Hosokawa Alpine Aktiengesellschaft

Hosokawa Alpine Aktiengesellschaft & Co. Ohg

Marcus Alex Adam

Stefano Zampini

Georg Konetzka

Bodo Furc Hner

This invention relates to an air classifier for the separation of granular material into three fractions, whereby each individual fraction is very precisely separated in a single housing. The classifier incorporates motor-driven separator/classifying wheels each of which is provided with a tangential separating-air supply at the level of the respective wheel, a fixed guide vane ring positioned at a radial distance from the circumference of the respective separating wheel, and at least one bulk-product feeder system as well as discharge provisions for fine, intermediate and coarse material, respectively. The wheels are provided with a closed cover disk at their respective first axial end and with fine and, respectively, medium fraction discharge port at their respective second axial end. The closed cover disks of the wheels form a free-flow gap in the space between the two stages of the classifier. An outward flow of air at the level of the upper and lower areas of the gap and an inward flow of air at the level of the center of the gap combine to produce a rotating eddy current or vortex in the separating zone. The vortex causes an extended dwell time of the dispersed bulk material particles in the transition zones of the two separating stages.

Air classifier

The method for air classification of toner used to develop electrostatic images, whereby a toner product consisting of a powder with a wide particle size distribution is converted into a higher-quality toner product with a narrow particle size distribution in that the residence time of the toner product is controlled by means of components, components which in the upper section of the classifying chamber quickly introduce the toner product in a homogeneous state into the classifying chamber, which in the central section of the classifying chamber permit a longer residence time of the toner product, and which in the bottom section of the classifying chamber permit rapid discharge of the toner product from the classifying chamber, all of which makes it possible to produce a toner end product with an extremely narrow particle size distribution.

Method for air classification of toner

A vertical-axis air classifier having a central product feed, a drive shaft, a tangential classifying air supply inlet located on a level with the rotor, a stationary guide vane ring arranged at a radial distance around the periphery of the rotor, a deflector-wheel rotor with one-sided bearing as well as a housing with fine material and coarse material discharge. The drive shaft, an annular-shaped fines discharge chamber arranged coaxially to the drive shaft, an annular-shaped coarse material discharge chamber arranged coaxially to the drive shaft and the bearing for the rotor are arranged on the same side and beneath the rotor to permit ease of cleaning and dismantling.

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Augsburg, Germany

Marcus Alex Adam