Heat transfer modelling of industrial rotary kilns for iron ore pelletizing

Other conference contribution, 2019

This work discusses the development and usage of a detailed heat transfer model of a rotary kiln in 3D, applying a discrete-ordinates method to solve the radiative heat transfer equation. The model includes conductive and convective heat transfer as well as heat release due to reactions in the bed and heat losses from the outside of the kiln. The rotation of the wall is considered along with a simplified mixing model of the bed. Measurement data gathered from a test furnace, is used in combination with temperature data and operation parameters gathered from a full-scale rotary kiln to calculate surface temperatures. Compared to measurements, the model predicts the temperatures well with errors less than 10%. Different contributions of the total heat transfer to the bed was studied, revealing that more than 80% originated from radiation.