DUAL-BED SYSTEM TO PREVENT THE POLLUTION OF BOILER HEATING SURFACE

摘要

A dual-bed system to prevent the pollution of a boiler heating surface is provided. The dual-bed system comprises a fluidized bed (4), a cyclone separator (5), a coal ash distributor (6), an ash and coal mixer (12), a downlink pyrolysis bed (14), a returning device (15) and a purifying device (13). The cyclone separator (5) is connected with the upper side of the fluidized bed (4), and an outlet of the cyclone separator (5) is connected with an inlet of the coal ash distributor (6). Two outlets of the coal ash distributor (6) are connected with the inlets of the returning device (15) and the ash and coal mixer (12) respectively. An outlet of the ash and coal mixer (12) is connected with an inlet of the downlink pyrolysis bed (14). Two outlets of the downlink pyrolysis bed (14) are connected with the inlets of the returning device (15) and the purifying device (13) respectively. The returning device (15) is close to the lower side of the fluidized bed (4) and connected with the inlet at the lower side wall of the fluidized bed (4). An outlet of the purifying device (13) is connected with the inlet at the lower side wall of the fluidized bed (4). By removing volatile sodium in the coal through pyrolysis in the dual-bed system, the content of sodium element in the coal and the pollution of the convection heating surface of the boiler can be reduced, the heat exchange efficiency of the heat exchange surface can be improved, and output of the boil can be stabilized.