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US 4,253,613 AGranted
Method and apparatus for controlling the effect of the centrifugal force on the stock in pulp defibrating apparatus
OwnerRolf B. Reinhallinventor
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OwnerRolf B. Reinhallinventor
Estimating the term…
A method and apparatus is provided for controlling the effect of centrifugal force on pulp stock while being ground in the grinding space of a defibrating apparatus defined between a pair of grinding discs which rotate relative to one another in a fluid environment under superatmospheric pressure and corresponding elevated temperature. The grinding space includes a central portion, a first outwardly extending grinding space and a second outer grinding zone extending at an inclined angle from the first grinding zone. Pulp stock to be ground is introduced into the central portion and accelerated through the first and second grinding zones by centrifugal force generated by the rotating discs. The inclined grinding zone serves to split the centrifugal force into a vector perpendicular to the direction of flow of the pulp material and a vector aligned with the axial flow to reduce the accelerating force on the pulp grist in the direction of outward flow. By reducing the outward acceleration, the dwell time of the grist in the second grinding space is increased, resulting in optimum utilization of the entire grinding space for optimum refining efficiency.
In the method of refining pulp stock in which the pulp material is ground in a grinding space defined between a pair of grinding discs having ridges and grooves providing opposing grinding surfaces, which discs rotate relative to one another in an environment of a fluid medium under superatmospheric pressure and correspondingly elevated temperature in a housing, and in which grinding space the pulp material is accelerated from a central portion outwards towards a peripheral portion by the centrifugal force generated by the relative rotational movement of the discs, the improvement for controlling the effect of the centrifugal force on the pulp, comprising:
In a pulp defibrating apparatus in which the pulp stock is ground in a grinding space defined between a pair of grinding discs having ridges and grooves providing opposing grinding surfaces, which discs rotate relative to one another in an environment of a fluid medium under superatmospheric pressure and correspondingly elevated temperature in a housing, and in which grinding space the pulp material is accelerated from a central portion outwards and towards a peripheral portion by the centrifugal force generated by the relative rotational movement of the discs;
Dependencies are inferred from the claim text.