| 摘要 |
<p>A ring float floating in the surface of the ballast liquid is arranged around a pump housing with suction port submerged in a ballast tank. The ring float runs around the pump housing and will form a barrier which prevents a contaminating layer on the liquid surface from being drawn in through the suction port, said barrier preventing the contaminating layer from reaching the port before the suction port loses its suction effect as result of it taking in air.</p> |
