Solids handling in an oil/grease separator

An oil/grease separation apparatus comprising

• a chamber for receiving a liquid flow containing water, oil/grease and gross solids, said chamber including an inlet section, a downstream section and an outlet in an outlet section,
• said inlet section being separated from said downstream section by a weir including a first wall extending upwardly from the bottom of said chamber to a top above the outlet and a second wall extending downwardly from a height above the liquid level to a submerged level, whereby a higher static water level is maintained in said inlet section than said downstream section, to facilitate one-way passage of oil/grease from said inlet section to said downstream section,
• a grinder/pump having an input port in a lower portion of said inlet section,
• said inlet section including an inlet port, a strainer separating said inlet port and the top of said first wall to inhibit passage by solids to the downstream section, and a bottom which slopes downwardly toward said input port of said grinder/pump, and
• an oil/grease separator located in said downstream section for removing oil/grease from water held in said downstream section,
• whereby the gross solids entering the chamber settle in said inlet section for periodic removal with some water by said grinder/pump, oil/grease and water entering the chamber pass to said downstream section where the oil/grease is removed from the water, and the residual water exits the chamber through the outlet section.

An oil/grease separation method comprising

• introducing a liquid flow containing water, oil/grease and gross solids into a chamber having an inlet section, a downstream section and an outlet in an outlet section,
• permitting the gross solids entering the inlet section to settle,
• periodically removing the solids from the inlet section with some water by a grinder/pump,
• permitting oil/grease and water to pass from the inlet section to a downstream section,
• removing oil/grease from the water in the downstream section, and
• permitting the residual water to exit the chamber through the outlet.

An oil/grease separation method comprising

• introducing a liquid flow containing water, oil/grease and gross solids into a chamber having an inlet section, a downstream section and an outlet in an outlet section,
• straining gross solids from the liquid flow in the inlet section to prevent passage of solids to the downstream section,
• permitting the gross solids entering the inlet section to settle,
• periodically removing the solids from the inlet section with some water by a grinder/pump that also creates a reverse flow of water through the strainer in order to backwash the strainer,
• permitting oil/grease and water to pass from the inlet section to a downstream section over a weir that maintains a higher static water level in the inlet section than the downstream section,
• removing oil/grease from the water in the downstream section, and
• directing the residual water exiting the chamber through the outlet section to a grease trap and directing the solids and water removed from the inlet section during the periodic removal step to bypass the grease trap.

An oil/grease separation apparatus comprising

• a chamber for receiving a liquid flow containing water, oil/grease and gross solids, said chamber including an inlet section, a downstream section and an outlet in an outlet section,
• a fluid flow conduit having an input port in a lower portion of said inlet section and an exit port connected to said outlet downstream of said outlet section, and
• an oil/grease separator located in said downstream section for removing oil/grease from water held in said downstream section,
• whereby the gross solids entering the chamber settle in said inlet section for removal to said exit port with some water through said fluid flow conduit, oil/grease and water entering the chamber pass to said downstream section where the oil/grease is removed from the water, and the residual water exits the chamber through the outlet section.