,
The housing is erected from the bottom surface of the housing, and a plate-shaped classification member having a tip provided with a gap between the housing and the ceiling surface of the housing, the interior of the housing is separated from the first collection chamber and the second collection chamber. It is divided into a collection room,
In the first collection chamber, a plate-like slurry introduction member standing from the bottom of the first collection chamber, or a side wall is formed by the slurry introduction member and the wall surface of the first collection chamber, and at the lower end. Is a slurry introduction chamber formed with a slurry introduction port connected to the slurry introduction mechanism and having an open upper end. An apparatus for classifying solid particles dispersed in a slurry using a difference in settling velocity,
The classifying device introduces the slurry and classifies the particles into large particles and small particles,
A slurry introduction mechanism for introducing slurry into the housing,
The casing is divided into a first recovery chamber and a second recovery chamber by a plate-shaped classification member that is erected from the bottom surface of the casing and has a plurality of closable openings. And
In the first collection chamber, a plate-like slurry introduction member standing from the bottom of the first collection chamber, or a side wall is formed by the slurry introduction member and the wall surface of the first collection chamber, and at the lower end. Is a slurry introduction chamber formed with a slurry introduction port connected to the slurry introduction mechanism and having an open upper end.   The classification device according to claim 1, wherein at least a part of the classification member is detachable.   The classification apparatus according to claim 1, wherein the slurry introduction chamber has a cross-sectional area that increases upward.   The classification device according to claim 1, further comprising an acceleration mechanism for accelerating the slurry at an upper end portion of the slurry introduction chamber.   The classification device according to claim 4, further comprising an acceleration mechanism for accelerating the slurry at an upper end portion of the slurry introduction chamber. The classification device according to claim 5, wherein a cross-sectional area of the slurry introduction member is gradually reduced upward by the acceleration mechanism.   The classification device according to claim 6, wherein a cross-sectional area of the slurry introduction member is gradually reduced upward by the acceleration mechanism. The slurry introduction mechanism includes a lift mechanism for lifting the slurry,
The classification device according to claim 1 or 2, wherein an introduction speed adjusting mechanism for adjusting an introduction speed of the slurry is disposed between the slurry introduction port and the lift mechanism. A blasting apparatus for performing blasting by spraying a slurry in which abrasive grains are dispersed in a liquid together with a high-pressure gas onto a workpiece,
The blasting apparatus includes a blasting chamber in which an injection nozzle is disposed,
A slurry tank for storing the slurry;
A sorting mechanism for classifying particles in the slurry in the slurry tank;
A separation mechanism for solid-liquid separation of a slurry containing small-sized particles classified by the classification device,
The blasting apparatus according to claim 1, wherein the sorting mechanism is the classification apparatus according to claim 1.   The blasting apparatus according to claim 10, wherein the separation mechanism is a magnetic separator. A cleaning nozzle for cleaning the workpiece after blasting is disposed in the blasting chamber,
The blast processing apparatus according to claim 10, wherein the cleaning nozzle ejects the liquid separated by the separation mechanism. A method for classifying solid particles dispersed in a slurry using the classifying apparatus according to claim 1 or 2,
Introducing the slurry from the slurry inlet into the slurry introduction chamber;
Diffusing and discharging the introduced slurry from the opening at the upper end of the slurry introduction chamber;
The small particles in the solid particles in the slurry are moved into the second recovery chamber through a gap between the classification member and the ceiling or an opening provided in the classification member, and the solid particles in the slurry Sinking the large-diameter particles in the bottom of the first recovery chamber;
Sinking the small diameter particles moved into the second recovery chamber to the bottom of the second recovery chamber;
Classification method characterized by including.   The diameter of the solid particles moving to the second recovery chamber is changed by changing the distance between the upper end of the classification member and the ceiling or the distance between the lower end of the opening and the ceiling. Classification method described in 1. A method for classifying solid particles dispersed in a slurry using the classifier according to claim 5,
Introducing the slurry from the slurry inlet into the slurry introduction chamber;
Accelerating the introduced slurry by the acceleration mechanism, and diffusing and discharging from the opening at the upper end of the slurry introduction chamber;
The small particles in the solid particles in the slurry are moved into the second recovery chamber through a gap between the classification member and the ceiling or an opening provided in the classification member, and the solid particles in the slurry Sinking the large-diameter particles in the bottom of the first recovery chamber;
Sinking the small diameter particles moved into the second recovery chamber to the bottom of the second recovery chamber;
Classification method characterized by including. A method for classifying solid particles dispersed in a slurry using the classifier according to claim 6,
Introducing the slurry from the slurry inlet into the slurry introduction chamber;
Accelerating the introduced slurry by the acceleration mechanism, and diffusing and discharging from the opening at the upper end of the slurry introduction chamber;
The small particles in the solid particles in the slurry are moved into the second recovery chamber through a gap between the classification member and the ceiling or an opening provided in the classification member, and the solid particles in the slurry Sinking the large-diameter particles in the bottom of the first recovery chamber;
Sinking the small diameter particles moved into the second recovery chamber to the bottom of the second recovery chamber;
Classification method characterized by including. A method for classifying solid particles dispersed in a slurry using the classifier according to claim 9,
Introducing the slurry from the slurry inlet into the slurry introduction chamber;
Diffusing and discharging the introduced slurry from the opening at the upper end of the slurry introduction chamber;
The small particles in the solid particles in the slurry are moved into the second recovery chamber through a gap between the classification member and the ceiling or an opening provided in the classification member, and the solid particles in the slurry Sinking the large-diameter particles in the bottom of the first recovery chamber;
Sinking the small diameter particles moved into the second recovery chamber to the bottom of the second recovery chamber;
Including
A classification method, wherein the introduction speed adjusting mechanism changes the slurry introduction speed to change the diameter of the solid particles moving to the second recovery chamber. A blasting method using the blasting apparatus according to claim 10,
Adding and dispersing liquid and abrasive grains into the slurry tank to obtain a slurry; and
Transferring the slurry in the slurry tank to the injection nozzle, mixing the high pressure gas and injecting the slurry from the injection nozzle toward the workpiece;
Storing the sprayed slurry and the cutting particles of the workpiece in a slurry tank;
Transferring the slurry in the slurry tank to the sorting mechanism;
Transferring the large diameter particles recovered in the first recovery chamber to the slurry tank as solid particles for blasting again;
Recovering small-sized particles recovered in the second recovery chamber as sludge;
A blasting method comprising: A blasting method using the blasting apparatus according to claim 11,
Adding and dispersing liquid and magnetic abrasive grains in the slurry tank to obtain a slurry; and
Transferring the slurry in the slurry tank to the injection nozzle, and mixing the high pressure gas and injecting the slurry toward the work piece having magnetism;
Storing the sprayed slurry and the cutting particles of the workpiece in a slurry tank;
Transferring the slurry in the slurry tank to the sorting mechanism;
Transferring the large diameter particles recovered in the first recovery chamber to the slurry tank as solid particles for blasting again;
Transferring the slurry containing small-sized particles recovered in the second recovery chamber to the magnetic separator;
Solid-liquid separation of the slurry transferred to the magnetic separator by magnetic force;
A blasting method comprising: An apparatus for classifying solid particles dispersed in a slurry by using a difference in sedimentation speed,
The classifier includes a cylindrical casing that introduces the slurry and classifies the particles into large particles and small particles, and a slurry introduction mechanism for introducing the slurry.
The housing is erected with a gap between the bottom surface of the housing and the ceiling surface of the housing, and a first recovery chamber and a bottom surface in which a large-diameter particle discharge port is formed on the bottom surface of the housing A plate-shaped classification member for partitioning into a second recovery chamber in which a small-diameter particle discharge port is formed, between a slurry introduction port opened in the bottom surface of the first recovery chamber and the large-diameter particle discharge port A plate-like slurry introduction member that is arranged upward from the bottom surface and diffuses upward the slurry introduced into the first recovery chamber from the slurry introduction port,
One of the slurry introduction mechanisms is in communication with the slurry introduction port, and the other end is in communication with a lift mechanism.

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