GB758813A - Improvements in milling apparatus - Google Patents

Abstract

758,813. Grinding mills. KUCHENMEISTER, H. J. Aug. 21, 1952 [May 21, 1952], No. 21018/52. Class 59. A mill with a plurality of milling stages arranged around a vertical axis and two of which stages are arranged at different mean heights has the milling members of at least one milling stage comprising a horizontally rotatable plate carrying milling members co-operating with counter-milling members arranged in groups to form milling points between which are provided either spaces free from milling members or gaps formed by milling points lying at a greater distance from counter milling points. The rotatable milling plate 1, Fig. 1, is provided with eight groups of milling points 2 having therebetween spaces 3 free from milling members. The plate is also provided with preliminary beater members 5 and with a ring 4 of finer milling members. In a modification, Fig. 2 (not shown), the milling plate is provided with twelve groups of milling points which are radially interrupted by spaces free from milling members. In a further modification, the milling plate 9, Fig. 3, has milling points 10 having below the level thereof milling points 11. A ring 12 of finer milling members is also provided. The milling members or groups of milling members may be inserted interchangeably in the milling plate. The mill shown in Fig. 7 comprises a rotatable milling plate 22 which has milling members 24 grouped to form milling points as shown in Fig. 1. Counter milling members 26 are provided on a ring flange 25 at the lower part of the container 20 to which the material to be ground is fed. On the plate 22 are provided preliminary beater members 30 which co-operate with beater arms 31 on the container 20. The material passes from the milling members 24, 26 into an annular channel 27 and is discharged into an outlet 29 by means of a rotatable ejector finger 28. In a modification, Fig. 8 (not shown), cooling ribs are fixed on the container and air vanes are provided to effect an additional cooling. In another modification, Fig. 9 (not shown), the stationary milling members are arranged below the rotatable milling plate. In a further modification, Fig. 10 (not shown), the rotatable milling plate is conical and is provided with openings through which the material to be ground is guided vertically. In another modification, Fig. 11 (not shown), a rotatable disc is provided on its upper and lower sides with milling members which co-operate with stationary milling members. In a further modification, a stationary disc 61, Fig. 12, is provided on its upper and lower sides with milling members 62, 63 which co-operate with rotatable milling members 64, 65. The number of milling discs arranged one upon the other can be as large as desired. The discs can be rotated at the same or different speeds, and in the same or opposite directions. Within one milling point milling members of different characteristics can be employed.