In our barrel, the whirling vortex is the product stream.  The black is the bottoms or heavy crude coming into the stream at the beginning of the process.  The purple and blue is the 60% or more that's remanufactured as product.

The red represents the intense heat used in the furnace.

The glowing yellow is the great value of the product, the fuel is like gold.

The chunks of coke that remain may be used for yet another valuable product-calcined coke and carbon.