Quenching tank with grid hoist carrying stack of workpieces - where hoist is lowered into tank to form part of closed circuit through which quenching liq. is driven by propeller

摘要

The workpieces are stacked on a grid in a vertical shaft forming a hoist which can be lowered into a tank filled with water, oil, or molten salt. The top and/or the bottom end of the shaft is provided with a row of curved ducts bent to form horizontal inlets or outlets. When the shaft is lowered into the tank, the ends of the curved ducts are aligned with pipes through which the quenching liq. is circulated by a propeller. The result is that the liq. can be driven up the shaft and thus over the surfaces of the workpieces. The propeller is pref. located inside a duct with bent inlet and outlet ducts so the liq. flows through a closed circuit. Uniform hardening is obtd. without uncontrolled and varying distortion of the workpieces.