Kay Buist

Heat transfer in dense particulate flow

 

Introduction

Gas solid contactors are readily encountered in industry of which the gas solid fluidized bed reactor is an important example. Due to favourable mass and heat transfer properties, gas fluidized beds are frequently applied in chemical, petrochemical, metallurgical, environmental and energy industries. Better understanding of the fundamentals of gas-solid flow can help in: design, operation and scale-up. This involves better understanding of large-scale phenomena, like overall mass and heat transfer as well as small-scale processes like particle-fluid and particle-particle interactions.
This particular project is part of an ERC grant that is aimed at providing insight in large-scale dense gas-solid flow on the level of interaction of individual particles and the fluid. A multi-scale approach for modelling of hydrodynamics of dense gas-solid flow has already successfully been employed (van der Hoef, et al., 2008). And this grant aims at an extension to mass and heat transfer and other geometries, polydisperse and heterogeneous systems.

The primary objective of this study is to develop new experimental techniques to study particle-fluid heat transfer. The second goal is to use these techniques to complement and validate the knowledge gained with the multi-scale modelling approach.

The basis for this study is found in the work of Gunn 1978. Experimental study of the particle fluid heat transfer have resulted in data which differ several orders of magnitude. By statistical analysis the well-known and currently standard Gunn equation was derived:

For momentum transfer between the two phases the range of equations is extended to multiple excepted forms: Ergun, Wen & Yu, Hill & Koch, Beetstra with extensions to polydispersity. Extra study on closure laws for heat transfer is needed.

Acknowledgement

This research project is carried out with funding by ERC Advanced Grant and 3TU Centre of Excellence – Multiscale phenomena