EFFECT OF THERMAL CONDUCTIVITY OF PACKING MATERIAL ON TRANSIENT HEAT TRANSFER IN A FIXED BED

The mathematical equations describing transient heat transfer between the fluid flowing through a fixed bed of packing are formulated for the situations where (1) there is resistance to heat transfer within the solid phase and (2) there is thermal conduction in the solid phase along the direction of fluid flow. Numerical analysis is presented for a computer solution of these equations and a parametric investigation of the models is used to show that the values of certain dimensionless groups arising from the mathematical formulation may be used to define the range of conditions under which the alternative heat-transfer mechanisms are important. Experimental observations of time temperature breakthrough profiles subsequent to a step change in the inlet fluid temperature have been compared with the theoretically predicted profiles in order to check the validity of the mathematical models. Critical values of the dimensionless groups defining the limiting range of applicability of the various models are presented. © 1969.