Troubleshooting fractionation

For troubleshooting fractionators see the troubleshooting section in this book. For a general understanding of how trayed and packed fractionating columns work, illus-... 

Lieberman gives two rules of thumb for troubleshooting fractionators that could also be used as checks on a design. First, the pressure drops across a section of trays must not exceed 22% of the space between the tray decks, to avoid incipient flood. Mathematical , hold... 

Fractions containing pectin are likely to be those obtainedfrom isolated cell walls following treatment with CDTA. Fractions obtained following treatment with solutions of alkali are not suitable (see Troubleshooting). Alternatively, commercial preparations of pectin can be analyzed. 

It is highly recommended (especially the first few times this method is used) that fractions be saved from each step of the purification procedure and small aliquots of these fractions analyzed by denaturing PAGE. Problems with the quality of the HMM protein, the transcription yields, binding to the column, etc. can be detected and appropriate troubleshooting conducted. 

Kister says that d/b plots are primarily used when there is a tight spec, on a nonkey component or a concern about the distribution of an intermediate key component. His book shows d/b curves for various feed stage locations on a plot of the mole ratio of a reference component in the distillate to the bottom product, versus the relative volatility of each component to this reference component. This plot is made on log-log paper. The optimum feed produced a curve closest to linear. The d/b plot is suggested as a troubleshooting tool in the subsection of the Troubleshooting section, Fractionation Operating Problems. ... 

FPE Fractionation outlet of product E chance of obtaining a run that one can troubleshoot ... 

Figure 1.1 Column troubleshooting case history, (a) Hot oil from the fractionator supplies heat to gas-plant reboilers.

Include events that may appear completely unrelated, as these may be linked in an obscure manner to the problem. In the debutanizer example, it was the observation that flooding in the fractionator coincided with the debutanizer becoming unstable that gave the troubleshooter the vital clue. At first glance, the two appeared completely unrelated. 

---