| 摘要 |
It is to be understood that embodiments of the present invention provide apparatus and a method for pumping a liquid, for example to recirculate liquid in a liquid storage tank by means of a gas lift pump.A perforated extension at the top of a gas lift allows the apparatus to be used in circumstances where the depth of liquid in the tank may vary over a wide range. Gases other than air may be used in the gas lift, so as to change the acidity and the concentrations of dissolved gases, particularly oxygen, in the liquid. The gas may be introduced into the gas lift through a whistle that generates intense sound waves and couples them into the liquid. These features when used in combination have particular application against invasive species in the ballast water of ocean-going tankers |
