Overview of Air Classifier

Airflow classifier is a kind of airflow classification equipment. The classifier, cyclone separator, dust collector and induced draft fan form a set of classification system. Under the action of the fan suction, the material moves at high speed from the lower end of the classifier to the classification area with the updraft. Under the strong centrifugal force generated by the high-speed rotating classification turbine, the coarse and fine materials are separated, and the fine particles meeting the particle size requirements are classified The gap between the wheel blades enters the cyclone separator or dust collector to collect, the coarse particles entrained part of the fine particles hit the wall and the speed disappears, and they descend along the cylinder wall to the secondary air outlet. After the strong elutriation of the secondary air, the coarse and fine particles are separated. The particles rise to the classification zone for secondary classification, and the coarse particles fall to the discharge port for discharge.
working principle 
The rotor impeller of the air flow classifier is a composite bidirectional centrifugal type. The impeller rotates at high speed and forms a negative pressure zone at the lower part of the impeller. The air in the classification cylinder enters through the air inlet of the lower part of the impeller, and is discharged from the outlet along the upper impeller flow path, and the fine particles are sprayed. The ring flows out, under the action of the control ring, the airflow rotates upwards, and there are partial speeds in the axial and circumferential directions.The airflow flows inward through the upper space of the grading disc, enters the lower impeller through the upper inlet of the impeller, and is discharged from the lower impeller outlet. The air flow rotates and moves downwards in the cylinder, and then flows upward through the middle of the inner cylinder to the air inlet at the lower part of the impeller, and the circulating flow forms a cross circulating air flow. The material input from the star-shaped feed valve falls into the high-speed rotating spoiler, and under the action of centrifugal force, the material is thrown toward the stopper ring. Under the action of the stopper ring, the material falls down in the grading cylinder. Under the action of the cross airflow, the coarse particle material slips from the wall of the control ring into the coarse material collector, while the fine powder is transported to the fine powder cyclone collector below (the inner tube of the grading cylinder) with the airflow from the suction port in the upper middle of the rotor. ), in this way, the raw material is divided into two parts, thick and thin, and the remaining air is sucked by the suction port in the middle of the lower part of the rotor, flows through the blades, the injection fine particle ring, and the control ring, and then flows from the periphery of the control ring to the suction port in the upper middle of the rotor. Back, forming a continuous automatic loop again and again. The excess air brought in by the material and the excess air due to the higher temperature of the classification chamber, the air expands and the excess gas is discharged from the residual air outlet to ensure the balance and stability of the air flow in the classification chamber. The air outlet is equipped with a filter cloth bag to prevent the discharged air from polluting the environment.
Performance characteristics
　　 is suitable for the fine classification of dry micron-level products. It can classify spherical, flake, and irregularly shaped particles, and can also classify particles of different densities. The particle size of the classified product can reach D97: 3～150 microns, the product particle size is steplessly adjustable, and the variety is easy to change. The classification efficiency (extraction rate) is 60% to 90%. The classification efficiency is related to the nature of the material and the content of particles that meet the particle size. The fluidity of the material is good, and the content of particles that meet the particle size requirements is high, the efficiency is high, and vice versa. The speed of the grading wheel is high and the apex is cut accurately. Multi-stage classifiers can be used in series to produce products of multiple particle sizes at the same time. It can be used in series with ball mill, vibration mill, Raymond mill and other grinding equipment to form a closed loop. The control system adopts program control, real-time display of running status and easy operation. The system runs under negative pressure, and the dust emission exceeds 40mg/m. After adopting the noise reduction measures, the operating noise of the equipment is not higher than 75dB(A).