Batch Distillation - Thermodynamic Systems
The thermodynamic systems used for equilibrium calculations are defined in this window.
Usage
Thermodynamic System Specification
By default, the thermodynamic system that was defined as the default system in the global Thermodynamic Data Window is used for all the stages in the unit. A different method may be selected for the batch still from the list of the methods specified in this data entry window. Alternatively, systems may be defined for individual sections of the column.
Condenser Thermo Specification
By default, the condenser uses the thermodynamic system that was defined as the default system in the global Thermodynamic Data Window. A different VLE or VLLE method may be selected from the list of the methods listed in this window. When a Vapor-Liquid-Liquid system is selected for calculated condenser phases, the first available VLLE thermo is displayed in the list box. If no VLLE thermo is defined in the flowsheet, then the list box turns red and blank is displayed.
Check for VLLE on all Trays
This checkbox can be activated to check the presence of 2 liquid phases on all trays, including the condenser and reboiler. This can be done only if VLLE thermo is listed in the Thermodynamic Data Window.
Thermodynamic System for Individual Sections
When different thermodynamic systems are defined for each section, they should be entered from the top stage downwards in the table. In the first row, enter the last stage for the top section; then select the thermodynamic system to be used from the drop-down list. The first row entry can only start at stage 2, since the condenser is always stage 1. The next section starts at the next stage down the column. Successive rows of the table are used to define systems for other sections. If the last stage number specified is not the stillpot, the default thermodynamic system will be used for the section of unassigned stages.
How to get to this window
The Batch Distillation - Thermodynamic Systems window is accessed by pressing the Thermodynamic Systems button on the Batch Distillation Main Window.
Related Topics