| 摘要 |
<p>Materials suspended in a liq. are sepd. by flotation or by electroflotation so that the floated matter can be evacuated continuously. the emission of very small bubbles of gas which become caught in the solid matter cuase the ascension of the latter to the free surface of the liq.; the particles then group together to form a flotation cake. The guiding device consists of a network of fixed surfaces placed side-by-side to form a grid mesh in the midst of the floated matter in a flotation appts. of suitable dimentions. The grid mesh is immersed in the upper part of the appts. and projects several cms. beyond the surface of the liq. The floated matter is evacuated from the top of the flotation cake by motor-driven rakes and by overflow gutters arranged on the free surface of the appts. When applied to the flotation of activated sludges, the flotation cake can be allowed to grow in thickness by press. from below, and natural evapn. in the atmos. so that the floated matter can be conc. to the extent that one kg. of dry matter may be obtd. from 19.6 kg. of sludge.</p> |
