MULTISTAGE-EVAPORATION STEAM GENERATOR Russian patent published in 1999 - IPC

FIELD: thermal engineering. SUBSTANCE: steam generator has waterwall heating surfaces connected to drum 1 and to external cyclones 2, 3 symmetrically arranged on both ends and interconnected by boiler-water pipelines, feedwater header 4 connected to drum 1, outlet pipeline 5, and blowdown-water pipeline 6; in addition, feedwater header 4 is connected to external cyclones 2, 3 whose outlet communicates with boiler-water pipelines 9 inserted in drum 1 at its butt ends; blowdown-water pipeline 6 is brought in drum 1 at its center. In addition, downcomer pipes connected to external cyclones 2, 3 and to butt ends of drum 1 are included in waterwall heating surfaces arranged in vicinity of furnace space where heat load is higher and those connected at drum center are included in waterwall heating surfaces located in vicinity of furnace space where heat load is lower. EFFECT: uniform salt distribution over evaporation stages and reduced salt content of boiler water which prevents hydrodynamic and thermal distortions in operation. 2 cl, 1 dwg