SU1366207A1 - Centrifugal impact mill - Google Patents

Abstract

The invention relates to devices for fine grinding of various materials with their simultaneous yushka. The purpose of the invention is to increase the grinding efficiency with simultaneous drying of materials and simplify the design of the mill. The mill contains loading 1, intake 2 and discharge 3 nozzles, assembled vertical stepped body 4. Intake nozzle 2 is located in the center of the housing lid, and loading nozzle 1 is offset relative to the mill axis. Each stage of the housing 4 cylindrical fender. ring 5 connected to a truncated cone 6. To the lower base of the cone is attached a separation ring 7, equipped with prehetochnye channels 8 and a central hole 9. The presence in the separation rings of the central hole 9 and the overflow channels 8 also eliminates the mixing of the thin and coarse fraction, prevents the deposition of the thin fraction to a larger one and ensures a constant separation of the finely divided material. For o (C (L

Description

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1366207

elimination of the overload of the steps of the melnik the distance between the loading nozzle 1 and the rotor discs 11, as well as between the overflow channels 8 and the discs is 1.5-2 times the diameter of the maximum particle size supplied

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on grinding. To avoid sticking of the material on the working surfaces of the housing, the larger base of the cone 6 is made equal to the internal diameter of the cylindrical fender. rings 5.1 hp f-ly, 1 ill.

The invention relates to devices for the fine grinding of various materials with their simultaneous drying and can be used in the chemical, pharmaceutical, construction and other industries.

The aim of the invention is to improve the efficiency of the grinding process while simultaneously drying materials and simplifying the design of the mill.

The drawing shows a mill, a longitudinal section.

The invention is illustrated by an example of a specific implementation on the grinding of hydrolytic lignin.

The centrifugal impact mill contains a loading 1, an air intake 2 and an unloading 3 nozzles, a prefabricated vertical stepped body 4, each stage of which is provided with a cylindrical fender ring 5 connected to a truncated cone 6. The ratio of the heights of the cylindrical part and the truncated cone is determined by the formula

hu (Rp + R ") - 1-n

 .-.

8M- | -d-fyPe

d

Rp

RS

n

PM

5. Where Rp is the separation radius;

particle diameter;

the radius of the rotor disk;

radius limiting the start of the beat;

number of beats;

material density;

air density;

length beat; and is 0.9. A separation ring 7 is attached to the lower base of the cone, equipped with overflow channels 8 and a central hole 9. Inside

0

five

0

five

0

five

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The housing on the vertical shaft 10 is arranged with a stepped disk rotor 11, the disks of which are equipped with separation holes 12 and double-sided beams 13 rigidly connected to the disks. On the rotor shaft In the lower part of the case there is a fan 14.

Centrifugal impact mill works as follows.

The source material — lignin — is fed through the loading nozzle 1 to the rotor's fast-rotating disk. 11 and due to the centrifugal scaling, it is thrown into the intensive grinding zone created by the thrusts 13 and the baffle ring 5. The baffle surface of the rings 5 is oriented in such a way as to ensure a frontal impact of particles material. For lignin, the fender surfaces are set relative to the direction of the disk radius at an angle of 26 °. The loading nozzle 1 and the pre-heating channels 8 are spaced from the rotor disks 11 by an amount equal to 1.5-2 diameters of the fraction of material fed to the grinding in the corresponding stage.

The grinding of the particle by the air flow created by the lower part of the bilateral beats 13 and the truncated conical part 6 of the housing 4 is directed along the channel forming between the housing edge and the first-stage rotor disk 11 and between the conical part of the body and the next-stage disk to the central part of the rotor. The smallest particles reach the center of the rotor, which are discharged through the separation holes 12 in the rotor disk 11 and the central holes 9 B of the separation rings 7. Particles, which have reached the optimum size for this stage, flow through the canals 3.1366207

ly 8 is diverted to subsequent stages. The overflow channels 8 prevent the mixing of fine material with coarser fractions.

On the right-sided bilateral bilas 13, the wet crushed material does not stick due to the fact that considerable centrifugal forces drop it

IU to

F

from

in the grinding zone, and ascending in the course of material movement.

Stuffing flow prevents material from adhering to fender surfaces. The required amount of air for drying the crushed material enters through the intake pipe 2. Air and the vapor released during the drying of the material is discharged through the discharge pipe 3 by the fan 14.

The angle of the truncated cone solution, equal to 60-90, creates the best conditions for circulation, grinding and separation of the material. When the angle is less than the specified limit, the working surfaces of the rotor and stator are overloaded due to adhesion of the material. With a larger value of this angle, the conditions for the circulation and separation of the material deteriorate, thereby increasing the energy consumption for grinding (for

larger diameter, located in the case of a stepped disk rotor with double-sided beaters, a loading nozzle placed along the axis

15 bodies and a discharge pipe in the bottom part of the body, characterized in that, in order to increase the efficiency of the grinding process while simultaneously drying the material

20 and simplify the design, the housing cover is provided with an axial air inlet pipe and an inlet pipe displaced relative to the axis, each stage of the body is made in the form of a cylinder and a truncated cone facing the large base towards the loading pipe, and the smaller one is equipped with separation ring-shaped disks from neh 8 if

35

Lc (Rp + Rj) where RC is the separation radius;

milling of lignin is the angle of the solution with cussetting nozzles, and the nous ratio is 120 °). The height of the cylinder and the truncated cone

The advantages of the proposed method are determined by the formula in comparison with the prototype are to increase the fracture efficiency of the material by 10-15% due to the use of beaters installed perpendicular to the rotor disk plane, thereby reducing the specific energy consumption with (except for the additional supply of drying agent) , which significantly reduces energy consumption and simplifies the construction of the chalk. nice Through the use of non-baffling surfaces, the elimination of guide visors, distribute the jacket and filter systems.

45

RP is the radius of the rotor disk; p - the number of hits; p is the density of the material; - length beat; d is the particle diameter;

Rg is the radius limiting the start of the beat;

Ra air density. 2 .. Mill pop.1, characterized in that the boot and

grinding of the material is reduced by 25%.

Claims (2)

1. A centrifugal impact mill comprising a vertical stepped body, each step in which. larger diameter, located in the case of a stepped disk rotor with double-sided beaters, a loading nozzle placed along the axis body and discharge pipe in the bottom part of the body, characterized in that, in order to increase the efficiency of the grinding process while simultaneously drying the material and simplify the design, the housing cover is provided with an axial air intake pipe and an inlet pipe displaced relative to the axis, each stage of the body is made in the form of a junction of a cylinder and a truncated cone facing a large base towards the loading pipe, and the smaller base is equipped with separation ring-shaped discs with . 8 if by formula 35 Lc (Rp + Rj) where RC is the separation radius;  is determined by the formula is determined by the formula RP is the radius of the rotor disk; p - the number of hits; p is the density of the material; - length beat; d is the particle diameter; Rg - radius, limiting the beginning of the beat; Ra air density. 2 .. Mill pop.1, featuring with the fact that the boot and