Hydrodynamics and heat transfer of gas–solid two-phase mixtures flowing through packed beds – a review

Flow of a gas–solid two-phase mixture through a packed bed is relevant to a number of industrial processes such as heat recovery and filtration of dusty flue gases, iron making in shaft reactors, gas purification, and sorption enhanced reaction processes. In spite of the industrial relevance, little work has been reported in the literature. The limited amount of research work has mainly addressed the macroscopic hydrodynamics in terms of pressure drop and solids hold-ups at the ambient temperature. Very little is done, until fairly recent, on solids motion at the single particle level, hydrodynamics at elevated temperatures and heat transfer. This paper reviews the recent development in the field including both the hydrodynamics and heat transfer of gas–solid two-phase mixtures flowing through packed beds, which is believed to represent the state-of-the-art in the field. The review is not aimed to be exhaustive but rather focused on our own work carried out over the past few years in the Institute of Particle Science & Engineering at the University of Leeds. And some of our results are compared with that of other groups.