Submerged clarifier launder

Patent metadata

Field	Value
Publication number	US-9919244-B2
Application number	US-201615063397-A
Country	US
Kind code	B2
Filing date	Mar 7, 2016
Priority date	Mar 7, 2016
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A clarifier in a wastewater treatment plant is provided with a submerged launder for effluent, the launder preferably having an integral density current baffle and scum baffle. In one embodiment an existing launder is modified, with its vertical leg replaced with a sloped plate defining launder conduit triangular in cross section, and with a sloping portion of the plate forming a density current baffle. Openings in the sloped plate permit entry of effluent liquid, and the liquid level in a clarifier is controlled without an overflow weir plate. In another form submerged pipe with entry holes serves as the launder, with support brackets integral with a density current baffle. A third form of the launder is a box formed beneath the shelf of an existing internal launder in the clarifier, again with a density current baffle extending down from the box. In another version an existing launder is covered and sealed, and holes are drilled through the launder wall to admit effluent. A submerged launder avoids problems of algae buildup and the need for algae sweeps or frequent cleaning of the launder.

First claim

We claim:

1. In a wastewater treatment clarifier having an effluent launder for withdrawal of effluent from the clarifier, the improvement comprising:
the clarifier having a peripheral clarifier wall, and the launder being connected to the inside of the clarifier wall,
the launder being at least partly submerged below the liquid level in the clarifier,
the launder having inlet orifices submerged below the liquid level of the clarifier, and
the submerged launder comprising an inwardly/downwardly obliquely angled plate connected to the internal side of the clarifier wall as an upper side of the launder, a shelf connected to the clarifier wall at a level below the connection of the obliquely angled plate to the wall to form a bottom of the launder, the obliquely angled plate being connected to an inward side of the shelf, at a level such that the obliquely angled plate extends beyond the shelf to form a density current baffle for the clarifier, and the obliquely angled plate having said inlet orifices to admit effluent water from the clarifier.

2. The improvement described in claim 1 , wherein the submerged effluent launder is formed by modification of an existing internal launder of the clarifier, with a vertical leg of the existing launder removed and said shelf comprising a remaining horizontal shelf of the existing launder.

3. The improvement described in claim 2 , wherein a density current baffle is formed as an extension of and integral to the angled launder plate, extending over and beyond the inward edge of the horizontal shelf.

4. The improvement described in claim 1 , further including vent holes near an upper end of the obliquely angled plate.

5. The improvement described in claim 1 , further including an integral vertical plate extending up from the upper end of the obliquely angled plate, the vertical plate being secured to the clarifier wall, and the vertical plate extending up sufficiently to form a scum skimming surface above the liquid level in the clarifier.

6. The improvement described in claim 1 , wherein the inlet orifices are just above the bottom of the launder, whereby the submerged orifices minimize sun exposure to prevent algae growth in the launder.

7. The improvement described in claim 1 , wherein the obliquely angled plate is connected to the inward side of the shelf by threaded fasteners occurring at selected spacing, and wherein the inlet orifices are located in the obliquely angled plate above the threaded fasteners so as to provide tool access to the threaded fasteners through the orifices.

8. A method for converting a clarifier of a wastewater treatment system having an interior concrete effluent launder on the clarifier wall, generally L-shaped in cross section with a horizontal shelf and a vertical leg, to a submerged effluent launder, comprising:
removing the vertical leg of the launder, throughout the circumference of the clarifier, and
attaching an obliquely angled plate onto the clarifier, to extend from an inward edge of the horizontal shelf obliquely up to a connection to the clarifier wall to thereby form a submerged launder triangular in cross section, and including orifices in the angled plate to admit clarifier effluent liquid, the launder being at least mostly submerged in the liquid of the clarifier.

9. The method of claim 8 , wherein the obliquely angled plate has an integral vertical plate at its upper end, and including securing the integral vertical plate against the clarifier using bolts, to retain the obliquely angled plate and to provide a smooth surface for scum skimming.

10. The method of claim 8 , further including providing a density current baffle as an extension of and integral to the obliquely angled plate, to extend over and beyond the inward edge of the horizontal shelf.

11. In a wastewater treatment clarifier having an effluent launder for withdrawal of effluent from the clarifier, the improvement comprising:
the clarifier having a peripheral clarifier wall, and the launder being connected to the inside of the clarifier wall,
the launder being at least partly submerged below the liquid level in the clarifier,
the launder having inlet orifices submerged below the liquid level of the clarifier, and
the submerged launder comprising an inwardly/downwardly obliquely angled plate connected to the internal side of the clarifier wall as an upper side of the launder, a shelf connected to the clarifier wall at a level below the connection of the obliquely angled plate to the wall to form a bottom of the launder, the obliquely angled plate being connected to an inward side of the shelf, and the obliquely angled plate having said inlet orifices to admit effluent water from the clarifier.

12. The improvement described in claim 11 , wherein the obliquely angled plate is connected to the inward side of the shelf by threaded fasteners occurring at selected spacing, and wherein the inlet orifices are located in the obliquely angled plate above the threaded fasteners so as to provide for use of a tool on the threaded fasteners through the orifices.

Assignees

• Ovivo Inc

Inventors

• Heimdal Tor
• Vorwaller John
• Clark Hugh Ryan
• Kline Todd
• Petrone Ralph
• Hugo Bruce A
• Peters Roger
• Beaman Tyson

Classifications

• B01D21/0003

  Making of sedimentation devices, structural details thereof, e.g. prefabricated parts · CPC title

• B01D21/2444

  Discharge mechanisms for the classified liquid · CPC title

• B01D21/0042

  Baffles or guide plates · CPC title

• B01D21/0006 Primary

  Settling tanks provided with means for cleaning and maintenance · CPC title

• Y02W10/37

  using solar energy · CPC title