JPH0347545A - Vertical grinder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides the following advantages:
This relates to a vertical crusher that crushes cement raw materials, coal, chemicals, etc.

[Prior Art] Vertical pulverizers equipped with a rotary table and pulverizing rollers are widely used as a type of pulverizer for finely pulverizing fluids such as cement raw materials, coal, and chemicals into powder. This type of crusher consists of a disk-shaped rotary table that is driven by a motor with a reducer to rotate at low speed in the lower part of a cylindrical casing, and a part that divides the outer circumference of the upper surface into equal parts in the circumferential direction, which is pressed by hydraulic pressure or the like. It is equipped with a plurality of rollers that are driven to rotate.

For example, in FIG. 7, which shows a conventional vertical crusher, the crusher, which is designated by the symbol l as a whole, is externally formed as a single tower body, with an electric motor 2 and a speed reducer 17 at its base.
A rotary table 3 rotated by a rotary table 3 is disposed.

A plurality of conical crushing rollers 4 are arranged to rotate in sliding contact with the rotary table 3, and the crushing rollers 4 are rotatably supported on a support arm 5. The support arm 5 is fixed to a support shaft 6 rotatably supported on the crusher side. One end of a rotating arm 7 is further fixed to this support shaft 6, and this rotating arm 7 extends downward through the side of a casing 8 surrounding the rotating table 3, and faces the lower space of the crusher. There is. The lower end of the rotary arm 7 is rotatably supported on the tip of a rod 10 of a pressure cylinder 9, which is rotatably supported at the lower end of the base of the crusher l.

Then, a supply pipe (not shown) is connected to the center of the rotary table 3.
The fluid supplied as the raw material is caught between the driven roller 4 and the rotary table 3 by the rotation of the table and is pulverized. On the other hand, hot air is guided into the casing 8 by a duct (not shown), and this hot air blows up from the annular space 14 between the outer peripheral surface of the rotary table 3 and the inner peripheral surface of the casing 8. The fine powder rises inside the crusher 1 while being dried, and is discharged from the discharge pipe 16 as a mixture with hot air and sent to the next process.

Note that some of the coarse particles also rise within the crusher 1, but are classified by the rotating blades 15 of the upper separator and returned onto the rotating table 3.

One type of separator that is widely used is a rotary separator, in which a rotating shaft 13 is provided in the classification section, and a plurality of rotating blades 15 are fixed to the rotating shaft 13 at equal pitches. It is rotated along with the shaft at an arbitrary rotation speed.

FIG. 8 is a horizontal cross-sectional view showing a schematic arrangement of the blades 15 of the rotary separator.
They are arranged in an annular and radial manner.

As this blade 15 rotates together with the rotating shaft 13,
Fine particles are separated from the airflow passing between the blades 15 and flowing into the separator, and the principle of this classification will be outlined with reference to FIG. 9.

In Fig. 9, when the rotating blade is rotating counterclockwise at a constant rotation speed (rotational speed ■), particles flowing from an arbitrary point P on the arc CD formed by the outer diameter end of the rotating blade are Resistance force due to airflow (inward flow) and centrifugal force (outward flow)
Under the influence of the air layer between adjacent rotating blades, the fine powder moves toward the inside of the separator while tracing an arbitrary trajectory depending on the particle size. In other words, fine powder with a small particle size follows the trajectory al. It passes between A and E, and the middle grain is A.
-B trajectory a3. The coarse powder traces a trajectory a5 between B-0 and reaches the inner wall of the rotating blade 15.

The particles that have come into contact between B and 0 do not lose their kinetic energy, and are then ejected radially outward along the B and 0 space due to the action of centrifugal force.

On the other hand, among the intermediate particles that have arrived between A and B, particles that move outward due to centrifugal force escape along the BC wall to the outside of the separator in the same way as the particles that abutted between B and C. However, if the inward force due to the airflow balances the centrifugal force between A and B, or if the inward force exceeds the centrifugal force, the particles fall along the line A and B and are returned below the separator.

As shown in FIG. 7, the conventional rotary separator has a configuration in which the diameter increases at the upper end. In this case, since each rotating blade rotates integrally, the peripheral rotational speed of the rotating blade increases in the upper direction. Furthermore, since the airflow rising inside the casing sequentially passes between the rotating blades from the lower part of the separator, the remaining airflow passes between the rotating blades at the upper part of the separator. In other words, the amount of air passing through the separator becomes smaller above the separator, and therefore the flow rate of the air flowing above the separator becomes smaller.

[Problems to be Solved by the Invention] In the rotary separator configured as described above, the inflow volume of dust-containing air passing between the rotary blades,
Even if the inflow rate is 1 particle size distribution and the separator rotation speed is constant and does not change, the gradient of the classification point of the classification performance characteristic curve is gentle as shown in Figure 5, and the classification accuracy, in other words, the classification It's not very sharp. That is, a large amount of coarse powder is mixed into the fine powder, and a considerable amount of fine powder is mixed into the returned powder.

On the other hand, as shown in Figure 6, there are cases where the slope of the classification point of the 1-classification performance characteristic curve is steep and it is desired to obtain a product with a sharp particle size distribution with classification accuracy using the same crusher. As long as the angle formed with the axis (hereinafter referred to as "blade angle θ") is fixed, the th.

A particle size distribution as shown in Figure 6 cannot be obtained.

In addition, the horizontal axis of FIGS. 5 and 6 is the particle size, and the vertical axis is the distribution ratio (partial classification efficiency) ZR, which indicates the ratio of the amount of returned powder to large particles for a certain particle size. .

[Means for Solving the Problems] The present invention provides particle size distribution of the product by using the same crusher,
Moreover, it is designed to be changed as necessary during operation, and as a means for this purpose, an opening is provided at the top of the casing for air flow of fine powder, and a separator is installed at the top of this casing. This separator is a rotary separator equipped with a rotating shaft installed in the vertical direction and rotating blades supported by the rotating shaft and arranged annularly and radially around the rotating shaft. In this vertical crusher, the rotary shaft is a double tube in which the outer tube can move forward and backward in the axial direction with respect to the inner tube, and the lower part of the rotary blade is attached to a support fixed to the inner tube. A beam is connected to the upper part of the rotary blade and the outer pipe by a pin, and a bearing for supporting the load of the inner pipe and a frame for supporting the bearing are provided at the upper part of the inner pipe, and a beam is connected to the upper part of the rotating blade and the outer pipe. A compression spring is disposed on the lower surface of the upper end flange via a bearing, and a hydraulic cylinder is connected between the upper surface of the upper end flange and the upper part of the mount via a bearing. The configuration has the following.

[Function] In a rotary separator, an increase in the rotational speed of the separator and a decrease in the airflow velocity when passing between the blades of the separator are factors that reduce the classification point (particle size). It acts as. On the other hand, a decrease in the rotational circumferential speed of the separator and an increase in the airflow velocity act as factors that increase the diameter of the classification point.

However, in the conventional vertical crusher, the rotary separator has a shape that expands upward, as shown in FIG. In such a rotary separator, the factors that reduce the diameter of the classification point due to the increase in the rotational circumferential speed and the decrease in the airflow velocity are synergistic in the upper direction.

The particle size, which is the classification point, rapidly shifts to the smaller diameter side. Conversely, below the separator, the classification point is on the large diameter side, and above the separator, the classification point is on the small diameter side.

Therefore, when looking at the separator as a whole, the classification points came to be distributed over a wide range, and only a product with the particle size distribution shown in FIG. 5 could be obtained.

On the other hand, when it is desired to obtain a product with the particle size distribution shown in Fig. 6, the diameter of the upper part of the rotating blade is smaller than that of the lower part, and the peripheral speed of rotation of the upper part is made smaller. The diameter-increasing factor offsets the classification point diameter-reducing factor due to the decrease in airflow velocity, so that the classification point substantially coincides at any position above or below the rotary blade, thereby achieving sharp classification.

In other words, if you want to obtain a product with sharp classification characteristics as shown in Figure 6, the outer tube is moved against the inner tube of the rotating shaft by retreating against the compression force of the rod compression spring of the hydraulic cylinder. Raise it upward to make the upper diameter of the rotating blade smaller than the lower diameter.

[Example] Examples will be described below based on the drawings.

1 to 4 show examples of the present invention, FIG. 1 is a side view showing the schematic structure of a rotary separator, and FIG. 2 is an explanatory diagram showing the state of the rotating blades of the separator. ) shows a state in which the blade angle θ1 is positive (the upper part of the blade has a large diameter), (b) shows a state in which the blade angle θ2 = 0, and (C) shows a state in which the blade angle θ3 is negative (the upper part of the blade has a small diameter). 3 is a plan view taken along the line m-m in FIG. 1, and FIG. 4 is an enlarged vertical sectional view of a main part of the bearing portion of the separator.

In the figure, 20 is a center chute for supplying pulverized raw materials, and a double pipe is arranged concentrically around this center chute, that is, an inner pipe 1
3a and an outer tube 13b, each of which constitutes a rotating shaft 13 of the separator. A plurality of rotary blades 15 each having a cross-section shaped like a letter L and arranged at equal intervals around the circumference have their lower ends connected to the inner tube 1.
The outer tube 13 is pin-connected via a pin 13e to a support 13c protruding from 3a, and is connected to the outer tube 13 at the upper part of the one-rotation blade 15.
pins 13e at both ends between b and the rotating blade 15.

They are connected by a beam 13d that is pin-joined at 13e.

The inner tube 13a and the outer tube 13b are connected to the inner tube 13 as shown in FIG.
By fitting the protrusion 13f provided on the outer tube 13a with the groove 13g provided on the outer tube 13b, the outer tube 13b can be slid in a reciprocating manner in the vertical direction, and can also rotate as a unit. The outer tube 13b is supported by bearings 21a and 21b housed in a bearing housing 18a provided on the casing 18 of the separator, and is kept airtight by an air seal 22. Bearing 21
A and 21b are those in which a rotating shaft fitted in a bearing is slidable in the axial direction. Alternatively, as shown in Figure 4,
It is also possible to use a ball or cylinder embedded in the inner surface of the bearing housing inside the inner race of the bearings 21a, 21b.

On the other hand, the inner 'fil 3a has the casing 18 at the top.
It is supported by a thrust bearing 23a provided in the uppermost plane plate 24a of the pedestal 24 which is erected and fixed above.

A chain wheel 40 is fitted to the uppermost end of the inner tube 13a, and is driven by a chain via a chain wheel 41 attached to the rotating shaft of a variable speed electric motor 42.

A compression spring (compression coil spring) 3 is attached to the lower surface of the flange provided at the uppermost end of the outer tube 13b via a bearing 31.
A plurality of cylindrical hydraulic cylinders 27 are disposed on the upper surface of the flange via a thrust bearing 23b and a fixed plate 25, and the rod end thereof is connected to the uppermost plane plate 2 of the pedestal 24.
It is pin-jointed to the lower surface of 4a. In order to prevent rotation of the fixed plate 25, a rotation prevention rod 26 is provided to slide through the fixed plate 25.

The above hydraulic cylinder 27. Compression spring 32. Fixed plate 259
Anti-rotation rod 26. Bearing 23a.

23b, 31, etc. constitute means for moving the outer tube 13b forward and backward in the axial direction.

To explain the operation of the separator section configured as described above, from the state shown in FIG. 2(a) to the state shown in FIG. 2(b) or FIG. 2(C), the rotation blade 15 and the axial direction are In order to change the angle of the outer tube 13b, it is necessary to raise the outer tube 13b upward, and to do so, oil is supplied to the rod side of the hydraulic cylinder 27 and the rod is moved back.
The expansion force of the compression spring 32 causes the outer tube 13b to rise.

Conversely, in order to change from the state shown in FIG. 2(C) to the state shown in FIG. 2(a), it is sufficient to supply oil to the head side of the hydraulic cylinder 27 and lower the outer tube 13b against the force of the spring.

These operations may be performed while the operation of the separator is stopped, but of course they can also be performed during operation. In addition,
In order to move multiple hydraulic cylinders up and down synchronously, consideration must be given to equalizing the piping resistance from the hydraulic unit to each hydraulic cylinder, so the hydraulic unit (not shown) is installed on the machine side. This is desirable.

Figure 2 shows the angle (blade angle θ 1
, θ2. θ3) shows a changed situation, where (&) has a reversed character shape, (b) has a parallel shape, and (C) has a reversed character shape.

The overall configuration of the vertical crusher incorporating the separator described above is the same as that shown in FIG. 7, so its explanation will be omitted.

The classification action of the separator of the present invention constructed as above will be explained.

First, the operation in the case of FIG. 2(C), in which the diameter of the one-rotation separator is configured to become smaller upwardly, will be explained.

In this case, as mentioned above, where is the upper part of the separator?

The circumferential rotational speed decreases, which acts as a factor that increases the diameter of the classification point. In addition, the velocity of the air passing between the rotating blades becomes smaller in the upper direction, and this acts as a factor that reduces the diameter of the classification point.In the present invention, these contradictory effects cancel each other out, , the classification point is almost the same as the lower part of the separator, and the entire separator is classified sharply.
The actions of 5a and 15c will be explained with reference to FIG.

In FIG. 10, the particles P flowing at a predetermined speed between the rotating blades 15 of the separator and the adjacent rotating blades 15 are
It is subjected to an inward force due to the inward airflow, a centrifugal force caused by the rotation of the gas sandwiched between the rotating blades, and an apparent force in the opposite direction of rotation in the circumferential direction caused by the rotation of the rotating blades. In FIG. 10, particles of any particle size that have passed through point P are:

Depending on the particle size, bl, b2. Draw a trajectory like b3, that is, fine powder b1 passes through the separator, coarse powder passes b
2. After hitting the rotating blade as shown in b3, there is a pocket (15a) on the inner diameter end of the rotating blade and a pocket 15c on the outer diameter part.
After that, it slides downward or falls freely due to its own weight, and is returned to the rotary table. By providing the pockets 15a and 15c in this way, the particles accommodated in these pockets are prevented from being agitated by the air current and being dispersed again, making it possible to perform classification with a sharp classification curve. be.

Incidentally, in the rotary blade with a simple L-shaped cross section shown in Figure 8.9, the particle group falling along the A-B line etc. is constantly exposed to the inward airflow and is likely to be re-dispersed. Furthermore, the particles returned to the outside of the separator from between the BCs can be carried by airflow again and flow into the separator.

Due to the above phenomenon, particles that should normally be classified as coarse particles are mixed in fine particles, resulting in the classification characteristics shown in Figure 5, where the slope near the 1st classification point is gentle and the classification accuracy (classification ) decreases.

In contrast, in this embodiment, pockets 15a and 15c are provided on one or both edges of the rotary blade, and the coarse powder that has reached the rotary blade is captured in these pockets 15a and 15c, ensuring that it is pulverized. Therefore, it is better to provide pockets 15a and 15c in the rotary blade 15 of a crusher that frequently produces products with particularly high classification accuracy.

That is, among the particles starting from point P in Fig. 10, fine powder follows a trajectory b1 toward the fine powder side, and particles with a larger particle size follow a trajectory b2 or b3, etc., and then come into contact with the rotating blade. , blur) 15a, corner B, pocket 150, etc., and slides and falls to become returned powder. Further, there is no re-scattering during this fall, and even sharper classification is performed.

[Effects of the Invention] As described above, according to the present invention, the rotation axis of the separator is made into a double tube, and the angle between the rotating blade and the rotation axis can be arbitrarily changed by raising and lowering the outer tube with respect to the inner tube. Therefore, products with different classification accuracies, that is, products with different particle size distributions, can be arbitrarily obtained using the same pulverizer. Moreover, since the rotary blade angle can be changed by remote control while the crusher and separator are in operation, it is easy to change the product powder distribution.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a separator showing one embodiment of the present invention, FIG. 2 is an explanatory view showing the state of the rotating blade, FIG. The figure is an enlarged vertical cross-sectional view of the main part of the bearing part of the separator, and FIGS. 5 and 6 are diagrams showing the classification characteristics of refined powder. 7 to 9 relate to a conventional example, in which FIG. 7 is a schematic vertical sectional view, FIG. 8 is a sectional view, FIG. 9 is a partially enlarged view of FIG.
Figure 0 is an explanatory diagram of the classification action. 3... Rotating table, 4... Grinding roller, 13... Rotating shaft, 13a...
・Inner tube, 13b... Outer tube, 13c...
Support, 13d...Beam, L3e...
・Bin, 18...Separator casing, 2
0... Center chute, 21a, 21b... Bearing. 23a, 23b... Thrust bearing, 24... Frame, 25... Fixed plate, 26... Anti-rotation rod, 27... Hydraulic cylinder, 28・・・・・・
Pin, 31...Bearing, 32...
...Compression spring, 40...Chain wheel, 41...Chain wheel, 42...Variable speed electric motor, a1. a2. a3. a4. a5
．． bl, b2. b3 ''Particle trajectory. P... Particle incident position, o, Ol, θ2.θ3... Blade angle.

Claims (1)

[Claims] The top of the casing is equipped with an opening for the air flow of refined powder, and a separator is installed in the upper part of this casing.
In a vertical crusher equipped with a rotary separator supported by the rotating shaft and having rotating blades arranged annularly and radially around the rotating shaft, the rotating shaft is connected to the inner tube. The outer tube is made into a double tube that can move forward and backward in the axial direction, and the lower part of the rotating blade is pin-joined to a support fixed to the inner tube,
A beam is connected to the upper part of the rotary blade and the outer pipe by a pin, and a bearing for supporting the load of the inner pipe and a frame for supporting the bearing are provided at the upper part of the inner pipe, and an upper end flange of the outer pipe is provided. A vertical shaft having a compression spring disposed on the lower surface of the outer tube via a bearing, and a means for moving the outer tube back and forth in the axial direction, the outer tube having a hydraulic cylinder connected via a bearing between the upper surface of the upper end flange and the upper part of the pedestal. mold crusher.