Aerator and wastewater treatment system

An aerator for treatment of liquid, comprising:

• a housing having an interior with an inlet for the entrance of the liquid, and an outlet for the exit of the liquid;
• an air inlet located in the housing between the liquid inlet and the liquid outlet;
• an inlet nozzle located in the housing between the liquid inlet and the air inlet, the inlet nozzle having an entrance face and a bore which extends through the nozzle to an exit face, wherein the bore has a substantially cylindrical exit portion of a first diameter which discharges at the exit face, and wherein the bore has an inlet portion of a second greater diameter than the first diameter and said bore inlet portion converges as it extends downstream, the bore inlet portion being joined to the bore exit portion and providing a smooth transition from said second diameter to said first diameter;
• portions of the inlet nozzle bore exit portion defining a spiral groove which extends from the inlet nozzle bore inlet portion to the exit face;
• a discharge nozzle located in the housing between the air inlet and the liquid outlet, the discharge nozzle having an entrance face and a bore which extends through the discharge nozzle to a discharge nozzle exit face, wherein the discharge bore has a substantially cylindrical exit portion of a third diameter which discharges at the discharge nozzle exit face, and wherein the discharge nozzle bore has an inlet portion of a fourth diameter which is greater than the third diameter and which is flared towards the inlet nozzle, and wherein the third diameter is greater than the first diameter;
• and
• an expansion chamber defined within the housing beneath the air inlet and between the inlet nozzle and the discharge nozzle, the expansion chamber having a gap between the inlet nozzle and the discharge nozzle which communicates with an annular region defined between the nozzles and the interior of the housing.

An apparatus for treatment of contaminated water, comprising:

• a housing having an inlet for entrance of contaminated water, an outlet for the exit of treated water, and an inlet for air located between the liquid inlet and the liquid outlet;
• an inlet nozzle located within the housing between the liquid inlet and the air inlet, the inlet nozzle having a bore which extends therethrough and which has an inlet portion which is flared and of greater diameter than an exit portion, and wherein portions of the inlet nozzle define a spiral path extending along the bore exit portion;
• a discharge nozzle located within the housing between the liquid outlet and the air inlet;
• and
• an expansion chamber located within the housing and defined between the inlet nozzle and the discharge nozzle, the apparatus being effective to introduce a quantity of oxygen into the contaminated water in excess of two kilograms per kilowatt hour of power expended in pumping the contaminated water through the aerator.

A system for the treatment of wastewater, comprising:

• a tank;
• at least one pump;
• a plurality of aerators connected to a discharge pipe which empties into the tank, and connected to receive water from within the tank as supplied by the pump, wherein each aerator comprises:
• a housing having an interior with an inlet for the entrance of liquid, and an outlet for the exit of liquid;
• an air inlet located in the housing between the liquid inlet and the liquid outlet;
• an inlet nozzle located in the housing between the liquid inlet and the air inlet, the inlet nozzle having an entrance face and a bore which extends through the nozzle to an exit face, wherein the bore has a substantially cylindrical exit portion of a first diameter which discharges at the exit face, and wherein the bore has an inlet portion of a second greater diameter than the first diameter and said bore is flared towards the housing liquid inlet, the bore inlet portion being joined to the bore exit portion and providing a smooth transition from said second diameter to said first diameter;
• portions of the inlet nozzle bore exit portion which define a spiral groove which extends from the inlet nozzle bore inlet portion to the exit face;
• a discharge nozzle located in the housing between the air inlet and the liquid outlet, the discharge nozzle having an entrance face and a bore which extends through the discharge nozzle to a discharge nozzle exit face;
• and
• an expansion chamber defined within the housing between the inlet nozzle and the discharge nozzle and in communication with the air inlet, the expansion chamber having a gap between the inlet nozzle and the discharge nozzle.

A process for the treatment of water with contaminants, comprising the steps of:

• introducing a flow of water with contaminants into a tank;
• withdrawing a portion of the water with contaminants from the tank and advancing the withdrawn water with contaminants through a plurality of aerators, and then back into the tank, wherein each aerator comprises:
• a housing having an interior with an inlet for the entrance of liquid, and an outlet for the exit of liquid;
• an air inlet located in the housing between the liquid inlet and the liquid outlet;
• an inlet nozzle located in the housing between the liquid inlet and the air inlet, the inlet nozzle having an entrance face and a bore which extends through the nozzle to an exit face, wherein the bore has a substantially cylindrical exit portion of a first diameter which discharges at the exit face, and wherein the bore has an inlet portion of a second greater diameter than the first diameter and said bore is flared towards the housing liquid inlet, the bore inlet portion being joined to the bore exit portion and providing a smooth transition from said second diameter to said first diameter;
• portions of the inlet nozzle bore exit portion which define a spiral groove which extends from the inlet nozzle bore inlet portion to the exit face;
• a discharge nozzle located in the housing between the air inlet and the liquid outlet, the discharge nozzle having an entrance face and a bore which extends through the discharge nozzle to a discharge nozzle exit face;
• and
• an expansion chamber defined within the housing between the inlet nozzle and the discharge nozzle and in communication with the air inlet, the expansion chamber having a gap between the inlet nozzle and the discharge nozzle.