RU2531438C2 - Sizing separator - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to crushing of minerals and can be used for their concentration. Sizing separator comprises rotary perforated drum 2 fitted at drive and support rollers 4 and 5 and working element arranged inside said drum 2. Said working element is equipped with separate drive and composed by grinding shaft 6 with replaceable working embossed plates 8. Said shaft is arranged with height-variable clearance 7 relative to perforated inner surface of the drum 2. Both said shaft 6 and said drum 2 allow variation of their rpm and sense of rotation while grinding shaft 6 rotation axis is located on vertical axis of drum 2 cross-section.

EFFECT: higher efficiency of crushing, power saving.

3 dwg

Description

The invention relates to techniques for grinding and classifying rocks, building materials and other materials.

Known rod mill (grinder) used for grinding various solid materials, containing a rotating drum, inside which is placed a working element in the form of remotely connected rings holding the rod load [1].

The disadvantage of this mill is the increased time spent on grinding the material to a predetermined fraction, since during the grinding process, the core load located inside the remotely connected rings locally affects the material, i.e. on a limited surface area of the drum, which significantly reduces the productivity of the mill and increases its energy consumption. In addition, the crushed material must be classified on additional equipment.

A known drum-type screen used in utilities for the destruction and classification of household waste, including a rotating perforated drum mounted on drive and support rollers, inside which a working element is installed in the form of a screw with rods [2].

The disadvantage of this technical solution is the impossibility of its use for the simultaneous destruction and classification of materials of high hardness.

The objective of the invention is to increase the productivity and energy efficiency of the grinding process with simultaneous classification due to the complex impact on the material from the perforated drum and the working element, as a result of which the material being destroyed, along with uniaxial compression, is subjected to shear (tangential) stresses due to the difference in peripheral speeds between the working element and perforated drum.

This is achieved by the fact that the chopper-classifier, including a rotating perforated drum mounted on the drive and supporting rollers, with a working element located inside it, characterized in that the working element is equipped with an individual drive and is made in the form of a chopper shaft with interchangeable working relief plates, installed with a height-adjustable gap relative to the inner surface of the drum, the gap is proportional to the size of the holes of the perforated drum, with the shaft the chopper and the perforated drum through individual drives have the ability to change the frequency and direction of rotation, and the axis of rotation of the shaft-chopper is located on the vertical axis of the cross section of the drum.

Figure 1 schematically shows a chopper-classifier, General view. Figure 2 is a section aa. The chopper-classifier contains a loading device (1), a rotating perforated drum (2), with holes (perforations) (3), supported by a drive (4) and supporting (5) rollers. Inside the perforated drum (2) there is a working element in the form of a shredder shaft (6) installed with a technological gap (7) proportional to the size of the holes of the perforated drum (3). The chopper shaft (6) is equipped with interchangeable working relief pads (8), the configuration of which is shown in Fig.3. The perforated drum (2) and the chopper shaft (6) are equipped with reversible individual drives (9, 10), respectively. An unloading device (11) is located under the perforated drum.

The device operates as follows.

Pre-prepared by size for grinding in this unit, the source material, through the loading device (1), falls on the inner surface of the perforated drum (2), which rotates and rests on the drive (4) and supporting (5) rollers. The peripheral speed of the perforated drum (2) differs from the peripheral speed of the chopper shaft (6) due to the use of individual drives (9, 10). The material falling into the gap (7) between the grinder shaft (6) and the perforated drum (2) is subjected to highly efficient grinding and through the holes of the perforated drum (perforation) (3) it enters the unloading device (11).

The increased material destruction efficiency is achieved due to the difference in the peripheral speeds of the rotating shredder shaft and the perforated drum, as a result of which the material being crushed is subjected to both normal and shear (tangential) stresses. This feature of destruction has a positive effect on energy costs and unit performance, as all natural and artificial stone materials are well resistant to uniaxial compression, while their ability to withstand shear failure is 8-12% of the compressive strength.

In addition, the difference in peripheral speeds of the shredder shaft and the perforated drum leads to the appearance of different directions of motion of the individual layers of material relative to each other, which positively affects the classification process. The use of linings on the inner surface of the perforated drum and the surface of the shredder shaft with increased frictional properties relative to the material being ground allows the creation of conditions under which external friction will exceed internal in the layer, which will positively affect both the fracture process and the classification process.

The use of an adjustable gap is due to an increase in the efficiency of the screening process. From the theory and practice of screening, it is known that material with a particle size of ≤0.85 V (where B is the size of the opening of the screening surface) is lightweight, the gap size is directly proportional to this criterion.

The use of replaceable working relief pads on the surface of the shredder shaft makes it possible to intensify the fracture process due to increased specific stresses in contact with the material being destroyed. The relief and size of the working plates is selected based on the specific physical and mechanical properties of the material. So, for example, for fragile rocks and materials, it is recommended to use a smooth surface of the lining of the shredder shaft or equipped with staggered hemispheres, for viscous and plastic - lining made in the form of a screw or pins arranged in a staggered manner. The arrangement of elements in a checkerboard pattern is due to an increase in the working surface of the chopper shaft.

Information sources

1. USSR author's certificate SU 1722574 A1, 04/23/1990, publication 03/30/1992, bulletin No. 12.

2. RF patent No. 2198746, 12.02.2001, publication 02.20.2003.

Claims (1)

A chopper-classifier, including a rotating perforated drum mounted on drive and supporting rollers, with a working element placed inside it, characterized in that its working element is equipped with an individual drive and is made in the form of a chopper shaft with interchangeable working relief plates and installed with an adjustable the height of the gap relative to the inner surface of the drum, while the chopper shaft and the perforated drum through individual drives are able to change h frequency and direction of rotation, and the axis of rotation of the shredder shaft is located on the vertical axis of the cross section of the drum.

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