Congrats! Can't be more grateful to our on-line commissioning team, with their efforts, our HTBS 3.0 coarse coal separator has been put into production in Mongolia during the outbreak. There are a lot of articles about TBS, the content is similar, but very few of them really reveals the core technology of TBS. Today, I’ll summarize the core technology of TBS in coal preparation field taking HTBS as the prototype which is designed and manufactured by Beijing HOT Mining Tech Co Ltd.
1. Critical Data
(1) The upward flow velocity of TBS is 0.003m/s~0.006m/s.
(2) The upward water flow per unit area of TBS is 11m³/h~22m³/h.
(3) The upward water pressure of TBS is about 100Kpa, which is equivalent to 10m water column.
(4) The mass concentration range of TBS feed is 40%~50%.
(5) The treatment capacity of TBS per unit area is 12~7t/h.
(6) The separation density of TBS is 1.3~1.90g/cm³, which can be more than 1.9g/cm³.
(7) The diameter of TBS turbulent plate sieve is 2~4mm.
(8) The flow velocity in TBS turbulence hole is 2~3m/s.
(9) The angle of TBS turbulence plate is between 10°and 15°.
(10) The height of TBS tank body is about 2500mm~3000mm.
With these data, you can basically build a TBS! However, how can we calculate the specifications of TBS based on these data? Here I give you a illustration:
You have learned the upward flow velocity of TBS is 0.003m/s~0.006m/s from above. Here, taking 3000mm TBS as an example, its one hour upward water flow is: 0.785*3*3*0.004*3600=102m³/h, and The treatment capacity is 0.785*3*3*15=106t/h.Don't tangle with these formulas, professional engineers can do it for you.
2. Key points of TBS process designing
✔Accurately analyze the representativeness, size composition and density composition of the feed. If there are too many particle sizes less than 0.125mm or the content of intermediate density particle is high, they should be treated rigorously.
✔Choose the appropriate TBS concentrate desliming process.
✔Accurately select the lift and flow of the clean water pump.
✔Attention should be paid to siphon when TBS is shut down. The vacuum breaking valve can be set on the upward water flow pipe.
✔The volume concentration of TBS tailings is more than 50%, the mass concentration is more than 60%, and the mass concentration is more than 800g/L. Therefore, the tailings should be diluted with water when pumping.
3. Key parts of TBS
(1) The actuator is the most critical part, and the discharge valve and actuator are the most likely to fail in TBS. Therefore, it is recommended that users choose manufacturers with reliable quality and high reputation.
(2) The turbulent plate is the second key part of TBS. If the hole is too small, the upward flow resistance is too large. If the hole is too large, coal is easily accumulated in the water distribution chamber, resulting in uneven water distribution and affecting the separation effect. The key of TBS design is to select the appropriate pore size and the flow velocity in the hole. These two parameters have been included in the important data. In addition, the lower part of the turbulence plate should be cleaned frequently.
(3) The control program is the third key part of TBS, which is easy to be mastered by personnel with electrical foundation.
4. Key points of TBS operation
✔There must be obvious coarse particles in the overflow of TBS. It should be noted that the coarse particles in the overflow are not washed up by the upward flow, but interfere with the exchange position of high and low density particles in the cylinder body under the settlement conditions, and the upward flow rate cannot be increased at will. The overflow thickness should be about 10mm higher than the overflow weir.
✔TBS takes the stable liquid level as the ideal separation state. If there is local fluctuating eddy current, it means that the water distribution of upward flow is uneven, and it is necessary to clean the lower part of the turbulent plate before the next start-up.
✔Prevent debris and large gangue from entering to affect the closure of the underflow valve.
5. The working principle of TBS
The principle of TBS can be explained by the stratification of a heterogeneous particle group in a glass tube. Check below photos.(This is an experiment with sand and a certain density of plastic balls. All the photos were taken under dynamic conditions.)
Fig. 1. When the water velocity is appropriate, the two materials are obviously been separated.
Fig. 2. When the water speed increases properly, the two materials are completely mixed.
As the water speed continues to increase, a strange phenomenon occurs. The low-density material sinks to the bottom, and the high-density sand runs to the top.
It can be imagined that if the water speed continues to increase, all materials will be washed out of the equipment. And that water velocity is the final velocity of free settling of particles.
Summary
According to the above phenomenon, it is certain that materials with different densities can be stratified in the upward flow. As for the density difference, particle size range and water velocity, the data can be obtained by experiments. There is also a set of calculation methods for settling velocity, including calculation of free settling velocity of particles and calculation of disturbing settling velocity, which are completed by professional engineers.
HTBS 3.0 in Mongolia Site
I'm happy share some of my views here, even if there may be some imperfections. Our vision is that the owners will be able to choose the appropriate coal preparation plan and equipment.
