| 摘要 |
<p>An apparatus for clarifying raw water containing suspended particulate matter comprises an upright conduit (1) with diameters increasing from an inlet for raw water at the top to an exit for clear water at the bottom. The inlet raw water is dosed with coagulant and/or flocculant and aerated with fine air bubbles before entry into the conduit. The bubbles become attached to flocs as they form in the upper part of the conduit. As the liquid descends in the conduit, the flaw velocity decreases enabling the flocs to float counter to the water stream and form a floating body within the conduit which functions as a filter medium. Clear water flows out of the conduit under an underflow weir and the outflowing clear water is raised by an exit duct to a level ensuring the duct remains full of water. Accumulated material is extracted from the bottom of the body through a co-axial discharge duct at a rate substantially equal to the rate of increase of fresh material from the influent raw water so that a steady state condition is achieved.</p> |
