IPC 2013 : D21D 1/16 : Beaters with means for returning the pulp over the head of the beater roll.

IPC2013 > D > D21 > D21D > D21D 1/00 > D21D 1/16[2] > Beaters with means for returning the pulp over the head of the beater roll.
D SECTION D — TEXTILES; PAPER.
D21 PAPER-MAKING; PRODUCTION OF CELLULOSE.
D21D TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE.
D21D 1/00 Methods of beating or refining; Beaters of the Hollander type (knotter screens D21F).
D21D 1/16 · · Beaters with means for returning the pulp over the head of the beater roll.