TY - JOUR TI - Heat transfer from an immersed fixed silver sphere to a gas fluidised bed of very small particles AU - Prins Wolter AU - Maziarka Przemyslaw AU - De Smedt Jonas AU - Ronsse Frederik AU - Harmsen Jan AU - Van Swaaij Wim JN - Thermal Science PY - 2019 VL - 23 IS - 15 SP - 1425 EP - 1433 PT - Article AB - Results of unique heat transfer measurement in beds of fine, cracking catalyst particles, fluidized by air or helium gas, are compared with predictions from a theoretical model presented in the literature [1], and also with an earlier established empirical correlation [2]. Moreover, the results have been related to dense phase flow conditions around a silver heat transfer probe by a simple turbulence model. A maximum heat transfer coefficient of h = 2300 Wm-2K-1 has been measured in a bed of 14μm (average diameter) particles, fluidized by helium gas. The data collected, and the model developed, can be used for the design of heat transfer tubes in fluidized beds of fine particles as for instance in Fluid Catalytic Cracking of crude oil heavy residues. FCC is one of the most important conversion process in the petroleum refineries.