The capacity range of vibrating screen is as follows:
Scope of application
Inertial vibrating screen
Inertial vibrating screen can be divided into single layer, double layer, seat type and hanging type. The vibrator of the screen is installed on the screen box and vibrates up and down with the screen box. The belt pulley centerline also moves in space, causing the belt to tighten and loosen, and the motor to work unstably. The greater the amplitude is, the more unfavorable it is to the motor.
Therefore, the inertial vibrating screen is only suitable for handling medium and fine materials. The amplitude of the screen box also fluctuates with the amount of ore feed, and the unstable ore feed will affect the screening efficiency. Therefore, uniform ore feeding is required.
Self centering vibrating screen
The self centering vibrating screen has the advantages of simple structure, easy manufacture, convenient operation and adjustment; The screen surface has strong vibration, and the material is not easy to block the screen hole; The screening efficiency is high (up to 90 〜 95%). The disadvantage is that the amplitude of the screen changes obviously with the fluctuation of ore feed (too large or too small), which makes the screening efficiency unstable;
In the process of starting and stopping, the amplitude of the sieve increases when passing through the resonance state, which has an impact on the building. The vibrating screen has a wide range of applications, and is widely used for screening medium and fine materials in large and medium-sized concentrators in China.
Heavy vibrating screen
The vibrating screen has a relatively solid structure and can withstand a large impact load. It is suitable for screening ores with large bulk and density, and the bulk size is 400mm. This machine can replace the easily clogged bar screen as the pre screening equipment before intermediate crushing. It can also be used as ore washing equipment for large ore containing mud. In recent years, this kind of vibrating screen has been used for pre screening before intermediate crushing in many foreign large concentrators.
The screen mesh is mostly composed of two layers to screen out products. In this way, the processing capacity of the crusher can be increased, and the impact of the powder ore with more water on the crushing operation can be reduced.
Circular vibrating screen
YA type circular vibrating screen can be divided into light and heavy type, pedestal type and hanging type, with a working area of 4m2 to 14m2. The screen has novel structure, high strength, reasonable vibration parameters, fatigue resistance, long service life, simple maintenance, low noise and high screening efficiency.
It is used for screening and classification of bulk materials in coal, metallurgy, mining, building materials, chemical industry and other departments. The screen structure includes woven screen, perforated screen plate, iron plate screen plate, etc.
Resonance sieve
Resonance screen is a kind of screening equipment working under resonance state. Its advantages are: large processing capacity, high screening efficiency; Compact structure and simple transmission mechanism; Stable operation, low energy consumption, easy adjustment of amplitude and frequency, and low noise.
The disadvantage is that the manufacturing and installation precision is high, and the ore feeding should be uniform and the price is high. Resonance screen is mainly used for screening, dehydration, desliming and medium removal in coal preparation plants, and also used in a few metal ore dressing plants.
The maximum dynamic load (resonant dynamic load) shall be calculated as 4-7 times of the above results. About the capacity range of the vibrating screen: i=the angle of incidence of the force line relative to the horizontal plane
E=eccentricity (mm)
App=peak to peak value (mm)=2 xe
Example: Determine the material velocity of a vibrating screen that vibrates at 900 RPM, has a 12 mm stroke, and a 40 ° angle of incidence.
When screening materials with a weight of 1.6t/m, the allowable depth of the bed shall not exceed 5 times of the screen, and when screening materials with a weight of 0.8t/m, the allowable depth of the bed shall not exceed four times of the screen hole.
General considerations
It is easy to calculate the bed depth to determine the optimal screen width. If the depth of the bed is too deep, the material will not contact the screen surface. The depth of the fine screen bed is very important, especially when cleaning, to ensure that the sprayed water penetrates the entire depth of the material.
The first third of the screen will allow 80% of the material to pass. The balance is used to obtain materials of close size to provide 95% efficiency. Cohesive, clayey material, UG 2, gypsum requires high-frequency linear horizontal to slightly inclined screens.
Finally, all the parameters needed to calculate the material flow rate on the screen are obtained.
