TEMPERATURE-VARIATIONS IN DRYING OF SULFURIC-ACID-SOLUTIONS IN SAND BEDS .1. TEMPERATURE-VARIATIONS IN THE BED DURING THE DRYING OF WATER

Local temperature variations were determined in sand beds during drying. Two different particle sizes of 200 mu m and 550 mu m's were used in the experiments. Drying was conducted at 80 degrees C and 150 degrees C. Highest temperature were observed at the bottom of the bed due to capillary lift during drying at 80 degrees C. Rapid evaporation at 150 degrees C ambient temperature caused heat to be transferred from both the surface and bottom of the bed, so the coolest section was at the center. Isothermal conditions were approached as the capillary size increased as in 550 mu m particle beds.