Process Equipment and Plant Design
At the following point for a given packing and set of fluids, the pressure drop per metre of packed height, with variation in fluid rates and operating pressure
Increases
Decreases
Remains same
May increase or decrease depending upon the solubility of the gas in the liquid
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
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
Maintenance cost for valve and seive trays are comparatively more than bubble cap tray due to their relatively complicated construction features
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
EXAMIANS