Abstract: The present pulp catcher is provided with a rotating brush roller for cleaning the sieve or straining drum in a container. The shaft ends of the rotating brush roller are movably supported in bearings which are pressed by biasing means radially inwardly relative to the rotational axis of the straining drum. The shaft ends of the rotation brush roller are sealed by stuffing box means which are connected to the container by means of compensating corrugated tubings. The movable support of the shaft ends makes it possible to maintain the rotating brush roller at a most efficient spacing relative to the straining drum even when the bristles of the brush roller become shorter due to wear and tear.