JP3147143B2 - Vertical crusher - Google Patents

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 crushing rollers. 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 a discharge port 17 for taking out the raw material.

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 guided to the base of the casing 15 by a hot air duct 20, and the gas is introduced into an annular space between the outer peripheral surface of the turntable 3 A and the inner peripheral surface of the casing 15. The fine powder pulverized by blowing up from the passage 14 is supplied to 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 made of the same flat plate or angle (unequal angle angle steel) having the same width and length are arranged at equal intervals around the rotation axis. It was arranged so that the diameter gradually increased as it proceeded (hereinafter, this is referred to as an expanded diameter array). In addition, a vertical pulverizer provided with a separator shown in FIG. 9 having vertical classification blades has been conventionally used. When the fine powder is classified by the rotary separator 13 provided with the classification blade 13, it is ideal that the flow direction of the fine powder flowing together with the gas flows orthogonally to the classification blade 13A. However, since the separator 13 is installed on the top of the crusher in the actual vertical crusher 1, the gas flow must cross obliquely from the lower side to the upper side when crossing the classification blade 13A. And crosses the classification blade 13A diagonally. In order to reduce this oblique as much as possible and make it closer to orthogonal, as described above,
The classifying blades 13A were not vertically arranged, and the classifying blades 13A were arranged so as to gradually increase in diameter from the lower side to the upper side, that is, the diameter of the classifying blades 13A was increased.

[0007]

However, such a conventional separator has the following problems. (1) In the conventional classifier blades of the separator, since the classifier blades adopt a diameter-enlarging arrangement in which the diameter increases (the diameter increases) upward, the centrifugal force caused by the rotation of the rotor of the separator increases. Nevertheless, since the blade width is constant, the classification particle size becomes coarser in the upper part than in the lower part, so that the separator has a wide classification range as a whole, and the classification accuracy is low. (2) Accordingly, all of the fine powder having reached the predetermined product particle size by the pulverization is not immediately discharged to the outside of the mill but circulates in the mill, which not only increases the differential pressure in the mill but also returns to the pulverization section. The fine powder dropped as powder hinders the pulverizing action, causing the mill to vibrate, or reducing the pulverization amount and increasing the power consumption per mill.

[0008]

In order to solve the above-mentioned problems, according to the present invention, in the first invention, a plurality of rotatable crushing rollers are arranged on an upper surface of an outer peripheral portion of a rotary table. A vertical type equipped with a rotary separator that applies a predetermined crushing pressure to the crushing roller to crush the raw material supplied to the center of the rotating table between the upper surface of the rotating table and the peripheral surface of the crushing roller, and classifies the crushed product at the top. In the pulverizer, the separator includes a rotor that rotates around a vertical rotation axis, a rotating means for the rotor, and a plurality of classifying blades arranged at equal intervals on the outer periphery of the rotor. , Its width
Formed of a flat plate or a bent plate having the flat plate disposed on the rotor such that the direction is in the radial direction of the rotor, disposed parallel to the rotation axis, and having a width length of the flat plate. Has a configuration formed so as to be gradually reduced from below to above. Further, in the second invention, the flat plate width center line of the classifying blade in the first invention is arranged parallel to and perpendicular to the rotation axis.

[0009]

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, in a vertical type pulverizer, the shape of a classifying blade provided around a rotor of a rotary separator rotating 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 circumference of the rotor so that the width direction is the radial direction of the rotor
It is formed of a flat plate or a bent plate having the flat plate arranged on the rotor, and stops the expanding arrangement to make a vertical array parallel to the rotation axis, and gradually reduces the width of the flat plate from below to above. As a result, the difference in centrifugal force resulting from the difference in radial distance between the upper and lower portions of the classifying blade 13A caused by the diameter expansion arrangement is eliminated, and the lower portion of the classifying blade is denser than the upper portion. The displacement of the classification point caused by the passage of the dust-containing air flow is offset by the difference in the width of the flat plate passing through the classification blade 13A, and the classification blade 13A
The classification particle size was equalized at each height position. as a result,
The ratio of the fine powder to the powder returned to the mill is reduced, the differential pressure in the mill is reduced, the power consumption per unit of separator is reduced, and at the same time, the processing capacity of the crusher is improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The 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 mill, FIG. 2 is a side view of a main part of a separator of a vertical mill 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. Comparison diagram,
FIG. 6 is a diagram illustrating the correlation between the classification position and the centrifugal force, and FIG. 7 is a diagram illustrating the classification operation. FIG. 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 pulverizer 1, a separator 13 is provided as shown in FIG. The separator 13 is
A rotating shaft 13C and a rotating shaft 13 that are driven to rotate by rotating means (not shown) (for example, a motor or a hydraulic motor).
It comprises a rotor 13B connected to C and a classifying blade 13A. As shown in FIGS. 1 and 3, a plurality of classifying blades 13A are provided around the rotating shaft 13C at equal circumferential intervals, and the lower end is connected to the rotor 13B. The shape thereof is as shown in FIG. 4 or an angle (an inequilateral angle steel) shape in which one end of the flat plate is bent as shown in FIG. 4 and arranged vertically like the rotating shaft 3C. The width was formed so as to gradually decrease from below to above (hereinafter, referred to as a tapered shape).

The separator 13 of the present invention has two features, that is, a vertical blade and a tapered shape. To explain the gist, in the first point,
The classifying blades of the conventional enlarged-diameter array are vertically set to classify the classifying blades 13.
A is to make the distance (rotation radius) between A and the rotation center 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. On the other hand, the second point is When the crushing unit is located below and the classifying unit is located upward, as in the vertical crusher handled in the present invention, the dust-containing airflow moving upward from below and entering the separator 13 is inevitable. Since the dust-containing airflow entering the lower part of the classifying blade 13A has a higher density of dust (fine powder) and a higher dust-concentration than the dust-containing airflow entering the upper part, the dust concentration is higher and lower in the vertical direction of the classification blade 13A. Due to the difference in the degree, the classification point shifts, the classification point becomes larger below the upper part, and the coarse powder is easily discharged. Therefore, in order to correct such a tendency and to equalize the classification points in the vertical direction, the width of the classifying blade 13A is made narrower at the upper side than at the lower side (in other words, at the lower side, the upper side is compared with the upper side. Shift the lower classification point from coarse powder to fine powder (decrease the classification point)
It was to be.

As shown in FIG. 1, the vertical blades of the present invention may be arranged such that the outer edge line 13a of the classifying blade 13A is vertical, or conversely, the inner edge line 13b of the classifying blade 13A is vertical. Also, an intermediate vertical arrangement between these two may be used. However, considering strictly, the intention of classifying blades 13A as vertical blades is that centrifugal force is the same,
That is, since the distance between the classifying blade 13A and the center of rotation, that is, the turning radius is the same, it is reasonable to make the center line of the blade width vertical. FIG. 2 shows another embodiment set from such a viewpoint (corresponding to the second invention).
And the center line P of the blade width of the classifying blade 13A was vertical.

Next, regarding the tapered shape of the classifying blade 13A, it is practically very difficult to theoretically determine the difference between the above-mentioned vertical dust concentration densities.
Determined by referring to the experimental results by the test equipment and the past operation results.

The principle of classification of the rotary separator 13 used in the present invention will be described.
As shown in FIG. 7, when the classification blade 13A is rotating counterclockwise at a constant rotation speed (rotation speed V), the classification blade 13A is rotated.
Particles flowing from an arbitrary point P of the arc CD formed by the outer diameter end of A are formed by a resistance force (inward flow) and a centrifugal force (outward flow) due to the flowing air flow, and the air layer between the adjacent classifying blades rotating. receiving the combined forces such as impact, but towards the internal separator 13 while drawing an arbitrary trajectory depending on the particle size, respectively, depending on the size of the particle size, for example, different from the trajectory a ₁ to the locus a ₅ behavior Is shown. That is, a small fine 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, classifying blades It reaches the inner wall of 13A. Particles abutting between B and C lose kinetic energy and are subsequently emitted 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 are the same as the particles that have come into contact between B and C, and are located outside the separator along the BC wall. However, if the inward force due to the airflow is balanced 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 the separator 1
3 Returned downward. Thus, the rotary separator 1
In 3, the classification point, that is, the factor that affects the classification particle size, includes the separator rotation speed, the inflow air volume of the dust-containing airflow, the inflow speed, the powder particle size distribution, the gap between adjacent separator classification blades, The blade width (the distance between DEs in FIG. 7) and the distance from the center of the blade width to the rotation center are involved.

A testing device (UV6 testing device) for a vertical pulverizer equipped with the separator of the present invention (the second invention in FIG. 2) constructed as described above;
In m), the results of tests performed using limestone 10 mm under as a raw material will be described. FIG. 5 is a correlation comparison diagram between the milling amount obtained from the test results and the mill differential pressure and the mill power consumption unit, and FIG. 6 is a correlation comparison diagram between the theoretical classification position obtained by calculation and the centrifugal force. The separator used in the test has a classification blade average diameter of 600m.
m, the center line of the classifier blade width is vertical, and the vertical height of the classifier blade is 300 mm. As is clear from FIG. 5, an improved machine (example of the present invention; vertical arrangement, blade width;
The lower end is 65 mm and the upper end is 35 mm). For the same raw material and the same processing amount (the same pulverizing amount), the mill differential pressure is reduced by 4%, the pulverizing capacity is increased by 8%, and the mill power consumption is 6% at the optimum value. Reduced.

On the other hand, according to FIG. 6, the improved machine of the present invention has a vertical, tapered shape having a lower end of 65 mm and an upper end of 35 mm, as compared with the conventional machine having a constant width and a large diameter of the classifying blade 13A. As a result, the difference between the classification points in the height direction of the classification blade is improved and equalized.

As described above, conventionally, the fine powder which tends to pass through the upper portion of the classifying blade 13A of the separator 13 has the classifying blade of the present invention (the first invention or the second invention) corrected to an appropriate classifying point. The product passes through the upper portion of 13A and is quickly discharged as a product outside the mill, and is prevented from circulating again in the mill as return powder. Therefore, the classification accuracy is sharpened and improved, and the circulation of the fine powder in the mill is reduced to reduce the differential pressure of the mill, and the reduction of the crushing action due to the mixing of the fine powder into the crushing section is prevented, and the crushing ability is improved. Mill power consumption 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 particle size configuration is obtained, and product quality is improved. (2) The differential pressure in the mill is reduced and continuous stable operation with less vibration can be continued. (3) The milling power can be reduced while the grinding capacity is increased.

[Brief description of the drawings]

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

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

FIG. 3 is a sectional plan view taken along line AA of FIG. 1 or FIG. 2;

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

FIG. 5 is a graph showing a correlation between a pulverization amount, a mill differential pressure, and a unit power consumption of a mill in a vertical pulverizer according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating a correlation between a classification position of a separator and a centrifugal force of the vertical pulverizer according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram of a classifying operation 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 conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical grinder 2 Reduction gear 3A Rotary table 3S Dam ring 4 Grinding roller 4a Rotary shaft 5 Arm 6 shaft (rotary shaft) 7 Arm 13 Separator 13A Classification blade 13B Rotor 13C Rotary shaft 13a Outer edge line 13b Inner edge line 14 Annular space passage 15 Casing 17 Material input chute P Blade width center line

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-U 2-142680 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B02C 15/00-15/16 B07B 1 / 00-15/00

Claims (2)

(57) [Claims] 1. A plurality of rotatable crushing rollers are arranged on an upper surface of an outer peripheral portion of a rotary table, and a raw material supplied to a center 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 a crushing roller are circulated. In a vertical pulverizer equipped with a rotary separator that classifies the pulverized product at the top, the separator is a rotor that rotates around a vertical rotation axis, and a rotating means of the rotor, A plurality of classifying blades arranged at equal intervals on the outer periphery of the rotor, wherein the classifying blades are arranged so that the width direction is the radial direction of the rotor.
The rotor is formed of a flat plate or a bent plate having the flat plate, the flat plate is disposed parallel to the rotation axis, and the width of the flat plate is formed so as to gradually decrease from below. Vertical crusher characterized by the following. 2. The vertical pulverizer according to claim 1, wherein the center line of the plate width of the classifying blade is arranged perpendicular to the rotation axis.