PROCESS AND DEVICE FOR DESULFURIZING EXHAUST GAS

摘要

PURPOSE:To reduce the amount of combustion ash in a recycle desulfurizer and obtain the sufficienly high desulfurizing rate without improving equipment as far as possible. CONSTITUTION:In a combustion device 1, a desulfurizer (lime stone, slaked lime) is sprayed to a high temperature desulfurizing section (900 deg.C or over: lime stone)/a low temperature desulfurizing section (500 deg.C or over: slaked lime) and reacted with SO2 in exhaust gas, and then recovered by dust collectors 5 and 6. A mixture of used desulfurizer of specified particle diameter between the average particle diameter of desulfurizer and the average particle diameter of combustion ash or under the average particle diameter of desulfurizer with the combustion ash recovered from powder is fed into an intermediate temperature desulfurizing section 7 (500-900 deg.C) or a high temperature desulfurizing section (900 deg.C or over). The recycling operation in which the amount of an unreacted desulfurizer can be picked up as much as possible and the percentage of combustion ash is lowered can be attained by classifying solid components after the desulfurizing reaction.