Some experiments have been performed to study the fouling of heat exchanger surfaces where heat is being transferred from a heated fluid to a cooled surface* The fluid studied was a suspension of V-5 microns mean diameter graphite powder in carbon dioxide gas at near atmospheric pressures. The solids loading range covered was from 5 to 30 lb. graphite/lb. carbon dioxide, and gas Reynolds numbers from 6000 to 16000. Temperature gradients across the cooler of from 20 to 120℃ were obtained. The heat transfer ratio is correlated to show the dependence upon the solids loading ratio of the suspension, the gas Reynolds number and the temperature gradient across the cooler.nThe results have demonstrated that stringent precautions are necessary to ensure complete dryness of the graphite powder and the loop flow surfaces before any quantitative fouling data can be obtained, as the presence of entrained moisture will accelerate the deposition of material on the cold walls of the heat exchanger and can result in plugging.
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