6 Types Vibrating Screen and How to Choose the Best One
In sand and gravel aggregate production line, screening is an essential stage, and the purpose of screening is mainly to separate materials with different properties. Therefore, the selection of vibrating screens has an important impact on the particle size distribution of the final product. In the following part, we mainly introduce 6 types of different vibrating screen and how to choose suitable vibrating screen.
6 types of vibrating screens
According to their structure and motion characteristics, vibrating screens are divided into the following 6 types, and different vibrating screens have their own advantages and applicability:
① Circular vibrating screen
② Resonance screen
③ Linear vibrating screen
④ Fixed sieve
⑤ Roller screen
⑥ Constant thickness screen
Among them, circular vibrating screen and linear vibrating screen are the most commonly used screening equipment in mining production.
Circular vibrating screen
Circular vibrating screen uses the centrifugal force generated by the rotation of the eccentric block in the vibrator to force the screen box, vibrator, and other parts to move in a continuous or approximately circular motion.
It has the characteristics of reliable structure, high screening efficiency, strong excitation force, durability, convenient maintenance, and safety use, widely used in mining, building materials, transportation, energy, chemical and other industries.
Linear vibrating screen
Linear vibrating screen uses vibrating motor to excite the force, causing the material to be thrown up on the screen and move forward in a straight line.
Linear vibrating screen has reasonable vibration parameters, smooth movement, low energy consumption, high yield, and high screening and dehydration efficiency.
Besides, it has fully enclosed structure, no dust overflow, automatic discharge, more suitable for assembly line operations.
Resonance screen
Resonance screen is a vibrating screen that the vibration frequency is consistent with the natural vibration frequency of the screen surface (including loaded materials).
It can effectively utilize the natural frequency of the equipment and operate in a state close to co vibration, thus consuming very little power.
But, the structure of resonance screen is relatively complex, difficult to adjust, and has a high failure rate. There are many issues with structural strength.
Fixed screen
The working part of the fixed screen is fixed and stationary, and the screening process of materials relies on the sliding of the material along the working surface under its own weight.
Fixed screen has the advantages of simple structure, convenient manufacturing, less power consumption, and the ability to directly unload ore onto the screen surface, saving costs.
It is widely used in mineral beneficiation plants, but with low productivity and screening efficiency, mainly used for pre-screening before coarse or medium crushing.
Roller screen
There are plates on the roller screen shaft, and fine materials pass through the gaps between the rollers or plates while large materials are moved towards one end by the roller belt and discharged from the other end.
The materials running at two different speeds begin to move axially when they meet at a certain position on the screen surface, achieving the goal of improving screening efficiency.
Constant thickness screen
The principle of constant thickness screen is an efficient screening technology developed on the basis of the theory of material group movement on the screen surface. The thickness of the material layer on the screen surface remains unchanged or increases during the screening process. The constant thickness screening method can greatly improve the processing capacity of the screening machine.
Zenith circular vibrating screen for you to choose
In sand and gravel aggregate production plant, circular vibrating screen is the most commonly used type. Zenith provides 3 different types of circular vibrating screens of you to choose, YK, YKN and S5X series. They have different production capacities to meet different requirements.
YK series vibrating screen
Max. Capacity: 700t/h
Max. Input Size: 400mm
Min. Power: 15Kw
YKN series vibrating screen
Max. Capacity: 850t/h
Max. Input Size: 400mm
Mesh Size: 6-150mm
Min. Power: 30Kw
S5X series vibrating screen
Max. Capacity: 1800t/h
Max. Input Size: 300mm
Mesh Size: 2-150mm
Min. Power: 11Kw
The three types of circular vibrating screens all have high screening efficiency and Zenith has many customer sample lines in China and abroad.
How to choose suitable vibrating screen
The main factors to consider when selecting vibrating screen are:
The characteristics of materials: such as the content of the particle size proportion of the material under the screen, the content of particles that are difficult to screen, the content of water and clay in the material, the shape of the material, the specific gravity of the material, etc.;
The structure of the vibrating screening: mesh area, mesh layers, mesh size and shape, mesh area ratio, motion mode of the vibrating screen, amplitude and frequency, etc.;
Production process requirements: processing capacity, screening efficiency, screening method, inclination angle of the vibrating screen etc.
In addition to considering the above mentioned factors, the following basic principles should also be followed:
- (1) After determining the screening area, the width of the screen surface should be at least 2.5-3 times the size of the largest block material to prevent the vibrating screen from being blocked by large blocks of material.
- (2) To ensure that the vibrating screen is in good working conditions, the ratio of screen length to width should be selected within the range of 2-3.
- (3) Reasonable material and structure of the screen surface should be selected according to the working conditions.
- (4) Determination of screen mesh size.
- For the linear vibrating screen used for fine grain screening, the size of the screen mesh is 2 ~ 2.2 times of the separation size, the maximum is not more than 3 times;
- For circular vibrating screen used for medium size material screening, the size of the screen mesh is 1.2 times of the separation size;
- For coarse material screening, the screen mesh size is 1.05 of the separation size;
- For probability screens, the size of the screen mesh is generally 2 ~ 2.5 times of the actual separation size.
(5) Determine whether to use double or multi-layer screen
When the particle size range of the screened material is wide, using a double layer screen as a single layer screen can improve the processing capacity of the vibrating screen, while also protecting the lower layer mesh screen and extending the service life of the lower layer mesh screen.
The selection of the upper screen mesh size of the double-layer screen should generally be determined according to the characteristics of the feeding particle size.
(6) Determine the effective working area of the screen
The screening area calculated according to the production process requirements is the effective area of the vibrating screen, while the specification of the screen is the nominal area of the vibrating screen.
For vibrating screens for screening medium sized materials, the effective screening area should be 0.8-0.85 times the nominal area of the screen.
(7) For materials above 200mm, heavy-duty vibrating screens are often used;
For materials larger than 10mm, circular vibrating screens are often used;
Linear vibrating screens and high-frequency vibrating screens are commonly used for desilting, dewatering, and grading.
(8) When conditions permit, select seat screens for easy maintenance and repair. When it is necessary to use suspending vibrating screen, the lifting height should be minimized as much as possible to reduce the swing amplitude of the vibrating screen and facilitate production operations.
When selecting screening equipment, we should not only consider one reason, but also fully consider various factors to ensure the selection of equipment suitable for the working conditions.
