Using ChemCAD

Emission Master can be configured to work with the standard ChemCAD software program to take advantage of special VLE treatment capabilities for specific process mixtures.  ChemCAD can be used to calculate the vapor pressures over process mixtures to be used within the basic EPA modeling.  Additionally, ChemCAD can be used to calculate the exit vapor streams from condensers and other devices such as liquid ring pumps and steam jets. 

The basic requirements for using ChemCAD with Emission Master are as follows:

1.  A ChemCAD design file must be created from within ChemCAD that contains a simple flash tank with inlet, vapor outlet, and liquid outlet streams. 

2.  Each compound that is contained in the Emission Master process mixture must also be included in the ChemCAD Compound List under the ThermoPhysical menu. 

3.  ChemCAD should be configured to solve the flash tank problem using constant temperature and pressure.  Also, the desired thermodynamic model to be used should be specified {UNIFAC, NTRL, PSRK, ...}. 

4.  The user should test the flash tank model from within ChemCAD to verify that the model works as expected using known conditions. 

5.  To use ChemCAD from Emission Master for the selected mixture, edit the Mixture and select the Vapor Pressure option.  Select ChemCAD from the Vapor Pressure support list.  Emission Master will present the basic ChemCAD configuration window where the user should select the correct ChemCAD design file to be used using the file browser button.  Also the stream numbers should be verified. 

6.  The ChemCAD capability has been implemented in a fairly flexible manner.  Each process mixture that is featured in Emission Master can theoretically use a different ChemCAD design file.