GF-ELTI Vertical Furnaces are plants used for the heat treatment of semi-finished products, typically shafts and rotors.
This type of plants is characterised by a maximum operating temperature of abt. 1,100 °C and it is designed to obtain excellent temperature uniformity, reheating and cooling gradients varying according to the types of heat treatment required by the Customer.
The furnace typically consists of:
The plant is built according to the logic of modular prefabrication, which enables to quicken the on-site assembly stages of the plant.
The refractory linings for insulation of the parts forming the furnace are generally made of fibrous materials.
These plants are equipped with GF-ELTI Auto-Recuperative Burners, characterised by high speed and fixed power, installed on half-shells, with open flame and tangential to the product. Their operation is managed through a PLC and the energy supply is kept under constant control by changing the ON and OFF times, to which every single burner is subject.
A special feature of this plant is its above-the-ground installation so as to facilitate maintenance operations and - if the furnace is added to a heat treatment line - to reduce the time necessary for transfer to the vertical quenching machine, placed in the proximity of the furnace.
The furnace can be either hanging from a bridge structure or placed on the floor surface. The two half-shells are closed / sealed by pneumatic ratchet gears. The product is put into the furnace through a dedicated bridge crane, to which it is hooked by means of pliers specifically designed for the purpose. According to the size of the product under treatment, the height of the useful charge volume of the furnace can be reduced by inserting a separation baffle intended to reheat the part of the furnace in question only.
According to the Customer’s various needs, this type of plants can be designed and realised in observance of the following international standards: API 6A, ASTM A991, AMS 2750, NADCAP, NORSOK, M-650, ABS.
Types of treated products: shafts and rotors of various diameters, weights and lengths.