The United States Environmental Protection Agency has sponsored two separate research contracts in the field of high-speed devices for the recovery of thin-film oil spills. Both projects involve deflecting oil that is moving relative to the device by means of an air jet so that the resulting oil and water spray can be captured and separated.
One project has been conducted by Tetradyne Corporation of Richardson, Texas, and involves the use of air jets to concentrate and subsequently deflect oil into a sump for gravity separation. This device has achieved up to 86% (vol/vol) recovery efficiency at a speed of six FPS in towing tank tests of a full-scale prototype; it is relatively insensitive to waves, small debris, and changes in oil viscosity.
The second project has been conducted by Science Applications, Inc., of McLean, Virginia, and involves use of a slightly submerged air jet to deflect oncoming oil in the form of a spray lofted into a rotating polyurethane foam belt used for oil-water separation. Collection efficiencies of up to 83% (wt/wt) have been achieved in towing tank tests of a section of a full-scale prototype at a speed of 5.5 FPS. This device operates satisfactorily in waves and is somewhat sensitive to oil viscosity.
Material is presented on the rationale for developing the devices, the testing technology that has been used for these efforts, and the test results for each device.