145 to about 175 degrees with the outside vertical wall of draft tube 2 from about 2 to 8 vertical inlet guide baffles 4 are inserted in conical inlet 5 the baffles being thin sheets of structurally rigid material preferably they are equilaterally spaced symmetrically positioned around conical inlet 5 the impeller 6 comprises turbulence promoter blades 7 affixed to the impeller shaft 3 for rotation with the shaft 3 by the motor 12 during operation at least a minimum liquid level 22 is maintained above conical inlet 5 appropriate liquid and gas inlets 8 and 9 and an upper pressure relief vent 11 are provided as well as structural support for vessel 1 and draft tube 2 a motor 12 is provided at the top of the vessel 1 to drive the impeller shaft 3 in the clockwise direction of arrow 13 the working gas is introduced under pressure through the inlet conduit 9 which discharges the gas below the liquid level into the inlet or suction end of the draft tube 2 typical gas pressures are in the range of about 0 1 psig pounds per square inch gauge to about 2000 psig and typical gas flow rates are in the range of about 1 scfm standard cubic feet per minute to about 1000 scfm the liquid is introduced and eventually withdrawn at inlet 8 near the base of the sidewall of vessel 1 typical liquid flow rates are in the range of about 2 to about 10 000 gallons per.