Patent ID: 6869504

Claim:
An apparatus for passing stock to a headbox of a paper machine, comprising: a deaeration tank, the deaeration tank when filled with wire water having a defined wire water surface within the deaeration tank; a vacuum pump connected to the deaeration tank to pull a vacuum on the deaeration tank; an inlet duct connected to the deaeration tank and to at least one source of wire water, so that wire water can flow from the at least one source of wire water to the deaeration tank; a discharge duct connected to the deaeration tank, the discharge duct having a discharge end, the discharge end having an overflow, the overflow defining an overflow surface, said overflow of the discharge duct and the overflow surface defined thereby being located below the defined wire water surface within the deaeration tank and opening to a free air space; and wherein the discharge duct includes a first branch duct extending from the discharge duct and in communication with the headbox.