Abstract: This invention is directed to a method and apparatus for improving fluid flow and gas mixing in boilers. More particularly, this invention pertains to a method and apparatus for improved fluid flow and gas mixing in kraft recovery boilers for increased energy efficiency, reduced TRS emissions and increased capacity. The method of introducing air into a boiler furnace comprises: (a) introducing air through at least one opening located on at least a first wall of the interior of the furnace; and (b) introducing air through at least one second opening located on a second wall of the interior of the furnace opposed to the first wall at the same, or slightly different, elevations.

Abstract: This invention is directed to a method and apparatus for improving fluid flow and gas mixing in boilers. More particularly, this invention pertains to a method and apparatus for improved fluid flow and gas mixing in kraft recovery boilers for increased energy efficiency, reduced TRS emissions and increased capacity. The method of introducing air into a boiler furnace comprises: (a) introducing air through at least one opening located on at least a first wall of the interior of the furnace; and (b) introducing air through at least one second opening located on a second wall of the interior of the furnace opposed to the first wall at the same, or different, elevations.

Abstract: A process of recausticizing kraft green liquor in which the green liquor containing sodium carbonate is passed in a stream in admixture with particles comprising slaked lime, in which stream the liquid phase becomes progressively weaker in sodium carbonate and stronger in sodium hydroxide. Lime is added in order to provide a continuous supply of slaked lime for reaction with the sodium carbonate, and the stream is passed to a solids/liquid separator which recovers liquid phase from said stream, strong in NaOH, continuously and separately from the solid phase of the stream, as white liquor. The rate of the recausticizing reaction is limited by the rate of diffusion of carbonate ion into the solid particles, and of hydroxyl ion out of the solid particles. Typically, these rates limit the amount of causticizing achieved to less than the equilibrium value.