Method of and apparatus for cleaning runoff water
Runoff water from parking lots and filling stations is cleaned by first passing via an inlet pipe tangentially into a vortex chamber where the swirling action separates the contaminants from the water. Floating contaminants are stored in the vortex chamber, trapped at the top of the chamber by the roof of that chamber and at the lower part of the chamber by a skirt. That roof has an access opening to permit removal of the floating contaminants. The body of the fluid thereafter moves downward into a settling chamber where heavier-than-water contaminants settle. As the fluid in the settling chamber builds up, it passes through cleaning screens to a clean water outlet. A by-pass overflow pipe to process very large volumes of water extends upward from the settling chamber. Each screen may have louvers for preventing contaminants from blocking the screen.
1. A system for cleaning runoff water that may vary from a low to a high flow rate, comprising:
a vortex chamber having an inner wall and an outer wall,
an inlet for receiving said runoff water and directing that water into said vortex chamber to produce a swirling action by the water,
an inclined wall, at least a portion of which is at a level below the elevation of said inlet, which extends downwardly and inwardly from said inner wall for increasing the velocity of the water passing through the inclined wall,
a settling chamber for receiving the water after it swirls,
an outlet fed by water from said settling chamber,
at least one permeable barrier in the path of the water passing from said settling chamber to said outlet, said permeable barrier defining a hole therethrough,
a by-pass conduit for diverting part of the water around said permeable barrier when the incoming flow rate is large, said by-pass conduit passing through said hole,
said outlet being at the same level as said vortex chamber,
a container having an inner wall surrounding said vortex chamber with a substantial space between said outer wall of said vortex chamber and said inner wall of said container, so that water passing through said vortex chamber may pass to said settling chamber and then upward through said space between said vortex chamber and said container to said outlet, said vortex chamber having a skirt at its downstream end, said skirt extending downwardly and outwardly into said space so that said permeable barrier is above at least a part of said skirt in said space,
said at least one permeable barrier located between said chamber outer wall and said container inner wall for cleaning the water passing from said settling chamber to said outlet.
2. A system for cleaning runoff water that may vary from a low to a high flow rate as defined in claim 1 , wherein said permeable barrier is a screen.