Tapered flocculation water treatment

• US 6,197,190 B1
• Filed: 04/07/1999
• Issued: 03/06/2001
• Est. Priority Date: 04/07/1999
• Status: Expired due to Fees

• Current Assignee: I. Kruger Inc. (Veolia Environnement SA)
• Original Assignee: Patrick Hanlon
• Inventors: Hanlon, Patrick
• Primary Examiner(s): Upton, Christopher
• Application Number:
  US09/287,768
• Time in Patent Office: 699 Days
• Field of Search: 210/194, 210/197, 210/207, 210/208, 210/219, 210/266, 210/299, 210/305, 210/520, 210/521, 210/532.1, 210/523
• US Class Current: 210/197
• CPC Class Codes: B01D 21/0012 Settling tanks making use of filters, e.g. by floating layers of particulate material
• CPC Class Codes: B01D 21/2405 Feed mechanisms for settling tanks
• CPC Class Codes: B01D 21/2488 bringing about a partial recirculation of the liquid, e.g. for introducing chemical aids
• CPC Class Codes: B01D 21/26 Separation of sediment aided by centrifugal force or centripetal forcecentrifuges B04B; cyclones B04C
• CPC Class Codes: C02F 1/5281 Installations for water purification using chemical agents

Abstract

Described herein is an improved water treatment process for separating particulate contaminants from raw water. The process is performed by introducing, into a single tank, raw water injected with a coagulating agent for neutralizing charges on the particles and a flocculating agent for agglomerating the neutralized particles; mixing, in the mixing area of said tank, the neutralized and agglomerated particles with a granular medium to increase the size and weight of the particles; directing the particles and water from the mixing area of said tank to a baffled quiescent zone for settling; further directing said water, free of settlement, in said quiescent zone through a buoyant medium to entrap unsettled particles; and wherein the improvement is characterized by conducting tapered flocculation in the mixing area of said tank with a turbine mixer having a plurality of radial blades of varying surface areas, said blades tapered in decreasing areas as the distance from the point of influent increases.

Claims

1. In an improved water treatment system for removing contaminants from raw water, said system comprising:

means for introducing into a single tank an influent of raw water that has been injected with a coagulating agent for neutralizing charged particles and a flocculating agent for agglomerating the neutralized particles;

means for mixing, in a mixing area of said tank, the neutralized and agglomerated particles with a granular medium to increase the size and weight of the particles;

means for directing the particles and water from the mixing area of said tank to a baffled quiescent zone for settling;

wherein the improvement comprises means for further directing said water, free of settlement, in said quiescent zone through a buoyant medium to entrap unsettled particles; and

means for conducting tapered flocculation in the mixing area of said tank with a turbine mixer having a plurality of radial blades of varying area, said blades tapered in decreasing area as the distance from the influent increases.

2. The improved water treatment system according to claim 1 wherein the influent enters the tank in the lower quadrant of said tank.

3. The improved water treatment system according to claim 1 wherein the granular medium is sand.

4. The improved water treatment system according to claim 1 having multiple baffled quiescent zones.

5. The improved water treatment system according to claim 1 wherein the mixing area of said tank further comprises a re-circulation area to intensify the mixing area of said tank.

6. The improved water treatment system according to claim 5 wherein the re-circulation area is defined by a draft tube.

7. The improved water treatment system according to claim 5 wherein the re-circulation area is defined by a re-circulation hood.