FREE VORTEX RECOVERY OF FLOATING OIL

Abstract

ABSTRACT A concept employing a free vortex for use in recovering oil from high seas oil spills is presented. An experimental evaluation program has been completed which demonstrates the feasibility of this concept as well as design limitations. An oil slick will migrate toward the center of the vortex due to the action of the water flow induced by an impeller. At an appropriate speed of rotation, the oil will submerge and accumulate within a central region of the vortex. This pocket will contain a concentrated mass of oil which can readily be removed by conventional pumping. Advantages of this technique include effective operation in high seas and the ability to both collect and concentrate an oil slick in a single operation. Tests were performed with a free vortex oil recovery model having an impeller diameter of one foot. Performance data were obtained both under quiescent water conditions and also under environmental conditions that simulated 10-foot deep water waves, 20-knot winds, and 2-knot currents. Detailed scaling considerations based on the test data indicate that a prototype device, with diameter on the order of 4-feet and larger, would be operable in all typically occurring 10-foot seas. Depending on its size, the prototype will recover in excess of 100 gallons per minute of oil with an oil-to-water ratio greater than 1.2 when operating with a crude oil film of only 0.1 inches in thickness.