JPS6366582B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a pulverizer.

As shown in FIGS. 1 and 2, a conventional pulverizing device supports a cylindrical rotor 2 having a large number of protrusions 1 along the generatrix of its outer surface on a rotating shaft 3. A stator 6 is fitted with a stator 6 having a gap 4 between the rotor 2 and a large number of convex portions 5 along the generatrix of the inner surface. The object is supplied and the rotor 2 rotates at high speed to crush the particles of the object to be crushed.

In the process of crushing the material to be crushed, the material to be crushed is supplied from the supply port 8 provided in the bottom plate of the lower casing 7 which is connected to the lower end of the stator 6 by operating a suction blower (not shown) connected to the product discharge port 12. The particles are sucked into the machine along with the air, and are moved along the inverted conical inner surface of the lower casing 7 by the airflow generated by the stirring blades 9 fixed to the lower surface of the rotor bottom plate, which rotates at high speed together with the rotor 2. The powder is raised at the same time and sent into the crushing chamber formed between the rotor 2 and the stator 6, and is given velocity energy by the rotational force of the rotor 2 rotating at high speed to cause it to collide with the stator 6. It is pulverized and crushed by impact by the convex part 1 of the rotor 2, and further crushed between the convex part 1 of the rotor 2 and the convex part 5 of the stator 6 to be further finely pulverized. The upper casing 1 is carried upward on the upward spiral airflow generated by the rotation and is connected to the upper end of the stator 6.
centrifugal blades 11 fixed to the upper surface of the rotor upper plate, which rotate the rotor 2 at high speed together with the rotor 2;
The product rotates along the inner peripheral surface of the upper casing 10, is discharged from the product discharge port 12 provided in the tangential direction of the upper casing 10, and is introduced into a bag filter (not shown), where the crushed product and air are separated. The air is separated and exhausted via a suction fan, and the crushed product is sent from a bag filter to a hopper and stored.

By the way, in the above-mentioned pulverizer, the gap 4 between the rotor 2 and the stator 6 is generally 2 to 5 mm or more, which is wide. weak.

(b) The probability of the rotor 2 hitting the particles of the object to be crushed is small.

C. The impact force exerted by the rotor 2 on the particles of the object to be crushed is small.

There were other drawbacks.

In addition, in the crushing chamber formed by the rotor 2 and the stator 6, air flows through the recess 1a of the rotor 2,
The particles to be crushed pass through the gap 4 and the recess 5a of the stator 6, and pass through the crushing chamber riding on this air, that is, the upward spiral airflow. Almost no particles of the material to be crushed pass through the concave portion 1a. Therefore, the particles to be crushed pass through two places: the gap 4 and the recess 5a of the stator 6. However, the convex portion 5 and the concave portion 5 of the stator 6
Since the cross-sectional shape of a is nearly rectangular, air flows from below to above in the recess 5a of the stator 6 while forming a vortex at a high rotational speed as shown in FIG.
Among the particles of the object to be crushed that are caught up in this vortex, some collide with the wall surface of the recess 5a, are discharged from the recess 5a into the gap 4, are subjected to a strong impact action by the projection 1 of the rotor 2, and are fixed. Grinding progresses due to the grinding action between the child 6 and the convex portion 5. However, there is a drawback in that some of the particles to be crushed are not crushed as described above, but remain caught up in the vortex and exit from the crushing chamber through the upper end of the recess 5a.

Therefore, the average particle size of the product crushed by such a pulverizer differs slightly depending on the particles of the material to be crushed, but for example, it can only be 60 μm for polished rice and 40 μm for toner, and it is difficult to say that it is sufficiently finely pulverized. However, it was not possible to obtain a finely pulverized product on the order of microns to several tens of microns.

Furthermore, in the conventional pulverizing device, if coarse particles are mixed in with the particles of the object to be pulverized, they may not be pulverized finely and may be discharged as coarse particles, or the rotor 2 or stator 6 may be severely damaged due to collisions of the coarse particles. To avoid wear, it is desirable to finely grind the particles of the material to be ground to a certain range of particle sizes before supplying the material.
This requires a great deal of effort.

The present invention has been made in view of the above circumstances, and it does not require pre-treatment, and even if the particle size of the particles to be crushed is non-uniform, the supplied particles to be crushed can be reliably and sufficiently processed. The object of the present invention is to provide a pulverizing device that performs a pulverizing action to increase the pulverizing efficiency and can obtain pulverized products with a narrow particle size range of the order of microns to several tens of microns.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pulverizing apparatus according to the present invention will be described below with reference to the drawings. In FIG. 4, 20 is a first crushing section, and 21 is a second crushing section. First crushing section 20
As shown in FIG. 5, a large number of crushers 24 are fixed radially along the generatrix of the outer surface of two support members 23, 23, upper and lower, which are fixed to a boss 22 supported at the lower part of the rotating shaft 3'. The upper and lower support members 23, 2
A first rotor 27 is formed by fixing an upper surface blade 25 and an auxiliary blade 26 to each of the first rotor 27, and a rectangular convex portion is fitted on the inner surface of the first rotor 27 with a constant gap 28 between the first rotor 27 and the first rotor 27. The first stator 30 has a section 29. The second crushing part 21 is supported on the upper part of the rotating shaft 3', and has a large number of rectangular convex parts 31 along the generatrix of the outer surface as shown in FIG. A second stator 36 is fitted with a second rotor 34 provided with auxiliary blades 33 with a gap 35 of 1 mm or less between the stator 36 and the second rotor 34 provided with auxiliary blades 33. Second stator 36
The inner surface has a substantially triangular recess 3 as shown in FIG.
7 and the convex portion 38 are formed into a continuous tooth shape, and one side 37a of the concave portion 37 of the tooth shape is directed toward the center of the second rotor 34 and has a length of about 1 to 5 mm,
The other side 37b of the recess 37 is oriented in the tangential direction of the second rotor 34, and the one side 37a of the recess 37 and the other side 37
The included angle α with b is 45 to 60 degrees. A circular arc surface 38a centered on the axis of the second stator 36 is formed at the tip of the convex portion 38.
The width of 8a is approximately 1 mm. The upper end of the recess 37 on the inner circumferential surface of the second stator 36 is
As shown in FIG. 2, a classification ring 39 that closes the opening surface of the upper end of the recess 37 is provided integrally or detachably. Since this classification ring 39 may close the upper end opening surface of all the recesses 37 in the circumferential direction on the inner circumferential surface of the second stator 36, the width in the radial direction and the length of the convex part 38 can be The difference δ may be zero. In addition, the classification ring 39 is connected to the second
It may be provided in the middle of the recess 37 on the inner circumferential surface of the stator 36, and in that case, it may be provided not only in one stage but also in two stages, three stages, and so on. Further, the classification ring 39 may be divided and arranged in a plurality of stages at different stages in the circumferential direction.

In FIG. 4, 7' is a lower casing connected to the lower end of the first stator 30, 8' is an air and pulverized particle introduction pipe, 10' is an upper casing connected to the upper end of the second stator 36, and 12' is a crushed casing. A product discharge port, 13' is a pulley, and 14' is a belt.

Next, the pulverizing action of the particles to be pulverized by the pulverizer of the present invention constructed as described above will be explained. An electric motor (not shown) is driven to run the belt 14' to rotate the rotary shaft 3' at high speed, and a suction blower (not shown) is operated to draw air into the lower casing 7' through the introduction pipe 8'. At the same time, the particles of the material to be crushed supplied to the introduction pipe 8' are introduced into the lower casing 7' in air. The particles to be crushed introduced into the lower casing 7' are transferred to the auxiliary blades 2 of the first rotor 27, which rotates at high speed together with the rotating shaft 3'.
6, the lower casing 7'
The first rotor 27 rises along the inverted conical inner surface of the
The coarse particles enter a first crushing chamber formed between the first rotor 27 and the first stator 30, where the coarse particles are crushed by the first rotor 27 and the first stator 30. The particles of the material to be crushed, which have been finely crushed to a particle size within a certain range, exit the first crushing chamber and ride the airflow generated by the rotation of the upper blade 25 and the auxiliary blades 33 of the second rotor 34, and are transferred to the second rotor 34. and the second stator 36, where all the particles are subjected to a pulverization action to become a pulverized product with a narrow particle size range of micron order to tens of microns. is sent into the upper casing 10', and the second rotor 3
The product is rotated along the inner circumferential surface of the upper casing 10' by the upper surface blade 32 that rotates at high speed together with the upper casing 10', and is discharged together with air from the product outlet 12' provided in the tangential direction of the upper casing 10'. It is introduced into the bag filter through a discharge pipe not shown. There, the pulverized product and air are separated, the air is exhausted from the exhaust pipe via the suction blower, and the pulverized product is sent from the bag filter to the hopper and stored there.

Next, details of the pulverizing action of the particles to be pulverized in the second pulverizing chamber will be explained with reference to the related structure of the second rotor 34, second stator 36, and classification ring 39.

Generally speaking, when considering the air surrounding a rotating body, the air attached to the surface rotates at the same speed as the circumferential speed of the rotating body, whereas the speed of the air at a position away from the surface is the distance The larger the value, the greater the delay from the circumferential speed of the rotating body, and the smaller the speed. However, considering the concave portion 37 of the second stator 36, a vortex is induced in this portion as shown in FIG. The rotational speed of the vortex is proportional to the circumferential velocity υ of the air along the opening surface of the recess 37. Therefore, the dimension h of the gap 35 between the second rotor 34 and the second stator 36
The larger the circumferential speed υ is, the later the circumferential speed υ is behind the circumferential speed υ ₀ of the second rotor 34, and the rotational speed of the vortex becomes smaller. Conversely, the smaller the dimension h of the gap 35, the higher the rotational speed of the vortex. The particles of the material to be crushed that are caught up in the vortex collide with the wall surface more intensely as the rotational speed of the vortex increases.
Furthermore, as the rotational speed of the vortex increases, particles with smaller diameters also collide with the wall surface, so that the particles of the object to be crushed are better crushed.

In addition, the probability of impact by the second rotor 34 on particles to be crushed coming out from the vortex in the recess 37 to the gap 35 is determined by the dimension h of the gap 35, the particle diameter d of the particles to be crushed, and the convex portion of the second rotor 34. 31, then P∝d/h×n, and when the dimension h of the gap 35 is small and the number n of the convex portions 31 of the second rotor 34 is large, the hit probability P increases, and the second The impact pulverization of the particles of the object to be pulverized by the rotor 34 is efficiently performed.

Further, a gap 35 is formed from the recess 37 of the second stator 36.
The particles of the material to be crushed that come out are accelerated by the air flow flowing through the gap 35. In this case, the larger the dimension h of the gap 35, the longer it takes for the particles to be hit by the second rotor 34, so the relative speed between the particles and the second rotor 34 during impact becomes smaller, and the second rotor 34 Although the impact force on the particles by the second rotor 34 is reduced, since the dimension of the gap 34 is extremely small, 1 mm or less, the time until the particles are hit by the second rotor 34 is shortened, so that the impact force on the particles at the time of impact is reduced. The relative speed with the second rotor 34 increases, and the impact force of the second rotor 34 on the particles increases. Therefore, the particles to be ground are reliably struck.

Now, since the shape of the recess 37 of the second stator 36 is approximately triangular as described above, the air flows in the recess 37 as shown in FIG. 10: a, a', a''...
and vortices b, b', b''. Vortices b, b',
The particles of the object to be crushed that have been caught up in b'' collide with the wall surface and are crushed in the same manner as in the case of the conventional rectangular recess 5a (see Fig. 3). 37a along the tip B of the convex portion 38
The material advances to the gap 35, where it is struck by the convex portion 31 of the second rotor 34, and is pulverized. The same effect is then applied to the concave portion 37 of the second stator 36 and the convex portion 31 of the second rotor 34, and the crushing progresses one after another. On the other hand, the conventional rectangular recess 5
In case a, the material to be crushed enters the recess 37 of the second stator 36 from the gap 35, which almost never occurs, and rides on the air flows a, a', a'', etc. that come out again to the gap 35. The particles advance along the other side 37b of the concave portion 37 to the tip A of the convex portion 38, are guided to the gap 35, and are struck by the convex portion 31 of the second rotor 34 at this portion, where they are pulverized. At the same time, the particles that have been subjected to the impact pulverization action are further
It is collided with and shattered. The same action is then applied to the concave portion 37 of the second stator 36, and as a result of the crushing progressing one after another, the impact by the second rotor 34 is only at point B, compared to the case of the conventional rectangular concave portion 5a. Since the pulverization is also carried out at point A, the probability of impact on the particles of the pulverized material increases, and the pulverized particles of the pulverized material are finely and efficiently pulverized.

However, in some or all of the recesses 37 in the circumferential direction of the inner circumferential surface of the second stator 36, the recesses 37 are partially formed in the vertical direction as shown in FIGS. Since the classification ring 39 that closes is provided, the particles of the object to be crushed that ride the high rotational speed vortex (see Fig. 3) inside the recess 5 as in the conventional case and go out of the second crushing chamber all at once can be prevented. Due to the classification action of the classification ring 39, which will be described later, the residence time of the particles to be crushed in the second crushing chamber becomes longer, and at the same time, the concentration of the particles to be crushed in the second crushing chamber increases. The longer the residence time, the higher the probability of being subjected to the pulverizing action, and the more fine the pulverized product can be obtained. Furthermore, when the concentration of the particles of the object to be crushed increases, the probability of collision between the particles of the object to be crushed increases, and the crushing action is promoted. Due to these two effects, the particles of the object to be ground are reliably pulverized. The particles that have been finely pulverized in this way are carried by the airflow and are about to exit into the gap 35 directly under the classification ring 39, because the centrifugal force caused by the rotation of the second rotor 34 is still acting here, so the particles have a certain size. The above particles are pushed back into the recess 37 of the second stator 36 again. The pushed back particles are again subjected to the crushing action and passed through the classification ring 3 until they become smaller than a certain size.
I can't get past the 9 part. Therefore, the particles of the object to be pulverized are sufficiently pulverized.

In this way, the finely pulverized particles that have passed through the second pulverizing chamber formed between the second rotor 34 and the second stator 36 are separated by the gap 35 of 1 mm or less and the side 37a.
is oriented toward the center, the other side 37b is oriented in the tangential direction of the second rotor 34 so as to face the rotating second rotor 34, and the included angle α between both sides 37a and 37b is 45 to 60.
A large number of approximately triangular recesses 37 are formed on the inner surface of the second stator 36, and the recesses are located at the upper ends or intermediate portions of some or all of the recesses 37 in the circumferential direction of the inner peripheral surface of the second stator 36. Due to the synergistic effect of the action with the classification ring 39 provided so as to partially close the 37 in the vertical direction, a finely pulverized product of the order of microns to more than 10 microns is obtained.

In addition to the above-mentioned pulverizer according to the present invention, there is one shown in FIG. This pulverization device includes a classifier 42 installed in the middle of a discharge pipe 41 connecting a product discharge port 12' and a bag filter 40, and a coarse powder discharge port 43 of the classifier 42 and an inlet pipe of the lower casing 7'. A coarse powder supply port 44 provided at the inlet of the classifier 8' is connected through a pipe 45, a fine powder discharge port 46 of the classifier 42 is connected to a bag filter 40 through a discharge pipe 41, and an outlet of the bag filter 40 is connected to the A discharge pipe 48 equipped with a suction blower 47 is connected in the middle. Reference numeral 49 denotes a feeder that feeds the particles to be crushed into a supply port 50 provided at the entrance of the introduction pipe 8'.
Reference numeral 51 denotes an electric motor which runs on the belt 14' and rotates the rotary shaft 3'.

According to this pulverizer, the pulverized product with a narrow particle size range, which is pulverized to micron order to tens of microns in the second pulverizer 21, is delivered to the product outlet 1 along with air.
2' and passes through the discharge pipe 41 to the classifier 4.
When it enters 2, it is classified into fine powder on the micron order and coarse powder on the order of 10 microns. Then, one of the fine powders is introduced into the bag filter 40 through the discharge pipe 41, where it is separated into fine powder and air, and the air is exhausted from the discharge pipe 48 via the suction blower 47.
The fine powder is sent from the bag filter 40 to a hopper (not shown) and stored therein. On the other hand, the coarse powder is fed from the discharge port 43 through the pipe 45 to the coarse powder supply port 44 and supplied to the introduction pipe 8', and the fresh powder is fed from the feeder 49 to the supply port 50 and supplied to the introduction pipe 8'. The particles are introduced into the lower casing 7' along with the particles to be crushed, and are again subjected to the crushing action in the first crushing section 20 and the second crushing section 21. Therefore, the pulverized product obtained by this pulverizer is a fine powder with an extremely narrow particle size range on the micron order.

As can be seen from the above description, the pulverizer of the present invention crushes coarse particles in the particles of the object to be crushed in advance in the first pulverizing section to form fine particles with a particle size within a certain range, and then Since the powder is finely pulverized by two pulverizers, wear of the second rotor and second stator is significantly reduced, and the product is highly durable. Moreover, unlike the conventional method, there is no need for pre-treatment of finely pulverizing the particles of the object to be pulverized to a certain particle size within a certain range, so that the great amount of labor required for this can be omitted.

Further, the pulverizer of the present invention has a second pulverizer in the second pulverizer.
The inner surface of the stator has a special shape, and the gap with the second rotor is extremely narrow, less than 1 mm.
It is possible to reliably, sufficiently, and efficiently pulverize the particles of the object to be pulverized, from micron order to fine pulverization.
Finely pulverized products with a narrow particle size range of 10-odd microns can be easily obtained in a short time.

In particular, if a finely pulverized product is classified with a classifier and the coarse powder on the order of 10-odd microns is returned and pulverized again, a pulverized product with an extremely narrow particle size range on the order of microns can be obtained.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing a conventional pulverizing device, Fig. 2 is a partially enlarged sectional view taken along the line - in Fig. 1,
Fig. 3 is a partial perspective view showing the air flow in the recesses on the inner surface of the stator of the pulverizer shown in Fig. 1;
The figure is a longitudinal sectional view of the pulverizer of the present invention, FIG. 5 is an enlarged sectional view taken along the line - in FIG. 4, and FIG.
7 is a partial horizontal sectional view showing the combination of the second rotor and second stator of the second crushing section in the pulverizing device of the present invention; FIG. Figures a and b are partial perspective views showing the classification ring provided at the upper end of the recess on the inner peripheral surface of the second stator, and Figures a and b are intermediate parts of the recess on the inner peripheral surface of the second stator. FIG. 10 is a partial perspective view and a partial vertical sectional view showing the classification ring provided in the 2nd rotor. FIG. 7 is an enlarged view for explaining the operation, and FIG. 11 is a system diagram showing another example of the pulverizer of the present invention. 3'...Rotating shaft, 7'...Lower casing, 8'...Introduction pipe, 10'...Upper casing, 12'...Product discharge port, 20...First crushing section, 21...Second crushing section, 24
...Crusher, 27...First rotor, 28...Gap, 29
...Protrusion, 30...First stator, 31...Protrusion, 34...
Second rotor, 35... Gap, 36... Second stator, 3
7... Substantially triangular recess, 37a... One side of the recess, 37
b...Other side of the recess, 38...Substantially triangular protrusion, 39...
Classifying ring, 40... Bag filter, 41... Discharge pipe, 42... Classifier, 43... Coarse powder discharge port, 45... Piping.

Claims (1)

[Claims] 1. A first rotor that is supported at the lower part of the rotating shaft and has convex portions on its inner surface with a constant gap between it and a first rotor that has crushers radially along the generatrix of its outer surface. A gap of 1 mm or less is provided between the first crushing part in which the stator is fitted and the second rotor, which is supported on the upper part of the rotating shaft and has a large number of convex parts along the generatrix of the outer surface. a second crushing section in which two stators are fitted;
The second pulverizer comprises an inlet pipe for introducing particles of the pulverized material and air provided in a lower casing connected to the lower end of the stator, and a pulverized product outlet provided in an upper casing connected to the lower end of the second stator. Part 2
The inner surface of the stator has a tooth shape in which approximately triangular concave portions and convex portions are continuous, and one side of the concave portion of the tooth shape is the second side.
The other side of the recess is oriented toward the tangential direction of the second rotor, and the included angle between one side of the recess and the other side is 45 to 60 degrees, and the inner peripheral surface of the second stator is At the upper end or middle of a part or all of the recess in the circumferential direction of
A pulverizer including at least one stage of classification ring that partially closes the recess in the vertical direction. 2. A first crushing section in which a first stator is fitted with a certain gap between the first rotor and the first rotor, which is supported at the lower part of the rotating shaft and has crushers radially along the generatrix of the external surface; a second crushing part in which a second stator is fitted with a gap of 1 mm or less between the second rotor, which is supported on the upper part of the rotating shaft and has a large number of convex parts along the generatrix of the outer surface; , an inlet pipe for introducing particles of the pulverized material and air provided in a lower casing connected to the lower end of the first stator, and a pulverized product outlet provided in the upper casing connected to the lower end of the second stator, The inner surface of the second stator of the second crushing section has a tooth shape in which approximately triangular concave portions and convex portions are continuous, one side of the concave portion of the tooth shape is directed toward the center of the second rotor, and the other side of the concave portion is It is oriented in the tangential direction of the second rotor, and the included angle between one side of the recess and the other side is 45 to 60 degrees, and At least one stage of classification ring is provided in the middle to partially close the recess in the vertical direction, and a classifier is provided in the middle of the discharge pipe connecting the crushed product discharge port of the upper casing and the bag filter. , a fine grinding device in which the coarse powder discharge port of the classifier is connected to the introduction pipe of the lower casing by piping.