Abstract: Concentrated aqueous hydrogen peroxide or another reactive compound in a liquid carrier is activated by atomization and contact with a suitable catalyst that is concurrently atomized in a carrier liquid. Concentrated hydrogen peroxide and a hydrogen peroxide activation catalyst are atomized into a droplet spray for catalytic activation of the hydrogen peroxide in this invention, useful for treatment of a combustion flue gas containing contaminants such as NO? and/or Hg.

Abstract: Interaction between two different species of particles in a fluid stream is promoted by generating turbulent eddies in the fluid stream. The turbulent eddies are designed to be of such size and/or intensity that the two species of particles are entrained into the eddies to significantly different extents. Consequently, the different species of particles follow different trajectories, and the likelihood of collisions or interactions between the particles is increased. Optimum collision rates will occur for a system which maintains a Stokes Number (St) much less than 1 for one species, and or order 1 or greater for the other species. The invention has particular application in air pollution control, by promoting agglomeration of fine pollutant particles in air streams into larger particles to thereby facilitate their subsequent removal from the air streams.

Abstract: A reactor cools humidifies gases produced by combustion or the like. The reactor has a chamber with an inlet at a lower end to receive a flow of gas, and an outlet at a upper end. The gas flows in a generally upward direction through the reactor. The horizontal cross-section of the chamber increases with height and the flow velocity of the gas decreases as it flows upwardly. The reactor includes at least one device for injecting water droplets into the upper region of the chamber, counter to the gas flow. As the water droplets fall, they gradually evaporate and lose mass and encounter a counterflow of increasingly higher velocity and temperature until the force of the upwardly flowing gas is sufficient to reverse their flow and carry them in an upward direction.

Abstract: An electrostatic filter (1) has a chamber (11) into which a gas stream is introduced. An ioniser (19) in the form of an electrode array (20) is located in the chamber (11) and creates an ionising zone through which the gas stream passes. A charged outlet (21) is located downstream from the ioniser (19). As the gas stream passes through the ionising zone, the unwanted particles therein are charged and urged away from the outlet (21) by the ioniser (19). Charged particles approaching the outlet (21) are also electrostatically repelled therefrom, permitting “clean” gas to be extracted through the outlet.

Abstract: Fine particles of dust and other pollutants in gas streams are agglomerated to form larger particles which are more easily filtered in downstream processing. In one embodiment, particles in successive portions of the gas stream are charged with opposite polarity, and the gas stream is introduced into an Evasé portion (12) to slow it down. Particles of different sizes have differential deceleration and therefore mix generally in the direction of flow, leading to agglomeration of oppositely-charged particles. In another embodiment, a gas stream is divided into substreams in respective parallel passages, and the particles in adjacent passages are charged to opposite polarity. Deflectors at the downstream end of the passages cause substreams of particles of opposite polarity to mix, with resultant agglomeration of oppositely charged particles.