The shaft furnace is characterized by an extremely stable steel structure, which is joined by a lining made of high-quality refractory material. Such a furnace combines two areas: a melting shaft and a holding shaft for the metal. The melting burner is controlled independently of the burners in the holding shaft.
The workpieces are charged fully automatically. As soon as a signal sounds, which indicates that there is again space in the shaft for new loads and the holding shaft is not completely loaded, the next charging immediately takes place automatically.
Since a shaft furnace is equipped with flat flame burners and thus direct contact of the flames with the metal surface is precluded, burn off is reduced and the stresses in the metal are reduced, which in turn results in reduced oxide formation.
If oxide should nonetheless form, the holding shaft can be equipped with a gas porous plug to remove any oxide or to degas the respective material. This type of furnace is also energy-saving, since the flue gases produced in the holding shaft pass directly through the melting shaft and are thus used twice.