Abstract: Rotary furnaces and processes for heat treating a workpiece generally include an external shell wall and a refractory lining abutting the shell wall to define a substantially cylindrically shaped interior chamber for treating one or more workpieces; an opening in the an external shell wall and a refractory lining for loading and unloading the workpieces; a rotatable hearth for receiving and rotating the workpieces within the substantially cylindrically shaped interior chamber; and a plurality of thermal isolation walls, wherein adjacent thermal isolation walls define a space effective to accommodate and thermally shield each one of the workpieces to be treated and have a height at least equal to a height of the workpiece. The presence of the thermal isolation walls substantially prevents heat transfer between the workpieces being treated.

Abstract: A ring mill apparatus and method utilizes at least one hydraulic or other direct drive motor to drive a roller in contact with a ring that is to be expanded by the ring mill. The motor may be two opposed radial piston hydraulic motors, to drive an upper king roller, which contacts the outside of the ring, which is inserted between the upper king roller and a lower mandrel roller, which contacts the inside of the ring. The lower mandrel roller is urged upwards against the ring by a ram driven carriage. Two hydraulic or other direct drive motors can be provided in-line with, and directly connected to, the king roller.