Patent ID: 7758750

Claim:
A flume for a filter system including at least one filter having a filter bed that is periodically washed with liquid, gas and/or a combination of liquid and gas; said flume comprising: (a) an enclosed chamber having a top wall, a bottom wall, a left sidewall and a right sidewall, said chamber being adapted to receive a washing liquid, a washing gas and/or a combination of washing liquid and washing gas, said chamber having a gas exit opening through which the washing gas exits said chamber en route to the filter bed; and, (b) at least a first inner wall and a second inner wall disposed in said enclosed chamber, each of said first inner wall and said second inner wall being free of any orifices, said first inner wall being positioned relative to said second inner wall such that an open space is formed between said first inner wall and said second inner wall, said open space creates a first washing liquid/washing gas interface upstream of said first inner wall and said second inner wall and a second washing liquid/washing gas interface downstream of said first inner wall and said second inner wall when washing gas and washing liquid are present in said chamber; said first interface being spaced from said bottom wall of said chamber a distance greater than said second interface, said second washing liquid/washing gas interface being disposed below said gas exit opening.