GB423898A - Improvements in or relating to grinding machines for paper pulp - Google Patents

Abstract

423,898. Paper - pulp grinding - machines. LORD, F., 26, Astbury Street, and WILBY, A. C., 5, Johnson Street, both in Radcliffe, Lancashire. Feb. 6, 1934, No. 3823. [Class 96] In a grinding-machine for paper pulp of the kind comprising a plurality of rotary grinding discs mounted on a vertical shaft to act on the pulp in co-operation with stationary discs as the pulp passes successively between them, the inlet is arranged at the lower end of the machine and the pulp is forced upwardly and is ground between shear-edged grinding blades provided only on the undersides of the rotary discs and the upper sides of the stationary discs, the grinding only taking place while the pulp is flowing outwardly from the shaft. A frame 1 carries an electric motor 2 with a shaft 3 coupled at 4 to a vertical shaft 5 supported by a ball thrust bearing 7 linked to a lever 8 fulcrumed at 9 and linked to a screw 10 engaged by a nut-wheel 11 between lugs 12 to permit the shaft 5 to be raised or lowered at will. Three stationary dished conical discs 13 are arranged one above the other round the shaft 5, the lowermost of which has a radial flange 14 attached to an inlet chamber 15, while the upper ones have inverted dish-shaped flanges 16 which fit over a lower disc 13 to form a series of chambers 17, the top disc 13 having a cover 19 provided with an outlet 20. Each disc has a central aperture 18 connecting one chamber with the next. The shaft 5 runs through all the chambers 17, glands 21, 22 forming water-tight points of entry and exit. Water leaking from the apparatus is caught in a trap disc 23 with drip channel 24 and drain pipe 25. The upper sides of the discs 13 have removable shear-edge blades 26 which co-operate with shear-edged blades 28 on the under side of discs 27 contained in the chambers 17 and mounted on the shaft 5. The upper sides of the rotary discs 27 have curved upwardly projecting radial vanes 29 while the flanges 16 have on their under sides curved radial vanes 30. Inspection doors 31 may be provided on the members 16. The conicity of the discs 13, 27 is sufficient to have a self-centring effect for the discs 27 but is not sufficient to produce any seizing effect between the blades 26, 28. The pulp is fed in at the first central aperture 18, passes outwardly between the shearing edges of the blades 26, 28 of the lowermost set of discs 13, 27, and then upwardly over the periphery of the disc 27, the vanes 29 being acted upon by the pulp to assist the driving of the disc 27, and the vanes 30 guiding the pulp to the second central aperture 18 which leads into the second chamber. Finally the pulp issues forth by the pipe 20 leading from the upper chamber 19.