Some customers asked about the powder concentrator in the grinding system. Today, Fodamon engineer explain the structure principle and common faults of the powder concentrator as follows.
一、 Function of powder concentrator
The milled materials are screened to obtain qualified finished products.
Greatly improve the powder selection conditions of the mill and make the system enter a virtuous cycle, so as to achieve the purpose of energy saving and production increase.
The finished products with qualified fineness will rotate the fan blade, and the unqualified materials will return to the mill from the lower cone bucket for grinding again. Until we reach the fineness we need.
二、 Performance and structure of powder concentrator
Internal composition of powder concentrator
- Guide vane
- Rotate the impeller
- Cone bucket
Wear prevention measures have been taken for all easily worn and vulnerable parts inside the powder concentrator.
三、 Working principle of powder concentrator
The powder separation gas is introduced into the bottom of the powder concentrator from the gas outlet of the mill. The gas rises to the upper outlet along the air inlet pipe, is diverted by the coarse powder collection cone (inner cone) around, enters the inner cavity composed of inner cone and shell body, and continues to rise. When the gas rises to the top, it enters through the upper part of the powder concentrator and meets the materials scattered by the spreading plate. The materials are dispersed by air flow and sorted for the first time (primary powder).
After coarse powder separation, most of the particles are introduced into the vortex separation area along with the gas by the guide vane, and the other coarser particles settle to the discharge port under the action of gravity. Driven by the rotating air flow generated by the high-speed rotation of the turbine blade, the particles entering the vortex separation area are further dispersed and obtain a certain centrifugal force. At the same time, the particles are also affected by the gas drag force. The centrifugal force is less than the gas drag force. The particles are brought into the inner vortex area in the turbine blade plane by the air flow, enter the cyclone, and the finished products fall into the ash collecting box.
If the centrifugal force of the particles is greater than the gas drag force, the particles are brought back to the dispersion area and fall down to the coarse particle collection cone due to the action of gravity. When the particles fall to the bottom of the cone, they are washed by the gas introduced from the bottom of the cone to separate the fine powder adhered to the particle surface, and enter the vortex area with the air flow and enter the cyclone for collection.
The coarse particles flow into the discharge port at the lower part of the powder concentrator from the inner cone in three ways, and then enter the ball mill or other kind of mill again.
四、 Common faults in production of powder concentrator
（1） Low yield
The general analysis of low product volume is as follows:
A. The angle of guide vane is not ideal
B. The circulating air volume cannot fully take away the surrounding materials (insufficient air volume)
Adjust the angle of the guide vane appropriately.
Check whether the air supply pipeline is blocked.
（2） Yield fineness problem
For the product fineness, we can change the rotor speed to adjust. The faster the rotation, the higher the product fineness. On the contrary, the lower.
Note: if the rotating speed is too high, it will cause too much material in the mill to form full grinding.
In case of unbalanced materials in the mill, we can reduce the rotor speed to reduce the materials in the mill (differential pressure) without affecting the product qualification rate. Empty grinding is the opposite.
（3） Energy consumption problem
The main reasons for high energy consumption of powder concentrator are:
- The stator blade position (angle / number on the ring) is incorrect
- The rotor blade position (angle / number on the ring) is incorrect
- The rotor rotation direction is incorrect
- Insufficient lubrication
Solution: check and adjust according to the installation support manual. Check whether the lubrication unit works normally and whether the movable part is flexible.
（4） Pressure loss
Cause: in case of large pressure loss under normal operation, check whether the sealing of the top cover and bottom cover of the powder concentrator is good, and whether there is air leakage inside and outside the system.
Solution: seal the air leakage part and solve (repair) any bad problems in time.
（5） Material blockage
The main reason for the blockage of the cone bucket is that the raw material humidity is too high, and the hot air can not be dried in the future, resulting in too much wet return material sticking to the bottom of the cone bucket of the powder concentrator to block the cone bucket.
Solution: control the moisture content of materials entering the mill and ensure the outlet air temperature.
五、 Fault prevention measures of powder concentrator
- Strengthen the periodic replacement of easily worn and vulnerable parts at the transmission part;
- Ensure high-quality lubrication of rotating parts;
- Regularly check whether the bolts of relevant connecting parts are loose;
- Strengthen inspection and maintenance of internal easily worn and vulnerable parts;
- Eliminate “running”, “emitting”, “dripping” and “leakage” on site;
- Strengthen the perception of “seeing”, “listening” and “touching” when the equipment is running;
- Optimize the operation, learn for practical use, data comparability, timely adjustment and multi-path problem finding.