WATER-TUBE BOILER Russian patent published in 1999 - IPC

FIELD: low- and medium-capacity boilers. SUBSTANCE: boiler has top and bottom drums communicating through convective-bank uptake and downcoming tubes 3 and 4, respectively, where tube-to-tube clearances form at least one separate gas conduit. Furnace 5 abutting against convective bank tubes is surrounded by waterwalls connected to respective headers joined with boiler drums. Boiler also has two-stage economizer communicating with its water space; economizer stages 13 and 14 are connected in series with convective bank tubes inserted in boiler natural circulation loop along heating-gas flow and their counterflow gas channels are connected to supply main. EFFECT: provision for augmenting thermal processes in convective heating surfaces. 3 dwg