Advantages of bubble cap trays Distillation is a procedure to separate the liquids that is we convert the liquid into vapor and then condensed back into the liquid. This process is widely used in industries. It can separate the mixture by taking advantage substances. If there is a big difference between the two substances, then separation is done by a single-stage distillation. If there is a small difference then many re distillations may be required. Feed Tray is available in two section one is top section and other is bottom section. Heat is supplied to the re-boiler to generate the vapor. The source of heat can be steam or any suitable fluid. The function of a tray is to facilitate contact between the vapour phase and liquid phase so that mass transfer between the 2 phases can take place. Each tray can be considered as being made up of 3 sections: weir, bubbling area, and downcomer The bubbling area is the place where vapour-liquid contact takes place. Vapour flows through the openings on the tray from below, and into the liquid flowing across the tray, forming a foaming, turbulent mixture. In the simplest design, sieves are provided for vapour-liquid contact. Alternatively, valves or bubble-caps may be used. During this foaming process, a high interfacial area for efficient vapour-liquid mass transfer is produced.
Bubble cap trays: A bubble cap tray has riser or chimney fitted over each hole, and a cap that covers the riser. The cap is mounted so that there is a space between riser and cap to allow the passage of vapour. Vapour rises through the chimney and is directed downward by the cap, finally discharging through slots in the cap, and finally bubbling through the liquid on the tray.
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Bubble cap trays are used primarily where large turndown ratios are required. Turndown ratio is the range of highest to the lowest flow rates. Their construction allows very low liquid rates to be handled with little or no leakage. Due to their ability to operate at low vapor and liquid rates, bubble cap trays