Batch Distillation - Charge Specification
Define charges to the batch distillation unit during its operation. Charges may be instantaneous or continuous. Multiple charges are allowed in any policy segment.
Usage
The batch distillation requires at least one initial charges to the stillpot. No Distill action is allowed until initial charging is complete. The first policy segment in the Overall Operating Policy table of the Batch Distillation Main Window must contain an initial charge to the unit. Further charges may be added to the unit later in its operation.
The time required for initial charging is not simulated. This means all initial charges are treated as instantaneous, even if specified as continuous,.
After the initial charge, a series of Distill actions cause the simulated time to advance. The duration of policy segments with Distill actions always is controlled by Run Until Conditions or Global Stop Criteria. A continuous charge that includes its own stopping criterion (e.g.., amount at a rate, amount or rate over a time period) cannot be put in the same policy segment as a Distill action, but may be in a parallel (concurrent) non-sequential segment.
Charge Identifier
Each charge identifier may contain up to 12 characters. It identifies the charge in the output reports.
Feed Stream
Select a feed stream to use as the source for the charge. A drop down list of feeds is attached to the unit on the Process Flow Diagram.
Charging Mode
Charges to the stillpot may be instantaneous or continuous. Continuous charges may be fed to any stage in the column excluding the condenser.
You may select the charging mode as:
Instantaneous amount: The specified amount is added instantaneously to the stillpot. Instantaneous charges are assumed to be added before any Distill action in the same policy segment.
At a rate: The charge continues at the specified rate until the end of the policy segment.
Amount at a rate: The charge continues at the specified rate until the specified amount has been fed. This is only available for non-sequential segments.
Amount over a time period: The charge is fed at a rate that gives the specified amount in the stipulated time period. This is only available for non-sequential segments.
Rate over a time period: The charge is fed at the specified rate for the stipulated time period. This is only available for non-sequential segments.
Amount/Rate/Time Period
The data required depends on the selected Charging Mode. The data values corresponding to the selected option are required entries (i.e., there are no defaults).
Charge Location
Indicate to which stage the charge is to be fed. An instantaneous charge may feed only to the stillpot. Continuous charges may feed any stage except the condenser (stage one).
To change the dimensional units for entries shown on the screen, depress the UOM button to activate the Unit of Measure Selection Window.
How to get to this window
The Batch Distillation - Charge Specification window is accessed by selecting Charge in the Action/Condition table in the Batch Distillation - Policy Segment window and then clicking on the linked text under Description.
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