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Papridry™ -Continuous Operation of Two Pilot Units at Paprican

Papridry™ -Fonctionnement en continu de deux units pilotes Paprican

Papridry™ -Fonctionnement en continu de deux units pilotes Paprican

Abstract: Incremental developments have increased the speed of the conventional dryer section, but have not eliminated its shortcomings, such as its enormous size, high capital and operating costs, and its failure to improve product quality. Papridry™ is a novel method for drying paper and board; it is designed to provide substantially higher drying rates and to improve the product quality. Two key elements of this technique are: pressing the wet web onto the surface of a large-diameter, heated, drying cylinder; and impingement of hot gas directly onto the uncovered paper from a hood surrounding the cylinder. Extensive pilot paper machine trials were conducted to test the method at nearly commercial speed in a series of long continuous trials. These trials, mostly conducted at 1000 m/min, demonstrated that the technique can reliably dry paper over an extended period of time. The drying rates measured in these trials ranged from 60 kg/h/m² to 240 kg/h/m². This work demonstrates that the technology is now ready for commercial application. The Papridry™ system could be installed on new machines or retrofitted into existing machines.

Paper presented at the PAPTAC Annual Meeting 2010 in Mon-treal, Que., February 2-3, 2010.

Keywords: DRYING, IMPINGEMENT DRYING, PRESSING, YANKEE DRIERS, YANKEE MACHINES, RUNNABILITY, NEWSPRINT, PAPER MACHINES, PAPER PROPERTIES, QUALITY

Full manuscript available at www.paptac.ca.