A NEW PAPER-MACHINE DRYING CONCEPT - A MULTIFUNCTIONAL, RADIAL-JET REATTACHMENT NOZZLE BLOW BOX

The report describes the design and operation of a blow box with radial-jet nozzles. The new design is presented as an alternative to conventional pocket ventilation systems, which can cause edge flutter and sheet bulging. Air is impinged directly on the unsupported web as it traverses the open draws in the dryer section. Air flow through each radial-jet nozzle creates a ring of negative force that pulls the web toward the nozzle. The turbulent air flow within these stabilizing rings scrubs the web surface and improves drying efficiency. Direct control of air flow through each nozzle makes it possible to correct sheet moisture profiles across the paper machine