GB208962A - Process and apparatus for disintegrating and finely grinding hard and soft substances also for squeezing and pressing out parts of plants and the like - Google Patents

Abstract

208,962. Rushen, P. C., (Krupp Akt.-Ges., Grusonwerke, F.). March 19, 1923. Roller mills; disc and like mills; edge-runners and pans and like mills; roller-and-ring mills. - Relates to a process and apparatus for disintegrating and finely-grinding hard or soft substances, and for squeezing and pressing- out parts of plants and the like. Both operative surfaces between which the disintegration &c. takes place, or the carriers or supports of both operative surfaces, are magnetized to increase the working pressure. A separation of the material according to its degree of magnetic susceptibility may be combined with the disintegration of substances containing magnetizable materials. Fig. 2 shows a roller mill with an exciting coil 4 on the shaft 1 between the rollers 2, 3. A coil may also be provided between the rollers of the shaft 5. The current is supplied to the coil 4 by the brushes 7, 8 and slip-rings 9, 10, the coil being protected by a guard-ring 6. The rollers are pushed on to cores on the shafts and may be held thereon by magnetic force. In the mill shown in Fig. 3, the exciting coil 11 is stationary and the two magnetized rollers 12, 13 rotate on the stationary shaft 14. The roller 13 is driven by a pulley 16, and rotation is transmitted to the shaft 15 and the roll 12 by magnetic power. Fig. 4 shows a mill with a number of magnetically induced or excited rollers 18, 19, 20 running in contact with a magnetically-excited roller 17. Pressures of different strengths are obtained at the various grinding points by making the small rollers 18, 19, 20 of different sizes or by exciting them in various strengths. A magnetic field for separating particles of iron from material to be ground may be arranged in front of the first grinding point. One roller may be formed as a hollow ring inside which one or more magnetically excited or induced rollers may be arranged. Magnetizable grinding-devices may travel over the end face or faces of ring or disc shaped poles. A number of concentric rings forming magnetic fields may travel over the magnetizable grinding- devices, or ring or disc poles arranged axially or movable relatively to each other can either rub directly on each other or on magnetizable grinddevices interposed between them. The ring or disc shafts may be vertical or horizontal. Fig. 5 shows a mill in which the magnetic field is formed by two concentric ring-poles 21, 22 excited by a coil 23 surrounded by a non-magnetic guardring 24. Conical rollers 25 running on inclined shafts bear on the surface of the rings. The rollers may rotate round the stationary shaft 26 and the rings be stationary; or the rings may rotate and the rollers be stationary, or the rings and rollers may rotate relatively to each other. The material is fed by a tube 2 and distributor 28 to the grinding-part, and the material may be withdrawn by suction through a cap 29 and tube 30. More than two pole-rings with coils interposed between them may be used. One or both rollers of a roller mill may be used for separating the ground material into its magnetic- and non-magnetic parts, or separate magnetizable grinding-rollers, may be used. Fig. 6 shows a separating roller 33 excited by induction from the magnetizable grinding-rollers 31, 32 arranged to separate magnetic material that is not to be disintegrated. Fig. 7 shows apparatus with magnetizable grinding-rollers 35, 36, 37 and two separating-rollers 39, 40. The roller 39' removes magnetizable material not to be disintegrated, and the roller 40 removes disintegrated magnetizable material. Fig. 8 shows a mill with two ring or disc poles arranged one above the other on a stationary shaft, the upper pole being axially displaceable relatively to the lower pole to adjust the fineness of the grinding. The upper pole 43 rotates above the fixed ring 42 which is excited by the winding 21 and induces magnetism in the pole 43. The material to be ground is fed bv a pipe 44, funnel 45, and ducts 46 to the annular grinding-slot between the opposite annular surfaces of the poles 42, 43. The upper pole 43 is supported by rollers 47 upon a disc 48 adjustable vertically. A hood 51 encloses the grinding path so that the ground material can be sucked off at 49. In another arrangement, rolling magnetizable grinding-bodies in the form of balls are inserted between the upper rotating pole 43 and the lower stationary pole 42, the grinding taking place between these balls and the upper surface of the pole 42.