| 摘要 |
1492090 Filtration; ultrafiltration ALFALAVAL AB 8 Dec 1975 [23 Dec 1974] 50248/75 Headings B1D and B1X In filtration or 'ultrafiltration' using a filter or in cleaning the filter fluid flows along the upstream side of a filter 3 and creats a pressure gradient along the upstream chamber 1, and a corresponding pressure gradient is maintained along the filtrate chamber 2 so that the pressure drop across the filter 3 is uniform over its whole area. In Fig. 1 pumps 5, 11 recirculate unfiltered fluid and filtrate, and a net flow of filtrate is discharged by valve 9. In Fig. 2 (not shown) filtrate chamber 2 is divided into sections, each connected to one branch of a manifold (17) along which a pressure gradient is maintained. Fig. 3 (not shown) illustrates three filter units as in Fig. 1 operating in parallel. In Fig. 4 (not shown) there is no recirculation of filtrate, but filtrate chamber 2 is of tapering section to produce a pressure gradient. In Fig. 5 (not shown) filtrate chamber 2 is defined between filter 3 and a rubber membrane (20), and some unfiltered fluid flows through a throttle (24) and along the other side of the membrane, which transmits its pressure to the filtrate chamber. In Fig. 6 (not shown) a uniform pressure drop is maintained by directing cleaning fluid, which may be a solvent, through the chambers on both sides of a filter, avoiding the creation of reverse pressure gradients. 'Ultrafiltration' means filtering particles below 0.5 micron dia. but above molecular weight of 500. |
