Increase in efficiency by using long, multi-turn coils

For induction heating or hardening applications, the design of the coil depends primarily on the fulfilment of the process. However, the aspect of energy efficiency is playing an increasingly important role in production within the scope of energy transition and rising cost of resources. In general, there are various ways for building the coil to meet the requirements of the process. In case that the frequently used ring coils are applied, it has been shown that the efficiency can be significantly optimised by the coil length and the number of turns. Therefore, this study analyses the influence of these two parameters on energy efficiency.