Large diameter steel pipe bending and forming uses medium frequency induction heating to locally heat the steel pipe

Large-diameter steel pipes must be heated for bending and forming. The use of medium-frequency induction heating to locally heat the steel pipes has its unique advantages and cannot be replaced by other heating methods.

Medium frequency induction heating pipe bending equipment consists of a pipe bending machine, a medium frequency induction heating power supply and an inductor. The sensor is placed at the front end of the pipe bending machine. When the induction heating is powered, the pipe bending machine also begins to slowly rotate the bent pipe. Since the induction coil has a small number of turns, the inductor is connected to a medium frequency step-down transformer.

The inductor for medium-frequency induction heating of large-diameter steel pipe bends is made of rectangular pure copper pipes. In order to improve thermal efficiency, the induction coil is lined with a heat-resistant and thermal insulation layer. Since the number of turns of the induction coil is very small, the width of the inductor is narrow, and the width of the heated part of the steel pipe is not large. The deformation of the pipe bending machine is not large during bending, and the steel pipe will not deform.

Generally, the diameter of large-diameter steel pipes is 700-1200mm, the thickness of the pipe wall is less than 40mm, and the current frequency can be selected from 1000 to 2500Hz. The current frequency can be calculated based on the steel pipe diameter, wall thickness and heating temperature. The power of the heating distance cover is determined based on the heating temperature and the moving speed of the steel pipe when bending.