To improve the screening efficiency of linear vibrating screen, these aspects cannot be ignored!
Linear vibrating screen is one of the main equipment for crushing and screening, and it is also the key equipment to provide qualified materials for subsequent operations. Its screening efficiency directly affects subsequent operations. In the actual dressing plant, the main factors affecting the screening efficiency of the linear vibrating screen include: material properties, screen surface structural parameters, vibration characteristic parameters and so on. Next, the vibrating screen manufacturer will specifically analyze how the above aspects affect the screening effect of the linear vibrating screen.
Material properties
The nature of the selected material is one of the main factors affecting the screening efficiency of the linear vibrating screen, and its material properties are mainly reflected in the loose density of the material, the particle size of the material, and the shape of the material.
1. Loose density of selected materials
Generally, the loose density of the material is large and the bulk particles are easy to pass through the screen, and the screening efficiency is high. The effective screening area of the sieve is reduced, which in turn affects the screening efficiency. In order to ensure the screening efficiency, it is necessary to control the bulk density of the selected materials.
2. Selected material particle size
The particle size of the selected material is also an important factor affecting the screening efficiency of the linear vibrating screen. The particle size of the material entering the sieve should meet the size of the sieve hole. Small particles are easy to sieve, and large particles are not easy to sieve. To ensure the screening efficiency, it should be strictly controlled. Into the sieve material particle size.
3. The shape of the material entering the sieve
The shape of the material entering the sieve will affect the sieving performance. Generally, the particles are fully ground and are easier to sieve than the mineral particles of the specification. The sieving rate of materials with irregular particle shapes such as long strips and flakes is poor. Therefore, it is necessary to ensure that the particle shape of the crushed material conforms to the sieve hole standard.
Screen structure parameters
The structural parameters of the linear vibrating screen are mainly reflected in the length and width of the screen surface and the size and shape of the screen hole.
1. Length and width of screen surface
The length of the screen surface of the linear vibrating screen mainly affects the screening efficiency, and the width of the screen surface mainly affects the productivity. The sieve surface of the linear screen is longer, the residence time of the material on the sieve surface is longer, and there are more opportunities to pass through the screen, which will improve the screening efficiency. In fact, the width of the screen surface has different effects on the screening efficiency and the length of the screen surface on the screening capacity.
The relationship between the screening efficiency and the time that the material experiences on the entire screen surface is: at the beginning, the probability of passing through the screen is high. Because there are more fine-grained materials on the sieve surface at the beginning, the probability of sieving per unit time is high. After a certain period of time, the particle size of the materials left on the sieve surface is mostly difficult-to-screen materials close to the size of the sieve holes. Even if the material stays on the screen surface for a long time (that is, the length of the screen surface is large), it is difficult to increase the probability of the material passing through the screen, resulting in a decrease in the working efficiency of the screen machine. Therefore, selecting the appropriate screen surface length can effectively improve the screening efficiency. Generally, the aspect ratio of the linear screen screen surface is 1:2~1:3.
2. Screen shape and size
The selection of the shape of the sieve hole of the linear vibrating screen mainly depends on the sieving particle size of the material entering the sieve and the use of the product under the sieve. Compared with the sieve holes of other shapes, for the same material, the round sieve hole is sieved through the round sieve hole. The particle size of the material is smaller, and the size of the material sieved by the rectangular sieve is larger. Therefore, in order to obtain higher screening efficiency, different sieve shapes must be selected for different screening materials.
Vibration characteristic parameters
The vibration characteristic parameters of linear vibrating screen include screen surface inclination angle, vibration direction angle, amplitude and vibration frequency.
1. The inclination of the screen surface
The size of the inclination angle of the screen surface of the linear vibrating screen is related to the processing capacity of the equipment and the screening efficiency. When the inclination angle of the screen surface increases, the throwing strength of the material on the screen will increase, and the moving speed of the material on the screen surface will increase, increasing the vibrating screen. However, the residence time of the material on the screen is short, the chance of the material being screened is less, and the screening efficiency is reduced. On the contrary, the processing capacity will be reduced, and the screening efficiency will be high.
In order to control the screening efficiency of the vibrating screen within an ideal range, the inclination angle of the screen surface of the linear vibrating screen is generally between 0 and 8°.
2. Vibration direction angle
The angle between the vibration direction and the upper screen surface is called the vibration direction angle. The larger the vibration direction angle is, the shorter the distance that the mineral particles move in each throwing motion, the slower the advancing speed on the screen surface, and the more sufficient the material is to be screened, so the screening efficiency is higher. The smaller the vibration direction angle is, the longer the material travels on the screen surface when thrown, and the shorter the time to pass through the screen surface, so that the material cannot be sufficiently screened, so the screening efficiency is low. In order to ensure the screening efficiency of the linear vibrating screen, the value range of the vibration direction angle is preferably 30-60°.
3. Amplitude
The magnitude of the amplitude of the linear vibrating screen determines the energy of the material particles moving on the screen surface. , the screening efficiency is better; otherwise, the screening efficiency is poor. Generally, the selection of the amplitude is determined according to the particle size and properties of the material to be screened. For materials with larger particle size, it is suitable to use a linear sieve with larger amplitude and lower frequency; for materials with finer particle size, it is easy to use a linear sieve with smaller amplitude and higher frequency.
4. Vibration frequency
The vibration frequency of the screen surface of the linear vibrating screen mainly affects the movement state of the mineral particles. Too low or too high frequency is not conducive to the material passing through the screen holes. If the vibration frequency is too low, the movement probability of mineral particles in the direction of the vertical screen surface is small, and the screen penetration rate is low; if the vibration frequency is too high, the vibration of mineral particles is easy to be chaotic, which affects the screening efficiency. Generally, the vibration frequency range of the screen surface of the linear vibrating screen should be controlled within 15Hz~30Hz.
The above are the major aspects that affect the screening efficiency of the linear vibrating screen. If you want to effectively improve the screening efficiency of the linear vibrating screen, these major aspects cannot be ignored!
In the actual dressing plant, each mineral has its own mineral characteristics, and there are differences in density, hardness, gangue content, etc. Therefore, when selecting equipment, a mineral processing test should be carried out first, and a suitable linear vibration should be selected based on the test results. sieve, so as to ensure that the parameters of the equipment are in line with the mineral particles.
