A model and experiments for heat transfer of single horizontal tube in the freeboard of fluidized bed

A theoretical model for the heat transfer between the gas-solid mixture and a horizontal tube in freeboard of fluidized bed is developed by adopting the well accepted concept that the total heat transfer is the sum of conductive (hcond) and convective (nconv) components in the absence of radiation. An experimental investigation is carried out at ambient condition to measure the local and average heat transfer coefficients around single horizontal tube. Relationships between th average heat transfer coefficient and operating factors are set up. The present model predictions for the average heat transfer coefficients are in good agreement with the experimental data. The proposed theory is recommended to be used for predictions and engineering calculations