THREE -PHASE CIRCULATING FLUIDIZED BED EVAPORATOR FOR WHEAT STRAW BLACK LIQUOR EVAPORATION

A novel vapor-liquid-solid circulating fluidized bed evaporator, meaning for enhancing heat transfer and preventing fouling, is applied to wheat straw black liquor, which is the primary pollutant in China′s papermaking industry. It is treated by alkali recovery,in which evaporation is a key process. The experimental results show that the vapor-liquid-solid three-phase boiling heat transfer coefficient is enhanced by 20% ～40% than that of vapor-liquid two-phase boiling flow, also, the novel evaporator exhibits an excellent function of fouling prevention.