GB836911A - Pulp refiner - Google Patents

Abstract

836,911. Disc mills. SUTHERLAND INTERNATIONAL Ltd. Aug. 15, 1956 [Sept. 1, 1955], No. 25017/56. Class 59 A, pulp refiner comprises discs 48, 71, Fig. 5, between which the pulp is passed, the disc 48 being secured to a rotary shaft 10 which is supported in bearings 11, 12, 13, so as to be held against relative endwise movement, the bearings being fixedly mounted in a closed housing 5 which is slidable along a guideway, to urge the disc 48 towards the disc 71, by means of a double-acting fluid pressure cylinder 75 secured to an end wall 76 of a base frame 1 and having its piston 77 secured to the housing 5, the disc 48 being held in operative position according to the setting of a solenoid-actuated 4-way valve 108 in the hydraulic circuit, Fig. 6, which also includes a reservoir 85 a pump 89 and a pressure regulating valve 116, and is characterized in that the supply line 107 from the pump 89 is provided with an accumulator 111 for continuously accommodating sudden variations in the nature of the pulp feed and consequent sudden pressure waves between the discs, without interrupting the operation of the discs. A stop nut 82, Fig. 5, adjustably mounted on the protruding rear end 77a of the piston 77 co-operates with the outer face of the fixed end wall 76 to limit the movement of the piston, and to facilitate adjustment of the stop nut, the latter is provided with a pointer 82a for co-operation with side graduations on the outer face of the wall 76. The pump 89 is driven by an electric motor 87 and draws fluid e.g. oil, from the reservoir 85 and delivers it through the pipe 107 to the valve 108 which is connected by pipes 109, 110 to ports 80, 81 at opposite ends of the cylinder 75. A further pump 88 driven by the motor 87 also draws fluid from the reservoir 85 and supplies it through a pipe 92, a cooler 93 and pipes 94, 95, 96 to ports 36, 37 at the top of the bearing housing 5 so as to lubricate the bearings. The electric motor 87 and an electric motor 130, Fig. 7, for driving the shaft 10 are included in an electric circuit which also includes switches 100, 135 which automatically break the circuit to stop the motor 130 in the event of reduced pulp pressure to the refiner or of abnormally low pressure in the lubricating system. The pulp to be refined is introduced under pressure through a pipe 72 and a tubular boss 65a to an axial port 71a in the disc 71 and after passage between the discs is discharged through an outlet 73. To refine pulp which is not pumpable, a screw feeder can be installed in the tubular boss 65a. In a modification, Figs. 10 and 11 (not shown), means are provided for impeding the flow of pulp between the discs. U.S.A. Specifications 2,156,320 and 2,651,976 are referred to.