Coal washing cyclone classification particle size
Writer： admin Time：2020-10-22 15:53 Browse：℃
The influence and control of the grading particle size of the coal washing cyclone is important for salt content. Let us and the cyclone manufacturer to understand:
It is well known that the influence of the coal washing cyclone on the grading particle size of the slime treatment is very important during the working process. If the grading particle size is too coarse, part of the coarse slime will enter the follow-up process, causing the thickening and filter press to fail to operate normally, thereby making the entire washing system unable to work normally; too fine grading particle size will reduce the underflow concentration of the coal washing cyclone, affecting Dewatering operations in the subsequent process links.
In view of the above problems, the adjustment of the coal washing cyclone is mainly realized by changing the feed volume and the size of the underflow port. The size of the underflow port has a great influence on the concentration of underflow. During operation, attention should be paid to make the underflow spin out in an umbrella shape and keep a central air column in the cyclone. If you want to reduce the particle size of the classification, you can increase the amount of feed and increase the underflow port accordingly, or increase the underflow port while the amount of feed remains unchanged, and the underflow concentration will decrease at this time. In actual use, the underflow opening should be adjusted according to the characteristics of the process design and the operation of the coal preparation cyclone. Only by grasping the law of the influence of the cyclone on the production process, can it be adjusted effectively to achieve the purpose of quality assurance.
At the same time, attention should also be paid to check whether the other aspects of the coal preparation cyclone are operating normally, including ensuring that the feed quality of the coal preparation cyclone is stable. This is the main guarantee for obtaining good technical indicators; reduce the input when possible. Concentration of the material in order to reduce the particle size of the classification; avoid connecting the bottom outlet of the cyclone directly to the closed pipeline. Since the atmosphere and the central air column of the cyclone cannot communicate freely, the shape of the air column is unstable, which will destroy the normal flow pattern in the coal preparation cyclone.
The working principle of the coal washing cyclone:
1. The principle of the heavy-medium cyclone is similar to that of the classifying cyclone. Both underflow and overflow are separated by huge centrifugal force.
2. Density: In the dense medium cyclone, the closer the medium density is to the cyclone wall, the greater the density, and the closer it is to the underflow port, the greater the density. On the contrary, the closer to the center and the lower the density of the overflow port.
3. Factors that determine coal quality: ① feed flow rate ② underflow port diameter ③ cyclone length and taper.
4. Principle: Similar to a tornado, the large centrifugal force of the outer layer causes a low pressure in the center. Air is sucked in from the underflow, and the coal with a smaller density spirals backwards and discharged from the overflow, while the outer gangue is discharged from the underflow due to excessive density.
5, 0 bit line: the boundary line of overflow spiral and underflow spiral. Within the 0 bit line, it is overflow; outside it is underflow.
6. The movement inside the heavy-medium cyclone is extremely complicated, and it is also a high-precision coal preparation equipment.