US 2012/0055858 A1 · TERTIARY WASTEWATER FILTRATION USING INCLINED FILTER MEDIA AND INTERNAL REVERSE FLOW BACKWASHING OF FILTER DISKS

Abstract

A wastewater tertiary media filtration system capable of enhancing filtration performance while including backwashing capabilities that eliminate turbidity spikes by using compressed fluid injected to the interior of submerged filter disks is disclosed. A tertiary wastewater treatment apparatus including a filter tank having an inlet and an outlet with a plurality of pile cloth media filter disks disposed in generally parallel relation between the inlet and outlet. Each filter disk preferably includes opposing filter panels disposed in generally parallel spaced relation and supported by a frame. Each filter panel preferably includes a quantity of pile cloth, or other suitable filtration media, sandwiched between opposing mesh panels. The filter disks may be angularly disposed at approximately 55-degrees relative to horizontal so as to maximize settlement velocity in accordance with the advantages of inclined plate technology. During the filtering process, influent flows into the tank and passes through the pile cloth, or other filter media, on opposing sides of each filter disk while depositing suspended solids on the filter media. The filtered effluent flows out from the outlet of each filter disk for discharge or other suitable use. Backwashing is primarily accomplished by injecting compressed fluid (such as air) to the interior of each filter disk assembly whereby accumulated solids are blown off of the cloth filter media by reverse flow. Injecting a compressed fluid medium into the interior of each filter disk assembly increases the internal pressure within each filter disk thereby avoiding turbidity spikes associated with externally applied suction backwash systems of the background art.

Claims9

Dependent claims

A wastewater treatment apparatus comprising:

a tank having a wastewater inlet;
a filter disk disposed within said tank;
said filter disk including filter media and defining an interior volume, whereby hydrostatic pressure causes water within said tank to pass through said filter media and into said interior volume, said filter disk having a filtered water outlet in fluid communication with said interior volume;
and
means for removing accumulated solids from said filter media by the introduction of compressed fluid within said interior volume.

2 more elements

A wastewater treatment apparatus comprising:

a wastewater tank having a wastewater inlet;
a plurality of filter disks removably received within said tank, said filter disks disposed in generally spaced side-by-side generally parallel relation with each of said filter disks angularly disposed at a generally 55-degree angle relative to horizontal;
each of said filter disks including filter media and defining an interior volume, whereby hydrostatic pressure causes water within said tank to pass through said filter media and into said interior volume, each of said filter disks further having a clean water outlet in fluid communication with the corresponding interior volume of the filter disk;
each of said filter disks further including a diffuser float disposed within the interior volume thereof and movable between lower most and upper most positions;
said diffuser float comprising a generally elongate hollow body defining a plurality air backwash scouring through bores disposed to expel air toward said filter media, and at least one air pocket release aperture defined along the top portion of said diffuser float;
a compressed air source in fluid communication with each diffuser float;
control apparatus for selectively activating and deactivating said compressed air source, said compressed air source supplying pressurized air to at least one of said diffuser floats when activated and not supplying pressurized air to said at least one diffuser float when deactivated;
whereby activation of said compressed air source supplies pressurized air to at least one of said diffuser floats thereby rendering said at least one diffuser float buoyant such that said at least one diffuser float traverses from its lower most position to its upper most position while expelling air toward said filter media;
and
whereby deactivation of said compressed air source renders said at least one diffuser float non-buoyant such that said at least one diffuser float returns to said lower most position under the influence of gravity.

7 more elements

Dependencies are inferred from the claim text.

Tertiary wastewater filtration using inclined filter media and internal reverse flow backwashing of filter disks

Life of this patent

Tertiary wastewater filtration using inclined filter media and internal reverse flow backwashing of filter disks

Life of this patent

Abstract

Claims9