| 摘要 |
<p>An aeration tank employing activated sludge for the purificn. of biologically polluted waste water. The liq. in the rectangular tank circulates around a longitudinal, vertical partition which has passages between its ends and the ends of the tank. The tank has a system for aerating the water which is independent of the circulating system. Circulation is by a multi-paddle, cylindrical rotor which turns on a horizontal axis at right angles to the partition. Aeration takes place at several points around the partition. The axis of the rotor is pref. at a higher level than the surface of liq. in the tank. The rotor pref. has between 6 and 30 paddles spaced at a pitch of not less than 5 cm. The rotor pref. turns at a rate which produces a rotor surface speed of 0.5 and 3.0 m/s. Saving of energy compared with tanks in which the aerator also circulates the liq.. At periods when the substantially aeration can be reduced without affecting the rate of circulation.</p> |
