| 摘要 |
<p>PURPOSE:To withdraw supernatant liquid without disturbing a sludge boundary by using a supernatant liquid withdrawing pipe having a float. CONSTITUTION:A communicating device 2 which communicates the inside and outside of a tank 1 with each other is provided to a tank wall 1a. the float 3 and a discharge port 4 for the supernatant liquid are provided to the top end of the supernatant liquid withdrawing pipe 5 and the base end of the pipe is connected freely vertically turnably to the open end of the device 2 on the tank inside and is vertically oscillated as the liquid level rises or falls. A cord 18 connected to the pipe 5 is alternately wound on movable pulleys 13a, 13b and a stationary pulley 14 of a luffing device 6. A moving cylinder 10 which moves the movable pulleys apart from or near to the stationary pulley is provided to the movable pulleys. The pipe 5 is moved to raise or fall around the base end by the operation of the cylinder 10. As a result, the supernatant liquid is withdrawn without disturbing the sludge boundary; in addition, the construction of the device is simple and the ease of maintenance and operation is good.</p> |
