Air stripper
An air stripper includes a vessel, a gas delivery tube to deliver a gas into the vessel and a contaminated liquid inlet that provides a contaminated liquid to the vessel at a rate sufficient to maintain a controlled constant level of process fluid within the vessel. A weir is disposed within the vessel adjacent the gas delivery tube to form a first fluid circulation path between a first weir end and a wall of the vessel and a second fluid circulation path between a second weir end and an upper end of the vessel. During operation, gas introduced through the tube mixes with the process fluid and the combined gas and fluid flow at a high rate with a high degree of turbulence along the first and second circulation paths defined around the weir, thereby promoting vigorous mixing and intimate contact between the gas and the process fluid.
1. A method of remediating a contaminated liquid having volatile contaminants in an air stripper having a weir disposed within a vessel to define first and second volumes within the vessel and a gas delivery tube extending into the vessel into the first volume, the method comprising:
supplying contaminated liquid to the vessel at a rate sufficient to maintain a process fluid surface level in the vessel above a first end of the weir and above a second end of the weir when the air stripper is operating;
providing a combustion gas through the gas delivery tube, which is oriented vertically within the vessel, the gas being forced downward through the gas delivery tube to an exit below a surface of the contaminated liquid and radially outward through the exit near an end of the gas delivery tube and into the first volume defined between the weir and the gas delivery tube to cause mixing of the combustion gas and the process fluid within the first volume by creating a circular flow of process fluid from the first volume around the first end of the weir into the second volume and from the second volume around a second end of the weir and into the first volume, the exit being formed in a gas delivery tube wall, which is oriented parallel to the weir;
removing process fluid through a fluid exit port; and
removing the combustion gas through a gas exit port in the vessel.
2. The method of claim 1 , further including removing process fluid with suspended particulate from the vessel.
3. The method of claim 1 , further including combusting a fuel to create the combustion gas.
4. The method of claim 1 , wherein the combustion gas or constituents within the combustion gas chemically react with the process fluid or constituents of the process vessel within the vessel.
5. The method of claim 1 , wherein the combustion gas at least partially evaporates the process fluid.
6. The method of claim 1 , wherein the contaminated liquid is industrial waste water.
7. The method of claim 1 , wherein the contaminated liquid is groundwater.
8. The method of claim 1 wherein the contaminated liquid is landfill leachate.
9. The method of claim 1 , wherein the contaminated liquid is produced water from oil or gas recovery wells.
10. The method of claim 1 wherein the contaminated liquid is surface water runoff from land used to raise livestock or crops.
11. The method of claim 1 , wherein providing the combustion gas through the gas delivery tube to force the combustion gas through an exit includes forcing the combustion gas through twelve exits.
12. The method of claim 1 , wherein the exit is substantially rectangular in shape.
13. The method of claim 1 , wherein providing the combustion gas through the gas delivery tube to force the combustion gas through an exit includes providing a ratio of combustion gas to the total combined open area of the exit of between 1,000 and 18,000 acfm/ft 2 .
14. The method of claim 1 , wherein providing the combustion gas through the gas delivery tube to force the combustion gas through an exit includes providing a ratio of combustion gas to cross-sectional area of the first volume of between 400 and 10,00 scfm/ft 2 .
15. The method of claim 1 , wherein providing the combustion gas through the gas delivery tube to force the combustion gas through an exit includes sequentially providing combustion gas to a multi-stage treatment chamber.
16. The method of claim 15 , wherein providing combustion gas to a multi-stage treatment chamber includes separating the vessel into a series of chambers with a series of baffles.