JPH07108388B2 - Classifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The classifying device of the present invention relates to a classifying device for centrifugally classifying solid particles of a dust-containing gas that is a solid-gas two-phase fluid.
It is a classifier used in the coal industry, chemical industry, food industry and other industrial fields handling powder, and is particularly suitable for classifying products after ultra-fine pulverization.

[Prior Art] A vertical crusher equipped with a rotary table and a crushing roller is widely used as a kind of crusher for finely crushing granular materials such as cement raw materials, coal, and chemicals into powder. 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. 4 showing a conventional vertical crusher, the crusher generally designated by reference numeral 1 is formed as a single tower in appearance, and the base thereof has a rotary table 3 rotated by an electric motor (motor) 2. Are 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. Support arm 5
Is a support shaft 6 which is rotatably supported on the crusher side at its center.
The support arm 5 extends downward through the side of the casing 8 surrounding the rotary table 3 and faces the lower space of the crusher. The lower end of the rotating arm 5 is rotatably supported by the tip of a rod of a pressure cylinder 9 whose lower end is rotatably supported by the base of the crusher 1. Reference numeral 10 indicates a coupling.

The granules as the raw material supplied from the raw material supply device (not shown) to the center of the rotary table 3 through the supply pipe 11 are the roller 4 and the rotary table 3 which are driven by the rotation of the table.
It is bitten in between and crushed. 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 12 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 the classification device 10
After passing through 0, it is discharged from the discharge port 13 as a mixture with hot air and sent to the next step.

Fig. 3 shows an overall system diagram of a vertical crusher with a built-in classifier, which is crushed by the vertical crusher 1, classified by the classifier 100 and entered into the cyclone 200, where the powder collected and recovered. Becomes a product, and the gas is released to the atmosphere via the suction fan 300, but the product contains a mixture of particles A that have passed through the rotor 110a and particles B that have passed through the labyrinth seal 120 and the gap 130.

It should be noted that some of the coarser particles ascend in the crusher 1 as well, but they are classified by the upper classifying device 100 and the rotary table 3
Returned to the top.

Further, the rotary table 3 has a rotary shaft (not shown) extending vertically downward, and the rotary force of the motor 2 is reduced in the reducer casing indicated by reference numeral 2A.
In addition to the speed reducer transmitting to the rotary shaft of
A thrust bearing mechanism and a radial bearing mechanism for supporting the rotary shaft are provided (both not shown).

On the other hand, the classification device 100 is composed of a rotor 110 attached to the lower end of a vertical rotary shaft 110b and a variable speed electric motor 110c that rotates a plurality of blades 110a arranged on the outer periphery of the rotor 110 via the rotary shaft 110b. A mechanical seal 120, for example, a labyrinth seal, is provided between the rotor and the housing 1a to minimize the leak gas from the gap 130.

[Problems to be Solved by the Invention] In a centrifugal force type classifying device having a rotor rotating at high speed, there is always a minute gap between the rotor and the outer housing. The particles pass through and merge with regular fine particles below the classification point that have passed through the rotor, resulting in a rough classification point and a change in the particle size distribution. For this reason, the maximum particle size of the product becomes large, and the evaluation of the entire product deteriorates.
This is a fatal defect when using ultrafine powder as a product.

In order to alleviate the above problems, if a contact-type sealing method is adopted instead of the non-contact type Rabins seal mechanism for this minute gap, the following drawbacks are exposed.

(1) If a contact type seal such as an oil seal is used, the peripheral speed is limited to 15 m / s, and if it is rotated at a higher speed, the sliding part will generate heat and the function and life will be significantly reduced. Therefore, although the oil seal method can be adopted for a small classifier, it cannot be used for a medium or large classifier because of its high speed.

(2) If the contact type seal structure is adopted for the rotor system that rotates at high speed, the rotational torque becomes very large due to the frictional force of the sliding part, the capacity of the motor must be increased, the equipment cost also increases, and the running cost of electricity is high. Basic unit also deteriorated (increased)
To do.

As described above, since the contact type cannot be substituted, the present invention adopts the non-contact type labyrinth seal structure and takes measures against the deterioration of the product quality due to leak air (particle size coarsening and particle size distribution change). .

[Means for Solving the Problems] In order to solve the above problems, the classifying device of the present invention is a centrifugal force type classifying device having a vertical rotating shaft,
A labyrinth seal mechanism is arranged in a minute gap between the rotor and the housing, and a discharge path of dust-containing gas that leaks and passes through the labyrinth seal is separated from a discharge path of dust-containing gas after passing through the rotor of the classifier. The configuration provided in.

[Operation] In the classifying device of the present invention, the labyrinth seal mechanism is provided in the minute gap between the rotor and the housing of the classifying device, and the exhaust path of the dust-containing gas after passing through the labyrinth seal mechanism is set to the rotor of the classifying device. Since it is provided separately from the discharge path of the dust-containing gas after passing, the powder of both dust-containing gases can be made into a product without being mixed.

[Examples] Hereinafter, details of the classification device of the present invention will be described with reference to the drawings.

1 and 2 show an embodiment according to the present invention, FIG. 1 is an enlarged vertical sectional view of a main part of a classifying device, and FIG. 2 is an overall system diagram of a vertical crusher having a classifying device (flow sheet). ).

In the figure, 100 is a classifier, 200 is a cyclone, 300 is a suction fan, 400 is a cyclone, 110 is a rotor, 11
Reference numeral 0a is a rotor blade, 120 is a labyrinth seal, and 130 is a minute gap.

As described above, the classifying device 100 is a rotor fixed to the lower end of the vertical rotating shaft 110b and having a plurality of blades 110a on the outer circumference.
The structure is such that the variable speed electric motor 110c can rotate the 110 around the vertical axis at an arbitrary number of rotations, and a labyrinth seal 120 is arranged in the gap between the upper surface of the rotor 110 and the lower surface of the housing 1a.

Then, inside the labyrinth seal 120, the path of the dust-containing gas passing through the blade 110a of the rotor 110 of the classification device 100 (LINE
In addition to A), a path for dust-containing gas (LINE B) that passes through the labyrinth seal 120 is provided, and as shown in Fig. 2, this dust-containing gas of LINE B is a cyclone that collects products.
Do not enter 200, but head toward cyclone 400. Cyclone 40
The powder collected at 0 can be separately collected and used for other purposes.

On the other hand, in the minute gap 130, compared to the negative pressure of LINE A, LINE B
By increasing the negative pressure of, only a small amount of gas will flow back to LINE A's dust-containing gas gas LINE B, and coarse powder will not be mixed into the product.

As described above, in the present invention, the dust gas of LINE A is separately collected by the cyclone 200, and the dust gas of LINE B is separately processed, so that the coarse powder after passing the labyrinth seal is mixed in the product. There is nothing to do.

In both LINE A and LINE B, the gas after dust collection can be combined by the suction fan 300 and discharged to the atmosphere, so even if there are two routes of exhaust gas, it can be processed by the same suction fan, but separately LINE B may be equipped with a small suction fan.

[Effect of the Invention] In the classifying device of the present invention, since the coarse powder of the seal portion is not mixed in the product composed of the regular fine powder that has passed through the rotor, the product quality is stable and the coarse powder is A high-quality ultrafine-milled product that does not mix with or a product having a desired particle size composition can be obtained.

Further, since the non-contact type seal is used, the rotating torque is small and the running cost can be reduced.

[Brief description of drawings]

1 and 2 show an embodiment according to the present invention, FIG. 1 is an enlarged longitudinal sectional view of an essential part, FIG. 2 is an overall system diagram, and FIGS.
The drawing shows an embodiment of a vertical crusher having a conventional classifying device, FIG. 3 is an overall system diagram, and FIG. 4 is an overall vertical sectional view. 1 ... Vertical crusher, 1a ... Housing, 3 ... Rotary table, 4 ... Grinding roller, 100 ... Classifier, 110 ... Rotor, 110a ... Blade, 110b ... Rotating shaft, 110c. Variable speed motor, 120 …… Labyrinth seal, 130 …… Micro gap, 200 …… Cyclone, 300 …… Suction fan, 400 …… Cyclone, A …… Powder after passing through the rotor, B …… After passing through labyrinth seal Powder, LINE A ... Powder A path, LINE B ... Powder B path.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References Japanese Patent Laid-Open No. 1-184084 (JP, A) Japanese Patent Laid-Open No. 1-184085 (JP, A) Japanese Patent Laid-Open No. 1-184086 (JP, A) Japanese Patent Laid-Open No. 61- 57278 (JP, A) Actually opened 53-105075 (JP, U) Actually opened 64-8982 (JP, U) JP-B 3-68736 (JP, B2) JP-B 3-8830 (JP, B2) Japanese Patent Publication 3-47900 (JP, B2)

Claims (1)

[Claims] 1. A centrifugal force type classifying device having a vertical rotating shaft, wherein a labyrinth seal mechanism is arranged in a minute gap between a rotor and a housing, and a discharge path for dust-containing gas leaking and passing through the labyrinth seal is provided. A classifier, which is provided separately from a discharge path of the dust-containing gas after passing through the rotor of the classifier.