Gas Phase Pressure Drop of a Water-Sparged Aerocyclone Reactor

Abstract

Air stripping of ammonia is a widely used process for the pretreatment of wastewater. Scaling and fouling on the packing surface in packed towers and a lower stripping efficiency are the two major problems in this process. New patented equipment that is suitable for the air stripping of wastewater with suspended solids has been developed. Air stripping of ammonia from water with Ca(OH)2, was performed in the newly designed gas-liquid contactor, a water-sparged aerocyclone (WSA). The pressure drop of gas phase was investigated in order to know the momentum transfer characteristic of the WSA. It was found that the gas phase pressure drop exhibited a different change tendency compared with the traditional aerocyclone, and could be divided into three characteristic stages, including low pressure drop, pressure drop jump and high pressure drop phases. The three different pressure drop areas corresponds to steady jet, spiral and fogged flow patterns of the liquid phase. The critical value for the air flow rate which caused the mass transfer coefficient to increase rapidly took place at the point where the steady jet was transformed into the spiral flow pattern.