Abstract: Several agitators for generating a mixture are described which generally have a housing and an impeller rotatably mounted within the housing. The impeller has a first end with a first end face, and plurality of protuberances and at least one compressed gas channel outlet disposed on the first end face. The agitator also has a mixing chamber that is located adjacent to the plurality of protuberances, a fluid inlet extending through the housing for supplying a mixing fluid to the mixing chamber, and a fluid outlet extending through the housing for discharging the mixture from mixing chamber. When the compressed gas and the mixing fluid are supplied to the mixing chamber, the compressed gas becomes uncompressed gas, and rotation of the impeller agitates the uncompressed gas and the mixing fluid and disperses the uncompressed gas and at least a portion of the mixing fluid to generate the mixture.