Heat transfer metrology issues in two‐phase bubble column reactors

The metrology and the impact of various parameters and operating conditions on the bulk‐to‐tube heat transfer coefficients in two‐phase bubble columns are investigated on a small‐scale mock‐up. It is shown that (1) quasi‐adiabatic conditions can be reached in the column; (2) the bulk‐to‐tube heat transfer coefficients for each U ‐tube downward and upward sections may or may not differ significantly, depending on the way uncertainty of the measurements is estimated; (3) using the different measurements and uncertainty estimates for given conditions, a mean heat transfer coefficient over all tubes is estimated within ±5%. The consequences for bulk‐to‐tube heat transfer coefficient prediction in a larger column are discussed.