Two-stage injector-mixer

An apparatus for injecting a gas into a liquid and for mixing the gas with the liquid, the apparatus comprising:

• an injection section comprising a hollow, generally cylindrical body having a first and a second end forming a flow passage inside said body from said first to said second end, a liquid inlet port at said first end, and a mixture outlet port at said second end, said injection section further including:
• a generally cylindrical entry portion interconnected to the liquid inlet port;
• a frustoconical nozzle connected to said entry portion;
• a generally cylindrical injection portion interconnected to said nozzle and further including an injection port traversing said injection portion,
• a gas inlet port connected to said injection portion;
• a gas conduit adapted to connect said gas inlet port with said injection portion;
• a frustoconical funnel interconnected to the injection portion;
• an expanding portion interconnected to the frustoconical funnel;
• a generally cylindrical exit portion interconnecting the expanding portion to the mixture outlet port;
• and
• a mixing section, adapted to mix the gas and the liquid and to maximize the production of bubbles, said mixing section comprising a generally hollow, cylindrical body having an open end and a closed end, a mixing chamber extending from said open end and terminating at said closed end, said mixing section including a mixture inlet port entering said mixing chamber through said body immediately adjacent to said closed end, a central axis of the mixture inlet port being substantially tangential to the body, and a conduit connecting said mixture inlet port of said mixing section with said mixture outlet port of said injection section.