Process Equipment and Plant Design
Ponchon Savarit method is based on the use of enthalpy concentration diagram, which contains the bubble point curve (saturated liquid curve), dew point curve (saturated vapour curve) and equilibrium tie lines. As compared to McCabe-Thiele's method, this method
Accounts for the enthalpy changes in the process
Facilitates direct calculation of heat load on reboiler & condenser from, the diagram used in this method
All of these
Is more accurate in finding the number of equilibrium stages
Valve trays have the highest turn down ratio (i.e. the ratio of the highest to the lowest vapour flow rates) and thus provides the maximum flexible operating range
Maintenance cost for valve and seive trays are comparatively more than bubble cap tray due to their relatively complicated construction features
Murphree efficiency of all the three trays are nearly equal, however the peak efficiency is generally higher for seive and valve trays than the bubble cap
Bubble cap trays though most expensive are the best in situations, where low vapour rates is to be handled and a positive liquid seal is essential at all flow rates
EXAMIANS