Filtration device for rainwater flowing down and rainwater storage device using the same

摘要

A filtration device, which can be installed at a relatively low place below the full water level of a storage tank, is obtained. The filtration device is provided with a housing 22 attached to a lower part of an upper vertical pipe 21a and an upper part of a lower vertical pipe 21b from above and below and having a rainwater flow chamber 23 and a valve chamber 24; a ball valve 29 with a specific gravity less than 1 and accommodated in the housing movably between the rainwater flow chamber and the valve chamber for blocking a lower rainwater hole 23b in the rainwater flow chamber; a storage chamber 27 for storing the rainwater having reached the valve chamber from the rainwater flow chamber; a valve-seat opening portion 24b capable of being blocked with the ball valve so as to seal the valve chamber; an upper guiding member 31 for guiding the rising ball valve from the rainwater flow chamber to the valve chamber; and a lower guiding member 32 for guiding the lowering ball valve from the valve chamber to the rainwater flow chamber. A first strainer 26 configured capable of being taken in/out through the valve-seat opening portion is detachably attached to the lower rainwater hole, and a second strainer 33 for filtrating the rainwater flowing into the storage chamber is detachably attached to the storage chamber.