| 摘要 |
<p>PURPOSE:To prolong the retention period of bubbles in water and to enhance oxygen absorption efficiency in a diffused-air aerator, by arranging an angular cylindrical draft tube on the periphery of an air-lift pipe. CONSTITUTION:Air 8 from an air-feed pipe 2 is introduced into the lower portion of a round or angular cylindrical air-lift pipe 3 vertically arranged inside an aeration vessel 1 for an active sludge process or the like. After an ascending water current in the air-lift pipe 3 swells into the air, the water flows downwards through a space 5 between the air-lift pipe 3 and an angular draft tube 4 having a triangular, square or the like cross section, arranged on the periphery of the air-lift pipe 3.</p> |
