Patent ID: 6213307
Filing Date: 2001-04-10
Classification: B07B

Abstract:
An apparatus for cleaning and classifying solid particles having different weights, said apparatus comprising:a) a vertical chamber having side walls and a cross-sectional area generally increasing in the upward direction,b) means for introducing particles of different weights into the chamber,c) means for creating in the chamber a vertical upward suspension air stream whose velocity varies in a substantially continuous manner with height, to thereby classify particles of different weights and volatilities at different chamber heights; whereby the lighter and more volatile particles are suspended at a height higher than the heavier and less volatile particles,d) a top section provided with outlet means and connected to the top of the vertical chamber to collect and remove particles lighter and more volatile than the particles suspended at the top of the vertical chamber,e) a plurality of at least one channel spaced vertically within the chamber, where particles within a range of similar weights and volatilities are suspended and conveyed horizontally toward channel outlet means arranged vertically along one side wall of the chamber for removing by suction the suspended, classified particles,f) a plurality of at least one ribbed section spaced vertically within the chamber and located adjacently to the channels; wherein a plurality of at least one deviating rib divides each such section in a plurality of pathways and deviates the upward air, to thereby homogenize the vertical velocity horizontally throughout adjacent channels; wherein the air velocity in each pathway has a substantial non-vertical component such that the air resistance to the gravity fall of particles is insufficient; wherein particles falling through the sections are conveyed horizontally toward air extraction means arranged vertically at one end of the ribbed sections along the side wall opposite to the chamber side wall on which the channel-outlet means are positioned, to thereby spread the particles more uniformly horizontally in the direction of length throughout the chamber; whereby at a specified height length is the distance between the side wall on which the air extraction means are positioned and the opposite side wall on which the channel outlet means are located and width is the distance between the other two opposite side walls,g) means to spread the particles horizontally in the direction of width; whereby said means are omitted in special situations where they are not found indispensable for air stability,h) means for creating a horizontal conveyor air stream to direct the particles suspended in the channels toward the respective channel outlet means on one chamber side wall,i) means to create a horizontal conveyor air stream of opposite direction to direct the particles falling through the ribbed sections toward the respective air extraction means on the wall opposite to the chamber side wall on which the channel outlets means are positioned; whereby said means are omitted in special situations where they are not found indispensable for air stability,j) means for the observation of the air streams, the streams of particles and the process in general by any selected from the group consisting of at least one operator and at least one process controlling device,k) means for the adjustment of the streams and the process in general by any selected from the group consisting of at least one operator and at least one process controlling device, andl) means to drive the apparatus.