Patent GB-1486793-A (GB)
Title: Separating device for separating grinding elements from a ground material in a liquid suspension in an agitating grinding mill
IPC: B02C17/16
Filed: 1974-09-23
Abstract: 1486793 Wet separating; agitator mills NETZSCH MASCHINENFABRIK Gebr 23 Sept 1974 [28 Sept 1973] 41371/74 Headings B2A and B2H A separating device 36, Figs. 1 and 4, for separating grinding elements from a liquid suspension of ground material produced in an agitating grinding mill 20 comprises at least two separating members 40, 42 (42, 44) defining a gap 56 between them and a vibrator 52 by means of which at least one separating member can be made to vibrate, the arrangement being such that in use, there is relative movement between said at least two separating members. The mill 20 comprises a tank 22 which could alternatively be arranged vertically, and which contains grinding elements and an agitator 28 and into which a liquid suspension of solid material to be ground is introduced at 24. The tank has an outlet 30 with a flange 32 to which a baseplate 34 of the separating device is attached. The separating member 40 is an annular plate attached to the base plate 34. The member 42 is a similar plate attached via connecting members 46, to a rod 48 extending through bellows 50 to the vibrator 52. The member 44 is a circular plate which has an annular bead thereon and is attached by connecting members (not shown) to the plate 40. In operation the suspension of ground material flows through the gaps 56 and through passages 47 in the connecting members 46 and are discharged at 38. The gaps 56 are smaller than the grinding elements which are thus retained in the mill. The vertical vibrations imparted to the plate 42 serve to avoid clogging of the gaps. Alternatively, the plates may be square or rectangular. A number of vibrating plates may be mounted between stationary plates, Fig. 5 (not shown) and may be horizontally vibrated. In another embodiment Fig. 6 (not shown) an annular gap (56') may be provided between the inner periphery of an annular plate (40) attached to the base plate (34) and the outer periphery of a circular plate (64) disposed in the aperture of the annular plate and connected to the vibrator. In a modification Figs. 7 and 8 (not shown) a number of vibratory circular plates (68) are mounted in circular apertures in a perforated plate (66) attached to the base plate (34). In another embodiment, Figs. 9 and 10 (not shown) the separating members consist of stationary concentric rings (70) between which are disposed vibratory circular rings or members (72). In Fig. 11, two vibrating plates 74, 76 are connected to different vibrators 52', 52 so that vibratory motions of different amplitudes and frequency can be applied to the plates. In Fig. 12, an intermediate plate 80,56 formed with six agitating elements 88 and connected to a shaft 90 form gaps 56 with outer plates 84, 86 which are connected by screws 82. A bush 94 attached by ribs 95 to baseplate 34 enables the plates 84, 86, which are sealed from the baseplate by a resilient diaphragm 96 and rings 97, to effect a rotary movement. A vibrator 52 rigidly connected via a casing 98 and a sleeve 98' to the plates 84, 86 sets up longitudinal vibrations while another vibrator 52' produces torsional vibrations and these vibrations are transmitted via the shaft 90 to the plate 80. The agitating elements 88, 89 give rise to hydrodynamic shocks which are applied to the gaps 56 to help keep them clean. In a modification, Fig. 14, the separating elements consist of another ring 102, an inner plate 103 and an intermediate ring 104 connected by three rods 105 to the vibratory shaft 90.