Estrutura de caldeira

摘要

A boiler structure capable of efficiently alleviating or preventing corrosion and slagging on furnace walls in a furnace is provided. A circulating firing boiler structure is configured so that fuel and combustion air supplied into a furnace (11) from burners (12) disposed at a plurality of positions on furnace walls (11a) forming a rectangular cross section are combusted so as to form a swirling flow. Air-supplying parts (20) are disposed near flame-affected portions of furnace wall surfaces, where flames formed by the respective burners (12) approach or contact, to form regions having a higher air concentration than the peripheries thereof.