Abstract: A process for purifying, by the wet method, fumes containing nitrogen oxides in which nitrogen monoxide is oxidized by an oxidizing agent into nitrogen dioxide which is itself reduced to nitrogen by using the reducing properties of sulfur dioxide present in the fumes and wherein the reduction is effected with the aid of an intermediate agent which prevents the transfer of nitrogen oxides in the form of nitrates to the effluent of the purification process.

Abstract: A process for the purification of flue gases by wet methods in which the inert part of the flue gases are separated from acidic pollutants by leaching with the acidic agents of the washing liquid to which recovered flue dust has been added. The leached toxic pollutants are then extracted from the washing liquid by appropriate treatment of the discharge of the recycling circuit.

Abstract: The present invention relates to improvements in centrifugal separators of the cyclone type, in which the liquid or gaseous fluid to be purified passes through an inlet blading which is shaped so as to cause the fluid to whirl rapidly in so-called irrotational flow with uniform longitudinal lamellar components, around a high voltage electrode. An outlet device firstly comprises a convergent portion which partly converts the energy of whirling into energy of longitudinal translation, then a blading which completes the conversion, and finally a divergent portion in which the excess of dynamic energy of flow is converted into static pressure in order to recover as much as possible of the whirling energy applied to the fluid upstream of the inlet of the cyclone device. The separated particles are evacuated through a tangential outlet. The invention is more particularly applicable to the purification of fluids.

Abstract: A chimney comprises a central column through which the combustion gases or the like are forced, this column terminating at its upper end in a nozzle of smaller cross-section, and an outer wall which surrounds the column while leaving an annular intermediate space into which air is forced under a pressure slightly above the pressure of the combustion gases within the central column, this outer wall joining the periphery of the column in the zone of the upper nozzle. Apertures are provided in the wall of the column just below the nozzle to connect the annular space and the inside of the column.

Abstract: In a process for the centrifugal treatment of liquid of liquid or gaseous fluids containing impurities in suspension, of the type in which the fluid to be treated is injected tangentially in a first end of an apparatus of circular transverse section in which this fluid forms a first, substantially cylindrical rotating layer, while at the other end, and starting from the periphery, a fraction containing heavy impurities is collected, then cleared fluid, then possibly a fraction containing impurities lighter than the fluid, it being provided to recycle at least one fraction of the fluid leaving the apparatus by tangential injection into the first end thereof, the fraction to be recycled independently of the initial fluid to be treated is injected at a point located at a radial distance different from that of the point of injection of said fluid, so as to create in the apparatus at least one second, substantially cylindrical layer concentric to the first, in contact therewith and rotating in the same direction s

Abstract: Treatment of fluid polluted with solid particles, for instance, from a dust removal or washing process, by pretreating the fluid to agglomerate the particles, then whirling the fluid to centrifugally concentrate the particles in a first fraction of the fluid and thereby substantially purifying a second fraction thereof, filtering the first fraction to recover the solid particles, collecting the particles and recirculating the purified fluid in the particle removal or washing process, the above treatment being carried out by apparatus having particular utility where the fluid is a liquid.

Abstract: In a process and apparatus for the treatment of liquids containing solid particles, the mixture is first formed into a film to run down the walls of an enclosure having a frustro conical top wall and be subjected to a drying gas flow, and the partially dried mixture is then led back to a spray inlet to discharge as an atomized spray within the same enclosure for a second stage of drying, which may include combustion of solid particles, also within the same enclosure.

Abstract: An atomizer for liquids having an annular body part with a circumferential groove in its inner periphery, and an inlet for injecting liquid tangentially into the groove whose depth decreases gradually away from the inlet is provided with a member which directs solid particles travelling along the groove with the liquid away from the groove to prevent them circulating in the groove. The member may be a curved tongue which forms an extension of the bottom wall of the groove at a position where the groove ends and which directs the particles inwardly and axially away from the groove.

Abstract: Treatment of fluid polluted with solid particles, for instance, from a dust removal or washing process, by pretreating the fluid to agglomerate the particles, then whirling the fluid to centrifugally concentrate the particles in a first fraction of the fluid and thereby substantially purifying a second fraction thereof, filtering the first fraction to recover the solid particles, collecting the particles and recirculating the purified fluid in the particle removal or washing process, the above treatment being carried out by apparatus having particular utility where the fluid is a liquid.