CIRCULATING FLUIDIZED BED (CFB) WITH IN-FURNACE SECONDARY AIR NOZZLES

摘要

A circulating fluidized bed (CFB) boiler includes a reaction chamber, where a bubbling fluidized bed (BFB) is contained within an enclosure within the lower portion of the reaction chamber and contains an in-bed heat exchanger (IBHX) that occupies part of the reaction chamber floor. A plurality of in-bed secondary air nozzles comprise a plurality of tubes which are grouped together and run across the width of the BFB between the BFB enclosure wall and an outside wall of the CFB. The nozzles are positioned to prevent the deflection of solids falling onto the BFB from the CFB by the secondary air jets while avoiding a complicated structure that would interfere with gas and/or solids movement in the furnace. The nozzles' exit openings are flush, or almost flush, with the BFB enclosure wall.