US Patent 7481076 Apparatus for making fibers

A duct assembly is employed for directing a central air flow upwardly toward the rotating spinner assembly of a rotary-type fiberizer that produces a downwardly flowing column of fibers. The central air flow eliminates the low-pressure zone that normally occurs beneath the spinner assembly of conventional fiberizers. The cross-sectional profile of a lower portion of the duct is vertically elongated where the duct passes through the fiber column so as to facilitate the flow of the fiber column over the duct. A shielding member can be positioned to deflect the central air flow away from the spinner assembly and against the interior of the fiber column to insulate the spinner assembly from the relative cool air flow. In another embodiment, a conduit extends through the fiberizer spinner assembly and directs a cooling gas beneath the spinner assembly within the interior of the fiber column.