FILTERING AND WASHING APPARATUS AND FILTERING AND WASHING METHOD

PROBLEM TO BE SOLVED: To provide a filtering and washing apparatus where a filter material does not outflow from a drain trough to the outside of a filtration tank when washing without a drainage operation.SOLUTION: A filtering and washing apparatus 1 comprises: a filter basin 10 storing raw water; a filtration tank 20 disposed in the filter basin 10 and formed with a filter material layer 30 at a lower part; a drain trough 50 which is disposed in the filtration tank 20 and where a screen 56 is disposed at a side wall 52; a drainage means 60 discharging the raw water stored in the filter basin 10 to the water level of the top edge 53 of the side wall 52 of the drain trough 50; and a washing means 70 performing the washing of the filter material layer 30 by any one of the combination washing of air washing and backwashing and the combination washing of surface washing and backwashing in a stage of discharging by the drainage means 60 and discharging washing drain water including a turbid material from the drain trough 50. 【課題】水抜き作業を実施しないでも洗浄時に、ろ材が排水トラフよりろ過槽外に流出しないろ過洗浄装置を提供する。【解決手段】原水が貯留されるろ過池１０と、ろ過池１０に設置され下部にろ材層３０が形成されているろ過槽２０と、ろ過槽２０に設置され側壁５２にスクリーン５６が設置される排水トラフ５０と、ろ過池１０に貯留される原水を排水トラフ５０の側壁５２の上端５３の水位まで排水する排水手段６０と、排水手段６０により排水された段階で、空洗・逆洗併用洗浄又は表洗・逆洗併用洗浄のいずれかによりろ材層３０の洗浄を実施し、濁質を含む洗浄排水を排水トラフ５０より排水する洗浄手段７０とで、ろ過洗浄装置１を構成した。【選択図】図１