Apparatus and method of filtering solids from a liquid effluent

Claim 2

(In an apparatus for removing solids from waste effluent having small particles and large particles, said apparatus include a particle filtering element having relatively small passages for blocking flow of said particles therethrough, said element having an upper surface, a lower discharge means below said element, said large particles tending to accumulate on said surface, an upper inlet for said effluent, and a lower discharge port communicated with said means to remove filtrate, the improvement comprising: means to maintain a body of effluent above said surface and mechanical means above said surface positioned to create positive currents in said effluent which Currents sweep over said surface and lift said large particles from said surface during the filtering action.)

Claim 3

(The improvement as defined in claim 1 wherein said filtering element includes a layer of particulate media.)

Claim 4

(An apparatus as defined in claim 1 wherein said mechanical means comprises a diffuser means for creating fine air bubbles above said surface and in said effluent.)

Claim 5

(A method for removing solids from waste effluent, having small and large particles, said method comprising the steps of: a. providing a particulate filter bed with an upper surface and adapted to block flow of said large particles; b. developing a body of said effluent above said surface; and, c. mechanically creating positive currents which sweep over said surface while said effluent is being filtered for lifting said large particles from said surface.)

Claim 6

(A method for removing solids from waste effluent, having small and large particles, said method comprising the steps of: a. providing a particulate filter bed with an upper surface and adapted to block flow of said large particles; b. developing a body of said effluent above said surface; and, c. mechanically creating positive currents which sweep over said surface while said effluent is being filtered for lifting said large particles from said surface.)

Claim 11

(In an apparatus for removing solids from waste effluent containing particulate matter, said apparatus comprising: a filter bed including granular material and having an upper surface; an effluent inlet above said upper surface; a filtrate outlet generally below said bed; a discharge tank; and a discharge conduit communicating said tank and said outlet, the improvement comprising: pump means in said conduit with a pump means inlet below said effluent inlet whereby effluent can flow by gravity through said filter, said pump means and out said pump means inlet, said pump means having a de-energized first condition in which filtrate can flow through both said conduit and said pump means into said tank and an energized condition in which filtrate is forced from said tank, through said pump means, through said conduit and through said bed; and means for selectively changing said pump means between said first and second conditions.)

Claim 12

(In an apparatus for removing solids from waste effluent containing particulate matter, said apparatus comprising: a filter bed including granular material and having an upper surface; an effluent inlet above said upper surface; a filtrate outlet generally below said bed; a discharge tank; and a discharge conduit communicating said tank and said outlet, the improvement comprising: pump means in said conduit with a pump means inlet below said effluent inlet whereby effluent can flow by gravity through said filter, said pump means and out said pump means inlet, said pump means having a de-energized first condition in which filtrate can flow through both said conduit and said pump means into said tank and an energized condition in which filtrate is forced from said tank, through said pump means, through said conduit and through said bed; and means for selectively changing said pump means between said first and second conditions.)

Claim 13

(The improvement defined in claim 7 wherein said pump means comprises a pump having a pump inlet and a pump outlet communicated through said pump, said pump inlet being said pump means inlet, said pump inlet anD pump outlet receiving flow of filtrate when said pump means is in either of said conditions.)

Claim 14

(An apparatus for removing solids from waste effluent comprising: a filter tank having a lower wall; a support element covering said lower wall and spaced upwardly therefrom to define a lower chamber; a fine mesh filter element secured onto said support element and having openings of a given size; a layer of particulate filter media covering said fine mesh filtering element and having an upper surface; said media having a grain size at least slightly larger than the size of said openings in said filter element; an effluent inlet above the surface of said media layer; an outlet port in said chamber; a clear fluid tank; a conduit between said clear fluid tank and said outlet port whereby clear fluid from said chamber flows into said clear tank during the filter cycle of said apparatus; flow through pump means connected to said conduit and having a pump inlet located below effluent inlet whereby fluid flows through said conduit, through said pump means and out said pump inlet into said clear fluid tank and means responsive to activation of said pump means for forcing fluid from said clear fluid tank through said pump means, into said chamber, and through said filter media.)

Claim 15

(An apparatus for removing solids from waste effluent comprising: a filter tank having a lower wall; a support element covering said lower wall and spaced upwardly therefrom to define a lower chamber; a fine mesh filter element secured onto said support element and having openings of a given size; a layer of particulate filter media covering said fine mesh filtering element and having an upper surface; said media having a grain size at least slightly larger than the size of said openings in said filter element; an effluent inlet above the surface of said media layer; an outlet port in said chamber; a clear fluid tank; a conduit between said clear fluid tank and said outlet port whereby clear fluid from said chamber flows into said clear tank during the filter cycle of said apparatus; flow through pump means connected to said conduit and having a pump inlet located below effluent inlet whereby fluid flows through said conduit, through said pump means and out said pump inlet into said clear fluid tank and means responsive to activation of said pump means for forcing fluid from said clear fluid tank through said pump means, into said chamber, and through said filter media.)

Claim 16

In an apparatus for removing solids from waste effluent having small particles and large particles, said apparatus include a particle filtering element having relatively small passages for blocking flow of said particles therethrough, said element having an upper surface, a lower discharge means below said element, said large particles tending to accumulate on said surface, an upper inlet for said effluent, and a lower discharge port communicated with said means to remove filtrate, the improvement comprising: means to maintain a body of effluent above said surface and mechanical means above said surface for creating a volume of reduced specific gravity within said body of effluent, said mechanical means being positioned to create generally non-destructive positive lifting currents in said effluent caused by the continuous displacement of said volume of reduced specific gravity with effluent in said body, which displacement induced currents sweep over said surface and lift said large particles from said surface during the filtering action, said mechanical means comprising an air diffuser means extending over said surface for creating fine air bubbles above said surface and in said effluent whereby said currents are caused externally of said mechanical means.

Claim 17

In an apparatus for removing solids from waste effluent having small particles and large particles, said apparatus include a particle filtering element having relatively small passages for blocking flow of said particles therethrough, said element having an upper surface, a lower discharge means below said element, said large particles tending to accumulate on said surface, an upper inlet for said effluent, and a lower discharge port communicated with said means to remove filtrate, the improvement comprising: means to maintain a body of effluent above said surface and mechanical means above said surface for creating a volume of reduced specific gravity within said body of effluent, said mechanical means being positioned to create generally non-destructive positive lifting currents in said effluent caused by the continuous displacement of said volume of reduced specific gravity with effluent in said body, which displacement induced currents sweep over said surface and lift said large particles from said surface during the filtering action, said mechanical means comprising an air diffuser means extending over said surface for creating fine air bubbles above said surface and in said effluent whereby said currents are caused externally of said mechanical means.

Claim 18

The improvement as defined in claim 10 wherein said diffuser means is an air diffuser including an elongated tube extending over said surface and openings in said tube for forming said air bubbles.