Centrifuge is a common equipment in coal preparation plant, but from the point of view of design and production, people seem to pay little attention to centrifugal liquid, which leads to problems such as rough flotation, blocking gutters, troublesome cleaning, excessive ash content of coarse slime and so on.
HCC Intelligence Coarse Coal Centrifuge is mainly used to separate suspended solid particles and liquids. It is widely used in coal processing, mineral processing, water treatment and other industries.Based on the IoT, sensors, and big data platform, HCC coarse coal centrifuge can be more intelligent--online fault monitoring and predictive maintenance.
HFC Fine Coal Centrifuge is designed for dewatering coal particle size ranges from 0.1-3mm. (The Vertical Slime Centrifuge is used for dewatering of 0.5 ~ 3mm coarse slime in coal preparation plant, horizontal centrifuge is mainly used for dewatering of 0.045 ~ 0.5mm fine slime).
Because the centrifuge has certain requirements for the feed concentration, the materials have generally been dehydrated through the vibrating screen or arc screen before entering the centrifuge. Assuming the horizontal vibration of 1500, the wet material is 250t/h, the moisture of the feed is 18%, and the moisture of the product is 6%, the amount of centrifugal liquid is about 30m3/ h. How much is this? Assuming that the pipe diameter is 100mm and the flow velocity in the pipe is 2m / s, the flow per hour is 57m3/ h. In contrast, the amount of centrifugal fluid is really small.
The coarsening of the centrifuge is serious. Therefore, it is necessary for the centrifugal liquid to return to the slime bucket in order to avoid the coarse and clean coal particles from running to the flotation link. If there is a thin medium barrel, return to the thin medium barrel for magnetic separation of centrifugal liquid (due to its small volume, it will not significantly increase the load of the magnetic separator). This has two advantages, preventing coarsening and reducing medium consumption. Although this is obvious, many coal preparation plants still do not pay attention to these small problems.
When the centrifuge is arranged at a low height, the centrifugal liquid will generally be discharged into the trench nearby, and coarse slime will often accumulate in the trench. There are two main reasons for this: ① the amount of centrifugal fluid is small, and ② the centrifuge runs rough frequently. It is for these two reasons that when the centrifugal liquid flows in the trench, the particles are deposited at the bottom and cannot flow (when the fluid Reynolds number is 40 times greater than the particle Reynolds number, the slurry will carry the particles for suspension flow). Over time, the trench will be blocked, affecting the health of the workshop.
The essence of centrifugal coarsening can be summarized in two sentences: ① the sieve gap determines the largest particle in the centrifugal liquid. ② The dynamic medium filter layer formed in the dehydration process of materials determines the interception particle size. (the dynamic media filter layer is related to the feed particle size composition, concentration, screen gap, speed difference between screen basket and scraper, gap, etc.) and there are a large number of materials smaller than screen gap in centrifugal products. Because there are a large number of materials smaller than the screen gap in the centrifugal products, the Slime Centrifuge can remove some fine materials with high ash in the process of TBS overflow dehydration, but the ash content is reduced slightly. This is noteworthy.
Nowadays, China's coal preparation technology is very mature, and the separation efficiency of coarse and fine particles is very high. To improve the process level of coal preparation, it often lies in the adjustment of some details, and tapping the potential points of each link in the coal preparation process can still bring considerable benefits to the coal preparation plant.