SYSTEM FOR SOLVING HIGH-SODIUM COAL COMBUSTION CONTAMINATION BY USING PYROLYSIS-COMBUSTION DUAL-BED

摘要

A system for solving high-sodium coal combustion contamination by using a pyrolysis-combustion dual-bed, comprising a fluidized bed (4), a cyclone separator (5), a coal ash distributor (6), an ash-coal mixer (12), a down pyrolysis bed (14), a back-feeder (16), and a purification device (13); the cyclone separator (5) communicates with the upper side of the fluidized bed (4); the outlet of the cyclone separator (5) communicates with the inlet of the coal ash distributor (6); the two outlets of the coal ash distributor (6) respectively communicate with the inlet of the back-feeder (16) and the inlet of the ash-coal mixer (12); the outlet of the ash-coal mixer (12) communicates with the inlet of the down pyrolysis bed (14); the two outlets of the down pyrolysis bed (14) respectively communicate with the inlet of an external bed (15) and the inlet of the purification device (13); the outlet of the external bed (15) is connected to the inlet of the back-feeder (16); and the back-feeder (16) is near the lower side of the fluidized bed (4), and communicates with an inlet on the lower side-wall of the fluidized bed (4); and the outlet of the purification device (13) communicates with the inlet on the lower side-wall of the fluidized bed (4). The system removes volatile sodium in coal through pyrolysis, reduces the sodium element content in the coal, and reduces the contamination on the convection heated surface of the boiler, thus improving the heat exchange efficiency of the heat exchange surface, and stabilizing the boiler steam rate.