Abstract: A cylindrical scrubbing column having a cylindrical water-separator head is provided with an upwardly converging partition defining a diametrically extending elongated slot which communicates between the scrubbing region of the column and the head, the slot being aligned with a radial outlet for the flue gases from the head. The slot is flanked by a pair of longitudinally-extending impingement baffle register walls which remove water from the entraining flue gas by impingement baffle separation techniques and a further wall is provided at the end of the slot turned toward the radial outlet. The walls can converge in the direction of flow of the gas upwardly and the compartments behind the walls communicate with the radial outlet. The system has reduced pressure drop without detrimental effect to the separating efficiency.

Abstract: Swirl nozzles, especially for plants with flue gas scrubbers for the physical and/or chemical purification of flue gases emanating from power plant boiler installations. The nozzles include a substantially cylindrical nozzle chamber, at least one tangential scrubber fluid inlet into the nozzle chamber, and at least one nozzle bore arranged in a nozzle chamber bottom and extending coaxially with its axis with respect to the nozzle chamber. A conduit for feeding scrubber fluid can be secured at the tangential scrubber fluid inlet, and this conduit carries the swirl nozzle apparatus. The nozzle chamber and the inlet are provided in a body made of ceramic wear material, with the respective ends of the chamber also made of ceramic wear material and connected to the body. At least one chamber bottom includes the nozzle bore. The body and the nozzle chamber bottoms are arranged between steel stress plates. At least the body can be held under pretension condition between these stress plates.

Abstract: A scrubber for flue gases from a fossil-fired power plant in which calcium sulfate dihydrate is produced by recirculating the scrubbing water suspension containing lime and introducing oxygen into the sump collection, has a discontinuously operated pump which withdraws the suspension for recovering of the solid product only discontinuously so as to maintain the solids concentration between 40 and 130 g/l.

Abstract: A scrubbing column for flue gases and especially power plant flue gases removes sulfur oxides by absorption in a calcium containing scrubbing liquid and is surmounted by a water separator which is subdivided into sectors readily traversed by the flue gas at the head of the column and around a central plenum. The passage around these sectors, which is connected with a radially offset flue gas outlet, has a cross section progressively increasing toward this outlet.

Abstract: A rotary heat exchanger surmounts a scrubbing tower provided with two scrubbing columns through which the flue gas of fossil fuel combustion is passed in succession so that the rotary heat storage mass of the regenerative heat exchanger is heated by the incoming flue gas and the flue gas cooled in the scrubbing columns is reheated by the rotary heat storage mass as it leaves the tower.

Abstract: A scrubber is provided with a grate in its sump through which oxygen is introduced to separate the oxidation zone above this grate from a reaction zone below the grate, a calcium containing additive being introduced into this reaction zone. Flue gas to be desulfurized is passed through a washing zone above the sump and there contacted with normally circulating scrubbing liquid containing the additive to absorb sulfur dioxide and sulfur trioxide. The sulfur dioxide is oxidized to sulfur trioxide and the additive induces precipitation of calcium sulfate in the sump. After a prolonged standstill, settled solids in the sump are induced into movement by drawing a portion of the sump liquid from an upper part thereof and injecting it into a lower part of the sump.

Abstract: A scrubber is provided with a grate in its sump through which oxygen is introduced to separate the oxidation zone above this grate from a reaction zone below the grate, a calcium containing additive being introduced into this reaction zone. Flue gas to be desulfurized is passed through a washing zone above the sump and there contacted with normally circulating scrubbing liquid containing the additive to absorb sulfur dioxide and sulfur trioxide. The sulfur dioxide is oxidized to sulfur trioxide and the additive induces precipitation of calcium sulfate in the sump. After a prolonged standstill, settled solids in the sump are induced into movement by drawing a portion of the sump liquid from an upper part thereof and injecting it into a lower part of the sump.

Abstract: Converter exhaust gases in a steel-refining plant are used for the recovery of energy, e.g. for the production of electrical energy. The steel-refining process is carried out in a closed converter maintained at a pressure of from 1 to several atmospheres gauge above ambient pressure. The converter exhaust gases at such elevated pressure is subjected to washing, preferably in the exhaust-gas stack or duct and the washed converter exhaust gases from several refining processes is stored and supplied to a gas consumer, e.g. an electrical generating plant, at a rate which is independent of the blowing period.

Abstract: The gases emerging from a high-pressure gas furnace are subject to coarse particle separation and then to washing and scrubbing with water before driving an expansion turbine which has a gas bypass so that the turbine can be cut off. The scrubbing water recycled to the scrubber when the turbine is cut off, is permitted to traverse a cooler of the washing-water recovery unit but, when the turbine is operative, the scrubbing water bypasses the cooler. The water introduced into the scrubber can thus have a temperature of about 25.degree. C. when the turbine is bypassed and about 50.degree. C. when it is effective.

Abstract: An aerator for the biological purification of waste water comprises an undulating annular disk of sheet material, centered on a vertical axis of rotation, forming interleaved sets of upper and lower sectors interconnected by generally vertical, radially extending webs. Each lower disk sector defines with the adjacent webs an upwardly open channel whereas each upper disk sector defines with its associated webs a downwardly open channel. A central sleeve, descending from the level of the alternately upwardly and downwardly open channels, obstructs the inner ends of the latter but opens into the inner ends of the former whose effective cross-sectional area is adjustable with the aid of a vertically shiftable shutter ring inside the sleeve.