G9 Fluid-Particle Heat Transfer in Flow Through Packed Beds of Solids

1 Introduction

Heat transfer coefficients between particles and fluid in packed beds are one of the basic pieces of information needed for unit operations and chemical reactor design. Heat transfer is of interest, for example, in chemical reactors with fixed beds of catalysts in which large amounts of heat are absorbed or released, or in fixed beds used as regenerative heat exchangers. Particles of very different shapes, such as spheres, cylinders, Raschig rings or Berl saddles are used as packing material. Chap. G9 deals with the calculation of heat transfer coefficients between a fluid flowing through a packed bed and the particles of the packed bed.

2 Definition of the Heat Transfer Coefficient

The average coefficient of heat transfer between the solid particles in a bed and a fluid flowing through the bed is defined by

$$\dot q = \alpha \;\rm \Delta T _{{\rm{LM}}}$$

The logarithmic mean temperature difference is given by

$$\rm \Delta T _{{\rm{L}}{\rm{M}}} = {{(T _{\rm{w}} -T...