How to improve the screening efficiency of the vibrating screen?
Vibrating screens are used in the production process of mining, chemical, metallurgical and other industries. It is a sorting and grading equipment. The screening efficiency of a vibrating screen refers to the ratio of the product under the screen to the total amount of selected materials. The factors that affect the screening efficiency of the vibrating screen include material characteristics, structural parameters of the vibrating screen, and motion parameters. After understanding these influencing factors, you can learn from these On the aspect of how to improve the screening efficiency of the vibrating screen, this issue is analyzed.
1. Reasonable choice of vibrating screen
In order to improve the screening efficiency of the vibrating screen, the vibrating screen should be selected reasonably according to the needs of the site. Different types of vibrating screens have different adaptability to the materials entering the screen, and the forms of screening movement of materials on different types of vibrating screens are also different. The material is vibrated on the vibrating screen surface in a direction approximately parallel to the screen surface, and the screening effect increases as the vibration frequency of the vibrating screen increases. Therefore, when selecting a vibrating screen, a comprehensive analysis of various factors such as on-site material characteristics and target products should be carried out, and a reasonable vibrating screen should be selected to maximize the screening effect.
At the same time, on the premise of meeting the product particle size requirements, try to choose a non-metallic sieve surface with a large sieve size and a high opening rate, and choose an appropriate sieve to improve the screening effect of the material. At the same time, when selecting the screen surface, it is necessary to satisfy that the screen surface has a reasonable aspect ratio, which can improve the efficiency of the vibrating screen without affecting the screening capacity.
2. Adjust the feeding mode
If the feed is insufficient during the screening process, the ore will be unevenly distributed on the screen; if the feed is too much, the screen will be too thick, resulting in large production, blocking the screen and reducing output. For the problem of uneven feeding, a distributor can be installed at the feeding port to evenly distribute the material on the surface of the screen to meet the requirements of improving output. Distributors can be installed to ensure uniform feeding. If the distributor is added unconditionally, care should be taken when manual feeding is required to ensure uniform feeding. Feeding must be carried out along the entire width of the screen to make full use of the screen surface.
3. Reasonably select the vibration motor and adjust the excitation force
(1) Reasonable choice of vibration motor
As the vibration source of the vibrating screen, the motor is closely related to the working performance, movement mode and screening effect of the vibrating screen. When choosing a vibrating screen motor, choose a motor with a relatively simple structure, high vibration excitation efficiency, and easy maintenance. Increasing the excitation force of the motor can increase the amplitude of the screen surface, accelerate the movement of the material, and reduce the blocking rate of the screen hole.
(2) Adjust the exciting force
Exciting force and material penetration rate and crushing rate show wavy changes to a certain extent, so the exciting force can be adjusted appropriately within a certain range, but the setting value of the exciting force must be within the range of the motor’s synthetic exciting force , Otherwise it is easy to cause material bounce and motor damage. Various measures should be taken when adjusting the excitation force.
4. Improve the movement of the screen surface
The movement mode of the screen surface has a great influence on the working efficiency of the vibrating screen. The ideal way of sieve surface movement is:
(1) The vertical amplitude at the feed end of the screen surface should be greater than the vertical amplitude at the discharge end. This is because the large vertical amplitude at the feed end can effectively stratify the thicker materials at this end, and at the same time, with the help of the inclination angle, the excess material at this end is quickly spread to the middle of the screen surface, so that the fine-grained materials are relatively thinner. The material layer is stratified through the screen, thereby improving the actual use efficiency of the screen surface; when the material reaches the discharge end, the material has been separated into layers, then only a small vertical amplitude is required to ensure the fine-grained material There are good penetrating conditions, but too large vertical amplitude disturbs the penetrating environment of fine-grained materials.
(2) Along the length of the screen surface, starting from the feeding end, the moving speed of the material should be in a decreasing state. This is because the moving speed of the material is decreasing, so that the material layer can maintain a certain thickness on the entire screen surface, so that the fine-grained material can be layered through the screen on a relatively longer range of screen surface, increasing the actual use area of the screen, and at the same time, The amount of penetration of the screen surface along the length of the screen tends to be uniform, giving full play to the screen surface’s penetration potential.
5. Reasonable design of vibration parameters
According to the different materials, the vibration parameters of the vibrating screen are reasonably designed to appropriately improve the throwing degree of the vibrating screen. For materials with larger particles, high-amplitude, low-frequency vibrating screens can be used, and for fine-grained materials, small-amplitude, high-frequency vibrating screens can be used. Under the premise of meeting the screening effect, the vibration direction angle of the vibrating screen can be reduced accordingly. , Appropriately increase the inclination angle of the vibrating screen surface, which is beneficial to improve the efficiency of material screening.
6. The use of non-metallic material screen
The use of a thin elastic screen as the screen base is very beneficial to improve the working efficiency of the vibrating screen. This kind of screen is generally made of rubber or polyurethane material. It can reduce the adhesion between the screen surface and the material being screened, cause the material to produce secondary high-frequency vibration, avoid the blockage of the screen hole, and enhance the permeability of the material. It can alleviate the mechanical effect of the material to be screened on the screen surface, and can withstand greater amplitude vibration than a steel wire screen.
The above is the answer to how to improve the screening efficiency of the vibrating screen, which can be improved by reasonable selection of the vibrating screen, adjustment of the feed mode, reasonable selection of the vibrating motor and adjustment of the exciting force. Improving the screening efficiency of the vibrating screen is conducive to improving the overall production yield, and also has an important impact on subsequent operations.