The UCX aerodynamic (pneumatic) classifier is combined with a cyclone, air filter and fan.
The batch material is evenly supplied to the classifier by means of a screw or vibrating feeder and pneumatic transport. In this type of separator, the material is tangential to the rotor chamber. The advantage of this type of supply is the initial velocity of the gas-powder mixture. Inside the classifier there is a rotor with a diameter depending on the size of the device, the speed of which determines the size of particles that are able to get through the spaces between the blades. In the UCX aerodynamic classifier, there are three phenomena that separate fine/light grains from coarse/heavy ones.
The first phenomenon occurs when the stream of material falls within the rotor, and more precisely – in its upper part. Then the fine grains closer to the rotor are immediately sucked in. The second phenomenon occurs a bit lower in the middle part of the rotor, where a stream of secondary air A is directed to the system through a tangential pipe and static blades. It causes dispersion of the material, release of fine grains, and then directing them between the spaces between the blades of the rotor. The third phenomenon occurs downstream, where the coarse/heavy fraction rejected by the rotor, still having small grain size/mass, is again blown through by additional secondary air B. This type of air allows the recovery of fine grains entrained with the coarse fraction.
The higher the rotor speed, the finer the material is obtained. The product that has passed through the impeller is pneumatically fed into the cyclone. There, almost all particles are removed from the air. The cyclone outlet is connected to a filter that separates very fine particles from the gas.
At the end of the installation there is a fan that provides negative pressure in the classification system. The air flow through the pneumatic classifier is controlled by flow sensors. Appropriate rotation of the classifier rotor and air flow ensure the required division of the feed material into fine/light and coarse/heavy fractions.