The difference between banana vibrating screen and circular vibrating screen
Coal washing vibration screening type
The two main purposes of the screening machine are material classification and material dehydration.
Coarse material classification
The classification of materials with sieve openings of 25 ram or more can be called coarse-grained classification. The available equipment is: circular vibrating screen and equal-thickness screen.
For coal preparation plants of large and medium-sized mines, equal-thickness screens are preferred. For small factories and mines, circular vibrating screens are selected. The circular vibrating screen has a simple structure, but it is not suitable for large-scale.
The following describes the process of material classification and the advantages of equal-thickness screens.
Vibrating screening process: the raw coal from the well head enters the vibrating screen, and a thick material layer is generally formed at the feeding end. Fine-grained materials must go through two processes before they can be separated from coarse-grained particles: one process is permeable layer or stratification. Vibration makes the fine materials sink in the lower part to contact the screen surface, and the coarse materials float on top. This process is necessary, otherwise it cannot Carrying out classification; another process is through sieve, fine-grained materials are separated through holes.
The screening process of the circular vibrating screen: The distribution of the screen surface material is that the feeding end is very thick, while the discharge end is very thin. The thick material layer at the feeding end is not conducive to the sedimentation of fine particles. Therefore, its screening efficiency It is very low and it is easy to clog the holes.
The banana vibrating screen is composed of multiple sections with different angles. The first section is 30～35 and the second section is 18～20 (here two sections are taken as an example). The material is fed into the first section. Due to the large inclination angle, the material immediately gains a great speed. (About 1,5~n/s), the material layer becomes thinner rapidly, the large particles jump (or even fly) due to the large kinetic energy, and the stratification is realized on a short screen surface. Therefore, the equal-thickness screen has a high screening efficiency. The second stage is used for inspection and screening, and the materials that have been stratified continue to be screened. Generally speaking, banana screens have a screening efficiency of more than 90. Due to the high-speed scouring of materials, it is impossible to block holes under the screen. The processing capacity of a uniform-thickness screen is 0.6 times larger than that of a circular vibrating screen of the same specification. According to the results of the test, The sieve production capacity can reach 600t/h, and the sieve efficiency is over 85.