Column RATEFRAC Tray Options

This window is used to enter the vapor and liquid mixing characteristics.

The driving force for mass transfer is the difference in the chemical potentials between the interface and the bulk phases. The chemical potential is a function of composition, and in a real operating tower composition gradients exist across trays. The liquid and vapor mixing options are used to specify different concentration profiles across trays.

Base Segment: Enter the Tray number on which the characteristics need to be set. Base Segment will be made available to the user only if you have selected the following in Column - Tray Hydraulics dialog box.

Internal - Trays
Calculation Type - Sizing

Liquid Mixing: Select the appropriate Liquid Mixing characteristics from the drop down list.

Vapor Mixing: Select the Vapor Mixing characteristics from the drop down list.

Complete - Select, if there is a complete mixing of liquid or vapor phase in the column. This corresponds to a flat concentration profile across a tray. It is the default value and for most cases provides good results.

Linear - This option indicates that there is a linear concentration profile across the tray.
Logarithmic - This option indicates that there is a logarithmic concentration profile across the tray.

Click Transport Calculation Methods ... to pop up Column RATEFRAC Transport Calculation Methods dialog box.

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