DEVICE FOR PNEUMATIC SORTING OF GRAINY MATERIALS, AND METHOD OF SORTING

摘要

The subject of the invention is a device for the pneumatic separation of grain materials and a separation method, especially of rock materials. It is known from the Polish patent application P.410602 there is a method and apparatus for processing coals, in particular for processing hard- enrichable coals with separation of concentrate and intermediate products suitable for use as a hard fuel. The method of processing coals is characterized by the fact that coal of the same grain-size class, larger than sieve dimension, is fed to a conveyor with a mesh band, and then, in form of monolayer, from chute from to a nozzle, where the lightest fraction of the material, with a density of 1250 - 1350 kg/m³ and ash content A_d = 8-11%, is sucked out by means of air. For this purpose, the nozzle is set to a suitable position in relation to the conveyor mesh surface; underpressure inside the nozzle is set to necessary value in range of 400-800 mm water column, where the sucked material falls out of the air stream into the jig. Additional nozzle located under the mesh band creates a negative pressure of a set value, which holds the fractions that are not meant to be sucked off.