WASHING METHOD OF MEMBRANE DEGASIFIER AND ULTRAPURE WATER PRODUCTION SYSTEM

To provide a washing method of a membrane degasifier enabling the membrane degasifier to be efficiently washed without requiring removal of the membrane degasifier from an ultrapure water production system and to provide the ultrapure water production system capable of performing the washing method.SOLUTION: There is provided the washing method of a membrane degasifier 5 which is provided in an ultrapure water production system having pretreatment means, a primary pure water production unit and a secondary pure water production unit, the washing method of the membrane degasifier 5 alternately performs a normal washing step of causing washing water to flow in the membrane degasifier 5 in the same direction as a flowing direction of water to be treated of the membrane degasifier 5 and a back washing step of causing the washing water to flow in the membrane degasifier in the direction reverse to the flowing direction of water to be treated of the membrane degasifier 5. The ultra-pure water production system is provided that has the pretreatment means, the primary pure water production unit and the secondary pure water production unit, and has the membrane degasifier 5 and a prescribed washing means in the primary pure water production unit or the secondary pure water production unit.SELECTED DRAWING: Figure 2 【課題】超純水製造システムから膜脱気装置を取り外すことなく、効率的に洗浄可能な膜脱気装置の洗浄方法及びその洗浄方法を実施可能な超純水製造システムを提供する。【解決手段】前処理手段、一次純水製造部及び二次純水製造部を有する超純水製造システムに設けられた膜脱気装置５の洗浄方法であって、膜脱気装置５に、洗浄水を膜脱気装置５の被処理水の通流方向と同じ方向に流して洗浄する順洗工程と、膜脱気装置５に、洗浄水を膜脱気装置５の被処理水の通流方向と逆の方向に流して洗浄する逆洗工程と、を交互に行う膜脱気装置５の洗浄方法及び前処理手段、一次純水製造部及び二次純水製造部を有し、一次純水製造部又は二次純水製造部に、膜脱気装置５及び所定の洗浄手段を有する超純水製造システム。【選択図】図２