SYSTEM FOR REGULATION OF PROTECTIVE ATMOSPHERE OF FURNACE Russian patent published in 1997 - IPC

FIELD: chemical-thermal treatment of steel. SUBSTANCE: this is intended for use in electric furnaces with controlled protective atmosphere, such as in bell-type furnaces for high-temperature annealing of electrical-sheet steel in nitrogen-hydrogen atmosphere. Device has working medium pipeline with gas blower and regulating valve, injector with injection manifold and injected medium pipeline in which additionally installed is throttle valve. Injection manifold of injector is connected by pipeline having regulating valve with injected medium pipeline before throttle valve inlet. This widens range of adjustment of relation of protective atmosphere components from 5% to 95% both as to hydrogen and nitrogen, ensures flexible regulation at any period of furnace operation without resetting of system. Fine adjustment of component ratio in nitrogen-hydrogen mixture improves magnetic properties and quality of surface of electrical-sheet steel. EFFECT: high efficiency.