GF-ELTI Roller Hearth Furnaces with Controlled Atmosphere (BAF – Bright Annealing Furnace) are plants used for the heat treatment of semi-finished products, typically bars and tubes.
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 plant 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 without requiring the realisation of foundations, but of an adequate support surface only.
The refractory lining for insulation of the (concave modular) vault, hearth and walls is generally cast; man-holes are pre-arranged in the vault for access inside the furnace.
Roller ways (inlet, furnace, cooling and outlet) are driven by one single inverter-controlled ratio-motor.
The on-the-way charge is reheated by GF-ELTI Auto-Recuperative Burners with straight radiant tubes and a flame-guide tube inside, arranged along the side walls of the furnace section, above and below the line of passage of the bars or tubes under treatment. The furnace section is subdivided into thermal zones and the temperature is controlled through thermocouples arranged in the vault and on the wall.
The inlet and outlet vestibules are equipped with a series of temperature-resistant curtain barriers, linear burner and suction hood.
The cooling section is substantially made of boxes, whose hearths, side walls and covers are complete with hollow spaces for water passage in order to subtract heat from the on-the-way bars or tubes; proper sensors supervise the flow rate and temperature of the cooling water.
Load and unload pallets are substantially made of sturdy beams, along which scratch-resistant transport chains slide. Hydraulic cylinders move the pallets up and down for placing on and taking from the furnace inlet and outlet roller ways.
Types of treated products: semi-finished products typically consisting of bars (round / square / other sections) and tubes (round / square / other sections) of various dimensions, weights and lengths.