Flame Refluxing: An Environment-friendly Alternative to Waste Incineration by Open Pit Burning

Kemal S. Arsava, Shijin P. Kozhumal, Ali S. Rangwala
Worcester Polytechnic Institute, Massachusetts, United States

Keywords: Pit burn, thermally conductive nonflammable objects, enhanced heat transfer, low emission, waste management

Controlled burning of the waste in the pit is a promising approach for quick clean up given that techniques such as bioremediation are slow and necessitate transporting the waste to a fixed land-based treatment facility which is impractical in remote locations. This motivates us to apply the patented flame refluxing technology, utilizing the noncombustible and conductive immersed objects to enhance the heat transfer from the flame back to the fuel (waste), in pit burns to achieve higher burning efficiency. The working principle is based on the rapid heat-up of the flame-exposed upper section. Consequent conduction of heat to the waste through the lower portion in the fuel bed significantly increases waste incineration rate. The efficiency of the proposed approach was demonstrated in a Bureau of Safety and Environmental Enforcement study (Project #1049), where a ten-fold increase in mass burning rate was experimentally observed by placing metal rods inside a pool fire. The scientifically designed burn pits, promoting partial premixing, will further improve the burning efficiency. The proposed solution is easy to use, store, transport, deploy, and reuse. Finding methods to recover the energy from the waste combustion and provide electricity for basic needs, is the next step.