Sludge digestion methods and apparatus
First Claim
1. An aerobic digester for organic material comprising:
- a vessel for containing a liquid comprising the organic material, the vessel having an interior comprising an upper portion, a lower portion and a lower interior surface;
a tube having a distal end disposed in the lower portion of the interior of the vessel, an opening in a wall of the tube for permitting liquid and air flow between an exterior and an interior of the tube, and at least one discharge port disposed in the distal end; and
a liquid conveyor connected in fluid communication with the interior of the tube for inducing flow of the liquid along the tube in the direction of the distal end, whereby the liquid conveyor induces entrainment of air drawn into the tube through the opening into the liquid drawn into the tube through the opening to form a liquid-air mixture and expulsion of the liquid-air mixture from the tube through the at least one discharge port into the lower portion of the vessel, thereby causing liquid contained in the vessel to be mixed and aerated.
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Accused Products
Abstract
The invention relates to an aerobic wastewater digestion unit useful for degrading organic material dissolved or suspended in a wastewater stream. The wastewater is fed to a vessel, wherein it is circulated by a liquid conveyor between the vessel and a downwardly-directed tube. Expulsion of fluid from the tube into the lower portion of the vessel agitates the liquid in the vessel and disperses into the liquid air that has been entrained in the liquid in the tube. The digester can be operated using varying liquid levels, and is amenable to batch, semi-batch, and continuous operation. The digester is suitable for use in combination with other components of wastewater treatment systems, and can be included as a module in modular wastewater treatment systems.
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Citations
49 Claims
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1. An aerobic digester for organic material comprising:
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a vessel for containing a liquid comprising the organic material, the vessel having an interior comprising an upper portion, a lower portion and a lower interior surface;
a tube having a distal end disposed in the lower portion of the interior of the vessel, an opening in a wall of the tube for permitting liquid and air flow between an exterior and an interior of the tube, and at least one discharge port disposed in the distal end; and
a liquid conveyor connected in fluid communication with the interior of the tube for inducing flow of the liquid along the tube in the direction of the distal end, whereby the liquid conveyor induces entrainment of air drawn into the tube through the opening into the liquid drawn into the tube through the opening to form a liquid-air mixture and expulsion of the liquid-air mixture from the tube through the at least one discharge port into the lower portion of the vessel, thereby causing liquid contained in the vessel to be mixed and aerated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43)
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44. A method of aerobically digesting organic material in wastewater, the method comprising the steps of:
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a) providing the wastewater comprising the organic material to a digester that comprises;
a vessel for containing a liquid, the vessel having an interior comprising an upper portion and a lower portion and a lower interior surface;
a tube having a distal end disposed in the lower portion of the interior of the vessel, an opening in the wall of the tube for permitting liquid and air flow between the exterior and interior of the tube, and at least one discharge port disposed in the distal end; and
a liquid conveyor disposed within the tube for inducing flow of the liquid through the tube in the direction of the distal end, the conveyor comprising an impeller disposed below the opening; and
b) circulating the liquid in the digester by way of the tube, whereby the conveyor induces entrainment of air into the liquid drawn into the tube by way of the opening to form a liquid-air mixture and expulsion of the liquid-air mixture from the tube through the at least one discharge port, thereby inducing mixing and aeration of the liquid in the vessel and digesting organic material in the wastewater. - View Dependent Claims (45, 46, 47, 48, 49)
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Specification