FILTERING DEVICE AND FILTERING METHOD

To provide a filtering device which can inhibit clogging of a screen, and to provide a filtering method.SOLUTION: A filtering device 10 includes: a passage 11 in which processed water flows in a rising direction; a filter material layer provided in the passage 11 and having a plurality of filter members 14; a screen 13 which is provided at the upstream side relative to the filter material layer in the passage 11 and has a filter surface intersecting with the passage 11; and air supply means 15 provided at the upstream side relative to the screen 13 in the passage 11. The air supply means 15 supplies air continuously or intermittently so that air bubbles, which are larger than a scale spacing L of the screen 13 when the screen 13 is viewed in a passage direction, keep accumulating dispersed over an entire area of a lower surface of the screen 13.SELECTED DRAWING: Figure 1 【課題】スクリーンが目詰まりすることを抑制するろ過装置及びろ過方法を提供すること。【解決手段】ろ過装置１０は、被処理水が上昇方向に流れる流路１１と、流路１１内に設けられた、複数のろ過部材１４を有するろ材層と、流路１１内であってろ材層よりも上流側に設けられ流路１１に対して交差するろ過面を有するスクリーン１３と、流路１１内であってスクリーン１３よりも上流側に設けられた空気供給手段１５と、を備え、空気供給手段１５は、スクリーン１３を流路方向からみてスクリーン１３の目幅Ｌよりも大きな気泡がスクリーン１３の下面の全域に分散して滞留し続けるように、空気を連続的又は断続的に供給する。【選択図】図１