GB746143A - A new or improved grinding mill for cement and similar materials - Google Patents

Abstract

746,143. Ball mills. BARGERO, C. April, 15, 1954 [April 24, 1953], No. 11212/54. Class 59. A grinding mill for cement and similar materials comprises a first grinding chamber at its forward end and a second grinding chamber separated from the first chamber by a partition and extending over the remaining length of the mill, the second chamber being subdivided longitudinally into a plurality of compartments having the cross-sectional shape of circular sectors enclosing coarse and fine grinding bodies and communicating with one another and with the first chamber in such a manner as to cause the material to be ground to travel from the first chamber through certain of the compartments in the second chamber towards one end of the mill and through the remaining compartment or compartments in a reverse direction. In the form shown in Figs. 1, 4 and 5, the second chamber is subdivided by means of radial walls 14, 15 into six compartments about a central tube 8, material from the first chamber 5 passing through openings 11 in the tube 8 and being conveyed through the tube by means of a screw 9 to the rear end of the mill where it passes through openings 20 in the tube to a pair of diametrically-opposite compartments A in which it is preliminarily finely ground by means of grinding bodies R as it travels in a forward direction to the partition 4 separating the two chambers. The material reaching the front ends of the compartments A passes through holes 16 in the walls 15 and through holes in an intermediate partition 17 into the compartments B in which it is ultimately refined by small grinding bodies S as it gradually reaches the rear end of the mill whence it issues through holes 21 in the end member 3. Dust is drawn from the first chamber by means of a tube 10. The first chamber encloses coarse grinding rollers 6 guided, due to the rotation of the casing 1, over an annular grinding track 7 in the casing. In a modification, Figs. 6 and 8, the second chamber is subdivided by means of radial walls 22, 23, 24 into three compartments C, D, E enclosing respectively grinding bodies R, S, T. of gradually diminishing size, the material from the first chamber reaching the compartment C through an opening 25 in the partition 4 separating the two chambers. From the rear end of the compartment C the material passes through holes 26 in the wall 22 to the compartment D in which it travels in a forward direction and reaches the front end of the mill where it passes through holes 27 in the wall 23 to the compartment E through which it travels in a rearward direction to the rear end of the mill and issues through openings 28.