1. Compared with heating by gas, fuel and coal, it is environmental friendly, easy operation, good working condition, heating instantly and consistently with good quality and without oxide layer. 2. Compared with SCR based medium frequency furnace or electrothermal furnace. It can save 10%-50% energy. Its’ size is smaller by 1/3 and weight is lighter by 1/5. 3. Equipped with cooling system and jacking system, easy to install and use.