JPH0319969Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotary classifier, and particularly to a rotary classifier suitable for being incorporated into a vertical crusher.

[Prior Art] In classifiers, there are cases where so-called sharp classification is required, in which the particle size distribution curve of the classified product is steep, and there are cases where so-called broad classification is required, where the particle size distribution curve is gentle. be.

An example of the latter is one built into a vertical crusher.

This vertical crusher consists of a disk-shaped rotary table that is driven by a motor with a reducer and rotates at a low speed in the lower part of a cylindrical casing, and a part that divides the upper surface of the rotary table equally in the circumferential direction, which is pressed by hydraulic pressure or the like. A classifier is installed in the upper part of the casing.

In this vertical crusher, powder as a raw material is supplied to the center of the rotary table through a supply pipe, and when the table rotates, the powder is subjected to centrifugal force in the radial direction of the table, and as it slides on the table, it is rotated by the table in the direction of rotation. It receives the force, slides between it and the table, and rotates somewhat slower than the table rotation speed. The above two forces, that is, the forces in the radial direction and the force in the rotational direction are combined, and the powder moves to the outer periphery of the rotary table while drawing a spiral trajectory on the table. Since the roller is in pressure contact with this outer periphery and is rotating, the particles with spiral lines enter between the roller and the rotary table from a direction forming a certain angle with the roller axis direction and are bitten. Smash.

On the other hand, hot air is guided to the base of the casing by a duct, and as this hot air blows up from the annular space between the outer circumferential surface of the rotary table and the inner circumferential surface of the casing, the fine powder is dried. It rises inside the casing, and is discharged from the outlet as a mixture with hot air and sent to the next process.

By the way, it is rare for the material to be crushed supplied to the crusher to be crushed into the fine powder particle size required by this crusher by being subjected to the crushing action by the crushing rollers only once, and the material may fall to the center of the rotary table. Not all of the crushed material is bitten by the crushing rollers, so even if the powder and granules that reach the outer peripheral edge of the rotary table rise up on the hot air current blowing up from the annular space, they will not be able to be crushed by the crusher. By the time the particles reach the classifier installed at the top, depending on their particle size, they may fall or be classified and rejected by the classifier and returned to the rotary table.

In this way, the material to be crushed that is constantly fed into the crusher rises from the rotary table to the classifier or rotates until it reaches the desired fine powder particle size that will become the final product and flows out of the crusher. The particles fall from the middle of the ascending path from the table to the classifier over and over again until they are gradually pulverized to the desired particle size.

One type of classifier that is widely used is a rotary classifier. This rotary classifier has rotating shafts in the vertical direction, rotating blades,
A plurality of them are fixed to the rotating shaft at equal pitches, and are configured to rotate together with the shaft at an arbitrary number of rotations. As is well known in this rotary classifier, the blades rotate together with the rotating shaft.
Fine particles are separated from the airflow that passes between each vane and flows into the classifier.

[Problems to be solved by the invention] Conventional rotary classifiers have relatively sharp classification characteristics (that is, a steep particle size distribution curve). Therefore, in a vertical pulverizer incorporating this, the particle size distribution of the product obtained by pulverization is narrow.

[Means for solving the problem] The rotary classifier of the present invention is provided with rotary blades of three or more different widths, and the widths of the rotary blades located symmetrically across the rotation axis are made equal. .

[Function] In a rotary classifier, the larger the width of the rotating blades, the more fine particles will be captured, and conversely, the smaller the width, the easier it is for large-diameter particles to pass between the rotating blades. Therefore, the rotary classifier of the present invention is provided with rotary blades having three or more different widths. Therefore, the range of classification is widened, and products with a wide particle size distribution can be obtained.

Furthermore, since the widths of the rotating blades located symmetrically across the rotation axis are equal, the rotary classifier has good balance.

[Example] Fig. 1 and Fig. 2 show a rotary classifier according to the present invention. The rotary classifier according to this embodiment is incorporated into a vertical crusher, and FIG. 1 is a schematic vertical cross-sectional view of the entire vertical crusher, and FIG. 2 is an explanatory diagram of the arrangement of rotating blades. It is.

In FIG. 1, a crusher 1 includes a casing 2 that houses the entire crushing section such as a rotary table 3, which will be described later.
0, and this casing 20 includes a lower casing 2 formed in a cylindrical shape and fixed to the floor surface.
0a, and an internal cone 20 with a circular cross section and a center drawing.
The casing includes a middle casing 20b having an inner casing 20b and an upper casing 20d joined to the upper end of the middle casing 20b.

A reducer 2 with a motor is disposed in the center of the lower casing 20a, and a rotary table 3 formed in a disc shape is attached to the output shaft facing upward. It is driven and rotates clockwise when viewed from above in FIG. Reference numeral 5 denotes a plurality of roller boss arms, and a plurality of roller boss arms are arranged at the upper outer circumferential end of the rotary table 3, and a truncated conical crushing roller 4, which is pivoted in a substantially horizontal position, is pivotally connected to the lower end of each roller boss arm. There is.

A pressure frame 6 having an annular shape is fixed to the upper surface of the upper inner peripheral end of the roller boss arm 5 by means such as bolt tightening. It is integrally formed and mounted on the upper surface of the rotary table 3.
On the other hand, the upper outer peripheral end of each roller boss 5 is connected to a pin 7.
The connecting rod 8, turnbuckle 9 and cylinder rod 1 are rotatably connected by the fork end 7a.
The lower end of the hydraulic cylinder 10 is connected to a base plate 13 via a rotating pin 11 and a rotating seat 12.

Each crushing roller 4 is rotatably supported on a roller boss 5 via a roller shaft 4a, and its circumferential surface is in contact with the outer circumferential surface of the upper end of the rotary table 3, so that it can be driven to rotate as the rotary table rotates. It is.

A rotary classifier 15 according to an embodiment of the present invention is installed above the center of the rotary table 3.
The classifier 15 includes a plurality of rotating blades 27 supported by a rotating shaft 23 made of a cylindrical tube via a stay 25 and an inverted conical bottom cover 26. In addition,
The rotating shaft 23 is supported by the refined powder discharge pipe 22 via a bearing 24. Although not shown, a drive device for the rotating shaft 23 is also installed. code 16
A raw material supply pipe is inserted through the rotating shaft 23.

In this rotary classifier 15, at least some of the rotary blades 27 are arranged so that the width thereof is different from the width of other rotary blades. In this example,
As shown in FIG. 2, the width of the rotating blade is arranged so as to change continuously in the rotation direction (specifically, this width is large→medium→small→medium→large...). Further, the rotating blades arranged at symmetrical positions across the rotating shaft 23 have equal widths, and are configured to balance the rotary classifier 15.

A duct 18 is provided below the outer periphery of the rotary table 3.
An annular hot air passage 21 is provided which is connected to the hot air generator by a hot air generator. Above this hot air passage 21, an inner circumferential wall 14a and an outer circumferential wall 14b are provided between the rotary table 3 and the casing 20a. An annular space portion 14 is defined by. In this annular space 14, a plurality of plate-shaped blades 14c are arranged and fixed at equal intervals around the circumference while maintaining a required inclination angle with respect to the horizontal plane.

In addition, a discharge chute 19 is installed at the bottom of the hot air passageway to temporarily discharge foreign matter during crushing and surplus materials to be crushed in the event of overload, and a discharge door 19b that is rotatable around a rotating pin 19a. The structure allows for easier removal.

The operation of the crusher configured as above will be explained next.

After starting the reducer 2 with a motor to rotate the rotary table 3, the material to be crushed is supplied from the supply pipe 16 to the center of the upper surface of the rotary table 3 while maintaining airtightness by a conveyor such as a conveyor (not shown). Then, due to the rotation of the rotary table 3 and the centrifugal force of the rotation, the object to be crushed draws a spiral trajectory and moves toward the outer periphery of the rotary table 3. rotary table 3
Since the crushing roller 4 is rotating on the outer periphery of the
Most of the moved material to be crushed is caught between the crushing roller 4 and the rotary table 3, and is crushed into fine powder by compression, impact, and shearing action. This fine powder, coarse particles and intermediate particles that are not bitten by the crushing roller 4 and come off the periphery of the rotary table 3 fall into the annular space 14, but at this time, they are sent through the duct 18 by the hot air generator. Since the hot air blows up from the hot air passage 21 into the annular space 14, these fine powders and intermediate particles rise inside the crusher together with the hot air. The fine powder and intermediate particles that have risen flow into the classifier 15 from the side of the classifier 15 through between the blades 27 . The classifier 15 is rotated at a predetermined speed (arrow R), and when passing between the blades 27, coarse particles collide with the blades 27 and fall along the blades 27. (Particularly large particles are pushed back toward the leading edge of the blade 27 by centrifugal force.)
In this way, the fine powder that has been classified by the classification action of the classifier and has reached the desired fine powder particle size is discharged into the discharge pipe.
It is sent to the next process via step 2.

Therefore, in the rotary classifier 15 of this embodiment, the widths of the blades 27 are not uniform. In the rotating blades having a small width, even particles having a relatively large particle size pass through the blades 27 without colliding with the blades 27, and are mixed into the product. On the other hand, in the case of a rotating blade having a large width, particles having a relatively small particle size also collide with the blade 27.
fall along.

For this reason, in the rotary classifier 15 of this embodiment, the particle size distribution of the classified product is wide.

In the above embodiment, the blades of the classifier are provided in the vertical direction, but the blades may have a shape that narrows downward, or a blade that narrows only at the lower part. Further, the cross-sectional shape of the blade can also be various shapes such as L-shape and J-shape.

The rotary classifier of the present invention can be used for purposes other than vertical crushers. In addition, when applied to a vertical crusher, it can also be applied to various vertical crushers other than those shown.
For example, in the illustrated vertical crusher, the liner of the rotary table may be of an inclined type or a dish type instead of a flat type, and the corresponding crushing rollers may be changed to a type that is compatible with these types.

[Effects of the Invention] As is clear from the above description, the present invention provides a rotary classifier in which the product powder obtained by classification has a wide particle size distribution.

In addition, the rotating blades are arranged symmetrically around the rotation axis, making the rotary classifier well-balanced.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic sectional view showing a vertical crusher incorporating a rotary classifier according to an embodiment of the present invention;
FIG. 2 is an explanatory diagram of the arrangement of rotating blades of the rotary classifier shown in FIG. 1. 1... Vertical crusher, 3... Rotating table, 4...
... Grinding roller, 6 ... Pressure frame, 14 ... Annular space section, 15 ... Classifier, 16 ... Raw material supply pipe, 23
...rotating shaft, 27...blade.

Claims (1)

[Scope of utility model registration request] In a rotary classifier 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, three or more widths are used. What is claimed is: 1. A rotary classifier comprising rotating blades arranged symmetrically across a rotating shaft, the widths of the rotating blades being equal.