Method and apparatus for aerating liquids

Claim 1

A TREATING TANK FOR MIXING AN OXYGEN CONTAINING GAS WITH A PRESETTLED SEWAGE LIQUID CONTAIING SUSPENDED THEREIN ACTIVATED SLUDGES, SAID TANK HAVING ONE FLAT VERTICAL SIDE, A HORIZONTAL ROTATING CYLINDRICAL BRUSH MOUNTED NEAR THE TOP OF AND HAVING AN AXIS PARALLEL WITH SAID SIDE SO THAT LESS THAN HALF OF SAID BRUSH MAY BE LONGITUDINALLY IMMERSED INTO THE SURFACE OF THE SEWAGE LIQUID IN THE TANK, A LONGITUDINAL BAFFLE MOUNTED IN SAID TANK ALONG SAID BUSH FROM BELOW THE AXIS OF SAID BUSH AT AN ANGLE UPWARDLY TOWARD TENGENCY WITH THE SURFACE OF SAID BRUSH ABOVE THE AXIS OF SAID BRUSH, AND MEANS FOR ROTATING SAID BRUSH ABOUT ITS CYLINDRICAL AXIS AT A PERIPHERAL SPEED OF BETWEEN 1.5 AND 3.5 METERS PER SECOND WHEREBY THE GASEOUS ATMOSPHERE ABOVE THE SURFACE OF THE LIQUID IN THE TANK MAY BE BEATEN INTO THE LIQUID AND WHEREBY TURBULENCNCE THROUGHOUT THE LIQUID IN SAID TANK MAY BE MAINTAINED, THE RATIO OF THE CROSS SECTIONAL AREAS OF SAID BRUSH TO THAT OF SAID TANK BEING BETWEEN ABOUT 1/5 AND 1/40 PER UNIT LENGTH OF SAID BRUSH, BOTH TAKEN IN THE PLANE PERPENDICULAR TO THE AXIS OF SAID BRUSH, WHEREBY THE TIME OF ACTIVATION OF THE SLUDGE IN THE SEWAGE LIQUID IS NOT OVER ONE HOUR TO REMOVE AT LEAST 90% OF THE B. O. D.5 CONTACT OF THE SEWAGE LIQUID.