The EnEffiSint project, funded by the German Federal Ministry of Education and Research under the 6th Energy Research Programme (funding code 03ET1640x) and running from 1 November 2018 to 31 October 2022, aimed to raise the energy efficiency of sinter furnaces used in powder metallurgy. The project was coordinated by GKN Sinter Metals Engineering GmbH, with partners ONEJOON GmbH, MESA Industrie‑Elektronik GmbH, HTCO GmbH, and the Fraunhofer Institute for Material Mechanics (IWM). The final report, dated 19 April 2023 and numbered 1018/2023, presents the technical findings and recommendations.
During the investigation the sintering step of the reference band furnace was found to be already largely energy‑optimised. The larger potential lay in the debinding stage, where volatile decomposition products such as methane contain significant energy that could be harnessed for pre‑heating. To evaluate this, a specialised measurement system was adapted to capture local gas composition (CO₂, CO, H₂) and temperature along the product path in the test furnace. Concurrently, a model of the inhomogeneous wax decomposition within the component was developed and coupled to a computational fluid dynamics model of the entire furnace. Numerical parameter studies of the coupled system identified optimal gas flow patterns that would allow the utilisation of the released gases for heating.
The project produced a comprehensive set of simulation results. First, the empty‑furnace flow and temperature distribution was simulated, followed by a loaded‑furnace scenario that incorporated the component model. A sequentially coupled simulation approach was then applied, linking the component and furnace models to capture the interaction between gas release and furnace dynamics. These simulations revealed that, while the concept of using the released gases for energy recovery is technically feasible, the required modifications to the existing plant would be extensive and costly.
A more practical outcome was the optimisation of the burner control range. By analysing the measurement data and simulation results, the team identified specific burner settings and positions that improved the temperature uniformity and reduced energy consumption. Additionally, adjustments to the flow guidance and plant technology were recommended to minimise hotspots and improve overall process stability.
The collaboration among the partners was tightly integrated. GKN provided the industrial context, the test furnace, and carried out the experimental runs. ONEJOON supplied the measurement hardware and data acquisition. MESA contributed the gas‑analysis instrumentation and expertise in sensor integration. HTCO performed the furnace CFD modelling, while the Fraunhofer IWM developed the component‑level wax‑decomposition model and carried out the coupling and optimisation studies. The project’s timeline was organised into phases of experimental data collection, model development, simulation, and optimisation, with regular coordination meetings and joint reviews.
In conclusion, the EnEffiSint project demonstrated that the energy savings achievable by exploiting the gases released during debinding are limited by the high retrofit effort required. A more immediate benefit comes from the refined burner control strategy and improved flow guidance, which together offer a tangible reduction in energy consumption for existing sinter furnaces. The report provides detailed recommendations for implementing these changes and outlines the potential for further optimisation through continued integration of measurement and simulation.