GB116583A - Improvements in or relating to Machines for Grinding Ores, Minerals, Stones and the like. - Google Patents

Abstract

116,583. Broadley, J. R. July 13, 1917. Ball mills.-A screening-compartment, arranged at the end of the mill and separated therefrom by a grid, is provided with devices, comprising a trunnion having ports communicating with shoots, for discharging fines or for returning large particles to the mill; the discharging and returning devices may be combined. In the returning- device shown in Fig. 1, a conical or cylindrical screen h secured to the drum a is provided with a radial plate or shoot z which is arranged opposite a port c in the trunnion d. A number of plates and ports may be provided. The plates may be solid or perforated. Preferably an outside screen g is provided for classifying the particles that pass the screen h. The screens may be built up on rings w, y which are secured to the trunnion bv bars x. The grid consists of a plate j formed with openings which are covered by detachable plates l having tapering slots m. The plates l are secured by bolts o engaging recesses in adjacent plates. Detachable liners n are arranged around the plates l. In the arrangement shown in Fig. 7, the trunnion d is formed with ports 20, 15 for returning large particles and discharging fines respectively. The screening-compartment 14 is provided with a number of segmental screens 17 each provided with a radial plate z arranged opposite one of the ports 20. The ports 15 each communicate through a radial trough 19 with a spiral trough e on the inside of the compartment 14. The troughs 19 are arranged between the screens 17. The ports 15 lead to a funnel f<11>.