Sistem Teknik designs and produces furnaces for the rapid heating of aluminium logs/billets before the extrusion process. These furnaces are direct gas-heated and have pre-mix jet type nozzle burners that are controlled by the PLC. Through the special arrangement of the burners, the logs/billets are heated swiftly with low gas consumption (<18 Nm3/ton Al.). The temperature is measured within a range that is determined by the surface thermocouples which can be moved back and forth. After the heating process, material surface remains within a range of ± 10 °C. Heating efficiency is maximised by reusing flue gases that generate in the preheating zone.
These furnaces are equipped with low thermal mass insulation materials and easily replaceable refractory blocks for insulation. The use of insulating materials with low heat retention capacity prevents melting. The furnace transfer system has a roller conveyor and is designed to work in congruity with the hot billet cutting machines. The first 200 mm can be heated above the set values with the front heaters and the last zone burners located at the furnace outlet (tapper heating).