Thermosiphon Reboiler Driving Head Calculator
Calculate natural circulation driving head, two-phase riser mixture density, frictional pressure loss, and liquid recirculation ratio in vertical thermosiphon reboilers.
Reboiler Elevation & Vaporization
Hydraulic Drive & Recirculation
Recommended Tools & Equipment
Tested hardware and components for high reliability
Frequently Asked Questions
How does a vertical thermosiphon reboiler work without a circulation pump?
Dense liquid in the column bottom sump feeds the reboiler inlet. Boiling inside the vertical tubes generates low-density vapor-liquid mixture. The hydrostatic pressure difference between the liquid inlet leg and two-phase riser drives spontaneous natural recirculation.
Why is vaporization percentage kept below 25%–30%?
Excessive vaporization reduces liquid film thickness on tube walls, leading to film boiling dryout, localized hot spots, severe fouling, and cyclic density wave oscillations.
What happens if the liquid level in the sump drops below the top tube sheet?
If sump liquid level drops significantly below 100% of tube bundle height, the static driving head collapses, stalling thermosiphon circulation and causing catastrophic reboiler overheating.