Is the reference area for the heat transfer coefficient of the quench tower in the RATEFRAC filler in PROII the surface area of the filler?

In the RATEFRAC module of PRO/II, when performing calculations for packed columns, the base area used to define the heat transfer coefficient is not the actual surface area of the packing; rather, it is usually defined based on the cross-sectional area of the column, that is, the cross-sectional area of the cylinder. This is different from the gas-liquid heat transfer coefficient calculated based on the specific surface area of the filler, which is familiar in our everyday engineering work. Specifically, the units of the gas-liquid heat transfer coefficient provided by PRO/II are often values based on the cross-sectional area of the tower; as a result, this value is significantly higher than the gas-liquid heat transfer coefficient derived from the surface area of the packing, as is common in engineering practice. This is precisely the reason for the extremely high values on the order of dozens to hundreds of kW/m²·K that you see. In other words, this is not a BUG or calculation error in the PRO/II software, but rather results from the area basis for the heat transfer coefficient defined by the software differing from our usual understanding. Therefore, when it is necessary to compare the PRO/II calculation results with conventional engineering experience data, it must be noted that: the area basis for the heat transfer coefficient reported by PRO/II is usually the cross-sectional area of the tower ； - In engineering practice, the reference area for the heat transfer coefficient reported is usually the surface area of the packing. When making comparisons, it is necessary to perform a conversion based on the specific surface area of the filler. After such conversion, the values obtained by PRO/II will be on a similar order of magnitude to the practical experimental values. This thus explains the significant difference you observe. .