摘要 |
<p>A rotary filter for polymers comprises an inward flow filter drum mounted in a housing and consisting of inner and outer filter barrels 7 and 6 which retain between them a cylindrical filter element 8 of wire gauze or porous sintered metal. The outer barrel has regularly spaced large openings in its outer surface which communicate through the thickness of the barrel wall and via divergent passageways with even larger openings on the inner surface of the barrel. In contrast, the inner barrel has a plurality of much smaller through openings in registry with each of the large openings. The drum is rotated by a hydraulic ram via a pawl and pinion drive to bring successive openings in the outer barrel into communication with passages 22, 23, through which accumulated solids are flashed from the corresponding areas of the filter element by the resulting reverse flow of filtrate. The filter minimizes downstream pressure fluctuations and may be used upstream of an extruder.</p> |