Patent ID: 8871093

Claim:
A filter system for filtering a liquid containing particles, the filter system comprising: an underdrain assembly having an underdrain wall defining an underdrain chamber adapted to contain a backwash fluid and a media retainer assembly, comprising: a filter media retainer plate having a top surface defining a filter media chamber, a bottom surface, and defining at least one hopper-shaped compartment having a first sloped wall defining a first slot and a base portion defining a second slot, the first slot and the second slot each spanning the top surface and the bottom surface of the filter media retainer plate, the filter media chamber in fluid communication with the underdrain chamber; a filter medium disposed on the top surface of the filter media retainer plate, the filter medium adapted to capture the particles from the liquid with the liquid passing from the filter media chamber to the underdrain chamber, and the filter medium adapted to scour the top surface of the filter media retainer plate with the backwash fluid passing from the underdrain chamber to the filter media chamber; a first baffle extending from the bottom surface of the filter media retainer plate; a second baffle extending from the bottom surface of the filter media retainer plate, the first baffle and the second baffle together adapted to direct the backwash fluid in a vertical direction through the first slot and the second slot and prevent the backwash fluid in a horizontal direction beneath the bottom surface of the filter media retainer plate beyond the first baffle and the second baffle; a third baffle extending from the bottom surface of the filter media retainer plate; and a fourth baffle extending from the bottom surface of the filter media retainer plate, the third baffle and the fourth baffle together adapted to direct the backwash fluid in the vertical direction through the first slot and the second slot and prevent the backwash fluid in the horizontal direction beneath the bottom surface of the filter media retainer plate beyond the third baffle and the fourth baffle, wherein the first baffle, the second baffle, the third baffle, and the fourth baffle together form a baffle enclosure.