JPH0677691B2 - Vertical crusher - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vertical crusher for crushing cement raw material, coal, scientific products, etc. by cooperation of a rotary table and a crushing roller.

[Prior Art] As a kind of crusher for finely crushing fluid such as cement raw material, coal, and scientific products into powder, a vertical crusher equipped with a rotary table and a crushing roller is widely used. This type of crusher is a disk-shaped rotary table that is driven by a motor with a speed reducer and rotates at a low speed in the lower part of a cylindrical casing, and is pressed by hydraulic pressure or the like to a portion that equally divides the outer peripheral portion of the upper surface in the circumferential direction. And a plurality of rollers that are driven to rotate.

For example, in FIG. 6 showing a conventional vertical crusher, the crusher generally indicated by reference numeral 1 is formed as a single tower in appearance, and its base is rotated by an electric motor (motor) 2 and a speed reducer 17. The rotary table 3 is arranged. A plurality of conical grinding rollers 4 are arranged so as to rotate in sliding contact with the rotary table 3, and the grinding rollers 4 are rotatably supported by a support arm 5. The support arm 5 is fixed to a support shaft 6 which is rotatably supported on the crusher side. One end of a rotary arm 7 is further fixed to the support shaft 6, and the rotary arm 7 extends downward through a side of a casing 8 surrounding the rotary table 3 to face a lower space of the crusher. There is. The lower end of the rotating arm 7 is rotatably supported by the tip of a rod 10 of a pressure cylinder 9 whose lower end is rotatably supported by the base of the crusher 1.

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

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

And, one of the types widely used as the structure of this separator is a rotary separator, the rotary shaft 13 is provided in the classifying unit, a plurality of rotary vanes 15 are fixed to the rotary shaft 13 at an equal pitch, It is rotated at an arbitrary speed with the shaft.

FIG. 7 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 sectional shape, and the L-shaped bent portion is on the inside of the separator. It is annularly and radially arranged.

The rotation of the blades 15 together with the rotary shaft 13 separates the fine particles from the air flow passing through the blades 15 and flowing into the separator.
Outline with reference to the figure.

In FIG. 8, when the rotary blade is rotated counterclockwise at a constant rotation speed (rotation speed V), particles flowing in from any one point P of the arc CD formed by the outer diameter end of the rotary blade are inflowed. A separator that draws an arbitrary trajectory according to the particle size by receiving a combined force such as the resistance force (inward flow) and centrifugal force (outward flow) due to the air flow that occurs and the influence of the air layer between adjacent rotating blades that rotate. Head inside. That is, fine powder with a small particle size draws a locus a ₁ and passes between A and E, and intermediate powder A to B
The locus a ₃ between them and the coarse powder draw the locus a ₅ between B and C and reach the inner wall of the rotary blade 15.

The particles abutting between B and C lose their kinetic energy, and then are discharged radially outward along B and C by the action of centrifugal force.

On the other hand, among the intermediate particles reaching between A and B, the particles that move outward due to centrifugal force escape to the outside of the separator along the BC wall in the same manner as the particles contacting between B and C above. But,
Between A and B, the inward force due to the air flow is balanced with the centrifugal force, or in the case of particles whose inward force exceeds the centrifugal force, they fall along A and B and are returned below the separator.

Thus, as shown in FIG. 6, the conventional rotary separator has a shape configuration in which the diameter increases as it goes upward. In this case, since each rotary blade rotates integrally, the rotational peripheral speed of the rotary blade becomes higher as it goes upward. Further, since the airflow rising in the casing sequentially passes between the rotary blades from the lower part of the separator, the remaining airflow passes between the rotary blades toward the upper side of the separator. In other words, this air flow passage amount becomes smaller as it goes up the separator, and therefore the flow velocity of the air flow also becomes smaller as it goes up the separator.

[Problems to be Solved by the Invention] In the rotary separator configured as described above, the inflow amount of the dust-containing airflow passing between the rotating blades,
Even if the inflow velocity, the particle size distribution, and the rotation speed of the separator are constant and do not change, the gradient of the classification point of the classification performance characteristic curve is gentle as shown in FIG. 4, and the classification accuracy, in other words, classification It's not too rusty. That is, a large amount of coarse powder is mixed in the fine powder, and a large amount of fine powder is mixed in the returned powder.

On the other hand, as shown in Fig. 5, there is a case where it is desired to obtain a product having a sharp particle size distribution with a sharp classification accuracy by using the same grinder, but the rotary blades are As long as the angle (hereinafter referred to as “blade angle θ”) formed with is fixed, the particle size distribution as shown in FIG. 5 cannot be obtained.

The horizontal axis in FIGS. 4 and 5 is the particle diameter D, and the vertical axis is the distribution ratio (partial classification efficiency) Z _R , which shows the ratio of the amount of returned powder to that of powder for a certain particle diameter D. Is.

[Means for Solving the Problem] The present invention is intended to change the particle size distribution of a product as needed by using the same crusher. As a means for that purpose, a refined powder is added to the top of the casing. The opening is provided for carrying out the air flow, and a separator is installed in the upper part of the casing. The separator is supported by the rotary shaft installed in the vertical direction and the rotary shaft. A vertical crusher comprising a rotary separator having a circularly-circular and radially-arranged rotary vanes, and a double tube in which an outer tube is axially forward / backward relative to an inner tube. The lower part of the rotary vane is pin-bonded to a support fixed to the inner tube, and the upper part of the rotary vane and the outer tube are respectively pin-bonded.

[Operation] In the rotary separator, the increase of the rotation speed of the separator and the decrease of the airflow velocity when passing between the blades of the separator are factors for reducing the classification point (particle diameter). Acts as. On the other hand, the decrease in the peripheral speed of rotation of the separator and the increase in the airflow velocity act as factors for increasing the diameter of the classification point.

In the conventional vertical crusher, however, the rotary separator has a shape configuration that expands upward as shown in FIG. In such a rotary separator, the diameter of the classification point is rapidly shifted toward the smaller diameter side as the upper part of the rotary separator increases and the factor of reducing the diameter of the classification point due to the decrease in the air flow velocity increases synergistically. On the contrary, the classification point is on the large diameter side below the separator, and the classification point is on the smaller diameter side toward the top.

Therefore, when viewed as the whole separator, the classification points are distributed over a wide range, and only the product having the particle size distribution shown in FIG. 4 is obtained.

On the other hand, when it is desired to obtain a product having the particle size distribution shown in FIG. 5, the diameter of the rotating blade is made smaller toward the upper side of the rotary blade compared to that at the lower side, and the peripheral speed of rotation is reduced toward the upper side, thereby increasing the classification point. The sizing factor cancels out the sizing factor reducing factor due to the reduction of the air flow velocity, so that the sizing points are made to substantially coincide with each other at any position above and below the rotary blade, thereby achieving a sharp sizing.

That is, when it is desired to obtain a product having sharp classification characteristics as shown in FIG. 5, the outer tube is moved upward with respect to the inner tube of the rotary shaft so that the upper diameter of the rotary blade is smaller than the lower diameter. .

[Examples] Examples will be described below with reference to the drawings.

1 to 3 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 rotary blades of the separator, each of which (a) ) Shows a state where the blade angle θ ₁ is positive (the upper portion of the blade has a large diameter), (b) shows a state where the blade angle θ ₂ = 0, and (c) shows a negative state of the blade angle θ ₃ (the upper portion of the blade has a small diameter). Show. FIG. 3 is a plan sectional view taken along the line III-III in FIG.

In the figure, 20 is a center chute for crushing supply,
Around this, there are concentric double tubes, namely the inner tube 13a and the outer tube 1
3b are provided, and each constitutes a rotary shaft 13 of the separator. The rotary vanes 15 having an L-shaped cross section arranged at equal intervals on the circumference are pin-joined to each other via a pin 13e with a support 13c projecting from the inner pipe 13a at the lower end, and an outer pipe 13b at the upper part. And the rotary vane 15 are connected by a beam 13d which is pin-joined with pins 13e, 13e at both ends.

As shown in FIG. 3, the inner pipe 13a and the outer pipe 13b are slidably movable in the vertical direction by the fitting of the projection 13f provided on the inner pipe 13a and the groove 13g provided on the outer pipe 13b, and are integrally formed. And can be rotated. The outer tube 13b is supported by a bearing 21 provided in a casing 18 of the separator, and airtightly maintained by an air seal 22. To adjust the outer tube 13b in the vertical direction with respect to the inner tube 13a, as shown in FIG.
The outer pipe 13b with respect to the inner pipe 13a by rotating the bolt 23a that penetrates the upper end flange of the outer pipe 13b and the upper pipe of the outer pipe 13b, and is screwed with the nut 24 fixed to the upper surface of the upper end flange of the inner pipe 13a. Move up and down.

Regarding the drive of the rotary shaft of the separator, the inner tube 13a is extended upward, and a chain wheel is attached to the inner tube 13a to drive it by a variable speed electric motor via the chain. Alternatively, the bearing 21 of FIG.
A chain wheel may be attached directly above the outer tube 13b to drive the outer tube 13b.
Since it moves up and down when changing the blade angle θ, it is necessary to take this into consideration.

Further, a thrust bearing 31 is disposed immediately below the uppermost flange surface of the inner pipe 13a, and a pedestal 30 fixed to the upper surface 18 of the casing of the separator supports the entire load of the separator.

FIG. 2 shows the angles (blade angles θ ₁ , θ ₂ ,
θ ₃ ) has been changed, (a) is (B) is (C) is Is doing.

In this embodiment, bolt nuts are used as the lifting means for the outer tube 13b, but hoisting with a hydraulic cylinder or winch may be used.

The overall structure of the vertical crusher incorporating the separator described above is the same as that shown in FIG. 6, and the description thereof is omitted.

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

First, the operation in the case of FIG. 2 (c) in which the diameter of the rotary separator becomes smaller as it goes upward will be described.

In this case, as described above, the peripheral speed of rotation becomes smaller as it goes up the separator, which acts as a factor for increasing the diameter of the classification point. Further, the flow velocity of the air flow passing between the rotary vanes becomes smaller as it goes upward, which acts as a factor for reducing the diameter of the classification point. In the present invention, these contradictory effects cancel each other out, so that even when reaching the upper side, the classification point is almost the same as the lower part of the separator, and sharp classification is performed as the whole separator.

Next, pockets 15a provided on the upper and lower edges of the rotary blade,
The operation of 15c will be described with reference to FIG.

In FIG. 9, the particles P flowing into the rotary blades 15 adjacent to the rotary blades 15 of the separator at a predetermined speed are the centrifugal forces caused by the inward force of the inward air flow and the rotation of the gas sandwiched between the rotary blades. It receives an apparent force that rotates in the opposite direction in the circumferential direction due to the force and rotation of the rotating blades. And the ninth
In the figure, a particle having an arbitrary particle size passing through the point P draws a locus such as b ₁ , b ₂ , b ₃ according to the particle size. That is, the fine powder b ₁ passes through the separator, and the coarse powder hits the rotary vanes like b ₂ and b ₃ , then reaches the pocket 15a at the inner diameter end of the rotary vane and the pocket 15c at the outer diameter portion, After that, it slides down or falls freely by its own weight and is returned to the rotary table. Thus, when the pockets 15a and 15c are provided in this manner, the particles contained in the pockets are prevented from being re-scattered by being swirled by the air flow, and a sharp classification curve can be obtained. is there.

By the way, in the point-adding vanes having a simple L-shaped cross-section shown in FIGS. 7 and 8, the particle group falling along between A and B is
It is constantly exposed to the inward airflow and is easy to re-spray. Also, the particles returned to the outside of the separator from between BC,
It can be conveyed again by air flow and flow into the separator.

Due to the phenomenon described above, particles that should be classified on the coarse powder side are mixed on the refined powder side, so the classification characteristics shown in Fig. 4 are exhibited, and the gradient in the vicinity of the classification point is gentle and the classification accuracy (classification is performed). ) Is reduced.

On the other hand, in the present embodiment, pockets 15a and 15c are provided on one or both edges of the rotary blade, and the coarse powder that reaches the rotary blade is captured in the pockets 15a and 15c and reliably crushed. Since it is sent back to the machine, the rotating blade 15 and pockets 15a and 15
It is better to provide c.

That is, among the particles starting from the point P in FIG. 9, fine powder traces a locus b ₁ toward the fine powder side, and particles with a particle size larger than that trace
After coming into contact with the rotary blade through b ₂ or b _3, etc., the pocket 15a, the corner portion b, the pocket 15c, etc. are slidably dropped to give back powder. Further, there is no re-scattering during the fall, and a sharper classification is performed.

[Effects of the Invention] As described above, according to the present invention, the angle between the rotary blade and the rotary shaft is arbitrarily changed by using the rotary shaft of the separator as a double pipe and moving the outer cylinder up and down with respect to the inner pipe. Since it is possible, it is possible to arbitrarily obtain products with different classification accuracy, that is, products with different particle size distributions, with the same crusher.

[Brief description of 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 rotary blades, and FIG. 3 is a plan sectional view taken along the line III-III in FIG. FIG. 5 and FIG. 5 are diagrams showing classification characteristics of refined powder. 6 to 8 relate to a conventional example, FIG. 6 is a schematic vertical sectional view, FIG. 7 is a sectional view, and FIG. 8 is a partially enlarged view of FIG. Further, FIG. 9 is an explanatory view of the classification action. 3 ... rotary table, 4 ... grinding roller, 13 ... rotary shaft, 13a ... inner tube, 13b ... outer tube, 13c ... support, 13d ... beam, 13e ... pin, 15 ... separator rotary blade, 15a, 15c … Pocket, 16 …… Discharge pipe, 20 …… Center chute, 21 …… Bearing, 22 …… Air seal, 23 …… Bolt, 23a… Bolt head, 24… Nut, 30… Stand, 31… Thrust bearing , A ₁ , a ₂ , a ₃ , a ₄ , a ₅ , b ₁ , b ₂ , b ₃ ... particle trajectory, P ... particle incident position.

Claims (1)

[Claims] 1. A casing is provided with an opening for carrying out an air flow of refined powder, and a separator is installed in an upper part of the casing. The separator has a rotating shaft installed in a vertical direction and the rotating shaft. A vertical crusher having a rotary separator supported by a shaft and having rotary vanes radially and annularly arranged around the rotary shaft. Is a double tube that can advance and retreat in the axial direction, the lower part of the rotary vane is pin-joined to a support fixed to the inner pipe, and the upper vane and the outer pipe are respectively provided with beams. A vertical crusher characterized by that.