Thermosyphon reboilers provide a simple, low-maintenance design
for distillation tower reboiler systems. Design of true thermosyphon
exchangers requires an intimate knowledge of a distillation tower's
heat balance, temperature levels, and pressure balance in the
reboiler loop. Depending on system relative volatilities, the
temperature levels vary strongly with composition gradients. This
paper compares the commonly used simulation networks for different
thermosyphon exchanger-distillation tower configurations. The
implications on exchanger design of the correct and incorrect
simulation configuration will be shown in case studies of two
industrial units. The two cases compare a low relative volatility
(alpha) system (ethylene-ethane splitter) and a high alpha system
(fluid catalytic cracking unit deethanizer). Main factors presented
include impact on equipment size and design. Proper design criteria
for the simulation of the thermosyphon exchanger and distillation
tower and for integrating process and equipment design are shown.
Part 1 - 8 pages including 11 tables and figures.
Part 2 - 10 pages including 20 tables and figures.
Electronic versions available in Adobe Acrobat PDF format files
034.PDF 1628k and 035.PDF 1593k.
Request papers 034 and/or 035.
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