Separator technology in the closed-circuit cement grinding system

The commonly used powder separator in the closed-circuit cement grinding system includes O-Sepa powder separator, rotor powder separator and combined powder separator.The working principle is: The grinding material enters the inner shell of the separator from the upper hopper and falls into the spiral sleeve space of the main shaft. After uniform distribution, dispersion and pressurization, the material is fully suspended. Under the action of the high speed rotation of the scattering tray, the material is scattered around by the inertial centrifugal force on the one hand, and is raised upward by the updraft generated by the scattering tray blade on the other hand, forming the boiling of the material in the upper space of the spreading tray. The finer particles in the material float upward and are in the state of suspension and dispersion, while the thicker material is dispersed along the wall of the feeding tray.

A rotor is arranged above the feeding tray, in the powder selection room, the air flow near the surface of the rotor grading ring and the material dispersed in the air flow rotate at high speed with the grading ring, so that the material in the air flow is subject to strong centrifugal force. The centrifugal force can be adjusted by changing the speed of the main shaft with the speed regulating motor. When the rotary speed increases, the centrifugal force also increases If the air volume is certain, the cutting diameter will be reduced and the product will be finer. If the speed decreases, the product becomes thicker, thus completing the powder selection.

This old type of powder separator has low efficiency, large circulating load ratio of the system, serious wear and tear of vulnerable parts such as rotor blades and guide blades, short life, bad system stability, not easy to operate, and it is easy to over-grinding or coarse material escape.

The high-efficiency dynamic separator developed by our company is equipped with a pre-separating device composed of a fluidized bed and a jet ring, which can pre-separate the material that passes through the fluidized bed retaining ring, so that the fine powder in the upper layer is easier to be carried by the high-speed upward air flow from the jet ring into the powder separator after pre-separation, and the coarse powder in the lower layer can smoothly enter the slag-drip discharging system from the nozzle ring.It solves the defect that the coarse powder of the existing separator also enters the self-test selection zone of the guide blade and rotor, and some fine powder enters the coarse material collection cone together with the coarse powder, and returns to the tube mill to continue grinding, which greatly improves the grinding efficiency of the tube mill. The product has the advantages of reasonable structure design, high efficiency of powder selection, low energy consumption, high output of equipment, reasonable particle size distribution and increased cement strength.

The core technology of the product has been applied for national intellectual property protection, and one utility model and one invention patent have been declared, which has improved the shortcomings of the design and production of cement powder separator in China, and the technology is advanced in China.