Sistem Teknik designs and produces aluminium log/billet fast heating furnaces (ABFHFs) for the rapid heating of the logs/billets before the extrusion process.
ABFHFs 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 in a short period with low gas consumption (<20 Nm3/ton Al.). The temperature is measured within a range that is determined by the surface thermocouples. These thermocouples can be moved back and forth in direct contact with the log/billet surface. After the heating, a temperature distribution of ± 10 ° C is achieved on the surface of the material. By reusing the formed flue gases in the preheating zone, the heating efficiency increases as the gas consumption is decreasing.
ABFHFs 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 materials to be molten in the furnace. This avoids the interruption of the extrusion due to the billet/log’s 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 portion can be heated above the set values with the front heaters and the last zone burners located at the furnace outlet (tapper heating).