Petlyuk columns defined

As one may expect, it is possible to operate this column under the same product specifications and R i value, but with alternate choices for d>yand d> , which again suggests multiple steady states. Minimum reflux in the Petlyuk column is defined as the lowest value of/ ai which still allows profile intersection, for any choice of v and d> ,. Put in another way, if / ai is decreased any further there will be no d>y d> pair that will result in a feasible design. 

The analogy with the process of open evaporation favored the fact that this mode was investigated earlier than the others. Systematic examination of distillation at the infinite reflux was initially carried out in works (Zharov Serafimov, 1975 Balashov Serafimov, 1984). The analysis of infinite reflux mode in the infinite columns was made (Petlyuk, 1979 Petlyuk, Kievskii, Serafimov, 1977 Petlyuk Serafimov, 1983) that allowed general regularities of separation to be defined for the mixtures with any number of components and azeotropes. A number of important investigations was realized (Doherty, 1985 Doherty Caldarola, 1985 Laroche et al., 1992 Bekiaris et al., 1993 Safrit Westerberg, 1997 Rooks et al., 1998) and others. 

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