The PROP module
The PROP module is another module to calculate the properties of pure substances and mixtures.
It uses the PROPER program to calculate the properties, provided that this program is installed.
PROPER is based on a new database from Prausnitz, "The properties of Gases and Liquids" [1]. The program calculates properties and equilibria for pure substances and mixtures of up to 15 components according to appropriate methods.
The PROPER program calculates:
· up to 14 properties at one temperature
· up to 14 properties in a temperature range
· equilibrium states of pure substances or mixtures
The PROP module is loaded and linked the same way as described for all other property modules.
After starting the PROP module the input and output mask of the module appears.
First you are asked to enter a material name, which means a mass flow file (standard extension *.Str). The PROP module can load a saved mass flow, containing the components, the concentrations, the methods, the pressure and the temperature, from your hard disk or from a floppy disk. Choose the menu item "Select stream file" in the "Module" menu to open the selection box with the saved mass flows. Click "*.*" to display all files. Mass flow files can only be created and saved with the PROPER program (see manual for the PROPER program).
After selecting the mass flow file you can select a phase equilibrium model in the PROP module:
0 - No calculation of the phase equilibrium
If you don't want to calculate the properties of the phase equilibrium.
1- Saturation with vapour pressure curve
If you want to calculate the properties of pure substances in saturated state (boiling liquid and saturated steam).
2 – DDB-Flash: Calculation of phase equilibrium with PSRK model and “Dortmunder Datenbank (DDB)
If you purchased the DDB flash (provided optionally with PROPER) and want to determine the properties of a mixture with it.
3 - RKS Flash: calculation of phase equilibrium with RKS equation of state
If you want to calculate the properties of the phase equilibrium using the RKS(Redlich-Kwonng-Soave) equation of state .
If you have selected the phase equilibrium model 1 (pure substances) you can specify now, if the program has to calculate the boiling temperature (with given pressure) or the boiling pressure (with given temperature).
In the phase equilibrium model 2 (DDB flash) and model 3 you can specify if the properties have to be calculated for the dew point or for the boiling point. If the pressure is given you can choose between the calculation of the dew temperature ("4") or the boiling temperature ("2"). If the temperature is given you can choose between the calculation of the dew pressure ("3") or boiling pressure ("1").
The remaining parts of the input and output mask of the PROP module are similar to all of our property modules.