JPH09131542A - Vertical pulverizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve classification accuracy by constituting the separator of a vertical pulverizer which is arranged with plural pieces of pulverizing rollers atop the outer periphery part of a turntable and is provided with a separator of a rotary type at its peak part by providing the separator with the rotor and classifying vanes of a specific shape disposed in plural pieces on the outer periphery of this rotor. SOLUTION: This pulverizer for forming powder by finely pulverizing limestone, cement raw materials, etc. has plural pieces of the pulverizing rollers in the outer periphery part on the front surface of the turntable and has the separator 13 of a rotary type for classifying te pulverized products after the pulverization in the peak part of the pulverizer. This separator 13 is composed of the rotor 13B connected to the revolving shaft 13C and the classifying vanes 13A. The classifying vanes 13A are circumferentially disposed in plural pieces at equal intervals around the revolving shaft 13C and are connected to their bottom ends to the rotor 13B. The shape thereof is planar of an angle shape and is arranged perpendicularly like the revolving shaft 13C. In addition, the separator is formed to a convergent shape by reducing the transverse length of the flat plate gradually upward from below.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical crusher for crushing and classifying raw materials such as cement raw materials, limestone, slag, clinker, ceramics and chemicals by cooperation of a rotary table and a pulverizing roller. is there.

[0002]

2. Description of the Related Art As one type of a crusher for finely pulverizing raw materials such as limestone, cement raw materials, and slag into powder, FIG.
As shown in FIG. 1, a vertical pulverizer 1 having a rotary table, a pulverizing roller, and a rotary separator is widely used.
This type of pulverizer includes a disk-shaped rotary table 3A that is driven by an electric motor 2B by a speed reducer 2 and rotates at a low speed at a lower portion of a cylindrical casing 15, and a hydraulic pressure is applied to a portion that divides an outer peripheral portion of the upper surface in a circumferential direction. And a plurality of crushing rollers 4 that are driven to rotate by being pressed by the like, and a rotary separator 13 that classifies crushed products after crushing is provided at the top of the crusher.

The crushing roller 4 is connected to a piston rod 10 of a hydraulic cylinder 9 via an arm 7 pivotally supported by a shaft 6 on a casing 15. 4 is pressed onto the rotary table 3A to give a pulverizing pressure to the raw material. 3S is a dam ring for adjusting the thickness of the raw material layer provided on the outer peripheral edge of the rotary table 3A, 14 is an annular space passage for blowing up gas around the rotary table 3A, 14A is a gas supply path,
13 is a rotary separator for classifying the pulverized product by the classification blade 13A, 16 is a product together with gas (refined powder after classification)
And 17 is a raw material charging chute.

In such a vertical pulverizer, the raw material supplied to the center of the rotary table 3A by the raw material charging chute 17 receives centrifugal force in the table radial direction by the rotation of the rotary table 3A, and moves on the rotary table 3A. When slipping, the rotation of the turntable 3A is performed somewhat slower than the rotation speed.
The above two forces, that is, the force in the radial direction and the force in the rotational direction are synthesized, and the raw material moves on the turntable 3A to the outer peripheral portion of the turntable 3A along a spiral locus. Since the crushing roller 4 is pressed and rotated on the rotary table 3A on this outer peripheral portion, the raw material depicting the spiral is in the roller axial direction between the crushing roller 4 and the rotary table 3A. It enters from an angled direction, is bitten, and is crushed.

On the other hand, a gas such as air or hot air is introduced into the base of the casing 15 by a hot air duct 20, and this gas is an annular space between the outer peripheral surface of the rotary table 3A and the inner peripheral surface of the casing 15. The fine powder crushed by being blown up from the passage 14 turns into the rotary table 3A.
Over the dam ring 3S at the outer peripheral end of the separator 13 and ascends in the casing 15 with the gas, undergoes the classification action by the classification blade 13A of the separator 13 located at the upper part, and the product having the predetermined particle size is discharged from the discharge port 16 together with the gas. And sent to the next step.

By the way, the conventional rotary separator 13
As shown in FIG. 8, a plurality of classifying blades 13A formed of flat plates or angles (unequal side angle steel) having the same width and length are arranged around the rotary shaft at equal intervals, and the classifying blades are arranged from bottom to top. It was arranged so that the diameter gradually increased as it headed (hereinafter, this is referred to as a diameter expansion arrangement). Further, a vertical crusher equipped with a separator shown in FIG. 9 in which the classification blade is vertical has also been used conventionally. When classifying fine powder with the rotary separator 13 provided with the classifying blade 13, it is ideal that the flow direction of the fine powder flowing together with the gas flows orthogonally to the classifying blade 13A. Since the separator 13 is installed at the top of the crusher in the actual vertical crusher 1, the gas flow is forced to cross obliquely from the lower outer side to the upper inner side when crossing the classification blade 13A. Then, the classification blade 13A is diagonally crossed. In order to relax this cross as much as possible and make it closer to the orthogonal, as described above,
The classifying blades 13A were not arranged vertically, but the classifying blades 13A were arranged such that the diameters gradually increased from the lower side toward the upper side, that is, the diameter expanding arrangement.

[0007]

However, such a conventional separator has the following problems. (1) In the conventional classifying blade of the separator, the classifying blade adopts a diameter-expanding arrangement in which the diameter is increased (the diameter is increased) as it goes upward, so that the centrifugal force caused by the rotation of the rotor of the separator is increased. Nevertheless, since the blade width is constant, the classification particle size becomes coarser in the upper part than in the lower part, and the separator as a whole has a wide classification range, which has a drawback that the classification accuracy is low. (2) Therefore, all the fine powders that have reached a predetermined product particle size by pulverization are not immediately discharged to the outside of the mill but circulate in the mill, which not only increases the differential pressure inside the mill but also returns to the pulverization section. The fine powder that fell as powder hinders the crushing action, causing the generation of mill vibration, or decreasing the crushing amount and increasing the unit power consumption of the mill.

[0008]

In order to solve the above problems, in the present invention, in the first invention, a plurality of rotatable crushing rollers are arranged on the upper surface of the outer peripheral portion of the rotary table, A vertical type equipped with a rotary separator that applies the predetermined crushing pressure to the crushing roller to crush the raw material supplied to the center of the rotary table between the upper surface of the rotary table and the peripheral surface of the crushing roller, and classifies the crushed product at the top. In the crusher, the separator includes a rotor that rotates around a vertical rotation axis, a rotating unit of the rotor, and a plurality of classification blades arranged at equal intervals on the outer circumference of the rotor. Formed from a flat plate along the center of rotation or a bent plate having the flat plate in a plan view, arranged parallel to the rotation axis, and the width length of the flat plate is gradually reduced from the lower side to the upper side. Formed configuration It was. Further, in the second invention, the first
The flat plate width center line of the classifying blade in the invention is arranged parallel to and perpendicular to the rotation axis.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, in a vertical crusher, the shape of a classification blade provided around a rotor of a rotary separator that revolves around a vertical rotation axis is changed from that of a conventional structure. A plurality of classifying blades arranged at equal intervals on the outer periphery of the flat plate are formed by a flat plate or a bent plate having the flat plate along the center of rotation in plan view, and the diameter expansion arrangement is stopped to make a vertical arrangement parallel to the rotation axis. Since the width of the flat plate is formed so as to be gradually reduced from the lower side to the upper side, the difference in centrifugal force caused by the difference in the radial distance between the upper portion and the lower portion of the classification blade 13A caused by the diameter expansion arrangement is eliminated. And the deviation of the classification point due to the passage of a dust-laden air flow that is denser in the lower part of the classification blade than in the upper part,
The difference in the width of the flat plate passing through the classifying blade 13A was offset, and the classifying particle diameter was made uniform at each height position of the classifying blade 13A. As a result, the ratio of fine powder to the powder returned in the mill is reduced, the differential pressure in the mill is reduced, the unit power consumption of the separator is reduced, and at the same time, the crusher processing capacity is improved.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 7 relate to an embodiment of the present invention,
FIG. 1 is a side view of a main part of a separator of a vertical crusher, and FIG. 2 is a side view of a main part of a separator of a vertical crusher showing another embodiment.
FIG. 3 is a cross-sectional plan view taken along the line AA of FIG. 1 or FIG. 2, FIG. 4 is a cross-sectional plan view of a separator showing another embodiment, and FIG. 5 is a correlation between the pulverization amount and the mill differential pressure and the mill power consumption rate. Comparison diagram,
FIG. 6 is a correlation comparison diagram between the classification position and centrifugal force, and FIG. 7 is an explanatory diagram of the classification action. 8 is an overall vertical sectional view of a conventional vertical crusher, and FIG. 9 is a side view of a conventional separator.

At the top of the vertical crusher 1, as shown in FIG. 1, a separator 13 is arranged. The separator 13 is
A rotary shaft 13C and a rotary shaft 13 which are rotationally driven by a rotating means (not shown) (for example, a motor or a hydraulic motor).
It is composed of a rotor 13B connected to C and a classification blade 13A. As shown in FIG. 1 and FIG. 3, the classification blades 13A are provided around the rotary shaft 13C at equal circumferential intervals, and the lower ends thereof are connected to the rotor 13B. The shape thereof is as shown in FIG. Is formed of a flat plate, or has an angle (unequal angle steel) shape in which one end of the flat plate is bent as shown in FIG. 4, and is arranged vertically like the rotating shaft 3C, and The width was gradually reduced from the lower side to the upper side (hereinafter referred to as a tapered shape).

The separator 13 of the present invention has two characteristics, namely, a vertical blade and a tapered shape. Explaining the purpose, in the first point,
The classification blade of the conventional diameter-expanding arrangement is made vertical and the classification blade 13
The distance (rotation radius) between A and the center of rotation is made the same, and as a result, the centrifugal force effect is made the same and the classification points in the vertical direction of the classification blade 13A are made uniform, while the second point is As in the vertical crusher handled in the present invention, when the crushing section is at the lower side and the classifying section is at the upper side, the dust-containing air current that moves from the lower side to the upper side and enters the separator 13 inevitably has. Since the dust-containing airflow entering below the classification blade 13A is denser than the dust-containing airflow entering above, and the dust-containing concentration is high, the dust density is high in the vertical direction of the classification blade 13A. Due to the difference in degree, the classification points are displaced, the classification points are larger in the lower part than in the upper part, and the coarse powder is easily discharged. Therefore, in order to correct such a tendency and to make the classification points in the vertical direction uniform, the width of the classification blade 13A is made narrower in the upper part than in the lower part (in other words, the lower part is compared to the upper part in the upper part). The lower classification point from the coarse powder toward the fine powder (decrease the classification point).
It was to be.

The form of the vertical blade in the present invention may be such that the outer edge line 13a of the classification blade 13A is vertical, or conversely, the inner edge line 13b of the classification blade 13A is vertical, as shown in FIG. Further, a vertical arrangement intermediate between these two may be used. However, when strictly considered, the intention of the classification blade 13A as a vertical blade is to have the same centrifugal force.
That is, since the distance between the classification blade 13A and the rotation center, that is, the radius of rotation is the same, it is rational to make the center line of the blade width vertical. FIG. 2 shows another embodiment (corresponding to the second invention) set from such a viewpoint.
The center line P of the blade width of the classification blade 13A is set to be vertical.

Next, the taper shape of the classification blade 13A will be described. It is actually very difficult to theoretically find the difference in the density of the dust density in the vertical direction.
It is decided by referring to the experimental results by the test equipment and the past operation record values.

The classification principle of the rotary separator 13 used in the present invention will be explained.
As shown in FIG. 7, when the classification blade 13A rotates counterclockwise at a constant rotation speed (rotation speed V), the classification blade 13
Particles flowing in from an arbitrary point P of the arc CD formed by the outer diameter end of A are the resistance force (inward flow) and the centrifugal force (outward flow) due to the inflowing air flow and the air layer between the adjacent classification blades that rotate. When receiving a combined force such as an influence, it moves toward the inside of the separator 13 while drawing an arbitrary locus according to the particle diameter, but, for example, a different behavior from the locus a ₁ to the locus a ₅ depending on the particle size. Indicates. That is, the fine powder having a small particle diameter draws a locus a ₁ and passes between A and E, the intermediate powder draws a locus a ₃ between A and B, and the coarse powder draws a locus a ₅ between B and C to classify the blade. Reach the inner wall of 13A. The particles abutting between B and C lose their kinetic energy and are then 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 are the same as the particles abutting between B and C above the separator outside along the BC wall. However, if the inward force due to the air flow is balanced with the centrifugal force between A and B, or if the inward force exceeds the centrifugal force, the particles fall along A and B, and the separator 1
3 Returned downward. In this way, the rotary separator 1
In 3, the classification point, that is, the factors that affect the classification particle size are the separator rotation speed, the inflow air amount of the dust-containing airflow, the inflow velocity, the powder particle size distribution, and the gap between adjacent separator classification blades. The blade width (distance between DEs in FIG. 7) and the distance from the center of the blade width to the center of rotation are involved.

A vertical crusher test apparatus (UV6 test apparatus; rotary table diameter of about 600 m) equipped with the separator of the present invention (the second invention of FIG. 2) configured as described above.
In m), the result of the test performed by using limestone 10 mm under as a grinding raw material will be described. FIG. 5 is a correlation comparison diagram of the pulverization amount, the mill differential pressure, and the mill electric power consumption unit obtained from the test results, and FIG. 6 is a correlation comparison diagram of the theoretical classification position obtained by calculation and the centrifugal force. The separator specifications used in the test have a classification blade average diameter of 600 m.
m, the center line of the classifying blade width is vertical, and the vertical height of the classifying blade is 300 mm. As is clear from FIG. 5, as compared with the conventional machine (the classifying blade 13A has an expanding arrangement and the blade width is constant at 65 mm), the improved machine (invention example; vertical arrangement, blade width;
(Lower end 65 mm, upper end 35 mm), the mill differential pressure is reduced by 4% and the pulverizing capacity is increased by 8% with the same raw material and the same treatment amount (the same pulverizing amount), and the unit power consumption of the mill is 6% at the optimum value. Will be reduced.

On the other hand, according to FIG. 6, in the improved machine of the present invention, the classifier blade 13A has a constant width and length, and the improved machine of the present invention has a lower end of 65 mm and an upper end of 35 mm in a vertical and tapered shape. Therefore, the difference in the classification points in the height direction of the classification blade is improved and equalized.

As described above, the classification blade of the present invention (the first invention or the second invention) in which the fine powder that has conventionally been apt to pass through the upper portion of the classification blade 13A of the separator 13 is corrected to an appropriate classification point. After passing through the upper part of 13A, the product is promptly discharged to the outside of the mill, and it is prevented from circulating again in the mill as returned powder. Therefore, as the classification accuracy is sharpened and improved, the circulation of fine powder in the mill is reduced and the mill differential pressure is reduced, and the reduction of the pulverization action due to the incorporation of fine powder into the pulverization part is prevented, and the pulverization ability is improved, Mill power intensity is reduced.

[0020]

As described above, in the present invention, the following excellent effects can be exhibited. (1) Classification accuracy is improved, a product having a sharp grain size structure is obtained, and product quality is improved. (2) The differential pressure inside the mill is reduced and continuous stable operation with less vibration can be continued. (3) Mill power consumption can be reduced as the crushing capacity is increased.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of a separator of a vertical crusher according to an embodiment of the present invention.

FIG. 2 is a side view of a main part of a separator of a vertical crusher according to another embodiment of the present invention.

3 is a cross-sectional plan view taken along the line AA of FIG. 1 or FIG.

FIG. 4 is a cross-sectional plan view of a separator showing another embodiment of the present invention.

FIG. 5 is a correlation comparison diagram of the pulverization amount of the vertical pulverizer according to the embodiment of the present invention, the mill differential pressure, and the mill electric power consumption rate.

FIG. 6 is a correlation comparison diagram of the classification position and centrifugal force of the separator of the vertical crusher according to the example of the present invention.

FIG. 7 is an explanatory diagram of a classification action according to the embodiment of the present invention.

FIG. 8 is an overall vertical sectional view of a conventional vertical crusher.

FIG. 9 is a side view of a main part of a separator showing another embodiment of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical crusher 2 Speed reducer 3A Rotary table 3S Dam ring 4 Grinding roller 4a Rotating shaft 5 Arm 6 Shaft (rotating shaft) 7 Arm 13 Separator 13A Classification blade 13B Rotor 13C Rotating shaft 13a Outer edge line 13b Inner edge line 14 Annular space passage 15 Casing 17 Raw material charging chute P Blade width center line

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akinori Miura 1980, Okiyama, Ogushi, Ube, Yamaguchi Prefecture Ube Industries, Ltd. Ube Machinery and Engineering Office

Claims (2)

[Claims] 1. A plurality of rotatable crushing rollers are arranged on an upper surface of an outer peripheral portion of a rotary table, and the raw material supplied to the central portion of the rotary table is applied with a predetermined crushing pressure to the crushing roller so that the upper surface of the rotary table and the peripheral surface of the crushing roller are provided. In a vertical pulverizer having a rotary separator for pulverizing between a surface and a crushed product at the top, the separator is a rotor rotating around a vertical rotation axis, and a rotating means for the rotor, A plurality of classifying blades arranged at equal intervals on the outer circumference of the rotor, the classifying blade being formed of a flat plate or a bent plate having the flat plate along the center of rotation in a plan view and being parallel to the rotation axis. A vertical crusher characterized in that it is arranged and the width of the flat plate is gradually reduced from the lower side to the upper side. 2. The vertical crusher according to claim 1, wherein a center line of the flat plate width of the classifying blade is arranged parallel to and perpendicular to the rotation axis.