| 摘要 |
A filter comprising a tubular filter membrane (1) within which is mounted a concentric core (2) formed with a helical groove (3) and leaving a gap (G). Fluid to be filtered is passed in the upwards direction into the space between the core (2) and the membrane (1) and is thus constrained to move in a helical path within a helical space (8) defined between the groove (3) and membrane (1), with leakage flow (7) through the gap (G) between adjacent turns of the helix. The leakage flow (7) shapes and enhances an already-existing vortex flow within the space (8) and ensures effective scouring of the membrane to prevent build-up of solids on the membrane surface. A version incorporating an externally threaded helical groove is also described. The filter is useful for a wide range of filtration purposes, particularly in ultrafiltration and microfiltration. |
