| 摘要 |
To remove a liquid phase (7) floating on the surface (6) of a water table, the liquid level (18) in a well shaft (1) is lowered by a submerged pump which continually pumps out the ground water. The resultant liquid phase (7), which floats on the surface (6) of the water table and collects in the region of the well, is withdrawn by a second submerged pump (12) arranged in a beaker-shaped container (8) which can be lowered on a hoisting device (9, 10) into the well shaft (1). The hoisting device (9, 10) is controlled by the liquid level (18) in such a way that the inlet openings (11) of the container (8) undercut the liquid level (18) but not the surface of the water table (6). |
