Patent ID: 8245963

Claim:
A grain size selection and/or pulverulent matter drying apparatus, for treatment of suspended mineral particles whereof at least 90% in weight have a size less than 60 mm, the apparatus comprising: a substantially vertical gas pipe, with an ascending flow, having a base with a lower opening, a gas inlet at said base, an upper opening, a supply opening between said lower opening and said upper opening for insertion of matter, wherein a portion of matter, called fines, can escape with the gas through the upper opening due to the bearing capacity of said ascending flow, while another portion of coarser matter is not carried away by gas and falls into the lower opening, the gas inlet is comprised of one plenum surrounding the lower portion of the gas pipe; and means for creating turbulence, favoring separation of different grain sizes and suspension of matter not immediately driven by gas at an introduction point, wherein said means for creating turbulence are situated between the lower opening and the supply opening being comprised of obstacles to the ascending gas flow, in the form of globally horizontal blades, fastened at an internal wall of the pipe, oriented longitudinally towards a center of the gas pipe, and arranged at least over two successive levels in height, staggered angularly between at least two successive levels in height, in order to stop the matter sliding along the walls of the gas pipe, and to create gas turbulence in the vicinity of the blades enabling separation of the diverse grain size fractions present as well as suspension of less coarse matter.