| 摘要 |
The liq. stream is divided into a number of sub-streams flowing either side of moving sieve surfaces. The upper surface is moving against the main liq. flow while the lower one moves with it. The flow velocity in the channels is sufficiently high to maintain turbulence. At the same time it is low enough to allow sedimentation of suspended material to form a clear layer with a significantly reduced content of suspended material in the upper part of the liquid stream. Over half of the liquid fed into the flow channel is filtered off by the upper sieve, of the channel. Less than half is sucked through the filter cake forming on the lower screen. The sediment is removed from the lower screen. For use in sepg. off suspended solids from water streams e.g. effluent streams from the paper industry. The solids may be formed by the addition of chemicals and flocculating agents. The problem with many filtration processes is that the formation of a cake causes a sharp rise in pressure drop and greatly reduces the throughput. Settlers often do not produce a very dry cake. The system described gives good throughput and clarity with relatively dry cake. |
