Aluminum shell furnace: simple structure. The service life is 5 to 8 years. It is applicable to the capacity of less than 2 tons. There is no guide magnet, furnace lining ejection mechanism, fire-resistant mastic layer, and the safety performance is poor. For example, when a set of 5-ton medium frequency furnace is full of molten iron, the overall weight of the equipment reaches 8 to 10 tons. If the aluminum shell structure is selected and the reducer rotates the furnace body to 95 degrees, the whole furnace will lean forward and the safety performance is very poor. Aluminum shell furnace is suitable for users who change production in a short time, with small tonnage.