an energy conversion system comprises a plurality of concentrically arranged combustion chambers for passing incinerated waste plastic fuel along a generally s - shaped combustion path into a discharge section for thermally coupling the incinerated waste plastic fuel to a fluid material to facilitate an energy conversion process . the combustion chambers are arranged concentrically around a single rotatable feed mechanism and the combustion chambers are in fluid communication with one another . the fluid material is contained within a boiler in fluid communication with the combustion chambers for heating the fluid material to facilitate the energy conversion process .