Splash-Zone Heat Transfer in Bubbling Fluidized Beds: an Experimental Study of Temperature Effects

Abstract

Abstract Experimental results are reported for the heat transfer between a high-temperature fluidized bed and a horizontal tube located within the splash zone. Of specific interest in this study is the effect of bed temperature. Four bed operating temperatures (700, 810, 908, and 1003 K) were investigated. At each temperature, five circumferential local time-averaged values of the total and blackbody radiative heat transfer coefficients were measured for three tube locations. The tube was located at 406, 64, and −127 mm relative to the packed bed-freeboard interface. These locations are representative of a tube in the freeboard, in the splash zone, and totally immersed in the bed, respectively. The tube outside diameter was 51 mm, the mean bed particle size was 2.9 mm, and the superficial fluidizing velocity varied from near minimum fluidization conditions ( U mf ) to over 1.5U mf . The work was performed in the Oregon State University high-temperature fluidized-bed test facility.