Diafiltration: 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

○ Rejection Coefficient (RC) (%) The rejection coefficient of a component.	0.0	0-100
○ Max Solids Conc. in Retentate (g/L) The maximum solids concentration in the retentate.	600.0	Positive
● Solids Conc. in Retentate (g/L) The actual solids concentration in the retentate.	0.0	Positive
○ Denaturation (%) The percent product denaturation.	5.0	0-100
○ Active Product Indicates the pure component that corresponds to the active product. Click on the list box to bring up a list of available components in order to select one.	<none>	Any Pure Component
○ Denatured Product Indicates the pure component that corresponds to the denatured product. Click on the list box to bring up a list of available components in order to select one.	<none>	Any Pure Component
○ Setup Time The amount of time (per cycle) spent before each operation is carried in preparation for the actual execution of the operation. It may involve actions like cleaning, vacuuming, setting up of equipment, etc. which the user opted not to model explicitly.	0.0	Positive
◙ Filtration Time (min) The actual duration of the operation (per cycle).	240.0	Positive
○ Filtrate Flux (L/m²-h) The volumetric flow rate of the filtrate per filter area.	20.0	Positive
● Diluant Stream Indicates the input port that is connected to the diluant stream. If an input stream is already present at the selected port, then the button next to the selection is active. Click on the button to bring up the attached stream’s simulation dialog in order to provide its composition.	<None>	Dedicated Input Port
○ Volume Permeated The volume permeated expressed in times of volume after initial concentration.	1.0	Positive
○ Pre-Diafiltration Checkbox Check this box to set pre-diafiltration concentration data.	No	Yes/No
○ Pre-Diafiltration Number of Concentration Stages The number of concentration stages.	1.0	Positive
○ Pre-Diafiltration Concentration Factor The feed to retentate mass ratio.	2.0	Positive
○ Post-Diafiltration Checkbox Check this box to set post-diafiltration concentration data.	No	Yes/No
○ Post-Diafiltration Number of Concentration Stages The number of concentration stages.	1.0	Positive
○ Post-Diafiltration Concentration Factor The feed to retentate mass ratio.	2.0	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 Diafiltration: Modeling Calculations.

•Filtration Time Options...

In Rating Mode (specified equipment size), the user has the option of setting either the Filtration Time or the Average Filtrate Flux.

•Product Denaturation...

Product denaturation during membrane filtration is common in bioprocessing. To account for product denaturation, the user must specify the active and denatured forms (must be different components) of the product as well as the denaturation percentage.

•Pre- and Post-Diafiltration Concentration...

This operation can handle pre- and post-diafiltration concentration of the broth in addition to its intended use of diafiltration. The same can be accomplished by utilizing batch concentration operations before and after this operation in the same procedure.