Gravitational separator and drainwater treatment system for use in a horizontal passageway

A drainwater treatment system positionable within a drainage system having an upstream pipe portion having an outlet through which drainwater enters the system and a downstream pipe portion having an inlet through which drainwater exits the system, the treatment system comprising:

• a gravitational separator including
• a) means for defining a collection cavity having substantially circular sidewalls, a bottom, an entrance opening through which drainwater enters the collection cavity from the upstream pipe portion, and an exit opening through which drainwater exits the collection cavity and which is connectable to the downstream pipe portion, and wherein the entrance and exit openings are disposed in an elevated and spaced condition above the bottom;
• b) the collection cavity-defining means being connectable to the upstream pipe portion at such an angle with respect thereto so that drainwater which enters the collection cavity through the entrance opening thereof is directed by the upstream pipe portion substantially tangentially along the inside surface of the sidewalls to impart a swirling motion to drainwater collected within the collection cavity of the cavity-defining means;
• and
• c) baffle means supported within the collection cavity of the cavity-defining means and adjacent the exit opening of the cavity-defining means for isolating the exit opening from swirling motion of the drainwater within the collection cavity of the cavity-defining means yet permit drainwater to exit the cavity-defining means through the exit opening when the level of drainwater collected within the cavity-defining means reaches the level of the exit opening;
• and
• a filter disposed downstream of the exit opening of the cavity-defining means so that drainwater which exits the cavity-defining means is subsequently routed through the filter.

A gravitational separator positionable within a drainage system having an upstream pipe portion having an outlet through which drainwater enters the separator and a downstream pipe portion having an inlet through which drainwater exits the separator, the gravitational separator comprising:

• means for defining a collection cavity having substantially circular sidewalls, a bottom, an entrance opening through which drainwater enters the collection cavity from the upstream pipe portion, and an exit opening through which drainwater exits the collection cavity and which is connectable to the downstream pipe portion, and wherein the entrance and exit openings are disposed in an elevated and spaced condition above the bottom;
• a length of conduit having two opposite ends, one end of which is joined to the collection cavity-defining means about the entrance opening thereof and the other end of which is connectable to the upstream pipe portion for receiving drainwater delivered therefrom;
• the length of conduit being disposed in such a relation to the circular sidewalls of the collection cavity so that drainwater which enters the collection cavity through the entrance opening thereof is directed by the length of conduit substantially tangentially along the inside surface of the sidewalls to impart a swirling motion to drainwater collected within the collection cavity of the cavity-defining means;
• and
• baffle means supported within the collection cavity of the cavity-defining means and adjacent the exit opening of the cavity-defining means for isolating the exit opening from swirling motion of the drainwater within the collection cavity of the cavity-defining means yet permit drainwater to exit the cavity-defining means through the exit opening when the level of drainwater collected within the cavity-defining means reaches the level of the exit opening.