Complete plant for the horizontal cast of billets, alloys AA6060-AA6063-AA6005-AA6082 and diameters 6”-7” -8”-9”-10”. The new plant entirely developed by the Presezzi Extrusion’s R&D department ensures the production of high quality billets with high metallurgical characteristics, such as not to require the homogenization heat treatment, minimizing specific energy consumptions and maximizing the melt yield of the scrap. The first advantage of the plant derives from the great saving, which is obtained from the internal recycling of extrusion scraps: the depreciation of the scrap is avoided and there is a certainty of supplying. The horizontal process allows flexibility and considerable savings of production costs as the machine preparation cycles (5-6 per day), typical of batch production, are avoided. Moreover, the head/tail scrap, typical of vertical casting, is eliminated, no deep foundations are required such as in the installation of casting pits and, thanks to the assisted stirrer solidification, the homogenization cycle is not necessary and subsequent cooling is performed as the billet is produced with crystalline structure suitable for direct extrusion.
The line generally consist of a melting furnace, a holding furnace, a refining system, a degasser, a ceramic filter and a horizontal casting machine equipped with an evaporative cooling system. The melting furnace in equipped with Low NOX regenerative burners and with an accurate internal pressure control system in order to assure the best results in terms of natural gas consumption.
The innovative Presezzi Extrusion’s Low Energy Consumption Stirrer ensures the metal circulation: a system that ensures excellent metal yields minimizing the oxidation of scrap.
The metal flow coming from the holding furnace is continuously treated by means of a TiB2 rod feeder, a degasser and a ceramic filter to ensure the correct H2 & inclusions and ensure an optimal crystalline refining. The metal is dosed in closed loop through a laser reading system and a linear actuator and it horizontally solidifies in three molds (molds).
The special Presezzi Extrusion’ Low Energy Consumption stirrer allows an optimal solidification eliminating the formation of dendrites and homogenizing the dimensions of the crystalline grain from shell zone to billet heart avoiding the subsequent homogenization cycle. A band saw will allow the billets to be cut to size with minimal material scrap.