A rotational hot gas heating system for bioreactors

A rotating arm made from Teflon® pipe perforated with slots for distributing hot gas in a bioreactor was developed. The hot gas discharge propelled the rotating arm around a Teflon® pivot at the centre of a bioreactor bottom. The rotating movement helps spread the hot gas to the slurry, which assists in mixing the suspended solids in the reactor. Air and water were used as substitutes for the hot gas and slurry in a heat transfer experiment. The heat transfer from hot air to water was found to be 50–60%. A gas burner for generating flue gas of low oxygen content was also developed to avoid disrupting the environment in anaerobic bioreactors. The gas burner can produce flue gas from both methane and biogas with very low oxygen content. Using Teflon® parts and a low oxygen flue gas burner, the system has the potential to lower the cost of heating bioreactors, aerobic or anaerobic.