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Claim 1

THE METHOD OF FORMING A FIBROUS WEB FROM DILUTE STOCK ON A CYLINDER MOLD OF A CYLINDER PAPER MACHINE, COMPRISING THE STEPS OF DELIVERING THE WHITE WATER LEAVING THE MOLD, FRESH STOCK AND RECIRCULATED STOCK IN SEPARATE STREAMS TO A COMMON MIXING ZONE HAVING AN ENTRY POINT AND A DISCHARGE POINT, COMBINING SAID STREAMS AT SAID MIXING ZONE ENTRY POINT AND CONFINING SAID COMBINED STREAMS WITHIN SAID MIXING ZONE TO FOLLOW A SPIRAL FLOW PATH RAISING AT A GRADUALLY DECREASING VELOCITY TO A PREDETERMINED POINT OF MAXIMUM AREA WITHIN SAID ZONE AND FROM SAID POINT DESCEDING AT A GRADUALLY INCREASING VELOCITY TO SAID ZONE DISCHARGE POINT THEREBY SIMULTANEOUSLY INTIMATELY MIXING AND DEAERATING SAID COMBINED FLOW OF WHITE WATER, FRESH AND CIRCULATED STOCK, AND FROM SAID MIXING ZONE DISCHARGE POINT DELIVERING SAID MIXED, DEAERATES, DILUTED STOCK TO THE CYLINDER MOLD.