GB1380313A - Method of and partition for controlling the amount of material mixed with grinding members in a grinding compartment of a tube mill - Google Patents

Abstract

1380313 Tube mills P SLEGTEN 18 Feb 1972 [18 Feb 1971] 7592/72 Heading B2A The flow of material through a tube mill is controlled by adjusting the level of material in a reservoir chamber. The mill comprises a grinding chamber 4, Fig. 1, and a smaller reservoir chamber formed by a partition 8 having two walls, viz an upstream wall 12 and a downstream wall 13. The reservoir chamber contains a deflector 29 which serves in operation to discharge the material either into a second grinding chamber 5 or into an outlet trunnion 2. The upstream wall 12 has preselected apertures 14 which permit passage only of sufficiently ground material 7 while retaining the grinding media 6. The reservoir chamber includes scoops 18 which are rotatable about shafts 22, Fig. 2, and held in a preselected position by springs 25. The scoops are rotated upon rotation of the mill by cooperation of rollers 27 in shaped tracks 28. The scoops are thus filled to a preselected amount and thereafter discharged over the deflector 29. In a further embodiment microphones 31 are used to control known apparatus which in turn maintains the desired flow by controlling the positioning of the guide track 28. The scoops may include movable portions 18', Fig. 4, which vary the lifting capacity; alternatively scoop volume may be kept constant and part of the material recycled via apertures 21, Fig. 5, in the casing 20, Fig. 1, adjustably registering with apertures 34 in an inner cylinder 33. Alternatively the scoops 18 may include adjustable apertures, or the deflector 29 may include a movable closure ring (35), Fig. 6 (not shown) so as to provide a variable degreeof recycling.