Water treatment system

Claim 2

A waste effluent tratment system comprising: means defining a closed chamber having an inlet at one end and an outlet at another laterally opposite end; a plurality of perforate septa substantially vertically disposed in spaced relation within said chamber between the inlet and outlet to divide same into subchambers through which an effluent flow path extends; a particulate filtering medium in at least one of said subchambers; backwash means for directing a backwash flow reversely to said effluent flow through at least one of said subchambers and, additional backwashing means for backwashing said medium at right angles to the flow path.

Claim 3

Apparatus as defined in claim 1 wherein the outlet end is elevated relative to the inlet end such that the flow path therebetween is inclined relative to the horizontal.

Claim 4

Apparatus as defined in claim 2 wherein said chamber is inclined corresponding to said inclination of said outlet end and inlet end and wherein said septa are disposed within the chamber so as to be fully vertical only when the chamber is inclined.

Claim 5

Apparatus as defined in claim 1 wherein said septa are plates of non-corrosive sheet metal perforated with spaced holes.

Claim 6

Apparatus as defined in claim 1 wherein said backwashing means comprises a first backwash inlet at the outlet end of the chamber and a first backwash outlet at the inlet end of the chamber, 1st valve means for connecting the first backwash inlet to a source of backwashing water, and second valve means for selectively controlling flow conditions through said backwash outlet; said first backwash inlet and outlet being effective to produce a flow of backwash water which is counter to the flow of effluent thereby to cleanse said septa and media of accumulated waste material.

Claim 7

Apparatus as defined in claim 5 wherein said additional backwashing means further comprises a second backwash inlet adjacent the bottom of said one subchamber, and third valve means for selectively causing backwash water to enter said second inlet and to flow vertically therethrough to cleanse the filtering medium in said subchamber.

Claim 8

Apparatus as defined in claim 6 wherein said chamber is constructed such that the vertical height of the one subchamber containing the medium is substantially greater than the height of the medium in said subchamber thereby to allow vertical expansion of the medium during vertical backwashing.

Claim 9

Apparatus as defined in claim 7 said additional backwashing means further including a second backwash outlet adjacent the top of said one subchamber, and fourth valve means in said second outlet to control flow therethrough.

Claim 10

Apparatus as defined in claim 8 including automatic programmer means connected to said first and third valve means for sequentially operating the vertical backwash and counter flow backwash.

Claim 11

Apparatus as defined in claim 9 wherein the programmer means includes means to partially open the second valve means during the vertical backwash to produce a component of counterflow during the vertical backwash.

Claim 12

Apparatus as defined in claim 1 wherein the particulate media in said one subchamber is sand having a particle size in the range between 0.8 mm and 3.5 mm, the next adjacent subchamber toward said effluent inlet containing a second filtering medium having a particle size greater than said range thereby to provide serial, reverse-graded filtering action in said chamber for effluent flow.

Claim 13

A waste effluent treatment system comprising: a closed tank having an effluent inlet at one end and an effluent outlet at an opposite end to provide an effluent flow path substantially horizontally through the tank; a plurality of septa disposed in spaced relation within the tank to subdivide the tank into subchambers serially along the effluent flow path; a fine particulate medium in at least one of the subchambers to filter the effluent; a coarse particulate medium in another subchamber and upstream in the effluent flow from said one subchamber; first means for horizontally backwashing at least the coarse medium; and second means for vertically backwashing and expanding the fine medium in said one subchamber.

Claim 14

A waste effluent treatment system comprising: a closed tank having an effluent inlet at one end and an effluent outlet at an opposite end to provide an effluent flow path substantially horizontally through the tank; a plurality of septa disposed in spaced relation within the tank to subdivide the tank into subchambers serially along the effluent flow path; a fine particulate medium in at least one of the subchambers to filter the effluent; a coarse particulate medium in another subchamber and upstream in the effluent flow from said one subchamber; first means for horizontally backwashing at least the coarse medium; and second means for vertically backwashing and expanding the fine medium in said one subchamber.

Claim 15

A waste treatment system as defined in claim 12 wherein the tank is constructed such that the vertical dimension of said one subchamber is greater than that of the remaining chambers of the tank thereby to permit vertical expansion of the fine medium during vertical backwashing.

Claim 16

A waste treatment system as defined in claim 13 including means for elevating the effluent outlet end of the tank at an angle less than about 45° relative to horizontal.

Claim 17

A waste treatment system as defined in claim 14 wherein the septa are angularly disposed within the tank relative to the tank floor but parallel to one another so as to be oriented substantially vertically only when the tank is elevated as aforesaid.

Claim 18

A waste treatment system as defined in claim 12 wherein the first means for backwashing comprises backwash water conduit means disposed within said tank between the coarse and fine media for introducing water to the tank and having outlets formed therein for flushing the coarse media.