Vented refiner and venting process

Abstract From the Canadian patent

In a refiner having ribbed refining disks to form a refining zone between such disks the refining, spaces of such disks including radial ribs forming grooves between them, which grooves are blocked at intervals by dams connecting the ribs at opposite sides of the grooves, intergroove slots connect neighboring grooves in a disk in an arrangement to provide venting passages for steam through the grooves forming zigzag courses which bypass the refining zone between the refining disks. The slots can be spaced apart progressively greater distances radially inward to favor flow of steam toward the periphery of the disk or radially outward to favor flow of steam toward the center of the disk. …