Heat transfer in packed beds: experimental evaluation of one-phase water flow

Abstract

-Experimental heat transfer studies were carried out in 50.8 mm diameter packed beds of glass beads percolated by water and heated from the wall. The tube-to-particle diameter ratio (D/d p ) ranged from 1.72 to 13.7 and the water flow rate from 1.1 to 9.9 l/min. Bed heights ranged from 100 mm to 700 mm. The radial temperature was measured above the bed surface by five aligned sheathed thermocouples. Variations in angular temperature were observed, independent of both radial position and particle diameter. Results of repeated tests with the same packing and with repacking did not differ statistically. The radial temperature profile at the bed entrance, measured by a ring-shaped sensor, was uniform except very close to the tube wall.

Evaluation of heat transfer on a backward acting grate

“…An additional parameter that influences the heat transfer in a packed bed is the ratio of thermal capacity of the packed bed and the fluid flow in the void space. If the thermal capacity of the fluid is high compared to the packed bed, rather homogeneous temperature profiles develop, as shown by measurements of Thomèo and Grace [8].…”

Simulation of thermal conversion of solid fuel by the discrete particle method

“…An additional parameter that influences the heat transfer in a packed bed is the ratio of thermal capacity of the packed bed and the fluid flow in the void space. If thermal capacity of the fluid is high as compared to a packed bed, a rather homogeneous temperature profile develops, as shown by measurements of Thoméo and Grace [12].…”

Heat transfer in packed-beds of agricultural waste with low rates of air flow applicable to solid-state fermentation

“…The equipment constructed for this work is illustrated in Fig. 1a and it is similar to experimental set-ups formerly used for heat transfer studies in non-reactional PBs Thoméo and Freire, 2000;Thoméo and Grace, 2004). Air supplied by a compressor percolated through the beds.…”