We investigate heat transfer to cylindrical heat exchange elements in shallow bubble columns

2014

We investigate heat transfer to cylindrical heat exchange elements in shallow bubble columns

2014

- Shallow bubble columns have more intricate fluid dynamics than tall columns as a result of the short distance between the gas sparger and the free surface
- Heat transfer coefficients on internal heat exchange elements in sieve tray columns, which are similar in depth to shallow bubble columns, have not been studied because sieve trays have historically been used without such elements
- We have previously shown that the heat transfer coefficient in a shallow column depends on the distance, H, from the sparger plate, and we wish to quantify this effect with a correlation that utilizes the vast amount of existing knowledge about heat transfer in tall bubble columns
- Some spread still exists because Eq 15 incorporates only the effect of probe height, whereas the more minor effects of flow regime, column region, and bubble impact are excluded from the correlation
- Heat transfer coefficients increase with cylinder height until reaching a critical height
- The critical height, the highest heat transfer coefficients occur when the cylinder is in the coalescing region and aligned over the sparger holes
- The more minor effects on heat transfer coefficient are discussed to provide insight into effective shallow bubble column design