DEVICE AND METHOD FOR HEAT TREATING METAL ARTICLES UNDER A PROTECTIVE GAS/REACTIVE GAS ATMOSPHERE IN A CONTINUOUS OPERATION

摘要

The invention relates to a device for heat treating metal articles under a protective gas/reactive gas atmosphere in a continuous operation, comprising a furnace housing (2) which surrounds a furnace chamber (1) as a heating zone (HZ), comprising a plurality of heating elements (4), which protrude into the furnace chamber (1), for heating the furnace chamber (1), and comprising a preheating zone (VZ) upstream of the heating zone (HZ), wherein the combustion exhaust gases do not contact the articles. The invention also relates to a corresponding heat treatment method. The aim of the invention is to improve the efficiency. This is achieved in that the device additionally has a collecting device (7) for capturing the exhaust gas of the heating elements and a heat transferring unit (9), which is supplied by the collecting device (7) and is arranged in the interior of the preheating zone (VZ), or the device is provided with lines (11, 13) for transporting hot air from the cooling element (3") into the preheating zone (VZ) according to claim 8 in order to recover heat; the exhaust gas exiting the heating elements is captured and supplied to an exhaust gas-heated preheating zone (VZ) upstream of the actual heating part; and in the exhaust gas-heated preheating zone, the heat of the exhaust gas is indirectly transferred to the protective gas /reactive gas contained in the preheating zone (VZ) via heat transferring surfaces.