Cleaning of oleaginous water III
The present invention comprises a process and apparatus for separation of hydrocarbons from hydrocarbon-containing produced water, wherein in stage 1 the hydrocarbon-containing produced water is supplied with a gas-containing component, whereupon a gas- and hydrocarbon-containing produced water mixture is fed to an inlet tube ( 22, 27 ) in the center of a tank, whereupon the said mixture is tangentially distributed via at least one nozzle ( 7 ) and at least one baffle plate ( 8.1 ), whereupon separated hydrocarbons are conveyed to at least one outlet from the tank and cleaned water is conveyed to an outlet ( 12 ) from the tank.
1. A method for separating oil from oil-containing water in a vessel comprising an upper chamber and a lower chamber, the method comprising:
injecting gas into the oil-containing water to generate an oil-containing water and gas mixture;
distributing the oil-containing water and gas mixture tangentially along a wall about an axis of the vessel in the upper chamber via an inlet tube extending along the axis of the vessel;
separating oil and gas from the oil-containing water and gas mixture in the upper chamber to produce a partially-cleaned water to be distributed in the lower chamber;
outputting separated oil and gas in the upper chamber through an upper oil outlet;
distributing the partially-cleaned water tangentially along the wall about the axis of the vessel in the lower chamber;
separating oil and gas from the partially-cleaned water in the lower chamber to produce a cleaned water; and
outputting separated oil and gas in the lower chamber through a lower oil outlet.
2. The method of claim 1 , further comprising outputting the cleaned water in the lower chamber through a water outlet.
3. The method of claim 1 , wherein the vessel further comprises a separation plate defining the upper chamber and lower chamber.
4. The method of claim 1 , wherein the upper chamber and lower chamber are in fluid communication.
5. The method of claim 1 , wherein distributing the oil-containing water and gas mixture tangentially along the wall about the axis of the vessel in the upper chamber comprises distributing the oil-containing water via an upper nozzle located in the upper chamber and extending from the inlet tube.
6. The method of claim 1 , wherein distributing the partially-cleaned water tangentially along the wall about the axis of the vessel in the lower chamber comprises distributing the partially-cleaned water via a lower nozzle located in the lower chamber and extending from a separation plate located in the vessel.
7. The method of claim 1 , further comprising flowing the cleaned water through a bed of gas coalescent material in the lower chamber.
8. The method of claim 2 , further comprising controlling flow of the outputted clean water via a valve in the water outlet.
9. The method of claim 1 , wherein separating oil and gas from the oil-containing water and gas mixture in the upper chamber to produce a partially-cleaned water to be distributed in the lower chamber further comprises passing the oil-containing water and gas mixture over a baffle plate in the upper chamber.
10. The method of claim 1 , wherein separating oil and gas from partially-cleaned water in the lower chamber to produce cleaned water further comprises passing the partially-cleaned water over a baffle plate in the lower chamber.