Water purification device

A water purification device comprising:

• a filter tank having water inlet means for the admission of water to be filtered and washing water thereinto, and filtered water outlet means;
• granular filter material for filtering of water and the like filling the lower portion of said filter tank with a space in said filter tank above said filter material;
• a separation tank mounted in said space in said filter tank and having a washing water inlet in the upper portion thereof from said space and directed generally tangentially of said separator tank;
• a washing water outlet means lying generally along the central vertical axis of said separation tank and communicating with the outside of the filter tank;
• a rod-like member positioned along said vertical axis of said separation tank, whereby when washing water is caused to flow into the tank and entrains the filter material and fills the tank, the filter material carrying washing water is directed by said washing water inlet in a vortex down along the inside surface of the wall of the separation tank, then inwardly thereof, and then along the peripheral surface of said rod-like member in reverse flow of water traveling upwards of the member with a gyratory motion and is discharged through said washing water outlet means;
• and
• a granular filter material outlet at the bottom of said filter material separation tank and having a cover means for closing and opening said outlet.