The present invention relates to a grinding apparatus that grinds a substance to be ground.
As an apparatus configured to grind a substance to be ground, a powder processing apparatus including a deposition surface for the substance to be ground to deposit on, a processing surface opposed to the deposition surface and curved in a convex shape, and moving unit for relatively moving the deposition surface and the processing surface along the deposition surface has heretofore been proposed (for example, see WO 2004/112964). The deposition surface corresponds to an inner peripheral surface about an axis of a container member in which the substance to be ground is accommodated. In the abovementioned powder processing apparatus, when the deposition surface and the processing surface are relatively moved along the deposition surface, the substance to be ground is pressed toward, and rubbed against, the deposition surface by the processing surface. In other words, the substance to be ground undergoes a compression force and a shear force from the deposition surface and the processing surface. As a result, the substance to be ground is ground by the powder processing apparatus.
Aside from the foregoing, there has been a planetary ball mill as a powder processing apparatus using centrifugal force, where a plurality of mill pots arranged around a rotation shaft are rotated and revolved (for example, see Japanese Patent Application Laid-Open Publication No. 2002-143706).
According to WO 2004/112964, however, the substance to be ground is unable to be ground at all unless the substance to be ground deposits on the deposition surface. The substance to be ground is unable to be efficiently ground if the substance to be ground is collected to the inner bottom surface of the container member in the depth direction thereof by gravity. Japanese Patent Application Laid-Open Publication No. 2002-143706 discloses a batch type apparatus, which is difficult to be scaled up by upsizing.
In view of the foregoing circumstances, an object of the present invention is to provide a grinding apparatus that efficiently improves throughput.
A grinding apparatus according to the present invention is a grinding apparatus configured to grind a substance to be ground, the grinding apparatus including: a rotating body configured to include therein a channel extending up to an opening formed in its own outer peripheral surface, the rotating body being configured to be capable of accommodating in the channel the substance to be ground and a grinding medium capable of grinding the substance to be ground; and a grinding container configured to include therein an accommodation space accommodating the rotating body and an opposed surface opposed to the opening of the rotating body, the opposed surface extending annular about a center axis of the rotating body. The grinding medium and the substance to be ground are capable of being moved from the channel to the accommodation space through the opening by rotating the rotating body.
In the grinding apparatus according to the present invention, the rotating body has an inlet opening capable of letting in the substance to be ground and the grinding medium, and the channel includes an interval where a channel width decreases outward in a radial direction of the rotating body.
The grinding apparatus according to the present invention also includes a moving mechanism configured to move the substance to be ground and the grinding medium separated from the rotating body into the channel of the rotating body again.
In the grinding apparatus according to the present invention, the grinding container has a reception opening capable of letting in the substance to be ground and the grinding medium, and a discharge opening capable of discharging the substance to be ground and the grinding medium to outside. The rotating body has an inlet opening that serves as an inlet for the substance to be ground and the grinding medium that have passed through the reception opening. The moving mechanism includes a circulation-path forming pipe that is connected to the grinding container through the discharge opening and the reception opening and forms a circulation path with the grinding container, and an airflow generation unit configured to generate an airflow from the discharge opening toward the reception opening in the circulation-path forming pipe. An opening of the circulation-path forming pipe on a side where the substance to be ground and the grinding medium are discharged is located inside the channel of the rotating body or in front of the inlet opening.
The grinding apparatus according to the present invention also includes a removal unit that is located between the opposed surface and the rotating body so as to be opposed to the opposed surface in a radial direction of the rotating body, and a moving unit configured to move the removal unit in a circumferential direction of the opposed surface. The removal unit is moved by the moving unit to come into contact with the substance to be ground deposited on the opposed surface and remove the substance to be ground deposited on the opposed surface.
In the grinding apparatus according to the present invention, the moving unit moves the removal unit so that the removal unit revolves about a rotation axis of the rotating body, and a revolving speed of the removal unit revolved by the moving unit is lower than a rotation speed of the rotating body.
The grinding apparatus according to the present invention also includes a guide blade that has a surface facing in a direction of rotation of the rotating body and extending in a radial direction of the rotating body and is disposed to be capable of revolving about a rotation axis of the rotating body. Revolution of the guide blade about the rotation axis generates an airflow in the accommodation space.
In the grinding apparatus according to the present invention, the opposed surface is formed of ceramics.
The grinding apparatus according to the present invention also includes a rotating-body rotating unit configured to rotate the rotating body about an axis parallel to an axis direction of the center axis of the rotating body.
In the grinding apparatus according to the present invention, when the rotating body is rotated by the rotating-body rotating unit, the substance to be ground in the channel is moved toward the opposed surface through the opening by a centrifugal force along with the grinding medium and collides with the opposed surface.
The grinding apparatus according to the present invention can provide an excellent effect that the substance to be ground can be efficiently ground.
An embodiment of the present invention will be described below with reference to the accompanying drawings.
A grinding apparatus 1 according to the embodiment of the present invention will be described with reference to
As shown in a cross-sectional view of the rotating body 2 taken along an axial direction A of the rotating body 2 (hereinafter, referred to simply as an axial direction A) shown in
As shown in the plan view of
Note that a plurality of protrusions 210 and a plurality of tapered channels 20 are located at regular intervals in the circumferential direction of the rotating body 2 or the disk portion 200. The protrusions 210 and the tapered channels 20 both only need to be at least two in number.
The entire rotating body 2 may be configured in a disk-like shape. Even in such a case, tapered channels 20, an inlet opening 21, and outlet openings 22 having similar structures to the foregoing are provided inside the rotating body 2.
As shown in
The grinding container 4 accommodates the rotating body 2. As shown in
As shown in
As shown in
As will be described below, the substance to be ground 100 flying out of the outlet openings 22 collides with the opposed surface 43. The substance to be ground 100 is ground by the impact. In this sense, the opposed surface 43 functions as a collision surface to the substance to be ground 100 flying out of the outlet opening 22.
As shown in
As shown in
All or a part of the grinding container 4 is desirably formed of ceramics, for example. If a part of the grinding container 4 is formed of ceramics, the portion constituting the opposed surface 43, in particular, of the grinding container 4 is desirably formed of the ceramics.
The grinding medium 5 is formed of a material capable of grinding the substance to be ground 100. For example, the grinding medium 5 can include at least one of the following types of beads: zirconia beads, carbide beads, and steel beads. However, this is not restrictive, and other types of beads may be included. The grinding medium 5 has a size that enables passage through a circulation path to be described below. The grinding medium 5 can thus circulate through the circulation path to be described below.
The circulation mechanism 6 repeatedly returns the substance to be ground 100 and the grinding medium 5 flying out of the rotating body 2 back into the rotating body 2. Note that a moving mechanism may be defined as a mechanism including not only the circulation mechanism 6 but also a return mechanism that returns the substance to be ground 100 and the grinding medium 5 flying out of the rotating body 2 back into the tapered channels 20 of the rotating body 2 not repeatedly but under an external operation. In such a case, the circulation mechanism 6 according to the present invention may be replaced with other moving mechanisms. The circulation mechanism 6 according to the present embodiment includes, for example, a circulation path-forming pipe 60 and an airflow generation unit 61.
As shown in
The airflow generation unit 61 generates an airflow from the discharge opening 46 toward the reception opening 47 in the circulation-path forming pipe 60. For example, as shown in
For example, the gas supply unit 611 includes a compressor, and supplies compressed air to the Coanda nozzle 610. As the gas supply unit 611 supplies the compressed air to the Coanda nozzle 610, the Coanda nozzle 610 amplifies the flow rate of gas per unit time. For example, the Coanda nozzle 610 amplifies the flow rate of gas supplied from the gas supply unit 611 by approximately seven times. The gas amplified in the flow rate per unit time then flows through the circulation-path forming pipe 60 from the discharge opening 46 toward the reception opening 47. As a result, a clockwise airflow is generated in the circulation path. The substance to be ground 100 and the grinding medium 5 flying out of the rotating body 2 are thereby passed through the circulation-path forming pipe 60 and discharged from the end opening 63, and supplied into the tapered channels 20 of the rotating body 2 again.
To stabilize the function of the Coanda nozzle 610, an air filter 62 is provided to release the gas. If, for example, secondary air (amplified air) taken into the Coanda nozzle 610 is not released from the air filer 62, the internal pressure of the circulation path increases and the Coanda effect due to negative pressure suction is not successfully obtained.
The circulation mechanism 6 according to the present embodiment can repeatedly circulate the substance to be ground 100 along the circulation path. The substance to be ground 100 can thus be made to collide with the opposed surface 43 repeatedly.
The removal mechanism 7 removes the substance to be ground 100 deposited on the opposed surface 43. As shown in
The removal unit 70 is located between the opposed surface 43 and the rotating body 2 so as to be opposed to the opposed surface 43. For example, in the present embodiment, the removal unit 70 includes two L-shaped plate members as illustrated in
As shown in
The rotation speed at which the removal-side shaft driving unit 72 rotates the removal-side driving shaft 71 is desirably such a speed as causes a difference in speed from that of the rotating-body driving shaft 30. In particular, the rotation speed is desirably lower than that of the rotating-body driving shaft 30. In other words, the revolving speed of the removal unit 70 is desirably lower than the rotation speed of the rotating body 2. This can prevent the two L-shaped plate members as much as possible from interfering with the collision of the substance to be ground 100 with the opposed surface 43.
Alternatively, the portions (depthwise extending portions 73B) corresponding to the other sides of the L shapes of the L-shaped plate members may be regarded as a removal unit 70. Furthermore, the portions (radially extending portion 73A) corresponding to one of the one of sides of the L shapes of the L-shaped plate members, the removal-side driving shaft 71, and the removal-side shaft driving unit 72 may be regarded as a moving unit configured to move the removal unit 70 (depthwise extending portions 73B) in the circumferential direction of the inner wall surface 42 of the grinding container 4.
The guide blades 8 are disposed to be capable of revolving about the rotating-body driving shaft 30. For example, the guide blades 8 are made of plate members. As shown in
As the guide blades 8 revolve about the rotating-body driving shaft 30, the flat portions agitate the air to generate an airflow in the accommodation space 49. As a result, the airflow moves the substance to be ground 100 in the accommodation space 49 and guides the substance to be ground 100 to the discharge opening 46.
An operation of the grinding apparatus 1 will be described with reference to
In the process of the substance to be ground 100 moving through the tapered channels 20, the substance to be ground 100 undergoes a friction force and a shear force from the grinding medium 5 and the tapered channels 20, and is thereby ground. The substance to be ground 100 and the grinding medium 5 flying out of the outlet openings 22 then collide with the opposed surface 43. The substance to be ground 100 is further ground by the impact of the collision. In the present embodiment, the substance to be ground 100 is thus ground not only by the impact force from the collision with the opposed surface 43 but also by the friction force and shear force from the grinding medium 5 moving together. The grinding apparatus 1 according to the present embodiment can thus grind the substance to be ground 100 more efficiently in a shorter time than heretofore.
As shown in
Meanwhile, the airflow generation unit 61 generates the airflow to circulate through the circulation path. As shown in
The grinding apparatus 1 according to the present invention can apply an impact force, a compression force, a shear force, and the like to the substance to be ground 100 by the foregoing operation. The use of the grinding apparatus 1 according to the present invention is thus useful in applying a treatment using a mechanochemical phenomenon to the substance to be ground 100. It will be understood that the grinding apparatus 1 according to the present invention is also useful for treatments other than that using a mechanochemical phenomenon.
The grinding apparatus 1 of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.
Number | Date | Country | Kind |
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2020-074891 | Apr 2020 | JP | national |
This application is a U.S. National Phase Application under 35 U.S.C. 371 of International Application No. PCT/JP2021/012036, filed on Mar. 23, 2021, which claims priority to Japanese Patent Application No. 2020-074891, filed on Apr. 20, 2020. The entire disclosures of the above applications are expressly incorporated by reference herein.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2021/012036 | 3/23/2021 | WO |