Abstract: A method for purifyiing flue gas derived form incinerators burning refuse, wood, or sludge, in which the flue gas is cooled in a spray drier. A dust remover removes the dust from the flue gas. The flue gas is filtered through a filter-bed adsorber having filtering surfaces and packed with an adsorbent containing calcium hydroxide. The filter-bed adsorber is cleaned at intervals for removing adsorbate from the filtering surfaces. An aqueous suspension is prepared from at least some of the adsorbate that is removed from the filtering surfaces, and the flue gas is brought into contact with the suspension in at least one location upstream of the filter-bed adsorber for further separation of contaminates. The aqueous suspension is supplied to the spray drier for improving the purification of the flue gas.

Abstract: Flue gas deriving from incinerators that burn refuse, wood, or sludge is cooled in a spray drier, freed of dust in a dust remover, optionally freed of hydrohalides and sulfur oxides in one or two washers, one downstream of the other, and filtered through a filter-bed adsorber packed with an adsorbent containing a calcium hydroxide and optionally activated charcoal or coke. The adsorber is cleaned at intervals. An aqueous suspension is prepared from some or all of the adsorbate collected from the filter when it is cleaned. The gas is brought into contact with the suspension in at least one part of the system upstream of the filter.