Treatment of flowable particulate solid with liq. - using flow passage with set of conical projections to induce vortices with good mixing

摘要

Particulate solids which can flow are contacted with a fluid as a suspension. The system has at least one contact space which is essentially a vertical channel where the solids are introduced into a stream of the contact fluid. The surface of the channel has a continuously changing shape. The walls have zig-zag profile and the passage itself can be of diverging cross section. The sharp edges of the points of the zig-zag locates vortices in the fluid and thus ensure good mixing. The process is for mechanical, thermal and/or chemical treatment of particulate solids esp. purification of crude salt crystals. The process ensures a narrow well defined residence time spectrum and allows the residence time to be tailored to the particle size range of the material.