GB943906A - Drum mill - Google Patents

Abstract

943,906. Ball mills. MIAG MUEHLENBAU UND INDUSTRIE G.m.b.H. July 13,1962, No. 26939/62. Heading B2A. In a drum mill with grinding compartments I, II, III, Figs. 1 and 4, formed by longitudinal walls 7, with discharge grates 13, 14 between the ends of the compartments for sufficiently fine-ground material and with screening and conveying channels 15 connected to the grates 13, 14, the walls are constructed as double walls and have interspaces 28, Fig. 6, to receive a cooling medium. Apertures 29, Figs. 5 and 6, are provided in the drum shell 1 for the entry of cooling air into the interspaces 28, bars 31 being provided for guiding the air in the interspaces, the air being drawn through space 32, part 33 and pipes 34, 36 leading to a blower 38. The interspaces are penetrated by bolts 46 the heads of which hold lining plates 44 in place. The channels 15, which serve for conveying the oversize into other grinding compartments, are radially subdivided by screening areas 16, a helical channel 20 for conveying the undersize being connected to the outer parts of the channels 15. The cooling air may be supplemented, or replaced, by cooling liquid in which case the apertures 29 are omitted and the cooling liquid pumped in or out through central pipes fitted one inside the other and which are led preferably through the axle arm 3 at the discharge side of the drum. A feed channel 50, Figs. 7 and 8, has its main part 51 connected to a central inlet opening 52 in a transverse wall 6 at the inlet end of the drum, the end part 53 of the channel having its mouth 54 pointing in a direction opposite to the direction of rotation of the drum. The leading wall 57 of the channel 50 merges, preferably tangentially, into the shell 58 of a cylindrical space 59 connected to the inlet opening 52. Reference has been directed by the Comptroller to Specification 786,219.