Patent ID: 6416724
Filing Date: 2002-07-09
Classification: B01D,F23J

Abstract:
A method for cleaning impurities from combustion gas, the method comprising the steps of:(a) providing a reactor vault formed of walls having at least an inner surface and further comprising: (i) a wetting zone, forming the lowermost portion of said reactive vault, wherein the uppermost portion of the walls of said wetting zone are arranged to slope inwardly forming above said walls a substantially horizontal aperture having a smaller horizontal cross-sectional area than the lower portions of said wetting zone, said inwardly sloping uppermost portion of said walls of said wetting zone are provided with nozzles mounted thereon, said nozzles provide a supply of wetting agent and compressed air, and wherein said wetting zone receives a supply of combustion gas, comprising impurities, provided at a lower portion thereto; (ii) a retardation zone, mounted on said wetting zone and above said aperture, wherein said retardation zone is an upwardly-opening conic section, wherein the lower portion of said retardation zone is provided with a co-axially-mounted feed tube having supplies of compressed air and reactive additive connected thereto, said feed tube oriented to discharge in the upward direction; (iii) a substantially cylindrical retention zone, mounted on said retardation zone; and (iv) a top, mounted on said retention zone, comprising a downwardly-opening gathering cone having a centrally-disposed opening, and an outlet channel coupled to said opening, and wherein any horizontal cross-section of said reactor vault is substantially circular; (b) flowing said combustion gas upwardly through said wetting zone at an average initial flow speed, wherein said gas flows under substantially laminar flow conditions; (c) wetting said combustion gas in said wetting zone; (d) contacting said combustion gas with at least one reactive additive by allowing said reactive additive to flow in the flow direction of said combustion gas in said upwardly opening retardation zone, wherein the combustion gas and the additive flow through the retardation zone without contacting any turbulence generation means; (e) increasing the time said at least one reactive additive contacts said gas by reducing the average flow speed of said combustion gas in said retardation zone such that at the exit of said retention zone said gas has an average final flow speed lower than said average initial flow speed; and (f) removing said gas from said reactor vault through said top.