Classifying Rotor and Classifying Apparatus
20220032343 · 2022-02-03
Inventors
- Mitsugi Inkyo (Hiroshima, JP)
- Makoto Sato (Saitama, JP)
- Masaaki Ogihara (Saitama, JP)
- Yuta Hosono (Saitama, JP)
Cpc classification
International classification
Abstract
A classifying rotor has a rotatable frame body and classifying blades. The frame body has an opening portion on an outer peripheral portion and an ejection port for ejecting a fluid having flowed into an inside through the opening portion to an outside. The classifying blades are disposed at a desired interval in a circumferential direction on an outer peripheral side part in the frame body. The classifying blades are provided in the frame body so that an angle formed by a direction of the classifying blade and a rotating direction of the frame body becomes a desired inclination angle. The desired inclination angle is an angle at which classification accuracy becomes better when the classifying blades are inclined so that the formed angle becomes gradually smaller from 90 degrees.
Claims
1. A classifying rotor comprising: a rotatable frame body having an opening portion on an outer peripheral portion and having an ejection port for ejecting a fluid having flowed into an inside through the opening portion to an outside; and a plurality of classifying blades disposed at a desired interval in a circumferential direction on an outer peripheral side part in the frame body, wherein the classifying blades are provided so that an angle formed by a direction of the classifying blade and a rotating direction of the frame body becomes a desired inclination angle; and the desired inclination angle is an angle at which classification accuracy becomes better when the classifying blades are inclined so that the formed angle becomes gradually smaller form 90 degrees.
2. The classifying rotor according to claim 1, wherein the desired inclination angle is the formed angle larger than 0 degrees and not larger than 45 degrees.
3. The classifying rotor according to claim 1, wherein the classifying blade has an arc shape formed following the Bernoulli curve.
4. The classifying rotor according to claim 1, further comprising: a plurality of rectifying blades disposed on an inner side part from the classifying blade in the frame body at a desired interval in the circumferential direction.
5. The classifying rotor according to claim 1, wherein a shape of the classifying blade is formed so that classification particle size becomes constant on an entire region in a radial direction from an outer periphery to an inner periphery in a classification chamber formed between the adjacent classifying blades.
6. A classifying rotor comprising: a rotatable frame body having an opening portion on an outer peripheral portion and having an ejection port for ejecting a fluid having flowed into an inside through the opening portion to an outside; a plurality of classifying blades disposed at a desired interval in a circumferential direction on an outer peripheral side part in the frame body; and a plurality of rectifying blades disposed on an inner side part from the classifying blade in the frame body at a desired interval in the circumferential direction.
7. The classifying rotor according to claim 6, wherein a shape of the classifying blade is formed so that classification particle size becomes constant on an entire region in a radial direction from an outer periphery to an inner periphery in a classification chamber formed between the adjacent classifying blades.
8. A classifying apparatus comprising: a housing; and a classifying rotor provided in the housing, the classifying rotor including a rotatable frame body having an opening portion on an outer peripheral portion and having an ejection port for ejecting a fluid having flowed into an inside through the opening portion to an outside; and a plurality of classifying blades disposed at a desired interval in a circumferential direction on an outer peripheral side part in the frame body, wherein the classifying blades are provided so that an angle formed by a direction of the classifying blade and a rotating direction of the frame body becomes a desired inclination angle; and the desired inclination angle is an angle at which classification accuracy becomes better when the classifying blades are inclined so that the formed angle becomes gradually smaller form 90 degrees.
9. The classifying apparatus as recited in claim 8, further comprising rotating means for rotating the classifying rotor, and an outflow chamber which causes particles classified by the classifying rotor and having flowed into the classifying rotor to flow out of the housing.
10. The classifying apparatus as recited in claim 8, further comprising rotating means for rotating the classifying rotor, the rotating means having a rotating shaft having a through hole extending in an axial direction therethrough for causing particles classified by the classifying rotor and having flowed into the classifying rotor to flow out of the housing.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0058] Examples of embodiments for embodying the present invention will be described below.
Embodiment 1
[0059] The embodiment 1 of the present invention will be described by reference to
[0060] In the present invention, a classifying rotor 21 is used instead of the conventional classifying rotors 3 and 11.
[0061] The classifying rotor 21 is constituted by a rotatable frame body having an opening portion for leading a fluid such as a liquid like a slurry and a gas in the housings 2 and 10 into an inside on an outer peripheral portion and an ejection port for ejecting fine particles having been led into the rotor to an outside of the rotor at a center part and a plurality of classifying blades disposed at a desired interval in a circumferential direction on an outer peripheral side portion in the frame body, and the classifying blades are provided with inclination so that an angle α formed by each of the classifying blades and a rotating direction of the classifying rotor 21 becomes a desired inclination angle.
[0062] The classifying rotor 21 is constituted by a frame body made of two circular plates 21a and 21b having the same shape and disposed vertically separately and coaxially and an ejection port 22 provided at the center part of the upper disc plate 21a and a plurality of classifying blades 23 connected and provided at an equal interval between outer peripheral side portions of surfaces facing each other of the two plates 21a and 21b.
[0063] Reference numeral 24 denotes a classification chamber formed between each of the adjacent classifying blades 23 and 23.
[0064] Note that each of the classifying blades 23 is formed having the same shape, respectively, for example. Moreover, each of the classifying blades 23 is constituted by a flat plate having a shape from a base portion (inner peripheral end) toward a distal end (outer peripheral end) of a blade surface on a front surface side (surface facing the rotating direction) being linear, for example. Moreover, each of the classifying blades 23 is provided by being disposed at an equal interval in the circumferential direction separated by an equal distance from the rotation center of the classifying rotor 21, for example. Furthermore, each of the classifying blades 23 is provided so that the formed angle α becomes the same angle, for example.
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[0066] Moreover, each of the classifying blades 23 may have a shape from the base portion toward the distal end being an arc shape other than the flat plate having the shape from the base portion (inner peripheral end) toward the distal end (outer peripheral end) of the front surface being linear. Furthermore, the arc may be an arc made of the Bernoulli curve, for example.
[0067] Moreover, the angle α formed by the classifying blade 23 and the rotating direction of the classifying rotor 21 refers to an angle formed by a direction (direction of the blade surface on the front surface side) from the distal end toward the base portion of the blade surface 23a on the front surface side of the classifying blade 23 and the rotating direction at the distal end of the blade surface on the front surface side of the classifying blade 23. In other words, the angle α formed by the classifying blade 23 and the rotating direction of the classifying rotor 21 refers to an angle formed by a line drawn between the distal end (outer peripheral end) and the base portion (inner peripheral end) of the blade surface 23a on the front surface side of the classifying blade 23 and a line crossing at a right angle the line from a rotation center point of the classifying rotor 21 to the distal end (outer peripheral end) on the front surface side of the classifying blade 23. More specifically, as illustrated in
[0068] Then, as the result of various experiments and the like, when the classifying blade is inclined so that the formed angle α gradually becomes smaller from 90 degrees, first, the classification accuracy becomes worse (mixing of the coarse particles increases), but when it is further inclined, such an angle is found at which the classification accuracy becomes better, and the angle is referred to as the desired inclination angle. And as the result of various experiments and the like, when the classifying blade is inclined so that the formed angle α becomes gradually smaller from 90 degrees, first, the classification accuracy becomes worse (mixing of the coarse particles increases), but when it is further inclined particularly to 50 degrees or smaller or to 45 degrees or smaller, such an angle is found at which the classification accuracy becomes greatly better than the classification accuracy prior to that, and the angle is referred to as the desired inclination angle.
[0069] The angle at which the classification accuracy becomes better refers to an angle at which, when the formed angle α is inclined so as to be gradually smaller from 90 degrees, the classification accuracy which has been worse starts to become better, for example. Alternatively, the angle at which the classification accuracy becomes better refers to an angle at which, when the angle is further inclined from the angle at which the classification accuracy starts to become better, the classification accuracy becomes better than the classification accuracy at the desired angle between the formed angle 90 degrees and the angle at which the classification accuracy starts to become better, for example. Alternatively, the angle at which the classification accuracy becomes better refers to an angle at which, when the angle is further inclined from the angle at which the classification accuracy starts to become better, the classification accuracy becomes better than the best classification accuracy at the angle between the formed angle 90 degrees and the angle at which the classification accuracy starts to become better, for example.
[0070] If there are a plurality of angles at which the classification accuracy starts to become better from the angle at which the classification accuracy becomes worse, any one of the angles is recognized as the angle at which the classification accuracy starts to become better.
[0071] Moreover, the angle may be determined by considering a shape coefficient which will be described later, for example.
[0072] And the desired inclination angle is a value set by various experiments, and the formed angle α is larger than 0 degrees and not larger than (or less than) 45 degrees, larger than 0 degrees and not larger than (or less than) 40 degrees, larger than 0 degrees and not larger than (or less than) 30 degrees or larger than 0 degrees and not larger than (or less than) 20 degrees, for example.
[0073] Subsequently, the action and effect of the classifying rotor 21 of the present invention will be described.
[0074] The wet type classifying apparatus will be described below, but the same applies to the dry type classifying apparatus.
[0075] In the wet type classifying apparatus 9, for example, a raw material slurry from the raw material slurry tank 14 is supplied by the metering pump 15 into the housing 10 of the classifying apparatus 9 through the supply port 10a. Then, the raw material slurry is classified into coarse particles and fine particles by the classifying rotor 21 provided in the classifying apparatus 9 and rotating at a high speed. Then, the coarse particles are ejected to outside the housing 10 through the ejection port 10b of the housing 10 of the classifying apparatus 9. Moreover, the fine particles having flowed into the classification chamber 24 of the classifying rotor 21 from the outer peripheral portion of the classifying rotor 21 flow through a through hole 31 communicating with the ejection port 22 and formed in the rotating shaft 12a fixed to the classifying rotor 21 from the ejection port 22 formed at the center part of the classifying rotor 21 and are recovered by the recovery tank 17.
[0076] As the raw material slurry, a dissolved silica dispersion liquid (tap water) by Denka was used. The peripheral speed of the classifying rotor was set to 20 m/s.
[0077] An experiment was conducted for the classification accuracy when the classifying blade 23 was inclined with the formed angle α gradually reduced from 90 degrees. As a result, when the formed angle α was inclined from 90 degrees to approximately 45 degrees, the shape coefficient and the classification accuracy became worse, but in the case of an angle not larger than the desired inclination angle, that is, steep inclination at 40 degrees or smaller, for example, a vortex in the classification chamber was reduced, and the classification accuracy was improved by preventing mixing of coarse particles. Moreover, it was found that power consumption was also reduced.
[0078] Then, the classifying blade is provided at the desired inclination angle so that the formed angle α is larger than 0 degrees and not larger than (or less than) 45 degrees, for example. Alternatively, the classifying blade is provided at the desired inclination angle so that the formed angle α is larger than 0 degrees and not larger than (or less than) 40 degrees. Alternatively, the classifying blade is provided at the desired inclination angle so that the formed angle α is larger than 0 degrees and not larger than (or less than) 30 degrees. the classifying blade is provided at the desired inclination angle so that the formed angle α is larger than 0 degrees and not larger than (or less than) 20 degrees. The desired inclination angle is preferably set as above since the classification accuracy can be improved, and the shape coefficient can be made smaller so as to reduce power.
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[0080] As illustrated in
[0081] However, the mixing of the coarse particles is decreased in the particle size distribution of the case of the formed angle α further inclined to 30 degrees (shape 3) as compared with the classification distribution of the case with the formed angle α at 75 degrees (shape 1) or 60 degrees (shape 2). Therefore, it is found that the classification accuracy is improved by steeply inclining the classifying blade.
[0082] Moreover,
[0083] As illustrated in
[0084] If the shape from the base portion to the distal end of the classifying blade is an arc shape such as the Bernoulli curve with the expanding/projecting front surface side of the blade surface, for example, the formed angle α refers to an angle formed by the direction from the distal end (outer peripheral end) toward the base portion (inner peripheral end) of the blade surface 23a on the front surface side of the classifying blade 23 and the rotating direction at the distal end (outer peripheral end) of the blade surface on the front surface side of the classifying blade 23 as illustrated in
[0085] Moreover,
[0086] Furthermore, the power consumption P required for the rotation of the classifying rotor can be expressed by the formula 6:
P=Np.Math.ρ.Math.N.sup.3.Math.d.sup.5 [Formula 6]
[0087] Reference character P denotes the power consumption, p denotes a fluid density, N denotes the rotation number of the rotary body, d denotes the diameter of the rotary body, and Np denotes the shape coefficient of the rotary body and the casing.
[0088] From the formula 6, the size of the power consumption P of the classifying rotor can be expressed by the shape coefficient Np. And from
[0089] Moreover, the power number Np can be reduced more than the linear classifying blade by forming the shape from the base portion to the distal end of the classifying blade with the Bernoulli curve. Therefore, unnecessary power consumption and wear of the classifying rotor can be reduced by forming the shape from the base portion to the distal end of the classifying blade with the Bernoulli curve.
[0090] According to the present invention, very few coarse particles are mixed, and sharp particle size distribution can be realized by setting the aforementioned angle to the angle α formed by the classifying blade.
Embodiment 2
[0091] In the embodiment 2 of the present invention, as illustrated in
[0092] Each of the rectifying blades 25 is formed having the same shape, respectively. Moreover, each of the rectifying blades 25 is formed by a flat plate having a linear shape from the base portion (inner peripheral end) to the distal end (outer peripheral end) of the blade surface on the front surface side, for example. Moreover, each of the rectifying blades 25 is provided by being separated by an equal distance from the rotation centers of the classifying rotors 21, 3, and 11 and disposed at an equal interval in the peripheral direction, for example. Moreover, each of the rectifying blades 25 is provided so that the inclination angle to the radial direction is the same, for example.
[0093] The numbers of the classifying blades and the rectifying blades 25 are not particularly limited. The number of the rectifying blades 25 is preferably smaller than the number of the classifying blades. However, if it is too small, the rectification effect is lost and thus, and the number of the rectifying blades 25 is an integral number of ¼ times or more of the number of the classifying blades, an integral number of ⅓ times or more of the number of the classifying blades or an integral number of ½ times or more of the number of the classifying blades, for example.
[0094] Moreover, the classifying blades and the rectifying blades 25 are provided by being separated by the desired distance.
[0095] In the embodiment 2 illustrated in
[0096] The angle β formed by the rectifying blade 25 and the rotating direction of the classifying rotor refers to an angle formed by the direction (direction of the blade surface on the front surface side) from the distal end (outer peripheral end) to the base portion (inner peripheral end) of the blade surface on the front surface side of the rectifying blade 25 and the rotating direction at the distal end (outer peripheral end) of the blade surface on the front surface side of the rectifying blade 25. In other words, the angle β formed by the rectifying blade 25 and the rotating direction of the classifying rotor refers to an angle formed by a line drawn between the distal end (outer peripheral end) and the base portion (inner peripheral end) of the blade surface on the front surface side of the rectifying blade 25 and a line crossing at a right angle the line from the rotation center point of the classifying rotor 21 to the distal end (outer peripheral end) on the front surface side of the rectifying blade 25. More specifically, as illustrated in
[0097] The example of the classifying rotor in
[0098] Moreover, each of the rectifying blades 25 may have an arc shape for the shape from the base portion to the distal end other than the linear flat plate. Moreover, it may be an arc made of the Bernoulli curve.
[0099] Subsequently, the action and effect of the classifying rotor having the rectifying blade 25 of the present invention will be described.
[0100] According to this embodiment, by providing the rectifying blade 25, the flow of the fluid on the inner side from the classifying blade in the rotor can be made constant in the peripheral direction.
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[0102] Moreover,
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[0104] In the conventional classifying rotor without the rectifying blade, a flowing state of the fluid flowing in form the outer peripheral portion and exceeding the classifying blade becomes unstable, which influenced the flowing state in the classification chamber and worsened the classification accuracy. However, the flow of the fluid on the inner side from the classifying blade can be made stable by providing the rectifying blade. And thus, the flowing state in the classification chamber is made stable, and the classification accuracy can be drastically improved.
INDUSTRIAL APPLICABILITY
[0105] The classifying apparatus of the present invention can be used in industrial fields in general handling classification of any powder bodies in the wet and dry types up to micron to submicron levels. This can be used in the metal industry, chemical industry, pharmaceutical industry, cosmetics industry, pigments, ceramic industry and other industries, for example.