Patent ID: 8992774
Filing Date: 2015-03-31
Classification: B01D

Abstract:
1. A filter system having a filter bed for filtering water or wastewater, where the filter bed is periodically washed between service runs by directing washing fluids upwardly through the filter bed, said filter system comprising: (a) a filter bed; (b) a plurality of underdrain laterals disposed below the filter bed, each of the plurality of underdrain laterals having a first end and a second end, each of the plurality of underdrain laterals being configured to receive a first washing fluid adjacent the first end and direct the first washing fluid upwardly to the filter bed, each of the plurality of underdrain laterals being configured to receive a second washing fluid adjacent the second end and direct the second washing fluid upwardly to the filter bed, the first washing fluid being different from the second washing fluid, each of the plurality of underdrain laterals are configured to receive the first washing fluid adjacent the first end without the first washing fluid previously passing through any other underdrain lateral, each of the plurality of underdrain laterals are configured to receive the second washing fluid adjacent the second end without the second washing fluid previously passing through any other underdrain lateral; (c) a first flume including a supply conduit for fluid communication with a source of the first fluid, the first flume being configured such that during washing of the filter bed between service runs the first flume receives the first washing fluid and directs the first washing fluid into the first end of each of the underdrain laterals the first flume being disposed adjacent the first end of each of said plurality of underdrain laterals, a first portion of each of the plurality of underdrain laterals forming an upper wall of the first flume, a second portion of each of the plurality of underdrain laterals forming a sidewall of the first flume; (d) a second flume including a supply conduit for fluid communication with a source of the second fluid, the second flume being spaced from the first flume, the second flume being configured such that during washing said second flume receives the second washing fluid and directs the second washing fluid into the second end of the plurality of underdrain laterals wherein a bottom wall of the second flume is aligned horizontally with a bottom wall of the first flume.