Continuous Fermentation Operations: Oper. Conds Tab

ContFermOperConds.jpg

This operating conditions tab is common between stoichiometric and kinetic continuous fermentation operations. Notice that the Assume No Phase Change(s) in Reactor option is only available in continuous kinetic fermentation operations when the thermal mode is set to Adiabatic or Set Duty.

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

 

◙ Final Temperature (oC)
The final temperature of vessel contents after the end of the operation.

37.0

Positive

◙ Heating Duty (kcal/h)
The heat transfer rate of the heating agent, if a heating agent is used.

0.0

Positive

◙ Cooling Duty (kcal/h)
The heat transfer rate of the cooling agent, if a cooling agent is used.

0.0

Positive

○ Heat Transfer Agent Name
Indicates the heat transfer agent used for the operation. Click on the list box to bring up a list of available heat transfer agents in order to select one.

<Chilled Water>

Any Heat Transfer Agent

● Inlet Temp. (oC)
The inlet temperature of the heat transfer agent.

5.0

Positive

● Outlet Temp. (oC)
The outlet temperature of the heat transfer agent.

10.0

Positive

● Rate (kg/h)
The mass flow rate of the heat transfer agent.

0.0

Positive

○ Heat Transfer Efficiency(%)
The heat transfer agent efficiency. If the value is lower than 100% then an increased heat transfer agent amount will be calculated by the program to satisfy the required duty.

100.0

[0,100)

○ 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

○ Gaseous Components Available to React
Check this box to consider gaseous components in reactions.

Yes

Yes/No

○ Assume No Phase Change(s) in Reactor
When this option is checked, the energy balance is done w.r.t the temperature change rate (dT/dt) otherwise, the enthalpy change rate form (dH/dt) is used. Only available in kinetic fermentation adiabatic/duty set modes.

Yes

Yes/No

○ Simulate a Split After the Reaction
Check this box to enable split after reaction.

No

Yes/No

○ Power Type
Indicates the power type that is used by the operation. Click on the list box to bring up a list of available power types in order to select one.

<Std Power>

Any Power Type

◙ Specific Power (Per Volume) (kW/m3)
The power consumed for agitation per volume of material.

0.1

Positive

◙ Total Power (kW)
The total power consumed for agitation (per cycle).

0.0

Positive

◙ Power Per Unit (kW)
The power consumed for agitation per equipment unit.

0.0

Positive

○ Power Dissipation to Heat (%)
The percentage of total power consumed for this operation that turns into heat, thereby raising the temperature of the material contained in the equipment.

100.0

[0,100]

○ Apply Broth Aeration
Check this box to apply broth aeration.

Yes

Yes/No

○ Air Supply Stream
Indicates the input port that is connected to the air supply 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>

Any Input Port

◙ Broth Aeration Rate (VVM)
Specify the volume of air per volume of liquid and per minute.

0.5

Positive

○ Use Secondary Aeration
Check this box to use secondary aeration.

No

Yes/No

○ Secondary Air Supply Stream
Indicates the input port that is connected to the secondary air supply 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>

Any Input Port

◙ Secondary (Broth Aeration) Rate (VVM)
Specify the volume of air per volume of liquid and per minute.

0.0

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 Continuous Stoichiometric Fermentation: Modeling Calculations.

•Pressure...

The pressure of the system, if not specified by the user, is set equal to the pressure of the previous operation.

•Aeration...

VVM stands for volume of air per volume of liquid and per min. When the ‘Set’ option is selected, the program adjusts the flowrate of the Air Supply Stream to correspond to the specified value of VVM. When the ‘Calculate’ option is selected, the program does not adjust the flowrate of the air supply stream. Instead, it simply calculates the VVM that correspond to the specified air flowrate.

•Gaseous Components Available to React...

If you don’t check the option ‘Gaseous Components Available to React’, then only the liquid components will be considered for the reaction.

•Simulate a Split After the Reaction...

If you check the option ‘Simulate a Split After the Reaction’, then the Split Tab becomes available. This tab allows you to specify either total flow or specific component splits to the various streams exiting the vessel.