A drainer for a feed system for a cellulose digester has a substantially open and hollow inlet (devoid of a spiral flow imparter or a like flow restriction) and a substantially annular screen within an elongated housing having a flow direction between the housing inlet and outlet. The screen is slotted and the slots are at an angle &agr; between 5-90° with respect to the flow direction, so as to minimize passage of cellulose material through the slots, or clogging of the slots.