Investigation of the Effect of Thermal Shields on the Calcination of Petroleum Coke in Rotary Disc Kilns

Due to various impurities, impure petroleum coke obtained during extraction processes is unsuitable for optimal use. The calcination process, commonly called coke baking, has gained considerable attention for its ability to purify coke and remove waste materials. Various devices and methods are available for coke calcination, among which the rotary disc kiln has been investigated in this study. This research aims to propose a simple numerical model for simulating heat transfer processes within a rotary disc kiln. It was observed that during the layer-by-layer baking of coke, the intense heat flux of the gaseous phase inside the kiln leads to a rapid temperature rise in the first and second coke layers. To address this, a novel thermal shield was introduced in this study to reduce the heat flux reaching the coke bed in the initial layers. Results demonstrated that applying a thermal shield reduced the coke bed temperature in the first and second layers by up to 8% and 52%, respectively, while maintaining the overall calcination process. Increasing the shield's thickness by 20% decreased the temperatures by 7% and 17% in these layers. The model also achieved an accuracy of less than 2% error compared to reference data, confirming its reliability. Additionally, using the shield reduced the refractory lining temperature by up to 7.74%, improving kiln durability and energy efficiency.