THERMAL AND HYDRAULIC PERFORMANCE OF A 3-PHASE FLUIDIZED-BED COOLING-TOWER

An experimental study was made of the thermal and hydraulic characteri stics of a three-phase fluidized bed cooling tower. The experiments we re carried out in a packed tower of 200 mm diameter and 2.5 m height. The packing used was spongy rubber balls 12.7 mm in diameter and with a density of 375 kg/m3. The tower characteristic was evaluated. The ai r-side pressure drop and the minimum fluidization velocity were measur ed as a function of water/air mass flux ratio (0.4-2), static bed heig ht (300-500 mm), and hot water inlet temperature (301-334 K). The expe rimental results indicate that the tower characteristic KaV/L increase s with increases in the bed static height and hot water inlet temperat ure and with decreases in the water/air mass flux ratio. It is also sh own that the air-side pressure drop increases very slowly with increas es in air velocity. The minimum fluidization velocity was found to be independent of the static bed height. The data, obtained were used to develop a correlation between the tower characteristic, hot water inle t temperature, static bed height, and the water/air mass flux ratio. T he mass transfer coefficient of the three-phase fluidized bed cooling tower is much higher than that of packed-bed cooling towers with highe r packing height.