| 摘要 |
<p>PURPOSE:To eliminate the need for control of returned sludge by enhancing the capacity for supplying oxygen in a sanitary sewage treating tank equipped with a settling chamber and an aeration chamber to the inside of one tank. CONSTITUTION:The inside of a sanitary sewage treating tank is comparted into an upper settling chamber 4 and an lower aeration chamber 6 by a hopper 7 having an inverse conical shape. This sanitrary sewage treating tank is provided with an internal cylinder 8 of the lower part which stands from the bottom part of the aeration chamber 6 and connected to a central opening 7a of the hopper 7, a separation front chamber 20 communicated with the upper part of the aeration chamber 6 in the bottom part to the outside part of the settling chamber 4, a cylindrical center well 5 arranged to the upper part of the hopper 7 in the settling chamber 4, a communication pipe 30 for passingly connecting the center well 5 to the separation front chamber 20 and a supply pipe of sanitary sewage arranged so that a supply port 1a is opened in the inside of the internal cylinder 8 of the lower part. Fluid in this internal cylinder of the lower part is sucked from the bottom part or the vicinity thereof by a circulation device 10. This fluid is nearly horizontally spouted in a state wherein large amount of air is mixed therewith in the vicinity of the bottom part in the aeration chamber 6.</p> |
