Abstract: A headbox for a paper making arrangement involves the use of internal Coanda type nozzles within the headbox for recirculation and agitation of slurry therein. The Coanda nozzle has an inlet, an outlet, and a primary flow slit adjacent a curved surface which recedes from the flow axis of the primary flow slit. The primary flow is recycled water which has drained from the slurry on the web-forming surface and which is delivered under pressure to the Coanda nozzle. This causes slurry in the headbox to be entrained and drawn into the inlet of the Coanda nozzle, from which it is thrust out through the outlet of the Coanda nozzle back into the headbox. The Coanda nozzle inlet is aligned with but spaced from a slurry supply nozzle in the headbox such that a portion of the entrained slurry comes from the supply nozzle and another portion comes from slurry already in the headbox.

Abstract: A paper stock diffuser system employing a plurality of spaced, generally V-shaped projections having adjoining shear surfaces diverging away from one another.