Template:Evaporator Model Theory

Vapour Liquid Equilibrium

The unit is configured to achieve vapour : liquid equilibrium at a required pressure (or temperature) using the user defined VLE method. Any solids that may be in the stream entering the unit are ignored in the flash calculations. However the enthalpy balance does include the solids. For further information on the theory for the VLE calculations see Vapour Liquid Equilibrium (VLE).

Pressure used for Evaluation Block Calculations

For an Evaporator in the Stand Alone mode the calculations, including the {{{EvapCalcType}}} may be performed at either:

• The Feed pressure; or
• The final pressure; or
• The pressure into the Body of the Evaporator if the user has chosen Final Temperature as the mode.

The user enables the 'UseFeedP' tickbox on the first tab of the Evaporator to use the Feed pressure.

Using the Feed or other pressure may produce small differences in the final results from the Evaporator.