Induktionsbiegen von Rohrmänteln

The present diploma thesis investigates an innovative bending process for steel pipes used for transporting liquids in production plants of the petrochemical industry. In the bending process an external jacket pipe is locally heated up by inductive currents and pulled over an internal high pressure pipe, which has been bended before. Thereby, the jacket pipe is also bended according to the bend radius of the high pressure pipe. The temperature patterns occurring inside the pipes during inductive heating are determined by experiments as well as by numerical simulations. Both of these methods are also employed for examining the bending behaviour of the jacket pipe. For the experiments, an induction heating device at laboratory scale and an industrial induction bending machine are used. The numerical 2D and 3D simulations are performed with a commercial finite element software package. The studies enable to identify crucial influence parameters on the heating behaviour of the pipes. These parameters include heating power, induction frequency, cooling as well as dimensions and surface conditions of the pipes. Based on the results of this work fundamental conclusions for the industrial practicability of the bending process can be derived.