Vibrating screen in the mining process

The screening is used to fraction ate bulk materials and separate the composition from the extraction of natural resources, the enrichment of iron ore and coal. This is a special plant complex in which the main role (infertility and eccentric) occupies a special place

1. Vibration screens history.
2. Types of modern vibrating screens.

1. Vibrating screens history.

The first signs of the use of screen technology can be found in Egyptian wall drawings from 1500 BC

The first signs of the use of screen technology can be found in Egyptian wall drawings from 1500 BC. With the advent of the Bronze Age, pigments, salt, metallic minerals and charcoal begin to undergo a detection process. After some time, non-metallic minerals and various chemical components enter the classification. During the European scientific and technological revolution (late 17th century), the popularity of screens for dry separation increased. And since the late 19th century, the selection of mineral materials has been favored by sieve models, predecessors of existing planar vibrational analogues.





The additional technical development followed the introduction of screens with more powerful vibration equipment to obtain more small portions of the classified material. The new high-performance vibratory device achieves working speeds of 700 to 3000 revolutions per minute and the vibration amplitude of the sieve surface is less than 10 mm.

2. Types of modern vibrating screens..

Models of resonance vibration

Modern vibrating screens are eccentric (or rotationally driven by an eccentric mechanism) and the inertia is driven by a vibrator. These include such models of resonance vibration.

The working equipment of vibration inertia screens consists of a sieve or sieve firmly fixed in a box in which the cyclic vibrations are supplied as the material is moved, moved and distributed into fractions. Sieves are usually in 2-3 cells, each lower cell has smaller cells. In the worktop, the screens are made of wire mesh and the extruded sheet steel screen with holes or a set of grids made of steel, rubber or plastic.

The working body of the eccentric vibrating screen also comprises a moving channel with 1, 2 or 3 sieves and 4 bearings, 2 of which are fixed in the fixed frame.

The size of the screen surface as well as the shape and size of the holes affect the screening performance. The screen area of ​​equipment for the construction sector is characterized by a width and length coefficient (1: 2.5). For thick grids this ratio is 1: 2. The performance of the equipment depends on the screen area in the ratio 1: 2.5.

The vibrating sieves are inclined and horizontal (they differ in the position of the screen surface). Raw materials classified horizontally without the aid of gravity. The movement takes place with an inclination of about 45 degrees to the horizontal.

The work of inclined umbrellas is carried out by a circular movement that oscillates in a vertical position.

Using inclined, eccentric and inertial vibrations, commercial fractions and gravel fractions are selected. At the same time, eccentric machines are more productive than others in difficult working conditions in intermediate processes. Regardless of the size of the load, the eccentrics ensure the stability of the vibration amplitude of the channel. In addition, they are easier to isolate.

Horizontal inertial sieves are now mainly used in mobile crushing and screening plants, which despite their small footprint have high filtration rates. As part of the plants, horizontal inertial screens with grids are used for the prior classification of materials. When steel screens or perforated plates are incorporated into the working equipment of the machine, this equipment is used for commercial and intermediate classification.

One promising technique is called resonant vibrating screens. These machines require less power. In addition, the balance of their masses allows the production of models with large screen areas. However, inertial development is currently the most popular type of technology. According to experts, inclined inertia strainers are much more reliable and unpretentious than other types. Inertia counterparts are very effective at sorting bulk solids.

According to GOST 5526-67, the inertial screens are divided by the weight of the load, which is classified as light (GIL), medium (GIS) and heavy (GIT). When labeling the technology, letters and numbers were used. For example, GIS-52. GIS - Average inertia model. The first digit (5) indicates the length of the car. The most commonly used vibrating sieves with a length of 4.5 m. The number 2 indicates the number of sieves, which depends on the work and the size of the material obtained after the selection. The length of the screen depends on the productivity and the surface of the screen.