DEVELOPMENT OF A CORELESS PRESSURE-POUR INDUCTION FURNACE - A NEW FURNACE TYPE.

The concept of a new coreless pouring furnace is now a reality after five years of development operation in ferrous foundries. The development of the new furnace arose from the desire to eliminate problems inherent with the conventional channel type press-pour automatic furnace. These are (i) freezing of the 'tea pot' ducts (ii) large temperature differential between the metal in the inductor channel and the metal discharge temperature (iii) slag adhesion to the walls of the 'tea pot' ducts. In the new furnace the ducts are placed within the magnetic field of the induction furnace coil and are heated continuously by the principle of induction heating. They are thus ready for the pouring cycle to start anytime and never freeze or suffer from slag adhesion. As the slag is fluid, it can be removed easily from the top of the molten metal in the duct. Two bonus features are also evident from the design. Firstly, it is possible and normal to discharge over 90% of the total molten metal in the furnace by pressure, thus enabling quick changes in metal composition. Secondly, a great metallurgical advantage of the furnace, is homogeneous mixing without excessive loss of expensive alloys. This is due to the shorter dwell time in the furnace.