Iron Furnace Problem - What is the porosity distribution in the iron ore hopper?

In the processing of iron ore, pellets are funneled into a furnace and reduced by contact with a gas. We consider the problem of determining whether significant spatial segregation occurs within the furnace based on pellet size. Experiments and computation are used to test whether such segregation may happen at the inlet or near the sides. Experimental results indicate that segregation at the inlet may occur, while segregation due to friction at the sides probably does not. The computational results provided are too crude to base conclusions on, but indicate what could be done with further resources.