| 摘要 |
<p>The invention describes a screw for a water treatment apparatus, such as an aerator or mixer, said apparatus comprising a power source (1) driving a shaft (2) on which is fitted a screw that sucks the water up or impels it downward. The screw consists of a helicoidal, spiral-shaped screw blade construction round said shaft, with an upper end part (A), a lower end part (C) and a middle part (B) between said two end parts, with at least one of said end parts comprising an extra screw blade.</p> |
