JPH058075B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention classifies powder and granules such as cement based on their particle sizes to obtain a desired fineness (cm ² /
g) and a classifier adapted to obtain particle size distribution.

Prior Art FIG. 8 is a simplified sectional view of a static type vertical mill 1 of the prior art. A table 2 having a vertical axis of rotation and a table liner 2a is disposed within a casing 1a of the vertical mill 1, and is rotationally driven by a drive means 3. A plurality of rollers 4 are arranged on the table 2 at intervals in the circumferential direction. The roller 4 is connected to an arm 5 via a pivot 6 so as to be angularly displaceable, and one end of the arm 5 is connected to a pressure means 7 extending outside the casing 1a. The roller 4 is pressed against the table liner 2a by the pressure means 7.

A supply chute 8 is opened and provided on the table 2 to supply the raw material to be crushed into the casing 1a. Furthermore, a classifier 9 is provided further above the table 2. The classifier 9 includes a cone 10 having an inverted truncated cone shape, and a large number of impingement vanes 11 disposed along the circumferential direction at the upper end of the cone 10. The ceiling plate 12 of the vertical mill 1 is provided with a discharge duct 13 for taking out the powder obtained by pulverizing the raw material between the rollers 4 and the table liner 2a to the outside of the casing 1a. Also, casing 1a
Below the table 2, an air blowing port 14 is provided that blows out gas from a nozzle 16 to blow up the powder and granules in the casing 1a.

In the vertical mill 1 having the above-described configuration, the raw material supplied from the supply chute 8 falls onto the table 2, and is separated by the table liner 2a and roller 4.
crushed between. After being crushed in this way,
The granular material rises inside the casing 1a by the gas from the air outlet 14, and enters the cone 10 through the guide hole 15 between the cone 10 and the ceiling plate 12. At this time, the impinging vanes 11 are arranged so that the gas and the powder and granules swirl within the cone 10, and the centrifugal force causes the powder and granules with a predetermined particle size or more to be pushed against the inner circumferential surface of the cone 10. It moves nearby, falls downward, and returns to the table 2 again. The powder thus returned is mixed with the raw material from the supply chute 8 and pulverized again between the table liner 2a and the rollers 4. Further, the remaining particulate material is discharged from the discharge duct 13 to the outside of the casing 1a.

Although the vertical mill 1 that performs pulverization in this manner has a relatively simple configuration, the powder and granules obtained from the discharge duct 13 cannot have an arbitrary particle size distribution. That is, although the fineness (cm ² /g) of the powder obtained from the discharge duct 13 can be adjusted to some extent by adjusting the angle between the impingement blade 11 and the radial direction of the cone 10, coarse particles are easily discharged. Moreover, it is not possible to obtain a powder or granular material with an arbitrary particle size distribution at a single powder degree.

FIG. 9 is a simplified cross-sectional view of another prior art so-called rotary blade type vertical mill 20.
The figure is a Rosin-Ramla diagram for explaining the classification function of the vertical mill 20. This prior art is similar to the prior art vertical mill 1 shown in Figure 8, and corresponding parts are given the same reference numerals. In the vertical mill 20 of the present prior art, the classifier 9 includes an eighth
A feature of this mill is that, in place of the cone 10 and collision blades 11 in the illustrated vertical mill 1, a plurality of rotary blades 21 are provided above the casing 1a in the circumferential direction. The lower end portions of the rotary blades 21 are commonly fixed to a support member 22, and the support member 22 is fixed to a rotating shaft 24 that is rotationally driven by a driving means 23.

In the vertical mill 20 having the above-described configuration, the raw material supplied from the supply chute 8 is
It ascends inside the casing 1a through a process similar to that described with reference to the figures. At this time, the gas and powder particles try to pass through the gaps between the plurality of rotary blades 21 that are being driven to rotate together with the gas from the air outlet 14;
The particles are subjected to a centrifugal force corresponding to the particle size by colliding with the particles, and particles larger than a predetermined particle size are subjected to a large centrifugal force and fall below the casing 1a. On the other hand, the remaining powder passes through the gaps between the plurality of rotary blades 21 and is discharged from the discharge duct 13 to the outside of the casing 1a.

In the vertical mill 20 having the above configuration, by changing the rotational speed of the rotary blades 21, the fineness of the powder obtained from the discharge duct 13 can be changed. When the rotor 21 is rotating at a certain speed, the discharge duct 13
It is assumed that the powder degree and particle size distribution of the powder obtained from the above are shown by line 1 in FIG.
Next, assuming that the rotational speed of the rotary blade 21 is reduced, the particle size structure of the powder obtained from the discharge duct 13 will be, for example, in the form of line 2 shown in the Rosin-Rammula diagram in FIG. becomes. At this time, if the angles formed by lines 1 and 2 in FIG. 10 with the horizontal axis are θ1 and θ2, respectively, then the tangent values obtained from these, ie, the n values n1 and n2, are expressed by the following equations.

n1=tanθ1...(1) n2=tanθ2...(2) At this time, in the vertical mill 20 in this prior art,
It is known that the n values n1 and n2 are approximately equal.

That is, by changing the rotational speed of the rotary blade 21, it is possible to obtain any predetermined fineness (cm ² /g); can't get it.

For example, in the case of pulverizing cement using the vertical mill 20, the above-mentioned n value is Therefore, it is desirable that the particle size structure of the powder shown in FIG. 10 be comprised of a relatively wide range of particle sizes. On the other hand, in the vertical mill 20, since the grinding time of the raw materials is short, as described above, the proportion of the part of the granular material obtained by grinding the raw materials in the casing 1a that is circulated and repeatedly ground is high. Therefore, there is a problem that the n value becomes large, that is, the particle size structure of the powder obtained from the discharge duct 13 becomes extremely narrow.

FIG. 11 is a simplified cross-sectional view of yet another prior art rotary vane type vertical mill 30. The vertical mill 30 is similar to the prior art described above, and corresponding parts are given the same reference numerals. The vertical mill 30 of the present prior art has an eighth classifier 9 as a classifier in the casing 1a.
This is a configuration in which the cone 10 and impingement blades 11 shown in the figure and the rotor blade 21 shown in FIG. 9 are provided together. The granular material pulverized by the roller 4 is subjected to a classification operation that is a combination of the above-mentioned classification operations performed by the impingement blades 11, the rotary blades 21, and the cone 10.

The vertical mill 30 having such a configuration also has the same problems as those pointed out in connection with the vertical mill 20 shown in FIG. That is, the width of the particle size composition of the powder and granules obtained from the discharge duct 13 is relatively narrow, and the stopping value of the particle size distribution of the obtained powder and granules changes by changing the rotation speed of the rotor blade 21. However, the width of the particle size distribution of this powder does not change, and therefore it is not possible to obtain a particle size distribution with an arbitrary width.

FIG. 12 is a cross-sectional view of a vertical mill 31, which was previously filed by the applicant (Japanese Patent Application No. 172,291/1982) in order to widen the particle size distribution in order to solve the above-mentioned problems. In the present technology, parts corresponding to the prior art shown in FIG. 9 are given the same reference numerals. With this technology,
The upper end portions of the rotary blades 21 are commonly fixed to a fixed ring member 32. At this time, a predetermined gap 33 is formed between the fixed ring member 32 and the ceiling plate 12. On the other hand, an annular collision member 34 that hangs down from the ceiling plate 12 and surrounds the upper part of the rotary blade 21 is provided so as to close the gap 33 . The shape of this collision member 34 is shown in FIG.

FIG. 13 is a perspective view of the collision member 34. 1st
The collision member 34 will be explained with reference to FIGS. 2 and 13. The collision member 34 has a substantially cylindrical shape and includes a cylindrical portion 35 that surrounds the rotary blade 21 and is longer than the gap 33, and a flange portion 36 fixed to the ceiling plate 12. A plurality of insertion holes 37 are formed in the flange portion 36, and the collision member 34 is fixed to the ceiling plate 12 with bolts (not shown) or the like through the insertion holes 37. Further, an opening 38 is formed in the cylindrical portion 35 .

Therefore, the gas and powder blown up from below within the casing 1a move through the opening 38 and the gap 33 to the space 39 inside the rotary blade 21 in the radial direction. That is, the granular material passing through the opening 38 is not subjected to the classification action by the rotary blade 21, and therefore contains granular material having a relatively large particle size. Such powder and granules are mixed with the powder and granules that have been classified by the rotary blades 21 and moved to the space 39, and are discharged from the discharge duct 13 to the outside of the casing 1a. The particle size distribution of the granular material that has been classified by the rotary blade 21 and moved to the space 39 is shown, for example, by line 1 in FIG. 14.
Further, the particle size distribution of the granular material that has moved to the space 39 through the opening 38 is shown by line 3. The tangent value n3 of line 3 n3 = tanθ3 ...(3) is calculated from the particle size structure of line 1 as described above.
is smaller than the tangent value n1. Therefore, the particle size distribution of the powder and granular material obtained by mixing these powder and granular materials in the space 39 is shown by line 4 in FIG. 14. Therefore, by changing the opening area of the opening 38 and therefore, for example, the length in the circumferential direction of the opening 38, the n of the line 3 can be changed.
The n value, and therefore the n value n4 n4 = tan θ4 (4) of the granular material obtained from the discharge duct 13, can be set to a desired degree.

However, in such a rigid mill 31, it is assumed that the powder and granules moving from the opening 38 to the space 39 may include powder and granules having an undesirably large particle size as a product. Therefore, regarding the powder and granular material obtained from the discharge duct 13, for example, the weight percentage of the powder and granular material with a particle size exceeding 88 μm,
For example, it has been desired to make it as small as possible, to about 1% or less.

Problems to be Solved by the Invention Problems common to each of the above-mentioned conventional techniques and the technique shown in FIG. 12 can be summarized as follows.
In other words, it is difficult to set the width of the particle size structure of the powder and granular material obtained from the discharge duct 13 to an arbitrary width at an arbitrary fineness (cm ² /g) depending on the purpose of the powder and granular material. It was hot. The purpose of the present invention is to solve the above-mentioned problems, and to calculate the fineness (cm ² /g) of the powder obtained by passing through a classifier and the width of the particle size distribution of the powder at each fineness. It is an object of the present invention to provide a classifier that can be set to any predetermined value.

Means for Solving the Problems The present invention provides an inverted truncated cone with an open lower end provided above the table in a casing to which gas and powder are supplied from below, and Between the plate and the cone, a large number of collision vanes that can be angularly displaced about the vertical axis are arranged in the circumferential direction, and inside these collision vanes and the cone, below the ceiling plate of the casing, there are collision vanes that can be angularly displaced around the vertical axis of rotation. Two upper and lower rotor blade groups, a second rotor blade and a first rotor blade, which are rotationally driven are integrally formed via a fixed ring member, and each rotor blade of the first rotor blade group is spaced apart from each other in the circumferential direction. The second rotary blade group has a smaller number of rotor blades than the first rotor blade group and has its upper end fixed to a fixed ring member at intervals in the circumferential direction. A cylindrical colliding member, which surrounds the second rotor blade and is suspended from the ceiling plate of the casing, is provided radially outwardly of the second rotor blade, and has a plurality of through holes formed at intervals in the circumferential direction. and a lid member that slides along the outer circumferential direction of the collision member and adjusts the opening area of the through hole of the collision member, whereby the second rotary blade has different classification characteristics from the first rotor blade, and the fineness of the powder and granular material is variable, and above these rotor blades, gas and powder from each rotor blade group are mixed and discharged. This classifier is characterized by being equipped with an outlet for

Function According to the present invention, the granular material in the casing is supplied together with gas from below in the casing. The gas and powder thus supplied are classified by a plurality of rotor blade groups arranged vertically and connected below the ceiling plate of the casing. Each of these rotor blade groups has a plurality of rotor blades arranged at intervals in the circumferential direction around the vertical axis of rotation, and the classification characteristics of each rotor blade group are set to be different from each other. In addition, among these rotor blade groups, radially outward of the second rotor blade in the upper stage, a plurality of rotor blades, which surround the second rotor blade and are suspended from the ceiling plate of the casing, are spaced apart in the circumferential direction. An aperture setting means is provided that includes a cylindrical collision member in which a through hole is formed and a lid member that slides along the outer circumferential direction of the collision member and adjusts the opening area of the through hole of the collision member. ing.

Therefore, a part of the powder or granular material is subjected to a classification action by the rotary blade group without going through the aperture setting means,
The remaining particulate matter is subjected to a classification action by a group of rotary blades through a circumferential opening having an area set by the opening setting means. The thus classified powder and granular materials are mixed and discharged from a discharge port provided near the rotation axis of the ceiling plate. Here, each of the plurality of rotary blade groups has different classification characteristics, and by adjusting the opening area to the upper rotary blade group by the aperture setting means, a desired fineness and a particle size structure at the fineness can be determined. You can get each.

Embodiment FIG. 1 is a cross-sectional view along the vertical axis of a vertical mill 40 according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken from the cutting plane line - in FIG. 1, and FIG. 4 is an exploded perspective view of a configuration related to the rotary blade 52 of the vertical mill 40, and FIG. 4 is a perspective view of a portion of the lid member 81. The configuration of the vertical mill 40 will be described with reference to FIGS. 1 to 4. A table 42 having a vertical axis of rotation is disposed within a casing 41 of the vertical mill 40 and is rotationally driven by a driving means 43 . The table 42 includes a table body 42a and a table liner 42b.

A plurality of rollers 44 are arranged on the table liner 42b at intervals in the circumferential direction. roller 4
The support shaft 45 of No. 4 is connected via an arm 46 and a pivot 47 so as to be angularly displaceable. Axis 4 of arm 46
The end opposite to 7 is connected to a pressurizing means 48 extending outward from the casing 41 . This pressurizing means 4
8 resiliently presses the arm 46, so that the roller 44 is pressed against the table liner 42b.

Below the table 42 of the casing 41, there is provided an air blowing port 49 for supplying gas to blow up and transport the pulverized granular material upward within the casing 41, as will be described later. The gas supplied from the ventilation port 49 is sent to the table 42 below the table 42.
Air blowing means 50 such as a duct provided surrounding the
While flowing through the nozzle 77 provided around the entire circumference outside the table 42 in the radial direction,
It is blown upwards.

Above the table 42 within the casing 41,
A supply chute 51 for supplying the raw material to be crushed,
It is provided with an opening near the center of the table 42 and above. Further above the table 42, an inverted conical cone 71 is provided, and the casing 41
Between the ceiling plate 57 and the upper end of the cone 71, a large number of impingement blades 72, each of which can be angularly displaced about an axis extending in the vertical direction, are arranged in the circumferential direction. The lower end of the cone 71 opens near the upper center of the table 42 as a drop port 74 through which relatively large-diameter powder particles classified by collision blades 72 and the like fall, as will be described later. In addition, the collision blade 72
are arranged to intersect the radial direction of the cone 71 at a common angle, and the gas and powder particles that have passed from the radial outside of the cone 71 between the collision vanes 72 and moved inside the cone 71 The body is arranged to pivot within the cone 71.

Inside the cone 71, a plurality of first rotary blades 52 that are rotationally driven around a vertical rotation axis are provided along the circumferential direction. A lower end portion of each first rotary blade 52 is fixed on a support member 53 at intervals in the circumferential direction. Further, the upper end portions of these first rotary blades 52 are fixed to an annular fixed ring member 54. On the opposite side of the fixed ring member 54 from the first rotor blades 52, second rotor blades 78, the number of which is approximately half the number of the first rotor blades 52, are fixed at intervals in the circumferential direction. Different classification characteristics are set for the rotor blades 52 and 78 groups due to the difference in the number of arrangement. The upper end portions of the second rotary blades 78 are commonly fixed to a fixed ring member 79. The second rotary blade 78 group and the first rotary blade 52 group are thus integrally formed in two stages, upper and lower. Also, the support member 53
A rotating shaft 56 that is rotationally driven by a driving means 55 is fixed at the center of rotation.

The ceiling plate 57 of the casing 41 has a first storage recess 80 large enough to accommodate the fixed ring member 79.
It is formed by concavely above the figure. This storage recess 8
A cylindrical collision member 58 that hangs down from the ceiling plate 57 at the peripheral edge of the rotary blade 58 and surrounds the second rotary blade 78 is provided so as to close the interval between the second rotary blades 78 . This collision member 58 has a plurality of through holes 62 (in this embodiment, three through holes 62 are spaced apart in the circumferential direction) for introducing powder particles having a relatively large particle size as described later.
) is formed.

Further, a cylindrical lid member 81 having an inner circumferential surface that is slidable on the outer circumferential surface of the collision member 58 is arranged.
A plurality of (three in this embodiment) through holes 82 are formed in the lid member 81 at intervals in the circumferential direction and in shapes and positions corresponding to the through holes 62 of the collision member 58. . A guide elongated hole 83 extending along the circumferential direction is formed between each through hole 82 . Bolts 84 are inserted into each of the guide holes 83 and screwed into the screw holes 59 of the collision member 58. Therefore, the lid member 81 can be angularly displaced around the axis of the collision member 58 along the guide elongated hole 83, and the through holes 62 of the collision member 58 and the lid member 81,
The circumferential length of the opening 84 shown in FIG. 2, which is the overlapping portion of the opening 82, and therefore the opening area of the opening 84 can be set to any value. Here, the collision member 58 and the lid member 81 constitute an opening setting means.

The cone 71, collision blade 72, lid member 81, collision member 58, first rotor blade 52, and second rotor blade 78 as described above basically constitute the classifier 63. The powder and granular material that has been classified by the classifier 63 and has passed through the classifier 63 and moved inward in the radial direction of the rotary blade 52 is transported to the casing by a discharge duct 64 which is a discharge port formed in the ceiling plate 57. 41.

The operation of the vertical mill 40 having the above configuration will be explained with reference to FIGS. 1 to 3.
The raw material supplied from the supply chute 51 falls onto the table 42. The table 42 is the driving means 4
3, so the table 4
The raw material on 2 is subjected to centrifugal force and is transferred to table liner 4.
It moves between the roller 2b and the roller 44, and is caught and crushed. The granular material obtained by pulverizing the raw material is blown up within the casing 41 by the gas flow through the nozzle 77 and rises.

The gas and powder that have risen inside the casing 41 flow between the collision vanes 72, enter the cone 71, and are swirled. At this time, the larger the particle size of the powder, the greater the centrifugal force it receives, reaching the vicinity of the inner peripheral surface of the cone 71, falling downward while rotating, returning to the table 42 through the drop port 74, and being crushed again. .

On the other hand, a portion of the remaining powder and granules are discharged into the discharge duct 64.
According to the gas flow discharged from the granules, the particles try to move further inward in the radial direction by passing between the rotary-driven first rotor blades 52, but the particles with a relatively large particle size in this powder and granule material The body is subjected to a relatively large centrifugal force due to collision with the first rotary blade 52, and is returned to the table 42 through the process described above. Particles that are not blown away by the first rotary blade 52 move inward in the radial direction of the first rotary blade 52 .

On the other hand, the remaining part of the powder inside the cone 71 is
Although it moves inward through the opening 84 formed by the lid member 81 and the collision member 58, due to collision with the second rotary blade 78 which is rotationally driven, etc.
Powder particles having a relatively large particle size are classified through a process similar to that described regarding the first rotary blade 52, and are returned onto the table 42. The granular material that has passed between the second rotary blades 78 is mixed with the granular material that has passed between the first rotary blades 52 and is discharged from the discharge duct 64 along with the gas flow.

FIG. 5 is a Rosin-Rammula diagram illustrating the classification operation of the vertical mill 40 of this embodiment. In FIG. 5, X on the horizontal axis is the particle size, and R on the vertical axis is the amount remaining on the sieve. In addition, lines 1, 3, and 4 indicated by two-dot chain lines in FIG. 5 are referred to as lines 1, 3, and 4 in FIG.
is the same as With reference to Figures 1 to 5 above,
The classification operation of the rigid mill 40 will be explained. As mentioned above, regarding the powder and granular material to be classified, the particle size distribution of the powder and granular material that has been classified by the first rotor 52 and moved radially inward is as shown in line 1 in FIG.
It is indicated by. On the other hand, the particle size distribution of the powder that has moved radially inward through the opening 84 and the second rotary blade 78 is shown by line 5 in FIG. That is, compared to the corresponding particle size distribution 3 in the prior art vertical mill 31 shown in FIG. 12 in which the second rotary blade 78 is not provided, ultra-coarse powder whose particle size is unnecessarily large is removed. Like this line 1,5
The powder having the particle size distribution shown in FIG.

Here, the n value of line 1 is basically constant if the raw materials are the same, and its lateral position can be adjusted by changing the rotation speed of the first rotor blade 52. On the other hand, the lateral position of line 5 and the n value can be changed by increasing or decreasing the number of second rotary blades 78 in conjunction with adjusting the rotation speed of second rotor blades 78 (same as the rotation speed of first rotor blades 52). This can be adjusted by adjusting the width of the second rotary blade 78. Therefore, the horizontal position of the line 6 indicating the particle size distribution of the granular material finally taken out from the discharge duct 64, that is, the fineness (cm ² /g) of the obtained granular material, is set to an arbitrary degree. At the same time, it is possible to set the n value of line 6 in FIG. 5, which shows the particle size distribution of the powder or granular material, to a desired degree.

On the other hand, as shown in FIG. 5, in the particle size distribution of the powder and granular material that has passed through the second rotary blade 78, larger particles are cut out than line 3 which shows the corresponding particle size distribution in the prior art, and therefore, for example, the particle size In the conventional technology, the content of powder particles with a diameter of 88 μm or more is
As shown in the figure, the content was R ₁ %, but in this example, the content R ₂ % can be much smaller than R ₁ . In this way, for example, when manufacturing cement, it becomes a factor that deteriorates the strength development of cement. The 88 μm residue can be reduced to a desired degree, eg, less than 1%.

FIG. 6 is a system diagram showing a configuration related to the vertical mill 40 having the configuration and operation as described above. That is, the discharge duct 64 of the vertical mill 40 is connected to a cyclone dust collector 85, and the casing 4
The gas and powder in the cyclone dust collector 8
5 and is sucked by a suction fan 86.
Also, the product discharge chute 8 of the cyclone dust collector 85
A damper 88 is connected to the cyclone dust collector 85 to prevent atmospheric air from flowing in through the product discharge chute 87 even if the inside of the cyclone dust collector 85 is made negative pressure by the suction fan 86.

The powder degree and particle size structure of the product taken out from the damper 88 are detected by the detection means 89, and the n value is calculated. The signal from the detection means 89 is given to the control means 90. A desired n value is set in advance in the control means 90, and a comparison operation is performed with the n value regarding the product calculated by the detection means 89, so that the n value of the product matches the desired n value.
Drive means 55 and drive means 92 of cylinder 91
control the driving state of the

FIG. 7 is a perspective view showing a configuration related to the cylinder 91 shown in FIG. 6. FIG. In the description with reference to FIGS. 1 to 3, the cover member 81 is attached to the collision member 58 so as to be freely angularly displaceable in the circumferential direction by inserting bolts 84 into guide slots 83. Such a lid member 81
One end of the crank 93 is fixed to. The other end of the crank 93 is the piston shaft 9 of the cylinder 91.
4 and pin-coupled. For example, the cylinder head side of the cylinder 91 is connected to the ceiling plate 57 of the casing 41.
It is pin-coupled to a bracket 95 provided on the base plate or the like. Therefore, when the cylinder 91 is expanded or contracted, the lid member 81 can be angularly displaced in the direction of the arrow A1 or the direction of the arrow A2. That is, the through holes 82 and 6 of the lid member 81 and the collision member 58
The opening area of the opening 84 formed from the opening 84 can be changed to a desired degree.

In this way, the control means 90 controls the rotor blades 52,
By changing the rotational speed of the rotor blades 78, lines 1 and 5 shown in FIG. By changing the opening area of the opening 84, the amount of powder taken in from between the second rotary blades 78 can be changed, and therefore the n value of line 5 in FIG. 5 can be changed. be able to. By combining these, the position in the left and right direction in FIG. 5 of the line 6 ^shown in FIG. The configuration can be made to match and maintain a predetermined value.

The present invention is not only implemented in the vertical mill 40 as in the above-described embodiment, but also can be widely implemented in connection with a wide range of other technical fields in which it is necessary to classify powder and granular materials.

Effects As described above, in the classifier according to the present invention, multiple stages of rotor blade groups are provided above and below the ceiling plate of the casing. Each group of rotors is arranged concentrically, and their classification characteristics are set differently. A cylindrical collision member that is vertically installed from the ceiling plate of the casing and has a plurality of through holes formed at intervals in the circumferential direction; An opening setting means is provided, comprising a lid member for adjusting the opening area of the section. Further, the ceiling plate above the rotor blade group is provided with an outlet through which the gas and powder from each rotor blade group are mixed and discharged.

In the classifier configured in this way, the particle size distribution of the powder classified from each rotary blade group and guided to the discharge port differs according to the classification characteristics of each rotary blade group, and the aperture setting Even after powder particles having a relatively large particle size are taken in through the opening set by the means and are classified by the group of rotary blades corresponding to the opening, the remaining other particles are taken in. Powder and granular material having a relatively larger particle size than the granular material taken in from the rotary blade group is taken in. Therefore, by changing the area of the opening, the particle size distribution of the granular material taken in from the rotary blade group corresponding to this opening can be set to a desired degree. Further, by changing the rotational speed of the rotary blade group, the fineness of the granular material to be taken in can be set to a desired degree. Therefore, by combining these, it is possible to set the fineness of the granular material taken out from the discharge port and the particle size distribution at the fineness, that is, the n value, to a desired level.

Furthermore, according to the present invention, the collision member associated with the aperture setting means for classification adjustment is installed vertically from the ceiling plate of the case, so it is easy to install, and accompanying aperture adjustment members such as the lid member can also be easily installed. Therefore, these aperture setting means can be installed at low cost and are easy to operate. In the present invention, the opening area can be adjusted only for the second rotor blade in the upper stage, and the classification effect by the first rotor blade in the lower stage is constant.
Even in parallel classification performed in combination with rotary blades, the adjustment can be performed only with the second rotary blade in the upper stage, resulting in high operability in parallel classification. In particular, it is possible to easily switch between normal classification performed using only the first rotor and the parallel classification.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a vertical mill 40 according to an embodiment of the present invention, FIG. 2 is a sectional view taken from the cutting plane line - in FIG. 4 is a perspective view showing a part of the lid member 81, FIG. 5 is a Rosin-Ramula diagram explaining the classification operation of the vertical mill 40, and FIG. 6 includes the vertical mill 40. A system diagram of the configuration, FIG. 7 is a perspective view showing the configuration for driving the lid member 81, and FIG.
FIG. 9 is a sectional view of the conventional vertical mill 1.
10 is a Rosin-Ramler diagram explaining the classification operation of the vertical mill 20, FIG. 11 is a sectional view of a third conventional vertical mill 30, Fig. 12 is a sectional view of the fourth vertical mill, Fig. 13 is a perspective view of the collision member of the vertical mill shown in Fig. 12, and Fig. 14 is a rosin illustrating the classification operation of the vertical mill shown in Fig. 12.・It is a Ramla diagram. 40...Vertical mill, 41...Casing, 49
...Blower port, 52...First rotor blade, 54, 79...
... Fixed ring member, 55 ... Drive means, 56 ... Rotating shaft, 57 ... Ceiling plate, 58 ... Collision member, 62,
82...Through hole, 63...Classifier, 64...Discharge duct, 72...Collision blade, 73...Classifier, 77
... Nozzle, 78 ... Second rotary blade, 81 ... Lid member, 84 ... Opening.

Claims (1)

[Claims] 1. In a casing to which gas and powder are supplied from below, an inverted truncated cone with an open lower end is provided above the table, and the cone is connected to the ceiling plate of the casing. In between, a large number of impingement vanes that can be angularly displaced about the vertical axis are arranged in the circumferential direction, and inside these impingement vanes and cones, below the ceiling plate of the casing, they are driven to rotate about the vertical axis of rotation. Two upper and lower rotor blade groups, a second rotor blade and a first rotor blade, are integrally formed via a fixed ring member, and each of the rotor blades of the first rotor blade group has a lower end portion spaced apart from each other in the circumferential direction. is fixed on the support member, and the second rotor blade group has a smaller number of rotor blades than the first rotor blade group, and the upper end portions of the second rotor blade group are fixed to the fixed ring member at intervals in the circumferential direction. A cylindrical collision member that surrounds the second rotor blade and is suspended from the ceiling plate of the casing and has a plurality of through holes formed at intervals in the circumferential direction, and a collision member that is radially outwardly provided. and a lid member that slides along the outer circumferential direction of the collision member and adjusts the opening area of the through-hole portion of the collision member, whereby the second rotary blade is rotated during the first rotation. It has classification characteristics different from those of the blades, and the fineness of the powder and granular material is variable. Above these rotary blade groups, there is an outlet for mixing and discharging the gas and powder from each rotor blade group. A classifier characterized by being provided with.