| 摘要 |
PCT No. PCT/EP94/01206 Sec. 371 Date Dec. 19, 1994 Sec. 102(e) Date Dec. 19, 1994 PCT Filed Apr. 19, 1994 PCT Pub. No. WO94/23820 PCT Pub. Date Oct. 27, 1994The invention relates to a backwashable filter, which comprises superimposed elements, particularly having an annular design, for producing filter candles. In the case of the filter candles the elements are subject to a radial through-flow from the inside to the outside in filter operation, whereas the flow direction is reversed for backwashing. On the inside of the filter layer is provided on each element a lip, elastically deflectable in the flow direction and facing the flow, which forms a gap opening with a fixed edge of the adjacent element. Under the action of the differential pressure of the flow acting on the wide front face of the lip, the lip performs a movement in which the gap opening is narrowed to a limited extent and as a result of the elastic deformation corresponding restoring forces are built up. If the flow is interrupted, particularly on passing from filter operation to backwashing operation, under the action of the restoring forces the lip automatically returns to its original position, so that the gap opening again becomes larger and in this way contaminants fixed in the gap opening are released and can be easily flushed out without leaving residues with the backwashing flow.
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