The ''classical'' control scheme for pulp pressure screens regards the
screen as a static system. Out of several faults that could occur dur
ing screen operation, it addressed only the possibility of plate plugg
ing. Among other drawbacks, this method restricts the screen throughpu
t. After testing different parametric and nonparametric methods for fa
ult detection on screens, it was could that a mathematical model devel
oped at the Pulp and Paper Centre in The University of British Columbi
a has potential for its use as diagnosis tool. By monitoring some of t
he process parameters of the screen included in this dynamic model, in
cipient malfunctions of the screen could be detected and failure could
be prevented. The pressure screen model is part of a general strategy
for diagnosing and controlling pressure screens.