High rate filtration system

Filtration apparatus comprising:

• a filter housing having a fluid inlet and a fluid outlet, wherein said fluid inlet is disposed below said fluid outlet and said filter is operated in an upflow mode;
• filtration media of adjustable porosity and collector size disposed in a filter bed within said filter housing between said fluid inlet and said fluid outlet;
• a first perforated panel immovably mounted within said apparatus;
• a second perforated panel movably mounted within said apparatus and spaced above said first perforated panel;
• and
• means for selectively moving said movably mounted second perforated panel toward and away from said first perforated panel, said means being located above said second perforated panel, whereby the porosity of said filter bed can be adjusted by compressing the media.

Filtration apparatus for wastewater treatment comprising:

• an inlet for introducing wastewater into said apparatus for upward flow through said apparatus;
• an outlet for discharging filtered wastewater from said apparatus;
• a first perforated panel immovably mounted within said apparatus;
• a second perforated panel movably mounted within said apparatus and spaced above said first perforated panel;
• means for selectively moving said movably mounted second perforated panel toward and away from said first perforated panel, said means being located above said second perforated panel;
• a compressible fibrous lump filtration media disposed between said first and second perforated panels and defining a filter bed, wherein said compressible media is compressed for filtration in a gradient proceeding from more compressed to less compressed in a direction opposite to the flow of fluid so that filtration proceeds in a direction from a more porous to a less porous filter bed, and wherein said filter bed is expanded for cleaning;
• and
• means for introducing a gas into said wastewater when said filter bed is expanded for cleaning.

A process for filtering a fluid comprising the steps of:

• a) passing fluid through a filtration bed comprising a compressible filtration media;
• b) compressing the filtration media to define a porosity gradient in the filter bed proceeding from more porous to less porous in a direction opposite to the flow of fluid so that filtration proceeds in a direction from a more porous to a less porous filter bed;
• and
• c) periodically expanding the filter bed while continuing to pass fluid through the filter bed to clean the filtration media.

A process for filtering a liquid to remove particles therefrom comprising the steps of:

• a) passing the liquid through a filtration bed comprising a compressible fibrous lump filtration media;
• b) compressing the filtration media to define a porosity gradient in the filter bed proceeding from more porous to less porous in a direction opposite to the flow of liquid so that filtration proceeds in a direction from a more porous to a less porous filter bed;
• c) removing progressively smaller particles from the fluid as filtration proceeds from a more porous to a less porous media;
• d) monitoring head loss across the filter bed;
• e) periodically expanding the filter bed when a maximum head loss has been reached while continuing to pass liquid through the filter bed to clean the filtration media.