The technology was developed at WPI by a team led by Ali Rangwala, professor of fire protection engineering, as an outgrowth of research funded by the U.S. Department of the Interior aimed at assessing the feasibility of using in-situ burns to clean up oil spills in remote locations in the Arctic, where harsh weather can make it difficult to quickly mobilize clean-up equipment and crews. When laboratory tests identified the challenges of igniting and sustaining oil fires on ice and in cold water, Rangwala and his team began exploring methods for making the oil easier to burn by transmitting heat from the flames to the oil. The Flame Refluxer is the product of that exploration.

“The technology is so simple, it has no moving parts, it’s inexpensive, and it significantly enhances the burning rate of oil. The tests we are doing at this unique facility will allow us to advance the technology closer to actual deployment” said Rangwala.

Prototypes of the technology were tested in the state-of-the-art Fire Protection Engineering Laboratory at WPI. This week’s tests at the Joint Maritime Test Facility used a larger prototype, a circular blanket nearly 1.5 meters (four feet, eight inches) across with up to 48 metal coils attached. The blanket was immersed in a layer of crude oil floating on water. Oil was pumped to the test apparatus to maintain the oil layer at about one centimeter (0.4 inches) throughout each 10-20 minute test burn. (Previous research has shown that crude oil burns most effectively when the oil layer that is maintained between one and four centimeters).

During test burns conducted with and without the Flame Refluxer, the researchers measured a number of parameters, including temperatures above the oil fire and the flow rate of oil delivered to the test apparatus, in order to determine how effectively the Flame Refluxer conveyed heat from the flames to the oil (a process known as heat flux) and how it changed the oil burning rate. An air sampling station collected emissions produced by the fire and continuously measured several combustion byproducts: carbon dioxide, carbon monoxide, nitrogen dioxide, sulfur dioxide, and particulate matter (PM2.5 and PM10). The copper blanket was weighed before and after each test to see how effectively it trapped residue from the oil fires.

While it will take time to analyze the large volume of data collected during the test burns and report official results, Rangwala said the research team made several observations that suggested that the Flame Refluxer technology performed as expected. “Where we observed thick black smoke during a baseline test, where we burned crude oil without the blanket and coils, when the Refluxer was in use, the smoke was thinner and grey, even though more oil was being combusted. In fact, our measurements show that between four and five times as much oil was burned per minute with the Flame Refluxer in place. Finally, we observed that virtually no residue was left over after our burns with the Refluxer, an indication that it promotes more complete combustion of the oil.”