Analysis of the coupled heat and mass transfer during fry-drying process of oily sludge

作者：Zhang Ke; Zhu Jianhua^*; Zhou Yong; Wu Bencheng

来源：Acta Petrolei Sinica / Petroleum Processing Section, 2014, 30(2): 298-304.

DOI：10.3969/j.issn.1001-8719.2014.02.017

• Convective heat transfer Coefficient
• Convective heat transfer coefficient (h)
• Coupled heat and mass transfer
• Dehydration rates
• Heat-mass transfer
• Inverse relationship
• Oily sludges
• Water evaporation

The fry-drying method was applied to dry oily sludge from Liaohe oilfield, and spent lubricating oil of vehicle was used as frying medium. The changes of water and oil contents, dehydration and oil uptake rates, average volume temperature and its variation rate, as well as convective heat transfer coefficient of oily sludge sample were investigated along fry-drying time. The whole fry-drying process was catalogued into four stages according to the different variation trends of oily sludge dehydration rate, which were the surface water evaporation stage, core and crust formation stage, capillary bound water drying stage and falling-rate drying stage. The experimental and calculated results demonstrated that between the dehydration rate and oil uptake rate of oily sludge sample expressed an inverse relationship during the former three stages, however, at the forth stage the two variables both decreased. The variation trend of convective heat transfer coefficient (h) in this process was similar to that of dehydration rate, and the maximum h during this process was 510 W/(m2·°C). Moreover, relatively smaller dehydration amount and larger oil uptake amount were observed at falling-rate drying stage than at previous stages. Therefore, the latest stage would be omitted in order to reduce the amount of oil uptake and operation cost.

• 出版日期2014
• 单位中国石油大学（华东）