The simulation results
showed droplet vaporization caused reduction of catalyst particle residence time. However, the behavior of
gas-solid fluidized systems is still not fully understood, despite their importance on the overall heat transfer
enhancement. Detailed experimental and numerical techniques are required to study the flow structures of
gas-solid fluidized systems in detail. From the other side , naphthalene , silica gel and sand are the most
common solid particles which are used in a wide range of applications. For example, naphthalene is mainly
used as a precursor to other chemicals. The single largest use of naphthalene is the industrial production of
phthalic anhydride. A literature review indicates that no studies have been done on gas-solid fluidization
using different solid particles such as naphthalene , silica gel and sand to study the effect of these materials
on the heat transfer performance of the fluidized bed. To reach this goal, the objective of the present work
is to examine experimentally the influence of using naphthalene , silica gel and sand on the heat transfer
enhancement of the gas-solid fluidization process.