Thin Film Evaporation: Oper. Conds Tab

Variable Definitions, Ranges and Default Values

The following table shows a brief description of the variables appearing in this tab. The table also displays their default values and their generally acceptable range:

Variable	Default Value	Range

○ Feed Vaporization (% mol)	50.0	0 – 100
○ Component Vaporization (% mol)	50.0	0 – 100
○ Ref. Comp. Indicates the component of the feed stream for which a reference component vaporization percentage is specified. Click on the list box to bring up a list of registered components in order to select one.	<None>	Any Pure Component
◙ Evaporation (%)	0.0	0 – 100
○ Operating Temp. (C)	25.0	Positive
○ Operating Pressure (atm)	1.0	Positive
○ Heat Transfer Coefficient (kcal/h-m²-^oC) The overall heat transfer coefficient between heat transfer agent and feed in the evaporator.	2,500.0	Positive
○ Agent Name Indicates the heat transfer agent that is used by the operation. Click on the list box to bring up a list of available heat transfer agents in order to select one.	<Steam>	Any Heat Transfer Agent
● Inlet Temp. (^oC) The inlet temperature of the heat transfer agent.	152.0	Positive
● Outlet Temp. (^oC) The outlet temperature of the heat transfer agent.	152.0	Positive
● Heating (kcal/h) The heat transfer rate of the heat transfer agent (if a heating agent is used).	0.0	Positive
● Agent Rate (kg/h) The mass flow rate of the heat transfer agent.	0.0	Positive
○ Heat Transfer Efficiency(%) The heating agent consumption efficiency. Specify a value below 100% to account for heat losses to the surroundings when a heating agent is used.	90.0	[0,100)
◙ Process Time (min) The actual duration of the operation (per cycle).	60.0	Positive
● Operating Throughput (Per Unit) (m³/h) The volumetric flow rate of the feed stream divided by the number of equipment units.	0.00	Positive

Symbol Key: ○ User-specified value (always input); ● Calculated value (always output); ◙ Sometimes input, sometimes output

Specification Choices / Comments

The following list describes the available specification choices in this tab; for more details on how these are implemented, see Thin Film Evaporation: Modeling Calculations.

The evaporation fractions can either be calculated with thermodynamic models or be set by the user. In the latter case the user needs to set the temperature. In both cases the user can specify if a component is volatile or not in the component table.

The following thermodynamic models are supported for the vapor phase:

● Ideal gas

● Van der Waals

● Redlich-Kwong

● Soave-Redlich-Kwong

● Peng-Robinson

The following thermodynamic models are supported for the liquid phase:

● Ideal mixture

● Soave-Redlich-Kwong

● Peng-Robinson

•Process Time Options...

The process time controls appear only if the flowsheet and procedure are in batch mode. In Rating Mode, you can set the process time or allow the process time to be calculated based on the throughput. In Design mode, you must specify the process time.