GB990380A - Improvements in and relating to grinding apparatus for fibrous materials - Google Patents

Abstract

990,380. Disc mills. DEFIBRATOR A.B. Nov. 3, 1961 [Nov. 8, 1960], No. 39398/61. Heading B2A. A grinding apparatus for fibrous material comprises a housing 12 wich is supported on a frame 10 and encloses a grinding member 14 secured to the housing and a grinding member 16 secured to a rotatable shaft 18, and compressing members 56, 60 for creating a grinding pressure between the grinding members, the housing being secured to the frame at the end adjacent the compressing members and. having its opposite end mounted in a support 48 permitting axial movement of the housing relative to the frame without substantial change in the relative positions of the central axis of the housing and the frame. The axial movement permitted by the support 48 prevents thermal stresses arising between the housing and frame from the passage of steam at superatmospheric pressure through the housing. One end of the housing is secured by bolts 34 to the frame and the other end of the housing is bolted to two uprights forming the support 48 which is secured by bolts 52 to the frame. The ends of the housing have seals 23, 24 through which passes the shaft 18 supporting the rotatable grinding member 14, the shaft being rotatable in bearings 26, 28 and connected by a coupling 20 to a motor 22. The bearing 28 has spherical rollers 130 and a casing 132 axially movable in a part 134 of the frame so that as the housing expands and contracts the slight movement of the axis of the shaft as the support 48 rocks about its base is accommodated, the casing 132 being movable radially against springs 136. The bearing 26 permits the shaft 18 to rotate in a casing 66 which is movable axially in the frame and is secured to the compressing members in the form of a hydraulic servomotor 56, 60 which may be controlled as described in Specification 821,938 to axially urge the grinding member 16 towards the stationary grinding member 14. The grinding member 16 can also be adjusted by a hand-operated worm-andwheel mechanism 118, 122. The grinding member 16 consists of a pair of holders 90 mounted on a disc 88, each holder carrying a plurality of segments 94 provided with radial or peripheral channels or grooves. The grinding member 14 is similar to the grinding member 16 and is adjustable by bolts 112 and screws 114 so as to be deformed until it has a conicity corresponding to the conicity of the rotatable grinding member under the grinding pressure. The fibrous material to be ground is supplied to an inlet 46 and passes through a sleeve 37 to the grinding members and an outlet 115 An interlock is provided to prevent operation of the motor except when the grinding members are separated.