Artificial sand used in buliding industry

The apparatus illustrated in the drawingcomprises a grinder I, such as a ball mill, any suitable standard type classifier 2, such .as the Dorr, and pulp-receiving vessels 3, 4 and 5 which are interconnected for the flow of pulp in series therethrough.Artificial Sand Making Machine. Each vessel has a power-driven paddlewheel W for agitating the pulp. Any suitable troughs, pipes, conveyors, or the likemay be used for transferring the carbon and the pulp through the system. For convenience, these members shall be referred to merely as con duits. In accordance with our invention, .as perforated members for receiving the carbon, we mount in each vessel a perforated cylinder 6, 1 and 8 which is partl or totally immersed in the pulp. While We show the cylinders in inclined positions, we maymount them horizontally "in the vessels.Artificial Sand Making Process. For-example, we may revolve in the pulp :cylindr'ica'l screens with attached interior screws to feed the carbon through from one end to the other and-discharge 'it'into "a conduit. We may submerge or -par-tly submerge in the pulp a perfora'tedcoritainer of any suitable shape, for example "one rectangular in cross-section, and move the carbon therethrough from one end to the-other by any suitable mechanical device-such as the rakes used in Dorr classifiers. The ves- 'sels 3, 4 and 5 are maintained almost full of pulp and the continuous agitation prevents short circuiting in "flowing through the system. The cylinders may be of perforated metal plate 'or-a screenhaving openings which are smaller than the minimum sizeof carbon partic'les'used in the operation. Inside the cylinders, hollowtrunnions '9, Hi and H are suitably mounted in "bearings and are rotated by power means at the upper ends (not shown). Worm screws I5, 15 and I! are mounted on the outside of the trunnions and rotate therewith.