Hi, I would like some help/orientation about heating furnaces. The issue is around the heating of steel billets (continuous cast billets). The furnace needs to heat a load of 104 billets placed face to face along its longitudinal axis from ambient temperature to ± 1,150°C. Each billet has this dimensions: 140 mm x 140 mm cross section, and 12.7 m. length. The furnace burns a mixture of natural gas and air. So, where in the Internet can I find theoretical models to calculate or design a furnace for such an application? Thank you.