Sewage treatment system

• US 4,021,347 A
• Filed: 01/09/1976
• Issued: 05/03/1977
• Est. Priority Date: 01/09/1976
• Status: Expired due to Term

• Current Assignee: Ray E. Teller, Sem G. Zachar
• Original Assignee: Ray E. Teller, Sem G. Zachar
• Inventors: Teller, Ray E., Zachar, Sem G.
• Primary Examiner(s): Spear, Jr., Frank A.
• Assistant Examiner(s): Spitzer, Robert H.
• Application Number:
  US05/647,670
• Time in Patent Office: 480 Days
• Field of Search: 210/7, 210/15, 210/170, 210/192, 210/195 S, 210/197, 210/220, 210/221 R, 210/256, 210/260, 210/261, 210/446, 210/314, 210/315, 210/317, 210/199, 210/202, 210/203 , 210/320, 210/411
• US Class Current: 210/195.1
• CPC Class Codes: B01D 29/01 with flat filtering elements B01D29/39 takes precedence
• CPC Class Codes: B01D 29/6438 nozzles
• CPC Class Codes: B01D 29/66 by flushing, e.g. counter-current air-bumps
• CPC Class Codes: C02F 3/1242 Small compact installations for use in homes, apartment blocks, hotels or the like
• CPC Class Codes: C02F 3/1252 Cylindrical tanks with horizontal axis
• CPC Class Codes: Y02W 10/10 Biological treatment of water, waste water, or sewage

Abstract

An improved sewage treatment system including a horizontally elongated tank divided transversely into a primary, aeration compartment, a secondary, settling compartment and a tertiary, filtering compartment. In a first aspect of the invention, overflow of treated effluent from the tank enters a further treatment section, which may constitute a longitudinal extension of the tank, wherein the effluent is constrained by baffles to flow in an elongated path while having chlorine or ozone mixed therewith to provide further purification. Another aspect of the invention resides in the novel structure of the filtering section wherein filter screens of different guage or opening size are used to achieve a greater degree of purification.

Claims

1. A sewage treatment system comprising in combination:

(a) an enclosed, horizontally elongated tank of substantially uniform cross section between two end walls having an inlet opening in one end wall and an outlet opening in the opposite end wall;

(b) an internal wall extending across the interior of said tank from the bottom thereof to an upper edge slightly below the level of the lowest edge of said inlet opening, dividing said tank into first and second compartments;

(c) a first filter screen extending partially across the interior of said tank on the side of said internal wall nearest said opposite end wall;

(d) a second filter screen arranged in substantially parallel, spaced relation to said first screen on the side thereof nearest said opposite end wall;

(e) both of said filter screens having upper edges higher than the level of the lowest edge of said outlet opening, lower edges substantially higher than the bottom of said tank and lower than said outlet opening and coplanar side edges;

(f) a pair of solid side walls extending from said opposite end wall to the side edges of both of said first and second screens, and a bottom wall extending from said opposite end wall only to the lower edge of said second screen whereby said side and bottom walls, said second screen and said opposite end wall define a third compartment;

(g) said side walls having openings in the portions thereof between the side edges of said first and second screens, the area of said openings being sufficiently small that normal flow is essentially longitudinal, through said first screen, and sufficiently large to permit essentially unobstructed lateral flow to the space between said first and second screens in the event of blockage of said first screen; and

(h) means within said first compartment for aerating liquid contents thereof, whereby sewage flowing through said tank from said inlet to said outlet openings is aerated in said first compartment, partially purified by gravity settling of a portion of the solids in said second compartment, and further purified by filtration through said screens in passing from said second to said third compartment.

2. The invention according to claim 1 wherein said first screen is coarser than said second screen.

3. The invention according to claim 2 and further including a fourth compartment arranged to receive liquid discharged from said third compartment through said outlet opening in said opposite end walls, said fourth compartment including a final discharge opening and a plurality of baffles defining an elongated, gravity flow path for liquid from said outlet opening to said final discharge opening.

4. The invention according to claim 3 and further including means for injecting an effluent purifying agent into said fourth compartment.

5. The invention according to claim 1 and further including a plurality of liquid spray nozzles arranged within said first compartment above the level of said inlet opening to direct a foam-cutting spray downwardly upon the surface of liquid in said first compartment, and a line for supplying liquid to said nozzles from said third compartment.

6. The invention according to claim 1 and further including backwash jet means disposed within said third compartment to direct a spray of liquid on the side of said second screen facing said opposite end wall, and a line for supplying liquid to said jet means from said third compartment.