An investigation on instantaneous local heat transfer coefficients in high-temperature fluidized beds—I. Experimental results

Experimental results are presented and analysed for instantaneous and time-averaged local surface temperatures and heat transfer coefficients around a water-cooled horizontal tube of 40 mm in outer diameter immersed in a 230 × 160 mm cross section high temperature fluidized bed. Such measurements are made using a specially-designed thin-film thermocouple probe. Silica sands with mean diameter of 0.662, 1.103 and 1.815 mm are used as bed materials. Measurements are taken over a wide temperature range from 270 to 1028°C.