PERFORMANCE TESTS OF FOUR SELECTED OIL SPILL SKIMMERS

Abstract

ABSTRACT From April through October, 1977, a series of oil spill skimmer performance tests were conducted at the United States Environmental Protection Agency's (EPA) Oil and Hazardous Materials Simulated Environmental Test Tank (OHMSETT), Leonardo, New Jersey. This program was sponsored by EPA, the Coast Guard, Navy, and Department of Energy combined as the OHMSETT Interagency Test Committee (OITC). The test devices selected were the commercially-available Oil Mop, Inc. Dynamic Skimmer, the Cyclonet 050 mounted on a Zodiac Inflatable boat, the Anti-Pollution, Inc. Clowsor Skimmer, and the Bennett Pollution Controls, LTD., Mark 6E Skimmer. A total of 198 test runs were performed during which each device was evaluated for recovery of two test oils through a wide range of simulated environmental conditions of waves and currents. The performance indicating parameters were: (1) throughput efficiency, the percentage of oil encountered which is collected; (2) recovery efficiency, the percent oil in the oil/water mixture collected; and (3) oil recovery rate, the volume of oil collected per unit time. The Oil Mop Dynamic Skimmer produced its highest average throughput efficiency (78 percent) with light oil (9 centistokes—cst) at a tow speed of 200 feet per minute (fpm) in calm water. Highest recovery efficiency (77 percent) was observed with heavy oil (3,000 cst) at 200 fpm in calm water, and maximum recovery rate was established with light oil at a tow speed of 400 fpm. The Cyclonet 050 showed its highest average performance with heavy oil (550 cst) at a tow speed of 150 fpm. Throughput efficiency was 34 percent in calm water, recovery efficiency was 27 percent in the 0.6 by 26.2 ft (height by length) wave and recovery rate was 14 gallons per minute (gpm) in calm water. The Clowsor Skimmer was tested as an advancing and stationary system. Highest average results occurred in the stationary mode with heavy oil (1,900 cst) and recovery efficiency was 91 percent. Maximum recovery rate observed was 95 gpm. The Bennett Mark 6E Skimmer performed best with heavy oil (3,200 cst). Throughput efficiency was 95 percent at a tow speed of 300 fpm, recovery efficiency was 88 percent at 100 fpm, and maximum oil recovery rate occurred at 200 fpm and was measured at 108 gpm. The general trend of performance for all devices tested showed diminishing performance with increased tow speeds and wave conditions.