| 摘要 |
The invention relates to a process for the purification of flue gases by feeding (7) limestone into the furnace (1) of a boiler, by separating (3) the dusts from the flue gases at a point after the furnace, by hydrogenating (14) the separated dust, which contains calcium oxide, by returning (12, 13) it to the flue-gas flow (11) at a point after the separation point but before the reaction zone (4), in which additional water or vapor is fed (15) into the dust-bearing flue gas, whereafter the dust which contains sulfated calcium hydroxide is separated (5) from the flue gases (6) thus purified. According to the invention, the hot, dust-bearing flue gas coming from the furnace is divided in the separation zone (3) into a dust-poor main flow (11) and a dust-rich secondary flow (12), vapor or water mist (14) being fed into the secondary flow at a point at which the temperature of the secondary flow is 300-600 DEG C. The invention also relates to an apparatus, such as a cyclone, intended for use in this process and having nozzles (19) for feeding in steam or for atomizing water, and a connecting duct (12) between the separation device (3) and the flue-gas duct (11) for the purpose of making the activated dust-rich secondaryflow of flue gas to join the dust-poor main flow at a point after the cyclone (3). |
