Optimum air feed locations on medical waste incineration rotary kiln by computational fluid dynamics (CFD)

Abstract

Twenty-four tons of medical waste is combusted every day in Istanbul. The plant is operated by ISTAÇ AŞ and combustor type is rotary kiln. The air was being fed manually along with the waste being introduced to the kiln. This case caused some problems regarding the combustion efficiency. The administration staff decided to open holes to supply air to the combustor. In this study, CFD was utilized in order to determine the optimum places for air inlets. Flow geometry of the air was prepared and then meshed for calculations. k-ε turbulence model was utilized in the calculations. Four air inlet pipes were placed on the edges of the circular inlet area. Different locations were tested. When the air was fed from the top, waste could not completely contact with the air. Additionally, different inlet angles were tested from zero degrees to thirty degrees. The degree of the inlet did not much change the combustion characteristics inside the kiln. Piping holes were burrowed from the bottom at zero degree angle.