The present study considers a "Multicrackex" unit constituted by a riser reactor with an upflow catalyst suspension exchanging heat with a surrounding fluidized-bed regenerator. A statistical-based analysis is developed to establish a semiempirical correlation able to describe the heat transport phenomena between a bundle of riser reactor tubes and a fluidized-bed regenerator. The proposed correlation is tested and developed under reaction and realistic conditions for fluidized catalytic cracking (FCC) units, and this adds special value to the study developed. In this respect, the present study provides data that may be of particular interest for the design of novel FCC processes.