JP2654993B2 - Vertical crusher - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vertical crusher for crushing cement raw materials, coal, chemicals and the like by cooperation of a rotary table and crushing rollers.

[Prior Art] A vertical pulverizer having a rotary table and a pulverizing roller is widely used as a type of pulverizer that pulverizes fluids such as cement raw materials, coal, and chemicals into fine powders. This kind of crusher is press-contacted with a hydraulic pressure or the like at a lower part of a cylindrical casing, which is driven by a motor with a speed reducer and rotates at a low speed, and at a location where an outer peripheral portion of the upper surface is equally divided in a circumferential direction. And a plurality of rollers that are driven and rotated.

For example, in FIG. 7 which shows a conventional vertical pulverizer, the pulverizer generally denoted by reference numeral 1 is externally formed as a single tower body, and has a motor (motor) 2 and a speed reducer 17 at its base.
The rotating table 3 rotated by the rotation is disposed.
A plurality of conical pulverizing rollers 4 are arranged so as to rotate while being in sliding contact with the rotary table 3, and the pulverizing rollers 4 are rotatably supported by 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 turning arm 7 is further fixed to the support shaft 6, and the turning arm 7 extends downward through the side of the casing 8 surrounding the turntable 3, and faces the lower space of the crusher. I have. The lower end of the rotary arm 7 is rotatably supported on the tip of a rod 10 of a pressure cylinder 9 whose lower end is rotatably mounted on the base of the crusher 1.

The fluid as a raw material supplied to the center of the rotary table 3 by a supply pipe (not shown) is caught and pulverized between the roller 4 driven by the rotation of the table and the rotary table 3. On the other hand, hot air is guided into the casing 8 by a duct (not shown), and the hot air blows up from an annular space portion 14 between the outer peripheral surface of the turntable 3 and the inner peripheral surface of the casing 8. The fine powder rises in 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 step.

Although some of the coarse particles also rise in the crusher 1, they are classified by the rotating blades 15 of the upper separator and returned to the rotating table 3.

One of the types widely used as a structure of this separator is a rotary separator, in which a rotating shaft 13 is provided in a classifying section, and a plurality of rotating blades 15 are fixedly mounted on the rotating shaft 13 at an equal pitch. It is rotated at an arbitrary rotation speed together with the shaft.

FIG. 8 is a horizontal sectional view showing a schematic arrangement of the blades 15 of the rotary separator. The blades 15 have a substantially L-shaped cross-section, and the L-shaped bent portion is located inside the separator. They are arranged in a ring and radially.

By rotating the blades 15 together with the rotary shaft 13, fine particles are separated from the airflow passing between the blades 15 and flowing into the separator. The principle of this classification is outlined with reference to FIG. .

In FIG. 9, when the rotating blade is rotating counterclockwise at a constant rotation speed (rotation speed V), particles flowing from an arbitrary point P of an arc CD formed by the outer diameter end of the rotating blade are:
Draws an arbitrary trajectory according to the particle diameter due to the combined force such as the resistance force (inward flow) and the centrifugal force (outward flow) due to the incoming airflow and the effect of the air layer between the rotating rotating blades. Go inside the separator. That is, a small fine powder of particle size passes between A~E draw a trajectory a _1, intermediate powder locus a ₃ between A-B, coarse powder with locus a ₅ between B-C,
It reaches the inner wall of the rotating blade 15.

The particles abutting between B and C do not lose their kinetic energy, and are subsequently discharged radially outward along B and C by the action of centrifugal force.

On the other hand, among the intermediate particles that have arrived between A and B, the particles that move outward due to the centrifugal force escape to the outside of the separator along the BC wall in the same manner as the particles that have come into contact between B and C. However, if the inward force due to the airflow balances with the centrifugal force between A and B, or if the inward force is larger than the centrifugal force, the particles fall along A and B and return below the separator.

Thus, as shown in FIG. 7, the conventional rotary separator has a configuration in which the diameter increases as it goes upward. in this case,
Since the rotating blades rotate integrally, the rotational peripheral speed of the rotating blades increases as it goes upward. In addition, the airflow that rises in the casing sequentially passes between the rotating blades from the lower part of the separator, so that the remaining airflow passes between the rotating blades as the separator goes upward. In other words, the flow rate of the air flow decreases as the distance increases, and accordingly, the flow velocity of the air flow decreases as the distance increases.

[Problem to be Solved by the Invention] In the rotary separator configured as described above, the inflow air volume, the inflow velocity, the particle size distribution, and the rotation of the separator including the dust-containing airflow passing between the rotary blades. Even if the number is constant and does not change, the gradient of the classification point of the classification performance characteristic curve is gentle as shown in FIG. 5, and the classification accuracy, in other words, the classification is not so crucial. That is, a large amount of coarse powder is mixed in the fine powder, and a small amount of fine powder is mixed in the returned powder.

On the other hand, as shown in FIG. 6, there is a case where the grade of the classification point of the classification performance characteristic curve is steep and it is desired to obtain a product having a sharp particle size distribution with a high classification accuracy by the same crusher. As long as the angle with the axis (hereinafter referred to as “blade angle θ”) is fixed, the particle size distribution as shown in FIG. 6 cannot be obtained.

5 and 6, the horizontal axis is the particle diameter D,
Ordinate allocation rate (partial classification efficiency) Z _R, shows the ratio of Modokona and Nyukona for certain particle size D.

Means for Solving the Problems The present invention is intended to change the particle size distribution of a product by using the same pulverizer, and to change the particle size distribution as necessary during operation. As means, an opening for airflow of fine powder is provided at the top of the casing,
A separator is installed at an upper part in the casing, and the separator is supported by the rotating shaft installed in a vertical direction and the rotating shaft, and is arranged in an annular and radial manner around the rotating shaft. In the vertical pulverizer having a rotary separator having a rotating blade, the rotating shaft is a double tube in which the outer tube can advance and retreat in the axial direction with respect to the inner tube, the lower part of the rotating blade Bearings and bearings that are pin-joined to a support fixed to the inner pipe and that are pin-joined to the upper part of the rotary blade and the outer pipe, respectively, and to support the inner pipe load on the upper part of the inner pipe. And a fixed disk supporting bearings disposed on both upper and lower surfaces of an upper end flange of the outer tube, and a hydraulic cylinder fixedly connected to the fixed disk with a pin is fixedly mounted on the outer tube. It has the structure which has an axial direction reciprocation means.

[Operation] In the rotary separator, the increase in the rotation speed of the separator and the decrease in the air flow velocity when passing between the blades of the separator are factors that reduce the classification point (particle size). Act as on the other hand,
The decrease in the peripheral speed of the separator and the increase in the air flow velocity act as factors for increasing the diameter of the classification point.

Thus, in the conventional vertical crusher, the rotary separator has a configuration that expands upward as shown in FIG. In such a rotary separator, the particle diameter serving as the classification point shifts rapidly toward the smaller diameter as the rotational speed increases and the factor for reducing the diameter of the classification point increases due to the decrease in the air flow velocity. Conversely, the classification point is on the large diameter side below the separator, and the classification point is on the small diameter side upward.

As a result, the classification points of the entire separator were distributed over a wide range, and only products having a particle size distribution shown in FIG. 5 were obtained.

On the other hand, when it is desired to obtain a product having a particle size distribution shown in FIG. 6, the diameter is smaller at the upper part of the rotary blade than at the lower part, and the peripheral speed is smaller at the upper part. The diameter reduction factor cancels out the classification point diameter reduction factor due to the decrease in the air flow velocity, so that the classification points substantially coincide with each other at the upper and lower positions of the rotating blade, thereby achieving sharp classification.

That is, to obtain a product having sharp classification characteristics as shown in FIG. 6, the rod of the hydraulic cylinder is advanced,
The outer pipe is raised upward with respect to the inner pipe of the rotary shaft so that the upper diameter of the rotary blade is smaller than the lower diameter.

Embodiment An embodiment will be described below with reference to the drawings.

1 to 4 show an embodiment of the present invention. FIG. 1 is a side view showing a schematic configuration of a rotary separator, and FIG. 2 is an explanatory view showing a state of rotating blades of the separator. ) Shows a state in which the blade angle θ ₁ is positive (the upper part of the blade has a large diameter), (b) shows a state in which the blade angle θ ₂ = 0, and (c) shows a state in which the blade angle θ ₃ is negative (the upper part of the blade has a small diameter). Show. FIG. 3 is a plan view taken along the line III-III in FIG. 1, and FIG. 4 is an enlarged vertical sectional view of a main part of a bearing portion of the separator.

In the figure, reference numeral 20 denotes a center chute for supplying a pulverized raw material, around which a double pipe, that is, an inner pipe 13 is concentrically formed.
a and an outer tube 13b are provided, and each constitutes a rotating shaft 13 of the separator. The rotating blades 15 having an L-shaped cross section arranged at equal intervals on a plurality of circumferences are pin-joined via a pin 13e and a support 13c having a lower end protruding from the inner tube 13a. Are connected between the outer tube 13b and the rotary blade 15 by beams 13d, both ends of which are joined by pins 13e, 13e.

As shown in FIG. 3, the inner tube 13a and the outer tube 13b are slidably and vertically reciprocally movable by fitting a projection 13f provided on the inner tube 13a and a groove 13g provided on the outer tube 13b. It can rotate. 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. As the bearings 21a and 21b, those in which a rotating shaft fitted to the bearing can slide in the axial direction are used. Or the fourth
As shown in the figure, a sphere or cylinder embedded in the inner surface of the bearing housing inside the inner race of the bearings 21a and 21b may be used.

On the other hand, the inner pipe 13a is supported by a thrust bearing 23a provided at the center of the uppermost flat plate 24a of a gantry 24 fixed on the casing 18 at the upper part. A chain wheel 40 is fitted on the uppermost end of the inner tube 13a, and is driven by a chain via a chain wheel attached to a rotating shaft of the variable speed motor.

Further, thrust bearings 23a and 23b are disposed and accommodated in bearing housings provided on the fixed disk 25 on both upper and lower surfaces of a flange provided on the uppermost end of the outer tube 13b, and a casing is provided on the lower surface of the fixed disk 25. A piston rod of a hydraulic cylinder 27 fixed to the bearing housing 18 of the 18 is pin-joined by a pin 28. And, in order to suppress the rotation of the fixed disk 25,
An anti-rotation rod 26 that slides through the fixed disk 25 is provided upright.

Hydraulic cylinder 27, fixed disk 25, anti-rotation rod 2
6, the thrust bearings 23a, 23b, etc., constitute means for moving the outer tube 13b in the axial direction.

The operation of the separator configured as described above will be described. As shown in FIG. 2 (a) or FIG. 2 (b) or FIG. In order to change the angle, it is necessary to raise the outer tube 13b upward. For this purpose, when the oil is supplied to the head side of the hydraulic cylinder 27 and the rod is advanced, the outer tube
13b rises. Conversely, in order to change from the state shown in FIG. 2 (c) to the state shown in FIG. 2 (a), oil may be supplied to the rod side of the hydraulic cylinder 27 and the outer pipe 13b may be lowered.

These operations may be performed while the operation of the separator is stopped, but can be performed during the operation. In order to move up and down the plurality of hydraulic cylinders synchronously, it is necessary to take measures such as equalizing the pipe resistance from the hydraulic unit to each hydraulic cylinder. For this reason, a hydraulic unit (not shown) is provided on the machine side. It is desirable to set up.

FIG. 2 shows the angle (blade angle θ) formed by the rotating blades of the separator with respect to the rotation axis by the adjustment by these hydraulic cylinders.
₁ , θ ₂ , θ ₃ ) are changed, (a) is an inverted figure of eight, (b) is a parallel figure, and (c) is an figure of eight.

Note that the overall configuration of the vertical pulverizer incorporating the separator described above is the same as that in FIG. 7, and a description thereof will be omitted.

The classification effect of the separator of the present invention configured as described above will be described.

First, the operation in the case of FIG. 2C configured so that the diameter of the rotary separator becomes smaller as it goes upward will be described.

In this case, as described above, the rotational peripheral speed becomes lower toward the upper part of the separator, and this acts as a factor for increasing the diameter of the classification point. In addition, the airflow velocity passing between the rotating blades becomes smaller toward the upper side, and this acts as a factor for reducing the diameter of the classification point. In the present invention, these opposing actions cancel each other out, so that the classification point is substantially the same as that of the lower part of the separator even when the separator reaches the upper side, and the sharp classification is performed as a whole of the separator.

Next, pockets provided on the upper and lower edges of the rotating blades
The operation of 15a, 15c will be described 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 caused by the inward force due to the inward airflow and the rotation of the gas sandwiched between the rotating blades. It receives the centrifugal force that occurs and the apparent force that is opposite to the rotation in the circumferential direction that occurs as the rotating blades rotate. Then, in FIG. 10, the particles having an arbitrary particle diameter passing through the point P draw a locus such as b ₁ , b ₂ , b ₃ according to the particle diameter. That is, the fine powder b ₁ passes through the separator, and the coarse powder hits the rotating blades as b ₂ and b ₃ , and then reaches the pocket 15 a at the inner diameter end of the rotating blade and the pocket 15 c at the outer diameter portion, Thereafter, it slides downward or falls freely under its own weight, and is returned to the rotary table. Thus, if the pockets 15a and 15c are provided in this manner, the particles contained in the pockets are prevented from being re-scattered by the air current, and a sharp classification curve can be obtained. is there.

In the meantime, in the rotating blade having a simple L-shaped cross section shown in FIGS. 8 and 9, the particles falling along the space between A and B are constantly exposed to the inward airflow, and are easily scattered again. . Also, particles returned from the space between the BCs to the outside of the separator may be again air-flowed and flow into the separator.

Due to the phenomena described above, the particles that should be classified into the coarse powder side are originally mixed in the fine powder side. Therefore, the classification characteristics shown in FIG. 5 are exhibited, the gradient near the classification point is gentle, and the classification accuracy (classification is performed). Is reduced.

On the other hand, in this embodiment, one of the edges of the rotating blade,
Alternatively, pockets 15a and 15c are provided at both edges, and coarse powder that reaches the rotating blades is captured in the pockets 15a and 15c and reliably returned to the pulverizing section. For high crushers, the rotating blades 15 have pockets 15a,
It is better to provide 15c.

That is, of the particles starting from the point P in FIG. 10, flour into fine powder side draw a trajectory b _1, particles of more particle size in the rotary blade through such path b ₂ or b ₃ equivalents After contact, the powder slides down the pocket 15a, the corner B, the pocket 15c, etc., and returns to powder. And there is no re-scattering during this fall,
Further sharp classification is performed.

[Effects of the Invention] As described above, according to the present invention, the angle between the rotating blade and the rotating shaft is arbitrarily changed by moving the outer cylinder up and down with respect to the inner tube with the rotating shaft of the separator being a double tube. Since it is possible, products with different classification accuracy, that is, products with different particle size distributions can be arbitrarily obtained with the same pulverizer. In addition, since the angle of the rotating blades can be changed while the pulverizer and the separator are in operation and by remote control, it is easy to change the product fineness distribution.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a separator showing one embodiment according to the present invention, FIG. 2 is an explanatory view showing a state of a rotary blade, FIG. 3 is a plan sectional view taken along the line III-III of FIG. The figure is an enlarged longitudinal sectional view of a main part of a bearing portion of a separator, and FIGS. 5 and 6 are diagrams showing classification characteristics of fine powder. 7 to 9 relate to a conventional example, FIG. 7 is a schematic longitudinal sectional view, FIG. 8 is a sectional view, and FIG. 9 is a partially enlarged view of FIG. Also,
FIG. 10 is an explanatory diagram of the classification action. 3 ... Rotating table, 4 ... Pulverizing roller, 13 ... Rotating shaft, 13a ... Inner tube, 13b ... Outer tube, 13c ... Support, 13d
…… Beam, 13e …… Pin, 18 …… Separator casing, 20… Center chute, 21a, 21b …… Bearing, 23…
... thrust bearing 23a, 23b ...... thrust bearing, 24 ...... gantry, 25 ...... stationary disks, 26 ...... anti-rotation rod, 27 ...... hydraulic cylinders, 28 ...... pin, 40 ...... thien wheel, a ₁ , a
_{2, a 3, a 4,} a 5, b 1, b 2, b 3 locus of ...... particles, the incident position of P ...... _{particles, θ, θ 1, θ 2} , θ 3 ...... vane angle.

Claims (1)

(57) [Claims] An opening is provided at the top of the casing for airflow of fine powder, and a separator is provided at an upper portion in the casing. The separator is provided with a rotating shaft installed in a vertical direction and the rotating shaft. A vertical crusher having a rotary separator having a rotary blade supported on a shaft and having annular and radially arranged rotary blades around the rotary shaft; A beam in which the pipe is a double pipe capable of moving forward and backward in the axial direction, the lower part of the rotary blade is pin-joined to a support fixed to the inner pipe, and the upper part of the rotary blade is pin-joined to the outer pipe and the outer pipe, respectively. And a bearing for supporting the load on the inner pipe and a pedestal for bearing support are provided above the inner pipe, and fixed disks for supporting bearings disposed on both upper and lower surfaces of an upper end flange of the outer pipe are provided. , Fix the hydraulic cylinder that is pin-joined with the fixed disc Vertical crusher having an axial reciprocating motion means of the outer tube with.