Single cell vertical static flow flotation unit

DETAILED DESCRIPTION The present invention achieves its objects and overcomes shortcomings of the prior art in a simple and straightforward manner.
A substantially cylindrical, vertically oriented vessel is provided, said vessel having a closure at the bottom and the top.
An interior chamber formed within the vessel is divided by an annular separation wall.
The separation wall divides a lower gasification chamber from a middle degasification chamber and an upper gas chamber.
The separation wall has a concave shape with a central opening, from which a funnel or conduit extends upwardly through the degasification chamber and terminates a distance below a conduit serving as a skim collection outlet.
The liquid to be treated is introduced into the vessel through one or more liquid distribution lines.
A primary distribution line provides for the use of at least one distribution header having an outlet adjacent a bottom of the vessel for introducing the liquid having suspended matter therein into the vessel.
In the alternative, in addition to the primary, a secondary liquid distribution system can be used which allows for intimate mixing of the liquid with a gas flow which is introduced into the vessel by an eductor means having an outlet inside the interior chamber slightly above the outlet of the primary liquid distribution system.
When a second alternative method is used, the flow of liquid into the vessel is controlled by a pressure controller through a three-way pressure control valve which diverts any excess liquid to the primary liquid distribution outlet, bypassing the secondary liquid distribution line.
A liquid recirculation line which connects the bottom of the degasification chamber with the liquid inlet line is provided with a normally closed check valve which is mounted upstream from a point of connection of recirculation line and the inlet line.
The check valve opens when pressure in the recirculation line less than the pressure in the main liquid inlet line is detected.
A gas recirculation line fluidly connects a gas chamber in the uppermost portion of the vessel with a gas eductor means which introduces gas at the bottom of the vessel to achieve better mixing of the liquid delivered into the vessel with the gas