GB1176412A - Improvements in and relating to an apparatus and method for Pulping and Defibering - Google Patents

Abstract

1,176,412. Pulp refiners. BOLTON-EMERSON S.A. 26 Jan., 1967, No. 3878/67. Heading B2A. [Also in Division D2] Pulping and defibering apparatus 30, Fig. 1, which may be a bottom- or side-drive pulper comprises a pulp container 31, a vaned circulation impeller 34, an imperforate stator member 55 coaxial with the impeller and having attrition means 61 and an adujstment mechanism 58 for a truncated-conical attrition gap 65, the gap receiving stock radially discharged from the impeller and directing the stock away from the interior of the container. The vanes 38 of the impeller are mounted on identical segmented plates 44, Fig. 3, which are bolted at 45 to the vane side 39 of the impeller 34 to form a circular disc. Vanes 46, 47 on opposite sides of the impeller are higher than the remaining vanes 38 to ensure vortical circulation of stock. The stator 55 is formed by bolted arcuate segments 57, Fig. 4, and on its inner face has attrition means 61 in the form of. blades 62 and channels 63. The gap adjuster 58 includes bolts 59 and shims 71, 72 which fix the stator 55 at a desired axial position. Pulp is extracted via a chamber 73 and conduit 75 or recirculated via a screen 79, Fig. 10, optional pump 76 and conduit 77. Flow passages 78, Fig. 10, or slots 83, Fig. 7 in the stator 55 and variation in the gap permit control of dwell time. Stator segments may be replaced by drilled extraction plates to permit increased throughput of easily defibred material. An actuator 86 responsive to freeness or consistency sensors axially adjusts the impeller. In modifications the stator 55 may surround the impeller by 180‹ or 270‹, leaving an unimpeded discharge portion. (For Figures see next page)