| 摘要 |
PCT No. PCT/SE92/00381 Sec. 371 Date Feb. 14, 1995 Sec. 102(e) Date Feb. 14, 1995 PCT Filed Jun. 3, 1992 PCT Pub. No. WO92/21422 PCT Pub. Date Dec. 10, 1992It is possible to filter a suspension or emulsion in a filter bed of particulate filter medium by allowing the suspension to flow upwards through the filter bed simultaneously as the medium flows downwards through a filtering tank wherein filtration takes place. Filtration thus takes place during counterflow between suspension and filter medium. The supply of suspension takes place in the lower part of the filter bed and the filtered liquid phase is taken away from a zone above the filter bed. The polluted filter medium close to the bottom of the filter tank is taken out for conveyance to a washing apparatus above the filter bed and after washing is returned to the upper side of the filter bed. For providing a filter which has a considerably lower construction height for a given and unchanged volume of the filter medium, the washing apparatus is lowered so that its lower part is at a level below the upper surface of the filter bed. |
