| 摘要 |
<p>A disc press for continuous pressing of aqueous or suspended pulp for fractionating the pulp in a liquid fraction and a dry substance fraction, comprises two plane parallel pressing discs mounted for rotation about a shaft and having strainer plates which haul the pulp therebetween by friction. The press also comprises inner and outer pressing means extending between the pressing discs and together with the latter define a curved pulp passage which in the transport direction has a varying cross section and constitutes a filling or dewatering zone, a pressing zone and a discharge zone. The passage zones of the pulp passage combined extend throughout an angle which is less than 360.degree., and the filling or dewatering zone has an approximately constant cross section. The subsequent pressing zone (B) has a uniformly decreasing cross section the centerline of the pressing zone following an arc having an approximately constant radius about the axis of rotation. The pressing zone of the pulp passage has an outer confining surface which is shaped as pivoted arm having a curved concave surface, the arm at its one end being mounted for swinging about a point at the start of the pressing zone and at its other end being connected to a power means in the form of an adjustable hydraulic cylinder which holds the arm with a predetermined force, and which when the pulp pressure in the press exceeds a predetermined value, will influence and displace the pivoted arm. Possibly, the pressing discs are kept at a correct mutual distance by an hydraulic cylinder which acts as an additional safeguard by automatically opening the complete pulp passage when the pressure in the press exceeds a given threshold value.</p> |
