Pressure screen’s structure and principle
A pressure screen contains two main components: the rotor and screen cylinder. Once the unscreened pulp enters the screen via the feed stream, the accept fibres pass through small slots or holes in the screen cylinder to the
accept stream, while oversized particles continue down the length of the cylinder to the reject stream.
The principal measures of screen performance are:
1) Contaminant removalefficiency, defined as the mass percentage of contaminants leaving the screen through the reject port to that entering the screen;
2) Capacity, defined as the maximum mass flow rate of pulp in the accept stream;
3) Power consumption, defined as the power required by the rotor;
4) Reject rate, defined as the mass flow of fibres rejected with the contaminants. Achieving high capacity and high efficiency with reduced energy demand at low reject rate is the goal of an
optimal rotor design.