Method and apparatus for aerating wastewater
AssigneeFBC Technologies, Inc.
InventorDavid G. Long
Life of this patent
Estimating the term…
Abstract
Oxygen depleted wastewater is introduced as a stream into the top of a vessel containing a set of perforated triangular vanes arranged to rotate about a vertical axis. The stream is directed downwardly in the vessel along a path that traverses the path of the rotating vanes so the vanes impact the stream. The force of the impact of the vanes against the stream and the perforations in the vanes cooperate to create a fine droplet mist in the vessel. Atmospheric air drawn into the vessel is mixed and entrained in the mist so that when the mist coalesces, micro-fine size air bubbles are formed. The triangular vanes further provide a pumping action to expel a now aerated stream of wastewater from adjacent the bottom of the vessel.
Claims20
A method of aerating wastewater to enhance aerobic treatment comprising:
- a) introducing a wastewater stream into an upper level of a vessel and down into the path of vertically oriented perforated vanes arranged to rotate in the vessel about a vertical axis;
- b) rotating the vanes and impinging the vanes at a right angle against the waste water stream with sufficient force to temporarily divide at least part of the wastewater stream into a fine droplet mist, the dividing of the waste water stream into the fine droplet mist and resulting surface area expansion creating a negative pressure within the vessel;
- c) drawing atmospheric air in to the vessel in response to the negative pressure, the air drawn into the vessel intimately mixing with fine droplet mist and becoming entrained in the mist and forming relatively small bubbles as droplets in the mist coalesce thereby facilitating the dissolving of atmospheric oxygen into the wastewater and enhancing the oxygen content of the wastewater;
- and
- d) expelling the now oxygen enhanced wastewater from a lower level of the vessel under the influence of a pumping action produced by the rotating vanes.
A method of aerating wastewater to enhance aerobic treatment comprising:
- a) introducing a stream of oxygen depleted wastewater from a lagoon into an upper level of a treatment vessel and directing the stream downwardly in the vessel and into the path of vertically oriented perforated vanes rotating about a vertical axis in the vessel;
- b) impinging the rotating vanes at a right angle against the downwardly flowing wastewater stream with sufficient force to temporarily divide at least part of the wastewater stream into a fine droplet mist, the dividing of the waste water stream into the fine droplet mist and resulting surface area expansion creating a negative pressure within the vessel;
- c) drawing atmospheric air in to the vessel in response to the negative pressure, the air drawn into the vessel intimately mixing with the fine droplet mist and becoming entrained in the mist and forming entrapped micro-fine bubbles as wastewater droplets in the mist coalesce thereby facilitating the dissolving of atmospheric oxygen into the wastewater and elevating the dissolved oxygen content to at least 10 mg/L thereby enhancing the oxygen content of the wastewater;
- and
- d) expelling the now oxygen enhanced treated wastewater from an outlet at a lower level of the vessel under the influence of a pumping action produced by the rotating vanes;
- and returning the oxygen enhanced wastewater back to the lagoon.
Apparatus for aerating wastewater comprising:
- a) a vessel having an oxygen depleted wastewater inlet at an upper level and an oxygen enhanced wastewater outlet at a lower level;
- b) a rotor within the vessel including a shaft arranged for rotation about a vertical axis and a plurality of vertically oriented vanes extending outwardly from the shaft, each of the vanes having a plurality of openings therethrough;
- c) means for rotating the rotor;
- d) the wastewater inlet being arranged to direct an oxygen depleted wastewater stream downwardly into the vessel along a path generally parallel to the rotor axis of rotation so that the vanes impinge against the oxygen depleted wastewater stream at a generally right angle, the impingement dividing the stream into a fine droplet mist and creating a negative pressure in the vessel;
- e) a valved inlet for admitting atmospheric air into the vessel in response to the negative pressure, the air mixing with the fine droplet mist in the vessel thereby enhancing the oxygen content of the wastewater stream;
- and
- f) pumping means for expelling the now oxygen enhanced wastewater stream from the oxygen enhanced wastewater outlet at a lower level of the vessel.
Dependencies are inferred from the claim text.