Discrete Freeze Drying: Oper. Conds Tab

DFreezeDryingOperConds.jpg
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

 

○ Volatile ?
Check the box next to a component to indicate that the corresponding component is volatile.

<No>

Yes/No

◙ Evaporation (%)
The evaporation percentage of a volatile component.

0.0

0-100

● Initial LOD (%)
The amount of volatile components in a cake sample measured using a Loss On Drying (LOD) test before cake drying.

0.0

0-100

○ Final LOD (%)
The amount of volatile components in a cake sample measured using a Loss On Drying (LOD) test after cake drying.

5.0

0-100

○ Freezing Temperature (oC)
The temperature that solvent freezing takes place.

-15.0

 

○ Sublimation Temperature (oC)
The temperature that the solvent sublimes at.

-12.0

 

○ Drying Temperature (oC)
The final temperature of the product.

20.0

Positive

○ Fusion Enthalpy (kJ/kg)
The fusion enthalpy of the solvent.

333.5

 

○ Freezing Percentage (%)
The percentage of solvent that freezes.

95

Positive

○ Sublimation Enthalpy (kJ/kg)
The sublimation enthalpy of the solvent.

3158.2

 

○ Setup Time (min)
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

○ Freezing Time (min)
The duration of the freezing step.

480.0

Positive

◙ Heating/Drying Time (min)
The duration of the heating/drying step.

600.0

Positive

○ Calculated Based on Spec. Evaporation Rate
Select this option to have the heating/drying time calculated based on the spec. evaporation rate. Only available in rating mode.

 

 

○ Calculated Based on Spec. Sublimation Rate
Select this option to have the heating/drying time calculated based on the spec. sublimation rate. Only available in rating mode.

 

 

◙ Spec. Evaporation Rate (kg/m2/hr)
The specific evaporation rate.

1.0

Positive

◙ Spec. Sublimation Rate (mm/hr)
The specific sublimation rate.

5.0

Positive

○ Pressure Set by User
Check this box to set the pressure.

No

Yes/No

◙ Pressure (atm)
The operating pressure of the equipment.

1.0

Positive

○ Vacuum Pump
Indicates the name of the engaged vacuum pump (a type of auxiliary equipment). Click on the list box to bring up a list of available vacuum pumps in order to select one.

<none>

Any Vacuum Pump

○ Vacuum Pump Power (kW)
The power consumption of the engaged vacuum pump.

0.0

Positive

○ Dried Vial Name
The name of the dried vial entities.

<Lyophilized Vial

Any Text

○ Area per Entity (cm2)
The area of each entity.

20.0

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 Discrete Freeze Drying: Modeling Calculations.

•Volatile ?...

All volatile components that are removed (evaporate) during drying must be identified as such.

•Volatile Component Evaporation...

If the removal (evaporation) of volatile components is calculated by the program based on Final LOD, all volatile components are removed equally (same removal %). If that is not the case, then, you need to set the removal percentage of the various volatile components.

•Dried Vial...

The user specifies a name for the dried entity, and the area that each entity occupies.