Abstract: A wet electrostatic precipitator (1) includes an inlet (2) for receiving a gas (4) containing a pollutant, and an outlet (6) for discharging therefrom the gas (8) from which said pollutant has been at least partially removed. Nozzles (24) are operative for purposes of spraying liquid onto at least one first vertical collecting surface (30) of at least one collecting electrode (18). A liquid distributor (42) is provided for purposes of pouring liquid onto at least one second vertical collecting surface (44), said at least one second vertical collecting surface (44) being located on a further collecting electrode (36), with said further collecting electrode (36) being located downstream of said at least one collecting electrode (18). The nozzles (24) are located upstream of the liquid distributor (42), as viewed with reference to the direction of flow of the gas.

Abstract: A wet electrostatic precipitator (1) comprises an inlet (2) for receiving a gas (4) containing a pollutant, and an outlet (6) for discharging therefrom the gas (8) from which said pollutant has been at least partially removed. Nozzles (24) are operative for purposes of spraying liquid onto at least one first vertical collecting surface (30) of at least one collecting electrode (18). A liquid distributor (42) is provided for purposes of pouring liquid onto at least one second vertical collecting surface (44), said at least one second vertical collecting surface (44) being located on a further collecting electrode (36), with said further collecting electrode (36) being located downstream of said at least one collecting electrode (18). The nozzles (24) are located upstream of the liquid distributor (42), as viewed with reference to the direction of flow of the gas.

Abstract: A device (1) for separating sulphur dioxide from a gas (4) by means of an absorption liquid has an inlet (2) for gas (4) containing sulphur dioxide, an outlet (18) for gas (16), from which sulphur dioxide has been separated, and as essentially horizontal apertured plate (8), which is arranged to allow passage from below of sulphur dioxide containing gas (4) and to carry, on its upper side (12), a flowing layer (14) of the absorption liquid. An outlet box (20) beside the apertured plate (8) is arranged to be passed by liquid, which is distributed in the gas (4) coming from the inlet (2). A first pumping means is arranged to feed a coolant flow to the outlet box (20) and a second pumping means is arranged to feed an absorption liquid flow, which is essentially independent of the coolant flow, to the apertured plate (8) to form the flowing layer (14). In a method of separating sulphur dioxide, the above-described device (1) can be used.

Abstract: A device (1) for separating sulphur dioxide from a gas has an inlet (2) for the gas (4) and an outlet (42) for gas (40), from which sulphur dioxide has been separated. An apertured plate (20) is arranged between the inlet (2) and the outlet (42) and allows the gas (4) to pass from below. On its upper side (22), the apertured plate supports a flowing layer (24) of absorption liquid. An inlet duct (12) connects a container (6) for absorption liquid to the upper side (22) of the apertured plate (20). A means (10) conveys the absorption liquid (8) from the container (6), through the inlet duct (12), to the upper side (22) of the apertured plate (20) and along the apertured plate (20).

Abstract: A device (1) for separating sulphur dioxide from a gas (4) by means of an absorption liquid has an inlet (2) for gas (4) containing sulphur dioxide, an outlet (18) for gas (16), from which sulphur dioxide has been separated, and as essentially horizontal apertured plate (8), which is arranged to allow passage from below of sulphur dioxide containing gas (4) and to carry, on its upper side (12), a flowing layer (14) of the absorption liquid. An outlet box (20) beside the apertured plate (8) is arranged to be passed by liquid, which is distributed in the gas (4) coming from the inlet (2). A first pumping means is arranged to feed a coolant flow to the outlet box (20) and a second pumping means is arranged to feed an absorption liquid flow, which is essentially independent of the coolant flow, to the apertured plate (8) to form the flowing layer (14). In a method of separating sulphur dioxide, the above-described device (1) can be used.

Abstract: A device (1) for separating sulphur dioxide from a gas has an inlet (2) for the gas (4) and an outlet (42) for gas (40), from which sulphur dioxide has been separated. An apertured plate (20) is arranged between the inlet (2) and the outlet (42) and allows the gas (4) to pass from below. On its upper side (22), the apertured plate supports a flowing layer (24) of absorption liquid. An inlet duct (12) connects a container (6) for absorption liquid to the upper side (22) of the apertured plate (20). A means (10) conveys the absorption liquid (8) from the container (6), through the inlet duct (12), to the upper side (22) of the apertured plate (20) and along the apertured plate (20).

Abstract: A process and an apparatus in black-liquor evaporation for the selective removal, by liquid absorption, of hydrogen sulphide from the generated gas (3) containing hydrogen sulphide as well as carbon dioxide, an disclosed. In the process, the gas is counter-currently brought into multistage contact, preferably comprising three stages (6, 7, 8), with circulating carbonate-containing alkaline solutions, preferably sodium carbonate solutions (25), the pH of which is adjusted during the absorption to about 9-12 by the addition of a hydroxide, preferably a sodium hydroxide solution (26, 27, 28). It is preferred that the gas flow is turbulent and the liquid flow is laminar when contacted with one another. The apparatus comprises a container (1) having a gas inlet (2), a gas outlet (4), and a packing (9) arranged in several successive stages (6, 7, 8).

Abstract: A method and a device for removing sulphur dioxide from a gas, preferably a flue gas, by means of an aqueous suspension of an absorbent, preferably limestone, are disclosed. In the method, the flue gas is conducted through a conduit topped with an apertured plate (3) on which is provided a flowing layer of the absorbent suspension having a static height of at least about 100 mm, preferably about 200-500 mm, and a volume of about 50-500 l, calculated per m.sup.3 of flue gas flowing through the layer every second. The layer of absorbent suspension flows along the apertured plate (3) at a flow rate of about 5-100 l/s, preferably about 10-30 l/s per 1 m.sup.3 of sulphur-dioxide-containing gas per second.

Abstract: A method for treating the fine-grained spend absorbent (primarily calcium sulfite and calcium sulfate) from a dry flue gas desulfurization process. The absorbent, having a small amount of binder therein, is oxidized in a fluidized bed reactor at a temperature in the range from about 700.degree. C. to about 1000.degree. C. to produce a dry essentially fully oxidized pelletized calcium sulfate product.Calcium sulfate pellets having an average diameter of from about 0.5 mm to 5 mm and containing from about 1% to about 3%, by weight, of binder constituents, are composed of agglomerated calcium sulfate particles having an average diameter of from about 50.mu. to about 100.mu. bound to each other by the binder constituents.

Abstract: A process for recovering sodium citrate from a solution utilized in an absorption/stripping process for SO.sub.2 recovery, which involves cooling a portion of the stripping solution to precipitate sodium sulfate, which is separated from the mother liquor. Thereafter, the mother liquor portion is subjected to an evaporative crystallization to precipitate sodium citrate, which is reintroduced along with fresh absorbent solution into the SO.sub.2 absorption/stripping process.

Abstract: Improved efficiency in recovering SO.sub.2 from waste gases is obtained in a system where the SO.sub.2 is absorbed into a solution which is then distilled. The method of this application entails compressing the steam-SO.sub.2 mixture issuing from the still before condensing out the steam, so that the heat from the compressed steam-SO.sub.2 mixture may be used in generating the steam for the still, and the condensate may be recycled through the still, preferably after reheating the same.